-Ti-c «_ 
 
 Frick Company 
 
 ic 
 
 mai 
 req 
 
 for 
 
 E( 
 
 THE 
 
 JOHN • CRAIG 
 
 LIBRARY 
 
 COLLEGE 
 
 OF 
 
 AGRICULTURE 
 
 NEW YORK STATE 
 COLLEGE OF AGRICULTURE, 
 
 PBPARTMENT OF HORTICULTURE, 
 
 CORMFI I IIMH/CQOiTV 
 
 ITHACA, N. Y, 
 
 of ECLIPSE SURFACE, SUBMERGED or DOUBLE FIFE style. 
 AMMONIA VALVES AND HEAVY FITTINGS 
 
 STEAM BOILERS AND TANKS 
 
 FRICK CORLISS ENGINES 
 
 Write us, if interested, and get our Red Book 
 
Cornell University 
 Library 
 
 The original of this book is in 
 the Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924000456230 
 
PRACTICAL 
 
 COLD STORAGE 
 
 THE THEORY, DESIGN AND CONSTRUCTION OF BUILDINGS AND 
 
 APPARATUS FOR THE PRESERVATION OF PERISHABLE 
 
 PRODUCTS, APPROVED METHODS OF APPLYING 
 
 REFRIGERATION AND THE CARE AND 
 
 HANDLING OF EGGS, FRUIT, 
 
 DAIRY PRODUCTS, ETC. 
 
 BY 
 
 MADISON COOPER 
 
 Author of "Eggs in Cold Storage," "Ice Cold Storage," etc. 
 
 •v.. 
 
 \y ■ ■ 
 
 publishers: 
 
 NICKERSON &r COLLINS CO. 
 
 CHICAGO 
 
 1905 
 
% 
 
 // 
 
 
 U\\ ,n 
 
 C7. ^ 
 
 copyright, 1904, 1905 
 By Nickerson & Collins Co. 
 
 ALL RIGHTS RESERVED 
 
 PRESS OF 
 
 ICE AND REFRIGERATION 
 
 CHICAGO 
 
TO MY FATHER 
 
 As a tribute to his matchless enterprise 
 and genius for practical and scientific 
 research, and in acknowledgment of 
 valuable assistance rendered, this work 
 is affectionately inscribed. 
 
 The Autho%. 
 
PREFACE. 
 
 The difficulties encountered in preparing a book on so broad 
 a subject as practical cold storage have been so great as at times 
 to discourage the author from continuing. The author has en- 
 deavored to collect the greater part of his own writings and at 
 the same time has compiled from all available sources. The 
 present book has the many shortcomings usually found in every 
 pioneer work, and there are many gaps in the chain of informa- 
 tion given for the reason that detailed knowledge has in many 
 cases been lacking. A large portion of the general matter which 
 has appeared on the subject of cold storage is of little or no value 
 as a part of a book on this subject, for the reason that it con- 
 tains many repetitions and contradictions, and for the most part 
 has been written by persons not familiar with refrigeration either 
 from a practical or scientific standpoint. The matter and in- 
 formation which appeared prior to about 1895 is mostly value- 
 less in the light of present information, as the earlier articles 
 were generally incomplete and in part erroneous. 
 
 The immense amount of labor involved in digging through 
 the great piles of chaff to find the few grains of wheat has been 
 out of all proportion to the actual results obtained. Reliable 
 scientific data and the records of tests have in many cases been 
 difficult or impossible to obtain. Very little along this line is 
 in existence and some of it is jealously guarded by its pos- 
 sessors. Practical information on the handling, packing and 
 storing of perishable products is obtainable only in a small way 
 for the reason that comparatively few operators of cold storage 
 houses have made any record of results and can put their experi- 
 ence in tangible form for the use of others. The author begs to 
 acknowledge the assistance of his many friends among the en- 
 gineers and cold storage men. It has been his aim to give due 
 credit where any considerable amount of matter has been fur- 
 nished by others. 
 
(i PREFACE 
 
 This book is intended to cover the field of applied refrigera- 
 tion with the exception of ice making, ice machines, and the 
 technical and theoretical side of the mechanical production of 
 refrigeration. These important matters are fully treated by sev- 
 eral valuable and comprehensive works. The reader is referred 
 to these books for the data, theory and information necessary to 
 a full understanding of the principles of thermodynamics and 
 refrigerating machine construction and operation. 
 
 There is much regarding the use of ice, both natural and 
 artificial, as a practical refrigerant, even on a large scale, which 
 has not heretofore been fully described. The possibilities of 
 successful refrigeration by means of ice have not been carefully 
 studied and given due consideration. If rightly applied ice either 
 natural or manufactured, in combination with salt, will produce 
 any results in the preservation of perishable products, which 
 may be produced by any means of cooling; limited of course, 
 by the range of temperature which can be obtained. The im- 
 portance and extent of this branch of the refrigerating industry 
 has not been appreciated by those who 'have given their time to 
 the study of refrigeration. The development of the mechanical 
 systems of refrigeration . came at a time when the use of ice as 
 a refrigerant had not been reduced to a scientific basis, conse- 
 quently our best talent was directed toward the perfecting and 
 introducing of the ice machine. Nevertheless, there are many 
 successful ice cold storage houses who are doing fully as per- 
 fect work as the best machine refrigerated houses. This is not 
 to the discredit of the machine cooled houses in the least, and 
 it is generally admitted that the average ice cold storage turns 
 out goods greatly inferior to the average machine cold storage. 
 At the same time the value of products which are daily refrig- 
 erated by ice for preservation, exceeds by far those refrigerated 
 by mechanical means. This statement is best appreciated when 
 we consider that a large part of the output of the hundreds of 
 ice factories is used in small refrigerators for the temporary safe 
 keeping of fruit, vegetables, meats, dairy products, etc. ; that the 
 immense natural ice crop annually harvested is consumed in the 
 same way ; that an important portion of the eggs, butter, cheese, 
 fruit, etc., are stored in warehouses cooled by ice, or ice and 
 salt, and that perishable goods during transportation are kept 
 
PREFACE 7 
 
 cool by ice almost exclusively. From these facts it is evident that 
 a description of the manner of securing and storing the natural 
 ice crop and the best methods of utilizing ice, either natural or 
 artificial, for cooling or freezing purposes, must be of consider- 
 able value to the users of refrigeration generally. 
 
 An important branch of cold storage design, and in fact 
 all work in refrigeration, is the design and construction of walls 
 which form insulation against heat, and built of such materials 
 as may be had at a moderate cost. The chapter on insulation has 
 aimed to give the results of the best information at present ob- 
 tainable on this subject, both in the United States and in foreign 
 countries. 
 
 The chapters on the practical operating of cold storage houses 
 and the care and handling of goods for storage have been writ- 
 ten largely from the author's practical experience, supplemented 
 by information obtained from others. So many different kinds 
 of goods are now placed in cold storage for preservation, that 
 the experience of many persons must necessarily have been added 
 together to aggregate the results given ; even then the information 
 is not as complete as it might be. General directions are given for 
 the handling of a cold storage house without reference to any 
 particular product, and if these are followed understandingly 
 and care and judgment used, the cold storage manager may avoid 
 many of the errors common to those new to the business. It 
 must be remembered that a good house poorly handled cannot 
 compete with an inferior house well handled. At least one-half 
 is in the management and too much care cannot be exercised in 
 looking after the details of a refrigerating installation, not only 
 for the purpose of securing economy in operation of same, but 
 alsu to insure the keeping of the stored goods in the best condi- 
 tion. 
 
 By far the major portion of what is printed in this book is 
 from the original writings of the author ; a portion of which has 
 appeared in the columns of Ice and Refrigeration ; The Ice Trade 
 lournal, etc., as articles under the titles of " Eggs in Cold Stor- 
 age," " Ice Cold Storage/' etc. It was because of the success 
 of the articles on " Eggs in Cold Storage," which were subse- 
 quently printed in pamphlet form, and the complimentary recep- 
 tion of same, which encouraged the author to undertake the pres- 
 
8 PREFACE 
 
 ent work. It is now submitted to the trade with a full appre- 
 ciation of its imperfections and incompleteness. As far as pos- 
 sible these will be remedied in future editions. It is the earnest 
 request of the author that those who find errors or omissions or 
 can suggest in any way improvements, correspond with the au- 
 thor to the end that " Practical Cold Storage " may be made as 
 complete and accurate as possible. 
 
 Any information which will further the interests of the busi- 
 ness, will in turn benefit all who are engaged therein. For any 
 one to believe that he is the possessor of secret information 
 which is vital to his success over competitors, is in a great ma- 
 jority of cases the extreme of absurdity. Much of the matter 
 appearing in this publication has at some time been considered 
 as trade secrets. The false and narrow-minded position taken 
 by some in connection with this matter is well illustrated by cer- 
 tain remarks made to the writer in regard to the publication of 
 this book. The following is a sample : " Now that you have 
 this information accumulated, why not keep it for your own 
 use instead of giving it away? " It is quite true that the author 
 has expended in time, effort and money in connection with the 
 preparation of the matter contained in this book, much more 
 than he can be remunerated for in its sale. It is, however, here 
 given for what it is worth and with the earnest wish that it 
 may be of substantial benefit to many readers. 
 
 It might not be out of place to call the reader's attention 
 to the fact that, in practically all the original matter by the 
 author contained in this book, reasons are given for statements 
 made so far as practicable. This enables the new beginner or 
 student to study intelligently the natural laws which govern the 
 principles of refrigeration. Comme'nt and criticism has been 
 freely bestowed without fear or favor on the various ideas, sys- 
 tems and methods which do not meet the approval of the author. 
 Matter which has been compiled or extracted from other sources 
 has in some cases been changed or modified to suit the individual 
 ideas of the author. Should the advocates of anything here criti- 
 cised feel that they have not had a fair presentation the author 
 will be glad to take the matter up and discuss the points involved. 
 
 While this work is in some respects imperfect and there is 
 no doubt room for the addition of much information, reliable data, 
 
PREFACE 9 
 
 and the results of extended observations and tests, there has not 
 heretofore been anything like as complete a presentation of the 
 entire subject; and in consideration of this fact the reader is 
 requested not to be too critical. If any errors or lack of details 
 are noted, the author would be pleased to acknowledge same and 
 will endeavor to explain the points at fault. No other object 
 has been in mind in preparing this book than a furtherance of 
 scientific knowledge on the subject of refrigeration as applied 
 to the preservation of perishable products, and the great assis- 
 tance rendered by those who have assisted is hereby acknowl- 
 edged. The combination and comparison of information is bene- 
 ficial, and if those who have further data or records of tests 
 will only put them before others in their line of business, no 
 loss will be sustained by the individual giving the information, 
 while much general good will result. 
 
INTRODUCTION. 
 
 There is no authentic history of the use of refrigeration as 
 applied to what is now popularly called " cold storage," and it 
 is only within the. past twenty-five or thirty years that the prac- 
 tical usefulness of refrigerated storage has been appreciated by 
 the world at large. In the year 1626 Lord Bacon is said to have 
 taken a chill from the stuffing of a chicken with snow, in order 
 to preserve it, which resulted in his death. It would seem that 
 the death of so eminent a person from such a cause should have 
 attracted attention to the possibilities of applied refrigeration, 
 but either the poor success of the experiment, or the fatal result 
 to its originator seems to have had a deterrent effect on fur- 
 ther investigation along this line at that period. 
 
 It is doubtful whether any scientific demonstration or com- 
 mercial enterprise of recent years has been of greater moment 
 to the human race than the science of refrigeration and its prac- 
 tical application in the modern cold storage industry. When 
 scientific inquiry had proven the efficacy of low temperatures in 
 preventing decay and had demonstrated the possibility of obtain- 
 ing and maintaining low temperatures at will, the cold storage 
 business of today was but the natural evolution resulting from 
 such demonstration. When it became apparent that profit was 
 obtainable by placing perishable goods in cold storage during a 
 period of glut or surplus and disposing of them at some sub- 
 sequent period of comparative scarcity or increased demand, the 
 building of cold storage houses and the perfection of machinery or 
 apparatus for their economical operation became the inevitable 
 result. The pioneers in the cold storage business were specula- 
 tors of the extreme kind, but this cannot be said of those in 
 the business today. Where in the early days the cold storage 
 operator owned the goods he stored almost entirely, and his 
 customers were uncertain, now the goods placed in cold storage 
 
INTRODUCTION 11 
 
 are. almost wholly owned by dealers, and are held for the sup- 
 plying of their trade. 
 
 Refrigeration has four chief uses in the economy of nature 
 and in commerce : 
 
 I- — To prevent premature decay of perishable products. 
 
 2. — To lengthen the period of consumption and thus greatly in- 
 crease production. 
 
 3- — To enable the owner to market his products at will. 
 
 4- — To make possible transportation in good condition from point 
 of production to point of consumption, irrespective of distance. 
 
 First : Without refrigeration there would be much actual 
 waste from decomposition before it would be possible to place 
 perishable food products in the possession of the consumers. 
 The immense fruit trade of the Pacific coast would never have 
 been developed without the assistance of refrigeration, nor could 
 the surplus meat products of the southern hemisphere have been 
 brought half way around the globe to relieve the shortage in 
 thickly settled England without its aid. Without the aid of 
 refrigeration to create a constant market, the production of 
 meats, of eggs, of fruits and other food products would be 
 greatly curtailed. 
 
 Second : In many classes of produce the ordinary season of 
 consumption was formerly limited to the immediate period of 
 production, or but briefly beyond. Now nearly all fruits may be 
 purchased at any season of the year and dairy and other products 
 are for sale in good condition and at reasonable prices the year 
 around. 
 
 Third : Instead of being obliged to sell perishable goods, 
 when produced or purchased, at any price obtainable, the owner 
 can now put away in coid storage a portion or all of his products 
 to await a suitable time for selling. This not only results in a 
 better average price to the producer, but places perishable food 
 stuffs at the command of the consumer at a reasonable price at 
 all times and greatly extends the period of profitable trading in 
 such products. 
 
 Fourth : The certainty and perfection with which food 
 products may be conveyed from the place of production to the 
 large centers of population where they are to be consumed is 
 one of the triumphs of refrigeration ; yet the refrigerator car 
 service is only in its infancy so far as perfection of results is 
 
12 INTRODUCTION 
 
 concerned. It is safe to say that our immense Pacific coast fruit 
 trade could not exist without it. The over sea carriage of prod- 
 ucts has also been developed along with the development of 
 refrigeration as applied to this work. 
 
 Cold storage is a benefit to all mankind in that it allows of 
 a greater variety of food during all seasons of the year. Health 
 and longevity are promoted by the free consumption of fruits, 
 and the placing of fresh fruits at the disposal of even the poor- 
 est of our citizens during every month in the year will certainly 
 result in a wholesale benefit to mankind, so far-reaching in its 
 effects as to be incalculable. 
 
 Physicians and scientists who have investigated the subject 
 unite in praising the modern practice of refrigeration as applied 
 to the preservation of food products and in arresting decay in 
 all articles of value liable to injury by exposure to high or nor- 
 mal temperatures. A prominent English physician* in an address 
 before the Sanitary Institute at their Congress at Birmingham 
 in 1898, after describing at length the various methods, namely : 
 Drying, smoking, salting, sugar and vinegar, exclusion of air 
 (canning), antiseptics, chemicals, etc., in use as food preserva- 
 tives, has this to say of refrigeration : 
 
 This brings us then to the last of the modern methods of food pres- 
 ervation on the large as well as on the small scale, and as it is the last, 
 so it is the best. The fishmonger avails himself of it in his ice well and 
 on his stall. It is by its agency that all the perishable food on our great 
 liners is preserved during even prolonged voyages, and it is used in 
 the great food depots of many of our large towns. In this town tons of 
 perishable foods arc continually preserved by its action, and where such 
 stores do not exist they ought to be provided. In this way all perishable 
 articles can be kept until such times as they shall be required for- sale 
 and distribution. 
 
 Formerly the methods of producing cold were complicated and dear, 
 and had many drawbacks, but these have been overcome. * * * Cold 
 acts not by killing the organisms that effect decomposition, but only by 
 inhibiting their action ; in which respect it differs from heat and certain 
 chemical antiseptics, such as chlorine, for instance. 
 
 Among the advantages of preservation by refrigeration may be men- 
 tioned : — • 
 
 1 — It has been proved the most effective as a preservative, surpassing 
 in efficiency, salting, boric compounds, or any other practical method. 
 
 2 — It adds nothing and subtracts nothing from the article preserved, 
 not even the water, and in no material sense alters its quality. 
 
 3 — It causes no change of appearance or taste, but leaves the meat 
 or other substance substantially in its original condition, while it renders 
 it neither less nutritious nor less digestible, which cannot be said of 
 some other methods in common use. 
 
 *Alfred Hill, M. D., F. R. S., Edin. F I. C. Medical Officer of Health and Public Ana- 
 lyst to the City of Birmingham, Eng. 
 
INTRODUCTION 13 
 
 My contention is that all additions to food whose influence on health 
 is doubtful ought to be prohibited and their use supplemented by refri- 
 geration.'' 
 
 Strong language like this coming from such an eminent 
 authority not only vouches for the usefulness of refrigeration, 
 but also for the perfection of its results, and to a thinking per- 
 son offers an assurance that an industry established on so broad 
 a basis must present an ever widening field of usefulness. New 
 products are constantly being added to those which are placed in 
 cold storage for safe keeping or preservation, and it seems not 
 a wild prediction to say that at some time in the future the great 
 majority of our food products and other perishable goods will be 
 handled in and sold from refrigerated rooms. 
 
 Considering the importance the cold storage industry has 
 already attained, its rapid growth and future outlook, the amount 
 of accurate information available to those engaged in the busi- 
 ness seems very meager. The difficulties to be overcome, the 
 skill required, and the importance of a well designed structure 
 are not usually explained by these interested in promoting new 
 enterprises in this line, and consequently not appreciated by those 
 making the investment. Financial disaster has overtaken many 
 large companies who have erected costly refrigerating ware- 
 houses ; those which have succeeded have in many cases been 
 forced to install new systems, make expensive changes, and 
 make a thorough study of the products handled. The experi- 
 ence of nearly all has been emphasized at times by heavy losses 
 paid in claims made by customers for damage to goods while in 
 storage, or the necessity of running a large house while doing 
 a very small business. Those about to become interested in 
 business may find food for thought in the above, and the his- 
 tory of a dozen houses, in different localities, will furnish valu- 
 able information for would-be investors. 
 
 The scarcity of knowledge on the subject in hand, while 
 being partly the result of the partially developed state of the 
 art until very recently, is also very largely owing to narrow- 
 mindedness on the part of some of the older members of the 
 craft who have largely obtained their skill by years of experience 
 and study, some of them having expended large sums on experi- 
 mental work. The same experiments have perhaps been made 
 before, and are of necessity to be made again by others, simply 
 
14 INTRODUCTION 
 
 because the first experimenter would not give other people the 
 benefit of his experience. It seems that at the present stage 
 in the development of refrigeration the improvements to be 
 made during the next twenty-five years will be of very much less 
 importance than those made during the last twenty-five years; 
 trade secrets, so jealously guarded by some, must disappear, as 
 they have in other branches of engineering. Storage men have 
 been obliged to work out their own salvation in solving problems, 
 sometimes, however, sending their most difficult points to be an- 
 swered through the columns of the trade journals, and, perhaps, 
 comparing ideas with those of their personal friends in the same 
 line of business. It is to be observed that the most progressive 
 and up-to-date manufacturing concerns in the United States are 
 today giving their contemporaries every opportunity to observe 
 their methods, and are. very willing and anxious to talk over mat- 
 ters pertaining to their work from an unselfish standpoint. So, 
 too, the successful cold storage of the future will be sure to make 
 " visitors welcome." 
 
 In anything which appears in this book, it is not the author's 
 intention to convey the idea that any mere theoretical knowledge 
 which can be acquired by reading and study, or even by an ex- 
 change of ideas in conversation, can take the place of practical 
 observation in actual house management ; but there are applica- 
 tions of well known laws which are not generally understood by 
 storage men and their progress is handicapped from lack of this 
 theoretical knowledge. The two following illustrations, bearing 
 on temperature and ventilation, are among the common errors 
 made in practice, yet easily understood when studied and tested : 
 Some storage houses formerly held their egg rooms at 33° F., 
 fearing any nearer approach to the freezing point of water (32° 
 F.), thinking the eggs would freeze. A simple experiment would 
 settle this point, giving the exact freezing temperature, as well 
 as the effect of any low temperature on the egg tissues. Eggs 
 will not freeze at 28° F. Again, others have thought to venti- 
 late by opening doors during warm weather. It never happens 
 that storage rooms can be benefited by this treatment at any 
 time during the summer months, and only occasionally during 
 the spring and fall. The dew point of outside air is rarely below 
 45" F. during summer, and when cooled to the temperature of 
 
INTRODUCTION 15 
 
 an egg room, moisture will be deposited on the goods in stor- 
 age, causing a vigorous growth of mildew. 
 
 The question of the proper temperature at which to carry 
 goods is of the first importance. Correct temperatures alone, 
 however, will not produce successful results, any more than a 
 good air circulation or correct ventilation would give good 
 results with a wrong temperature. The common impression of 
 cold storage is what the name implies — simply a building in 
 which the rooms may be cooled to a low degree as compared 
 with the outside air. Even those who manufacture and install 
 refrigerating machinery and apparatus often show either gross 
 carelessness or ignorance of the requirements of a house which 
 will produce successful results. After a careful examination of 
 some of the recently constructed houses supposed to be strictly 
 modern and up-to-date, the writer got the impression that the 
 designers regarded temperature as the only requisite for perfect 
 work. Some of the rooms in these new houses are simply insul- 
 ated and fitted with brine or ammonia pipes, the proper loca- 
 tion of same having received no attention whatever, being placed, 
 in most cases, in convenient proximity to the pipe main, and in 
 one or two instances, the top pipe of the cooling coils was fully 
 two feet from the ceiling. The necessity for providing for air 
 circulation seemed not worthy of consideration, to say nothing 
 of the lack of anything like an efficient ventilating system. These 
 things are mentioned here for the purpose of cautioning against 
 a superficial study of cold storage problems. It is advisable for 
 everyone interested to understand the underlying laws which 
 govern the results to be obtained. Read carefully the chapters 
 on " Air Circulation," " Humidity " and " Ventilation." 
 
 Cold storage, if the right system is installed and properly 
 handled, will produce some remarkable results in the preserva- 
 tion of perishable products. It must not be expected, however, 
 that the quality and condition of the goods are improved by 
 storage. Cold storage does not insure, against natural deteriora- 
 tion. Goods for cold storage must be in prime condition and 
 selected by an experienced person if it is expected to carry them 
 to the limit of their possible life. A cold storage house suc- 
 cessfully operated and managed will supply a uniform tempera- 
 ture at the proper degree throughout the storage season. It 
 
16 INTRODUCTION 
 
 will regulate the humidity at the proper point and will supply 
 fresh air properly treated to force out the accumulated gases. 
 The storing of unsuitable, imperfect and inferior goods has led to 
 much misunderstanding and some litigation between the man 
 who stores the goods and the warehouse man. B'oth should, if 
 possible, be familiar with the condition of the goods they are 
 handling; the different stages of ripeness, quality and liability 
 to deterioration. Cold storage cannot improve the physical con- 
 dition of perishable goods and is in no way responsible for 
 damage or decay which may arise from improper picking, grad- 
 ing, packing or handling before placing in the storage house. If 
 these things are properly understood by all concerned much mis- 
 understanding will be avoided, and greater satisfaction and profit 
 will result to all concerned. 
 
CHAPTER I. " :. 
 
 HISTORICAL. 
 
 THE DEVELOPMENT OF COLD STORAGE. 
 
 Mother earth as a source of available refrigeration, is with- 
 out doubt a pioneer. In the temperate zone at a depth of a 
 few feet below the surface, a fairly uniform temperature is to 
 be obtained at all seasons of about 50° to 60 ° F. In some cases 
 a much lower temperature is obtained. The same principle is 
 true in any climate, the earth acting as an equalizer between ex- 
 tremes of temperature, if such exist. Caves in the rock, of nat- 
 ural formation, are in existence, in which ice remains the year 
 around, and many caves are used for the keeping of perishable 
 goods. The Ruskin Co-operative Colony, located at Ruskin, 
 Tennessee, has a fine large cave on its property which is utilized 
 as a cold storage warehouse. The even temperature, dryness and 
 purity of the atmosphere to be met with in some caves are quite 
 remarkable, owing no doubt to the absorptive and purifying 
 qualities of the rock and earth, as well as to the low temperature 
 obtainable. 
 
 CELLARS. 
 
 Cellars are practically caves built by the hand of man, and 
 if well and properly built are equally good for the purpose of 
 retarding decomposition in perishable goods. A journey through 
 the Western states reveals many farmers who are the possessors 
 of "root-cellars," considered the first necessity of successful 
 farming, the new settler building his cellar at the same time as 
 his log house. A root-cellar is used partly as a protection against 
 frost, but it also enables the owner to keep his vegetables in fair 
 condition during the warm weather 'of the spring and summer 
 months. The use of cellars for long keeping of dairy products 
 is familiar to all. Many of us can recollect how our mothers put 
 
 (2) 
 
18 PRACTICAL COLD STORAGE 
 
 down butter in June and kept it until the next winter, and per- 
 haps it will be claimed by some, that the butter was as good in 
 January as when it was put down. It was not as good, far from 
 it. If you think it was, try the experiment to-day and you will 
 see how it will taste and how much it will sell for in January in 
 competition with the same butter stored in a modern freezer. 
 The butter made years ago was no better either. No better but- 
 ter was ever made than we are producing to-day. In short, cel- 
 lars were considered good because they had no competition — 
 they were the best before the advent of improved means of cool- 
 ing. Cellars are still of value for the temporary safe keeping of 
 goods from day to day, or for the storage of goods requiring 
 only a comparatively high temperature, but with a good refrig- 
 erator in the house, the chief duty of a cellar, nowadays, is to 
 contain the furnace, and as a storage for coal and other non- 
 perishable household necessities. 
 
 ICE. 
 
 The use of ice as a refrigerant during the summer months 
 is a comparatively modern innovation, and not until the nine- 
 teenth century did the ice trade reach anything like systematic 
 development. The possibility of securing a quantity of ice dur- 
 ing cold weather and keeping it for use during the heated term 
 seems not to have occurred to the people of revolutionary times. 
 About 1805 the first large ice house for the storage of natural 
 ice was built, and with a constantly increasing growth, the 
 business rose to immense proportions in i860 to 1870. The 
 amount harvested is now much larger than at that time and con- 
 stantly increasing, but the business is now divided between nat- 
 ural ice and that made by mechanical means. 
 
 The first attempt at utilizing ice for cold storage purposes 
 was either by placing the goods to be preserved directly on the 
 ice or by packing ice around the goods. These methods are in 
 use at present as for instance in the shipping of poultry, fish and 
 oysters, and the placing of fruit and vegetables on ice for pres- 
 ervation and to improve their palatability. The first form of re- 
 frigerator proper consisted merely of a box with ice in one end 
 and the perishable goods in the other. This form of cooler is 
 illustrated in the old style ice chests, which are now mostly su- 
 
HISTORICAL 19 
 
 perseded by the better form of house refrigerator with ice at the 
 top and storage space below. On a larger scale small rooms were 
 built within and surrounded by the ice in an ice house. These 
 rooms were of poor design and did not do good work, largely the 
 result of no circulation of air within the room. The principle of 
 air circulation was recognized later, and by placing the ice over 
 the space to be cooled, a long step in the right direction was 
 taken. By this method the air was induced to circulate over the 
 ice and down into the storage room. During warm weather the 
 circulation of air in contact with the ice purified the air and 
 produced a more uniformly low temperature. Many houses on 
 this system are still in existence, although rapidly being super- 
 seded by improved forms. 
 
 About the time when the overhead ice cold storage houses 
 were being installed freely, mechanical refrigeration came into 
 the field. Mechanical refrigeration in which the storage rooms 
 are cooled by frozen surfaces, usually in the form of brine or 
 ammonia pipes, was much superior to ice refrigeration, in that 
 the temperature could be controlled more readily and held at 
 any point desired and that a drier atmosphere was produced. 
 Ice and mechanical refrigeration will be discussed fully in treat- 
 ing of construction and in discussing the value of different sys- 
 tems for different purposes. It may be remarked in passing that 
 ice is at present and will probably always remain a very useful 
 and correct medium of refrigeration, especially for the smaller 
 rooms and some purposes. 
 
 MACHINERY. 
 
 The first method of mechanical refrigeration to come into 
 general use, and one which is still largely in use on ocean going 
 steam vessels, was by means of the compressed air machines. 
 These operate by compressing atmospheric air to a high tension, 
 -cooling it, and expanding it down to atmospheric pressure di- 
 rectly into the chamber to be cooled. These machines are very 
 uneconomical in that the compressed gas is not liquefied. Pres- 
 ent practice in compression machines mostly employs either am- 
 monia gas or carbon dioxide gas, both of which may be liquefied 
 by pressures and temperatures readily obtainable. Other gases 
 are in use also, but ammonia is the favorite as it liquefies more 
 
20 PRACTICAL COLD STORAGE 
 
 easily. The apparatus known as the absorption ammonia sys- 
 tem is really a chemical rather than a mechanical process, but 
 is usually classed along with the mechanical systems. In this 
 system, the ammonia gas is driven off from aqua ammonia under 
 pressure, by heating; the gas is liquefied by cooling, and the re- 
 frigerating effect obtained by expanding the liquid ammonia 
 thus obtained through pipes surrounded by the medium to be 
 cooled. This system is quite largely in use and preferred by 
 many to the compression system, although the latter is most 
 largely in use. In the so-called vacuum machines water is used 
 as the refrigerating medium, its vaporization at low temperatures 
 being effected by producing a vacuum by means of pumps, the 
 vacuum being assisted by sulphuric acid. This system is very 
 little used. 
 
 The history of the development of cold storage up to the 
 present shows that much time, money and skill has been expended 
 in perfecting machinery and apparatus for the production of 
 refrigeration. Comparatively little attention has been given to 
 the application of the cold produced, through scientific systems, 
 to the preservation of perishable products. It was deemed suf- 
 ficient that temperature should be fully under control, and the 
 providing of means for regulating humidity, air circulation, ven- 
 tilation, etc., has been overlooked. It is one of the purposes of 
 this book to fully explain the practical application of refrigera- 
 tion to cold storage purposes, irrespective of how the refrigeration 
 is primarily produced. The best means of creating refrigeration 
 are necessarily determined by purely local conditions, while prin- 
 ciples of application remain always the same. 
 
ORGANIZING AND OPERATING A COLD STORE 21 
 
 CHAPTER II. 
 ORGANIZING AND OPERATING A COLD STORE. 
 
 POSSIBILITIES OF THE BUSINESS. 
 
 As a means of preserving perishable food products, and in 
 some cases other goods, from decay or deterioration, refrigera- 
 tion has come into use with a rapidity that has surprised its most 
 sanguine advocates. The author has been identified with the 
 produce and refrigerating industries for more than twenty years, 
 and during the last half of this period has feared that the cold 
 storage business was likely to be overdone. At present there 
 seems no immediate prospect of such a condition, and it is prob- 
 able that some years will elapse before there will be more cold 
 storage space than goods to fill it. This seems the more probable 
 when we consider the diversified products which are now stored 
 in refrigerated rooms for preservation. Furs, as an illustration, 
 are now placed in cold storage to prevent damage from moths, 
 and to preserve the texture of the skins, and the best furriers 
 report the results as greatly superior to the old method of treat- 
 ment. Not only are the ravages of the moths prevented, but the 
 furs come out of cold storage actually improved in appearance. 
 Dried fruits are now perfectly kept during the warm months by 
 placing in cold storage. Nuts are kept in the best possible con- 
 dition by storing in cold rooms. Potatoes and cabbage are carried 
 through the winter and turned out in a condition not thought pos- 
 sible years ago. These are only a few of the products compara- 
 tively new to cold storage. Each year finds something new in 
 cold storage for safe keeping, and new uses are being found for 
 refrigeration continually. There seems no limit to the possibili- 
 ties of the business. It is certainly only a matter of time when 
 the bulk of perishable products will be handled in and sold from 
 cold storage. 
 
 The starting and building up of a cold storage business re- 
 quires all the business sagacity and ability usually necessary to 
 
22 PRACTICAL COLD STORAGE 
 
 success in any other line, and in addition there are some special 
 qualifications which it may be worth while to consider. The 
 formation of a company, the selection of a system of refrigera- 
 tion, and the proper construction of the cold storage building are 
 merely preliminary to the ■actual hard work and care necessary 
 to success, and the cold storage business may develop into more 
 of an undertaking than the average person has any idea of. Even 
 after some investigation the points are not always as plain as 
 they should be. After the house is built business must be ob- 
 tained, and satisfactory results given to customers or the ven- 
 ture will prove a failure. 
 
 There are many cold storage men now operating houses who 
 complain of poor business, and think there is no demand for cold 
 storage in their locality, when the simple truth is that they have 
 not the proper facilities for the preservation of the goods they 
 try to handle. They turn out musty eggs, strong butter and 
 rotten apples, and consequently their customers .only place in 
 storage what they are compelled to. Cases may be cited where 
 a properly-equipped house has been started in competition with 
 the kind above described, and obtained a profitable business from 
 the start. In progressive times like the present, when competi- 
 tion is sharp, it is poor business policy, if not positively suicidal, 
 to go into business with anything except the best facilities. If 
 you are going into the cold storage business, build a good house, 
 and equip it with modern apparatus from designs by a practical 
 man. A cheap house should not be considered. 
 
 An enterprising and self-reliant man is usually at the head 
 of a new cold storage enterprise. It requires both these qualifi- 
 cations to establish a house where apparently little demand exists 
 for such a concern, and generally this is about the situation where 
 there is no cold storage house. There cannot, of course, be busi- 
 ness done in the cold storage line where no cold storage house 
 exists ; but an intelligent canvass of the situation should indicate 
 the probability or not of business following the erection of a 
 house. If the situation shows fair prospects there can be no 
 failure if the enterprise is handled with the same care and ability 
 necessary for success in other lines of business. Cold storage 
 houses have been constructed with small apparent demand for 
 the space, but after being in business for a year or two to prove 
 
ORGANIZING AND OPERATING A COLD STORE 23 
 
 an ability to carry goods well, the house has done a good busi- 
 ness. In not a single instance known to the author has a well- 
 built, properly-equipped and carefully-handled cold storage house 
 been a source of loss to its owners. In determining the advisa- 
 bility of erecting a house, it is well to have enough business as- 
 sured, if possible, to pay operating expenses. If this much can 
 be had the first season, the success of the business is no longer in 
 doubt, and the house will generally pay nicely the second or third 
 year. Should the owners be in the produce business, and buy 
 and store enough goods to pay the operating expenses, they can 
 demonstrate the success of the house the first year or two on their 
 own account, and in future seasons obtain outside business very 
 easily. Of course many houses are run for private use only, and 
 the remarks above do not apply to such cases. It is true that 
 there have been a good many failures in the cold storage business, 
 but they are invariably the result of a poor house or poor han- 
 dling, with the resulting heavy claims for damage to goods in 
 storage, or over-capitalization and mismanagement. 
 
 Very little reliable information can be obtained by those 
 who contemplate the erection of a cold storage house from people 
 already in the business; especially if in the immediate vicinity 
 of the proposed house. This is because those in the business al- 
 ready, regard the building of a new plant as more or less direct 
 competition, and are quite liable to be biased in their views ■ of 
 the cold storage business in general, and of the proposed plant in 
 particular. There is one thing which may be put down as un- 
 necessary, that is the putting up of a small, cheap house as a 
 trial, expecting, if it pays, to put up a larger and a better one. 
 A small, cheap house, while not certain to be a failure, is more 
 than likely to be so, and consequently the larger and better house 
 is never built, and another is added to the ranks of those who 
 think cold storage of no value, and a failure in a business way. 
 Build well, if at all — it is not necessary to experiment, as this 
 has been done repeatedly already, and the results from a well- 
 built cold storage house are to be depended upon. The popula- 
 tion of a town or city does not always indicate its ability to sup- 
 port a cold storage warehouse. A large residence population 
 has very little, need for such an establishment, while a compara- 
 tively small wholesale center at once makes a demand for stor- 
 
24 PRACTICAL COLD STORAGE 
 
 age for perishable goods. A large town, located in a rich pro- 
 ducing district, generally gives a good opening for the upbuild- 
 ing of a business, particularly where the chief articles of pro- 
 duction are eggs, butter, cheese or fruits. 
 
 COST OF BUILDINGS OF VARIOUS SIZES. 
 
 The cost of a fully-equipped cold storage building is some- 
 thing startling to many who contemplate embarking in the busi- 
 ness. It is sometimes two or three times as much as was thought 
 possible — many persons having an idea seemingly that a cold 
 storage house can be put up for about the same cost as an ordi- 
 nary structure. The shell of a cold storage house is only a por- 
 tion of the total cost, and never exceeds half the cost. In many 
 cases it is only one-third the cost of the finished building. 
 This varies with the character of the structure, class of in- 
 sulation, and type of refrigerating equipment. It may be 
 stated as positive that there is no such thing as a 
 cheap cold storage house which will at the same time do 
 good work. Because of the cost of internal arrangements and 
 equipment, a cold storage cannot be compared with any other 
 kind of a building, and the reason why people are surprised at the 
 cost is because they make comparisons with buildings of ordi- 
 nary construction. Probably two out of three persons who in- 
 vestigate with the idea of building are deterred because of the 
 expense running higher than anticipated. The reader who has 
 preconceived ideas on the cost of a properly-equipped plant, 
 may safely prepare for a shock should he wish to obtain estimates. 
 
 The cost of a well-insulated and carefully-equipped house 
 cannot be stated accurately without knowing the cost of ma- 
 terials and labor at the building site, and the exact plan and de- 
 tails of construction, but a few suggestions are made here as a 
 guide to those interested. A good frame building, well insu- 
 lated and equipped with machinery under the "Cooper System," 
 as illustrated in the chapter on "Refrigeration from Ice," arid in- 
 cluding the cost of a cheaply-constructed ice room built adjoin- 
 ing the storage house, will be, for a house of twenty carloads 
 capacity, between $7,000 and $10,000. This cost does not in- 
 clude the value of a building site, which necessarily would be 
 much greater in some localities than in others. In case an ice 
 
ORGANIZING AND OPERATING A COLD STORE 25 
 
 dealer, with no ice house to build, and perhaps some available 
 power for ice-crushing and elevating, should undertake the busi- 
 ness, the cost might be cut down probably $500 to $1,000. A 
 smaller house, of ten or twelve cars capacity, could be built for 
 about $5,000 to $7,000. The cost is more in proportion as the 
 capacity grows less. A larger house, of say eighty carloads ca- 
 pacity, could be built and equipped for about $20,000 to $30,000, 
 including ice house. A small room holding from one to three 
 cars may be built for $800 to $2,000 complete. A wide range is 
 given in these estimates for the reason that it is necessary owing 
 to widely varying costs in different parts of the country. Prod- 
 ucts stored and number of rooms a house is divided into also in- 
 fluence costs materially. The figures here given are approxi- 
 mate costs of cold storage rooms or buildings equipped with the 
 Cooper system, but this cost is not much more than a w'ell-built 
 house with the overhead ice systems, described in the chapter on 
 "Refrigeration from Ice." The mechanical or ammonia system 
 costs much more, for the smaller size of houses or rooms, as the 
 capacity is increased the costs approach each other more nearly, 
 but everything else being equal the Cooper system may be in- 
 stalled in a house of any size for less than an ammonia system 
 with brine circulation. Direct expansion may be installed for 
 less, but direct expansion is not to be considered for first class 
 cold storage work. 
 
 The question is often asked as to the size of house to be 
 built in a given locality. The author always withholds an answer 
 until he is personally' acquainted with all the conditions which 
 can possibly be known. Only in exceptional cases are houses of 
 a smaller capacity than twenty carloads recommended, for the 
 reason that the cost of building and operating is so much more in 
 proportion.! For private use there is no limit to size, and rooms 
 of as small capacity as one or two cars have been designed, giving 
 good service and satisfaction to their owners. These small rooms 
 are intended for temporary holding, but very successful results 
 are obtained for long-period holding, when the rooms are 
 equipped with the brine system. 
 
 CLASS OF GOODS PLACED IN COLD STORAGE. 
 
 The product which may be depended upon to furnish the 
 largest portion of the business to a newly-established cold storage 
 
26 PRACTICAL COLD STORAGE 
 
 depends on the location. Some houses are built solely for cheese, 
 others for eggs, and others only for apples ; but generally speak- 
 ing, eggs form the largest and best paying product which is han- 
 dled in cold storage. Eggs are probably the most difficult of all 
 products to successfully carry for a period of six or eight 
 months. If they are stored in a too dry atmosphere they dry out 
 or shrink, and in this condition decay more quickly. If the air 
 is too moist the eggs will mold and become musty. There is 
 more danger of having a room too moist than too dry, and the 
 damage resulting from too moist a room is also' much greater. 
 The best temperature for eggs is 29° to 30 F., and they are car- 
 ried at this temperature by the best houses. A forced circulation 
 of air is beneficial, and the moisture in the air should be regulated 
 to the proper degree. For testing the air moisture of a cold stor- 
 age room an instrument called the sling psychrometer is used. 
 The subject of humidity is rather complicated, and the' reader is 
 referred to chapter on "Humidity," and "Eggs in Cold Storage," 
 for a more comprehensive treatment of this subject. 
 
 Butter is probably second in importance to eggs, and all 
 cold storage houses have rooms fitted up especially for this prod- 
 uct. The correct temperature for carrying butter has not been 
 definitely settled by a majority agreeing on some one tempera- 
 ture, and at present butter is held in cold storage at tempera- 
 tures ranging from below zero to 25 ° F. The most common tem- 
 perature now is between 12 and 15° F., and the author believes 
 this to be low enough. Many practical men insist that zero is 
 better, and some houses are carrying it at this temperature. Still 
 others are holding temperatures for butter at from zero to 10° F. 
 There seems a decided movement toward zero and below and we 
 may all have to accept this at some future time. A butter stor- 
 age room should only be kept dry enough to prevent the forma- 
 tion of mold, and generally no attention is paid to the matter of 
 humidity ; the room being amply dry, nothing further is thought 
 of it. If butter rooms are too dry, as they frequently are, it 
 leads to a bad drying out of the packages, and the surface of the 
 butter as well, causing it to get "air-struck" or "strong" and 
 shrink in weight. Butter, in order to keep well in cold storage, 
 must be protected from contact with the air. Much has been said 
 about freezing butter, but the butter fat practically has no freez- 
 
ORGANIZING AND OPERATING A COLD STORE 27 
 
 ing point, and it simply gets harder and harder the lower the 
 temperature; so the idea that butter freezes at a temperature just 
 under 32" F. is entirely erroneous. (See chapter on " Butter in 
 Cold Storage " for more complete information.) 
 
 Cheese is not ordinarily considered so difficult a product as 
 butter and eggs to successfully refrigerate, but this idea comes 
 largely from the fact that cheese has only recently been well han- 
 dled in cold storage, and the possibilities of refrigeration for this 
 purpose have not been demonstrated fully. Cheese will not 
 spoil if stored in cellars or basements ; nevertheless a properly- 
 equipped cold storage room will quickly pay for itself in the im- 
 proved results obtainable. Cheese should be carried at about the 
 same degree of humidity as eggs, and at a temperature ranging 
 from 38° down to 30° F. It is very common practice now to 
 place cheese in cold storage when only eight or ten days old. 
 At this age it is not properly cured, and should not be placed in 
 a lower temperature than 38° F. The temperature may be grad- 
 ually lowered after a month or two, and at an age of three or 
 four months the temperature of the room should reach 30° F., 
 but should not go any lower. If the temperature is carried much 
 below 30° F. for any length of time it will injure the texture of 
 the cheese, and even at 30° F. some claim that it makes the cheese 
 "short" or brittle in texture. Cheese will freeze so as to be un- 
 fit for market at about 20 to 25 " F. The reason why cheese 
 should not be placed in too low a temperature while new, is that it 
 may not ripen or "cure up" properly, and is liable to develop a 
 bitter flavor. It must be remembered in considering this sub- 
 ject that cheese is of many different kinds and widely varying 
 quality. What is said above refers to an average make of Amer- 
 ican cheddar cheese. (For further information on the cold cur- 
 ing of cheese see chapter entitled "Cheese in Cold Storage") 
 
 Apples are stored in large quantities during the fall and win- 
 ter months. The quality of the fruit should be prime, and not 
 too fully matured. It is customary to place apples in egg rooms 
 as fast as eggs can be removed in the fall, and no bad effect will 
 result. Apples and eggs should not, of course, be placed in the 
 same room together, but when a room is emptied of eggs it is 
 customary to fill it with apples. After the apples go out and 
 before again filling with eggs, the room should be thoroughly 
 
28 PRACTICAL COLD STORAGE 
 
 whitewashed. (See chapter on "Keeping Cold Stores Clean.") 
 There are many different varieties of apples, and some of them 
 require special treatment in cold storage, but the generally ac- 
 cepted temperature for apples for long-period storage is 30" or 
 31° F. Some apple men prefer higher temperatures, and get 
 good results, but the lower temperatures are the favorite. Ap- 
 ples should not be quickly cooled when placed in cold storage. 
 If a week or two is consumed in reducing them to the correct 
 temperature so much the better. (See chapter entitled "Apples 
 in Cold Storage.") 
 
 Lemons and oranges are very successfully cold-stored at 
 temperatures of from 35° to 40° F. Lemons are very sensitive to 
 cold, and may be seriously damaged if the temperature ap- 
 proaches near the freezing point. Thirty-eight degrees is thought 
 best for lemons. Oranges are carried at a temperature of 34 
 or 35 F. Lemons and oranges must be stored by themselves, 
 and carefully isolated from products like eggs and butter. It 
 is best not to handle these in the same building unless through 
 a separate outside entrance, as much damage results to eggs and 
 butter if flavored with the odor of citrus fruits. Some promi- 
 nent cold storage houses have been very heavy losers from being 
 obliged to pay for damage from this cause. 
 
 Dried fruit and nuts, flour, and other goods known as gro- 
 cers' sundries, are now a large item for cold storage in some 
 wholesale centers. This business comes largely from the wholesale 
 grocers and commission men. These goods are stored at a tem- 
 perature of 35° to 45° F. The storage of furs, woolens, etc., 
 is an important and lucrative business in many cities, and where 
 the volume of business is sufficient a room may be set aside for 
 the purpose, and made to pay well. Any temperature below 40° 
 F. is all that is necessary for this class of goods. Potatoes may 
 be kept in cold storage at a temperature of 34 F., and carried 
 until spring in prime condition. Potatoes freeze easily, and are 
 entirely ruined when frozen, so the temperature must never 
 touch the freezing point. Cabbage may be carried some time in 
 a green condition, at a temperature of 33° F. Freezing will not 
 damage cabbage materially if the frost is drawn out slowly. The 
 freezing and storage of poultry is a remunerative business, and 
 much poultry is handled through cold storage. The freezing 
 
ORGANIZING AND OPERATING A COLD STORE 29 
 
 may be accomplished at ia° and 15 F. with good results if 
 stock is freshly killed and in small packages. For temporary 
 holding without freezing a temperature of 30 F. is best. Poul- 
 try can only be held' a few weeks at this temperature, a month 
 to six weeks being the extreme limit. Beer and meat are han- 
 dled by some houses. Beer should be held at 35 ° to 38° F., and 
 meat at 30° to 38° F., depending on length of time it is to be 
 carried. 
 
 RATES FOR COLD STORAGE. 
 
 The rates to be obtained for storing different products vary 
 with the locality, competition, etc., but the following will serve 
 as a guide. These rates are mostly higher than average rates 
 on carload lots, but will serve as a guide to those not familiar 
 with local rates. Each locality has its own rates to some extent : 
 
 Per Season Season 
 
 Month. Rate. Ends. 
 
 Eggs, per 30., doz. case $ .15 $ .60 January 1 
 
 Butter, per 100 lbs 25 1.00 January 1 
 
 Cheese, per 100 lbs 20 .75 January 1 
 
 Apples, per barrel- ,15 .60 May 1 
 
 Lemons, per box 10 .40 July 1 
 
 Oranges, per box 08 .30 July 1 
 
 Dried Fruit, per 100 lbs 08 .35 November 1 
 
 Nuts, per 100 lbs 10 .40 November 1 
 
 Furs, Coats, etc 2.00 January 1 
 
 Potatoes, per 100 lbs 10 .35 April 1 
 
 Cabbage, per ton 1.50 4.00 April 1 
 
 Poultry freezing, per cwt 25 1.00 April 1 
 
 Beer, space rented at 15c. per cubic foot per year. 
 Meat, per 100 lbs., 15c per month. 
 
 EARNINGS OF COLD STORES. 
 
 To show the prospective earnings of a small house we will 
 take one of twenty-five carloads capacity operated on the "grav- 
 ity brine" system, and assume that we secure the first year half 
 its capacity, or twelve cars of eggs. Twelve cars of eggs equal 
 4,800 cases. If we secure a season rate on all, at the carload- 
 rate of 50 cents, this will give us a gross income of $2,400. Oper- 
 ating costs are difficult to obtain even with the simple ice and 
 salt system owing to widely varying circumstances under which 
 plants operate. An estimated cost of the ammonia or other mechani- 
 cal systems is out of the question as the item of attendance alone 
 
30 PRACTICAL COLD STORAGE 
 
 is never the same. The operating expenses of the house will be 
 
 about as follows : — 
 
 Ice, 500 tons, 30c $150.00 
 
 Salt, 30 tons, $6.00 180.00 
 
 Power 125.00 
 
 Labor 150.00 
 
 $605.00 
 Interest, insurance, repairs, etc. on an investment of 
 
 $8,000 at 8 per cent $640.00 
 
 $1,245.00 
 From these figures it is seen that with our house half full 
 of goods, the business would pay a fair profit above actual ex- 
 penses. It may be well to note here that it costs practically as 
 much to operate a cold storage house half * filled with goods as 
 it would if completely filled. The only difference is a small labor 
 item of the handling, and the cost of cooling the extra quantity 
 of goods in the first place to the temperature of the room, both 
 very small items. The moral of this is that the cold storage man- 
 ager should aim to have his house filled every year. If apples 
 are to be had as the eggs go out in the fall, the income for the 
 year is materially increased with little cost, as apples require only 
 a small amount of refrigeration during the cool weather of fall 
 and winter. 
 
 ADVICE TO THOSE NEW TO THE BUSINESS. 
 
 A few words of advice to prospective investors regarding 
 the danger of experimenting in cold storage construction. It is 
 dangerous from the fact that a failure means the damage of a 
 very valuable product, and a consequent heavy money loss. The 
 most absurdly foolish schemes have been tried by men with no 
 practical or scientific information, and the result has been what 
 any thorough-going cold storage man could foresee, — either flat 
 failure or no tangible results from the experiments tried: Some- 
 times it occurs that the would-be cold storage man thinks to save 
 architect's and engineer's fees by planning his own building, or 
 by taking some of the plans and ideas which appear from time 
 to time in the agricultural or trade papers, and working them over 
 to suit his case. It is the author's positive opinion that four 
 times as much money is wasted in this way as there is saved. 
 No two houses properly use the same construction and arrange- 
 ment, and each case requires special study by the designer in 
 
ORGANIZING AND OPERATING A COLD STORE 31 
 
 order to do it justice, and he is a poor engineer indeed who can- 
 not save twice his fees to his client. The above advice is given 
 with an intimate knowledge of the subject, as the author has 
 spent much money on experiments and tests of various kinds, and 
 never expects to be properly reimbursed for the time and effort 
 expended. All lines of industry are more and more specialized, 
 and the planning and equipping of a cold storage house is just 
 as much a special business as the buying and selling of produce. 
 
 As has already been pointed out, the results possible to at- 
 tain by the use of ice are equally as good, within certain limits, as 
 may be obtained by employing the ammonia or mechanical sys- 
 tems. The ice and salt system has the advantage of being 
 cheaper to install, cheaper to operate, and a better control of tem- 
 perature is possible. These are all very good reasons why the 
 ice and salt system should be adopted where ice is a sure crop, 
 and can be put in the house at a moderate price. There is abso- 
 lutely no question about the results obtained from storing goods 
 in such a house, well-built and properly managed. The most 
 perfect results possible in refrigeration may be obtained, and at 
 a small cost as compared with the mechanical systems. Where 
 manufactured ice is in use the small cold storage house, butcher, 
 produce dealer, or any other business requiring refrigeration in 
 comparatively small amounts, can in many cases obtain the best 
 results at a lower cost by the use of ice and salt than by the in- 
 stalling of a small machine. Besides this they are absolutely 
 safe against a breakdown. 
 
 The question is often asked, "How long will a cold storage 
 house and its equipment of piping and iron work remain in good 
 operating condition?" No positive answer can be made, as a 
 great deal depends on the building and the apparatus, and the 
 way it is handled and cared for. The average life of a cold stor- 
 age building and the insulation should not be essentially different 
 from that of an ordinary building of the same construction, and 
 this means that it will last indefinitely. The equipment, with 
 ordinary repairs, would do good service for from fifteen to twen- 
 ty-five years, probably longer under favorable conditions. An 
 ice house will remain in good condition for from ten to fifteen 
 years, and it is probable that it would be serviceable for the pur- 
 pose for a much longer time. 
 
32 PRACTICAL COLD STORAGE 
 
 CHAPTER III. 
 GEOMETRY OF COLD STORAGE HOUSES. 
 
 BEST PROPORTIONS FOR COLD STORES. 
 
 An important factor in the cost of constructing and cost of 
 refrigerating cold storage rooms, as independent rooms, or as 
 a complete warehouse, is the relation of dimensions (length, 
 breadth and height) to area of outside exposure. This point 
 is often lost sight of in the design of refrigerated structures, 
 and the desire to gain all the space possible on main floor some- 
 times leads to some very absurd arrangements from a theoreti- 
 cal, practical or business standpoint. The installing of first-class 
 elevator facilities in a cold storage warehouse is very important 
 and with a fairly high rate of speed and a commodious car, space 
 on the floors above is practically as valuable as space on the 
 ground floor. The idea that storage rooms should be low, say 7 
 feet to 9 feet, has often been carried to an unwarranted extreme. 
 It is where rooms are to be used for temporary purposes only that 
 it is desirable to have the rooms low to avoid unnecessary labor in 
 handling the goods. Rooms for long period storage purposes as 
 a general rule should be made from 10 feet to 12 feet in height; 
 not only as a matter of economy of space and cost of construc- 
 tion, but the circulation of air in the room is much more perfect. 
 This is especially true of direct piped rooms. The importance of 
 this subject has been so often overlooked in the construction of 
 cold stores that it has been thought advisable to direct attention 
 to it here. The relation of the cubical contents of a building to 
 its outside exposure or superficial area is readily appreciated by 
 noting a few figures, as follows : 
 
 Take three rooms or buildings of equal storage capacity, with 
 cubical contents of 1,000 cubic feet, and whose three dimensions 
 vary. The cube with length, breadth and height each 10 feet 
 (see Fig 1) has an outside exposure of 600 square feet. 
 
GEOMETRY OF COLD STORAGE HOUSES 
 
 33 
 
 fig. I. — BxLxH equals 1,000 cubic feet. 
 
 10x10 equals 100; 100x6 equals 600 sq. 
 Ratio of cubical contents to outside 
 exposure 1,000 to 600. 
 
 ft. 
 
 Comparing with another rectangular space of equal capacity 
 — whose breadth is 10 feet, height j'6" and length i3'4". (See 
 Fig. 2.) 
 
 fig. 2. — BxLxH equals 1,000 cu. ft. 
 
 io'xi3'4"x2 equals 266 2-3 sq. ft. 
 
 io'x 7'4"x2 equals 150 sq. ft. 
 
 7'6"xi3'4"x2 equals 200 sq. ft. 
 
 Total 616 2-3 sq. ft. 
 
 Ratio of cubical contents to outside 
 exposure 1,000 to 616 2-3. 
 
 (8) 
 
34 
 
 PRACTICAL COLD STORAGE 
 
 It will be noted that the change of dimension in this case 
 is but slight from the cube, so the increase of outside exposure 
 is only 2.77 per cent. 
 
 Taking another and more pronounced departure from the 
 cube and still retaining the capacity of 1,000 cubic feet, where 
 the breadth is 6'8", length 25'o" and height 6'o" (see Fig. 3). 
 
 3. — BxLxH equals 1.000 cu. ft. 
 
 6'o"x2S'o"x2 equals 300 sq. ft. 
 
 6'8"x2S'o"x2 equals 333 sq. ft. 
 
 6'8"x 6'o"x2 equals 80 sq. ft. 
 
 Total 713 sq. ft. 
 
 Ratio of cubical contents to outside 
 exposure, 1,000 to 713. 
 
 To sum up the comparison of the cube with the other two 
 rectangular rooms or buildings would be as follows : 
 
 Fig. 1 
 Fig. 2 
 Fig. 3 
 
 Cubical contents 
 in cubic feet. 
 
 IOOO 
 1000 
 IOOO 
 
 Superficial area 
 or outside expos- 
 ure in square 
 feet. 
 
 600 
 
 616 2/3 
 713 
 
 Percentage of 
 
 increase over 
 
 cube. 
 
 2.77 
 18.83 
 
 The result is important in view of the fact that the loss of 
 refrigeration from heat leakage through the walls is on the 
 average probably three-fourths of the total amount necessarv 
 
GEOMETRY OF COLD STORAGE HOUSES 35 
 
 to supply and maintain temperature in cold storage rooms. The 
 amount of heat leakage will be directly proportional to the ex- 
 posed outside surface or superficial area of the room or house. 
 The cost of insulation which is usually figured by the square 
 foot of wall surface is also increased proportionately, and the 
 cost of building is also greater. The cost of insulation and cost 
 of cooling to make good the heat leakage will be 18.83 P er cent 
 greater if the room or building is built as in Fig. 3, than if built 
 in the form of a cube, as in Fig. 1. Therefore, in the design of 
 cold storage rooms or buildings, the nearer a cube may be ap- 
 proximated, the cheaper the first cost and cost of operation, 
 other things being equal. 
 
 This must not be carried to an extreme which will make the 
 conduct of the business laborious or expensive. Some classes of 
 trade require much floor space and little height, while others may 
 use a high room. For a business where many goods are han- 
 dled in and out, daily, ground floor space is extremely valuable. 
 In extreme cases it may be necessary, on account of expense 
 and time consumed in handling, to arrange all storage rooms on 
 the ground floor. To do this the advantages obtained must more 
 than offset the increased cost of construction and operation. For 
 a business where goods are mostly in for long-term storage a 
 house of several floors is practically as convenient, costs less, is 
 cheaper to operate and requires less ground space. 
 
36 PRACTICAL COLD STORAGE 
 
 CHAPTER IV. 
 INSULATION.* 
 
 GENERAL CONSIDERATION. 
 
 The selection and correct use of materials for insulation is 
 one of the most important considerations in the design of cold stor- 
 age warehouses. It is purposed in this chapter, to condense the 
 available information and data on the subject in a general way, 
 describing the methods and materials as they have been used up 
 to the present time. In giving the insulating values of different 
 materials it is intended to eliminate mathematical formula as far 
 as possible so as to serve the average cold storage man in a 
 practical manner. At the same time the author will consider it 
 a duty to describe apparatus used to determine these values and 
 give tables of the results obtained, although seemingly complicated. 
 
 There is no other part of cold storage work on which there 
 has been a greater diversity of opinion and practice ; consequently 
 a great variety of materials has been used in many combinations 
 to serve as insulation. This is natural, because until recently the 
 designers were largely cold storage men who had designed their 
 own houses, and the insulation was commonly a matter of guess 
 work, personal fancy or an original idea ; hence they were apt 
 to think that the particular kind of insulation in their own houses 
 was about the best unless it proved very bad. The character of 
 the insulation in each case has been largely the result of the 
 general educational standard of the individual. Some would 
 content themselves with a small quantity of the cheapest kind 
 of material available and literally "throw" it into place, forget- 
 ting meanwhile that their insulation was a most important factor 
 in the successful and economical operation of their house. Oth- 
 ers have availed themselves of the best materials on the market, 
 and after observing the results of their work, they know that 
 
 *This chapter was largely written by the Author's Associate, Chas. A. Berger who 
 also prepared the drawings and conducted the original tests as described. 
 
INSULATION 37 
 
 "the best is none too good," when intelligently applied. This 
 "pioneer" work has of course been essential to the development 
 of scientific cold storage insulation. The selection of the best 
 materials for a given duty was very difficult, owing to the claims 
 of the manufacturers and salesmen of the various insulating 
 materials, they sometimes distorting their laboratory tests of the 
 non-conducting properties of various, substances to suit their own 
 particular material.. - These tests, while perhaps correct, were 
 often misleading to the customer because other considerations 
 besides non-conductivity must be considered. 
 
 In connection with the foregoing we should not lose sight 
 of the fact that reliable information on the subject was very 
 meager up to nearly the last decade, there having been prac- 
 tically no reliable literature or data published up to that time. 
 The refrigerating machine manufacturers usually devoted a page 
 or two of their catalogues to "approved" insulations, but they 
 seldom had advanced or progressive ideas on the subject. The 
 insulations they recommended were as a rule insufficient for 
 economical operation. It was found much easier to sell a larger 
 machine than to convince the customer that he should invest 
 more money for better insulation. 
 
 Laboratory tests of the heat conductivity of materials cannot 
 be absolutely relied upon when these materials are to be used 
 for cofd storage insulation. These tests are usually made under 
 high temperature conditions and relatively low humidity, such 
 as steam pipe covering. Such conditions do not obtain in cold 
 storage work where the lower temperatures and relatively higher 
 humidity are the conditions. Numerous articles and papers have 
 been written for the trade periodicals and read before various 
 associations on the subject of insulation. Some of these articles 
 are very theoretical and are based altogether too much on labor- 
 atory test tables of heat conductors, which makes them almost 
 ■useless for practical application in cold storage construction. It 
 must be said, however, that they are along the right lines as 
 underlying the science of thermal conductivity. 
 
 In recent years many tests of composite insulations put to- 
 gether just as they would be erected in a cold storage house wall 
 have been conducted and tables compiled therefrom by experi- 
 menters who have made the subject of insulation a study, and 
 
38 PRACTICAL COLD STORAGE 
 
 who have had much practical experience in its application in 
 their capacity as designing architects and engineers. These tests 
 show in many cases a wide variation in results, owing no doubt 
 to the fact that the tests have been made under widely varying 
 conditions and methods and also to the changeable factor of 
 human error or personal equation in the observation of the tests. 
 The work of these experimenters shows much painstaking care, 
 and much good has resulted in raising the standard of the con- 
 struction of scientific and practical insulation. 
 
 In order to properly apply materials for the purpose of pre- 
 venting heat transmission, it is necessary that the theory of heat 
 and its behavior should be understood. It is proposed therefore 
 to review the simple natural laws which underlie this subject. 
 
 HEAT. 
 
 According to the modern scientific theory, heat is not a sub- 
 stance, but a form of energy; a mode of motion or vibrations, 
 like light and sound. Primarily, there is but one source of heat, 
 the sun, from which all lesser sources receive their supply by 
 radiation. These lesser sources are : Friction, percussion and 
 pressure, terrestrial heat, molecular action, change of condition, 
 electricity and chemical combination. Like all other forces of 
 nature that are manifested to us, the molecular, kinetic energy 
 of heat has a tendency to equilibrium, or like water, to seek 
 its level; but unlike water, it cannot be confined by any known 
 material or substance. If there is a difference in temperature on 
 the two sides of a wall, heat will pass through that wall until 
 the temperature on both sides is the same, regardless of what 
 the wall consists of. The flow of heat through a wall can, how- 
 ever, be controlled to a great extent by using materials that will 
 retard its passage. 
 
 The transmission of heat is affected in three different ways : 
 first ; by radiation ; second, by convection ; and third, by conduc- 
 tion. Radiation is the direct passage of heat through the air 
 from one body to another without perceptibly heating the air, 
 and is manifested to the senses by the heat which is felt when 
 standing by an open fire. By radiation, heat is thrown off in 
 every possible direction from every point of a hot body. In an 
 inclosed air space with different temperatures as shown in Fig. 
 i, the radiant heat would pass from the high to the low tern- 
 
INSULATION 
 
 39 
 
 perature side directly across the space indicated by arrows. The 
 scientific definition of radiant heat is that it is in the nature of a 
 wave motion communicated through an exceedingly subtle ether, 
 which is supposed to pervade all space, and that it is obedient 
 to the laws of refraction, reflection, polarization, etc., the same 
 as light. 
 
 Convection of heat is the transfer from one place to another 
 by the bodily moving of the heated substance, such as when air, 
 
 Outside 
 
 Wall 
 
 HO°r 
 
 FIGS. I, 2 AND 3. — ILLUSTRATING WAYS OF HEAT TRANSMISSION. 
 
 water or any other gas or fluid comes in contact with a heated 
 surface; the particles touching the heated surface become warm 
 and lighter, therefore ascending and giving place to the colder 
 and heavier particles below. This action is illustrated by the 
 heating of rooms with stoves ; the air as warmed rises to the top 
 of the room and its place is taken by the colder air from below. 
 
40 PRACTICAL COLD STORAGE 
 
 The principle of convection, or circulation as it is generally un- 
 derstood, is shown by Figs. 2 and 3, where the air in the inclosed 
 space with one side warmer than the other, being heated on 
 that side, becomes lighter by expansion and rises; as it gets to 
 the top of the confined space, it passes over to and down the cold 
 side where it gives up heat ; as it is cooled, it contracts and be- 
 comes heavier; it then sinks and returns to its original place. 
 This circulation will continue indefinitely or until the temperatures 
 on both sides of the space are equalized. Fig. 3 illustrates this 
 principle when a wall is subdivided into a number of such spaces, 
 and the circulation becomes more complicated and retarded, pass- 
 ing less heat for the same thickness of wall in a unit of time than 
 a single space, as illustrated in Fig. 2. 
 
 Conduction is a term applied to heat flowing from a warmer 
 to a colder part of a body, or if a solid substance is placed in 
 contact with a body having a higher temperature, the particles 
 ■of the substance nearest are warmed, and they in turn give up a 
 portion of the heat received, to particles next to them and so on 
 from particle to particle until the whole substance is heated ; this 
 is accomplished without any sensible motion. A more familiar 
 •example of conduction is putting one end of an iron poker in the 
 fire; after a time, the other end will become heated and apparent 
 to the sense of feeling. 
 
 As heat then is not a substance but a vibration of the mole- 
 cules that compose a body, and that the rapidity of these vibrations 
 is the cause of the difference of temperature, it is really improper 
 to speak of heat and cold as such; but it is convenient to use 
 these old familiar terms in describing the phenomena, just as it is 
 said that the sun rises and sets, where it is in fact the earth that 
 moves. 
 
 Theoretically, all bodies and substances transfer heat by 
 radiation, convection and conduction at the same time, and this 
 is called complicated transfers of heat. Scientists state that 
 bodies at high temperatures will lose more heat by radiation than 
 "by convection and conduction, and that heat radiated by a coal 
 fire is estimated to be about one-half of the total heat generated. 
 At lower temperatures, such as is dealt with in refrigerating 
 work, transmission of heat by radiation is very small, and that, 
 practically, convection and conduction only need be considered 
 
INSULATION 41 
 
 in cold storage construction. With the understanding of the 
 definitions given above, it is readily seen that walls can be so 
 constructed as to retard or facilitate either mode of transfer. 
 This will be discussed more fully when considering insulating 
 materials. 
 
 UNITS OF HEAT.* 
 
 " The quantity of heat contained in a body is the sum of the 
 kinetic energy of its molecules. Heat is measured quantitatively 
 by the heat unit, which also varies in different places like other 
 standards. The unit used in the United States and England is 
 the British Thermal Unit (abbreviated B. T. U.), and represents 
 the amount of heat required to raise the temperature of one 
 pound of water i° F. The French unit is the Calorie, and is 
 the quantity of heat required to raise the temperature of one 
 kilogram of water from o° to i° Celsius. 
 
 Some writers define the B. T. unit as the heat required to 
 raise the temperature of one pound of water from 32° to 33 . 
 Others make this temperature from 60° to 61 ", and still others 
 define it as the amount of heat required to raise 1/180 pound of 
 water from the freezing to the boiling point. The last two defi- 
 nitions give nearly the same result, and may be considered prac- 
 tically identical." 
 
 The unit of heat transmission or insulating value is the num- 
 ber of B. T. U. that will pass through one square foot of a sub- 
 stance per hour, per degree difference in temperature between 
 the two sides of the substance. Some engineers prefer (in refrig- 
 erating work) to use a time unit of one day (24 hours) instead 
 of one hour in their values. This is perhaps more comprehensive, 
 as refrigerating capacity is usually figured per day, and it also 
 is an advantage in that the values are more likely to be expressed 
 in whole numbers and less in decimals. 
 
 CONDUCTORS OF HEAT. 
 
 Many laboratory experiments conducted by noted physicists 
 during the past century have given us tables of heat conducting 
 properties of the metal, mineral, liquid and vegetable substances ; 
 these tables vary from one another, depending upon the methods 
 used and the nature of the experiments. These experiments 
 demonstrate that the metals are the best conductors of heat; 
 
 Dr. J. E. Siebel, "Cornpend of Mechanical Refrigeration." 
 
42 
 
 PRACTICAL COLD STORAGE 
 
 that the vegetable and animal substances are the poorest conduc- 
 tors of heat, and that between these the minerals and liquids are 
 all arranged in varying degrees of heat conductivity. 
 
 The following table of the relative heat conductivity of a 
 number of substances is taken from Sir William Thompson's 
 article on "Heat" in the Encyclopaedia Britannica, reduced to a 
 unit of conductivity of one for water; this includes authorities 
 that he regarded as reliable on that subject. Part of this table 
 was taken from experiments made by Peclet, whose table is also 
 given below in B. T. units : 
 
 TABLE OF RELATIVE HEAT CONDUCTIVITY. 
 Article on "Heat" in Encyclopedia Britannica. 
 
 Copper 455. 
 
 Iron 80. 
 
 Sandstone 5.; 
 
 Stone 2.( 
 
 Traprock 2.< 
 
 Sand 1 
 
 Water 1 
 
 Oak (across fiber) 
 
 Walnut (along fiber) 
 
 Fir (along fiber) 
 
 Walnut (across fiber) 
 
 Fir (across fiber) 
 
 Hemp cloth (new) 
 
 Wool (carded) 
 
 Hemp cloth (old) 
 
 Writing paper (white) 
 
 Cotton wool 
 
 Eiderdown 
 
 Gray paper (unsized) 
 
 Air 
 
 Cork '.'.'.'.'.'.'.'.'.'.'. 
 
 Note: The figure for air has been fixed by J. Clark Maxwelf's bril- 
 liant investigations. He gives its conductivity at 1/20,000 that of copper, 
 as 1/3,360 that of iron, a determination reached by mathematical deductions' 
 from the kinetic theory of gases. 
 
 In the latter part of the eighteenth century, Count Rumford, 
 who did much work in the experimental study of heat, maintained 
 that liquids had no conducting power at all, but gained heat by 
 convection only. This was afterward found to be incorrect, as 
 shown in the above table, and shows in fact that water stands 
 next to the mineral substances in conductivity. 
 
 As to quantitative or rate of transmission, the following table 
 from experiments made by M. Peclet* gives the amount of heat 
 in B. T. units transmitted per square foot per hour, through 
 various substances one inch in thickness. He terms these poor 
 
 •Peclet's "Traite de la Chaleur," IV Ed., Tome 1, Pgs. 542 to 555. 
 
 34 
 95 
 075 
 31 
 
 295 
 
 24 
 
 235 
 
 MS 
 
 13 
 
 072 
 
 061 
 
 0595 
 
 0595 
 
 0555 
 
 054 
 
 047 
 
 0295 
 
 0145 
 
INSULATION 43 
 
 conductors (to distinguish them from the metals). The results 
 of these experiments are considered quite reliable, as they are 
 used extensively by heating engineers of Europe in their calcu- 
 lations for the heating of buildings. The experiments were made 
 by heating one side of the substances with hot water, and cooling 
 the other side with cold water, the difference between the tempera- 
 ture of ihe two sides being i°F. 
 
 TABLE OF POOR HEAT CONDUCTORS. 
 
 By M. Peclet. ^iTJiutf. 
 
 Gray marble, fine grained 28. 
 
 White marble, coarse grained 22.5 
 
 Limestone, fine grained 14.8 
 
 Limestone, coarse grained. 10.5 
 
 Glass 6. 
 
 Brick 5.6 
 
 Terra cotta 4.8 
 
 Plaster of paris 3.6 
 
 Sand 2.2 
 
 Oak, across the grain 1.7 
 
 Fir, across the grain 0.75 
 
 Fir, along the grain 1 .4 
 
 Walnut, across the grain 0.83 
 
 Walnut, along the grain 1.4 
 
 Guttapercha 1 .37 
 
 India-rubber 1.36 
 
 Brick dust, sifted 1.33 
 
 Powdered coke 1.3 
 
 Iron filings • 1.26 
 
 Cork 1. 15 
 
 Powdered chalk ' 86 
 
 Powdered wood charcoal 63 
 
 Straw, chopped 56 
 
 Powdered coal, sifted 54 
 
 Wood ashes 5 
 
 Canvas, new . : 41 
 
 Calico, new 40 
 
 Writing paper 34 
 
 Cotton, raw or woven 32 
 
 Eiderdown 31 
 
 Blotting paper 26 
 
 In an article written by Prof. John M. Ordway*, on "Non- 
 conductors of Heat," which treats of insulation tests conducted 
 on steam pipes, he subjoins the following table of non-conduc- 
 tivity of various substances. The figures in the last column are 
 for covering, one inch thick, with a difference of 100° F. on each 
 side of the covering. In most of the tests a stream of water at 
 about 176° F. was kept running through the heater. In some 
 cases the source of heat was steam at 310° F. as stated: 
 
 * Ice and Refrigeration, October, 1891, Page 216. 
 
44 
 
 PRACTICAL COLD STORAGE 
 
 NON-CONDUCTORS OF HEAT. 
 
 Net cubic in. 
 of solid 
 Non-conductors one inch thick. matter in 100 
 
 Still air 
 
 Confined air .... 
 
 Confined air=3io° .... 
 
 Wool=3io° 4.3 
 
 Absorbent cotton 2.8 
 
 Raw cotton 2 
 
 Raw cotton I 
 
 Live-geese feathers=3io° 5 
 
 Live-geese feathers=3io° 2 
 
 Cat-tail seeds and hairs 2.1 
 
 Scoured hair, not felted 9.6 
 
 Hair felt 8.5 
 
 Lampblack=3io° 5.6 
 
 Cork, ground .... 
 
 Cork, solid .... 
 
 Cork charcoal=3io° 5.3 
 
 White-pine charcoal=3io° 11. 9 
 
 Rice-chaff 14.6 
 
 Cypress (Taxodium) shavings 7 
 
 Cypress (Taxodium) sawdust 20.1 
 
 Cypress (Taxodium) board 31.3 
 
 Cypress (Taxodium) cross-section.... 31.8 
 
 Yellow poplar (Liriodendron) sawdust 16.2 
 
 Yellow poplar {Liriodendron) board. . 36.4 
 
 Yellow poplar (Liriodendron) cross-sec. 30.4 
 
 "Tunera" wood, board 79-4 
 
 Slag wool (Mineral wool) 5.7 
 
 Carbonate of magnesium 6 
 
 Calcined magnesia=3io° 2.3 
 
 "Magnesia covering," light 8.5 
 
 "Magnesia covering," heavy 13.6 
 
 Fossil meal=:3io° 6 
 
 Zinc white=3io° 8.8 
 
 Ground chalk=3io° 25.3 
 
 Asbestos in still air 3 
 
 Asbestos in movable air 3,6 
 
 Asbestos in movable air=3io° 8.1 
 
 Dry plaster of paris=3io° 36.8 
 
 Plumbago in still air 30.6 
 
 Plumbago in movable air=3io° 26.1 
 
 Coarse sand=3io° 52 o 
 
 Water, still '. . . . .'. . 
 
 Starch jelly, very firm, " 
 
 Gum-Arabic, mucilage, " 
 
 Solution sugar, 70 per cent, " 
 
 Glycerin, " 
 
 Castor oil, " 
 
 Cotton-seed oil, " 
 
 Lard oil, " .[..'. ' 
 
 Aniline. " 
 
 Mineral sperm oil, " 
 
 Oil of Turpentine, " 
 
 Heat units trans- 
 mitted per sq. ft. 
 per hour 
 
 43 
 108 
 203 
 
 36 
 
 36 
 
 44 
 
 48 
 
 41 
 
 50 
 
 5° 
 
 52 
 
 56 
 41 
 
 45 
 49 
 50 
 
 58 
 78 
 60 
 84 
 83 
 145 
 75 
 76 
 141 
 156 
 50 
 50 
 52 
 58 
 78 
 60 
 72 
 80 
 56 
 99 
 210 
 
 131 
 134 
 296 
 264 
 335 
 345 
 290 
 
 251 
 197 
 136 
 
 129 
 
 125 
 
 122 
 
 115 
 95 
 
INSULATION 45 
 
 A careful study of these tables shows that still air is one 
 of the poorest conductors of heat available for practical pur- 
 poses. The distinction between confined air and still air, and 
 the greater conducting qualities of the former has not been gen- 
 erally understood, and it is perhaps on this account that air 
 space construction has been used so much for cold storage insu- 
 lation. Note what Dr. Hampson, an English authority, has to 
 say on air spaces. The conclusions reached by him have also 
 been demonstrated by the author and other experimenters in this 
 country, and the result is the present tendency to use materials 
 which will subdivide the air into an infinite number of spaces. 
 As insulators against heat Dr. Hampson, in a series of lectures 
 at University College, Liverpool, England, sums the various sub- 
 stances up as follows: 
 
 Conduction and convection are best prevented by a totally empty 
 space intervening between the external objects and the internal cold ob- 
 jects — in other words, by having a vacuum between two air-tight walls. 
 Radiation can be to a great extent prevented by having a bright metallic 
 surface between the inside and outside. The efficiency of this combina- 
 tion was shown in one of the silvered vacuum vessels designed by Pro- 
 fessor Dewar, which contained liquid air which had been made half a 
 week before. Where such an arrangement was impossible, the best thing 
 to do was to fill the insulating space as far as possible with the substance 
 that had the smallest capacity for conducting heat. Iron has about one- 
 seventh the conducting power of copper, wood or other organic substances 
 still less, ice has only about one two-hundredth, and air not more than a 
 twenty-thousandth part of the conducting capacity of copper. Air, there- 
 fore, is the best insulating substance available ; but its value depends upon 
 its stillness, for if free to move in spaces of considerable size, it will be 
 in constant circulation, convection currents carrying in heat from the 
 warmer outside walls to the colder inside walls of the insulating spaces. 
 These spaces should therefore be very shallow, so that the viscosity of 
 the air, which is very small, will be able to prevent it from moving. 
 It is their possession of a large proportion of air, prevented by septa or 
 filaments from moving, that determines the excellence of the usual insu- 
 lating materials, such as eider down, wool, feathers, hair, chaff, cork, 
 slag-wool, asbestos, charcoal, wood, sawdust, etc. 
 
 A VACUUM THE POOREST CONDUCTOR. 
 
 Physicists seem to have proved that a vacuum is a poorer 
 conductor of heat than air, and a reference is made to it by Dr. 
 Hampson, as noted above. This was discussed by Dr. H. W. 
 Wiley in an address before the American Warehousemen's Asso- 
 ciation convention at Washington, D. C, December, 1903, and 
 as it is interesting in connection with the subject, we quote in 
 part as follows :* 
 
 •Reported in Ice and Refrigeration, January, 1904, page 35. 
 
4(5 PRACTICAL COLD STORAGE 
 
 There is one practical suggestion which these theories present, namely, 
 that a vacuum is by far the best protection against radiation that has 
 ever yet been discovered. Sawdust, shavings, cork, cloth, wood and many 
 other substances have been extensively used to protect cold spaces against 
 radiation, but none of these have anything like the obdurating properties 
 of a vacuum Liquid air and even liquid hydrogen contained in a vacuum 
 receiver, that is, a receiver surrounded by a vacuum, retain their liquid 
 state for hours and even days. There is, of course, a loss by radiation 
 and evaporation from the exposed surface, because pressure dare not be 
 used in confining these bodies, but this loss is comparatively slow. The 
 vacuum becomes an almost perfect protector against heat. If, therefore, 
 the refrigerating rooms which you use could be surrounded with a vacuum 
 space, it would most certainly reduce very largely the expense of main- 
 taining the low temperature. There are, of course, practical objections to 
 the use of a vacuum for this purpose of a very serious character. The 
 two chief objections would be the difficulty of maintaining an airtight 
 space so that there would be no leakage into the vacuum and the enormous 
 pressure upon the walls of the vacuous space produced by the atmosphere 
 itself. It is easy to construct a steam boiler which will bear a pressure 
 of from 400 to 600 pounds to the square inch, and it ought not to be dif- 
 ficult to construct a vacuous space around a refrigerating room which 
 would resist a pressure of 15 pounds to the square inch. The expendi- 
 ture and the energy required to evacuate this space and keep it practically 
 free from air would, in my opinion, be profitably expended, providing the 
 two conditions of imperviousness and pressure could be regulated. The 
 idea is at least worthy of experimental trial and it is hoped that some of 
 you will submit it to a practical test. 
 
 Mr. James Wills of New York has made a practical trial 
 
 of a vacuum as insulation for brine piping with good results, 
 
 but it has not been learned that the experiment has met with 
 
 sufficient success to warrant its adoption on the more recent work 
 
 constructed under that gentleman's supervision. 
 
 VARIATION OF HEAT TRANSMISSION. 
 
 M. Peclet proved experimentally that the rate of transmis- 
 sion of heat was directly proportional to the difference of tem- 
 perature on each side of a substance, and was inversely pro- 
 portional to the thickness. That is; if a substance one inch thick 
 transmitted say, one B. T. U., the same substance two inches 
 thick would transmit one-half B. T. U. under same conditions. 
 
 The results of later experiments, on poor conductors and on 
 those used in combination (such as used in the construction of 
 cold storage warehouses) show, however, that these conclusions 
 are in doubt. John E. Starr, in an article* on results of tests, 
 conducted by himself, states : "It is a well known fact that the 
 amount of heat transferred per degree of difference increases 
 somewhat with each degree of increase of difference of tem- 
 
 * "Non-conductors of Heat," in Ice and Refrigeration, July, 1891, page 37. 
 
INSULATION 47 
 
 perature." This same experimenter illustrates this principle 
 graphically by a diagram of tests* showing ice meltage in ordi- 
 nary domestic refrigerators at various differences of temperature 
 between inside and outside. If the transmission had been directly 
 proportional, the plotted curve on the diagram would have been 
 a straight line. 
 
 This increase of transmission per degree of difference as the 
 difference increases is also shown by a chart published in Ice 
 and Cold Storage (British), March, 1901 (see Fig. 4, page 48), 
 of results of tests with eight different constructions of the same 
 thickness. It is a matter of regret that the methods of testing 
 were not described in this case so that we could judge of their re- 
 liability. Referring to the chart it will be found that the line 
 plotted for the rate of transmission of each material is a curve, 
 having a range of temperature difference of 80° F. Calculating 
 down to per-degree difference at each end of the chart and divid- 
 ing the result by the range of difference (80° F.) shows co- 
 efficients of increase, varying from 25 to 50 per cent. 
 
 The author, in conducting a series of tests in 1900 and 1901 
 (which will be described further on), obtained results that tended 
 to prove the correctness of the observations cited above. This 
 co-efficient of increase varies for different substances and combi- 
 nations of materials, and to determine these co-efficients accu- 
 rately would be a difficult task indeed. From the above facts it 
 is obvious that the co-efficients of heat transmission obtained by 
 tests of substances which were made under a temperature dif- 
 ference of only one degree, are too small for practical application, 
 and they should be increased about 50% when used for de- 
 signing cold storage insulation. This is of increasing importance 
 when we consider that the tendency of modern cold storage prac- 
 tice is toward maintaining lower temperatures, often resulting 
 in a difference of temperature of from 70° to 90° F. between 
 inside and outside of walls. This is comparatively a high range 
 of temperature and the conditions to this extent are similar to 
 heating work. 
 
 That transmission of heat through any substance is not in- 
 versely proportional to the thickness seems evident by an exam- 
 ination of the following table converted from the metric system 
 
 * "The Cost and Value of Low Temperatures," in Ice and Refrigeration, Sep- 
 tember, 1891. 
 
INSULATION 
 
 49 
 
 by Chas. F. Hauss, Antwerp, Belgium. This writer states* that 
 this table is used by Adolph Block of Hamburg, one of Ger- 
 many's most reliable engineers : 
 
 TABLE OF CO-EFFICIENTS OF TRANSMISSION IN B. T. U. PER 
 SQ. FT. OF SURFACE PER HOUR. 
 
 Cooling 
 
 Thick- 
 ness 
 of Walls 
 
 Difference in Temperature — Fahrenheit 
 
 
 1" | 5° | 10° | 15° | 20° | 25° I 30° | 35° | 40° | 45° | 50° | 55" | 60° | 65° | 70° 
 
 
 i%" 
 
 0.48 
 
 2.40 
 
 4.80 
 
 7.20 
 
 9.60 
 
 12.00 
 
 14.40 
 
 16.80 
 
 19.20 
 
 21.50 
 
 24.00 26.50 
 
 28.80 
 
 31.20 
 
 33.60 
 
 
 10" 
 
 0.34 
 
 1.70 
 
 3.40 
 
 5.10 
 
 6.40 
 
 8.50 
 
 10.20 
 
 11.90 
 
 13.60 
 
 15.30 
 
 17.00 
 
 18.70 
 
 20.40 
 
 22.00 
 
 23.80 
 
 Solid 
 
 15" 
 
 0.26 
 
 1.30 
 
 2.60 
 
 3.90 
 
 5.20 
 
 6.50 
 
 7.80 
 
 9.10 
 
 10.40 
 
 11.65 
 
 13.00 
 
 14.30 
 
 15.60 
 
 16.90 
 
 18.20 
 
 
 20" 
 
 o n 
 
 1.10 
 
 2.20 
 
 3.30 
 
 4.40 
 
 5.50 
 
 6.60 
 
 7.70 
 
 8.80 
 
 10.011 
 
 11.00 
 
 12.00 
 
 13.20 
 
 14.3(1 
 
 15 40 
 
 Brick 
 
 25" 
 
 0,18 
 
 90 
 
 1.80 
 
 2.70 
 
 3.60 
 
 4.50 
 
 5.40 
 
 6.30 
 
 7.20 
 
 8.1(1 
 
 9.00 
 
 9.90 
 
 10.80 
 
 11.70 
 
 12.60 
 
 
 30" 
 
 0.16 
 
 0.80 
 
 1.60 
 
 2.40 
 
 3.20 
 
 4.00 
 
 4.80 
 
 5.60 
 
 6.40 
 
 7.2(1 
 
 8.00 
 
 8.80 
 
 9.60 
 
 10.40 
 
 11.20 
 
 Walls 
 
 35" 
 
 0,13 
 
 0.65 
 
 1.30 
 
 1.95 
 
 2.60 
 
 3.25 
 
 3.90 
 
 4.55 
 
 5.20 
 
 5.85 
 
 6.511 
 
 7.15 
 
 7.80 
 
 8.45 
 
 9.10 
 
 
 40" 
 
 01 if 
 
 60 
 
 1.20 
 
 1.81) 
 
 2.40 
 
 3.(111 
 
 3.60 
 
 4.21) 
 
 4.80 
 
 5.4(1 
 
 6.011 
 
 H.60 
 
 7.20 
 
 7.80 
 
 8 40 
 
 
 45" 
 
 0.11 
 
 0.55 
 
 1.10 
 
 1.65 
 
 2.20 
 
 2.75 
 
 3.30 
 
 3.85 
 
 4.40 
 
 4.95 
 
 5.50 
 
 6.05 
 
 6.60 
 
 7.15 
 
 7.70 
 
 
 12" 
 
 45 
 
 2.25 
 
 4.50 
 
 6.75 
 
 9.00 
 
 11.25 
 
 13.50 
 
 15.75 
 
 18.00 
 
 20.25 
 
 22.50 
 
 24.75 
 
 27.00 
 
 29.25 
 
 31 .50 
 
 Solid 
 
 16" 
 
 3!) 
 
 195 
 
 3 90 
 
 5.85 
 
 7.X0 
 
 9.75 
 
 11.711 
 
 13.65 
 
 15.60 
 
 17.95 
 
 19.5(1 
 
 21.45 
 
 23:40 
 
 25 26 
 
 29 30 
 
 
 20" 
 
 35 
 
 175 
 
 3,50 
 
 5.25 
 
 7.00 
 
 X.75 
 
 10.511 
 
 12.25 
 
 14.00 
 
 15.65 
 
 17.5(1 
 
 19.25 
 
 21 .(HI 
 
 22.75 
 
 24 50 
 
 Walls 
 
 24" 
 
 33 
 
 1 60 
 
 3.20 
 
 4.80 
 
 6.4(1 
 
 8.00 
 
 9.60 
 
 11.20 
 
 12.80 
 
 14.40 
 
 16.00 
 
 17.6(1 
 
 19.20 
 
 20.80 
 
 22.40 
 
 
 28" 
 
 2!) 
 
 1.45 
 
 2.90 
 
 4.35 
 
 5.80 
 
 7.25 
 
 8.70 
 
 10.15 
 
 11.60 
 
 13.05 
 
 14.50 
 
 15.95 
 
 17.40 
 
 18.85 
 
 20.30 
 
 For Lime- 
 
 32" 
 
 0.26 
 
 1.30 
 
 2.60 
 
 3.90 
 
 5.20 
 
 6.50 
 
 7.80 
 
 9.10 
 
 10.20 
 
 11.65 
 
 13.00 
 
 14.30 
 
 15.60 
 
 16.00 
 
 18.20 
 
 
 36" 
 
 II 24 
 
 1 20 
 
 2.4(1 
 
 3.60 
 
 4.80 
 
 6.00 
 
 7.20 
 
 8.4(1 
 
 9.60 
 
 10.4(1 
 
 12.011 
 
 13.2(1 
 
 14.4(1 
 
 15.611 
 
 16 8(1 
 
 
 40" 
 
 2?, 
 
 1 10 
 
 2.20 
 
 3.30 
 
 4.40 
 
 5.50 
 
 6.60 
 
 7.70 
 
 8.80 
 
 10.0(1 
 
 11.01) 
 
 12.IKI 
 
 13.20 
 
 14.30 
 
 15.40 
 
 
 44" 
 
 20 
 
 100 
 
 8,1)0 
 
 3 00 
 
 4.0(1 
 
 5.0(1 
 
 6.011 
 
 7.011 
 
 X.0II 
 
 9.01) 
 
 111.01) 
 
 11.011 
 
 12.0(1 
 
 13.01) 
 
 14 00 
 
 
 48" 
 
 0.19 
 
 0.95 
 
 1.90 
 
 2.85 
 
 3.80 
 
 4.75 
 
 5.70 
 
 6.65 
 
 7.60 
 
 8.55 
 
 9.50 
 
 10.45 
 
 11.40 
 
 12.35 
 
 13.30 
 
 Solid Plaster 1 J"- 2i" 
 
 60 
 
 3.00 
 
 6.00 
 
 9.00 
 
 12.00 
 
 15.00 
 
 18.00 
 
 21.00 
 
 24.00 
 
 27.00 
 
 30.00 
 
 33.00j36.00 
 
 39.00 
 
 42.00 
 
 Partitions 2*"-3i" 
 
 0.48 
 
 2.40 
 
 4.80 
 
 7.20 
 
 9.60 
 
 12.00 
 
 14.40 
 
 16.80 
 
 19.20 
 
 21.50 
 
 24.00 
 
 24.00|28.80 
 
 31.20 
 
 33.60 
 
 Floors 
 
 Joists with 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 double floors 
 
 11.117 
 
 0.35 
 
 0.70 
 
 1.05 
 
 1.40 
 
 1.75 
 
 2.10 
 
 2.45 
 
 2.80 
 
 3.15 
 
 3.60 
 
 3.85 
 
 4.20 
 
 4.55 
 
 4.90 
 
 
 Stone floor on 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 arches 
 
 1.2(1 
 
 1.0(1 
 
 2.00 
 
 3.00 
 
 4.00 
 
 5.00 
 
 6.00 
 
 7.00 
 
 8.00 
 
 9.00 
 
 10.00 
 
 11.00 
 
 12.00 
 
 13.00 
 
 14.00 
 
 
 Planks laid on 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (1.16 
 
 0.80 
 
 1.60 
 
 2.40 
 
 3.20 
 
 4.00 
 
 4.80 
 
 5.60 
 
 6.40 
 
 V.20 
 
 8.O0 
 
 8.80 
 
 9.60 
 
 10.40 
 
 11.20 
 
 
 Planks laid on 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 asphalt 
 
 0.20 
 
 1.00 
 
 2.00 
 
 3.00 
 
 4.00 
 
 5.00 
 
 6.00 
 
 7.00 
 
 8.00 
 
 y.oo 
 
 10.00 
 
 11.00 
 
 12.00 
 
 13.00 
 
 14.00 
 
 
 Arch with air 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 space 
 
 0.(1!) 
 
 0.45 
 
 0.90 
 
 1.35 
 
 1.80 
 
 2.25 
 
 2.70 
 
 3.15 
 
 3.60 
 
 4.06 
 
 4.60 
 
 4.9b 
 
 6.40 
 
 5.85 
 
 6.30 
 
 
 Stones laid on 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 earth 
 
 0.08 
 
 0.40 
 
 0.80 
 
 1.20 
 
 1.60 
 
 2.00 
 
 2.40 
 
 2.80 
 
 3.20 
 
 3.60 
 
 4.00 
 
 4.40 
 
 4.80 
 
 6.20 
 
 5.60 
 
 
 3 Joist with 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 single floors 
 Arches with 
 air spaces 
 
 0.10 
 
 0.50 
 
 1.00 
 
 1.50 
 
 2.00 
 
 2.50 
 
 3.00 
 
 3.50 
 
 4.00 
 
 4.50 
 
 5.00 
 
 5.50 
 
 6.00 
 
 6.50 
 
 7.00 
 
 
 0.14 
 
 0.70 
 
 1.40 
 
 2.10 
 
 2.80 
 
 3.50 
 
 4.20 
 
 4.90 
 
 5.60 
 
 6.30 
 
 7.00 
 
 7.70 
 
 8.40 
 
 9.10 
 
 9.80 
 
 
 100 
 
 5 00 
 
 10.00 
 
 15.00 
 
 20.00 
 
 25.00i30.00 
 
 35.00 
 
 40.00 
 
 45.00 
 
 50.00 
 
 55.00 
 
 60.00 
 
 65.00 
 
 70.00 
 
 I Double 
 
 0.46 
 
 2.30 
 
 4.60 
 
 7.05 
 
 9.20 
 
 11.5013.80 
 
 16.10 
 
 18.40 
 
 20.70 
 
 23.00 
 
 25.30 
 
 27.60 
 
 30.00 
 
 32.20 
 
 
 106 
 
 5 30 
 
 10.60 
 
 15.90 
 
 21.20 
 
 26.50131.80 
 
 37.00 
 
 42.40 
 
 47.70 
 
 53.00 
 
 58.30 
 
 63.60 
 
 69.00 
 
 74.20 
 
 1 Double 
 
 0.48 
 
 2.40 
 
 4.80 
 
 7.20 
 
 9.60 
 
 12.00| 14.40 
 
 16.80 
 
 19.20 
 
 21.60 
 
 24.00 
 
 26.50 
 
 28.80 
 
 31.20 
 
 33.60 
 
 Doors 
 
 0.40|2.00| 4.00| 6.00| 8.00|10.00|12.00|14.00|16.00|18.00|20.00|22.00|24.00|26.00|28.00 
 
 Dif. in Temperature 
 
 1° | 5° | 10° | 15° | 20° | 25° | 30° | 35° | 40°| 45° I 50° | 55° | 60° | 65° | 70° 
 
 This table is of limited value for cold storage work, but 
 serves to show the great variation in results obtained by different 
 experimenters. It will be noted that this table is based on M. 
 Peclet's first proposition, viz : _ That the rate of transmission is 
 proportional to the difference of temperature on each side of the 
 substance. 
 
 The fact that the transmission of heat through any substance 
 is not inversely proportional to the thickness is also shown by 
 
 *Paper read before American Society of Heating and Ventilating Engineers, 
 New York, January, 1904. 
 
50 
 
 PRACTICAL COLD STORAGE 
 
 the following tables after Box* Where N. is the value in B. 
 T. U. transmitted per square foot for a difference of i" F. be- 
 tween temperatures each side of wall in 24 hours. 
 
 y 2 brick aVi inches thick N. equals 5-5 B. T. Units 
 
 9 
 
 14 
 
 " 18 
 
 " V 
 
 " 36 
 
 Stone walls 
 
 " 12 
 
 M « 
 
 " 18 
 
 t 11 (t 
 
 " 24 
 
 ' 
 
 " 30 
 " 36 
 
 I it it 
 
 4-5 
 
 " 3-6 " 
 
 " 3.o " 
 
 " 2.6 " 
 
 " 2.2 " 
 
 equals 6.2 B. T. U. 
 " 5-5 
 " 5-0 
 
 " 4-S 
 " 4-3 
 " 4-1 
 
 HEAT TRANSMISSION THROUGH WALLS. 
 
 The following formula for calculating the amount of heat 
 that will pass through a wall of a certain area is by Dr. Siebel.* 
 
 If the number of square feet contained in a wall, ceiling, 
 floor or window be f, the number of units of refrigeration, R, 
 that must be supplied in 24 hours to offset the radiation of such 
 wall, ceiling or floor may be found after the formula: 
 
 R=fn (t— 1 ± ) B. T. units, 
 
 fn (t— t t ) 
 
 or, expressed in tons of refrigeration: R= tons. 
 
 284,000 
 
 In these formula?; t and tj are the temperatures on each 
 side of the wall, and n the number of B. T. units of heat trans- 
 mitted per square foot of such surface for a difference of 1" F. 
 between temperatures on each side of wall in twenty-four hours. 
 The factor n varies with the construction of the wall, ceiling or 
 floor from 1 to 5. For single windows the factor n may be taken 
 at 12 and for double windows at 7. (Box.) For different ma- 
 terials one foot thick we find the following values for n: 
 
 Pinewood 2.0 B. T. U. 
 
 Mineral Wool 1.6 " 
 
 Granulated Cork 1.3 " 
 
 Wood Ashes 1.0 " 
 
 Sawdust 1.1 " 
 
 Charcoal, powdered 1.3 " 
 
 Cotton 0.7 " 
 
 Soft Paper Felt 0.5 
 
 From "Compend of Mechanical Refrigeration,*' Page 181. 
 
INSULATION 51 
 
 If a wall is constructed of different materials having differ- 
 ent known values for n, viz, n 1; n 2 , n 3 , etc., and the respective 
 thickness in feet d 1; d 2 , d 3 , the value, n, for such a compound 
 wall may be found after the formula cf Wolpert, viz : 
 
 di d 2 d 3 
 
 n= — + — + — 
 
 n, n, n, 
 
 The value of n may be obtained from any of the foregoing 
 tables that are based on the transmission per hour by multiply- 
 ing by 24, the number of hours in a day, and where the values 
 given are for materials one inch in thickness, n and d should be 
 in inches. 
 
 INSULATION OF COLD STORAGE WAREHOUSES. 
 
 It is the purpose of cold storage warehouses to maintain 
 temperatures below that of the outside air, and in order to accom- 
 plish this refrigeration must be applied to withdraw the heat in 
 the warehouse. In doing this, as has been already noted, the 
 equilibrium of temperatures is disturbed, and the transmission 
 of heat through the walls from the outside into the warehouse 
 takes place. As the materials of which the walls of buildings 
 are usually constructed transmit heat quite rapidly, it is neces- 
 sary to "line'' them with materials that will retard this transfer 
 to a greater degree. These materials as used and applied col- 
 lectively are called "Insulation," as distinguished from the walls 
 of the building proper, although these insulate to a certain ex- 
 tent. 
 
 Knowledge of heat teaches that a perfect insulation is im- 
 possible. No matter of what materials or how thick the walls 
 are made, a certain amount of heat will pass through them, and 
 this must be taken up by the refrigerating medium. If it were 
 possible to stop all heat transmission through walls, doors, etc., 
 no refrigeration would be necessary after the goods in storage 
 had been cooled down to the required temperature. On the con- 
 trary, it is a well established fact that one-half to seven-eighths 
 of the refrigeration applied to cold storage rooms is expended in 
 removing the heat transmitted through the walls of the building, 
 
52 PRACTICAL COLD STORAGE 
 
 depending of course upon the amount of goods stored and the 
 frequency with which they are handled in and out. 
 
 The great importance of proper and efficient insulation is 
 evident when it is considered that all the heat passing through it 
 must be taken up by the refrigerating apparatus, which, in the 
 case of poor insulation, will need to be from 25% to 50% larger 
 than if the insulation were first-class. This larger apparatus 
 means a greater first investment than if a smaller apparatus 
 could have been used, and this difference might better have been 
 invested on the insulation. The additional operating expense of 
 the larger apparatus would be continuous from year to year and 
 would amount to many times as much as it would if first-class 
 insulation had been constructed in the first place. The invest- 
 ment put into good insulation has to be made but once, while 
 with poor insulation the loss of refrigeration through removing 
 the greater heat leakage makes a continual heavy expense. In- 
 sulation should be considered in the light of a permanent invest- 
 ment, same as buildings and equipment, the returns of which 
 should be based on the savings effected by the lower operating 
 cost. It is a great deal cheaper to prevent heat from entering 
 a building than to remove it by means of refrigeration. In the 
 light of what is now known concerning insulation, even though 
 it is not very extensive, there is no excuse for poor insulation, 
 except that ol ignorance. 
 
 PRACTICAL CONSIDERATIONS. 
 
 Another element in cold storage practice that will require 
 the construction of first-class insulation is that goods should be 
 carried at a uniform temperature throughout every part of the 
 room. With poor insulation this is not possible, no matter how 
 large the cooling apparatus may be, as the parts of rooms nearest 
 the outside walls will be higher in temperature than those nearest 
 the cooling surfaces. This condition often results in the goods 
 being carried at a higher temperature than they should be, en 
 account of danger of freezing those that are nearest to cooling 
 surfaces. 
 
 The comparative value of the insulating materials depends 
 upon their efficiency in preventing the transmission of heat from 
 the outside to the inside of the building. A study of the heat 
 conducting properties of the various materials and substances as 
 
INSULATION 53 
 
 shown by tables here given leads to the conclusion that with a 
 few exceptions we must turn to the vegetable and animal sub- 
 stances for this efficiency. In selecting materials of this class 
 for practical insulation, we are limited by many requirements be- 
 sides non-conductivity of heat. These are enumerated Below in 
 order of their importance, viz : 
 
 i. — It should be odorless, so as not to taint the perishable goods stored 
 in the houses. 
 — It should have the minimum capacity for moisture, and in case 
 it should become damp, it should not rot or ferment. 
 It should be vermin proof, and give no inducement for rats or mice 
 to nest within it. 
 . — It should not be liable to inherent disintegration or spontaneous com- 
 bustion. 
 It should be of light weight, not so much on account of lightness itself, 
 because buildings are usually built sufficiently heavy where they 
 are to be used for warehouse purposes, but because the lighter 
 materials are usually better non-conductors of heat. 
 6. — If used as a filler, it should be elastic so that when it is once packed 
 firmly, it will not settle further and leave open spaces which will 
 be almost impossible to find and costly to repair. 
 7. — It should be reasonably cheap and economical of labor so as not to be 
 
 prohibitive for general use. 
 8. — It should lend itself to practical application in general work. 
 
 There are two other requirements which need careful atten- 
 tion, viz : That materials should be waterproof and fireproof. 
 The best non-conductors of heat possess neither of these in them- 
 selves. It is evident then that we must satisfy these require- 
 ments by proper design and construction. The former of these, 
 namely — waterproofing — is essential, as all materials that are 
 damp or wet transmit heat more rapidly, and waterproofing is 
 usually obtained by inclosing the non-conductor with waterproof 
 material. The latter of these requirements — fireproofing — is 
 sometimes desirable or necessary and can be accomplished by 
 surrounding the non-conductor with masonry walls or other non- 
 combustible materials. The requirements above noted have been 
 met to a greater or less extent in practical work, some classes of 
 insulators possessing part and other classes possessing other of 
 these qualities. It is proposed to discuss some of the materials 
 that are used for insulation and ascertain their good and bad 
 qualities. 
 
 MATERIALS. 
 
 There are a great many kinds of materials that are used as 
 insulators in various localities, depending upon their availability, 
 
54 PRACTICAL COLD STORAGE 
 
 cost and abundance, and on the character and quality of the work 
 for which they are to be used. It has, in the past, been the gen- 
 eral practice to construct a space inside of the main wall of the 
 building by erecting the studding and sheathing same inside with 
 boards ; then filling this space so formed with a "filler" in a loose 
 state, that would be light in weight and dry (when put in) 
 without protecting it against future accumulation of moisture. 
 This sort of insulation was considered sufficient and efficient for 
 all purposes, without regard to durability. There is much of 
 this kind of insulation now being put up, where the importance 
 of the work and operating conditions would warrant something 
 better. 
 
 From the tables of experiments already given, it will be 
 noted that still or perfectly motionless air is one of the best insu- 
 lators against heat. But to keep it motionless it is necessary to 
 confine it in very small spaces to prevent circulation and convec- 
 tion of heat. This is best accomplished by properly constructing 
 spaces and filling them with some sort of material in bulk. The 
 value of these fillers depends upon the number of minute spaces 
 into which they divide the air. Their value follows closely upon 
 their specific gravity; that is, the lighter the material, the better 
 insulation it is, owing to the microscopically confined air in the 
 cells or structure of the material itself. Again the value of these 
 fillers depends upon the density to which they are packed ; it has 
 been found that if they are packed too loosely they will permit 
 air circulation, and if packed too close, the conduction of: heat 
 will increase. With all the materials at present in use, the best 
 results seem to be obtained when packed to a density of from 
 nine to twelve pounds per cubic foot. Starr gives a specific grav- 
 ity of about .160 as being the lowest density to which a material 
 should be packed. This corresponds to about ten pounds per 
 cubic foot, which is, in the experience of the author, higher than 
 such materials as straw, wood shavings or cork shavings can be 
 packed in actual practice. In using fillers in walls, attention should 
 be given as to whether or not the materials of which they are 
 composed are in their natural state good or poor conductors of 
 heat. Mineral wool, for instance, is made from furnace slag or 
 lock which are considered comparatively good conductors. If 
 materials of this nature are packed very tight, their value as in- 
 
INSULATION 55 
 
 sulation is greatly lessened. Materials which in a raw state are 
 poor conductors, such as straw, sawdust, wood shavings or cork 
 may be packed very tight without decreasing their insulating 
 value. In fact, the insulating value of such materials is increased 
 by close packing. 
 
 STRAW, CHAFF, ETC. 
 
 Such materials as chopped straw and hay, dried grass and 
 leaves, chaff and hulls of the various grains have all been used 
 as fillers, as described above, and under certain conditions, they 
 are fairly efficient as non-conductors of heat. They are frequently 
 abundant and cheap, but as the life of such substances is com- 
 paratively short and the use of some of them dangerous when 
 applied to cold storage insulation, they are seldom if ever used 
 at the present time. In country locations and on the farm 
 they are often used to considerable advantage as a packing mate- 
 rial for temporary ice houses, fruit houses, etc., their availability, 
 far from manufacturing centers, making them naturally fit for 
 such purposes. 
 
 SAWDUST. 
 
 Sawdust as an insulating material practically belongs with 
 those noted above, but it is still used to such a large extent for 
 various purposes connected with refrigeration that it deserves 
 separate mention. It has been in the past in much favor and 
 was used extensively for insulating cold storage warehouses on 
 account of its abundance and cheapness, but as its short life and 
 deteriorating qualities became evident, it was gradually sup- 
 planted by more indestructible materials. There seems to be no 
 preference for the sawdust of any particular wood, as they are all 
 about the same in insulating value. This value is very high 
 when the sawdust is dry and clean, but if it becomes damp, it 
 will rot, ferment and heat, and in this state will disintegrate and 
 settle down, leaving spaces at top for leakage of heat. It may 
 become a nesting place for rats and mice even when the house 
 is under the best care. The most undesirable feature developed 
 by the use of sawdust, when it becomes damp, is the liability of 
 a moldy or musty condition of the rooms, and this may affect the 
 goods in storage. Nearly all sawdust available is from green 
 lumber, and this is very undesirable for insulating purposes. 
 
56 
 
 PRACTICAL COLD STORAGE 
 
 The most useful application of sawdust is for packing ice 
 in houses storing natural ice, where it is open to the action of 
 the air at all times and renewed each year. For this use, durabil- 
 ity is of no moment, but for modern cold storage plants, its use 
 cannot be defended in any particular. It is with regret that we 
 read a description of a modern packing plant in a periodical a 
 short time ago, where the machinery and other equipment were 
 of the best that modern refrigerating science can produce, but 
 the insulation was sawdust. Even though this sawdust is in- 
 closed between masonry walls, the moisture and air will pene- 
 trate and cause its deterioration in a comparatively short time. 
 
 SHAVINGS. 
 
 Planing mill shavings have superseded sawdust as a com- 
 mon material for insulation, as they are free from many of the 
 
 ■BALE OF SHAVINGS. 
 
 objections that have proved very undesirable in the use of saw- 
 dust. Shavings are specified by the author in the composite in- 
 sulations designed by him, and he believes that when they are 
 properly used and protected there can be no great objections 
 made to them, but they should not be used in large bulk (nor 
 should any filler for that matter), but rather in combination with 
 several other materials, as illustrated further on. Shavings will 
 not rot, ferment or settle down under similar conditions as rap- 
 idly as will sawdust, because the cell structure of the wood has 
 not been destroyed. Shavings are elastic and clean to handle, 
 and if properly packed (about 9 pounds to. the cubic foot) will 
 remain in position for an indefinite period. They should be de- 
 
INSULATION 57 
 
 livered to the building thoroughly dry and free from bark, dirt 
 or sawdust. 
 
 Many firms, particularly in the eastern and part of the mid- 
 dle western states, make a practice of putting up shavings in 
 bales This is a great advantage, both for shipping and handling, 
 as it permits of their use at points distant from their manufac- 
 ture. They are put up in compressed bales weighing 80 to 120 
 pounds, ten and fifteen cubic feet per bale, respectively, and have 
 the appearance shown in Fig. 5. The demand for shavings for 
 fuel and other purposes makes them extremely hard to obtain 
 in some localities during the fall and winter, and this difficulty 
 will no doubt increase with time, as the settled portions of our 
 country are being rapidly denuded of forests. The shavings of 
 the soft woods are preferable, as they are less brittle and lighter 
 than those from the hard woods. It is also preferable to use 
 shavings from some odorless wood, such as spruce, hemlock, 
 whitewood, etc. 
 
 MINERAL WOOL. 
 
 One material much used is commonly known as mineral 
 wool, granite rock wool, or rock cotton, in this country, and as 
 silicate cotton in England. The mineral wool is usually made 
 from the slag of blast furnaces, with limestone added; and the 
 rock wool or rock cotton, from granite and limestone. The prin- 
 ciples involved in manufacture are the same in either case and 
 the process is comparatively simple. The rock is first crushed, 
 then mixed with coke and fed into' furnaces, where it is fused 
 at a high temperature, about 3,000° P". The molten slag or lava 
 is then run out at the bottom of the furnace through a high pres- 
 sure steam blast which blows it into fleece or wool, much re- 
 sembling sheep's wool, except that the fibers are brittle. These 
 fibers are very fine, and interlace each other in every direction, 
 forming innumerable minute air spaces. In common slag wool 
 about 92% of the mass consists of air spaces and in the best 
 rock wool the proportion is about 96% when it is very lightly 
 packed. It will be seen that for this reason it is a very good in- 
 sulator, regardless of the fact that it is made from a material 
 having a comparatively high conductivity. Used as an insulator, 
 it should be free from "shot" and all other solid pieces, as much 
 as possible. It has the qualities of being vermin and fire proof 
 
58 PRACTICAL COLD STORAGE 
 
 and is not liable to decay, but if it is packed too tightly in the 
 walls, its brittleness will cause it to disintegrate, which decreases 
 its insulating value. It should not be packed closer than about 
 twelve pounds to the cubic foot. Mineral wool will absorb mois- 
 ture quite freely, and it is stated by some authorities that if it 
 becomes wet and then freezes, the water that has penetrated the 
 air cells of the fibers, will expand and break the structure of 
 the material into a granulated mass, which will settle or pack 
 down, and in this state it is a poor insulator. One of the chief 
 objections to mineral wool as a filler is its difficulty in handling, 
 as the fibers will prick the skin and in a very short time will cause 
 the hands to become sore, but the more important objection is 
 the minute particles of wool floating through the air as it is 
 handled, making it bad for the eyes and injurious to breathe. 
 It is for this reason that workmen dislike to handle it, and this 
 dislike indirectly causes the work to be slighted and poor insula- 
 tion is the result. Owing to its nature, mineral wool or any of 
 its manufactured products are very desirable as a retardent to 
 rats and mice, and it is valuable to use in protecting other ma- 
 terials from their ravages. Two inches of this material on the 
 exterior of an insulated wall makes it mouse and rat proof. 
 
 There has been, in the last few years, a tendency to manu- 
 facture insulating material that would be portable, easily handled 
 and put in place, not liable to settle, etc. This has been accom- 
 plished by making the material into compressed slabs or sheets to 
 a density and stiffness sufficient to be easily handled, sawed and 
 fitted same as if it were lumber. Slabs made of mineral wool 
 are thus manufactured by two or three different firms in this 
 country, and have the appearance shown in Fig. 6. These slabs 
 are usually made in standard sizes of 18x48 inches and 36x48 
 inches and from one-half to three inches in thickness, the manu- 
 facturers being willing to cut these slabs to any size smaller 
 than this, if specified. These slabs are a great improvement over 
 mineral wool in bulk form, as they can be adapted to modern con- 
 struction where it is the purpose to stratify or laminate the mate- 
 rials to form a composite insulation, as such is now considered 
 the most efficient in retarding heat transmission. 
 
 Many methods of applying this "felt" or mineral wool slab 
 have been devised by tbe manufacturers, but these are more or 
 
INSULATION 
 
 5!) 
 
 less impracticable on account of. the assumption that these slabs 
 are sufficiently strong to hold nails and support the construction ; 
 and the fact that these boards are not air or moisture proof is 
 overlooked and therefore the construction must make good these 
 necessary requirements. Fig. 6 shows a method used by the 
 author in applying this material. It will be noticed that the slabs 
 are not necessary to the solidity of the construction, but they 
 are placed between battens or furring and slightly tacked in 
 place ; waterproof paper is placed on each side and between each 
 slab, thus preventing any leakage of air or moisture through the 
 wall. Fig. 7 (see following page) shows a method recommended 
 
 f//////////y//////////////////////m////////^ .-^ 
 
 - 1paWBS«i£g^E3^g BS^«BBa agBg»3 ^ tcttWTftargsgTzyg 
 
 WATERPROOF COATING 
 INCH .SUE. BOARDS 
 __ J» WATERPROOF PAPER 
 |§i§f£- %INCH D.*M. BOARM 
 
 MINERAL. WOOL. SLAB^ 
 FIG. 6. — MINERAL WOOL SLAB AND ONE METHOD OF APPLICATION. 
 
 by the manufacturer of applying mineral wool slabs to brick or 
 stone walls in the construction of fireproof insulation. The wall 
 is first coated with waterproof cement put on hot, into which 
 the slabs or sheets of insulating material are set. Two or more 
 courses of two or three inch slabs may be used, with the water- 
 proof cement between. After setting the slabs, another coating 
 of waterproof cement is applied and the surface plastered with 
 Portland cement troweled down to a smooth surface. If the 
 mechanical difficulties of this method of applying may be over- 
 come, the merits of this construction are apparent. 
 
60 
 
 PRACTICAL COLD STORAGE 
 
 CHARCOAL. 
 
 Charcoal is described as a more or less impure form of 
 carbon obtained from various vegetable and animal materials by 
 their partial combustion out of contact with air. That most in 
 general use is obtained from wood and is a hard and brittle black 
 substance which in a granulated or flaked form is used to a 
 large extent in England and in Europe for insulation. It is used 
 as a filler and applied in the same manner as mineral wool or 
 
 KIG. 7.— METHOD FOR APPLYING MINERAL WOOL SLABS. 
 
 shavings. Charcoal has not been used to any considerable ex- 
 tent in this country for insulation, except for the ordinary family 
 refrigerator. Its use is not to be commended; and on account 
 of its black, dusty nature, it is very dirty, to say the least. The 
 abundance of many other materials at hand, equally efficient, 
 does not warrant giving it even a trial. 
 
 CORK. 
 
 Granulated cork is considered one of the most efficient and 
 high-grade fillers for insulating purposes that we have, and it is 
 
INSULATION 
 
 61 
 
 odorless, clean, elastic, durable and does not absorb moisture 
 readily, but like all other fillers, except mineral wool, is subject 
 to attack by vermin, unless properly protected. It is well known 
 that cork is the bark of a particular tree growing on the coasts 
 of Northern Africa and Southern Europe. This bark is deprived 
 of its non-elastic and impure substances, after which it is cut up 
 into proper sizes for commercial use. The granulated cork is 
 the waste product in the manufacture of stoppers, handles, etc. 
 
 FIG 8. — SHEET CORK INSULATION WITH CEMENT PLASTER FINISH. 
 
 When filling spaces with the material, it should be rammed in 
 tightly, so as to reduce the size of the air spaces between the 
 particles, and to prevent future settling. Granulated cork mixed 
 with hot pitch or asphalt has been used and is considered by the 
 author to be a good insulator around brine mains where they 
 pass through masonry walls or are laid under ground. With 
 this material, molds or forms are placed around pipes and the 
 mixture poured in hot, thus completely surrounding the pipes 
 and making an indestructible covering. 
 
62 
 
 PRACTICAL COLD STORAGE 
 
 Cork has also been made up into compressed sheets, bricks, 
 etc., of various sizes. The appearance of the sheets is shown 
 in Fig. 8, and are usually made 12x36 inches in size and vary 
 from one inch to three inches in thickness. These sheets are 
 made by compressing the granulated material or shavings of cork 
 in iron molds and baking in a temperature of about 5°°° F- 
 This is done without the addition of any cement or binding ma- 
 terial, but the process liquefies the natural gum of the cork 
 sufficiently to bind the granules into a solid mass. In some 
 processes a cementing material is used, making what are termed 
 impregnated cork sheets. These boards are more or less porous, 
 
 Inserted spruce nailing strip. 
 
 Brick wall. 
 
 Pitch, paint or paraffine. 
 
 Nonpareil sheet cork. 
 
 Nonpareil sheet cork. 
 
 j Paper, if inside finish is wood. 
 I Paint, if inside finish is cement. 
 
 Spruce sheathing or cement. 
 
 FIG. 9. — SHEET CORK WITH INSERTED NAILING STRIPS OF WOOD. 
 
 and therefore to apply them practically the author has used them 
 in constructions similar to mineral wool slabs, as shown in Fig. 
 7, set between furring strips and with waterproof paper between 
 each layer of sheet cork. 
 
 The manufacturers evidently recognized the difficulty of 
 applying the sheets (otherwise than shown in Fig. 7) without 
 nailing through them. This was impracticable because the sheets 
 lack sufficient strength to hold nails and nails are also objection- 
 able on account of tearing the paper and cork. Consequently the 
 two inch and three inch thicknesses of sheet cork can now be 
 obtained with inserted nailing strips of wood, as shown in Fig. 
 9. This is unquestionably a good improvement, as it gives a 
 
INSULATION 
 
 63 
 
 more solid construction for nailing, and does away with furring 
 strips to some extent. Referring again to Fig. 9, the author 
 would consider it impracticable and difficult to fasten the first 
 sheet to the brick wall as shown. A better method would be to 
 set horizontal nailing strips of wood in the brick wall every 
 sixth or seventh course, or nail horizontal furring strips to the 
 inside of the wall, set 18-inch centers and set the sheets ver- 
 tically with joints lapped over the furring strips, as shown in 
 
 Fig. 10. 
 
 Another method of erecting cork sheets, which possesses 
 several advantages, is to cement them solidlv to brick or tile walls 
 
 m 
 
 lis 
 
 SI WATERPROOF COATING 
 
 J7=-=- COMPRESSED CORK 
 AIR SPACE 
 
 __ .^WATERPROOF PAPER 
 - - % INCH Ht-n BOARDS 
 
 FIG. IO. — COOPER'S METHOD OF APPLYING SHEET CORK. 
 
 in a bed of Portland cement. A single course of the cork sheets 
 either two or three inches thick is used, or a double course with 
 paper between, as shown in Fig. 8, according to the 
 severity of the conditions. The interior finish may be 
 either matched boards, which are nailed to the inserted wood 
 strips in the cork sheets above referred to, as shown in Fig. 9, 
 or a fireproof cement finish of either Portland cement or White 
 Marble (Magnesian) cement may be applied directly to the ex- 
 posed surface of the cork sheets, as shown in Fig. 8. This 
 method gives an efficient insulation which is both waterproof 
 and fireproof and is being used at present with very satisfactory 
 results. 
 
64 PRACTICAL COLD STORAGE 
 
 As above stated compressed cork is made in shape and size 
 resembling brick, which, for partitions and inside walls, are laid 
 up in the same manner as brick with liquid or asphalt cement as 
 a binder for the joints. Cork bricks are also made that are im- 
 pregnated with hot asphalt or pitch so as to surround each par- 
 ticle, the purpose being to produce an article that should be water- 
 proof. This treatment would without doubt decrease the insu- 
 lating value of the cork bricks and its purpose is therefore ques- 
 tionable. 
 
 HAIR FELT. 
 
 Hair felt material has very appropriately been termed "Na- 
 ture's Insulation," as there is no question but that nature created 
 
 FIG. II. — HAIR FELT 
 
 hair for the sole purpose of protecting life on this planet from 
 the changes of temperature. It is one of the most indestructible 
 materials with which we have to deal, and when properly ap- 
 plied it is one of the best insulators available. Cattle hair as it 
 comes from the tanners is thoroughly washed and air dried, put 
 through pickers and blowers until all dirt, etc., is removed and 
 the hair thoroughly deodorized. It is then put through felting 
 machines where it is formed into sheets of one-quarter of an 
 inch to two inches in thickness, put up in rolls twenty-four 
 inches to seventy-two inches wide and fifty feet long. This felt 
 has the appearance shown in Fig. u. In specifying this mate- 
 
INSULATION 
 
 65 
 
 rial the author requires it to be furnished in narrow widths (pref- 
 erably 24 inches) and applied between furring strips and paper 
 set vertically as indicated in Figure 7. The sheets should run 
 from floor to ceiling continuously and may be held in place by 
 nails driven into side of furring strips at an angle and then bent 
 in as shown in Fig. 12. No nails should be driven directly 
 through the hair felt and papers, as that destroys the air and 
 waterproof qualities to that extent and thereby decreases the 
 value of the insulation. In applying the sheets of hair felt to the 
 
 W////////////////////////////////////, 
 
 VJATERPROOF TAPER.' 
 
 FIG. 12. — METHOD OF APPLYING HAIR FELT. 
 
 ceiling, it has a tendency to sag. This can be avoided by nailing 
 temporary cross cleats to the furring strips every five or six feet, 
 as the sheets of felt are put into place, and these can be removed 
 as the inside wood finish is put on. If the hair felt is ordered in 
 the proper width for use, there will be very little cutting to be 
 done except to cut off the lengths as needed. The. best method 
 of cutting hair felt is with a long bladed sharp knife or chisel, 
 guided along a straight edge held down firmly; some workmen 
 with accurate aim can do a fair job with a sharp hand axe. 
 
 Besides being used as it comes from the manufacturer, hair 
 felt is put up in many ways by applying paper, etc., to the sur- 
 face. At present it may be obtained with a waterproof paper on 
 one side put on with a waterproof glue. In some situations this 
 would be very desirable. 
 
 QUILT INSULATORS. 
 
 Those insulating materials known as "quilts" are in the na- 
 ture of a felt held in place between two papers and stitched to- 
 gether, and are usually made in one-quarter and one-half inch 
 thicknesses, thirty-six inches wide, put up in rolls of from 100 
 to 500 square feet. These quilts were originally designed and 
 
 (5) 
 
66 PRACTICAL COLD STORAGE 
 
 manufactured for deafening purposes, viz.: to absorb and dissi- 
 pate the sound waves penetrating through floors and partitions 
 in dwellings, etc., where with proper construction they serve 
 both as deafeners and insulators. 
 
 There are various filling materials used for making up these 
 quilts, such as hair felt, mineral wool, flax fibre and eel-grass, 
 all of which are very durable, each possessing qualities that 
 recommend them for use. The nature of the hair felt and 
 mineral wool has already been touched upon. The so-called flax 
 fibre, recently introduced, is made from flax straw, that has 
 been crushed, picked and deodorized, and the sap or gum re- 
 moved, leaving a light fibrous material that if properly protected 
 makes a good insulator. Eel-grass is used in "Cabot's Quilt" 
 
 FIG. 13. — CAEOTS INSULATING QUILT. 
 
 exclusively and has been on the market for a number of years as 
 a deafening material. The quilt has the appearance shown in 
 Fig. 13. This eel-grass, or sea weed, as it is often called, is a 
 long, grass-like material of great durability.* It has great re- 
 sistance to fire, and owing to the large percentage of iodine 
 (common to all sea-plants) which it contains, it is repellant to 
 rats and vermin. 
 
 For the application of these quilts to cold storage and re- 
 frigerator car construction, they have been made in thicknesses 
 up to one-half inch, and waterproof papers have been placed on 
 one or both sides of the quilt instead of the common building 
 papers. Some makers have coated one side of the quilt with a 
 waterproof asphalt coating, this to be turned toward the damp 
 side of the wall. These improvements have enhanced the value 
 of these quilts for insulating purposes and they compare very 
 favorably with other materials for practical use. 
 
 * "A sample of eel-grass, 250 years old and in a perfect state of preservation, may 
 be seen at Mr. Cabot's office." — F. 15. Kidder in "Building Construction." 
 
INSULATION 
 
 67 
 
 The common method of applying is to place a layer of quilt 
 between two sheathings of flooring and nail through it, and then 
 apply more sheathings and quilt as shown in Fig. 14. While 
 fair results can be obtained by this construction, it is somewhat 
 impracticable on account of the elastic nature of the quilt, and is 
 also wasteful of lumber. A better method of applying these 
 quilts and saving lumber and increasing the insulating value 
 
 FIG. 14. — METHOD OF APPLYING CABOT QUILT. 
 
 would be as recommended by the author and shown in Fig. 15, 
 on following page. In case it is desired to omit the shavings, the 
 wall may be furred with %-inch strips and the quilt then applied, 
 as shown, to the number of thicknesses desired. 
 
 INSULATING PAPERS. 
 
 As already stated, the very nature of insulating materials 
 or fillers is their porosity, and therefore air under even a light 
 
68 
 
 PRACTICAL COLD STORAGE 
 
 pressure will flow through them quite easily. To prevent this 
 flow of air and the penetration of moisture is absolutely neces- 
 sary, otherwise the insulation will become damp, and in time al- 
 most worthless on account of deterioration and decay. It is the 
 general practice to use air-tight and waterproof papers on each 
 side of the insulating materials for the purpose of preventing 
 this flow of air and moisture through the walls. 
 
 FIG. 15.— ANOTHER METHOD OF APPLYING CABOT QUILT. 
 
 There has been a widespread impression that papers possess 
 a high insulating value, and consequently many expensive and 
 complicated insulations have been constructed, using paper as 
 the chief material. It is now generally recognized by refriger- 
 ating engineers that although paper has some insulating quali- 
 ties, its chief value is in its resistance to the passage of moisture 
 and direct flow of air through the walls. Its use also tends to 
 make an insulated wall more composite without increasing its 
 
INSULATION 69 
 
 thickness, as it changes the density of the insulation and thereby 
 retards the transmission of heat. Besides the requirements of 
 being air and water proof, papers must be odorless, having 
 strength and durability, and should not be brittle and liable to 
 crack in low temperatures, as this makes them difficult to handle 
 and results in leaky insulation. 
 
 There are a great many insulating papers on the market, 
 some of which are reliable and durable, but all rosin-sized, oiled 
 and tar coated or tar saturated papers should be avoided on ac- 
 count of their odor, and the rosin-sized papers also avoided on 
 account of the positive certainty of disintegration, because they 
 carry their own destructive elements. It is also advisable to 
 avoid all so-called "coated" papers, that are coated on both sides 
 and have a white center, as they will disintegrate sooner or later, 
 if unfavorable conditions arise. Papers should be selected that 
 have been saturated and thoroughly impregnated with pure as- 
 phalt or similar material or have a center layer of asphalt, as 
 thus they are practically indestructible when used for cold storage 
 insulation; these qualities, combined with the requirements above 
 stated, make them superior to all others for insulating purposes. 
 These high grade papers are more expensive in first cost, but 
 their durability makes them cheaper in the end. As the cost of 
 using good papers is usually less than 5% of the total cost of 
 the insulation, it is poor economy to select an inferior grade. 
 Insulating papers are usually manufactured thirty-six inches wide 
 and come in rolls of 500 or 1,000 square feet. 
 
 The papers should be applied with the greatest care in lap- 
 ping around corners, etc., all joints should be lapped at least two 
 inches and under severe conditions these joints should be ce- 
 mented. It should be kept in mind that the proper application 
 of the papers is one of the most important parts of the insulating 
 work, because, as already noted, the insulation must be air and 
 water proof to remain efficient for any length of time. If the 
 workmanship is poor, the advantages of using first-class papers 
 are neutralized. 
 
 WOOD FOR INSULATION. 
 
 Wood has, of course, played as important a part in construct- 
 ing insulation as it has in general building operations, because of 
 the ease with which it can be procured and worked, together with 
 
70 PRACTICAL COLD STORAGE 
 
 its strength, lightness and durability. In addition to its general 
 use for floor construction in brick warehouses (except in thor- 
 oughly fireproof structures), it is used for forming the air spaces 
 or filled spaces and inside finish of the insulated rooms. Wood 
 has been regarded as a good insulator, and this belief has, in 
 manv cases, tended to its excessive use in constructing insula- 
 tions, such as, for instance, the use of from six to ten thicknesses 
 of boards in one wall. Considering the greater insulating values 
 of fillers over solid wood, it is becoming the general opinion of 
 most refrigerating engineers that many thicknesses of boards 
 built up with air spaces in such a manner, is not only extremely 
 expensive, but it is not efficient as an insulator in proportion to- 
 the cost and space occupied. One of the chief requirements in 
 the use of wood, already stated as essential to other insulating 
 materials, is that it should be odorless. This applies particularly 
 to the inside sheathing and finish. This requirement restricts the 
 kind of woods available to a very few, of which spruce, hemlock, 
 basswood and whitewocd are the most desirable. Spruce is to 
 be preferred on account of being easier to work and not so liable 
 to have loose knots and shakes as hemlock, but it cannot be easily 
 obtained at reasonable prices in large quantities except in the 
 eastern states and the far west. Hemlock is abundant in all the 
 northern, middle and eastern states, where it is used extensively 
 in all building operations, but it is cross-grained, rough and 
 splintery, and very prone to split when nails are driven into it. 
 It is stated that owing to its splintery nature, hemlock is prac- 
 tically mice and rat proof. White pine may sometimes be used, 
 when the other kinds are not available, but it should be as free 
 as possible from rosin and thoroughly seasoned. For a ware- 
 house in Butte, Mont., designed by the author, it was necessary 
 to use tamarack for the inside finish as the only native wood 
 available that did not have a strong odor, and its use in this case 
 was very satisfactory. Where it is necessary to use a wood that 
 may have a slight odor, it should be given one or two coats of 
 properly prepared whitewash or other deodorizer as soon as the 
 walls are finished. 
 
 That lumber should be thoroughly dry to get the best results 
 in efficiency and durability of the insulation it is almost unneces- 
 sary to state. If the lumber is even partially green, it carries a 
 
INSULATION 71 
 
 considerable amount of moisture with it into the insulation, caus- 
 ing more or less injury. The use of under-seasoned lumber 
 should be properly guarded against. In erecting insulation dur- 
 ing cold weather it is very necessary to keep fires going so as to 
 have all materials as dry as possible. This is often neglected. 
 
 •All boards for sheathing should preferably be dressed and 
 matched, as it gives more air-tight work, and particularly for 
 inside finish, as it has a much better appearance. Rough board- 
 ing may often be used for the interior of the insulated walls 
 where the joints are properly protected, and rough boarding has 
 often been used for inside finish solely for the purpose of giving 
 a rough surface for whitewashing, as it is claimed that whitewash 
 will peel or flake off of a dressed wall. This is, however, not 
 considered a valid reason by the author, as whitewash properly 
 prepared will not peel off. (See chapter on "Keeping Cold Stores 
 Clean.") 
 
 NAILS. 
 
 The use of any particular kind of nail may, on first thought, 
 seem to be of little importance, but when we consider that the 
 efficiency of the completed work depends upon every detail of 
 construction and that nails are good conductors of heat, there is 
 no question that the kind of nails and the manner of their use 
 is of some importance. The author usually specifies that "cement 
 coated wire box nails" be used. These nails have a smaller diam- 
 eter than the ordinary wire nails, but the cement coating gives 
 them greater holding power. This fact permits the use of a 
 smaller size nail for the same class of work, for instance : where 
 8d and lod common nails are used for sheathing, 6d and 8d 
 cement coated may be used for the same work. It is therefore 
 evident that using cement-coated nails not only reduces the heat 
 transmission on account of their smaller diameter, but also on 
 account of being able to use nails one-half inch shorter, as indi- 
 cated above. The cement coating also protects the nails from 
 rusting. 
 
 COMPOSITE INSULATION. 
 
 Strictly speaking, all constructions are composite (except 
 solid wood or masonry construction), as they are necessarily 
 made up of materials having different densities and different 
 
72 PRACTICAL COLD STORAGE 
 
 values as insulators. An English authority divides insulated 
 walls into two classes, which he calls the "forced" and "optional" 
 insulation. The former is of course the masonry wall of the 
 building proper, and the latter the "lining" or material added 
 as insulation. Where the building is a frame structure, as is 
 often the case, the whole wall may be termed optional insulation, 
 because the space between the studding of walls may be insulated 
 with any filling material desired. 
 
 As already stated, even if the insulating value of one inch or 
 one foot in thickness of this or that material be known, it gives 
 no practical basis on which to design insulations, except as a 
 guide as to what materials may be used. To calculate the value 
 
 FIG. l6. — INSULATION TESTING APPARATUS. 
 
 of composite insulations by the use of formulae is extremely inac- 
 curate, as account should be taken of the papers used which have 
 more or less value. It is for the purpose of determining the 
 value of composite insulations that various testing apparatus have 
 been designed by different experimenters. It may not be out of 
 place to describe these brief!}', so as to be able to judge the relia- 
 bility of the results obtained in the different cases. 
 
 INSULATION TESTERS. 
 
 The most common and inexpensive apparatus used is a box 
 constructed of the material that is to be tested and provided in- 
 side with a watertight tin box having a drain pipe with a trap 
 
INSULATION 73 
 
 connected at the bottom, similar to that shown in Fig. 16. Top 
 of box is provided with a removable tight cover. This complete 
 box is then placed in a room where a constant temperature is 
 maintained and a known quantity of ice is placed inside the box. 
 At stated intervals the ice meltage can be determined by weigh- 
 ing the water coming from the ice through the drain pipe in bot- 
 tom. To get comparative results boxes made of various mate- 
 rials, but of the same size and thickness, can be fitted up and all 
 tested under the same conditions. The quantities of ice melted 
 in each case can be compared and the relative efficiency of each 
 material judged. 
 
 To determine the rate of heat transmission in B. T. units 
 for this kind of tester, it will be necessary to consider time, dif- 
 ference of temperature, square feet of surface in box and ice 
 melted. This can be illustrated by an imaginary test case as 
 follows : Take a tester two foot cube inside measurements with 
 walls four inches thick, the inside and outside temperatures being 
 respectively 32° F. and 70° F. (assuming the inside temperature 
 to be the same as the ice) and the meltage of ice per day (24 
 hours) is 50 pounds, we then have: 
 
 Inside surface 24 sq. ft. 
 
 Outside surface 426 sq. ft. 
 
 2)66.6 
 
 Mean surface between inside and outside of box 33.3 sq. ft. 
 
 Difference of temperature between inside and outside of box 38° F. 
 
 Ice melted per day (24 hours) 5° lbs. 
 
 142x50 equals B. T. U. transmitted per day =7100 
 
 I 7100 
 B. T. U. transmitted per sq. ft. per day < — — — = 213.2 
 
 B. T. U. transmitted per sq. ft. per hour per deg. difference . ■< „ 2 , = 0.233 
 
 Testers similar to the one above described with changes in 
 details, spaces provided for thermometers, etc., have been de- 
 signed with the purpose of getting more accurate results, if pos- 
 sible. Riege and Parker* designed and used a tester which they 
 described as follows : 
 
 In testing the value of insulating walls or partitions there should be 
 some means of determining accurately the rate of flow of the heat through 
 the wall or partition. This can be done with accuracy in several different 
 ways, though in the following test the apparatus used consisted essentially 
 
 * Ice and Refrigeration, January, 1895. 
 
74 PRACTICAL COLD STORAGE 
 
 of a wooden box, a tin box, thermometers, and a pail to catch the drip 
 from the ice, the agent used in cooling. The boxes were respectively 
 forty-four inches and twenty-five inches cube on the inside, the tin box 
 containing the ice to be melted. The wooden box was made of ^5-inch 
 white pine tongue-and-groove boards, nine inches wide, and really was 
 a double box, the boards of the inner one running at right angles to 
 those of the outer in order to make the box as air-tight as possible. The 
 lid of the box, which was twelve inches deep on the inside, had a 12-inch 
 band around the edge where the lid rested on the box, and to make the 
 joinings of the two as air-tight as possible, the edge was lined with felt. 
 Both the lid and the box were then lined with what is known as builder's 
 paper or "sheathing," which secured a still better protection against out- 
 side changes of temperature. The tin box rested on a couple of wooden 
 horses, twelve inches high, so that when placed in position, there was a 
 space of twelve inches all around the tin to the sheathing. From the 
 bottom of the tin box led a tube which passed into an inch pipe, this 
 latter pipe extending through the wooden box, and the lower end being 
 immersed in a can of water, prevented any outside air from entering either 
 box. All fittings were air-tight. Thermometer tubes were let in from the 
 four sides to within six inches of the tin box, as well as a long tube from 
 the wooden box cover through the tin box cover to within a couple of 
 inches of the ice. 
 
 Before starting a test the ice was allowed to melt until the drip from 
 the can showed a regular flow, thereby allowing the true weight of ice 
 melted during the test to be determined. During a test temperatures were 
 noted on all four sides of the wooden box, also within six inches of the 
 tin box, and also inside the latter, the readings being taken half hourly 
 and the weight of ice melted hourly. When the thermometer tubes were 
 not in use, they were closed with corks. Comparison tests were made of 
 each substance, each test lasting from six to twenty-four hours. Tests 
 were made of air, shavings and cork, first at ordinary temperature and 
 later with a steam coil an inch above the wooden box to represent the 
 effect, when steam was circulated, of the sun on the roof of a storage house. 
 
 A later improvement on the above described tester, which is 
 used by some experimenters to-day, where simplicity and cost 
 must be considered, is to construct it similar to* a domestic refrig- 
 erator, and about the same size, with an ice bunker and air ducts 
 installed so as to get a uniform circulation and temperature in- 
 side. Small windows with three or more thicknesses of glass are 
 placed in sides of testers to read the thermometers which are 
 hung inside. The heat transmission is calculated in the same 
 manner as described for small tester above. 
 
 The comparative results that can be obtained with the above 
 described testers are quite accurate when the different materials 
 tested are of the same thickness in each case. But in comparing 
 different thicknesses of material, there is a chance for great error 
 unless the inside dimensions of tester are changed so as to give 
 the same proportionate mean surface. This fact is readily seen 
 if the tester shown in Fig. 16 is taken and the walls made eight 
 
INSULATION 75 
 
 inches thick instead of four inches. The mean surface of the 
 tester in that case would be 45.3 square feet, as against 33.3 
 square feet in the first case. This difference in mean surface 
 would favor the thicker insulation when calculated in B. T. U. 
 John E. Starr, in an article on "Non-conductors of Heat,"* 
 describes the testing apparatus he designed and used at that time, 
 which was quite complicated as compared with those above de- 
 scribed, but was no doubt intended for greater ranges of tempera- 
 ture than could be obtained with them. He describes his tester 
 as follows : 
 
 The writer, in investigating the value of insulating construction, has 
 used a rather simple but effective apparatus for accurately measuring the 
 flow of heat. He has a box carefully constructed and thoroughly insu- 
 lated on the top, bottom and two sides. The two ends remaining (expos- 
 ing an area of something over four square feet) were used as the test 
 ends, and the various styles of construction to be tested were built in these 
 ends. In this way two tests could be made at the same time. Directly 
 against these two ends were placed water reservoirs of thin galvanized 
 iron of the same superficial area as the test ends, that is to say, something 
 over four feet square. These reservoirs were about one inch wide and 
 each held from twenty-five to twenty-seven pounds of water. Outside 
 of these reservoirs was another very thick insulation against the outer air, 
 all except a small opening in the middle of the top for thermometer 
 readings. A steam coil was placed inside of the box, and connected at 
 its inlet with a steam boiler and at its outlet with a steam trap. By regu- 
 lating the steam pressure the interior of the box can be kept at any desired 
 temperature ; and the construction is such that any heat that finds its 
 way into the water must come through the insulation to be tested, and 
 that all the heat that comes through the insulation must find its way into 
 the water, as the water exactly covers the insulation. The tests, there- 
 fore, can be made quantitative, as well as qualitative, by observing the 
 rise of temperature of the water, and taking into account its weight. 
 Readings are taken at regular periods of the temperature inside the box, 
 and of the water in each cap, or reservoir, and of the surrounding atmos- 
 phere. The water caps, however, are so thoroughly insulated from the sur- 
 rounding atmosphere that unless the temperature of the water in the 
 caps rises to a very high degree, and unless the test is of very long dura- 
 tion, only a small amount of heat escapes from the water and passes 
 into the air. The value of the insulation surrounding the caps being 
 known, however, a correction can be made, if necessary, for such escape 
 of heat from the water. 
 
 What is probably the most valuable and scientifically accu- 
 rate testing apparatus in use was constructed by the Nonpareil 
 Cork Manufacturing Co. at their factory at Bridgeport, Conn. 
 A description of this apparatus was published in Ice and Refrig- 
 eration, June, 1899, and is reproduced here as follows : 
 
 Their apparatus consists of an insulated room, 12x10x8 feet, the tem- 
 perature of which can be held at any point desired from zero Fahrenheit 
 
 * Ice and Refrigeration, July, 1891. 
 
76 PRACTICAL COLD STORAGE 
 
 up, by means of a W. M. Wood compression machine operating with 
 direct expansion. A uniform temperature throughout the room is secured 
 by forced circulation, an electric fan being used to drive the air up over the 
 expansion coils which are inclosed at one end of the room. The air 
 passes out and down through a false ceiling having graduated perfora- 
 tions arranged to allow a uniform amount of cold air to fall in all parts 
 of the room. This is the method employed in various refrigerating plants 
 with entire success, by Mr. John E. Starr. In the center of the room is 
 an insulated box, 3x3x6 feet inside measurement, having one side remov- 
 able. It contains an electric heating coil and a small electric fan arranged 
 to give a circulation of air and insure uniform temperature in all parts 
 of the box. Standard thermometers, both mercurial and recording air 
 pressure, reading 1/10' F., are placed so as to give the temperature of the 
 refrigerated room and the heated box, the readings being taken outside 
 the room. This obviates any necessity of the operator entering the refrig- 
 erated chamber while the test is being made. The Weston standard 
 ammeter and voltmeter measure the electricity supplied in the fans and 
 heating coil, and a suitable rheostat regulates the amount of the current. 
 
 The method of determining the heat conductivity of any in- 
 sulating construction is as follows : 
 
 The temperature of the room and box are respectively lowered and 
 raised until they conform to the conditions under which the proposed 
 insulation will be used. Then the amount of heat or electricity supplied 
 to the box is gradually diminished by means of the rheostat, until the 
 point is reached where the temperature in the box remains constant. It 
 is evident that at this point the radiation must exactly equal the amount 
 of heat supplied, or there would be a rise or fall in temperature, as the 
 case might be. After the supply and radiation have been maintained con- 
 stant for two hours, readings are taken every five minutes for three hours 
 more. If they do not vary more than 1/10 of i°F., they are considered 
 practically exact. The average is taken as the permanent radiation of the 
 box under the given conditions. The box contains 100 square feet of 
 surface, measured at the center of insulation, consequently 1/100 of the 
 total radiation is the rate per square foot. This rate being obtained, the 
 removable side of the box is replaced with a side constructed of the 
 insulation whose value is desired. The test is then repeated, and the 
 total heat loss from the changed box will be greater or less, as the case 
 may be. The removable side contains twenty square feet surface, there- 
 fore eighty square feet of the box remain unchanged, and the radiation 
 through this must be the same as before. This amount is at once deter- 
 mined from the previous tests, and the difference between the total heat 
 loss from the box in its changed condition, and this amount must give 
 the radiation through the twenty square feet, comprising the new side 
 which has been put in. One-twentieth of this amount is of necessity the 
 rate per square foot, and this divided by the difference in temperature 
 between the room and box, will give the exact radiation per square foot 
 of surface per degree of difference in temperature. 
 
 A testing apparatus which has been used by the author is 
 based on the same principles as that above described, but some- 
 what smaller in size and of simpler construction. The tester was 
 built with one side removable and arranged so that any kind of 
 insulating material could be tested in same. This tester was 
 
INSULATION 
 
 77 
 
 placed in a cold storage room where a temperature of 15° F. 
 could be obtained and which was equipped with an air circulating 
 system. The inside of the tester was heated by eight incandes- 
 cent electric lamps, each controlled by a button switch from the 
 
 /THERtlONETEFL 
 
 REMOVABLE COVER 
 WITH INSULATION " 
 TO BE TESTED 
 
 BUTTON .SWITCH 
 
 FIG ij — cooper's insulation testing apparatus. 
 outside. The temperatures inside of the tester were observed by 
 means of a specially made long-stem thermometer projecting 
 through top of tester and read from the outside. The ther- 
 mometer was graduated to read to 1/5 of a degree. The appa- 
 ratus is shown in Fig. 17. 
 
78 PRACTICAL COLD STORAGE 
 
 The incandescent lamps used were no and 52 volts of 16 
 c.p. on a 52-volt circuit. These would give approximately 50 
 B. T. units and 200 B. T. units respectively per hour, but they 
 were accurately calibrated by a water calorimeter test. This con- 
 sisted of an insulated tank, capable of holding twenty-five or 
 more pounds of water, which was allowed to stand in a constant 
 temperature until the temperatures of the water and tank were 
 equal. Under such conditions each lamp was put in a water- 
 proof socket and tested separately by immersing in the water and 
 noting time taken to raise twenty-five pounds of water 1° F. In 
 this way the B. T. units of each lamp per hour were obtained, 
 and with each lamp controlled separately, the temperatures in 
 tester were controlled at will up to 150° F. Owing to the fact that 
 the life of incandescent lamps is limited, they will, after a certain 
 time, decrease in power. This made it necessary to retest them 
 periodically. The author believes that the results obtained with 
 the above apparatus are as accurate as those that have been ob- 
 tained by other experimenters. 
 
 INSULATING VALUES OF COMPOSITE STRUCTURES. 
 
 The results obtained by the different experimenters have 
 been illustrated and published in various trade papers, pamphlets 
 and catalogues. The author has assembled and illustrated these 
 results in the following figures as accurately as information per- 
 mits. Figs. 18 and 19 give the result o<f tests made by John E. 
 Starr (some of which were made by the Nonpareil Cork Mfg. 
 Co.), at different times and for different purposes. Most of 
 these were presented by him in a paper read before the eleventh 
 annual convention of the American Warehousemen's Association 
 in October, 1901.* 
 
 Figs. 20 and 21 give the results of other tests made by the 
 Nonpareil Cork Manufacturing Co. with their elaborate testing 
 apparatus, described above, comparing their material, for the 
 most part, with the wood board and air space construction. 
 
 Fig. 22 is a reproduction from an article in Ice and Refrig- 
 eration, September, 1896, on "Cold Storage Buildings." The 
 drawings are there credited to the Fred W. Wolf Co., who give 
 the heat transmission as having been determined from practical 
 
 * Reported in Ice and Refrigeration, November, 1901. 
 
INSULATION 79 
 
 experience, but do not describe how or by whom these tests were 
 made. 
 
 Fi g- 23 gives the result of tests made by the author with 
 the testing apparatus above described as designed by him. These 
 show the tests on a variety of materials and were not made in 
 the interests of any of them in particular, but were made chiefly 
 to determine the value of air space construction as compared with 
 filled spaces and sheet material. 
 
 The above described tests are all based upon the amount of 
 heat transmitted per square foot, per degree of difference between 
 inside and outside temperatures, per day (24 hours). 
 
 Figs. 24 to 28 are reproductions from drawings made by 
 George H. Stoddard and accompanying his paper on "Insula- 
 tion," which was read before the eleventh annual convention of 
 the American Warehousemen's Association.* The nature and 
 form of testing apparatus which was used to obtain the results 
 shown in these drawings was not given by him in his paper. In 
 explanation of these drawings we quote in part from his paper 
 as follows : 
 
 It may be of interest to consider how the transmission of heat takes 
 place through an outside wall, such as is often used for a cold storage, 
 warehouse. Fig. 24 shows a section of such a wall. Starting from the 
 outside, it is made up as follows : 24 inches of brick, 2-inch air space, 
 two %-inch matched spruce sheathing with paper between, then twelve 
 inches of spruce mill shavings, then two ^-inch spruce sheathing, with 
 paper between. We will assume a temperature of 92 F. for the air and 
 objects outside, and a temperature of 32 F. for the air and objects inside 
 of the warehouse. Heat is transmitted through this compound wall as 
 follows : To the outer surface of the brick by radiation and contact of 
 air, through the brick by conduction, across the air spaces by radiation 
 and contact of air, through the inner wall of sheathing and shavings by 
 conduction, and from the inner surface of the wall by radiation and 
 contact of air. 
 
 Knowing that the rate of transmission must be the same to and 
 through and from the wall, it is of interest to note the temperatures of 
 the different faces of the wall, and see how they vary from the outside 
 temperature of 92 , to the inside temperature of 32 . There is only the 
 difference between 92 and 90.7 between the outer air and the outer 
 surface of the wall, then the temperature drops to 81.8 at the inner 
 surface of the brick, to 80. i° at the other side of the air space, to 76° 
 at the inner surface of the outer double sheathing, to 37.4 after passing 
 the shavings, to 33.3° at the inner surface of the inner sheathing, and 
 then to the temperature of 32 in the room. 
 
 In Fig. 25 are shown curves representing the rate of transmission 
 through walls similar to that which we have just considered, with the 
 brick wall varying from eight to twenty-eight inches in thickness, com- 
 bined with inner walls having the shavings from two to twelve inches 
 
 * Published in Tee and Refrigeration, November, 1901. 
 
B. T. U. 
 
 -&INCH PINE BOARD 
 
 , 1 IHCH LAMP BUACK. 
 
 *""*^% IHCH OAt 
 V W> PAPER, 
 
 5.70 
 
 „ , B SPRUCE BOARDS 
 ^-■^W. P. PAPERS 
 
 ^^^-'BIHCH BOARDS 
 -W.R PAPER. 
 ~~ IlHCH AIR- SPACE 
 
 ^^^<i^r-v.r PAPER. 
 
 ^-pfclNCH BOARDS 
 
 4.©0 
 
 4.Z5 
 
 ■4JZ.0 
 
 5.71 
 
 -T__ TfeiNCH BOARDS 
 5"*~~"AND W.Tf PAPER- 
 
 T" 1 IHCH AIR-SPACE 
 
 r~~- %'fS0ARD3 tW-R mPERS 
 
 AMD VJ.RPAPER 
 
 VZ.X5 
 
 -T 
 
 -' /fl INCH BOARD 
 — -W R PAPER. 
 ""-7&INCH BOARD 
 ^_ 8 IHCH AIR SPACE 
 
 — % INCH BOARD 
 "^*-WR PAPER. 
 ""781HCH BOARDS 
 ^_ -8INCH AIRSPACE 
 
 S^— * "%INCH BOARD 
 - C~-WPPAFER- 
 
 "Tfl IHCH BOARD 
 8 INCH AIRSPACE 
 
 _-*% INCH BOARD 
 
 _ .; W.RPAPER, 
 
 =" 76IHCH BOARD 
 
 >z.io 
 
 _-/aiHCH BOARP 
 -W p. PAPER- 
 INCH BOARD 
 ~H INCH HMR FELT 
 ■~~-yeiHCH BOARI" 
 " W.P. FAPER. 
 
 IHCH BOARD 
 
 "^^W P. PAPER. 
 
 ?B INCH BOARD 
 
 ^ 3.318 
 
 >Z.5Y1 
 
 4 INCH SHEET CORK 
 ^> 'TfelNCHBOAKP 
 
 TaiHCH BOAW> 
 
 5.30 
 
 -B. T. U. TRANSMITTED PER SQ. FT. PER DAY, PER DEGREE OF DIFFER- 
 ENCE OF TEMPERATURE. — STARR'S TEST. 
 
INSULATION 
 
 81 
 
 ■11- 
 
 ^,^6 INCH BOARD 
 -V" I INCH MINERAL WOOL 
 "ViP PAPER, 
 ^7BIMCH DOAE.D 
 
 B. T. U. 
 
 4.&0 
 
 
 -13- 
 
 
 BINCH BOARD | 
 
 IP. PAPER- | 
 
 tlHCHMlHEB.AL.WDOU 
 r^^W-P. PAPER. I 
 
 ^"TblNCH BOARD J 
 
 .^CINCH BOARD 
 
 W.P. PAPER. 
 
 — %INCH BOARD 
 ■— Z.IHCH -MR- SPACE 
 2-tNCHLlTH "BLOCK. 
 W-P. PAPER. 
 •%tNCH BOARD 
 
 3.62. 
 
 M-79 
 
 .<-*6lHCH BOARD 
 — W.R PAPER- 
 — J /6 INCH BOARD 
 
 — eVlILL 3HAVING.S }»■" 
 
 -78 INCH BOARD 
 -W.P PAPER. 
 -% INCH BOARD 
 
 Dr.y155. 
 5ame a.ishtly 
 Moist 1.80. 
 Same IkMp £30. 
 
 -15- 
 
 6 PATENTED 3ILICATED *5TRAWBOARD 
 AIR CELL FINISHED INSIDE 
 
 --%, 
 
 INCH BOARD 
 
 --PATENTED CEMENT 
 
 >ZA& 
 
 
 _-- TbINCH BOARD 
 
 *•** W.P PAPER 
 
 Z'CALCPMED PUMICE 
 
 -X^W.P. PAPER. 
 ""?B INCH BOARD 
 
 >33e> 
 
 ,^-7aiHCHB0AKD 
 
 W.R PAPER- 
 
 ^--78 INCH BOARD 
 -tf*»." ~~-| INCH PLAT FIBER 
 sN> N REFR CAR LINING 
 \'W p PAPER. 
 
 T6INCH BOARDS 
 
 £.30 
 
 -le- 
 
 af 
 
 
 „.7felNCH BOAR.P 
 r_-W.RPAPER. 
 ---3INCH SHEET COB* 
 
 W.P. PAPER. 
 
 -7B1NCHB0AR-P 
 
 ^Z..10 
 
 % INCH BOABP 
 
 P. PAPER. 
 
 — 781NCH OOAR.0 
 
 'QRAHDLATED COR.K 
 INCH BOARD 
 -WP. PAPEP- 
 ~?6INCH BOAR.D 
 
 -1.70 
 
 FIG 19.— B. T. U. TRANSMITTED PER SQ. FT. PER DAY, PER DEGREE OF DIFFER 
 ENCE OF TEMPERATURE.— STARR'S TEST. 
 
 (6) 
 
-w. 
 
 . ,. -% INCH D.tM. SPRUCE 
 
 »" W.F. PAPER. 
 
 ^\-i"N.P.5.C0EK 
 ^^-W.F.PAPEE. 
 
 ~,%INCH D.4M SPRUCE 
 
 __J% INCHTHM. SPRUCE 
 ~~ -W.PPAPER. 
 
 —Z INCH N.RS. CORK. 
 
 -WP PAPER. 
 
 ~~7b INCH D.»M. SPRUCE 
 
 B. T. 
 
 3X5 
 
 2.60 
 
 " 5 " ltv s - = -2 _' . SHE- 
 
 ,Jb|NCHD«M. SPRUCE 
 
 -Wf PAPER 
 
 — S INCH N.RS. COER 
 
 -- W P PAPER. 
 
 —7a INCH BtM.SPEUCE 
 
 ^— ^_- -%1NCH DtfM.SPRUCE 
 3S?— - -W.P PAPER 
 Bg~C—-7k INCH DIM. SPRUCE 
 k£j>fO~-| INCH NPS.CORK. 
 
 ■1- 
 
 ^W.R PAPER. 
 
 i D.tM. SPRUCE 
 
 _ _-& INCH 0,«H. SPRUCE 
 £~- — W.PPAPER. 
 XCZ*~y& INCH DaM. SPRUCE 
 
 ~ W.P PAPER. 
 
 ^TfelNCH SPRUCE 
 
 3.10 
 
 ____-% INCH D.tM.SPRUCE 
 
 ~'~- W.P PAPER 
 
 ~ ~% INCH D.tttSPRUCE 
 - ^CMINCH AIRSPACE 
 Vlffi PAPER. 
 
 ^■jfe INCH D.«M.5PRUCE 
 
 ^.--%INCH D.*M SPRUCE 
 --VJ.R PAPER. 
 
 1 INCH AIR SPACE ' 
 
 ^8 INCH DIM. SPRUCE 
 W.PPAPER. 
 " INCHD.TM.3PRUCE 
 Ol INCH AIRSPACE 
 S'WP.PAPER 
 
 78 INCH D.*M. 5PRUCE 
 
 \\ \i 
 
 INCHD.tMSPRUCE 
 W.PPAPER 
 2. INCH AIR. SPACE 
 '^'BOARDS * W.P PAPER 
 -Z. INCH AIRSPACE 
 VBOARDSf PAPER 
 
 -z. inch air. space 
 k boards tpaper. 
 inch Air space 
 
 %'D.iM, SPRUCE *WPPAPEE 
 
 ,. %DtM SPRUCE *WP PAPER- 
 
 IINCH AIRSPACE 
 
 ... 7&"D.t-M. SPRUCE *W.R PAPER 
 
 I'lNCH AIR SPACE 
 
 76" DtM. SPRUCE *W.P PAPER 
 
 • — IINCH AIRSPACE 
 
 — -7a*DlM.3PR0CEtViPPAPER 
 
 yz.no 
 
 •ig- ezacz 
 
 ,- -Ts INCH D,«M. SPRUCE 
 -. W.PPAPER 
 
 FIG. 20. — B. 
 
 "*~-~ 1 INCH PUM1ST0NE V 
 
 ^S^~~W.P.FAPER M0I5T Z 
 
 ~~7bINCH D.tM.SPRUCE J 
 
 T. TJ. TRANSMITTED PER. SO. FT. PER DAY, PER DEGREE OF DIFFER- 
 ENCE OF TEMPERATURE. — NONPAREIL CORK MFG. CO. 
 
INSULATION 
 
 83 
 
 TiQ 
 
 l^^S^ti.V^^^^^^^^-i^i^N^^'-"^ W.P.PAPER 
 
 -W ' '^^^^^m^^m^M^m^JM^^ ^-1 INCH ftft -R , 
 ■^a^SW^h^W^ — -?B INCH DtM I 
 
 _--7aiNt.. DtV ..SPRUCE 
 
 ^ W.P.PAPER 
 
 ■FSCORtt 
 -P/-CE 
 SPRUCE 
 
 ^~-7B|NCHD+ri.3PR.UCE 
 
 B. T. U. 
 
 l.£0 
 
 ---/klNCH D.tM.5PBUCE 
 
 W.PPAPER- 
 
 3INCH H.RSCOBK. 
 
 2.IHCHK.R3 <■ 
 
 ,, 1 INCH AIRSPACE 
 
 j^H- %IHCH D.tM. SPRUCE 
 
 AHDW-PPAPER- 
 
 - .90 
 
 _-^7B D1M.SPB.UCE 
 
 W.P PAPER- 
 
 2. INCH H.RS CORK. 
 
 ; — -I INCH AIRSPACE 
 ■-.ye INCH DtttSPRUCE 
 AND W.P PAPER. 
 
 Z.10 
 
 Z..Z.0 
 &i*To Cub.Pt 
 
 %INCH D.+M.SPRUCE 
 
 ?^ W.R PAPER, 
 
 ^-%IHCH D.+M. SPRUCE 
 BINCH ^P-AM COfUC 
 
 _----%JNCH D.+M. SPRUCE 
 
 ^ W, P PAPER- 
 
 76 INCH D+M.SPR.UCE 
 
 1.9 
 8i*ToCuB.Pr. 
 
 -&INCH D.iM.SPEUCE 
 
 AND W.R PAPER 
 -—I INCH AIR. SPACE 
 ■"""--WWlSPtUCEtWRMPEI!. 
 
 4INCHCjRAN.CC.uk. 
 
 T&'D.tNSPRUCEI-WPAPER. 
 
 _ — I. INCH AIE. SBACE 
 ye 'W M. SPEUCE « W.PFWPER 
 
 -1.15 
 
 -%D.m3PEUCE 
 -W.P PAPER. 
 -31NCH N.RS.CORK. 
 - 1 INCH AIE. SPACE 
 -%" D.trtSPRUCE *W.PP/>PEE 
 
 hnp 
 
 FIG. 
 
 21. — B. T. U. TRANSMITTED PER 
 ENCE OF TEMPERATURE. 
 
 SQ. FT. PER DAY, PER DEGREE OF DIFFER- 
 — NONPAREIL CORK MFG. CO. 
 
B. T. U. 
 
 -33CRATCHE0 HOLL'OW TILES 
 _4*SPACE ril_LED WITH 
 
 MIMEB.AL WOOL 
 ~3"3CRATCHED HOLLOW TILES 
 ..CEIIEnT PLASTER. 
 
 Wall Construction -FTREPRoor 
 
 CONCRETE TLOOO. 
 
 3'DOOK.TILES 
 
 «'DB1 C1HDCP.ni.LINO 
 
 ., DOUBLE SPACE HOLLOW TILE 
 
 ARCHES 
 — CEMEHTPLASTER 
 
 Tloor. Construction -HkEPRoor 
 
 "Wall Construction -Wood 
 
 AIR SPACE 
 -■"JfelHCH D 1M. BOAR.P3 
 ^WATERPROOP PAPER. 
 •+'3PACE FILLED WITH 
 MTMERAL. WOOL 
 — 1 AIR SPACE 
 ^WATERPROOr PAPERS 
 ^-TklNCH D.fN. BOARDS 
 
 „^3IDINa 
 
 " WATERPROOr PAPER 
 7b INCH BOARDS 
 
 it 6'3T UDS - 16" 0-C . 
 
 ^YfilNCH B0ARD3 
 --WATERPROOF PAPER 
 3PACE FILLED WITH 
 ^£5^'-- ""MINERAL WOOL 
 ~ Kj. ^i'AIR. SPACE 
 
 ^<j*».TERPR00r PAPERS 
 ■7b INCH B0ARD3. 
 
 1.74 
 
 Z90 
 
 ^'SPACES FILLED 
 WITH MINERAL WOOL 
 WATERPROOF" PAPERS 
 
 -ffclNCH BOAR.D3 
 
 z.n 
 
 Floor. Construction 
 
 ,-1%'PLAMK. TLOORINq 
 t _— WATERPROOF PAPERS 
 78 INCH BOARDS 
 -4" JPACE PILLED WITH 
 
 MINERAL WOOL 
 
 gV ' J* WATERPROOF 1 PAPER. 
 
 -ye INCH BOARDS 
 
 BEDDED IN DRY 
 --ClNDERriLLtNq tt-'WOH 
 
 1.91 
 
 Floor Construction 
 fig. 22. — b. t. u. transmitted per sq. ft. per day, per degree of differ- 
 ence of temperature. — fred w. wolf co. test. 
 
INSULATION 
 
 85 
 
 2 % 
 
 IMCH QtM. BOARDS 
 
 14 -4 IHCH AIR. 3RACE3 
 W.RPAPEB.3 
 
 ^=* &IMCH D«M.BCKR.D3 
 
 ■T&IHCH D.tM.BOARM 
 
 V*t IHCH AIR SPACES 
 W.P PAPERS 
 
 — fe IMCH ntM.PQAIZ.P5 
 
 .... .— %JHCH D.fM. BOARR3 
 ,..'.'■ -3<&~- 4IHCH MINERAL WOOU 
 
 ' itt&i^ - W.R PAPER. 
 
 ——%=-*- -7felHCH D.fM BOARDS 
 
 -&IHCH D.rK.B0AEP3 
 -W.T7 PAPER. 
 
 -« 4IHCH MILL SHAVIH<T3 
 
 W.P.PAFER. 
 
 — 7felMCHD.TM. BOARDS 
 
 B. T. U. 
 
 >3l16 
 
 ■4X1 
 
 3-46 
 
 £.05 
 
 %IHCH D.ttT. BOARDS 
 
 — - fclNCHD.rft BOARDS 
 
 -TfelNCH D.TM.BOARP3 
 
 SlNCH D>rt BOARDS 
 
 --W.P.PAPEB. 
 "~~-%LNCH D.tM.BOARDS 
 
 4 INCH MILL 3HAVINQ3 
 
 11.06 
 
 Z.€>1 
 
 - .->-;-■■■■' .-—^INCHni-M. BOARDS 
 
 r^j-y^ 3 ^ — -w.rpapeo. 
 
 — - — &INCH D.tM BOARDS 
 
 fclNCHD.t-M. BOARDS ] 
 
 — -W.P. PAPER- I 
 
 ;>3IMCHHAIR.PELT-|3HECTJ > \&Q 
 
 ^--ftlHCH D.tM. BOARDS 
 
 C W. P. PAPER. 
 
 IlHCH HAIR- TELT 
 
 *' — W.P- PAPER. 
 
 "^-TblHCHtM-M.B&ARRS ■ 
 
 j*- IlHCH SHEET CORK. 
 
 ^-^T— -W.P. PAPER. -■ 
 
 """fclHCH H*K. BOARDS 
 
 ^ % IHCH RtK BOARDS 
 
 * W.R PAPER. 
 
 -— llMCH AIR 3PACE 
 
 - -W.P. PAPER. 
 ~"~7blHCH MM BOARDO 
 
 ■4.91 
 
 i.n 
 
 9.12. 
 
 IG, 23.— B. T. U. TRANSMITTED PER SQ. FT. PER DAY, PER DEGREE OF DIFFER 
 ENCE OF TEMPERATURE.— COOPER'S TEST. 
 
si-; 
 
 PRACTICAL COLD STORAGE 
 
INSULATION 
 
 87 
 
 
 .00 
 
 ft' 
 
 
 
 
 
 
 
 
 
 
 
 or 
 
 « 
 
 
 
 ^12; 
 
 
 
 
 
 
 
 
 
 
 
 C 
 Q 
 
 
 l.- 
 
 or 
 
 "Iff 
 
 \\ 
 
 
 
 
 
 
 
 
 
 
 0-= 
 
 7 
 
 a. 
 
 Z> 
 
 ,o& 
 
 £4 
 
 ^ 
 
 V\ 
 
 \ 
 
 
 
 
 
 
 
 
 Ul 
 
 a. 
 
 u*i 
 
 a: 
 
 X 
 
 ft 
 
 u 
 
 I 
 
 U 
 
 ,0f) 
 
 
 
 § 
 
 fe 
 
 ^x 
 
 
 
 
 
 
 
 EC 
 U 
 Q. 
 
 E 
 
 ,^ 
 
 L. 
 
 
 
 
 
 \X 
 
 [*&i 
 
 <x 
 
 
 
 
 
 
 o 
 
 
 O 
 
 a: 
 
 m 
 
 
 
 
 \ 
 
 ^ 
 
 H 
 
 N 
 
 ^ 
 
 
 
 
 a: 
 
 a 
 
 4 
 
 a. 
 Q 
 Ul 
 
 H 
 £' 
 
 z 
 
 ,m 
 
 
 
 
 
 
 
 
 
 
 
 
 b 
 
 u 
 
 SI 
 
 ■ u 
 
 fl 
 
 ,03 
 
 
 
 
 
 
 
 
 
 
 
 
 li- 
 o 
 
 a 
 
 z 
 
 2 
 
 h 
 H 
 
 0/ 
 
 
 
 
 
 
 
 
 
 
 
 
 8- 
 
 i- 
 
 z 
 
 ,/ 
 
 
 ,00 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 .0 
 
 
 0_ 
 
 1" 
 
 Z 
 
 3" 
 
 4" 
 
 6" 
 
 fe" 
 
 ?~ 
 
 6" 
 
 r 
 
 lo- 
 
 ir 
 
 w 
 
 
 FIG. 25.- 
 
 rNCHESor5HAVING5 '"c2" 
 -Stoddard's diagram showing rate of heat transmission through 
 
 A WALL. 
 
 % - SPRUCESHOTHING - 
 
 fig 25a.— stoddard's diagram showing construction of above wall. 
 
88 
 
 PRACTICAL COLD STORAGE 
 
 !%, 
 
 ■j j a^d ynoH a: « iooj jyvDos- »?■> p:u±iwsNvyi '?ni'g 
 
INSULATION 
 
 89 
 
 thick. The vertical distances in all of the similar diagrams represent the 
 B. T. U. transmitted per square foot per hour per i° F. difference in 
 temperature between the inside and outside of the wall, and also the 
 equivalent pounds of ice melted per square foot per twenty-four hours 
 for a difference of a little over 59° F. 
 
 Fig. 26 shows a similar curve for a partition of typical construction 
 (see Fig. 27), with the thickness of shavings varying from two to 
 twenty-four inches. 
 
 B.T.U-1402. 
 ICE =1.402 
 
 //jvx 
 
 
 ^K\ 
 
 
 s 
 
 i 
 
 
 
 
 
 
 Z 
 
 
 u 
 
 
 
 UJ 
 
 N 
 
 y, 
 
 
 & 
 
 in 
 < 
 
 1 
 
 i 
 
 in 
 
 < 
 
 p 
 
 i 
 
 B.T.U.=.0959 
 ICE = 0.959 
 
 B.T.U.=.07Z3 
 ICE -- 07Z°> 
 
 BT.U.-.0587 
 ICE =0.587 
 
 I"-- — — 1 
 
 1 1 
 
 B.T.U.= 076 
 ICC = 0.76 
 
 PAPER /AIR SPACES 
 
 FIG. 27.- 
 
 -PARTITION OF SHEATHING AND AIR SPACES SHOWING RATE OF HEAT 
 TRANSMISSION. — STODDARD. 
 
 In Fig. 27 are shown partitions made up of sheathing and with one, 
 two, three and four air spaces, and also one made up of sheathing and 
 paper with nine air spaces, and the rate of transmission of heat through 
 such insulation is given in B. T. U. and ice melted. In Fig. 28 is given 
 the actual thickness of different partitions packed with various insulating 
 materials of such a thickness that all of the complete partitions shall be 
 of the same insulating value. There is also shown one made up of 
 sheathing with air spaces. From this is seen how much more space is 
 taken up by one form of insulation than by another. 
 
90 
 
 PRACTICAL COLD STORAGE 
 
 An examination of Figs. 27 and 28 will show the comparatively 
 small value of air spaces for the purpose of insulation, and it may be 
 stated, that, for this purpose, a wide air space has no greater value than 
 a narrow one, and that any space over one-half inch in width, if it can be 
 
 HAIR FELT 
 
 GRANULATED CORK 
 
 ^■ J _'','j, i i '.-'-.---.^< l .S- : -.-/ fc5 4l',.--^ - , - v -. tui 
 
 ■Jp*&?S,?S-. 
 
 vNy-r^vC.-W 
 
 
 -7/&" SPRUCE SHEATHING 
 
 B.T.U. .0+83 
 ICE 483 
 
 ?S"5PRUCESHEATHIN& 
 
 FIG. 28.— RELATIVE THICKNESS OF PARTITIONS PACKED WITH VARIOUS 
 INSULATING MATERIALS. 
 
FOR CEILING OF 
 
 AND ICE HOUSE. 
 
 MINERAL WOOL OR CORK 
 a"TH)CK.OF T. & G. BOARDS 
 air - PArt PAPER BETWEEN \ COLD STORAGE ROOMS 
 
 ~THICK.OF T. St Q. BOARDS 
 
 " " PAPER EET'.VEE 
 
 ICK WALL TO BE WELL COATEO WITH ?;7CH 
 a"AIR SPACE 
 2"THICK. of t, a. g. boards 
 
 PAPER BETWEEN 
 AIR SPACE FILLED WITH MINERAL WOOL OR CORK AS SHOWN 
 
 a'THICK. OF T. 6. G. BOARDS 
 ■3" " ' " PAPER BETWEEN 
 
 !' AIR SPACE FILLED AS ABOVE AS SHOWN 
 -a"THICK. OF T. A G. BOARDS 
 
 PAPER BETWEEN 
 
 FOR WALL OF 
 v COLD STORAGE ROOM 
 r AND ICE HOUSE 
 
 WHEN MADE OF BRICK. 
 
 FOR INTERMEDIATE FLOORS. 
 
 a B THICKN ESSES OF T. * G. BOAHDB 
 
 " " PAPER BETWEEN 
 
 4"MINERAL WOOL OR CORK 
 3THICK. OF T. A G. BOARDS 
 
 1 l( PAPER BETWEEN 
 
 MINERAL WOOL OR COHK 
 
 FOR PARTITION WALLS. 
 
 a "THICKNESSES OF T. J G. BOARDS 
 * <■• n ", PAPER BETWEEN 
 
 'AIR £P>CE FILLED AS SHOWN 
 ■z'THICK. OF T. i. G. BOAROS 
 9" " ■■ ' " PAPER BETWEEN 
 
 2"A1R SPACE FILLED AS SHOWN 
 a"THtCK. OF T. & a. BOARDS 
 
 " ■' " PAPER BETWEEN 
 
 MINERAL WOOL OR CORK 
 
 FOR GROUND FLOORS. 
 
 ICK. OF T. A G. BOARDS 
 
 " * PAPLR BETWEEN 
 
 a'AIR SPACE 
 
 2"tH(CK. OF T. 4 G. BOARDS 
 3 " ii .( PAPER BETWEEN 
 
 MINERAL WOOL OR CORK 
 
 X a SHELVING 
 a"x a" STUDDING 
 
 FIG. 29. — AIR SPACE INSULATION. — FRICK CO. 
 
92 PRACTICAL COLD STORAGE 
 
 kept dry, will be of greater value if filled with an insulating material as 
 good as mill shaving's, than if left as an air space. 
 
 AIR SPACES. 
 
 It is evident from the results shown with the various con- 
 structions, that those built up out of wood boarding and air 
 spaces, or air spaces formed with battens and paper make the 
 poorest showing when the space occupied and cost in labor is 
 taken into consideration. The author considered the one-half 
 inch air spaces formed by battens and paper as shown in his tests 
 to be efficient until practical experience and the tests conducted 
 by him proved otherwise. The workmanship in building such 
 spaces is usually poor, as unusual care, not appreciated by the 
 average workman, must be taken so as not to puncture them 
 when under construction. Air space construction is difficult to 
 erect so as to be air and moisture proof. 
 
 Another extensive use of air spaces has been between the 
 brick wall and the insulation, as shown in Figs. 25 and 29. The 
 alleged purpose of its use at this point has been, first, proof 
 against moisture entering the insulation; second, for the insulat- 
 ing value it may have. With the growing disbelief in the use 
 of air space construction, this second purpose can be considered 
 of little value. The prevention of moisture entering the insula- 
 tion from brick walls by the use of air spaces is only partially 
 true, as may be readily understood. The moisture will enter the 
 air space and will eventually affect the insulation more or less. 
 There are sometimes local conditions that would warrant the use 
 of an air space between the brick wall and insulation, but in the 
 opinion of the author, such design should be avoided wherever 
 possible by waterproofing the brick wall and placing the insula- 
 tion against the waterproofing. This method saves both space 
 and material for the same insulating efficiency obtained. The 
 question of the amount of space occupied by the insulation is of 
 much importance, as it represents a certain money value, both 
 in first cost and as storage space, and it should be the designer's 
 aim, within practical limits, to use the best insulation and that 
 requiring the least space. 
 
 TYPES OF INSULATION. 
 
 Fig 30 illustrates a construction used to a great extent by 
 the author in his cold storage work. The inside of the masonry 
 
INSULATION 
 
 •Plan or Insulation- 
 
 FIG. 30. — COOPER'S DESIGN FOR INSULATED CONSTRUCTION. 
 
94 
 
 PRACTICAL COLD STORAGE 
 
 7& INCH D.ttt BOARDS' j' 
 ^— _i"lTINERAL WOOL BLOCK^ 
 CORK OR HAIR. FELT 
 
 PAPER.-- 
 7 /&3VRF. BOARDS 
 Z"*lo"3TVD,3- FILLED 
 WITH SHAVINGS 
 
 ;// 
 
 / 7&INCH D.<rT BOARDS 
 
 / Z-"mIHERAL WOOL BLOCK. 
 
 / f~ CORK OR HAIR FELT 
 
 / //' r ^ WATE1RPROOf; ' PAPERS 
 llj jj i% INCH SVRF. BOARDS 
 
 FIG 31.— SECTION SHOWING INSULATION FOR A FRAME BUILDING. 
 
INSULATION 
 
 95 
 
 FIG 31a. — PLAN OF SUBDIVISION OF SPACES AS SHOWN IN, FIG. 31. 
 
 walls are waterproofed and the filled space of from six inches 
 to ten inches is placed against it, then the sheathing, sheet ma- 
 terial and papers are placed inside, next to the storage rooms. 
 With an eight-inch filled space and four-inch sheathing and 
 sheet material as shown, a total of twelve inches, we have an 
 insulation for a storage temperature of 30° F., and the basement 
 with a total of thirteen inches, for a temperature of from 20° 
 to 25 ° F. For sharp freezing purposes there should be a ten-inch 
 filled space and an additional thickness of sheet material. 
 
 Fig. 31 illustrates the construction and insulation of a frame 
 building suitable for a temperature of 30 F. The space between 
 the studs should be subdivided, as shown in plan Fig. 31 -a. This 
 lessens the liability of settling of the filler and the penetration of 
 moisture. The use of wide filled spaces such as shown in Fig. 24 
 is not considered good practice, as heat passes through a construc- 
 tion of uniform density more rapidly than through one made up 
 of successive layers of different densities, therefore the thickness 
 of the wall in the former case will be greater than that in the 
 latter to obtain the same insulating value. This is evident by 
 referring to 1 Figs. 24 and 30, the former with twelve- inch brick 
 wall, air space and twelve-inch shavings, as shown, a total of 
 thirty inches in thickness, transmitting % B. T. U. per square 
 foot per day per degree difference between inside and outside 
 
96 PRACTICAL COLD STORAGE 
 
 temperature. The latter, with twelve-inch brick wall, eight-inch 
 shavings and five inches of sheathing, sheet material and paper, 
 as shown, total twenty-five inches in thickness, will transmit same 
 amount of heat. Here is a saving of five inches in storage space 
 which will earn the difference in cost between the two construc- 
 tions in a short time. 
 
 Another feature in the construction shown in Fig. 30 of 
 equal importance to the space saved, is durability. This is accom- 
 plished by placing the indestructible materials, such as water- 
 proof paper, and mineral wool block, sheet cork or hair felt in 
 successive layers on the side next to the storage room where the 
 conditions are most severe. These severe conditions are caused 
 by a tendency of the enmeshed air in all insulating materials to 
 condense the moisture held in suspension when subjected to low 
 temperatures. This moisture will impair the durability of "some 
 materials, such as sawdust, shavings, etc. - That such condensa- 
 tion does take place within the insulation, near the low tempera- 
 ture side, was demonstrated to the author in the tests made by 
 him. Between each test the removable cover was unscrewed 
 from the tester, which was located in the cold storage room, and 
 taken into a room having an ordinary temperature, where the 
 material in the cover was changed for the next test. The en- 
 meshed air in the material put into the tester, was of an ordinary 
 temperature and held a certain proportion of moisture in sus- 
 pension, and when the material was reduced to the low tempera- 
 ture in the cold storage room, this moisture would condense on 
 the cold side of the layer confined by the waterproof paper. In 
 some cases where the room temperatures were very low the con- 
 densed moisture would freeze on the cold side. These conditions 
 obtained, depending on the dryness of the material when it was 
 put into the tester, but would show more or less moisture in 
 almost every case. The moisture condensed would be greatest 
 in the layer nearest the cold side of the partition and would grad- 
 ually diminish in each layer toward the high temperature side, 
 where it would be perfectly dry. This was not moisture that had 
 been carried into the insulation by the leakage of air, but was the 
 condensation of the moisture held in suspension by the air en- 
 meshed in the material. Air space construction showed the great- 
 est condensation, wide filled spaces came next and the high grade 
 
INSULATION 
 
 97 
 
 of sheet materials divided by waterproof paper showed the least. 
 From the above it is evident that high-grade materials should 
 be used next to the storage rooms, as they will not deteriorate 
 as rapidly with the presence of moisture. This construction also 
 protects the loose filler in the filled space, which is removed fur- 
 ther from the inside wall, therefore making its duty less severe 
 as regards the action of moisture. This construction is shown in 
 Fig. 30, as used by the author. It is also evident from the above 
 described action of moisture in the insulation, that the importance 
 of using dry materials cannot be urged too strongly, and this 
 fact has probably as much to do with durability and efficiency of 
 the insulation as the nature of the material used. 
 
 Where the storage space occupies two or more stories, it 
 has frequently been the practice to insulate the intermediate floors 
 out to the masonry walls and then erect the wall insulation inde- 
 pendently for each story, as shown in Fig. 29. This is a ques- 
 tionable practice, as it increases the number of joints in the con- 
 struction and consequently the chance of air leakage into the 
 rooms. Cases illustrating the damage from air leakage between 
 joints and above ceiling or beneath floors of storage rooms come 
 to the author's attention frequently. The last one was so pro- 
 nounced a case that the entire ceiling of an upper room became 
 so rotten in a few years' time that it practically fell, making the 
 entire renewal necessary. The damage was caused by leakage of 
 air, and consequent deposit of moisture on the cold ceiling. 
 Where the building is a fireproof structure with steel beams 
 and masonry floors, it cannot of course be insulated otherwise 
 than by treating each floor independently, or in a similar way 
 to that shown in Fig. 38. 
 
 A better method than that shown in Fig. 29 would be to 
 carry the wall insulation continuous from floor of lower story 
 to ceiling of upper story, as shown in Fig. 30. Where the ends 
 of joists bear into the wall, the insulation should be scribed and 
 closely fitted around each joist. This is easily done where the 
 construction is properly designed to allow a wide spacing of the 
 joists. Insulation constructed in this way decreases the chances 
 of leakage to the minimum. 
 
 Referring again to Fig. 29, it will be noticed that the spaces 
 between joists are but partially filled with the filling material, 
 
 (7) 
 
98 
 
 PRACTICAL COLD STORAGE 
 
 leaving an empty space in each case. This would have been of 
 greater insulating value if packed full to the top. The spaces 
 between the lower floor joists should first have been lined with 
 waterproof paper before the filler was put in, as shown in Fig. 
 31, to prevent the penetration of air and moisture. 
 
 The insulation detail for a steel ice freezing tank, as shown 
 in Fig. 32, is of the general form used by most designers. At- 
 tention is here again called to the use of the high-grade insu- 
 lators at what will be the coldest point of the insulation for the 
 reasons already discussed. In the light of our present informa- 
 
 V«*"STUD3 -34'CEN.— 
 I*3PACE TILLED WITH PITCH 
 TfclNCH P-tl-I BOARDS.^ 
 4 INCH FILLED 3PACE— . 
 3"HAIR FELT, CORK OR_ 
 MINERAL WOOL BLOCK*" 
 WATERPROOF PAPER. < 
 
 FIG. 32. — INSULATION OF BRINE TANKS. 
 
 tion, the use of a 2-inch or 4-inch air space next to the steel 
 tank would be considered a waste of space. This would much 
 better be filled with granulated cork and hot pitch or asphalt, 
 as shown in detail, as this would prevent the condensation of 
 moisture and protect the steel tank from corrosion. The space 
 under bottom of tank should first be filled level with top of floor 
 cleats and then the tank set in place, after which the space 
 around sides can be poured full from the top. A frequently neg- 
 lected detail is covering the top edge of tank insulation with 
 galvanized iron or other waterproof material, as shown in Fig. 
 32. This detail should not be overlooked or slighted, as the 
 
INSULATION 99 
 
 unavoidable spilling of water and dripping of brine in connection 
 with ice making will eventually damage the insulation. 
 
 FIREPROOF INSULATION. 
 
 The tendency of modern building construction, especially in 
 our large cities, is toward the solution of the problem of fire- 
 proofing, so as to decrease the danger and risk of fire. It is 
 natural that this same problem should confront the cold storage 
 man, but the difficulties of providing insulation that would be 
 fireproof, and remain at the same time insulation in fact, is a 
 problem not easily solved. 
 
 In the article on "Insulation for Cold Storage," read before 
 the eleventh annual convention of the American Warehousemen's 
 Association, Starr stated regarding fireproof insulation, as fol- 
 lows : 
 
 I cannot refrain from alluding to the subject of fireproof insulation, 
 more in the hope of drawing out information than adding to it. Steel 
 frame work has in the past been a considerable bugbear to cold storage 
 men, but the time is already at hand when the problem of entirely fire- 
 proof construction, both as to building and insulation, must be solved. 
 As to the insulation end of the problem, the difficulty is not so much with 
 the question of obtaining a fireproof filling material, but to find a sub- 
 stitute for wood, to hold the material in position. Cementing insulating 
 material in the shape of blocks has been experimented with, but if the 
 cementation is enough to give sufficient ruggedness to the block the insula- 
 tion qualities are, as a rule, impaired, and the cost as well as the space 
 occupied by the insulation is increased. 
 
 If a semi-fireproof insulation that might be classed as fire-retardant 
 construction is permissible, the problem is somewhat simpler, as several 
 materials are at hand that can be classed as retardants, such as compressed 
 cork, hair felt, silicated paper, air spaces, etc., but if the whole structure, 
 studs, filling material and wearing face, are to be fireproof, we are practi- 
 cally restricled to mineral wool, mica and calcined pumice for filling 
 material ; and for retaining and wearing wall, to brick or some of the 
 various cement fireproof boards on the market. The use of the latter 
 would seem somewhat experimental, and the question of fireproof studs 
 for supporting them, so far as I know, has not been answered. 
 
 As nearly all building materials available that can be called 
 fireproof are poor insulators against heat, it is evident that the 
 walls must be extremely thick to have the same insulating value, 
 or the machinery must take up the extra heat transmitted through 
 them. The former course, with the present method of construct- 
 ing fireproofing, is almost prohibitive on account of first cost and 
 the space occupied; the second course necessitates a continuous 
 heavy operating expense. The advisability of fireproof insula- 
 tion, especially in small bouses, is questionable, as the items of 
 
100 PRACTICAL COLD STORAGE 
 
 interest on investment, space lost, and increased operating ex- 
 penses will oftentimes equal the difference in insurance rates ob- 
 tained between a fireproof and a well designed "mill constructed" 
 warehouse. 
 
 It is the observation of the author that the greatest number 
 of fires occurring in cold storage warehouses originate outside of 
 the storage rooms, except in occasional instances where it is 
 caused by defective electric wiring. Therefore, if the cold stor- 
 age portion were surrounded and divided by fire walls, openings 
 properly protected and the electric wiring installed according to 
 approved methods, it would seem that the fire risk was cut down 
 to a minimum, as the nature of the machinery and the goods 
 usually stored are not of an inflammable character. This point 
 must, however, be appreciated by the fire underwriters to make 
 it of any value to the storage man in the way of lower rates. 
 That they will appreciate it in the near future there is no doubt, 
 and then the requirements of fireproof insulation will seem un- 
 necessary, except perhaps in the large warehouses in the large 
 cities. 
 
 Cold storage warehouses have been erected on the lines indi- 
 cated above with "mill construction" and wood insulation and 
 have obtained a very low insurance rate, considering the general 
 attitude of the fire underwriters toward the cold storage ware- 
 house business. 
 
 The necessity of fireproof insulation is felt in storage vaults 
 for furs and fabrics, and justly so, as these articles are usually 
 of great value and oftentimes could not be replaced if lost or 
 damaged. This class of storage will permit a greater operating 
 expense to offset the poorer insulating value of the fireproof in- 
 sulation. Figs. 33 and 34 are details of the wall and ceiling 
 insulation in the storage vaults of the Lincoln Safe Deposit Co., 
 New York. The plaster blocks were fastened to the brick walls, 
 every alternate block in every alternate row with iron anchors. 
 The ceiling blocks were supported by tee irons, which in turn 
 were suspended from the brick arches, as shown. These plaster 
 blocks usually consist of plaster-of-paris and some binding ma- 
 terial, such as manila fibre or common straw, and in the event 
 of a severe fire they would probably fail and allow the filling 
 material to fall out. The failure of plaster blocks was fully dem- 
 
INSULATION 
 
 101 
 
 onstrated by the recent Baltimore fire, where, in every case 
 noted, partitions erected of them were completely destroyed. The 
 company above named, in making later extensions to their plant, 
 used cork blocks applied directly to the brick wall and plastered 
 inside, as shown in Fig. 9. 
 
 ■krr Hr- C0ATE:D WITH pitch 
 
 -4 OF MINERAL WOOL 
 
 ;| — iK PLASTER. BLOCK 
 
 -ADAMANT PLASTER. 
 
 DETAIL OF WALL INSULATION. 
 
 a^J^Watb&Ji^toS 
 
 
 
 ^Ji<Zk,%/.'l£J-;i MINERAL WO 11. PILLII 
 
 
 
 -•!«ffifr«»-E 
 
 T -"r '..-■.-' - -.'.''■'~ r : < -i^x'C 
 
 COATED / 
 WITH PITCH 
 
 Ceiling- 
 
 adamant PLASTER.' 
 
 FIG. 34. — DETAIL OF CEILING INSULATION. 
 
 Constructions such as shown in the two upper details of 
 Fig. 22 are strictly fireproof and may be used where the tempera- 
 ture difference between the inside and outside would not be more 
 than 25" to 30 F. 
 
102 
 
 PRACTICAL COLD STORAGE 
 
 Figs- 35, 36 and 37 are reproduced from illustrations de- 
 signed by Alfred Siebert* These constructions were intended 
 
 PJaster 
 
 FIG . 35. — siebert's brewery insulated construction. 
 
 for brewery refrigeration where the temperatures required are 
 comparatively high, as their heat transmission would be prohibi- 
 tive for cold storage work. The difference of detail between Figs. 
 35 and 36 is in the method of bonding the tiles to the main wall ; 
 
 FIG. 36. — SIEBERT'S BREWERY INSULATED CONSTRUCTION. 
 
 in the former case, some of the tiles are laid headers with one 
 end secured in the brick wall and in the latter case iron anchors 
 are used. 
 
 Polei^for pour/a c? in plfcb 
 
 fispholt 
 
 FIC. 37. — SIEBERT S BREWERY INSULATED CONSTRUCTION. 
 
 If a fireproof building is to be insulated where a slow burn- 
 ing or fire retardant material can be used, a construction as shown 
 
 * In "American Handy-Book of the Brewing, Malting and Auxiliary Trades." 
 
INSULATION 
 
 103 
 
 Intermediate Tloor 
 
 , ICEMENT TLOOB. 
 
 / , — -WPCOATING 
 
 ///--i^'FLANK. 
 
 ' ' -W.P PAPER 
 
 cork, hair felt or 
 'Mineral wool block 
 ■ffBDtMDOARDJ 
 
 ///fa 
 
 ill 
 
 Mm 
 
 ,2'nl*5LEXPER5 
 
 /.CEMENT* CINDERS 
 
 •WW 
 
 
 
 V ?&D»M BOARDS 
 
 ■WP PAPER, 
 
 \\ v. 
 
 LCORK.rTIHERALWOOL BLOCK 
 
 \ \ 
 
 OR HAIR FELT 
 
 
 -VI F COATINQ 
 
 
 -1 'CEMENT -METAL LATH 
 
 Outride Walls 
 
 -fCEMEMT- METAL LATH 
 -W.PCOATIHG 
 
 --WDtM BOARDS 
 ,.4'CORK , HAIR FELT OR 
 MINERAL WOOL BLOCK 
 •-W.F PAPER 
 
 Basement Floor. 
 
 -- \% CEMF_HT FLOOR- 
 -W.FCOATINQ 
 
 -tV flank. 
 
 1 1 1 A S'CORK.HAIRFELTOR. 
 
 ' I .' ¥i f Mtt- 
 
 FIG _ 38.— INSULATION OF FIRE PROOF STRUCTURES. 
 
104 PRACTICAL COLD STORAGE 
 
 in Fig. 38 is the most practical and with the proper sheet or 
 block material would be almost thoroughly fireproof. Such insu- 
 lation can be finished inside with cement or plaster, as shown. 
 
 The inside finish on the walls of the rooms is of some im- 
 portance as a fire retardant. With the use of hard oils, var- 
 nishes, shellacs, etc., the spread of a fire would be rapid, as 
 these materials are very inflammable, but with the use of prepa- 
 rations such as cold water paint or whitewash, the spread of fire 
 would be retarded, as these mixtures are not inflammable, ano 
 would give some protection to the woodwork on that account. 
 
 BRINE PIPE INSULATION. 
 
 The importance of thoroughly protecting the pipes that carry 
 the cooling agent to the various parts of the storage building is 
 as great as insulating the rooms. On account of the low tem- 
 perature of these pipe surfaces, they condense much moisture, 
 
 
 
 
 /oj ■-=■'"-■ :■>*■ ;-'->--';•■. "J 
 
 
 
 
 
 
 
 &£ 
 
 '.■'■i - -" -J_-':- : <''<"--:. ; '.;," '.'- ; . '('-■'- 'Ak 
 
 ■;,V i 
 
 5^= 
 
 
 ----- ■» 
 
 
 
 
 ■:;■.:■•-•■:■:>--"--.'.' J. — wJ 
 
 FIG. .39. — CORK BRINE PIPE INSULATION. 
 
 and if the covering is poor and not well protected on the outside 
 from air leakage, a dripping and soggy condition is sure to follow 
 each time the cooling agent is shut off. If this condition is once 
 obtained the value of the covering is permanently impaired. 
 
 There are some pipe coverings on the market, especially suit- 
 able for brine piping, made of cork or mineral wool in block form 
 in the same manner as already described for wall insulation, 
 and are made sectional to fit any size pipe or fitting, having the 
 appearance shown in Fig. 39. Some of these sectional coverings 
 are provided with canvas cemented to the sections with ample 
 lap at the joints, and these laps are cemented together as the sec- 
 tions are put in place. Directions for putting 011 are usually sent 
 with the material by the manufacturers. Hair felt is also a good 
 material to use if properly applied, as indicated in Fig. 40, and 
 can be handled very well, if cut in lengths of five or six 'feet, 
 
INSULATION 
 
 105 
 
 wrapped around the pipe, and thoroughly wired with galvanized 
 or copper wire. If a second layer is to be put on, waterproof 
 paper should be put between the two layers and wired on, and the 
 second layer then applied in same manner as above. The outside 
 layer should have waterproof paper wired on and then covered 
 with strip canvas, binding it on spirally with a good lap at the 
 joints. The canvas must be bound on tight. The covering 
 should then have at least two coats of a good elastic waterproof 
 paint. 
 
 It is of primary importance that the pipes should be dry and 
 should be given a coat of paint before covering is put on. The 
 
 •WATERPROOF PAINT 
 
 OKI PIPE 
 
 ■1INCH HAIR. FELT 
 -WATERPROOF PAPER 
 
 1 INCH HAIR FELT 
 -WATERPROOF PAPER 
 .CANVASjCOATED WITH 
 
 WATERPROOF PAINT' 
 
 FIG. 40. — HAIR FELT BRINE PIPE COVERING. 
 
 author recommends that the layers of covering should be thin, 
 not more, than one inch in thickness, and that at least two thick- 
 nesses be used, having waterproof paper between each layer with 
 cemented joints, so as to insure the air-tightness of the covering. 
 For brine mains laid under ground, through brick walls or 
 up through partitions, a covering of granulated cork mixed with 
 hot pitch or asphalt is best, as described under cork materials. 
 This method was used by the Quincy Market Cold Storage Co. 
 of Boston, Mass., in running a street pipe line from one of their 
 buildings to the other. The pipes were laid in creosoted plank 
 boxes of proper size to permit sufficient space around them, and 
 the mixture of cork and pitch was then poured in. 
 
106 
 
 PRACTICAL COLD STORAGE 
 
 Fig. 41 illustrates a form of tunnel for underground brine 
 pipes that has been used by the author. In this case, as shown, 
 the tunnel was constructed of brick, waterproofed both inside 
 and outside and the top constructed so as to be removable in case 
 of necessity. The brine mains inside were covered in the usual 
 way, leaving an unfilled space around them in the tunnel. 
 
 WATER AND DAMP PROOFING. 
 
 The results of the penetration of moisture into the insula- 
 tion has already been discussed under the various sub-heads ; and 
 the functions of waterproof paper in the interior of the insulation 
 
 /COATED WITH HOT PITCH--. 
 
 FIG. 41. — TUNNEL INSULATED CONSTRUCTION. 
 
 to stop this moisture, should by this time be pretty well under- 
 stood. But the penetration of moisture through the masonry 
 walls to the insulation must be prevented by special treatment. 
 
 The tendency of masonry to absorb moisture is fully recog- 
 nized and provided for in the building trades. It frequently hap- 
 pens in heavy and driving rain storms, of some duration, that 
 the water will be driven through a 9-inch and even through a 
 13-inch brick wall. This is counteracted in general building 
 operations, if it is desired to plaster on the inside of the wall, 
 by constructing a 2-inch air space in the masonry wall. This 
 space will prevent the passage of moisture sufficiently so as not 
 
INSULATION 107 
 
 to damage the plaster. A second method is to line the inside of 
 a solid masonry wall with hollow brick or porous terra-cotta 
 blocks. The third and most common method is to form an air 
 space on the inside of the wall by vertical furring, and the lath 
 and plaster is then put on. All of these methods have been used 
 in cold storage warehouse construction, especially the last, as has 
 been shown by the illustrations given. 
 
 Basement walls are usually coated on the outside with 
 cement and pitch or asphalt to prevent the moisture in the soil 
 from penetrating to the inside. If the soil is very wet and there 
 is danger of the water level reaching above basement floor at 
 some periods of the year, as is often the case in some localities, 
 there should be a dampproof course extended under basement 
 floor, through the masonry walls and up on the outside of them 
 to grade. This work belongs to building construction rather than 
 to our present subject and it is therefore unnecessary to treat of 
 it in detail. The position of this damp course is indicated in 
 Fig. 30- 
 
 The common method of protecting the insulation from the 
 moisture in the masonry walls is to coat the walls on the inside 
 with various preparations, such as paraffin, pitch, asphalt, etc. 
 These are usually put on hot in a liquid state. No preparation 
 having a strong penetrating odor, such as coal tar, should be 
 used, as it is liable to taint the goods in storage. Pitch, if prop- 
 erly put on, makes a fair coating, but on account of its quick 
 hardening and brittleness, it is very difficult to apply in cold or 
 even cool weather, and when cooling it will contract and fine 
 cracks will appear running in every direction. To avoid this, 
 the roofing men will mix coal tar with it to give elasticity, but 
 it is then, of course, unfit for the inside walls of cold storage 
 rooms on account of the odor, as stated. 
 
 The best material for coating inside walls is pure asphalt, 
 and it is specified almost exclusively by the author for this pur- 
 pose. This material is odorless after it is applied, the odor given 
 off when subject to heat is not penetrating and quickly disap- 
 pears. Unlike coal tar or pitch, which are products of distilla- 
 tion from gas works, pure asphalt is a natural mineral bitumen, 
 and although it is similar in appearance to pitch, it is not so 
 dense or brittle and it has sufficient elasticity so that it will not 
 
108 PRACTICAL COLD STORAGE 
 
 crack when cooling. Besides the commercial paving asphalts 
 which are very impure, there are also refined asphalts on the 
 market which are claimed to be over 90 per cent pure. These are 
 the product of distillation from the oil wells of Texas and Cali- 
 fornia, and because they contain a higher percentage of bitumen 
 are more elastic than the paving asphalts. Asphalt is difficult to 
 apply to cold storage walls on account of quick hardening, but 
 not so much so as pitch. The chief difficulty, especially in small 
 cities, is to obtain a pure asphalt and also to get workmen who 
 have had experience in applying it. The local roofing men have 
 little or no need of pure asphalt, as the common material for flat 
 roofs in this country is pitch and coal tar, and consequently they 
 do not carry asphalt in stock. In fact, man}'' of them are under 
 the impression that asphalt, pitch and coal tar are the same thing 
 and will attempt to use the latter materials when asphalt is 
 specified. 
 
 The commercial paving asphalt comes as a solid cake in 
 barrels weighing from 500 to 550 pounds and containing, when 
 melted to a liquid, about fifty gallons. The refined asphalts come 
 also in 250-pound barrels, containing twenty-five gallons. As- 
 phalt is melted in large kettles, such as used by roofers, without 
 the addition of any oils or coal tar. Care should be taken not 
 to boil the asphalt, as its natural oils are thereby evaporated, and 
 when cooled down it will become more brittle. This mistake is 
 very likely to be made by the ordinary roofer, because asphalt 
 melts and boils at lower temperatures than pitch. The hot 
 asphalt should be applied to the surfaces with string mops to get 
 the best results, the process is slow and tedious on account of 
 the heavy consistency and its quick cooling. The surface should 
 afterward be examined and all holes and crevices pointed up 
 with asphalt. If the walls are dry and the weather warm, a gal- 
 lon of asphalt will cover about thirty square feet of ordinary brick 
 surface ; in cold weather a gallon will cover about twenty square 
 feet, or 6,000 and 4,000 square feet per ton, respectively. Where 
 the walls are very rough or constructed of rubble masonry the 
 asphalt coating will not cover much more than 3,000 square feet 
 per ton. The surfaces that are to be coated must be free from 
 frost or ice, and should be thoroughly dry to obtain the best re- 
 sults. 
 
INSULATION 109 
 
 While a good coating of asphalt on inside of wall will pre- 
 vent moisture from reaching the insulation, it does not water- 
 proof the brick wall itself. Brickwork full of moisture is a much 
 poorer insulator than when dry, and as we should get the great- 
 est insulating value possible out of the construction, it is evident 
 that the outside of the walls should also be waterproofed. There 
 are a great many preparations on the market that are being used 
 for waterproofing external walls with more or less success, but 
 as they will all oxidize and disintegrate in time, the coating has 
 to be renewed at intervals to prevent the absorption of moisture. 
 The coating may receive proper attention when applied for the 
 first time, just after the building is erected, but it is very likely 
 that necessary future coatings will be neglected or forgotten; on 
 this account it is not safe to rely upon the outside coating only, 
 the inside walls should also be waterproofed as indicated above. 
 Boiled linseed oil is often used on external walls with very 
 good results. If three coats are first given, one coat applied 
 every three to five years thereafter will be sufficient. The oil 
 does not change the color of ordinary brickwork to any extent, 
 but tends to give it a darker and richer appearance. 
 
 White or red lead, ground in boiled linseed oil, is more 
 durable than the oil alone, but it entirely changes the appearance 
 of the building and in most cases would not be permissible on 
 that account. New work should not be painted until the walls 
 have been finished two or three months, and at least three coats 
 should he given the first time. The above two preparations are 
 probably as good, if not better, than any of the patented prep- 
 arations on the market. 
 
 Cabot's Brick Preservative, made in Boston, Mass., has been 
 used in general building operations as a waterproofing quite 
 extensively, and, it is claimed, with good success. This prepara- 
 tion is made both colorless and with a red color, so as to be adapt- 
 able to any color of brick, and it is applied with a brush in the 
 same way as oil, no heat being necessary. 
 
 Mr. Stoddard, in his paper on "Insulation," previously re- 
 ferred to, describes in detail tests on the waterproofing of brick, 
 using various preparations and materials. These tests are about 
 as complete as anything that has been attempted in this line, and 
 being pertinent to the subject, are given in full, as follows: 
 
110 
 
 PRACTICAL COLD STORAGE 
 
 During the summer of 1899 a large variety of paints, oils, varnishes, 
 cements and so-called waterproof coatings were tested for a cold storage 
 company in the hope of finding some coating that would make waterproof 
 and airproof the brick walls of its warehouses. The tests were made with 
 quarter bricks with good, fair surfaces, free from large holes, and, as 
 nearly as possible, like those used in the exterior walls. Quarter bricks 
 were used instead of whole bricks, so that sensitive balances could be 
 used for the different weighings. All weighings were made to within one- 
 thousandth of a gram. The results of the more satisfactory tests are 
 tabulated below, and besides these, many other tests were made, but they 
 were either unsatisfactory or the materials tested of no value for the 
 desired use. The quarter bricks to be tested were immersed in water of a 
 temperature of about 70°. the brick being placed on its side, with one inch 
 of water over it. Weighings were made as follows : 
 
 Of the brick before coating. 
 
 Of the brick after coating. 
 
 Of the brick after immersion 24 hours. 
 
 Of the brick after immersi6n 48 hours. 
 
 Of the brick after immersion 72 hours. 
 
 Of the brick after immersion 96 hours. 
 
 Of the brick after immersion 120 hours. 
 
 At the end of each twenty-four-hour period the quarter bricks were 
 taken from the water, the outer surfaces carefully dried by cloth and 
 blotting paper, and then the bricks were immediately weighed before any 
 evaporation could take place from the pores of the brick. This was 
 repeated in most of the tests until the bricks had been immersed for a 
 period of 120 hours. After this continued immersion the bricks were taken 
 from the water and their surfaces examined in order to see what change; 
 if any, had taken place in the coating. In some cases the coating had 
 softened, in some shriveled, and in one case the coating, naphtha and a 
 paramne-like substance, which before immersion was evidently well into 
 the pores of the brick, had gradually worked out into the water. 
 
 The nature of the substances tested varied greatly. Some were in 
 the nature of paints and varnishes, and were retained mostly upon the 
 surfaces of the bricks. To this class belonged the materials used in 
 tests marked A, B, D, G, L, O, P and Q. Other substances were more in 
 the nature of a paste or coating applied upon the surface of the bricks. In 
 this class may be included the substances used in tests marked C, I, K, 
 N, R, S, T and U. Another class of substances was supposed to soak into 
 the bricks, and by filling the pores exclude moisture. To this class be- 
 longed the substances used in tests E, F and J. Other coatings consisted 
 of two substances, which, when combined, were supposed to form an 
 insoluble compound or compounds which would fill up the pores of the 
 brick. The tests of this class are marked H, M and V. 
 
 Some substances which were submitted for test could be applied to 
 the bricks only by soaking, and so were not available. Some bricks 
 offered for test were soaked full of the so-called waterproofing, and of 
 course would not absorb water or anything else while in that condition, 
 as the pores of the brick were already filled. Many resins, gums and oils 
 were tested, but were of no practical use. 
 
 Pitch, asphaltum, etc., were objectionable, because of their odor and 
 color. The results of the tests giving the most favorable results are as 
 shown in following tables : 
 
 In regard to the result of the tests it is worthy of remark that some 
 of the substances that have been considered as among the best waterproof 
 materials proved to be either of little value or very inferior to some of the 
 other substances. 
 
INSULATION 
 
 TESTS OF WATERPROOFING BRICK. 
 
 Ill 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 
 WEIGHT — GRAMS 
 
 
 INCREASE IN WEIGHT BY 
 ABSORPTION OF WATER 
 
 COMPARED TO 
 BARE BRICK 
 
 S 
 « 
 
 O 
 
 'u 
 
 « 
 
 S3 
 M 
 
 u 
 
 CO. 
 
 V 
 o 
 
 u 
 
 a 
 
 as 
 o 
 U 
 
 03 
 
 a 's 
 
 u 
 
 01 
 
 pu 
 
 O 
 
 to 
 
 1- 
 
 3 
 O 
 
 X 
 
 1-1 
 
 p 
 
 O 
 N 
 
 U 
 
 a 
 o 
 X 
 \o 
 
 U 
 
 P 
 
 o 
 
 X 
 o 
 
 N 
 
 6 
 
 £^ 
 
 ** ES 
 
 S — ffl 
 
 6 
 
 0. ^ 
 
 A 
 B 
 C 
 D 
 E 
 F 
 G 
 H 
 I 
 J 
 K 
 L 
 M 
 N 
 
 P 
 Q 
 R 
 
 630.32 
 556.71 
 578.43 
 527.80 
 616.10 
 633.80 
 584.40 
 499.52 
 504.12 
 666.94 
 607.29 
 519.68 
 652.50 
 510.20 
 570.87 
 496.20 
 502.87 
 
 639.10 
 571.11 
 581.92 
 537.70 
 637.60 
 706.87 
 588.92 
 551.00 
 523.40 
 670.07 
 610.90 
 527.34 
 692.99 
 529.10 
 586.20 
 503.00 
 515.12 
 543.60 
 602.20 
 606.31 
 581.16 
 621.85 
 
 8.78 
 
 14.40 
 
 3.49 
 
 9.90 
 
 21.50 
 
 73.07 
 
 4.52 
 
 51.48 
 
 19.28 
 
 3.13 
 
 3.61 
 
 7.69 
 
 40.49 
 
 18.90 
 
 15.33 
 
 6.80 
 
 12.25 
 
 1.39 
 2.59 
 0.60 
 1.88 
 3.49 
 
 11.53 
 0.77 
 
 10.31 
 3.82 
 0.47 
 0.59 
 1.48 
 6.21 
 3.70 
 2.69 
 1.37 
 2.44 
 
 0.30 
 
 1.39 
 
 1.15 
 
 1.00 
 
 2.10 
 
 4.75 
 
 4.88 
 
 7.30 
 
 3.73 
 
 20.33 
 
 7.00 
 
 3.76 
 
 24.78 
 
 23.10 
 
 26.98 
 
 24.85 
 
 29.08 
 
 3.72 
 
 3.10 
 
 2.35 
 
 6.46 
 
 21.15 
 
 2.18 
 
 5.55 
 12.13 
 7.48 
 9.70 
 6.33 
 21.13 
 8.60 
 5.78 
 
 28.00 
 
 30.70 
 5.00 
 5.55 
 4.69 
 9.69 
 
 29.60 
 
 1.10 
 2.16 
 3.25 
 2.88 
 7.15 
 
 12.83 
 9.68 
 
 11.30 
 
 21.63 
 9.30 
 
 27.16 
 23.80 
 28.00 
 28.75 
 31.28 
 6.15 
 7.35 
 8.07 
 12.69 
 31.02 
 
 "i'M' 
 3.49 
 4.00 
 
 11.43 
 13.30 
 12.12 
 23.13 
 
 12.68 
 
 28.71 
 
 7.15 
 9.20 
 10.21 
 15.64 
 
 1.50 
 2.89 
 5.13 
 5.10 
 9.99 
 14.13 
 14.38 
 15.32 
 15.63 
 
 21.83 
 21.72 
 28.24 
 23.72 
 28.70 
 28.72 
 32.03 
 
 1.63 
 3.11 
 1.14 
 2.84 
 5.11 
 
 13.75 
 3.23 
 
 13.36 
 6.93 
 3.94 
 4.19 
 5.66 
 
 10.53 
 8.35 
 7.71 
 7.16 
 8.85 
 
 0.24 
 0.52 
 0.89 
 0.97 
 1.62 
 2.23 
 2.46 
 3.07 
 3.10 
 3.47 
 3.59 
 4.18 
 4.33 
 4.65 
 5.03 
 5.79 
 6.37 
 •1.32 
 
 S 
 
 
 
 
 
 *1.53 
 
 T 
 
 
 
 
 
 *1.68 
 
 U 
 
 
 
 
 
 *2.69 
 
 V 
 
 
 
 32.15 
 
 
 *5.17 
 
 w 
 
 
 
 
 X 
 
 
 
 
 
 
 
 
 
 
 
 
 Y 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Brick 
 
 489.04 
 
 
 
 21.26 
 
 
 39.69 
 
 39.69 
 
 42.43 
 
 
 *8.68 
 
 
 
 
 
 * Compared to coated brick. 1 gram equals 15.43 grains; 28.35 grams equals 1 ounce avoirdupois. 
 KEY TO TESTS OF WATERPROOFING BRICK. 
 
 A. — Bay State air and waterproofing 3 coats. 
 
 B.— Red mineral paint, ground in oil 2 coats. 
 
 C. — Spar varnish with plaster of paris 2 coats. 
 
 D— Spar varnish 2 coats. 
 
 E— New York sample, No. 2 Soaked. 
 
 F. — New York sample, No. I Soaked. 
 
 G.— Shellac i coat. 
 
 H. — Portland cement, I coat; soap and alum, 3 coats. 4 coats. 
 
 I. — White enamel paint 3 coats. 
 
 J.— Paraffine in naphtha 3 coats. 
 
 K.— Hot paraffine 3 coats. 
 
 L.— Water paint 3 coats. 
 
 M. — Portland cement mixed with Ca Ci 2 , 1 coat. 
 
 Water glass, 3 coats 4 coats. 
 
 N. — Portland cement 2 coats. 
 
 O.— Black varnish, No. 2 3 coats. 
 
 P. — Spar varnish J coat. 
 
 Q.— Black varnish, No. 1 3 coats. 
 
 R. — Waterproofing, No. 1. 
 
 S— Waterproofing, No. 4. Similar to "R." 
 
 T.— Waterproofing, No. 3. Similar to "R.^ 
 
 U.— Waterproofing, No. 2. Similar to "R." 
 
 V.-^-Bi-chromate potash and glue— exposed to sunlight. 
 
112 PRACTICAL COLD STORAGE 
 
 The Sylvester process, H, soap and alum, proved to be of little 
 value, even when applied to a surface made as smooth as possible with 
 Portland cement. This process was also tried without the cement, but 
 was even less effective. Hot parafnne has often been used to waterproof 
 walls; but, under the conditions of these tests, it proved to be very far 
 from waterproof. Portland cement is another substance which did not 
 prove to be as good as its reputation. 
 
 Of all the materials tested, those used in tests A, B, C and D ren- 
 dered brick, to which they were applied, more nearly waterproof. Spar 
 varnish, used in tests C and D, was very good under test; but it is a 
 very expensive material, and will withstand exposure to the weather 
 only for a rather limited time. 
 
 The material used in B was a common mineral paint ground in oil. 
 It was very good under test; but the best authorities on paint predicted 
 for it a very short life in actual use, as it would disintegrate after a 
 short time by the oxidation of the oil. 
 
 The substance used in test A not only proved to be the best water- 
 proofing substance of any tested, but it seems to have all the qualities 
 necessary for the coating of the outside of brick walls'. It is moderate 
 in price, and is easily and quickly applied, being put on with a brush the. 
 same as a varnish or paint. When applied to a brick wall, it forms a 
 glossy, hard, transparent coating, and, instead of defacing the wall, it 
 greatly improves its appearance, making the common brick look like 
 enamel or glazed brick. The substance is a specially prepared and highly 
 oxidized oil that has been and is used in the best varnishes. As it is 
 thoroughly oxidized in its preparation, exposure to air should affect it 
 but little, and it should not need to be renewed for many years. The 
 brick walls of a number of large warehouses were coated with this sub- 
 stance one and two years ago, and the coating is apparently as good as 
 when first applied. One gallon will cover from eighty to ioo square feet 
 of surface with three coats, the first coat taking considerable oil, but 
 each successive coat taking less. A brick wall should be as dry and 
 warm as possible when the coating is applied. It should not be applied 
 to a damp wall just laid, or when the outside temperature is below 40 P. 
 This oxidized oil is known commercially as "Bay State Air and Water- 
 proofing." 
 
 If the coatings of this substance continue to wear as well in the 
 future as they have in the past two years, the substance will prove of the 
 greatest value for airproofing and waterproofing the brick walls of cold 
 storage warehouses. Any efficient waterproofing that can be applied to 
 the outside surface of a cold storage warehouse is of the greatest import- 
 ance, as there is where the entrance of moisture would best be stopped ; 
 but this outside coating should not be depended upon alone to prevent 
 the entrance of moisture into the warehouse, and there should always 
 be inner layers of some air-tight material, like an air-tight paper, with 
 the joints cemented. 
 
 If we make use of a durable insulating material of good efficiency, 
 apply it carefully and of a proper thickness, and make it air tight and 
 moisture proof, we have done all that is practical to well insulate a cold 
 storage warehouse. 
 
 A better method than using preparations will, in the opinion 
 
 of the author, be used in the future for waterproofing external 
 
 walls. This is to face them with glazed brick or salt-glazed 
 
 terra-cotta blocks, laid with thin joints or rich cement mortar. 
 
 The glazing is absolutely waterproof and would last for an in- 
 
INSULATION 113 
 
 definite time, but the present cost of glazed brick would make 
 their use almost prohibitive, as they cost from $80.00 to $100.00 
 per thousand. Glazed terra-cotta on tile in the form of hollow 
 building blocks can now be obtained, and are used as a facing 
 for outside walls in the same manner as pressed brick. In this 
 position these blocks, if properly laid, will practically prevent 
 the absorption of moisture, and would cost about the same, laid 
 in the wall, as selected common brick. 
 
 COST. 
 
 There are very little reliable data available on the cost of con- 
 structing insulation. This is owing mostly to the fact that this 
 kind of construction is comparatively new in the building trades, 
 and is usually done by the cold storage men with day labor. As 
 a rule no separate accounts of costs are kept, as it is not apparent 
 to the owners what future service such information would yield — 
 they do not expect to build any more cold storage houses. There 
 is also the variable factors of labor and material which may affect 
 each locality differently, often to the extent of 50% difference 
 in cost. This is of course true of all building operations, but 
 especially so of constructing insulation, as the work is new and 
 unfamiliar to workmen generally. All these conditions make it 
 difficult to determine the cost of any particular insulation, with- 
 out knowing exactly the conditions of each individual case. 
 
 The advantages of sufficient and properly constructed insu- 
 lation will usually appeal to the prospective cold storage man 
 until the question of cost is brought up. It is the mistaken idea 
 in general that when the building proper is finished, the greater 
 part of the investment necessary for a complete cold storage 
 house is expended. The construction of a cold storage house 
 may be divided into three general operations; first, construction 
 of the building proper; second, insulation; third, machinery or 
 cooling apparatus. The additional cost of the insulation may 
 generally be taken as one-half to two-thirds the cost of the build- 
 ing proper. 
 
 Generally speaking, the cost of insulation, erected in place, 
 for temperatures of 30 F. down to 0° F., will be from about 25 
 cents up to 50 cents per square foot, in proportion to the above 
 temperatures. The Nonpareil Cork Manufacturing Co. gives the 
 cost of the construction, shown as style No. 20 in Fig. 21, as 
 
 (8) 
 
114 PRACTICAL COLD STORAGE 
 
 about 22 cents per square foot; that shown as style No. 13 in Fig. 
 21 as about 38 cents per square foot, and that shown as style No. 
 16 in Fig. 21, as about 48 cents per square foot. A construction 
 shown in Fig. 24, with air space next to the brick wall, four 
 %-inch boards and twelve inches of shavings, will cost from 20 
 to 25 cents per square foot. A construction shown in Fig. 30, 
 with eight inches of shavings and two inches of hair felt, sheet 
 cork or mineral wool blocks, may be constructed for 25 to 28 
 cents per square foot. This construction is suitable for tem- 
 peratures of from 30° to 35" F. This construction shown in the 
 lower part of Fig. 30, which is suitable for a temperature of 
 20 to 25° F., may be constructed for 28 to 32 cents per square 
 foot. A construction of the same character suitable for tem- 
 peratures of from 5" to io° F. may be built for about 40 cents per 
 square foot. Referring to the five constructions shown in Fig. 
 28, giving the same insulating value for various thicknesses of 
 different materials, and comparing the hair felt with the air 
 space and wood board construction, there is a total thickness of 
 eight inches with the hair felt partition, and a total thickness of 
 thirteen inches with the board and air spaces ; giving a difference 
 of five inches in thickness with the same insulating value. The 
 hair felt construction would cost from 35 to 40 cents per square 
 foot, and the board and air space construction would cost 30 to 
 35 cents. 
 
 The waterproofing of the brick walls has been included in the 
 estimates given above. The cost of waterproofing wfth hot as- 
 phalt, when that product can be obtained at $40.00 per ton, will 
 be about 2)4 cents per square foot. Waterproof and odorless 
 papers cost from $2.50 to $5.00 per roll (1,000 square feet), 
 depending on the thickness and quality. 
 
 The insulating material in the form of blocks or sheets, such 
 as mineral wool block, sheet cork and hair felt, varies in cost 
 from four to six cents per square foot per one inch thick. This 
 does not include freight, which would increase the cost, depend- 
 ing on the locality. Mineral wool is sold by the pound or ton 
 and can be obtained at from $25.00 to $30.00 per ton. 
 
 The cost of planer mill shavings is variable, depending upon 
 the proximity to the mills, season of the year, etc. In some 
 cases known to the author they have been obtained for the mere 
 
INSULATION 115 
 
 trouble of hauling them away, but in most cases they are sold 
 either by the .load or by the bale. The cost per bale of 80 or 100 
 pounds varies from 15 to 25 cents. 
 
 SUPERINTENDENCE. 
 
 On account of the special character of cold storage insula- 
 tion, the work should be carefully and frequently inspected to 
 see that the materials are of the quality specified and that the 
 work is executed according to details. The construction of in- 
 sulation requires more care in the way of tight joints and first- 
 class workmanship throughout, than is usually obtained in ordi- 
 nary buildings. The labor required is mostly such as belongs to 
 carpenters, and as they are accustomed to do work along certain 
 lines common in ordinary building operations, it is sometimes 
 difficult to train them into the high class work necessary for cold 
 storage insulation. It must be constantly kept in mind that the 
 insulation must be air and water proof. The materials and the 
 combination in which they are used, no matter how excellent they 
 may be, are much decreased in insulating value if these points 
 are neglected. The materials, as they arrive at the work, should 
 be inspected to determine if they are dry, and they should be 
 kept under cover until used, to prevent them from becoming wet 
 or damp. Planing mill shavings are sometimes damp when thev 
 arrive at the work and the bales should be loosened up and spread 
 out in the building to allow them to air dry. The materials 
 .should be delivered sufficiently in advance to admit of proper in- 
 spection and of being replaced with new material, if found un- 
 satisfactory. 
 
 The superintendent should see that all filling materials, such 
 as granulated cork, mineral wool, shavings, etc., are properly 
 packed into the spaces to about the proper density. (See Mate- 
 rials.) The prevention of the future settling of the filler is 
 mainly a question of personal care in seeing that it is properly 
 packed, and all corners and tops of filled spaces, which are diffi- 
 cult to pack, will need particular attention. The waterproof 
 papers, as already stated, are used to prevent the passage of air 
 and moisture and their application, therefore, is of prime im- 
 portance. All joints should be lapped two or more inches, and 
 each course of papers should be lapped around corners and angles 
 
116 PRACTICAL COLD STORAGE 
 
 of rooms. In case the paper should be torn by the workmen, it 
 should be replaced or another sheet should be placed over it. All 
 sheathing and matched boards should be free from large or loose 
 knots, should be fitted up close in all corners and angles, and 
 nailed at bearings only. No nails should be driven through 
 boards and paper, and project into> the filled spaces or into the 
 sheet material. As a proper finish for the inside corners and 
 angles of rooms and around door jambs, the author recommends 
 and uses %-mch or %-inch quarter-round mouldings as giving 
 air-tight, neat-appearing and serviceable finish. 
 
AIR CIRCULATION 117 
 
 CHAPTER V. 
 AIR CIRCULATION. 
 
 IMPORTANCE OF PROPER AIR CIRCULATION. 
 
 A circulation of air is necessary to produce the best possible 
 conditions in a cold storage room, and this necessity is now real- 
 ized by the most progressive people engaged in the business. 
 Considerable controversy has taken place between those who 
 advocate the cooling of rooms by piping placed directly in the 
 room, and those who have adopted some form of fan or forced 
 circulation in which the pipes are placed in a coil room or entirely 
 outside the storage room, and the air distributed through the 
 room by means of air ducts. The people who have been longest 
 in the business do not like to believe that any improvement can 
 be made on placing the pipes in the room, and insist that they can 
 turn out as good stock as their more progressive competitors 
 who use some form of forced circulation. To substantiate this 
 argument, they refer to So-and-so who tried fans and had to put 
 pipes in the rooms to hold his temperature, and claim that the 
 results from the forced circulation system are no better than from 
 the old methods of gravity air circulation. This argument is 
 not sound, and it is proposed in this chapter to show clearly why 
 a circulation of air is necessary, and also why a positive circula- 
 tion, by means of fans, with a proper system of air distribution, 
 is better than direct piped rooms, or any circulating system 
 which depends on a difference of temperature in the air in differ- 
 ent parts of the room for its operation. 
 
 Notwithstanding the attention which this subject has at- 
 tracted, and the resulting discussion, there is yet much which is 
 but imperfectly understood, such as the confusing of the terms, 
 "air circulation" and "ventilation." The two are as distinct as 
 can be, and it should be borne in mind to begin with that ventila- 
 tion is what the name implies— the introducing of fresh air from 
 
118 PRACTICAL COLD STORAGE 
 
 an outside source for the purpose of purifying the room. Circu- 
 lation refers only to the movement of air within the room, and in 
 no case should the term, "ventilation," be applied to this sub- 
 ject in connection with refrigeration. Ventilation is mentioned 
 only in explaining the difference between the two, and is not 
 under consideration here, but is taken up in a separate chapter. 
 Our present subject for discussion is air circulation in refriger- 
 ated rooms — the same air over and over — and has no connection 
 with the supplying of outside air. To the end that the misunder- 
 stood features of the subject may be cleared up somewhat, the 
 history and underlying principles of refrigeration and air cooling 
 will be taken up, to show as clearly as possible the gradual devel- 
 opment of the industry leading to the systems and methods of 
 cooling now in use. The advantages of a forced circulation of 
 air in cold storage rooms will be so plainly demonstrated that 
 any thinking man must acknowledge them. 
 
 HISTORICAL. 
 
 The most primitive form of cold storage consists in employ- 
 ing the comparatively low temperature to be obtained in cellars 
 or caves for the keeping of products subject to rapid decompo- 
 sition. In this way they are protected from the extreme heat of 
 summer, and to this extent preserved by a natural source of re- 
 frigeration. In this crude form of cold storage, air circulation 
 was unknown, and if any existed it was by accident. Articles 
 placed in a cellar or cave are cooled by radiation or conduction 
 from the earth altogether, and not by a circulation of air. After 
 caves and cellars, natural ice was employed for cooling purposes, 
 and came quickly into general use, for the reason that lower 
 temperatures and a dryer air were to be obtained. For cooling 
 purposes, ice was first stored in underground pits dug in the 
 earth, with the idea that the melting of the ice would be retarded. 
 Goods for preservation were placed on or within the mass of ice. 
 This was an improvement over the use of cellars in the matter 
 of temperature only. Even after the ice house was placed above 
 ground and provided with insulated walls, the favorite method 
 was to build a room within the ice house, and surrounded on 
 three sides by the ice, for the storage of goods to be preserved. 
 Circulation of consequence did not exist, and goods placed there- 
 
AIR CIRCULATION 119 
 
 in quickly deteriorated, caused by a growth of mold and a musty 
 condition of the air, induced by a very moist atmosphere. 
 
 A bit of personal experience will serve to illustrate some of 
 the early phases of ice cold storage. About the year 1875 the 
 author's father constructed a large ice house adjoining a cheese 
 factory and creamery. In one corner of the ice house, and open- 
 ing into the creamery, was built a fair sized room for the storage 
 of butter. The ice was placed on top of this room and also 
 
 FIG. I — DIAGRAM IMPROPERLY CONSTRUCTED ICE COLD STORE. 
 
 against two of its sides. Openings were provided at the top for 
 the cold air from the ice house to come into the room, but no 
 circulation of consequence took place, because the laws governing 
 air circulation were not given proper attention. A large part of 
 the cooling in the room was by direct conduction through its 
 walls. The room carried fairly cold, at about 37° F. A large 
 block of fine creamery butter was stored in the room for about 
 three months. When removed, the tubs were very moldy, and 
 the butter as well ; the butter, even during the short time stored, 
 
120 
 
 PRACTICAL COLD STORAGE 
 
 being decidedly injured in flavor. This room was very damp, 
 the ceiling and walls showing very wet, and moldy to some ex- 
 tent. In the light of present experience, this method of storing 
 butter seems absurd, and it is mentioned simply to illustrate how 
 a lack of circulation and some means of absorbing the moisture 
 will cause bad symptoms in a cold storage room in a compara- 
 tively short time. Fig. i illustrates the construction of this room, 
 in the corner of the ice house. It will be noted that no flues were 
 provided to conduct the warm air to the top of the ice house, 
 and the cold air toward the bottom of the storage room. Open- 
 ings from the ice chamber only were provided, and this will not 
 promote a circulation of air except under accidental conditions. 
 
 Shortly after the above related experience, a large room in 
 the basement of the stone store building was fitted up for the 
 
 y' £TOf{RSC. HOOH 
 
 / 
 
 / 
 
 / / 
 
 \ 
 
 / 
 
 / 
 
 4mmm^Mmmmmmzmmmmmmmmwm , / 
 
 
 % 
 
 w/////////////////////////////////////////////////////^^^ 
 
 FIG. 2.— FULL ICE RACK WITH GOOD AIR CIRCULATION. 
 
 storage of cheese. This was built on the side icing plan, the ice 
 being placed in a rack or crib along one side of the room, which 
 was about twenty-five feet wide. The room was insulated by 
 studding and sheathing against the walls, and filling behind with 
 sawdust. It was surprising to see the ice disappear, and the 
 temperature could not be held below an average of 45 F. This 
 room was superior in one respect, however, to the butter storage 
 room just described. It had a fairly strong circulation of air 
 as long as the ice rack was kept full, and cheese came out in fair 
 condition, though moldy, after a three or four months' carry. A 
 serious drawback to the successful working of the room was that 
 when the ice was partly melted in the ice rack, the top of the room 
 would become much warmer than near the floor. This was 
 especially noticeable during warm weather. When the ice rack 
 
AIR CIRCULATION 121 
 
 was full this condition was greatly improved, but when the ice 
 was much reduced, the air at the top of the room became warm 
 and dead. Fig. 2 illustrates a full ice rack and a comparatively 
 perfect circulation of air to the top of the room. Fig. 3 shows a 
 sluggish circulation, with a dead stratum of warm air at the top 
 of the room, resulting from the small quantity, and location of 
 ice in the rack. 
 
 As a natural improvement on the side icing plan mentioned 
 above a structure two stories high was constructed, with ice at 
 the top and storage space below. The ordinary domestic refrig- 
 erators are mostly built on about this plan, and this idea has 
 been developed to the fullest possible extent. Many patents have 
 been granted to inventors for improvements in details of con- 
 
 ''fi 
 
 I 
 
 fnuaq 
 
 W\ 
 
 V 
 
 wnffM firr^/fTR or Ft If? 
 
 $TOP{RGL F(OOA{ 
 
 COLO fiTfftlTri QFRIFl \ // 
 
 t in ci^cuufTion t //. 
 
 W/////////////////////M 
 
 1 ! 
 
 FIG. 3. — SHOWING SLUGGISH AIR CIRCULATION. 
 
 struction and the promoting and control of circulation in cold 
 storage rooms with overhead ice. Fig. 4 shows why overhead 
 ice produces a good circulation, if properly designed, with up 
 and down flues. Prominent among the old overhead ice systems 
 are the Jackson, Stevens, McCray, Dexter, Nyce and Fisher. 
 These systems, as compared with any method of end or side 
 icing, are markedly superior, and many of these old houses are 
 still in service. Any system using natural ice only as a cooling 
 agent is now considered obsolete, when compared with the pres- 
 ent day methods of air cooling by means of chilled pipe surfaces 
 in the form of brine or ammonia piping, but in the early days of 
 cold storage these old systems were very satisfactory. Circula- 
 tion of air may be mentioned as the keynote of whatever success 
 was attained by the overhead ice systems. So much for the value 
 
122 
 
 PRACTICAL COLD STORAGE 
 
 of a circulation of air in any room cooled by ice. It has been 
 proved in practice that a circulation of air is necessary in such 
 
 FIG. 4. — OVERHEAD ICE "WITH GOOD AIR CIRCULATION. 
 
 a room. It is equally true of a room cooled by metal surfaces 
 through which a refrigerant at a low temperature circulates. 
 
 CIRCULATION PURIFIES THE AIR. 
 
 A penetrating and fairly strong circulation of air is absolutely 
 necessary in cold storage rooms because it is a part of the process 
 which purifies the air. Nearly all goods which are ordinarily 
 placed in cold storage for the purpose of retarding decomposition 
 give off moisture. Along with the moisture given off are impuri- 
 ties in the form of finely divided decomposed matter from the™ 
 
AIR CIRCULATION 123 
 
 surface of the goods. Gases resulting from surface decomposi- 
 tion, and the ripening of the goods in some cases, are also pres- 
 ent. Besides the moisture given off by the goods, other moisture 
 is continually finding its way into cold storage rooms by the 
 opening of the doors, leakage through the insulation, and from 
 the lungs of persons present in the rooms, all of which contains 
 a greater or less percentage of impurities. These last sources 
 are small in comparison with the amount of moisture and im- 
 purities given off by the stored goods, but, nevertheless, are quite 
 large in some cases, and worth considering. To prove beyond 
 a question that goods give off large quantities of moisture and 
 impurities, it may be well to consider what would be the result 
 should the moisture and impurities be allowed to accumulate in 
 the storage room. Let us assume an absolutely tight room, 
 cooled from an outside source without exposed pipe surfaces or 
 other means of taking up the moisture and impurities which are 
 contained in the air of the room, say a room within another room, 
 the outside room being cooled, and taking up all heat from the 
 inside room. An experiment conducted by the author, described 
 in chapter on " Eggs in Cold Storage," under the heading of 
 " Packages," illustrates fully the necessity of taking up moisture 
 as given off by the stored goods. These experiments demonstrate 
 conclusively what would result if goods were placed in a refrig- 
 erated room which did not contain means for absorbing the moist- 
 ure and impurities that are given off by the stored goods. It is 
 imperative that the moisture be continually removed from a cold 
 storage room containing moisture-giving goods. 
 
 The relation between moisture and impurities in cold storage 
 rooms is very close, as these elements are united to a large ex- 
 tent. It is a well known fact that water has a great affinity for 
 impurities of various kinds. The same is true of water in the 
 form of vapor or moisture in the air of cold storage rooms, which 
 has a great attraction for the gases and impurities which are 
 given off by the stored goods. In fact, it is probable that the 
 greater part of the impurities never part company with the mois- 
 ture when they are both exhaled by the goods. It is, then, easy 
 to understand that a room which has means of absorbing moist- 
 ure also has means of purifying the air, and that the air is puri- 
 fied to a large extent in proportion to the thoroughness with 
 
124 PRACTICAL COLD STORAGE 
 
 which it is circulated and brought in contact with the means for 
 absorbing moisture. It must not, however, be understood that 
 the air of a cold storage room is absolutely purified by having 
 the moisture removed. There are gases which have little or no 
 affinity for moisture which cannot be disposed of in this way. 
 Fresh air must be supplied to maintain perfect conditions in cold 
 storage rooms where goods are stored for long periods. (See 
 chapter on "Ventilation.") If a cold storage was perfectly puri- 
 fied by the removal of moisture there would be no odors of con- 
 sequence present in such a room. How many cold storage rooms 
 has the reader ever seen that were free from noticeable odors? 
 Probably the worst form of impurity which is met with in 
 cold storage rooms is the germs which produce a growth of 
 fungus, or mold. These germs are no doubt present in the at- 
 mospheric air everywhere. Their presence is manifested only 
 under certain favorable conditions of moisture and temperature. 
 Conditions of excessive moisture in the presence of decaying ani- 
 mal or vegetable matter, together with a moderate degree of heat, 
 are favorable for a very rapid growth of fungus. It is a well 
 known fact that in the dry mountain districts of California or 
 Colorado freshly killed meat may be hung in the open air without 
 decomposition. The air contains so little moisture that the germs 
 will not propagate. Fresh meat exposed in the same way in 
 the moist, tropical climate of Florida or Cuba would be quickly 
 decomposed so as to be unfit for food. Germs of mold and de- 
 cay flourish in a warm, moist atmosphere, but quickly succumb 
 where it is dry and cool. As the moisture is absorbed and re- 
 moved from the air of a cold storage room, with it are largely 
 removed the germs and other impurities. Low temperature 
 pipe surfaces freeze the moisture from the air, and in this way 
 a large portion of the impurities is disposed of. It may already 
 have occurred to the reader to ask what all this has to do with 
 air circulation in cold storage rooms. We have discovered that 
 a room may be cooled from an outside source and still be an un- 
 fit place for goods when no means of taking up the moisture 
 are present. Even should the pipes be placed directly in the 
 room, the results would be bad unless there is a circulation of 
 air. A circulation of air is absolutely essential to a perfect cold 
 storage room, because the air must be continually moving in con- 
 
AIR CIRCULATION 
 
 125 
 
 tact with the pipe surfaces or other means of absorbing moisture. 
 The question of what means are the best for removing the moist- 
 ure from a storage room is not under discussion. Our problem 
 is to ascertain the best means for circulating the air in contact 
 with the means for absorbing the moisture. 
 
 METHODS OF PIPING THAT HINDER CIRCULATION. 
 
 When mechanical refrigeration first came into the field, the 
 arrangement of cooling surfaces and a provision for air circu- 
 lation was neglected about as it was by the pioneers in natural 
 ice refrigeration. The cooling pipes were placed almost any- 
 where, regardless of the laws of gravity which control air circu- 
 lation. At first the ceiling of the room was a favorite place for 
 
 FIG. 5. — SHOWING CEILING PIPE WITH IMPERFECT AIR CIRCULATION. 
 
 locating the coils of pipe for cooling the room. The ceiling was 
 utilized because thus the' pipes were out of the way in piling up 
 goods, and also on the theory that "cold would naturally drop." 
 Cold, or, more accurately speaking, cold air, will naturally drop, 
 but placing the pipes on the ceiling of a room will not assist the 
 circulation; it will, in fact, produce practically no circulation at 
 all if the whole ceiling of the room is covered with pipes uni- 
 formly. Ceiling pipes have generally been abandoned for the 
 more rational method of placing the pipes on the side walls of 
 the room. Fig. 5 shows ceiling piping, and should make plain 
 why no circulation is created when the pipes cover nearly the 
 
126 PRACTICAL COLD STORAGE 
 
 whole top of the room. The left half of the diagram shows the 
 pipes covering the entire ceiling, the right half in two sections. 
 Note the arrows showing the resulting circulation in each case. 
 As is well known, cold air is heavier than warm air and, if free 
 to move, the cold air will seek a lower level than the warm air. 
 This movement of the cold air downward and the warm air up- 
 ward is what is known as gravity air circulation. A slight dif- 
 ference in the temperature will cause a circulation of air if the 
 warm and cold air are separated from each other and not al- 
 lowed to mix, which would cause counter-currents and retard 
 the circulation. In a cold storage room, the air in contact with 
 the cooling coils, as it is cooled, flows downward toward the 
 floor by reason of its greater specific gravity. The compara- 
 tively warm air above is drawn down to the pipes, where it is 
 in turn cooled, and the flow is continuous. If the entire ceiling 
 is covered with pipes, what results? The air in contact with the 
 pipes cannot fall because it cannot be replaced by warm air from 
 above. The result is that practically no circulation of air takes 
 place in such a room. A slight local circulation in the vicinity 
 of the pipes is all that results, except under unusual or accidental 
 conditions. The goods are cooled for the most part by direct 
 conduction and radiation ; the top tier of goods would be cooled 
 directly from the pipes and each tier under successively from its 
 neighbor above in the same manner. Goods are cooled by radia- 
 tion by the passage of heat from the goods directly to some colder 
 object without the heat being conveyed by the movement of the 
 air, as it should be, and as it is where a good circulation is pres- 
 ent in the room. In a room in which the goods are cooled by 
 radiation mostly, the moisture instead of being deposited entirely 
 on the cooling pipes, as it should be, is also likely to be deposited 
 on the walls or ceiling of the room, or on the goods themselves. 
 The result of such a condition may be serious. This cooling by 
 radiation, as compared with cooling by a circulation of air, may 
 seem like a very finely spun theory to some, but let the skeptic 
 watch his house for a demonstration. Is there any practical cold 
 storage man now in the business who has not noticed an accu- 
 mulation of frost or moisture on goods if they were piled too 
 near to the exposed cooling pipes? What causes this result? 
 Radiation — nothing else. 
 
AIR CIRCULATION 
 
 127 
 
 METHODS OF ASSISTING GRAVITY CIRCULATION. 
 
 The bad effects of radiation cannot be altogether overcome 
 by placing the pipes on the sides of the room, but it is counter- 
 acted to some extent by the resulting circulation of air. Fig. 6 
 shows side wall piping and the resulting circulation, which is 
 
 VA STRRTR nrWJJBM Rio y 
 
 IV 
 
 Ik 
 
 prquTH orunFfM niff 
 
 ■<\\ 
 
 ,\ 
 
 V 
 
 \\-l 
 
 / 
 
 JO 
 
 'O 
 
 \ 
 
 FIG. 6. — SHOWING SIDE WALL PIPING 
 
 i 
 
 /J 
 
 <//p 
 
 -SHOWING SIDE WALL PIPING. 
 
 confined largely to a small space near the coils. The arrows 
 show approximately the path of circulation. If the room is wide, 
 no circulation at all will take place near the center. In some 
 cases pipes have been carelessly placed two or three feet down 
 from the ceiling, as shown in the illustration. This results in the 
 air of the room becoming stratified— a warm layer of air in the 
 
 AIR CIRCULATION WITH DIRECT PIPING. 
 
 top of the room resting on a cold layer beneath. Figs. 2 and 3 
 illustrate this clearly. This may be operative to such an extent 
 as to cause a difference in temperature between floor and ceiling 
 as great as 10 ° F. A case has come to the author's notice with 
 exactly these conditions. Another bad arrangement of side wall 
 piping was that of a room more than fifty feet square piped com- 
 
128 
 
 PRACTICAL COLD STORAGE 
 
 pletely around on the side walls from floor to ceiling, with the= 
 exception of the doors. No circulation could penetrate to the 
 center of such a room, and conditions were very poor, in conse- 
 quence. 
 
 The placing of a screen in front of the side wall piping, 
 hung well up toward the ceiling of the room, as illustrated in 
 Fig. 7, marks the first scientific step toward a betterment of air 
 circulation in a room with direct piping. It prevents the action 
 of radiation, and assists the volume, velocity and area of circu- 
 lation, but does not well take care of the center of the room, 
 although the increased velocity forces the air to cover a greater 
 area and flow to a greater distance from the coils. The screen 
 or apron should be of wood or any moderately good non-con- 
 
 FIG. 8. — SAME AS FIG. 7 WITH FALSE CEILING. 
 
 ductor. By separating the warm from the cold currents of air, 
 the velocity is increased on the same principle that a fire burning 
 in a flue creates a greater draft than when burning in the open 
 air. Radiation is prevented in the same way that a fire screen 
 protects one from a too hot fire in a grate, only the radiation, as 
 already explained, is in a reverse direction. 
 
 In Fig. 8 the same arrangement of apron is shown as in 
 Fig. 7, but added thereto is the false ceiling extending out to- 
 ward the center of the room. This addition to the perpendicular 
 apron causes the air, after circulating over the coils, to spread 
 out more toward the center of the room and cover the cross- 
 sectional area much more uniformly. While it decreases the ve- 
 locity proportionately, it is considered a superior arrangement to 
 the perpendicular apron alone, placed in front of the coil. The 
 
AIR CIRCULATION 
 
 129 
 
 false ceiling should have a slant of about one foot in twenty, and 
 the opening on the outer edge near center of room need not be 
 over four or five inches in depth in most cases. Without the 
 false ceiling some space must be left for a circulation of air at 
 the top of the room; with it, the goods may be piled close up to 
 the false ceiling, so no space of consequence is wasted in using it. 
 The arrangement shown in Fig. 9 was first originated by 
 Mr. C. M. Gay, and was described in the August, 1897, issue of 
 Ice and Refrigeration-. Barring the space occupied, it is by far 
 the best arrangement of room piping now in use. The following 
 is quoted from Mr. Gay's description : "Upper pipes of box 
 coils should be about ten inches below ceiling of the room, to 
 prevent sweating. [Sweating in such a case is caused by radia- 
 
 W/ M/////////////////////////////////////////////////W 
 
 FIG. 9. — MR. GAY'S ARRANGEMENT OF ROOM PIPING. 
 
 tion, as already explained.] When brine or ammonia is turned 
 into these pipes the cold air around the pipes seeks an outlet 
 downward, and passes between the false partition and the side 
 wall of the room, thus displacing or pushing along the air in 
 center of room, the cold air naturally seeking the lowest point 
 and the warm air the highest point, each by reason of its relative 
 gravity. Thus, as the cold air falls from the cooling surfaces 
 it is replaced by the warm air from highest point in center of 
 room. This secures a natural circulation and a dry room, there 
 being no counter-currents nor tendency to precipitate moisture 
 on walls or ceiling." Mr. Gay's remarks regarding his system 
 apply with still greater force to the St. Clair system, and to a 
 greater or lesser extent to any system which provides for a re- 
 moval of the cooling pipes from the room. 
 
 (9) 
 
130 
 
 PRACTICAL COLD STORAGE 
 
 The St. Clair system, illustrated in Fig. 10, is sometimes 
 called the pipe loft system, because the cooling coils are placed 
 above the storage room in a pipe loft or coil room. This is a 
 favorite arrangement where an overhead ice cold storage house 
 is remodeled and equipped with the mechanical system. In this 
 case the pipes are placed in a portion of the old ice room, and 
 perhaps the old air ducts used for air circulation. If the storage 
 house consists of several floors of storage the pipe loft may be 
 placed at the top and the rooms below all cooled from one pipe 
 loft, but a much better method is to have an independent coil 
 room for each room, and circulate the air through separate air 
 
 ww///// / ////////// m 
 
 FIG. 10. — THE ST. CLAIR PIPE LOFT SYSTEM. 
 
 ducts. This prevents contamination from foreign odors when 
 different products are stored in different rooms. The circulation 
 is more vigorous and effective with the St. Clair system than 
 with any pipe-in-the-room system, depending on the law that 
 the higher the column of air the stronger the draft, in the same 
 manner that a tall chimney gives a stronger draft than a short 
 one. The effect of this is to produce a good circulation of air 
 with a comparatively small variation of temperature. The St. 
 Clair system is also better because by suitable trap doors on the 
 air ducts, the pipes may be shut off from the room, when the tem- 
 perature is such outside as not to require the circulating of the 
 
AIR CIRCULATION 131 
 
 refrigerant. The necessity of keeping the air of a storage room 
 from contact with the frosted pipes when the refrigerant is shut 
 off will be considered in connection with the forced or fan circu- 
 lation system, to be described further on. 
 
 ARGUMENTS FOR IMPROVED SYSTEMS OF AIR CIRCULATION. 
 
 We have seen how rooms for the storage of perishable prod- 
 ucts are cooled by natural or gravity circulation or by direct 
 radiation. Reasons have been given why each succeeding method 
 was superior to the former one. It is very easy to see that 
 where a room is cooled by direct piping, or by any system of 
 gravity air circulation, the goods within such a room cannot all 
 be exposed to the same conditions. Goods piled at the floor and 
 near coils where the air circulates direct from coils are certainly 
 exposed to a much colder air and stronger circulation than those 
 farthest from coils and near the ceiling of room. Gravity air 
 circulation, as its name indicates, depends on a difference in 
 weight, and therefore a difference in temperature of the air in 
 different parts of the room, for its existence, and there must, 
 therefore, be varying temperatures in different parts of the 
 rooms. The difference in temperature will range generally from 
 2° to 5° F.. with the best arrangements here described. The 
 greater the difference the stronger the circulation, usually. With 
 a difference in the temperature of the air in different parts of the 
 room goes a variation of other conditions ; especially as to dry- 
 ness and purity of the air. 
 
 Many cold storage warehouses, equipped in many different 
 ways, even some of them cooled by natural ice, are producing 
 results satisfactory to their owners; to use a familiar phrase, 
 "are having good results." This is not at all surprising, when it 
 is considered that a result which is satisfactory to one man would 
 not be satisfactory to another; but it is very confusing to an 
 interested person who undertakes to investigate the various cold 
 storage houses of his acquaintance, with a view to ascertaining 
 which system is best suited to his needs.. The variety of opinion 
 expressed depends largely on the individual prejudice of the 
 person giving the opinion. The investigator, if not fairly well 
 posted on the subject himself, usually is so confused that he 
 takes the advice of his most intimate acquaintance, and adopts 
 
132 PRACTICAL COLD STORAGE 
 
 some old time system which has been found reliable. This 
 means, in a majority of cases, that he is adopting some out-of- 
 date ideas for a new house, which should embody all the latest 
 improvements. Should the investigator be a fair minded man 
 and well informed on the subject, new improvements, with logic 
 and practical results behind them, are adopted, after due consid- 
 eration. Results are, of course, the final test, but it is very nec- 
 essary that a person should have actual and not fancied results, 
 and unless new ideas for improvement are investigated and 
 adopted, cold storage men will get "behind the procession," the 
 same as in other mechanical and scientific lines. When a new 
 system or device can show results equal to or better than the 
 older ones, costs no more to install and operate, and, further, is 
 based on scientific principles and common sense, that system is 
 the one to adopt. It will surely demonstrate its superiority in the 
 long run. There are many in the business who still think that 
 direct expansion piping placed directly in the room is the acme 
 of perfection and cannot be improved upon. Argument for im- 
 proved systems in such a case is useless. 
 
 A comparison of the methods of heating our best public 
 buildings in former years, with those in use at the present time, 
 will show us the past and present, or rather the past and future 
 of cooling the best cold storage houses. In years gone by, the 
 best and most costly structures were heated directly by stoves, 
 later by hot-air furnaces, and lastly by the indirect or fan sys- 
 tem. A stove for heating a room may be compared with direct 
 piping for the cooling of a storage room. We all know the dis- 
 advantages of a stove for house heating — too much direct radia- 
 tion, and a poor distribution of heat. The same may be said of 
 a room cooled by direct piping, only it is the refrigeration that 
 is poorly distributed. Cooling a room by the pipe loft system is 
 about the same as heating a room with a furnace, with the disad- 
 vantages common to both. The advantages of handling the air 
 of a cold storage room by means of a fan are likewise com- 
 parable with the advantages to be had from a well designed 
 forced system of heating. The best heating work is now done by 
 means of fans, and the best cold storage work of the future will 
 be done by means of fans. To prove the advantages of the fan 
 system of heating, it is not necessary that people should suffocate 
 
AIR CIRCULATION 133 
 
 and die in a building heated by stoves or furnaces; neither is 
 the fact that goods do not completely spoil or decay rapidly in a 
 room cooled by direct piping any evidence that the fan or forced 
 circulation system is not superior by far to the pipe-in-the-room 
 or any gravity method. Unquestionably the fan system of heat- 
 ing gives a control of temperature, humidity and purity of air, 
 not obtained in any other way. The forced circulation system of 
 cooling also gives a control of temperature, humidity and purity 
 of air in a cold storage room, not to be had otherwise. 
 
 PROS- AND CONS OF FORCED CIRCULATION. 
 
 The chief, and in fact the only objection known to have been 
 urged against forced circulation for cold storage rooms is a 
 fancied notion that it will lead to a greater drying out or shrink- 
 age in weight of goods which are placed in storage for preserva- 
 tion than if a system of gravity air circulation or pipes in the 
 rooms were used. The author has searched long and faithfully 
 for the origin of this old tradition, but has never been able to 
 discover that it was founded on fact. At least none of the most 
 modern houses employing the fan system, so far as known, have 
 ever had complaints from excessive evaporation. The worst 
 shrunken goods which ever came to the writer's notice were some 
 eggs from a house cooled by direct expansion piping placed 
 directly in the room. It is probable that the claim that goods 
 evaporate or lose weight more in a room cooled by the fan sys- 
 tem is wholly a matter of theory, based, no doubt, on the assump- 
 tion that the air is circulated at a much higher velocity. It is 
 well known that a movement of the air aids evaporation. Every 
 intelligent housewife knows that linen hung in the open air to 
 dry will be freed of moisture quicker when a moderately strong 
 breeze is blowing than when the air is still. The same principle 
 applies to the goods stored in a refrigerated room, but evapora- 
 tion from the goods in storage is dependent not only on the 
 movement of air in the room, but on the humidity or dryness as 
 well. If the humidity is properly regulated no harm will result 
 from a very thorough circulation of air, even at a brisk speed. 
 It may have happened in the early days of fan circulation, that 
 the air was rapidly circulated with little or no distribution, and 
 the goods exposed directly to the blast of air where it was blown 
 
134 PRACTICAL COLD STORAGE 
 
 into the room were excessively evaporated; but in the numerous 
 houses designed by the author, and using one or the other of the 
 two systems of air circulation described further on, no such 
 trouble has been experienced. If the humidity of the air is at 
 the correct point, and the circulation of air well distributed 
 throughout the room, and not too strong, no excessive or dam- 
 aging evaporation will occur, and where trouble from this cause 
 has been experienced it will be found in every case that no sys- 
 tematic control of humidity has been attempted. It is as easy to 
 control humidity as it is to control temperature, if proper means 
 are provided, and we go about it in the right way. Absorbents 
 and ventilation are both useful for this purpose, but this feature 
 of cold storage is not under consideration here, and is treated 
 on elsewhere under the proper heading. 
 
 With a positive and well distributed circulation of air, a 
 storage room may be maintained at a humidity which would be 
 dangerous if only a sluggish gravity circulation of air were in 
 operation. A brisk movement of air in all parts of the room 
 quickly removes the moisture and impurities from the vicinity 
 of the goods, and carries them to the cooling coils, where they 
 are, for the most part, condensed or frozen on the pipe surfaces. 
 This should explain how goods may be carried in good condition 
 and with very little shrinkage in a room where a well designed 
 system of forced circulation is employed. Two of the houses 
 designed by the author are used exclusively for the storage of 
 cheese. It is well known that cheese loses weight very rapidly 
 in cold storage, and the problem heretofore has been to carry 
 the cheese reasonably free from mold, and with as little evap- 
 oration as possible. Cheese has been stored in the houses re- 
 ferred to for three months, with very little mold, and with no 
 shrinkage from marked weights, and the proprietors assert that 
 there is less shrinkage, even on "long-carry" goods, than there 
 was with the overhead ice system which they formerly had in 
 service. This is a sufficient proof of the value of forced circula- 
 tion for the cold storage of cheese. The same applies equally to 
 other classes of goods. With a room equipped with any of the 
 gravity systems of air circulation, already described, the circu- 
 lation of air cannot be regulated, because it depends on the tem- 
 perature of the refrigerant (generally brine or ammonia) circu- 
 
AIR CIRCULATION 135 
 
 lating through the pipe coils. As the temperature of the refrig- 
 erant is regulated to suit outside weather conditions (lower in 
 warm weather, and higher in cold weather), the velocity of air cir- 
 culation is not constant, being least in the cold weather of fall and 
 winter, when most needed. With a good system of forced circu- 
 lation installed, the chief problem of the cold storage man is to 
 employ a proper degree of humidity. (See chapter on "Hu- 
 midity.") Our discussion now brings us to a consideration of 
 the various methods of mechanical air circulation in use. The 
 weak as well as the strong points of the various systems which 
 have been put in operation will be considered, regardless of where 
 or by whom originated. 
 
 UNDESIRABLE FORCED CIRCULATION. 
 
 The simplest, and probably the most unscientific, form of 
 mechanical air circulation in cold storage rooms is the small elec- 
 tric fan. These fans are usually of the four or six-bladed disk 
 type, of from twelve to eighteen inches in diameter, attached 
 directly to the shaft of a % or j4-horse power electric motor. 
 The electric current for operating is usually obtained from the 
 socket for an incandescent electric lamp. Electric fans are usu- 
 ally placed on the floor in the end of an alleyway, or in an open- 
 ing in the piled goods, and are used for creating a flow of air 
 from one extremity of the room toward the other. If the circu- 
 lation is strong enough, these fans tend to create a uniform tem- 
 perature in the room; but, as the air from the fan will follow a 
 path of least resistance, the circulation resulting from their use 
 is largely confined to the alleyways and openings in the piles of 
 stored goods — it does not penetrate through and behind the 
 goods where it would be most useful. The use of this type of 
 fan in cold storage rooms is of doubtful utility, and is liable at 
 times to lead to a positive, harm by causing a condensation of 
 moisture on the goods in storage, as a result of the warm upper 
 stratum of air coming in contact with the cold goods near the 
 floor of the room. In some cases electric fans have been used to 
 propel the air from the cooling pipes, for which purpose they 
 are placed in an opening in a screen or mantle covering the pipes, 
 forcing the cooled air outwardly into the room. This is a first 
 step toward scientific forced circulation, and is useful as far as 
 it goes. In many cases the electric fan is useful only as a "talk- 
 
136 PRACTICAL COLD STORAGE 
 
 ing point," as it is likely to impress a person, who is not familiar 
 with cold storage work, with the cooling power of the refrig- 
 erating apparatus, to stand for a few seconds in the breeze cre- 
 ated by one of these high-speed fans. Their use has been adopted 
 to an extent not at all warranted by the results to be obtained, 
 and they will no doubt be gradually discontinued as the fallacy 
 of the idea becomes apparent. Those who use electric fans as 
 above described, by so doing admit the superiority of forced cir- 
 culation over the gravity system, and also admit that their rooms 
 are in bad condition, and that some mechanical means of agitat- 
 ing or circulating the air is necessary. Instead of such a poor 
 makeshift it seems that they will eventually come to the idea of 
 installing a scientific system of forced circulation. 
 
 Having proved a circulation necessary, it is evident that a 
 method which will cause the circulation to be continuous, and 
 at the same velocity, regardless of outside weather conditions, 
 etc., must be better than depending on natural circulation, which 
 varies greatly with the varying conditions and appliances which 
 produce circulation as we have already seen. It follows further, 
 then, that the system which will produce a circulation which is 
 continuous, and at the same velocity, and besides is uniformly 
 distributed to all parts of the room, must be the most nearly 
 perfect way of handling the air for cold storage rooms. Any of 
 the methods of gravity air circulation in which the pipes are 
 placed in the room or otherwise, as shown in Figs. 5 to 10, are 
 dependent on the outside weather conditions, temperature of 
 room, temperature of refrigerant in pipes, length of time goods 
 have been in storage, etc., for their operation. A continuous and 
 uniform air circulation can only be obtained by the adoption of 
 some mechanical means, and is usually secured by the use of a 
 fan of some kind. 
 
 VARIOUS FORMS OF FORCED CIRCULATION. 
 
 So far as known to the writer, the systems of forced circula- 
 tion here described include all of the recognized equipments 
 which have been installed in one or more prominent houses. The 
 patent records show a large number of crude developments which 
 have in most instances been abandoned without having been put 
 into practical use. A system which has been installed in several 
 
AIR CIRCULATION 137 
 
 large houses in the United States, and to some extent abroad, 
 is what may be termed a primitive form of forced circulation. 
 This term fully expresses just what the system is, as no method 
 could be applied in a more crude way. It consists simply in 
 placing the refrigerating pipes outside the storage room, and 
 using a fan to propel the air to and from the room. Fig. II 
 shows a floor plan of a room so equipped. The air is forced into 
 the room at each end, and the return air to coil room drawn out 
 in the center as shown. Cold air in this connection is spoken of as 
 being the air from coil room to storage room, and warm air is 
 mentioned as the air from storage room to coil room. These 
 terms are used relatively only, and will be employed in the de- 
 scriptions contained in this article. It should be understood that 
 
 ^// /////////////////////////////////^^^^ 
 
 1 
 
 '/A \ - 
 
 m \cOLDX„DUCT nOClRCULKTIon OtRin\<>n THIS SIDE. COUXOTPIct! 
 
 1 ! 
 
 I 
 
 
 I 
 
 » ! ; \PETunn mrquct | yC 
 
 
 FIG. II. — PRIMITIVE FORM OF FORCED CIRCULATION. 
 
 in actual practice the difference in temperature between the in- 
 coming and outgoing air is very small. In a well designed sys- 
 tem this need not be over two or three degrees at the most. The 
 cold air inlets at ends of room are in some cases placed near the 
 floor and in others near the ceiling, but further than this no distri- 
 bution of air is attempted other than that resulting from the loca- 
 tion of the inlet and outlet. Sometimes the ducts are arranged 
 to force the air into the room at the center, and the return air to 
 the coil room is taken out at the ends, or the cold air is allowed 
 to flow from the several openings in a duct running across the 
 center of the room, but no adequate distribution results from this 
 method. 
 
138 
 
 PRACTICAL COLD STORAGE 
 
 Employing the forced circulation system in this way is very 
 much like the indirect systems of steam heating as at first in- 
 stalled. It is noticeable now that the best steam heating work 
 provides a thorough distribution of the heated air throughout 
 the apartments through a great many small openings rather than 
 forcing a large volume of air into the room at one or two places. 
 It needs no argument or demonstration to show that a room heated 
 or cooled by air forced in at one or two openings must have 
 varying degrees of temperature, humidity and, circulation de- 
 pending on the remoteness or proximity to the direct flow 
 
 / ^- i + i j„ * j -' //. 
 
 
 COIL ROOM 
 
 TflLSE CEtLinG 
 
 y 
 
 1 
 1 
 
 WMM/m!i7Am77m^m7mm77m77m7mmmmmmm7Mmm^m. 
 
 FIG. 12. — A SYSTEM OF FORCED AIR CIRCULATION. 
 
 of air from inlet to outlet, for the reason that the air from inlet 
 always seeks the most direct path to the outlet and moves through 
 the area of least resistance, usually through the center 
 alley of room. This is a positive fact and not a theory. 
 The author once visited a large room of the kind above de- 
 scribed, and despite the manager's statement that he had tested 
 in every known way and found conditions absolutely uniform, 
 the author for himself saw a temperature variation of two de- 
 grees, and this between two thermometers hung in the center 
 alley of room at the same height from floor, and without any 
 extraordinary conditions to cause such a variation. As a matter 
 of fact the real difference in temperature in this room between 
 the coldest and warmest point could not have been less than 
 five or six degrees. 
 
AIR CIRCULATION 
 
 139 
 
 The longitudinal section of a room shown in Fig. 12 illus- 
 trates a system of forced air circulation which has been installed 
 to a moderate extent, but has not become as well established as 
 the one first described. A false ceiling is provided for distributing 
 the cold air from cooling coils at the top of the room, but as with 
 the system just described, no collecting ducts are provided for 
 the purpose of uniformly removing the air from the room. The 
 air from coil room comes into the room through narrow, slit-like 
 openings in the false ceiling, and is returned to the cooling coils 
 through and by the disk fan located in the partition between coil 
 room and storage room. It would seem that this is working 
 
 ■///w/////////n//i///////////////]////////////////iini///////i///t/////////////. 
 
 ■ZTVRn ft/R QIJCT 
 
 FIG. 13. — COLLECTING AND DISTRIBUTING AIR DUCTS. 
 
 counter to the natural laws of gravitation, although it may be 
 looked at in another light also. It is often remarked that "cold 
 will naturally drop," but this should not confuse us when study- 
 ing the means for promoting circulation. If the cold air is ad- 
 mitted to the room at the top, it will of course fall to the 
 floor if allowed to do so; but why admit the cold air at the 
 top of the room if it is wanted at the floor? In a room 
 fitted with direct piping the cold air does not drop through 
 the goods in storage, but down over the cooling coils, and rises 
 through the goods in storage as it is warmed. It would seem, 
 then, that any method of distributing the cold air at the top of 
 the room is wrong in principle, especially as no means of uni- 
 formly drawing off the air at the bottom of the room is provided. 
 
140 
 
 PRACTICAL COLD STORAGE 
 
 When warm goods are placed in a room equipped in this way, 
 the moisture given off as the goods are cooled must be very liable 
 to collect on the cold false ceiling. To provide uniform tem- 
 peratures and humidity with this system it is necessary to pro- 
 vide a strong blast of air, which is to be avoided, as goods 
 directly in front of the fan may be exposed to too great a drying- 
 influence. 
 
 The arrangement of collecting and distributing air ducts 
 shown in the cross section of room, Fig. 13, has been installed 
 in a number of houses in America, and, like some of the others, 
 depends on the "cold will naturally drop" theory for its operation. 
 
 >I MM////////////////////////////////////////////M 
 
 COLO UlR DUCT 
 
 B 
 
 
 /I 
 
 y / 
 
 / 
 
 j 
 
 FIG. 14. — SMALL ROOM WITH TWO DUCTS. 
 
 The arrows show the natural tendency of the air circulation 
 from the cold air ducts on the sides of the room to the warm air 
 collecting duct in the center. In some cases the cold air is dis- 
 tributed in the center and collected at the sides of the room, and 
 where the room is narrow only two ducts are used, as in Fig. 14, 
 a cold air distributing duct on one side of the room and a warm 
 air collecting duct on the opposite side. In every case the ducts 
 are placed at the ceiling, on the theory that the air from cold 
 air duct will drop and distribute itself along the floor before 
 being drawn back to the coil room through the return duct. The 
 openings provided in the air ducts of this system are usually 
 square openings, fitted with sliding gates to regulate the flow of 
 air into the room and its return to cooler. These gates are placed 
 
AIR CIRCULATION 
 
 141 
 
 five or six feet apart, consequently a good distribution of air is 
 not provided, and goods exposed to the rapid flow of air directly 
 in front of the openings will get a much greater volume of circu- 
 lation than is to be found in any other part of the room. When 
 a room of this kind is filled with goods, preventing the air from 
 falling from the cold air duct to the floor, no circulation 
 of consequence will be obtained near the floor, for the reason 
 that air will travel through path of least resistance, almost di- 
 rectly from feeder duct to return duct, about as shown by the 
 arrows. 
 
 A method somewhat similar to the one just described is that 
 in which the cold air distributing ducts are placed at the floor and 
 
 y///////// ////////////////////y 
 
 FIG. IS- — ARRANGEMENT OF WARM AND COLD AIR DUCTS. 
 
 the warm air return duct is placed at the ceiling, as represented 
 by the cross sections of rooms, Figs. 15 and 16. In narrow 
 rooms only one distributing duct is used, as shown in Fig. 16. 
 In wider rooms two distributing ducts on opposite sides of the 
 room at the floor are used, and one collecting duct at ceiling in 
 center of room. This arrangement has the merit of operating 
 according to the laws of gravity, but still lacks the thorough dis- 
 tribution of cold air and collection of warm air, as shown in the 
 system described further on. It is, however, considerable of an 
 improvement on any of the preceding methods, and the author 
 has demonstrated in actual service that it will produce fairly 
 
142 
 
 PRACTICAL COLD STORAGE 
 
 uniform circulation and temperatures with a comparatively gentle 
 flow of air. This system is to be recommended for goods which 
 
 // //////mw//w////rriini/m//////mf//ff////// fr. 
 
 /A ^^r DUCT """"/"" * " 'A 
 
 /J, ycouD r;r duct- y. 
 
 FIG. l6. — ARRANGEMENT OF WARM AND COLD AIR DUCTS. 
 
 do not give off much moisture. It is preferable to use numerous 
 small holes rather than a few large openings in the supply and 
 return ducts. 
 
 COOPER SYSTEMS OF AIR CIRCULATION. 
 
 The system shown in the cross section of room (Fig. 17) 
 was developed by the author after some experiment and has since 
 been improved by two successive steps, the details of which will 
 be described. It was the old trouble of sluggish circulation, 
 especially during the fall and winter, which impelled the author 
 to experiment for its betterment. As an improvement over the 
 small electric fan already mentioned, an exhaust fan was fitted 
 up to take air from the cooling apparatus and deliver it to the 
 rear end of the room through a perforated duct. The air was 
 allowed to find its way back to the coils as best it could. 
 
 This method was applied to a long narrow room, and cer- 
 tainly was a decided improvement over the sluggish natural 
 circulation which it superseded. Following this, the perforated 
 false ceiling was applied, with distributing cold air ducts on the 
 walls, as shown in Fig. 17. The cold air from coil room was 
 forced into the side ducts and flowed into the room through a 
 great number of small holes in the top, bottom and sides of the 
 
AIR CIRCULATION 143 
 
 cold air ducts. The warm air from the room flowed upward 
 through the small perforations in the false ceiling and through 
 the space between the ceiling of the room and false ceiling and 
 thence to the coil room, where the air was cooled, and caused to 
 repeat the same circuit continuously. The first apparatus was 
 clumsy and the proportions of the various parts not correct, but 
 the efficacy of a forced circulation of air, and a thorough dis- 
 tribution and collection of the incoming and outgoing air of a 
 cold storage room so plainly proven, that a further development 
 of the idea was undertaken. 
 
 It was demonstrated by above described experiments that 
 a compafatively small amount of air, well distributed and uni- 
 
 ^7nmimrm7rrrTnnn/m/uff//fa^/r///u////m/fim/f/i/////f/fum 
 
 
 //. T 7" ri 
 '' > i i // 
 
 FIG. 17. — COOPER'S FIRST SYSTEM OF AIR CIRCULATION. 
 
 formly drawn off at the top of the room after flowing upward 
 through the goods in storage, would produce very uniform con- 
 ditions throughout the entire area of the room. Following up 
 this information, the apparatus was reduced to a more practical 
 form by substituting one broad duct near the floor, as in Fig. 18, 
 for distributing the cold air, in place of the two distributing ducts 
 as used in the apparatus shown in Fig. 17. The top duct of the 
 two did not accomplish any result of consequence, and was con- 
 sidered objectionable, as the air passing from this duct to the 
 false ceiling did not percolate through the goods to any con- 
 siderable extent, -and resulted, practically, in a loss of the work 
 done by the air flowing from the top duct. Two ducts also made 
 the apparatus more complicated. Using the broad single dis- 
 
144 
 
 PRACTICAL COLD STORAGE 
 
 tributing duct near the floor in combination with the false ceiling 
 resulted in a very penetrating and uniform circulation of air, and in 
 practical service it has been found to produce superior results. No 
 practical objections have been urged against it. As shown by 
 the arrows, the air is caused to cover very uniformly the entire 
 cross-sectional area of the room. This was accomplished by 
 perforating the distributing ducts with small holes, and so pro- 
 portioning them that a larger part of the flow of air is from the 
 bottom of the ducts. The ducts are also perforated to some extent 
 on sides and top. By piling the goods a few inches off the floor 
 the air from bottom of ducts flows under the goods and out to 
 
 '/ /MmmJm^mmmMMMULmmMMm/Mmmzzm^mmma , 
 
 fig. 18. — cooper's improved system of air circulation. 
 
 center of room. This action is also assisted.by having the greater 
 number of the perforations in false ceiling in the middle third or 
 quarter of the room, so as to draw the air out from sides of room. 
 As indicated by the arrows, the air moves up from the distribut- 
 ing duct, is drawn into space above false ceiling, and returned 
 to coil room to be cooled. 
 
 The system described in the foregoing paragraph is nearly 
 theoretically perfect so far as a uniform circulation of air is 
 concerned, and a more thorough method than any of its prede- 
 cessors, but it still remained to design the perforated false floor 
 and false ceiling combination (Fig. 19) to produce a system which 
 
AIR CIRCULATION ]45 
 
 cannot be improved upon theoretically. Not only is the system 
 theoretically perfect, but its practical application is so simple as 
 to be unobjectionable. As shown clearly by the sketch, the flow 
 of air is directly upward from floor to ceiling, consequently all 
 goods piled in such a room are exposed to exactly the same con- 
 ditions as to circulation, temperature, humidity and purity of 
 the air. In a room equipped with this system, with the parts 
 correctly proportioned, it is entirely safe to pile goods closely, 
 only allowing a fraction of an inch between the packages and 
 at sides of room and placing thin strips beneath the goods to 
 allow air to flow from perforations in false floor. Where, in 
 rooms fitted with direct piping and some of the fan systems as 
 
 i/////////mm/m uu/m//l/nmiuiiiu//m/minmm/imiiiimiiniiiimmuii////ta 
 
 FIG. 10,. — COOPER'S LATEST IMPROVED SYSTEM OF AIR CIRCULATION. 
 
 well, a large space must be left at floor and ceiling for a circu- 
 lation of air, with this system goods may be piled close up to 
 ceiling leaving only half an inch for the air to flow into per- 
 forations in false ceilings. As the space occupied in height by 
 false floor and the space underneath is, in most cases, only one and 
 three-fourths inches and that occupied by false ceiling only one 
 and one-fourth inches, it is apparent that much space will be saved 
 by using this system. After a room is filled with goods and cooled 
 down to the correct carrying temperature, no difference in tem- 
 perature can be noticed in different parts of the room. No blast 
 of air can be felt in any place, a gentle flow from perforations 
 only is noticeable, therefore no particular place has more circu- 
 lation than another to cause a drying out of the goods. The 
 
 (10) 
 
146 PRACTICAL COLD STORAGE 
 
 advantages of this system over any of the others may be summed 
 up as follows : 
 
 1. A more equal distribution of air, especially when the 
 room is filled with goods. Goods in center of room are exposed 
 to the same temperature, circulation, etc., as those at sides. 
 
 2. Saving in space, as it allows the room to be filled full 
 of goods without leaving large spaces at top and bottom for a 
 circulation of air. 
 
 3. Where the air is so perfectly distributed and collected 
 it is not necessary to circulate such a large volume, saving in 
 power and lessening the liability of evaporation of goods. 
 
 The objections which have been offered are of no practical 
 consequence. The first one usually mentioned by an inquirer 
 is that the space under false floor is likely to collect litter and 
 become foul. The author admits that this apparent objection 
 for some time kept him from introducing this system to prac- 
 tical service, but when once tried, this was found of no conse- 
 quence, as the false floor is made in sections, easily handled, and 
 it is as easy to raise these and sweep underneath as to remove the 
 2x4s or 4x4s generally used to pile goods on. Another ob- 
 jection is the supposedly high initial expense. A contract was 
 awarded for the construction of this system for a fair sized house, 
 in which the cost for air circulating system, including fans and 
 motors, did not exceed $20 per 1,000 cubic feet. It will be seen 
 that the cost is of very small importance as compared with the 
 practical results obtained and the savings in space effected. Those 
 who are skeptical about the advantages of forced circulation, 
 and of this system in particular, are invited to visit some of the 
 plants designed by the author. 
 
 The objections against forced circulation are largely fanciful 
 and are not substantiated when investigated. The idea that goods 
 dry out or evaporate rapidly in a room so equipped, has never 
 been even suggested by the author's experience,' and this objec- 
 tion may be dropped without further comment, as this ground 
 has been thrashed over before. It is thought by many that a 
 forced circulation system is unnecessary, expensive to install and 
 costly to keep in operation. It may be admitted that forced cir- 
 culation is unnecessary in the same sense that refrigeration was 
 unnecessary fifty years ago. People are getting along without 
 
AIR CIRCULATION 147 
 
 it because they donot know or understand its advantages. Many 
 other applications of machinery are not absolutely necessary, but 
 are used for the improved results obtained. If properly designed, 
 the cost of equipping a house with an improved system of forced 
 ■circulation need not be much greater than with direct piped rooms, 
 for the reason, mainly, that only half or two-thirds as much piping 
 is needed, and because of the saving in main pipes by locating the 
 ■cooling coils centrally and blowing the air to and from the room 
 with a fan. As to cost of power for operating, this is very small, 
 if using the fans specially designed by the author for this pur- 
 pose. (Fans for use with air circulating systems should be of 
 special construction. This is considered under the chapter on 
 ■"Ventilation.") It is customary to install a half horse power 
 motor for handling the air in a room of 15,000 cubic feet. The 
 actual power necessary is from one-quarter to three-eighths of a 
 horse power. As an offset to the cost of operating the fan may 
 be placed the great saving in space gained by the use of the fan 
 system. In no case is this less than 5 per cent of the space re- 
 frigerated, and sometimes will amount to over 10 per cent. Even 
 if all the objections urged against the system were true, this alone 
 is enough to compensate and more besides. When from 5 to 10 
 per cent may be added to the earning capacity of a storage house 
 without additional cost of operation it means a big increase in the 
 -net profit of the business. 
 
 Not the least of the advantages of the forced circulation 
 system is, that during cold weather when the ammonia or brine 
 is shut off from circulating through the pipes, their frosted 
 ■surfaces are not exposed in the storage room. It is comparatively 
 ■easy to clean the pipes, as they are more accessible than they are 
 in any of the direct piping systems. A still greater advantage 
 may be gained .by using a process invented by the author, which 
 •consists in placing chloride of calcium above the pipes, so that 
 the brine resulting from a union of the moisture in the air with 
 the calcium will drip down over the pipes. (See chapter on 
 " Uses of Chloride of Calcium.") This prevents the formation 
 of frost on the pipes at all times, and during cold weather, 
 when the refrigerant is shut off, by keeping up the supply 
 of calcium, the moisture and purity of the air are under perfect 
 control. 
 
148 PRACTICAL COLD STORAGE 
 
 That the tendency is toward the adoption of forced circu- 
 lation for the best new work cannot be doubted, even by those 
 who do not advocate these systems. It cannot be expected that 
 they will come into use all at once, but the writer feels justified 
 in predicting that ultimately more than half the high grade in- 
 stallations will be done under these systems. The present oppo- 
 sition comes largely from the "old line" people in the business 
 who do not like to see changes and improvements made on 
 methods with which they have "had good results" for so many 
 years. 
 
VENTILATION 14 < 
 
 CHAPTER VI. 
 VENTILATION. 
 
 NECESSITY FOR VENTILATION OF COLD STORES. 
 
 In discussing humidity and circulation, it has been explained 
 how a large portion of the gases of decomposition and impurities 
 of various kinds, which are incident to the presence of perish- 
 able products in cold storage, are carried by the moisture existing 
 in the air, arid that when this moisture is frozen on the cooling 
 pipes, or absorbed by chemicals, the foul matter is largely ren- 
 dered harmless. It may now be noted further that even with a 
 good circulation and ample moisture-absorbing capacity, there 
 will still be some impurities and gases, detrimental to the welfare 
 of the stored goods, which have little or no affinity for the water 
 vapor in the air, and consequently accumulate in the storage 
 room. Ventilation is necessary to rid a refrigerator room of these 
 permanent gases. 
 
 This subject of ventilation for refrigerator rooms has been 
 very much talked of, but about which really little is known, so 
 far as any practical information is concerned. Some of the more 
 progressive cold storage managers have given some attention to 
 this part of the business, but many of the largest and best known 
 houses do not ventilate their rooms at all, except perhaps during 
 the winter or spring, when rooms are aired out for the purpose 
 of whitewashing. In some cases the change of air incident to 
 opening and closing of doors, when goods are placed in storage 
 or removed therefrom, is relied on to supply ventilation. This is 
 quite inefficient, because goods are mostly stored during two or 
 three months, and removed from storage likewise, leaving several 
 months when no fresh air of consequence can penetrate to the 
 room, except as the doors may be opened for the purpose of 
 taking the temperature of the room. Furthermore, this kind 
 of ventilation during the warm weather of summer and during 
 
150 PRACTICAL COLD STORAGE 
 
 a large part of the spring and autumn months is worse than no 
 ventilation at all. Some storage men even take so radical a posi- 
 tion on this matter of opening doors during warm weather, as to 
 insist that the door shall not be opened for the purpose of read- 
 ing the thermometer. A double window is placed in the door of 
 each room, with the thermometer hanging so that it can be read 
 from the outside without opening the door. While the author 
 has not practiced this method, it seems to be a good idea, and it is 
 certainly preferable to ventilating the room through doors which 
 open to the outside air. When doors into rooms open into a cor- 
 ridor, the evil is partly prevented, but opening the door or win- 
 dow of a storage room directly to the outside air when the tem- 
 perature outside is materially higher will always result in more 
 or less bad effect on the goods, because of the water vapor in the 
 warmer incoming air being condensed on the stored goods. 
 
 Another source of ventilation similar in its results to the 
 opening of a door or window is that resulting from the leakage 
 of air directly into the storage room, through the pores and 
 crevices in the walls, around the doors and windows, etc. — leak- 
 age of air literally — air that gets in when everything is supposed 
 to be closed. The amount is usually imperceptible, but is enough 
 in some houses to be a serious detriment to the quality of work 
 done. In small houses with large outside exposure and poor in- 
 sulation this air leakage is considerable, but in the big refrig- 
 erators of several hundred thousand cubic feet capacity, and with 
 thorough insulation, it is reduced to practically nothing. The 
 loss of refrigeration caused by air leakage, while of some im- 
 portance, is of small moment beside the bad effects resulting from 
 the moisture and impurities brought in by the warm air from the 
 outside. The value of prime, tight insulation, as a conserver 
 of refrigeration, aside from a matter of keeping out the warm, 
 moist air, is discussed in the chapter on "Insulation," but a word 
 about windows and doors is properly in line with the present 
 discussion. , 
 
 WINDOWS AND DOORS. 
 
 Rather than consider what might be a good way of placing 
 windows in a cold storage building, their use should be dis- 
 couraged. Even with four or five separate glass, divided by air 
 
VENTILATION 151 
 
 spaces, and with all joints set in white lead, the loss of refrig- 
 eration is large. It is also very difficult to fit insulation around 
 the window frame so as to make a good job; and even if a pass- 
 able job were practicable, the expense of putting in windows is 
 sufficient to condemn their use. The increased fire exposure is of 
 some consequence, too, and with the low cost of electric light, 
 windows should not be thought of for cold storage work. Barring 
 the small amount of heat given off, the incandescent electric lamp 
 is an ideal device for lighting cold storage rooms, as the air is 
 not vitiated by gases and odors as is the case when using gas, 
 kerosene or candles. 
 
 Doors which will shut tight, forming a nearly perfect air 
 seal, with a small amount of pressure, have long been wanted for 
 cold storage rooms. Most of the ordinary bevel doors, either 
 with or without packing on the bevel, will not shut even ap- 
 proximately tight; and in operation nine out of every ten stick 
 and refuse to open except after many persuasive kicks and 
 surges — we all know how it is. The special cold storage doors on 
 the market, the author believes to be far above anything else 
 in this line, and does not hestitate to recommend them to those 
 wanting a door which will prevent air leakage. The prices are 
 very reasonable, considering the excellent material and fine work 
 put into their construction. The slight additional cost over the 
 common door will be quickly saved, by reason of their quick 
 action — opening quickly when the fastener is worked. If a door 
 is built on the job, the chief idea to be considered in its construc- 
 tion is to build a door which is tight at one point all around. It 
 is absolutely impossible to make a door fit on a' long bevel, but 
 the effort is very frequently made. 
 
 AIR LEAKAGE. 
 
 Having presented the subject of air leakage, we may as well 
 ask how it is caused and why it must be guarded against. It is 
 amenable to the same law as gravity air circulation, which was 
 explained quite thoroughly in the first part of the chapter on 
 " Air Circulation." When the outside air is very much warmer 
 than that of the storage room, the air in the storage room pro- 
 duces a pressure on the floor and lower part of the room, by 
 reason of its greater weight, and consequently it seeks to escape 
 
152 PRACTICAL COLD STORAGE 
 
 there. If there are openings near the floor where the air can 
 flow out, and others at the ceiling or upper part of the room, the 
 air will flow in at the top and out at the bottom of the room. 
 Reverse the conditions of temperature, and the direction of flow 
 of air is also reversed. That is, when the air outside is colder than 
 the air of the room, the cold air will flow into the room at the 
 bottom and the comparatively warm air of the room out at the 
 top. This action is nicely illustrated by noting the air currents 
 in a door which is opened into a cold room when the temperature 
 is very warm outside. The warm air rushes in at the top of 
 door and the cold air of room out at the bottom. In cold weather 
 the direction of air flow will be reversed. 
 
 Perfect inclosing walls for a cold storage room would be 
 perfectly air tight, as they would be if lined with sheet metal, 
 with soldered joints. The interior conditions would then be 
 under more perfect control. It is hardly necessary to do this 
 (although it has been done in cases of some old time houses), as 
 a practically tight job may be had by using the right materials, 
 well put on. Air leakage may not be exactly ventilation, but it 
 is a kind of ventilation which has given the writer some trouble 
 in the past, and does still, consequently the difficulties of operating 
 a house with defective insulation and large outside exposure, and 
 still turning out first-class goods are very thoroughly appreciated. 
 
 PRACTICES TO AVOID. 
 
 Methods of ventilation which are permissible when applied 
 to the work of supplying fresh air to ordinary structures are 
 generally dangerous when used to ventilate cold storage rooms. 
 The problem in ventilating non-insulated structures is merely 
 the supplying of fresh air from the outside without causing a 
 marked change in the temperature, and without creating strong 
 drafts. Air for the ventilation of refrigerator rooms, during 
 warm weather, must be of very nearly the same temperature and 
 relative humidity as the air of the room to be ventilated, and free 
 from the germs which hasten decay and cause a growth of fungus 
 on the products in storage. If a door or window of a storage 
 room is opened directly to the outside atmosphere, there will be 
 little or no circulation of air into and out of the room when the 
 temperature outside and in is about the same, unless the wind 
 
VENTILATION 153 
 
 should be favorable. As we cannot ventilate in this way when 
 the air outside is colder than the storage room, on account of 
 freezing the goods, and the introduction of fresh air, which is 
 warmer than the storage room, is not permissible, for reasons 
 already given, the matter reduces itself to not ventilating at all 
 during warm weather (which most houses practice) or of prop- 
 erly cooling and purifying the air before forcing it into the storage 
 room. It will bear repeating that it is positively bad practice 
 to allow air from the outside to get into a cold storage room 
 during the summer months, also during a large portion of the 
 spring and fall months, unless cooled and purified first. The 
 fact that we cannot see the moisture deposited in the form of 
 beads of water, or floating in the air in the form of fog or mist, 
 does not indicate that it is not present. The sling psychrometer, 
 described in discussing humidity, will give an accurate indica- 
 tion of the result of this unscientific method of ventilating. 
 
 MEANS FOR AIR HANDLING. 
 
 Any natural means of handling air for ventilation is in- 
 accurate and inoperative, or it may be positively harmful, except 
 under favorable conditions. If depending on natural gravity for 
 ventilation it will be guesswork, to a greater or less extent, be- 
 cause depending on conditions which vary with the season, tem- 
 perature, direction and force of the wind, etc. The late. Robert 
 Briggs, an authority on ventilation, makes a concise statement 
 of the advantages of using fans for ventilation, in his "Notes on 
 Ventilating and Heating."* He says : "It will not be attempted 
 at this time to argue fully the advantages of the method of 
 supplying air for ventilation by impulse through mechanical 
 means— the superiority of forced venlilation, as it is called. This 
 mooted question will be found to have been discussed, argued 
 and combated on all sides in numerous publications, but the con- 
 clusion of all is, that if air is wanted in any particular place, at 
 any particular time, it must be put there, not allowed to go. 
 Other methods will give results at certain times or seasons, or 
 under certain conditions. One method will work perfectly with 
 certain differences of internal and external temperature, while 
 another method succeeds only when other differences exist. 
 
 proceedings Am. Soc. Civil Engineers, May, 1881. 
 
15-1 PRACTICAL COLD STORAGE 
 
 s * * Xo other method than that of impelling air by direct 
 means, with a fan, is equally independent of accidental natural 
 conditions, equally efficient for a desired result, or equally con- 
 trollable to suit the demands of those who are ventilating." 
 
 PLENUM VS. EXHAUST METHODS OF VENTILATING. 
 
 There are two general methods, with some modifications, for 
 handling air for ventilation : The plenum or pressure method, 
 in which the fresh air is forced into the room; and the vacuum 
 or exhaust method, in which the foul air is drawn out. The 
 exhaust method is to be avoided for ventilating cold storage 
 rooms, for reasons which we shall see presently. With this 
 method, sometimes the exhaust steam from an engine is utilized 
 to induce a draft of air upward from storage room, by heating 
 the air in a stack or ventilation flue connected at its lower end 
 with the room to be ventilated. In some cases no provision is 
 made for an inflow of fresh air, in which case it will seep in at 
 every crack, crevice and pore (by reason of the partial vacuum 
 created by exhausting the foul air), bringing a load of moisture 
 and germs of disintegration into the storage room. This ex- 
 haust steam method is no different in its result than if a fan 
 were placed so as to draw the air out of the storage room under 
 conditions which are otherwise the same as described in con- 
 nection with the exhaust steam method. Should we provide an 
 inlet for fresh air, through proper absorbents, the same law 
 would be operative, only to a lesser degree, as a partial vacuum 
 must in any case be created before the air from outside would 
 flow into the room, tending to the dangerous air leakage already 
 fully discussed. 
 
 The plenum or pressure method is by far the best for our 
 purpose. The air should be forced into the room by a fan, 
 after first properly cooling, drying and purifying it. An outlet 
 for the escape of the foul gases which it is desired to be rid of 
 should be provided near the floor, as these gases, by reason of 
 their greater gravity, tend to accumulate in the lower part of 
 the room. It will be observed that forcing the fresh air in creates 
 a pressure inside the room, and if there is any air leakage, it 
 will be outwardly from the room — exactly the way we want it to 
 go. Having brought our subject to the point where it is found 
 
VENTILATION 155 
 
 that the best way to ventilate is by the use of fans forcing the 
 air into the storage room, we will determine what type of fan is 
 best adapted to our needs. What is said of fans for ventilation 
 is equally true if they are to be used for forced air circulation, 
 described in chapter on " Air Circulation." 
 
 FANS FOR VENTILATION. 
 
 It is admitted by a majority of experts on air moving ma- 
 chinery that the disk or propeller wheel type of fan, through 
 which the air moves parallel to the axis of fan, is not efficient 
 or desirable for work where the air has to travel through a series 
 of tortuous air ducts, as in the forced air circulation system for 
 cold storage work, or for ventilation purposes where there is 
 some resistance. Where any resistance of importance is en- 
 countered, the disk fan must be driven at a high rate of speed, 
 and at an immense loss of power, to compel it to deliver its full 
 quota of air. Another disadvantage of the disk type is the dif- 
 ficulty of belting to the shaft, or of getting power to the fan in 
 any form, if it is inclosed entirely in an air duct. The disk type 
 will therefore be dismissed, and the well known centrifugal, or 
 peripheral discharge fan taken up. 
 
 This type of fan draws the air in at its center parallel to 
 the shaft, and delivers it at right angles to the shaft at the 
 periphery or rim of the fan wheel, the law governing its action 
 being the well understood centrifugal force, which is commonly 
 illustrated when we see the mud fly from a buggy wheel, or the 
 water off a grindstone. The advantage of these fans over the 
 disk type is that the centrifugal action set up by the rotary motion 
 of the fan is utilized to give velocity to the air in its passage over 
 the fan blades. In the selection of a fan for the purpose of forced 
 circulation in the storage room, or for forcing in fresh air for 
 ventilation, it should be noted that a large, slow running fan 
 wheel is very much more economical of power than a small fan 
 running at a high rate of speed, both doing the same amount of 
 work. The loss of refrigeration, too, in a rapidly moving fan, 
 is of consequence, because the air is warmed by impact with 
 the blades. The proportion of power saved by the use of a large 
 fan running at a slow rate of speed rather than a small fan run- 
 ning at a high rate of speed, both delivering the same amount of 
 
156 PRACTICAL COLD STORAGE 
 
 air, is almost phenomenal, and does not seem at all reasonable at 
 first view. The volume of air delivered by a fan varies very 
 nearly as the speed, while the power required varies about as 
 the cube of the speed. That is, doubling the speed doubles the 
 volume of air, while the power required is increased eight times. 
 We will take a specific case. A 45-inch fan wheel, revolving at a 
 speed of 200 revolutions per minute, delivers, say, 5,000 cubic 
 feet of air per minute, and requires but one-quarter of a horse 
 power to operate it. If the speed is increased to 400 revolutions, 
 the volume of air delivered will be only about 10,000 cubic feet, 
 while the power required to drive it will be raised to two horse 
 power. These figures are theoretical, but within certain limits 
 are approximated in practice. 
 
 For use in cold storage work the objection common to nearly 
 all the air moving machinery found listed by the manufacturers 
 is the seemingly unnecessary amount of metal used in its con- 
 struction. The heavy weight of the fan wheels, and the large 
 diameter of shaft necessitated by such weight, causes much fric- 
 tion on the journals, so that when running at the slow speeds 
 desirable for cold storage work, more power is required to over- 
 come the mechanical friction than is actually required to move 
 the air. 
 
 No doubt the high speeds necessary for some work have 
 obliged the manufacturers to make their fans amply strong for 
 the highest speeds, consequently they are not economical for the 
 slower speeds. It would hot be appropriate for a person to fan 
 himself with a dinner plate — it would do the work, but would not 
 be economical of power. 
 
 Having been unable to find a fan wheel well suited to the 
 requirements of cold storage duty, the writer has designed and 
 constructed a line of fan wheels especially for slow speeds, which 
 are amply strong and capable of moderately high speeds, when 
 necessary, but are very much lighter than most fans on the mar- 
 ket, and consume proportionately less power in mechanical fric- 
 tion. 
 
 TREATING AIR FOR VENTILATION. 
 
 So far we have found out what kind of ventilation is not 
 desirable, and have an inkling of what kind would be desirable. 
 
VENTILATION 157 
 
 The question before us now is to properly treat the air before 
 introducing it into the storage room, so that it may be fresh— 
 i. e., pure oxygen and nitrogen, without excessive moisture, 
 and free from the impurities and germs which may contaminate 
 the product which is being refrigerated. 
 
 The free outside air during warm weather, especially in 
 the vicinity of our large cities, contains, among many others, 
 germs which produce the parasitic plant growth which is called 
 mildew or mold. The exhalation from the lungs of the many 
 animals and men who inhabit our cities, and the evaporation from 
 the dust, dirt and decaying matter of various kinds peculiar to 
 the street, render the air a receptacle and conveyor for impurities 
 and germs of many species. The species of germs which con- 
 cern us are active in proportion to the temperature and humidity 
 of the air. In a warm atmosphere which contains much moisture 
 they take root and grow rapidly, throwing off more germs of 
 their kind, which impregnate the air in an increasing ratio as 
 the humidity and temperature are increased. The humidity of 
 the outside air is not necessarily increased with the temperature, 
 but it is always increased to some extent, and as the temperature 
 of the outside air rises we must necessarily be more and more 
 careful how we treat and handle the air which we are to use for 
 the ventilation of refrigerated rooms. 
 
 It is readily understood why it is necessary to cool the air 
 before introducing it into the storage room to at least as low a 
 temperature as that of the room to- be ventilated, and some cold 
 storage managers have ventilated on this basis, thinking that 
 this was all that was necessary for successful ventilation. Air 
 cooled only to the temperature of the storage room will be 
 saturated with moisture at that temperature, and will be in con- 
 dition to develop mold rapidly. An improvement on this man- 
 ner of handling is to cool the air to be used for ventilation to 
 a few degrees (say five or six) below the temperature of the 
 storage room. The air will then be rendered as dry as that of 
 the storage room. This is a good method of ventilation, and 
 one which the author has practiced, but it is open to criticism, 
 because of the fact that the air is not purified fully at the same 
 time it is cooled and dried. If the air is first cooled to several 
 degrees below the temperature of the room to be ventilated it will 
 
158 
 
 PRACTICAL COLD STORAGE 
 
 be of benefit to the room, if not overdone, but in results will not 
 be equal to a system to be described and illustrated further on 
 in this chapter. 
 
 °* 
 
 [3RIMEOR 
 COIL. 
 
 STEAl-l 
 Coiu 
 
 FIG. I. — BRINE OR AMMONIA COOLER. 
 
 Several houses known to the author ventilate by letting the 
 warm outside air in at a point near to the ceiling, directly over 
 cooling coils, expecting that the air will be properly cooled and 
 dried before it flows into the room itself. The same objections 
 
VENTILATION 159 
 
 are applicable to this system as are applicable to any plan of 
 ventilating where the air is cooled only to the temperature of the 
 room to be ventilated, because the air will be at the 
 saturation point, and will therefore raise the humidity of the 
 room, as well as introduce a quantity of germs and impurities. 
 
 SIMPLE AIR COOLER FOR VENTILATING. 
 
 If we ventilate by simply cooling the air, the simplest and 
 most effective method, as shown in Fig. i, is to take the air from 
 as high and sheltered a place as is accessible about the building ; 
 draw it down over frozen surfaces in the form of brine or am- 
 monia pipes, which may be arranged anywhere along the wall of 
 a room, outside of the storage entirely, if more convenient. An 
 exhaust fan takes the air from the coils in the ventilating flue 
 and forces it into the room to be ventilated, allowing it to escape 
 in the neighborhood of the cooling coils, where it will mix with 
 the air circulation, and flow into the room through the regular 
 channel. It is necessary to provide an outlet for the escape of 
 foul air whenever fresh air is forced into the room. This outlet 
 should be near the floor, and of about the same area as the inlet 
 pipe. A steam coil may be provided beneath the cooling coil 
 in ventilating flue, as shown in the sketch, for the purpose of 
 melting the frost off the pipes. The casing around the cooling 
 coil should, of course, be insulated moderately, as well as the 
 pipe leading from it to the storage room, wherever exposed to 
 the warm outside air. The size of apparatus necessary for this 
 purpose need not be large, as the quantity of air which is gen- 
 erally required for the ventilation of storage rooms is quite small, 
 comparatively. 
 
 "Americus"* mentions a method of washing air for ventila- 
 tion, which seems to have advantages. The idea is to draw or 
 force air through a body of water or brine by immersing the in- 
 take pipe so that the air will bubble up through the liquid. 
 This seems quite simple, but when it comes to forcing air through 
 a liquid with a fan it is not so simple, as nothing short of an air 
 pump will drive air through a pipe submerged as above de- 
 scribed, unless the opening from pipe is placed quite near the 
 surface of the liquid ; in which case the benefit to the air is very 
 
 *In Ice and Refrigeration, July, 1898. 
 
VENTILATION 
 
 161 
 
 small. Experiments conducted by the author along this line were 
 considered failures. 
 
 COOPER SYSTEM FOR WARM WEATHER VENTILATION. 
 
 Shown in Fig. 2 is what appears as a rather complicated ap- 
 paratus, but on investigation it proves to be quite simple. There 
 are three parts to this apparatus, as follows : 
 
 First.— The air-washing tank, in which the air flows up- 
 ward against a rain of water from a perforated diaphragm above, 
 as clearly shown in the sketch. This not only cools the air to the 
 temperature of the water, say 55° or 60° F, but it also takes 
 out a large portion of the impurities of various kinds. From the 
 washing tank the air is passed on, in a comparatively pure and 
 cool state, to be still further cooled. 
 
 Second. — The cooling tank, in which the air is cooled to 
 several degrees lower temperature than that of the storage room. 
 This removes the moisture which holds in suspension the few 
 impurities which may have passed the washing tank, the moisture 
 being deposited on the frozen surfaces within the cooler. 
 
 Third. — The drying box, into which the air from the cooler 
 is passed, and which contains chloride of calcium. This chemical 
 is a well known absorber of moisture, what is technically known 
 as a deliquescent substance. If moisture of any account passes 
 the cooler it is surely stopped in the dryer, which "makes assur- 
 ance doubly sure," so far as delivering a pure, dry air is concerned. 
 It would be a hardy germ, indeed, that would not succumb to 
 the washing, cooling and drying processes of this system of ven- 
 tilation, which is as thorough as it well may be theoretically, and 
 practically is very effective. 
 
 FREQUENCY AND AMOUNT OF VENTILATION. 
 
 The volume of air necessary for ventilating a given size of 
 storage room can only be estimated, and probably no two storage 
 men will agree as to what is a correct quantity. Some say that 
 the introduction of a volume of air equal to that of the room 
 to .be ventilated should take place each day ; others twice each 
 day; some even take so radical a view of it as to say the oftener 
 the better if the air is properly dried and cooled. This is of 
 course true enough, but foul gases which can be gotten rid of 
 by ventilation accumulate but slowly in a storage room, and it is 
 probable that the introduction of a volume of fresh air, properly 
 
162 PRACTICAL COLD STORAGE 
 
 treated, equaling that of the storage room, twice each week- 
 will be ample for the purpose of keeping the room in good con- 
 dition, and in most cases once each week may do nearly as well. 
 There is much to be developed yet in the direction of ventilation 
 of refrigerated rooms, more particularly in the way of some 
 method of knowing when a room requires ventilating. Perhaps 
 some bright chemist will in time make investigations and ascer- 
 tain what the gases are which we must dispose of, and indicate 
 some simple method of determining their presence, and in what 
 proportion. 
 
 All that has been said about ventilation so far applies only 
 to the ventilation of cold storage rooms when the air without 
 is warmer than the air of the storage room. We will now give 
 our attention to another kind of ventilation that is applicable 
 when the air without is at about the same temperature as the 
 storage room, or at some degree lower. This will be designated 
 as cold weather ventilation, as this term seems to express its 
 function perfectly. 
 
 COLD WEATHER VENTILATION. 
 
 It has long been a well understood fact that products held 
 at about 30° F. or higher are more liable to be injured in 
 cold storage during the cool or cold weather of fall and winter 
 than during a long carry through the heated term. Much has 
 been said and written about why the old style overhead ice cold 
 storages give such poor results during fall and winter, the reason 
 assigned being lack of circulation, as the meltage of ice ceases 
 when the cool weather comes. This is true ; further, the large 
 body of ice becomes an evaporating surface, and the dirt and 
 impurities which are found in all natural ice, to a greater or less 
 extent, have accumulated on the top of this ice, and the evapora- 
 tion which takes place carries gases from this miscellaneous mat- 
 ter into the air of the storage room, with consequent bad results. 
 In some houses this may be avoided by closing the trap doors 
 covering circulation flues, but it is seldom done, and in many 
 houses it is impossible. 
 
 Now are we who cool our storage rooms with brine or 
 ammonia pipes very much better off in this one respect than those 
 who have these much despised overhead ice cold storages? Our 
 rooms are cooled by frozen surfaces, on which accumulates the 
 
VENTILATION 163 
 
 evaporation from the goods in store, which, as we have already 
 plainly seen, contains much foul matter and impurities. Pre- 
 cisely as in the ice cold. storages, the cooling surfaces, which ab- 
 sorb moisture during warm weather, become evaporating sur- 
 faces, and give back to the air of the room a considerable portion 
 of the various impurities and germs which have been accumu- 
 lated during the warm weather of summer. To make this point 
 more plain it may be considered thus : During the period when 
 the outside air is considerably warmer than the air of the storage 
 room it is necessary to keep some refrigerant at work cooling 
 the air within. This is usually done by circulating brine or 
 ammonia through pipes and the air of the room is circulated 
 in contact with the pipes. When the outside temperature is 
 high, more of the refrigerant must be circulated, or its tem- 
 perature must be lowered; as the weather turns cooler in the 
 fall, less refrigerant, or the same amount at a higher temperature, 
 must be circulated, and when the air without reaches the tem- 
 perature of the room, the circulation of refrigerant must be 
 discontinued altogether. When this is done the moisture on 
 the cooling pipes begins to evaporate. This evaporation added 
 to that which is given off by the goods themselves soon causes 
 the air to be saturated with very impure and poisonous vapors 
 which cause the goods to deteriorate very rapidly. 
 
 DISPOSAL OF MOISTURE. 
 
 The influence which the temperature of the refrigerant flow- 
 ing in the cooling pipes has on the condition of a storage room 
 may be better understood by taking a specific case : A room with 
 a temperature of 33° F. and a humidity of 70 per cent has a dew 
 point (temperature at which the air precipitates moisture) of 
 25° F. Therefore any cold surface (as a pipe surface), having 
 a temperature of 25° F. or lower, will attract moisture when ex- 
 posed to the air of the room. If the pipe surfaces are heavily 
 coated with frost, as they usually are as cold weather approaches, 
 the frost acts as an insulator, and the refrigerant flowing in pipes 
 must be at a considerably lower temperature than the air of the 
 room, or no moisture is attracted. We have all noted how the 
 accumulation of moisture on pipe coils is slower and slower as 
 the thickness increases, until finally a limit is reached where no 
 
164 PRACTICAL COLD STORAGE 
 
 more frost will form ; yet owing to the largely increased surface 
 the room can be kept at its normal temperature. If pipes are 
 badly loaded with frost, sometimes no absorption of moisture will 
 take place when the refrigerant flowing in the coils is 10" or 15° 
 below the temperature of the room. The surface exposed to the 
 air of the room, whether in the form of frost or otherwise, must 
 be at or below the temperature of the dew point, or no moisture 
 will be absorbed. The value of suitable moisture-absorbing sur- 
 faces as the cool weather of fall and winter approaches cannot 
 be overestimated, as many have found to their sorrow that two 
 weeks stay in cold storage under bad conditions in cold weather 
 will do more harm to eggs in particular than four months during 
 hot weather. 
 
 The remedy for this trouble is found in keeping the air of the 
 room from coming in contact with the poisonous frost which has 
 been accumulated on the pipes during their period of duty during 
 warm weather ; or what is still a better way is not to allow the 
 frost to accumulate on the pipes at all, by using a device, described 
 elsewhere under head of " Absorbents." How to keep the air 
 from contact with the frost on pipes is not an easy matter, and in 
 case of piping suspended directly in the room it is an impossibility. 
 
 With a system of screens arranged around coils, as described 
 in the first part of the chapter on " Air Circulation," trap doors 
 may be very easily fitted to the openings and the air circulation 
 shut off in this way ; but the simplest and best way is to' equip 
 the rooms with forced circulation, and locate the pipes outside 
 of the room entirely. Then it is only a matter of shutting 
 off the circulation over coils, or allowing it to continue through a 
 by-pass, or if the process described in the chapter on "Uses of 
 Chloride of Calcium" is used, the circulation may be allowed to 
 continue over coils. It seems quite clear, from what has been 
 written, why a storage room gets foul quickly during cool weather, 
 and also that the bad conditions may be bettered by cold weather 
 ventilation. The harm resulting from the foul evaporation from 
 frost on cooling pipes may be obviated by not allowing contact 
 between it and the air of room, but the evaporation from the 
 products themselves must be taken up by other means when cool- 
 ing surfaces are no longer operative. 
 
VENTILATION 165 
 
 HINTS ON COLD WEATHER VENTILATION. 
 
 By carefully observing conditions a storage room may nearly 
 always be kept in prime condition during cold weather by no 
 other means than the introduction of fresh outside air at as' fre- 
 quent intervals as right conditions of temperature and humidity 
 will permit. It is quite safe to force in plenty of air which has 
 about the same temperature and humidity as the room to be ven- 
 tilated. There are few impurities in the clear, crisp air of a 
 "bright fall day, and many such are available for our purpose in the 
 latitude of Minnesota and New York, and a somewhat smaller 
 number, perhaps, in the latitude of Iowa or Ohio. It is only 
 a matter of handling the free air of heaven understandingly. 
 One's impressions, however, will hardly do in judging what air 
 is good to use for ventilating purposes. If you have a bright, 
 clear day, or, what is still better, a clear cold night, which has 
 the appearance of being what you want, get out your sling 
 psychrometer and set all guesswork aside. It is frequently pos- 
 sible to fill your storage rooms with fine, pure air at a temper- 
 ature about the same as that of the room, as early as the latter 
 part of October, if you are watching for the opportunity. Pro- 
 vide a good big fan wheel, which will handle a large volume of 
 air in a short time, and when conditions are right blow your 
 rooms full of it. Repeat this whenever the weather conditions 
 will permit. 
 
 We may now consider cold weather ventilation under an- 
 other condition, viz. : When it is colder outside than inside the 
 storage room. Whenever the outside air is 8° or 10" below that 
 •of the storage room it is always perfectly safe to introduce it 
 into the storage room, after it has been first warmed to the tem- 
 perature of the room to be ventilated. That is, it is safe so far 
 as introducing moisture or impurities is concerned. If we should 
 ventilate in this way continuously our humidity would be low- 
 ered to a point where the goods might suffer from evaporation. 
 It is necessary, therefore, that observation of the humidity of 
 the room so ventilated be taken, so that this kind of ventilation 
 may not be overdone. 
 
 The method of getting air into the rooms under these last 
 two systems of ventilation is of no special moment, except that 
 at be under control, and we have already noted that the only 
 
166 PRACTICAL COLD STORAGE 
 
 good way of handling air was by the use of fans, preferably large 
 and of light weight, and running at a slow speed. Where the 
 forced circulation is installed, it is sometimes practicable to so 
 connect the fans used for this purpose, that cold weather ven- 
 tilation may be handled by them ; but a separate fan is much 
 better and while it seems more complicated it is really simpler to 
 operate, because handled independently. When using an inde- 
 pendent fan or when using the forced circulation fan for ven- 
 tilating, the fresh air mixes with the circulation and is well dis- 
 tributed by it to various parts of the room. 
 
 The ventilation of cold storage rooms is not a matter which 
 can be safely left to such help as may be at hand, and if good 
 results are to be secured "the boss" should see to it himself. 
 Cold weather ventilation, especially, must be handled carefully 
 and scientifically or trouble may result instead of benefit. No 
 absolute rules can be given for handling ventilation because of 
 widely varying conditions, but if what has been written is read 
 and studied carefully the subject can be taken up intelligently 
 and followed out to its legitimate conclusion. 
 
HUMIDITY 167 
 
 CHAPTER VII. 
 HUMIDITY. 
 
 IMPORTANCE OF ASCERTAINING HUMIDITY IN COLD STORES. 
 
 Up to about the year 1898 the subject of humidity of cold 
 storage rooms was given very little or no attention by cold stor- 
 age operators, and no successful means of testing humidity had 
 been found for the requirements of refrigerated rooms. About 
 the year above referred to the author secured a sling psychrom- 
 eter, such as is used at stations of the United States Weather 
 Bureau, and made some tests. This instrument is now in gen- 
 eral use for the purpose, and is well adapted for obtaining the 
 humidity of cold storage rooms. More attention has been given 
 to the subject each year, and as it costs practically nothing and 
 requires very little time, all houses should make tests to know 
 how they stand in this important respect. 
 
 The humidity of a cold storage room under ordinary condi- 
 tions depends on the season to a moderate extent, and the con- 
 dition of the room, as regards ventilation, in some cases. In 
 late fall or winter, especially, if air is taken directly into the room 
 from the outside, the humidity will be low. As- cool weather 
 approaches, the tendency is for the humidity to rise, and unless 
 kept down by ventilation or by the use of absorbents, serious 
 consequences are sure to follow. 
 
 To enable us to thoroughly understand the meaning of rela- 
 tive humidity, as it is called, we will study a few extracts from 
 "Instructions to Voluntary Observers."* Humidity is consid- 
 ered on a decimal scale, with 100 the saturation point of the air, 
 at which it will hold no more water vapor, and o the point at 
 which air contains no moisture whatever. The various percent- 
 ages between these points is a degree of humidity relative to 
 these two extremes, or relative humidity. The quotations below 
 
 "Issued by the United States Weather Bureau, Washington, D. C. 
 
UiS PRACTICAL COLD STORAGE 
 
 are not contained in the recent issue of instructions, but are from 
 the issue of 1892, which is now superseded by that of 1897. 
 
 WATER VAPOR IN AIR. 
 
 The air contains vapor of water, transparent and colorless like its 
 other gaseous components. It only becomes visible on condensing to fog 
 or cloud, which is only water in a fine state of division. The amount is 
 very variable at different times, even in the vicinity of the ocean. The 
 amount of moisture that can exist as vapor in the air depends on the tem- 
 perature. There is a certain pressure of vapor, corresponding to every 
 temperature, which cannot be exceeded ; beyond this there is condensation. 
 This temperature is called the temperature of saturation for the pressure. 
 When the temperature of the air diminishes until the saturation tempera- 
 ture for the vapor contained is reached, any further fall causes a con- 
 densation of moisture. The temperature at which this occurs is called 
 the dew point temperature of the air at that time. The less the quantity 
 of moisture the air contains, the lower will be the temperature of the dew 
 point. For different saturation temperatures, the weight of vapor, in 
 grains, contained in a cubic foot of air is as follows : 
 
 Temperature Weight in a 
 
 of Saturation, Cubic Foot, Grains. 
 
 Degrees F 
 
 o 0.56 
 
 10 0.87 
 
 20 I.32 
 
 3° I.96 
 
 40 2.8s 
 
 50 4.08 
 
 60 5-74 
 
 70 7.g8 
 
 80 10.93 
 
 9° 14-79 
 
 100 19.77 
 
 The air is never perfectly saturated, not even when rain is falling; 
 neither is it ever perfectly dry at any place. Relative humidity expresses 
 relative amount, of moisture in the air only as long as the temperature of 
 the air remains constant. For this reason relative humidity is an imperfect 
 datum. At a low temperature even a high relative humidity represents 
 a very small amount of vapor actually in the air, while a low relative 
 humidity at a high temperature represents a great deal. 
 
 The most important law relating to above concise statements, 
 and one which, if carefully noted and applied, will make all work 
 in humidity easily understood, is best expressed thus: The ca- 
 pacity of air for moisture is increased with its temperature. 
 Strictly speaking, air has no capacity for moisture, the water 
 vapor being simply diffused through the air, after the nature of 
 a mechanical mixture. For all practical purposes, we may regard 
 it as being absorbed by the air, and it is usually so treated. 
 
 At a temperature of 40 F., air will hold in suspension more 
 water vapor than at any lower temperature (see table) ; and 
 when the difference is as much as 10° F., the difference in the 
 
HUMIDITY 169 
 
 amount of moisture the air will hold is very considerable. To 
 illustrate : Air which is saturated with moisture at 30° F., when 
 raised in temperature to 40° F., then holds but 68 per cent of 
 its total capacity. 
 
 INSTRUMENTS FOR DETERMINING HUMIDITY. 
 
 There are two kinds of instruments in use for determining 
 humidity, hygrometers and psychrometers. The hygrometer de- 
 pends on the expansion and contraction of some substance, as a 
 human hair, in the presence of more or less moisture in the air. 
 The hair used is fastened at one end, the other end passing 
 around a pulley, to which is fastened a pointer, which moves 
 over a graduated arc as the hair changes its length. The scale 
 reads from o to 100. The chief advantage of these instruments 
 is that results are obtained at once, the reading corresponding 
 to the percentage of saturation or relative humidity; but these 
 instruments are affected by changes of temperature, and shocks 
 or vibration materially affect the reading. Further, they are 
 more expensive in first cost, and not so convenient to use, as they 
 must hang for some time in the room to be tested, while with the 
 sling psychrometer, described in another paragraph, an observer 
 can pass from room to room, getting observations in less than two 
 minutes in each room, needing but one instrument and making 
 all observations at practically the same time. 
 
 A psychrometer is simply two thermometers mounted on a 
 frame ; the bulb of one being covered with muslin so as to retain 
 a film of water surrounding it. The working of this instrument 
 depends on a law which may be roughly expressed, as "evapora- 
 tion carries off heat." The evaporation of water from the bulb 
 incased in muslin, known as the wet bulb, cools it somewhat, 
 depending on how dry the air surrounding it may be. The dif- 
 ference between the reading of the wet bulb thermometer and 
 the reading of the dry bulb thermometer, when compared with 
 reference to a prepared table, gives the relative humidity of the 
 air at the time of making the observation. Psychrometers are of 
 two kinds, stationary and sling. 
 
 The stationary psychrometer is essentially like the sling 
 psychrometer, both depending on the same principle. The sling 
 instrument is more compact and provided with a handle for 
 
170 
 
 PRACTICAL COLD STORAGE 
 
 1/ 
 
 m 
 
 FIG. I. — 
 SLING 
 PSYCHRO- 
 METER. 
 
 whirling, while the stationary instrument is 
 intended to be fastened against the wall, or on 
 a post, the muslin covering the wet bulb being 
 connected by a porous cord with a reservoir 
 of water, to keep the supply of water con- 
 tinuous. This is essential, as it takes some 
 little time to obtain a correct reading with 
 this pattern of instrument. For this reason 
 it is open to the same objections as the hygro- 
 meter. Also, after short use the muslin cov- 
 ering the wet bulb, and the cord feeding 
 water to it, become clogged with solid matter and 
 fungous growth affecting its accuracy. At any tem- 
 perature below 32° F. this instrument is useless, as 
 the water will freeze in the cord supplying the muslin 
 on the wet bulb, and the muslin becomes dry in con- 
 sequence. 
 
 For practical, accurate and quick results at any 
 temperature there is no instrument so reliable and 
 convenient as the sling psychrometer, preferably of 
 the pattern known as Prof. Marvin's improved psy- 
 chrometer, shown in Fig. 1. This is a standard 
 Weather Bureau instrument, and when used in con- 
 nection with the tables of humidity published by the 
 bureau, any needed results may be obtained with a 
 fair degree of accuracy. The sling psychrometer, >as 
 illustrated, consists of a pair of thermometers 
 mounted on an aluminum plate, one higher than the 
 other, the lower having its bulb covered with a small 
 sack of muslin. At the top, the frame or plate sup- 
 porting the thermometers is provided with a handle 
 for whirling, this handle being connected by links to 
 the plate, and provided with a swivel to allow of a 
 smooth rotary motion. The bulb of the lower ther- 
 mometer is wet at the time of making an observation, 
 the muslin serving to retain a film of water, surround- 
 ing and in contact with what is known as the wet bulb 
 of the psychrometer. The muslin should be renewed 
 from time to time, as the meshes between the threads 
 
HUMIDITY m 
 
 will gradually fill with solid matter left by the evaporation of the 
 water and the natural accumulation of dust from the air. The 
 muslin in this condition will neither absorb nor evaporate the 
 water readily. 
 
 HOW TO USE THE SLING PSYCHROMETER. 
 
 To make an observation dip the muslin-covered bulb in a 
 small cup or other wide-mouthed receptacle containing water. 
 Whirl the thermometer for ten or fifteen seconds, then dip the 
 wet bulb of the psychrometer into the water again. Whirl again 
 for ten or fifteen seconds, stop and read quickly, reading the 
 wet bulb first. Repeat once or twice, noting the reading each 
 time. When two successive readings of the wet bulb agree very 
 nearly, the lowest point has been reached. Dip the wet bulb only 
 after the first whirling, as this is done only to make sure that 
 the muslin is thoroughly saturated with water. If the water 
 used is of nearly the same temperature as the room, correct read- 
 ings are sooner obtained. If the psychrometer and water are at 
 a much higher temperature than the air of the room, it will take 
 a proportionately longer time to reach a correct reading, but the 
 accuracy will not be impaired, if sufficient time is allowed for the 
 mercury to settle. It is very important that the muslin-covered 
 bulb should not become dry in the least; it should be saturated 
 with water during the full time of observation. There will be 
 no difficulty in getting accurate readings down to 29° F., as 
 indicated by the dry bulb. At about this temperature, and with 
 the wet bulb at about 27 F., ice will form on the wet bulb and 
 cause the psychrometer to become somewhat erratic in its be- 
 havior. Readings below 30° F. are therefore very difficult to 
 obtain, and it is only after repeated trials that results may be ob- 
 tained in some cases. By dipping the instrument in water at a 
 temperature near the freezing point and then rapidly whirling it 
 results may usually be obtained. A stationary hygrometer is en- 
 tirely inoperative at any temperature below 32 F., as the water 
 in the fountain and cord will freeze solid. The sling psychrometer, 
 according to Prof. Marvin, its originator, is supposed to be as 
 accurate when the wet bulb is covered with ice as when covered 
 with water, but this is not borne out by the author's personal ex- 
 
172 PRACTICAL COLD STORAGE 
 
 perience. There is something to be desired in the way of further 
 information on this point. 
 
 It is difficult to describe the proper movements for whirling 
 the sling psychrometer, a little practice being the best instructor. 
 The handle is held in a horizontal position, the frame mounting 
 the thermometers revolving around the pivot, after the manner 
 of the weapon with which David slew Goliath, and from which 
 our moisture-tester gets the easy part of its name. A high rate 
 of speed is unnecessary, a natural, easy motion of the forearm 
 or wrist being all that is required. When stopping the psychrom- 
 eter the arm should follow the thermometer from the highest 
 point of the circle of rotation, whereby the radius of the path of 
 the psychrometer is increased, and the momentum overcome. 
 The stopping can be accomplished in a single revolution, after a 
 little practice. The psychrometer will come to rest very nicely 
 by simply allowing the arm to stand still, but the final revolution 
 will be quite irregular and jerky. 
 
 In making observations in a storage room, the psychrometer 
 should be held as far from the body as convenient, and toward 
 the direction from which the circulation comes — the observer 
 standing to the leeward, as it were. In some cases it is necessary, 
 or advisable, to step slowly back and forth a few steps, and the 
 observer should turn his head from the direction of the psychrom- 
 eter so that his breath will not affect the reading. In reading a 
 thermometer, read as quickly as possible, and do not allow the 
 breath to strike the bulb. It is a common practice with the 
 author to hold his breath while reading a thermometer. It is 
 unnecessary to caution against allowing the psychrometer to 
 strike any object while whirling. In case it should, the observer 
 will have $5 worth of experience, but no psychrometer. 
 
 The following short table needs no explanation further 
 than has been already given. It will cover most cases in cold stor- 
 age, observations. It was not intended for cold storage work, 
 being a part of the regular humidity tables published by the 
 Weather Bureau. The full set of tables can be had by addressing 
 the chief of the Weather Bureau, Department of Agriculture. 
 Washington, D. C. They are published in pamphlet form, along 
 with tables giving dew point temperatures. Observers must, 
 work out the small fractions for themselves, if they think neces- 
 
HUMIDITY 
 
 173 
 
 sary, but results within the limits covered by the table are near 
 enough for practical purposes. 
 
 TABLE OF RELATIVE HUMIDITY, PER CENT. 
 
 
 Difference between dry and wet thermometers [t — t'). 
 
 2 
 
 H 
 
 u 
 
 
 o".5 
 
 i°.o 
 
 l°.5 
 
 2°.0 
 
 2".5 
 
 3°.o 
 
 3°.5 
 
 4°.o 
 
 4°-5 
 
 5°.o 
 
 5°-5 
 
 6°.o 
 
 a 
 
 25 
 
 94 
 
 87 
 
 81 
 
 74 
 
 68 
 
 62 
 
 56 
 
 5° 
 
 44 
 
 38 
 
 32 
 
 26 
 
 25 
 
 26 
 
 94 
 
 88 
 
 81 
 
 75 
 
 69 
 
 63 
 
 57 
 
 51 
 
 45 
 
 40 
 
 34 
 
 28 
 
 26 
 
 27 
 
 94 
 
 88 
 
 82 
 
 76 
 
 70 
 
 64 
 
 59 
 
 53 
 
 47 
 
 42 
 
 36 
 
 30 
 
 27 
 
 28 
 
 94 
 
 88 
 
 82 
 
 76 
 
 7i 
 
 65 
 
 60 
 
 54 
 
 49 
 
 43 
 
 38 
 
 33 
 
 28 
 
 29 
 
 94 
 
 89 
 
 83 
 
 77 
 
 72 
 
 66 
 
 61 
 
 56 
 
 50 
 
 45 
 
 40 
 
 35 
 
 29 
 
 3° 
 
 94 
 
 89 
 
 84 
 
 78 
 
 73 
 
 67 
 
 62 
 
 57 
 
 52 
 
 47 
 
 4i 
 
 36 
 
 30 
 
 3 1 
 
 95 
 
 89 
 
 84 
 
 79 
 
 74 
 
 68 
 
 63 
 
 58 
 
 53 
 
 48 
 
 43 
 
 38 
 
 31 
 
 32 
 
 95 
 
 90 
 
 84 
 
 79 
 
 74 
 
 69 
 
 64 
 
 59 
 
 54 
 
 5° 
 
 45 
 
 40 
 
 32 
 
 33 
 
 95 
 
 90 
 
 85 
 
 80 
 
 75 
 
 70 
 
 65 
 
 60 
 
 56 
 
 5i 
 
 47 
 
 42 
 
 33 
 
 34 
 
 95 
 
 91 
 
 86 
 
 81 
 
 75 
 
 72 
 
 67 
 
 62 
 
 57 
 
 53 
 
 48 
 
 44 
 
 34 
 
 35 
 
 95 
 
 9 1 
 
 86 
 
 82 
 
 76 
 
 73 
 
 69 
 
 65 
 
 59 
 
 54 
 
 5° 
 
 45 
 
 35 
 
 36 
 
 96 
 
 91 
 
 86 
 
 82 
 
 77 
 
 73 
 
 70 
 
 66 
 
 61 
 
 56 
 
 5i 
 
 47' 
 
 36 
 
 37 
 
 96 
 
 91 
 
 87 
 
 82 
 
 78 
 
 74 
 
 70 
 
 66 
 
 62 
 
 57 
 
 52 
 
 48 
 
 37 
 
 38 
 
 96 
 
 92 
 
 87 
 
 83 
 
 79 
 
 75 
 
 7i 
 
 67 
 
 63 
 
 58 
 
 54 
 
 5° 
 
 38 
 
 39 
 
 96 
 
 92 
 
 88 
 
 83 
 
 79 
 
 75 
 
 72 
 
 68 
 
 63 
 
 59 
 
 55 
 
 52 
 
 39 
 
 40 
 
 96 
 
 92 
 
 88 
 
 84 
 
 80 
 
 76 
 
 72 
 
 68 
 
 64 
 
 60 
 
 56 
 
 53 
 
 40 
 
 4 1 
 
 96 
 
 92 
 
 88 
 
 84 
 
 80 
 
 76 
 
 72 
 
 69 
 
 65 
 
 61 
 
 57 
 
 54 
 
 41 
 
 42 
 
 96 
 
 92 
 
 88 
 
 84 
 
 81 
 
 77 
 
 73 
 
 69 
 
 65 
 
 62 
 
 58 
 
 55 
 
 42 
 
 43 
 
 96 
 
 92 
 
 88 
 
 85 
 
 81 
 
 77 
 
 74 
 
 70 
 
 66 
 
 63 
 
 59 
 
 56 
 
 43 
 
 44 
 
 96 
 
 92 
 
 88 
 
 85 
 
 81 
 
 78 
 
 74 
 
 70 
 
 67 
 
 63 
 
 60 
 
 57 
 
 44 
 
 45 
 
 96 
 
 92 
 
 89 
 
 85 
 
 82 
 
 78 
 
 75 
 
 7i 
 
 67 
 
 64 
 
 61 
 
 58 
 
 45 
 
 46 
 
 96 
 
 93 
 
 89 
 
 85 
 
 82 
 
 79 
 
 75 
 
 72 
 
 68 
 
 65 
 
 61 
 
 58 
 
 46 
 
 47 
 
 96 
 
 93 
 
 89 
 
 86 
 
 83 
 
 79 
 
 76 
 
 72 
 
 69 
 
 66 
 
 62 
 
 59 
 
 47 
 
 48 
 
 96 
 
 93 
 
 89 
 
 86 
 
 83 
 
 79 
 
 76 
 
 73 
 
 69 
 
 66 
 
 63 
 
 60 
 
 48 
 
 49 
 
 97 
 
 93 
 
 90 
 
 86 
 
 83 
 
 80 
 
 76 
 
 73 
 
 70 
 
 67 
 
 63 
 
 60 
 
 49 
 
 It is of no use to test for moisture unless having the means 
 to control it, any more than a thermometer would be of use 
 unless the means of regulating temperature were at hand. Hu- 
 midity can be controlled by ventilation, already discussed, and 
 the use of absorbents, which are considered in the following 
 chapter. 
 
174 PRACTICAL COLD STORAGE 
 
 CHAPTER VIII. 
 ABSORBENTS. 
 
 USE OF ABSORBENTS IN COLD STORAGE. 
 
 The use of absorbents in cold storage rooms has been com- 
 mon since the industry was in its infancy ; their use originating, 
 no doubt, from an appreciation of the fact that the air of a stor- 
 age room quickly became too moist and impure to do the work 
 of preservation perfectly. When absorbents and ventilation are 
 applied to refrigerator rooms they practically have one duty in 
 common — that of purifying the air. Ventilation purifies by fur- 
 nishing pure air which displaces the foul air ; absorbents by at- 
 tracting the moisture, and with it the impurities of the storage 
 room. But while ventilation is largely for the purpose of forcing 
 out the permanent gases or impurities which have little affinity 
 for moisture, absorbents are for the purpose of taking up the 
 moisture and the germs and impurities which are absorbed by it. 
 
 Active absorbents can be made to perform duty in absorb- 
 ing the moisture which is usually condensed on the cooling coils, 
 as illustrated in one style of the antiquated overhead ice cold 
 storages, called Prof. Nyce's system. In this system the ice is 
 supported above a water-tight sheet iron floor which forms the 
 ceiling of the storage room, the air of the room being cooled 
 merely by contact with this cold metal surface, which is cooled 
 by the ice above. The moisture given off by the goods in storage, 
 and that resulting from air leakage was taken up by an absorbent, 
 chloride of calcium being the chemical mostly in use for this pur- 
 pose. It was applied by suspending it in pans at the ceiling of 
 the room, or in some cases on the floor under the goods. Prof. 
 Nyce's system gave good results years ago in competition with 
 the Jackson, Dexter, McCray, Stevens, etc., systems of overhead 
 ice cold storage, which low temperatures, and the improved sys- 
 tems of air circulation now in use have rendered obsolete to a 
 
ABSORBENTS 175 
 
 greater or less extent. Mention is made of this system not as 
 recommending it, but to show the possibilities of absorbents in 
 drying and purifying storage rooms. 
 
 LIME. 
 
 The two chemical absorbents in general use for taking up 
 moisture and the impurities from cold storage rooms are chloride 
 of calcium and lime (either unslaked or air-slaked, or in the 
 form of whitewash). (See chapter on "Keeping Cold Stores 
 Clean.") Occasionally waste bittern from salt works is used, 
 but the active principle of bittern is chloride of calcium. Or- 
 dinary quicklime has the property of absorbing moisture and 
 impure gases from the air, and is used in very much the same 
 way as chloride of calcium; that is, it is placed around the 
 room on trays or pans. Lime, however, has very little ca- 
 pacity for moisture as compared with chloride of calcium, and 
 when exposed to the air it will simply air-slake, which means 
 that it will absorb moisture enough from the air to disinte- 
 grate into the form of a powder. Lime in this form is known 
 as air-slaked lime, and is used to a large extent in storage 
 rooms. Air-slaked lime as it comes from the lime house will 
 absorb very little moisture, but it gives off minute particles 
 of lime which have a good effect in preventing the growth of 
 fungus, which we have already fully discussed. Air-slaked .lime 
 is usually applied by spreading on the floor of the room, between 
 the 2x4s (which are used at the bottom of each pile of goods), 
 to the depth of an inch or more. This must necessarily be done 
 when the goods are piled, and consequently its efficiency is very 
 low when the cool weather of fall comes. This defect has been 
 overcome by scattering fresh air-slaked lime through .the rooms 
 so as to create a cloud of lime dust, but this is objected to be- 
 cause it musses up the cases. A better way of using lime is in 
 the lump form — quicklime— which can be placed around the top 
 of the room in trays or pans and renewed from time to time 
 through the season. 
 
 CHLORIDE OF CALCIUM. 
 
 Chloride of calcium is the most vigorous absorbent (or 
 drier, as it is called) which we are discussing. It is the same 
 
176 PRACTICAL COLD STORAGE 
 
 salt of the metal calcium as common salt (chloride of sodium) 
 is of the metal sodium. Both have a strong affinity for water, 
 but chloride of calcium is much the more energetic of the two. 
 Where, in a moist air, common salt simply attracts enough mois- 
 ture to become damp, chloride of calcium will absorb enough 
 water to lose its solid form entirely, uniting with the moisture 
 of the air to form a solution or brine. The strong affinity of this 
 salt for water has been utilized for the purpose of drying and 
 purifying refrigerator rooms, and in this capacity has been a 
 general favorite for years. The most primitive method of ap- 
 plying it is to place it in a simple iron pan, allowing the brine to 
 run off into a pail as fast as formed. A better way is to support 
 the calcium on a screen of galvanized wire, with a galvanized 
 pan below for catching the brine. This allows of a free circula- 
 tion of air around the calcium. This apparatus should be sus- 
 pended near the ceiling of the room, one end slightly higher, to 
 allow the brine to run off into a galvanized iron pail, supported 
 at the low end of the pan. Galvanized iron is specified because 
 black iron rusts badly when exposed to the air. (In the chapter 
 on "Uses of Chloride of Calcium" a complete description of the 
 uses of this material and illustrations of methods of applying are 
 given.) 
 
 Do not in any method of using chloride of calcium evaporate 
 the water from the brine and use the salt over again. The im- 
 purities will stay in the salt to a large extent, which is quite 
 harmful, and the calcium has at least lost its value as a purifier, 
 to a large extent. The quantity of calcium necessary depends 
 on the conditions under which it is to be used, but in any case 
 it is safe to use much more than the author saw in use in one 
 eastern house. A room about 30x50 and about fourteen feet 
 high had the refrigerant shut off, and the room was in rather 
 bad condition as to moisture, etc. In each end of the room a pail 
 was placed, on which rested a wire screen, with perhaps ten or 
 fifteen pounds of chloride of calcium on it. Electric fans were 
 playing on the calcium, which was doing its best, but it seemed 
 "like trying to dip the sea dry with a clam shell." This room 
 should have had at least two drums (about 1,200 pounds) at work 
 in it to do it justice. 
 
USES OF CHLORIDE OF CALCIUM 177 
 
 CHAPTER IX. 
 USES OF CHLORIDE OF CALCIUM. 
 
 CALCIUM CHLORIDE AS AN ABSORBENT. 
 
 Chloride of calcium is a substance which is known in chem- 
 istry as a deliquescent salt, which term means that it will become 
 liquid by the absorption of moisture from the air. It is obtained 
 as a by-product in the preparation of ammonia from ammonium 
 chloride and lime ; in the preparation of potassium chlorate from 
 calcium chlorate and potassium chloride; in the ammonia-soda 
 or Solvay process, and in the manufacture of carbon dioxide or 
 carbonic acid gas. The greater portion of the commercial prod- 
 uct comes from the waste bittern from the salt works, and the 
 Solvay process for the manufacture of soda. 
 
 The capacity of chloride of calcium for water depends 
 largely on the temperature at which the solution from which it 
 is prepared is evaporated, and to the presence of a greater or less 
 percentage of impurities (chloride of magnesium, chloride of 
 sodium, gypsum, sulphates, etc.), some of which possess com- 
 paratively little or no value as absorbents. Commercial chloride 
 of calcium, as generally prepared, holds about 25 per cent of 
 water, and it will absorb in addition to this, when exposed under 
 average conditions in cold storage rooms, somewhere from one- 
 half to nearly its own weight of water, depending on humidity of 
 the air, temperature, method of applying, etc. It is the most 
 active moisture absorber, or drier — as it is sometimes called — • 
 in common use, and because of its low price ($10 to $15 per ton), 
 it has come into general use for many purposes. In general 
 character, common salt (chloride of sodium) and chloride of 
 calcium are similar, both having strong affinity for moisture. 
 
 It is a well known fact that cold storage rooms are purified 
 to a large extent by extracting the water vapor which is held in 
 
 (12) 
 
178 PRACTICAL COLD STORAGE 
 
 suspension by the air contained in the rooms. The water vapor 
 contains a greater part of the foul gases, germs of decay, etc., 
 which are given off by the goods, or introduced into the rooms by 
 admitting impure moist air from the outside. The water vapor 
 laden with these impurities is disposed of in mechanically refriger- 
 ated cold storage rooms by being frozen on the cooling pipes. Be- 
 cause of the strong affinity of chloride of calcium for moisture, it 
 can be utilized to accomplish the same duty in moisture absorbing 
 and purification which can be accomplished by the refrigerating 
 pipes. It has been in use for years for this purpose; the nat- 
 ural ice cold storage houses having used it largely before the 
 advent of the refrigerating machine. When used in a room 
 cooled by air circulated directly from the ice, it is of very little 
 service except during very cold weather, because such a room 
 is held at a positive humidity by the air circulating continually in 
 contact with the moist surface of the melting ice. 
 
 The possibilities in the use of chloride of calcium for mois- 
 ture absorbing are well illustrated in the system of overhead ice 
 cold storage originated by Professor Nyce. (See chapter on 
 "Absorbents.") 
 
 The success of this system depends on chloride of calcium 
 as its only agent for moisture absorbing and purification, and 
 proves conclusively its value for the purpose, and those who 
 are operating mechanically refrigerated houses can take some 
 ideas from this old system which will assist them through the cold 
 weather of fall and winter, when they are obliged to discontinue 
 the flow of refrigerant through the cooling pipes. When this 
 becomes necessary, the frost on pipes must be promptly cleaned 
 off (which is at times impossible, owing to the stock of stored 
 goods in the room), or the frost will throw off water vapor which 
 is laden with impurities which have been absorbed from the air 
 of the room. The result is easy to foresee. The air becomes 
 moist and foul, and goods stored in such an atmosphere deter- 
 iorate very rapidly. The remedy for such a state of things is to 
 expose to the air of the storage rooms a large quantity of chloride 
 of calcium ; or, what is better still, this condition can be made im- 
 possible by preventing the formation of frost on pipes by the 
 application of chloride of calcium by a process invented by the 
 author, which will be described further on. 
 
USES OF CHLORIDE OF CALCIUM 
 
 179 
 
 DEVICES FOR APPLICATION. 
 
 The methods of applying chloride of calcium to the work of 
 moisture absorbing are numerous, but the devices illustrated and 
 described here have been found to do well and will fit almost any 
 case that may come up. Fig. i is a cheap, simple way of sup- 
 porting the calcium near the ceiling of room. It is best to 
 support the calcium near the ceiling, as the space is less valuable 
 and the moistest air is to be found there. The pan or trough of 
 
 FIG . l — CALCIUM SUPPORTED NEAR CEILING. 
 
 galvanized iron, shown in the sketch, should be inclined toward 
 the outlet, so that the liquid calcium will flow off into a recep- 
 tacle as fast as formed. The pan is usually suspended over the 
 alley-way between goods, so that it may readily be refilled as 
 required. These pans may be of any size and shape desired, 
 corresponding to the space which they will occupy, but in plac- 
 ing them in the room plenty of space should be left on the sides 
 for the free access of air. The pan shown in Fig. 2 is an im- 
 
180 
 
 PRACTICAL COLD STORAGE 
 
 provement on the first, in that the calcium is supported on a wire 
 screen, several inches above the pan below, allowing a free flow 
 of air around the calcium, exposing a greater surface to the 
 action of the air. The liquid dripping from above covers the 
 pan beneath with a film of brine, and the air in contact with this 
 brine will give up its moisture to some extent, resulting in a 
 more dilute brine and, consequently, greater economy in the con- 
 sumption of the calcium. In other words, a pound of the cal- 
 cium used in the device shown in Fig. 2 will absorb more mois- 
 
 ORIP 
 
 FIG. 2. — METHOD OF CONSTRUCTION OF CALCIUM PANS. 
 
 ture than the same quantity used in the device illustrated in Fig. 
 1. The general explanation of proper method of using, given in 
 connection with Fig. 1, is equally applicable to Fig. 2. These 
 pans should be constructed of galvanized iron throughout, as 
 they are exposed intermittently to the action of the chloride and 
 the dry air outside when they are out of service ; and, as the cal- 
 cium will keep them moist a long time, the action of the air in 
 connection with this moisture will cause them to rust badly. Any 
 
USES OF CHLORIDE OF CALCIUM 
 
 181 
 
 iron surface continually covered with calcium brine will rust 
 very little — no more, probably not as much, as it would if ex- 
 posed to the atmosphere under ordinary conditions. 
 
 The device shown in Fig. 3 is a more positive and powerful 
 arrangement for drying the air of storage rooms than either of 
 
 FIG. 3. — ARRANGEMENT FOR DRYING THE AIR IN ROOMS BY USING CHLORIDE 
 
 OF CALCIUM. 
 
 the two described. The chloride is placed in a tank or box on 
 wire screen shelves, as shown, and the air forced or drawn 
 through the box by an exhaust fan, which may be placed on the 
 
182 PRACTICAL COLD STORAGE 
 
 inlet or outlet end, as may be most convenient. The moist air 
 should be taken from the top of the room to be dried, and con- 
 ducted to the bottom of box, the dry air to be taken out of 
 the top of box and discharged at the opposite end of the 
 room. In this way the moist air comes first in contact 
 with the liquid calcium, or brine, which lies at the bottom of the 
 box. As the drip from the top shelves drops from one shelf 
 to another, always in contact with the air moving upward, it 
 becomes more and more dilute. It will be seen therefore that 
 the air which is moistest comes first in contact with the dilute 
 brine at bottom of tank, and last with the dryest calcium at the 
 top of box. This results in a greater economy in the use of cal- 
 cium, and gives a more perfect drying effect. The devices shown 
 in Figs, i and 2 are much slower in their action, because depend- 
 ing on the ordinary air circulation in the room to bring the air 
 containing the mixture in contact with the calcium. 
 
 COOPER CHLORIDE OF CALCIUM PROCESS. 
 
 A better method of utilizing chloride of calcium than those 
 described has been designed and thoroughly tested by the au- 
 thor. Claims fully covering this process have been allowed by 
 the patent office at Washington, and it has been put in service in 
 a large number of refrigerating plants. In this system the 
 calcium is made to perform two distinct duties, that of keep- 
 ing the pipes free of frost during warm weather, arid during cold 
 weather, that of maintaining the air of the storage room at its 
 correct degree of humidity, at the same time maintaining it 
 in a pure state. The process is applicable to any of the me- 
 chanical systems of refrigeration wherein a refrigerant is cir- 
 culated through coils of pipe, or to any system where the rooms 
 are cooled by refrigerated metal surfaces. A smaller amount of 
 surface is required to do a given refrigerating duty when the 
 pipes are clean than when the frost is allowed to accumulate 
 on the pipes, and the economy of a device which will keep 
 the refrigerating pipes free of frost at all times will be ap- 
 preciated by any person familiar with the business, as it is well 
 known that frosted pipes are insulated partly, the degree to 
 which they are insulated depending on the thickness of the coat. 
 We have Mr. E. T. Skinkle's ("The Boy") opinion that this is 
 
USES OF CHLORIDE OF CALCIUM 
 
 183 
 
 probably about as the square of the thickness of the frost. Mr. 
 John Levey states that the efficiency of the coils is increased from 
 1 5 to 25 per cent by this process. The author's process consists 
 simply in placing a quantity of chloride of calcium in proximity 
 to the refrigerating surfaces, so that the brine resulting from a 
 union of the moisture in the air with the calcium will drip over 
 the refrigerating pipes. After passing down over the pipes, the 
 brine falls onto a water tight floor, which is provided with drip 
 
 Chloride or Calcium 
 
 is. Pi 
 
 FIG. 4. — COOPER S CHLORIDE OF CALCIUM PROCESS. 
 
 connections to the sewer, or the brine may be collected and used 
 as a circulating medium in the system. This effectually and con- 
 tinually disposes of the brine which contains the moisture and 
 impurities from the air of the storage room, therefore contami- 
 nation from this source is impossible. The apparatus illustrated 
 in Fig. 4 is a simple and effective manner of applying the cal- 
 cfurn, although it can be applied in any other manner to produce 
 the desired result ; as in case of ceiling coils the calcium may be 
 placed directly on the pipe. The film of brine, covering the pipes, 
 
184 PRACTICAL COLD STORAGE s 
 
 which is produced in this way, practically prevents the, formation 
 of frost, and the cooling surfaces of the pipes are therefore 
 maintained at their maximum efficiency at all times. The eco- 
 nomical advantages of this process are great, the cost of installing 
 the apparatus very small, and the expense for calcium not large. 
 
 The disadvantages of the system are very few, if any. The 
 chief one which has been suggested so far is that the chloride of 
 calcium brine trickling over the pipe surfaces would cause the 
 pipes to rust. Rather than rust the pipes, the brine has a cleaning 
 and protective effect, and coils which have been equipped with 
 this process show freer of rust after being in service for a few 
 weeks than when first fitted up. It is generally conceded by 
 those who have observed carefully that the most favorable con- 
 dition for rusting of iron is alternately wetting and drying in the 
 presence of a free circulation of air. When the pipes are coated 
 with a film of brine, no corroding action of consequence will take 
 place, because the air cannot have free access to the surface of 
 the pipes. 
 
 The expense for chloride of calcium has also been cited as an 
 objection to the process. When it is considered that it is only 
 necessary to supply about the same weight of the salt as of the 
 frost to be kept off the pipes, it will be seen that expense for this 
 salt is of very small importance. The estimated weight of frost 
 which will accumulate on the pipes during the season in a room 
 of 20,000 cubic feet is about 2,000 pounds. The amount will vary 
 greatly with the season of the year, product stored, and whether 
 room is opened often or not, but above figures will cover average 
 conditions. The cost of calcium as compared with the economy 
 which results from maintaining clean pipes at all times is of small 
 moment, amounting to only a very small percentage of the sav- 
 ing effected by maintaining the refrigerating surfaces at their 
 maximum efficiency at all times. 
 
 To show the possibilities of this process, combined with the 
 system of forced air circulation designed by the author and fully 
 described in the chapter on " Air Circulation," the following is 
 quoted from a letter received from a gentleman using these sys- 
 tems. He says : 
 
 A remarkable thing is the small amount of cooling surface required. 
 I put eleven coils, sixteen and one-half feet long, fourteen pipes to the 
 
USES OF CHLORIDE OF CALCIUM 185 
 
 coil, in th'e coil room, and I am indeed surprised to find that with this 
 system I only need one of these coils, containing 231 feet of i-inch pipe, 
 brine entering at 14 F. from our ice tank. 
 
 This statement refers to the cooling of a room of about 
 20,000 cubic feet capacity to a temperature of 33" F. This 
 means that a lineal foot of i-inch pipe is cooling about eighty- 
 five cubic feet of space, with brine at an initial temperature of 
 14 F. 
 
 Naturally, this process, like all others, would have some limi- 
 tation as to its application; and this limitation is found when a 
 temperature of about io° F. is reached. It has been used suc- 
 cessfully in a room where the temperature was carried at 12° to 
 15° F., but when tested in a freezer at a temperature of 8° F. 
 the action of the calcium was very slow and the process inopera- 
 tive. At a temperature of 30 F. the action is rapid, and no 
 difficulty was experienced in keeping a coil of sixteen i-inch brine 
 pipes, one above another, practically free of frost. 
 
 PREPARING AND HANDLING. 
 
 The preparation of chloride of calcium for use is attended 
 with some very disagreeable features, unless a person has had 
 experience and knows the nature of the material to be handled. 
 Some of those who have used calcium have been discouraged 
 from using it again by the hard labor required to put it in shape, 
 and the wetting of floors it causes when carelessly handled. For 
 the benefit of those who have never handled this salt, and for 
 those who have experienced difficulty in its preparation, the fol- 
 lowing directions are given, which if adhered to, will make the 
 preparing of calcium for use as simple a matter as any of the 
 routine work about a cold storage warehouse. 
 
 Chloride of calcium in the commercial form comes from the 
 manufacturers in the form of a solid cake, encased in an air tight 
 sheet iron jacket. These jackets are known as drums. They are 
 simply ordinary black sheet iron of a very light gauge, and are of 
 no value, and when removed from the calcium may as well be 
 thrown away at once. The drums of calcium weigh about 600 
 pounds each, and, though heavy, are easily rolled or trucked, 
 and require very little space for storage. 
 
 For use, the calcium needs to be broken into lumps, ranging 
 in size from ten pounds downward. This is for convenience in 
 
186 PRACTICAL COLD STORAGE 
 
 handling and for the purpose of exposing a fair amount of sur- 
 face to the action of the air. For breaking the calcium select a 
 clear floor space, where nothing can be injured by the moisture, 
 which soon collects on the small pieces which are scattered in 
 breaking. Pound the drum with a sledge hammer, using strong, 
 vigorous blows, working around the drum and do not strike 
 twice in the same place (see Fig. 5), as this tends to pulverize 
 the calcium too much for easy handling and for air drying pur- 
 poses, though for brine making the finer the calcium is broken 
 the better. After pounding the drum outside thoroughly, stand 
 it on end and take off the top of the drum by prying it out with 
 an old ax or chisel. It is then an easy matter to cut down the 
 side with an ax, when the sheet iron jacket may be easily re- 
 
 FIG. 5. — BREAKING UP DRUM OF CALCIUM. 
 
 moved. Any large pieces needing further breaking may be re- 
 duced in size without much trouble by striking on the flat side. 
 It is a very simple and easy matter to break the calcium in this 
 way. An active man will prepare and place a drum in an hour 
 or two. 
 
 The calcium begins absorbing moisture from the air very 
 quickly, especially in warm, humid weather, and for this reason 
 when a drum is once broken into, it should be disposed of as 
 quickly as possible. The small pieces which fly about when the 
 cake is being broken should be swept up promptly to prevent 
 making a muss ; some dry sawdust, scattered over the place where 
 the cake was broken, will be found useful in taking up the mois- 
 ture which accumulates. As before stated, chloride of calcium 
 is of a similar character to common salt, and aside from the dis- 
 
USES OF CHLORIDE OF CALCIUM 187 
 
 agreeable property of making everything damp with which it 
 comes in contact, and keeping it so for some time, is entirely 
 harmless. 
 
 CHLORIDE OF CALCIUM BRINE. 
 
 A non-congealable liquid is used in refrigeration as a sec- 
 ondary or circulating medium for absorbing the cooling effect 
 of an expanding gas, and applying it directly to the work to be 
 done. This non-congealable liquid has been in the past usually 
 a solution of common salt in water; but of late chloride of cal- 
 cium has come into use quite generally for this purpose. Prob- 
 ably the chief reasons why it has not come into general use be- 
 fore to the entire exclusion of common salt brine, are: That it 
 is, or has been, much more expensive in first cost ; that it is more 
 difficult to prepare and handle the solution, and also that it can- 
 not be obtained everywhere like common salt. Chloride of cal- 
 cium possesses positive advantages over common salt for brine 
 making. It is now used by many of the leading engineers in the 
 business, and where once adopted, has not, in a single instance 
 known to the writer, beten discarded for common salt. As the 
 use of the so-called brine coolers have made the brine circulating 
 system more desirable, and the brine system is now in favor for 
 most purposes, the proper understanding of chloride of calcium 
 and its use should be a part of the information possessed by 
 every engineer connected with the business. 
 
 Those who have written on the subject of refrigerating ma- 
 chinery and refrigeration, have had very little to say regarding 
 the merits of the two different salts for brine purposes. Most 
 of the information formerly available relates to common salt 
 brine, which is a sort of tacit recommendation for its use; but 
 brine and brine making in a general way have until recently been 
 given very little attention by writers on refrigeration. Tn con- 
 nection with some investigations bearing on the process for pre- 
 venting frost on refrigerating pipes already described, the author 
 has collected all the available information on the general subject 
 of chloride of calcium, and all facts obtainable show that calcium 
 brine has important advantages over that made from common 
 salt. 
 
 The manufacturers or venders of chloride of calcium claim 
 that it is a better conveyor of refrigeration and that "it does not 
 
188 PRACTICAL COLD STORAGE 
 
 eat up the pipes like salt." These claims are, roughly speaking, 
 true, and if the reasons why had been given, the claims would 
 have more weight with engineers. The author's reason why 
 chloride of calcium brine will not rust refrigerating pipes has 
 already been given in connection with the explanation why cal- 
 cium brine trickling over the pipes in the frost preventing proc- 
 ess will not rust the pipes. Probably ordinary salt brine will 
 not corrode the pipes very much more on the inside, but wherever 
 it has access to the exterior of the pipes in contact with air, as 
 from a leaky joint, the corrosion and deterioration are much more 
 rapid than where calcium brine is used. It is probable that the 
 impurities encountered in common salt are responsible to a great 
 
 FIG. 6. — PIPE USED FOR FOUR YEARS WITH CALCIUM CHLORIDE. 
 
 extent for the peculiar rotting action which it has in some cases 
 on cast or wrought iron or steel. Calcium also contains damag- 
 ing impurities at times. Figs. 6, 7 and 8 illustrate the "pitting" 
 or corrosion of pipe when using salt brine, and freedom from same 
 when chloride of calcium brine is employed. The surfaces of pipes 
 moistened by common salt brine, are, owing to varying condi- 
 tions causing a tendency to dry at one season of the year and 
 become moist at another, subject to the action so favorable for the 
 corrosion of the metal. Calcium brine will not, under any con- 
 ditions to be met with in cold storage rooms, give up enough 
 water to lose its liquid form, so will not allow of a drying out on 
 the pipes except after a considerable length of time has elapsed. 
 
USES OF CHLORIDE OF CALCIUM 
 
 189 
 
 Without the aid of chloride of calcium the present perfect 
 types of brine coolers would not have been possible. Now the 
 
 FIG. 7- — INTERIOR OF A UNION USED IN SALT BRINE FOR THREE YEARS. 
 
 brine cooler is recognized as a feature of nearly all up-to-date 
 cold storage plants, and in many ice factories the brine for freez- 
 ing is cooled in a brine cooler. The saving of space, low cost, 
 
 FIG. 8. — PIPE USED FOR FIVE YEARS -WITH SALT BRINE. 
 
 and perfection of interchange of temperature between the am- 
 monia and the brine, make the brine cooler an ideal device. Op- 
 erating engineers appreciate the saving to them in care of looking 
 
190 PRACTICAL COLD STORAGE 
 
 after a large number of expansion valves scattered throughout 
 the plant. 
 
 Obviously calcium brine has a great advantage over common 
 salt brine at temperatures below zero F. Common salt brine at 
 its maximum density will freeze at about 7" below zero F., while 
 calcium brine can be made which will not freeze at 50 below 
 zero F. It will be seen that where a temperature of zero F. 
 or lower is required in cold storage rooms with brine circulation, 
 calcium brine only can be used. For a given minimum brine 
 temperature a less dense brine of calcium can be used than of 
 common salt, giving more conducting power per pound. The 
 advantages of this are that a given weight of calcium brine can 
 be made to convey more units of refrigeration than the same 
 weight of salt brine, saving in the weight and amount of brine 
 to be circulated. Chloride of calcium brine has the advantage 
 of not being liable to deposit crystals in the pipes should the 
 temperature drop below normal, and there is practically no dan- 
 ger of freezing if reasonable care is used in its preparation. Ref- 
 erence to the subjoined table shows that calcium brine has an 
 ultimate freezing point of about 54° below zero F. with a 30 
 per cent solution. A 25 per cent solution is all that is required 
 in almost any work, and for most purposes a 20 per cent solution 
 is amply dense. For ice making, where a brine temperature of 
 io c to 20 F. is carried in the tank, a brine ranging from 12 to 
 18 per cent is all that is required. The brine must, of course, 
 be strong enough to prevent ice forming on the expansion coils, 
 so that the temperature of the expanding ammonia must largely 
 regulate the density of the brine. It will be noted from the table 
 that a very strong solution of chloride of calcium has a much 
 higher freezing point than a more dilute brine. A brine contain- 
 ing too much calcium is therefore to be guarded against. The 
 most common test for brine is the salometer, a hydrometer scaled 
 from zero of pure water to 100 per cent or more, which is about 
 the point of a saturated solution of common salt brine. A Baume 
 hydrometer scale can also be used for ascertaining percentage of 
 calcium. The per cent of calcium given in the table represents 
 the total per cent, and as the commercial fused chloride of cal- 
 cium already contains about 25 per cent of water, more of this 
 article will be required for a given quantity of water than is 
 
USES OF CHLORIDE OF CALCIUM 19] 
 
 FIG. 9. — HYDROMETER IN GLASS JAR. 
 
 stated in the table. The small sub-table of approximate practical 
 proportions of the commercial calcium and water, for brine of 
 a required test, will be found useful in the making of brine. (See 
 the following page.) 
 
 The preparation of brine, using chloride of calcium, is a 
 simple matter but somewhat slower than where common salt is 
 
192 
 
 PRACTICAL COLD STORAGE 
 
 used, owing to the much smaller surface exposed to the action of 
 the water. It is difficult to break calcium by hand into small 
 grains like salt, therefore it dissolves comparatively slowly. The 
 simplest way is to put the correct proportion of calcium and 
 water in a barrel or barrels, and stir slowly with a piece of gas 
 pipe to facilitate solution. Another method is to put the correct 
 quantity of calcium and water in the brine tank, and start the 
 pumps running. The circulation of water in contact with the 
 surface of the calcium is what is necessary. Others use a steam 
 pipe lead directly into the brine tank or other receptacle. This 
 is perhaps the more rapid way, but it is not desirable, from the 
 fact that the solution may not be at the correct degree when com- 
 pleted, because of the indefinite amount of steam necessary to 
 effect a solution. It is best to have the solution amply strong at 
 first, as it can be readily reduced by adding water in sufficient 
 quantity. If the live steam method is used, a good proportion to 
 put into the brine receptable is six pounds of the calcium to each 
 gallon of water, or a drum to each ioo gallons. This will make 
 a very strong brine which can be diluted as required. In testing 
 brine it is necessary to have the solution at a temperature of 60° 
 F., as any variation from this temperature will cause error in the 
 test. The brine is easily warmed or cooled to the correct degree. 
 A glass hydrometer jar (see Fig. 9) is useful, as supplying a 
 convenient tall vessel, and the scale on the hydrometer can be 
 read more accurately than with a piece of gas pipe with a cap on 
 one end, which some use. 
 
 The following table is the one referred to above for the making 
 of calcium brine and will be found of practical value : 
 
 PRACTICAL TABLE FOR MAKING CALCIUM BRINE. 
 
 Pounds Chloride 
 of Calcium 
 (Commercial 
 
 fused) to One Gal- 
 lon of Water. 
 
 Degrees Salome- 
 ter, 6o°F. 
 
 Degrees 
 Baume, 
 60° F. 
 
 Freezing 
 
 Point, 
 
 Degrees F. 
 
 2^ 
 3 
 
 1% 
 4 
 
 4^ 
 
 5 
 
 5'A 
 
 80 
 
 88 
 
 96 
 
 104 
 
 113 
 
 IZO 
 
 20 
 22 
 24 
 26 
 28 
 30 
 32 
 
 4 
 
 — 3 
 
 — 9 
 -17 
 —27 
 
 — 39 
 —54 
 
USES OF CHLORIDE OF CALCIUM 
 
 193 
 
 PROPERTIES OF SOLUTION OF CHLORIDE OF CALCIUM. ( CALCIUM 
 
 BRINE. ) 
 
 b 
 
 
 
 6 . 
 
 
 
 a 
 
 
 o 
 O 
 
 b 
 
 
 
 sa 
 
 <->.3 
 
 .5 
 '0 
 
 ~.2 
 
 O 
 
 ffl 
 
 ID 
 
 a - 
 o ^ 
 
 
 
 to 
 
 
 £6 
 
 «^1 
 
 .9 • 
 
 5 » 
 
 . rt 
 
 '3 
 
 X 
 
 g g 
 
 £S 
 
 'o"> 
 
 o° 
 
 N V <u 
 
 u ^ t- 
 
 
 a 
 
 '0 
 
 m° 
 
 M3 
 
 V rf 
 
 "■§ 
 
 S 0fJ3 
 
 " Sf 
 
 a 
 
 u 
 
 °> ca 
 
 <u rt 
 
 0. u 
 
 
 u <"> rt 
 
 U « 
 
 0. 
 
 Qtn 
 
 sn 
 
 wO 
 
 P. "S 
 
 IcQh 
 
 fcQ 
 
 < 
 
 W 
 
 
 
 
 
 
 Pressures. 
 
 
 4 
 
 1 
 
 1.007 
 
 1 
 
 - -31.IO 
 
 — -5 
 
 46 
 
 .996 
 
 8 
 
 2 
 
 1. 015 
 
 2 
 
 --30.38 
 
 — -9 
 
 45 
 
 .988 
 
 12 
 
 3 
 
 I.024 
 
 3 
 
 - -29.48 
 
 — i-4 
 
 44 
 
 .980 
 
 16 
 
 4 
 
 I.032 
 
 4 
 
 --28.58 
 
 — 1-9 
 
 43 
 
 .972 
 
 22 
 
 5-5 
 
 1. 041 
 
 5 
 
 --27.68 
 
 — 2.4 
 
 41-5 
 
 .964 
 
 26 
 
 6-5 
 
 I.049 
 
 6 
 
 --26.60 
 
 — 3-° 
 
 39-5 
 
 .960 
 
 32 
 
 8 
 
 1.058 
 
 7 
 
 --25.52 
 
 -3-6 
 
 38 
 
 •936 
 
 36 
 
 9 
 
 1.067 
 
 8 
 
 --24.26 
 
 — 4-3 
 
 37 
 
 •925 
 
 40 
 
 10 
 
 1.076 
 
 9 
 
 --22.8 
 
 — 5-i 
 
 35-5 
 
 .911 
 
 44 
 
 11 
 
 I.085 
 
 10 
 
 --2I.3 
 
 — 5-9 
 
 34 
 
 .896 
 
 48 
 
 12 
 
 I.094 
 
 11 
 
 --I9.7 
 
 — 6.8 
 
 32-5 
 
 .890 
 
 52 
 
 13 
 
 1. 103 
 
 12 
 
 --18.I 
 
 — 7-7 
 
 3°-5 
 
 .884 
 
 58 
 
 14-5 
 
 i.II2 
 
 13 
 
 --I6.3 
 
 -8.7 
 
 28 
 
 .876 
 
 62 
 
 15-5 
 
 1. 121 
 
 14 
 
 --I4-3 
 
 -9.8 
 
 26 
 
 .868 
 
 68 
 
 17 
 
 I.I3I 
 
 15 
 
 --12.2 
 
 — 11. 
 
 23-5 
 
 .860 
 
 72 
 
 18 
 
 1. 140 
 
 16 
 
 --10.0 
 
 — 12.2 
 
 21.5 
 
 .854 
 
 76 
 
 19 
 
 1. 150 
 
 17 
 
 -- 7-5 
 
 —13.6 
 
 20 
 
 •849 
 
 80 
 
 20 
 
 I-I59 
 
 18 
 
 --4.6 
 
 —15-2 
 
 18 
 
 •844 
 
 84 
 
 21 
 
 1. 169 
 
 19 
 
 + 1.7 
 
 —16.8 
 
 15 
 
 •839 
 
 88 
 
 22 
 
 1. 179 
 
 20 
 
 — i-4 
 
 —18.6 
 
 12.5 
 
 .834 
 
 92 
 
 23 
 
 1. 189 
 
 21 
 
 — 4-9 
 
 —20.5 
 
 10.5 
 
 .825 
 
 96 
 
 24 
 
 1. 199 
 
 22 
 
 — 8.6 
 
 — 22.6 
 
 8 
 
 .817 
 
 100 
 
 25 
 
 1.209 
 
 23 
 
 — 11.6 
 
 —24.8 
 
 6 
 
 .808 
 
 104 
 
 26 
 
 1. 219 
 
 24 
 
 —17. 1 
 
 —27-3 
 
 4 
 
 •799 
 
 108 
 
 27 
 
 1.229 
 
 25 
 
 —21.8 
 
 —29.9 
 
 i-5 
 
 Vacuum, 
 
 .790 
 
 112 
 
 28 
 
 1.240 
 
 26 
 
 — 27.9 
 
 —32.8 
 
 I 
 
 .778 
 
 116 
 
 29 
 
 1.250 
 
 27 
 
 —32.6 
 
 —35-9 
 
 5 
 
 .769 
 
 120 
 
 3° 
 
 1. 261 
 
 28 
 
 —39-2 
 
 —39-6 
 
 8-5 
 
 •757 
 
 
 3 1 
 
 1.272 
 
 29 
 
 —46-3 
 
 —43-5 
 
 12 
 
 
 
 32 
 
 i,a83 
 
 30 
 
 —54-4 
 
 —48.0 
 
 15 
 
 
 
 33 
 
 1.294 
 
 3i 
 
 —52-5 
 
 —46.9 
 
 10 
 
 
 
 34 
 
 i-3°5 
 
 32 
 
 —39-2 
 
 —39-6 
 
 4 
 
 
 
 35 
 
 1.316 
 
 33 
 
 —25.2 
 
 —31.8 
 
 i-5 
 
 
 
 35-5 
 
 1-327 
 
 34 
 
 — 9-7 
 
 —23.2 
 
 
 
 
 36-5 
 
 1.338 
 
 35 
 
 + 2.8 
 
 — 16.2 
 
 
 
 
 37-5 
 
 1-349 
 
 36 
 
 +H-3 
 
 — 9.8 
 
 
 
 Note.— The + sign denotes temperature above zero, the — sign, 
 temperature below zero. 
 
 A part of the preceding tables and some of the informa- 
 tion contained therein has been kindly supplied by the manu- 
 facturers of chloride of calcium, and while the tables have been 
 proved inaccurate, they will answer for practical purposes. 
 
 (13) 
 
194 PRACTICAL COLD STORAGE 
 
 CHAPTER X. 
 EGGS IN COLD STORAGE. 
 
 IMPORTANT FACTORS TO BE CONSIDERED. 
 
 Eggs are the most important product now taken care of by 
 cold storage methods, both as regards aggregate value and bene- 
 fits to the community. They are also among the most difficult 
 products to successfully refrigerate. Over five years ago the 
 author estimated the total value of eggs under refrigeration for 
 safe keeping at about $20,000,000 annually for the United States 
 alone. Statistics show that the consumption of eggs doubles 
 about every five years. <■ -Therefore the value of eggs annually 
 cold stored in the United States at this time (1904) cannot be 
 very far from $40,000,000. Appreciating the importance of the 
 industry and the lack of accurate information available, the author, 
 in the interest of a better understanding and dissemination of 
 knowledge on the cold storage of eggs, communicated with quite 
 a large number of individuals and companies, requesting that 
 they give full answers to a printed list of questions sent them. 
 The result has been most gratifying ; nearly one-half of those writ- 
 ten to acknowledged receipt of the inquiry, and more than one- 
 half of this number gave fairly complete replies to the questions 
 submitted. Considering the fact that the inquiries were regarded 
 by some as being of a rather personal nature, the proportion of 
 managers sending replies in full is large. Several gentlemen 
 were frank enough to say that personal considerations prevented 
 them from giving any information; others gave guarded or 
 partial replies. In the main, however, storage men have shown 
 themselves willing to give information and exchange ideas. 
 
 The list of inquiries sent out covers the subject quite thor- 
 oughly, and divides it into six different parts, namely, tempera- 
 ture, humidity, air circulation, ventilation, absorbents and pack- 
 ages, with three separate questions relating to each. To the data 
 
EGGS IN COLD STORAGE 195 
 
 so cheerfully furnished- by others is added information from the 
 author's experience and practice with such explanation of theory 
 and practice as may seem necessary to a clear understanding of 
 the principles of successful egg refrigeration. It is hoped that 
 those who are new to the business may obtain valuable informa- 
 tion from these collected data, and that those with experience may 
 derive some benefit in the way of a review, and possibly pick up 
 some new ideas as well. 
 
 TEMPERATURE. 
 
 Questions regarding the correct temperature of egg rooms 
 have been asked repeatedly of storage men who have been in the 
 business long enough to be looked to for advice, the same person, 
 perhaps, giving a different answer from time to time, as his 
 ideas change. At present there is no temperature on which a 
 large majority of persons can agree as being right, and as giving 
 superior results to any other. The claims made by the advocates 
 of different temperatures will be considered, to determine, if 
 possible, what degree is giving the best results in actual practice. 
 The three questions relating to temperature were written 
 to draw out opinion as to the right temperature, the lowest safe 
 -temperature, and what deleterious effect, if any, the egg sus- 
 tained at low temperatures, which did not actually congeal the 
 egg meat. The three temperature queries were : 
 
 First. — At what temperature do you hold your rooms for 
 long period egg storage? 
 
 Second. — What temperature do you regard as the lowest 
 limit at which eggs may be safely stored? 
 
 Third. — What effect have you noticed on eggs held at a 
 lower temperature? 
 
 All the replies received contained answers relative to tem- 
 perature, and by a very small majority 32° F. is the favorite 
 temperature for long period egg storage. Some few, 33° F. and 
 34° F., with a few scattering ones up to 40° F. Under the freez- 
 ing point, none recommended a temperature lower than 28° F., 
 and for a very obvious reason, this being near to the actual freez- 
 ing temperature of the albumen of a fresh egg. A very respect- 
 able minority say a temperature ranging from 30° F. to 31° F. 
 is giving them prime results; and several recommend 30 F. 
 
196 PRACTICAL COLD STORAGE 
 
 straight, and say they should go no lower. In recent years there 
 has been a decided tendency among storage men to get the tem- 
 perature down near the safety limit, but many houses are so 
 poorly equipped that they are unable to maintain a uniform low 
 temperature below 33° F., without danger of freezing eggs where 
 they are exposed to the flow of cold air from coils. A house 
 must be nicely equipped to maintain low temperatures with 
 safety. More houses would use temperatures under 32° F. were 
 they able to without danger to the eggs. A very successful 
 eastern house issued a pamphlet in 1892. At that time they 
 maintained a temperature of from 32 to 34° F. in their rooms. 
 In sending out this little book during the winter of 1897-98 a post- 
 script was added, as follows: "This pamphlet was published 
 in 1892, when our plant was started. Since that time all first- 
 class cold storage houses have lowered their temperatures ma- 
 terially." No better illustration than this can be cited to show 
 the tendency of the times. These people now use a temperature 
 of 30 F. for eggs. 
 
 Most of the replies received contained answers to the second 
 question, and the greater portion state this as being about 2° F. 
 lower than that recommended for long period storage. It is 
 presumed that these two degrees are allowed as leeway, or margin 
 of safety, for temperature fluctuations. Some state that eggs 
 cannot be safely held below 32° F., but give no reason why, while 
 two or three say a temperature of 27° F. will do no harm to 
 eggs in cases. One reply states that eggs held in cut straw at 
 25° F. for three months showed no bad symptoms. It has never 
 been made clear how the package can be any protection against 
 temperature, when the temperature has been continuously main- 
 tained for a length of time sufficient to allow the heat to escape; 
 and we know that eggs will positively freeze at 25° F., as proven 
 by experiments mentioned in another paragraph. 
 
 The answers to the third question were few in number, but 
 cover a wide range. The scarcity of data on this point indicates 
 that few have experimented with eggs at temperatures ranging 
 from 25" F. to 30° F. Some say: "dark spot, denoting germ 
 killed" ; others, "white gets thin" ; others, "eggs will decay more 
 quickly"; or, "they will not 'stand up' as long when removed 
 from storage." It is also claimed that "yolk is hardened or 
 
EGGS IN COLD STORAGE 197 
 
 'cooked' when temperature goes below 32° F." Some answers 
 state a liability of freezing if eggs are held in storage at a tem- 
 perature below 32° F. for any length of time. 
 
 As far as possible, we will dig out reasons for the claims 
 made by advocates of both high and low temperatures, both 
 having equal consideration. Taking 29° F. or 30 F. and 38 F. 
 or 40° F., as representing the lowest and highest of general prac- 
 tice, we will see what is claimed by each; and also the faults of 
 the other fellow's way of doing it, as they see it. Those who are 
 holding their egg rooms at 40° F. say it is economical, that the 
 eggs keep well,' that the consistency of the egg meat is more 
 nearly like that of a fresh egg after being in storage six months, 
 than if held at a lower temperature. As against a low temper- 
 ature they say : A temperature of 30° F. is expensive to main- 
 tain; the yolk of the egg becomes hard and the white thin, after 
 being in store for a long hold ; and that when the eggs are taken 
 from storage in warm weather it will require a longer time to 
 get through the sweat than if held in storage at a somewhat 
 higher temperature, resulting in more harm to the eggs. Some 
 claim that the keeping qualities are impaired by holding at a 
 temperature as low as 30 F., and others note a dark spot, or 
 clot, which forms in the vicinity of the germ, when eggs are held 
 below 33 F. Against this formidable array of claims, the low 
 temperature men have some equally strong ones, although fewer 
 in number. They say: "There is very much less mildew, or 
 must, at 30° F. than at temperatures above 32 ° F. ; the amount 
 of shrinkage or evaporation from the egg is less ; an egg can be 
 held sweet and reasonably full at this temperature from six to 
 eight months." This last claim is a broad one, and comparatively 
 few houses are turning out eggs answering to this description. 
 
 The following, relating to high temperatures, is quoted from 
 a letter written by one of the best posted men in the business, who 
 has spent much money and time on experiments, and studied the 
 question for years. He says : "A temperature of 40 F. is very 
 good for three months' holding, but if they run over that, it is 
 more than likely the eggs will commence to cover with a white 
 film, which grows the longer they stand, and finally makes a 
 musty egg." This gentleman advocates a temperature of 30° F. 
 for long period holding. It should- be noted that the high tern- 
 
198 PRACTICAL COLD STORAGE 
 
 perature men ignore entirely the effect of high temperatures on 
 the growth of this fungus, spoken of above as a white film. The 
 worst thing about most storage eggs is the taste caused by this 
 growth (usually called mildew or mold), which results in what 
 is commonly called a musty egg. To enable us to understand the 
 validity of these claims made by the 30° F. people, it will be 
 necessary for us to ascertain the conditions which are favorable, 
 and also the conditions which are unfavorable for the propagation 
 of this growth of fungus, which has given storage men so much 
 trouble, ever since cold storage was first used for the preserva- 
 tion of eggs. 
 
 Heat and moisture are the two conditions leading to its 
 rank growth, and the opposite — dryness and cold — will retard 
 or stop the growth entirely. In moist, tropical countries many 
 species of this parasite grow, while in the cold, dry regions of 
 the north its existence is limited to a single variety. The causes 
 leading to a growth of the fungus on the outside of an egg are not 
 far to seek. It feeds on the moisture and products of decom- 
 position which are being constantly given off by an egg, from 
 the time it is first dropped until its disintegration, unless im- 
 mersed in a liquid, or otherwise sealed from contact with the 
 air. This evaporation not only takes moisture from the egg, 
 but carries with it the putrid elements from the egg tissue, re- 
 sulting from a partial decomposition of the outer surface of the 
 egg meat. Conditions of excessive moisture and the presence of 
 decaying animal or vegetable matter, together with a moderate 
 degree of heat, are essential to the formation of fungus of the 
 species which are found growing on eggs in cold storage. As 
 the heat and moisture are increased, the growth of fungus will 
 be proportionate. Furthermore, we all understand that heat 
 hastens decomposition, and the partial decomposition of an egg 
 results in a growth of the fungus, as before explained, when 
 conditions of temperature and humidity are favorable. If the 
 temperature is low, this growth is slow ; for instance, if eggs are 
 held at a temperature of 30° F in an atmosphere of given hu- 
 midity, the growth of fungus is less rapid than if held at any 
 temperature higher, with the same per cent of humidity. As our 
 subject merges into humidity here, the reader is referred to what 
 is said in regard to this under the head of "Humidity." 
 
EGGS IN COLD STORAGE 199 
 
 Returning to the objections urged against low temperatures, 
 we will see what damage is claimed from the use of a tem- 
 perature of 29° to 30" F. The objections are : Liability of freez- 
 ing; germ is killed; white becomes thin; yolk is hardened, and 
 eggs will not keep as long when removed from storage. Some 
 interesting results are obtained from experiments made by the 
 author. Half-rotten or "sour" eggs freeze at temperatures just 
 a trifle under 32° F. Fresh eggs freeze at 26 to 27" F. In 
 testing eggs which had been held in storage for several months, 
 it was noted that the freezing point had been reduced from 1° 
 to 2 F. An egg which is leaky will freeze at 2° to 3° higher 
 temperature than one which is sound, probably owing to the 
 evaporation from the uncovered albumen resulting in a lower 
 temperature. The freezing point of eggs, as above, is under- 
 stood as being the degree at which they begin to form ice crystals 
 inside. Of the replies received touching on the freezing point of 
 eggs, nearly all agree with above experiments. The "dead germ" 
 theory the author has never been able to locate in fact, having 
 never seen anything of the kind in eggs held as low as 28 ° to 29° 
 F. for several weeks' time ; nor in eggs held at 30° F., or a trifle 
 under, through the season. As only two or three mention having 
 noted this result, it would seem that some local conditions, and 
 not low temperature, were responsible. 
 
 The matter of the white becoming thin when eggs are 
 held at low temperatures has some bearing ; in fact, any egg held 
 at a cold storage temperature for a long carry will show this 
 fault, to a certain extent, especially if cooled quickly when stored, 
 or warmed suddenly when removed from storage. It is the au- 
 thor's opinion that a difference of 4° to 6° F. in carrying tem- 
 perature will not be noticeable in its effect on the albumen of an 
 egg; and as to the effect of a low temperature on the egg yolk, 
 it has been demonstrated that any temperature, which will not 
 actually congeal the albumen, will not harm the yolk of an egg. 
 There is a slight tendency, in this case, to a similar effect to that 
 produced by a low temperature on cheese; that is, causes it to 
 become "short" or crumbly. 
 
 In regard to a low temperature egg not keeping as long when 
 removed from storage, it has been the experience of the author 
 that no difference was noted between eggs put out from storage 
 
200 PRACTICAL COLD STORAGE 
 
 and the current receipts of fresh eggs, so far as any complaint 
 or objection was concerned, the eggs being shipped in all di- 
 rections, in all weathers and subject to many different conditions. 
 A test was also made, by placing three dozen of eggs, which had 
 been carried in storage at a temperature of 28° to 30° F. for five 
 months, in a case along with three dozen fresh eggs. After three 
 weeks no pronounced change was noted in either, both showing 
 considerable evaporation as a result of exposure to the dry fall 
 atmosphere. They were exposed to the temperature of the re- 
 ceiving room, fluctuating from 50° F. to 80° F. The eggs from 
 storage went through a "sweat," while the fresh were not sub- 
 jected to any such trial. As most eggs are consumed inside of 
 three weeks after being removed from storage, this would seem 
 like a good practical test of the vitality of a low temperature 
 egg. A mere matter of economy between holding a room at 
 40 F. and from 29 ° to 30° F., while readily appreciated and ad- 
 mitted, seems of very small importance, when a positive advan- 
 tage can be obtained by carrying eggs at the lower temperature; 
 and a difference of from 4 to 5° F. would be scarcely worth con- 
 sidering. 
 
 An advantage of low temperature, not yet mentioned, is the 
 increased stiffness, or thickness, of the white of the egg while in 
 storage, holding the yolk in more perfect suspension. When 
 eggs are held at a temperature of 36 F., or above, for any period 
 longer than four months, the yolk has a decided tendency to rise 
 and stick to the shell, causing rotten eggs, known as "spots." It 
 is usually understood that the yolk settles; but, being of a fatty 
 composition, it is lighter than the albumen, and rises instead. 
 If the albumen is maintained in a heavy consistency, the yolk 
 is retarded from rising, and held in a more central position. It 
 was long a practice with storage men to turn eggs at least once 
 during the season, to prevent the above trouble, and some recom- 
 mend it even now; but the practice has been generally aban- 
 doned with the advent of low temperatures for egg storing. 
 
 When eggs are put in cold storage they should not be cooled 
 rapidly. The effect on the egg tissues is bad — they should have 
 time to rearrange themselves to the changed temperature. This 
 is especially true where eggs are placed in storage in extreme 
 warm weather. Sudden warming is also detrimental to the wel- 
 
EGGS IN COLD STORAGE 201 
 
 fare of an egg, for a similar reason to above. The most notice- 
 able effect of either is a thinned albumen. If this process of 
 cooling and warming could be accomplished slowly (which is 
 not always practicable commercially), a well kept storage egg 
 would come out of storage with nearly the same vitality it had 
 when fresh. 
 
 HUMIDITY. 
 
 Information on the subject of humidity, as applied to the 
 cold storage of eggs, is very meager. Not more than a dozen 
 of the replies received in answer to the list of inquiries sent out 
 contain information on the three queries under the head of hu- 
 midity. Considering the amount of talk we have all heard, with 
 dry air as a subject, this scarcity of knowledge is rather sur- 
 prising. Those who have had experience with cold storage work 
 and the products handled are well aware that an essential for 
 good results in egg refrigeration is a dry atmosphere in the egg 
 room; but just how dry, very few are able to give even an ap- 
 proximate estimate. Very likely if a cold storage man is asked 
 in regard to it, he will reply that an egg room should be "neither 
 too moist nor too dry." What this "happy medium" is, that will 
 not shrink or evaporate the eggs badly, and yet keep down the 
 growth of fungus to a minimum, is what all are striving for, and 
 very few have the means of knowing when this point is reached. 
 A few years ago a prominent commission man, in conversation 
 with the author, speaking of storage eggs, said: "You storage 
 men are between the devil and the deep sea. You always shrink 
 'em or stink 'em" ; meaning that eggs which were held long in 
 storage would show either a considerable evaporation or a radical 
 "musty" flavor. To some extent this is true, but with a pene- 
 trating circulation, careful ventilation and a judicious use of 
 absorbents (all of which are considered under their proper heads) 
 eggs can be, and are, turned out of storage without this strong, 
 foreign flavor, and with little evaporation or shrinkage. 
 
 The questions relating to humidity were written with a full 
 understanding of the scarcity of information on the subject, 
 and were designed to locate, if possible, those who were making 
 tests of air moisture, and get opinions on the correct humidity 
 for a given temperature. The following are the queries : 
 
202 PRACTICAL COLD STORAGE 
 
 First—What tests, if any, have you. made of the dryness 
 or humidity of your egg rooms? 
 
 Second. — What per cent of air moisture do you find gives 
 the best results at the temperature you use? 
 
 Third. — What instrument do you use for testing air moisture? 
 
 The first and third questions are practically the same, the 
 latter being written simply to make the query more plain and 
 indicate whether an instrument or some other test was used for 
 determining air moisture. Four houses reporting are using the 
 dry and wet bulb thermometers ; the others are using hygrometers 
 of French or German make. 
 
 The answers to the second question vary greatly; some also 
 giving the actual testing humidity of their rooms and their opinion 
 of a correct degree as well. From 70 to 80 per cent of humidity 
 is the test of nearly all reporting, and of the rooms tested by 
 the author, nearly all show a similar humidity, with one occa- 
 sionally going as high as 85 per cent, and some as low as 65 
 per cent. Two answers recommend a humidity of 65 per cent, 
 and one a humidity of 60 per cent, with a temperature of 30° 
 to 32" F. Others hold that their testing humidity of 70 to 80 
 per cent is correct. 
 
 Under the head of "Temperature," it is stated that: "If 
 eggs are held at a temperature of 30° F. in an atmosphere of a 
 given humidity, the growth of fungus is less rapid than if held 
 at any temperature higher with the same per cent of humidity.'' 
 By referring to the table on page 168 we see that a cubic foot 
 of air, when saturated at a temperature of 40 F., contains 2.85 
 grains of water vapor, while at 30 F. it contains but 1.96 grains, 
 or only about two-thirds as much as at 40° F. 
 
 The same holds true with any relative humidity, the same 
 as when the air is saturated. Take, for instance, air at a tem- 
 perature of 40° F., with a humidity of 75 per cent, then a cubic 
 foot of air holds 2.14 grains of water vapor per cubic foot; and 
 at a temperature of 30 F., with the same relative humidity, it 
 would hold but 1.47 grains. This great difference in the amount 
 of moisture contained in the air at different temperatures, and 
 still having the same relative humidity, has as radical an effect 
 on the growth of fungus as does the difference in temperature. 
 This is no mere theory, as the writer has demonstrated it, to his 
 
EGGS IN COLD STORAGE 203 
 
 own satisfaction, at least, during several seasons' observation. 
 If it is hoped to keep down the growth of fungus in a temperature 
 of 40° F. by maintaining an atmosphere with a lower relative 
 humidity, the result is a badly evaporated egg, which loses its 
 vitality and value very rapidly when held in storage for a term 
 exceeding three or four months; the white becomes thin and 
 watery, with a strong tendency to develop "spot" rotten eggs. 
 As the fullness or absence of evaporation is of only secondary 
 consideration to their sweetness, when eggs are tested by buyers, 
 it is necessary to prevent this trouble if the eggs turned out from 
 storage are to be considered first-class. 
 
 From the foregoing it seems clear that to turn out sweet 
 eggs at a temperature of 40° F. it is necessary to maintain a 
 lower relative humidity than at any temperature lower, and the 
 result cannot fail to be as described. The author has already 
 given a summary of the replies to the questions relating to hu- 
 midity, which are few in number, and not very complete. A 
 little is better than nothing, however, and by comparing his own 
 data with the results obtained by others, and paying careful at- 
 tention to their opinions, the following table of correct humidity 
 for a given temperature in egg rooms has been compiled. There 
 are no data on the subject in print, so far as known, and no 
 claim for absolute accuracy is made in presenting this first effort 
 in that direction, but as the figures are taken from actual re- 
 sults, no great mistake can be made by depending on them. The 
 percentages of humidity given are modified, to some extent, by 
 the intensity and distribution of the air circulation employed : 
 
 RELATIVE HUMIDITY FOR A GIVEN TEMPERATURE IN EGG ROOMS. 
 
 Temperature Relative Humidity, 
 
 In Degrees F. Per Cent 
 
 28 8s 
 
 29 83 
 
 30 80 
 
 31 79 
 
 32 75 
 
 33 74 
 
 34 7° 
 
 35 68 
 
 36 66 
 
 37 64 
 
 38 6l 
 
 39 59 
 
 i 40 50 
 
204 PRACTICAL COLD STORAGE 
 
 CIRCULATION. 
 
 A vigorous and penetrating circulation of air must be main- 
 tained in a cold storage room for eggs if good results are to be 
 insured, and the importance of this condition is quite generally 
 appreciated. It is also a fact that a strong, searching circulation 
 will do much to counteract defects in a cooling apparatus, or wrong 
 conditions in the egg room in some other particular. 
 
 The reason why a vigorous and well distributed circulation 
 of air in an egg room will give superior results over a sluggish 
 or partial circulation may not be readily apparent. A circulation 
 of air is of benefit in combination with moisture absorbing capacity 
 in the form of frozen surfaces or deliquescent chemicals. Stirring 
 up the air merely, as with an electric motor fan, without pro- 
 vision for extracting the moisture, is of doubtful utility, and 
 may, in some instances, prove positively detrimental, as it is 
 liable to cause condensation of moisture on the goods, or walls 
 of storage room, instead of its correct resting place — the cooling 
 coils and absorbents. Let us see how the circulation of air in 
 a storage room operates to benefit its condition. 
 
 Under head of "' Temperature," we have seen that the evap- 
 oration from an egg contains the putrid elements resulting from a 
 partial decomposition of the egg tissues, and that the air of a 
 storage room carries them in suspension. It is probable that 
 these foul elements are partly in the form of gases absorbed in 
 the moisture thrown off from the egg; and if, therefore, this 
 moisture is promptly frozen on the cooling pipes, or absorbed by 
 chemicals, the poisonous gases and products of decomposition 
 are very largely rendered harmless. This is also true of the 
 germs which produce mold and hasten decay, which are ever 
 present in the atmosphere of a storage room, being carried to a 
 considerable extent by the water vapor in the air, along with 
 the foul matter of various kinds referred to. If the vapor laden 
 air surrounding an egg is not removed and fresh air supplied 
 in its place, the air in the immediate vicinity of the egg becomes 
 fully charged with elements which will produce a growth of 
 fungus on its exterior, affecting and flavoring the interior — the 
 flavor varying in intensity, depending on how thoroughly im- 
 pregnated with fungus-producing vapor the air in which the 
 egg is kept may be. In short, then, circulation is of value because 
 
EGGS IN COLD STORAGE 205 
 
 it assists in purifying the air. It should be kept up so that the 
 air may be constantly undergoing a purifying process to free it 
 from the effluvia which is always being thrown off by the eggs, 
 even at very low temperatures. 
 
 The questions bearing upon circulation contained in the 
 list of inquiries sent out by the author are as follows : 
 
 First. — In piping your rooms what provision was made for 
 air circulation? 
 
 Second. — What difference in temperature do you notice in 
 different parts of the same room? 
 
 Third.— Do you use a fan or any kind of mechanical device 
 for maintaining a circulation of air in the rooms? 
 
 More answers were received on this subject than on the 
 subject of humidity, but not exceeding one-third contained prac- 
 tical replies to all three inquiries. Several of the answers con- 
 founded circulation with ventilation, as before alluded to. The 
 first question, in particular, was badly neglected, indicating, no 
 doubt, that no provision was made for circulation in a majority 
 of cases. The common device in use for causing air to circulate 
 more rapidly over the cooling coils, when they are placed directly 
 in the room, is some form of screen, mantle, apron, false ceiling 
 or partition. Many of these have been put up after the house 
 has been in operation for some time, and are very crude affairs, 
 applied in all conceivable combinations with the pipe coils. In 
 some cases canvas curtains, or a thin wooden screen, have been 
 suspended under ceiling coils with a slant to cause the cold air 
 to flow off one side, and with surprising improvement to the 
 room, considering the simplicity of the device. Forced circula- 
 tion with a complete system of distributing air-ducts is coming 
 into general use, as the merits of this way of producing circula- 
 tion are better understood and appreciated. 
 
 The second question was answered more generally, but that 
 some of the answers were mere guesses, 1 '- or statements made 
 without testing, is very evident, as they state that no difference 
 was noticed in different parts of the same room. With open 
 piping or gravity air circulation, this is aH- impossibility — it is 
 only possible with a perfectly designed forcedf^irculation system. 
 In contrast to this claim some answers state a difference in tem- 
 perature of as high as 4° to 5° F., but most answers show a 
 
206 PRACTICAL COLD STORAGE 
 
 difference of i° to 2° F. ; a few of Yi° to i° F. ; and, still 
 others, as before stated, none at all. A marked variation of tem- 
 perature in different parts of a room, while in most cases caused 
 by defective circulation, is due sometimes partly to location of 
 room as to outside exposure, proximity to freezing rooms, char- 
 acter of the insulating walls, etc. An egg room placed over 
 a low temperature freezing room will show more variation be- 
 tween floor and ceiling than when located over another egg 
 room, conditions being otherwise the same. Where this ar- 
 rangement occurs, and the egg rooms are operated on a natural 
 gravity air circulation system, eggs may be frozen near the floor, 
 when a thermometer hanging at the height of a person's eyes 
 would read 30 F. or above. Even with the very best insulation, 
 the result of this very common arrangement is a defective cir- 
 culation and more or less variation in temperature between floor 
 and ceiling. 
 
 In reply to the third question, about a dozen state that they 
 are using some form of mechanical forced circulation. The ad- 
 vantages of this method are discussed quite fully elsewhere in 
 this book. About double this number are using the small electric 
 fans. These also have been treated in the discussion of mechan- 
 ical air circulation in another chapter. 
 
 As air circulation is a somewhat neglected subject, and 
 comparatively few have experimented enough to have positive 
 opinions, based upon practical experience, regarding the merits 
 of different devices and methods, some of the more prominent 
 and successful ones are illustrated and discussed elsewhere in this 
 book. (See chapter on "Air Circulation.") 
 
 VENTILATION. 
 
 The introduction of a large volume of fresh air is not es- 
 sential for the purpose of purifying rooms in which eggs are 
 stored, because the accumulation of permanent gases in an egg 
 room is quite slow, comparatively (as in rooms where well ripened 
 fruit is stored) ; but a small supply of fresh air continuously, or 
 at regular intervals, is of much benefit. 
 
 The questions referring to ventilation contained in the letter 
 of inquiry sent out by the author are as follows : 
 
 First. — What plan do you pursue in ventilating egg rooms? 
 
EGGS IN COLD STORAGE 207 
 
 Second. — Under what circumstances and how often do you 
 ventilate ? 
 
 Third. — How often do you consider it advisable to make a 
 complete change of air? 
 
 Outside of a bare dozen, the replies on this much-talked-of 
 subject were of no value whatever for our purpose. Most of 
 those answering do not ventilate ; many others get their ventila- 
 tion through the opening of doors ; some ventilate through an ele- 
 vator shaft, by opening doors at top and bottom, etc. Only three 
 or four were properly cooling and drying the air before intro- 
 ducing it into the egg rooms. One successful storage manager 
 says that : • "It is trouble enough to take microbes, bacteria, 
 moisture, etc., out of one batch of air" (meaning the air in his 
 rooms at the beginning of the season), without adding to his 
 troubles by sending in more air loaded down with the same 
 mischief makers. As pointed out in the chapter on "Ventila- 
 tion,'' unless the air to be used for purifying the rooms is itself 
 first cooled and purified, this man's idea is perfectly correct. 
 Ventilated egg rooms will, however, turn out eggs which are in 
 every way better than from rooms not ventilated, other conditions 
 being equal. Eggs from ventilated rooms are clearer and stronger 
 bodied (albumen thicker) than from non-ventilated rooms. 
 
 No accurate data have yet been established regarding the 
 volume of fresh air which is advisable to use for ventilating egg 
 rooms, but it is a simple and inexpensive matter to supply enough, 
 and too much cannot be used if it is first properly dried and 
 purified and brought to about the same temperature as that of 
 the storage room. Ordinarily it is unnecessary to ventilate egg 
 rooms until filled with goods and closed for the season. After 
 a short time (two to four weeks) begin ventilating, as the accu- 
 mulation of gases commences at once as soon as the rooms are 
 permanently filled and closed. Ventilate in small quantities and 
 for several hours at a time once or twice a week, rather than in 
 large quantities less often. 
 
 For a discussion of the principles involved and mechanical 
 details of this subject see chapter on "Ventilation." 
 
 ABSORBENTS. 
 
 The letter of inquiry sent out by the author contained three 
 questions referring to absorbents, written with an idea of ascer- 
 
208 PRACTICAL COLD STORAGE 
 
 taining the coating used for the walls of a storage to the greatest 
 extent; what absorbent was the favorite, and in what manner 
 applied. The questions are as follows : 
 
 First. — Do you use an absorbent or purifier in your egg 
 
 rooms 
 
 ? 
 
 Second. — In what way do you use or apply them ? 
 
 Third. — Do you paint or whitewash? What kind and how 
 often applied? 
 
 The most common wall coating in use for egg rooms is plain, 
 every-day whitewash, in various proportions of lime and salt. 
 Several recommend one part of lime and one of salt. This makes 
 a very good whitewash, giving a firm, hard surface, but unless 
 some method of blowing warm, dry air through the rooms is 
 feasible, it will dry very slowly, which is likely to cause it to have 
 a mottled appearance instead of the pure white which gives a 
 storage room such an attractive appearance. A better propor- 
 tion for ordinary cold storage work is two parts of lime and 
 one of salt. This mixture will dry faster, and will give a white 
 surface which will not easily rub or flake off. There are many 
 formulas for good whitewash, some of them so complicated as 
 to be impracticable ; but plain lime and salt, with perhaps the 
 addition of a little Portland cement, will be good enough for our 
 purpose. See chapter on "Keeping Cold Stores Clean" for de- 
 tails of whitewash making, etc. ; also chapter on "Uses of Chloride 
 of Calcium" for application of this material, also chapter on 
 "Absorbents." 
 
 PACKAGES. 
 
 Eggs are continually giving off moisture from the time they 
 are first dropped by the hen until they disintegrate, unless sealed 
 from contact with the air, and we can therefore never hope to 
 keep them in cold storage for several months without their losing 
 some weight by evaporation. To prove that eggs must evaporate, 
 the following experiment was tried by the author in his early 
 experience: An ordinary 30-dozen egg case was lined with tin, 
 with all joints carefully soldered. The eggs were then placed in 
 the fillers in the tin lined case in the usual way, and an air-tight 
 tin cover soldered on, forming a hermetically sealed package. 
 After about sixty days' stay in an ordinary refrigerator the tins 
 
EGGS IN COLD STORAGE 209 
 
 were unsoldered. The result noted was peculiar and startling. 
 The inside of the tins was dripping wet, and very foul smelling, 
 and the eggs were all rotten. This same experiment was tried 
 by a friend, working independently and without knowledge of 
 the author's experiment. He used an ordinary fruit jar, with 
 screw top fitting onto a rubber ring. His results were similar. 
 In addition this gentleman packed some eggs in flour in a fruit 
 jar, otherwise under the same conditions as the other experi- 
 ment. The eggs packed in this way were all found to be in good 
 condition when the jar was opened, as the moist evaporation 
 from the eggs had been taken up by the flour. These experi- 
 ments prove beyond a doubt that an egg must evaporate con- 
 tinually, and they prove further that the eggs must be surrounded 
 by some medium which will absorb this evaporation. 
 
 In the chapter on "Air Circulation" it is explained how the 
 air is best circulated so as to remove the moisture and impure 
 gases from the vicinity of the goods. This must be done, other- 
 wise the fillers and package containing the eggs would shortly 
 be in as bad condition as the fillers in the experiment just men- 
 tioned. The theory and explanation of the other conditions in 
 the storage room necessary for successful egg refrigeration have 
 also been taken up under the various heads. We will now look 
 into the requirements of the package containing the eggs while 
 in cold storage. 
 
 The questions contained in the letter of inquiry relating to 
 the egg package are as follows : 
 
 First. — What egg package have you found to turn out the 
 sweetest eggs? 
 
 Second. — Have you used any kind of ventilated egg case, and 
 with what results? 
 
 Third. — Have you ever used open trays or racks, and with 
 what results? 
 
 As many different people have experimented with different 
 packages, hoping to get something which would turn out per- 
 fectly sweet eggs, with little evaporation, the replies received to 
 the questions relating to packages are interesting, and many 
 contained information valuable as data. The favorite package 
 is the ordinary 30-dozen egg case, made of whitewood, using 
 medium weight hard calendared fillers. The term whitewood 
 
 (14) 
 
210 PRACTICAL COLD STORAGE 
 
 is usually meant to include either poplar, cottonwood or bass- 
 wood, but two or three other varieties of wood, not so well known, 
 are designated as whitewood. Basswood is by some not placed 
 in the whitewood list, but the best authority known to the author 
 says that basswood is as properly a whitewood as poplar or south- 
 ern whitewood. Poplar and cottonwood are most in use for 
 storage purposes, and many insist that basswood is objectionable 
 becaue of its liability to ferment or sour and cause' tainted or 
 musty eggs. All kinds of cases have been in storage in the house 
 operated by the author, and if all were thoroughly dry, no differ- 
 ence could be noted in the carrying qualities of the dif- 
 ferent kinds of whitewood, and the preference has been 
 for well seasoned basswood cases. It may be that bass- 
 wood is more likely to sour and affect the eggs than 
 poplar or cottonwood, but it is always advisable to get 
 stock for egg cases in the fall and have them nailed up during 
 the winter, allowing two or three months for the cases to season 
 and dry out before the opening of the egg storing term. Some 
 have dry kilns for cases, but a naturally seasoned case is to be 
 preferred, as then it has a chance to deodorize as well as dry out. 
 In some localities other woods are used for egg cases. Ash, 
 maple, hemlock and spruce have been used for storage cases, 
 generally because they are cheaper than whitewood in that locality. 
 Any strong scented wood like pine will not do> because of the 
 flavor imparted to the eggs. 
 
 ■ The pasteboard frames and the horizontal dividing or sepa- 
 rating pasteboard pieces which form for each egg an individual 
 cell in the case are usually spoken of as fillers. For years only 
 one grade of these was made — those of ordinary strawboard. 
 When moistened by the evaporation from the eggs this material 
 has a peculiar rank odor, which was taken up to some extent by 
 the eggs if they were allowed to remain in the fillers for several 
 months. Much of the flavor resulting from a growth of fungus 
 has been laid to the fillers, and much of the flavor resulting from 
 fillers has been laid to a growth of fungus or must, but there is 
 no question about strawboard fillers not being a perfect material 
 for cold storage use. Many kinds of fillers have been tried, and 
 many ideas suggested for the improvement of cold storage eggs. 
 A whitewood pulp filler made its appearance some years ago, but 
 
EGGS IN COLD STORAGE 211 
 
 did not come into general use. After being in storage a few 
 months, it absorbed moisture to such an extent as to become 
 very soft, and they were objectionable on this account. A good 
 manila odorless is now on the market which is giving good satis- 
 faction where tried. Ordinary strawboard fillers have been 
 coated with various preparations, shellac, paraffine, whitewash, 
 etc. Any substance in the nature of waterproofing might better 
 be left off for the reason, as we have seen, that eggs must evap- 
 orate, and a waterproof filler would hold the moisture and not 
 allow it to escape into the air of the room. It is essential to the 
 well being of an egg that it should evaporate, as proven by the 
 experiments in hermetically sealing, before described. Many have 
 gone to the expense of transferring the eggs into dry fillers in 
 the middle of the season. One season of this was enough for the 
 author. A better way is to decrease the humidity of the room 
 as the fillers become more and more loaded with moisture. The 
 humidity may be decreased by the use of absorbents or by ventila- 
 tion, as already discussed in their proper places. Fillers made of 
 thin wood have been used in years gone by with fair success, 
 but their manufacture has now been entirely discontinued. They 
 were made of maple, shaved very thin, and were a prime filler so 
 far as odor was concerned, but in cold storage the frames warp 
 "badly, and the time and eggs wasted in getting the eggs out 
 of the fillers was a serious item against their use. As a shipping 
 filler they were also a failure because of the excessive breakage. 
 Some years ago an eastern company began the manufacture of 
 what is known as the odorless fillers. These fillers are light 
 hrown or buff in color, and from the best information the author 
 •can obtain, are composed largely of scrap paper stock, with some 
 long fibre like manila added for strength. In the manufacture 
 the stock is treated to a thorough washing and deodorizing proc- 
 ess, and the result is a filler with very little odor. Eggs put up 
 in these so-called odorless fillers and subjected to the same con- 
 ditions as a similar grade of eggs packed in common straw- 
 board fillers, have come out of cold storage in better condition 
 in a good many cases. A number of imitations of the original 
 odorless filler are now on the market, some of them almost if 
 -not quite the equal of the original. Another filler which has 
 given good results is the fibre filler, which is made from a material 
 
212 PRACTICAL COLD STORAGE 
 
 similar to the now well known fibre ware. They have very little 
 odor, and remain hard and firm while in cold storage. A new 
 odorless filler made from pure spruce pulp has been put on the 
 market. This is a beautiful appearing filler, and unless appear- 
 ances and the ordinary tests are deceptive will make its mark 
 after a trial of a year in cold storage to prove what it can do. 
 A ventilated filler made by a well known creamery supply house, 
 has been suggested as an ideal filler for cold storage, but they 
 are so poor mechanically that they are not to be thought of. 
 The material cut away to form the air circulation space weakens 
 the structure of the filler to such an extent as to make it danger- 
 ous as a shipping filler. Whatever filler is used, it should fit the 
 cases, not crowding in, nor still so loose as to shake. If this point 
 is looked after much breakage and consequent poor results from 
 storage in the cold room may be avoided. 
 
 Many styles of ventilated egg cases have been placed on 
 the market in years past, but very few or none survive the test of 
 time. A ventilated case, made by having the sides cut an inch 
 narrower than the ends, has come into use, especially in one 
 large eastern city. Making the sides narrower forms a space of 
 half an inch on both sides of case at top and bottom, for the 
 ready access of air to the interior of the case. This case is of 
 very simple construction, and efficient in allowing a free circula- 
 tion of air into the case. Others, however, prefer a case with 
 sides in two pieces, claiming that the cracks will allow enough 
 air circulation. Still others prefer the shaved or veneered 
 cases with solid sides and bottom, claiming that this kind of a 
 case will prevent excessive evaporation from the eggs. As pointed 
 out elsewhere, humidity and circulation have much to do with the 
 evaporation from eggs ; in fact, are more of a ruling factor than 
 the package, although the package necessarily has much to do 
 with it. A tight package will allow of less evaporation than an 
 open one. In a very dry room with a vigorous circulation a mod- 
 erately tight package is the thing, but in a comparatively moist 
 room with poor circulation the more open the package the better. 
 
 An appreciation of the poor circulation and damp air of the 
 overhead ice systems has caused many of their operators to resort 
 to the use of open trays or racks for the storage of eggs. Very 
 palatable eggs have been turned out in this way, but the use of 
 
EGGS IN COLD STORAGE 213 
 
 trays in any ammonia or brine cooled room would lead to very 
 excessive shrinkage of the eggs and consequent heavy loss in 
 candling. On a commercial scale, too, the storing of eggs in 
 trays is hardly practicable, as it increases the risk of breakage 
 immensely, and the eggs must be transferred from the cases when 
 received at the storage house, and back into cases again when 
 shipped, involving much labor, and perhaps loss of valuable time 
 at some stages of the market. In any but a very moist room, 
 eggs stored in open trays, in bulk, will lose much from evapora- 
 tion, and the loss will be proportionately higher than on an equal 
 grade of eggs stored in ordinary cases and fillers. The ad- 
 vantage of trays, if any, for some houses, is that contamination 
 from fillers is avoided, and about 40 per cent more eggs can be 
 stored in a given space. The eggs are, however, more liable to 
 must as a result of moisture condensing on their surface with 
 change of temperature, or on the introduction of warm goods 
 into the storage room. 
 
 The material used for forming a cushion in the case on top 
 and bottom of the fillers to protect the eggs from contact with the 
 case, and so that they will carry in shipping, is generally either 
 excelsior, which is finely shaved wood, usually basswood, or the 
 chips made in the manufacture of corks, known as cork shavings. 
 The big cold storages have in the past recommended cork in 
 preference to the best excelsior. Here again comes a question 
 of dryness. If the excelsior has been in stock for a year and 
 stored in a dry place it is to be preferred to cork shavings, 
 otherwise cork is the best, because we know cork is always dry. 
 Cork makes a very poor cushion as compared to excelsior; it is 
 liable to shift in the case, leaving one side without protection. 
 As a matter of cost, too, cork is much more expensive than ex- 
 celsior. A company known to the author manufacture a beautiful 
 grade of basswood excelsior, which is always fairly dry when 
 received, and makes as fine a cushion for protecting the 
 eggs as can be desired. If people want cork in their cases 
 they can have it by paying the price, but dry, seasoned, fine 
 basswood excelsior is better, for reasons stated. The best 
 houses are now recommending dry excelsior in place of cork 
 on account of the excessive breakage when a cushion of cork 
 is used. 
 
214 PRACTICAL COLD STORAGE 
 
 Eggs have been packed in oats for years, but the practice 
 has gradually fallen off, as eggs stored in cases from the best 
 cold storage houses have been improved in quality from year 
 to year. Oats, if dry, will absorb moisture from the eggs quite 
 rapidly, and are objectionable on this account. If the oats are 
 not dry the germs of mold are developed rapidly, and as the 
 moisture is given off by the eggs the mold will grow, causing the 
 eggs to become "musty." Therefore the main difficulty in using 
 oats as packing for eggs in cold storage is to have them at the 
 correct degree of dryness. It is almost impossible to have them 
 in the same condition at all times. Oats have also been used in 
 cases inside the fillers; that is, the layers of eggs are first put 
 into the filler ; then the oats are sifted into the spaces around the 
 eggs flush with the top of the filler. This is repeated through 
 the whole case ; all the space in the case not occupied by the eggs 
 being filled with oats, excepting the small space taken by the 
 fillers themselves, the object being, of course, to prevent the 
 "filler taste." 
 
 At intervals we read of some method of preserving eggs, 
 which is said to be sure to supersede ordinary cold storage for the 
 good keeping of eggs. A scheme was tried on a large scale 
 somewhere across the water, in which the eggs were suspended 
 in racks in a cold room — the racks being turned at regular in- 
 tervals by automatic machinery to keep the eggs from spoiling; 
 that is, to keep the yolk from attaching to the shell. A low 
 temperature will prevent this, as pointed out in this chapter 
 under the head of " Temperature," and why a man should waste 
 good energy inventing such a machine is passing all comprehen- 
 sion. The quantity of various chemical preparations manufac- 
 tured and sold for egg pickling or preserving is even now quite 
 large, but the high class stock now turned out by the best 
 equipped cold storage houses has made any other method of pre- 
 serving eggs at the present day almost entirely obsolete. 
 
 HINTS. 
 
 There is a long string of "don'ts" in regard to* packing, 
 handling and storing eggs which might be put down, but the 
 author will be content with a few of the simpler and most useful 
 ones. To start with, don't store very dirty, stained, cracked, 
 
EGGS IN COLD STORAGE 215 
 
 small or bad appearing eggs of any description. Have your 
 grade as uniform as possible. The culled eggs will usually 
 bring within two cents of the market price, and it pays better 
 to let them go at a loss rather than try to store them. Don't 
 use fillers and cases the second time; they are more likely to 
 cause musty eggs than new ones. Don't ship eggs in cold cars, 
 or set eggs which are intended for storage in ice boxes. In 
 shipping eggs from the producing section to the storage house 
 in refrigerator cars, no ice should be put in the bunkers, be- 
 cause if the eggs are cooled down and arrive at their destination 
 during warm or humid weather they will collect moisture or 
 "sweat," and an incipient growth of mold will result. Don't 
 use heavy strawboard fillers for storing eggs. If "the best 
 way to improve on a good thing is to have more of it," then 
 the best way to improve on a poor thing is to have less of it; 
 and if strawboard fillers are objectionable, then the thinner they 
 are the better, because less of the material is present to flavor the 
 eggs. Further, the thin board fillers are more porous, and allow 
 of a freer circulation of air around the eggs. The grade known 
 as "medium" fillers are best for cold storage purposes. As already 
 stated, odorless fillers are better than any strawboard fillers. Don't 
 use freshly cut excelsior. It should be stored in a dry place at 
 least six months. Use no other kind but basswood or whitewood. 
 Don't store your cases, fillers or excelsior in a basement or any 
 damp place. Don't run warm goods into a room containing 
 goods already cooled when it can be avoided. For this reason 
 very large rooms are not to be desired. A small room may 
 be quickly filled with goods and closed until goods begin to go 
 out in the fall. If a large room is used it may require several 
 weeks to fill completely, during which time the fluctuation of 
 temperature is at times excessive, causing condensation on the 
 goods, which will propagate must quickly. 
 
 To illustrate: We will suppose the egg room partly filled 
 with goods cooled to a temperature of 30 F. Several cars of 
 eggs at a temperature of, say, 70° F. are run into the same 
 room. The new arrivals, in cooling to the low temperature, 
 give off large quantities of vapor from cases, fillers and the 
 eggs themselves, the vapor condensing, of course, on any ob- 
 ject in the room which is below the dew point of the air from 
 
216 
 
 PRACTICAL COLD STORAGE 
 
 which the warm goods came. This may seem like a finely spun 
 theory, but the author has had some experience which amply 
 justifies this explanation. That the moist vapor given off by 
 the warm goods does not show in the form of beads of water, 
 or fog, or steam, is no proof that it does not exist. If the ex- 
 tremes of temperature are as great as 25° F. condensation will 
 occur on nine days in ten during the egg storing season. The 
 goods already in storage are raised in temperature materially 
 
 FIG. I. — VIEW IN EGG TESTING ROOM. 
 
 by placing in warm goods, which is harmful to some degree. 
 The logical deduction from above seems to indicate that warm 
 goods should not be placed in a room with goods which have 
 been reduced to the carrying temperature. A separate room 
 should be provided for this purpose near the receiving room 
 in which the goods coming in warm may be cooled to very near 
 the temperature of permanent storage room. This is a refine- 
 ment which small houses cannot afford, and which most of the 
 larger ones do not have. 
 
EGGS IN COLD STORAGE 
 
 217 
 
 If you wish to progress compare your results with those 
 of others. Don't say: "My eggs are as good as fresh;" test 
 carefully from time to time through the season and compare 
 quality with those from other houses. 
 
 It should be positively understood that merely theoretical 
 knowledge on this subject is of only limited assistance; and 
 those who undertake new work are advised to put a man in 
 charge who has had experience with the product which it is 
 
 ,/JW//////////////////////////&////////^^ 
 
 l— 
 
 "' 
 
 t 
 
 3U 
 
 r r p 1 
 
 ' Candler 
 I EI99 Case Table 
 
 .__ 
 
 • '1 
 
 •SLalf for pail 
 
 for rati 
 
 l*r-r,i,r, BOOTH 
 
 5-6- 
 
 Curtain -^"^ 
 
 FIG. 2. — PLAN OF EGG TESTING BOOTH. 
 
 VjUjj 
 
 J 
 
 BOOTH 
 
 proposed to handle in storage, as well as acquaintance with 
 the mechanical details of the plant. 
 
 CONSTRUCTION OF EGG CANDLING ROOM. 
 
 The construction of rooms to be used for the testing or 
 candling of eggs has not reached a stage where it may be 
 stated that there is any design which might be called standard 
 or that is generally approved by the trade. Nearly every pro- 
 prietor has his individual ideas on this subject, and, therefore, 
 nearly every different plant is fitted up in a different way. The 
 booth system, which consists of individual stalls or separate 
 small rooms for each person, is coming into general favor. The 
 advantage of this system is that each person works by him- 
 self, and, therefore, better work is possible, and each operator 
 must stand on his own individual merits. In other words, the 
 
218 
 
 PRACTICAL COLD STORAGE 
 
 system allows of a closer inspection and a closer systematizing 
 of the important operation of candling eggs. 
 
 The number of booths necessary depends upon the volume 
 of business to be handled and any number of booths may be 
 arranged in a large room, which may be called the "Candling 
 Room." (See Fig. 6.) Candling is simply a misnomer in this 
 connection and originated from the fact that a candle was or- 
 
 FIG. 3. — SECTION OF EGG TESTING BOOTH. 
 
 iginally used for testing eggs. Very few candles are now in 
 use for this purpose and the electric light is in general favor. 
 
 The construction of the booth is subject to some modifica- 
 tions ; the one shown in accompanying view, plan, section and 
 elevation, also detail of candling box or candler (see Figs. 1, 
 2, 3, 4, and 5), has been proved by practical service to be eco- 
 nomical of space and, withal, convenient. As shown, sufficient 
 
EGGS IN COLD STORAGE 
 
 219 
 
 shelf room is provided for fillers above a plank table on which 
 rest cases which contain the eggs to be tested and for the dif- 
 ferent grades into which the eggs are classed. With the size 
 booth shown, sufficient room is provided for five cases on the 
 table. The booth may be constructed of a single thickness of 
 boarding on three sides and top, the fourth side being closed by a 
 curtain of heavy, dark colored denim, or any suitable material. 
 This curtain should be hung on a wire or rod with rings so as 
 to slide easily, and it may or may not be divided in the center. 
 
 Holes mJwn 
 
 FIG. 4. — DETAIL OF CANDLER. 
 
 In Fig. 1, which is reproduced from a photograph, is shown 
 the booth system in service. The white candling boxes show 
 plainly in the center of the booths. Cork shavings used as a 
 cushion at top and bottom of egg cases are shown in the box 
 between booths. The barrels are intended to receive the litter 
 of various kinds, such as old newspapers, which accompany 
 country packed eggs. The pail for rots is shown above the 
 
 barrel. 
 
 The candling box or candler which contains the electric 
 light or lamp may be constructed of ordinary egg case material 
 
220 
 
 PRACTICAL COLD STORAGE 
 
 one-quarter of an inch thick. One-half-inch quarter round is 
 nailed into three corners of this box, inside, to strengthen it. 
 The fourth corner is pierced with two holes placed close together, 
 as shown in the detail. The holes should be one and one-quarter 
 inches in diameter. The bottom of the candler is left open so 
 that light from the electric lamp may be thrown into the cases 
 on the table below. The top of the candler may be partly 
 closed by a piece of cardboard, or otherwise, in case too much 
 light is reflected to the ceiling so as to make the candling room 
 
 <#-. 
 
 __* 
 
 Box ior 
 
 Cvmd-ler 
 
 N. 
 
 r 
 
 T 
 
 o© 
 
 'lo"*5h« 
 
 X 
 
 Y 1.1 
 
 1%'HariU TikU 
 
 >h 
 
 ¥ 
 
 FIG. 5. — FKONT ELEVATION OF EGO TESTING BOOTH. 
 
 too light for close candling. The circulation of air, however, 
 through the candling box should not be entirely shut off, for the 
 reason that it will cause rapid destruction of the electric lamps 
 by overheating. 
 
 In the place of the candler shown in the drawings, many 
 prefer to use a round tin candler with a single hole, which will 
 accommodate either one or two eggs as desired. There is also 
 now on the market a very simple and perfect little rig which 
 may be had at a reasonable price for use with either the electric 
 light or kerosene lamp. 
 
EGGS IN COLD STORAGE 221 
 
 The details of candler or tester are subject to many modi- 
 fications to suit individual ideas. The question of candling two 
 eggs at once or singly has been much discussed among profes- 
 sional egg candlers. Many prefer the candler with two holes, 
 and still others insist that one hole is sufficient. The author 
 has personally used the booth and candler described and be- 
 lieves it to be equal to anything which has come to his knowledge. 
 All dimensions are given on the diagrams so that the construc- 
 tion of the booth system as above described will be simple for 
 those who desire to test the practicability of the scheme as ap- 
 plied to their local requirements. 
 
 The room in which the booths are arranged, or what may 
 be called the candling room proper (see Fig. 6), should be of 
 sufficient size to accommodate the handling of goods in and 
 out of the room and allow space for empty cases, fillers, etc., 
 and it should also be large enough to provide storage space for 
 one or two days' packing. The room should be insulated in 
 any fairly substantial manner, and means for maintaining same 
 at about 6o° F. in warm weather should be provided. In other 
 words, we should provide a cold storage room for candling 
 eggs. Eggs coming in from the country during warm weather 
 may be placed at once in this room and should be reduced to a 
 temperature of about 60° F. before being candled. 
 
 It is fully understood among practical egg shippers that 
 when eggs come in from the country in hot weather they often 
 appear to be in very much worse condition than they really are. 
 After being cooled to about 60° F. the eggs may be candled and 
 judged for their actual quality. A refrigerated candling room 
 is also a great benefit in stopping further immediate deteriora- 
 tion when the eggs come in heated. The more progressive 
 modern egg houses which are being erected at the present time, 
 where cold storage is an adjunct, have refrigerated candling 
 room facilities. The value of these arrangements will be at 
 once appreciated by those who have had experience in candling 
 eggs during the heated term. 
 
 The candling room may be refrigerated in any suitable 
 way, but a fan system of air circulation is generally preferred 
 about on the lines shown in plan of candling room. In this way 
 the cold air from coils is distributed along the floor on the 
 
222 
 
 PRACTICAL COLD STORAGE 
 
EGGS IN COLD STORAGE 223 
 
 opposite side of the room from the operators and the warm air 
 is taken out over their heads, above the booths. It is advisable 
 to provide openings in the top of the booth for a circulation of 
 air; these openings to have hinged doors so as to regulate the 
 circulation. 
 
 The cooling pipes may be placed in a box or bunker near 
 ceiling of the room and a drip pan provided underneath. This 
 will avoid all dripping or spattering on the goods or cases, and, 
 by distributing and drawing off the air as suggested, uniform 
 temperatures are obtained and strong drafts are prevented. If 
 the room is reasonably high, fairly good results may be obtained 
 by placing the cooling pipes on the side walls near the ceiling 
 and providing drip gutters beneath, or the room may be cooled 
 by natural ice by proper arrangement of openings from the 
 source of ice supply. If the refrigerated candling room is once 
 put in service for use during hot weather, its advantages will 
 be so apparent that the operator will wonder how he was ever 
 able to get along without it. 
 
224 PRACTICAL COLD STORAGE 
 
 CHAPTER XL 
 BUTTER IN COLD STORAGE. 
 
 TEMPERATURE. 
 
 In the early days of butter refrigeration it was thought 
 that temperatures of from 35 ° to 40 F. were sufficiently low. 
 These temperatures kept the butter in a reasonably solid state, 
 and for periods of two or three months gave good results in 
 preserving the flavor and preventing deterioration. The ten- 
 dency has been steadily toward lower temperatures until now 
 zero and below is thought by many to be best for butter storage. 
 This is by no means a general impression, and the majority of 
 produce men still believe that any temperature below 20" F. is 
 sufficiently low for ordinary commercial results. It may be 
 stated that the average of opinions on the subject at this time 
 favors 12 to 15 F., and as there are no results of accurate 
 tests available at this time to prove any particular temperature 
 as best for varying conditions and purposes, the present status 
 of the matter is presented for the consideration of the reader. 
 The author has maintained for some time that any temperature 
 below 20° F. was low enough for periods of two to five months, 
 which covers the average time for which three-fourths of the 
 butter is cold stored. If the butter is stored in suitable packages, 
 and is well made to begin with, no good may be accomplished 
 by storing at lower temperatures. On the other hand if the butter 
 is in packages not suitable, of inferior packing and grade, and 
 it is desired to store for long periods, or it becomes necessary 
 to carry from one year to another, temperatures of from io° 
 above zero to below zero Fahrenheit may produce improved 
 results. It is certain that 20° F. and below will retain the desir- 
 able butter flavors better than from 35" to 40 F., so it appears 
 reasonable that 10° F. above zero and still lower will retain 
 flavors better than 20" F. or thereabouts. For a number of 
 
BUTTER IN COLD STORAGE 225 
 
 years the author has constantly recommended a temperature of 
 from 12° to 1 5° F. for average butter storage, and sees no reason 
 at this time to change. If tests which are at all conclusive prove 
 differently he will not be backward about recommending lower 
 temperatures. 
 
 FREEZING BUTTER. 
 
 We hear nowadays about freezing butter for holding in 
 storage. This commonly refers to any temperature below the 
 freezing point of water (32° F.). Some houses have recom- 
 mended and practiced "freezing" the butter at zero or there- 
 abouts for a few days, and then storing permanently in a tem- 
 perature of from io c to 20° F. above zero. Butter does not 
 freeze in the ordinarily, accepted sense of the term. It is of an 
 oily nature, and simply gets harder and harder as the tempera- 
 ture is reduced. The freezing point of butter, if it may be so 
 called, is from 92 F. to 96° F. as determined by test. (See 
 "Specific Heat of Butter" further on.) The freezing point of a 
 substance, as ordinarily understood, means the temperature at 
 which it changes from a liquid to a solid, and butter therefore 
 freezes at many degrees above the freezing point of water. The 
 talk about rupture of fat globules in butter by freezing, there- 
 fore, is not well applied. Butter does not freeze at any cold 
 storage temperature, but simply becomes harder and denser as 
 the temperature is reduced. It will, however, probably be ulti- 
 mately shown by Government tests that storing butter at an 
 extremely low temperature will cause a "shortness" or rup- 
 ture of the grain, but this is advanced by the author on his own 
 responsibility. 
 
 PROTECTION FROM THE AIR. 
 
 The successful holding of butter in cold storage has in the 
 past hinged as largely on the protecting of the product from the 
 air as in maintaining a low temperature in the cold room. Pos- 
 sibly with extreme low temperatures of zero or thereabouts, pro- 
 tection from the air will be of less consequence, but this point 
 cannot at present be overlooked if best results are desired. 
 Butter being composed largely of an oil or fat, is susceptible of 
 becoming rancid or " air-struck " when exposed to the air for a 
 
 (15) 
 
226 PRACTICAL COLD STORAGE 
 
 considerable time; the higher the temperature the quicker the 
 butter becomes rancid. It is reasonable to suppose, therefore, 
 that the lower the temperature the longer butter may be held in 
 contact with the air without becoming rancid. In other words 
 as the temperature of a butter storage room is held lower, the 
 less the necessity of care in protecting the butter from the air of 
 storage room. It is in any case desirable that the package should 
 be as air-tight as possible. It cannot be known at time of 
 storing how long the butter will be held, and the nearer air-tight 
 a package is, the longer will it keep the butter in good flavor 
 and condition. Butter packed under direction of the United 
 States Government for export and use in warm climates is put 
 up in hermetically sealed cans, and some of our "boys in blue" 
 bear witness to the palatability of same, even when carried under 
 insufficient and inferior methods of refrigeration. Another means 
 of canning is the method formerly in use for packing butter for 
 shipment to California. The butter was made up in rolls and 
 packed in tight casks which were afterwards headed up and all 
 spaces between rolls and at sides and ends of casks were filled 
 with brine or "pickle" as it is called. As the refrigerating means 
 were formerly inadequate, this method was necessary in order 
 that the butter might be carried through to destination in pal- 
 atable condition. Firkins (kegs holding about ioo lbs. of but- 
 ter) were much in use at one time, especially for shipment to 
 foreign countries. These wooden packages were thoroughly 
 soaked with brine, packed solid and nearly full. The head was 
 put in and when the butter was cooled, the remaining space was 
 filled with pickle composed of salt, saltpetre, and sugar. At- 
 tempts have also been made to cover the butter in ordinary tubs 
 with brine pickle after the tubs were placed in storage, in order 
 to protect the butter from the air, but the muss and slop resulting 
 made this scheme impracticable. These methods of packing 
 butter are mentioned as representative of the former practices in 
 use to prevent the butter becoming air-struck and rancid. At 
 this time very little butter is stored under any of these methods, 
 owing to the expense of packing and impracticability of the 
 packages for the retailer. Butter stored immersed in pickle also 
 has a soaked appearance, where it comes in contact with the 
 pickle, which is objectionable. 
 
BUTTER IN COLD STORAGE 227 
 
 BUTTER FLAVOR AND AROMA. 
 
 It was at one time thought that flavor and aroma of butter 
 were due to the food upon which cattle were fed. During the 
 "full grass" months of May, June, and July, this was especially 
 noticeable, and at this time cows give milk which makes a fine 
 quality of butter. The bacteriologist has changed our ideas on 
 this matter, and by the use of a "culture," nearly as fine an 
 aroma and flavor may be produced in midwinter as on full grass. 
 By Pasteurization and ripening the cream by the use of a culture 
 of suitable bacteria, fine flavored butter may be made at all sea- 
 sons of the year. One of the chief desires in cold storing butter 
 is to retain the flavors and aroma which are produced by the 
 ripening or souring bacteria of milk and cream. Loss of these 
 is prima facie evidence that butter is no longer fresh. Low 
 temperature and protection from the air will accomplish the 
 desired results. 
 
 PREPARING BUTTER FOR COLD STORAGE. 
 
 Butter intended for cold storage purposes should have the 
 buttermilk thoroughly removed by washing and working mod- 
 erately in water. The working should not be carried too far so as 
 to spoil the grain of the butter, but as much of the buttermilk as 
 practicable should be worked out and a moderate amount of pure 
 water and salt incorporated in its place. The butter should be 
 well salted so that the water content shall be in the form of strong 
 brine. Butter containing a large portion of moisture keeps best 
 in cold storage. Butter made by the old deep setting process or 
 by 'raising the cream by setting in cold water, keeps much better 
 than the best separator butter. No doubt some will be somewhat 
 surprised to learn this. The reason is that more of the casein 
 is left in the butter by the centrifugal separator which causes a 
 fermentation which deteriorates the butter more rapidly. The 
 author has seen two lots of butter placed in cold storage at the 
 same time and stored in the same room — one lot was fancy 
 separator creamery butter worth about 18c per lb. ; the other 
 lot was a second grade gathered-cream creamery, worth 14c 
 per lb. When removed from storage four or five months later 
 the 14c butter sold the best on the open market. The gathered- 
 cream butter, as most of my readers are aware, is made from 
 
228 PRACTICAL COLD STORAGE 
 
 cream skimmed by the farmer and collected and churned at a 
 creamery. The resulting product is always inferior in flavor 
 when first made. The case above is mentioned to show the com- 
 parative keeping quality of centrifugal separator and gravity 
 raised cream butter when placed in cold storage. Possibly at the 
 low temperatures now advocated by some, this difference will 
 disappear. 
 
 PROCESS BUTTER. 
 
 "Process" or renovated butter, which is made from a mis- 
 cellaneous lot of dairy butter melted, purified, regranulated and 
 flavored by the use of a bacteria culture, has comparatively poor 
 keeping qualities in cold storage and therefore very little is 
 stored. The most common way is for the process operator to 
 store the original package or by repacking into barrels. If 
 barrels are used they should be soaked well with brine and then 
 lined with parchment paper before packing in the butter. Don't 
 store rancid butter for processing — select only that which is fresh 
 and reasonably sweet. Butter which is slightly sour from pres- 
 ence of buttermilk is not as good for cold storage, but in process- 
 ing this largely disappears, and butter which is sour from this 
 cause may be stored to advantage if fresh. In fact, it is difficult 
 to get the medium grade dairy butter which is largely used for 
 processing, during the months of June and July, which does not 
 have more or less this sour character. The chief point of im- 
 portance to guard against in selecting butter to be cold stored 
 for future processing is rancidity. Butter which has once become 
 even slightly rancid will deteriorate more rapidly in cold storage 
 and is unfit for making anything but low grades of process 
 butter. Store in the original package if possible, providing it is 
 in good condition, as repacking breaks the grain and injures the 
 keeping quality. If it is necessary to repack, pack solidly with- 
 out leaving air holes. 
 
 USE OF JARS FOR BUTTER STORAGE. 
 
 For a limited local trade a good grade of dairy butter in 
 small jars is very desirable. Select good flavored, even colored 
 butter for storage, and turn everything else into "packing stock" 
 or low grades. Remove all miscellaneous cloth and paper cover- 
 
BUTTER IN COLD STORAGE 229 
 
 ings, replacing by cloth or parchment paper circles or caps and 
 spread on evenly a fine grade of dairy salt to a thickness of one- 
 eighth of an inch, or sufficient to cover the surface of the butter 
 thoroughly. Over this tie a cover of light colored manilla wrap- 
 ping paper, and you have a package which is practically air 
 tight. It is also in good shape for sale when removed from 
 storage. The jars may be piled one upon another to a height 
 of three or four feet. Racks are best for piling jar butter with 
 shelves at intervals of three or four feet. In piling in an ordinary 
 room without racks, there is great danger of a collapse of piles 
 of jars and the result may be imagined. Jars are undesirable 
 for shipping, hard to handle, and liable to be broken, but they 
 make a fine package for cold storage, and are desirable for retail- 
 ing, especially during the fall of the year before roll butter makes 
 its appearance. For storage in a small way, for local consump- 
 tion use jars. 
 
 STORING BUTTER IN TUBS. 
 
 Tubs of various sizes larger at the top are the standard 
 butter packages, and by far the greater portion of the butter 
 made in the United States is handled in tubs containing about 
 sixty pounds. The best material for tubs is white ash, but some 
 markets, notably Boston, prefer tubs made from white spruce. 
 The covers of tubs should be of the same material as the staves 
 and bottom, or of some sweet hard wood. The soft woods, par- 
 ticularly pine, may impart a foreign flavor to the butter. The 
 following directions for soaking tubs and preparing them for 
 packing are given by P. M. Paulson:* 
 
 In packing butter it is first necessary to properly prepare the pack- 
 age; this I do by soaking the tub and then placing in a tank of brine 
 so that the tubs are held completely in the brine for about 12 to 14 hours. 
 The liners 1 also place in brine for about the same length of time. When 
 butter is worked sufficiently and ready for packing, I line the tubs. If 
 I am alone to pack, I line five or six tubs at a time ; if my helper has time 
 to help me, we line enough tubs to hold what butter we have in a work- 
 ing. The liners we place in smoothly in the tubs in a way so that the top 
 edge of the liner can be turned down over the edge of the tub about Y> 
 inch. Next I put the bottom circle in position. If I am packing alone, 
 I take five or six pounds of butter (not more) and put in each tub that I 
 have lined ; I then press it firmly together with the packer, seeing that 
 there are no holes left in th'e butter and also that it is pressed firmly 
 against the edge of the tub. I repeat this operation until tub is filled and 
 
 *In New York Produce Review. 
 
230 PRACTICAL COLD STORAGE 
 
 enough more so that there is from one to two pounds on top. When this 
 has been pressed firmly down, I take a string, wet it, and cut the butter 
 off level with the tub ; next I take the paper lining and turn it back oyer 
 the edge of the tub and on to the butter, neatly and with care, being 
 careful not to tear the paper, and smooth it down. Then I place ' the 
 cloth circle on the tub; this should be large enough to reach to the out- 
 side edge of the tub. Then I take a little water with my hand and moisten 
 the cloth, next sprinkle a little salt on, and rub it lightly with my hand, 
 so that it is even all over. In placing^ the cover on, care must be taken 
 to get it on properly; if it don't go on easily I place my knee on the 
 cover and tap the edge lightly with a hammer until I get the cover on ; 
 it is better to hammer on the edge of the cover than to hit the staves on 
 the tub, as it keeps the butter in better shape. In placing the tins, I place 
 the first one on over the end of the cover rim ; this will prevent the rim 
 from tearing off if it should by accident get caught ; the second tin I place 
 directly across from the first one, the third and fourth at equal distance 
 between first and second. I always try to place the tins so that they will 
 reach down into the top hoop on the tub ; last I drive a ^jd. nail in the 
 lower end of tin ; the end on the cover I have always found does very 
 well with one nail. I always use a tin that has one nail in each end ; 
 they are the most convenient to use. Wire tub fasteners should not be 
 used, the trade does not like them. Before I place butter in refrigerator 
 I always see that the tubs are perfectly clean. 
 
 The liners mentioned by Mr. Paulson are of parchment paper 
 and come ready cut to proper size for tub used. A pint of brine 
 in the bottom of the tub when starting to pack, is desirable, as it 
 fills all cavities and the pores of the wood. In packing keep the 
 butter pressed down in the center first and then at the sides so as 
 not to leave openings in the butter which may later become air 
 spaces and cause the butter to sooner become " air-struck." 
 
 l/oLEOMARGARINE AND BUTTERINE IN STORAGE. 
 
 Oleomargarine and butterine are of a similar nature and 
 resemble butter, but are much more easily preservable by re- 
 frigeration, and may be kept for long periods in fine condition. 
 The reason is that they contain very little casein or other sub- 
 stance liable to fermentation and decay, being composed almost 
 wholly of fats and oils which do not spoil quickly, even at ordi- 
 nary temperatures. A temperature somewhat higher than that 
 recommended for butter is generally used for butterine and oleo- 
 margarine. Temperatures of from 20° to 30° F., are in com- 
 mon use for the storage of these products. 
 
 LADLE BUTTER. 
 
 "Ladle" butter is butter reworked, resalted and repacked, 
 so as to put it in marketable condition and give it a uniform 
 
BUTTER IN COLD STORAGE 231 
 
 grade. Much of this is butter of good quality, but lacking in 
 uniformity of color, salt, and package. The ladler takes the mis- 
 cellaneous "farmers," "dairy," "store" or "packing stock" butter, 
 and by rehandling turns out a butter which is improved com- 
 mercially to an extent which has in the past made the business 
 profitable. The ladler makes his profit in intelligent grading 
 and in the increase of weight by resalting, washing, and rework- 
 ing. "Ladling" has now been largely superseded by "process- 
 ing." Very little ladle butter is placed in cold storage at the 
 present time. Those who have had experience, know that 
 "ladles" do not keep well in cold storage. The reworking incor- 
 porates thoroughly throughout the mass any rancidity or bad 
 flavor present in any part of the butter, and the result is that 
 after standing a comparatively short time "ladles" are off flavored 
 and take on a "ladley" taste and odor, even when carried in low 
 temperatures. As in processing, butter intended for ladling is 
 cold stored as original butter and rehandled as wanted by the 
 trade. Directions given for the handling of original butter apply 
 equally when used for processing or ladling. 
 
 CREAMERY BUTTER. 
 
 Creamery butter is so well known as not to need much de- 
 scription. At the present time nearly all creamery butter is 
 made from cream which is separated from the milk by a centrifu- 
 gal machine known to the trade as a separator. Separator 'butter 
 has poorer keeping qualities than butter made from cream raised 
 by setting the milk in cold water or what is called the gravity 
 process, for reasons already stated, but for the ordinary com- 
 mercial storage term of three to five months, keeps well enough 
 for practical purposes when held at temperatures below 15° to 
 20 F. The sixty-pound tub is the package generally used, par- 
 ticularly by the retailer, but much butter after having been 
 stored in large tubs is tempered to soften slightly and then 
 repacked into smaller packages ; the one pound print, wrapped in 
 paraffine or parchment paper being a favorite. Butter which is 
 to be "printed" before sale should be stored in as large, air- 
 tight and well soaked or impervious packages as possible. Some 
 dealers use firkins or butter carriers holding 100 to 200 pounds. 
 Do not try to store butter in prints for any length of time as 
 
232 PRACTICAL COLD STORAGE 
 
 the grain is somewhat broken in printing and its keeping qualities 
 therefore impaired. For the same reason do not store in small 
 packages which are not impervious to air and moisture. The 
 directions for packing previously given apply especially to cream- 
 ery butter. In some cases a covering of paste salt (salt which 
 is ground fine) is used. This is mixed with water and is put 
 on as a paste, which hardens on drying, forming an air tight 
 crust over the top of the butter. The butter cannot well be 
 examined without mussing or destroying this paste salt covering, 
 and it is not used to any extent except for cold storage purposes. 
 
 MOLD IN BUTTER PACKAGES. 
 
 Mold in butter packages has given much trouble, both in 
 cold storage and in the regular cooling rooms when held for 
 temporary storage. This may be caused by improper soaking 
 of the tubs or a badly constructed refrigerator or cooling room 
 at the creamery, or the empty tubs may be stored in a damp 
 place such as a cellar or basement at the creamery. A growth 
 of mold once started is quite likely to continue to grow and may 
 in a short time affect and flavor the butter. A growth of mold 
 may be prevented by storing the empty packages in a dry place ; 
 providing a good refrigerator with suitable air circulation at 
 the creamery; and by care and attention in packing the butter, 
 as already outlined. Instead of using water for soaking the 
 tubs, use brine. Water promotes mold — brine destroys it. Salt 
 is cheap. Use it in connection with your butter packages, and 
 mold will not trouble you. Use parchment paper liners and use 
 brine for moistening at time of packing. See chapter on "Cream- 
 ery and Dairy Refrigeration" for information regarding suitable 
 facilities for cooling rooms, etc., in connection with creameries. 
 
 SPECIFIC HEAT OF BUTTER. 
 
 The following regarding the specific heat of butter* by 
 G. H. King, Agricultural Physicist, University of Wisconsin, is 
 reproduced here for the valuable scientific information it 
 contains : 
 
 It would be a very difficult, if not an impossible, task to determine 
 the true specific heat of the butter fat of commerce, making correction* 
 
 *Krom Ice and Refrigeration, June, 1901, page 278. 
 
BUTTER IN COLD STORAGE 233 
 
 for the elements of latent heat, for the reason that butter is so complex 
 a product, and the butter fat itself varies so much in composition with the 
 season and with the stage of the lactation period, and even with the 
 individuality of the animal producing the butter. 
 
 I have made an approximate determination of the specific heat of but- 
 ter fat between ioo° C. and o° C, and find it to be .5494. 
 
 This result was obtained by taking ordinary butter, melting it and 
 boiling until all water was driven off, and skimming to remove solids not 
 fat, and then filtering hot. 
 
 There was then placed into a pocket in a block of ice 200 grams' of 
 the clear butter fat at a temperature of 100° C, and brought quickly 
 to o° C, when the butter fat and ice melted were weighed. Calculating 
 the specific heat from the amount of ice melted, the result found was 
 ■5494- 
 
 Butter fat, leaving the other ingredients out of consideration, is largely 
 a solution of tripalmitin and tristearin in triolein, or, in commercial 
 language, butter fat is a solution of palmitin and stearin in olein. But in 
 addition to these three fats there are also, found varying amounts of five 
 others, viz., butyrin myristin. caproin, caprylin and caprin. 
 
 The pure triolein, or olein of vegetable fats' and oils, becomes solid 
 only at a temperature as low as 21 ° F. The tripalmitin, or palmitin of 
 vegetable and animal fats, occurs in three isomeric or allotropic forms, 
 with melting points as high as 115°, 142 and 144 F., respectively, while 
 the tristearin, or animal and vegetable stearin, also occurs in three forms, 
 which remain solid, when pure, until a temperature of 124 , 148 and 157° 
 F., respectively, is reached. 
 
 The temperature at which butter becomes' solid, or .semi-solid, varies 
 with the relative amounts of the three chief fats which happen to be 
 present in the sample. It is stated that ordinarily butter becomes fluid 
 or melts at between 92° and 96 F., which should be understood that be- 
 low these temperatures the olein is no longer able to hold all of the 
 palmitin and stearin in solution. Pure lard melts at 78 to 87° F., and its 
 composition is' given as 62 per cent olein and 38 per cent of palmatin and 
 stearin. Butter fat, in the spring, from fresh cows on green grass has a 
 composition near 50 per cent of olein, 30 per cent of stearin and 20 per 
 cent of palmitin ; but later in the period of lactation, and in the fall when 
 the feeds are drier, its composition may change to 30 per cent olein, 50 
 per cent stearin and 20 per cent palmitin. 
 
 It seems likely from these observations' that the amount of heat neces- 
 sary to be applied to butter, in raising it from freezing to its melting 
 point, and to be withdrawn from it in cooling it from its melting point 
 down to freezing, will not be very far from the amount which would be 
 required to make a corresponding change in temperature of water, pound 
 for pound. 
 
 HUMIDITY, CIRCULATION, VENTILATION. 
 
 Humidity, air circulation and ventilation have been given 
 ■comparatively little attention as applied to the storage of butter. 
 At the low temperatures at which butter is generally stored the 
 air contains so little moisture as to be amply dry to prevent mold, 
 and, nothing further is thought of it. In fact, most butter storage 
 rooms are dryer than necessary, and it is difficult to prevent the 
 butter drying out from this cause. It is only necessary to have 
 
234 PRACTICAL COLD STORAGE 
 
 a butter room dry enough to prevent mold on packages, as the 
 goods are supposed to be sealed from air contact. What this 
 humidity should be there are no records to show, but moisture 
 does not trouble the general run of storage rooms for butter. A 
 circulation of air in butter storage rooms is of no great conse- 
 quence, as sufficient air circulation for purification of the air is 
 usually present. Most butter storage rooms are equipped with 
 direct piping, but some are provided with air circulation by 
 means of fans, when a quicker cooling is possible. Ventilation 
 of butter storage rooms is advisable at regular intervals, using the 
 apparatus described in the chapter on " Ventilation." Gases from 
 the oxidizing of butter fat and odors from the wooden packages 
 accumulate in the storage room unless disposed of by ventilation. 
 
COLD STORAGE OF CHEESE 235 
 
 CHAPTER XII. 
 COLD STORAGE OF CHEESE. 
 
 THE DESIRABILITY OF COLD STORAGE FOR CHEESE. 
 
 The cold storage of cheese on an extensive scale is one of 
 the recent additions to the cold storage business. Formerly it 
 was considered sufficient to store cheese in an ordinary cellar 
 or basement room, but about twenty-five to thirty years ago 
 cheese were first placed in cold storage, both with the old over- 
 head ice method of cooling and the first ammonia refrigerated 
 houses. The author remembers distinctly when as a boy he vis- 
 ited the old St. Johns Park Depot in New York, which was then 
 cooled with one of the first ammonia systems to be put in com- 
 mercial cold storage service and was used quite largely for 
 cheese storing. The success of the early experiments in keeping 
 cheese in cold storage was such as to extend the practice and 
 at the present time practically all cheese which are to be held for 
 consumption at some future time are placed in cold storage for 
 preservation. In fact the advantages of cold,; storage have been 
 so thoroughly appreciated that it has led the various experiment 
 stations of the United States Department of Agriculture to con- 
 duct some very extensive experiments in what they call "the 
 cold curing of cheese." 
 
 As a matter of fact, cheese "ripen" or mature at any low 
 temperature at which they may be safely stored. In reality, there- 
 fore, cold curing of cheese is simply the cold storing of cheese. 
 Cheese is one of the' products that improve with age. It is 
 not at its best when first made ; in fact it is unpalatable and un- 
 healthful when new or "green." It requires "curing" in order 
 to make it a healthful and palatable article of food. Under 
 ordinary conditions the curing process goes on regardless of 
 temperature, but the action is much slower as the temperature 
 is lower. The results of experiments which are here given prove 
 
236 PRACTICAL COLD STORAGE 
 
 conclusively that a much better quality of matured cheese results 
 when the cheese are placed in cold storage soon after being made. 
 It seems that the low temperature prevents the development of 
 bad flavors and deleterious gases which injure the flavor and 
 texture of the cheese. At the same time it allows the rennet 
 which is used in the manufacture of cheese to fulfill its mission 
 of curing or ripening. The experiments which are described in 
 detail further on need no additional explanation. 
 
 The results of these experiments seem to prove the advisa- 
 bility of establishing centralizing stations, which are in reality 
 cold storage plants, for the receiving of cheese when first made. 
 A plant of this character may be built at any convenient railroad 
 point and the cheese from a number of different factories hauled 
 thereto at frequent and regular intervals. They are then placed 
 under suitable temperature and other conditions and are ready for 
 immediate shipment at any time. The advantage of this method 
 over the old factory system of allowing the cheese to remain on 
 the curing room shelves for a time is that the flavor is improved, 
 shrinkage reduced to a minimum and the cheese are protected 
 from exposure to hot weather, which is one of the worst things 
 that the cheese manufacturer has to contend with. Appreciating 
 this difficulty, the sub-earth duct system has been adopted by 
 some of the more progressive factories. This is simply an air 
 duct running underneath the ground through which circulates 
 air which is introduced into the curing room. In passing below 
 the surface of the earth, the temperature of the air is reduced to 
 6o° to 65° F. and the temperature of the curing room is there- 
 fore modified during extreme warm weather. It was found that 
 this system in many cases had the disadvantage of causing cheese 
 to mold badly and no doubt it will be abandoned in favor of 
 the cold storage or cold curing method. There is an advantage 
 in having cheese brought to a central cold storage or curing 
 station in that it is easier for buyers to inspect and brings the 
 cheese all into a market center as it were. There is no reason 
 why they should be out of possession of the salesman anv more 
 with this system than they would under the old method. Co- 
 operation and consolidation will enable cheese manufacturers to 
 realize much better prices for their product, owing to improved 
 quality, if they will but adopt the cold storage system instead of 
 
COLD STORAGE OF CHEESE 237 
 
 the old-time curing room method. A large part of the expense 
 of a central cold curing station would be paid by the saving 
 effected at the factory in not being obliged to provide for shelves 
 and curing room space. 
 
 The best refrigerating system for use in connection with 
 cold curing will depend upon the section where located and local 
 conditions to a large extent. In cooling with air circulating in 
 direct contact with ice, a temperature below 40° F. cannot be 
 depended upon and as experiments demonstrate that cheese cured 
 at a temperature of 30 to 35° F. are of a better flavor and 
 texture, it is evident that some system which will produce a 
 lower temperature would be advisable. In addition, the humid- 
 ity of a room cooled directly from the ice is very high (in other 
 words, very moist). It has been demonstrated that the relative 
 humidity of such a room when used for the cold curing of cheese 
 would be at times somewhat above 90 per cent. These condi- 
 tions are very favorable for the growth of mold. The direct ice 
 system therefore is not advisable for the reason that sufficiently 
 low temperatures and regulation of humidity cannot be obtained. 
 The gravity brine system cooled with ice and salt, described else- 
 where in this book, is recommended as a system which will con- 
 trol temperatures, and in connection with the chloride of calcium 
 process, also described elsewhere, the humidity of the room may 
 be regulated to any desired degree. In situations where natural 
 ice cannot be obtained cheaply, the use of refrigerating machin- 
 ery is advisable and the temperature and humidity can thereby 
 be controlled in the same way as with the gravity brine system. 
 
 THE COLD CURING OF CHEESE.* 
 
 The prevalent opinion among cheese dealers has always 
 been that low temperatures, varying from 35° to 50° F., or there- 
 abouts, resulted in the production of an inferior quality of cheese, 
 in comparison with that from 60° to 70° F. No carefully con- 
 trolled experiments bearing on this problem have been recorded 
 earlier than those undertaken by Babcock and Russell at the 
 Wisconsin Agricultural Experiment Station, and described in 
 the fourteenth (1897) annual report of that station. The results 
 
 *Extracts from Bulletin No. 49, Bureau of Animal Industry, U. S.'Agr. Dept., giving 
 results of experiments conducted under the directions of Henry E. Alvord, Chief of Dairy 
 Division. More detailed information may be obtained by consulting same. 
 
238 PRACTICAL COLD STORAGE 
 
 of those tests showed that cheese placed at refrigerator tempera- 
 tures (45 to 50" F.), directly from the press, was of superior 
 quality as to flavor and also as to texture, and that such cheese 
 was wholly free from any bitter or other undesirable taints. 
 
 In connection with their studies on the influence which 
 galactase and rennet extract exert on the progress of cheese 
 ripening, the same investigators later employed still lower tem- 
 peratures (25 to 30 F.). Cheeses were kept at these exces- 
 sively low curing temperatures for a period of eighteen months. 
 The quality of these cheeses, cured as they were below the freez- 
 ing point throughout their whole history, was exceptionally fine, 
 and emphasized still more than the previous experiments did the 
 fact that the ripening of cheese can go on at much lower tempera- 
 tures than has heretofore been considered possible. 
 
 These results led to an extended series of experiments, in 
 which cheese made on a commercial scale was cured at a range 
 of temperature from below freezing (15 F.) to 60 ° F. — a point 
 which common practice has now accepted as the best obtainable 
 temperature that can be secured without the use of artificial 
 refrigeration. [No doubt the term "artificial refrigeration" as 
 here used means cooling by any means other than natural earth 
 or air temperature, and not the generally accepted meaning, viz., 
 refrigerating machinery. — Author. ] 
 
 In these experiments (consisting of five series made at in- 
 tervals throughout a period of two years) 138 cheeses were used, 
 for which 30,000 pounds of milk were required. These experi- 
 ments were upon a scale which represented commercial condi- 
 tions, and therefore obviated the objection which is often urged 
 in commercial practice against the application of results derived 
 simply from laboratory experiments. 
 
 The Ontario Agricultural College began experiments on the 
 cold curing of cheese in April, 1901. As a result of these tests, 
 the conclusion was drawn that the cheese cured at low tempera- 
 tures (37.8 F.) was much superior to that cured in ordinary 
 curing rooms (average temperature during season 63.8 F.j. 
 Mr. R. M. Ballantyne, a prominent cheese expert, said of this 
 cheese that "they (the merchants) universally expressed surprise 
 at the condition of the cheese that was put into cold storage at 
 the earliest period (that is, directly from the press), as they 
 
COLD STORAGE OF CHEESE 239 
 
 expected to find the cheese still curdy and probably with a bitter 
 flavor."* If this experiment is borne out by other experts, it 
 would appear as if the best way to handle hot-weather cheese 
 would be to ship it to the cold storage directly after making, 
 and this would certainly mean a great revolution to the trade. 
 
 A considerable number of experiments have also been made 
 at other stations (Dominion government tests and New York 
 State and Iowa experiment stations), where somewhat lower tem- 
 peratures were used than those which are normally employed for 
 ripening. The results obtained all show an improvement in 
 quality that becomes more marked as the temperature is reduced. 
 
 In order that a much larger experiment might be instituted, 
 covering the different types of cheese as represented by eastern 
 as well as western manufacture, Drs. Babcock and Russell, of the 
 Wisconsin Station, presented this matter for consideration to the 
 Dairy Division of the Bureau of Animal Industry. As a result 
 of this proposal the officers of the New York Agricultural Ex- 
 periment Station were also consulted and plans perfected for the 
 cooperative experiments conducted simultaneously in Wisconsin 
 and New York. [The eastern experiments are not given here 
 as the results differ in detail only, general conclusions being the 
 same in both series of experiments.] It should be noted that 
 it was so late in the season of 1902 when the arrangements for 
 this work were completed that it was impossible to obtain favor- 
 able conditions in all respects. 
 
 In addition to the influence which a range in temperature 
 exerts on the quality of cheese, as determined by flavor and tex- 
 ture scores, instructions were also issued to secure data regard- 
 ing the loss in weight which the different lots of cheese suffered 
 at the different temperatures. The commercial quality of the 
 product was to be determined by a jury of experts who were 
 thoroughly in touch with the demands of the market. Although 
 the effect of coating cheese with paraffin soon after being taken 
 from the hoop was not at first proposed as a part of this work, it 
 was finally included. 
 
 The reasons for selecting 40 , 50°, and 60" F. as the tem- 
 peratures to be used in these experiments are fully given on a 
 later page. It may be assumed that the advantages of a cool 
 
 *BulIetin No. iai, Ontario Agricultural College, June, 1902. 
 
240 PRACTICAL COLD STORAGE 
 
 and even temperature in curing Cheddar cheese have been already 
 established in preference to a warm temperature or to very vari- 
 able conditions which frequently include periods above 70 F. 
 and sometimes much higher. As already stated, 6o° F. or there- 
 abouts is regarded as the lowest temperature practicable without 
 artificial refrigeration; this may therefore be taken as fairly 
 representative of what may be called a "cool" temperature for 
 curing cheese. And rooms held at 40" and 50° F. were selected 
 as representative of a "cold" temperature for curing, or compara- 
 tively so. It is thus hoped to emphasize by these experiments 
 the distinction between cool curing and cold curing. 
 
 The cheese for these experiments was purchased by the 
 United States Department of Agriculture, which also paid all 
 expenses of transportation and storage and for the experts who 
 made the periodical examinations. The two experiment stations 
 selected the cheese, arranged all details of storage and examina- 
 tion, supervised the work throughout, performed the chemical and 
 other incidental scientific work, kept the records, and reported 
 results. 
 
 Each of the reports, prepared by the two experiment sta- 
 tions participating in this work, treats the same general subject 
 and similar lines of experiment and observation from its own 
 point of view. The reports therefore differ in many respects, 
 and yet they may be easily compared upon all essential points. 
 Both support the same general conclusions as to the advantages 
 of curing cheese at low temperatures, summarized as follows: 
 
 1. — The loss of moisture is less at low temperatures, and 
 therefore there is more cheese to sell. 
 
 2. — The commercial quality of cheese cured at low tempera- 
 tures is better, resulting in giving cheese a higher market value. 
 
 3. — Cheese can be held a long time at low temperature* 
 without impairment of quality. 
 
 4- — By utilizing the combination of paraffining cheese and 
 curing it at low temperatures the greatest economy is effected. 
 
 THE WESTERN EXPERIMENTS.* 
 
 For the purposes of this experiment Chicago would natur- 
 ally have been chosen as a curing station, but it was found dif- 
 
 *Conducted by S. M. Babcock and H. L. Russell, assisted by U. S. Baer, all of 
 the Wisconsin Agricultural Experiment Station. 
 
COLD STORAGE OF CHEESE 241 
 
 ficult to make arrangements for the range of temperatures de- 
 sired. Suitable arrangements, however, were made at the cold- 
 storage warehouse of the Roach & Seeber Co., Waterloo, Wis., 
 where rooms were fitted up and the desired temperatures secured. 
 As Wisconsin is the leading cheese-producing state of the 
 west, the bulk of the product selected for experiment was of 
 the type of cheese manufactured in this state. In order, how- 
 ever, to cover more thoroughly the cheese-producing territory 
 of the west samples were also secured from a number of the 
 neighboring states. In this way all types of American cheese 
 were obtained, ranging from the firm, typical Cheddar cheese, 
 suitable for export, to the soft, open-bodied, moist cheese, in- 
 tended for early consumption. For convenience we may group 
 these various lots of cheese under three different types, as 
 follows : 
 
 I- — Close-bodied, firm, long-keeping type, suitable for export 
 trade (typical Cheddar). 
 II. — Sweet-curd type. 
 
 Ill- — Soft, open-bodied, quick-curing type, suitable for early 
 consumption. 
 
 Type I represents the class of cheese that is especially manu- 
 factured in Wisconsin, while, as a rule, type III represents the 
 kind of cheese that is chiefly made in Michigan. The repre- 
 sentatives of the sweet-curd type were taken from Iowa and 
 Illinois, although this class is made to some extent in all sections. 
 In having the cheese made at these various factories direc- 
 tions were given for the use of a uniform amount of rennet and 
 salt. Color was left optional for each maker to follow his cus- 
 tomary practice. The use of 3*4 ounces of Hansen's rennet 
 extract and 2.y 2 pounds of salt per 1,000 pounds of milk was 
 recommended in each case with the exception of the smaller 
 cheeses (dairies and 10-pound prints), which were salted at the 
 rate of 2% pounds per 1,000 pounds erf milk. The cheese was 
 made from September 26 to October 4. The condition of the 
 milk was influenced in several instances by the fact that severe 
 frosts had occurred in some sections, which injured the quality 
 of the product. This was particularly true in the case of the 
 Alma cheese, which was in consequence somewhat tainted. The 
 milk from which the Iowa cheese was made was also reported as 
 
 (16) 
 
242 PRACTICAL COLD STORAGE 
 
 of inferior quality. The Michigan goods were too high in acid, 
 and were cooked low, making a soft cheese, which was quick- 
 curing and which kept poorly. 
 
 Where it was necessary to secure cheese from such a wide 
 range of territory it was manifestly impossible to expect that the 
 curing could be carried out as satisfactorily as if it had been 
 done at or near the factories. The varying period of transit to 
 which the cheese was subjected, with no especial temperature 
 control, affected, of course, the initial stages of curing, but the 
 conditions of the experiment prevented the carrying out of im- 
 mediate installation of the cheese in the cold curing rooms, es- 
 pecially in the case of those made outside of Wisconsin, although 
 the shipments were made in October, when the temperature 
 range was moderate. 
 
 TEMPERATURES AT WHICH THE CHEESE WAS CURED. 
 
 The cheese was weighed and put in the . respective rooms as 
 soon as received at Waterloo. It was stored in boxes during 
 the curing, as is the custom in the handling of cold-storage goods. 
 The temperatures at which it was desired to hold the cheese for 
 curing were 40°, 50 , and 60° F. These points were selected 
 for the following reasons: In our previous experiments we had 
 found that the character of the cheese cured at the lower tem- 
 peratures (40° and 50 ) was much better than that produced at 
 6o° F. Perhaps it would have been better for the purpose of 
 the experiment if the cold-cured cheese could have been com- 
 pared with the same make of cheese cured under the widely 
 variable conditions which prevail in most factories, where often 
 the maximum temperature is in the neighborhood of 80° F. and 
 the fluctuation is 20 or more ; but we have made this comparison 
 with the very best conditions that obtain in factories provided 
 with subearth ducts and other means of temperature control. 
 In such cases a temperature of 6o° F. can be maintained with a 
 fair degree of constancy. The experiments, therefore, compare 
 the cold-curing process with that of the best prevailing con- 
 ditions. 
 
 The temperatures actually maintained varied only slightly 
 from the chosen points, and in the two colder rooms were re- 
 markably uniform. The 60° room was subject to somewhat 
 
COLD STORAGE OF CHEESE 243 
 
 wider fluctuations, but was much more uniform than is obtained 
 in summer where no artificial refrigeration is practiced. 
 
 DETAILS OF SCORING THE CHEESE. 
 
 It would have been advisable to have the cheese examined a 
 considerable number of times by the commercial judges, but it 
 was impossible to carry out this test so frequently. The tests 
 were therefore arranged to come at those periods which would 
 give the judges the most accurate idea of the character of the 
 cheese held at the different temperatures. 
 
 As a jury of commercial experts, representing the different 
 markets, the following gentlemen were selected : C. A. White, of 
 Fond du Lac, resident representative in Wisconsin of a leading 
 dairy produce house of New York; T. B. Millar, of London, 
 Ontario, a cheese expert and large buyer for the export trade, 
 and John Kirkpatrick, a member of a leading produce firm of 
 Chicago. 
 
 For the jury trials representative cheese were taken from 
 storage and shipped by refrigerator service to Chicago, where 
 they were submitted to a thorough examination by the commer- 
 cial judges. The first of these commercial scorings was made 
 when it was found that the 6o° product was ready for market. 
 This test was made on January 6, 1903. Another test was made 
 on March 23, when the cheese was about 7 months old. 
 
 It might at first thought seem preferable to have had the 
 cheese sold in the open market and thus secured a strict commer- 
 cial valuation on the product, but, as everyone knows, a consider- 
 able variation in quality may exist without an appreciable differ- 
 ence being made in the market price. Then, too, the inevitable 
 fluctuations in the market price would render comparisons at 
 different periods untrustworthy. To obviate these difficulties the 
 cheese was scored on the basis of a standard price (13 cents). 
 The fact that but few of the cheese reached this standard should 
 not be interpreted as indicating a poorer quality than the average 
 market product, for the cheese was adjudged by the jury to be 
 superior in quality; but the price was in part determined by the 
 market appearance of the goods, which was somewhat inferior 
 hecause of the fact that they had been box-cured and had received 
 
244 PRACTICAL COLD STORAGE 
 
 practically no care in curing, as the curing station was located at 
 a distance from Madison. 
 
 The scores of the commercial jury were supplemented by a 
 series of scores made by Mr. Baer which covered the entire his- 
 tory of the cheese from the time it was received until its final 
 disposition. In this study it was possible to follow more closely 
 the course of the ripening. 
 
 SHRINKAGE OF CHEESE IN WEIGHT WHEN CURED AT DIFFERENT 
 TEMPERATURES. 
 
 The losses in weight which cheese undergoes in the curing 
 process is a matter of such practical importance that it is ad- 
 visable when possible to accumulate data relating to it. This is 
 all the more important in this connection because no studies have 
 yet been reported on cold-cured cheese, and it was therefore 
 deemed advisable to keep a record of the losses in weight so 
 that the shrinkage at these lower temperatures might be com- 
 pared with those which normally obtain at the best temperatures 
 now employed. The average shrinkage under existing curing 
 conditions in the majority of factories results in a loss of 5 to 7 
 per cent for the first thirty days, with a gradually diminishing 
 rate for longer curing periods. This results in a heavy tax to 
 the producer, and any factor which reduces these losses increases 
 thereby the total receipts from the milk produced. 
 
 There are a number of factors which modify the rate at 
 which a cheese loses its water content during the course of ripen- 
 ing. The following factors are known to exert a more or less 
 marked influence, although it is impossible to arrange them in 
 order of their relative importance, as they are always inter- 
 dependent : 
 
 1. — Temperature of curing room. 
 
 2. — Relative humidity of air in curing room. 
 
 3. — Size and form of cheese. 
 
 4. — Moisture content of the cheese. 
 
 5. — Protection to external surface of the cheese. 
 
 The influence of temperature is closely connected with the 
 relative humidity of the curing room; but, in addition to the 
 effect which the higher temperatures exert on this factor, it 
 should be observed that water evaporates more rapidly at a high 
 
COLD STORAGE OF CHEESE 245 
 
 than at a low temperature, even though the relative humidity 
 remains the same. The more potent influence of temperature is, 
 however, the effect which varying degrees of heat exert on the 
 relative humidity of the atmosphere. A fall of 20° F. from 
 ordinary air temperatures practically doubles the relative humid- 
 ity, provided the point of saturation is not passed. As the 
 average relative humidity of the air is generally over 50 per 
 cent, it therefore follows, in cold-curing rooms supplied with 
 outside air, the temperature of which is from 30° to 40 F. 
 higher in summer than the inside temperatures, that the air of 
 these rooms is practically saturated, thus greatly reducing the 
 loss of moisture from the cheese. [Conclusions so positive as 
 these are not warranted. Temperature and humidity are not 
 necessarily closely related. Water evaporates more rapidly at 
 high temperature because the capacity of air for moisture is 
 increased with its temperature, but it does not necessarily follow 
 that the humidity is increased as the temperature is reduced, and 
 a room in which the air is nearly saturated with moisture seldom 
 exists. If it did it would be a bad place to store cheese because 
 mold would grow rapidly. See chapter on "Humidity."] 
 
 So far as the cheese itself is concerned, the moisture of the 
 . room may be materially altered by the way in which the cheese 
 is handled during the curing process. If the cheese is shelf- 
 cured, as is the custom in most factories, the surrounding air 
 more nearly approximates the average relative humidity of the 
 entire room than is the case where the goods are box-cured. In 
 the latter case the air is more nearly saturated, as is shown by the 
 greater liability to mold and rind-rot. 
 
 This point is well shown in a series of observations on the 
 relative humidity of the air in a box containing a cheese placed 
 directly therein from the press. 
 
 A factor which is frequently overlooked is the varying mois- 
 ture content of the cheese. The more moisture there is left in 
 the cheese the more rapid the evaporation. The varying mois- 
 ture content of different types of cheese is determined by the 
 temperature at which the curds are cooked, the time of exposure, 
 and the acidity of the curd. A cheese in which the acidity is 
 developed is materially drier than a sweet-curd cheese. Salt also 
 has a tendency to diminish the water content. In the foregoing 
 
246 PRACTICAL COLD STORAGE 
 
 cases the cause of this diminution in moisture is due to the 
 shrinking of the curd particles under the influence of these fac- 
 tors. An increase in fat lessens the drying of the curd. Much 
 loss of moisture can also be prevented by coating the cheese with 
 paraffin, a practice which is now coming into very general use 
 for the prevention of mold and to lessen shrinkage in weight. 
 
 EXPERIMENTS IN SHRINKAGE OF COLD-CURED CHEESE. 
 
 In these experiments the first careful weighings were made 
 when the cheese was received at the cold-storage plant in Water- 
 loo. The cheese was shipped from the factories directly after it 
 was removed from the press, but was in every case several days 
 upon the road. In no instance was the interval between making 
 and installing in cold-curing rooms less than five days, and it 
 ranged from this up to seventeen days with one lot from Michi- 
 gan, which was delayed in transit. During this period, which 
 was in early October, the cheese was subjected to varying condi- 
 tions of temperature and exposure. In a few cases boxes were 
 broken, and in other instances the cheese was delayed at points 
 of transfer. It was impossible to obviate these difficulties, as 
 the cheese was purchased at distant points in order to secure 
 representation from a wide range of territory and from different 
 types of cheese. This variation in initial drying changed, of 
 course, the rate of loss when cheese was placed in cold-curing 
 rooms, so that this factor must be taken into consideration in 
 studying the data presented below. 
 
 The losses reported here cover those only which took place 
 in the cheese after it had reached the cold-curing rooms, but 
 careful records have been kept for the entire curing period; and 
 these data, we believe, are of sufficient importance to warrant full 
 consideration in this connection. 
 
 DETAILS OF WEIGHING. 
 
 The cheese was all weighed on counter scales, weighing ac- 
 curately to fractions of an ounce. In order to check the accuracy 
 of the weights, each cheese was weighed separately and the 
 weight recorded; then the whole lot was weighed collectively. 
 As these weights agreed within a few ounces, they show the 
 accuracy of the weighings. For practical purposes it is desirable 
 
COLD STORAGE OF CHEESE 247 
 
 to know the losses which occur for stated periods. It was, how- 
 ever, impracticable for all of the cheese to be weighed at exactly 
 the same intervals, as it was put in storage at different dates, but 
 it was designed to secure at least three weighings for the first 
 month of storage, two weighings for the. second, and at about 
 monthly intervals thereafter. If these data are charted, it is 
 possible to deduce an estimated loss for any stated period, and 
 in doing so we have selected the following intervals as being 
 those concerning which data would be most frequently desired. 
 For this purpose ten, twenty, thirty, sixty, ninety, etc., days have 
 been selected. 
 
 CONDITIONS UNDER WHICH THE CHEESE WAS STORED. 
 
 In this work the attempt was made to hold the cheese at 
 4°°> 5°°; an d 6o° F. The actual temperatures secured averaged 
 36.8 , 46.9°, and 58.5° F. The variation in temperature in the 
 two lower rooms was practically negligible, as it was only 2 to 
 2.\° . The temperature of the 60° room oscillated somewhat more 
 (4° F.), but was very much more uniform than ordinary factory 
 curing rooms. 
 
 Hygrometric data were not secured during the whole 
 period, as it was at first thought that a saturated atmosphere 
 would prevail where the cheese was box-cured, but during the 
 course of the experiments it was noted that the 50 cheese was 
 not molding as much as was that at 40° and 60°. This fact could 
 only be explained by the assumption that a less humid atmosphere 
 was present in the case of the 50 room. [See previous remarks 
 on temperature and relative humidity.] 
 
 DISCUSSION OF RESULTS. 
 
 As there are several factors which affect the rate of shrink- 
 age which the cheese suffers in curing, it will be desirable to 
 discuss the data collected under several heads. The conditions 
 of the experiment were such as to temperature that an espe- 
 cially favorable opportunity was had for the study of the influence 
 which this factor exerts on the cheese. It is, of course, neces- 
 sary in a study of this sort to have the cheese uniform in size. 
 The moisture contents of the cheese can not, of course, be made 
 alike, but in this study the cheese of the same type have been 
 
248 PRACTICAL COLD STORAGE 
 
 grouped together — that is, as firm Cheddars suitable for export 
 and softer, moister cheese intended for home trade. 
 
 INFLUENCE OF TEMPERATURE ON SHRINKAGE. 
 
 To study the rate of loss of Cheddar cheese when kept at 
 different temperatures, 129 flats were selected from nine different 
 lots of cheese made by six different makers. These were exposed 
 at three different temperatures, which averaged, respectively, 
 36.8 , 46.9 , and 58.5" F. The results obtained were calculated 
 upon the number of cheese which were subjected to stated weigh- 
 ings. During the experiments much more data were collected on 
 the lower temperatures than on the 60° lot. This was regarded 
 necessary, as up to this time we have no published data on cheese 
 cured at so low a temperature. 
 
 For purposes of convenience the different lots of cheese 
 were divided into three types, depending upon their character : 
 
 I. — -Firm-bodied cheese (export type), of Wisconsin. 
 
 II. — Sweet-curd type, as represented by the Iowa and 
 Illinois makes. 
 
 III. — A very moist, soft type, suitable for home trade 
 (Michigan). 
 
 The general conclusions arrived at were : 
 
 1. — The losses sustained by the different lots were very 
 much less at 40° F. than at either of the other two temperatures. 
 For a ninety-day period the losses of the 40° cheese ranged from 
 1 to 1.4 per cent, while the 50" and 6o° product shrunk from 3.4 
 to 4.5 per cent for the same time. In other words, by the use of 
 the lower temperature for curing practically two-thirds of the 
 losses which occurred at the temperatures of 50° and 6o c F. were 
 prevented. If these results are compared with what happens 
 under ordinary factory conditions, the loss at these low tempera- 
 tures for a period of ninety days (the minimum curing period 
 recommended) will not be more than one-fourth of that which 
 obtains under average factory conditions when the cheese are 
 held for a period of about twenty days. The saving for any such 
 factory making 500 pounds of cheese daily would amount to at 
 least 15 pounds of cheese (or $1.50) per day as an average for 
 the season, and considerably more than this for cheese made 
 during hot weather. This saving in itself would go far toward 
 
COLD STORAGE OF CHEESE 249 
 
 i 
 meeting the extra expense of lower temperature curing, even if 
 the product was no better than that cured at higher temperatures. 
 
 2. — The differences between the cheese cured at 50 and 60° 
 F. are not so marked as between 50 and 40 F. It is quite prob- 
 able, as before mentioned, that the 50" room was somewhat drier 
 than the 60 ° (as shown by the lessened mold growth), and hence 
 the rate of loss was abnormally increased in this room. [The 
 reason why evaporation is less at the lower temperatures is not 
 necessarily owing to higher relative humidity, but to the lesser 
 capacity of the air for moisture at low temperatures. — Author.] 
 
 3- — If the firm Wisconsin type is compared with the softer 
 variety, as shown in types II and III, it appears that the losses 
 are considerably less, especially at the higher temperatures, al- 
 though this difference is not so observable at 40 F. 
 
 4. — The data referred to above showed a marked saving in 
 losses where the cheese was cold cured, but in these experiments 
 it must be remembered that the cheese was subjected to higher 
 temperatures during transit, and hence dried out somewhat more 
 than would have occurred if put in storage as soon as removed 
 from the press; also, that this cheese was box-cured, and there- 
 fore under conditions which prevented rapid evaporation. Under 
 other conditions the losses would have been greater than repre- 
 sented here, and the difference in the rate of loss between the 
 different lots wider than reported above. This would still fur- 
 ther increase the saving. 
 
 It must be remembered that the entire loss in weight during 
 the curing of cheese is not due to evaporation. A cheese in cur- 
 ing is constantly breathing out carbon dioxide the same as any 
 living organism, due to the development of microorganisms 
 (bacterial growth within the cheese as well as molds on surface). 
 Aside from these biological factors, it has been shown by Van 
 Slyke and Hart* that profound proteolytic decompositions also 
 give rise to an appreciable amount of C0 2 . With cheese at 6o° 
 F., in which external mold growth was suppressed, they found 
 a loss of approximately one-fourth of 1 per cent in ninety days. 
 In our cold-cured cheese, copious mold development occurred, 
 and hence the losses of carbon from the cheese due to this growth 
 would be considerably greater than if no such growth occurred. 
 
 *Bulletin No. 231, New York State Agricultural Experiment Station, p. 36. 
 
250 PRACTICAL COLD STORAGE 
 
 With the nearly uniform rate of shrinkage shown in these cold- 
 cured cheese, regardless of size, it is quite problematical whether 
 this loss in weight may not be chiefly due to the operation of the 
 foregoing factors. If this is so, we may consider such losses as 
 absolutely unavoidable under normal conditions, for the action 
 of microorganisms which can not be suppressed will inevitably 
 result in the production of some volatile products. [This inter- 
 esting deduction is supported by the tests by the author and others 
 on the keeping of eggs in sealed packages. See chapter on "Eggs 
 in Cold Storage."] 
 
 At the temperatures of 50° and 60° F., where the relative 
 humidity was below saturation, the factor of evaporation is 
 apparent and is inversely related to the size of the cheese. From 
 a practical point of view, it is worth noting that the losses in 
 both sizes of cheese cured at 6o° F. are approximately 50 per 
 cent more than they are in the cheese ripened at 50° F. 
 
 INFLUENCE OF PARAFFINING CHEESE ON SHRINKAGE 
 DURING CURING. 
 
 Within the last few years the custom of coating the cheese 
 with an impervious layer has been suggested, with the object 
 mainly of preventing the development of mold. For this pur- 
 pose paraffin has been found to be the most suitable agent. The 
 application of such a layer to the cheese not only prevents the 
 growth of mold spores by excluding the air, but materially re- 
 tards the rate at which the cheese loses its moisture. Paraffined 
 cheese then dries out much more slowly than the untreated prod- 
 uct, and the application of this method is of particular service in 
 the handling of the smaller types of cheese, which have a rela- 
 tively larger superficial area exposed to the air. 
 
 In the paraffined cheese at 40 F. the losses were reduced 
 practically to a minimum, as was also the case with the unparaf- 
 fined at this temperature. As evaporation would certainly be 
 lessened in the paraffined lot, the uniformity of loss between these 
 and the unparaffined still further substantiates the view advanced 
 earlier that these losses are not so much due to shrinkage from 
 evaporation as they are to metabolic activities of organisms and 
 possibly chemical transformations within the cheese. 
 
COLD STORAGE OF CHEESE 251 
 
 EFFECT OF TEMPERATURE ON QUALITY OF CHEESE. 
 
 Originally it was planned to have the cheese judged by com- 
 mercial experts, but it was found impossible to arrange for a 
 sufficiently large number of such tests to closely follow the pro- 
 gressive changes which occurred in the course of the ripening 
 of the cheese. Hence, in addition to the examinations made by 
 the jury of commercial experts, the cheese was carefully scored 
 at Waterloo by Mr. Baer at frequent intervals. 
 
 COURSE OF RIPENING IN TYPE I. 
 
 Type I was represented by four different lots of Wisconsin 
 cheese. All of them were well-cooked, firm-bodied, slow-ripen- 
 ing cheese that may be regarded as typical Cheddars. In one case 
 the milk from which the cheese was made was evidently tainted, 
 as the cheese was slightly off at the outset. 
 
 The results of these periodical scores by Mr. Baer show that 
 good cheese was produced at all temperatures in the first three 
 lots. Naturally that cured at 60° F. developed more rapidly 
 than the goods cured at lower temperatures, but it should be 
 noticed that even at this temperature some of the firm-textured 
 cheese went off in five months. At 50° and 40 F. the cheese 
 was about six weeks to two months behind the 60 ° in develop- 
 ment, but in time it reached as high as the 60 ° lot, and generally 
 of a better quality, and kept this maximum condition much longer 
 than the 60°. This enhanced keeping quality was more pro- 
 nounced at 40° than at 50 F. 
 
 In the lot made from tainted milk the imperfect condition 
 was pronounced at all temperatures, but was more prominent 
 at 6o° than below. 
 
 In studying the scores by Mr. Baer, it is possible to combine 
 the numerical scores of the four different lots of Wisconsin 
 cheese belonging to the same type and so obtain a set of averages, 
 as to flavor, texture, and price, which indicate clearly the progress 
 of the curing of these various lots at the different temperatures. 
 
 The variation in flavor observed at the different tempera- 
 tures is more marked than any other characteristic. It appears 
 that at the higher temperatures the flavor is more developed dur- 
 ing the earlier ripening stages, but as the cheese increases in age 
 
252 
 
 PRACTICAL COLD STORAGE 
 
 the quality of the flavor at the higher temperatures deteriorates 
 more rapidly than in the cold-cured goods. At the end of five 
 months the 40° was still improving, and even at this time was 
 higher than at any period with the 50 and 60°. At the end of 
 
 FIG. I. — THREE CHEESE SECTIONS — TYPE I. 
 Cheese at top cured at 40 , in middle at 50 , and at bottom at 6o°. 
 
 eight months the cold-cured cheese was still of excellent quality, 
 and showed no signs of deterioration. 
 
 The texture of the cheese followed quite closely a develop- 
 ment similar to that noted above. In the earlier stages the 60° 
 had the highest score, but it reached its maximum in three 
 months, while the 50° and 40° continued to improve up to the 
 
COLD STORAGE OF CHEESE 
 
 253 
 
 end of the test, and was higher in the 40 at this time than at any 
 time in the 60°. 
 
 FIG. 2. — TWO VERTICAL CHEESE SECTIONS — TYPE I. 
 Cheese cured at 40° on left and cheese cured at 6o° on right. 
 
 The beneficial effect of cold-curing on this firm type of 
 cheese is strikingly apparent from the above data. Not only was 
 this cold-cured cheese free from any bitterness or taint incident 
 
254 
 
 PRACTICAL COLD STORAGE 
 
 to the curing process, but it was much improved in texture, as 
 is evident from Fig. i, which shows the appearance of cheese 
 made from the same vat but cured at approximately 40°, 50 , and 
 60° F. When the cheese is cold-cured the body is much closer, 
 
 FIG. 3. — TWO CHEESE SECTIONS — TYPE II. 
 Cheese cured at 40 on top, cheese cured at 60° on bottom. 
 
 as the curd particles are subject to more pronounced shrinkage at 
 higher temperatures, which causes the formation of these irregu- 
 lar, ragged cracks. This is perhaps rendered more obvious in 
 cheese cured at 40° and 6o° F., as shown in Figs. 2 and 3. When 
 
COLD STORAGE OF CHEESE 255 
 
 it is remembered that the results ordinarily obtained in factory 
 curing are not anything like as satisfactory as those shown in 
 the cheese cured at 6o° F., the improvement in quality, as shown 
 by the texture of the cheese cured by the cold-curing process over 
 that now in vogue, is emphasized still more. 
 
 The 50° cheese stands intermediate between the distinct- 
 ively cold-cured product and that obtained under best present 
 conditions without artificial refrigeration. Emphasis has already 
 been laid upon the fact that a considerable improvement in qual- 
 ity is to be expected where a slight diminution in temperature 
 is secured over that found in the best type of factory curing now 
 in vogue. This system of "cool-curing" — that is, the use of a 
 temperature from 52° to 58° F., as recently advocated by the 
 Canadian authorities*- — stands midway between the cold-curing 
 process and the system now most frequently in use. The benefits 
 to be gained by this system are evident from the Canadian ex- 
 periments, in which 480 pairs of cheese were cured, one of each 
 lot being kept at 52 to 58 F., while the other was ripened in 
 an ordinary curing room (61° to 70 ). Quoting Mr. Ruddick's 
 paper, he says that "in every case the cool-cured (cheese) has 
 been pronounced the best in quality." 
 
 From the experiments detailed above it appears that further 
 improvement in quality is possible if the curing temperature is 
 still further reduced (40 to 50° F.). It must be remembered in 
 this comparison that the highest temperature we employed is 
 much lower than the average factory curing room. The differ- 
 ence in quality between cold-cured and ordinary-cured cheese 
 would be much greater than that represented in this work. 
 
 The cheese of this type at 60" F. ripened rapidly and showed 
 an excellent quality in all lots but one, which was tainted from 
 the beginning, but they all passed their prime in three months 
 and showed marked deterioration by the end of five months. 
 
 With this type of cheese it must be remembered that the 
 quality of the flavor produced at low temperatures is quite dif- 
 ferent from that found at 60 ° F. Cold-cured cheese possesses a 
 very mild but perfectly clean flavor, together with a solid, waxy 
 texture. 
 
 *J. A. Ruddick in paper presented at the Ontario Dairymen's Association, January 
 1903. 
 
256 PRACTICAL COLD STORAGE 
 
 COURSE OF RIPENING IN TYPE II. 
 
 The cheese in Type II is not so uniform in its make-up as 
 that of Type I, but it represents that type of American product in 
 which less acid is developed than is found in the normal Cheddar 
 cheese. This cheese is more open in texture and contains a con- 
 siderable number of mechanical and small Swiss holes, as shown 
 in Fig. 3. The cheese was somewhat low in flavor, due in all 
 probability to the milk and method of manufacture, and not to 
 the curing, as this defect was quite as apparent at the lower tem- 
 peratures as at 60° F. 
 
 The Iowa cheese was found to be of only fair quality, but 
 at all ages was better at 40° F. than at other temperatures, al- 
 though the difference is considerably less than it was with the 
 firmer Wisconsin type of cheese. 
 
 The Illinois cheese was quite similar to the Iowa lot, but 
 the texture of this cheese at 6o° F was considerably more im- 
 paired than that obtained at the lower temperatures. 
 
 COURSE OF RIPENING IN TYPE III. 
 
 Type III represents the softer make of cheese intended for 
 home trade, and one which cures more quickly, and therefore 
 does not keep as long as the firmer Cheddar type. This type is 
 represented by four different lots of Michigan cheese made at 
 the same factory. They were not of standard quality, but were 
 too acid. The first three lots were materially delayed in transit 
 and consequently had undergone considerable change before 
 being cold-cured. From the detailed data it is evident that lot 
 four was the best, and in this lot the 40 and 50° were both bet- 
 ter than the 6o°. 
 
 In this case the flavor of the four lots was poor, only once 
 exceeding 40 points. While the 6o° scored higher at one time 
 than the cheese at the other two temperatures, the 40° cheese at 
 five months equaled the flavor of the higher temperature cheese 
 at this time. 
 
 The difference in price of this cheese at three months was 
 inconsequential, and from this date the cheese at all temperatures 
 fell off rapidly in value. 
 
 All four lots of these Michigan goods were more or less de- 
 layed in transit, although lot four was no more so than some of 
 
COLD STORAGE OF CHEESE 257 
 
 the cheese in the other types. But with this moist, quick-curing 
 cheese it was much more susceptible to temperature influences, 
 and hence was materially impaired before being put in storage. 
 This condition, taken in connection with the inferior make (high 
 acid), renders this part of the experiment unsatisfactory. 
 
 In the first test the jury consisted of Messrs. White, Millar, 
 and Kirkpatrick. In the second test, made when the cheese was 
 five months old, one of the judges (Kirkpatrick) was unfortun- 
 ately unable to assist. It is therefore impossible to compare with 
 each other the average scores secured in these two tests, as the 
 judgment of the different members of the jury naturally is not uni- 
 form. In comparing, therefore, the course of ripening in the 
 three and five months' tests, it will be necessary to correct the 
 averages given by eliminating the score of the judge who was 
 absent in the second test. 
 
 For purposes of study, however, the two tests can be con- 
 sidered independently and the influence of the different tempera- 
 tures on the character of the cheese determined. 
 
 RESULTS OF .FIRST JURY TRIAL. 
 
 When the cheese had been cured for three months, the sam- 
 ple cheese which had been tested previously at monthly inter- 
 vals by Mr. Baer, was shipped by refrigerator service to Chicago 
 and submitted to the jury for examination. 
 
 Type I. In the four lots of cheese which comprised this 
 group the 50° product was higher in flavor twice, the 40 once, 
 and once the 40° and 50° were alike. In no case, even at this 
 age, when the 60 ° cheese was at its best (as shown by the serial 
 examinations made by Mr. Baer), did this cheese reach as fine 
 a flavor as at the lower temperatures. 
 
 In texture the 40° lot was ahead twice, once the 50° and 6o° 
 were alike, and once the 6o° was the highest. 
 
 As to price, in no case did the 60 ° equal the value set upon 
 the cheese cured at the lower temperatures, although the differ- 
 ence given by the judges was slight. It must be remembered 
 that the price assigned by the commercial jury was influenced 
 materially by the fact that there is considerable difference in qual- 
 ity, even among the best types of cheese, without a corresponding 
 difference in price. In the majority of cases, when the cheese 
 
 (17) 
 
258 PRACTICAL COLD STORAGE 
 
 scored within one or two points of perfect, the price was cut 
 from a quarter to a half cent below the market standard (13 
 cents), simply because the appearance of the cheese on the sur- 
 face (mold, etc.) warranted this reduction from a purely com- 
 mercial point of view. The judges were free to admit that in- 
 trinsically the cold-cured cheese was of much better quality than 
 is usually obtained in the market. This cheese was box-cured 
 and received no especial care throughout the experiment; con- 
 sequently the exterior appearance of the same had been impaired. 
 With proper control this condition could have been entirely 
 obviated, as we have been able to show repeatedly where cheese 
 was cold-cured under our direct supervision. 
 
 Type II. In this type, in which less acid was developed, 
 little or no difference was observed in the Iowa goods ; but in the 
 Illinois cheese the 40 product had "a better flavor and texture 
 than the cheese cured at 50° or 60° F. Fig. 4 shows the appear- 
 ance of the Illinois cheese cured at the three temperatures when 
 three months old. 
 
 Type III. This type is represented by four different lots 
 from the same factory. All of the lots were highly acid and were 
 of somewhat inferior make. Then, too, the earlier lots were de- 
 layed in transit from "the factory to the curing station, so that 
 the results of the experiment should not be considered as neces- 
 sarily typical of the cold-curing process. In this group of four 
 tests the 50° goods were ahead twice on flavor, the 6o c once, and 
 once the 40° and 60 ° were alike. In texture the 50° was highest 
 three times out of four. 
 
 GENERAL SUMMARY OF THE FIRST (THREE MONTHS) TEST. 
 
 The cheese was examined at this date by the commercial 
 judges, as it was thought that the highest temperature cheese 
 (60°) had reached its maximum condition. It was naturally ex- 
 pected that the 60° product at this time would rank higher in 
 quality than the cold-cured goods. 
 
 From this it appears that the 50° cheese was superior in 
 flavor and texture, not only on the basis of the total scores, but 
 also as to the number of times they ranked highest or equal to the 
 cheese cured at either of the other temperatures. This test was 
 
COLD STORAGE OF CHEESE 259 
 
 made before the 40° goods were marketable, but even at this 
 time this cheese compared favorably with the 6o° product. 
 
 RESULTS OF SECOND JURY TRIAL. 
 
 The second commercial scoring was made at the end of five 
 months, at which time it was thought that the cold-cured goods 
 
 FIG# 4.—THREE CHEESE SECTIONS— ILLINOIS CHEESE. 
 Cheese at top cured at 4 o«, in middle at 50°, and at bottom at 6o°. 
 
 could best be judged from a market point of view. The results 
 of this scoring follow: 
 
 Type I. In the four lots tested of this firm-bodied cheese, 
 the 40 was highest in flavor three times and the 6o° once. 
 Averaging the total scores shows that the 40 cheese scored 2.8 
 points higher than the 60°, and even the 50° was 1.6 points above 
 
260 PRACTICAL COLD STORAGE 
 
 the cheese held at what has been considered ideal curing con- 
 ditions. 
 
 In texture the 40° was highest twice, while in the other 
 cases the scores were equal. Numerically, the average texture of 
 the 40° was nearly a point above the 60°. At this age the 60° 
 goods began to show signs of deterioration, while the cold-cured 
 goods kept much better. 
 
 Type II. In this test one lot of the 60° goods (Iowa) was 
 mislaid in transit, and hence was not tested, but in this case the 
 40° was 2 points above the 50 in flavor, and 1 point on texture. 
 In the Illinois cheese but little difference was observed. 
 
 Type III. In this softer cheese, twice the 40° scored high- 
 est in flavor, the 50° and 6o° once each. On texture the 40° 
 scored highest twice, the 50° once, and the 50 and 60° tied once. 
 
 GENERAL SUMMARY OF SECOND (FIVE MONTHS) TEST. 
 
 In this test the average score, as well as the number of times 
 any lot has scored the highest, shows that the 40° cheese was su- 
 perior to those at either of the other temperatures, while at this 
 age the 60° cheese showed that it had passed its prime. 
 
 COMPARISON OF THE FIRST AND SECOND JURY TRIALS AS INDICAT- 
 ING THE KEEPING QUALITY OF THE CHEESE. 
 
 It is important to compare the scores of the commercial 
 judges made at the first and second jury trials, as in this way it 
 is possible to study the keeping quality of the cheese cured at 
 different temperatures. Unfortunately one of the judges could 
 not be present at the second test. Therefore the judgment of the 
 other two has been used in comparing the data of the two tests. 
 
 Type I. With reference to flavor, type I showed its better 
 keeping qualities, inasmuch as it held its own at 40 F., while at 
 50° F. the cheese had deteriorated 2 points and at 6o° F. 2.9 
 points. The texture improved at all temperatures as the age in- 
 creased, but was much more pronounced (over a point) at 40° 
 than at 50 or 60° F. This improvement in flavor and texture 
 is also reflected in the enhancement in commercial value. The 
 40 gained 0.2 cent per pound in three to five months, while the 
 50° fell off 0.1 cent and the 60° 0.2 cent per pound. Thus in all 
 
COLD STORAGE OF CHEESE 261 
 
 ways the advantage of cold curing is evident on this firm, solid 
 type of the Winconsin cheese. 
 
 Type II. In this type, in which less acid was developed than 
 in the typical Cheddar type, the deterioration in flavor was less 
 at 40 F. than at either 50 or 60 ° F. In texture, however, all 
 scored lower at five months, the data showing a wider difference 
 at 40 F. than at the other two temperatures. In price, how- 
 ever, the cheese was considered to be worth 0.2 cent per pound 
 more at 40°, while the 60° cheese had depreciated 0.7 cent. 
 
 Type III. In the softer Michigan make, in which more 
 rapid deterioration would be expected, the falling off in flavor 
 was 2 points at 60° F. as against 1.1 points at 40° F. In texture 
 the 40° improved 0.4 point, while the other two depreciated 0.8 
 and 0.3 point, respectively. In price, all these goods were of less 
 value at five months than at three, but they had depreciated 0.5 
 cent at 60° and only 0.1 cent at 40° F. 
 
 Summarizing the above, there can be no question but that 
 the keeping quality of all of these various types of American 
 cheese is improved by curing them at these lower temperatures. 
 This is more evident with the firm, solid Wisconsin type of Ched- 
 dar than with the softer, quick-curing goods ; but even these can 
 be held with less deterioration at these temperatures than is pos- 
 sible under present curing conditions. 
 
 SUMMARY OF EFFECT OF TEMPERATURE ON QUALITY. 
 
 As the three different types of cheese represented in these 
 experiments varied so much in character, it will be fairer to 
 state the conclusions with relation to each separately. The scores 
 on these lots of cheese were made separately by our own cheese 
 expert throughout the whole curing period, and also at stated 
 intervals by the commercial judges. 
 
 Type I. At 6o° F. flavor developed more rapidly than at 
 lower temperatures, but the maximum score at this temperature, 
 as indicated by Baer, was equaled or exceeded by the maximum 
 score at 50° or 40 F. In the scoring made by the commercial 
 jury the 50° averaged 0.6 point higher than the 60 °, when cheese 
 was three months old. When five months old, the 40 was 2.8 
 points higher than the 60°, and the 50° 1.6 points higher. 
 
262 PRACTICAL COLD STORAGE 
 
 In texture the course of development was quite the same, 
 the judges scoring the 50 ahead at three months, but at five 
 months the 40 averaged nearly a point higher than the 60°. 
 
 Type II. In this low-acid cheese the course for ripening 
 followed the same rule as in the above type, although this cheese 
 was inferior in quality to the preceding type. 
 
 Type III. The results on this quick-curing type of cheese 
 were affected by the delay in transit, which permitted of a con- 
 siderable degree of ripening before the cheese was put in the 
 curing rooms. In this type of cheese the improvement was less 
 marked, but when the enhanced keeping quality is considered, 
 the cold-curing process was found to be advantageous even under 
 these advanced conditions. 
 
 INFLUENCE OF PARAFFINING ON QUALITY OF CHEESE. 
 
 With the use of lower temperatures for curing, a higher 
 degree of saturation of the atmosphere is always found, which 
 greatly promotes the development of mold, and this growth in- 
 jures the salability, though not the quality, of the cheese, and 
 hence many attempts have been made to overcome the difficulty. 
 [The statement that the lower the temperature the higher the 
 relative humidity cannot be allowed to stand in the light of pres- 
 ent information. Further, mold is checked by the lower tem- 
 perature. See chapter on " Humidity."] The most efficient 
 method yet proposed is to coat the surface of the cheese with an 
 impervious layer, which, by excluding oxygen, prevents develop- 
 ment of molds. For this purpose the cheese are immersed in 
 a bath of melted paraffin, which, upon cooling, adheres closely 
 to the surface. While this effectually accomplishes the desired 
 end, it is a question of importance whether the quality of the 
 cheese so treated is affected prejudicially or not. It is possible 
 to conceive that the retention of all volatile decomposition prod- 
 ucts within the cheese might injure the flavor of the product. 
 
 In these cheese-curing experiments it was thought advisa- 
 ble to institute a series of trials to determine what influence 
 paraffining had on the quality, as shown by the flavor and texture 
 scores. For this purpose the cheese which was used in the ex- 
 periments on shrinkage (La Crosse lot) was scored by Mr. Baer, 
 
COLD STORAGE OF CHEESE 263 
 
 and was also submitted to the experts for scoring at the regular 
 periods. 
 
 It is evident that the difference between the same lot of 
 cheese when paraffined or unparaffined is very slight. If the 
 course of curing is considered, as is shown by the scores of Mr. 
 Baer, which were taken when the cheese was one, two, three, 
 and five months old, it is apparent that the application of par- 
 affin has not injured either the flavor or the texture of the cheese. 
 It will be further noted that in the "daisies" the unparaffined 
 cheese was, with one exception (6o°), better at the beginning; 
 but throughout the remainder of the curing and to the end of the 
 experiment the paraffined improved much more rapidly, arid 
 without exception was as good as or better than the unparaffined. 
 
 With the prints the difference in scores was practically negli- 
 gible. 
 
 This same cheese was scored by the commercial experts 
 when it was three and five months old, and it should be noted that 
 the opinions of these experts coincided quite closely with those of 
 Mr. Baer. 
 
 It would be unsafe from these limited experiments to draw 
 any general conclusions, but so far as they go these trials show 
 that no injurious effect was observed on either the flavor or the 
 texture of the paraffined cheese. 
 
 GENERAL SUMMARY. 
 
 The purpose of the experiments detailed above was to test 
 the value of low temperatures for the curing of cheese made under 
 widely different but commercial conditions. To accomplish this 
 purpose, it was deemed advisable to purchase the product from 
 a wide range of territory. This condition rendered it impossible 
 to install the cheese in the curing rooms immediately after it 
 was taken from the press, and hence the full effect of the process 
 is not so evident as would have been the case if the cheese had 
 not had any preliminary curing. 
 
 Naturally a comparison of the cold-curing process would 
 be made with the conditions most frequently found in factories, 
 but in these studies the low temperature cured product has been 
 compared with cheese ripened at about 60° F. — a temperature, 
 
264 PRACTICAL COLD STORAGE 
 
 which has hitherto been considered as the best for the ripening of 
 Cheddar cheese. 
 
 EFFECT ON SHRINKAGE. 
 
 When cheese is cold-cured, the losses due to shrinkage in 
 weight are greatly reduced over what occurs under ordinary 
 factory conditions. 
 
 i. — Influence of temperature.- — Cheese cured at 40 F. de- 
 creased in weight in ninety days from 1 to 1.4 per cent, while 
 that cured at 50° and 6o° F. lost fully three times as much. This 
 saving would be still further increased if comparison were made 
 between the results of cold curing and existing factory conditions. 
 Under prevailing factory practice cheese is sold at a much earlier 
 date than is advisable with cold-cured goods, but the loss under 
 present conditions, for even as brief a curing period as twenty 
 days, is fully four times as great as has occurred in these experi- 
 ments in a ninety-day period (the minimum curing period recom- 
 mended) under cold-curing conditions (40 F.). This saving 
 in a factory making 500 pounds of cheese daily would average 
 not less than 15 pounds of cheese per day for the entire season, 
 or considerably more than this if only summer-made cheese was 
 cold cured. [It seems to the author that undue stress is being 
 laid on the great benefit to be derived from a saving in evapora- 
 tion or shrinkage in weight. If this loss is saved to the manu- 
 facturer the retailer or consumer is the sufferer, because mois- 
 ture has no value as food, and the loss of moisture is practically 
 all that evaporation means. More importance should be given to 
 the improved quality, because the saving in weight comes out 
 of the retailer or consumer.] 
 
 2. — Influence of type of cheese. — In these experiments dif- 
 ferent types of cheese were used, ranging from the firm, typical 
 Cheddar to the soft, moist, quick-curing cheese made for the 
 home trade. The losses with the firmer type were considerably 
 reduced in comparison with the other, but the conditions to which 
 the softer types of cheese were subjected were not as favorable 
 (because of initial delays), and hence the losses with these types 
 can not be relied upon with such definiteness. As this cheese was 
 exceedingly moist, the total losses from the press were undoubt- 
 edly greater than here reported. 
 
COLD STORAGE OF CHEESE 265 
 
 3. — Influence of size of cheese. — The size of package ex- 
 erts a marked effect on the rate of loss. At ordinary tempera- 
 tures, the smaller the cheese the more rapidly it dries out. This 
 difference in loss diminishes as the temperature is lowered, and 
 in our experiments at 40 F. was practically independent of the 
 size. This condition, however, was undoubtedly attributable to 
 the relative humidity of the curing room, which at 40 F. was 
 100 per cent. 
 
 4. — Influence of paraffin. — By coating the cheese with melted 
 paraffin the losses at 60° were reduced more than one-half; at 
 50° the saving was somewhat less, and at 40° the losses observed 
 on the paraffined cheese of both sizes used were slightly in excess 
 of those noted on the uncoated cheese. [Retailers of cheese in 
 England have in some cases made strong objection to the par- 
 affining of cheese for the reason that they suffer much greater 
 loss from shrinkage when cutting up the cheese for retailing. 
 From these experiments it seems that the cold-curing of cheese 
 has much more to do with preventing loss of weight than par- 
 affining.- — Author. ] 
 
 5. — As some loss occurs even in a saturated atmosphere, 
 where evaporation is presumed not to take place, it implies that 
 the shrinkage in weight of cheese under these conditions is not 
 wholly due to desiccation, but is possibly affected by the produc- 
 tion of volatile products that are formed by processes inherent in 
 the curing of cheese. 
 
 EFFECT ON QUALITY. 
 
 6. — The three types of cheese before referred to can scarcely 
 be compared closely with each other, as they were so different in 
 their make-up and subjected to somewhat different conditions 
 during transit. By far the most satisfactory portion of the ex- 
 periment is that which relates to Type I, in which the best quality 
 of cheese was represented. With these firm, typical Cheddars 
 the influence of temperature on curing could best be studied. 
 This cheese was also placed in storage nearer the press than any 
 of the other types, and hence the test as to the effect of the curing 
 temperature was more satisfactory. In this type the 60° cheese 
 was of excellent quality and naturally developed faster than the 
 cold-cured goods, but in time it was surpassed by the cheese at 
 
266 PRACTICAL COLD STORAGE 
 
 the lower temperatures (50 and 40 ), and, when the keeping 
 quality of the latter was taken into consideration, it was found 
 to be superior in every way to that cured at 60 ° F. Even when 
 the condition of the milk was not entirely perfect, the quality 
 of the cold-cured cheese was better, although the original taint 
 was not removed. 
 
 With the sweet-curd (type II) and the soft home-trade 
 cheese (type III) the effect of the disturbing influences pre- 
 viously noted rendered it impossible to obtain as satisfactory 
 results, but, even under these adverse conditions, the 40 ° and 50 
 cheese generally ranked better than the 6o°, and, when keeping 
 quality was taken into consideration, was materially better. 
 
 This same cheese was also scored independently by com- 
 mercial experts when three and five months old. The results 
 obtained conform very closely to those mentioned above, and in- 
 dicate the superiority of the cold-cured product (either at 50 
 or 40 ) in comparison with the cheese cured at 6o° F. This im- 
 provement in quality reflects itself also in the commercial values 
 which were placed upon the cheese cured at different temperatures, 
 both by our own expert and also by the commercial judges. 
 
 In this low-temperature-cured cheese the flavor was remark- 
 ably mild but clean, and was free from all trace of bitterness or 
 other taint. The texture was fine and silky and the body close. 
 
 7. — Keeping quality. — The keeping quality of the cold-cured 
 cheese far excels that of the cheese ripened at higher tempera- 
 tures. The better types of cheese cured at 40 F. were at the end 
 of eight months still in their prime, while the 60° cheese had long 
 since greatly deteriorated. 
 
 8. — Effect of paraffin on quality. — Portions of two lots of 
 cheese were paraffined as they came from the press, but were 
 otherwise handled the same as the unparaffined cheese. The 
 results obtained showed that paraffining did not prejudicially 
 affect their quality at any temperature. As paraffining greatly 
 reduced the shrinkage, the beneficial effect of the system is ob- 
 vious. The rapid introduction of the method in commercial prac- 
 tice further attests its value. 
 
 9. — The production of a thoroughly broken-down Cheddar 
 cheese of mild, delicate flavor and perfect texture meets a de- 
 mand which is impossible to satisfy with cheese cured at high 
 
COLD STORAGE OF CHEESE 267 
 
 temperatures. Without any question, if the general market can 
 be supplied with this mild, well-ripened cheese, consumption will 
 be greatly stimulated, not only by increasing the amount used by 
 present consumers, but by largely extending the use of this valua- 
 ble and nutritious article of food. 
 
 10. — The improvement in quality of cold-cured cheese, the 
 enhanced keeping quality, and the material saving in shrinkage 
 due to lessened evaporation are sufficient to warrant a consid- 
 erable expenditure on the part of cheese producers in installing 
 cold-curing stations. 
 
 The principle of increasing cost of equipment to lessen cost 
 of production or augment gross earnings is recognized as a sound 
 financial method by all large enterprises, and, while the expense 
 involved is considerably more than is incurred under existing 
 conditions, yet the advantages enumerated more than compensate 
 for such expense where carried out under proper conditions. 
 
 1 1 . — This system is particularly applicable where the product 
 of a number of factories can be handled at one point, and such 
 consolidated curing stations must be established before the cold- 
 curing process can be economically introduced. Such stations 
 are now successfully used in a number of localities. The greatest 
 advantage will undoubtedly accrue from the use of this system 
 of curing with summer-made cheese, but the process is equally 
 applicable to cheese made at any season of the year. 
 
 author's concluding remarks. 
 
 The foregoing report of the result of experiments by the 
 Wisconsin Station demonstrates fully the desirability of low 
 temperatures for cheese storing, and for the curing of cheese 
 by placing it in a low temperature as soon as manufactured. 
 The experiments do not, however, include temperatures of from 
 30" to 32 ° F., which are now considered best for long period 
 storage of cheese. It is desirable that the best temperatures for 
 the most successful curing of cheese should be determined and 
 additional experiments should be made for this purpose. It is 
 practicable to extend the experiments so as to include foreign 
 makes as well as the various types of American cheese. 
 
 The cheese business is now practically all handled through 
 cold storage, and temperatures ranging from 30° to 40° F. are 
 
268 PRACTICAL COLD STORAGE 
 
 in use. The use of cold storage for the curing of cheese is, 
 therefore, not in an experimental stage, and it is to be regretted 
 that the experiments of the Department of Agriculture did not 
 include temperatures of 30° F. and 35 F. as representing the 
 commercial practice of the times, and a still lower range, to de- 
 termine the possibilities in this direction. 
 
 The initial quality of cheese has much to do with what is 
 best for it in the way of temperature while curing or cold stor- 
 ing, but nothing positive may be said on this point at the pres- 
 ent time, as no results of experiments are at hand as a guide. 
 The author recommends that a good average clean-flavored make 
 of American cheese be first placed in a temperature of about 40° 
 F. After being in storage for a month or two reduce the tem- 
 perature gradually so that at the end of two or three months the 
 temperature reaches 30° F., which is recommended for a perma- 
 nent storage temperature. This temperature is somewhat lower 
 than is generally considered best, but if handled as suggested 
 better results may be had than at any higher temperature. 
 
CREAMERY AND DAIRY REFRIGERATION 269 
 
 CHAPTER XIII. 
 CREAMERY AND DAIRY REFRIGERATION. 
 
 NECESSITY FOR REFRIGERATION. 
 
 It has been estimated that the total amount of butter pro- 
 duced in the United States is about 1,500,000,000 pounds each 
 year. It is probable that the amount is in excess of this rather 
 than less. The consumption of butter is rapidly increasing and 
 the average quality of same is likewise being improved, but it 
 is probable that not more than one-half of the butter made reaches 
 the consumer in prime condition. The most important reason 
 for this is, no doubt, that refrigeration is not employed to a suf- 
 ficient extent, or where employed, not intelligently or scientifically 
 applied. 
 
 Though nowadays not of the same importance to the dairy 
 as it was before the centrifugal creamers were invented, yet in 
 our climate ice or refrigerating machinery is indispensable to 
 the production of fine butter. To fully control the process, the 
 butter maker must be able to heat and cool the cream at will, 
 and the butter often requires a cooling which cannot be effected 
 without ice or a refrigerating machine. Every creamery and 
 dairy not provided with a machine should, therefore, have an ice 
 house, and a refrigerator or cooling room should always be con- 
 structed. 
 
 Refrigeration is absolutely necessary to the proper manu- 
 facture of butter, and is likewise necessary to the proper keeping 
 or preserving of same after it is made. Refrigeration is applied 
 in the manufacture of butter to the manipulation and proper 
 tempering of the raw materials and the keeping of the butter 
 when made at a low temperature to prevent deterioration. Con- 
 sidering the great importance of refrigeration as applied to 
 creamery products, comparatively little attention has been given 
 to this branch of the business. It is not meant by this that those 
 
270 PRACTICAL COLD STORAGE 
 
 who are operating creameries have not given careful thought to 
 this matter, but that the refrigerating engineers and the makers 
 of refrigerating machinery have not studied its application to 
 creamery and dairy service as fully as they might. 
 
 As in all other branches of the refrigeration of perishable 
 food products, the United States is in advance of other countries 
 in the preservation, by cold, of milk, butter and cheese. Until 
 a comparatively recent day, however, the most progressive of the 
 dairy companies often cooled their cans of milk by immersing 
 them in a bath of cracked ice. This process was not only cumber- 
 some, in that it necessitated the repeated handling of the heavy 
 cans, but the cans themselves were thus injured. The ice and 
 water were scattered over the premises, which rendered cleanli- 
 ness very difficult. A dairy establishment refrigerated artificially 
 presents a neater appearance. The milk as it is brought in from 
 the country is first tested for quality. It is then placed in a large 
 tank, from which it passes through three sets of fine strainers, 
 which remove all small particles of dirt or dust that may have 
 gotten into' the cans. It then passes through a series of pipes, 
 which are submerged in a large brine tank. The tank contains 
 the ammonia expansion coils, by which the brine is kept at the re- 
 quired temperature. After passing through these coils the milk 
 is drawn off into cans, which, in turn, are stored in a large re- 
 frigerator, kept at a temperature of about 35". 
 
 Denmark and Sweden in Europe have made the greatest ad- 
 vance in the refrigeration of the products of the dairy, ma- 
 chinery being extensively employed for that purpose. The cream- 
 eries and butter factories of Belgium and Holland are also be- 
 coming more modern in this respect year by year. A late inno- 
 vation in the dairy industry in northern Germany and Denmark 
 is the process of freezing milk into blocks, and shipping it abroad 
 as milk ice, mostly to England. The required machinery agitates 
 the milk during the freezing process, so that when ready for 
 the market the substance of the frozen milk is uniform through- 
 out. 
 
 The pasteurization of the milk, which is now becoming quite 
 general in the larger creameries in this country, as it is in Euro- 
 pean countries, notably Denmark and Belgium, calls for addi- 
 tional demands on refrigerating apparatus, as it is found essen- 
 
CREAMERY AND DAIRY REFRIGERATION 271 
 
 tial to reduce the temperature after pasteurization as rapidly as 
 possible. 
 
 ICE VERSUS REFRIGERATING MACHINE. 
 
 There is at the present time considerable controversy be- 
 tween those who advocate the use of ice for creamery or dairy 
 refrigeration and those who recommend refrigerating machinery. 
 There should be no quarrel between these two different methods, 
 as each one has its proper sphere, and there are cases where the 
 selection of either one or the other would be a matter largely of 
 individual opinion. Where natural ice can be stored cheaply at, 
 say, a cost of $1.00 a ton or less, and where the quantity of milk 
 to be handled would not exceed 10,000 or 15,000 pounds per day, 
 the use of natural ice is usually to be preferred to installing re- 
 frigerating machinery. On the other hand, where the quantity 
 of milk to be handled is large and ice comparatively expensive, a 
 refrigerating machine can profitably be employed. 
 
 The advantages and disadvantages of the mechanical sys- 
 tems over ice have recently been quite fully investigated by Prof. 
 Oscar Erf, late of the College of Agriculture, University of Illi- 
 nois. His deductions, however, were based on conditions which 
 do not apply in states of about the same latitude as New York, 
 Michigan, Wisconsin and Minnesota, and even south of these 
 latitudes there are places where natural ice can be housed at much 
 less cost than 90c. per ton, which he has taken as a basis. His 
 investigation seems to have been conducted from an intelligent 
 and fair minded standpoint, and his results are useful to creamery 
 men, if proper allowances are made for the difference in latitude 
 and other working conditions. Prof. Erf gives his results in de- 
 tail, but we will only consider his summary of the disadvantages 
 of mechanical refrigeration, as follows :* 
 
 1. — Large capital invested. 
 
 2. — Necessitates daily or continual operation, unless provided with 
 large storage tanks. 
 
 3. — Operating expenses for labor, coal, oil, ammonia and repairs. 
 
 4. — Excessive dryness in such refrigerators', often causing a great 
 shrinkage in the products. 
 
 5_Great risks for accidents that might happen, such as breakage 
 on machines and the delay of repairs. 
 
 6. — Expense of pumping water for condensing ammonia. 
 
 *From Ice and Refrigeration, June, 1902. 
 
272 PRACTICAL COLD STORAGE 
 
 The advantages offsetting these disadvantages by using machinery 
 for refrigeration, as compared with the use of natural ice : 
 
 i. — No risks to run in securing cold whenever needed. 
 
 2. — Practically no variation in cost of producing cold from year to 
 year. 
 
 3. — The refrigerator is under better control. 
 
 4. — Any temperature may be practically obtained above zero. 
 
 5. — Atmosphere is dryer in refrigerator; hence butter is less' suscepti- 
 ble to mold. 
 
 6. — Less' disagreeable labor, such as the handling of ice. 
 
 7. — Cold room can be kept cleaner. 
 
 8. — Does away with the impurities imbedded in river and pond ice. 
 
 9. — Provides for a more perfect method of cream ripening, which 
 results in a better product. 
 
 10. — Secures economy of space in the cool room, which lessens the 
 radiating surface for same amount of refrigeration. 
 
 The disadvantages as set forth are sufficiently plain to all 
 who have had experience with refrigerating machinery. The 
 advantages which are cited are more or less true, especially as 
 applied to the ordinary application of ice as generally used in 
 creameries. Should the gravity brine system be used, as de- 
 scribed further on, there would be : 
 
 1. — Absolutely no risk to run in securing cold whenever needed. 
 
 2. — Any temperature may be practically obtained down to 15 F. 
 
 3. — The refrigeration would be under fully as good control and a more 
 
 uniform temperature could be obtained than by the use of re- 
 frigerating machinery. 
 4. — The moisture in the atmosphere of the cold room could be carried 
 
 at any temperature desired and under as good control as with the 
 
 mechanical system. 
 5. — The amount of disagreeable labor required, should an ice crusher 
 
 and ice elevator be used, would be very small indeed. 
 6. — The cold room can be kept as clean as with any system. 
 7.- — Impurities in th'e ice would have no influence on the air of the room 
 
 for the reason that the air does not come in contact with the ice. 
 8.' — As perfect results can be had in the ripening of cream. 
 9. — The economy of space in the cold room would be as great as with any 
 
 system. 
 
 In other words, the gravity brine system will produce any 
 results which can be had with refrigerating machinery down 
 to a temperature of 15° F., and besides this it is absolutely sure 
 against a break-down. 
 
 THE CREAMERY REFRIGERATOR. 
 
 A cooling room for maintaining the butter at a low tem- 
 perature after being made, is admitted to. be absolutely necessary 
 in every creamery, and it cannot be dispensed with, except in 
 cases where butter is loaded into a refrigerator car each day. 
 
CREAMERY AND DAIRY REFRIGERATION 
 
 273 
 
 Even then the butter will handle much better and arrive on the 
 market in much better condition if it is hardened so that it will 
 carry without shaking or slopping in the tub, to say nothing of 
 the advantages of always having it at a low temperature until 
 consumed. Butter is practically at its best when first made, and 
 the nearer it can be retained in this condition until consumed, 
 the better satisfaction it will give the customer and the greater 
 
 S 
 
 522 
 
 Jbetveem wjruna fil)|uduitm ^.3hm™g5 )( { 
 
 COOLIMG ROOM 
 
 IW/^//////////^ 
 
 W/////////Ms™^™»W/////// 
 
 H BETUEEnA 3TVDS FIL I LED WITH I i 
 
 SPACE U BETUEEnA 3TVDS TIL I LED WITH V JHAVIrlflS 
 
 FIG. I. — PLAN SMALL COOLING ROOM. 
 
 will be the ultimate gain to the creamery man. When butter is to 
 be shipped frequently, a small cooling room, constructed with ice 
 chambers above the storage room, essentially as outlined in Figs. 
 I and 2, should be built in every creamery not provided with me- 
 chanical refrigeration. It is much better to place the ice over the 
 room than it is to put the ice in a rack at one end or one side of 
 the room. A lower temperature will be obtained and a dryer 
 atmosphere will result, owing to the circulation of air, as indi- 
 cated by the arrows. A room of this kind should be well 
 
 (18) 
 
274 
 
 PRACTICAL COLD STORAGE 
 
 built, and a few dollars extra spent in the insulation of same 
 will be saved in a short time in the saving in the quantity of 
 
 FIG. 2. — SECTION SMALL COOLING ROOM. 
 
 ice required. The temperature to be obtained in the room 
 also depends on good insulation. If the insulation is thor- 
 ough, a temperature of 36 to 40 F. may be depended upon. 
 
CREAMERY AND DAIRY REFRIGERATION 275 
 
 Of course, at the time when warm butter is placed in the room, 
 the temperature will naturally rise to quite an extent. The con- 
 struction of a room of this kind can be adapted to suit local con- 
 ditions and the nature of the materials which can be most readily 
 obtained. The detailed description which follows, of a room con- 
 structed on the plan as laid down in the preceding paragraphs, 
 wiil be of considerable value and interest to owners of creameries. 
 The floor joists, ceiling joists and side wall studding should 
 all be filled with mill shavings, sawdust, tan bark, cut straw or 
 any similar material. This material, however, must be dry and 
 protected on the outside and inside by the best grades of insulat- 
 ing paper (not the ordinary rosin sized or common building 
 papers). Care should be taken that in all corners the paper is 
 thoroughly lapped to make an absolutely air tight surface, so as 
 to prevent a circulation of outside air into the space which is 
 filled with the insulating or packing material. It is best to 
 double-board the outside of the room and put the insulating paper 
 between. On the inside of the studding and on the top of the 
 floor joists and on the bottom of the ceiling joists use matched 
 boarding. Covering this interior surface should be placed a 
 much better grade of insulating material than the filling between 
 studs and joists. This may be of hair felt, sheet cork, 
 granulated cork, rock fiber felt, mineral wool, Cabot 
 quilt, or any of the best grades of insulating materials. If 
 there is any liability of trouble from rats or mice, they can be 
 kept out of a room of this kind by using an inch or two of 
 rock fiber felt or mineral wool on the outside of all walls. 
 Rats or mice cannot work in either of these materials. The rock 
 fiber felt spoken of is practically a mineral wool made up in the 
 form of sheets or boards. The materials indicated may be used 
 to a thickness of 2, 3 or 4 inches, depending upon the amount of 
 money the owner is willing to spend and cost of refrigeration. 
 These various materials must of course be put on between bat- 
 tens or cleats of sufficient thickness to flush up even with the lay- 
 ers of insulating material. If hair felt, sheet cork or rock fiber 
 felt is used, the different thicknesses should be separated by a 
 good grade of insulating paper. The interior of the room should 
 be lined with matched stuff, preferably of poplar, spruce or hem- 
 lock. (The chapter on "Insulation" may be of interest in, this 
 
276 PRACTICAL COLD STORAGE 
 
 connection.) If it is desired to wash out a refrigerating or 
 cooling room of this kind from time to time, the interior finish 
 may be of shellac or hard oil, preferably shellac, or, the inside 
 surface may be coated with whitewash, which may be renewed 
 from time to time. (See chapter on "Keeping Cold Stores 
 Clean.") The joists for supporting the ice should be of fairly 
 strong material, depending on the size of the room and should 
 be pitched slightly toward the drain end of the ice floor. The 
 joists for supporting the ice are not carried into the insulation, 
 but rest on ribbands of 2x4s spiked onto the outside of the 
 insulation. A batten should be set in the insulation for receiving 
 these ribbands. The pan or floor under the ice consists simply of 
 two thicknesses of dressed and matched stuff with a covering or 
 lining of No. 20 galvanized iron. A loose rack of wood should 
 be placed on this iron floor to prevent its wearing or getting 
 punctured in handling the ice thereon. The galvanized iron 
 should be turned up on the sides 4 to 6 inches. The circulation 
 of air is provided for by placing a tight board screen on one side 
 of the ice space which is carried up to near the ceiling. The 
 other or opposite side of the ice space has cleats or slats which 
 keep the ice in place and allow a circulation of air. This screen 
 and the slats mentioned are of course fastened to 2x4s or to 
 2x6s, which form the open spaces for the circulation of air on 
 the two sides of the ice chamber. The screen and cleats should 
 be beveled on the top and bottom so that any dripping will be on 
 the galvanized iron pan and not into the air flues and then down 
 into the room. These various parts are illustrated in Fig. 2, but 
 are not shown in detail. For filling ice into the ice chamber, a 
 door may be provided at any point, but should not be on the side 
 where the air flows down from the ice room to the storage room 
 or up from the storage room into the ice chamber. This ice door 
 may be at the top, and the room can be filled from the floor above 
 if convenient. Both the ice door and the door for entering the 
 room are preferably one of the special doors which are on the 
 market and which cost but very little more than the home-made 
 door, and are superior in every way. 
 
 The above cooling room is intended to be filled from an in- 
 dependent ice^ house, which should be located as near the cooling 
 room as convenient. 
 
CREAMERY AND DAIRY REFRIGERATION 277 
 
 COMBINATION ICE HOUSE AND REFRIGERATOR. 
 
 The following description,* by W. G. Newton, will be of 
 interest : 
 
 The ice house is in the opposite end of the building from the boiler 
 room and the ice is put right in on the ground floor and the refrigerator 
 is built next to it and holes cut through next to the floor for the cold 
 air to enter and same at top for warm air to go out. The ceiling over 
 the ice needs to be from four to six feet higher than it is in the refrig- 
 erator, then if the outlets for the warm air are right up close to the 
 ceiling (not having so much as a piece of molding between the top of 
 the hole in the side and the ceiling overhead), the dampness will all go 
 off with the warm air up over the ice, leaving your refrigerator dry and 
 sweet. 
 
 As to the expense of building, it is not much, as a room 20x20 or 20x30 
 feet at most will hold ice enough to cool most of the creamery refrigerators 
 if they have some ice stored elsewhere for other uses. All that is neces- 
 sary is to have the walls of the ice house properly insulated with sawdust 
 and air spaces and then the yearly renewal of sawdust in which to pack 
 the ice is saved. 
 
 Not only creameries but several large meat markets here have this 
 kind of an ice house and refrigerator combined and they are giving the 
 best of satisfaction. There is a patent on them. The days of building 
 refrigerators with ice overhead have gone by in this section of the country. 
 
 This appears like a fine arrangement to save labor and pro- 
 duce the lowest possible temperature with ice. The ice room 
 must be as well finished and insulated as the refrigerator and 
 no sawdust or packing material used on the ice. It would be 
 advisable to build the ice room more than four to six feet higher 
 than the refrigerator, and ten or fifteen feet would be better. 
 An ice room of say 20x30x20 feet dimensions should be suf- 
 ficient for an ordinary creamery, but this depends on what is to 
 be done with the milk. The storage of ice in a building, as is 
 well known, tends to cause it to decay and deteriorate rapidly, 
 and this is the only real objection to the plan, as the ice room 
 would be in bad condition long before the refrigerator. A well- 
 built house on a stone or brick foundation would be almost a 
 necessity for the purpose. 
 
 In practice, in some extreme cases, it has been found advisa- 
 ble to fill into the ice house as many pounds of ice as there are 
 pounds of milk to be treated, or to harvest 100 cubic feet of ice 
 for each cow furnishing milk to the dairy or creamery. Less 
 than one-half this quantity may be ample in many cases, so much 
 depends on the treatment to which the milk and manufactured 
 
 *From New York Produce Review. 
 
278 PRACTICAL COLD STORAGE 
 
 product is subjected. Where pasteurizing is practiced, much 
 more ice is required, especially where no well water is available. 
 During the winter ice or snow may be used which is simply 
 hauled together in a heap near the creamery, so that no ice is 
 taken from the ice house until April or May. 
 
 Where separators are used, no ice is needed for raising the 
 cream, but the latter needs cooling either as it runs from the 
 separator or after the ripening, before churning. 
 
 Ice is also needed in the hot summer months to cool the 
 butter before or between the workings, and for keeping it firm 
 in texture before it is shipped, so that it may leave in the very 
 best condition for standing exposure to heat while in transit to its 
 destination. Butter in prints is sometimes shipped in cases with 
 an ice box filled with crushed ice in the center. 
 
 The amount of ice required for these various purposes 
 varies according to local conditions, and cannot be definitely 
 stated, though it may be calculated approximately. The chapters 
 on "Harvesting, Handling and Storing Ice" and "Ice Houses" 
 give methods of handling ice and details for construction of ice 
 houses of various capacities. 
 
 TRANSPORTATION OF MILK AND CREAM. 
 
 In the transportation of milk and cream, baggage cars, re- 
 frigerator cars, and cars especially constructed for the purpose 
 are employed. The railroads adopt the style of car best suited 
 to their individual requirements. In the case of light shipments 
 and short hauls, superannuated baggage cars appear to meet every 
 requirement and are generally moved in conjunction with local 
 passenger trains. In the case of long hauls, however, refriger- 
 ator or special milk cars are used. These cars are plentifully 
 supplied with ice during the warm summer months and, in ex- 
 tremely cold weather, are often steam-heated to prevent the milk 
 from freezing. Cleaning generally takes place after each run, 
 the cars being either swept or washed by means of a hose. 
 Trains making long hauls are usually composed entirely of 
 refrigerator or special milk cars and are operated on about pas- 
 senger schedule time, the actual running time being as fast as 
 fifty miles an hour. The capacity of a large milk car is 325 
 ten-gallon cans. 
 
CREAMERY AND DAIRY REFRIGERATION 279- 
 
 Nearly all railroads which handle a large milk traffic have 
 well-built covered receiving and shipping stations along their 
 lines, nearly all of them with an ice house connected in which 
 natural ice in sufficient quantity is stored during the winter. 
 
 Shipping stations are equipped with large cooling vats in 
 which cans of milk are placed immediately after being delivered 
 by the farmers. These vats are filled with water and ice, the 
 milk is stirred and cooled down to 40 F. within forty minutes 
 from the time it is received, and kept in ice water until the train 
 arrives, when it is loaded direct from the vats into a refriger- 
 ator car. 
 
 GRAVITY BRINE SYSTEM. 
 
 The application of the Cooper gravity brine system to the 
 refrigeration of a creamery cooling room and freezing room is 
 shown in Figs. 3 and 4. They also show the arrangement of 
 ice crushing and ice handling apparatus, which will deliver 
 crushed ice to any convenient point in the creamery workroom 
 for the cooling of cream, butter, shipping, or other purposes. 
 Fig. 3 shows the plan view of one end of the creamery with 
 ice house adjoining. The refrigerated space in the creamery 
 consists of a cooling room with a capacity of about one carload. 
 The butter freezing room has a somewhat larger capacity. The 
 relative size of these rooms can, of course, be changed to suit 
 any conditions. The cooling room and freezing room are both 
 entered from the vestibule and not from the workroom. This 
 prevents the access of warm air into the rooms, which is very 
 important, especially in the freezing room. If it is desired, the 
 cream cooling vats may be placed in a cooling room of this kind, 
 but as planned, it is intended that the cream should be cooled 
 with crushed ice or cold well water. There are a number of 
 different ideas on arrangements of this kind, but with the ap- 
 paratus shown any arrangement can be provided to suit the ideas 
 of the owner or local requirements. 
 
 The gravity brine system, patented by the author, which 
 refrigerates the cooling room and freezing room, may need a 
 few words of explanation. Referring to the section (Fig. 4) 
 it will be seen that the gravity brine system consists of a series 
 of pipe coils and connections. In this case there are two coils 
 
280 
 
 PRACTICAL COLD STORAGE 
 
 isssssa^^ 
 
CREAMERY AND DAIRY REFRIGERATION 281 
 
 in the tank for the cooling room and two coils in the tank for 
 the freezing room. These coils are connected to similar coils 
 of larger size which are located in the cooling room and freezing 
 room. It will be noted that the coils in the tank are connected 
 at their lowest extremity to the lowest point of the coils in the 
 room, and that the coils in the room are connected at their highest 
 point to the highest point of the coils in the tank. This estab- 
 lishes means for a complete circulation of brine with which the 
 coils are filled. The coils in the tank are filled around and be- 
 tween with crushed ice and a small quantity of salt. This cools 
 the brine in the coils in the tank, and by reason of its being 
 heavier, the brine flows down into the coils in the room. It is 
 here warmed by contact with the air of the rooms and flows 
 upward to the highest point of the coils in the tank. A very 
 slight difference in temperature will cause a circulation. The 
 advantages of this system over direct icing, as shown in Fig. I, 
 are that the temperature can be controlled as desired, and the 
 rooms being cooled by pipe surfaces, the humidity of the room 
 may be maintained at a proper point. In the freezing room a 
 temperature as low as 15° F. is comparatively easy to obtain, 
 and a temperature as low as 10° or 12 may be had by crowding 
 the apparatus and using an increased quantity of salt. The 
 gravity brine system is automatic in its action, requiring no 
 power to produce circulation, and any results may be obtained 
 which can be produced by refrigerating machinery, limited only 
 by the temperature which can be produced. If it is desired to 
 convey cold brine through pipes for use in cooling cream or 
 pasteurizing, the brine may be pumped to any point desired in 
 the creamery. 
 
 ICE HANDLING MACHINERY. 
 
 The ice crusher and ice elevator which are clearly shown 
 in Fig. 4 are quite simple in their operation, and as labor saving 
 machines are the best form of apparatus which has been applied 
 to the handling of ice. It only requires that the ice be broken 
 into irregular pieces of 20 to 30 pounds or thereabouts, and 
 fed into the ice crusher. The crusher breaks the ice into small 
 pieces the size of hen's eggs or smaller, and it drops into the 
 bucket elevator where it is raised to a point sufficiently high to 
 
282 
 
 PRACTICAL COLD STORAGE 
 
CREAMERY AND DAIRY REFRIGERATION 283 
 
 allow its being spouted to a convenient point in the creamery 
 and to the flexible spout which is used to feed ice into the tanks 
 containing primary coils of the gravity brine system. Four or 
 five tons of ice may be handled with an apparatus of this kind in 
 half an hour. As recommended in connection with the "Model 
 Creamery Ice House" described in the chapter on "Ice Houses," 
 the ice should not be covered with sawdust or packing material 
 of any kind, and where the ice is clean in the ice house, the 
 labor of handling same to the crusher and delivering to any con- 
 venient point in the creamery is very little as compared with 
 the old-fashioned method. This outfit and apparatus is not rec- 
 ommended for the average small creamery, but where several tons 
 of ice are to be handled each day, or where it is desired to store 
 a certain portion of the product of the creamery and carry it for 
 several months, as good results may be obtained with the gravity 
 brine system as with a refrigerating machine. The expense of 
 installing, while it is considerably more than any of the old style 
 refrigerators, is less than for a good refrigerating machine. 
 
 COOLING OF MILK AND CREAM.* 
 
 The following is a portion of an address by Loudon M. 
 Douglas, read before the Cold Storage and Ice Association at 
 Islington, England: 
 
 The main object in view in cooling fresh milk for immediate con- 
 sumption is to arrest the development of the spores which produce bac- 
 teria, and which, in their turn, destroy the milk — that is to say, the milk 
 becomes sour. It will be understood, however, that the bacteria referred 
 to are those which are always found in the milk produced, even under 
 proper hygienic conditions. Heat is the essential condition for their 
 development, and, in the absence of that condition, they will remain in- 
 active. Of pathogenic bacteria we need not speak here. 
 
 Properly speaking, under good hygienic conditions, it should only be 
 necessary to cool the milk before sending it out, and this is practiced 
 by some retailers. It may, however, be considered an advantage to pre- 
 viously pasteurize the milk at a high temperature, and then cool it down. 
 It is not easy to say which way is the better. In any case both methods 
 are in use. 
 
 In cooling town's milk direct from a temperature of, say, 68° to 38 
 F., all that is necessary is a small refrigerating machine connected to a 
 circular cooler. The cold brine from the machine is circulated through 
 the flutings of the cooler and the milk run over. When it reaches the. 
 bottom and escapes', the temperature will be about 38 F, the balance of 
 the heat units having been absorbed by the brine. But by means of a 
 similar small machine a very large cooling effect may be produced by 
 
 *Extracted from Ice and Refrigeration, June, 1904. 
 
284 PRACTICAL COLD STORAGE 
 
 having a large insulated store tank fitted with agitating gear and filled 
 with either water or non-freezable brine 
 
 It is' obvious that, by working the small machine for a lengthened 
 number of hours upon this' store, the heat will be extracted and a large 
 volume of a very cold medium will be available. This can be utilized 
 to cool in turn a very large quantity of milk in a short time, a quantity 
 quite beyond the power of a small machine to deal with directly. Thus, 
 by intelligent working a small machine costing a comparatively small 
 sum can be made to perform a large amount of work. 
 
 In the case where milk is previously pasteurized the procedure is 
 different, and can not be better demonstrated than by referring to a 
 large dairy where the work is carried out. The dairy in question handles 
 1,000 gallons' of fresh milk per day, all of which is distributed either 
 directly to consumers or to shops for such distribution, and, in consider- 
 ing the question of refrigeration, it was stipulated that the cooling of 
 the quantity named should be performed in one hour, and that there 
 should also be provision made for cooling a churn store, a cream store, 
 and a butter store of certain dimensions'. Now, the machine necessary to 
 cool the 1,000 gallons from 68° to 45° F. in one hour, equal to the 
 elimination of 230,000 B.T.U., would be a very large one, whereas the 
 B.T.U. to be eliminated from the accessory stores would be comparatively 
 iew\ Obviously, therefore, if a large machine had been installed it would 
 have been much of its time idle. The problem, therefore, was to find 
 a machine which would perform the whole work during working hours. 
 This was done by providing storage tanks for 1,000 gallons of brine, 
 and the heat is' extracted from this during a series of hours. Obviously 
 all this brine when cooled down is available, and it is only necessary to 
 run it through a large capillary cooler while the milk to be cooled is run 
 over the outside. The heat of the milk is transferred to the brine, and 
 thus the cooling is accomplished with great rapidity. The pasteurized 
 milk is first of all cooled with ordinary water from the town's' supply 
 to 68" F., and from that temperature is lowered through 23 to 45° F. 
 The machine used is capable of eliminating 45,000 B.T.U.s per hour. 
 But the total number of B.T.U.s to be eliminated are altogether 355,000, 
 taking into account the accessory work to be done ; thus, if 355,000 is di- 
 vided by the output of the machine, viz., 45,000, you get the number of 
 hours' work necessary, viz , eight, or an ordinary working day. There 
 is a margin of 5,000 B.T.U.s allowed for contingencies. 
 
 The creamery system has now become well established through- 
 out Europe, and feeding stations to main creameries are recognized as 
 essential to economical working. The process which is usually carried 
 out in these places is as follows : 
 
 The milk is brought by the farmers to the creamery, sampled, weighed, 
 pasteurized, and separated. When the cream leaves the separator it may 
 be at a temperature of from 170 to 180 F., and is therefore immediately 
 run over a circular capillary cooler, through which water is circulated, 
 and reduced to about 65° F. It is then run over another cooler, through 
 which brine is circulated and cooled to about 45 F., being caught in 
 churns, and in this state taken to the main creamery to be ripened and 
 made into butter. The separated milk is treated in very much the same 
 way. A large surface water cooler reduces the temperature to 68° F., 
 and the milk is' then run over a small cooler and reduced to 48 F., at 
 which temperature it is returned to the farmer. 
 
 Some actual tests of a machine (at Ballinorig) might be appropri- 
 ately recorded here : 
 
 1. — 100 gallons of brine were cooled from 40° F. to 27 F. in one 
 hour (condensing water 57° F), or equal to the elimination of 13,000 
 B.T.U. per hour. 
 
CREAMERY AND DAIRY REFRIGERATION 285 
 
 2.— ioo gallons of brine were cooled from 27 F. to 17° F. in one 
 hour (cooling water, 58 F.) =10,000 B. T. U. per hour. 
 
 3.— 100 gallons of brine were cooled from 45 F. to 31° F. in one 
 hour (cooling water, 57° F.) =14,000 B.T.U. per hour. 
 
 These tests bring out very strongly the fact that at comparatively 
 high temperatures cooling is' effected at a much more rapid rate than at 
 the lower range of temperatures, and the amount of energy consumed is 
 greater at lower or ice-making temperatures than at the higher, and this 
 must be borne in mind in specifying the duty of the machine. The 
 machine in question is one of the very smallest made, but the same 
 result is obtained with machines of all sizes. 
 
 Perhaps 1 the greatest interest is attached to the application of refrig- 
 eration to a central or main creamery, for in such a place all the im- 
 portant applications can be put into effect. These may be classified thus: 
 A, cooling cream from separator; B, cooling separated milk; C, cooling 
 ripened cream; D, cooling water for washing butter; E, cooling a butter 
 store. 
 
 As in the auxiliary creamery, the cream is' first of all cooled with water 
 to about 68° F., so in the main dairy. The cream is brought down to 
 a temperature of 48 F. by passing it over a circular capillary cooler, and 
 is then run into the ripening vats. Here the process of ripening rapidly 
 increases the temperature again, and in about eighteen or twenty hours 
 it is at about 65° F. At such' a temperature it would be ruinous to churn, 
 inasmuch as the texture of the butter would be oily and bad, and there 
 would also be an excessive loss of butter fat in the buttermilk. The per- 
 fect churning temperature (in summer) may be anything between 48° 
 and 52 F., and to attain this it is obvious that the temperature of the 
 cream must be lowered some 13 to 17° F. The most economical ar- 
 rangement by which this can be accomplished is by having the cream- 
 ripening vats sufficiently high up in the creamery to enable the cream to 
 run over a capillary cooler, then flow into the churn. Such an arrange- 
 ment is simple and works' well. By proper arid intelligent adjustment of 
 the appliances, the cream can be reduced in temperature to 48 F. pre- 
 cisely, if wanted. 
 
 Separated milk in the main creamery is treated in the same way as 
 in the auxiliary, viz., first of all passed over a large circular cooler, in 
 which water takes' up the heat from the milk. It is then passed over a 
 small cooler in which brine is the cooling medium, and delivered to the 
 farmer at 48 F. 
 
 Cold water in a creamery is very desirable. The average temperature 
 of well water in the British Isles is 52° F, but that is not considered to 
 be low enough for washing purposes; besides, if it were, well water 
 is not always available. Hence, provision has to be made for cooling 
 water to a very low temperature. This is done in a separate tank, usually 
 placed in a sufficiently elevated position to command the butter worker 
 and churn. An insulated tank of, say, one to 500 gallons' capacity, is 
 fixed on the wall with brackets, or on a platform, and in this is fixed 
 a direct expansion or brine coil connected to the machine. The cooling 
 is more quickly produced if a small agitator is placed in the tank, as by 
 that means the water is more quickly brought in contact with the cooling 
 surface Water at from 45° to 58° F. seems to be generally preferred. 
 
286 PRACTICAL COLD STORAGE 
 
 CHAPTER XIV. 
 APPLES IN COLD STORAGE.* 
 
 INFLUENCE OF COLD STORAGE ON THE APPLE INDUSTRY. 
 
 ' Cold storage is having an important influence in developing 
 the apple industry as a stable business. Instead of an incidental 
 feature of the general farm, the apple is now the principal crop 
 in large sections of the country, and its production and the 
 handling and marketing of the crop are becoming highly special- 
 ized forms of agriculture and of trade. 
 
 Formerly the marketing of the crop was largely controlled 
 by the apple grower, but now the growing of the crop and its 
 sale are rapidly differentiating into two distinct lines. In many 
 of the principal fruit-growing districts the handling of the crop 
 and its marketing are controlled largely by fruit organizations or 
 by apple merchants who buy the fruit in the orchards and who, 
 through the special development of fruit and market statistics, 
 are better able than the fruit grower to regulate its distribution 
 and sale. This greater stability and specialization in apple grow- 
 ing is accompanied by a large amount of speculation. Through 
 a combination of the buyers the fruit may not always sell in the 
 orchard for its real value, but on the other hand the severe com- 
 petition in buying in those sections where the industry is es- 
 pecially well developed frequently brings the grower the highest 
 prices. 
 
 Apple storage is not always profitable. It is an insurance 
 against the premature deterioration of the fruit, but when the 
 picking season is unusually hot and there are delays in getting 
 the fruit into storage, the subsequent losses are sometimes very 
 heavy. On the other hand the autumn may be unusually cool 
 
 * Extracts from Bulletin No. 48, Bureau of Plant Industry, United States Depart- 
 ment of Agriculture, by G. Harold Powell, Assistant Pomologist in charge of Field 
 Investigations, and S. H. Fulton, Assistant in Pomology. 
 
APPLES IN COLD STORAGE 287 
 
 and favorable for storing large quantities of apples in common 
 storage. As a result the markets are well supplied with this 
 fruit through the winter, causing the cold storage stock to be. 
 held back till late in the season, when it lias to be rushed on the 
 market and sold at a sacrifice on account of the approaching 
 warm weather and the free use of southern early fruits. 
 
 On the whole the development of the cold storage business is 
 proving beneficial to the apple industry in encouraging the de- 
 velopment of apple growing over large territories, in making the 
 investment of capital in it safer, in developing it as a highly 
 specialized type of agriculture and trade, and in making a val- 
 uable food product available to an increasing number of people 
 over a greater part of the year. 
 
 THE FUNCTION OF THE COLD STORAGE WAREHOUSE. 
 
 There is a good deal of misapprehension as to the function 
 of the cold storage house in the preservation of fruits. This 
 condition leads to frequent misunderstandings between the ware- 
 houseman and the fruit storer, though they might be avoided and 
 the condition of the fruit storage business improved if there was 
 a clearer definition of the influence on fruit preservation of cul- 
 tural conditions, of the commercial methods of handling, and of 
 the methods of storage. 
 
 A fruit is a living organism in which the life processes go 
 forward more slowly in low temperatures, but do not cease even 
 in the lowest temperatures in which the fruit may be safely 
 stored. When the fruit naturally reaches the end of its life it 
 dies from old age. It may be killed prematurely by rots, usually 
 caused by fungi which lodge on the fruit before it is packed, 
 and sometimes afterwards. The. cold storage house is designed 
 to arrest the ripening processes in a temperature that will not 
 injure the fruit in other respects and thereby to prolong its life 
 history. It is designed also to retard the development of the 
 diseases with 'which the fruit is afflicted, but it cannot prevent the 
 slow growth of some of them. It follows that the behavior of 
 different apples or lots of apples in a storage room is largely de- 
 pendent on their condition when they enter the room. If they 
 are in a dissimilar condition of ripeness, or have been grown or 
 handled differently, or vary in other respects, these differences 
 
288 PRACTICAL COLD STORAGE 
 
 may be expected to appear as the fruit ripens slowly in the low 
 temperature. If the fruit is already overripe, the low tempera- 
 ture cannot prevent its deterioration sooner than would be the 
 case with apples of the same variety that were in a less mature 
 condition. If the fruit has been bruised, or is covered with rot 
 spores, the low temperature may retard but can not prevent its 
 premature decay. If there are inherent differences in the apples 
 due to the character of the soil, the altitude, and to incidental 
 features of orchard management, or variations due to the meth- 
 ods of picking, packing, and shipping, the low temperature must 
 not be expected to obliterate them, but rather to retard while not 
 preventing their normal development. 
 
 In general it is the function of the cold storage warehouse 
 to furnish a uniform temperature of the desired degree of cold 
 through its compartments during the storage season. [The ex- 
 periments so far conducted cover only the influence of tempera- 
 ture in cold storage. Much has yet to be done in determining 
 the best methods of refrigerating which control air circulation, 
 ventilation and humidity. More is promised along these lines.] 
 The warehouse is expected to be managed in other respects so 
 that the deterioration of the fruit or any other injury may not be 
 reasonably attributed to a poorly constructed and installed plant, 
 or to its negligent or improper management. The warehouseman 
 does not insure the fruit against natural deterioration; he holds 
 it in storage as a trustee, and in that relation is bound to use only 
 that degree of care and diligence in the management of the ware- 
 house that a man of ordinary care and prudence would exercise 
 under the circumstances in protecting the goods if they were his 
 private property. 
 
 If the temperature of the storage rooms fluctuates unduly 
 from the point to be maintained and causes the fruit to freeze 
 to its injury, or to ripen with abnormal rapidity, or if the man- 
 agement of the rooms or the handling of the fruit in other re- 
 spects can be shown to have been faulty or negligent, the ware- 
 house has failed to perform its proper function. 
 
 OUTLINE OF EXPERIMENTS IN APPLE STORAGE. 
 
 An outline of the apple storage experiments of the United 
 States Department of Agriculture is presented here. The fol- 
 
APPLES IN COLD STORAGE 289 
 
 lowing problems were under investigation during two apple 
 seasons : 
 
 i- — A comparative test of the keeping quality of a large 
 number of varieties grown in different regions and of the same 
 varieties grown under different conditions and in different lo- 
 calities. 
 
 The fruit was stored in closed 50-pound boxes in a tempera- 
 ture of 31° to 32^ F. One-half of the fruit in each box was 
 wrapped in paper. 
 
 2. — A determination of the influence of various commercial 
 methods of apple handling on the keeping quality of the most im- 
 portant varieties in the leading apple-growing regions of the 
 eastern United States. 
 
 Each variety was picked at two different degrees of ma- 
 turity : First, when nearly grown but only half to two-thirds 
 colored, or about the time when apples are usually picked ; sec- 
 ond, when the fruit was fully grown and more highly colored, 
 but still hard. In each picking the fruit was separated into two 
 lots, representing the average of the lightest and of the darkest 
 colored or most mature specimens. 
 
 Part of the fruit of each series was sent to storage as soon 
 as picked. A duplicate lot was held two weeks in the orchard 
 or in a building, either in piles or protected in packages, before 
 it was sent to storage. 
 
 Comparative tests were made to determine the efficiency of 
 different kinds of fruit wrappers on the keeping of the fruit, 
 and observations on the behavior of the fruit in closed and ven- 
 tilated packages were recorded. 
 
 3. — A determination of the influence of various cultural and 
 other conditions of growth on the keeping quality of the fruit. 
 
 Comparison was made with the same variety from heavy 
 clay and from sandy soils, from sod, and from cultivated land, 
 from young, rapidly growing trees, and from older trees with 
 more steady habits. 
 
 4.— A determination of the behavior of the fruit under the 
 conditions outlined in temperatures of 31" to 32 ° F., and in 34° 
 to 36 F. 
 
 5. — A determination of the behavior of the fruit when re- 
 moved from storage, and of its value to the consumer. 
 
 (19) 
 
290 PRACTICAL COLD STORAGE 
 
 The fruit used in the investigations was taken from central 
 and eastern Kansas, southwestern and central Missouri, southern 
 and central Illinois, western Michigan, northeastern West Vir- 
 ginia, northern and western Virginia, western North Carolina, 
 central Delaware, southern Maine, central Massachusetts, and 
 from eastern, central, and western New York. A description of 
 each orchard accompanies the data included in the account of the 
 variety test. 
 
 It was necessary to duplicate the work in different parts of 
 the country, as the climatic and other conditions and the varieties 
 differ in each section. The work must be repeated for several 
 successive seasons before general conclusions can safely be drawn 
 from it, as the climatic conditions differ each year and thereby 
 affect the results. 
 
 FACTORS INFLUENCING THE KEEPING QUALITY OF APPLES. 
 
 In recent years there has been a tendency to pick the apple 
 crop relatively earlier in the season than formerly. It is quite 
 generally supposed that the longest keeping apples are not fully 
 developed in size or maturity and that the most highly colored 
 fruit is less able to endure the abuses that arise in picking, pack- 
 ing, and shipping. 
 
 Aside from these general impressions, several important 
 economic factors have influenced the picking time. A large 
 proportion of the apple crop is purchased in the orchard by the 
 barrel or by the entire orchard by a comparatively few apple mer- 
 chants. The fruit may be picked and barreled either by the 
 grower or by the purchaser, but with the growing scarcity of 
 farm hands and other labor it has become necessary to begin 
 picking relatively earlier in the autumn to secure the crop before 
 the fall storms or winter months set in. 
 
 The general increase in freight traffic during the past few 
 years has overtaxed the carrying capacity of the railroads as 
 well as their terminal facilities for freight handling, and has in- 
 fluenced the apple dealers to extend the picking and shipping 
 season over the longest possible time, in order to avoid con- 
 gestion and consequent delays in shipping and in unloading the 
 fruit. The facilities at the warehouses are often inadequate for 
 the quick handling of the fruit from the cars when it is received 
 
APPLES IN COLD STORAGE 291 
 
 in unusually large quantities, and this condition has also favored 
 a longer shipping season. 
 
 In localities where the entire crop is sometimes ruined by 
 the bitter rot after the fruit is half grown the picking of the 
 apples is often begun early in the season in order to secure the 
 largest amount of perfect fruit. 
 
 It is not generally the case, however, that the immature and 
 partly colored fruit has the best keeping quality. On the other 
 hand, an apple that is not overgrown and which has attained 
 full growth and high color, like the lower specimen of York 
 Imperial in Fig. i, but is still hard and firm when picked, equals 
 the less mature fruit (upper specimen, Fig. i) in keeping qual- 
 ity, and often surpasses it. The mature fruit is superior in flavor 
 and texture ; it is more attractive to the purchaser, and therefore 
 of greater money value. It retains its plumpness longer and is 
 less subject to apple scald. If, however, the fruit is not picked 
 until overripe, it is already near the end of its life history, and 
 will deteriorate rapidly unless stored soon after picking in a low 
 temperature. 
 
 In the experiments with the Tompkins King and the Sutton 
 apples grown in New York on rapidly growing young trees pro- 
 ducing unusually large apples, the fruit that was three-fourths 
 colored kept longer than the fully colored apples from the same 
 trees. Dark red Tompkins King showed 28 per cent of physio- 
 logical decay in February- following the storage. Light, half red 
 Tompkins King from the same trees, picked at the same time, 
 showed 10 per cent of physiological decay in February following 
 the storage. Fig. 2 shows Tompkins King in February at two 
 degrees of maturity in September, 1902, from young, rapidly 
 growing trees. The upper specimen represents fruit that was 
 highly colored but firm when picked; the lower specimen shows 
 fruit one-half to two-thirds colored. The less mature fruit kept 
 in good condition a month longer than the highly colored apple. 
 These apples were overgrown — a condition likely to occur on 
 young trees. Whether the same conditions hold true of other 
 varieties that are overgrown has not been determined. 
 
 From older trees, apples that are fully grown, highly col- 
 ored, and firm when picked have kept as well in all cases (and 
 
292 PRACTICAL COLD STORAGE 
 
 FIG. I. — SCALD ON YORK IMPERIAL APPLES. 
 
APPLES IN COLD STORAGE 293 
 
 better in many, as shown in Fig. i) than immature and under- 
 colored fruit. 
 
 A considerable number of later varieties may be picked when 
 they are beginning to mellow, and will keep for months in prime 
 condition provided they are handled with great care and quickly 
 stored after picking in a temperature of 31° to 32 ° F. Fruit 
 in this ripe state can not be left in the orchard or in warm freight 
 cars, or in any other condition that will cause it to ripen after 
 picking, without seriously injuring its value. In this ripe con- 
 dition it should be stored in boxes, and a fruit wrapper will still 
 further protect it. 
 
 Apples that are to be stored in a local cold storage house 
 to be distributed to the large markets in cooler weather may be 
 picked much later than fruit requiring ten days or more in 
 transit, but the use of the refrigerator car makes late picking 
 possible where the fruit must be in transit for a considerable time 
 in warm weather in reaching a distant storage house. 
 
 While it is not the purpose of this publication to discuss 
 cultural practices in the orchard, some suggestions in relation to 
 the methods of securing more mature and more highly colored 
 fruit may not be without value to the fruit grower. 
 
 A large proportion of the poorly colored fruit from old or- 
 chards is caused by dense-headed trees and close planting, which 
 prevent the free access of air and sunlight and delay the maturity 
 of the fruit in the fall. The fundamental corrective in such cases 
 lies in judicious pruning, by which means the fruit may be ex- 
 posed to the sunlight. 
 
 In other cases the poor color may be due- to a combination 
 of heavy soil, tillage, frequent turning in of nitrogenous cover- 
 crops, spraying, and neglect in pruning. These conditions stim- 
 ulate the trees to active growth, the foliage increases in health, 
 size, and quantity, and, as the water-holding capacity of the soil 
 is enlarged by the incorporation of the cover-crops and is re- 
 tained by the tillage, the trees grow late in the fall and the fruit 
 does not properly color before the picking season arrives. It is 
 often possible to overcome the difficulty by severely pruning the 
 top to let in more air and light. If this treatment does not prove 
 efficient, the cover-crops may be withheld, when the fruit will 
 usually mature earlier in the fall, unless the season is wet. As 
 
294 
 
 PRACTICAL COLD STORAGE 
 
 FIG. 2. — TOMPKINS KING APPLES. OVERGROWN ON YOUNG TREES. 
 
APPLES IN COLD STORAGE 295 
 
 an additional treatment where necessary, the growth of the or- 
 chard may be still further checked by seeding it down until the 
 desired condition is attained. 
 
 It is not possible to secure a uniform degree of maturity 
 and size when all the apples on a tree are picked at one time, as 
 fruit in different stages of growth is mixed together on the same 
 tree. The apples differ in size and maturity in relation to their 
 position, the upper outer branches producing the large, highly 
 colored and early ripening fruit, while the apples on the side 
 branches and the shaded interior branches ripen later. Greater 
 uniformity in these respects is approached by proper pruning 
 and by other cultural methods, but the greatest uniformity can 
 be attained when, like the peach or the pear, the apple tree is 
 picked over several times, taking the fruit in each picking that 
 approaches the desired standard of size and maturity. 
 
 Summer apples, like the Yellow Transparent, Astrachan, 
 and Williams, are usually picked in this manner, and fall varie- 
 ties, like Twenty Ounce, Oldenburg, and Wealthy, are sometimes 
 treated similarly. In recent years a few growers of winter ap- 
 ples have adopted the plan for the late varieties, with the result 
 that the size, color, and ripeness of a larger proportion of the 
 fruit are more uniform. This method of picking is not usually 
 adapted to the apple merchant who buys the crop of a large num- 
 ber of orchards, and who can not always secure efficient or abun- 
 dant labor, but for the specialist who is working for the finest 
 trade and who has a storage house near by or a convenient re- 
 frigerator car service to a distant storage house, the plan has 
 much to commend it. 
 
 INFLUENCE OF DELAYING THE STORAGE OF THE FRUIT. 
 
 The removal of an apple from the tree hastens its ripening. 
 As soon as the growth is stopped by picking, the fruit matures 
 more rapidly than it does when growing on the tree and matur- 
 ing at the same time. The rapidity of ripening increases as the 
 temperature rises, and it is checked by a low temperature. It 
 appears to vary with the degree of maturity at which the fruit 
 is picked, the less mature apples seeming to reach the end of 
 their life as quickly as or even sooner than the more mature 
 fruit. It varies with the conditions of growth, the abnormally 
 
296 PRACTICAL COLD STORAGE 
 
 large fruit from young trees or fruit which has been overgrown 
 from other causes ripening and deteriorating very rapidly. It 
 differs with the nature of the variety, those sorts with a short 
 life history, like the summer and fall varieties, or like the early 
 winter apples, such as Rhode Island Greening, Yellow Bellflower, 
 or Grimes Golden, progressing more rapidly than the long-keep- 
 ing varieties like Roxbury, Swaar, or Baldwin. 
 
 Any condition in the management of the fruit that causes 
 it to ripen after it is picked brings it just so much nearer the 
 end of its life, whether it is stored in common storage or in cold 
 storage, while treatment that checks the ripening to the greatest 
 possible degree prolongs it. 
 
 The keeping quality of a great deal of fruit is seriously in- 
 jured by delays between the orchard and the storage house. This 
 is especially true in hot weather and in fruit that comes from 
 sections where the autumn months are usually- hot. If the apples 
 are exposed to the sun in piles in the orchard, or are kept in 
 closed buildings where the hot, humid air can not easily be re- 
 moved from the pile ; if transportation is delayed because cars 
 for shipment can not be secured promptly, or if the fruit is de- 
 tained in transit or at the terminal point in tight cars(^ which 
 soon become charged with hot, moist air, the ripening progresses 
 rapidly and the apples may already be near the point of deter- 
 ioration or may even have commenced to deteriorate from scald, 
 or mellowness, or decay when the storage house is reached. 
 
 On the contrary, the weather may be cool during a similar 
 period of delay and no serious injury result to the keeping qual- 
 ity, or the ripening may be checked in hot weather by shipping 
 the fruit in refrigerator cars to a distant storage house. 
 
 The fungous diseases of the fruit, such as the apple scab 
 (Fusicladium dcndriticum (Wallr.) Fckl.) and the pink mold 
 (Cephalothecium roseum Cda.) which grows upon the scab, the 
 blue mold (Penicillium glaucum Link) which causes the com- 
 mon, soft, brown rot, the black rot (Sphceropsis maiorum Pk.) 
 and the bitter rot (Glceo'Sporium fructigenum Berk.), develop very 
 fast if the fruit becomes heated after picking. The conditions 
 already enumerated which cause the fruit to ripen quickly during 
 the delay between the orchard and the storage house are also 
 most favorable to the development of fruit diseases. It is there- 
 
APPLES IN COLD STORAGE 297 
 
 fore of the greatest importance that the fruit be stored imme- 
 diately after picking, if the weather is warm, in order to insure it 
 against the unusual development of the fungous rots. 
 
 In the fall of 1901, when the weather in western New York 
 was cool, there was no apparent injury from delaying the storage 
 of a large number of varieties two weeks and then shipping the 
 fruit to Buffalo, the transit occupying from one to three days. 
 There was also no apparent injury to the fruit from Virginia 
 treated in a similar manner, but in southwestern Missouri, where 
 it was warmer, the apples delayed two weeks before storing were 
 seriously injured in their commercial keeping qualities. 
 
 The results accomplished during 1902 have been of the most 
 instructive character. During the latter half of September the 
 temperature in eastern New York averaged about 62° F., with 
 a humidity of 84 . During the first half of October the average 
 temperature was 53 F. and the humidity 8o°. 
 
 Rhode Island Greening, Tompkins King, and Sutton apples 
 picked September 15, 1902, and stored within three days, were 
 firm till the following March, with no rot or scald, but fruit from 
 the same trees not stored till two weeks after picking was badly 
 scalded or decayed by the 1st of January. None of the imme- 
 diate-stored fruit was scalded or decayed by the 1st of February, 
 but the delayed Sutton and Rhode Island Greening apples were 
 soft and mealy, and one-third were scalded at that time, while 
 nearly 40 per cent of the delayed Tompkins King were soft and 
 worthless. The commercial value of these varieties was injured 
 from 40 to 70 per cent by the delay in storage. 
 
 Apples of these varieties picked from the same trees on Oc- 
 tober 5, 1902, and stored immediately, and also some stored two 
 weeks later, were less injured by the delay, as the temperature 
 and humidity were not sufficiently high to cause rapid ripening 
 or the development of the fruit rots. 
 
 From the standpoint of the orchardist or apple dealer who 
 can not secure quick transportation to the large storage centers, 
 or who can not obtain refrigerator cars, or who is geographically 
 situated where the weather is usually warm in apple-picking 
 time, the local storage plant in which the fruit can be stored at 
 once and distributed in cool weather offers important advantages. 
 The importance of this phase of the fruit-storage business and its 
 
298 PRACTICAL COLD STORAGE 
 
 relation to the fruit-growing industry are emphasized as the 
 apple business enlarges. 
 
 INFLUENCE OF STORAGE TEMPERATURE. 
 
 The investigations indicate that the ripening processes are 
 delayed more in a temperature of 31° to 32 ° F. than in 35 ° to 
 36° F. The apple keeps longer in the lower temperature, it 
 scalds less, the fruit rots and molds are retarded to a greater 
 extent, while the quality, aroma, flavor, and other character- 
 istics of the fruit are fully as good, and when removed from 
 storage it remains in good condition for a longer period. 
 
 The impression is quite general that fall varieties and the 
 tender early winter sorts, like Fameuse, Wealthy, and Grimes, 
 are injured in some way by the low temperature, but the investi- 
 gations of the Department of Agriculture indicate that these 
 varieties behave more satisfactorily in every respect when stored 
 at 31" to 32° F. 
 
 If the fruit is intended for storage for a short time only, 
 and it is desired to have it ripen before removing it from the 
 storage house, then a higher temperature may be desirable to 
 hasten the maturity. 
 
 The influence of the temperature on the ripening processes 
 appears to depend on the condition of the fruit. Baldwin, Esopus 
 Spitzenburg, Roxbury, Jonathan, Lady Sweet, and other long- 
 keeping eastern-grown varieties have been held in prime com- 
 mercial condition throughout the storage season in a temperature 
 of 35 F., when carefully picked and handled and stored soon 
 after picking; but when the fruit was carelessly handled or the 
 storage was delayed in hot weather, then a temperature of 31° 
 to 32 ° F. was required to retard the ripening. 
 
 It might be safe to use a temperature of 34 to 35 F. in a 
 storage house located near the orchard, in which the fruit may 
 be stored immediately after harvesting, but for general commer- 
 cial apple handling, a temperature as low as 32 F. is needed to 
 overcome the abuses that usually arise in picking, packing, and 
 shipping. 
 
 No definite investigations have been made by the Depart- 
 ment of Agriculture as to the effect of temperatures lower than 
 31" F. The exact freezing point of apples has not been deter- 
 mined, but it is below this point. It may possibly vary with the 
 
APPLES IN COLD STORAGE 299 
 
 composition or condition of the variety. Under the most favor- 
 able conditions, apples are sometimes commercially stored at 30° 
 F. without injury, but 31° F. should be considered a critical 
 temperature below which it is unsafe to store this fruit, except 
 in houses that are properly constructed and in which the tem- 
 perature is maintained uniform in all parts of the rooms. [The 
 author's personal experience is that a temperature of 30" F. is 
 better than any degree above that, and 29 ° F. is practicable and 
 advisable for long-period storing of the better keeping varieties. 
 To safely store at 29 ° to 30° F. it is necessary that a thorough 
 forced circulation of air be employed (see chapter on "Air Cir- 
 culation"), and in cooling the fruit down to the final carrying 
 temperature, the refrigeration must not be applied too suddenly. 
 If, say, the fruit has a temperature of 60° or 70° F. when placed 
 in storage, a period of two or three weeks should be consumed 
 in reducing to 29 or 30° F. This applies to the better keeping 
 kinds only. Softer varieties must be cooled quickly, as their life 
 is shorter, and too much deterioration will take place during 
 cooling process if handled as suggested above.] 
 
 Apples are sometimes frozen in the storage rooms owing to 
 a considerable drop in the temperature or to a poor distribution 
 of the cold air. If the fruit compartment adjoins a freezer room 
 and the insulation is poor, the fruit may be frozen in packages 
 piled close to the freezer wall. Apples placed near the refriger- 
 ating pipes or near the cold-air duct where it enters the room 
 may be injured by freezing if the plant is improperly installed or 
 managed; or if the piping or air circulation is faulty, the tem- 
 perature at the botton may be lower than that at the top of the 
 room. 
 
 The frosting of the fruit does not necessarily injure it. 
 When the apple freezes, the water in the cells is withdrawn and 
 frozen in the intercellular spaces, and if it thaws slowly and the 
 freezing has not been too severe, the cells may regain the water 
 without injury and resume their living function. If the thawing 
 is rapid, the cells may not reabsorb the water with sufficient 
 rapidity, and in this case it remains in the intercellular spaces 
 and is lost by evaporation. In addition, the tissues next to the 
 area of greatest freezing may be forced apart by the formation 
 of ice crystals in the intercellular spaces. 
 
300 PRACTICAL COLD STORAGE 
 
 If the freezing is so severe as to withdraw too much of the 
 cell water, the cells may not be able to absorb it and will be killed 
 in the same manner as if dried out in any other way. Occasion- 
 ally the freezing is so rapid that besides the withdrawal of water 
 the cell contents are disorganized or possibly frozen outright ; 
 at any rate, the cell may be directly killed by a sudden change of 
 temperature. It is probable that varieties may differ as to the 
 degree of freezing they will stand without injury, and further, 
 that the same sort may vary in this respect when grown under 
 different conditions or subjected to different treatment. 
 
 The most characteristic results of injurious freezing are a 
 translucent appearance of the skin of the fruit, a water-logged 
 and springy or spongy condition of the flesh, a forcing apart of 
 the tissues, and a brownish discoloration of the flesh. The brown- 
 ing may result from any cause which results in the death of the 
 cells and is not necessarily characteristic of freezing. It often 
 happens that the skin of the fruit retains its normal brightness 
 after the interior has discolored. 
 
 In the practical handling of frozen stock, the temperature 
 should be raised very slowly until the frost is withdrawn. If 
 possible, the fruit should not be moved until it is defrosted, as 
 it discolors quickly wherever a slight bruise occurs, or even where 
 the skin is lightly rubbed. With these precautions observed it 
 is often possible to defrost stock that is quite firmly frozen with- 
 out apparent injury to it. 
 
 INFLUENCE OF A FRUIT WRAPPER. 
 
 In the storage investigations under discussion a comparison 
 has been made between wrapped and unwrapped stock on the 
 keeping quality of the fruit, and the efficiency of different kinds 
 of paper for wrappers — tissue, parchment, waxed or paraffin, 
 and imprinted news — has been tested. A box of unwrapped fruit, 
 with packages of fruit wrapped with the kinds of paper mentioned 
 in order above, is shown in Fig. 3. 
 
 It has been found that the wrapper may influence the keep- 
 ing quality in several different ways. It extends the life of the 
 fruit beyond its normal period by retarding the ripening processes. 
 The influence of the wrapper in this regard is apparent especially 
 at the end of the normal storage season of the naked fruit when 
 
APPLES IN COLD STORAGE 
 
 301 
 
 the flesh begins to grow mealy from overripeness. At this time 
 the wrapped apples may be firm and remain in prime condition 
 for several weeks or even months. The wrapper is especially 
 useful in extending the season of early winter sorts, or in making 
 the long-keeping varieties available for use over a still longer 
 period of time. 
 
 The wrapper may be useful in preventing the transfer of 
 rot from one apple to another. If the fungous is capable of 
 growing in the storage temperature, it is not likely that the wrap- 
 per retards its growth, but when the spores develop they are 
 confined within the wrapper and their dissemination is difficult 
 or impossible. 
 
 FIG. 3. — APPLES UNWRAPPED AND IN TISSUE, PARCHMENT, AND WAX WRAPPERS. 
 
 The importance of a wrapper in protecting the fruit from 
 decay and in extending its season may be better appreciated by 
 reference to the following table : 
 
 AMOUNT OF DECAYED FRUIT APRIL 20. IN BUSHEL PACKAGES. 
 
 Variety. 
 
 News 
 
 paper 
 
 wrapped. 
 
 Un- 
 wrapped. 
 
 Variety. 
 
 News 
 
 paper 
 
 wrapped. 
 
 Un- 
 wrapped. 
 
 Baker 
 
 Per cent. 
 
 3-7 
 6.4 
 
 7-7 
 19.7 
 
 Per cent. 
 27.2 
 43^0 
 
 15-0 
 
 32.0 
 
 Northern 
 
 Spy 
 
 Wagener.... 
 Wealthy ... 
 
 Per cent. 
 
 5-6 
 38.0 
 42.0 
 
 Per cent. 
 
 Dickenson .. 
 Mcintosh .... 
 
 Mcintosh 
 (second lot) 
 
 52.0 
 63.O 
 60.0 
 
302 PRACTICAL COLD STORAGE 
 
 The wrapper protects the apple against bruising and the dis- 
 coloration that may result from improper packing or rough han- 
 dling; it checks transpiration, and by the preservation of the at- 
 tractive appearance and firmness of the fruit adds to its com- 
 mercial value. 
 
 No important difference was noticeable in the efficiency of 
 the different wrappers, except that a mold developed freely on 
 the parchment paper in a temperature of 36° F. This mold grew 
 only to a slight extent in 32 F. 
 
 A double wrapper is more efficient in retarding ripening and 
 transpiration than a single wrapper. A good combination con- 
 sists in a porous news paper next to the fruit, with an impervious 
 wax or paraffin wrapper on the outside. The wrappers vary in 
 cost from 20 cents per thousand for news paper, 9x12 inches, to 
 70 cents per thousand for the better grades of paraffin. 
 
 INFLUENCE OF CULTURAL CONDITIONS. 
 
 Preliminary studies have been made on the influence of cult- 
 ural and other conditions surrounding the growing fruit on its 
 storage quality. Considerable data along this line will be brought 
 out in the comparison of the same variety grown in different sec- 
 tions. It has been observed that the Tompkins King, Hubbards- 
 ton, and Sutton apples from rank-growing young trees ripen 
 faster than smaller fruit from older slower-growing trees, and 
 therefore reach the end of their life history sooner. From older 
 trees these varieties have kept well till the middle of April, while 
 from young trees the commercial storage limit is sometimes three 
 months shorter. 
 
 It has been noticed that Rhode Island Greening apples from 
 old trees remain hard longer than the same variety from young 
 trees, but the greener condition of the fruit from the older trees 
 when picked at the same time made it more susceptible to scald. 
 Rhode Island Greenings from Mr. Grant G. Hitchings, South 
 Onondaga, N. Y., showed 50 per cent of scald from young trees 
 on April 28, 1903, and 82 per cent in smaller, greener fruit from 
 older trees. 
 
 Rhode Island Greening, Mann, and Baldwin apples grown 
 on sandy land ripened more rapidly than similar fruit from clay 
 land, where all of the other conditions of growth were similar. 
 
APPLES IN COLD STORAGE 
 
 303 
 
 FIG. 4. — BALDWIN APPLES FROM CLAY AND SANDY SOIL. 
 
304: PRACTICAL COLD STORAGE 
 
 Fig. 4 shows the average condition of Baldwin apples on April 
 28, 1903, grown on sandy and clay soil in the orchard of Mr. W. 
 T. Mann, Barker, Niagara County, N. Y., and stored in a tem- 
 perature of 32° F. The upper apple was grown on clay; the 
 lower, on sandy soil. 
 
 This fruit was picked in October, 1902, and was stored soon 
 after picking. The fruit from the heavy clay soil was generally 
 smaller and was much less highly colored. Both lots kept well 
 throughout the storage season. The fruit from the sandy land 
 was riper at the end of the storage season, better in quality, and 
 worth more to the dealer and to the consumer. 
 
 The subject will require critical study over a period of years 
 before it will be possible to fully understand the influence of 
 various cultural, climatic, and other conditions of growth on the 
 life processes in the fruit. 
 
 INFLUENCE OF THE TYPE OF PACKAGE. 
 
 The principal storage packages for apples are barrels of 
 about 3 bushels capacity and boxes holding 40 to 50 pounds. 
 The larger the bulk of fruit and the more it is protected from 
 the air the longer it retains the heat after entering the storage 
 room. If the fruit is hot and the variety a quick-ripening sort, 
 it may continue to ripen considerably in the center of the package 
 before the fruit cools in that position. The long-keeping varie- 
 ties that are harvested and shipped in cooler weather are less 
 likely to show the effect of the type of the package. The smaller 
 package therefore presents distinct advantages for the early, 
 quick-ripening varieties and is most useful in the hottest weather, 
 as the fruit cools down quickly throughout the package and its 
 ripening proceeds uniformly. 
 
 There is a wide difference of opinion concerning the com- 
 parative value of ventilated and closed packages for apple stor- 
 age. The chief advantage of the ventilated package appears to 
 lie in the greater rapidity with which its contents cool off, and 
 its value in this respect depends on the amount of ventilation in 
 the package. The contents of an ordinary ventilated apple barrel 
 do not cool much more quickly than the contents of a closed bar- 
 rel, and the value of the ventilated barrel for the purpose for 
 which it is designed is somewhat doubtful. 
 
APPLES IN COLD STORAGE 305 
 
 Apples in a ventilated package are likely to shrivel if the 
 fruit is stored for any length of time. In the ordinary ventilated 
 apple barrel the exposure is not sufficient to affect the fruit to any 
 extent, but in boxes in which there is much exposure the fruit 
 may be corky or spongy in texture if held until spring. 
 
 The size of the package may have an important influence on 
 the length of the storage season. Its influence in this respect is 
 especially marked when the fruit begins to mellow in texture. 
 Barrel stock in this condition needs to be sold to prevent the 
 bruising of the fruit from its own weight, but apples equally ripe 
 may be carried in boxes safely sometimes for several weeks 
 longer. 
 
 BEHAVIOR OF THE FRUIT WHEN REMOVED FROM STORAGE. 
 
 There is a general impression that cold-storage apples deter- 
 iorate quickly after removal from the warehouse. This opinion 
 is founded on the experience of the fruit handler and the con- 
 sumer, but the impression is not generally applicable to all stor- 
 age apples. In fact, it is probable that storage apples do not de- 
 teriorate more quickly than other apples that are equally ripe and 
 are held in the same outside temperature. If the fruit is overripe 
 when taken from storage — and a good deal of stock is stored 
 until it reaches this condition — it naturally breaks down quickly ; 
 but firm stock may be held for weeks and even months after it 
 has been in storage. [This is confirmed by the author's expe- 
 rience, and applies not only to apples, but also to other goods 
 which are cold stored. The popular idea that cold storing goods 
 weakens them for exposure to ordinary temperatures after being 
 removed from storage is largely erroneous. If the temperature 
 is not lowered too suddenly when the goods are stored nor raised 
 toe quickly when the goods are removed from storage they will 
 have nearly the same vitality for rough usage that they would 
 have had originally if never placed in cold storage. Avoid sud- 
 den changes in temperature. See experiment described in chapter 
 on " Eggs in Coid Storage."] 
 
 The rapidity of deterioration depends also on the tempera- 
 ture into which the fruit is removed. The following table shows 
 the amount of decay in Baldwin apples from the same barrel after 
 removal and subjection to different temperatures : 
 
 (20) 
 
306 
 
 PRACTICAL COLD STORAGE 
 
 AMOUNT OF DECAY AFTER REMOVAL FROM STORAGE TO DIFFERENT 
 
 TEMPERATURES. 
 
 
 Date re- 
 moved from 
 storage 
 (1903)- 
 
 Date in- 
 spected. 
 
 Per cent rot. 
 
 
 44° F- 
 
 48° F. 
 
 6r° F. 
 
 67° F. 
 
 Baldwin 
 
 Jan. 29 
 
 Jan. 29 
 Feb. 10 
 Feb. 13 
 Feb. 16 
 Feb. 20 
 Mar. 3 
 Mar. 7 
 Mar. 24 
 Apr. 6 
 
 
 O 
 O 
 O 
 O 
 
 5 
 
 5 
 
 20 
 
 36 
 
 O 
 
 _ 
 
 O 
 
 
 
 4 
 10 
 
 15 
 
 
 
 3 
 12 
 21 
 23 
 
 O 
 10 
 
 14 
 24 
 28 
 
 
 
 
 
 
 
 
 
 Late in the spring the fruit is far advanced in its life and 
 the weather is becoming warmer. All apples similarly ripe, 
 whether in cold storage or not, break down more quickly at this 
 time than in the winter. 
 
 In commercial practice the dealer often holds the apples for 
 a rise in price, and finally removes them from the warehouse, 
 not because the market has improved, but for the reason that he 
 finds that a longer storage would result in serious deterioration 
 from fruit rots and overripeness. When a considerable amount 
 of stock is decayed on removal from the warehouse the evidence 
 is conclusive that the apples should have been sold earlier in the 
 season. In the purchase of cold-storage stock the consumer will 
 have little cause to complain of the rapid deterioration of the 
 fruit if he exercises good judgment in the selection of apples that 
 are still sound and firm. 
 
 THE IMPORTANCE OF GOOD FRUIT. 
 
 Apples do not improve in grade in cold storage. In han- 
 dling a crop too much care can not be given to grading the fruit 
 properly before it enters the storage house. The contents of 
 many packages are injured by the spread of disease from a few 
 imperfect apples. Rots enter the fruit most easily wherever the 
 skin is bruised or broken, and in the early stages of the rot devel- 
 opment it is common to see the diseases manifesting themselves 
 around worm holes or bruises occasioned by rough handling, 
 
APPLES IN COLD STORAGE 
 
 307 
 
 from nails that protrude through the barrels, or from other 
 causes. 
 
 When the crop is light it may pay to store apples that are 
 not of the first grade, but such fruit should be rigidly eliminated 
 from the best stock and stored where it can be removed earlier 
 in the season than the better qualities. 
 
 The attractiveness and the value of the best fruit is often 
 injured by careless handling. A bruised spot dies and discolors. 
 Finger marks made by pickers, graders, and packers, and injuries 
 from the shifting of the fruit in transit or from rough handling, 
 become more apparent as the season advances. In fact, all of the 
 investigations of the Department of Agriculture emphasize the 
 
 FIG. 5.— WELL PACKED ESOPUS FIG. 6 — "SLACK" PACKED NORTHERN 
 
 SPITZENBDRG APPLES. SPY APPLES. 
 
 fundamental importance of well-grown, carefully handled fruit 
 in successful storage operations. 
 
 Fig. 5 shows a well packed barrel of Esopus Spitzenburg 
 apples removed from storage in March, 1903. The fruit was 
 properly packed in the orchard and repacking was not needed 
 when the fruit was sold. 
 
 Fig. 6 shows a "slack" packed barrel of Northern Spy 
 apples removed from storage in March, 1903. The fruit was not 
 packed firmly in the orchard. It settled in the barrel, leaving it 
 " slack " when removed from storage. Barrels in this condition 
 need to be repacked. The fruit is easily bruised and it deteri- 
 orates more quickly in the storage house and after removal when 
 it is loosely packed. 
 
308 PRACTICAL COLD STORAGE 
 
 APPLE SCALD. 
 
 When some varieties of apples reach a certain degree of 
 ripeness the part of the fruit grown in the shade often turns 
 brown, not unlike the color of a baked apple. This difficulty does 
 not extend deep into the flesh, but it detracts from the appear- 
 ance of the fruit and reduces its commercial value. This trouble 
 is commonly called "apple scald." It may appear in fruit held 
 in common or in cold storage. 
 
 The exact nature of scald is not well understood, though 
 apple men have many theories by which its appearance is popu- 
 larly explained. The most common theory gives rise to the name 
 of scald — that is, the brown, cooked appearance is thought to be 
 due to the overheating of the fruit when it is stored, or to a tem- 
 perature too low for the variety, or to picking the fruit when too 
 ripe; and other matters relating to the growth and handling of 
 the fruit are thought to develop it. 
 
 As the scald is an important commercial problem it has been 
 considered from several standpoints in the fruit-storage investi- 
 gations of the Department. The nature of the scald, the influ- 
 ence of the degree of maturity of the fruit when picked, of com- 
 mercial methods of handling, of fruit wrappers, of different tem- 
 peratures, and of cultural conditions on its development are 
 among the problems investigated. 
 
 Apple scald is not a contagious disease. According to Dr. 
 A. F. Woods, Pathologist and Physiologist of the Department of 
 Agriculture, it is a physiological disturbance not connected in 
 any way with the action of parasitic or saprophytic organisms 
 such as molds or bacteria. Briefly, it is the mixing of the cell 
 contents or premature death of the cells and their browning by 
 oxidation through the influence of the normal oxidizing ferments 
 of the cell. There are many conditions which influence the de- 
 velopment of this trouble. It appears to be closely connected 
 with the changes that occur in ripening after the fruit is picked, 
 and is most injurious in its effects as the fruit approaches the 
 end of its life. Several of the factors that influence it will be dis- 
 cussed. Fig. 7 shows scald en a Rhode Island Greening apple. 
 The cross section shows that the scald is a surface trouble onlv. 
 
 The scald always appears first on the green or less mature 
 side of an apple, and if the fruit is only partly ripe it mav spread 
 
APPLES IN COLD STORAGE 
 
 309 
 
 FIG. 7. — SCALD ON RHODE ISLAND GREENING APPLE. 
 
310 
 
 PRACTICAL COLD STORAGE 
 
 entirely over it; but the portions grown in the shade and under- 
 colored are first and most seriously affected. The upper speci- 
 men in Fig. i shows the distribution of scald on an immature 
 York Imperial apple in March, 1903. The apples that are more 
 mature and more highly colored when picked are less susceptible 
 to injury, and the side grown in the sunlight may remain en- 
 tirely free from it. The lower specimen in Fig. 1 (picked from 
 the same tree at the time, October, 1902, when the upper speci- 
 men was picked) shows a well-colored York Imperial apple and 
 its freedom from the scald is noticeable. A trace only is shown 
 on the right-hand side of the apple, where the color is not as 
 dark as elsewhere. 
 
 When the apple crop is picked before it is mature the fruit 
 is more susceptible to scald than it would have been later in the 
 season. The relative susceptibility of immature and more ma- 
 ture apples is brought out in the table following. The fruit was 
 picked two weeks apart. At the first picking the apples were 
 partly colored, or in the condition in which a large proportion 
 of the commercial apple crop is harvested. At the second picking 
 the fruit was more mature, with better color, but still hard. The 
 differences in ripeness are fairly represented in the fruit in Figs. 
 1 and 2. The percentages do not represent the relative suscepti- 
 bility of the different varieties to scald, as the fruit was grown 
 in different States and the observations were made at different 
 times. The percentages show the average amounts of scald in 
 fruit stored at temperatures of 31" to 32 F. and 34 to 36° F. 
 
 SCALD ON MATURE AND IMMATURE APPLES. 
 
 Variety. 
 
 Locality grown. 
 
 Mature, 
 
 well 
 colored. 
 
 Immature, 
 
 partly 
 
 colored. 
 
 Baldwin 
 
 Ben Davis 
 
 Do 
 
 Rhode Island Greening.. 
 
 Winesap 
 
 Yellow Newtown 
 
 York Imperial 
 
 Average.. 
 
 New York.. 
 
 Illinois 
 
 Virginia 
 
 New York . 
 
 Illinois 
 
 Virginia ... . 
 do 
 
 3-i 
 2.6 
 
 13- 1 
 
 25.4 
 0.2 
 
 2.3 
 
 2.0 
 
 ~oTo~ 
 
 Per cent, 
 29.2 
 
 15.8 
 41.6 
 
 43-4 
 
 3i-8 
 
 9.4 
 
 18.2 
 
 27.0 
 
APPLES IN COLD STORAGE 311 
 
 In the practical handling of orchards the fundamental cor- 
 rective of scald lies in practicing those cultural and harvesting 
 methods that develop maturity and a highly colored fruit. These 
 methods have already been briefly discussed. The picking of the 
 fruit when too green, dense-headed trees that shut out the sun- 
 light, heavy soil, a location or season that causes the fruit to 
 mature later than usual and makes it still green at picking time — 
 these are among the conditions that make it particularly suscep- 
 tible to the development of the scald. 
 
 After the fruit is harvested its susceptibility increases as its 
 ripening progresses. Early in the storage season the scald may 
 not appear, but later the same variety may have developed enough 
 to injure its commercial value. The amount of scald at different 
 periods of the season on the same lot of Baldwin apples stored at 
 32 F. is brought out in the following statement : 
 
 AMOUNT OF SCALD AT DIFFERENT PERIODS OF STORAGE SEASON. 
 
 Per cent. 
 
 January 29, 1903 
 
 February 21, 1903 
 
 March 20, 1903 20 
 
 April 21, 1903 23 
 
 It should be the aim of the apple storer to remove the fruit 
 from storage before a variety normally begins to scald, and to 
 hold until late in the season only those sorts that do not scald. 
 
 INFLUENCE OF TEMPERATURE ON SCALD. 
 
 The temperature that checks the ripening to the greatest 
 degree also retards the appearance of the scald. In some of the 
 apple-growing sections it is quite generally believed that bad 
 scalding varieties should be stored in a temperature of 36 to 
 38 ° F., and that a temperature as low as 32 ° F. hastens its devel- 
 opment. The investigations of the Department have shown that 
 this impression is not well founded, but on the contrary they indi- 
 cate that the scald develops more freely in the higher tempera- 
 ture. To illustrate, one lot of York Imperial apples, a variety 
 which is greatly affected by scald, had developed 16.9 per cent 
 of this trouble by January 22, 1902, in a temperature of 36° F., 
 while a similar lot stored in a temperature of 32° F. developed 
 only 3.4 per cent. One lot of Rhode Island Greening apples by 
 February 3, 1903, had developed 21 per cent in 32 F., while a 
 
312 
 
 PRACTICAL COLD STORAGE 
 
 similar lot, in 36 F., showed 55 per cent. In the case of the 
 Sutton apple, investigation showed 25 per cent of scald in apples 
 stored at 32 , and 42 per cent when stored at 36 F. 
 
 If the fruit is stored as soon as it is picked, or is shipped in 
 refrigerator cars or in cool weather, and if it has been handled 
 in the most careful manner, the ripening may not proceed much 
 more rapidly and the scald may not develop more freely in the 
 higher than in the lower storage temperature. 
 
 When the fruit is removed from the storage house the scald 
 sometimes develops rapidly. Its appearance at this time seems 
 to depend on at least two important conditions — the ripeness of 
 the fruit and the temperature into which it is taken. Late in the 
 storage season the scald is most severe ; first, because the fruit 
 is more mature, and, second, for the reason that the warm weather 
 prevailing at that season develops it quickly. [It is suggested 
 that scald develops much more rapidly in case the fruit is allowed 
 to rise in temperature suddenly. When removed from storage, 
 apples, as well as other goods, should not be exposed at once to 
 comparatively high temperatures. — Author.] 
 
 The development of the scald also seems to be influenced by 
 the amount of humidity in the air. So long as the fruit remains 
 cold and condenses the moisture of the atmosphere upon it the 
 scald is retarded more than in a dry air of the same temperature. 
 
 The accompanying table shows the rapidity with which the 
 scald may develop on Baldwin apples when portions of the same 
 barrel are removed to different temperatures. There was no in- 
 crease in the amount of scald in any of the lots after nine days. 
 
 SCALD DEVELOPED IN DIFFERENT TEMPERATURES WHEN 
 APPLES WERE REMOVED FROM STORAGE. 
 
 Variety. 
 
 Date re- 
 moved from 
 storage. 
 
 Date in- 
 spected. 
 
 Per cent of scald. 
 
 44° F - 
 
 48° F. 
 
 61° F. 
 
 67° F. 
 
 Baldwin ... . . 
 
 do 
 
 do 
 
 do 
 
 do 
 
 1903 
 
 Jan. 29 
 
 do 
 
 do 
 
 do .. 
 
 ...do... 
 
 1903. 
 Jan. 29 
 Feb. 3 
 Feb. 4 
 Feb. 6 
 Feb. 7 
 
 
 
 
 4 
 4 
 4 
 
 
 
 6 
 n 
 25 
 25 
 
 
 
 21 
 21 
 40 
 41 
 
 O 
 
 22 
 
 37 
 63 
 63 
 
APPLES IN COLD STORAGE 
 
 313 
 
 FIG. 8.— WAGENER APPLE — SCALD DEVELOPED AFTER REMOVAL FROM STORAGE. 
 
314 PRACTICAL COLD STORAGE 
 
 The upper specimen in Fig. 8 shows the average condition 
 of a lot of Wagener apples in March, 1903, having been picked 
 in October, 1902, and stored at a temperature of 32" F. There 
 was no scald on the apples when removed. Forty-eight hours 
 later, after the fruit had been in a temperature of 70° F., the 
 light-colored portion of the apples was badly scalded, as shown 
 in the lower apple. Late in the storage season the fruit is more 
 susceptible to scald, and a high temperature when the fruit is 
 removed from the storage house may develop it quickly. 
 
 It should be the aim of the fruit storer not only to remove 
 the fruit before the scald normally appears, but to hold the ap- 
 ples after removal in the lowest possible temperature to prevent 
 its rapid development. 
 
 INFLUENCE ON SCALD OF DELAYTNG THE STORAGE OF THE 
 FRUIT AFTER IT IS PICKED. 
 
 The ripening of the fruit between the time of picking and its 
 storage increases its susceptibility to scald. 
 
 When the picking and shipping seasons are cool and dry it 
 may be possible to delay the storage of the fruit for some time 
 without injury so far as the predisposition to scald is concerned. 
 In the investigations of 1901-2 in western New York there was 
 no apparent injury from delaying the storage, but the weather 
 conditions at this period were ideal for apple handling. 
 
 The scald develops seriously when the storage of the fruit 
 is delayed in hot weather. Detentions in the orchard, in transit 
 in closed cars, in unloading at the terminal, or in the warehouse 
 cause the fruit to ripen quickly and favor the rapid growth of 
 the fruit rots, as they bring the fruit much nearer the end of its 
 life before it enters the storage room. Under these circumstances 
 the fruit may scald badly, mellow early in the season,- and rot, 
 and no storage treatment can correct the abuses to which it has 
 been subjected. 
 
 The following table brings out the injury that may be caused 
 by delaying the storage of the fruit in hot weather. The mean 
 average temperature between September 15 and 30, 1902, was 
 about 62 u F. and the mean average humidity about 84° Fruit 
 picked from the same trees on October 4, 1902, and stored two 
 weeks later, when the temperature was about 53 ° F. and the 
 humidity about 8o c , was not injured by the delay. The apples 
 
APPLES IN COLD STORAGE 
 
 315 
 
 referred to were grown in eastern New York and stored in Bos- 
 ton, and these records were taken the following February. 
 
 SCALD ON IMMEDIATE- AND DELAYED-STORED APPLES IN 
 FEBRUARY, I903. 
 
 Variety. 
 
 Rhode Island Green 
 
 ™g 
 
 Sutton 
 
 Tompkins King 
 
 Picked 
 
 Sept. 12, 
 
 1902, stored 
 
 Sept. 15. 
 
 Picked 
 Sept. 15, 
 
 stored 
 Sept. 30. 
 
 38 
 33 
 
 15 
 
 Picked Oct. 4, 
 stored Oct. 9. 
 
 Per cent. 
 
 (No record) 
 o 
 o 
 
 Picked Oct. 5, 
 stored Oct. 19. 
 
 Per cent. 
 
 (No record) 
 o 
 o 
 
 INFLUENCE OF A FRUIT WRAPPER ON SCALD. 
 
 The influence of the various fruit wrappers mentioned has 
 been studied in connection with the scald. Sometimes the wrap- 
 pers retard it to a slight degree, but often the trouble is as severe 
 or more severe in the wrapped fruit. Whenever the wrapper has 
 been effective in retarding the scald the wax or paraffin paper 
 was most useful. 
 
 The following table gives a comparison between wrapped 
 and unwrapped fruit, and emphasizes the fact that for commer- 
 cial purposes the wrapper should not be looked upon as an affect- 
 ive means of preventing the trouble. The records of each variety 
 are based on 8 to 32 bushels of fruit, one-half of which was 
 wrapped. 
 
 SCALD ON WRAPPED AND UNWRAPPED FRUIT. 
 
 Variety. 
 
 Locality. 
 
 Wrapped. 
 
 Unwrapped. 
 
 
 New York 
 
 Illinois 
 
 Virginia 
 
 Illinois 
 
 Per cent. 
 12.4 
 
 5-8 
 27.1 
 47.8 
 22.9 
 
 32-3 
 
 30.0 
 
 17.9 
 
 9.6 
 
 Per cent. 
 19.9 
 
 
 2.8 
 
 Do 
 
 28.7 
 
 
 4°-3 
 
 
 do 
 
 20.1 
 
 Rhode Island Greening. 
 
 New York 
 
 Virginia 
 
 Illinois 
 
 37-6 
 47.0 
 
 Do 
 
 10.2 
 
 
 Virginia 
 
 12.9 
 
 
 
 
316 PRACTICAL COLD STORAGE 
 
 VARIETIES MOST SUSCEPTIBLE TO SCALD. 
 
 All varieties are not equally susceptible to scald, and there 
 appears to be a wide difference in the amount developed in the 
 same variety grown in different parts of the country. While the 
 light-colored portion of an apple is more susceptible than the 
 more highly-colored part, it does not follow that green or yellow 
 varieties are more susceptible than red ones. Of the important 
 commercial sorts used in the investigations of the Department 
 of Agriculture, the varieties named in the subjoined list have 
 proved most susceptible. The season when the scald is most 
 likely to appear is given with each kind, though there may be a 
 wide variation from year to year. The time of the appearance 
 of the scald is influenced to an important degree by the method 
 of handling the fruit and by its degree of ripeness. 
 
 Arctic, serious, midwinter. Smith, Cider, serious, early 
 Arkansas, often serious, after winter. 
 
 midwinter. Stayman Winesap, sometimes 
 Baldwin, often serious, late in serious, midwinter. 
 
 season. Wagener, serious, midwinter. 
 
 Ben Davis, often serious, late White Doctor, serious, mid- 
 
 in season. winter. 
 
 Gilpin, often serious, late in White Pippin, slight, late in 
 
 season. season. 
 
 Green Newtown, slight, late in Willow, slight, late in season. 
 
 season. Winesap, often serious, late in 
 Grimes, serious, early winter. season. 
 
 Huntsman, serious, midwinter. Yellow Newtown, slight, late 
 Lankford, serious, midwinter. in season. 
 
 Nero, serious, midwinter. York Imperial, serious, mid- 
 Paragon, sometimes serious, winter. 
 
 midwinter. York Stripe, slight, late in 
 Ralls, slight, midwinter. season. 
 
 Rhode Island Greeninp, se- 
 rious, midwinter. 
 
 COMPARISON OF VARIETIES IN COLD STORAGE. 
 
 A large number of varieties of apples grown under various 
 conditions were under observation by the Department of Agri- 
 culture. It was the purpose of the investigation to determine the 
 keeping quality of the varieties during the commercial apple- 
 storage season, which usually terminates May i, or shortly after- 
 wards. It was not attempted to carry the varieties longer than 
 the apple-storage season, though many of them when finally 
 taken from the storage house were in prime condition and would 
 have kept well for a longer period. 
 
APPLES IN COLD STORAGE 317 
 
 There is a wide difference in the keeping quality of the same 
 variety when it is grown in different parts of the country. There 
 is a striking variation also in the behavior of the same variety 
 when it is grown in the same locality under different cultural 
 conditions and in different seasons. There may be a permanent 
 difference in the keeping quality of the apples of one region when 
 compared with those of another, but it is not safe to draw general 
 conclusions in this regard until the varieties of each have been 
 under observation during several seasons and have been grown 
 under different cultural conditions. No attempt was made in the 
 investigations to draw comparisons between the keeping quality 
 of the same sort from different places. The behavior of each lot 
 is given in commercial terms rather than in detailed notes, so 
 that the grower or apple handler may know something of the 
 storage value of a variety under the conditions in which it has 
 been observed by the Department of Agriculture. The fruit was 
 stored in bushel boxes in a temperature of 30° to 32° F. 
 
 OUTLINE OF CULTURAL CONDITIONS. 
 
 A statement follows, summarizing the orchard conditions in 
 which the fruit used in the experiments of the Department of 
 Agriculture was grown. In the variety catalogue each sort is 
 credited to the grower from whom it was received : 
 
 Boggs, A. H., Waynesville, Haywood County, N. C, 1902: 
 
 Clay loam, stony, with clay subsoil ; altitude, 3,000 to 3,5°o feet ; trees, 
 12 to 15 vears old; thoroughly sprayed; sod culture. 
 Bradley, F. L. ~ Barker, Niagara County. N. Y., 1902 : 
 
 Sandy loam, with clay subsoil; altitude, about 300 feet; sprayed; 
 tillage; on Lake Ontario. 
 Brown, J. E., Wilson, Niagara County. N. Y., 1901 : 
 
 Sandy loam, with sandy loam subsoil ;. altitude, about 300 feet ; trees, 
 40 years old ; sprayed ; tillage ; on Lake Ontario. 
 Derby, S.' H., Woodside, Kent County, Del., 1902: 
 
 Sandy, with clay-loam subsoil; altitude, about 60 feet; trees, 10 to 
 25 years ; thorough spraying and tillage ; annual use of clover cover 
 crops ; trees unusually vigorous. 
 ©odd, G. J., Greenwood, Jackson County, Mo., 1902: 
 
 Black prairie soil, with clay subsoil; altitude, 1,000 feet; trees 18 
 years old, except Ben Davis, 11 years; sprayed; sod culture after 
 trees were 7 years old. 
 Dunlap. H. M., Southern Illinois, 1901 : 
 
 Fruit from orchards in southern Illinois ; data not available. 
 Flournoy W. T.. Marionville, Lawrence County, Mo., 1902: 
 
 Heavy clay, with rocky limestone clay subsoil; altitude, about 1,250 
 feet; age of trees, 7 years; spraying and tillage. 
 
318 PRACTICAL COLD STORAGE 
 
 Gilbert, Z. A., Farmington, Franklin County, Me., 1902 : 
 
 Granite drift, with' so-called pin-gravel subsoil ; altitude, about 365 
 feet; age of trees, 20 years; no spraying or tillage; land top dressed 
 with wood ashes. 
 Hitchings, Grant G., South Onondaga, Onondaga County, N. Y., 1901 
 and 1902: 
 Clay loam, stony, with heavy red clay or gravel-and-clay subsoil ; 
 altitude, about 1,200 feet; age of trees, 4 "to 100 years; sprayed; 
 sod culture, with grass left in orchard for mulch. 
 Hutchins, Edward, Fennville, Allegan County, Mich., 1902 : 
 
 Clay loam ; altitude, 700 feet ; age of trees, about 35 years ; sprayed ; 
 tillage. 
 Kansas Agricultural Experiment Station, Manhattan, Riley County, 
 Kans., 1901 : 
 Clay loam, with clay subsoil; altitude, about 1,000 feet; age of trees, 
 
 10 years ; spraying and tillage. 
 Orchards near the experiment station, 1901 : Soil and altitude same 
 as above ; no spraying or tillage ; fruit received through Kansas Sta- 
 tion. 
 Lupton, S. L., Winchester, Frederick County, Va., 1901 and 1902 : 
 
 Clay loam, with red clay subsoil ; altitude, 750 feet ; age of trees, 8 
 years; sprayed'; sod culture, grass cropped. 
 Maine Agricultural Experiment Station, Orono, Penobscot County, 
 Me., 1901 : 
 Sandy loam, with clay subsoil; altitude, about 150 feet; age of trees, 
 
 10 to 12 years ; sprayed ; clean culture, with fall cover crop of rye. 
 Mann, W. T., Barker, Niagara County, N. Y., 1902: 
 
 Clay loam, with clay subsoil, and sandy loam with sandy subsoil; al- 
 titude, about 300 feet ; age of trees, about 30 years ; sprayed thor- 
 oughly; tillage; clover cover crops. 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass., 1902 : 
 Gravelly soil, with clay subsoil, moist; altitude, 250 feet; age of trees, 
 30 years; sprayed; tillage. 
 Michigan Agricultural College Experiment Substation, South Haven, 
 Van Buren County, Mich., 1902 : 
 Rich, sandy loam, with clay subsoil ; age of trees, 9 to 14 years ; al- 
 titude, 625 feet ; on Lake Michigan ; spraying and cultivation thor- 
 ough. 
 Miller, W. S., Gerrardstown, Berkeley County, W. Va., 1901 : 
 
 Soapstone, derived from Romney shale, clay subsoil; altitude, 700 
 feet ; age of trees, 12 to 26 years ; sprayed and cultivated. 
 New York State Experiment Station, Geneva, Ontario County, N. Y., 
 1901 and 1902 : 
 Rather heavy clay loam, with heavy clay subsoil ; altitude, about 600 
 feet; age of trees, generally from 15 to 25 years; sprayed and cul- 
 tivated with cover crops. 
 Ozark Orchard Company, Goodman, McDonald County, Mo., 1901 and 
 1902: 
 Flinty clay, with clay, shale, or gravel subsoil; altitude, 1,250 feet; 
 age of trees, 6 years ; sprayed and cultivated. 
 Powell, George T., Ghent, Columbia County, N. Y., 1902 : 
 
 Gravelly loam, with clay-gravelly subsoil ; altitude, about 400 feet ; 
 age of trees, 35 to 45 years, except Tompkins King and Lady Sweet 
 
 11 years, Sutton 8 years, Hubbardston 5 years; spraying and culti- 
 vation thorough, with clover cover crops annually. 
 
APPLES IN COLD STORAGE 319 
 
 Reeks, M., Douglas, Allegan County, Mich., 1902: 
 
 Clay loam, with' clay subsoil several feet below surface; age of trees, 
 12 to 15 years; sprayed and cultivated; altitude, 650 to 675 feet. 
 Spohr, G. E., Manhattan, Riley County, Kans., igoi : 
 
 Sandy loam, with sandy subsoil; altitude, about 950 feet; age of 
 trees, about 20 years, except Jonathan 10 years ; no tillage or spray- 
 ing; fruit received through Kansas Experiment Station. 
 Speakman, F. H., Neosho, Newton County, Mo., 1901 : 
 
 Clay loam, gravelly and stony, with red clay subsoil, mixed with flint 
 stone ; altitude, 1,100 feet ; age of trees, 12 years ; sprayed and culti- 
 vated. 
 Taylor, J. F., Douglas, Allegan County, Mich., 1902: 
 
 Sandy loam, with clay subsoil is feet below surface; altitude, 650 to 
 675 feet; from 8-year top grafts on stocks of "Cannon Redstreak," 
 25 years old; sprayed and cultivated. 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, -.Va., J901 : 
 Rather heavy, mostly of limestone origin, with some sand, not stiff, 
 subsoil of same nature but heavier; altitude, 2,170 feet; age of trees, 
 12 years ; sprayed but not cultivated in igoi. 
 Wellhouse, F., Tonganoxie, Leavenworth County, Kans., 1901 : 
 
 Rich prairie loam, with red clay subsoil, with some sand; altitude, 
 about 900 feet; age of trees, 7 years; not sprayed but cultivated. 
 
 VARIETY CATALOGUE. 
 
 Bulletin No. 48 gives a very complete list of varieties used 
 in the investigations, with comparative keeping qualities in cold 
 storage. Prof. Powell has at the request of the ruthor selected 
 some of the most important as follows : 
 
 Arkansas. Synonyms: Blacktwig, Mammoth Blacktwig. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Hard, No. 
 
 1; picked October 12, igoi, stored October 18; May 1, 1902, bright, 
 
 firm, and sound, no rot or scald. 
 Ozark Orchard Company, Goodman, McDonald County, Mo. : No. 
 
 2 stock; badly affected with "flyspeck" fungus; picked October 11, 
 
 1902, stored October 28; March 10, 1903, shriveled, considerable 
 
 rot, no scald. 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 
 County, Va. : Small, sound ; picked September 26, 1901, stored 
 
 October 6; May 1, 1902, firm, no decay/ nearly all slightly scalded 
 
 on light side. 
 Baldwin. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : Mixed grade, dull, 
 
 scabby; picked October 9, 1902, stored October 15; May 1, 1903, 
 
 firm, no scald or rot. 
 J. E. Brown, Wilson, Niagara County, N. Y. : No. 1, fair color ; 
 
 picked October 8, 1901, stored October 15 ; May 1, 1902, firm, no 
 
 rot, slight scald. 
 H. M. Dunlap, Southern Illinois : Firm, somewhat wormy ; picked 
 
 October 8, igoi, stored' October 10 ; March 18, 1902, commencing 
 
 to scald and decay. 
 Z. A. Gilbert, Farmington, Franklin County, Me. : Medium sized, 
 
 dull colored; date of picking undetermined, stored November 10, 
 
 1902; May 1, ig03, firm, no decay or scald. 
 
320 PRACTICAL COLD STORAGE 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Large, 
 dark red, No. I ; trees 12 years old ; picked October 1, 1902, stored 
 October 4; May 1, 1903, firm, no scald or rot. 
 
 W. T. Mann, Barker, Niagara County, N. Y. : Hard, finely colored, 
 No. 1; picked October 16, 1902, stored October 18; May 1, 1903, 
 hard, no scald or rot. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Dull greenish red, No. 1 ; picked Oc- 
 tober 11, 1902. stored October 15; May I, 1903, no scald or rot, 
 hard. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, light colored, small ; picked October 12, 1902, stored October 
 15; May 1, 1903, hard and sound; similar in 1901. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Bright, well colored, 
 No. 1; picked October 16, 1902, stored October 19; May I, 1903, 
 firm condition, no scald or decay. 
 
 Virginia Experiment Station, Blacksburg, Montgomery County, Va. : 
 Firm, light colored, No. 1 ; picked September 26, 1901, stored 
 October 6; May 1, 1902, semi-firm, no scald or decay; kept unus- 
 ually well for a northern variety and was of much better grade and 
 color than most of the other sorts from same source. 
 Ben Davis. 
 
 G. J. Dodd, Greenwood, Jackson County, Mo. : Hard, well colored, 
 No. 1; picked October 1, 1902, stored October 4; March 10, 1903, 
 in good market condition ; scald and rot slight. 
 
 H. M. Dunlap. Southern Illinois : No. 1 stock ; picked October 8, 
 
 1901, stored October 10; March 18, 1902, in fair market condition; 
 somewhat injured by scald and decay. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Hard, 
 medium sized, highly colored; trees 12 years old; picked October 
 22, 1901, stored October 26; May 1, 1902, firm and sound, no scald. 
 
 S. L. Lupton, Winchester, Frederick County, Va. : Firm, light col- 
 ored, wormy; picked October 4, 1901, stored October 12; March 27, 
 
 1902, considerable scald, decay slight. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Small and hard ; picked October 13, 
 1902, stored October 15 ; May 1, 1903, firm and sound. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Firm, well 
 colored, No. 1; picked October 2, 1901, stored October 18; May I, 
 1902, firm, no rot or scald. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Small, hard, light colored ; date of picking undetermined, stored 
 November 12, 1902; May I, 1903, semi-firm, no scald or decay; 
 similar in 1902. 
 
 Ozark Orchard Company, Goodman, McDonald County, Mo. ; Me- 
 dium to very large, well colored ; picked October 10, 1902, stored 
 October 28; March 10, 1903, overripe, slightly wilted, considerable 
 decay. 
 
 F. H. Speakman, Neosho, Newton County, Mo. : Sound, well col- 
 ored, No. 1 ; picked October 24, 1901, stored October 28 ; March 20, 
 1902, in good market condition, slight rot and scald. 
 
 G. E. Spohr, Manhattan, Riley County, Kans. : Small, poorly colored ; 
 picked October 11, 1901, stored October 18; March 20, 1902, badly 
 shriveled, no decay or scald ; received through Kansas Experiment 
 Station. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Small, well colored, somewhat wormy ; picked Sep- 
 
APPLES IN COLD STORAGE 321 
 
 tember 26, 1901, stored October 8; May 1, 1902, semi-firm, no scald, 
 
 decay slight. 
 Black Gilliflower. Synonym: Gilliflower. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Light 
 
 colored, No. 1; trees about 100 years old; picked October 1, 1902, 
 
 stored October 4 ; May I, 1903, in prime commercial condition ; 
 
 similar for fruit picked in 1901. 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 
 Hampshire County, Mass. : Dull colored, No. 2 ; picked October 10, 
 
 1902, stored October 15; firm until January 1, 1903; decayed badly 
 
 after February 1. 
 G. T. Powell, Ghent, Columbia County, N. Y. : Well colored, No. 1 ; 
 
 picked October 16, 1902, stored October 19; February 1, 1903, badly 
 
 injured by rot. 
 Esopus. Synonyms : Esopus Spitzenburg; Spitzenburg. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : Scabby and poorly 
 colored; picked September 27, 1902, stored October 3; firm until 
 March 1, 1903. when the fruit commenced to decay around scab 
 spots. / ' v 
 
 G. G. Hitchings, South Onondaga, Onondaga' County, N. Y. . Dark 
 red, No. 1 ; trees about 100 years old ; picked October 1, 1902, stored 
 October 4; May 1, 1903, firm, no scald or decay.'-". 3 '' 
 
 New York State Experiment Station, Geneva, Ontario Gpunty, N. Y. . 
 No. 1; picked October 21, 1902, stored October 2?; May 1, 1903, 
 semi-firm, no decay or scald; in barrels should be sold April 1. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Well colored, No. 1 ; 
 picked October 16, 1902, stored October 19; in prime commercial 
 condition until April 1, 1903, after which the fruit began to mellow ; 
 no rot. 
 
 The flesh of this variety becomes mealy when overripe. 
 Fall Pippin. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Large, bright, No. 1 ; picked September 
 30, 1902, stored October 3; in firm condition until January 1, 1903, 
 when the fruit began to mellow. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Bright, No. 1 ; picked September 24, 1902, stored Septernber 29 ; 
 January 27, 1903, commencing to soften; fruit picked in 1901 kept 
 in good condition until January 10, 1902; may be held in boxes 
 till February 1. . 
 
 Fameuse. Synonym : Snow. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Well 
 colored, No. 1 ; trees 12 years old ; picked October 7, 1902, stored 
 October 12 ; in good commercial condition until March 15, 1903. 
 Fruit picked in 1901 kept in good condition until February 15, 1902. 
 
 Maine Agricultural Experiment Station, Orono, Penobscot County, 
 Me. : Slight colored, No. 1 ; ripe and somewhat bruised ; picked 
 October 7, 1902, stored October 24; January 23, 1903, in good condi- 
 tion for box storage, no scald or decay; March n, overripe and past 
 commercial condition. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. ; Bright, No. 1 ; picked September 30, 1902, 
 stored October 3 ; February 15, firm, no scald or rot ; commercial 
 limit about March 1. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, bright, No. 1 ; picked October 12, 1901, stored October 21 ; 
 January 31, 1902, mellow, no decay or scald; March 14, very ripe 
 but still sound. 
 (20 
 
322 PRACTICAL COLD STORAGE 
 
 Geo. T. Powell, Ghent, Columbia County, N. Y. . Bright, dark red, 
 No. i; picked October 13, 1902, stored October 19; February i, 
 1903, in prime commercial condition; March I, mellow, free from 
 scald and decay. 
 
 This variety reaches its commercial limit usually between January I 
 and March 1. 
 Gano. , 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. . 
 Small, hard, half colored; picked September 27, 1902, stored October 
 1; May 1, 1903, semi-firm, some rot; commercial limit April I. 
 
 Ozark Orchard Company, Goodman, McDonald County, Mo.: Very 
 large, highly colored; picked October 6, 1902, stored October 11; 
 March 11, 1903, overripe, 18 per cent decay; behavior similar in 
 1901-2; commercial limit February 1. 
 
 G. E. Spohr, Manhattan, Riley County, Kans. : Fruit large, well 
 colored, firmer than Ozark Orchard stock; picked October I, 1901, 
 stored October 6; March 20, 1902, firm, no decay or scald; would 
 probably have kept well a month longer; received through Kansas 
 .experiment Station. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va.: Well colored, firm, medium grade, considerable 
 codling-moth injury; picked September 26, 1901, stored October 16; 
 February 1, 1902, firm, with' no decay or scald, after which the 
 decay proceeded quite rapidly. 
 Golden Russet (N. Y.). 
 
 Maine Agricultural Experiment Station, Orono, Penobscot County, 
 Me. : Bright, hard, well russeted, No. I ; picked October 7, 1901, 
 stored October 24, igoi ; commercial limit May I, 1902, when stock 
 was hard, but mellowing began soon after. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, greenish russet. No. 1 ; picked October 24, 1902, stored No- 
 vember 15; May I, 1903, prime commercial condition, no decay; 
 similar in 1901-2, but by June 1 the fruit was mellow and decay 
 was setting in. 
 Grimes. Synonym : Grimes Golden. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Bright, No. I ; 
 picked September 20, 1901, stored October 16; mellow when stored; 
 began to deteriorate from decay after January I, 1902. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 No. 1, fair color; picked October 2, 1902, stored October 11; in 
 good condition commercially till February 1, 1903, when scald began 
 to develop; May 1, all scalded, semi-firm. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : No. 2; considerable codling-moth injury; picked Sep- 
 tember 26, 1901, stored October 16; limit December 1, 1901, after 
 which the fruit rotted badly ; scald began to develop in March, 1902 ; 
 probably injured by delay in storage. 
 Hubbardston. Synonyms : Hubbardston Nonesuch, Nonesuch. 
 
 Z. A. Gilbert, Farmington, Franklin County, Me. : Medium size, well 
 colored, mixed grade ; picking date undetermined, stored November 
 10, 1902; after December 1, 1902, the flesh softened throughout; 
 probably ripe when stored. 
 
 G. G. Hitch'ings, South Onondaga, Onondaga County, N. Y. : Large, 
 finely colored, considerable codling-moth injury; trees six years old; 
 picked October 5, 1902, stored October 12; prime commercial condi- 
 tion till February 1, 1903, when it began to shrivel ; April 1, soft. 
 
 Kansas Agricultural Experiment Station, Manhattan, Riley County, 
 Kans.: Medium to small, pale greenish red; picked October 8, 1901, 
 
APPLES IN COLD STORAGE 323 
 
 stored October 12; no softening and but little decay till April 1, 
 1902; fruit began to wilt after February 1, 1902. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Medium size, rather dull color ; picked 
 September 30, 1902, stored October 3 ; good commercial condition 
 for barrel storage till January 15, 1903 ; for box storage till February 
 x 5> 1903, after which the fruit mellowed and became mealy. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Small, hard, immature; picked October 4, 1902, stored October n; 
 prime condition May 1, 1903. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Very large, overgrown, 
 highly colored; picked October 4, 1902, stored October 9; firm until 
 December 1, 1902, after which the flesh grew mealy; January 15, 
 1903, all burst. 
 
 The flesh of this variety usually becomes mealy when it passes ma- 
 turity. 
 Jonathan. 
 
 G. J. Dodd, Greenwood, Jackson County, Mo. : Large, well colored, 
 firm, No. 1 ; picked September 22, 1902, stored September 24 ; com- 
 mercial limit probably February 1, 1903; March 11, 1903, 20 per cent 
 decayed. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Dark red, 
 bright, No. 1; trees 6 years old; picked October 5, 1901, stored Oc- 
 tober 12; in fine condition for barrel storage till April 1, 1902; 
 in good condition for box storage till June 1, 1902 ; no rot ; held well 
 for a long time after the fruit began to mellow. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Small, hard, considerably russeted; picked October 23, 1902, stored 
 October 27; May 1, 1903, hard, no rot, in prime commercial condi- 
 tion. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Medium sized, highly 
 colored ; picked October 16, 1902, stored October 19 ; in prime con- 
 dition for barrel storage till March I, 1903, when fruit began to mel- 
 low ; good condition for box storage till May 1 ; no rot or scald. 
 
 F. H. Speakman, Neosho, Newton County, Mo. : Large, highly col- 
 ored, No. 1; picked September 25, 1901, stored October 16; commer- 
 cial limit about February 1, 1902 ; when inspected March 20 the 
 fruit was mellow, with considerable decay; probably injured by de- 
 layed storage. 
 
 G. E. Spohr, Manhattan, Riley County, Kans. : Well colored, No. 1 ; 
 picked October 1, 1901, stored October 12; prime till February 1, 
 1902, when the fruit began to mellow ; received through Kansas Ex- 
 periment Station. 
 
 Lawver. Synonym: Delaware Red Winter. 
 
 Near Kansas Agricultural Experiment Station, Manhattan, Riley 
 County, Kans. : No. 1, rather dull red ; picked October 18, 1901, 
 stored October 21 ; good commercial condition March 20, 1902, and 
 apparently would have kept well throughout storage season; re- 
 ceived through Kansas Experiment Station. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Small, dull red, very hard ; picked Octo- 
 ber 11, 1902, stored October 15 ; May 1, 1903, hard, no scald or decay. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Large, bright, 
 dark red; picked October 11, 1901, stored October 16; good commer- 
 cial condition till March 15, 1902, when some of the apples began 
 to grow mealy; ripened unevenly; fruit overgrown. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Small, No. 2; considerably injured by codling moth; 
 
324 PRACTICAL COLD STORAGE 
 
 picked September 27, igoi, stored October 16; May I, 1902, hard and 
 in good condition ; a few decayed from bruising. 
 McIntosh. Synonym : Mcintosh Red. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Well 
 colored, No. 1 ; trees 12 years old ; picked October 7, igoi, stored 
 October 12 ; firm till January 15, 1902, after which it became mel- 
 low ; behavior similar in igo2-'o3. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Well colored, No. 1 ; picked October 12, igoi, stored October 21 ; 
 firm till January 15, 1902 ; good condition for box storage till March 
 1, 1902; in igo2-'o3 the fruit was firm a month longer. 
 Missouri. Synonym : Missouri Pippin. 
 
 F. H. .Speakman, Neosho, Newton County, Mo. : Large, highly col- 
 ored, No. 1; picked October 20, 1901, stored October 30; March 20, 
 1902, prime commercial condition, hard, no scald or decay; behavior 
 similar in 1903; commercial limit probably April 15 to May I. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : No. 2, scabby, considerable "flyspeck" fungus and 
 codling-moth injury; picked September 26, 1901, stored October 16; 
 firm till March 1, 1902, after which the fruit decayed badly. 
 Nero. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Large, not 
 well colored, immature; picked September 27, 1901, stored October 
 18; semi-firm when stored, in good condition till March 1, igo2, after 
 which the fruit softened and scald appeared. The delay in storing 
 undoubtedly shortened its storage period. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : No. 2, badly affected with codling moth, well colored ; 
 picked September 26, igoi, stored October 16 ; after February 1 the 
 fruit decayed considerably, though still firm ; scald appeared March 
 1, 1902. 
 
 This varietv is inclined to scald considerably after midwinter, unless 
 it is highly colored. 
 Northern Spy. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : Poor grade, light col- 
 ored ; picked October 9, ig02, stored October 15 ; May 1, ig03, firm 
 and in good condition ; no rot or scald. 
 
 A. A. Boggs, Waynesboro, Haywood County, N. C. : Large, dark red, 
 fancy; picked September 25. igo2, stored September 30; firm until 
 December 1, igo2, after which it decayed and softened rapidly. 
 
 G G. Hitchings, South Onondaga, Onondaga County, N. Y. : Large, 
 highly colored, fancy: trees 6 years old; picked October 22, 1901, 
 stored October 26; May 1, 1902, prime commercial condition, firm, 
 no scald, slight rot. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. ; 
 Well colored, No. 1; picked October 12, igoi, stored October 21; 
 May 1, 1902, firm, good commercial condition; picked November 3, 
 1902, stored November 15; light colored; in good condition till 
 March 1, 1903, after which the fruit decayed considerably. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Fancy, medium size, 
 dark red; picked October 16, 1902, stored October 19; May 1, 1903, 
 hard, no rot or decay, and in prime condition. 
 
 This variety is variable in its storage behavior. It is particularly sus- 
 ceptible to decay from blue mold, especially if bruised or delayed in 
 reaching storage. If well colored, picked, packed, and handled with 
 great care, and stored soon after picking, it may be carried in storage 
 as long as most winter varieties. 
 
APPLES IN COLD STORAGE 325 
 
 Pewaukee. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Well 
 colored, No. I ; trees 12 years old ; picked September 25, 1902, stored 
 September 29; May 1, 1903, firm, no rot or scald; fruit picked in 
 1901 kept in similar condition. 
 
 Maine ' Agricultural Experiment Station, Orono, Penobscot County, 
 Me. : Well colored, No. 1 ; picked October 7, 1902, stored October 
 24; May I, 1903, firm, decay slight, no scald. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Well colored, No. 1 ; picked October 
 8, 1902, stored October 12; May 1, 1903, firm, no scald or decay. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Well colored, 
 No. 1; picked October 8, 1901, stored October 18; May 1, 1902, 
 no scald or rot, firm. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Small, hard, and undercolored ; picked October 4, 1902, stored Octo- 
 ber 11; May 1, 1903, hard and green, no rot; fruit picked in 1901 
 kept in similar condition. 
 Ralls. Synonyms: Gcniton; Ralls Genet; Neverfail. 
 
 H. M. Dunlap, Southern Illinois: Small, imperfect, No. 2; picked Oc- 
 tober 9, 1901, stored October 15; January 17, 1902, firm, no decay 
 or scald; March 18, considerable decay and some scald. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Bright, clean, 
 No. 1; picked October 12, 1901, stored October 18; May 1, 1902, in 
 prime condition, no rot, or decay. 
 Red Canada. Synonyms : Canada Red; Steele's Red Winter. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Dark 
 red. No. 1 ; trees 6 years old ; dates of picking and storing undeter- 
 mined; in prime commercial condition until April 15, 1902, after 
 which date the fruit softened very quickly. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Immature, hard, No. I ; picked October 12, 1901, stored October 21 ; 
 May 1, 1902, firm, free from scald and decay. 
 Rhode Island. 
 
 F. L. Bradley. Barker, Niagara County, N. Y. : Firm, poorly graded ; 
 picked September 27, 1902, stored October 3 ; in commercial condi- 
 tion until March 15, 1903; May 1, injured by scald and decay. 
 
 J. E. Brown. Wilson, Niagara County, N. Y. : Not closely graded ; 
 many small and wormy fruits ; dates of picking and storing unde- 
 termined ; March 13, 1902, considerable scald, decay slight. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Bright, 
 dark green, No. 1 ; picked October 7, 1901, stored October 12 ; in 
 prime commercial condition until March 15, 1902, when the fruit 
 began to scald; May 1, firm but badly scalded; fruit picked in 1902 
 kept in similar condition. 
 
 Z. A. Gilbert, Farmington, Franklin County, Me. : Small, green, fair, 
 No. 1 ; picking date undetermined, stored November 14, 1902 ; May 
 I, 1903, in good commercial condition, free from scald and decay. 
 
 W. T. Mann, Barker, Niagara County, N. Y. : Bright, large, No. 1 ; 
 from heavy soil, very green ; from sandy soil, larger and yellower ; 
 picked October 11. 1902, stored October 13; May 1, 1903, in prime 
 commercial condition, no scald or decay. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass.: Dull green, No. 2. covered with "fly- 
 speck" fungus ; picked October 8, 1902, stored October 12 ; in com- 
 mercial condition until February 1, 1903, when the fruit began to 
 mellow and grow mealy, while very green outside. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 
326 PRACTICAL COLD STORAGE 
 
 Hard, sound, No. i; picked October 3, 1902, stored October 11; in 
 good commercial condition until March' 15, 1903, when the fruit 
 began to discolor and soften; fruit picked in 1901 kept 111 similar 
 condition until the middle of March, 1902, except for the appear- 
 ance of considerable scald. 
 
 George T. Powell, Ghent, Columbia County, N. Y. : Bright, well col- 
 ored, No. 1 ; picked October S, 1902, stored October 9; in good com- 
 mercial condition until May 1, 1903, when the scald began to ap- 
 pear. 
 Rome. 
 
 A. A. Boggs, Waynesville, Haywood County, N. C. : Large, dark 
 red, No. 1 ; picked September 15, 1902, stored September 26; March 
 1, 1903, firm, no scald or rot. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, light colored, No. 1 ; picked November 5, 1902, stored Novem- 
 ber 15; March 14, 1903, firm and sound; fruit picked in 1901 in 
 good commercial condition until May 1, 1902. 
 
 G. E. Spohr, Manhattan, Riley County, Kans. : Small, poorly colored ; 
 dates of picking and storing undetermined; March 20, 1902, consid- 
 erably shriveled, but free from rot and scald. 
 Roxbury. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : Sound, No. I ; picked 
 October 1, 1902, stored October 3 ; in good commercial condition 
 until May 1, 1903, aside from slight shriveling. 
 
 J. E. Brown, Wilson, Niagara County, N. Y. : No. 1 ; dates of picking 
 and storing undetermined; May I, 1902, in prime commercial condi- 
 tion, no shriveling, free from rot. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Medium sized, green, not well russeted ; 
 picked October 13. 1902, stored October 15; May 1, 1903, in good 
 commercial condition, no rot, some wilting. 
 
 W. S. Miller, Gcrrardstown, Berkeley County, W. Va. : No. 1 ; picked 
 November 4, 1901, stored November 12 ; May I, 1902, in prime com- 
 mercial condition, no wilting, free from rot. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 No. 1 ; picked October 24, 1902, stored November IS; May 1, 1903, 
 firm, no decay ; fruit picked in 1901 kept in similar condition. 
 
 George T. Powell, Ghent, Columbia County, N. Y. : Large, bright, 
 No. 1; picked October 16, 1902, stored October 19; in prime com- 
 mercial condition until May I, 1903. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Bright, No. 1 ; picked September 26, 1901, stored Oc- 
 tober ; May 1, 1902, in prime commercial condition, no wilting or 
 decay. 
 Stark. 
 
 Maine Agricultural Experiment Station, Orono, Penobscot County, 
 Me. : Large, well colored, bright, No. I ; picked October 7, 1901, 
 stored October 14; in prime commercial condition June 14, IQ02, 
 when removed from storage ; no scald or decay. 
 
 W. S. Miller, Gerrardstown, Berkeley County, W. Va. : Medium sized, 
 hard, fair colored, No. I ; picked October 2, 1901, stored October 8; 
 scald appeared after April 1, 1902, but fruit remained hard through- 
 out storage season. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, greenish red, No. 1 ; picked October 12, 1901, stored October 
 2\ ; hard with no scald or decay June 6, 1902, when removed from 
 storage. 
 
APPLES IN COLD STORAGE 327 
 
 Sutton. Synonym : Sutton Beauty. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass. : Medium sized, bright, dark red, No. I ; 
 picked October 8, 1902, stored October 12; firm for barrel storage 
 till February I, 1903 ; semi-firm and in good condition for box storage 
 till March 15, 1903, after which the fruit became mellow; no scald 
 or rot. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Medium sized, well colored, but rather dull, No. 1 ; picked October 
 21, 1902, stored October 27; firm for barrel storage till March 15, 
 1903 ; in good condition for box storage till April 15, 1903. 
 
 George T. Powell, Ghent, Columbia County, N. Y. : Fancy, large, 
 bright, dark red, from young trees ; picked October 6, 1902, stored 
 October 9; firm for barrel storage till February 1, 1903; semi-firm 
 and in good condition for box storage till March 1, after which the 
 flesh' softened and became mealy; no rot or scald. 
 
 This variety does not keep as long as Baldwin from the same or- 
 chards. 
 Tompkins King. Synonym : King. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : Well colored, No. 1 ; 
 picked October 9, 1902, stored October 15; in good commercial con- 
 dition until April 15, 1903, after which the fruit became mellow. 
 
 J. E. Brown, Wilson, Niagara County, N. Y. : Well colored, No. I ; 
 picked October 9, igoi, stored October 17; April 9, 1902, in good 
 commercial condition, decay slight, no scald ; commercial limit 
 May 1. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Large, 
 dark red, No. 1; trees 13 years old; picked October 5, 1901, stored 
 October 12; May 1, 1902, firm, no scald or rot; fruit picked in 1902 
 did not keep later than April 1, 1903. 
 
 Massachusetts Agricultural College Experiment Station, Amherst, 
 Hampshire County, Mass.: Medium sized, bright, half colored; 
 picked September 30, 1902, stored October 3 ; May 1, 1903, firm, no 
 rot or scald. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Small, hard, and green : picked September 23, 1902, stored Sep- 
 tember 27; May 1, 1903, green and hard, no decay or scald; fruit 
 picked in 1901 kept in sound condition until May I, 1902. 
 
 George T. Powell, Ghent, Columbia County, N. Y. : Very large, well 
 colored, No. 1, from young, rank-growing trees ; picked October 4, 
 1902, stored October 9; held well until January 1, 1903, when the 
 fruit began to soften and become mealy. 
 Wagener. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Fair, 
 No. 1; picked October 1, 1902, stored October 4; began scalding 
 February I, 1903, and by March 15 over 50 per cent of the fruit was 
 scalded ; commercial limit about February 1 on account of scald. 
 
 New York State Experiment Station, Geneva, Ontario County, N. Y. : 
 Hard, well colored, No. 1 ; picked November 5, 1902, stored Novem- 
 ber 15; March 14, firm, no decay or scald; May 1, 1903, soft, con- 
 siderable decay, no scald. 
 
 George T. Powell, Ghent, Columbia County, N. Y. : Half red, No. 1 ; 
 picked October 16, 1902, stored October 19 ; held in prime condition 
 until April I, 1903 ; no rot or scald ; after February 1 the light side 
 of the fruit would scald badly within forty-eight hours after removal 
 from storage. . 
 
 This variety unless highly colored is one of the worst to scald after 
 midwinter. 
 
328 PRACTICAL COLD STORAGE 
 
 Willow. Synonym : W illowtwig. 
 
 H. M. Dunlap, Savoy, 111. : No. i ; picked October 10, igoi, stored 
 
 October 15; March' 18, 1902, firm, slightly injured by scald and rot. 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 
 County, Va. : No. 2; cloudy and wormy; picked September 20, 1901; 
 
 date of storing undetermined; May 1, 1902, commencing to shrivel, 
 
 no scald, decay slight. 
 Winesap. 
 
 S. H. Derby, Woodside, Kent County, Del. : Hard, light red, No. 1 ; 
 
 picked September 29, 1902, stored September 31 ; May 1, 1903, hard, 
 
 no scald or rot ; in prime condition to carry tor many weeks. 
 G. J. Dodd, Greenwood, Jackson County, Mo. : Well colored, No. 1 ; 
 
 picked October 1, 1901, stored October 4; March 10, 1903, in prime 
 
 commercial condition, no rot, scald very slight; commercial limit, 
 
 on account of scald, March 15. 
 H. M. Dunlao. Savoy, Champaign County, 111. : No. 1 ; slightly 
 
 wormy; picked October 23, 1901, stored October 28; January 17, 
 
 1902, sound and in good commercial condition ; March 18, firm, no 
 scald, decay slight; fruit picked two weeks earlier and lighter in 
 color was one-third scalded. 
 
 G. G. Hitchings, South Onondaga, Onondaga County, N. Y. : Small, 
 hard, dark red ; trees six years old ; picked October 13, 1902, stored 
 October 16; kept well until March 1, 1903, when scald began to de- 
 velop. Fruit picked in 1901 kept in similar condition. Hard 
 throughout storage season. 
 
 Near Kansas Agricultural College, Manhattan, Riley County, Kans. : 
 Hard, small, poorly colored; picked October 4, 1901, stored Octobei 
 10; March 20, 1902, hard, no rot or scald; commercial limit proba- 
 bly April 15. 
 
 S. L. Lupton, Winchester, Frederick County, Va. : Fair, No. I ; color 
 fair; somewhat cloudy and wormy; picked October 18, 1901, stored 
 October 22 ; March 27, 1902, firm, decay slight, one-third scalded. 
 
 Ozark Orchard Company, Goodman, McDonald County, Mo. : Well 
 colored, No. 1 ; picked October 8, 1902, stored October 13 ; March 10, 
 
 1903, firm, no scald, 20 per cent of rot; commercial limit February 1. 
 New York State Experiment Station, Geneva, Ontario County, N. Y. . 
 
 Hard, small, light colored ; picked October 12, 1901, stored October 
 21 ; March 14, 1902, firm, no decay or scald; April 30, about 75 per 
 cent of scald, no decay, hard. 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Medium sized, fair, No. 1 ; picked September 30, 1901, 
 stored October 17; May 1, 1902, firm, no scald, very slight decay, 
 and wilting. 
 Yellow Bellflower. Synonym : Bellfloiver. 
 
 F. L. Bradley, Barker, Niagara County, N. Y. : No. 2 grade, scabby 
 and russeted ; picked October 9, 1902, stored October 15 ; May 1, 
 1903, semi-firm and free from scald and decay. 
 
 G. T. Powell, Ghent, Columbia County, N. Y. : Highlv colored, No. 
 1; picked October 9, 1902, stored October 13; April 1, 1903, begin- 
 ning to mellow, no scald or rot. 
 
 Yellow Newtown. Synonyms: Albemarle: Newtown Pippin; Yellow 
 Newtown Pippin. 
 S. L. Lupton, Winchester, Frederick County, Va. : Medium sized, 
 well colored, wormy; picked October 7, 1901, stored October 10; 
 May 1, 1902, firm, decay and scald slight; commercial lirhit April 1! 
 W. S. Miller. Gerrardstown, Berkeley County, W. Va. : Bright, No. 
 1; picked October 10, 1901, stored October 18; June 14, 1902, in 
 prime commercial condition, no scald or decay. 
 
APPLES IN COLD STORAGE 329 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Somewhat wormy; picked September 27, 1901, stored 
 October 17 ; June 14, 1902, firm, color and quality good ; decay and 
 scald slight ; commercial limit May 15. 
 York Imperial. Synonym : Johnson's Fine Winter. 
 
 A. A. Boggs, Waynesville, Haywood County, N. C. : Hard, bright, 
 half colored, No. 1 ; picked September 18, 1902, stored September 25 ; 
 May 1, 1903, firm, no scald or decay. 
 
 S. L. Lupton, Winchester, Frederick County, Va. ; Medium grade, 
 greenish red, considerable codling moth; picked October 4, 1901, 
 stored October 12 ; scalded badly after January 1, 1902 ; fruit picked 
 October 23, dark red, began to scald after February 1, but did not 
 scald as badly as the early picked fruit; the commercial limit of the 
 dark fruit was six weeks longer. 
 
 New York Mate Experiment Station, Geneva, Ontario County, N. Y. : 
 Medium to small, light colored, very hard ; picked October 1-12, 
 
 1901, stored October 21 ; began to scald February 15, 1902, and a 
 month later three-fourths of the fruit was lightly scalded on the 
 green side ; remained firm throughout season ; commercial limit 
 February 15 to March 15. 
 
 Ozark Orchard Company, Goodman, McDonald County, Mo. : Large, 
 well colored, No. 1 ; picked October 8, 1902, stored October 13 ; 
 March jo, 1903, overripe, somewhat shriveled, one-third of the fruit 
 deca5 r ed, no scald; commercial limit January 15. 
 
 Virginia Agricultural Experiment Station, Blacksburg, Montgomery 
 County, Va. : Bright, well colored, No. 1 ; picked September 26, 1901, 
 stored October 17 ; January 24, 1902, firm, no decay, one-third of the 
 fruit slightly scalded ; commercial limit January I. 
 
 F. Wellh'ouse, Tonganoxie, Leavenworth County, Knns. : Two-thirds 
 colored ; picked October 8, 1901, stored October 12 ; March 20, 
 
 1902, slightly wilted, some decay, one-fourth of the fruit scalded ; 
 commercial limit February 15. 
 
 SUMMARY. 
 
 An apple should usually be fully grown and 'highly colored 
 when picked to give it the best keeping and commercial quali- 
 ties. When harvested in that condition it is less liable to scald, 
 is of better quality, more attractive in appearance and is worth 
 more money than when it is picked in greener condition. 
 
 An exception to the statement appears to exist in the case 
 of certain varieties when borne on rapidly growing young trees. 
 Such fruit is likely to be overgrown, and under these conditions 
 the apples may need picking before they reach their highest 
 color and fullest development. 
 
 Uniform color may be secured by pruning to let the sunlight 
 into the tree, by cultural conditions that check the growth of 
 the tree early in the fall, and by picking over the trees several 
 times, taking the apples in each picking that have attained the 
 desired degree of color and size. 
 
330 PRACTICAL COLD STORAGE 
 
 Apples should be stored as quickly as possible after picking. 
 The fruit ripens rapidly after it is picked, especially if the 
 weather is hot. The ripening which takes place between the 
 time of picking and storage shortens the life of the fruit in the 
 storage house. The fruit rots multiply rapidly if storage is 
 delayed and the fruit becomes heated. If the weather is cool 
 enough to prevent after-ripening, a delay in the storage of the 
 fruit may not be injurious to its keeping quality. 
 
 A temperature of 31" to 32 ° F. retards the ripening processes 
 more than a higher temperature. This temperature favors the 
 fruit in other respects. 
 
 A fruit wrapper retards the ripening of the fruit; it pre- 
 serves its bright color, checks transpiration and lessens wilting, 
 protects the apple from bruising, and prevents the spread of 
 fungous spores from decayed to perfect fruit. In commercial 
 practice the use of the wrapper may be advisable on the finest 
 grades of fruit that are placed on the market in small packages. 
 
 Apples that are to be stored for any length of time should 
 be placed in closed packages. Fruit in ventilated packages is 
 likely to be injured by wilting. Delicate fruit and fruit on which 
 the ripening processes need to be quickly checked should be 
 stored in the smallest practicable commercial package. The 
 fruit cools more rapidly in small packages. 
 
 Apples should be in a firm condition when taken from 
 storage, and kept, in a low temperature after removal. A high 
 temperature hastens decomposition and develops scald. 
 
 The best fruit keeps best in storage. When the crop is 
 light it may pay to store fruit of inferior grade, but in this case 
 the grades should be established when the fruit is picked. The 
 bruising of the fruit leads to premature decay. 
 
 The scald is probably caused by a ferment or enzyme which 
 works most rapidly in a high temperature. Fruit picked before 
 it is mature is more susceptible than highly colored, well-devel- 
 oped fruit. 
 
 After the fruit is picked its susceptibility to scald increases 
 as the ripening progresses. 
 
 The ripening that takes place between the picking of the 
 fruit and its storage makes it more susceptible to scald, and de- 
 lay in storing the fruit in hot weather is particularly injurious. 
 
APPLES IN COLD STORAGE 331 
 
 The fruit scalds least in a low temperature. On removal 
 from storage late in the season the scald develops quickly, es- 
 pecially when the temperature is high. 
 
 It does not appear practicable to treat the fruit with gases 
 or other substances to prevent the scald. 
 
 From the practical standpoint the scald may be prevented 
 to the greatest extent by producing highly colored, well-devel- 
 oped fruit, by storing it as soon as it is picked in a temperature 
 of 31" to 32° F., by removing it from storage while it is still 
 free from scald, and by holding it after removal in the coolest 
 possible temperature. 
 
 A variety may differ in its keeping quality when grown in 
 different parts of the country. It may vary when grown in the 
 same locality under different cultural conditions. The character 
 of the soil, the age of the trees, the care of the orchard — all of 
 these factors modify the growth of the tree and fruit and may 
 affect the keeping quality of the apples. The character of the 
 season also modifies the keeping power of the fruit. 
 
332 PRACTICAL COLD STORAGE 
 
 CHAPTER XV. 
 COLD STORAGE OF THE PEAR AND PEACH.* 
 
 INFLUENCE OF COLD STORAGE ON THE PEAR INDUSTRY. 
 
 Before the advent of the cold-storage business the supply of 
 summer pears frequently exceeded the demand. This condition 
 of the markets, which were demoralized in hot, humid seasons, 
 pertained especially to the early varieties, like the Bartlett, which 
 ripen in hot weather and need to be sold in a short time to pre- 
 vent heavy losses from rapid decay. The introduction of the 
 refrigerator car and of the cold storage warehouse, together with 
 the rapid growth of the canning industry, has done much to im- 
 prove the pear situation by artificially establishing a well regulated 
 and more uniform supply of fruit throughout a longer period of 
 time. The pear acreage of the country has more than doubled 
 within a decade, and is enlarging the relative importance of 
 cold storage to the pear-growing business, though a large part 
 of the increase, especially in California, along the Atlantic coast 
 from New Jersey southward, in Texas, and in the central west, 
 is primarily related to the canning industry. 
 
 Pear storage has developed most largely in the east. In 
 New York and Jersey City from 60,000 to 100,000 bushels of 
 summer pears, 30,000 to 60,000 bushels of later varieties, and 
 many cars of California pears are stored annually. In Boston, 
 since 1895 there have been stored each year from 5,000 to 15,000 
 bushels of early pears, principally Bartlett, and from 7,000 to 
 20,000 bushels of later varieties, such as Anjou, Bosc, Angouleme 
 (Duchess), Seckel, and Sheldon. In Buffalo 10,000 bushels 
 are sometimes stored in a single season, and in Philadelphia from 
 30,000 to 35,000 bushels. While there are no accurate statistics 
 available and the quantity fluctuates from year to year, it is 
 
 ^Extracts from Bulletin No. 40, Bureau of Plant Industry, United States Depart- 
 ment of Agriculture, by G. Harold Powell, Assistant Pomologist in charge of Field 
 Investigations, and S. H. Fulton, Assistant in Pomology. 
 
COLD STORAGE OF THE PEAR AND PEACH 333 
 
 probable that as many as 300,000 bushels are stored in a single 
 year throughout the country at large. 
 
 There are many practical difficulties in pear storage. The 
 early-ripening varieties which mature in hot weather, like the 
 Bartlett, often "slump" before they reach the storage house, or 
 are in soft condition, especially if they have been delayed in 
 ordinary freight cars in transit. They may afterwards decay 
 badly in storage, break down quickly on removal, or lose their 
 delicate flavor and aroma. When stored in a large package like 
 the barrel, the fruit, especially of the early varieties, often softens 
 in the center of the package, while the outside layers remain 
 firm and green. Frequently no two shipments from the same 
 orchard act alike, even when stored in adjoining packages in 
 the same room, and the warehouseman and the owner, not always 
 knowing the history of the fruit, are at a loss to understand the 
 difficulty. It has been the aim in the fruit-storage investigations 
 of the Department of Agriculture to determine as far as possible 
 the reasons for some of these storage troubles, and to point out 
 the relation of the results to a more rational storage business. 
 
 OUTLINE OF EXPERIMENTS IN PEAR STORAGE. 
 
 The investigations in pear storage were of a preliminary na- 
 ture only. The experiments undertaken have been planned with 
 a view to determining the influence in the storage room of 
 various temperatures, of the character of the storage package, 
 of a fruit wrapper, of the degree of maturity of the fruit when 
 picked, and of other factors in relation to the ripening processes 
 in the storage house, and also to ascertain the behavior of the 
 fruit and its value to the. consumer when placed on the market. 
 
 The Bartlett and Kieffer pears principally were used in 
 the experiments, but several- other kinds were under limited 
 observation. The Bartlett represents the delicate-fleshed,- tender 
 pears, ripening in hot weather, which are withdrawn from stor- 
 age before the weather becomes cool. The Kieffer, on the other 
 hand, is a coarse, hard pear, ripening later in the fall in cooler 
 weather, and in which the normal ripening processes are slower. 
 It is a longer keeper, and like other fall varieties is withdrawn 
 in cool weather. 
 
 The Bartlett experiments extended through the season of 
 1902. The fruit was grown by Mr. F. L. Bradley, Barker, N. Y., 
 
334 PRACTICAL COLD STORAGE 
 
 in a twelve-year-old orchard on a sandy loam, with a clay subsoil. 
 The orchard is a half mile from Lake Ontario and is 50 feet 
 above the level of the lake. The fruit, which was full grown, 
 but green, was picked early in September, and was packed in 
 tight and ventilated barrels, in 40-pound closed boxes, and in slat 
 bushel crates. Part of the fruit in each lot was wrapped in un- 
 printed news paper, and an equal amount was left unwrapped. 
 Part was forwarded at once by trolley line to the warehouse of 
 the Buffalo Cold Storage Company at Buffalo, N. Y., and a 
 similar quantity was held four days before being stored. The 
 fruit reached the storage house within ten hours after leaving 
 the orchard. 
 
 The Kieffer experiments have extended over two years. In 
 1901 the fruit was grown by Mr. M. B. Waite, Woodwardsville, 
 Md., in a Norfolk sandy soil, on rapidly growing five-year-old 
 trees, from which the fruit was large, coarse, and of poor quality. 
 It was stored in the cold storage department of the Center Market 
 at Washington, D. C. In 1902 the fruit with which the experi- 
 ments were made was grown by Mr. S. H. Derby, Woodside, 
 Del., on heavy-bearing ten-year-old trees on sandy soil with a 
 clay subsoil. The fruit was smaller, of finer texture, and of 
 somewhat better quality than that used the previous year. It was 
 stored in the cold storage department of the Reading Terminal 
 Market in Philadelphia, Pa. 
 
 The Kieffers were picked at three degrees of maturity : 
 First, when two-thirds grown, or before the fruit is usually 
 picked; second, ten days later, or about the time that Kieffers 
 are commonly picked, and third, ten days later, when the fruit 
 was fully grown and still green, but showing a yellowish tinge 
 around the calyx. In each picking, part of the fruit was shipped 
 to storage and was placed in rooms with a temperature of 36° 
 and 32° F. within forty-eight hours. Equal quantities stored in 
 each temperature were wrapped in parchment paper, in imprinted 
 news paper, and were left unwrapped. A duplicate lot of fruit 
 remained in a common storage house ten days in open boxes, 
 when it was packed in a similar manner and sent to storage. 
 This fruit colored considerably during the interval, but was still 
 hard and apparently in good physical condition on entering the 
 storage house. The pears were stored in 40-pound closed boxes 
 
COLD STORAGE OF THE PEAR AND PEACH 335 
 
 and in five-eighths bushel peach baskets. One hundred and 
 fifty bushels were used in the experiments. 
 
 INFLUENCE OF THE DEGREE OF MATURITY ON KEEPING QUALITY. 
 
 The experiments with the Kieffer pear show that under con- 
 ditions similar to those in Delaware and eastern Maryland this 
 variety may safely be picked from the same orchard during a 
 period of at least three weeks, or when from two-thirds grown 
 to full size, and that the fruit in all cases may be stored success- 
 fully until the holidays, or much longer if there is still a demand 
 for it. It is absolutely essential that the fruit be handled with the 
 greatest care, that it be sent at once to storage after picking, 
 that it be packed carefully to prevent bruising (preferably in 
 small packages, like a bushel box), and that it be stored in a 
 temperature not above 32° F. if it is desired to hold it for any 
 length of time. If stored by the middle of October, the fruit, by 
 the latter part of December, will take on a rich, yellow color 
 when kept in a temperature of 32" F., and earlier if a higher 
 temperature is used. The fruit may be withdrawn during the 
 holidays, and will stand up, i. e., continue in good condition, for 
 ten days or longer if the weather is cool, and will retain its 
 normal quality if the rooms have been properly managed. While 
 the later picked fully grown pears keep well, they are already 
 inferior in quality at the picking time, as the flesh around the 
 center is filled with woody cells, making it of less value either 
 for eating in a fresh state or for culinary purposes. These coarse 
 cells in the Kieffer and some other late varieties do not develop 
 in the early picked fruit to so large an extent. Pears of all 
 kinds need to be picked before they reach maturity and to be 
 ripened in a cool temperature if the best texture and flavor are 
 to be developed. ..It is a matter of practical judgment to deter- 
 mine the proper picking season, but for cold storage or other 
 purposes the stem should at least cleave easily from the tree 
 before the fruit is ready to pick. Many trees bear fruit differing 
 widely in the degree of maturity at the same time, and in such 
 cases uniformity in the crop can be attained only when the or- 
 chard is picked several times, the properly mature specimens be- 
 ing selected in each successive picking. This practice not only 
 secures more uniformity in ripeness, but the fruit is more even 
 
336 PRACTICAL COLD STORAGE 
 
 and the average size is larger than when all the pears are picked 
 at the same time. 
 
 INFLUENCE OF DELAYED STORAGE ON KEEPING QUALITY. 
 
 Pears ripen much more rapidly after they are picked than 
 they do in a similar temperature while hanging on the tree. The 
 rapidity of ripening varies with the character of the variety, the 
 maturity of the fruit when picked, the temperature in which it 
 is placed, and the conditions under which it has been grown. 
 If the fruit is left in the orchard in warm weather in piles or in 
 packages, if it is delayed in hot cars or on a railroad siding in 
 transit, or if it is put in packages which retain the heat for a long 
 time, it continues to ripen and is considerably nearer the end of 
 its life history when it reaches the storage house than would 
 otherwise be the case. The influence of delay in reaching the 
 storage house will therefore vary with the season, with the 
 variety, and with the conditions surrounding the fruit at this time. 
 A delay of a few days with the quick-ripening Bartlett in sultry 
 August weather might cause, the fruit to soften or even decay 
 before it reached the storage house, though a similar delay in 
 clear, cooler weather would be less hurtful. A delay of a like 
 period in storing the slower ripening Kieffer would be less in- 
 jurious in cool October weather, though the Kieffer pear, es- 
 pecially from young trees, can sometimes be ruined commercially 
 by not storing it at once after picking. 
 
 From the experiments with the Bartlett and the Kieffer 
 pears, from which these general introductory remarks are de- 
 duced, it was found that the Bartlett, if properly packed, kept in 
 prime condition in cold storage for six weeks, provided it was 
 stored within forty-eight hours after picking in a temperature of 
 32 ° F. ; but that if the fruit did not reach the storage room until 
 four clays after it was picked there was a loss of 20 to 30 per 
 cent from softening and decay under exactly similar storage 
 conditions. 
 
 The Kieffers stored within forty-eight hours in a tempera- 
 ture of 32° F. have kept in perfect condition until late winter, 
 although there is little commercial demand for them after the 
 Holidays. The fruit grown by Mr. Waite on young trees in 
 1 901, which was still hard and greenish-yellow when stored ten 
 days after picking, began to discolor and soften at the core in a 
 
COLD STORAGE OF THE PEAR AND PEACH 337 
 
 Ef • 
 
 FIG !, — KIEFFER PEARS IN MARCH — REDUCED ONE-FIFTH. 
 
338 PRACTICAL COLD STORAGE 
 
 few days after entering the storage room, though the outside of 
 the pears appeared perfectly normal. After forty to fifty days 
 the flesh was nearly all discolored and softened, and the skin 
 had turned brown. The fruit from the older trees on the Derby 
 farm in 1902, which was smaller and finer in texture, appeared 
 to ripen as much as the Waite pears during the ten days' delay. 
 This fruit, however, did not discolor at the core and decay from 
 the inside outward, but continued to ripen and soften in the 
 storage house and was injured at least 50 per cent in its com- 
 mercial value by the delay. Fig. 1 shows the condition of the 
 Kieffer pears stored in a temperature of 32° F. as soon as picked 
 and withdrawn in March. Under these conditions the fruit kept 
 well until late in the spring. Fig 2 shows the condition of fruit 
 picked at the same time and stored in the same temperature ten 
 days after picking, when withdrawn in January. The delay in 
 storage caused the fruit to decay from the core outward. 
 
 Fig. 3 shows the influence of immediate and delayed stor- 
 age on Maryland Kieffer pears. The fruit in the box at the 
 right represents the average condition of pears picked October 
 21, stored October 22, and withdrawn March 3. Storage tem- 
 perature 32° F. The fruit was wrapped in parchment paper. 
 It was in prime commercial condition when withdrawn from 
 storage. The fruit in the box at the left represents the average 
 condition of pears picked from the same trees at the same time. 
 It was stored in the same temperature ten days later and with- 
 drawn March 3. All of the fruit had decayed. 
 
 The results of the experiments point out clearly the injury 
 that may occur by delaying the storage of the fruit after it is 
 picked, and emphasize the importance of a quick transfer from 
 the orchard to the storage house. If cars are not available for 
 transportation and the fruit can not be kept in a cool place, it is 
 safer on the trees so far as its ultimate keeping is concerned. 
 It is advisable to forward to storage the delicate quick-ripening 
 varieties, like the Bartlett, in refrigerator cars. The common 
 closed freight car in warm weather soon becomes a sweat box 
 and ripens the fruit with unusual rapidity. The results show 
 clearly that the storage house may be responsible in no way for 
 the entire deterioration or even for a large part of the deteriora- 
 tion that may take place while the fruit is in storage, and that the 
 
COLD STORAGE OF THE PEAR AND PEACH 339 
 
 FIG 2.— KIEFFER PEARS IN JANUARY— REDUCED ONE-FIFTH. 
 
340 
 
 PRACTICAL COLD STORAGE 
 
 different behavior of two lots from the same orchard may often 
 be due to the conditions that exist during the period that elapsed 
 between the time of picking and of storage. 
 
 INFLUENCE OF DIFFERENT TEMPERATURES ON KEEPING QUALITY. 
 
 There is no uniformity in practice in the temperatures in 
 which pears are stored. Formerly a temperature of 36° to 40 
 F. was considered most desirable, as a lower temperature was 
 supposed to discolor the flesh and to injure the quality of the 
 fruit. The pears were also believed to deteriorate much more 
 
 FIG. 3. — WRAPPED KIEFFER PEARS, REMOVED FROM STORAGE (32° F.) MARCH 3. 
 
 rapidly when removed to a warmer air. In recent years a num- 
 ber of storage houses have carried the fruit at the standard apple 
 temperatures, i. e., from 30° to 32 F. Large quantities of Bart- 
 lett, Angouleme, and Kieffer pears have been stored in 32° and 
 36° F. in the experiments of the Department. The fruit of all 
 varieties has kept longer in the lower temperature and the flesh 
 has retained its commercial qualities longer after removal from 
 the storage house. Bartlett pears were in prime commercial 
 condition four to five weeks longer, Angouleme two months 
 longer, and Kieffer three months longer in a temperature of 32° 
 F. Figs. 1 and 5 show the condition of Kieffer pears in March, 
 
COLD STORAGE OF THE PEAR AND PEACH 
 
 341 
 
 1902, in 32" and 36° F., the two lots having received similar 
 treatment in all respects except in storage temperatures. The 
 fruit held at 36° F. did not keep well after December 1. 
 
 Fig. 4 also shows the influence of 36° and 32 F. storage 
 temperature on the keeping of Kieffer pears. The fruit in both 
 packages was picked October 21, and stored October 22. The 
 package at the left represents the average condition of the fruit 
 when withdrawn March 3 from a temperature of 36 F. All 
 of the pears were soft and discolored, and some of them decayed. 
 The fruit in the package at the right, kept in a temperature of 
 
 w 
 
 FIG. 4. — WRAPPED KIEFFER PEARS, REMOVED FROM STORAGE (36° AND 32° F.) 
 
 MARCH 3. 
 
 32° F., was bright yellow, firm, and in prime commercial con- 
 dition. 
 
 In the higher temperature the fruit ripens more rapidly, 
 which may be an advantage when it is desirable to color the fruit 
 before it leaves storage; but the fruit in that condition is nearer 
 the end of its life history and breaks clown more quickly on 
 removal to a warm atmosphere. 
 
 There is a much wider variation in the behavior of pears 
 that have been delayed in storage or that are overripe when they 
 
342 PRACTICAL COLD STORAGE 
 
 enter the storage room at 32 and 36 F. than in pears stored at 
 once in these temperatures. In the higher temperature the fruit 
 that has been improperly handled ripens and deteriorates more 
 quickly. The lower temperature not only keeps the fruit longer 
 when it is stored at once, but it is even more essential in pre- 
 venting rapid deterioration in fruit that has been improperly 
 handled. 
 
 INFLUENCE OF THE TYPE OF PACKAGE ON THE KEEPING 
 QUALITY OF THE PEAR. 
 
 Pears are commercially stored in closed barrels, in ventilated 
 barrels, in tight boxes holding a bushel or less, and in various 
 kinds of ventilated crates. The character of the package exerts 
 an important influence on the ripening of the fruit and on its 
 behavior in other respects, both before it enters the storage house 
 and after it is stored, though this fact is not generally recog- 
 nized by fruit handlers or by warehousemen. The influence of 
 the package on the ripening processes appears to be related pri- 
 marily to the ease with which the heat is radiated from its con- 
 tents. The greater the bulk of fruit within a package and the 
 more the air of the storage room is excluded from it the longer 
 the heat is retained. Quick-ripening fruits, like the Bartlett 
 pear, that enter the storage room in a hot condition in large, 
 closed packages, may continue to ripen considerably before the 
 fruit cools down, and the ripening will be most pronounced in 
 the center of the package, where the heat is retained longest. The 
 influence of the package, therefore, will be most marked at the 
 time during which the fruit is exposed to the hottest weather 
 and on those fruits that ripen most quickly. 
 
 In the experiments of the Department of Agriculture the 
 Bartlett pears were stored in tight and in ventilated barrels, in 
 closed 40-pound boxes, and in slat bushel crates. After three 
 weeks in the storage house the fruit that was stored in barrels 
 soon after picking in a temperature of 32 ° F. was yellow in the 
 center of the package, while the outside layers were firm and 
 green. Fig. 6 shows the average condition of the fruit in these 
 two positions one week after storing. The upper specimen shows 
 the condition of the fruit in center of a barrel. In this position 
 
COLD STORAGE OF THE PEAR AND PEACH 343 
 
 FIG. 5. — KIEFFER PEARS IN MARCH — REDUCED ONE-FIFTH. 
 
344 PRACTICAL COLD STORAGE 
 
 the fruit cools more slowly than that near the staves or ends 
 and it therefore ripens considerably before the temperature is 
 reduced. The lower specimen shows the condition of the pears 
 at top and bottom and next to the staves of the same barrel. 
 In these positions the fruit cools quickly and the ripening proc- 
 esses are retarded. For quick ripening fruits that are handled 
 in hot weather small packages are preferable. After five weeks 
 in storage the fruit in the center of the barrel was soft and of 
 no commercial value, while the outside layers were still in good 
 condition. The difference was still greater in a temperature of 
 36° F., and was more marked in both temperatures in fruit that 
 was delayed in reaching the storage house. 
 
 In both the closed 40-pound boxes and the slat crates the 
 fruit was even greener in average condition than the outside 
 layers in the barrels, and it was uniformly firm throughout the 
 entire package. 
 
 There was apparently no difference between the fruit in 
 the commercial ventilated pear barrel and the common tight pear 
 barrel. 
 
 With the Kieffer, which enters the storage room in a cooler 
 condition and which ripens more slowly, a comparison has been 
 made (in 1902) between the closed 40-pound box and the barrel, 
 and while the difference has been less marked the fruit has kept 
 distinctly better in the smaller package. The fruit in barrels was 
 the property of Mr. M. B. Waite, and was under observation by 
 the Department through his courtesy. 
 
 There is a wide difference of opinion concerning the value 
 of ventilated in comparison with tight packages for storage pur- 
 poses. No dogmatic statements can be made that will not be 
 subject to many exceptions. The chief advantage of a ventilated 
 package for storage appears to lie in the greater rapidity with 
 which the fruit cools, and the quickness with which this result 
 is attained depends upon the temperature of the fruit, its bulk, 
 the temperature of the room, and the openness of the package. 
 The open-slat bushel crate, often used for storing Bartlett pears, 
 with which rapid cooling is of fundamental importance, may be 
 of much less value in storing later fruits that are cooler and 
 which ripen more slowly, and it may be of even less importance in 
 Bartletts in cool seasons. 
 
COLD STORAGE OF THE PEAR AND PEACH 345 
 
 ».•- 
 
 
 r , 
 
 
 FIG. 6.— BARTLETT PEARS AFTER ONE WEEK IN STORAGE— REDUCED ONE-FIFTH. 
 
346 PRACTICAL COLD STORAGE 
 
 The ordinary ventilated pear barrel does not appear to have 
 sufficient ventilation to cool the large bulk of fruit quickly. 
 
 The open package has several disadvantages. If the fruit 
 is to remain in storage for any length of time its exposure to the 
 air will be followed by wilting, which, in fruits held until late 
 winter or spring, may cause serious commercial injury. The 
 ventilated package, especially if made of slats, needs to be han- 
 dled with the utmost care to prevent the discoloration of the fruit 
 due to bruising where it comes in contact with the edges of the 
 slats. 
 
 There was little difference in the behavior of the Bartletts 
 in the closed 40-pound boxes and the slat crates at the end of five 
 weeks, and it would appear that a package of this size, even 
 though closed, radiates the heat with sufficient rapidity to quickly 
 check the ripening. Therefore the grower who uses the 40- 
 pound or the bushel pear box for commercial purposes can store 
 the fruit safely in this package, but if the barrel is used as the sell- 
 ing package, and the weather is hot, it is a better plan to store 
 the fruit in smaller packages, from which it may be repacked in 
 barrels at the end of the storage season. While this practice is 
 followed in several storage houses, it is not to be encour- 
 aged, as the rehandling of the fruit is a disadvantage. Rather 
 the use of the pear box should be encouraged as a more desirable 
 package, both for storage and for commercial purposes. 
 
 The fruit package question, as it relates to the storage house, 
 may be summed up by stating that fruits like the Bartlett pear 
 and others that ripen quickly and in hot weather may be expected 
 to give best results when stored in small packages. If the storage 
 season does not extend beyond early winter, an open package 
 may be of additional value, though not necessary if the package 
 is small. But fruits like the winter apples and late pears, which 
 ripen in the fall in cool weather and remain in storage for a long 
 period, should be stored in closed packages to prevent wilting. 
 In such cases the disadvantages of a large package, like a barrel, 
 are not likely to be serious. 
 
 INFLUENCE OF A WRAPPER ON KEEPING QUALITY. 
 
 The life of a fruit in cold-storage is prolonged by the use of a 
 fruit wrapper, and the advantage of the wrapper is more marked 
 
COLD STORAGE OF THE PEAR AND PEACH 347 
 
 as the season progresses. In Figs. 7 and 8 are shown the aver- 
 age quantity of sound specimens of Kieffer pears in unprinted 
 news paper and in parchment wrappers in comparison with the 
 quantity of commercial unwrapped pears in boxes in January, 
 the fruit having been picked October 21 and placed in storage 
 on the following clay in a temperature of 32" F. Nearly 50 per 
 cent of the unwrapped fruit (see Fig. 7) had decayed at that 
 time, while that in unprinted newspaper and in parchment 
 wrappers (see Fig. 8) kept in perfect condition. Early in the 
 season the influence of the wrapper is not so important, but if 
 the fruit is to be stored until late spring the wrapper keeps the 
 fruit firmer and brighter. It prevents the spread of fungus 
 
 FIG. 7. — KIEFFER PEARS FROM COLD STORAGE ON JANUARV ZU, UNWRAPPED. 
 
 spores from one fruit to another and thereby reduces the amount 
 of decay. It checks the accumulation of mold on the stem and 
 calyx in long-term storage fruits, and in light colored fruits it 
 prevents bruising and the discoloration that usually follows. 
 
 Careful comparisons were made of the efficiency of tissue, 
 parchment, unprinted news paper, and waxed papers, and but 
 little practical difference was observed, except that a large amount 
 of mold had developed on the parchment wrappers in a tempera- 
 ture of 36 F. A double wrapper proved more efficient for long 
 keeping than a single one, and a satisfactory combination consists 
 of an absorbent, unprinted news paper next to the fruit, with a 
 more impervious paraffin wrapper outside. 
 
348 PRACTICAL COLD STORAGE 
 
 The chief advantage of the wrapper for the Bartlett pear, 
 which is usually stored for a short time only, lies in the mechan- 
 ical protection to the fruit rather than in its efficiency in pro- 
 longing its season. Its use for this purpose is advisable if the 
 
 FIG. 8. — KIEFFER PEARS FROM COLD STORAGE ON JANUARY 20. 
 
 fruit is of superior grade and designed for a first-class trade. 
 For the late varieties the wrapper presents the same advantages, 
 and has an additional value in increasing the commercial life of 
 the fruit. It is especially efficient, if the package is not tight, 
 in lessening the wilting. 
 
COLD STORAGE OF THE PEAR AND PEACH 349 
 
 IXFDUENCE OF COLD STORAGE ON THE FLAVOR AND AROMA OF 
 
 THE FRUIT. 
 
 There is a general impression that cold storage injures the 
 delicate aroma and characteristic flavors of fruits. In this publi- 
 cation the most general statements only can be made concerning 
 it, as the subject is of a most complicated nature, not well under- 
 stood, and involving a consideration of the biological and chem- 
 ical processes within the fruit and of their relation to the changes 
 in or to the development of the aromatic oils, ethers, acids, or 
 other products which give the fruit its individuality of flavor. 
 
 It is not true that all cold storage fruits are poor in quality. 
 On the contrary, if the storage house is properly managed the 
 most delicate aromas and flavors of many fruits are developed 
 and retained for a long time. The quality of the late fall and 
 winter apples ripened in the cold storage house is equal to that 
 of the same varieties ripened out of storage, and the late pears 
 usually surpass in quality the same varieties ripened in common 
 storage. 
 
 The summer fruits, like the peach, the Bartlett pear, and 
 the early apples, lose their quality very easily, and in an improper- 
 lv managed storage house may have their flavors wholly de- 
 stroyed. Even in a room in which the air is kept pure the flavor 
 of the peach seems to be lost after two weeks or more, while the 
 fruit is still firm, much as the violet and some other flowers 
 exhale most of their aromatic properties before they begin to wilt. 
 
 It is probable that much of the loss in quality may be at- 
 tributed to overmaturity, brought about by holding the fruit in 
 storage beyond its maximum time; but it should be remembered 
 that the same change takes place in fruits that are not ripened in 
 cold storage, the aroma and fine flavor often disappearing before 
 the fruit begins to deteriorate materially in texture or appear- 
 ance. 
 
 On the other hand, it is certain that the quality of stored 
 fruits may be injuriously affected by improper handling or by the 
 faulty management of the storage rooms. Respiration goes on 
 rapidly when the fruit is warm. If placed in an improperly ven- 
 tilated storage room, in which odors are arising from other 
 products stored in the same compartment or in the same cycle 
 of refrigeration, the warm fruit may absorb these gases and 
 
350 PRACTICAL COLD STORAGE 
 
 become tainted by them, while the same fruit, if cool when it 
 enters the storage room, will breathe much less actively, and 
 there will be less danger of injury to the quality, even though the 
 air is not perfectly sweet. The atmosphere of the rooms, in 
 which citrus fruits or vegetables of various kinds — such as cab- 
 bage, onions, and celery — are stored, is often charged with the 
 odors arising from these products, if the ventilation is not thor- 
 ough. In small houses, in which a single room can not be used 
 for each product, fruits are often stored together during the 
 summer months, and at this period the storage air is in greater 
 danger of vitiation, since it is more difficult to provide proper 
 ventilation. 
 
 The summer fruits, therefore, being generally hot when 
 placed in the storage room, are in condition to absorb the odors 
 which are likely to affect the rooms during the warm season, and 
 as the biological and chemical processes are normally more active 
 in the case of such fruit than in fruits maturing later, the flavors 
 deteriorate more quickly, even in well-ventilated rooms. The 
 fruits that are picked in cool weather and enter the storage rooms 
 in a cooler and less active condition are not in the same danger 
 of contamination. 
 
 From the practical standpoint it may be pointed out that 
 summer fruits should be stored in rooms in which the air is 
 sweet and pure. They should not be stored with products which 
 exhale strong aromas, and the danger of contamination is less- 
 ened if the fruit can be cooled down in a pure room before it is 
 placed with other products in the permanent compartment pro- 
 vided for it. For the same reason the winter fruits should be 
 stored in rooms in which the air is kept pure, and preferably in 
 compartments assigned to a single fruit. 
 
 The experiments furnished no evidence that the quality de- 
 teriorates more rapidly as the temperature is lowered. On the 
 contrary, all of the experience so far indicates that the delicate 
 flavors of the pear, apple, and peach are retained longer in a 
 temperature that approaches the freezing point than in any 
 higher temperature. 
 
 BEHAVIOR OF THE FRUIT WHEN REMOVED FROM STORAGE. 
 
 There is a general impression that cold storage fruit de- 
 teriorates quickly after removal from the warehouse. This 
 
COLD STORAGE OF THE PEAR AND PEACH 351 
 
 opinion is based on the experience of the fruit handler and the 
 consumer, and in many cases is well founded, but this rule is not 
 applicable to all fruits in all seasons. The rapidity of deteriora- 
 tion depends principally on the nature of the fruit, on its degree 
 of maturity when it leaves the warehouse, and on the temperature 
 into which it is taken. A Bartlett pear, which normally ripens 
 quickly, will ripen and break down in a few days after removal. 
 If ripe or overmature when removed, it will decay much more 
 quickly, and in either condition its deterioration will be hastened 
 if the weather is unusually hot and humid. In the practical man- 
 agement of this variety it is fundamentally important that it be 
 taken from storage while it is still firm and that it be kept as cool 
 as possible after withdrawal. It is probably true that all fruits 
 from storage that are handled in hot weather will deteriorate 
 quickly, but it appears to be equally true that similar fruits that 
 have not been in storage break down with nearly the same rapid- 
 ity, if they are equally ripe. The late pears, which ripen more 
 slowly, if withdrawn in cool weather will remain firm for weeks 
 when held in a cool room after withdrawal. If overripe they 
 break down much sooner, and a hot room hastens decay in either 
 case. The same principles hold equally true with apples. The 
 winter varieties, if firm, may be taken to a cool room and will 
 remain in good condition for weeks and often for months and 
 will at the same time retain their most delicate and palatable 
 qualities, but in the spring, when the fruit is more mature and 
 the weather warmer, they naturally break down very much more 
 rapidly. 
 
 In commercial practice fruits of all kinds are often left in the 
 storage house until they are overripe. The dealer holds the fruit 
 for a rise in price, but sometimes removes it, not because the 
 price is satisfactory, but because a longer storage would result 
 in serious deterioration. If considerable of the fruit is decayed 
 when withdrawn, the evidence is conclusive that it has been stored 
 too long. Fruit in this condition normally decays in a short time, 
 but the root of the trouble lies not in the storage treatment, but 
 rather in not having offered it for sale while it was still firm. 
 In the purchase of cold storage fruit, if the consumer will exer 
 cise good judgment in the selection of sound stock that is neither 
 
352 PRACTICAL COLD STORAGE 
 
 fully mature nor overripe, he will have little cause to complain 
 of its rapid deterioration. 
 
 SUMMARY. 
 
 A cold storage warehouse is expected to furnish a uniform 
 temperature in all parts of the storage compartments throughout 
 the season, and to be managed in other respects so that an unusual 
 loss in the quality, color, or texture of the fruit may not reason- 
 ably be attributed to improper handling or neglect. 
 
 An unusual loss in storage fruit may be caused by improper 
 maturity, by delaying the storage after picking, by storing in an 
 improper temperature, or by the use of an unsuitable package. 
 The keeping quality is influenced by the various conditions in 
 which the fruit is grown. 
 
 Pears should be picked before they are mature, either for 
 storage or for other purposes. The fruit should attain nearly 
 full size, and the stem should cleave easily from the tree when 
 picked. 
 
 The fruit should be stored at the earliest possible time after 
 picking. A delay in storage may cause the fruit to ripen or to 
 decay in the storage house. The effect of the delay is most 
 serious in hot weather and with varieties that ripen quickly. 
 (See Figs, i, 2 and 3.) 
 
 The fruit should be stored in a temperature of about 32° 
 F., unless the dealer desires to ripen the fruit slowly in storage, 
 when a temperature of 36 or 40° F.. or even higher, may be ad- 
 visable. The fruit keeps longest and retains its color and flavor 
 better in the low temperature. It also stands up longer when 
 removed. (See Figs. 2, 4 and 5.) 
 
 The fruit should be stored in a package from which the 
 heat will be quickly radiated. This is especially necessary in 
 hot weather and with quick-ripening varieties like the Bartlett 
 pear. For the late pears that are harvested and stored in cool 
 weather it is not so important. Bartletts may ripen in the center 
 of a barrel before the fruit is cooled down. A box holding not 
 more than 50 pounds is a desirable storage package, and it is not 
 necessary to have it ventilated. The chief value of a ventilated 
 package lies in the rapidity with which the contents are cooled, 
 but long exposure to the air of the storage room causes the fruit 
 to wilt. (See Fig. 6.) 
 
COLD STORAGE OF THE PEAR AND PEACH 353 
 
 Ventilation is essential for large packages, especially if the 
 fruit is hot when stored and ripens quickly. 
 
 A wrapper prolongs the life of the fruit. It protects it from 
 bruising, lessens the wilting and decay, and keeps it bright in 
 color. A double wrapper is more efficient than a single one, and 
 a good combination consists of absorptive unprinted news paper 
 next to the fruit, with a more impervious paraffin wrapper out- 
 side. (See Figs. 7 and 8.) 
 
 The quality of a pear normally deteriorates as it passes ma- 
 turity, whether the fruit is in storage or not, or it is never fully 
 developed if the fruit is ripened on the tree. The quality of 
 the quick-ripening summer varieties deteriorates more rapidly 
 than that of the later kinds. Much of the loss in quality in the 
 storage of pears may be attributed to their overripeness. The 
 quality is also injured by impure air in the storage rooms, and 
 the warm summer pears will absorb more of the odors than 
 the late winter varieties. The fruit will absorb less if cool when 
 it enters the storage room. The air of the storage room should 
 be kept sweet by proper ventilation. 
 
 The rapidity with which the fruit breaks down after re- 
 moval depends on the nature of the variety, the degree of ma- 
 turity when withdrawn, and the temperature into which it is 
 taken. Summer varieties break down normally more quickly 
 than later kinds. The more mature the fruit when withdrawn the 
 quicker deterioration begins, and a high temperature hastens de- 
 terioration. If taken from the storage house in a firm condition 
 to a cool temperature, the fruit will stand up as long as other 
 pears in a similar degree of maturity that have not been in 
 storage. 
 
 It pays to store the best grades of fruit only. Fruit that is 
 imperfect or bruised, or that has been handled badly in any re- 
 spect, does not keep well. 
 
 INFLUENCE OF COLD STORAGE ON THE PEACH INDUSTRY. 
 
 Cold storage has not materially influenced the development 
 of the American peach business, and it is not likely to do so to 
 any extent in the future. In the early days of peach growing 
 the industry was localized in sections like the Chesapeake penin- 
 sula, New Jersey, and Michigan. The use of the fruit in consid- 
 
 (23) 
 
354 PRACTICAL COLD STORAGE 
 
 erable quantities was then limited to a few nearby markets and to 
 a short time in July, August and September. Now peach growing 
 is rapidly extending to all parts of the country where the climatic 
 conditions and the facilities for transportation are favorable. The 
 refrigerator-car service has brought the peach belts and the dis- 
 tant markets close together, and whenever the crop is general 
 the New York or the Chicago trade may be supplied almost 
 continuously from May till late October with fruit from Florida, 
 Texas, Georgia, the Chesapeake peninsula, New Jersey, the 
 Ozark mountain region, Michigan, New England, California, 
 West Virginia, western Maryland, and other peach-growing sec- 
 tions. 
 
 The chief value of cold storage to the peach industry will 
 probably lie in the temporary storage of the fruit during an 
 overstocked market, when, however, there is a reasonable pros- 
 pect of a better market within two or three weeks. It might be 
 useful also in filling the gaps between the crops of different 
 regions, especially when there are local failures which prevent a 
 continuous supply. It is not now profitable to store the fruit for 
 any length of time, nor under any circumstances unless the 
 condition of the fruit and the storage conditions are most favor- 
 able. The life processes in the peach and the weather conditions 
 in which it is handled make it even more critical as a storage 
 product than the delicate Bartlett pear. In normal ripening it 
 passes from maturity to decay in a few hours in hot, humid 
 weather. The aroma and flavor are most delicate in character 
 and are easily injured or lost, and the influence of any misman- 
 agement of the fruit in the orchard, in transit, or in the storage 
 house is quickly detected by the consumer. 
 
 PRACTICAL DIFFICULTIES IN PEACH STORAGE. 
 
 Under the most favorable conditions known at present, peach 
 storage is a hazardous business. Before the fruit is taken from 
 the storage house the flesh often turns brown in color, while 
 the skin remains bright and normal. If the flesh is natural in 
 color and texture it frequently discolors within a day or two 
 after removal. There is a rapid deterioration in the quality of 
 stored peaches when the fruit is held for any length of time, the 
 delicate aroma and flavor giving way to an insipid or even bitter 
 
COLD STORAGE OF THE PEAR AND PEACH 355 
 
 taste. Sometimes the flesh dries out, or under other conditions 
 it may become '"pasty." Dealers in storage peaches frequently 
 sell them in a bright, firm condition, and shortly afterwards the 
 purchasers complain of the dark and worthless quality of the 
 flesh. It has often been noticed that fruit in the various packages 
 in the same room does not keep equally well, some of it ripening 
 and even softening while the fruit in other packages is still firm. 
 In fact, the difficulties are so numerous that few houses attempt 
 to store the fruit. 
 
 It has been the aim in- the cold storage investigations of the 
 Department of Agriculture to determine, as far as possible, the 
 cause of the peach-storage troubles and to indicate the conditions 
 under which the business may be more successfully developed. 
 
 OUTLINE OF EXPERIMENTS IN PEACH STORAGE. 
 
 The investigations were conducted in the cold-storage de- 
 partment of the Reading Terminal Market in Philadelphia, Pa., 
 with Elberta peaches from the Hale Orchard Company, Fort 
 Valley, Ga., and in the warehouse of the Hartford Cold Storage 
 Company, Hartford, Conn., with Elberta and several other varie- 
 ties grown by J. H. Hale at South Glastonbury, Conn. 
 
 In Georgia the fruit was packed in the Georgia peach car- 
 riers, left unwrapped, and divided into two lots, one representing 
 fruit that was nearly full grown, well colored, and hard; the 
 other, highly colored fruit, closely approaching but not yet mel- 
 low. Three duplicate shipments were forwarded at different 
 times in the two bottom layers of refrigerator cars, and in 
 each shipment part of the fruit was placed in the car within 
 three or four hours after it was picked, and an equal quantity 
 delayed in a packing shed from ten to fifteen hours during the 
 day before it was loaded. Equal quantities of each series were 
 stored in temperatures of 32 , 36 , and 40° F. The transfer from 
 the refrigerator car to the storage house was made by wagon at 
 night, the interval between the car and storage varying from 
 two to five hours. 
 
 In Connecticut the fruit represented two degrees of matu- 
 rity, similar to the Georgia -shipments, except that the most ma- 
 ture fruit was mellow when stored. This fruit was grown at 
 an elevation of 450 feet on trees six years old. It was medium 
 
356 PRACTICAL COLD STORAGE 
 
 in size, firm, highly colored, and of excellent shipping quality. 
 Equal quantities were wrapped in California fruit paper and 
 left unwrapped, and packed in the Connecticut half-bushel bas- 
 ket, in Georgia carriers, and in flat, 20-pound boxes, holding 
 two layers of fruit. The peaches were forwarded by trolley to 
 the storage house, which was reached in two hours after the 
 fruit left the packing shed. Duplicate lots of all the series were 
 stored in temperatures of 32 , 36°, and 40° F. 
 
 GENERAL STATEMENT OF RESULTS. 
 
 The general outcome of the experiments, both with the 
 Georgia and the Connecticut fruit, is similar and may be summed 
 up as follows : 
 
 The fruit that was highly colored and firm when it entered 
 the storage house kept in prime commercial condition for two 
 to three weeks in a temperature of 32° F. The quality was 
 retained and the fruit stood up two or three days after removal 
 from the storage house, the length of its durability depending 
 on the condition of the weather when it was removed. After 
 three weeks in storage the quality of the fruit deteriorated, 
 though the peaches continued firm and bright in appearance for 
 a month, and retained the normal color of the flesh two or three 
 days after removal. If the fruit was mellow when it entered 
 the storage house it deteriorated more quickly, both while in 
 storage and after withdrawal. If unripe it shriveled consider- 
 ably. 
 
 In a temperature of 40° F. the ripening processes pro- 
 gressed rapidly, and the flesh began to turn brown in color after 
 a week or ten days in storage. The fruit also deteriorated much 
 more quickly after removal, as it was already nearer the end 
 of its life history. It began to lose in quality at the end of a 
 week. 
 
 In a temperature of 36° F. the fruit ripened more rapidly 
 than in 32", and more slowly than in 40° F. It reached its 
 profitable commercial limit in ten days to two weeks, when the 
 quality began to deteriorate, and after this period the flesh be- 
 gan to discolor. 
 
 Fig. 9 shows average condition of Georgia Elberta peaches 
 two weeks in storage after forty-eight hours withdrawal to a 
 
COLD STORAGE OF THE PEAR AND PEACH 357 
 
 FIG. 9.— ELBERTA PEACHES, STORED FOR TWO WEEKS AT 36" F. AND 32° F. 
 
358 PRACTICAL COLD STORAGE 
 
 warm room. The upper specimen represents the average condi- 
 tion of fruit stored in a temperature of 36° F. The lower speci- 
 men represents the average condition of the fruit stored in 
 32" F. The lower temperature gave better results in every 
 respect. 
 
 The fruit kept well in all of the packages in a temperature 
 of 32" F. for about two weeks, after which that in the open bas- 
 kets and in the Georgia carriers began to show wilting. In the 
 20-pound boxes, in which the circulation of air is restricted, 
 the fruit remained firm throughout the storage season. 
 
 It is necessary that the fruit be packed firmly to prevent 
 bruising in transit, but if the peaches pressed against each 
 other unduly it was found that the compressed parts of the flesh 
 discolored after a week in storage. A wrapper proved a great 
 protection against this trouble, especially in the baskets of the 
 Georgia peach carrier, and in all of the packages the wrapped 
 fruit retained its firmness and brightness for a longer time than 
 that left without wrappers. 
 
 The fruit should be removed from storage while it is still 
 firm and bright. The peach normally deteriorates quickly after 
 it reaches maturity, and the rapidity of deterioration is influenced 
 by the nature of the variety, by the degree of ripeness when 
 removed, and by the temperature into which it is taken. A 
 quick ripening sort, like Champion, is more active biologically 
 and chemically than the Elberta variety, and the warmer the tem- 
 perature in which either is placed the sooner decomposition is 
 accomplished. It is advisable, therefore, to remove the fruit 
 while firm and keep it in the coolest possible temperature. 
 
 The peaches in the top of a refrigerator car that has been 
 several days in transit in hot weather are sometimes overripe 
 and need to be sold as soon as the market is reached, while at 
 the same time the fruit in the bottom layers may still be firm. 
 The rapidity with which the fruit cools down in the car depends 
 on the care with which the car is iced, and on the temperature at 
 which the fruit enters the car. Fruit that is loaded in the middle 
 of a hot day and that has been picked in a heated condition may 
 be 20 or more degrees warmer than fruit picked and loaded in 
 the cool of the morning. Such warm fruit ripens much more 
 rapidly, consumes more ice in cooling down, and takes longer 
 
COLD STORAGE OF THE PEAR AND PEACH 359 
 
 to reach a low temperature. When the temperature in the top 
 of the car is higher than that of the lower part the ripening of 
 the upper layers of fruit will be hastened. If the fruit is des- 
 tined for cold storage, these upper layers, if more mature, should 
 be piled separately, and sold as soon as their condition warrants 
 it. Under these conditions, if the fruit from this position is 
 mixed in with the rest of-the load it may begin to deteriorate be- 
 fore the remainder of the fruit shows mellowing. 
 
 The general principles outlined in former pages for the 
 handling of the Bartlett pear apply to the storage of the peach, 
 except that the latter fruit is more delicate and the ripening 
 processes are even more rapid. Every condition, therefore, sur- 
 rounding the peach in the orchard, in transit, in the storage house, 
 and at withdrawal must be most favorable. The fruit must be 
 well-grown and well-colored but firm when picked. The packing 
 must be done with care to prevent bruising. If the fruit is to be 
 transported in refrigerator cars, it should be loaded soon after 
 picking, and preferably before it loses the cool night temperature. 
 The peaches should be transferred from the cars to the storage 
 house, or from the orchard to the storage house if the latter is 
 near the orchard, in the quickest possible time. The air of the 
 storage room should be kept sweet and pure. The fruit should 
 always be removed to the coolest possible temperature, usually 
 at the end of two weeks, while it is still firm, and it should be 
 placed in the consumer's hands at once. 
 
 If the fruit is overripe when picked, or becomes mellow 
 from unfavorable handling before it enters the storage house, 
 it is already in a critical condition and may be expected to de- 
 teriorate quickly. 
 
 If the conditions outlined are observed in the handling of the 
 peach, it is possible to store it temporarily with favorable re- 
 sults. 
 
360 PRACTICAL COLD STORAGE 
 
 CHAPTER XVI. 
 COLD STORAGE FOR FRUIT GROWERS.* 
 
 ADVANTAGES OF LOCAL COLD STORAGE. 
 
 The experiments conducted by the United States Depart- 
 ment of Agriculture (described in previous chapters) to deter- 
 mine the best methods of handling and storing fruits have re- 
 sulted in securing information of much value. Information be- 
 fore well known to the author and others connected with the 
 industry has been verified by the experiments and put in the 
 form of plain statements of facts. It has been fully demon- 
 strated that better results are secured by the placing of fruit in 
 storage promptly when picked, and that fruit, especially apples, 
 should remain on the trees until well colored and fairly ripened 
 before picking for storage. These facts argue strongly in favor 
 of the fruit grower operating his own cold storage. Professor 
 G. Harold Powell, who had the experiments in charge, says : 
 "The local warehouse is ideal for quick storage and for the 
 grower who is competent to handle his own crop. Capital has 
 developed the warehouse business in the large cities, as it is 
 more convenient to distribute the fruit from them and more 
 economical to maintain a plant where a general storage business 
 can be operated. But as the importance of quick storage at 
 harvest time is more generally appreciated, it will probably lead 
 to a greater development and concentration of local storage houses 
 and to a greater use and improvement of the refrigerator car serv- 
 ice. * * * I believe that one of the developments that will take 
 place in the future is the building of warehouses in the apple 
 producing regions, and the distribution of the product from these 
 warehouses in cooler weather." The part in italics is used by the 
 author to emphasize the point under consideration, viz. : That 
 best results and greatest profits to the grower can only be secured 
 
 *Extracted from a series of articles written for Green's Fruit Grower by the author 
 
COLD STORAGE FOR FRUIT GROWERS 361 
 
 by placing the fruit in cold storage as soon as removed from the 
 trees. This does not necessarily mean that the grower must have 
 a cold storage house on his premises, although in many cases this 
 is the best and most practical plan; but the cold storage house 
 should be easily accessible in order to secure the best results. 
 Many fruit growers are at present so situated that their fruit is 
 packed in barrels and shipped by refrigerator car to the nearest 
 storage point, requiring only two or three days in transit. Even 
 this short time causes deterioration of some of the softer varieties 
 of fruit, as the warm fruit going to the car cooled with ice only 
 will not in all probability become cooled below 45° or 50° F. 
 With a local cold storage the fruit requiring quick work may be 
 cooled down rapidly to a temperature of 30° F., thus improving 
 its keeping qualities, and shipped out later in the season when 
 outside temperatures are lower. Many times refrigerator cars 
 are not available and the damage is then much greater. 
 
 As an instance of one of the benefits to be derived from 
 home cold storage may be cited the barrel situation in the east 
 during the season of 1903. It was impossible to obtain barrels 
 in sufficient quantity to take care of the crop at harvest time, and 
 it is reasonable to say that many thousands of dollars were lost 
 to the grower from this reason on account of deterioration of 
 quality of fruit while lying in the orchards waiting for barrels. 
 In many cases total losses occurred. Apples may be successfully 
 stored without barrels; and boxes and crates are regularly used 
 for this purpose. They may also be stored in bulk, but this is 
 not as good. A grower provided with suitable cold storage 
 facilities does not have to wait for barrels. 
 
 Apples to stand shipment long distances before placing in 
 storage must be picked while still somewhat immature. The 
 bothersome apple scald is increased by too early picking, as 
 it has been shown by the experiments and by practice that ma- 
 ture, well colored fruit does not scald to any extent. On this 
 score Professor Powell states : "The experiments indicate that 
 so far as maturity is concerned, the ideal keeping apple is one 
 that is fully grown, highly colored, but still hard and firm when 
 picked. Apples that are to be stored in a local cold storage house 
 to be distributed to the markets in cooler weather may be picked 
 much later than fruits requiring ten days or more in transit. 
 
362 PRACTICAL COLD STORAGE 
 
 * * * Therefore, to sum up in a general way, the results of 
 the experiments which have been made seem to indicate that the 
 ideal fruit for storage purposes is that which is taken from the 
 tree to the warehouse in the quickest possible time, in order to 
 prevent the fruit from consuming a large proportion of its own 
 life history during the delay that may take place." 
 
 COMMERCIAL ASPECT OF THE PROBLEM. 
 
 These are some of the benefits of home or local cold storage. 
 Many instances could be cited where large profits have been 
 made by placing fruit in cold storage for a time and selling when 
 the market was comparatively bare, but these seasons are excep- 
 tions, and in going into a cold storage proposition, the grower 
 should not expect more than a reasonable profit, amounting to 
 interest and a fair remuneration for the risk assumed. One 
 season with another, a good profit is certain if the business is as 
 well handled as it should be, and none but a careful person of 
 methodical habits will succeed in the operation of a cold storage 
 plant. In the future the grower with modern cold storage fa- 
 cilities will have the advantage over his less progressive neighbor 
 from the fact that his losses will be less and he will be able to 
 place in the hands of the consumer a better preserved and more 
 attractive grade of fruit. 
 
 The question may arise as to the probable result of the 
 erection of a much larger number of cold storage houses than 
 are now in use throughout the section of the country where com- 
 mercial orcharding is largely practiced, and also the probable 
 result of the great increase of acreage of fruit bearing trees. The 
 application of cold storage is still in its infancy. It cannot be 
 said that its use so far has been in any way detrimental to' the 
 development of the industry, on the contrary, it has been a great 
 benefit, as fruit growers well know. If the development of cold 
 storage has been beneficial in the past, why should not further 
 development be beneficial? It may be true that the profits will 
 not be as great in the future with more storage houses in use, 
 but the profits will be more certain and regular. The old cry of 
 overproduction has been raised in connection with fruit growing 
 and storing, but with the country only half populated, growing 
 fast, and with developing tastes and rapid improvements in trans- 
 
COLD STORAGE FOR FRUIT GROWERS 363 
 
 portation, overproduction is impossible. If there has at times 
 been a temporary overproduction in the past, it has not been due 
 to a surplus, but to lack of facilities in distributing and trans- 
 portation. Commercial orcharding is rapidly expanding and cold 
 storage will be necessary as an auxiliary. There can be no dis- 
 astrous glut of the market when cold storage will absorb the 
 surplus at harvest time and distribute it as needed by refrigerated 
 transportation to the markets of the world. Nearly every one 
 can remember when the cold storage of apples was almost un- 
 known — they were stored in basements, cellars or "fruit houses" 
 without refrigeration. Probably a few are still doing this, but 
 it is safe to say that not more than 30 or 40 per cent of the fruit is 
 so stored for temporary purposes, and storers of this 30 or 40 per 
 cent would save money in improving the quality of the fruit by 
 employing artificial refrigeration. Owing to the considerable in- 
 vestment necessary it is improbable that the construction of cold 
 storage plants will ever be on a scale large enough to cause an 
 oversupply of cold storage space, but the time will shortly arrive 
 when practically all perishable goods will be handled in and sold 
 from cold storage. Those who first provide themselves with 
 cold storage will be the ones to be benefited largely thereby. 
 
 DESIGNS FOR SMALL COLD STORES. 
 
 The absolute necessity of cold storage at or near the orchard 
 in order to secure the most perfect results seems unquestionable. 
 What then should a modern cold storage plant consist of? The 
 answer depends largely upon climatic conditions and extent and 
 character of the crop to be handled. We will here consider only 
 the needs of the comparatively small grower who will store say 
 from 200 to 2,000 barrels. The use of natural ice for cold storing 
 of fruit dates back thirty years or more. As has been previously 
 pointed out, and as generally understood among the trade, the 
 natural ice systems with which we are all more or less familiar 
 have not been generally successful for the purpose. The chief 
 objections to these methods were found to be lack of control as 
 to temperature and too much moisture in the air of the rooms. 
 The lowest dependable temperature during warm weather was 
 about 38° to 40 F., oftentimes higher. The moisture in the air 
 was excessive at times, especially during cold weather when the 
 
364 
 
 PRACTICAL COLD STORAGE 
 
 temperature was lowest in the storage room. At the present time, 
 a temperature of 30° F. is considered best for apple storage, and 
 any apparatus which cannot produce this temperature cannot be 
 considered for practical purposes as a modern system. Humidity 
 also should be under control. It is for this reason that the ice 
 systems have gone into disuse, and the ammonia or mechanical 
 systems are understood to be the best. The advantages of sim- 
 plicity and low operating cost when using ice for cooling, com- 
 bined with the positive control of temperature and moisture ob- 
 tainable with the ammonia or mechanical system, are all em- 
 
 FIG. I. — VIEW OF HOUSE FOR FKUIT GROWERS, PLAN NO. I. 
 
 bodied in the gravity brine system, described in a previous chap- 
 ter. This system has none of the disadvantages of complicated 
 machinery, requiring skilled labor, as is necessary with the me- 
 chanical or chemical systems. 
 
 The buildings here illustrated are planned to meet the needs 
 of those who have a crop large enough to make storing profitable. 
 Tt is not recommended that a cold storage plant of less capacity 
 than 200 to 300 barrels be built, except under special local con- 
 ditions which might warrant a smaller capacity. The cost of con- 
 structing a very small house is greater in proportion as will be 
 seen by the subjoined estimates. The cost of operating is also 
 
COLD STORAGE FOR FRUIT GROWERS 
 
 365 
 
 greater in proportion and the time and care necessary to make 
 a success of a very small plant will operate a much larger one 
 equally well. The relative cost of a plant of 600 barrels capacity 
 and one of 1,500 barrels capacity are here figured with some de- 
 gree of accuracy for average conditions. The operating cost 
 would be in about the same proportion. The cost of building and 
 operating a house of say 300 barrels would be more than half 
 as much as the house here described for 600 barrels. It will be 
 apparent that an extremely small house is not profitable under 
 average conditions. 
 
 FIG. 2. — FLOOR PLAN, HOUSE FOR FRUIT GROWERS, PLAN NO. I. 
 
 Plan No. 1, which is illustrated by perspective, plan and 
 sectional views (see Figs. 1, 2, 3 and 4), is suitable for a capacity 
 of from 200 to 1,000 barrels of apples or other fruit, without 
 change in arrangement of rooms and general plan of building. 
 The cold storage space consists of a large storage room 12 feet 
 in height, which may easily be maintained at a temperature of 30 
 F. during the warmest midsummer weather, and a smaller cooling 
 room, shown in Fig. 2, 8 feet in height, which is used for bringing 
 down the temperature of the fruit partly before placing in the large 
 
366 
 
 PRACTICAL COLD STORAGE 
 
 storage room. Access to the storage room is only had through the 
 cooling room, preventing at all times the inflow of warm air. This 
 cooling room is most useful during comparatively warm weather, 
 for instance, while storing the summer or winter varieties of 
 fruit, or for cooling and storing Bartlett pears or similar fruit 
 which require quick cooling. By placing the fruit over night 
 in the cooling room a large part of the heat may be removed and 
 
 FIG. 3. — SECTION A-E OF PLAN NO. I, HOUSE FOR FRUIT GROWERS. 
 
 then, when removed to the storage room no marked change of 
 temperature will take place. The cooling room has pipe coils 
 of sufficient capacity to carry a uniform temperature of 30° F. 
 during the cold weather of fall and winter and this room may be 
 used for permanent storage of the hardy winter varieties which 
 are not placed in storage as a rule until cold weather in the fall. 
 The cooling room is entered from a packing or receiving room, 
 as it is generally called. The packing room may be made larger 
 if desired, or it may be omitted if cold storage is to be built adja- 
 
COLD STORAGE FOR FRUIT GROWERS 
 
 367 
 
 cent to a fruit packing shed already in use. The packing 
 room is provided with a chimney, so that a fire may 
 be built in extreme cold weather if necessary to prevent low 
 temperature in the storage room and cooling room, or when it is 
 desired to work in packing room in winter. From the packing 
 room, stairs lead up to lofts above storage, packing and cooling 
 rooms. These lofts are useful for the storage of empty packages, 
 etc. The ice room adjoins both the packing and storage rooms, 
 
 mm 
 1 S 
 
 ■ 
 
 _ 
 
 FIG. 4. — SECTION C-D OF PLAN NO. I, HOUSE FOR FRUIT GROWERS. 
 
 and is thus protected from the sun on two sides. There are no 
 openings from the ice room to any part of the building except 
 to tank house for the purpose of raising ice to tank. 
 
 Plan No. 2 (illustrated in Figs. 5, 6, 7 and 8) is in most 
 respects like plan No. 1, but is adapted to larger houses. Plan 
 No. 2 may be readily built ranging in capacity from 1,000 to 
 2,000 barrels. The estimate is based on a capacity of 1,500 bar- 
 rels. The ice room is placed at one end of the house in this case 
 
368 
 
 PRACTICAL COLD STORAGE 
 
 and the storage room between the ice room on one side and pack- 
 ing and cooling rooms on the other. The storage, cooling and 
 packing rooms bear the same relation to each other and are of 
 the same height and similarly equipped as in plan No. I. 
 
 It should be understood that both these plans include about 
 as much space in the packing room and lofts as is contained in 
 the storage rooms equipped with the cooling apparatus. In 
 case it is desired to dispense with this storage space for empty 
 packages, etc., as would be the case when the cold storage was 
 
 FIG. 5. — VIEW OF HOUSE FOR FRUIT GROWERS, PLAN NO. 2. 
 
 built against a barn or fruit house already existing, a considerable 
 saving could be had by some slight changes in plans. Old build- 
 ings may be remodeled in most cases to good advantage and a 
 handsome saving thereby effected. The estimates here given 
 are for good, though plain construction, and cold storage houses 
 built in this way will do good service for many years. 
 
 The estimated cost of constructing and insulating a cold 
 storage house of 600 barrels capacity on plan No. 1 is $1,365. 
 The cost of refrigerating equipment, consisting of piping, gal- 
 vanized iron work, etc., $650, making a total of $2,015. Plan 
 No. 2 is estimated at $2,545 for building and $1,075 f° r equip- 
 
COLD STORAGE FOR FRUIT GROWERS 
 
 369 
 
 merit, total $3,620. These figures are based on average costs 
 and conditions, and will of course vary somewhat in different 
 "sections. Country locations are usually much cheaper to build 
 in than cities, but this is not always true. 
 
 The ice room in this style cold storage house is merely a 
 storage place for ice, and there are no openings from the ice into 
 
 FIG. 6. — FLOOR PLAN, HOUSE FOR FRUIT GROWERS, PLAN NO. 2. 
 
 the storage part of the building. The ice room is to be filled in 
 winter, and will accommodate sufficient ice not only for the 
 operation of the cold storage plant for an entire season, but for 
 any ordinary farm or family uses as well. No packing material 
 of any sort is used on or around the ice. The floor, sides and 
 
 (24) 
 
370 
 
 PRACTICAL COLD STORAGE 
 
 ceiling of ice room are well insulated with mill shavings or some 
 similar material. This saves considerable unpleasant labor in 
 taking out ice, and the ice will keep as well or better than it will 
 in the old style way of covering with sawdust or other material. 
 The ice is also clean and ready for use when taken out. Ice is 
 filled into the ice room through an ice door extending from floor 
 to ceiling, consisting of inner and outer sections which are filled 
 between with shavings or other material after filling the room 
 with ice. Ice may be removed from the ice room for uses out- 
 side of the building through the filling door. Ice for use in the 
 
 FIG. 7. — SECTION A-B OF PLAN NO. 2, HOUSE FOR FRUIT GROWERS. 
 
 primary tank of the gravity brine system is first broken or pul- 
 verized in the ice room and then raised by a rope through a trap 
 door to the tank house. 
 
 The operation of the gravity brine system which cools the 
 rooms is based on well known natural laws that heat expands and 
 cold contracts. 
 
 For cold storage houses of a capacity greater than about 
 2,000 barrels of fruit, the complete "Cooper Systems" are in- 
 stalled. (For description of the Cooper systems see chapter on 
 "Refrigeration from Ice.") In addition to the gravity brine 
 
COLD STORAGE FOR FRUIT GROWERS 
 
 371 
 
 system and chloride of calcium process, they consist of the forced 
 air circulating and ventilating systems, viz., an improved method 
 of circulating the air of the storage rooms over the secondary 
 coils in the storage rooms, and a system for ventilating cold 
 storage rooms by the forcing in of air which has been thoroughly 
 purified, dried, and brought to about the temperature of the 
 storage room. These air circulating and ventilating systems are 
 
 FIG. 8. — SECTION C-D OF PLAN NO. 2, HOUSE FOR FRUIT GROWERS. 
 
 necessary in larger houses where the arrangement is more com- 
 plicated and the rooms are larger and the natural circulation 
 of the cooled air is not uniform in all parts of the rooms; thus 
 making advisable the use of a forced air circulation induced by 
 a power driven fan. On account of requiring continuous power, 
 the air circulating system has not been applied to the small houses 
 here described. 
 
372 PRACTICAL COLD STORAGE 
 
 CHAPTER XVII. 
 COLD STORAGE FOR NURSERYMEN.* 
 
 WINTER STORING OF NURSERY STOCK. 
 
 It is within recent years that the digging of trees from 
 nursery row in the fall and storing during the winter for spring 
 shipment has come to be an established feature of the nursery 
 business. This subject was brought to the author's attention by 
 a discussion between nurserymen of the advisability of the 
 method. In this discussion the term "cold storage" was 
 used in reference to the cellars or sheds in use for the purpose. 
 Having a great interest in cold storage matters, the author de- 
 termined to get the best information obtainable from those actu- 
 ally using the storage method. Letters of inquiry were therefore 
 sent out to representative nurserymen. That nurserymen are 
 in the main progressive and liberal minded is evident from the 
 interest shown and the careful replies received. The author 
 hopes that nurserymen will excuse the conceit which allows an 
 outsider to write regarding a business with which he is not inti- 
 mately familiar. This chapter, however, gives no mere theory 
 or opinion by the author, but information carefully gleaned from 
 those actually engaged in the business and put in shape by one 
 who has had a long experience with the cold storage of perishable 
 products. 
 
 From the information obtained, it is beyond doubt a fact 
 that a majority of nurserymen, especially the larger and more 
 progressive, are using frost-proof winter storage facilities of one 
 kind or another. A few are using artificial cooling, but as a gen- 
 eral proposition, this is not as yet fully appreciated. In time, no 
 doubt, this feature will also come to be permanent, not only for 
 maintaining regular temperatures during winter, but should 
 there be an overstock of certain varieties in the spring, it would 
 
 *Originally published in The National Nurseryman by the Author. 
 
COLD STORAGE FOR NURSERYMEN 373 
 
 result in a great saving to store* the surplus over until the next 
 shipping season. Artificial cooling is another step in advance of 
 frost-proof storage in the same sense that fall digging and frost- 
 proof storage is a step in advance of the old .method of digging 
 at shipping time in the spring. It is natural that every planter 
 should want his trees immediately as soon as the frost is out of 
 the ground. The result is that they all want their stock at the 
 same time. As a consequence, nurserymen who do any consid- 
 erable amount of business and have no storage facilities have 
 more than they can attend to in the spring. Even with this almost 
 impossible problem to solve, there are many who are not con- 
 verted to the storage method, so a few words regarding its ad- 
 vantages and alleged disadvantages will be timely. The ad- 
 vantages may be stated as follows : 
 
 i. — Protection from Loss: — A few years ago thousands of dol- 
 lars' worth of trees and vines were killed during a severe 
 spell of extreme low temperature during the winter at a 
 time when the ground was nearly bare of snow. It is also 
 believed that nursery stock is in better condition to thrive 
 when dug in the fall and stored in an even temperature 
 approximating the freezing point than if allowed to stand 
 in the nursery subject to wide fluctuations of temperature 
 which will cause injury to a greater or less extent, depend- 
 ing upon severity of the winter and snow protection afforded. 
 
 2. — Prompt Shipment:- — If no storage is provided digging must 
 be done in the spring after frost is out of the ground. Frost 
 is not generally out of the ground until April i, sometimes 
 later. This means that a large part of the trees are not 
 finally planted until May i to June i, and perhaps not 
 until the leaves have started. Trees set under those condi- 
 tions do not thrive as well and many die. 
 
 3. — Saving in Labor: — The shipping season is so short that if 
 trees were all dug and shipped after frost is out of the 
 ground the necessity of having a large and well trained force 
 to get the shipments out promptly would be very expensive. 
 With storage facilities, stock can be graded at convenience, 
 counted and put in bundles ready for packing by cheap help 
 during the winter. Trees >may be dug in the frill at a much 
 
374 PRACTICAL COLD STORAGE 
 
 lower cost than in the spring, owing to more abundant avail- 
 able labor and dryer working conditions. Less hands are re- 
 quired as the labor is more evenly distributed. 
 4. — Theoretically Correct: — Trees dug late in the fall are dor- 
 mant from natural causes and will stand handling, shipping 
 and planting much better than trees dug after frost is out 
 of the ground in the spring. After frost is out, sap starts 
 and the tree is more liable to be damaged by rough usage 
 and replanting. A dormant tree held at about the freezing 
 point will retain its vitality almost indefinitely. 
 
 The disadvantages or bad effects of winter storage as claimed 
 by those who oppose the method, are that trees dry out and mould 
 when stored and that when finally set the percentage of trees 
 which die is greater. It is also claimed that among the stock 
 which survives, the growth is retarded and the trees handicapped 
 by at least a year's growth as compared with freshly dug trees. 
 Plenty of evidence is obtainable from disinterested parties that 
 these effects result in some cases. These bad effects are, how- 
 ever, not from defects in the method, but from careless or unskill- 
 ful handling, or lack of suitable storage facilities. Farther on 
 we will take up the construction of suitable buildings. It is 
 notable that the advocates of freshly dug trees are almost wholly 
 of the "old line" element who stick to old customs, because some 
 few failures have resulted from the winter storage method. This 
 method, which has barely passed the experimental stage, can not 
 but record some failures on account of improper application. 
 Nurserymen who practice the selling of freshly dug trees are 
 handicapped in the handling of their business, and the increasing 
 of same to any considerable proportions is practically impossible. 
 From the preponderance of evidence in favor of winter storing, 
 it seems that this will be universal in due time. We have then 
 to consider the most approved methods now in use and sugges- 
 tions for possible improvements. 
 
 IMPROVED METHODS OF STORING. 
 
 Some of the nurserymen who do not advocate winter stor- 
 age, admit the need of something better than spring digging by 
 "heeling in" or "trenching" their trees for the winter in a pro- 
 
COLD STORAGE FOR NURSERYMEN 375 
 
 tected place which will drain naturally. They admit that this 
 allows of possible damage to the tops of the trees in severe 
 weather, but it saves time and wet digging in the spring. As 
 an improvement over this it is only another step towards the solu- 
 tion of our problem to put a shed over these heeled-in trees to pro- 
 tect the tops from low temperature during severe weather. This 
 is a common method and is practiced by some very large nursery- 
 men. A frost-proof cellar or shed is provided in which the trees 
 are heeled-in in the fall, so as to have them ready for spring ship- 
 ment. The storage shed is kept at the freezing point or some- 
 what above, so that sorting, grading and packing may go on inde- 
 pendent of weather conditions outside, enabling shipments to be 
 made as early as desirable in the spring. Much storage space is 
 needed with this method and under such conditions the trees may 
 dry out or shrivel, but the heeling-in in storage method has the 
 advantage of being more independent of temperature changes 
 than where the stock is piled up with roots exposed. A change of 
 temperature is largely what causes the drying out of trees, owing 
 to the change of humidity with the temperature changes. 
 
 Most of the winter storage structures in service are built 
 partly below the surface,, but many of the largest are wholly above 
 the ground. Nearly all are insulated by building air spaces into 
 the walls or by a filling of shavings, sawdust or similar non-con- 
 ducting materials. It is the idea in building partly below ground 
 to secure the protection afforded by the earth. It is a well known 
 fact that at a depth of a few feet below the surface of the earth a 
 nearly stationary temperature of about 55" F. may be obtained 
 winter and summer. This will prevent freezing in winter if the cel- 
 lar is rightly built, but it will likewise cause a marked rise in tem- 
 perature whenever a winter thaw occurs and it becomes necessary 
 to close the building tightly. The heat of the earth will then 
 work up into the storage room and a temperature of 40 ° F. to 
 50° F. may result. Another disadvantage of the cellar is that 
 when the first trees are stored during the fall, the surface of the 
 earth is quite warm, and it is very difficult to keep the tempera- 
 ture of the cellar low enough. Ventilators, windows and doors 
 are opened on a cold day or at night, and in this way the tem- 
 perature is, after considerable delay, finally reduced to the desired 
 point. A warm spell alternating with cold weather in the fall 
 
376 PRACTICAL COLD STORAGE 
 
 after storing commences will cause a great deal of damage by 
 causing the temperature of the cellar to vary greatly. A varia- 
 tion of temperature and consequent variation of humidity will 
 cause a drying out or shriveling of the trees, and may cause a 
 growth of mold or mildew. A building wholly above ground has 
 many of the disadvantages above mentioned, and also the disad- 
 vantage of lack of protection during extremely cold weather. 
 There are, however, advantages in above-ground construction, in 
 that, if the building is built of frame, it will not rot out as 
 quickly, and it may be cooled more readily in the fall, and it is 
 not affected so much by heat from the earth. It is stated by many 
 nurserymen that temperatures are very difficult to maintain in 
 any of the ordinary sheds or cellars in use, especially during the 
 storage season in the fall and during the shipping season in the 
 spring. Winter storage for nursery stock should be so arranged 
 that when natural temperature is suitable, air may be taken from 
 the outside and forced into the room for refrigerating, and when 
 natural temperatures are not suitable, as during a warm spell 
 in fall or spring, or during a winter thaw, artificial refrigeration 
 may be applied. Moisture brought in with stock, — especially if 
 the fall has been a wet and warm one., — might cause mold. A 
 proper cooling and temperature regulating system would pre- 
 vent this. 
 
 From the data at hand, it seems clear that ■ practically all 
 of the damage to nursery stock experienced in winter storing in 
 cellars or sheds as ordinarily practiced, comes from changes of 
 temperature, and a generally too high temperature, which can 
 not by present methods be avoided. It has been noted that trees 
 dug late in the fall and placed in storage after the temperature of 
 storage room has been reduced to about the freezing point have 
 carried through in better condition than those dug at an earlier 
 date and placed in storage while the temperature of the room 
 was still comparatively high. This may be partly because the 
 wood is more dormant, but is probably largely because it is easier 
 after about November 15 to keep down the temperature of 
 the storage room. A high temperature and frequent changes of 
 temperature will cause stock to dry out and shrivel. This is 
 especially true of vegetation of quick growth, such as peach trees. 
 To prevent this drying out, a spraying with water is often resorted 
 
COLD STORAGE FOR NURSERYMEN 377 
 
 to, but this again leads to mold or mildew if the temperature is 
 high and not very carefully handled. One nurseryman states: 
 "When stock is put in late in October and November, it needs no 
 wetting at all, but stays damp all winter and spring;" another 
 says : "In our own case, we find on account of the ups and downs 
 of temperature, we must sprinkle with water more or less, but 
 we believe that with a fixed temperature that did not vary to any 
 great extent, the water could be omitted." No better argument 
 could be made for low and uniform temperatures. There is no 
 question at all that trees may be dug any time after October 
 I, or after the tree is dormant from natural causes, placed in a 
 temperature of from 28 to 30 F., held steadily until spring, and 
 come out in better condition for planting than stock allowed to 
 remain in the nursery all winter and dug at the shipping time. 
 Humidity must be attended to, but this is very easy to regulate 
 at the low temperatures mentioned. As to temperatures at which 
 trees should be held there seems to be a wide difference of 
 opinion ; no doubt this opinion is largely influenced by the tem- 
 peratures it is possible for each individual nurseryman to main- 
 tain in his storage cellar. Nearly all admit the difficulty of keep- 
 ing uniform temperatures, and opinions, as to correct temperatures 
 vary from 30" to 50° F. No doubt 30° F. will produce better 
 results than any of the higher temperatures. It has been demon- 
 strated in the history of preserving perishable products by refrig- 
 eration that the lower the temperature at which any particular 
 product may be carried without damage from such low tempera- 
 ture, the better and longer it may be kept in cold storage. Cer- 
 tainly a temperature of 30° F. can not injure nursery stock if it 
 is able to withstand severe winter weather with any degree of 
 safety. It seems reasonable, therefore, that this is a suitable tem- 
 perature to maintain. 
 
 HUMIDITY AND TEMPERATURE. 
 
 At a temperature of 30° F. the air contains very little mois- 
 ture, and in fact it can not hold much, so the possibility of drying 
 out nursery stock is much less when stored in a temperature of 
 30° F. than at from 40° to 50 F., which many recommend. The 
 capacity of air for moisture is a direct property of its tempera- 
 ture — the higher the temperature, the more moisture air will take 
 
378 
 
 PRACTICAL COLD STORAGE 
 
COLD STORAGE FOR NURSERYMEN 379 
 
 up and hold. At 30 F. air will hold less moisture than at any 
 higher temperature. Air which is saturated with all the moisture 
 it will hold at 30° F. contains 1.96 grains per cubic foot. At a 
 temperature of 40 F. ; 2.85 grains per cubic foot. This shows 
 the rapid increase in capacity for moisture as the temperature of 
 the air is increased. Suppose we are holding our storage room 
 for nursery stock at 30 ° F. and a warm spell of weather comes, 
 one which obliges us to close tightly all openings leading to the 
 outside air. After a few days the temperature goes up to 40° F. 
 What is the result? The air, say, was at the 84 per cent relative 
 humidity at 30° F. When the temperature has increased to 
 40 F., the relative humidity will be 56 per cent. What does 
 this mean? Simply that the air has become comparatively very 
 dry and that moisture-containing products like trees will' dry 
 out very quickly. This case is stated to show the operation of 
 this simple natural law in connection with the winter storage of 
 nursery stock. Possibly these exact conditions might not occur 
 in practice, but they would be approximated. The great import- 
 ance of maintaining uniform temperature and humidity is plainly 
 illustrated, and the cause of the drying out of trees by fluctuating 
 temperatures is readily seen. 
 
 To overcome the difficulties of winter storing as above out- 
 lined it is proposed to apply artificial refrigeration when neces- 
 sary to maintain sufficiently low temperatures. By the term arti- 
 ficial refrigeration it should not be understood that a complicated 
 ice machine is necessary. The term is used to express cooling 
 effects other than those produced by outside atmospheric condi- 
 tions. Such a refrigerating equipment is embodied in the gravity 
 brine system described in chapter on " Refrigeration from Ice." 
 
 BUILDINGS AND APPARATUS. 
 
 The accompanying illustrations show a combination winter 
 and summer storage building constructed wholly above ground. 
 The storage space is divided by a partition into two rooms, one 
 small room 30x50 feet, and one larger room 50x80 feet. These 
 rooms are both cooled from one battery of pipe coils, but the air 
 ducts are provided with gates so that the entire refrigerating 
 effort may be applied to the smaller room. The refrigerating 
 equipment is of sufficient capacity to maintain a temperature of 
 
380 
 
 PRACTICAL COLD STORAGE 
 
 30 F. in the small 'room during midsummer, and to maintain the 
 same temperature in both rooms during comparatively cold 
 weather, say from November 1 to May 1. Both rooms may 
 be used for winter storage, and during the summer the large 
 room may be shut off and only the small room used. If it is not 
 desired to store nursery stock during the summer, other goods 
 may be taken for storage if they are to be had, or the plant may 
 be shut down during the summer. No expense whatever is neces- 
 sary when the plant is not in operation. The main part of the 
 storage building, 50x110 feet, is essentially like many storage 
 cellars or houses now in use, consisting of as plain and as cheap 
 
 FIG. 3. — PLAN OF VENTILATING ROOM ABOVE COIL ROOM. 
 
 a building as can be built, and roughly insulated. At one end of 
 the storage building is the ice room, which also contains the com- 
 plete refrigerating and mechanical equipment. The ice room is 
 50x25 feet on the ground, 30 feet high inside and will hold about 
 750 tons of ice, which is more than sufficient to maintain the tem- 
 perature as above stated during the year. The room containing 
 the secondary coils of the gravity brine system is located on the 
 ground. Above this room is located the tanks containing the 
 primary coils and the ventilating room containing the heater for 
 use during extremely cold weather and at such times as it is 
 necessary to warm or dry the storage rooms. The gasoline engine 
 or other power used for driving the fan for circulating the air 
 
COLD STORAGE FOR NURSERYMEN 
 
 381 
 
 through the storage room and for ventilating, is also located in 
 the room above the tank and ventilating room, where access is 
 had to top of tank for filling with ice. On this floor is also 
 provided storage bins for salt. In houses the size of the one 
 here illustrated, or larger, an ice crushing machine and ice ele- 
 vator as shown is desirable, especially as the power is at hand 
 for operating the same. In smaller plants this may be dispensed 
 with. 
 
 The operation of the plant is as follows : Ice is fed to the 
 ice crusher, which reduces it to about the size of hens' eggs; 
 
 CROSS SECTION AT C-D OF FIG. 2. 
 
 from the crusher the ice drops into a bucket elevator, which lifts 
 it up above the tank containing the primary coils and drops it 
 into the tank through a flexible spout. It will be noted that very 
 little labor is necessary with this arrangement. As the ice falls 
 :'nto the tank a small amount of salt is sprinkled in. This pro- 
 duces a low temperature in the tank, which cools the chloride of 
 calcium brine in the primary coils and causes a circulation as 
 already described. The actual cooling of the storage rooms is 
 
382 PRACTICAL COLD STORAGE 
 
 accomplished by drawing the air in through small ducts on the 
 sides of the rooms by means of the fan and causing it to pass over 
 the secondary coils of the gravity brine system in coil room, 
 where it is cooled; then forcing it from fan into large duct in 
 center, where it is evenly distributed to the rooms. When neces- 
 sary to heat the storage rooms, the return air to coil room is 
 caused to circulate over the large, jacketed heater in ventilating 
 room, or fresh air for ventilation may be drawn over heater for 
 ventilating and heating at the same time. When weather condi- 
 tions are right, a large volume of air from the outside may be 
 forced into the storage rooms for the purpose of cooling the 
 rooms. Many times greater cooling results may be secured in 
 this way than by the opening of doors and windows, and the cold 
 air is evenly distributed to the rooms so that no freezing or harm 
 can result, as is possible to goods stored near open windows or 
 doors on frosty nights. 
 
 The estimated cost of complete apparatus, aside from the 
 buildings, for a house the size shown, completely erected in place, 
 is from $2,500.00 to $2,800.00. 
 
 The plant described will maintain uniformly low tempera- 
 tures at about the freezing point in the entire building during the 
 cold weather when most of the nurserymen's products are stored, 
 and in one- fourth of the house during the summer. The initial 
 cost of the apparatus is not excessive, the cost of operation almost 
 nominal and the results to be obtained positive. Only a moderate 
 amount of refrigeration is required in storing nursery products, 
 but when required, it is very important, and the cost is so small 
 that it will soon pay for itself in saving of loss and perfection of 
 results possible to obtain. In many cases the nurseryman is a 
 fruit grower as well, and cold storage would be a good auxiliary 
 to add for the purpose of taking care of the softer fruits tem- 
 porarily and the hardy fruits for a longer term of storage. 
 
 This description of a suitable plant for nurserymen is de- 
 signed for northern locations where the nursery business has 
 had greatest development. In the south or extreme west the 
 mechanical systems of refrigeration would be best adapted; or 
 in a large plant in the north. The other features of the plant 
 would remain the same so far as construction, air circulation, 
 etc., is concerned. 
 
FREEZING AND STORING FISH 383 
 
 CHAPTER XVIII. 
 FREEZING AND STORING FISH.* 
 
 IMPORTANCE AND GROWTH OF THE INDUSTRY. 
 
 In the artificial freezing of fish and their subsequent reten- 
 tion in cold storage is found one of the most recent methods of 
 food preservations, originating about thirty-five years ago, and 
 while it has acquired considerable importance in certain localities, 
 its practical value is scarcely appreciated by the general public. 
 It is applied in the various marketing centers of the United 
 States, and to some extent in the countries of Europe and South 
 America. Its greatest development and most extensive applica- 
 tion exists along the great lakes, in freezing whitefish, trout, 
 herring, pike, etc., about 7,000,000 pounds of which are frozen 
 each year. On the Atlantic coast of the United States it is used in 
 preserving bluefish, squeteague, mackerel, smelt, sturgeon, her- 
 ring, etc., the trade in these "tailing on" or immediately following 
 the season for fresh or green fish. On the Pacific coast large 
 quantities of salmon and sturgeon are frozen and held in cold 
 storage until shipped, the trade extending to all parts of America 
 and northern Europe. At various points throughout the interior 
 of the country there are cold storage houses where fishery prod- 
 ucts are held awaiting demand from the consumers. In Europe 
 there is comparatively little freezing of fish, although the process 
 is applied very extensively to preserving beef, mutton, etc., and 
 the markets of Hamburg and other continental cities receive an- 
 nually several million pounds of frozen salmon from our Pacific 
 coast. In England large fish freezers were erected several years 
 ago at Grimsby and Hull, and trawlers are in some cases supplied 
 with refrigerating plants where the fish are plunged alive into 
 cold brine which freezes them solid. 
 
 *By Charles H. Stevenson in Ice and Refrigeration , February, 1900. 
 
384 PRACTICAL COLD STORAGE 
 
 During warm weather the temperature of the fish storage 
 room can never be kept below 32 ° F. by the use of ice alone. 
 While a temperature of 32 ° F retards decomposition, the fish 
 acquire a musty taste and loss of flavor, and eventually spoil. 
 To entirely prevent decomposition the fish must be frozen imme- 
 diately after capture, and then kept at a temperature of several 
 degrees below freezing. The belief held by some persons that 
 freezing destroys the flavor of fish is not well founded, the result 
 depending more on its condition when the cold is applied and the 
 manner of such application than upon the effect of the low tem- 
 perature. Fish decreases less in value from freezing than meat 
 does, but it is especially subject to two difficulties from which 
 frozen meat is free ; first, the eye dries up and loses its shining 
 appearance after considerable exposure to cold, and second, the 
 skin, being less elastic than the texture of the fish, becomes hard 
 and somewhat loose on the flesh. Frozen fish is not less whole- 
 some than fish not so preserved. The chemical constituents are 
 identical, except that the latter may contain more water, but 
 the water derived from in jested fish has no greater food value 
 than water taken as such. The principal objection to this form 
 of preservation is the tendency to freeze fish in which decomposi- 
 tion has already set in, and the prosperity of the industry requires 
 that any attempt to freeze fish already slightly tainted should be 
 discountenanced. When properly frozen and held for a reason- 
 able period, the natural flavor of fish is not seriously affected 
 and the market value approximates that of fish freshly caught. 
 The process is of very great value to the fishermen supplying 
 the fresh fish trade, since it prevents a glut on the market, and 
 it is also of benefit to the consumer in enabling him to obtain 
 almost any variety of fish in an approximately fresh condition 
 throughout the year. 
 
 DEVELOPMENT OF COLD STORAGE. 
 
 The first practical device for the freezing and cold storage 
 of fish was invented by Enoch Piper, of Camden, Me., to whom 
 a patent was issued in 1861. His process, based on the well 
 known fact that a composition of ice and salt produces a much 
 lower temperature than ice alone, consisted in placing the fish 
 on a rack in a box or room having double sides filled with non- 
 
FREEZING AND STORING FISH 385 
 
 conducting material, and metallic pans containing ice and salt 
 were set over the fish, and the whole inclosed. The temperature 
 in the room would soon fall to several degrees below the freezing 
 point of water, and in about twenty-four hours the fish would be 
 thoroughly frozen. The fish were then covered with a coating 
 of ice by immersing them a few times in ice cold water, forming 
 a coating about J/jj-inch in thickness, after which the fish were 
 wrapped in cloth, and a second coating of ice applied. In some 
 instances they were covered with a material somewhat like gutta 
 percha, concerning which much secrecy was exercised. The 
 fish were then packed closely in another room well insulated 
 against the entrance of warmth, and in which were a number 
 of perpendicular metallic tubes, several inches in diameter, filled 
 with a mixture of ice and salt to keep the temperature below the 
 freezing point. 
 
 The process was also patented in the Dominion of Canada, 
 and a plant was established at Bathurst, New Brunswick, in 
 1865, the output consisting almost entirely of salmon, a large 
 proportion of which were imported into the United States. In 
 order to hold the frozen fish in New York, while awaiting a 
 market, Piper constructed a storage room in a shop on Beekman 
 street, that being the first cold storage room for fish in the United 
 States. The walls of the room were well insulated, and around 
 the sides were two rows of zinc cylinders, ten inches in diameter 
 at the top, and decreasing in size toward the bottom, connecting 
 at the lower end with a drainage pipe. The cylinders were filled 
 with a mixture of ice and salt, which was renewed whenever 
 necessary. Whatever may have been the imperfections in his 
 process of freezing, the system of storage was quite satisfactory, 
 and differs little from that in use at the present time. Piper re- 
 fused to sell rights to others for the use of his process, and after 
 maintaining a monopoly of the business for three or four years 
 his exclusive right to it was successfully contested by other fish 
 dealers in New York, who applied it to storing other fish besides 
 salmon. 
 
 The principal objection to Piper's process is that the fish 
 are not in contact with the freezing mixture during the opera- 
 tion of freezing, and, consequently, too much time is required 
 for them to become thoroughly frozen. Several devices have 
 
 (85) 
 
38ti PRACTICAL COLD STORAGE 
 
 been used for overcoming this objection, among which are cover- 
 ing the fish with thin sheet rubber or other waterproof material, 
 and packing them in the mixture of ice and salt. 
 
 The greatest improvement, and the one used almost ex- 
 clusively when ice and salt form the freezing agency, originated 
 
 FIG. I. — PANS OF FROZEN WHITEFISH, SHOWING ARRANGEMENT OF FISH IN 
 THE PANS. — DAVIS SYSTEM. 
 
 in 1868 with Mr. William Davis, of Detroit, Mich., the descrip- 
 tion being as follows : Two thin sheet metal pans are made to 
 slide one over the other, the object being to place the fish in one 
 
FREEZING AND STORING FISH 387 
 
 pan, slide the other pan vertically over it, and the box is then 
 placed in direct contact with the freezing mixture. By having 
 the box constructed in this manner, it is capable of being ex- 
 panded or contracted to accommodate the size of whatever may 
 be placed therein, and the top and bottom always be in contact 
 with the articles to be frozen. After the fish are inclosed in the 
 pans, the latter are placed in alternate layers with layers of the 
 freezing mixture between and about them. When the fish are 
 thoroughly frozen they are removed from the freezing pans and 
 placed in a cold storage chamber at io° or 12° F. below freezing. 
 As the trade developed the size of the storage rooms in- 
 creased and improvements were adopted in the arrangement and 
 form of the ice and salt receptacles, and in the method of handling 
 the fish. But the freezing with pans immersed in ice and salt, 
 as in the Davis process, and the subsequent storage in the manner 
 used by Piper, continued without great modification until the 
 introduction of mechanical refrigeration into the fishing trade 
 in 1892. At that time ice and' salt freezers and storage rooms 
 existed at nearly all the fishing ports on the great lakes ; eight or 
 ten small ones were in New York City, and several were in use 
 on the New England coast. Some of those on the great lakes 
 were quite large, with storage capacity of 700 or 800 tons or 
 more, and the aggregate capacity of all in the country approxi- 
 mated 8,000 tons. Cold storage houses fitted with ammonia 
 machines had been established at various places along the coast 
 and in the interior during the ten or fifteen years preceding, 
 and in these some frozen fish had been stored. But the first 
 establishment using a refrigerating machine for freezing fish ex- 
 clusively was erected at Sandusky, Ohio, in 1892. The method 
 of freezing in these establishments differs from the ice and salt 
 process in that the pans of fish are placed on and between tiers of 
 pipes carrying cold brine or ammonia instead of being immersed 
 in ice and salt. In the storage rooms less difference exists, coils 
 of brine carrying pipes taking the place of the ice and salt re- 
 ceptacles, the blocks of fish being removed from the pans and 
 stored as in the older process. 
 
 DESCRIPTION OF ICE AND SALT FREEZERS. 
 
 The outfit of an ice and salt freezer consists principally of 
 temporary stalls or bins where the fish are frozen, and insulating 
 
388 PRACTICAL COLD STORAGE 
 
 rooms where the frozen fish are stored at a low temperature. 
 In addition to these there are ice houses, salt bins, freezing pans, 
 and the various implements for the convenient prosecution of 
 the business. The freezing bins are usually temporary struc- 
 tures within the fish house, and are generally without insulation. 
 The walls of the fish house may form the back, while loose boards 
 are fitted in to form the sides and front as the bin is filled, in the 
 manner hereafter described. A better way is to construct the bin 
 with permanent sides and back four or five inches thick, fitted 
 with some non-conductor, with double or matched floor, and with 
 movable front boards. 
 
 The storage rooms are commonly arranged in a series side 
 by side and separated from each other by well insulated parti- 
 tions the capacity of the rooms ranging from 25 to 250 tons each. 
 The outer walls of these rooms, as well as the floors and ceilings, 
 are well insulated, made usually of heavy matched boards, with 
 interior packing of some non-conductor of heat, such as planing 
 mill shavings, sawdust, pulverized charcoal, chopped straw, rock 
 wool, slag wool, etc. Most of the walls are sixteen or eighteen 
 inches thick, filled with planing mill shavings or sawdust, and 
 in some freezers the damaging effect of rats is obviated by plac- 
 ing linings of cement between the shavings and the board walls. 
 Most of these loose materials have their economic drawbacks, 
 chiefly because of their strong hygroscopic tendency, the material 
 losing its insulating power and decaying, this decay also attack- 
 ing the wood of the walls. Because of this, many of the storage 
 rooms recently constructed are insulated by having the walls 
 made up of a combination of rock or mineral wool, insulating 
 paper, air spaces and inch boards. 
 
 The sides, and in some cases the ends of the room, are lined 
 with the ice and salt receivers, consisting of galvanized sheet iron 
 tanks, eight or ten inches wide at the top, narrowing to three or 
 four inches at the bottom, and placed about four inches from the 
 wall in order to expose their entire surface to the air in the room. 
 These tanks open at the top, which extends above the ceiling, so 
 that they may be filled without opening the storage rooms. At the 
 bottom is usually a galvanized iron gutter, into which the water 
 resulting from the melting ice flows, whence it is conducted 
 through the floor of the room by a short pipe, protected from 
 
FREEZING AND STORING FISH 389 
 
 the entrance of air at its lower end by a small drip cup, into 
 which the brine falls and runs over at the top. The ice and salt 
 tanks must be cleaned from time to time in order to rid them 
 of dirt and sawdust. Their capacity should be in proportion to 
 the size of the room and the excellence of the insulation, and 
 they should be large enough to render it unnecessary to fill them 
 oftener than once a day, even in the warmest weather. 
 
 FREEZING BY MECHANICAL REFRIGERATION. 
 
 In the freezing houses using mechanical refrigeration there 
 is, as customary with cold storage houses used for other products, 
 a machinery room containing the boilers, compression pump or 
 absorption tank, according to the system employed, brine pump, 
 etc. Apart from these, and within well insulated walls, are the 
 cold rooms, of which there are two kinds, one for the freezing of 
 fish and the other for their storage after being frozen, the capacity 
 of the latter being usually much greater than that of the former. 
 In the freezing room the circulating pipes containing the cooling 
 material are one-half inch to two inches in diameter, and ar- 
 ranged in shelves or nests with horizontal layers four or five 
 inches, and sometimes ten inches apart, ranging from the floor 
 to the ceiling, the entire room being occupied with these nests, 
 except sufficient space for moving about. The temperature de- 
 pends, of course, on the quantity of green fish and the progress of 
 the freezing process ; but with direct expansion, or using brine 
 made of chloride of calcium as the circulating medium, a tem- 
 perature of — io° F., or less, is obtainable. In this room the 
 fish are frozen, and then they are removed to the storage rooms. 
 These are constructed similarly to the storage rooms in ice and 
 salt freezing houses, the only difference being that brine carrying 
 pipes are substituted for the ice and salt receptacles. The pipes 
 in the storage rooms are usually larger, but are not so numerous 
 as in the freezing room. They are arranged at the ceiling, and 
 sometimes about the upper side walls also. 
 
 In freezing fish, as in preserving most food products, close 
 attention must be given to the economy of the process as well as 
 to the excellence of the product, and the expense of the best proc- 
 ess frequently prevents its use. Tex secure the best results, the 
 stock to be frozen should be perfectly fresh and free from bruises 
 
390 PRACTICAL COLD STORAGE 
 
 and blood marks. It improves the appearance, and therefore 
 increases the value, if the fish are graded according to size, but 
 this is rarely done. All kinds of fish keep and look best when 
 frozen just as they come from the water, with heads on and 
 entrails in, and it is better that the fish be not eviscerated before 
 freezing, except in case of very large fish, such as sturgeon. 
 But since the freezers receive the surplus from the fresh fish 
 trade, many have been already split and dressed. Generally, fish 
 that are frozen with heads off and viscera removed are not 
 strictly fresh, but this rule has several exceptions. 
 
 Whether round or eviscerated, the fish are first washed by 
 dumping them into a wash box or trough containing fresh cold 
 water, which is frequently renewed, and stirring them about 
 with an oar-shaped paddle or cloth swab, to remove the slime, 
 blood, etc. Some freezers consider it inadvisable to wash flat 
 fish, because of their being too thin. From the wash box the 
 fish are removed by hand and placed in the pans in such a manner 
 as to make a neat and corhpact package entirely filling the pan, 
 so that the cover will come in contact with the upper surface of 
 the fish. It is desirable, when the size of the fish so admits, that 
 the bellies be placed upward, since that portion has greater ten- 
 dency to decompose, and, as the cold passes down, this arrange- 
 ment results in freezing the upper portion of the block first, and 
 also in less compression of the soft portion of the fish by remov- 
 ing the weight therefrom. It is also desirable to have the backs 
 of the fish at the sides of the pan and the heads at the ends, so 
 as to protect the blocks in handling, but this is by no means a 
 uniform practice. In case the fish have been split and eviscerated 
 it is desirable to place them slanting on the sides, but with backs 
 up, so as to permit the moisture to run from the stomach cavity. 
 Some freezers place herring and other small fish on their sides, 
 two layers deep in the pans, while others place a bottom layer 
 of three transverse rows, the end rows with the heads to the 
 edge of the pan, and a top layer of two transverse rows laid in 
 the two depressions formed between the bottom rows. In case 
 of pike and some other dry fish a small quantity of water is 
 sprinkled over them, since they do not ordinarily retain sufficient 
 moisture to hold together when frozen, as is the case with most 
 species. As soon as the pans have been filled and the covers 
 
FREEZING AND STORING FISH 391 
 
 fitted on they are placed in the sharp freezers, which have been 
 described. 
 
 In those houses using ice and salt as the freezing medium 
 the arrangement of the ice, salt and fish pans is as follows : The 
 ice, after being passed through a grinder, where it is crushed into 
 small particles, is mixed with salt in the proportion of from 
 eight to sixteen pounds of salt to one hundred pounds of ice. 
 The mixing is most conveniently done by scattering salt over each 
 shovelful of ice as the ice is shoveled from the grinder to a 
 wheelbarrow. Many varieties of salt are used, most houses pre- 
 ferring a coarse mined salt because of its cheapness. Others 
 use finer salt because it comes into closer contact with the ice and 
 results in a lower degree of cold and the more rapid freezing of 
 the fish, although the mixture does not last as long. 
 
 ^ The amount of ice and salt required in freezing a given 
 quantity of fish depends principally on the fineness of the ma- 
 terials and the proportions in which they are used, and to a less 
 extent on the outside temperature, the amount of moisture in 
 the atmosphere, the size of the pans and the manner in which 
 the fish are placed therein. The finer the ice and salt, the quicker 
 the freezing and the consumption of the ice. A larger proportion 
 of salt results also in quicker freezing. The most economical 
 quantities appear to be about eighty-five pounds of salt and 1,000 
 pounds of ice to each 1,000 pounds of fish, although some freezers 
 use much more sait and less ice. Much larger quantities of ice 
 and salt are required during warm weather, and more is neces- 
 sarv also when the atmosphere is moist than when it is dry. 
 Some of the ice and salt generally remains unmelted, and this 
 may be used over again in connection with fresh materials, addi- 
 tional salt being mixed with it ; and as it is weaker than new 
 ice it should be used mainly at or near the bottom, the top of 
 the pile taking care of the bottom, since the cold descends. 
 
 In making the freezing pile, an even layer of ice and salt, 
 about three or four inches deep, is placed at the bottom, on which 
 is laid a tier or layer of pans filled with fish, about three inches 
 of ice space intervening between the pans and the sides of the 
 bin. This is followed successively by a layer of ice and salt 
 about two or three inches deep, and a layer of pans, the surface 
 .of each layer of ice being made even and smooth by means of a 
 
392 PRACTICAL COLD STORAGE 
 
 straight edge. Sideboards are placed as the height of the pile 
 requires, and a wide board laid on the pile furnishes a walk for 
 the workmen in placing the freezing mixture and the pans. Some 
 freezers place the pans in double tiers between the layers of ice 
 and salt, and in this case the thickness of the layers of freezing 
 material must be increased. In some freezers a light sprinkling 
 of salt is thrown on top of the pans as they are successively 
 placed. The pile is built up as high as it is convenient for 
 handling the pans of fish, which usually does not exceed six feet. 
 A double quantity of the freezing material is put on top, and 
 the whole should be covered with wood or canvas to exclude 
 the air. The fish are usually frozen completely in about fifteen 
 or eighteen hours, but they usually remain in the pile until the 
 following morning, when they are ready to be placed in cold 
 storage. 
 
 METHOD OF STORING THE FROZEN FISH. 
 
 Being moist, the fish are frozen solidly to each other and 
 to the surfaces of the pans while in the sharp freezer. To remove 
 them from the pan the latter is usually passed for a moment 
 through cold water, which draws the frost sufficiently from the 
 iron to allow the fish to be removed in a block without breaking 
 apart. In one or two freezing houses the thawing of the fish 
 from the sides of the pan is omitted, the cover being loosened and 
 the block of fish removed by striking the pan at the ends and 
 sides, after which the block of fish is dipped for a moment in 
 cold water. 
 
 Considerable moisture adheres to the fish from its being 
 dipped in water, and this being frozen by the surplus cold forms 
 a coat of ice about one-fiftieth inch thick, entirely surrounding 
 the irregular block. The process of freezing dries the fish to 
 some extent, the loss in weight amounting to about 2 per cent, 
 but the ice coating adds about 4 per cent to the weight. 
 
 After the coating of ice has been applied, the fish are passed 
 to the cold storage room, where they are arranged in neat piles, 
 the blocks being placed vertically in some instances ; but more 
 frequently they are arranged horizontally in piles extending from 
 the floor nearly to the ceiling. Strips two or three inches thick 
 are laid on the floor to keep the fish slightly elevated, and allow 
 the cold air to circulate underneath. 
 
FREEZING AND STORING FISH 393 
 
 The quantity of ice and salt required in the establishments 
 which use those materials in the storage rooms is dependent on 
 the outside temperature and the excellence of the wall insulation, 
 and is independent of the amount of frozen fish in the room, 
 requiring no more freezing material to keep fifty tons of frozen 
 fish at an even temperature than to keep two tons in a room 
 of equal size. With 16-inch or 18-inch walls, well insulated, 
 it requires the melting of about forty pounds of ice per day for 
 each ioo square feet of wall surface when the outside tempera- 
 ture is 60° F., to maintain a temperature of 18° F. inside, this 
 calculation leaving the opening of doors and the cooling of fresh 
 material out of consideration. The temperature in the storage 
 room should be constant, and about 16° or 18° F. is considered 
 the most economical. Above 20° F. the fish are likely to turn 
 yellow about the livers, a result generally attributed to the burst- 
 ing of the "gall." 
 
 The storage rooms should be free from moisture, since the 
 latter offers a favorable place for the settlement and development 
 of micro-organisms of all kinds, which tend to mold the fish. 
 To reduce excessive moisture, a pan of unslaked lime, chloride 
 of calcium or other hygroscopic agency, may be placed in the 
 room, the material being renewed as exhausted. If the storage 
 rooms are very moist, they should be dried out before storing 
 fish in them, this being readily accomplished by using a small gas, 
 coke or charcoal stove. The storage rooms cooled by refrigerat- 
 ing machines may be dried by passing hot water through the 
 pipes, which, of course, should, under no circumstances be done 
 when there are fish in the rooms. In case of mold appearing 
 on the fish, it might be well to try spraying them with a solution 
 of formalin, consisting of ten parts of formalin and ninety parts 
 of water, which should be used at the first sign of mold. 
 
 DETERIORATION OF FISH AFTER FREEZING. 
 
 All fish deteriorate to some extent in cold storage, depreciat- 
 ing both in flavor and firmness. The amount of this decrease 
 is dependent primarily on the condition of the fish before freez- 
 ing and the care exercised in the process of freezing, and, sec- 
 ondarily, on the length of time they remain in cold storage. The 
 loss in quality during storage is due principally to evaporation, 
 
394 PRACTICAL COLD STORAGE 
 
 which begins as soon as the fish are placed in storage, and in- 
 creases as the ice coating is sapped from the surface. 
 
 Evaporation proceeds at very low temperatures, though not 
 so rapidly as at higher ones ; even at a temperature of o° F. the 
 evaporation during two or three months is considerable. The 
 heavier the ice coating the less the evaporation ; but it is almost 
 impracticable to entirely prevent it, and under ordinary condi- 
 tions it amounts to about 5 per cent in weight in six months, but 
 the loss in quality is greater than the loss in weight. 
 
 The most practicable method of restricting evaporation, 
 other than coating with ice, is to wrap the fish in waxed or parch- 
 ment paper and place them in shipping boxes, whose length 
 and width are slightly greater than the blocks and deep enough 
 to contain four or five blocks, or 120 to 150 pounds of fish. 
 
 Along the great lakes the most popular fish for cold storage 
 are whitefish, lake trout, lake herring, blue pike, saugers, stur- 
 geon, perch, wall eyed pike, grass pike, black bass, codfish and 
 eels. In addition to these species, the great lakes freezers receive 
 large quantities of blue fish and squeteague (sea trout) from the 
 Atlantic. On the Atlantic coast bluefish, halibut, squeteague, 
 sturgeon, mackerel, flat fish, cod, haddock, Spanish mackerel, 
 striped bass, black bass, perch, eels, carp and pompano are frozen. 
 Salmon, sturgeon and halibut are the principal species frozen on 
 the Pacific coast. 
 
 Some varieties of fish are so very delicate that it is not 
 deemed profitable to freeze them, especially shad, but even these 
 are frozen in small quantities. Oysters and clams should never 
 be frozen, the best temperature for cold storage being 35 to 
 40° F., and when stored in good condition they will keep about 
 six weeks. As an experiment they have been kept twelve weeks, 
 but storage for that length of time is not advisable. Caviar also 
 should never be frozen, but held at about 40° F. Scallops and 
 frogs' legs, however, are frozen hard in tin buckets and stored 
 at a temperature of 16° to 18° F. Sturgeon and other fish too 
 large for the pans are frequently hung up in the storage rooms 
 by large meat hooks, and when frozen are dipped in cold water 
 and stored in piles. 
 
 In some of the largest freezing houses on the Atlantic sea- 
 board, which freeze and store fish as well as other food products, 
 
FREEZING AND STORING FISH 395 
 
 the fish to be frozen are simply hung up in the sharp freezer, the 
 heads being forced on to the sharp ends of wire nails protruding 
 from cross-laths arranged in series. After the fish are frozen 
 they are removed and piled in storage rooms, where the tempera- 
 ture is from 15" to 18 F. When the handling of fish is of 
 minor importance compared with other food products, they are 
 generally placed on slat-work shelves in either a special freezing 
 room or in a storage room where the temperature is kept below 
 20 F., or they are retained in bulk in baskets, boxes or barrels 
 in the same room. But these methods are not productive of 
 results even approximating those in the great lakes freezers. 
 
 The cost of cold storage and the deterioration in quality 
 make it inadvisable to carry frozen fish more than nine or ten 
 months, but sometimes the exigencies of trade result in carrying 
 them two and even three years. In the latter case they are 
 scarcely suitable for the fresh fish trade unless the very best of 
 care has been exercised in the freezing and storage, and it is 
 usually better to salt or smoke them. 
 
 The rate of charges in those houses which make a business 
 of freezing and storage for the general trade is usually from a 
 half cent to one cent for freezing and storage during the first 
 month, and about half of that rate for storage during each sub- 
 sequent month, depending on the quantity of fish. However, the 
 cost of running a first-class plant at its full capacity is probably 
 less than one-third, or even one-fourth, of the minimum above 
 quoted, since it costs no more to run a storage room full of fish 
 than one-fifth full. 
 
396 PRACTICAL COLD STORAGE 
 
 CHAPTER XIX. 
 COLD STORAGE OF FURS AND FABRICS. 
 
 A NEW BRANCH OF THE COLD STORAGE INDUSTRY. 
 
 The use of refrigeration for the protection of furs, fur and 
 woolen garments, rugs, carpets, trophies, fine furniture, etc., 
 against the ravages of moths or carpet beetles is comparatively 
 recent, and prior to the year 1895 no business of consequence 
 was done in this line. Now many of the larger household goods 
 warehouses, and some of the regular cold storage houses, have 
 rooms devoted to this purpose, and several large concerns, both in 
 America and Europe, are operating refrigerating equipments 
 exclusively for the preservation of furs and fabrics. 
 
 The use of cold storage for this line of goods is not as yet 
 fully or even moderately developed. The prejudice of furriers 
 is largely responsible, and wherever the cold storage manager 
 endeavors to obtain business in this line, he usually has a strug- 
 gle with the furrier. The time honored method of caring for 
 furs, etc., during the heated term, has been to periodically beat, 
 brush, comb ov treat them with various chemicals or liquids for 
 the purpose of destroying or preventing the hatching of the egg 
 which produces the larva; of the destructive miller and beetle. 
 These pests are very generally known as moths. The care of 
 furs during the hot weather of summer has been one of the 
 sources of the furrier's income during his dull season. Natur- 
 ally, therefore, he looks upon any new method of protecting furs 
 with suspicion and in an unfriendly light. 
 
 In nearly every instance where the author has obtained the 
 experience of warehousemen on this subject, the same conditions 
 prevail. In some instances where cold storage is largely in use 
 for this purpose, it has been introduced by interesting a promi- 
 nent local furrier, and making concessions which would attract 
 his business. This furnishes the cold storage warehouseman 
 with a good reference. After acquiring such a customer, busi- 
 
COLD STORAGE OF FURS AND FABRICS 
 
 397 
 
 ness should be solicited by distributing attractive descriptive ad- 
 vertising matter from house to house. A number of warehouses 
 known to the author have secured their business almost wholly in 
 this way, and without help of local furriers. It is only a question 
 of time when the prejudice of furriers will be overcome, and they 
 
 FIG. I. — COLD STORAGE ROOM FOR CARPETS, SHOWING PIPING. 
 
 will become the heaviest customers of the cold storage house ; but, 
 for the present, their preconceived ideas and fancied financial in- 
 terests make them the competitors, to a great extent, of the cold 
 storage house. 
 
 Foot for foot, the storage of furs and fabrics pays better 
 than any other class of goods, and cold storage houses located 
 
398 
 
 PRACTICAL COLD STORAGE 
 
 in or near the residence portion of cities, in latitudes where furs 
 are worn, should make an effort to obtain this business. The 
 detail of looking after it is considerable, but it works in nicely 
 with other business. So far the business has been largely 
 developed bv the household goods warehousemen, and at present 
 
 FIG. 2. — COLD STORAGE ROOM FOR FABRICS. SHOWING PIPING. 
 
 the largest and most successful businesses in this line are con- 
 ducted by such houses, chiefly because these already have a 
 clientage from whom to draw business, and are equipped with 
 facilities for collecting and delivering goods. To the warehouse- 
 man who handles both household goods in dry storage and per- 
 ishable goods in cold storage, the setting aside of a room for 
 
COLD STORAGE OF FURS AND FABRICS 
 
 399 
 
 the purpose is a comparatively inexpensive experiment, and it 
 may result in a good business. The largest and most successful 
 houses handling these goods have fireproof buildings. The large 
 value stored in a small space makes the fireproof building es- 
 pecially adapted to this class of goods. 
 
 The correct temperature for a fur and fabric room has not 
 been accurately determined as yet. Rooms are in operation rang- 
 ing in temperature from 15 to 40° F. It has been demon- 
 strated that a temperature of 40 F will prevent the operation of 
 
 FIG. 3. — COLD STORAGE ROOM FOR RUGS, SHOWING PIPING. 
 
 damaging larvae, but does not destroy them. A safe working 
 temperature for the cold room would be anywhere between 25° 
 and 35" F., and it is believed that the latter temperature is amply 
 low, if continuously maintained. 
 
 Raw silk has been placed in cold storage for other reasons 
 than to prevent the working of damaging moth. When stored 
 at ordinary temperatures a loss of weight and lustre results, 
 caused by the evaporation of the natural moisture and volatile 
 matter contained in the silk. A temperature below 30° F. pre- 
 vents the evaporation and maintains the lustre. Inferior grades 
 
400 
 
 PRACTICAL COLD STORAGE 
 
 are especially liable to damage when exposed on the shelves for 
 a time and cold storage is necessary to a successful holding. 
 
 Furs and fabrics should not be stored in a room with goods 
 giving off moisture, as at times the moisture in such a room may 
 be excessive and harm result. A room containing nothing but 
 furs will be comparatively dry, because furs do not give off 
 moisture, and the only source from which moisture may be 
 added to the air of the room is by air leakage, opening doors, 
 and the exhalation from persons working in the room. A well 
 
 FIG. 4. — COLD STORAGE ROOM FOR LARGE RUGS. 
 
 insulated fur room, protected by a properly designed air lock or 
 corridor, is so dry that the pipes rarely show white, the coating 
 of frost is so very light. It has been advanced as a theory that 
 a very low temperature, like say zero or io° F. above, would be 
 detrimental to the skins or leather of furs, causing them to dry 
 out. Evaporation is caused by a low relative humidity, entirely 
 independent of temperature, so this theory is not tenable. (See 
 chapter on "Humidity.") The average humidity during winter, 
 when furs are in use, is much lower in most localities where furs 
 are worn than that of a cold storage room under ordinary con- 
 
COLD STORAGE OF FURS AND FABRICS 401 
 
 ditions. No data are at hand regarding the humidity at which 
 fur rooms should be carried, but it is no doubt lower than for 
 goods which throw off moisture; that is, the room should be 
 dryer. It may happen that .furs removed from a refrigerated 
 room and taken into a comparatively warm atmosphere will 
 show dampness on their outer surfaces. This is not from any 
 fault of the storage room, but because the moisture is condensed 
 from the warm air upon the cold surface of the goods. This 
 may be avoided by packing the goods inside the cold storage 
 
 FIG. 5- — COLD STORAGE ROOM FOR GARMENTS. 
 
 room in tight boxes before delivery, so that the goods will be 
 warmed slowly and condensation prevented. If furs and fabrics 
 are kept in a room by themselves, no harm will result from the 
 moisture, unless conditions are radically wrong. If, when re- 
 moved from storage, goods show a condensation of moisture, 
 they should be thoroughly aired until dry before delivering, by 
 placing where a gentle current of air will flow over them, as cus- 
 tomers may think the moisture was caused by some defect in the 
 system of cold storage. 
 
 (26) 
 
402 
 
 PRACTICAL COLD STORAGE 
 
 The forced air circulation system is particularly applicable 
 to the storage of furs and fabrics, and it is recommended, not 
 especially as a matter of purifying the rooms or producing 
 greatly improved conditions, but as a means of avoiding the use 
 of cooling pipes, placed directly in the rooms. Pipe coils on 
 the walls or ceilings of a room may drip at times and cause a 
 spattering of water, which will damage the goods. Space will 
 also be saved, which is an important item, especially in expen- 
 sive fireproof warehouses. The accompanying illustrations of 
 rooms used for fur storage show clearly the large space occupied 
 
 / /mM//////////////////////////////////////M/^ 
 
 J //////////////////////////W< 
 
 FIG. 6- 
 
 -AUTHORS DIAGRAM, SHOWING DUCTS FOR AIR CIRCULATION IN FUR 
 COLD STORAGE ROOMS. 
 
 by piping. It is not only the loss of space actually occupied by 
 the pipes, but also that the goods must be stored at a safe dis- 
 tance from them. Thoroughly distributed circulation of air is 
 not essential when using the forced circulation system for furs ; 
 all that is necessary is a distribution of air which will produce 
 uniform temperatures. A cross-section of the ducts arranged in 
 a fur room designed by the author is shown in diagram. The 
 perforations in these ducts are on the sides of the flow and re- 
 turn ducts. No marked difference in temperature can be noted 
 in different parts of the room when the fan is kept in continuous 
 operation. This arrangement of air distribution is not recom- 
 
COLD STORAGE OF FURS AND FABRICS 
 
 403 
 
 mended for any goods which throw off moisture, but is sufficient 
 for furs and fabrics. The first rooms to be used exclusively for 
 the storage of furs and fabrics were equipped with brine piping 
 directly in the room, and such an arrangement is still largely in 
 use, but the forced circulation or indirect system outlined above 
 is rapidly coming into use. 
 
 The ventilation of fur rooms may be easily accomplished; 
 and while not absolutely necessary to the welfare of the goods, 
 
 FIG. 7. — COLD STORAGE ROOM FOR FURS, SHOWING PIPING. 
 
 it is much better to have a nice sweet smelling room to show 
 prospective customers than one which has the lifeless and impure 
 atmosphere encountered in some fur rooms. The warm weather 
 ventilating system invented by the author for use in summer is 
 desirable at frequent intervals. (See chapter on "Ventilation.") 
 At one of the houses designed by the author a quantity of cloth- 
 ing containing moth balls was received, and the fact was not 
 discovered until the room was well scented. A few hours' opera- 
 
404 
 
 PRACTICAL COLD STORAGE 
 
 tion of the warm weather ventilating system was sufficient to 
 sweeten the air of the room perfectly. The rooms may be blown 
 out and thoroughly ventilated by forcing in fresh cold air from 
 the outside by using the cold weather ventilator in winter. 
 
 One of the first difficulties of the cold storage manager is 
 to educate his customers to do away entirely with the use of 
 moth balls, camphor balls, tar camphor, carbolic camphor, pow- 
 ders, tar paper or any of the ill smelling trash of various kinds 
 
 FIG. 8. — COLD STORAGE ROOM FOR GARMENTS, SHOWING PIPING. 
 
 which has for years been used to keep out the damaging moths. 
 Some warehousemen have also been troubled by the stable odor 
 from robes and coachmen's garments. Goods received containing 
 these objectionable odors should be carefully aired for some days 
 before placing in the cold storage room. If the odors cannot be 
 eradicated, the goods must be isolated in a room by themselves, 
 or rejected for storage and returned to the owners. It should 
 be the warehouseman's study to return goods in as good or better 
 
COLD STORAGE OF FURS AND FABRICS 405 
 
 condition than when received. To this end, all objectionable 
 goods must be excluded from the storage rooms. 
 
 The services of an expert furrier are provided in some 
 cases, and where the volume of business is sufficient, one may be 
 regularly employed. Any bright young man may be trained to 
 inspect furs on arrival at the storage house. Any blemishes or 
 imperfections should be noted on the receipt given to the cus- 
 tomer as a protection to the warehouseman. All furs should be 
 carefully beaten, dusted and aired before placing in the refrig- 
 erated rooms, and properly placed or stored to keep them in the 
 best possible condition. 
 
 Trophies like stuffed animals, heads, skins, etc., are best 
 hung or laid on racks. The best method of storing coats, cloaks, 
 etc., is to hang them on forms or shoulder stretchers to preserve 
 the shape and hang of the garment. If any metal hooks with 
 shoulders are used they should be wrapped with tissue paper 
 to prevent discoloring light colored furs or garments. The forms 
 are suspended from racks, and the whole covered by a piece of 
 heavy unbleached sheeting. This arrangement is plainly shown 
 in the accompanying view of a cold storage room (Fig. 8). The 
 illustrations (Figs, i to 9) also show the method of storing fur 
 rugs, stuffed heads, carpets, trunks, etc. In some cases each 
 individual garment is encased in a separate cloth cover. Sepa- 
 rate closets are sometimes provided for the use of single indi- 
 viduals, furriers and large customers, or for the storage of 
 especially valuable garments, the keys to which may be carried 
 by the customer. Such closets are usually made of slat or open 
 wire work, to allow of a free circulation of air. 
 
 A few of the advantages of refrigeration for the protection 
 of furs and fabrics are here concisely stated for the benefit of 
 those preparing printed matter for distribution : 
 
 Cold is instrumental in the production of furs, and it is as necessary 
 to their preservation. 
 
 Cold develops and enriches the fur when on the animal's back and 
 preserves its color and gloss • when manufactured into useful coverings. 
 Cold storing is like putting the fur back into its native element. 
 
 Cold prolongs the life of the fur by retaining the natural oils, which 
 are evaporated by the hot, dry air of summer. 
 
 Not only is the appearance of the fur improved, but the flexibility 
 and softness of the leather which supports it are retained. 
 
 Carpets, rugs and other woolens lose color and life in the hot sum- 
 mer air. A cold atmosphere revives the colors and rejuvenates the fiber. 
 
406 PRACTICAL COLD STORAGE 
 
 The wear and tear on furs, carpets and rugs by excessive beating is 
 entirely eliminated. 
 
 Garments stored on forms in refrigerated rooms are ready for imme- 
 diate use; in fact, can be removed from cold storage, worn for a single 
 night, and returned. 
 
 Curtains or draperies may be suspended from racks, avoiding damage 
 from folds. 
 
 Furriers who have used the system heartily indorse it. 
 
 Obnoxious odors from use of moth preventives are avoided. 
 
 Cold storage rooms are dust proof. 
 
 Cold storage gives absolute security against moth. 
 
 The usual storage rates for fur and fabric cold storage are 
 given below. The prices are in some cases less, in fact, some- 
 times only one-half those given. Each warehouseman must 
 be governed by local conditions and competition, and in most 
 cases the charges made by the furrier under the old method must 
 be approximately met. A furrier's charges nearly always in- 
 clude a guarantee against fire and moth. 
 
 SEASON RATES ON FURS. 
 
 Muffs $0.75 l° $i-°o 
 
 Boas, caps or gloves 75 to i.oo 
 
 Collarettes i.oo to 1.50 
 
 Capes not exceeding 20 'in. in length 1.00 to 1.50 
 
 Capes or sacques not exceeding 24 in. in length 1.00 to 1.50 
 
 Capes or sacques not exceeding 28 in. in length 1.50 to 2.00 
 
 Capes or sacques not exceeding 36 in. in length 2.00 to 2.50 
 
 Garments', such as dolmans, long sacques, etc 1.50 to 2.50 
 
 Overcoats, etc., not exceeding 40 in. in length 1.50 to 2.50 
 
 Garments exceeding 40 in. in length 2.00 to 3.00 
 
 Lap robes 1.50 to 2.50 
 
 Rugs, according to size 1.00 and up 
 
 Stuffed animals, birds, mounted heads, etc 1.00 and up 
 
 Monthly rate, one-third of season raies. 
 
 Season, nine months. 
 
 SEASON RATES ON WOOLENS, ETC. 
 
 Woolen garments stored in same manner as fur garments', two-thirds 
 of fur rates. 
 
 Blankets, clothing or other garments stored in trunks or boxes, rate 
 of seven cents per cubic foot per month, or fifty cents per cubic foot per 
 season of nine months. 
 
 Carpets and rugs not in boxes or trunks, four cents per cubic foot 
 per month. 
 
 Suits and dress suits, $1.50 per season. 
 
 Furniture, forty cents to sixty cents per cubic foot per season. 
 
 Monthly rate, one-third of season rate. Season, nine months. 
 
 Some warehouses make the season only six months, but the 
 usual season is nine months, and in most cases is figured to end 
 January 1. Goods carried beyond January 1 are usually charged 
 for at a short season (/'. c, January 1 to April 1) rate, at one- 
 
COLD STORAGE OF FURS AND FABRICS 407 
 
 third the long season rate. It is customary for warehousemen to 
 make a rate which insures against fire, moth and theft, although 
 this is by no means a universal rule. When so done the usual rate 
 is i per cent per season on valuation, insurance rate to govern 
 to some extent. 
 
 The form of warehouse receipt here shown has been found in 
 practice to answer the purpose for furs, etc., very well, but is 
 subject to many limitations and modifications. The words "Not 
 negotiable" should be printed or stamped across the face of the 
 receipt. It need not necessarily take this form, but should in- 
 clude the items mentioned and should read somewhat as follows : 
 
 TWENTY-FOUR HOURS' NOTICE REQUIRED FOR WITHDRAWALS. 
 
 NEW YORK FUR AND FABRIC STORAGE CO. 
 ioo Main Street. 
 
 No ' New York, 10.04. 
 
 RECEIVED for the account of 
 
 from 
 
 (contents' of packages unknown), to be stored in cold storage, for which 
 the sum of dollars paid to this com- 
 pany for storage from the date hereof until 
 
 The responsibility of the company for any piece or package, or the 
 contents thereof, is limited to the sum of one hundred dollars, unless the 
 value thereof is made known at the time of storing, and receipted for in 
 the schedule. An additional charge will be made for a higher valuation. 
 
 In consideration of the additional sum of dollars, the 
 
 said New York Fur and Fabric Storage Co. agrees to protect the said 
 articles from loss or damage by moths, fire and theft. 
 
 Should the above goods be withdrawn before the expiration of the above 
 term of storage, no portion of the charge shall be remitted, and, if con- 
 tinued longer, it shall be deemed a renewal under the same conditions, for 
 which a like rate shall be chargeable. 
 
 The said goods' are hereby valued, for the purpose of insurance, at 
 
 the sum of 
 
 dollars. 
 
 When the property covered by this icccipt is withdrawn, this receipt 
 should be surrendered to the company. 
 
 , Supt. 
 
 This chapter would not be complete without the addition of 
 an extract from the article on the "Cold Storage for Fabrics," 
 by Dr. Albert M. Read, of the American Security and Trust Co., 
 Washington, D. C, published in full in the June, 1897, issue of 
 Ice and Refrigeration. Dr. Read has taken up the subject and 
 handled it in a masterly and exhaustive way. Credit is also 
 
408 
 
 PRACTICAL COLD STORAGE 
 
 due to Walter C. Reid, of the Lincoln Safe Deposit Co., New 
 York, and Albert S. Brinkerhoff, of the Utica Cold Storage and 
 Warehouse Co., Utica, N. Y., for assistance in securing much 
 of the information contained in the foregoing. Following is a 
 portion of Dr. Read's article, referred to : 
 
 COLD STORAGE FOR FABRICS. 
 
 In order to conduct our business intelligently, it became necessary 
 to ascertain the effect of low temperatures upon the moth and beetle 
 
 FIG. g. — COLD STORAGE ROOM FOR CARPETS, SHOWING PIPING. 
 
 in the various forms of egg, larvae and perfected ins'ect. We, therefore, 
 had a small room fitted with brine pipes, divided into several sections by 
 stop-cocks, so that the temperature could be controlled to within about 
 5°, and began operation at from 20° to 25° F. Wh'en we thought we had 
 exhausted the subject at these temperatures, we took the next in order, 
 from 25° to 30° F, and progressed in this manner upward until the tem- 
 peratures of from 50° to 55° F. were reached. Each of these tests neces- 
 sarily consumed considerable time, the series having occupied the full 
 period of two years. Early in the first year, however, we learned that 
 the line of safety lay somewhat higher than the freezing point (32°), 
 and our plant was run for the balance of the season at that temperature. 
 
COLD STORAGE OF FURS AND FABRICS 409 
 
 The Egg— It is probable tbat the egg of the moth and beetle requires 
 a temperature somewhat higher than 55 F. for hatching. I say probably, 
 because, owing to the difficulty of obtaining the eggs, my experiments on 
 them havcjiot been sufficiently numerous to allow'of positive conclusions, 
 although those that have been made point strongly to the possibility stated. 
 
 The Larvae. — The larval condition is the one in which all the damage 
 to fabric is done by the insects in question. In passing from the egg 
 through this condition to the perfected insect, the fiber of the wool, fur, 
 etc., is eaten by the larva: of both the moth and the beetle for the grease 
 and animal juices in it, these constituting the principal source of food, 
 and by the larva of the moth for material out of which to spin the web 
 that constitutes a large proportion of the cocoon used for its protection. 
 In the larval state it was found that any temperature lower than 45° F. 
 was sufficient to keep the insect from doing damage to fabric, although 
 at that temperature, and at a temperature as low as 42 F., there was slow 
 and sluggish movement of the animal. At temperatures below 40 F. 
 movement was suspended, and the larva became dormant. At tempera- 
 tures above 45 F. the movements' of the larva became active, and it began 
 to work upon the fabric, the amount of this work and the .quickness of 
 movement increasing with each degree of temperature up to 55° F., when 
 the normal condition of activity appeared to be reached. 
 
 The Perfected Insect. — The miller and beetle, when subjected to 
 temperatures below 32° F.. were soon killed, as they were also after a 
 longer time at all temperatures between that and 40° F. At temperatures 
 between 32° and 40 F., 'however, when the insects were placed in the 
 center of a roll of heavy woolen rugs, they appeared to enjoy an immunity 
 from death for several weeks, although during this' period they were 
 entirely dormant. 
 
 It will be seen from the above that the investigations made have 
 quite conclusively proven that cold storage rooms for the preservation of 
 furs and fabrics from the ravages of moth and beetle may be kept at a 
 temperature as high as 40° F. with perfect safety, so far as these insects 
 are concerned. There may, in some plants, however, be trouble . from 
 the drip from the cooling pipes of the storage room at this temperature, 
 which will, of course, be very objectionable, and should be obviated by 
 a slight lowering of the temperature of the room. We have run our 
 rooms at temperatures varying from 35 to 40 F. without trouble in 
 this regard. 
 
 In the course of the investigation some matters of interest in con- 
 nection with the effect of cold upon these insects came to my notice. As 
 these may prove of value in the future, I will state them in a few words. 
 It was found that the larvae of both the moth and the beetle had the 
 power of resisting temperatures as low as 18° F. for a long period without 
 apparent harm, and that they came out of the dormant condition super- 
 induced by the low temperature in the same physical condition as' when 
 they entered it. and apparently took up their natural avocation at the 
 precise point where it was interrupted. When these larvae were alternately 
 exposed to low and higher degrees of temperature, so that they passed 
 from the dormant to the active condition and back again several times 
 in succession, their power of resistance was' considerably lessened, and 
 they died much sooner th'an when kept dormant in a low temperature 
 continuously. This would indicate that a winter, during which short 
 periods of cold are followed by similar periods of warm weather, would 
 he followed by a summer of decreased insect life. 
 
410 PRACTICAL COLD STORAGE 
 
 CHAPTER XX. 
 KEEPING COLD STORES CLEAN. 
 
 CARE OF COLD STORAGE ROOMS WHEN EMPTY. 
 
 The care of cold storage rooms during periods of idleness, 
 or when no goods are in storage, is of the greatest importance 
 for the reason that good results in storage of goods depend 
 largely on the condition of the storage room. With this fact in 
 mind the author sent out a circular letter of inquiry to a number 
 of cold storage warehousemen containing a list of questions 
 which embrace the subject of whitewashing; whether it should 
 be done by hand or machine ; whether any other preparation is 
 as good as whitewash ; whether it would properly purify rooms 
 for the storage of such goods as eggs after storing apples or 
 other fruits ; whether it is necessary to whitewash each year and 
 also in regard to painting, at the time of whitewashing, the pipes 
 or refrigerating surfaces which cool the room. Questions were 
 also asked in regard to the methods of preparing whitewash and 
 whether means of ventilating are provided at the time of white- 
 washing. Further information of a general character was so- 
 licited. 
 
 The number of replies received was rather disappointing, 
 but some of the more careful and conscientious cold storage men 
 gave detailed and very full information. It is evident from a 
 majority of the answers received that comparatively little atten- 
 tion is given to the cold storage rooms when they do not contain 
 goods. Cold storage rooms need as careful attention, although 
 in a different way, when they do not contain goods, as when 
 goods are stored therein. When the flow of refrigerating me- 
 dium (usually ammonia or brine) is shut off at a time when there 
 is frost on the pipes, this frost will evaporate in the form of air 
 moisture, even though it does not actually melt, and cause the 
 air of the room to become damp. Dampness with a compara- 
 tively high temperature will in time cause a growth of mold and 
 
KEEPING COLD STORES CLEAN 411 
 
 a musty condition of the room. Systematic whitewashing with 
 ventilation will kill this growth of mold, but it is much better to 
 prevent a trouble of this kind than to overcome it after it has 
 obtained a foothold. 
 
 As soon as the goods are removed from cold storage rooms 
 the frost on cooling pipes should be removed and taken out of the 
 room. If the fan system of air circulation is employed, with the 
 coils all located in a coil room or bunker, this is a comparatively 
 easy matter to attend to. Where the pipes are directly in the 
 room, the resulting slop will necessarily cause the floor and walls 
 to become damp to a greater or less extent. Moisture on floors 
 of cold storage rooms should be taken up by throwing clown dry 
 sawdust or air slaked lime. It should be removed at once and 
 not allowed to soak into the floor lining or insulation. A few 
 barrels of dry sawdust should be on hand at all times for the 
 purpose of soaking up melting frost or possible leakage from 
 any cause. With the coil room and fan system the floor of 
 coil room is usually water tight and properly connected with out- 
 let to drain system so that damage to insulation cannot occur 
 in this way. 
 
 After removing the frost from refrigerating pipes, meas- 
 ures- should be taken to keep the rooms dry and pure. This may 
 be done by exposing a quantity of quicklime in the room. It 
 may be placed on the floor, but should not be placed on any wet 
 spots unless it has already been air slaked and is in powdered 
 form. It might under some circumstances cause the starting of 
 a fire from the heat of slaking. Chloride of calcium placed on 
 trays or pans or supported on a screen shelf above a water-tight 
 pan, as illustrated in the chapter on "Uses of Chloride of Cal- 
 cium," may be used to good advantage. Where the coil room and 
 fan system are in use, chloride of calcium may be supported in 
 the coil room as in the author's patented chloride of calcium 
 process, or in any other suitable way, and by operating the fan 
 a short time at intervals the room may be kept in a pure and dry 
 state. During cool or cold weather it is a good plan to allow 
 the air to blow through the rooms when it is dry outside and 
 about the same or a little lower than the temperature of the room. 
 What is still better is the cold weather ventilating system, which 
 is described in the chapter on "Ventilation." With this sys- 
 
412 PRACTICAL COLD STORAGE 
 
 tern fresh air ma)' be taken from outside the cold storage building 
 and forced into the room in large quantities and the foul air from 
 the room is allowed to escape through a suitable vent. The in- 
 coming air may be forced directly into the room without heating, 
 or it may be heated to any required temperature by passing it 
 over a steam coil or jacketed heater. 
 
 A few words in regard to the proper preparation of new 
 cold storage buildings for the receiving of goods may not be out 
 of place here. In the finishing up of a cold storage building it 
 very often occurs that the work has to be rushed and enough 
 time is not allowed for the proper whitewashing of the wood 
 lining or interior surfaces of the room. This situation demands 
 care and rapid work and advantage must be taken of all 
 opportunities for whitewashing the rooms as fast as they are 
 ready or as soon as a portion of their surfaces is ready. Keep 
 men at work whitewashing following up the carpenters. By 
 keeping the doors open and using the ventilating system intelli- 
 gently, if one is installed, some of the rooms may be ready to 
 receive goods as soon as the refrigerating equipment is ready to 
 supply refrigeration. If no other means of properly drying are 
 at hand, use chloride of calcium as illustrated in chapter referred 
 to. In whitewashing cold storage rooms for the first time, it is 
 advisable to apply first a thin coat of whitewash so that it may 
 penetrate the wood as much as possible. It will also make a 
 better ground for the second coat. The second coat may be 
 somewhat thicker and should not be applied until the first coat 
 is thoroughly dry. 
 
 WHITEWASHING AND MAKING WHITEWASH. 
 
 The proper drying out of whitewash in cold storage rooms 
 is a difficult matter, owing to the inclosed nature of the rooms, 
 which are usually provided with but one opening, also to the 
 low outside and inside temperatures which usually prevail at 
 the time of whitewashing. The cold weather ventilating system, 
 already referred to, is of great assistance at such a time. By 
 applying heat to the rooms and allowing the cold, moist air to 
 escape as the dry, warm air is forced in, the whitewash may be 
 dried very thoroughly. It is customary in some plants, especially 
 in the larger cities where some of the rooms are in service during 
 
KEEPING COLD STORES CLEAN 413 
 
 the greater part or all of the year, to dry out the rooms by placing 
 a "salamander," or sheet iron heater for burning coke or char- 
 coal, in the room. This is not a very scientific nor. practical 
 method, as the moisture driven out of the room in which the 
 salamander is placed is conveyed to other rooms of the house or 
 into the, corridor to some extent ; besides this, the salamander 
 will dry out only a portion of the room at .a time. The gas gen j 
 erated is also very objectionable and even dangerous to persons 
 working in the room. In using a salamander it is best to light 
 the fire and allow it to get well started before taking into the 
 storage room. In this way a large part of the gas is avoided. 
 For the most nearly perfect job of whitewashing from five to 
 eight days are required to dry thoroughly. If the whitewash 
 dries rapidly, as it may when a salamander is used, it will flake 
 off and not be permanent. On the other hand, if it does not dry 
 within a reasonable length of time, the water in same will soak 
 into the wood and, in finally drying, the whitewash will have a 
 dark or mottled appearance. Rapid drying, therefore, should be 
 avoided as well as slow drying. 
 
 The importance of attending to the matter of whitewashing 
 in new houses which are rushed to completion can not be too 
 strongly dwelt upon. The author has repeatedly come in contact 
 with this situation and much time and effort have been expended 
 by him in trying to get whitewashing properly done and at the 
 right time. Those new to the business do not appreciate the 
 importance of whitewashing and the necessity of looking after it 
 carefully. Very bad results have in numerous cases followed 
 the careless daubing on of whitewash, and allowing it to dry at 
 its own pleasure. In some cases butter has been very strongly 
 flavored in a way which could not be accounted for; again, eggs 
 are damaged, and other goods to a greater or less extent, de- 
 pending on their sensitiveness. If whitewash is plastered on the 
 walls too thick and does not dry, the water contained therein 
 penetrates the wood and may cause a fermentation, which leads 
 to a peculiar bitter or strong smell in the room, which in turn 
 will flavor the goods. If the case is an aggravated or serious 
 one, mold will develop, and the serious nature of this trouble 
 is too well understood to need description. Whitewashing should 
 be done in the winter or during weather when the air is about 
 
4U PRACTICAL COLD STORAGE 
 
 as cold or colder outside than inside the storage rooms. It is 
 then much easier to get the rooms dry. Bad effects have followed 
 whitewashing during warm weather, because it is so difficult to 
 get the rooms to dry properly. 
 
 It is a popular idea, and yet entirely wrong, that most any- 
 body can prepare and apply whitewash. Of those who think 
 they know how to whitewash, probably not one in ten knows how 
 to slake the lime. This should be done in one of two ways, either 
 of which is good. The author recommends the following : Take 
 one-half bushel of lime and place it in a half-barrel (an oil bar- 
 rel or vinegar barrel which has been cut down makes a good 
 utensil for this purpose) ; pour on a small quantity of boiling 
 water, barely sufficient to cover the lumps of lime ; keep the lime 
 well stirred clear to the bottom (a piece of one-inch gas pipe 
 about five or six feet long is the best stirring stick). In case the 
 lime is very quick, it should require two persons to slake the lime, 
 one to pour on the water as needed and one to stir. The stirring 
 should be kept up continuously from the time the lime begins to 
 slake until it is reduced to a paste, and water should be added as 
 fast as the lime slakes, so as to keep it at a rather thin, pasty con- 
 sistency. It is very common to see lime placed in a barrel and 
 water turned on and the lime allowed to slake itself. The result 
 is that the whitewash is full of small pieces or lumps which are 
 not slaked, but are burned as the result of water not coming in 
 contact with the lime at the right time. It is not absolutely neces- 
 sary that boiling water should be used, but unless the lime is 
 quite quick, it facilitates the operation and results in more thor- 
 ough slaking. Another method which may be employed is to 
 place the lump lime on a cement floor and sprinkle water on 
 slowly as the lime slakes. If this is handled carefully and at- 
 tended to the result will be a finely-powdered slaked lime, which 
 may be mixed with water to a proper consistency. The author 
 does not recommend this method as compared to the one first 
 described, as it is slower and there is much more danger of burn- 
 ing the iime and causing the whitewash to be lumpy. 
 
 A large number of those who replied to the circular letter 
 of inquiry are using the Government formula for making white- 
 wash, but one of the ingredients of this formula is rice boiled 
 to a thin paste, which makes it seem difficult to the average per- 
 
KEEPING COLD STORES CLEAN 415 
 
 son, and, further than this, the author does not believe in using 
 any organic substance in preparing whitewash. For those who 
 prefer the Government formula it is here given : 
 
 Slake half a bushel of quick lime with boiling water, keep it covered 
 during the process. Strain it and add a peck of salt dissolved in warm 
 water, three pounds of ground rice put into boiling water and boiled to 
 a thin paste, half a pound of powdered Spanish whiting, a pound of clean 
 glue, dissolved in warm water ; mix these well together and let the mix- 
 ture stand for several days. Keep the wash thus prepared in a kettle or 
 portable furnace and put it on as hot as' possible with either painters' or 
 whitewash brushes. 
 
 It is better to use the mineral substances, and the following 
 has given good satisfaction under most circumstances : One- 
 half bushel of lime, slaked with hot water, as previously de- 
 scribed. When the lime is thoroughly slaked, add one peck of 
 salt. It will be necessary to add more water as the salt is added, 
 in order to keep the whitewash at the proper consistency ; or 
 the salt may be dissolved separately in as small an amount of hot 
 water as will absorb it readily. The proper consistency for 
 whitewash is a thin paste and it may be tempered as it is used. 
 To each twelve-quart pail of whitewash, composed of lime and 
 salt as above, add a good, fair handful of Portland cement and 
 about a teaspoonful of ultramarine blue. The cement and blue 
 should be added only as the wash is being used and should be 
 thoroughly stirred into the whitewash ; otherwise, when applied, 
 it will be streaked. Cement is used for the purpose of giving 
 the whitewash a better setting property so as to make it ad- 
 here better to the surface to which it is applied. The ultramarine 
 blue is used simply to counteract the brownish color of the Port- 
 land cement. If white hydraulic cement is obtainable, it is better 
 to use than Portland cement, and in this case the ultramarine 
 blue may be dispensed with. It is, however, best to use a small 
 amount, sav half a teaspoonful to the pail, as a whiter surface 
 results. The wash should be strained through a fine wire-cloth 
 strainer before using, to remove the lumps if there are any 
 present. 
 
 WHITEWASHING MACHINES. 
 
 The advisability of using whitewashing machines or spray- 
 ing pumps in cold storage work has been an open question for 
 some time. Of the replies received, about one-half recommend 
 
416 PRACTICAL COLD STORAGE 
 
 the use of the machine. Some say the machine will do the best 
 work, but this is not the author's experience. There are some 
 situations where the machine is a decided advantage ; for in- 
 stance, on overhead work, between open joists, or any surface 
 which is difficult to get at with a brush. It is hardly possible to 
 get as smooth and even a job with the machine as it is by hand, 
 and, besides, a machine will necessarily put a good deal more 
 whitewash on a given amount of surface than is put on with 
 brushes. This is objectionable, for the reason that a heavy bed 
 of whitewash on drying will flake off much more quickly. In 
 some cases, those who use a machine go over it with a brush while 
 still green in order to make it smooth and even. Another ob- 
 jection to a machine is that it will cause a mist in the air and the 
 whitewash will spatter over any object in the room. A room 
 must be entirely empty in order to use a machine. It should not, 
 of course, be inferred that it would be practicable to whitewash 
 a room while goods are stored in same, but it is necessary to 
 clean a room out of everything that is liable to be injured by the 
 whitewash in order to use a machine. The spray is also verv 
 uncomfortable for the operator. A moderately thin coat of white- 
 wash on old work is as good for purifying purposes as a thick 
 one ; and for this reason handwork is to be preferred to machine, 
 as much less material may be applied. The more whitewash 
 put on the more water to be gotten rid of in some wav, and if 
 the water is not removed promptly very bad effects may result, 
 as already noted in discussing the drying out of cold storage 
 rooms after whitewashing. 
 
 The author's impression is strongly in favor of hand-work, 
 but it is not a desirable job for the man who has to do the work. 
 It is probable for this reason that the machines are gaining head- 
 way. They have also been perfected to quite an extent during 
 the past few years. There are a good many different makes of 
 first-class machines on the market. The same machine that fruit 
 growers use for spraying trees is available for whitewashing 
 and the same machine is commonly sold for both purposes. 
 
 Good work in whitewashing should look well, be perfectly 
 white or nearly so, should be hard and not liable to flake off or 
 dust off onto the hands or clothing, and should have complete 
 disinfecting and germ-killing properties. The slaking of the lime 
 
KEEPING COLD STORES CLEAN 417 
 
 is the most important part of the operation and the success of 
 same depends upon the care and attention given. Too much care 
 can not be given to this detail, and cold storage men should see 
 to it that whoever has this in charge looks after same conscien- 
 tiously, Lime that is burned or drowned in slaking is not firm 
 in texture when applied and is not as disinfecting nor fireproof 
 as it should be. 
 
 PAINT FOR ROOMS AND PIPING. 
 
 There are many good cold-water paints on the market under 
 various names which are advisable in some places for which 
 whitewash is not well adapted, and many use them for all interior 
 surfaces. For butcher's boxes or retail coolers especially they 
 are preferred to whitewash, for the reason that they will not flake 
 off readily. It is also good for doors and corridors of cold storage 
 houses. Most of these cold-water paints are composed of secret 
 ingredients, and some contain organic substances like glue, which 
 makes their use inadvisable for cold storage purposes, except in 
 special situations. Shellac is also largely in use for cold storage 
 rooms, but it has no disinfecting or cleansing properties like 
 whitewash. It makes a beautiful finish where the lumber in use 
 has a good natural grain. Shellac has the advantage of being 
 waterproof, and therefore walls may be easily washed at any 
 time. It is, perhaps, unnecessary to state that any oil paint, or 
 any other preparation with strong odor, has no place about the 
 cold storage rooms or the corridors or other approaches thereto. 
 
 In connection with the whitewashing of rooms and their 
 care during periods of idleness, it has seemed proper to take up 
 the cleaning and painting of the pipes or refrigerating surfaces 
 which cool the room. The answers to the questions covering this 
 subject indicate that it is not customary among cold storage 
 men to paint their pipes after they are once installed, and this is 
 strictly in line with the author's ideas and experience on the 
 subject. 
 
 There are two good reasons why the painting of pipes is 
 not advisable after they are once put in place in the cold storage 
 plant ; first, it does not pay ; second, it is dangerous. It does 
 not pav, because after the pipes are once put in place a good job 
 of painting cannot be done unless the coils are entirely removed 
 
 (27) 
 
418 PRACTICAL COLD STORAGE 
 
 from their supports so that they can be painted on both sides. 
 The labor involved in removing the refrigerant, taking down 
 the pipes, cleaning them and applying the paint is considerable, 
 and the cost of the paint is no insignificant item. A good paint 
 put on the pipes before they are set up in the cold storage house 
 will protect them fairly for a period of from two to three years, 
 more or less. Before the coils are set in place it is comparatively 
 easy to paint them and it is recommended that coils should be 
 painted when new. It is especially desirable to paint them at this 
 time, as the pipes are clean and free from scale or rust. After 
 the pipes become rusty from service, it is almost impossible to 
 get them sufficiently clean so that the paint will adhere properly. 
 Considering the low price of pipe and its comparatively long life 
 when used with ammonia or chloride of calcium brine, it does not 
 seem to warrant the expense. It is dangerous to paint pipes in 
 a cold storage room for the reason that no paint known to the 
 author is non-odorous or anywhere near it. The pipes should, 
 therefore, be removed from the rooms for painting and allowed 
 to dry and deodorize before they are returned to the cold storage 
 room. This, however, is rather impracticable and it adds to the 
 expense. 
 
 For painting pipes, various preparations have been used with 
 more or less success. There are a number of patented and pro- 
 prietary preparations on the market which are good and are 
 sold at a reasonable price. Red lead and boiled oil is also an old 
 stand-by for. this purpose, but it is much more expensive than 
 some of the preparations above mentioned. Boiled linseed oil 
 without any pigment as a coating for refrigerating surfaces will 
 give. good protection from rust for a limited time, but the com- 
 mercially prepared products will be found superior though some- 
 what more expensive. 
 
SHIPPING PERISHABLE PRODUCTS 419 
 
 CHAPTER XXL 
 SHIPPING PERISHABLE PRODUCTS.* 
 
 PROTECTION FROM INJURIOUS TEMPERATURES. 
 
 The information following is largely a compilation of the 
 opinions of farmers, merchants and shippers in all parts of the 
 country, which were received in reply to a circular letter sent out 
 by the United States Weather Bureau. The principal kinds of 
 goods which are considered perishable, and for which protection 
 from excessive heat or cold is necessary are: All fruits and 
 vegetables, milk, dairy products, fresh meats, poultry, game, fish, 
 oysters, clams, canned fruits and vegetables, and most bottled 
 goods. In the transportation of perishable freight there are 
 three primal objects to be attained : 
 
 i. — The protection of the shipment from frost or excessive 
 cold. 
 
 2. — The protection of the same from excessive heat. 
 
 3. — The circulation of air through the car, so as to carry off 
 the gases generated by some classes of this freight. 
 
 [It is not plain how a circulation of air will carry off gases 
 from goods. Probably what is meant is to call attention to the 
 importance of air circulation to purify the air and maintain 
 uniform temperature. See chapter on "Air Circulation."] 
 
 The degree of cold to which perishable goods may be sub- 
 jected without injury varies greatly with different commodities, 
 and depends somewhat on the time the shipment will be on the 
 road, its condition when shipped, whether it is kept continually 
 in motion, and also on whether it is unloaded immediately upon 
 arrival at its destination, or allowed to stand some time. The 
 direction of shipment, whether toward a cold area or away from 
 it, should also be considered. 
 
 *Abstracted from Farmers' Bulletin No. 125, United States Department of Agricult- 
 ure. 
 
420 PRACTICAL COLD STORAGE 
 
 CARS, APPLIANCES AND METHODS OF SHIPPING. 
 
 Precautions taken in shipping to protect from cold are pack- 
 ing in paper, straw or sawdust, ■ boxing, barreling with paper 
 lining, shipping in paper lined cars, refrigerator cars, and cars 
 heated by steam, stoves and salamanders. 
 
 Shippers and agents concur in the statement that danger in 
 transportation by freezing can be practically eliminated by the 
 shipment of produce by modern methods; the lined car suffices 
 in spring and autumn, and usually during winter, while in ex- 
 tremely cold weather specially built cars are used. 
 
 In ordinary freight cars perishable goods can be shipped 
 with safety with the outside temperature at 20° F., and in refrig- 
 erator cars at 10°. In the latter these goods may be safely 
 shipped with an outside temperature of from zero to io° below, 
 if the car is first heated, and at the end of the journey the goods 
 are immediately taken into a warm place without being carted 
 any great distance. 
 
 [Any statement cannot be as positive as this and be accurate 
 when applied to so varying a subject as shipping of perishable 
 goods. The protection of food products in shipment during 
 extreme cold weather depends on several things with a great 
 variation of conditions. Fully as much depends on the tempera- 
 ture of the goods themselves as on the temperature of the car 
 and the use of insulating substances for packing the goods or 
 the use of an insulated car. Take as an example the shipping 
 of eggs : If loaded into a good refrigerator car at a temperature 
 of 30° F. (as when loading from the cold storage room) no 
 amount of protection or the use of an extra well insulated car 
 will prevent freezing if on the road for several days with an 
 outside temperature below zero. On the other hand, if started 
 at a temperature of from 45 ° to 50° F. a moderate protection will 
 suffice, and the regular refrigerator car will take them through 
 safely.] 
 
 To protect goods shipped in an ordinary car, the sides of 
 the car should be protected by heavy paper tacked to the wall, 
 and by the addition of an inner board wall, a few inches distant 
 from the outer one. A car thus equipped and packed with prod- 
 uce, surrounded by straw, will retain sufficient heat to prevent 
 injury for twenty-four hours, the average air temperature inside 
 
SHIPPING PERISHABLE PRODUCTS 421 
 
 the car being at least twelve degrees higher than the outside 
 air. Cars are sometimes warmed by steam from the locomotive 
 when in motion, and by stoves when steam is not available. Cars, 
 after being loaded, are carefully inspected as to temperature 
 within ; their destination is considered ; and, if the weather is 
 exceedingly cold, or is liable to be, the car is often accompanied 
 by an attendant ; otherwise it is inspected from time to time on 
 the road. Lined cars — that is, cars lined with tongued and 
 grooved boards on the sides and ends — are considered the best 
 for shipping potatoes, as they can be heated by an ordinary stove 
 and will stand a temperature outside of 20° below zero, when 
 a man is in charge to keep up the fires. 
 
 [The most approved arrangement in a potato shipping car 
 is a false floor and a partial false ceiling to allow of a circulation 
 of air. The stove is placed in the center and the warm air 
 ascends to the ceiling where it passes along to the ends of the 
 car, descending and returning under the false floor to the stove 
 in center of car.] 
 
 REFRIGERATOR CARS. 
 
 The better class of refrigerator cars will carry all perishable 
 goods safely through temperature as low as 20° below zero, pro- 
 vided they are not subjected to such temperature longer than 
 three or four days at a time ; but with the ordinary refrigerator 
 cars a temperature of zero- is considered dangerous, especially if 
 the goods they contain be of the most perishable kind. 
 
 In winter time refrigerator cars are used without ice in for- 
 warding goods from the Pacific coast; in passing through cold 
 belts or stretches of country the hatches are closed, and the cars 
 being lined and with padded doors, the shipment is protected 
 against the outside temperature; in passing through warmer 
 climates the ventilators are opened in order to prevent the perish- 
 able goods from heating and decaying. 
 
 It is stated, however, that for the shipment of fruit the ordi- 
 nary refrigerator car is not entirely satisfactory, and that there 
 is a strong demand for a better refrigerator car than can now 
 be obtained. [The author knows this to be a fact. The re- 
 frigerator cars now in use have been designed for the most part 
 by men of moderate scientific or mechanical knowledge, and 
 
422 PRACTICAL COLD STORAGE 
 
 present great opportunity for improvement. Owing to the 
 nature of the companies controlling the refrigerator car business, 
 the practical engineer has little opportunity of introducing im- 
 proved methods in the construction of refrigerator cars.] A 
 car is wanted that will carry oranges, bananas, etc., without clan- 
 ger of chill through the coldest climates of the country, as the 
 delays in housing are injurious to the keeping qualities of the 
 fruit, and the dealer is also kept out of the use of his goods. 
 
 The following is a description of a much used patent refrig- 
 erator car : 
 
 "The car is double lined and has at each end of the interior 
 four galvanized iron cylinders, reaching from the floor to near 
 the top. Ice is broken to pieces about the size of the fist, and 
 the cylinders filled with this ice and salt, the whole being tamped 
 down hard. It is claimed that cars iced in this manner do not 
 need re-icing in crossing the continent, as other styles of cars do. 
 The car is iced in winter in the same manner as in summer, as 
 such icing prevents freezing." 
 
 [An absurd statement. Icing and salting will not prevent 
 freezing, and there is no use in icing during cold weather. If 
 tanks could be filled with water, freezing of goods in the car 
 would be in some cases prevented.] 
 
 The car that has the most floor space and will hold the 
 greatest quantity of ice is preferred by most shippers. 
 
 Mistakes are often made in building fires in round-houses 
 where cars of produce are stored, unnecessarily heating it, a 
 uniform temperature, just above the danger point, being the most 
 favorable. 
 
 VENTILATED CARS. 
 
 In 1895 an experiment for testing the advantages of dif- 
 ferent modes of ventilation during the shipment of fruit was 
 made under the direction of the Riverside Fruit Exchange, of 
 Riverside, Cal. Five cars loaded with oranges were shipped a 
 distance requiring a seven days' run. Four refrigerator cars 
 and one ventilated or fruit car were used. Two of the refrig- 
 erator cars had the ventilators closed from 4 a. m. till 8 p. m. 
 each day, and open the remainder of the time. The other two and 
 the fruit car had ventilators open during the entire trip. Ob- 
 
SHIPPING PERISHABLE PRODUCTS 423 
 
 servations were made of the outside and inside temperatures at 
 4 and 9 a. m. and 3 and 8 p. m. In the first two cars the inside 
 temperature ranged from 46° and 42° F. minimum to 56 and 
 58° F. maximum, respectively ; in the second two, from 48° and 
 44 F. minimum, to 58 and 62 ° F. maximum, respectively; and 
 in the fruit car from 42° minimum to 68° maximum. The out- 
 side temperatures ranged from eight degrees lower to nineteen 
 degrees higher than the inside. It was found that the tempera- 
 ture varied less in the refrigerator cars than in the fruit cars, 
 owing to the fact that they were better insulated. It was also 
 found that the fruit in the cars which had the ventilators closed 
 during the day arrived in much better condition than that in the 
 cars which had the ventilators open. 
 
 OUTSIDE AND INSIDE TEMPERATURES. 
 
 The relation between the outside air temperature and the 
 temperature within the car varies largely, depending on the kind 
 of car, whether an ordinary freight or refrigerator car, whether 
 lined or not, whether standing still or in motion ; and also on the 
 weather, whether windy or calm, warm or cold. In an ordinary 
 freight car the difference ranges from two to fifteen degrees, and 
 in a refrigerator car from fifteen to thirty degrees. If the latter 
 be provided with heating apparatus, the temperature in winter 
 can be kept at any required degree. 
 
 From six observations taken at intervals of ten minutes, it 
 was found that on a warm day, when the mean of the six read- 
 ings outside was 68°, it was 66° F. on the inside of an ordinary 
 freight car, and 63° F. inside of an uniced refrigerator car. On 
 a cold day the mean of six observations was 38° F. outside and 
 35" F. inside of an ordinary car, and 36° F. inside of a refrig- 
 erator car ; the cars were stationary. 
 
 Freight from the Pacific coast to the Mississippi valley, or 
 to the Atlantic coast, has to pass through several varieties of 
 climate at any time of the year, so that at one time the tempera- 
 ture inside the car will be materially above the outside tempera- 
 ture, while perhaps a few hours later it will be below. 
 
 Products sent loose in a car are packed in straw on all sides, 
 particular attention being paid to the packing around doors, and 
 to see that the car is full. Manure is largely used to protect 
 
424 PRACTICAL COLD STORAGE 
 
 perishable goods, the bottom of the car being thickly covered 
 with it, and in some cases it is put on top of the goods. 
 
 [Xo sane man would use manure in a car with perishable 
 goods unless they were in some sealed package like cans or 
 bottles. In any case straw, or better still, mill shavings are 
 better than manure for any purpose of this kind.] 
 
 The temperature of the produce when put into the car is 
 quite a factor to be observed. If it has been exposed to a low 
 temperature for a considerable time before, it is in a poor condi- 
 tion to withstand cold, and the length of time so exposed should 
 be taken into account. It is also claimed that a carload of 
 produce, like potatoes, will stand a lower temperature when the 
 .car is in motion than when at rest. 
 
 [One of the old popular ideas without material foundation. 
 Men and animals will withstand low temperature best when in 
 motion, but this does not apply to perishable goods.] 
 
 Goods at a temperature of 50 to 60° F., packed in a refrig- 
 erator car, closed, have been exposed to temperatures 10° to 20° 
 below zero for Hour and five days without injury. 
 
 FRESH MEATS. 
 
 In shipping fresh meats the almost universal practice is to 
 ship in refrigerator cars where the temperature can be main- 
 tained at any desired degree, a temperature from 36 to 40 F. 
 being considered the best. 
 
 Beef. — Fresh beef for shipping should be chilled to a tem- 
 perature of 36° F., although under favorable conditions it will 
 arrive in a good state if chilled to only 40° F. The cars should 
 be at the same temperature as the chill room, and it is considered 
 very important to have an even temperature from the time the 
 beef is taken from the chill room until its arrival at its des- 
 tination. 
 
 In shipping long distances in summer, it is necessary to 
 re-ice the cars, the frequency depending on the prevailing tem- 
 perature, so that no fixed rule can be given. In winter the tem- 
 perature is kept up to 36° F. by means of stoves or oil lamps. 
 
 If refrigerator cars are not used, the meat should be wrapped 
 in burlaps, and the carcasses hung so as not to touch each other. 
 With an outside air temperature of 50 F., or below, in dry 
 
SHIPPING PERISHABLE PRODUCTS 425 
 
 weather, meat that has been thoroughly cooled will keep a week 
 if shipped in an ordinary box car. 
 
 Pork. — Pork is injured more quickly by high temperature 
 than other meats, and greater care should be taken with it in 
 storing and shipping. Sudden changes in temperature of from 
 io° to 20° F. are very injurious to fresh meats, and should be 
 provided against when possible. 
 
 Poultry. — Poultry, if shipped at a temperature of 50° F. 
 or higher, should be packed in ice and burlaps ; if under 50 F., 
 in dry weather, no extra precautions are needed. In shipping 
 live poultry the coops are frequently overcrowded, resulting in 
 the death or great deterioration of many of the fowls. 
 
 DAIRY PRODUCTS AND EGGS. 
 
 Milk. — Milk for shipping requires great care to prevent 
 souring ; it should be reduced after drawing to a temperature of 
 40° F., which extracts the animal heat. It should never be 
 frozen, as it becomes watery and inferior in quality when 
 thawed out. 
 
 Eggs. — Eggs are packed in crates with separate pasteboard 
 divisions, with a layer of excelsior top and bottom. Pickled 
 eggs are injured by cold sooner than fresh ones. 
 
 A prominent wholesale dealer in butter, eggs, and cheese at 
 Chicago, says : 
 
 Eggs in storage and transportation cannot stand a lower temperature 
 than 28° F. ; if packed well in cases and loaded in a refrigerator car they 
 usually come through in good condition at from 5° to io° below zero, and 
 at 10° above zero in common cars, if not exposed more than forty-eight 
 hours. 
 
 Butter and Cheese. — A wholesale butter and cheese firm of 
 Chicago writes as follows : 
 
 Butter is probably unaffected by extreme cold. We have never ex- 
 perienced any damage by butter being too cold ; in fact, in carrying it in 
 cold storage, it is carried at from zero to io° above ; but extremely warm 
 weather is very injurious and damages the article to a considerable extent. 
 To preserve butter it should be kept as 1 cold as possible, as we sta.te above, 
 all the way from 32° above down to zero. It all depends upon what the 
 facilities are for carrying the same. Of course, when we place it in 
 cold storage the temperature we would require would be zero to io° above, 
 and, of course, that temperature we cannot have in handling it when we 
 come to sell it out in our store, but we take great care not to take out 
 of storage any more than can be readily sold. In regard to cheese, extreme 
 cold and extreme heat are both injurious to same. For instance, extreme 
 
426 PRACTICAL COLD STORAGE 
 
 heat will cause cheese to swell and ferment [Not if the cheese is well 
 made. Extreme heat injures cheese by starting the butter fat, which 
 causes the cheese to become dry and crumbly.], while extreme cold will 
 freeze it; the curd becomes dry and like sawdust, and it will never 
 again be firm and stick together, but will crumble. It takes quite a 
 temperature to freeze cheese, say 10° above for one or two days' out on 
 the road would freeze it. It is very slow in freezing and very slow in 
 thawing out. A skim-milk cheese will freeze quicker than a full cream 
 cheese. 
 
 FISH AND OYSTERS. 
 
 Fish. — Fish are shipped by express and also by freight. 
 When shipped by express they are packed in barrels with ice. 
 When shipped by freight they are packed in casks holding 600 
 pounds each, or in boxes on wheels, holding about 1,000 pounds 
 each. When shipped in carload lots they are packed in bins 
 built in the car and thoroughly iced. The amount of ice supplied 
 should equal one-half the weight of the fish. Fish keep best 
 when the temperature of the box in which they are stored is 
 about that of melting ice. Under favorable conditions fish 
 remain sound and marketable for thirty days after being caught 
 and packed in ice. The entrails of fish should be removed before 
 shipping, as they are the parts that most readily decay, and taint 
 the flesh of the fish. This is especially necessary in shipping 
 long distances. 
 
 Oysters. — Shucked oysters, shipped in their own liquor in 
 tight barrels, will not spoil if frozen while in transit. Thick or 
 fat clams or oysters will not freeze as readily as lean ones, as 
 the latter contain much more water. Oysters will not freeze as 
 readily as clams. It is safer when oysters or clams in the shell 
 are frozen to thaw them out gradually in the original package 
 in a cool place. 
 
 In freezing weather oysters and clams, in the shell, are 
 shipped in tight barrels lined with paper. 
 
 FRUITS. 
 
 It is important to note that in shipping fruits, etc., many of 
 the precautions taken in packing to keep out the cold will also 
 keep in the heat, and there is really more danger in some in- 
 stances from heating by process of decomposition than from cold. 
 All fresh fruit tends to generate heat by this process. A car load 
 
SHIPPING PERISHABLE PRODUCTS 427 
 
 of fresh fruit approaching ripeness, closed up tight in an uniced 
 refrigerator car, with a temperature above 50° F., will in twenty- 
 four hours generate heat enough to injure it, and in two or three 
 days to as thoroughly cook it as if it had been subjected to steam 
 heat. [This heating action is of small moment if the fruit is 
 cooled before placing in the car to a temperature of 40 F. or 
 lower.] Suitable refrigerator transportation must, therefore, 
 provide for the heat generated within, as well as the outside heat. 
 The perfection of refrigeration for fruit is not necessarily a low, 
 but a uniform temperature ; a temperature from 40" to 50° F. 
 will keep fruit for twenty or thirty days, if carefully handled. 
 Strawberries have been transported from Florida to Chicago, 
 transferred to cold storage rooms, and remained in perfect con- 
 dition for four weeks after being picked. [An uncommon or 
 trial shipment. These results cannot be duplicated on a commer- 
 cial scale.] 
 
 Fruit intended for immediate loading in cars should be 
 gathered in the coolest hours of the day, and that which has been 
 subjected to a high temperature before being shipped should 
 be cooled immediately after being loaded. Ordinary refrigera- 
 tion will not cool a load of hot fruit within twenty-four hours, 
 and during that time it will deteriorate in quality very much. 
 It should be cooled in four or five hours in order to prevent 
 fermentation. It is stated that the more intelligent of the large 
 shippers of fruit in the south have about concluded that it is 
 impracticable with any car now in use to load fruit, especially 
 peaches and cantaloupes, direct from the orchard into the car 
 with assurance of safety. In deference to this opinion one south- 
 ern railroad has announced its intention of establishing at the 
 largest shipping points along its lines, cooling rooms for the 
 purpose of putting the fruit in satisfactory condition for trans- 
 portation before being loaded. 
 
 Shipments of tropical fruits in ordinary freight cars cannot 
 be safely made when the temperature is below 30° F., except in 
 cases where the distance is so short as not to expose them for a 
 longer period than twelve hours, and even then they must be 
 carefully packed in straw or hay. The hardier Northern fruits 
 and vegetables can be safely shipped in a temperature of about 
 25" F., but the same protective measures must be employed as 
 
428 PRACTICAL COLD STORAGE 
 
 in the case of tropical fruits when lower temperatures prevail. 
 Long exposure to temperature of 20 c F is considered dangerous 
 to their safety. Foods preserved in cans or glass should not be 
 shipped any distance when the temperature is below the freez- 
 ing point. 
 
 Oranges and Lemons. — Oranges shipped from Florida to 
 points as far north as Minnesota are started in ventilator cars, 
 which are changed at Nashville to air-tight refrigerator cars, 
 the ventilators of which are kept open, provided the temperature 
 remains above 32 F., until arrival at St. Louis, from which point 
 the ventilators are closed and the cars made air tight. Lemons 
 and oranges are packed in crates. Each layer of crates in the car 
 is covered by and rests upon straw, usually bulkheaded back 
 from the door and car full. Oranges loaded in ventilated or 
 common cars should be transferred to refrigerator cars when the 
 temperature reaches 10° above zero; in transit, with a falling 
 temperature, the ventilators should be closed when the ther- 
 mometer reaches 20° F., and with a rising temperature the ven- 
 tilators should be opened when it reaches 28° F. For lemons, the 
 minimum is 35" F. for opening and closing the,. ventilators, and 
 for bananas 45° F. for opening- or closing. Some shippers say 
 that ventilators on cars containing bananas, lemons and other 
 delicate fruits should be closed at a temperature of 40 F. 
 
 Bananas. — In shipping carloads of bananas a man is usually 
 sent in charge to open and close the ventilators. Bananas should 
 be put in a paper bag and a heavy canvas bag, and then covered 
 with salt hay, unless put in automatic heaters, when the fruit is 
 packed only in salt hay. Bananas are particularly susceptible to 
 injury by cold, and require great care. If exposed to tempera- 
 tures as low as 45" F. they almost invariably chill, turn black 
 and fail to ripen. Cars containing them are sometimes, in ex- 
 treme cold weather, protected by throwing a stream of water on 
 them, which, freezing, forms a complete coating of ice. The 
 method adopted by some firms, of shipping this fruit in winter, 
 is to heat refrigerator cars to about 90 F. by oil stoves, remove 
 the stoves and load the fruit quickly, put the stoves back and heat 
 up to 85 ° or 90 F., then remove the stoves again, close the car 
 tight, and start it on its way. Bananas shipped in this manner 
 
SHIPPING PERISHABLE PRODUCTS 429 
 
 are held to be safe for forty-eight to sixty hours, even though 
 the temperature goes to zero. 
 
 Quinces, apples, and pears are packed in barrels, each layer 
 of barrels covered with and resting on straw. [Straw is really 
 only necessary on the bottom, top, sides and ends of car; no 
 useful result is obtained by packing straw between barrels.] 
 
 VEGETABLES. 
 
 Potatoes are packed in straw, bulkheaded back, the center 
 of the car left empty, and the car filled as high as the double 
 lining. When the temperature is 12° F. or more below freezing, 
 the rule is to line the barrels with thick paper, and at extremely 
 low temperatures, as a matter of extra precaution, the barrels are 
 covered over the outside with the same kind of paper. 
 
 In shipping early vegetables to a northern market from the 
 South, for distances requiring more than forty-eight hours to 
 cover, openwork baskets, slatted boxes, or barrels with openings 
 cut in them should be used to allow a circulation of air. 
 
 As a rule, truckers will not haul vegetables to the cars for 
 shipment when the temperature reaches 20° F. or lower, and in 
 no case when it is near 32 ° F. if raining or snowing. 
 
 [A point in connection with the transportation of perishable 
 goods not touched on is the importance of not overloading refrig- 
 erator cars with fruit or other goods of like nature. The warm 
 air from goods will accumulate in the upper part of the car, and 
 no refrigerator car now in service so far as known to the author 
 has a circulation of air sufficiently perfect to give even approxi- 
 mately uniform temperatures. It is generally necessary to leave 
 at least a foot or eighteen inches space at top and space between 
 packages for air circulation. California fruit shippers fully ap- 
 preciate this and always tack strips of wood between packages, 
 which holds the packages in place and allows of good air cir- 
 culation.] 
 
 USE OF WEATHER REPORTS. 
 
 In connection with the shipment of food products liable 
 to injury by heat or cold, much benefit may be derived from an 
 intelligent use of the information contained in the daily weather 
 reports and forecasts published by the Weather Bureau, which 
 
430 PRACTICAL COLD STORAGE 
 
 show the temperature conditions prevailing over the whole coun- 
 try at the time of the observations, the highest and lowest tem- 
 peratures that have occurred during the past twenty-four hours, 
 and the probable conditions that will prevail during the next 
 twenty-four or thirty-six hours. These reports and forecasts are 
 received at nearly every Weather Bureau office, of which there is 
 one or more in nearly every State and Territory, and published 
 on maps and bulletins, which are posted in conspicuous places 
 in the city where the office is located, and mailed to surrounding 
 towns. The reports, or a synopsis of them, are also generally 
 published in the daily papers. 
 
 Fuller information than is obtainable from either of these 
 sources may be had at the Weather Bureau office itself, from the 
 observer in charge, or, where none of these means is available, 
 arrangements may be made with the observer to supply special 
 information by mail, telephone, or telegraph. In the large cities 
 of the country, dealers, in perishable goods are guided in their 
 transactions very largely by the information thus obtained. The 
 temperature of the region to which shipments are to be made is 
 carefully watched, and the shipments expedited or delayed, ac- 
 cording as the conditions are favorable or unfavorable. Ship- 
 ments on the road are protected from injury by telegraphic in- 
 structions as to the necessary precautions to be taken. As ship- 
 ments in ordinary box cars, or as freight, are less expensive 
 than in refrigerator cars or by express, advantage is taken of a 
 favorable spell of weather to use the former methods. 
 
 Information as to the altitude of the regions traversed by 
 the shipping routes, such as may be obtained from the contour 
 maps published by the United States Geological Survey, the lo- 
 cation and capacity of the roundhouses along the routes, and the 
 points on the railroads where transportation is liable to blockage 
 by snowdrifts, in connection with that given by the daily weather 
 maps, will prove of value to the shipper in the supervision of his 
 consignment. 
 
 In shipping early vegetables North from Southern ports 
 the weather reports are utilized to determine whether to use 
 water or railroad transportation, the former being the cheaper. 
 Dealers in certain kinds of produce, by careful attention to the 
 daily weather reports and the weekly crop bulletins, keep them- 
 
SHIPPING PERISHABLE PRODUCTS 431 
 
 selves informed as lo the sections where conditions most favorable 
 for large crops have prevailed, and are thus enabled to judge of 
 the probable supply and to know where to purchase to advantage. 
 
 As illustrations of the manner in which advantageous use 
 may be made of the weather reports, suppose a merchant in Ohio 
 has an order in January for. a load of apples or potatoes to be 
 shipped to St. Paul ; when his shipment is ready he may ascer- 
 tain by personal inquiry at the Weather Bureau office, or by a 
 study of the published reports and forecasts, the probable tem- 
 perature conditions between Ohio and Minnesota for the period 
 that the shipment is likely to be on the road, and regulate the 
 same accordingly. If neither of these means of information is 
 accessible to him, he may telegraph the observer at the nearest 
 Weather Bureau office, Cincinnati, Columbus, Cleveland, San- 
 dusky, or Toledo, as the case may be, requesting the information, 
 or he may arrange beforehand with the observer to be informed 
 by telegraph when the conditions are favorable for making the 
 shipment, the cost of all telegrams, of course, to be borne by him- 
 self. While the consignment is on the road he should still keep 
 himself informed as to the temperature conditions of the region 
 through which it passes, and if injuriously low temperatures 
 are likely to occur, may telegraph to have it housed or otherwise 
 protected until the conditions are again favorable. By the use of 
 similar means, a packer having a large number of hogs to 
 slaughter may ascertain in advance when temperatures favorable 
 for that purpose are likely to prevail in his locality ; or a South- 
 ern merchant having a consignment of tropical fruit on the road 
 to the North may insure its protection from injuriously high or 
 low temperatures by telegraphic instructions as to the opening 
 or closing of ventilators, or the use of ice or artificial heat. 
 
 During the season when cold waves are liable to occur, a 
 careful watch of the reports and forecasts will often enable 
 dealers and others to protect from injury large quantities of prod- 
 uce in storage. Instances are numerous where the use of such 
 information has resulted in large pecuniary benefit. 
 
 During the severe cold wave of January i to 5, 18.96, which 
 overspread nearly the entire United States east of the Rocky 
 Mountains, over three and one-half million dollars' worth of 
 property was saved from destruction by the warnings of the 
 
432 
 
 PRACTICAL COLD STORAGE 
 
 Weather Bureau, which were sent out in advance of the wave. 
 
 TEMPERATURE TABLE. 
 
 In the following table are given the highest and lowest tem- 
 peratures which perishable goods of various kinds will stand 
 without injury, whether packed in ordinary packages, stored in 
 freight cars or placed in regular refrigerator cars. [The tem- 
 peratures given seem to the author to be too' arbitrary and in 
 some cases incorrect, but are useful as a guide. There are many 
 things to be considered in fixing the lowest and highest safe 
 temperatures for perishable goods, chief of which are : First. — ■ 
 Initial temperature of goods when loaded into car. Second. — 
 Temperature to which exposed en route. Third. — Time on the 
 road. Other conditions, like ripeness of fruit and variety, have 
 much to do with the temperature it will withstand without in- 
 jury.] 
 
 LOWEST AND HIGHEST TEMPERATURES TO WHICH PERISHABLE GOODS MAY 
 BE SUBJECTED WITHOUT INJURY. 
 
 (The — sign denotes temperature below zero Fahrenheit.) 
 
 Perishable Goods. 
 
 Ale, ginger 
 
 Apples, in barrels 
 
 Apples, loose 
 
 Apricots, baskets 
 
 Aqua ammonia, barrels. 
 
 Asparagus 
 
 Bananas 
 
 Beans, snap 
 
 Bear 
 
 Beef extract 
 
 Beer or ale, kegs 
 
 Beets 
 
 Bluing 
 
 Cabbage, early or late. 
 
 Cantaloupes 
 
 Carrots 
 
 Catsup 
 
 Cauliflower 
 
 Celery 
 
 Lowest Outside 
 Temperature. 
 
 .2.5 Si 
 
 30 
 
 20 
 
 28 
 
 35 
 3° 
 
 28 
 
 5° 
 
 32 
 
 Zero 
 
 25 
 
 32 
 26 
 
 3° 
 
 25 
 32 
 
 3° 
 25 
 
 22 
 
 20 
 10 
 15 
 24 
 20 
 22 
 
 .32 
 
 26 
 
 —20 
 
 15 
 20 
 20 
 20 
 20 
 25 
 25 
 15 
 15 
 Zero 
 
 < u 
 in 3 
 03--. 
 
 - C 
 
 £3 2 
 h 
 
 
 
 
 
 —10 
 
 
 —10 
 
 75 
 
 — 10 
 
 75 
 
 10 
 
 70 
 
 — 10 
 
 
 
 70 
 
 
 90 
 65 
 65 
 
 — 10 
 
 
 Zero 
 
 75 
 
 
 70 
 
 — 10 
 
 
 Zero 
 10 
 
 75 
 80 
 
 20 
 
 
 — 10 
 
 
 
 70 
 
 f-5 
 
 How Packed. 
 
 Covered with straw. 
 Packed in straw. 
 
 In boxes covered with moss. 
 In boxes with straw. 
 In barrels or crates. 
 Shipped loose. 
 
 In manure and shavings. 
 In crates. 
 
 Barrels or crates. 
 
 In barrels with straw. 
 Packed in crates. 
 
SHIPPING PERISHABLE PRODUCTS 
 
 433 
 
 LOWEST AND HIGHEST TEMPERATURES TO WHICH PERISHABLE GOODS MAY 
 BE SUBJECTED WITHOUT INJURY — CONTINUED. 
 (The — sign denotes temperature below zero Fahrenheit.) 
 
 Perishable Goods. 
 
 Cheese 
 
 Cider 
 
 Clam broth and juice... 
 
 Clams in shell 
 
 Cocoanuts 
 
 Crabs 
 
 Cranberries 
 
 Cucumbers 
 
 Cymlings, or squashes. . 
 
 Deer 
 
 Drugs (non-alcoholic) . . 
 Eggs, barreled or crated 
 
 Endive ' 
 
 Extracts (flavoring) 
 
 Fish 
 
 Fish, canned 
 
 Flowers 
 
 Grapes 
 
 Grapefruit 
 
 Groceries, liquid 
 
 Ink 
 
 Kale 
 
 Leek 
 
 Lemons' 
 
 Lettuce 
 
 Lobsters 
 
 Mandarins 
 
 Medicines, patent 
 
 Milk 
 
 Mucilage 
 
 Mustard, French .... 
 
 Okra 
 
 Olives, in bulk 
 
 Olives, in glass 
 
 Onions 
 
 Oranges 
 
 Oysters, in shell 
 
 Oysters, shucked 
 
 Parsley 
 
 Parsnips 
 
 Partridges 
 
 Paste 
 
 Pears 
 
 (27) 
 
 Lowest Outside 
 Temperature. 
 
 3° 
 
 22 
 30 
 20 
 
 3° 
 10 
 28 
 32 
 32 
 
 Zero 
 32 
 3° 
 10 
 
 20 
 
 18 
 35 
 34 
 32 
 32 
 20 
 
 15 
 
 28 
 
 32 
 26 
 
 25 
 32 
 32 
 32 
 25 
 26 
 
 25 
 28 
 
 25 
 20 
 28 
 20 
 3° 
 32 
 32 
 10 
 32 
 32 
 
 cO 
 
 25 
 18 
 20 
 10 
 20 
 
 Zero 
 20 
 20 
 22 
 
 — 20 
 28 
 20 
 
 Zero 
 
 15 
 Zero 
 
 15 
 20 
 20 
 20 
 20 
 
 15 
 
 Zero 
 
 20 
 
 20 
 
 15 
 20 
 20 
 28 
 28 
 
 15 
 20 
 20 
 
 25 
 20 
 10 
 20 
 10 
 20 
 20 
 20 
 Zero 
 
 25 
 20 
 
 tu rn to 
 
 10 
 — 10 
 — 10 
 — 10 
 
 Zero 
 
 Zero 
 
 Zero 
 Zero 
 
 Zero 
 
 — 10 
 —10 
 Zero 
 Zero 
 Zero 
 10 
 
 10 
 
 Zero 
 
 Zero 
 Zero 
 Zero 
 Zero 
 -10 
 
 Zero 
 Zero 
 Zero 
 Zero 
 to 
 Zero 
 
 10 
 10 
 
 
 
 75 
 
 70 
 80 
 
 65 
 
 90 
 
 65 
 
 65 
 
 75 
 65 
 
 80 
 70 
 
 65 
 
 65 
 65 
 75 
 70 
 
 75 
 
 75 
 
 75 
 
 80 
 80 
 
 65 
 70 
 
 75 
 70 
 
 65 
 
 80 
 
 How Packed. 
 
 In barrels. 
 
 In barrels or crates. 
 
 In baskets and barrels. 
 
 In boxes with moss. 
 In crates. 
 Shipped loose. 
 
 In boxes' or crates. 
 
 In barrels 'always iced. 
 
 Packed in moss. 
 Packed in cork. 
 
 In boxes or crates. 
 In boxes. 
 
 In boxes or crates. 
 Do. 
 
 In boxes. 
 In sawdust. 
 
 In baskets or boxes. 
 In barrels. 
 
 In barrels or crates'. 
 
 In baskets, barrels or crates. 
 
 In barrels. 
 
 Do. 
 In baskets. 
 
 In baskets or barrels. 
 In bunches in boxes'. 
 In barrels. 
 
434 
 
 PRACTICAL COLD STORAGE 
 
 LOWEST AND HIGHEST TEMPERATURES TO WHICH PERISHABLE GOODS MAY 
 BE SUBJECTED WITHOUT INJURY— -CONCLUDED. 
 
 (The — sign denotes temperature below zero Fahrenheit.) 
 
 Perishable Goods. 
 
 Peaches, fresh, baskets.. 
 
 Peaches, canned 
 
 Peas 
 
 Pickles, in bulk 
 
 Pickles, in glass 
 
 Pineapples 
 
 Plums 
 
 Potatoes, Irish 
 
 Potatoes, sweet 
 
 Preserves 
 
 Radishes 
 
 Rice 
 
 Shrubs, roses or trees. .. 
 
 Spinach 
 
 Strawberries 
 
 Tangerines 
 
 Tea plants 
 
 Thyme 
 
 Tomatoes, fresh' 
 
 Tomatoes', canned 
 
 Turnips, late 
 
 Vinegar, barrels 
 
 Watermelons 
 
 Waters, mineral 
 
 Wines, light 
 
 Wild boar 
 
 Wild turkey 
 
 Yeast 
 
 Lowest Outside 
 Temperature. 
 
 O o 
 
 .Ecu 
 
 32 
 
 20 
 32 
 22 
 
 20 
 
 32 
 
 35 
 33 
 35 
 
 20 
 
 35 
 15 
 33 
 25 
 28 
 20 
 
 33 
 
 28 
 
 15 
 22 
 20 
 28 
 22 
 Zero 
 Zero 
 28 
 
 
 30 
 
 15 
 
 20 
 
 18 
 16 
 
 25 
 32 
 
 25 
 
 28 
 10 
 
 15 
 10 
 10 
 15 
 25 
 15 
 20 
 10 
 28 
 
 25 
 
 Zero 
 
 18 
 
 10 
 
 25 
 
 15 
 
 — 20 
 
 — 20 
 
 25 
 
 2"> 5 
 
 10 
 Zero 
 
 10 
 10 
 Zero 
 Zero 
 10 
 10 
 10 
 
 — 10 
 Zero 
 
 10 
 -5 
 
 Zero 
 Zero 
 
 Zero 
 
 1° 
 < t 
 
 0.32 
 H 
 
 80 
 
 80 
 
 75 
 75 
 80 
 80 
 
 65 
 90 
 
 75 
 65 
 70 
 
 95 
 90 
 90 
 
 75 
 
 35 
 
 65 
 65 
 65 
 
 How Packed. 
 
 In baskets or barrels. 
 In barrels'. 
 
 In barrels or crates. 
 In boxes with paper. 
 In barrels or baskets. 
 Do. 
 
 In baskets. 
 
 In barrels and sacks. 
 In canvas or sacking. 
 In barrels or crates. 
 
 In boxes. 
 In boxes. 
 In small baskets. 
 
 In boxes. 
 In barrels. 
 
 In barrels or in bulk. 
 
 Shipped loose. 
 Do. 
 
REFRIGERATION FROM ICE 435 
 
 CHAPTER XXII. 
 REFRIGERATION FROM ICE. 
 
 PRINCIPLES OF ICE REFRIGERATION. 
 
 A cold storage house may be successfully cooled by ice 
 mixed with a small proportion of salt. Many persons who em- 
 ploy ice in an ordinary refrigerator or otherwise, are perhaps 
 not fully aware that it may be employed with entire success for 
 practical cold storage, even when placed in direct competition 
 with the ammonia or other mechanical systems. In the city of 
 Minneapolis are seven concerns who employ refrigeration oper- 
 ated under the author's systems, aggregating about 400,000 cubic 
 feet of storage space, which is cooled by ice, and ice mixed with 
 salt. These houses are successfully competing for business with 
 other houses equipped with the ammonia system, and are car- 
 rying goods admittedly equal to the very best. Temperatures 
 as low as from io c to 15° F. are maintained in the freezing- 
 rooms, and eggs are held at 30° F. with a pure and dry atmos- 
 phere. These facts should establish beyond a question the possi- 
 bilities of ice in the cold storage field. The system of natural ice 
 cold storage which will produce these results is fully described 
 further on in this chapter. Numerous plants are in operation else- 
 where which use manufactured or artificial ice with a small ad- 
 mixture of salt as a primary refrigerant. Artificial ice is as use- 
 ful for this purpose as natural ice and for small plants is very 
 desirable as compared with a small ice machine. 
 
 The immense natural ice crop is, for the most part, consumed 
 in the temporary safe keeping of perishable products, which are 
 stored in the common house refrigerator or the larger refrigerator 
 of the retailer. Many cold storage houses utilizing natural ice 
 are in operation, which give more or less satisfactory results : 
 generally the latter. Some persons have an idea that a cold 
 storage house is a room with sawdust-filled walls with ice in it, 
 but there are many points about cold storage not understood by 
 
436 PRACTICAL COLD STORAGE 
 
 the average person. It is the purpose in this chapter to discuss 
 the various methods of cold storage by means of ice so that 
 the careful reader may discriminate between them and under- 
 stand the underlying natural laws. 
 
 In discussing ice cold storage, it may be admitted at the out- 
 set that the use of ice in any form for the preservation of food 
 products, like eggs, butter, cheese and fruits, for what is known 
 as long-period storage, has fallen into disrepute, owing to defects 
 in the older systems. There are reasons for this, although the 
 idea that the ammonia system is so much superior has been carried 
 to an extreme not warranted by the existing facts. The real 
 reason why the ammonia system has a better reputation is that 
 natural ice has usually been misapplied to< the work of cold storage, 
 that is, it has been improperly used. The problem of cooling stor- 
 age rooms by utilizing the stored refrigeration of the winter 
 months in the form of natural ice has had the attention of many 
 persons, among them the author and his father before him. The 
 author's father always said that "expensive steam-driven ma- 
 chinery could not successfully compete with God Almighty and 
 a Minnesota winter" in creating refrigeration. With this as a 
 principle the Cooper system has been developed. Several sys- 
 tems had previously been developed with varying success, but it 
 is believed that up to the time the "Cooper System Gravity Brine 
 Circulation'' was first put in service, no -system was in existence 
 which could successfully compete with the ammonia or other 
 mechanical systems. 
 
 The use of ice as a refrigerant was long antedated by the 
 use of natural refrigeration, which may be obtained in cellars 
 or caves. It is well known that at a depth of a few feet below 
 the surface, the earth maintains a comparatively uniform temper- 
 ature of about 50 F. to 6o° F. during all seasons of the year. 
 This temperature varies somewhat, but above would cover a 
 great majority of cases in any northern latitude where snow falls, 
 and as compared with a summer heat ranging from 70 ° F. to 90° 
 F. it will be readily observed that this natural low temperature 
 of the earth is of considerable service in retarding decay and the 
 natural deterioration of perishable products. By digging beneath 
 the surface of the earth a cellar was formed which would produce 
 results in refrigeration which were quite satisfactory during the 
 
REFRIGERATION FROM ICE 487 
 
 early history of the perishable goods business, but would hardly 
 withstand the critical test to which goods from modern cold 
 storage houses are subjected. With the advent of the natural 
 ice trade, ice came into use for household and other refrigerating 
 purposes. Ice is at present and will probably always remain the 
 most practicable means of placing concentrated refrigeration at 
 the disposal of the comparatively small consumer. It seems that 
 prior to the nineteenth century the great cooling effect to be ob- 
 tained from a small quantity of ice was not known nor appreciated 
 by the world at large. The preservation of natural ice was like- 
 wise not thought practicable for a time sufficiently long to allow 
 of its use as a cooling agent during the heat of summer. With 
 a knowledge of the cooling power possessed by the earth during 
 warm weather the first ice houses were constructed below ground, 
 without provision for drainage. The result of such an arrange- 
 ment is easy to understand. Now ice men are careful to build 
 above ground and provide good drainage as being necessary to 
 the successful keeping of the ice. The first ice house did not 
 provide protection for the ice, other than a roof overhead; all 
 ice houses now employ sawdust or some other non-conductor of 
 heat to protect the ice from contact with the air, and prevent 
 the penetration of heat. Ice stored in the underground ice houses 
 was mostly melted by July, while ice stored in a modern ice house 
 may be kept until fall with a meltage of only ten or fifteen per 
 cent. The evolution of the modern ice house from the under- 
 ground pit has been gradual, and was not made all in one jump. 
 It seems remarkable that the loss from meltage in the house is 
 now so little, and this is accounted for only by considering the 
 tremendous amount of refrigeration which is stored up in a 
 small quantity of ice, and a knowledge of proper means for pro- 
 tecting same. (For further information on ice harvesting and 
 storing and the construction of ice houses, see separate chapters 
 on these subjects.) 
 
 The refrigerating value of ice as compared with an equal 
 weight of cold water at 32° F. is as 142 is to 1. That is, ice has 
 142 times as much cooling power in passing from ice at 32° F. 
 to water at 32° F., as an equal weight of water in passing from 
 32 ° F. to 33 F. It has perhaps been noticed that ice forms quite 
 slowly even in extremely cold weather. This is because the water 
 
438 PRACTICAL COLD STORAGE 
 
 must give up a large amount of heat before it will become ice. 
 The natural bodies of water are quickly reduced in temperature 
 to about the freezing point by a cold spell of weather in the fall, 
 but the freezing of the water into ice at the freezing point (32° 
 F.) is quite a different matter. This natural phenomenon is ac- 
 counted for by what is known as latent heat. It is this latent 
 heat in water which makes it so slow to freeze, and when once 
 frozen, makes the ice so slow in melting, as the same latent heat 
 which is given off in freezing must be absorbed from surrounding 
 objects before the ice will melt into water. To fully understand 
 this it is necessary to become familiar with the unit of measure- 
 ment used in determining quantity or amount of refrigeration 
 produced by melting ice, and the relation between heat and cold. 
 
 Heat is a positive quantity, that is, possesses character, so 
 to speak, while cold is simply the absence of heat. It follows, 
 therefore, that any unit of measurement applicable to heat will 
 also measure refrigeration. If heat is extracted from any object 
 it becomes cold, and it becomes cold in exactly the same amount 
 or proportion as the heat is absorbed. The quantity of heat ab- 
 sorbed is measured by the British Thermal Unit, generally ab- 
 breviated to B. T. U. One B. T. U. is equal to the raising in 
 temperature of one pound of water one degree, as shown by an 
 ordinary thermometer. The standard American thermometer 
 is named after its originator, Fahrenheit, and measurements by 
 this thermometer are usually abbreviated to a simple F., to dis- 
 tinguish from some other thermometers in use. In writing tem- 
 peratures the F. is placed after the degree mark. We would say 
 then that one pound, of ice in changing from ice to water at 32 
 F. absorbs 142 B. T. units. When a pound of water is raised in 
 temperature from 32 ° F. to 33 ° F., only one B. T. U. is absorbed. 
 In other words ice in melting has 142 times the refrigerating 
 value that the same weight of water has when raised in tem- 
 perature 1" F. This latent heat of liquefaction, as it is called, 
 explains why ice melts so slowly, and why a comparatively small 
 quantity will perform such a large refrigerating duty. 
 
 When used for cold storage purposes, the temperatures ice 
 alone will produce are limited. As the melting point of ice is 
 32° F., the temperature which can be obtained in a room cooled 
 by ice only must necessarily be somewhat higher. The lowest 
 
REFRIGERATION FROM ICE 439 
 
 practicable temperatures are about 36° F. to 38 F. during warm 
 weather. By mixing finely crushed ice with a small proportion'of 
 salt the melting of the ice is hastened, and a much lower temper- 
 ature results. This is caused by the great affinity which salt has 
 for water. When salt comes in contact with ice this property 
 causes it to extract the water from ice rapidly, reducing it from 
 a solid to a liquid, causing a rapid production of refrigeration 
 or rather the absorption of heat. A pound of ice will do a given 
 amount of work in refrigeration regardless of whether it is 
 melted naturally at 32° F. or at some lower temperature in com- 
 bination with salt. The lowest temperature obtainable with a 
 mixture of ice and common salt is slightly below zero, Fahren- 
 heit. This is directly in the mixture. A room cannot be cooled 
 as low as this with ice and salt. By using chloride of calcium 
 salt mixed with crushed ice a temperature many degrees below 
 zero may be obtained. This salt costs about double what common 
 salt does, and is not at present in use for freezing purposes. A 
 freezing-room designed by the author was cooled to a tempera- 
 ture of 6° F., with the gravity brine system, and held for a few 
 days to demonstrate the possibilities of ice and salt refrigeration. 
 Temperatures of 12° F. to 15" F. are easy to maintain, and at 
 comparatively small expense. 
 
 Moisture in cold storage rooms has been the source of much 
 discussion and solicitude among cold storage operators, and a 
 knowledge of the action of this condition in rooms artificially 
 cooled, and its relation to temperature, will assist in our present 
 study. When a storage room is cooled by ice only, the higher 
 the temperature at which the room is held the dryer will be the 
 atmosphere, and the better will be the circulation. This state- 
 ment is general, and may be modified by exceptional conditions. 
 A moderately dry air and a good circulation are necessary to 
 successful cold storage, but with these two conditions must go, 
 as an imperative adjunct, a low temperature if good results are 
 to be obtained. It has been stated already that the lowest de- 
 pendable temperature with ice only was 36 F. to 38 F. Com- 
 paratively few products are- now stored in a temper.ature above 
 32" F. to 34 F., and a large bulk of the business is handled at 
 a temperature ranging from 30° F. to 32 F. It is therefore 
 evident that ice alone will not produce temperatures sufficiently 
 
440 PRACTICAL COLD STORAGE 
 
 low for the handling of a successful cold storage business. Tem- 
 peratures sufficiently low can be obtained only by ice mixed with 
 salt or by the use of refrigerating machinery. As before stated. 
 in a room cooled directly from ice, the nearer the temperature of 
 the storage room approaches the temperature of melting ice, 
 the poorer will be the circulation, and the higher per cent of 
 moisture the air will contain. Circulation of air within a stor- 
 age room is caused by a difference in weight of air in different 
 parts of the room. The air in immediate contact with the ice is 
 cooler and heavier, and therefore falls to the bottom of the stor- 
 age room. The warmer and lighter air at the top of the storage 
 room at the same time rises to the ice chamber. As long as the 
 difference in weight and temperature exists, circulation will take 
 place. The principle underlying air moisture is quite compli- 
 cated, but may be understood by a little study. It is well known 
 that when warm, moist air is circulated in contact with a cold 
 surface the moisture will be condensed upon the cold surface. 
 This is illustrated by the so-called "sweating" of a pitcher of 
 ice-water in warm, humid weather. This same action takes place 
 in every cold storage room. When the room is cooled directly 
 by ice the moisture contained in the comparatively warm air of 
 the storage room is continually being condensed on the cold 
 surface of the ice. As the air becomes nearer and nearer the 
 temperature of the melting ice, less and less moisture will be 
 condensed, and the air becomes in consequence more and more 
 saturated with moisture. If it were possible to cool a storage 
 room to 32° F. with ice melting at 32 F., the air of the room 
 would be fully charged with moisture, and totally unfit for the 
 storage of any food product. If a room is cooled to 35° F. with 
 ice melting at 32" F. the per cent of moisture in the air would be 
 91 per cent of what it would be if the room were cooled to 32 
 F. in the manner above indicated. If the room is cooled to 38 
 F. the air would contain 79 per cent, and if the room be cooled to 
 40° F., it would contain 70 per cent. In actual practice these 
 air moistures would be somewhat higher, owing to the presence 
 of moisture which is continually given off by the goods in stor- 
 age. Even the temperatures with their corresponding percent- 
 ages of air moisture as here stated are known to be too high for 
 the successful preservation of food products for long periods of 
 
REFRIGERATION FROM ICE 441 
 
 three months and upwards, and even for shortei periods results 
 will not be as perfect as with a dryer atmosphere and lower tem- 
 perature. Further than this the circulation, temperature and 
 humidity in a room cooled by ice only are largely dependent on 
 outside weather conditions. The temperature will of course be 
 higher during the hot weather of summer. The humidity is, 
 as we have seen, controlled by the temperature of the air in the 
 room, as is also the circulation. When the temperature outdoors 
 during fall and winter is at or near the melting point of the ice 
 in the storage room (32 F.) no circulation will take place. The 
 air will become very damp and impure from the moisture and im- 
 purities given off by the goods in storage, the goods will mold 
 and decay rapidly. This is a condition to be met with in every 
 house which is cooled by placing natural ice in direct contact 
 with the air of the storage room. (For further information on 
 the relation between humidity and air circulation see separate 
 chapters under these headings.) 
 
 EARLY SYSTEMS OF ICE COLD STORAGE. 
 
 Reasons have been given why natural ice, as generally used, 
 will not produce satisfactory conditions for the storage of food 
 products for long periods. This information will enable the 
 reader to fully understand the weak as well as the strong points 
 of the various systems here described which utilize ice as a re- 
 frigerant. Ice alone may produce useful and even satisfactory 
 results if the goods need only to be carried for a period of one, 
 two or even three months, but where it is desired to erect a build- 
 ing with the idea of handling a variety of products for long 
 storage and with intention of building up a permanent business, 
 the old primitive methods of overhead, or side, or end ice, will 
 result in disappointment and loss. This has been the history of 
 at least nine-tenths of the public cold storage warehouses cooled 
 in this way. If those who contemplate embarking in the business 
 cannot build a house which will carry the various products suc- 
 cessfully, it is better to keep out of the business altogether. The 
 author has had occasion to remodel and even tear down cold 
 storage houses in which ice was the only refrigerant, and in not 
 a single instance known, has a house, operated in this way, been 
 able to build up a substantial and profitable business for its 
 
442 
 
 PRACTICAL COLD STORAGE 
 
 owner. Quite a number of such houses are now in use, and a 
 few are being put up at the present time, but they are mostly 
 operated for private use for one or two products only, and for 
 comparatively short time storage. They do not give successful 
 results when used for sensitive goods like butter and eggs. 
 
 The first application of natural ice to the preservation of 
 food products was that of placing goods directly in contact with 
 the ice, in a similar manner to the method now employed in ship- 
 ping fish or poultry or in cooling melons for temporary holding. 
 This method can be employed for but few products, because 
 the goods become wet and water soaked, The air in such a 
 
 FIG. I. — THE FISHER SYSTEM — SECTIONAL VIEWS. 
 
 chamber has not the benefit of the purifying and drying influence 
 of circulation, and goods in condition favorable for such action 
 mold and decay rapidly. As an improvement on this method, 
 it was natural to separate the goods from the ice, by placing the 
 ice at one end or side of the chamber and the goods at the other, 
 and not in contact with each other. The wetting of the goods is 
 thus avoided, but when the goods are not placed in contact with 
 the ice, they are of course carried at a somewhat higher temper- 
 ature. No circulation of consequence is present, and the air be- 
 comes moist and impure very rapidly. Improving on the side or 
 
REFRIGERATION FROM ICE 443 
 
 end icing plan, a two-compartment refrigerator was constructed, 
 with the ice above and the goods to be preserved stored below. 
 By providing openings for the flow of cold air from the ice down 
 into the storage compartment, and for the flow of comparatively 
 warm air up into the ice compartment, a circulation of air was 
 produced, which was the first really important principle discov- 
 ered in cold storage work. Air is purified and dried by circula- 
 tion under proper conditions. The reason for this is discussed 
 in the chapter on "Air Circulation." The first successful ice cold 
 storage houses were built with ice above the storage chamber, 
 and a large majority of those still in use are of this general plan, 
 with, of course, many modifications. As before stated, they are 
 useful mostly for short-time storage. When placed in competi- 
 tion with a house equipped with a system which gives positive 
 control of circulation, moisture, temperature and purity of the 
 atmosphere, they soon lose business and fall into disuse. Many 
 patents have been issued on the various systems of ice cold stor- 
 age. A few only of those systems which have come to the au- 
 thor's attention will be briefly described, with the idea of show- 
 ing the development of ice cold storage, and also that the reader 
 may form some impression as to the relative merits and weak 
 features of the different systems which have been more or less 
 prominent in the past. 
 
 The Fisher System. — One of the oldest systems of ice cold 
 storage and one on which many houses have been erected, is the 
 "Fisher System," (See Fig. i.) The points of this system 
 which are covered by patent are not known to the author, but the 
 main essentials of the houses as constructed by Fisher, were an 
 ice chamber located above a storage room with an insulated 
 waterproof floor separating the two. Openings were provided 
 for the circulation of air from the ice chamber to the storage 
 room, and flues from the storage rooms to the top of the ice 
 chamber. One who is familiar with the operation of this system 
 says that Fisher's houses, when new, would do fair work, but 
 when they became old the results were very bad. None of these 
 houses known to the author is now in operation. The principle 
 was very simple, and as good results might be obtained by this 
 system as with a majority of the later ones using ice only. 
 
444 
 
 PRACTICAL COLD STORAGE 
 
 The Wickes System.— The "Wickes System" has been 
 largely introduced among certain lines of trade, more particularly 
 in the refrigerator car service. It is claimed that several thou- 
 sand of the Wickes cars are in constant service. The Wickes 
 company some years ago installed a number of cold storage 
 
 FIG. 2. — THE WICKES SYSTEM. 
 
 plants, but it is believed that they do not now recommend their 
 system for such use. The devices which make up the Wickes 
 system (see Fig. 2) consist of a basket-work ice bunker, com- 
 posed of galvanized iron strips. Attached to the strips where 
 the air flows into the ice bunker are projecting tongues, which, 
 it is claimed, give largely increased cooling and moisture-absorb- 
 
REFRIGERATION FROM ICE 
 
 445 
 
 ing surface, which dry and purify the air more thoroughly. 
 Where the air flows out at the bottom of the ice bunker, it passes 
 down over a network of galvanized wire, which is kept cold and 
 moistened by the water dripping from the melting ice above. 
 These devices which have been added to the ordinary construc- 
 tion of the ice box no doubt add somewhat to the efficiency of the 
 system, but are scarcely worth their cost. Any system like the 
 Wickes, employing side or end icing, must be greatly inferior 
 to the overhead ice system, because the circulation of the air 
 becomes stagnant when the ice is reduced in the ice bunker. The 
 temperature also rises under these conditions, and unless a very 
 
 yw///////^ ^/////////////////////////////////vm 
 
 f/ ////////////////77m ///////////M / 
 
 '//h LONGITUDINAL 5ECTI0N [^ 
 
 FIG. 3. — THE STEVENS SYSTEM — SECTIONAL VIEWS. 
 
 large ice bunker is provided and the supply of ice fully main- 
 tained it is not possible to produce as low temperatures as with 
 an overhead ice system. 
 
 The Stevens System. — A good many houses have been 
 erected on what is known as the "Stevens System." (See Fig. 
 3.) This differs somewhat from other systems of overhead icing 
 in having an arrangement of fenders and drip troughs forming 
 an open pan over the entire floor of the ice room, except at the 
 ends and sides, which are left open for the flow of warm air up- 
 ward from the storage room. The cold air from the ice works 
 down through the open pan. The pan is formed by a series of 
 
446 
 
 PRACTICAL COLD STORAGE 
 
 gutters suspended between the joists and capping pieces over 
 the joists to cause the water to drip into the gutters, at the same 
 time allowing a circulation of air between gutters and capping 
 pieces. Those who have used the system state that trouble re- 
 sulted from spattering of water from the troughs. This sys- 
 tem has the advantage of maintaining fairly uniform tempera- 
 tures, regardless of the amount of ice in the ice chamber. Quite 
 a number of these old houses are still in use. The results obtain- 
 
 'W/. 
 
 W////////////////////////////////M 
 
 FIG. 4. — THE NYCE SYSTEM — SECTIONAL VIEW. 
 
 able are not essentially different from those to be had by other 
 overhead ice systems. 
 
 The Nyce System. — The system invented by Professor 
 Nyce is one of the old-timers still to be found in use- Irr this 
 system (see Fig. 4) the cooling effect of melting ice, and the 
 drying and purifying effect of chloride of calcium, are depended 
 upon to produce the desired result. It is an overhead ice system, 
 but the air is not circulated from the ice chamber into the stor- 
 age room. The storage room is cooled by contact with the met- 
 
REFRIGERATION FROM ICE 
 
 447 
 
 allic ceiling of the storage room, which also forms the floor of 
 the ice chamber. Professor Nyce no doubt studied out this sys- 
 tem from having observed the bad effects which result in the 
 ordinary overhead ice cold storage during cool or cold weather. 
 To absorb the moisture which is given off by the goods and 
 from the opening of doors, the well-known drying qualities of 
 chloride of calcium were used. The results obtained by cooling 
 and drying a room in this way were quite satisfactory, and com- 
 pared favorably with any of the other ice systems in general use. 
 
 FIG. 5. — THE JACKSON SYSTEM — SECTIONAL VIEW. 
 
 The patents on this system have long ago run out, but the sys- 
 tem was not sufficiently successful to encourage its general use, 
 and so far as known, no new houses of this kind are being built 
 at present. 
 
 The Jackson System— -The "Jackson System" of overhead 
 ice cold storage is one of the most general in use, and it is 
 claimed that over three hundred houses have been constructed. 
 The system (see Fig. 5) is extremely simple, and the chief 
 patent is on a removable pan suspended under an open ice floor. 
 
448 PRACTICAL COLD STORAGE 
 
 It is, of course, an overhead ice system, with air circulating from 
 the ice chamber down into the storage room. The spaces be- 
 tween the joists supporting the ice are left open, and aprons of 
 galvanized iron protect the girders which support the joist, and 
 conduct the drip to the removable pans before referred to. In 
 some cases cylindrical tubes or tanks of galvanized iron are pro- 
 vided. These are filled with ice and salt for the purpose of re- 
 ducing the temperature still lower than is possible with the ice 
 alone. The use of tanks in a room provided with a circulation of 
 air from the ice cannot result in any great benefit to the rooms, 
 as the circulation is retarded or stopped, and a pollution of the 
 air results to a considerable extent. Tanks of different shapes 
 and sizes are used in a number of systems, and will be considered 
 by themselves in another paragraph. The "Jackson System," so- 
 called, is principally a pan hung below the ice joist so as to pro- 
 mote a circulation of air from the ice chamber into the storage 
 room. Other devices as simple will accomplish the same result. 
 Nothing new of consequence has been added to this system for 
 a number of years, but a few houses are being installed on this 
 plan, largely because it has been advertised and pushed in former 
 years. 
 
 The Dexter System. — The Dexter patents cover a much 
 more complicated apparatus than any system or prior invention 
 which utilizes ice as a refrigerant. The "Dexter System" of in- 
 direct circulation is a very ingenious device. (See Fig. 6.) It 
 consists of a series of air flues between the exterior and interior 
 walls of the cold storage room. The cold air from the ice cham- 
 ber flows down through one set of flues, and as it is warmed 
 returns through another set located outside of the first set. This 
 effectually prevents the penetration of outside heat, and makes 
 the regulation of temperature comparatively easy, even in warm 
 weather. This is practically like putting one cold storage room 
 inside of another. Dexter uses also the galvanized tubes or 
 tanks filled with ice and salt for bringing down the temperature 
 to the desired point. The circulation of air within a room cooled 
 in this way is sluggish, and the air too moist for most products 
 which are generally placed in cold storage for safe keeping. 
 Dexter also has patents on a method of circulating air from the 
 ice chamber down through or around tanks filled with ice and 
 
REFRIGERATION FROM ICE 
 
 449 
 
 salt, into the storage room, but the writer is not aware that these 
 devices have proven to be possessed of any particular merit or 
 that they have been brought into general use. Other patents 
 have been taken out on a scheme for constructing an ice floor or 
 
 W;///f//////////////Mw//////////////////////////m 
 
 FIG. 6. — THE DEXTER SYSTEM — SECTIONAL VIEW. 
 
 pan. This has been found leaky in a number of cases, and has 
 been removed and built over. Still other patents are on a system 
 of ventilation, and a method of insulating the ends of joist where 
 they enter the walls of a building. 
 
 Any system of cooling storage rooms in which the air is 
 circulated directly from the ice has the constant trouble with 
 
 (28) 
 
450 PRACTICAL COLD STORAGE 
 
 dampness of the ice room or bunker. Moisture always con- 
 denses on the ceilings or side walls of the ice receptacle, and mold 
 results very soon. The air circulating over the molded surface 
 carries mold spores into the storage room. The goods stored 
 therein suffer in almost every case. A house which has been 
 in service for some time may be very bad in this respect, espe- 
 cially during cool weather of fall or early winter, as the temper- 
 ature is lower and the air of storage room more moist. Damp- 
 ness of ice room also causes decay of woodwork and insulation. 
 
 The Direct Tankage System. — There are or have been a 
 number of cold storage houses, cooling rooms and freezers re- 
 frigerated by what the author calls the "Direct Tankage System." 
 This system consists simply of placing metal receptacles filled 
 with ice and salt in the room to be cooled. There are several 
 forms of tanks in service, the more common of which are the 
 square cornered or rectangular tanks, the thin tanks, or what are 
 sometimes called "freezing walls," and the cylindrical or round 
 tanks. Usually these tanks are made of galvanized iron. They 
 may be made of a thickness of iron ranging from gauge 18 to 
 gauge 24 metal. Gauge 20 iron is usually the best to use. These 
 tanks are almost invariably filled from the top through the ceil- 
 ing, or what would naturally be the floor of the room above. 
 They have, however, in some extreme cases been filled from the 
 side, either from without or from within the room. 
 
 The rectangular or square tanks, as at first employed, have 
 gradually gone out of use, because they are difficult to make 
 and keep in shape and, as built in a number of cases, were so 
 large that the meltage of ice would be largely near the tank sides, 
 and very little towards the center. Tanks of this class have been 
 used which were as large as three feet in their smallest dimen- 
 sion, and as the meltage was almost entirely within eight or 
 ten inches of the outer surface, the waste of space and lack of 
 economy are at once apparent. 
 
 The thin or flat tanks, which are sometimes called "freezing 
 walls," as usually constructed, are only about four to ten inches 
 in thickness, and are sometimes narrower at the bottom than at 
 the top. These of course are iced from the top, and many fish 
 freezers, built years ago, did good service when equipped in this 
 manner. One serious objection was that only one surface of the 
 
REFRIGERATION FROM ICE 451 
 
 tank was available to any considerable extent for cooling service, 
 as the back or that portion of the tank near the wall received 
 comparatively little air circulation, in fact, in many cases the back 
 of the tank was placed directly against the wall of the room with 
 no space left between. The construction of these tanks, also, is 
 difficult. 
 
 Furthermore, any flat surface when used for a purpose of 
 this kind has a tendency to bulge outward, owing to the pressure 
 of the ice and salt within. The result is that the tanks become 
 leaky and will rust out rapidly. 
 
 The cylindrical tanks are very much the best of the three 
 kinds mentioned. They are easy to make, and owing to the 
 cylindrical shape will not readily get out of order and are 
 much more practical than either the freezing walls or the rec- 
 tangular tanks. It has been found in actual practice that in 
 producing refrigeration through a metallic surface from the 
 meltage of ice, where one side of the metal is exposed to the air 
 of the cool room, and the other has ice and salt in direct contact, 
 comparatively little refrigerative effect is obtained from the ice 
 lying more than six inches away from the exposed metallic sur- 
 face. Cylindrical tanks, therefore, have been built of a diameter 
 of eleven inches, that being a size readily constructed mechanically 
 and one which will give best results when used for freezing or 
 cooling. In the illustration of the Dexter System (page 449) 
 may be seen the cylindrical tanks suspended from the floor of 
 the ice chamber. 
 
 The direct tankage system, while it has been in use quite 
 extensively, is not at present being installed to any great extent, 
 as its disadvantages are many. The nastiness and muss occa- 
 sioned by the icing of tanks through the ceiling of the storage 
 room is in itself sufficient to -condemn the system. The contin- 
 uous slop resulting from handling the ice and salt upon the floor 
 above the storage room will result in the rotting and decay of 
 timbers and insulation in a comparatively short time. It will 
 also readily be seen that the great amount of space wasted by 
 thus icing the tanks is a serious drawback to this system. Prac- 
 tically nearly as much space is required for the mere charging 
 of the tanks as is available for refrigerating purposes. Another 
 disadvantage of the direct tankage system is that it is wasteful 
 
452 PRACTICAL COLD STORAGE 
 
 of space in the storage rooms, as the tanks do not present as much 
 surface to the air of the room proportionately as does iron piping 
 in the form of coils. The tanks in the room are also sloppy and 
 wet and the pan underneath is liable to become choked up and 
 overflow on the floor of the storage room. Further than this it 
 is extremely difficult to regulate the temperature of a room with 
 this system, owing to the fact that there is no control or balance 
 on the refrigerating effect. Directly after charging the tanks, 
 the temperature will run down and then slowly rise until the next 
 time of charging. The author has worked with this system for 
 a number of years and has abandoned its use entirely in favor 
 of the gravity brine system cooled with ice and salt, which is 
 described further on in this chapter. 
 
 Mr. J. A. Ruddick, Chief Dairy Division, Department of 
 Agriculture, Ottawa, Canada, has this to say regarding the dis- 
 advantages of the direct tankage system : "I am doubtful, after 
 some years' experience, if it is the best system to recommend. 
 The cylinders are not always kept full, causing insufficient and 
 irregular refrigeration, and excessive dampness is likely to result 
 because of insufficient air circulation or because of the moisture 
 from the cylinders whenever the ice is allowed to melt off the 
 outside of the cylinders." 
 
 WHY THE AMMONIA SYSTEM IS SUPERIOR TO ICE. 
 
 These various systems of ice refrigeration which have come 
 into general use during the past thirty-five years, have been briefly 
 outlined and commented on by the author, so that the reader 
 may comprehend, roughly, the history of and the reasons why 
 ice refrigeration has not given satisfaction when placed in 
 competition with the mechanical systems which are now gen- 
 erally understood to be the best for all purposes. It is now 
 necessary for us to make an investigation of the "ammonia" or 
 "mechanical" system, when applied to cold storage, in order to 
 ascertain in what vital particular this system surpasses the old- 
 time ice systems. In visiting such a cold storage warehouse, we 
 find a building with insulated walls not differing from those of 
 an ice cold storage. The interior we find divided by insulated 
 partitions into separate rooms for various products; goods hav- 
 ing a strong or disagreeable odor being carefully isolated from 
 
REFRIGERATION FROM ICE 453 
 
 delicate goods like butter and eggs. In this respect the ammonia 
 cold storage has the advantage over the old style ice cold storage, 
 as the latter, even if divided into different rooms, generally has 
 an ice chamber common to all, making contamination of one 
 product from another probable. Each room of an ammonia cold 
 storage is equipped with a coil or coils of piping placed on the 
 walls or any convenient location. Through this piping flows a 
 liquid or a gas at a low temperature. This cools the piping, 
 which in turn cools the air of the storage room. The surface 
 of the pipe being at a low temperature, frost accumulates on the 
 pipe. This frost is moisture which is taken from the air of 
 the room. The low temperature of the pipe thus causes a con- 
 stant drying, of the air of the room. The main difference be- 
 tween a room cooled in this way and one cooled by ice, is that 
 it is much dryer, because cooled by frozen surfaces at a tempera- 
 ture which will collect moisture from the air of the room in the 
 form of frost. In three houses out of four, no circulation of air 
 is provided for, nor means for supplying fresh air. If we pursue 
 our investigation further and enter the machine room, we find 
 a complete steam plant, with which we are all fairly familiar, 
 and much other machinery and apparatus besides, which takes a 
 bright engineer some time to successfully master in all its de- 
 tails. This, then, is the average "ammonia" cold storage, as seen 
 by an outsider. The real and only reason why such a plant pro- 
 duces better results than the average ice system, aside from a con- 
 trol of temperature, may be summed up in the two words "DRY 
 AIR." It is now purposed to describe a system which has all 
 the advantages of the ammonia system in the respect of pro- 
 ducing a dry atmosphere in the storage room, and yet has the 
 advantage of the ice systems in being simple to operate, econom- 
 ical and sure against breakdown. 
 
 THE COOPER SYSTEM GRAVITY BRINE CIRCULATION. 
 
 It has already been pointed out that it is impossible to pro- 
 duce a dryness or humidity of air in a cold storage room cooled by 
 ice, beyond a percentage which is fixed by the temperature of the 
 room. That is to say, practically no control of humidity is possi- 
 ble in such a room. Further than this, the air in an ice-cooled 
 room is almost invariably moister than in a room of the same tern- 
 
454 PRACTICAL COLD STORAGE 
 
 perature cooled by pipe surfaces. In a room cooled by frosted 
 pipe surfaces, the moisture which is given off by the goods, and 
 that which finds its way into the room when doors are opened 
 or otherwise, is frozen on the pipes in the form of ice or frost. 
 This is because the pipes have a temperature below the freezing 
 point of the moisture in the air, causing the moisture to freeze on 
 the surface of the pipes, and leading to a greater drying of the air 
 than where ice is the cooling agent. Not only will pipe surfaces 
 at a temperature below the freezing point of the air moisture 
 produce a dryer room, but they will also produce a lower tem- 
 perature, and make the control of temperature possible. It has 
 already been stated that the reason why the ammonia cold stor- 
 age houses produced better results aside from a control of tem- 
 perature, was their ability to give a dryer air. A system which 
 will utilize natural ice as a primary refrigerant and yet give a 
 dry air and low temperature, would then necessarily be able to 
 compete on an even basis with the ammonia or mechanical sys- 
 tems of refrigeration. 
 
 With a due appreciation of the facts as stated above, there 
 was begun a series of experiments to demonstrate the possibilities 
 of ice refrigeration, and the refrigerating apparatus now known 
 as the Cooper system is the result. At the time of beginning these 
 experiments, the house experimented with was a nearly new one, 
 equipped with what was supposed to be the very best and latest 
 system of ice refrigeration (Dexter System), and at that time 
 the writer was familiar with nearly all the prominent systems 
 of ice cold storage, as already described. It was thought that 
 if brine cooled by the ammonia system and circulated through 
 pipes for cooling storage rooms would give better results than 
 ice, the same results might be produced by cooling brine with a 
 mixture of ice and salt, and circulating the brine through pipes in 
 the same way. To demonstrate the practicability of the idea, a 
 small room was fitted up for a test. An insulated tank was con- 
 structed, in which was placed a pipe coil surrounded by ice and 
 salt. Another coil was placed on the wall o<f the room, and the. 
 two connected together. A pump driven by an electric motor, 
 caused the brine to flow from the coil in the tank through the 
 coil on the wall, and then again through the tank coil continu- 
 ously. A temperature of brine ranging from 12° F. to 18° F. 
 
REFRIGERATION FROM ICE 
 
 455 
 
 was readily obtained, and the experiment was such a marked 
 success, even with this crude apparatus, that it was extended 
 to two other rooms, larger than the first. This time the pipes 
 were so arranged that a partial circulation of brine would take 
 place without the operating of the pump, but still another trial 
 was necessary to fully demonstrate that the system could be 
 operated entirely without a pump; that is, by the natural or 
 gravity circulation of brine. This was obtained in a manner 
 similar to the circulation of water in the hot water heating systems 
 
 1 SEconnflrar coils in 
 
 COII. OH STORAGE ROOM 
 
 FIG. 7. — DIAGRAM SHOWING ARRANGEMENT OF BRINE COILS IN 
 cooper's SYSTEM. 
 
 used in heating buildings. In the gravity brine system, the tank 
 which contains the ice and salt, and the tank coils or primary 
 coils, as they are called, are located at a higher level than the 
 secondary coils which do the air cooling in the rooms. Fig. 7 
 shows the arrangement of coils in use. When the tank is filled 
 with ice and salt, the brine standing in the primary or tank coil 
 is cooled by contact with the ice and salt which surrounds the 
 pipes, to a lower temperature than the brine contained in the 
 secondary coils, and consequently flows down into the secondary 
 
456 PRACTICAL COLD STORAGE 
 
 coils. At the same time the brine from the secondary coils rises 
 into the primary coils, where, as it is cooled, it repeats the circuit 
 in the direction shown by the arrows. The term "gravity," as 
 applied to this system of brine circulation, refers to the cause 
 of circulation which is owing to the difference in specific gravity 
 (weight) between the cold brine in the primary coils and the com- 
 paratively warm brine in the secondary coils. The temperature 
 of the circulating brine will range from 5" F. to 20 c F. It is com- 
 paratively easy to cool a room to 10° F. or 15° F. with the 
 gravity brine system. As a matter of experiment, a room was 
 cooled to 6° F. for a short time. The brine which circulates in 
 the primary and secondary coils is usually a solution of chloride 
 of calcium, which is used in preference to common salt brine for 
 the reason that it rusts the pipes less and will not freeze as 
 readily. The circulating brine is entirely independent of the 
 brine which runs out of the tank as a result of the mixture of 
 ice and salt. The refrigeration in the waste brine is utilized 
 for cooling purposes by running it through a coil of pipe of 
 suitable size at any convenient place in the building, and it is 
 afterwards led to the sewer. The chloride of calcium brine, 
 on the other hand, remains always in the pipes, the only loss 
 being from leakage, which is, of course, very small. It will be 
 appreciated, by experienced persons, that this system of cooling 
 is simple in principle, very unlikely to get out of order, and when 
 once in operation, will continue as long as the supply of ice and 
 salt is maintained in contact with the primary coils in the tank. 
 In operation it is usually necessary to fill the tank but once each 
 day with ice and salt, and the circulation will remain continuous 
 and automatic through the twenty-four hours. The ice in the 
 tank will melt down one to four feet per day, depending on how 
 hard the apparatus is being worked, and it is only necessary to 
 refill with enough ice and salt to keep the tank full. (See direc- 
 tions for operating further on in this chapter.) 
 
 Rooms cooled by the gravity brine system are subject to pre- 
 cisely the same drying and purifying influences as are rooms 
 cooled by any of the mechanical systems of refrigeration. The 
 moisture and impurities in the air are, to a great extent, frozen 
 on the surface of the pipes, and temperatures are easily con- 
 trolled. In applying ice to cold storage work by this system, the 
 
REFRIGERATION FROM ICE 457 
 
 ice has no more connection with the air of the storage room than 
 if it were miles away. The ice is, in fact, generally placed in 
 an ice room of cheap construction, built independently of the cold 
 storage rooms. Where the ice room is already built, it is only 
 necessary to build the cold storage rooms alongside of the ice 
 house, equip them with cooling apparatus and means for getting 
 the ice to the tank containing the primary coils. Even the loca- 
 tion of ice house is not important. The cold storage house may 
 be located in the center of the business district, and the ice on 
 the ice field. The necessary quantity may be hauled each day. 
 This is entirely practicable, and its feasibility has been demon- 
 strated in several different localities. 
 
 Except in plants of very small size, the ice is usually crushed 
 and elevated to the tank by machinery. This saves much labor, 
 and results in better work. The. machine for crushing the ice 
 is generally located at or near the floor of the ice room. 
 The ice is fed into the crusher through a chute, which is made 
 in sections. As the ice is worked down in the house, a section 
 is removed to bring the top of the chute about on a level with 
 the top of the ice. The ice is first chopped into irregular pieces 
 of twenty or thirty pounds or less, then shoveled into the chute, 
 which drops the ice into the crusher. From the crusher, in 
 pieces not larger than a hen's egg, it drops into a bucket elevator 
 which raises it to a point near the tank, and somewhat above it, 
 where the elevator dumps the ice into an inclined tube terminating 
 in a flexible spout. The flexible spout is pivoted, and will deliver 
 ice to any part of the tank without shoveling. The only hand 
 labor necessary on the ice is the chopping of the ice and shovel- 
 ing it into the chute. Two men will easily handle four tons of 
 ice an hour in this way. Four tons of ice a day will cool a stor- 
 age house with forty carloads capacity, during average summer 
 weather. The section, Fig. 8, on following page, shows the ice- 
 handling apparatus in conjunction with the other parts of a fully- 
 equipped storage house. It may be noticed that the storage rooms 
 have no communication with the ice house, and that the cooling 
 is effected by circulating the air of the rooms in contact with 
 the secondary coils of the gravity brine system. 
 
 The storage rooms are cooled and the temperature regulated 
 directly by the gravity brine system. This may be done by placing 
 
458 
 
 PRACTICAL COLD STORAGE 
 
 the secondary coils of the brine system directly in the room, but 
 a better method is by using the forced air circulation system, 
 especially if the rooms are fairly large. For this purpose, the 
 
 FIG. 8. — ILLUSTRATING COOPER' S GRAVITY BRINE SYSTEM OF REFRIGERATION. 
 
 This diagram is for the purpose of showing the different systems clearly, but is not in 
 good proportion, as the storage room is shown much smaller than it is. The apparatus is 
 really quite small as compared with the rooms. 
 
 secondary coils are placed in a room by themselves, known as 
 the coil room. A fan draws the air from the coil room and dis- 
 tributes it to all parts of the storage room. The air is returned 
 to the coil room by being drawn off at the top of the storage 
 
REFRIGERATION FROM ICE 459 
 
 room through a perforated false ceiling. Depending on various 
 conditions, either perforated side air ducts or perforated false 
 floors are used for distributing the air uniformly throughout the 
 room. (In the chapter on "Air Circulation'' are discussed the 
 various phases of air circulation and the relation of refrigerating 
 surfaces thereto, describing the various designs by the author for 
 improving air circulation. See also chapter on "Ventilation" 
 and " Uses of Chloride of Calcium " for other simple devices 
 which are installed in combination with the gravity brine system 
 as illustrated in Fig. 8.) 
 
 DISCUSSION AND DIRECTIONS AS APPLIED TO THE GRAVITY BRINE 
 SYSTEM AND OTHER ICE AND SALT SYSTEMS. 
 
 It has been thoroughly demonstrated by the author that 
 tanks of a greater length than 10 feet were usually unnecessary 
 and the additional length when used was practically wasted. 
 In practical operation ice in the tank does not settle or melt down 
 generally, more than from one to three feet per day of twenty- 
 four hours. All that is required, therefore, in the length of the 
 tank is that it should be sufficiently long to allow the salt brine 
 which is dripping down through the ice to become thoroughly 
 diluted and expend its ice-melting power before reaching the 
 bottom. While the largest amount of refrigerating duty is ac- 
 complished where the ice and salt are in direct contact with one 
 another, near the top of the tank, yet there is considerable re- 
 frigerating value or ice-melting power in the brine which results 
 from a union of the ice and salt. This brine trickles down 
 through the finely crushed ice in the tank and has the same action 
 on the ice as the salt, only to a lesser extent. As the brine be- 
 comes more and more dilute, it has less and less value in this 
 respect and finally possesses practically none, if the tank is of 
 sufficient length. 
 
 As before stated, the practical limit of length for the tank 
 is ten feet, although for some purposes a length of twelve feet 
 may give more satisfactory results. The author has had in ser- 
 vice for freezing purposes tanks which were sixteen feet in 
 length. With tanks of this length the meltage in the lower 
 three or four feet is very small. In fact, the bottom six feet of 
 these tanks will not do any considerable amount of work. The 
 
460 PRACTICAL COLD STORAGE 
 
 further down in the tank, the less meltage of ice there will be, 
 depending on the temperature at which the room is being carried. 
 
 The work of charging the tanks with ice and salt is compara- 
 tively simple, but at the same time there is a chance for the ex- 
 ercise of considerable skill and sound common sense. It is an 
 old idea in connection with freezing ice cream that the ice and 
 salt should be filled into the freezer in alternate layers instead of 
 being thoroughly mixed together. There is no question at all 
 but that this is a mistake. The more thoroughly the ice and salt 
 can be mixed together, the better the freezing action to be ob- 
 tained, and the greater the economy of ice and salt. 
 
 If the ice and salt are filled into the tank in alternate layers 
 there are two bad results which interfere with the practical and 
 efficient operation of the plant. One is that the salt will cake 
 and form lumps, which will probably go clear to the bottom of 
 the tank without entirely dissolving ; another is that quite a large 
 portion of the refrigeration which is developed where the ice 
 and salt do come in direct contact is used in the freezing to- 
 gether of the ice which has no salt mixed with it. This is es- 
 pecially true at the top of the tank, where there would be very 
 little or no brine dripping down through. 
 
 The proper way to charge the tanks of the gravity brine sys- 
 tem, therefore, is to thoroughly mix the ice and salt together. In 
 a few cases this is done before the ice is filled into the tanks, but a 
 better way is to salt the ice as the tanks are being filled. If the 
 ice is crushed by a machine and the tanks are filled through a 
 spout, this is a comparatively easy matter. Where the ice has 
 to be crushed by hand it should be broken as finely as possible 
 and no pieces of ice larger than a man's fist allowed to go into the 
 tank. This is sometimes difficult to do where the ice is broken 
 with a sledge hammer or an axe, but with care big pieces may 
 be avoided. It might be stated here that the finer the ice is 
 broken the better is the action obtained from the salt ; that is, the 
 less salt it will take to do a given amount of refrigerating. 
 
 In refilling tanks it is well to first put on a certain amount 
 of salt, whatever is required, and then settle the honeycombed 
 ice already in the tank by stirring with a stirring stick. After 
 the tank is filled a small amount of salt may be placed on top and 
 thoroughly stirred into the ice by the use of the stirring stick. 
 
REFRIGERATION FROM ICE 461 
 
 This stirring stick may be constructed of a piece of i% by 3 
 inch hard wood with a tapering point at one end, smoothed off 
 to a handle at the other end, and made about four to six feet in 
 length. 
 
 The tanks of the gravity brine system should be cleaned out 
 at least once a year, as a certain amount of mud and dirt will ac- 
 cumulate at the bottom even with the most careful handling of 
 salt and the cleanest possible ice employed. In filling the primary 
 tanks of this system the instructions above may be followed 
 closely and may be much more readily carried out, as plenty of 
 space is available for the stirring of the' ice and salt. The best way 
 to proceed in filling the primary tanks of the gravity brine sys- 
 tem is to detail two men in the tank house, one for salting the 
 tank, and the other for stirring the salt into the ice. If only one 
 man is available the ice should be handled slowly so he may get 
 salt fully stirred into the ice. In this way a very thorough mix- 
 ture can be obtained and economy will result. The flexible spout 
 which feeds the ice into the primary tank can be arranged so 
 that it may be held in any position by the use of a rope. It is. not 
 necessary that this should be held in the hand. 
 
 The direction and remarks regarding the gravity brine sys- 
 tem as above apply equally to any tank system employing ice and 
 salt. No exact directions can be given as to quantity of ice and 
 salt required for the reason that the conditions are constantly 
 changing. It may be remembered as a rule, however, that the 
 quantity of ice melted, goods cooled and temperatures produced 
 are in almost direct proportion to the amount of salt used in the 
 tank. The more salt, the more ice melted, the more refrigeration 
 produced, the more goods cooled, or the lower temperature ob- 
 tained. Pay no attention whatever to the amount of ice being 
 used. It is the salt on which you depend for gauging the opera- 
 tion of the house. As a guide it may be said that from five to 
 fifteen pails (25 lbs. each) will be used on. a primary tank of the 
 gravity brine system which has a dimension of about 4x5 feet 
 at the top and 10 feet deep, under average conditions. 
 
462 PRACTICAL COLD STORAGE 
 
 CHAPTER XXIII. 
 HARVESTING, HANDLING AND STORING ICE. 
 
 THE GENERAL ICE CROP. 
 
 It is not expected that this chapter will be of much assist- 
 ance to the experienced ice harvester, but those new in the busi- 
 ness and persons having a comparatively small amount of ice 
 to house may be able to obtain some information in regard to 
 the methods used, and select such tools and devices from those 
 described as will best suit their particular needs. Natural ice 
 has been talked down, legislated against and generally speaking 
 has come to be regarded as a back number for cold storage pur- 
 poses, but a large percentage of the perishable goods stored in 
 the two northern tiers of states and in Canada are still stored 
 in structures cooled with natural ice, and the harvesting, handling 
 and storing of the natural ice crop is therefore of sufficient im- 
 portance to warrant a fair description. In the states which are 
 in about the same latitude as New York and Minnesota and 
 throughout Canada, a failure of the ice crop is unknown, and 
 ice forms quite regularly to a thickness of from fifteen to thirty 
 inches. In Pennsylvania and Iowa and the states in the same lati- 
 tude and isothermal conditions, ice is usually harvested of a 
 thickness ranging from eight to fifteen inches, sometimes thicker. 
 
 Before the introduction of the ice machine, natural ice was 
 harvested as far south as Tennessee and Missouri. In some 
 isolated cases this is still done, but the crop is uncertain, and as 
 the ice is thin it is very expensive to harvest. Probably the thick- 
 est ice on record is harvested at Winnipeg, Manitoba, Canada, 
 where it reaches a thickness of forty inches, at times even more, 
 and almost invariably of excellent quality. The lake ice harvested 
 in Minnesota and Wisconsin is almost marvelous in its purity 
 and brilliancy. Ice has been cut in these states during three sue- 
 
HARVESTING, HANDLING AND STORING ICE 463 
 
 cessive winters, eighteen or more inches in thickness, free from 
 snow or white ice, and clear and transparent as spring water. 
 Lake Superior ice, owing to the beautiful, clear water from which 
 it is frozen, is of excellent quality. It is on record that ordinary 
 newspaper print has been read through a cake of Lake Superior 
 ice twenty-nine inches in thickness. The immense harvests of 
 the Kennebec and Penobscot rivers of Maine and the Hudson 
 in New York, are of national reputation. Ice from these rivers is 
 used largely among the populous coast cities of the East, and be- 
 fore the advent of the ice machine, was used extensively in the 
 Southern states. The shipment of ice south has now practically 
 ceased, and even some of the chief cities of the North Atlantic 
 seaboard now use the manufactured article to a large extent, 
 because, owing to the Board of Health regulations in many 
 places, natural ice can only be used for cooling purposes. 
 
 Ice of a thickness of from ten to sixteen inches handles 
 well and cuts up economically if used for retailing by wagon — 
 a thickness of fourteen inches being probably the most desirable. 
 It is not of course always possible to get the thickness desired 
 owing to the exigencies of the weather during harvest. The 
 maximum thickness which is formed in the locality where har- 
 vested, also necessarily limits in this direction. In southern 
 locations it is difficult to get ice thick enough, while further north 
 the ice often becomes too thick to handle to best advantage. 
 To get a good quality of ice into the house at a low per ton cost 
 is the serious problem of the ice harvester during the winter. 
 To the end that advantage may be taken of favorable conditions 
 of the weather and other related matters, these should be closely 
 studied. 
 
 COST OF HARVESTING AND HOUSING ICE. 
 
 No accurate figures can be given as to the cost of ice de- 
 livered in the ice house, owing to local conditions, which are of 
 necessity different in every instance. Ice has been housed in a 
 Lake Michigan town in Wisconsin for the seemingly impossible 
 cost of six cents per ton. The conditions were ideal for the cut- 
 ting of ice, and were as follows: House on lake shore; steam 
 hoist, with low fuel cost, for hoisting ice directly from water 
 into house; no snow to contend with; perfect ice harvesting 
 
464 PRACTICAL COLD STORAGE 
 
 weather with temperature ranging from zero to twenty degrees 
 above; ice of a uniform thickness of eighteen to twenty inches; 
 labor cost 75 cents per day for experienced men. It may be 
 noted that these exceptional conditions are exceedingly rare, 
 so that the cost as here given cannot be duplicated except in a 
 very few cases, but by taking the above as a basis for calculation, 
 it is possible to estimate approximately the cost of harvesting 
 under conditions varying from the above. 
 
 Ice cut and handled, during fairly favorable weather and 
 hauled not more than a mile, may be housed in northern latitudes 
 for twenty-five cents per ton, perhaps somewhat less. Further 
 south, with ice much thinner and contending perhaps with more 
 or less snow, rain, or thawy weather, the cost will be from two to 
 four times as much. Should the house be situated at the ice 
 field, the cost may be reduced ten to fifteen cents per ton, or 
 more, according to the length of haul avoided. It is assumed in 
 these estimates that no haul will exceed four miles. 
 
 The cost of hauling ice depends also greatly on whether the 
 ice is hauled on runners or wheels, as a much larger load may be 
 hauled on runners. A fall of snow sufficient for sleighing is 
 therefore a boon to the harvester whose house is located at some 
 distance from the field. The snow must of course be removed 
 from the field, but this is more than offset by the improved fa- 
 cility afforded for transportation. An excessively heavy snow- 
 fall, however, may add much to the cost of harvesting, as the 
 ice has to be uncovered. Should a heavy rain follow the plow- 
 ing and making ready of the field, the rain being perhaps followed 
 by sleet and snow, the ice harvester's lot is not a happy one. Not 
 only must the work be done over again, but perhaps the recent 
 fall of snow must be removed, or the snow ice resulting planed 
 off. Other minor items, like loss or breakage of tools, and con- 
 tingencies which come up from time to time, influence the ulti- 
 mate per ton cost of ice delivered in the house. 
 
 CARE AND PREPARATION OF THE ICE FIELD. 
 
 Before undertaking to harvest a supply of ice the harvester 
 should inform himself regarding the legal and sanitary regula- 
 tions of his locality. He should be fully satisfied that the field 
 is lawfully his property, and that all Board of Health and other 
 
HARVESTING, HANDLING AND STORING ICE 465 
 
 rules are fully complied with. Most of the larger cities and 
 many of the smaller ones have quite stringent ordinances regu- 
 lating the harvesting and sale of ice. When used for refrigera- 
 tion or cooling purposes only and not for family use, ice can 
 usually be cut from any source. Some cities, however, will not 
 allow ice to be harvested for any purpose whatever from waters 
 suspected of pollution by sewage or otherwise. 
 
 The selection in the first place and the care of the field prior 
 to harvesting, are both essential for securing a good quality of 
 ice, and an economical cut. The prompt removal of snow from 
 the surface of the field as fast as it falls constitutes the chief 
 
 FIG. I. — STARTING CHISEL. 
 
 labor of preparing the field for harvest. It is seldom that a field 
 of ice freezes sufficiently thick to cut without one or more snow- 
 falls upon it. Flooding, or "wetting down," the ice, is resorted 
 to by some with the first fall of snow, especially in the southern 
 tier of natural ice states. When the ice is intended for family 
 trade this process should not be resorted to, as all dirt and impuri- 
 ties lying on the surface of the ice are frozen on and become im- 
 bedded in the ice. 
 
 The "wetting down" process consists simply in flooding 
 the surface of the ice, which saturates the snow with water so 
 that it may be frozen into ice, protects the under strata of clear 
 
 o 
 
 FIG. 2. — KING CHISEL. 
 
 ice from thawing weather, and serves to increase the thickness 
 of the ice rapidly. A snow ice coating is also thought to make 
 the cake tougher and less liable to break in cutting and handling. 
 The "wetting down" is accomplished by a gang of men armed 
 with narrow bladed ice chisels. A starting chisel (Fig. i), or 
 ring chisel (Fig. 2) may be used. The men should proceed in a 
 row across the field, punching holes at intervals of say six feet, 
 and working at a distance apart of from six to twenty-five feet, 
 depending on the thickness of the ice and amount of snowfall. 
 A small hole only is necessary. "Wetting down" should be done 
 
 (30) 
 
466 PRACTICAL COLD STORAGE 
 
 on a cold, still day, when it is reasonable to suppose that the Wet 
 snow will be frozen solid. In comparatively warm climates, 
 where the natural ice crop is precarious, a fall of snow must be 
 dealt with promptly by "wetting down" or removing from the 
 field. As small a quantity as an inch of dry snow greatly retards 
 the freezing, and the surface of the ice should therefore be kept 
 free from the protecting snow blanket. 
 
 In northern latitudes flooding is not often resorted to, and 
 the snow is removed largely to prevent the formation of snow 
 ice in case of a thaw or rain. Should a rain come on with snow 
 on the ice, the snow becomes saturated with water, which when 
 frozen makes snow ice. Snow ice also results from a thaw when 
 snow lies on the surface of the field. It will thus be seen that in 
 some localities snow ice is desired and in others it is avoided. 
 
 FIG. 3. — HOME-MADE SCRAPER. 
 
 Snow ice is porous and white, because it contains air in fine cells. 
 Its presence lessens the selling value of the ice, but does not in- 
 terfere with its refrigerating value. Perfectly clear ice is de- 
 sired and readily obtained in the North, but natural ice free 
 from snow is seldom seen in the southern tier of ice states. Any 
 heavy fall of snow must necessarily be removed before the mark- 
 ing out and plowing can be commenced, and a field of ice per- 
 fectly free from snow is desirable at all times. An experienced 
 ice harvester will know how to proceed under these different 
 weather conditions and varying stages of the harvest, and these 
 must be taken into consideration at all times if the novice would 
 proceed intelligently. 
 
 For the removal of snow from the field, various devices 
 are in use, depending on the magnitude of the work in hand. 
 
HARVESTING, HANDLING AND STORING ICE 467 
 
 Good progress can be made on a small field by the use of a hand 
 scraper or large snow shovel, especially where the snowfall is 
 dry and light. This method is also useful where the snow is to 
 be removed from ice which will not bear the weight of a horse. 
 For general use in harvesting small crops in northern latitudes, 
 the home-made scraper illustrated in Fig. 3 will be found of ser- 
 vice. It is easily and cheaply made, and can be made of any de- 
 sired size to suit the work in hand. An oak plank, two or three 
 inches thick and ten to sixteen inches wide may be used, of any 
 length up to twelve or fourteen feet. A piece of J^xi^ inch 
 iron fastened to the lower edge will improve the efficiency and 
 wearing qualities greatly. A small scraper of this kind may be 
 fitted with shafts for one horse and the larger ones with a pole 
 for two horses. A small one may be constructed to be operated by 
 
 FIG. 4. — IMPROVED SNOW SCOOP SCRAPER. 
 
 two men. A handle of round iron flattened and screwed to 
 plank, as shown, is useful in swinging the scraper into position 
 or in lifting over banks at the dump and as a means of holding 
 on. If preferred, a rope may be attached in a similar manner 
 for this purpose. 
 
 The larger and more durable cleaning-off scrapers which 
 are used on larger fields may be purchased from the manufac- 
 turers. Fig. 4 illustrates a very good machine for this purpose. 
 Fig. 5 is a common form to be purchased at a low cost. Its opera- 
 tion is similar to the home-made scraper shown in Fig. 3. Where 
 the snow is heavy or deep the scoop scraper illustrated in Fig. 
 6 is used. These range from six to eight feet in width, depend- 
 ing on the character of the work. After the heaviest snow is 
 removed the cleaning off scraper may be put on for removing 
 the loosened snow. Should a thick crust form on the snow some 
 
468 
 
 PRACTICAL COLD STORAGE 
 
 expedient must be resorted to for loosening it, so that it may 
 be scraped; a disc harrow or a modern ice field cultivator will 
 sometimes be found useful for this purpose. 
 
 FIG. 5. — SIMPLE SNOW SCRAPER. 
 
 As the snow is scraped from the ice it is generally best to 
 remove it to some distance from the place of cutting, either to 
 the shore, or far enough from the field to prevent the ice from 
 "flooding," either before or after cutting commences. Where 
 
 FIG 6. — SCOOP SCRAPER. 
 
 the field is located on a large body of water, the snow is sometimes 
 scraped into piles or windrows know as "dumps." The "dumps" 
 may be hauled away on sleds or with the scoop scrapers or self 
 dumping scrapers, or they may be allowed to remain on the ice. 
 
HARVESTING, HANDLING AND STORING ICE 469 
 
 If allowed to remain on the ice a deep groove is sometimes plowed 
 around the "dump," the weight of the snow causing the ice in 
 this place to break loose and sink beneath the level of the cutting 
 field. This method is not resorted to except on large fields and 
 in case of an exceptionally heavy fall of snow. 
 
 |-J I 
 
 =*#?»WTwmf* 
 
 FIG. 7. — ICE AUGER. 
 
 A careful harvester will observe the thickness of his field 
 from the time it will safely bear his weight, and will know from 
 day to day the exact thickness he can depend upon, so that when 
 the time comes he may act promptly. The thickness is ac- 
 curately determined by the use of an ice auger (Fig. 7), and 
 measuring iron (Fig. 8). The measuring iron has inch marks 
 
 =* 
 
 FIG. 8. — MEASURING IRON. 
 
 on it, and is bent up on the end, so that it can be inserted through 
 the hole made by the ice auger and drawn up against the under 
 side of the ice. The thickness of snow ice, if any, may be noted 
 at the top. For more accurate work three holes may be bored, 
 forming a triangle, and slanting toward each other at the bot- 
 tom ; a small saw is used for cutting the triangular plug by saw- 
 ing from hole to hole. 
 
 FIG. 9. — FIELD ICE PLANER. 
 
 If sufficient snow ice or dirty ice is present to be a detri- 
 ment to the quality of the crop, in the northern latitudes, it is 
 generally removed before the ice is housed. This may be done 
 by the use of the snow ice planer on the field, or by the elevator 
 ice planer as the cakes pass up the incline. Where the endless 
 
470 
 
 PRACTICAL COLD STORAGE 
 
 chain elevator is not in use, the snow ice must of course be re- 
 moved on the field. The field planer (Fig. 9) is used in con- 
 nection with the marker with swing guide. The plane is usually 
 set to remove two inches of ice at a time, as a smoother job re- 
 sults than where a deeper cut is made. If it is necessary to re- 
 move more than this, a second or third grooving and planing 
 takes place. The best job of planing may be done by using a 
 2 1 -inch guide on the marker and using a check gauge, by which 
 the groove is cut to the exact depth of the snow ice to be re- 
 moved. Then the plane being twenty-two inches wide, and the 
 
 FIG. 10. — ELEVATOR PLANER. 
 
 knife set at the bottom of the guide plates, will lap over one inch 
 on the planed portion, removing the marked grooves com- 
 pletely, and leaving the surface as smooth as new ice. An im- 
 proved ice field cultivator requiring no marking has now largely 
 superseded the above method. 
 
 A marker with guide which can be adjusted from twenty- 
 two to twenty-one inches is very convenient for use in planing. 
 The chips of ice resulting are removed in the same way that a 
 heavy fall of snow would be. The chips being very heavy make 
 the planing of snow ice on the field a very expensive operation. 
 
HARVESTING, HANDLING AND STORING ICE 471 
 
 Where the harvest is of sufficient magnitude to warrant, the use 
 of the elevator planer (Fig. 10) is greatly to be desired. This will 
 remove any thickness of snow ice, reduce the cakes to the same 
 thickness and leave the upper surface of the ice corrugated, which 
 will prevent breakage when removing ice from the house. A 
 chip conveyor (Fig. n) removes the ice chips and slush a dis- 
 tance from the elevator, and is almost a necessity in conjunction 
 with the elevator planer. 
 
 HARVESTING THE ICE. 
 
 With the field clean, free from show and of the desired thick- 
 ness, the marker is put to work. It is best to start the marking 
 
 FIG. II. — ICE CHIP CONVEYOR. 
 
 plow by stretching a strong line between two stakes driven into 
 auger holes in the ice about 200 feet apart, to serve as a guide. 
 As all following marks are made from the first, it is important 
 that this should be straight. A long plank as a straight edge is 
 used to guide the hand plow (Fig. 12) or a line marker (Fig. 
 13) may be used as a substitute. Either is followed by the regu- 
 lar marker (Fig. 14) with guide which goes over the field, cut- 
 ting grooves parallel to the first. The marker is used only for 
 
472 PRACTICAL COLD STORAGE 
 
 the first grooving, the greater part of the cutting being done by 
 the deeper field plow (Fig. 15). In marking out the first groove 
 the operator should take care to hold the marker upright to pre- 
 
 FIG. 12. — HAND ICE PLOW. 
 
 vent cutting irregular shaped cakes. After the first groove is 
 made the guide on the marker runs in this groove, gauging the 
 distance of the second. This is repeated over the entire field. 
 
 FIG. 13. — LINE MARKER. 
 
 It is important that the cross marking should be at right 
 angles to the first, or parallel marking, for which purpose a large 
 wooden square ten or twelve feet long is used. By this method 
 it is comparatively easy to have the cakes square. Cakes 22x22 
 
 FIG. 14. — MARKER PLOW WITH SWING GUIDE. 
 
 inches, or 22x32 inches are the common sizes. Marking and 
 plowing may be done with one machine, where the ice field is 
 small. The swing guide plow (Fig. 16) is the one used for this 
 purpose. After the ice is marked out the guide is removed and 
 
HARVESTING, HANDLING AND STORING ICE 473 
 
 the field plowed over as with the regular field plows. Swing 
 guide plows are generally made with seven teeth and either six, 
 seven or eight inches in depth. 
 
 A well equipped harvester has several different plows for 
 the different purposes. Following the marker a six-inch, nine- 
 
 FIG. 15. — FIELD ICE PLOW. 
 
 tooth plow is run in the marker grooves, making these about five 
 inches deep. Following immediately behind is another plow, 
 eight inches deep, with eight teeth, making the grooves seven 
 inches deep. This is deep enough for ten or twelve inch ice, 
 but if the ice is fourteen or sixteen inches thick, still another 
 
 SWING GUIDE ICE PLOW. 
 
 plow follows, ten inches deep with six teeth, making the grooves 
 about eight or eight and a half inches deep. Should the plows 
 be somewhat dull, perhaps this depth is not reached, and a sec- 
 ond plowing with the ten-inch plow becomes necessary, probably 
 making the grooves nine or ten inches deep, which is sufficient for 
 ice sixteen inches thick, or even more. 
 
474 
 
 PRACTICAL COLD STORAGE 
 
 The headlines in which the large floats are to be barred off 
 are run deeper, some of the large companies having a twelve- 
 inch, five-tooth plow for this purpose ; still others deem it economi- 
 cal to use a fourteen-inch plow on very thick ice. Where the 
 harvest is comparatively small, a number of the plows mentioned 
 may be dispensed with, even to doing the total cutting with the 
 
 FIG. 17. — ICE PLOW ROPE. 
 
 swing guide plow (Fig. 16). A set of plows commonly used 
 by the smaller harvester consists of a marker, an eight-inch, 
 eight-tooth plow and a ten-inch plow. If the ice to be cut does 
 not exceed twelve inches the ten-inch plow may be dispensed 
 with ; a marker and a nine-inch seven-tooth plow is used as a 
 set also, and is a favorite with the small harvester. 
 
 FIG. l8. — ICE PLOW HARNESS. 
 
 The plow rope (Fig. 17) by which markers and plows are 
 drawn, should be nine or ten feet long. This prevents the front 
 end of the plow from rising and causing a "chatter," or irregu- 
 lar cutting. Many, however, use shorter ropes or none at all. 
 The regular plow or grooving harness with whiffle-tree well 
 elevated as shown in Fig. 18, is more convenient and easier on 
 horses than the ordinary harness. Generally speaking, about 
 
HARVESTING, HANDLING AND STORING ICE 475 
 
 half or two-thirds of the thickness of the ice should be cut through 
 by the plow ; but not less than four inches of ice should be left 
 between the bottom of the groove and the water below. Four 
 inches of solid ice is necessary to safely bear the weight of a 
 team of horses. Too much ice should not be plowed in advance 
 of the housing capacity ; enough for two or three days is ample ; 
 then in the event of a thaw or rain labor is saved, as the grooves 
 freeze up very quickly. 
 
 1 
 
 /CE % 
 
 //oust „ 
 
 1 
 
 5 
 
 I ELEI/ATOR 
 = MCU/VE 
 
 •SHOPE L/A/E 
 
 %. __ :: : : 
 
 I „ 
 
 S , :_ 
 
 5 ___ „IL 
 
 _ __ ,l'J^ 
 
 ,c f b 
 
 _. ___,. f,' 
 
 ,e£_:_ " 
 
 + cit'_ 
 
 g£ b _ " 
 
 
 
 in mini nil i-miif— -+ 
 
 FIG. 19. — DIAGRAM FOR ICE HARVEST. 
 
 No matter how small the harvest of ice, floats of some size 
 are used, as they facilitate the floating of the ice to the channel 
 where they are separated. A float consists of a number of cakes 
 of ice, usually from fifty to one hundred, and if floated some dis- 
 tance they are made much larger. The size on large fields is de- 
 termined by the deep grooves already referred to as forming 
 headlines for floats. The channel to the elevator extends across 
 the end of the field. The deep grooves for sawing are located 
 
476 
 
 PRACTICAL COLD STORAGE 
 
 about twelve or fifteen cakes apart and run lengthwise of the 
 field, while barring-off grooves run in the opposite direction, 
 or parallel to the channel and are from four to eight cakes apart. 
 By barring off the longest side of the float much sawing is saved. 
 Fig. 19 shows a diagram of the layout of an ice field, house, 
 channel, etc. The location of the channel for floating the cakes 
 to the incline should, of course, be selected before marking out 
 and plowing the field. The channel should be plowed with a 
 
 FIG. 20. — ICE SAW. 
 
 deep groove on each side, and the ice removed by sawing out 
 with the hand ice saws (Fig. 20). Or, if plows are not plentiful, 
 the channel may be sawed out while the field is being plowed. 
 The ice from the channel may be sunk under the ice along the 
 sides of the channel, as it is usually more or less irregular and 
 broken. 
 
 In sawing out for a channel the cakes should be sawed 
 slightly narrower at the top, so that they may be readily sunk 
 
 FIG. 21. — CHANNEL BRACE.. 
 
 under the channel sides. Any broken or odd shaped pieces 
 which come into the channel should also be sunk in the same 
 manner. This disposes of them easily, and as this broken ice 
 freezes to the under side of the ice field it aids greatly in sup- 
 porting the channel sides, which have a strong tendency to flood 
 from the continued weight and travel. Where the field is on a 
 river, or where the channel is long, it may be necessary to put 
 braces across to prevent the channel from closing. A simple 
 
HARVESTING, HANDLING AND STORING ICE 477 
 
 device of this kind is shown in Fig. 21. It should extend the 
 same distance above and below the ice, and be out of the way of 
 
 FIG. 22. — CAULKING BAR. 
 
 passing cakes. Water sprinkled around the uprights where 
 they pass through the ice will soon freeze solid and make a strong 
 anchorage. 
 
 FIG. 23. — BREAKING BAR. 
 
 In breaking out the floats from the planed field, it is best 
 to select only a sufficient area for the day's pack. The grooves in 
 the field adjoining this area are calked tightly with chips to 
 
 *a 
 
 FIG. 24. — KNOB HANDLE FORK BAR. 
 
 prevent the water running into and freezing in the grooves. 
 The calking bar (Fig. 22) is used for this purpose. With the 
 
 o 
 
 ' FIG. 25. — RING HANDLE FORK BAR. 
 
 ice saws the grooves at the end of the selected area are sawn 
 through and a float is broken off by striking into the groove at 
 
 _Z> 
 
 >■ 
 
 FIG. 26. — RING HANDLE SPLITTING FORK. 
 
 the back, in several places, with the barring-off tool, or breaking 
 bar (Fig. 23). The fork bars (Figs. 24 and 25) are likewise 
 
 ts 
 
 FIG. 27. — WOOD HANDLE CANAL CHISEL. 
 
 used for this purpose. The splitting fork (Fig. 26) is also much 
 used for barring off thick ice, and is a general favorite for the 
 purpose, even on moderately thin ice. 
 
478 PRACTICAL COLD STORAGE 
 
 The floats at the channel are broken up into strips, or small 
 floats of single or double rows of cakes, and when these are in 
 the channel they are separated into single cakes. For this pur- 
 pose the channel chisels (Figs. 27 and 28) are used. When the 
 grooves are much frozen the three tined fork bar (Fig 29) is 
 used to good advantage. When the weather is frosty and the 
 
 FIG. 28. — STEEL HANDLE CANAL CHISEL. 
 
 grooves in good condition the ice will cleave very accurately 
 from top to bottom of the grooves ; but if the weather be soft 
 and the grooves badly frozen, it is often necessary, on thick ice, 
 to use the house-axes (Fig. 30) to trim up the cakes. It is only 
 possible to do this on a comparatively small harvest where the 
 ice is hauled out on a table before loading. This house-axe trim- 
 
 FIG. 29. — KNOB HANDLE 3-TINED FORK BAR. 
 
 ming is impossible where the endless chain elevator is used. 
 When trimming with the house-axe it is best to hew the cakes 
 a trifle narrower at the bottom, as the ice will then loosen much 
 easier from the house and with less breakage. 
 
 The methods of removing the cakes of ice from the water 
 are so numerous that the ice harvester may easily select the one 
 
 FIG. 30. — HOUSE AXE. 
 
 best adapted to his needs. For the handling of a small harvest 
 of less than one hundred tons an inexpensive rig must of course 
 be selected, but when housing several thousand tons or more 
 the most improved endless chain elevators make a great saving 
 in the cost per ton. Two men with tongs will pull a small cake 
 of ice from the water, but some simple device is generally to be 
 
HARVESTING, HANDLING AND STORING ICE 479 
 
 preferred even for the filling of a farm ice house of ten to 
 twenty-five tons capacity. 
 
 A simple and easily portable rig for raising ice from the 
 water and placing it directly on the conveyance is shown in Fig. 
 
 SIMPLE ICE LIFT. 
 
 31. It consists of a simple lever or pole, supported on a post set 
 in a base or platform. The lever is supported from the top of the 
 post by a rope or chain giving play enough so that the cakes may 
 be lifted and swung over the sleigh or wagon. The necessary 
 
 FIG. 32. — WINDLASS OR CRAB HOIST. 
 
 leverage for lifting any size of cake may be obtained by adjusting 
 the chain at the required point on the pole. A rope attached to 
 the long end of the pole enables the operator to secure a lift 
 which would otherwise be impossible. Fig. 32 shows a rig fre- 
 quently used, especially in some parts of the West. It will raise 
 
480 
 
 PRACTICAL COLD STORAGE 
 
 the ice with little effort and deposit it directly on the conveyance, 
 but has the disadvantage of not being easily transported, and is 
 very slow in action. 
 
 The inclined slide and table (Fig. 33) is the most common 
 device in use for removing the cakes from the water and placing 
 them in a position to be easily loaded. Two active men with ice 
 hooks will pull out on the table a great many cakes per day, 
 
 
 fedtesAv 
 
 FIG. 33- — INCLINED SLIDE AND TABLE. 
 
 but quite often a horse is employed, in which case a draw-rope 
 is used, that passes through a pulley fixed to a cross-bar above the 
 table (see Fig. 34). The jack (Fig. 35) is also used for this 
 work. Sometimes the horse or horses pull directly across the 
 table without using the pulley ; two> horses, working both ways 
 and using a grapple on both sides of the incline, will haul out a 
 surprising number of cakes, enough to keep busy a large number 
 
 FIG. 34. — TABLE WITH SLIDE AND DRAW ROPE. 
 
 of teams. Fig. 36 shows a good arrangement of table on shore 
 and a direct pull across the table. Where a table is used, it 
 should, to facilitate handling, be slightly higher than the con- 
 veyance. 
 
 HOUSING AND PACKING THE ICE. 
 
 The endless chain elevator already referred to, may be pur- 
 chased from the manufacturers with almost any variation to fit 
 individual needs, and is a necessity for the economical housing 
 
HARVESTING, HANDLING AND STORING ICE 481 
 
 of ice on a large scale. Fig. 37 shows an apparatus of this kind. 
 Some of the large companies harvest and place ice in the houses 
 at an almost incredible speed with these improved facilities. It 
 is on record that 720 tons of ice per hour have been transported 
 from the water to the houses by a single apparatus. 
 
 JACK GRAPPLE. 
 
 Where ice is hauled from the field to the house, the simplest 
 method in use for elevating into house where a very small amount 
 is stored, is the inclined slide, up which the ice may be pushed 
 by two men with ice hooks. The hoisting crab (Fig. 38) with 
 hoisting tongs (Fig. 39), together with the slide, may also' be 
 used, or the single gig elevator as shown in Fig. 40. In this cut it 
 is shown raising ice directly from the water. It is also well 
 
 ■titaJkmA&$%M^ 
 
 ""]'""''iiliilll»«*"i.M, 
 
 FIG. 36. — ILLUSTRATING DIRECT PULL ACROSS TABLE. 
 
 adapted to handling ice delivered by conveyance. A double gig 
 elevator, operated by means of a hoisting engine, makes a first- 
 class rig for moderately large houses, and where the amount of 
 ice is sufficiently large, the regular endless chain elevator with 
 bars, same as used for removing ice from the water, is largely 
 in use. Hoisting tongs (Fig. 39) are in some localities largely 
 
 (31) 
 
482 
 
 PRACTICAL COLD STORAGE 
 
HARVESTING, HANDLING AND STORING ICE 483 
 
 in use for housing ice, and are used for lifting cakes directly 
 from the water to the chute conducting it to the house ; usually 
 two pairs of tongs are arranged so that one pair goes down as 
 the loaded pair goes up. This is a comparatively slow process, 
 but it is a good outfit where small quantities are handled. 
 
 The method of storing ice in the house should be governed 
 by the purpose for which it is to be used. If the ice is to be used 
 for cooling purposes in the old overhead ice cold storage house, 
 and none of it to be removed, it should be packed as closelv as 
 possible, and the joints between the cakes calked or packed with 
 
 HOISTING CRAB. 
 
 chips, using the calking bar already illustrated in Fig. 22. This 
 method is satisfactorily employed where the ice is not to be re- 
 moved from the house, but in other cases it is not to be recom- 
 mended, as the ice freezes together quickly as soon as the top 
 tier begins to melt. When the ice is to be removed from the 
 house it is best not to pack it too closely. 
 
 There are several ways of packing, any of which will make 
 it possible to remove the ice from the house with very little 
 labor or trouble. Where the ice is quite thick the cakes may be 
 
484 PRACTICAL COLD STORAGE 
 
 hewn narrower at the bottom, as already suggested, and the 
 cakes stored as closely as they will pack. With thinner ice it is 
 best to leave a space of one to three inches on the sides of the 
 cakes all around. Care must be taken to have the seams in a 
 straight line in each direction. The starting chisel (Fig. 41) 
 is useful for this purpose. Should the cakes be of different 
 thicknesses, as when harvested from a running stream, they 
 should be adzed off to an even thickness, if this work has not al- 
 ready been done by the snow ice plane or the elevator planer. 
 
 No matter what method of storing is used, the successive 
 tiers of ice should be so placed as to break joints, the object being 
 
 FIG. 39. — HOISTING TONGS. 
 
 to bind the ice into one solid body and prevent it from caving 
 or spreading. If this simple rule is followed, pressure on the 
 sides of the house is avoided. Disastrous results have followed 
 the careless packing of ice. Ice 22 x 32 inches is very good for 
 breaking joints, as one tier may be placed in one direction, and 
 the next in the opposite. Where the 22 x 22 inch cakes are stored, 
 it is best to harvest some double-sized cakes for binding pur- 
 poses. Many harvesters do not break joints oftener than 
 every six or eight feet but "every tier broken" is better and safer. 
 Where some kind of covering is used, usually the two top tiers 
 of ice in the house are packed close together to prevent the 
 
HARVESTING, HANDLING AND STORING ICE 
 
 485 
 
 covering from working down into the seams. In the modern 
 houses, where no covering is used, and for cold storage purposes, 
 this is unnecessary. 
 
 Some harvesters pack ice largely on edge, placing only 
 enough on the flat side to form a binder to prevent the ice from 
 moving. The small edging-up tongs (Fig. 42) are much used for 
 
 . ' LJ 
 
 FIC. 40. — SINGLE GIG ELEVATOR. 
 
 this method of storing. The main advantage claimed for edge 
 storing is that for a given space used, ice will loosen much more 
 easily from the house and with less waste. One tier on edge and 
 one flat makes a good combination for easy loosening. 
 
 For covering ice in the house, shavings, sawdust, straw or 
 hay is used. Salt or marsh hay is thought best for the purpose. 
 
486 PRACTICAL COLD STORAGE 
 
 Ice dealers use covering material, but for cold storage uses it 
 is not customary. 
 
 It should be borne in mind in every case that where ice is to 
 be removed from the house for sale or use, chips made in the 
 house during the filling of same should be thrown out and not 
 chinked into the ice. Where ice is chinked the chips melt first, 
 running down into the seams of the lower tiers, freezing there 
 
 FIG. 41. — STARTING CHISEL. 
 
 and forming a solid body of ice, difficult to remove without much 
 labor and breakage. 
 
 The prevailing idea that thick ice will keep better and longer 
 than that which is comparatively thin, is erroneous. Regardless 
 of the thickness of the ice, the cakes in the interior of the pile do 
 not melt until exposed to the action of the air, the meltage being 
 almost wholly on the top, sides and bottom of the mass. When 
 ice is put into the house in quite cold weather, it will take the 
 temperature of the outside air when exposed during transit to 
 
 FIG. 42. — EDGING UP TONGS. 
 
 the house. If the house is filled with ice at the temperature of 
 the air, say at 20" F., the first ice to melt is at the top of the 
 house, and the water from the meltage runs down into the joints 
 between the cakes of ice lower down in the pile. These being at 
 a temperature somewhat below the freezing point of water, the 
 meltage from above is frozen into ice, in some cases cementing 
 the cakes into a solid mass, as above described. Ice removed 
 from the interior of the house in the fall generally shows no 
 signs of meltage whatever. 
 
 TOOLS FOR HARVESTING AND HANDLING ICE. 
 
 The following lists are given as a guide to those who are 
 unaccustomed to cutting ice. The five lists here given, with the 
 
HARVESTING, HANDLING AND STORING ICE 487 
 
 size of the harvest for which each is suited, are offered as a basis 
 on which the new beginner may form an estimate for his own 
 particular conditions. 
 
 Set No. i. — Suitable for use in harvesting up to ioo tons. 
 I ice plow with swing guide. 2 ice hooks. 
 
 I splitting chisel. 2 pairs ice tongs and 1 4-foot saw. 
 
 Set No. 2. — Suitable for harvesting 100 to 1,000 tons. 
 1 ice plow with swing guide. 
 
 I breaking bar— pad end used as calking chisel. 
 1 splitting chisel. 
 I 4-foot saw. 
 
 1 grapple — to raise up incline — or 1 market tongs if sweep arrange- 
 ment is used. 
 1 plow rope. 
 
 1 line marker. 
 
 2 to 6 ice hooks. 
 
 3 tongs. 
 
 Set No. J. — Suitable for harvesting 1,000 to 2,000 tons of ice, 
 using six to ten men and two horses ; hoisting with one grapple. 
 1 8-in. swing guide plow. 1 plow rope. 
 
 I breaking bar. 1 line marker. 
 
 1 calking bar. 2 to 3 doz. 45^-ft. ice hooks. 
 
 1 bar chisel. 1 to 6 doz. 6-ft. ice hooks. 
 
 1 No. 2 splitting chisel. 1 to 12 doz. 14-ft. ice hooks. 
 
 2 5-foot saws. 1 12-in. top gin. 
 
 1 grapple and handle. 1 12-in. wharf gin. 
 
 Set No. 4. — Adapted for harvesting 2,000 to 5,000 tons of 
 
 ice, using ten to fifteen men and three or four horses; hoisting 
 
 with two grapples. 
 
 I 3/^2-in- marker, 22-in. Sw. Gd. 2 grapples and handles. 
 
 1 g-in. plow (or 8-in.). 2 plow ropes. 
 
 1 No. 1 splitting fork. 1 line marker. 
 
 1 breaking bar. 1 doz. 4^-ft. ice hooks. 
 
 1 calking bar. 1 to 6 doz. 6-ft. ice hooks. 
 
 2 bar chisels. 1 to 6 doz. 14-ft. ice hooks. 
 I No. 1 splitting chisel. 2 12-in. top gins. 
 
 3 S-ft. saws. 2 12-in. wharf gins. 
 
 Set No. 5. — Outfit for harvesting 10,000 to 15,000 tons of 
 ice, or more, engaging, say, fifty men and four horses; hoisting 
 with incline elevator, and filling three chambers at once. 
 1 3/^-in. marker, 22-in. sw. gd. (ex- 6 bar chisels. 
 
 tra 32-in. guide for 22 x 32-in. 1 No. I canal chisel, 
 ice.) (Extra 44-in. guide for 2 No. 2 splitting chisels. 
 22x44-in. or 44-in. sq. ice.) 6 s-ft. saws. 
 
 1 6-in. 7-tooth plow. 4 plow ropes. 
 
 1 8-in. 7-tooth plow. 1 scoop net. 
 
 1 10-in. 6-tooth plow. 1 auger. 
 
 1 6-in. hand plow. 1 measure. 
 
 2 No. 1 splitting forks. 4 doz. 4^-ft. ice hooks. 
 
 1 No. 1 fork bar, 1 to 4 doz. 8-ft. ice hooks. 
 
 2 calking bars. 1 to 2 doz. 12-ft. ice hooks. 
 
488 PRACTICAL COLD STORAGE 
 
 The quality or number of tools required is largely governed 
 by the speed with which it is desired to harvest the crop. The 
 sets listed above are for average work ; if fewer men are employed 
 the sets may be decreased, and for rapid work increased. It is 
 of course desirable to get the ice housed as quickly as possible 
 to avoid changes in the weather, snows, etc. Many, however, 
 prefer to harvest slowly, with a small crew of men, so as to 
 keep their hands at work during the winter, in which case, of 
 course, they run the risk of having their ice break up because of 
 mild weather before they have their houses filled. 
 
ICE HOUSES 489 
 
 CHAPTER XXIV. 
 ICE HOUSES. 
 
 STORING ICE AND SNOW IN PITS. 
 
 By freezing, water expands so that eleven volumes of water 
 become about twelve volumes of ice. Consequently the specific 
 gravity of ice is less than that of water, and ice will float on water. 
 When water is transformed into ice its temperature is not 
 changed, but remains at the "freezing point" so long as it remains 
 in contact with water. So also when ice is melting, the tempera- 
 ture remains at 32° F. until all the ice is transformed into water. 
 By freezing, the latent as well as the sensible heat of the liquid 
 is liberated, and when the ice melts a certain amount of heat is 
 absorbed, being taken from the surroundings. 
 
 Snow is equal to ice in refrigerating value, and a pound of 
 dry snow has the same cooling effect as a pound of dry ice, but 
 if the ice or snow contain water, their cooling effect is corres- 
 pondingly reduced. If, for instance, one-tenth part of the ice is 
 water, there only remains nine-tenths to be melted, and the cool- 
 ing effect is reduced correspondingly. Usually, however, ice har- 
 vested in a thaw does not contain to exceed 3% of water, and its 
 cooling effect is nearly equal to that of dry ice. On the other 
 hand, "frozen ice" (ice below the freezing point of 32 F.) re- 
 quires but one-half the heat required by water to raise it to the 
 freezing point.* Even during a hard frost the ice on the surface 
 of the water is only at 32 ° F., and while harvested it is more or 
 less submerged in water at 32" F., so that its temperature will 
 rarely be much below the freezing point, except when carted for 
 long distances in very cold weather. Supposing it is put into the 
 ice house at ten degrees below the freezing point, it only takes five 
 heat units to bring it to the freezing point, and its cooling value 
 is therefore only equal to one-half that of water through the same 
 range of temperature. It follows that it is of comparatively 
 
 *So stated by the late Pro£. N. J. Fjord, of Copenhagen, Denmark. 
 
490 
 
 PRACTICAL COLD STORAGE 
 
 small moment whether ice is harvested in a thawing or freezing 
 condition. The difference in its value varies only about 5%. 
 
 FIG. I. — INTERIOR OLD STYLE ICE CELLAR. 
 
 It is more important, however, that the ice be packed closely 
 
 in the house. A solid block of ice, a foot cube, weighs about 57 
 
 pounds, but a cubic foot of the ice house will hold only of : 
 
 Ice thrown in at random, about 30 to 35 lbs. 
 
 Ice thrown in and knocked to pieces 35 to 40 lbs. 
 
 Ice piled loosely 40 to 45 lbs. 
 
 Ice piled closely and chinked with fine ice 45 to 50 lbs'. 
 
 The limits in ordinary practice are usually between 40 and 
 
 50 pounds, a difference of 20%. The same amount will melt in 
 
 the ice house whether the ice is packed loosely or carefully. Sup- 
 
 FIG. 2. — ROOF OF OLD STYLE ICE CELLAR. 
 
 pose 15 pounds per cubic foot would melt in the summer, there 
 would be left only 25 pounds, where there was originally 40 
 pounds, but 35 pounds when 50 pounds were stored. The dif- 
 ference in the ice left would therefore be 40%. So it is evident 
 that it pays to pack the ice well and fill the house to its utmost 
 capacity, consistent with ease in removing, cost of the ice, and 
 the purpose for which the ice is to be used. 
 
 EVOLUTION OF THE MODERN ICE HOUSE. 
 
 The common use of ice is comparatively recent, and the mod- 
 ern ice house is therefore of recent development. History records 
 
ICE HOUSES 
 
 491 
 
 that the Romans made use of a form of underground cellar or 
 pit to preserve snow, which was used for cooling beverages dur- 
 ing the heated term. A similar receptacle has been used in many 
 places in this country, especially in the South, and may still 
 be met with in remote and thinly settled neighborhoods. Figs. I 
 and 2 show the outline of the construction adopted in the old 
 
 FIG. 3. — MODERN ICE PIT. 
 
 style, and the construction of the modern ice pit is seen in Figs. 
 3 and 4. 
 
 PRIMITIVE CONSTRUCTIONS. 
 
 The first commercial ice houses were built below the sur- 
 face of the ground, but. at present all are constructed above 
 ground, for the reason that drainage is more easily secured, and 
 the ice is more easily removed from the house. The protection 
 afforded by the earth is of comparatively small value when the 
 disadvantages of storing below ground are taken into consider- 
 
 FIC. 4. — CONSTRUCTION OF MODERN ICE PIT. 
 
 ation. Nevertheless, in places where ice forms only one, two or 
 three inches in thickness, or where snow is housed to be used for 
 cooling purposes, the ice pit has its sphere of usefulness. Mr. J. 
 W. Porter, of Virginia, gives the following interesting informa- 
 
492 PRACTICAL COLD STORAGE 
 
 tion, which, among other things, shows that one of our most 
 esteemed presidents was a progressive and up-to-date man : 
 
 Pits are dug in the ground, of such size and depth as is desired to 
 hold from thirty to fifty loads of ice. The shape is an inverted truncated 
 cone. The walls are lined with slabs of wood, split or sawed, or they 
 may be walled with brick or stone. My own is 14 feet deep, 18 feet across 
 the top and 10 feet across bottom, walled up with stone and then lined 
 with boards standing on end. A one-story tool room projecting beyond 
 walls two feet is erected ; a very common way is to have a half pitch 
 shingle roof start from sills laid outside of walls, with door to pitch in 
 and take out. After filling, it is' leveled fine and filled with clean straw 
 or forest leaves. The ice is rapidly gathered in pieces and shoved in 
 from the wagon, with much less labor than cutting, laying and packing, 
 which would be impracticable. Sometimes when ice is not produced, 
 great snow balls are rolled and pitched in and trodden. Upon "Issen- 
 tiallo," where Jefferson lived and died, within a rifle shot from where I 
 write, is' such an ice house, built by Jefferson, which is 54 feet deep and 
 is still used for ice or snow.* 
 
 In packing snow in the ice house, it is advisable to have it 
 thoroughly wet when it is put in. More cooling material can be 
 packed into the same space when the snow is wet all through than 
 when dry and frozen, because it may be tramped together and 
 packed more nearly solid. It is then possible to get 50 pounds of 
 wet snow into each cubic foot of space, 44 pounds of which is 
 dry and as durable and good in every respect as 44 pounds of 
 solid ice. Many people think that the snow should be frozen, 
 but that is a mistake. If it is dry, wet the snow as it is stored 
 or wait until it rains. When it is thoroughly wet it is time to 
 harvest and pack it. 
 
 The water is expelled by trampling, and drains off, leaving 
 comparatively dry cooling material, which is as effective and 
 keeps practically as well as an equal amount of dry ice. One 
 active man can pack and trample together 500 to 1,000 cubic feet 
 of snow a day, and with this insignificant amount of labor, snow 
 may be used to the same advantage as ice. On the other hand, 
 of newly fallen, light snow thrown into the ice house and care- 
 fully trampled, only 25 to 30 pounds can be packed within a cubic 
 foot, and it will keep no longer than wet snow. 
 
 Ice may be put up and protected from the heat of summer 
 at very small expense. The simplest method is "stacking," which 
 consists simply of piling up the ice and enclosing it with a fence- 
 like structure, leaving space between the ice and the fence for 
 a couple of feet of sawdust or other filling material. No roof is 
 
 *From Green's "Fruit Grower." 
 
ICE HOUSES 493 
 
 put on, but the ice is covered with a goodly quantity of the same 
 material that is used for the sides. This method is not practicable 
 for a small harvest as the wastage is too great, but where a 
 thousand tons or more are put up in this way, the meltage is 
 sometimes surprisingly small, perhaps no greater than 20% to 
 30%. Some ice dealers fill their houses and put up a certain 
 amount in stacks as well, using the stacks first. This method is, 
 of course, only possible where ice can be cut of sufficient thick- 
 ness to tier up regularly and could not be used where it was 
 desired to put up thin ice or snow, as with the ice pit. It is at 
 best only a crude makeshift and can not be recommended except 
 in case of insufficient capacity or temporary disabling of ice 
 house. Sometimes it is desirable to put up ice in this way while 
 awaiting the completion of the cold storage house in which it is 
 to be used. 
 
 By the smaller users a variety of means are employed. We 
 have known farmers who selected sloping ground that would 
 have good drainage and then put down some old rails and cov- 
 ered them well with straw. On this foundation the blocks of ice 
 were placed, and when the weather was freezing they would pour 
 water over the ice and thus freeze the entire mass into one huge 
 block. This was then well covered with straw and boards and a 
 temporary roof put over it. Ice thus packed on the north side of 
 the barn by one farmer furnished the family ice for making but- 
 ter and ice cream during an entire summer. Ice may be kept 
 piled in a heap on a 2-foot thick layer of sawdust or peat, and 
 covered with the same material. 
 
 CONSTRUCTION AND INSULATION OF ICE HOUSES. 
 
 It is a common idea that the insulated walls of an ice house 
 should have air spaces, which if "dead"— that is, all connection 
 with the outside air prevented— are supposed to be fully as good 
 or even better insulators than the same space filled with sawdust 
 or other filling material. This is a mistake. In a vacant space 
 between a cold and warm wall, a circulation of the air will always 
 take place, conducting the heat from the warm wall to the cold 
 one. If such space is closely packed with dry chaff, sawdust, mill 
 shavings, or a like material, the circulation, while not entirely 
 prevented, is greatly retarded. Of course tight walls effectively 
 
494 PRACTICAL COLD STORAGE 
 
 stop circulation and prevent, to an extent, conduction, and sev- 
 eral partitions of paper pr boards in the wall are therefore use- 
 ful, but the "dead air space" itself is of comparatively small 
 account. It is important that the insulating material with which 
 the space is filled, should be dry, and however well it is packed, 
 there will always be a slight circulation, the air passing down 
 along the cold side of the wall, and up on the outer or warm side, 
 and unless the outer surfaces of the wall are air tight, moisture 
 will find its way in, will be deposited on the cold side of the wall, 
 and will gradually saturate the insulating material. In such cases it 
 may be advisable, if convenient, to take the insulating material 
 out occasionally to be dried before it is replaced, or it may be 
 entirely renewed. The moisture which collects in the material 
 nearest the inside wall, is generally supposed to pass through the 
 woodwork from the ice. It is, however, really due to a circula- 
 tion of air, as stated, and which can not be entirely prevented. 
 The reader is referred to the chapter on "Insulation" for further 
 information and details. 
 
 FILLING WITH ICE. 
 
 In filling an ice house care should be taken to have the ice 
 piled in such a manner that in melting or shrinking it will not 
 press upon the walls. This is easily accomplished by having the 
 floor slightly pitched towards the center of the house, then there 
 is less danger of ice sliding towards the outer walls. Disastrous 
 results have sometimes occurred from this cause. If covering 
 material is used on top of the ice it should be inspected frequently 
 and any holes found must be filled at once. Bad meltage toward 
 the center of the pile may cause a portion of the ice to break away 
 and damage the house. 
 
 In refilling an ice house or the ice room of a cold storage 
 plant, it is best to cut away any portion of ice remaining in the 
 room which has melted in an irregular way, and remove it from 
 the house. This applies to the top layer of ice and the sides. Fill 
 around the old ice with the new, adzing off so that both are 
 level at the top and form a level bed on which to begin refilling. 
 Do not attempt to fill up the spaces left from meltage by throwing 
 in irregular shaped pieces or fine chips, as they have no sustain- 
 ing power and when the weight comes on them will settle and 
 may result in a wrecked or badly sprung building. A case is 
 
ICE HOUSES 495 
 
 in mind where the chips and loose ice were used for filling and 
 after the house was filled it was found necessary to remove a 
 considerable amount of ice at great expense and stay up the front 
 of the building with heavy timbers. This job cost nearly as much 
 as the total cost of filling the house with ice. 
 
 WASTE OF ICE IN HOUSE. 
 
 Waste of ice in an ice chamber is largely caused by meltage 
 from the top, the sides and bottom. Under proper ice house condi- 
 tions no serious waste ever takes place inside a pile of ice. The 
 melting from the sides, bottom and top is caused by incomplete in- 
 sulation. During the summer in some houses in Denmark (The 
 experiments on which the following figures are based were made 
 in Denmark, and in applying them to this country proper allow- 
 ance must be made for difference in climatic conditions ; they are 
 too high for average conditions in natural ice territories of the 
 United States) the waste from the bottom may vary from one foot 
 to five feet according to more or less careful insulation. If the ice 
 house is provided with an absolutely tight floor, laid on a thick 
 layer of dry sawdust, the bottom waste rarely exceeds eight to 
 twelve inches during the year. On the other hand, .if the ice is 
 piled in the house on the bare ground the waste may reach five 
 feet. Placed on a layer of two feet (after being pressed together 
 by the weight of ice) of sawdust or peat, the ice heap will not be 
 wasted from the bottom to the extent of more than one to one and 
 one-half feet. The causes of waste from the top and sides are, 
 first, circulation of air ; second, penetration of heat through walls 
 and loft. 
 
 Circulation of air is produced by cracks or openings near 
 the floor through which cold air escapes, being replaced by warm 
 air entering at the top of the house and striking the ice on its 
 downward passage. Such circulation is prevented by having the 
 walls as tight as possible, especially near the bottom. It is of less 
 consequence whether the house is more or less tight at the top, 
 if only the cold air can not escape at the bottom. This fact also 
 shows the importance of having the door or doors to the ice 
 house as high up on the walls as convenient. In a well-built ice 
 house but little waste is caused from a circulation of air coming 
 into the house from the outside. 
 
496 PRACTICAL COLD STORAGE 
 
 The main source of waste is the penetration of heat through 
 the insulated walls. Experiments have shown that in ice hoxes 
 of the same construction and all exposed alike, the ice melted 
 in the following proportions according to the insulating material 
 used, chaff (cut-up straw) being considered the standard, and 
 the ice melted in the ice box insulated by that material being 
 expressed by the figure ioo: 
 
 Cotton dried in a warm room 79 
 
 " on a loft 88 
 
 Husk of barley, dried on loft 90 
 
 Husk of wheat, dried on a loft 92 
 
 Husk of oats, dried on a loft 94 
 
 Leaves " " " " 96 
 
 Chaff " " " " 100 
 
 Husk of rice ' " " " 101 
 
 Wheat straw " " " " no 
 
 Saw-dust ' " " " 114 
 
 Peat, dry " " " " 116 
 
 Saw-dust, green 170 
 
 Peat, moist 260 
 
 Saw-dust, thoroughly wet 260 
 
 Peat " " 320 
 
 Loam " " 560 
 
 Sand " 630 
 
 From this it is evident that the more moisture there is in the 
 material the better it conducts the heat, and the poorer it is as 
 insulating material. The difference in the value, as non-con- 
 ductors, of the materials usually at hand is comparatively small, 
 so that material should be used which is most easily procured, 
 be it husk of any grain, or chaff, or sawdust. Only see to it that 
 it is dry. For the bottom under the ice, however, chaff or leaves, 
 or husks should not be used, as these easily ferment, develop 
 heat, and rot. Sawdust or mill shavings is usually the best 
 available material for the bottom layer. Branches of spruce or 
 the like may also be used to advantage. 
 
 The waste from top and sides of the pile of ice depends upon 
 the temperature outside and upon the proportion of surface inside 
 of the house as compared with the ice capacity. As the result of 
 many careful experiments with large and small ice houses, Profes- 
 sor Fjord, of Denmark, established a law according to which the 
 daily waste in a well built ice house, for every 100 square feet of 
 inside surface is 1.7 pounds for each degree Centigrade of average 
 heat. Thus in a house of 1,000 square feet inside surface, in 
 
ICE HOUSES 
 
 497 
 
 thirty days of an average temperature of 15 C. (59° F.) the 
 waste would be 1.7 pounds x 15 x 30 x 10, equals 7,650 pounds. 
 
 If there is 45 pounds of ice to the cubic foot, the waste would 
 be 170 cubic feet, and if there is only 35 pounds to the cubic 
 foot, the waste would be 220 cubic feet. In Denmark, the yearly 
 waste would be about 45 pounds for every square foot of the 
 inside surface, or if there is 45 pounds to the cubic foot, \y% cubic 
 feet ; and with only 35 pounds to the cubic foot, 1 2/7 cubic feet. 
 
 If the house is filled with ice to its fullest capacity, the bal- 
 ance of ice left, i. e., the house full, less the yearly waste, which 
 represents the ice that can be taken from the house during the 
 year (it makes very little difference whether much or little is 
 taken first or last, provided some is to be kept the year around, 
 for whether there is much or little left in the house, the amount 
 melted in a day is practically the same) varies according to the 
 size of the house, and it may be calculated from the following 
 table, the headings of the last three columns representing the 
 amount of ice packed in each cubic foot of the house: 
 
 
 
 
 
 
 Left in a Weil-Built 
 
 
 
 
 Ice 
 
 Souse, Cu 
 
 Ft. 
 
 No. 
 
 Dimensions 
 Ft. 
 
 Surface 
 Sq. Ft. 
 
 Volume 
 Cu. Ft. 
 
 45 lbs. 
 
 40 lbs. 
 
 35 lbs. 
 
 I 
 
 10 X 10 X 10 
 
 600 
 
 1000 
 
 400 
 
 325 
 
 229 
 
 2 
 
 12 X 12 X 10 
 
 768 
 
 1440 
 
 672 
 
 S76 
 
 453 
 
 3 
 
 13 X 13 X 12 
 
 062 
 
 2028 
 
 1066 
 
 946 
 
 791 
 
 4 
 
 ISXISXI2 
 
 1 170 
 
 2700 
 
 IS30 
 
 1384 
 
 1 196 
 
 S 
 
 l8 X l8 X 12 
 
 1512 
 
 3888 
 
 2376 
 
 2187 
 
 1944 
 
 6 
 
 20 X 20 X 12 
 
 1760 
 
 4800 
 
 3040 
 
 2820 
 
 2547 
 
 7 
 
 25 X 20 X 12 
 
 2080 
 
 60O0 
 
 3920 
 
 3660 
 
 3326 
 
 8 
 
 30X25 X 12 
 
 2820 
 
 9OOO 
 
 6180 
 
 5828 
 
 5374 
 
 9 
 
 40 X 25 X 12 
 
 3500 
 
 12000 
 
 8440 
 
 7995 
 
 7423 
 
 10 
 
 50 X 25 X 12 
 
 4300 
 
 15000 
 
 10700 
 
 10163 
 
 9471 
 
 n 
 
 60 X 25 X 12 
 
 5040 
 
 18000 
 
 12960 
 
 12330 
 
 11520 
 
 12 
 
 80 X 25 X 12 
 
 6520 
 
 24OOO 
 
 17480 
 
 16665 
 
 1 561 7 
 
 In this table the waste from the bottom is calculated at one 
 foot. If the bottom is poorly insulated, more waste should be 
 calculated, as mentioned before. Supposing the bottom waste to 
 be two feet instead of one foot, an additional waste of 8y 3 % of 
 the ice harvested must be expected in a pile twelve feet high. 
 
 By means of these figures it is possible to calculate the size 
 of an ice house needed for any purpose in which the amount of 
 
498 PRACTICAL COLD STORAGE 
 
 ice required is known. In the United States a waste of more 
 than 20% is considered excessive, and in the larger houses from 
 10% to 15% is commonly figured. Professor Fjord's figures here 
 given represent too great a wastage, but as they are the only 
 known data obtainable they are used as a basis and are given for 
 what they are worth. 
 
 SIMPLE FARM ICE HOUSE. 
 
 For a good simple plan for a farm ice house, that given below 
 has been designed by the author. It will be found cheap to con- 
 struct and thoroughly practical. The advantages of a supply of 
 ice on the farm which will last through the summer are well 
 understood by those who are provided with an ice house. Those 
 who have never put up ice should arrange to do so during the 
 next harvesting season. 
 
 Once tried, and the advantages of a supply of ice in hot 
 weather experienced, it will become a permanent rule to house 
 ice every winter. A systematic course can then be followed, and 
 the use of labor-saving tools and methods which expedite the 
 work employed. While securing the ice is the chief considera- 
 tion, no one should be content with anything short of the best 
 methods obtainable; this is a necessity during mild-winters, when 
 the crop must be secured speedily or not at all. 
 
 The ice house as here illustrated in Fig. 5, by plan and sec- 
 tion, is twelve feet square outside and eleven feet high. After 
 allowing for a foot of sawdust or other filling material at top. 
 bottom and sides, about eighteen tons of ice can be stored in it. 
 If the house is to be built on a sand or gravel soil where drain- 
 age is good, no precaution need be taken in regard to the drain- 
 age. If, on the other hand, the house is built on a clay soil, 
 it would be advisable to excavate a few inches and fill with coarse 
 gravel or pounded stone, and if necessary, a porous drain tile 
 may be laid through the center of the house and carried to a 
 low place outside for conducting away the meltage from the ice. 
 
 The sills consist of double 2 x 4's on which are erected 2 x 
 4 studding, 24-inch centers. These are topped with a double 
 plate of two 2 x 4's on which rest 2x6 joists, 24-inch -centers. 
 The studs are boarded up outside with novelty or drop siding. 
 There is no inside boarding, the sawdust being allowed to fill the 
 
ICE HOUSES 
 
 499 
 
 Shmqies 
 
 h-_ 
 
 F IQ. 5. SECTION- AND PLAN FOR SIMPLE FARM ICE HOUSE. 
 
500 PRACTICAL COLD STORAGE 
 
 space between the studs. The roof is constructed of 2 x 4 
 rafters, 16-inch centers, boarded and covered with shingles. In 
 each gable is a louvre or slat ventilator for the purpose of allow- 
 ing free circulation of air. One of these may be made remov- 
 able or hung on hinges to allow access for covering the ice with 
 packing material. The ice door should be built in two or more 
 sections hinged to open outwardly. 
 
 On the inside, pieces of 2-inch plank are placed to keep the 
 sawdust or other filling material away from the outer doors. As 
 the ice is removed from the house the pieces of plank are removed 
 as necessary. The actual material for constructing this ice house 
 will cost, under average conditions, from $30 to $40, and after 
 figuring labor, the entire cost of the house should not exceed $50. 
 
 This plan is subject to modification as to size and construc- 
 tion. By using 2 x 8's or 2 x 6's for studs a larger house may 
 be constructed with the plan otherwise unchanged. If the joists 
 above ice are objectionable, they may be omitted by using heavier 
 studs and rafters, in which case the ice door is extended up into 
 gable, making top sections of door in the form of a slat ventilator. 
 
 FILLING THE HOUSE. 
 
 If ice-cutting tools are not available, it is no reason why you 
 should be discouraged. With two or three cross-cut saws, an axe 
 or a pointed bar, two or three ice hooks and a pair of tongs, the 
 house can be filled. If it is desired to secure a more extended kit 
 of tools for next season, it would be well for several farmers to 
 combine and exchange work in filling their ice houses. (See 
 chapter on "Harvesting, Handling and Storing Ice" for further 
 particulars.) 
 
 The standard size of an ice cake is 22 by 22 inches or 22 by 
 32 inches. From 40 to 50 cubic feet of ice-house measure will 
 represent a ton. If the ice is packed solid, 40 feet is correct, 
 whereas if it is packed an inch or two apart, as some prefer, 50 
 feet is about right. 
 
 When filling ice into the house about a foot of sawdust, 
 chopped straw or mill shavings should be placed under the first 
 tier of cakes. 
 
 Leave at least a foot of space inside the studding all around, 
 which should be filled with packing material as the ice is put in, 
 
ICE HOUSES 501 
 
 and it is also advisable to fill on top of the ice with a foot or more 
 of sawdust or up to the top of the joists. It is advisable to cut 
 the cakes of ice as regular in shape as possible, oblong rather 
 than square. In this way each alternate tier can be reversed so 
 that the joints will be broken, as shown in section. This will bind 
 the ice together and prevent it from sliding or breaking apart. 
 
 As the ice is removed from the house, see that the remain- 
 ing ice is kept covered with sawdust, and if any holes appear, 
 fill them at once. If dry sawdust is not available, straw, marsh 
 grass or mill shavings or tanbark may be used. Whatever is 
 used should be tramped down solidly. 
 
 Ice houses are sometimes built with double walls, with a 
 space of one to two feet wide between, firmly filled with dry 
 sawdust or other similar material. It is cheaper and serves the 
 purpose well to pile the ice without a floor directly on the ground, 
 on a thick layer of sawdust or brush wood. Good drainage must 
 be provided, though sometimes in a porous soil no direct outlet 
 for water is needed. The outside wall should rest on a stone 
 foundation built up slightly above the ground, on the top of which 
 the wall may be built of studding and matched boards, the inside 
 wall should also be made of matched boards, the space 
 between being filled with closely packed insulating material. On 
 the beams a loft floor should be laid of loosely packed boards, 
 which may be removed while the house is being filled with ice. 
 On the loft floor a layer of insulating material should also be 
 laid. The entrance should be placed near the top of the wall 
 and be provided with double doors which may be furnished with 
 windows to allow light to enter. 
 
 It often occurs that an ice house may be placed inside of 
 another building, for instance in the corner of a barn. Instances 
 are known where ice has been successfully kept in a hay mow or 
 under a straw stack, by providing an opening with double doors. 
 Where a room is built within a building, it is best to construct 
 the sides, floor and ceiling double, with some non-conducting 
 filling material between. The walls should be at least one and 
 one-half feet thick, and the ice inside of the room protected by 
 a foot or two of marsh hay or clean straw. This is to be kept in 
 place as the ice is removed. In building inside of a structure 
 used for other purposes provision should be made for draining 
 
502 PRACTICAL COLD STORAGE 
 
 away the drip from the melting ice, so that this may not serve 
 to rot the timbers or injure the foundation of the building. 
 
 The following is a description of a house which has given 
 good service to its owner : The ground was tiled thoroughly 
 for drainage and a shallow surface gutter made all around the 
 outside. The foundation was hollow, square building tiles, 
 10 x 10 x 36 inches, being used. The sills, 2x8, were doubled 
 and lapped and well bound at the corners. The 2x6 studs were 
 toe-nailed to the sills, so that the sills projected two inches over 
 studs on the outside ; girths, 2x4, were spiked two and one-half 
 feet apart horizontally and flatwise on the studs, so as to be flush 
 with plates and sills. The weather boards were put up and down 
 and battened. The lining of 1 x 12-inch boards was nailed hori- 
 zontally on the studs so an 8-inch air space was left, and one 
 inch of said space left open at the top for the escape of warm 
 air. (The author believes that if this 8- inch air space was filled 
 with a good insulating material like dry sawdust or mill shavings 
 better protection would be afforded.) For free circulation and 
 to accelerate the escape of hot air a ventilator was placed in 
 the middle of the ridge of the roof and an opening left in each 
 gable end close under the roof. The door extended from three 
 feet above the ground level to the level of the eaves, and was 
 placed on the up-hill side of the ice house. There was a small 
 door in the gable to receive the last two layers. 
 
 The following description is of an ice house intended for a 
 somewhat larger harvest than the preceding and the building is 
 more thoroughly constructed. It also presents a better appear- 
 ance architecturally. The foundations and floors are of cobble 
 stones to provide drainage. The course of cobble stones should 
 be a foot or eighteen inches thick, and project slightly above the 
 surface of the ground. The sills are double 2-inch stuff ten or 
 twelve inches in width ; the studding of 2 x 10 or 2 x 12 set 24- 
 inch centers; the rafters or roof joists to be of sufficient strength, 
 depending on the size of the building and kind of material em- 
 ployed. Floor joists of 2 x 8, or 3 x 8 may be used, or a floor may 
 be laid clown loosely on the sawdust which is filled in over the 
 cobble stones to a depth of a foot or more. If floor joists are 
 used the floor should be of 2-inch stuff, laid open at joints to 
 allow meltage to drain readily. The studs are boarded with 
 
ICE HOUSES 503 
 
 matched lumber outside and inside, and the space between filled 
 with insulating material, preferably of sawdust (perfectly dry) 
 or mill shavings, well rammed down. The rafters should like- 
 wise be boarded underneath and filled, or ceiling joists may be run 
 across at the top of the studs forming a floor and an attic. This 
 space should be suitably ventilated by slat ventilators in the gable 
 ends over attic floor. If an attic floor is put in, the rafters need 
 not be filled, the attic floor being filled instead. The general de- 
 scription of a model creamery ice house a little further on may be 
 consulted in connection with the above. It is not necessary to 
 place hay or straw on the ice where all the surfaces in the build- 
 ing are insulated as above described, and the room may be filled 
 full to the ceiling or within a few inches of same. A little experi- 
 ence will show whether or not a covering of any kind is necessarv 
 or advisable. 
 
 The above methods of constructing ice houses, with one 
 exception, are not minutely described with drawings because of 
 their simplicity and because individual ideas and judgment can 
 best modify them to suit local conditions. The information given 
 will enable any experienced carpenter, or even a person ordi- 
 narily familiar with tools, to take the material at hand, and erect 
 a structure of suitable size and character to meet the conditions. 
 The houses already described are not well adapted for ice houses 
 intended to hold more than ioo to 150 tons of ice. For larger 
 houses one of the designs described further on is more suitable. 
 In any case the amount of money which can be profitably 
 expended on an ice house depends largely on the cost of deliv- 
 ering ice to the house. If it costs but twenty cents per ton to 
 store the ice in the house, it is not advisable to spend much money 
 in building a house to preserve same ; it would be better business 
 policy to build a cheap house, making it larger to allow for 
 greater meltage. On the other hand, if the ice in the house costs 
 from seventy-five cents to a dollar per ton, it would pay well to 
 build in a first class manner after the best plans obtainable. 
 Between these two extremes are all the variations which may be 
 met by considering cost of ice and cost of construction. These 
 remarks apply equally well to ice houses of any capacity. The 
 greater the cost of the ice the more money can be profitably exr 
 pended in protecting same from meltage when housed. 
 
504 
 
 PRACTICAL COLD STORAGE 
 
 Although a similar construction may not be advisable or 
 practicable in this country, on account of the expense, yet 
 
 FIG. 7. — SECTION OF DANISH ICE HOUSE. 
 
 a description of the Danish methods herewith given, may be of 
 interest. The designs shown have been particularly recommended 
 for creamery use.* 
 
 *Abstracted from J. H. Monrad's Dairy Messenger. 
 
ICE HOUSES 
 
 50E 
 
 The illustrations taken from Bernhard Boggild's Maelkeribruget repre- 
 sent an ice house as usually built for creameries or dairies in Denmark 
 
 FIG. 9. — SECTION SMALL DANISH ICE HOUSE. 
 
 FIG. 10.— SECTION ON C-D SMALL DANISH ICE HOUSE. 
 
506 PRACTICAL COLD STORAGE 
 
 The larger one, (Figs. 6 and 7) will hold 15,000 cubic feet of ice, and 
 is built in connection with the creamery- Fig. 7 is a section through 
 A-B of Fig. 6. The inside lining is of matched and varnished boards 
 placed vertically, on the outside walls, but horizontally on the partition 
 and ceiling. D represents the drainage; M is doors for putting in ice; 
 L, doors for renewing the saw-dust; V, window; T represents peat or 
 sawdust on the floor; H, chaff, husk, sawdust, or other insulating 
 material in the hollow walls. All doors are made as tight-fitting as 
 possible by tacking cloth on the edges. A, small hall, K connects the 
 ice house with the creamery, the ice being thrown out through the flue, 
 t, through the upper door, later through the lower ones. 
 
 The small ice house, Figs. 8, 9 and 10, will hold 1,650 cubic feet of 
 ice. Fig. 9 is a section through E-F, and Fig. 10 is a section through 
 C-D of Fig. 8. M is a door through which the ice is put into the 
 house ; L, a door for renewing the saw-dust ; v, window. 
 
 For the benefit of our readers we subjoin an estimate of the materials 
 needed for, and the cost of building these two houses. This estimate 
 was made by an American builder. 
 
 COST OF BUILDING. 
 
 Large Ice House of Brick $1,343.30 
 
 Large Ice House of Wood 1,044.70 
 
 Small Ice House of Brick 38950 
 
 Small Ice House of Wood 393-50 
 
 The outside walls are represented in the illustration as built of brick. 
 In the estimates, the cost is figured for brick as well as for wood. It 
 will be noticed that the small house costs about the same whether built 
 of brick or wood, while for a large house wood is the cheaper. Of 
 course, wages and the price of material differ in various sections of 
 the country, and these figures can only be a guide, which we trust may 
 be useful to dairymen contemplating the erection of ice houses. 
 
 MODEL CREAMERY ICE HOUSE. 
 
 The plans and details shown in Figs. II, 12 and 13, repre- 
 sent a building designed by the author for a model creamery 
 ice house. The cost of this building is very much less in propor- 
 tion to its capacity than that for any of the buildings constructed 
 according to the customary Danish practice as described in the 
 foregoing. The walls also are much thinner and it is quite prob- 
 able that the ice will not keep as well under the same condition of 
 outside temperature ; at the same time the difference in the melt- 
 age of ice in the house insulated as detailed and the Danish houses 
 would probably not exceed 20% if the ice were carried through 
 to the end of the season without removing any from the house. 
 In Northern latitudes, where natural ice may be stored cheaply 
 at a cost ranging from 15 to 50 cents per ton, it is not good prac- 
 tice to invest too much money in an ice house for its protection. 
 It is better to build the ice house a little larger to allow for addi- 
 tional meltage. This model ice house is intended to be insulated 
 with mill shavings in the floor, ceiling and sides, and the ice is 
 
ICE HOUSES 
 
 507 
 
 1 
 
 
 > 
 
 4 
 
 4 
 
 V- 
 
 4- 
 
 V 
 
 rs 
 
 * 
 
 1 
 
508 
 
 PRACTICAL COLD STORAGE 
 
ICE HOUSES 
 
 509 
 
 -/i>/y #r£ Giant' hktTgriiroof- 
 
 W7, 
 
 VM- 
 
 Vd~*6 D.t/Z reitam 
 
 •/A>J MiH, p/omt- sjL> 
 
 'A P'arif farmer '° "'"■ " 
 
 Derm/, of doop 
 
 FOR ICF OUTLET 
 WS/VD OF BI/MD/fi/G 
 
 <mm& ' 
 
 
 
 ■Jt fleage 
 
 7 »M(«ir /wjA- 
 
 FIG. 13.— DETAILS OF CONSTRUCTION COOPERS MODEL ICE HOUSE FOR 
 CREAMERIES. 
 
510 PRACTICAL COLD STORAGE 
 
 not to be packed or covered in any way. This is a very decided 
 advantage over the older methods of storing ice, as when the ice 
 is clean, without any hay, sawdust or chaff thereon, the labor of 
 removing from the house and applying to the purposes for which 
 it is to be used is probably not more than one-half what it is 
 where some covering material is employed. No doubt those who 
 have had experience in digging ice out of the old style ice house 
 will appreciate this method of construction. The cost of con- 
 struction, too, is not greatly in excess of what the old method 
 would be. 
 
 Referring to the plans, it will be seen that the house is 27' 
 8" long by 17' 8" wide, inside measurement, giving an outside 
 measurement of 20 x 30 feet. The height is 20 feet, making the 
 house very nearly a cube and with comparatively small outside 
 exposure. The space inside is a rectangle, as it is intended to 
 fill the house just as close to the ceiling as possible, and this may 
 readily be done, as the outside doors open up to the top of the 
 ice storage space. The roof is what is known as a "half pitcb 
 roof" and is provided with ventilators at both ends, one of which 
 is in the form of a door for entering the attic space. This allows 
 for circulation of air through the space above the ice and pre- 
 vents to a large extent the penetration of heat from the roof. 
 
 The house as planned shows doors for icing at the side and 
 removing from the end, but both the filling and removing doors 
 may be placed in any location desired. The door for removing 
 ice is fitted with a frame work within the room which leaves a 
 space in the body of ice which may be utilized for lowering ice 
 from the top of pile or it may be removed through the filling door. 
 A ladder is located in the space inside the door for ascending to 
 the top of the ice. There is no opening whatever through the 
 ceiling of the ice room into the attic. There is an old popular 
 idea that ventilation over the ice is necessary, but this is only true 
 where the ice is covered with a packing or non-conducting ma- 
 terial like sawdust, hay, etc. It should not be employed where 
 ice is not covered, as it is unnecessary and results in melting the 
 ice badly. 
 
 As shown in the drawings, the walls of the building are 
 erected on a stone foundation which is carried down to a sufficient 
 depth. A deep foundation is not necessary, however, as the 
 
ICE HOUSES 511 
 
 entire weight of the ice rests on the ground and not on the foun- 
 dation of the building. Good drainage may be provided by filling 
 in gravel between the walls of the building to form a floor to the 
 depth of twelve inches. If the soil should be of clay, it would 
 be well to lay a porous tile drain through the center of the house 
 connected with some drainage point. If the soil is sandy or 
 gravelly, the layer of gravel and tile drain may be dispensed with 
 entirely. 
 
 The floor is formed by placing 2x8 joists 24-inch centers 
 and slanting them slightly towards the center to the drain tile. 
 On the top of the 2 x 8 joists is laid a floor consisting of 2 x 6 
 plank laid two inches apart. The space between the joists is to 
 be filled with mill shavings, tightly rammed. Mill shavings are 
 specified all the way through this building, although other ma- 
 terials like dry sawdust, cut straw or tan bark might be used. 
 Mill shavings are, however, to be preferred. The floor of the 
 ice house is entirely independent of the walls of the building 
 and is intended to be laid last, and the floor joists not set over 
 the foundation wall. This allows the ice to settle independently 
 of the building. The side walls are constructed by laying a sill 
 of 2 x 10 stuff on the stone wall. On this sill are erected the 2 x 10 
 studding, placed 24-inch centers. As planned, these studdings 
 are double-boarded inside and out, with water-proof insulating 
 paper between and filled with mill shavings. If it is desired to 
 cheapen the cost of the house, the studding may be single- 
 boarded on each side with paper underneath, care being taken 
 not to tear the paper when filling the space with shavings. 
 
 The roof is designed to be of shingles, but it may be of any 
 other material. The doors where the ice is to be filled into the 
 house are made in sections and hinge on the outside. Remova- 
 ble plank pieces are placed inside and the space between filled 
 with shavings. 
 
 Ice houses of the character similar to the one here described 
 have been built of a capacity of 1,000 tons; and, considering the 
 cost, are very successful in every way. The estimated cost of 
 the house which is described is, under ordinary conditions where 
 lumber can be obtained from nearby mills, $300.00 to $400.00. 
 If lumber is expensive and labor high, and ice may be housed 
 cheaply, the house may be cheapened by leaving out the gravel 
 
512 
 
 PRACTICAL COLD STORAGE 
 
ICE HOUSES 513 
 
 and stone foundation wall and single boarding the studs inside 
 and outside instead of double boarding. The ceiling joists like- 
 wise can be single-boarded, and in case of necessity the floor can 
 be left out entirely. The details for a house of this kind depend 
 upon the location and must be selected by the builder or architect 
 in order to provide proper protection for the ice and at the same 
 time not have the cost too high. 
 
 MODEL COMMERCIAL ICE HOUSES.* 
 
 The accompanying plans show in detail the construction of 
 two ice houses on the most modern ideas in the art of ice house 
 building. The endeavor has been to devise a house which will, 
 according to the opinions of experienced men, not only offer every 
 facility for putting up the ice quickly and economically and re- 
 moving it in quantities as desired at lowest possible cost, but 
 also to preserve the ice for the longest possible periods with the 
 least possible waste, and at a cost for construction which is not 
 prohibitive. 
 
 As two different uses are made of ice houses, differing con- 
 siderably in their effect upon the ice itself, it is necessary to ac- 
 commodate the house to the purpose. Some houses are used for 
 retail delivery only, and a room is opened several times a day 
 perhaps and ice removed in small lots of a few tons during a 
 number of weeks. Such a house should be planned differently 
 from those from which the ice is taken by the car or boat load as 
 fast as it can be broken out and stowed away. The first plans, 
 Figs. 14 to 19, inclusive, are for a house for the former purpose, 
 and Figs. 20 to 29, inclusive, are for a house from which large 
 shipments are made and the house soon emptied. 
 
 The first plans are for a twelve-room, single-posted house. 
 The capacity is 6,400 tons. The house is 126 feet 11 inches long 
 by 83 feet 6 inches wide and 30 feet 2 inches high from sill to 
 plate. The outside walls are 14 inches thick, the partitions are 
 11 inches wide and the middle walls, dividing the interior of 
 the house into two sections, each of which is again divided into 
 six rooms, is 14 inches thick, just as are the outside walls. Each 
 room is, then, 40x20 feet in the clear, and has a capacity of 
 535 tons. 
 
 *From fee Trade Journal. Plans by Gifford Bros., Hudson, N. Y. 
 (33) 
 
514 
 
 PRACTICAL COLD STORAGE 
 
ICE HOUSES 
 
 515 
 
 I 
 «3 
 
516 
 
 PRACTICAL COLD STORAGE 
 
 X 
 
 B 
 
 1 
 
 nc 
 
 " " — ^ i H 1 — 
 
 s 
 
 la 
 
 1 
 2 
 
 | 
 
 i iP i t 1 1 i a j 
 
 
 IP 
 
 V-o-J ' 
 
 o 
 b 
 
 X 
 
 z 
 
 E 
 Z 
 E 
 
 > ■ 
 7 2 
 
 £ 
 
 i 
 
 2 
 
 5" 
 
 2 B 
 
 
 
 £ 
 E 
 
 c 
 ^ ■ 
 
 z 
 
 ■S 
 
 J 
 
 a < 
 t - 
 
 X 
 
 c 
 is 
 
 13 
 
 ■o 
 
 * 
 
 1 
 
 a 
 
 •) 
 
 o 
 
 B o 
 
 X ( 
 
 a o ( 
 .* * 
 
 B 
 
 a 
 
 a 
 
 a 
 
 £ 
 £ 
 
 « 
 
 X 
 K 
 
 "! = 
 
 3 £ 
 c 
 3 3 2 
 t '_ 
 
 Z 
 
 z 
 
 N 
 
 
 
 £ 
 
 9 
 
 »r 
 
 
 
 h 
 
 > 
 
 ! 
 1 
 
 a 
 
 z 
 
 B — '- 
 
 .< 2 
 _l ~\ * , 
 
 r 5 
 
 M 
 
 +-■ 
 
 M 
 
 +-■ 
 
 el 
 K 
 
 ■ 
 
 ■ 
 
 
 1 H^B 6^— "11 1 JS R H 
 
 
ICE HOUSES 517 
 
 The posts are 3 x 12 inches and 4 x 12 inches, all 30 feet 
 long. They are covered on the outside by i-inch novelty siding, 
 laid horizontally, and on the inside by i-inch matched boards! 
 laid diagonally. It is recommended that a high grade of build- 
 ing paper be used on the inside and outside of the posts under 
 the novelty siding and the matched boards. The space between 
 posts should be filled with either mill shavings, fine dry sawdust 
 or dry tanbark well packed clown. These three materials are 
 recommended in the order named. 
 
 The posts beside the doorways are each 4 x 12 inches for 
 additional strength at these points. The partition posts are 3x10 
 and 30 feet long, that width being sufficient for the inside 
 of the rooms. The plans call for i-inch matched boarding 
 put on diagonally on one side of the partition only. If thought 
 desirable for better insulation, the boards may be put on both 
 sides and the space filled with sawdust or shavings, as in side 
 walls. In some houses boards are put across between partition 
 posts half way up and only the space from the boards to the top 
 of the partition filled in. 
 
 The diagonal boarding on partition walls and inside of front 
 and side walls is called for by the plans, as that method of cov- 
 ering adds some to the strength of the structure, but it is more 
 wasteful of lumber than horizontal boarding, and the latter may 
 be substituted for the diagonal at the discretion of the one doing 
 the building. 
 
 The posts are placed 24 inches apart, center to center, for 
 greater strength, but 30 or 36 inches is considered by many as 
 not too great a distance. Such changes in detail may be made in 
 several places, as will be readily seen from the plans, in the in- 
 terests of economy, but they do not affect the general condition 
 materially. Such departures from the plans are not, however, 
 recommended, as the better the house is built the better it will 
 keep the ice and the longer it will last without repairs. Par- 
 simony does not pay in ice house building in the long run. 
 
 The detailed instructions for boarding and filling in the door- 
 ways are sufficiently elaborate without further description. The 
 drawings give the sizes and position of the trusses, so that no 
 difficulty should be experienced in understanding the roof con- 
 struction and supports. 
 
518 
 
 PRACTICAL COLD STORAGE 
 
 |*^9-.£— J 
 
 
 
 
 
 
 
 
 
 B 
 
 
 1 
 
 
 f 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 10 
 d 
 
 z 
 
 
 
 
 e 
 
 
 k 
 
 » 
 
 
 « 
 
 
 
 
 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 
 
 
 
 
 
 h 
 
 
 
 
 *. 
 
 
 
 
 E 
 
 
 oc 
 
 <* 
 
 9:£X.0l».e 
 
 
 
 
 
 
 O 
 
 
 
 
 
 
 
 IT 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Z 
 Ul 
 
 
 
 
 
 
 
 L. 
 
 o 
 
 
 
 
 o 
 
 10 
 
 
 O 
 
 Z 
 
 o 
 
 
 
 
 .X 
 
 6 
 
 \A 
 
 
 w 
 
 
 
 
 .K 
 
 
 X 
 
 
 
 
 
 10 
 
 
 •0 
 
 
 
 
 
 tf. 
 
 |.OI>f..£ 
 
 N\ 
 
 11 
 
 ^ 
 
 
 M 
 
 
 
ICE HOUSES 
 
 -J — *^ — i — i— i- -•{- 
 
520 
 
 PRACTICAL COLD STORAGE 
 
 f 
 
 10" 
 
 r, 
 
 10 
 
 5ill-6"x/^ 
 
 4X/0 
 
 W8V 
 
 S'x/c 
 
 T 
 
 . i 
 to 
 
 1 
 
 18" 
 -5'-o"- 
 
 J5'-S- 
 
 |j£, 5HI-fc"x6"g 
 
 3^5 
 
 FIG. 21. — DETAIL PLAN OF CORNER, SIDE AND REAR WALLS. 
 
 "~ 
 
 4- 
 
 X 
 
 id 
 
 
 5 
 
 X 
 10 
 
 
 __ 
 
 
 
 
 
 
 i" 
 10 
 
 ~) 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 k&6&? 
 
 
 1-6" X IZ" 
 
 
 
 
 
 
 Dll 
 
 
 
 
 FIG. 22. — ELEVATION OF CORNER, FRONT AND SIDE WALL. 
 
ICE HOUSES 
 
 521 
 
 If of any advantage in filling, as it probably would be, ex- 
 cept in very unusual natural surroundings, doorways four feet 
 wide may be cut in the middle partition at the back of each room, 
 so that the back rooms may be filled through the front. To get 
 rid of chips and give more light, doors are also frequently cut 
 in the center of end walls and the partition walls at the sides of 
 the rooms. As no loft floor is provided for in the plans, this 
 
 li">5'x ^ Door4-'-0" "^ 
 
 j±-* 5 "-^m 
 
 w+*>\ 
 
 FIG. 23. — DETAIL OF PARTITION. 
 
 being considered unnecessary, the openings under the eaves are 
 left free for ventilation. 
 
 With these brief explanations, the drawings should be easily 
 comprehended not only by any builder, but by any ice man, how- 
 ever unfamiliar with building operations; and by their aid, 
 no matter how inexperienced, he should be able to erect a house 
 at once moderate in cost and correct in structure and one most 
 likely to give excellent results. 
 
 K Door5'-0" -* 1 
 
 r'±"* z "SiM-6"X6" 
 
 5 
 
 *lite." 
 
 5ill-6"x/2" 
 
 FIG. 24.-— DETAIL PLAN FRONT AND REAR DOORS. 
 
 Nothing has been said in connection with the first house as 
 to the foundation and the much mooted drainage question, but 
 as advice on these important points will apply as much to the 
 second house, now to be considered, as to the first, they will be 
 touched upon now. 
 
 The foundations should be of stone laid in cement, and the 
 same should be liberally applied, both inside and outside, so as 
 
PRACTICAL COLD STORAGE 
 
ICE HOUSES 
 
 523 
 
 < D 
 
 £3 
 
524 
 
 PRACTICAL COLD STORAGE 
 
ICE HOUSES 525 
 
 to prevent air and dampness from finding its way in and under- 
 mining the stored piles of ice. Most of the damage done by the 
 shifting and sliding of ice, by which side and end walls are 
 pushed out of position, is due to imperfectly protected founda- 
 tions. These walls are not intended to support or hold up the 
 ice. That is supposed to stand square and true, and will if the 
 various tiers are reversed so as to tie the whole in an erect posi- 
 tion, as it should be. Some ice men reverse every other tier and 
 some every second or third one. The first plan is considered the 
 safer and better practice, as affording better security to the ice 
 house. In a house built on these plans, sawdust between the 
 walls and the ice is entirely unnecessary, if good quality of paper 
 and well dried and tamped filling is used between the posts. The 
 sills should be laid in cement of course. 
 
 The matter of putting in drains is such an open question — 
 experienced men differing entirely as to their value and their 
 construction if used — that it should be determined entirely by the 
 geological structure of the land where the house is to be erected 
 in each case. A gravelly or sandy soil with a substratum of blue 
 clay is desirable, but not always to be found or made. If a drain 
 of any kind is used, its construction requires the very greatest 
 care, because where water can flow out air not only may, but 
 almost invariably does, find an easy access. Hemlock boards 
 laid loosely along the floor will serve both to distribute the weight 
 of the ice and to allow the meltage to settle into the ground. 
 
 Figs. 20 to 29 are plans for a house of 24,888 tons; 227 feet 
 long by 151 feet wide, and 36- foot posts, divided into 12 rooms, 
 each 36 x 72 feet clear, and each of 2,074 tons capacity. This 
 house has double walls. The construction is of i-inch novelty 
 siding, one layer of paper, 3 x 10 posts, one layer of paper, i-inch 
 matched boarding, 18-inch air space, i-inch matched boarding, 
 one layer of paper, 3x4 posts, one layer of paper, i-inch matched 
 boarding. The spaces between posts in both walls to be filled 
 with either mill shavings, sawdust or tanbark, as in first house. 
 The partition walls consist of i-inch matched boarding, 3 x 10 
 posts and i-inch matched boarding. They may be lined with 
 paper and filled for entire or part height if desired. Whenever 
 any partition or wall is filled with any insulating material, each 
 side of the posts should be covered with a good quality of build- 
 
526 
 
 PRACTICAL COLD STORAGE 
 
 ing paper, not only for additional insulation, but for protection 
 of the filling from dampness, which destroys its usefulness. The 
 outer and inner walls are supported by i-inch iron ties, which 
 hold them rigidly. The posts at the doorways are 4 x 10. The 
 sills are 6x12 and 6x6 for the outer and inner walls respectively. 
 The posts are distanced four feet center to center in the walls. 
 
 ''yi'""""' ■ 
 
 1 1 ■ J ■ a ■ I 
 
 FIG. 28. — INTERIOR OF WHOLESALE ICE HOUSE, SHOWING TRUSS SUPPORTING ROOF. 
 
 This house requires from its size and use a loft floor, which 
 the plans indicate is to be placed five feet two inches above the 
 plate, so as to allow room for stowing ice to> the plate and cov- 
 ering with hay. Hinged doorways should be provided in the 
 floor over each room to allow easy access, light, etc. 
 
 Ventilation is afforded by the doorways, which are carried 
 up above the plate to the roof and provided above the loft floor 
 with doors on hinges, which may be opened or closed according 
 
ICE HOUSES 
 
 527 
 
 to season, wind direction, etc. The roof is carried out beyond 
 the eaves, and openings left between the rafters for additional 
 ventilation. There should be no openings of any kind into the 
 ice rooms. Plenty of air is needed through the loft to break up 
 radiation through the roof, but none should be permitted to enter 
 the ice chambers. The whole purpose of the construction of this 
 house is to keep air from penetrating, in even the slightest 
 amount, to the ice. Above the plate, plenty of air ; below it, none 
 
 Trubi tov bi<t« Rooms 
 FIG. 29. — DETAIL OF TRUSS CONSTRUCTION OF WHOLESALE ICE HOUSE. 
 
 whatever. Openings may be cut in the roof and scuttles put 
 on which may be readily opened and closed if the loft is found 
 too warm with the doors open and the eave spaces free. 
 
 COLD STORAGE IN CONNECTION WITH ICE HOUSE. 
 
 A cold storage plant may be operated in combination with 
 the storage and sale of natural ice at a comparatively small cost. 
 There are many localities, especially in large towns and the 
 
52S 
 
 PRACTICAL COLD STORAGE 
 
 smaller cities, where the natural ice dealer could work up a good 
 business in the cold storage line, especially as he sells ice to many 
 produce dealers who would become his customers for cold storage 
 space as well. In many cases where an artificial ice plant has 
 
 FIG. 30. — FRONT ELEVATION COMBINATION ICE AND COLD STORAGE HOUSE. 
 
 been installed, a cold storage house has been erected as an ad- 
 junct and made a success. There is no reason why the sarat 
 thing cannot be done with the natural ice business. Heretofore 
 owing to the fact that there has not been a successful system 
 of refrigeration which could be operated by the use of natural 
 
 FIG. 31. — SIDE ELEVATION COMBINATION ICE AND COLD STORAGE HOUSE. 
 
 ice, nothing of any consequence has been attempted along this 
 line, but with the introduction of the gravity brine system, using 
 ice and salt as the refrigerant, equally good results may be ob- 
 tained down to a temperature of io c F. as by the mechanical sys- 
 
ICE HOUSES 529 
 
 terns of refrigeration. Many of these plants are now in opera- 
 tion and uniformly successful. This system is fully described 
 elsewhere in this book. 
 
 Figs. 30 to 32 show the outlines of the plan, sections and 
 elevations of the combination ice storage and cold storage house 
 which has been designed by the author. These plans may of 
 course be adapted to any location. The cold storage part may 
 be built in any shape and of any size and for any purpose. It 
 may be built in one, two or three floors, or more if desired. The 
 plant, as designed and illustrated in the sketches, shows the cold 
 storage part, with its ice house, as separate from the regular ice 
 storage rooms. This is for the reason that the ice produced in 
 many localities is not a very sure crop and in other cases it is 
 contaminated by sewage, etc. The ice used for the cold storage 
 part of the building need not be from a pure source, as it is used 
 for cooling purposes only or for icing cars. The ice stored in the 
 regular ice storage rooms is supposed to be from a pure source, 
 and may, if necessary, be shipped in in cars. 
 
 In connection with the cold storage part of this plant an ice 
 crusher and ice elevator are employed for handling the ice. The 
 spout leading from the elevator is arranged so as to deliver ice 
 at several points on the railroad track for the purpose of icing 
 refrigerator cars with crushed ice. Cars may be iced with this 
 device with great rapidity, and it is consequently economical, as 
 the ice need not be handled except to feed it into the ice crusher 
 in large pieces. The ice storage rooms of this plant are insulated 
 with mill shavings, are separated into two divisions and protected 
 inside and outside by the best grade of insulating paper. The 
 floor and ceiling are insulated in about the same manner, and 
 no packing or covering material is used on the ice. Ice men will 
 appreciate the advantage of this method, as it saves a large 
 amount of labor, and that too at a time when labor means a good 
 deal to the ice man. It is calculated that the meltage of ice in 
 this house will not exceed 15%, and under ordinary conditions 
 should not exceed 10% or 12^%, which is about as small as 
 any ice man can figure on. 
 
 As shown by the plan, the receiving room for the cold stor- 
 age department is located on the corner and a platform runs 
 around three sides of the building. This makes the loading and 
 
 (34) 
 
530 
 
 PRACTICAL COLD STORAGE 
 
 FIG. 32. — FIRST FLOOR PLAN AND TRANVERSE SECTION ON A-B COMBINATION ICE 
 AND COLD STORAGE HOUSE. 
 
ICE HOUSES 531 
 
 unloading of goods from cold store and cars a comparatively 
 small matter, and, as the receiving room fronts on the street, 
 makes deliveries to and from wagons equally simple. The office, 
 which is located in the receiving room, is intended to be used not 
 only for the cold storage department, but for the ice business as 
 well, and is so located that the ice business may be readily looked 
 after. In this plant no basement is constructed, and the cold 
 storage plant is all on the first floor. It will be noted, however, 
 that the second and third floors are reserved and may be insulated 
 and equipped with cooling apparatus as the business is extended. 
 An elevator serves the second, third and attic floors, and the 
 attic over the cold storage and also over the ice storage rooms 
 may be utilized for ordinary warehouse purposes. 
 
 The cold storage rooms, as divided, are intended for eggs 
 or fruit, one room for butter and two rooms for meat or beer. 
 These meat or beer rooms open directly onto the platform, mak- 
 ing them accessible from the railroad siding and from the street. 
 These rooms may be rented to the meat or beer agencies and 
 the owner need not have anything to do with the same except to 
 regulate the temperature. The insulation of the cold storage 
 department consists of mill shavings and hair felt properly di- 
 vided and protected by the best grades of insulating paper. The 
 butter room, meat or beer rooms are cooled by piping placed 
 directly in the room. The egg or fruit rooms are cooled by the 
 forced circulation of air, the coils for which are located over the 
 corridor. A ventilating system furnishes fresh air at any season 
 of the year to all of the rooms. The "Cooper systems" : gravity 
 brine system, forced air circulation, ventilating system and 
 chloride of calcium process, with which the plant is equipped, are 
 fully described elsewhere in this book. 
 
532 PRACTICAL COLD STORAGE 
 
 CHAPTER XXV. 
 ICE BOXES AND REFRIGERATORS. 
 
 PRINCIPLES THAT SHOULD GOVERN CONSTRUCTION OF REFRIG- 
 ERATORS. 
 
 The construction of refrigerators for domestic purposes, for 
 butchers and other small users, is mostly in the hands of large 
 companies who manufacture them in immense quantities. In 
 the main they are only fairly well designed but poorly insulated, 
 and in a large number of cases poorly designed as regards the 
 promotion of a circulation of air. Besides the large manu- 
 facturers there are many small concerns, and the construction of 
 small rooms for retailers, butchers, etc., is to a considerable extent 
 in the hands of the carpenter, contractor and builder. The points 
 covering the design of such work will no doubt be of interest to 
 those having occasion to build, and to users of refrigeration as 
 well. An English writer* on this subject has the following to 
 say: 
 
 "We do not propose to deal in this article with the insulation 
 of the refrigerator, but to endeavor to point out, as briefly as 
 possible, what is the best location for the ice in the refrigerator, 
 and how proper ventilation [Ventilation is incorrect in this con- 
 nection, the term "air circulation'' covering all that is meant.] 
 and air circulation can be secured, so that the odors arising from 
 the contents will be carried off to the ice surfaces and condensed 
 upon these latter, instead of condensation taking^place upon the 
 surfaces in the refrigerator. We will assume that the insulation 
 of the refrigerator is good and will proceed to investigate the 
 points above mentioned. , 
 
 "The most usual location for the ice in a refrigerator is on 
 the side of the box, and when this arrangement is in use (and 
 
 *In the Refrigerating Engineer, London. 
 
ICE BOXES AND REFRIGERATORS 533 
 
 it must be remembered that it is an absolutely necessary one in 
 all cases in which the refrigerator is limited in height) it is best 
 to keep the ice tanks or receptacles as high up as practicable, 
 and to provide cold air ducts leading downwards to near the bot- 
 tom of the refrigerator, thus insuring a sufficient air circulation. 
 
 "When the ice tanks or receptacles are placed centrally in 
 the box, in order to secure a uniform circulation of air through- 
 out its length and width, it is necessary to provide warm air ducts 
 which rise from the highest point in the cooling chamber to a 
 level above that of the ice in the ice tanks or receptacles, and 
 also cold air ducts from the bottom of the ice tanks or receptacles 
 to a low level in the refrigerator chamber. This arrangement will 
 be found fairly effective where the boxes are not of too large 
 an area. 
 
 "An arrangement which would probably be found to give 
 considerably superior results to the above is the placing of the 
 ice tanks or receptacles right at the extremities of the box. This 
 location of the ice tanks or receptacles would give two means 
 of producing circulating currents, and in this manner would of 
 course tend to appreciably improve the refrigerating effect pro- 
 duced. 
 
 "In cases where the ice tank or receptacle is situated at one 
 end of the extremities, or at one of the sides of the box, it is 
 recommended to employ an arrangement which has been patented 
 in America* and in which the wall of the ice tank or receptacle 
 is formed of a series of inverted S shaped metallic slats, placed 
 the one above the other and extending for the entire length of 
 the ice tank or receptacle. The advantage claimed for this form 
 of construction is that it insures a constant and efficient air cir- 
 culation through the storage chamber of the refrigerator. In 
 this manner the moisture given off from the articles stored away 
 in the refrigerator chamber will become condensed upon the ice, 
 and will pass away out of the refrigerator with the drip, thus 
 maintaining the refrigerator chamber cool and dry. 
 
 "Whenever practicable, however, there can be no doubt that 
 the most advantageous place for the ice is overhead. A refrig- 
 erator with a top ice tank or receptacle gives by far the best 
 results in practice, that is to say of course provided that the 
 
 The Bohn Syphon System. 
 
534 PRACTICAL COLD STORAGE 
 
 warm and cold air ducts are properly placed. The first of these, 
 or the warm air ducts, must be taken from the most elevated 
 point in the cooling chamber up to a level somewhat higher than 
 that of the ice in the ice tank or receptacle. The second, or the 
 cold air ducts, should be led from the bottom of the ice tank or 
 receptacle down to near the bottom of the refrigerator chamber. 
 In this manner, a regular and continuous circulation of air will be 
 maintained, and the warm, impure air will be forced to rise up- 
 ward into the space above the ice in the ice tank or receptacle, 
 the impurities becoming condensed upon the surface of the ice 
 in the latter, and being carried away with the water resulting 
 from the meltage of this ice. 
 
 "In conclusion, we desire to particularly impress upon our 
 readers, that in order to insure the utmost efficiency, anything in 
 the shape of cross currents in a refrigerator must be carefully 
 avoided, as when the air circulation is such as to allow of these 
 taking place there is always a great danger of the cold and warm 
 currents of air meeting in the refrigerating chamber, with the 
 result that condensation to a greater or lesser extent will take 
 place on the cold surfaces in the latter, thereby greatly inter- 
 fering with the carrying off of impure gases to be condensed on 
 the surface of the ice in the ice tank or receptacle, and removed 
 with the drip." 
 
 There are few if any refrigerators in service which fulfill 
 the above ideal conditions, even to an approximate degree. Seldom 
 has the author seen anything in the shape of a cold air duct ex- 
 tending from the bottom of the ice chamber to near the bottom 
 of the storage space, and the warm air duct from the top of stor- 
 age space to near top of ice chamber is in many cases lacking. 
 The principle of air circulation in refrigerated rooms is more 
 fully set forth in the chapter on "Air Circulation in Cold Stores." 
 
 It is not to be wondered at that the small refrigerators are 
 not properly insulated. It can hardly be expected that the manu- 
 facturers are well informed on the subject when those who make 
 a specialty of the cold storage business are not familiar with its 
 underlying principles. Further, competition between makers leads 
 to a cheapening of construction, and as the appearance must be 
 maintained that part of the work not exposed to view must suffer. 
 A refrigerator known to the author, when taken apart for ex- 
 
ICE BOXES AND REFRIGERATORS 535 
 
 amination, revealed no insulation at all, simply a two-inch air 
 space. A dollar or two extra cost on the average refrigerator 
 would be easily saved in one season where ice costs $5.00 per 
 ton, put in the box. It is difficult to state exactly what material 
 should be used and in what thickness and how applied. This can 
 only be determined when character of work, cost of ice and 
 service are known. The chapter on "Insulation" may profitably 
 be studied by those interested in improved methods of insulating. 
 
536 PRACTICAL COLD STORAGE 
 
 CHAPTER XXVI. 
 REFRIGERATION FOR RETAILERS. 
 
 GENERAL SUGGESTIONS. 
 
 The conservation of dairy products consisting of milk and 
 its manufactured products, butter and cheese, constitutes one 
 of the most important uses to which refrigeration is applied. 
 At present it is, in fact, difficult to imagine how a dealer in this 
 class of goods, either as a wholesaler or a retailer, could do 
 business without some form of cold storage, cooling room or ice 
 box. In the United States even the smallest retailer has his 
 refrigerator, and it is a rare exception to find such an establish- 
 ment without one. Our European neighbors generally do busi- 
 ness on a radically different basis, buying only a day's supply at 
 a time, in the same way that vegetables and green groceries are 
 handled. The losses resulting from this practice are consider- 
 able. 
 
 Without refrigerating facilities, goods must necessarily be 
 purchased in a hand-to-mouth manner, obtaining supplies daily 
 so as to have them in a more marketable condition. A large 
 aggregate loss results from this method. Goods purchased in a 
 small way necessarily pay a higher percentage of profit to the 
 wholesalers, and in some cases, also, much difficulty may be ex- 
 perienced in purchasing supplies daily, owing to failure of trans- 
 portation from any cause, or a natural scarcity of goods in the 
 open market. A retailer need not go into the cold storage busi- 
 ness to the extent of putting away his season's supply (although 
 many of the larger ones do this, and make a good yearly profit 
 thereby), but every retailer, no matter how small, should have 
 cooling space. If his business is properly systematized and ad- 
 vantage taken of his storage for perishable goods, a sure profit 
 may be realized by buying in round lots at a time when products 
 are obtainable at the lower price. 
 
REFRIGERATION FOR RETAILERS 537 
 
 The form of refrigerator suitable for the widely varying 
 requirements of dealers doing a large or small business, may 
 vary from the cheap ice chest which can be built by any car- 
 penter for $10 to a completely equipped cold storage plant, which 
 will keep dairy products in good condition for several months. 
 There is a large retail establishment in New England, the pro- 
 prietors of which own and operate a cold storage plant and in 
 addition do some storing with the regular cold storage houses. 
 
 For an average business, the large refrigerator which only 
 requires to be filled with ice once or twice a week, is in use. 
 In general all retailers use ice only for cooling purposes, except 
 the large users who do practically a cold storage business with 
 their own goods. Ice will produce, when used in the ordinary 
 way, a temperature of 36 to 45" R, and probably most of the 
 larger refrigerators would show a temperature of about 40 F. 
 in warm summer weather. This temperature answers nicely for 
 temporary storage from day to day, or for two or three weeks, 
 or even longer on some classes of goods, but for long storage of 
 several months, only an apparatus that will give a control of tem- 
 perature at all times should be used, such as brine circulating 
 system cooled by ice and salt or a mechanical system of refrig- 
 eration. 
 
 The dairy products ; butter, cheese, milk and eggs (eggs are 
 not strictly speaking a dairy product, but are generally so called) 
 are all more or less liable to deterioration. Butter, especially 
 when exposed to the air and heat of summer, becomes rancid 
 and unfit for use in a few days. In days gone by basement rooms 
 or cellars were used very generally, and a good cool cellar was 
 a thing to be proud of so long as people did not know the value 
 of ice or artificial refrigeration. A dairyman who would store 
 his June butter in a cellar for winter use in these days would 
 find it very unprofitable when compared with the results from a 
 modern cold storage house. This would show that modern meth- 
 ods must also be applied by the dealer if he is to meet competi- 
 tion and keep abreast of the times. 
 
 America has led, and is still leading the old world in refrig- 
 eration. Even the smallest retail dealers who handle butter and 
 other dairy products have large, well built refrigerators similarly 
 constructed to those used for domestic purposes. Some of these 
 
538 PRACTICAL COLD STORAGE 
 
 are indeed a work of art, with beautiful glass fronts so arranged 
 as to show off the goods to advantage and so constructed that 
 they may be opened for cutting out the goods without exposing 
 the interior of the room to warm currents of air. Some are 
 arranged so that each package of butter or cheese rests on a 
 pivoted table, one-half enclosed by glass. By turning this table 
 half way around the goods are accessible and the glass front of 
 the table is turned back, shutting off the interior of the refriger- 
 ator from outside air. These are in use very largely for butter 
 and cheese, but may be used for Other goods as well. 
 
 The facilities needed by retailers for the correct and eco- 
 nomical handling and sale of dairy products depend largely 
 on the quantity of goods to be handled, length of time to be 
 cared for and climatic conditions of the locality in question. In 
 the northern part of the United States and throughout Canada 
 the use of natural ice is universal, as the ice crop is a certainty. 
 In the southern states manufactured ice and mechanical refrig- 
 eration are a necessity. 
 
 Ice (either natural or manufactured), when used in a refrig- 
 erator or cooling rooms, will give a fairly dry air at a tempera- 
 ture of 40° to 45" F., providing proper arrangements are pro- 
 vided for promoting a circulation of air over the ice. At this 
 temperature well made fresh butter will remain firm in texture 
 and will not lose quality tp any great extent for several weeks. 
 Cheese at this temperature will remain in good condition for a 
 much longer period. Cheese is often retailed from the original 
 package without the use of refrigeration, but during the warm 
 weather of summer it will dry out and lose quality rapidly. It 
 must also be sold very quickly when cut. Eggs may be kept for 
 a few days or even longer at temperatures above mentioned. 
 
 Eggs and butter should be kept separated from fruits, meats 
 or strong smelling cheese, as they give off odors very rapidly. 
 Milk and cream are kept from day to day in a refrigerator to 
 prevent souring, which takes place at high summer temperatures 
 very quickly. Meat is one of the chief commodities sold from 
 refrigerated rooms, and no retailer of meats can do business 
 without refrigeration. The limit of time at which fresh meat 
 may be stored in a temperature of 40 F. or thereabouts is 
 two to four weeks. It is well known that meat kept at a tern- 
 
REFRIGERATION FOR RETAILERS 539 
 
 perature of the ordinary ice cooler for two weeks is in more 
 palatable condition then when first killed. 
 
 Small refrigerators may be purchased ready made and set 
 up ready for business, and the larger ones which may be dignified 
 by the name of rooms are to be had from the makers in sections 
 to be put together by any carpenter. If a first class and eco- 
 nomical job is wanted, a skillful cold storage architect or engineer 
 should be employed to furnish plans, as it is well known that 
 the average refrigerator is not fully insulated, nor properly con- 
 structed. Regular cold storage rooms intended for storage of 
 goods for long periods, must be designed and arranged with 
 care, and only a thoroughly competent architect should be em- 
 ployed for this work. The construction should be carefully at- 
 tended to, and the management of the rooms should be of the 
 most intelligent, if good results are to be expected. Retailers 
 should not go into this unless their volume of business is large 
 enough to warrant it. It will pay much better to purchase sup- 
 plies during the flush of the producing season, when the quality 
 is best and price lowest, and store in a regular well-handled 
 and thoroughly equipped cold storage warehouse. It is better 
 to do this, paying the moderate charges which are now made for 
 such service than to put away goods for a long carry in a com- 
 mon refrigerator. A refrigerator cooled by ice is not intended 
 for any such work. Its duty is the temporary safe keeping of 
 goods and all dealers should have one for this purpose, and it 
 should be used for this purpose only. 
 
 REFRIGERATION FOR BUTCHERS BOXES. 
 
 One of the hardest services to which refrigeration can be 
 applied is that of cooling small rooms, such as "Butchers Boxes," 
 as thev are called. The continued running in and out of the 
 room admits a large quantity of comparatively warm air, and 
 at times when the atmosphere is damp on the outside, this leads 
 to a condensation not only on the ceiling of the room, which 
 naturally gets the first flow of warm air which rises as it enters 
 the room, but also on the goods themselves. Much thought has 
 been applied to the design of rooms for retail business and con- 
 siderable improvement has been made in the utilization of ice 
 (which is mostly used) for this purpose. The difficulty from 
 
540 
 
 PRACTICAL COLD STORAGE 
 
 condensation, however, cannot be entirely eliminated by any 
 method of cooling without providing a vestibule or ante-room of 
 some character, so that the condensation will occur in the vesti- 
 bule and not in the room itself. The arrangement of the ante- 
 room or vestibule is moreover a cumbersome affair, as it neces- 
 sarily means that two doors instead of one must be opened and 
 shut every time the room is entered. About the best that can be 
 done is to locate the refrigerating surfaces so that the warm moist 
 air from the outside as it enters the room will deposit its mois- 
 ture on these surfaces instead of on the goods in storage. The 
 trouble can also be obviated to some extent by providing a spring 
 on the door so that it will close itself quickly when opened. 
 
 FIG. I. — PLAN COOPER S GRAVITY BRINE SYSTEM APPLIED TO BUTCHERS BOX. 
 
 Another very desirable feature is a tightly fitting door which will 
 not stick or bind. There is at present no such satisfactory door 
 for cold rooms, especially those of small size, as the patented 
 doors now on the market owing to rapidity and ease of operation. 
 The plan and section (Figs, i and 2) show the applica- 
 tion of the author's gravity brine system to the cooling of 
 small rooms for butchers boxes or for grocers or others re- 
 quiring refrigeration in small units. This arrangement shows 
 the system applied to a store room which is 13 feet high. This 
 makes the cold room or refrigerator 9 feet in the clear, and 
 allows access to the primary tank from the floor above, which 
 is a decided advantage, as all of the rough work and muss of 
 the icing is in this way entirely removed from the store itself. 
 
REFRIGERATION FOR RETAILERS 
 
 541 
 
 As will be seen by the plan, the pipes which cool the room ex- 
 tend across one side and to the ceiling. They also are near the 
 door so that warm moist air entering from the inside will come 
 in contact with the pipes and moisture be deposited thereon. The 
 coils are provided with drain gutters underneath so that the 
 drip from the pipes is caught without any spatter and led out- 
 side the room to the sewer. The cooling coils in the room, at- 
 tached to the top pipe, as shown in the sections, are also provided 
 with chloride of calcium gutters for the application of the chlor- 
 
 FIG. 2. — SECTION COOPER'S GRAVITY BRINE SYSTEM APPLIED TO BUTCHER'S BOX. 
 
 ide of calcium process for preventing frost on pipes and purify- 
 ing and drying the air of the room. If necessary to keep the 
 room sufficiently dry these gutters may be made extra large, pro- 
 viding in that way for an extra quantity of chloride of calcium 
 to be supported thereon. The humidity of the room can be 
 controlled at will in this way by using a greater or less quantity 
 of chloride of calcium. This chloride of calcium process, as it 
 is called, is described elsewhere in this book, as is also the 
 gravity brine system. 
 
542 PRACTICAL COLD STORAGE 
 
 CHAPTER XXVII. 
 MISCELLANEOUS. 
 
 INTRODUCTORY. 
 
 The following miscellaneous information and facts bearing 
 on cold storage matters is added here in the form of notes or 
 paragraphs for the reason that a larger part of it cannot be 
 properly classified under the regular chapter headings of the 
 balance of the book. The various products which are placed 
 in cold storage and treated here in a brief manner are not gen- 
 erally as important as those which are treated under the various 
 chapter headings. No doubt, as the business is developed, many 
 of the products here mentioned will become more generally im- 
 portant and the information obtainable will be sufficiently in 
 detail so that they may be treated as a separate chapter. There 
 are many products not mentioned in detail which are given in 
 the alphabetical list of correct temperatures for cold storage. 
 
 RURAL SITE FOR COLD STORE. 
 
 The advantages of a location somewhat remote from the 
 large cities as the site of a cold storage house for perishable 
 products, especially the more sensitive, like butter and eggs, is 
 well known, and it is the author's opinion that the tendency is 
 more and more toward the establishment of storages for the 
 greater bulk of products and perishable goods in the country at 
 or near the locality where produced. The pure country atmos- 
 phere is far better than the gaseous and comparatively polluted 
 air of our large cities. This is especially true during cool or cold 
 weather when the purifying effect of the refrigerating surfaces 
 is very small or entirely absent. It has been remarked to the 
 author by a prominent produce dealer that eggs and butter would 
 keep better in cold storage in the air where they were produced 
 than they would if shipped to a distance and stored in a different 
 
MISCELLANEOUS 543 
 
 atmosphere. There is considerable question about this but there 
 seems to be no question whatever about the advantage of a rural 
 location for the perfect keeping of perishable goods. 
 
 SHAVINGS AND SAWDUST AS INSULATION. 
 
 The comparative value of sawdust and mill shavings for in- 
 sulation purposes has been a much discussed problem among cold 
 storage men. Thoroughly dry sawdust is beyond doubt a bet- 
 ter insulator than mill shavings, but thoroughly dry sawdust is 
 practically out of the question in anything like sufficient quan- 
 tity to make it a commercial practicability. The greater part of 
 the sawdust available is wet or green just as it comes from the 
 mills, sawed generally from wet logs from the water. Mill 
 shavings on the contrary are generally fairly dry, being taken 
 from the surface of the lumber which dries out very quickly after 
 being sawed. Mill shavings though partially green or damp are 
 far better to use than sawdust which is even slightly so. If shav- 
 ings are thoroughly rammed into the wall they will not settle 
 down in drying out, as they are elastic and will hold their place. 
 Sawdust on the contrary cannot be packed sufficiently tight so 
 that it will not settle down when it dries out, leaving open spaces 
 in the insulated wall. Dry sawdust, in case it becomes wet or 
 damp from any cause, at any time after it is placed in the wall, 
 is liable to heat or ferment and disintegrate or dry rot, and so 
 lose its insulating value. Baled mill shavings which are received 
 in a damp condition may be much improved by shaking out the 
 baies and allowing them to lie exposed to a free circulation of 
 air. Stirring them occasionally will also facilitate the drying 
 process. They also may be kiln dried without opening the bales 
 if facilities are available. ( Chapter on " Insulation " gives some 
 further information.) 
 
 PAINTING METAL SURFACES. 
 
 The question as to whether it is advisable to paint gal- 
 vanized iron piping, galvanized iron tanks and other iron and 
 steel surfaces, whether galvanized or not, is one which comes up 
 very often in cold storage practice. In many cases it is not 
 advisable to paint, as it is cheaper to renew the piping, etc., than 
 it is to go to the expense of painting periodically. In other 
 
544 PRACTICAL COLD STORAGE 
 
 cases it is a positive detriment to paint piping in a cold storage 
 room. An odor may be created which cannot be easily removed. 
 Whether or not it is advisable to> paint metal surfaces de- 
 pends a great deal on whether they are readily accessible and 
 easily cleaned or not. Good galvanized surfaces should stand 
 well without painting and this is one of the reasons why gal- 
 vanized surfaces are used instead of black. For painting metal 
 surfaces use nothing but the very best obtainable preparations. 
 A number of these are on the market and sold at a reasonable 
 price. A good homemade paint may be prepared from red lead 
 and boiled linseed oil. It will require about twenty-five pounds 
 of dry lead to a gallon of oil. A pound of lamp black to each 
 twenty-five pounds of lead will give a rich dark brown color 
 which is more agreeable than the natural color of the red lead. 
 See also chapter on " Keeping Cold Storage Clean." 
 
 DEODORIZING COLD STORAGE ROOM. 
 
 Questions are frequently asked the author in regard to prop- 
 erly deodorizing cold storage rooms which have been used for 
 the storage of vegetables, fruit, etc., so as to make them suitable 
 for the storage of sensitive products like butter, eggs, etc. In 
 some cases it is possible to do so, in others not. If rooms have 
 been used for some years for some strong smelling product and 
 have not been properly aired out, whitewashed, etc., it is hardly 
 possible to disinfect them sufficiently to make them available for 
 the storage of eggs or butter. Thorough ventilating and white- 
 washing will do a great deal, however, to improve rooms in a bad 
 condition. (See chapter on " Keeping Cold Stores Clean.") 
 
 WHITEWASHING. 
 
 Whether or no it is necessary to whitewash cold storage 
 rooms each year is a problem which comes up very often. The 
 most thoroughgoing cold storage manager insists that rooms 
 which are used for the storage of eggs must be whitewashed 
 every year while the rooms are empty, and the author recom- 
 mends that it is a very good practice to whitewash all other 
 rooms yearly as well as egg rooms. It is perhaps not absolutely 
 necessary but if a rule is established of yearly whitewashing it 
 will be attended to, whereas if it is understood that it is only 
 
MISCELLANEOUS 545 
 
 necessary to whitewash occasionally, the rooms may not be 
 whitewashed for several years, or possibly not at all. The ex- 
 pense is comparatively small and the work is usually done at a 
 time of year when there is very little for the help to do in the 
 regular line of business. Practically speaking the cost of white- 
 wash is nothing, and it is a sort of insurance against must and 
 moid. It will not absolutely prevent must and mold, but if 
 carefully done it will at least demonstrate the fact that these 
 troubles are not caused by a bad condition of the interior wood 
 work of the room itself. 
 
 HUMIDITY. 
 
 The influence of a large or small quantity of goods stored 
 in a given space on the humidity of such space is not generally 
 considered or understood. The pipes which cool a storage room 
 act as moisture absorbing surfaces. These moisture absorbing 
 surfaces are constantly in action, as it requires the same amount 
 of refrigeration to maintain the temperature of an empty room 
 as it does a room which is filled with goods. If a room is only 
 partly filled with eggs, for instance, the humidity of such a room 
 will be much lower (i. e. much less moist) than would be the 
 same room filled to its capacity. This point is of no consequence 
 where there is no attempt to regulate humidity, but in a modern 
 and progressive plant these things should be watched closely. A 
 room partly filled with eggs and carried through the season will 
 certainly turn out shrunken or evaporated eggs as compared with 
 a similar room which is carried through the season filled to its 
 capacity. Owing to the fact' that a room filled with goods will 
 be much more moist than one only partly filled, in some cases 
 where circulation is imperfect this will lead to must or mold. 
 A complete and thorough system of air circulation makes the 
 control of conditions of cold storage rooms very simple. Such 
 a room may be filled with goods just as full as possible without 
 any bad effect resulting. 
 
 SPACE REQUIRED FOR STORING VARIOUS PRODUCTS. 
 
 In estimating the storage capacity of a cold storage room 
 or house it is frequently convenient to know the space required 
 by different products. The following is given as the author's 
 
 (35) 
 
546 PRACTICAL COLD STORAGE 
 
 personal experience : A sixty-pound tub of butter will require 
 about 2,y 2 cubic feet of space; a case of eggs containing thirty 
 dozen requires about 3 cubic feet of space ; a sixty-pound box of 
 cheese requires about 2 cubic feet and a three-bushel barrel of 
 apples from 8 to 10 cubic feet. These figures allow a reasonable 
 margin for what is known as " piling alleys;" that is, space lead- 
 ing from the door back through the piles of goods so that differ- 
 ent lots may be accessible. The actual cubic space required there- 
 fore is somewhat less than the figures given. These figures have, 
 however, been found in actual practice to work out quite closely. 
 The space required by any particular product may be ascertained 
 by finding the cubic space required for each package and adding 
 thereto from 15 per cent to 25 per cent. In making such calcu- 
 lation it is necessary to figure the actual space occupied by each 
 package as it will be placed in stowing in the house. It is per- 
 haps unnecessary to state that the capacity of a given room 
 depends greatly on how carefully the goods are piled. The care- 
 less man may waste a large amount of space which might be 
 saved by careful work. 
 
 TRUCKS FOR HANDLING GOODS FOR STORAGE. 
 
 The correct method of handling goods, when delivered by 
 car or by wagon at the platform, into the storage rooms, and 
 again from the storage rooms to the car or wagon and platform, 
 appears to be a simple matter; nevertheless, there is a vast 
 amount of valuable time wasted by not adopting the most prac- 
 ticable and labor-saving method. In smaller plants a hand truck 
 with two wheels on which may be handled three or four tubs 
 of butter or cases of eggs is best adapted to the work providing 
 the distance which is to be covered is not too great. These hand 
 trucks are very convenient for the handling of small loads even 
 in comparatively large plants, and therefore should be provided 
 even where the larger trucks are generally used. In compara- 
 tively small plants a four-wheel truck 30 inches wide and $y 2 
 feet long is the most convenient means of handling goods in and 
 out of the storage room. A truck of this size is all that one 
 man can conveniently handle when it is fully loaded with goods. 
 In larger plants a wider and somewhat longer truck may be 
 used, in which case it is necessary that the doors and corridors 
 
MISCELLANEOUS 547 
 
 be proportionately wider to allow proper turning of same. The 
 four-wheel trucks are generally of two types. One with two 
 large wheels about in the center and a smaller wheel or caster 
 at either end, and another kind with two large wheels a short 
 distance from one end and two castors at the other end. If 
 there are inclines which must be traveled this latter type is by 
 far the best and they are now generally used. Trucks should 
 be provided with a hand rail at one end only. For hand trucks 
 the regular cheese truck of a somewhat modified type is the 
 most convenient, as boxes, barrels, tubs and cases may be readily 
 handled on same. The foot of a cheese truck is generally half 
 round. By special order these can be made square and should 
 be placed at such an angle with the frame that the truck will 
 stand up without leaning against anything when not in use. 
 
 STOWING GOODS IN COLD STORAGE. 
 
 In piling goods in the refrigerated room there are two ob- 
 jects which should be borne in mind. The goods must be so 
 stacked or piled that they may be subjected to the best possible 
 conditions, and they must be so stacked or stored that they 
 will occupy the least room consistent with the keeping of them 
 in good condition. It is also desirable to handle goods in such 
 a way- that they may be easily stored and quickly removed as 
 they are wanted. It is, however, hardly necessary to speak of 
 this, especially as most warehouse foremen will see to it with- 
 out being told, that he does not do any more work than is neces- 
 sary in getting the goods in and out. He is much more likely 
 to sacrifice his space unnecessarily, or carelessly pile goods, so 
 that they may be injured while in storage. 
 
 Goods may be materially injured by piling to a great height 
 without properly providing for sustaining the weight which tends 
 to crush the lower tiers, or by piling goods so closely in a com- 
 pact mass that the air cannot circulate between and around the 
 packages. A familiar instance of damage from crushing will be 
 seen in almost every warehouse when apples are being removed 
 in the spring of the year. If apples are piled more than five or 
 six tiers in height they should be piled one barrel directly above 
 another with a 2x4 inch strip on each end between each tier 
 so that the weight of the upper tier of barrels is supported on 
 
548 PRACTICAL COLD STORAGE 
 
 the heads of the barrels and not on the center or bilge. Dam- 
 age from too close piling often occurs when eggs are stored 
 without placing strips between the cases, and leaving spaces on 
 the sides and ends. Directions for each separate product can- 
 not very well be given here, but by bearing in mind the principle 
 which makes it necessary to pile goods so that the air may circu- 
 late freely, the cold storage manager can determine for himself 
 what is necessary in connection with the particular product he is 
 handling. Goods like eggs, cheese, apples, oranges, or any prod- 
 ucts which give off moisture, must not be piled closely. If such 
 goods are piled so that the air cannot circulate freely through 
 them they are liable to become moldy or musty from, the collection 
 of moisture in the centre of the pile. On the other hand goods like 
 butter, canned fruit, dried fruit, etc., cannot be piled too closely 
 as these "goods do not give off moisture or at least it is not 
 necessary that they give off moisture in order that they be pre- 
 served properly. The same is true of the greater proportion of 
 goods which are actually frozen, like poultry, fish, etc. Where 
 carefully kept, as much as possible, from contact with air the bet- 
 ter the results, generally speaking. 
 
 What is said above will make it clear to the reader why 
 a forced circulation of air is better than a gravity circulation, 
 both as regards economy of space in storing goods and the best 
 results obtainable. The chapter on " Air Circulation in Cold 
 Stores " treats this subject thoroughly. 
 
 REMOVING GOODS FROM STORAGE. 
 
 The reasons for the sweating of goods when removed from 
 cold storage to the comparatively warmer outside atmosphere 
 are not generally understood. This phenomenon is caused by a 
 condensation of moisture on the cold surface of the goods and 
 may be prevented by protecting them from direct contact with 
 the warm outside air. A method which has been used with suc- 
 cess is to pile the goods closely on the receiving room, floor and 
 cover them tightly sides and top with a tarpaulin or heavy canvas 
 like a wagon cover. It will take somewhat longer for the goods to 
 acquire the temperature of the outer air but they may be warmed 
 in this way without sweating. In extremely warm weather it may 
 take thirty-six hours or possibly forty-eight hours, but in com- 
 
MISCELLANEOUS 549 
 
 paratively cool weather, if goods are removed at night and cov- 
 ered in this way, they may be ready for delivery the next morn- 
 ing. This method of handling is only possible where sufficient 
 notice may be had in advance and is particularly useful for the 
 removing of eggs from cold storage during a warm spell in 
 summer or early fall. This method of treatment prevents the 
 depositing of moisture or " sweating " and the goods are warmed 
 more slowly, which aids greatly in their preservation. Those 
 who operate their own cold storage plant in connection with the 
 produce business will find this method very useful and beneficial 
 as they can generally anticipate their needs. For the removing 
 of eggs before candling it is especially desirable, as it always 
 musses and soils the eggs to handle them while damp, to say 
 nothing of the actual damage to the quality likely to occur. 
 
 SLOW COOLING OF GOODS FOR COLD STORAGE. 
 
 Economy of cooling goods which are to be stored at low 
 temperatures, by stages, is not perhaps well understood. Take 
 for instance : Butter which is now sometimes stored at zero and 
 below. It is not only far more economical but it is better for the 
 goods to cool gradually than to place them immediately in the 
 room which is carried at the extremely low temperature of zero. 
 If a temporary cooling room at a temperature of say 25° to 35 
 F. be provided, where the butter could be run in temporarily be- 
 fore placing in the sharp freezer, it would be easier to maintain 
 a iow temperature in the freezer and at the same time result in 
 a better carry in the stored goods. It also makes it unnecessary 
 to provide a large amount of piping in the permanent sharp 
 freezing room. What is said here cannot be applied to poultry 
 or other goods which deteriorate rapidly if not frozen. Poultry 
 for instance, as generally frozen in the large cities, is some- 
 times from one to two weeks killed before it is finally placed in 
 storage. Under these conditions it is necessary to freeze as 
 quickly as possible. Any product, however, which does not 
 deteriorate rapidly is kept better, when cooled slowly when placed 
 in storage and warmed slowly when removed from storage, than 
 the reverse. Some storage people have an idea that if goods are 
 frozen quickly the original flavor and aroma will be preserved, 
 which, if the goods are thawed slowly, will be better retained 
 
550 PRACTICAL COLD STORAGE 
 
 than if cooled or frozen by stages. This idea is erroneous so 
 far as it applies to any goods known to the author. 
 
 STORING VARIOUS PRODUCTS IN THE SAME ROOM. 
 
 There is a strong temptation in the comparatively small cold 
 storage plant, say for instance, one which is operated in con- 
 nection with an ice factory, and where one or two or a few 
 rooms at the most are available, to store several different prod- 
 ucts in the same room. This is in fact done as a matter of reg- 
 ular practice and is one of the reasons why the small auxiliary 
 cold storage plant is not considered a success. Satisfaction can- 
 not be given the owners of a miscellaneous line of goods which 
 are all stored together and at the same temperature. There are 
 but few classes of goods which may be successfully stored in the 
 same room and at the same temperature for comparatively long 
 periods with good results. For instance : Butter requires a 
 lower temperature than cheese, and fruit and vegetables a higher 
 temperature than cheese, so they cannot be successfully stored 
 in the same compartment for any length of time. Generally 
 speaking, each product should be stored by itself, but for short 
 periods of a few days, it is customary to use a room for the stor- 
 age of several different products like cheese, butter, fruits, eggs, 
 etc. If a small quantity of eggs or butter is stored in a room 
 with a large quantity of fruit and vegetables they are very likely 
 to absorb an odor within a very few days. Nothing definite, 
 of course, can be stated in this respect, as conditions vary widely, 
 especially as to ventilation. For anything like regular cold stor- 
 age purposes it is not only advisable but almost absolutely nec- 
 essary to provide different rooms for different products. This, 
 however, may be qualified to some extent by storing fruit and 
 vegetables together under favorable conditions. Dried fruits, 
 nuts, flour, etc., known as grocers' sundries are also stored in 
 the same room at a temperature varying usually from 35 to 45 
 F. Any temperature under 45° F. will keep them in fair condi- 
 tion. See proper heading for temperature at which to store 
 various goods. 
 
 MOLD IN COOLING ROOM. 
 
 Troubles from mold forming on the walls or ceiling of meat 
 rooms or other small temporary storage rooms which are used by 
 
MISCELLANEOUS 551 
 
 retailers and others is quite frequent. This is caused in a large 
 number of cases by a lack of circulation of air in the room; by 
 improperly locating the ice bunker or cooling pipes; or by im- 
 properly locating a door, or the excessive opening of same. 
 Mold always results from a surplus of moisture and compara- 
 tively high temperature. If the circulation is inferior the air 
 near the ceiling of the room becomes charged with moisture and 
 this may be deposited on the ceiling or side walls. This will 
 quickly cause a growth of mold. If a door is left standing open 
 in warm humid weather the warm air rises to the ceiling of the 
 room and is condensed thereon. This also causes mold. If the 
 cooling surfaces and the door into the room are properly located 
 with reference to each other, the warm air which comes in when 
 the door is opened will come in contact first with the cooling 
 surfaces. Mold which has formed may be removed by wiping 
 with a damp cloth. Small retail rooms may be whitewashed, 
 or if it is desirable to wash them out frequently, shellac finish is 
 best. 
 
 FREEZING AND STORING POULTRY. 
 
 Most of the large houses freeze and store poultry at a tem- 
 perature of zero and below. Good work, however, can be done 
 at a temperature of io° to 15° F., if the poultry is frozen when 
 fresh killed and the packages in which it is frozen are not too 
 large. At the large receiving centers it is necessary to freeze 
 at extremely low temperatures, as the poultry has usually been 
 from one to two weeks killed and it is important that the heat 
 be taken out of it as rapidly as possible. In freezing poultry it 
 is very desirable that it should first be cooled down to below 
 40 ° F. before it is packed in the permanent storage packages. 
 It is then best to wrap each bird in paper and pack in flat boxes. 
 These should be placed in the freezing room on edge and on 
 strips on the floor, and with a space of 3 to 6 inches between the 
 boxes. This will allow a circulation of air and rapid freezing. 
 After being thoroughly frozen the boxes may be piled up sol- 
 idly, but with strips on the floor and with space between the 
 piles and the walls of the room. 
 
 LONG PERIOD BUTTER STORING. 
 
 During the past twenty years there have been a number of 
 seasons when the market was so poor during the fall and win- 
 
552 PRACTICAL COLD STORAGE 
 
 ter that quite large quantities of butter have been carried over 
 from one season to another. This has created a great deal of 
 interest in the results obtained by keeping the butter under 
 extremely low temperatures. The question has come up, whether 
 temperatures of zero and below would preserve the flavor and 
 keep butter in better condition than comparatively high temper- 
 tures of from 15° F. and upwards. Some experiments made by 
 the United States Department of Agriculture tend to show, al- 
 though they do not prove conclusively, that these low tempera- 
 tures result in a greatly improved carry for long period storing. 
 Cold storage houses with no facilities for maintaining a tem- 
 perature of zero or thereabouts should not attempt to carry butter 
 longer than six to eight months as an extreme limit. Customers 
 ■having goods in storage after the usual selling time has expired 
 should be notified as to the probable results of keeping it over 
 from one season to another. The deterioration is considerable 
 when carried for a year or more even in the extreme low tem- 
 peratures of zero and lower; therefore, those who have no facili- 
 ties for low temperature work should not attempt it. 
 
 FREEZING EGGS IN BULK. 
 
 For ordinary commercial purposes eggs which are to be 
 frozen in bulk, in the form of egg meat, after having been re- 
 moved from the shell, are best handled in an hermetically sealed 
 package. Tin is better than glass or crockery, as the liability 
 of breakage in handling is less, less danger of bursting in freez- 
 ing, less space required in storage and less weight to handle. 
 The only weak point of the tin package is its liability to rust if 
 a cheap grade of tin is used, especially when the white and yolk 
 are frozen separately. The white may be discolored by the rust- 
 ing of the tin. This may be reduced to a minimum by using a 
 good grade of tin. 
 
 Some of the large packers pump the air out of the package 
 before soldering, with the object in view of preventing contam- 
 ination by the impure imprisoned air. Good results may be had, 
 however, by soldering tight after the egg meat is frozen solid, 
 as the small amount of air trapped in the tins contains little 
 moisture and impurities, and is partly sterilized by exposure to 
 the low temperature of the freezing room. Soldering or other- 
 
MISCELLANEOUS 553 
 
 wise sealing the package is not absolutely necessary for success- 
 ful results, but it makes a more practical package to handle, and 
 prevents evaporation from the surface of the egg meat, which 
 evaporation makes a leathery "skin," which may necessarily be 
 a waste. The author is one of the pioneers in successful egg 
 freezing, and the standard package at first in use was the ordi- 
 nary lard can holding about twenty-five pounds. These cans 
 were provided with slip covers with no pretense of making them 
 air tight, and very successful results were obtained. It is ab- 
 visable, however, to protect the surface of the egg meat in some 
 way. 
 
 To prevent the yolks from becoming solid as if cooked, 
 which prevents their proper melting or dissolving when thawed, 
 they must be effectually broken, and thoroughly mixed with the 
 white. This is sometimes done by placing the egg meat in a 
 churn and churning vigorously for a few minutes, but this has 
 the disadvantage of not surely breaking all the yolks, or if they 
 are broken, the mass may become frothy from the beating up 
 of the whites. The method used by the author was to dump the 
 eggs after removing from the shell on a wire screen of about a 
 Y% or y 2 inch mesh, and scrape the yolks through with a wooden 
 paddle or scraper. The screen should be of tinned or galvanized 
 wire, and should be arranged in the bottom of a basin about four 
 inches deep. This screen bottom basin should be fitted to a pail 
 or utensil of convenient size. The pail may be provided with a 
 spout about lYz inches in diameter to facilitate pouring into the 
 permanent storing packages. Before pouring the egg meat into 
 the permanent storing package, stir thoroughly from the bottom, 
 as the yolk has a tendency to remain on top, being lighter than 
 the white. Forcing through the screen will break every yolk 
 without fail, and if stirred carefully, the white and yolk will be 
 mixed together, and when thawed no lumpiness or specks will 
 be present. 
 
 In freezing, fill the package only about two- thirds full at 
 first. When frozen solid there will be some expansion of the 
 egg meat, causing it to bulge or hump up in the center. After 
 freezing solid two-thirds full, complete filling, and when all 
 frozen there will be very little hump in the center of the package. 
 Do not fill the package completely, but leave from J / 2 to i inch 
 
554 PRACTICAL COLD STORAGE 
 
 at the top, depending on the size of package. When the filled 
 package is frozen solid, solder on the cover if the package 
 is to be hermetically sealed, or if an ordinary package is used, 
 without sealing, proceed as follows: If the eggs are separated 
 (yolk and white to be frozen separately), reserve some of the 
 white to apply to the tops of cans after freezing. Pour on about 
 half an inch of the white on the yellow, and allow to freeze, 
 then put parchment paper circles on the top of both white and 
 yolk, pasting or sticking it down carefully with the egg white. 
 The effect of this treatment is to make the top of the package 
 fairly air-tight and protect the egg meat from the air, and the 
 half inch of white on top of yolk will prevent the leathery 
 " skin " already referred to. Some packers reserve a little of 
 the white to cover eggs, frozen yolks and whites together. A 
 parchment circle stuck on top of package with a little of the 
 white, will prevent largely the formation of the leathery " skin," 
 which is caused by the drying out of the surface of the egg 
 meat. After the tins are filled, frozen and capped as above, the 
 slip covers are put on, and they are stacked up in the permanent 
 storage room. Sometimes the tin cans are placed in wood crates 
 to facilitate handling, but more space is required in storage. 
 
 In freezing the white and yolk separately, -which is very de- 
 sirable for the better class of trade, it is advisable to keep the 
 white and yolk about even in quantity, and this may be done if 
 the people who do the work are skillful, and the eggs are of 
 good quality. In fact, the white will naturally run a little ahead 
 of the yolk. It is better that the yolk have a little of the white 
 mixed with it, as it is easier to thaw out smooth without lumps. 
 It is better to keep whites and yolks of even quantity, as then 
 it is easier to sell an equal amount of each. The white should 
 not be sold separately except at a much higher price. 
 
 The author has demonstrated by actual trial that a tem- 
 perature of 20° F. is best for freezing and storing egg meat in 
 bulk. It has been recommended that eggs be frozen at i8° F. 
 or 20° F. and stored at a somewhat higher temperature, say 
 25° to 28 F. It has also' been recommended that zero or there- 
 abouts was better than any of the higher temperatures. At tem- 
 peratures of 25 ° F. and above, the white of the egg softens and 
 becomes gummy, and deteriorates rapidly in quality. The dam- 
 
MISCELLANEOUS 555 
 
 age is especially noticeable when white and yolk are frozen sep- 
 arately. When frozen at 10° F. and lower a greater expansion 
 of the egg meat takes place, and when thawed it is watery, and 
 not as useful for all purposes as the stock frozen at somewhat 
 higher temperature. One of the best bakers in Boston informed 
 the author that he could use the separated eggs frozen and held 
 at about 20 ° F. for any purpose for which a perfectly fresh egg 
 was adapted. In putting up eggs for freezing they should be 
 placed in a cold room (not necessarily a freezing room) imme- 
 diately when removed from the shell, as fermentation begins 
 soon in warm weather, and loss of quality results. If the eggs 
 are broken out of the shell at the storage house, remove them 
 to the freezing room every hour. If they are made ready at a 
 distance, provide a refrigerator room for temporary cooling, and 
 see that all broken stock is in the freezer every night. If the 
 frozen stock is thawed by setting in a tank of cold water, better 
 results are to be had than when allowed to thaw in a warm room. 
 The egg meat should be used up at once when thawed, as fer- 
 mentation commences soon, and the stock soon becomes useless. 
 
 STORING EGGS AND LEMONS. 
 
 It is absolutely unsafe to store eggs and lemons in the same 
 building. This has been done in a few cases without damage 
 to the eggs, but it cannot be recommended for the reason that 
 some heavy losses have been sustained from the eggs becoming 
 flavored with the odor of lemon. Eggs which have become 
 flavored even slightly with this odor are almost unsalable and 
 will not be taken by the best class of trade. Oranges as well 
 as lemons will cause this trouble. The citrous fruits, as they 
 are called, after being in storage for some length of time give 
 off a gas which is very penetrating. It has even been claimed 
 that this gas would penetrate a solid brick wall. This is hardly 
 probable, but the fact remains that it is very dangerous to store 
 citrous fruits in the same building with sensitive goods like 
 butter and eggs. The best large houses have separate buildings 
 detached from their main building for the storage of citrous 
 fruits and other odorous products, and the first-class smaller 
 houses have rooms independent of their main building. In the 
 designing of houses for the handling of general products includ- 
 
556 PRACTICAL COLD STORAGE 
 
 ing fruits, etc., the author recommends, and in his regular prac- 
 tice plans to have, a room of this character which is entered 
 from a separate outside entrance. The room may possibly be 
 in the same building but it is better to erect it as an addition to 
 the main building. 
 
 STORING VEGETABLES IN CELLARS. 
 
 Vegetables are not usually placed in cold storage, but bet- 
 ter results may be obtained from cold storing than by storing in 
 the old fashioned way in the cellar. A few notes on cellar stor- 
 age, however, are here given as a matter of general information. 
 A suitable cellar for the storage of vegetables during winter 
 must be clean and should either have a cement floor or a clean 
 sand floor. It should have a few openings to the outside atmos- 
 phere which are provided with curtains to exclude the light. The 
 correct temperature for most vegetables is a few degrees above 
 the freezing point, say from 35 ° to 40 ° F. It is very difficult 
 or impossible to regulate the humidity of a cellar. It should 
 not be damp so as to promote mold, neither should it be so dry 
 as to cause a drying out and shrinkage of the stored products. 
 If the cellar is damp it is well to use a pail or two* of lime, which 
 must be renewed from time to time or as soon as it absorbs 
 moisture enough to make it fine and powdery. The lime will not 
 only absorb dampness, but it will absorb the unpleasant odors 
 and purify the air in the cellar. A cellar should be ventilated 
 from time to time during the winter, as the outside tempera- 
 ture will permit. Too much ventilation will destroy the flavor 
 of vegetables and cause them to dry out and shrivel. This, 
 however, applies more to ventilation during cold weather and is 
 not true to as great an extent during the fall or spring. A ven- 
 tilator extending from the floor of the cellar to a few feet 
 above the ground outside is sometimes used, but such an arrange- 
 ment is more or less inoperative and it is better to depend on 
 the opening of windows as opportunity presents itself. 
 
 Do not store vegetables in too large bulk. It is also best 
 to keep each variety by itself. They should be well matured 
 and gathered before they are chilled or frozen. If gathered 
 on a warm day, allow them to cool before placing in the cellar. 
 Onions and potatoes are best stored on shelves or in bins. Pump- 
 
MISCELLANEOUS 557 
 
 kins and squashes require more air and must be kept dryer than 
 the softer vegetables like carrots, turnips, beets, etc. Onions 
 keep best without removing the tops. Pumpkins and squashes 
 should be placed on a shelf near the top of the room and should 
 not touch each other. Inspect them frequently, and when one 
 becomes soft it can be used or removed. 
 
 Cabbage may be wrapped in newspaper, packed in barrels 
 and stored in the coolest part of the cellar. If it is desired to 
 keep potatoes, beets, carrots, turnips, etc., for late spring use 
 pack them closely in boxes or barrels, fill in between and cover 
 with sand or garden soil. 
 
 CABBAGE IN COLD STORAGE. 
 
 For the best results in the cold storage of cabbage, they 
 should be grown especially for this purpose. . Late planted cab- 
 bage, which barely close the heads before frost, keeps much 
 better than early cabbage. The " Holland Seed " variety is 
 known to be very satisfactory as a good keeper. It is essential 
 that only good firm heads be accepted for storage. It is desira- 
 ble that the cabbage be " trimmed " before storing about in the 
 same manner as is required for shipping to market. The cab- 
 bage should be either packed in crates not more than 2^2 feet 
 in height or they should be piled on racks spaced about this 
 distance apart. A fair circulation of air is necessary to the 
 best results. Racks are easily constructed by erecting upright 
 side, placing cross pieces six inches wide horizontally on cleats. 
 The cross pieces should only be close enough together to pre- 
 vent the cabbage from dropping through. The racks may be 
 of any width and height when constructed in this way, and it 
 is customary to allow to or three tiers of cabbage to rest on 
 each set of cross pieces. A thickness o<f 3 to 4 feet of cabbage 
 would not be objectionable if a thorough system of air circu- 
 lation is installed. 
 
 Owing to the fact that cabbages are composed largely of 
 water and are of a porous nature, it is necessary to provide a 
 good circulation of air throughout the storage room and ample 
 moisture absorbing surfaces. This may be done by the use of 
 chloride of calcium in cold weather. Ventilating the room by 
 introducing outside air will prevent an undue accumulation of 
 
558 PRACTICAL COLD STORAGE 
 
 moisture and gases. Care must be taken in ventilating in this 
 way to prevent freezing the goods by admitting air which is 
 too cold or by causing dampness or too high a temperature by 
 letting in warm air. A fan system of air circulation and a 
 thorough ventilating system is very desirable, and the best re- 
 sults cannot be obtained without them. (See chapter on "Air 
 Circulation and Ventilation.") 
 
 It has been found that a temperature of 31 ° F. will produce 
 the best results in cold storing cabbages, 32° to 36° F., however, 
 have been used with success, but if the higher temperatures 
 are employed it is especially necessary to hold them reasonably 
 steady and uniform in all parts of the room. Under favorable 
 storing conditions, and when stored in a well equipped house, 
 cabbages may be carried from fall until spring with a shrink- 
 age of not more than 5 to 10 per cent, which is practically 
 nothing as compared with the shrinkage experienced when stor- 
 ing in the old style frost-proof house without refrigeration. 
 
 POTATOES IN COLD STORAGE. 
 
 Potatoes may be successfully and profitably stored, but 
 comparatively little has been done along this line and it is a great 
 field for development. Potatoes are a cheap product and must 
 be stored at a comparatively low cost in order to make the ven- 
 ture profitable, but as they are stored only during comparatively 
 cool or cold weather the actual expense for refrigerating , is small. 
 Potatoes will keep well in ordinary cellars or basement stor- 
 age, but they will keep far better in refrigerated storage where 
 the temperature can be regulated closely, and the improved 
 quality of stock and saving in shrinkage resulting from carry- 
 ing at uniform temperatures will aggregate a nice profit entirely 
 independent of advance in price. The possibilities of potato 
 cold storage have been known for some time, but developments 
 have been very slow and it has not been used to any great ex- 
 tent for this purpose up to the present time. When potatoes 
 are stored in cellars, basements or pits dug for the purpose they 
 will sprout badly during mild weather, and during an extreme 
 cold winter large quantities are entirely ruined by freezing solid. 
 Cold storage makes the temperatures controllable regardless 
 of outside weather conditions. It is very important that pota- 
 
MISCELLANEOUS 559 
 
 toes do not freeze, as they are entirely ruined, and they freeze 
 quickly when the temperature reaches the freezing point of 
 water (32 F.). The safest and most reliable temperature for 
 the storage of potatoes is 34° F., and this should be watched 
 very carefully. Light should be excluded from a potato stor- 
 age room. 
 
 COLD STORAGE OF ONIONS. 
 
 This vegetable ma)' be successfully cold stored for long 
 periods, and if carefully harvested and properly cared for prior 
 to being placed in the cold storage room, they may be taken out 
 of storage in good condition as late as May or June following 
 the season of production. It is best not to store in large bulk, 
 but rather in trays, or crates, or racks, so that the air may cir- 
 culate freely. A temperature of 32" F. is thought best for the 
 storage of onions and the room should be only moderately dry. 
 Onions do not freeze easily and require a temperature several 
 degrees below the freezing point of water (32° F.) to materially 
 injure them, providing they are thawed slowly. In some cases 
 onions have been stored where they have been purposely frozen 
 so as to keep them in better condition, but this practice is not 
 recommended, as better results are obtainable by keeping a uni- 
 form temperature in cold storage. 
 
 COLD STORAGE OF CELERY. 
 
 The storage of celery varies a great deal in different places. 
 In some of the large cities celery is kept in storage the year 
 round. Generally, however, celery is stored early in the fall or 
 on maturity of the plant, and the goods are not placed in stor- 
 age until the ground freezes in the fall. A temperature of as 
 near the freezing point as possible is recommended. Celery 
 storage rooms are usually held at from 32° to 34° F. The 
 keeping qualities vary with the different varieties and condition 
 of the goods. Hardy varieties arid " green top " keep well for 
 three months or possibly more. Some of the varieties will not 
 keep longer than from one to two months. Celery after being 
 trimmed, or what is known as " dressed goods," will not keep 
 for any length of time. A few days only being about the limit. 
 
560 PRACTICAL COLD STORAGE 
 
 COLD STORAGE OF FRUITS. 
 
 Cantaloupe. — This fruit may be stored with good success at 
 a temperature of 33 F., but for a few days' storage only a tem- 
 perature of 35 to 40° F. is sufficiently low. A great deal de- 
 pends on the condition of the goods when received as to how long 
 they may be carried, but from four to six weeks is the extreme 
 limit under favorable conditions, and they must be in prime and 
 sound condition to be held more than a few days or a couple of 
 weeks. They are usually stored only for a short period to tide 
 over a temporary glut in the market. 
 
 Bananas. — These are not considered a cold storage product 
 as they are generally received in an unripe condition and are 
 only cold stored in exceptional cases for a short period to prevent 
 ripening. The rapidity of ripening depends on the temperature 
 in which they are stored. Some recommend a temperature as low 
 as 34° to 36 F., but usually a temperature of 40° to 45" F. is 
 considered suitable for the temporary or short period for which 
 they are stored. Care must be taken that they do not get near to 
 the freezing point or they will become chilled and turn black and 
 therefore unsalable. 
 
 Oranges. — These will keep best for from one to three months 
 at a temperature of 34 for the average fruit. The fan system of 
 air circulation is best, and a ventilating system which will supply 
 pure, cold and dry air to force out the gas which accumulates from 
 the citrous fruits is also beneficial. This will also lessen the dan- 
 ger of contaminating other goods, such as butter and eggs. Do 
 not store these products in the same building with citrous fruits. 
 See what is said elsewhere in this chapter on storing " Eggs and 
 Lemons.'' 
 
 Lemons. — This fruit should have the same general treatment 
 as oranges, but a temperature of 38° F. is considered as low as is 
 safe for average fruit. A lower temperature is detrimental and 
 will cause them to decay. 
 
 Melons. — These are put in storage but very little, and for 
 short holding only, the value of the product and limited possibility 
 of keeping not as yet warranting a large business in this line. By 
 removing from the vines very carefully, cutting the stem an inch 
 or so from the melon, then shellacking the stem and wrapping the 
 melon in wax paper, they may be stored from two to three months. 
 
MISCELLANEOUS 561 
 
 Care must be taken not to bruise or mar the rind of the melon. 
 Provide racks and store as loosely as possible to prevent bruising 
 and crushing. A temperature of from 34° to 36° F. is considered 
 best for long period holding, and a temperature of 40° F. is suf- 
 ficiently low for short periods. 
 
 Plums. — This fruit is extremely perishable and not generally 
 considered as cold storage goods except for a few days at a time 
 to tide over an overstocked market. By rigid attention to quality 
 of stock and providing the best facilities for cold storage good 
 results may be obtainable on a comparatively long time carry. 
 Green gage plums have been kept in good condition for a period 
 of ten weeks at a temperature of 32°F. 
 
 Cherries. — Quite perishable and can only be stored for com- 
 paratively short periods at best. A temperature of 32 to 34 F. 
 is recommended. 
 
 Strawberries. — It is practically out of the question to cold 
 store this fruit. They are only placed in refrigerated rooms 
 at a temperature of 40 to 50 F. to prevent rapid ripening and 
 deterioration. Some experimenting has been done in freezing 
 strawberries and holding in this condition for a long period. The 
 actual results cannot be given and it is doubtful if this is commer- 
 cially practicable. Nevertheless, some experimenting along this 
 line might prove interesting. 
 
 Currants. — These may be kept from four to six weeks at a 
 temperature of from 32° to 34° F. The red varieties keep better 
 than the black or white currants. They should be protected from 
 the air by paper coverings. 
 
 DRIED FRUIT IN STORAGE. 
 
 Dried fruit has been stored in large quantities of late years 
 for the purpose of preventing loss of weight by evaporation during 
 warm weather and to prevent mold and fermentation. One of the 
 objects of storing is also to prevent the development of insect life. 
 Certain forms of grubs or worms germinate at comparatively high 
 temperatures and damage the stock. A temperature of from 40 ° 
 to 45° F. is sufficient to prevent this, and is in common use for 
 these products, but a temperature of from 36 to 38 F. is said 
 to absolutely prevent any insect life from maturing or germinat- 
 ing. If a room is available at a somewhat lower temperature 
 
 (36) 
 
562 PRACTICAL COLD STORAGE 
 
 there is no damage to most goods of this class even as low as 
 25 F. 
 
 florists' goods in cold storage. 
 Florists are storing quite a variety of goods at the present 
 time and a constantly increasing variety is being stored each year. 
 The following are a few of the common goods which are placed in 
 storage for safe keeping. Lily-of-the-valley pips at a temperature" 
 of about 25" F., storage period November until spring; Chinese, 
 Japanese and Bermuda lily bulbs stored at a temperature of 34° to 
 36° F., storage period from fall to spring; wild smilax, tempera- 
 ture 32 ° to 34 F., through the winter season ; galaxia leaves at 
 25° F. ; ferns stored from early in the fall or after first frost at 
 a temperature somewhat under the freezing point, about 25° to 
 28° F. is considered best; lucothia, at a temperature of 30 F., 
 through the winter season. The storage of ferns in some sections 
 of New England is quite an important industry. The fern pick- 
 ing begins after the frost comes for the reason that the ferns are 
 tougher and will stand handling and transportation better. They 
 are sorted, tied in bundles, packed in wooden boxes, and slightly 
 moistened. They are then shipped to the cold storage house and 
 stored at a temperature below the freezing point. It has been 
 found that any temperature which will thoroughly stiffen the ferns 
 so that they are frozen will preserve them for a sufficiently long 
 period. They are stored during the entire year and are shipped 
 out on orders to all parts of the country. The holiday season 
 especially requiring a large quantity. 
 
 REGULATION OF PLANT GROWTH BY REFRIGERATION. 
 
 Plant growth may be regulated by maintaining proper tem- 
 peratures. This principle is applied in retarding the develop- 
 ment of bulbs and flowering plants so as to produce blossoms at 
 any time of the year as the demand may be. Lily-of-the-valley, 
 for instance, is made to blossom at Easter time, and roses which 
 naturally blossom in summer, are made to blossom at Christmas. 
 Potted plants are held at a temperature of 30° to 35" F., and 
 then transplanted to the comparatively high temperature of the 
 green-house at such a time as will bring them to flowering or 
 fruitage at the date desired entirely independent of outside 
 weather conditions. The possibilities along this line are being 
 developed as rapidly as the demand warrants. 
 
MISCELLANEOUS 563 
 
 REFRIGERATION APPLIED TO THE SILK INDUSTRY. 
 
 One of the serious obstacles to be overcome in applying 
 refrigeration in the silk industry is the danger that the silk 
 worm will hatch from the eggs at the time when the mulberry 
 leaves have not reached sufficient maturity to constitute a proper 
 food. Refrigeration has been applied to prevent premature 
 hatching of the eggs, if on account of a backward season or for 
 any other reason the matured mulberry leaves are not to be had. 
 A temperature of about 32 ° F. will retard the hatching of the 
 eggs at will and without affecting the silk worm in any way 
 whatever. 
 
 EXPERIMENTS IN GRAIN GROWING. 
 
 It is reported from Stockholm, Sweden, that experiments 
 are in progress whereby it is expected to produce a hardier 
 grain for severe weather conditions. These experiments have 
 been undertaken owing to failure to secure a grain which would 
 be hardy under the severe climate of Norway and Sweden. 
 Canadian and other grains have been sown, but have not shown 
 proper seed producing qualities after having been thoroughly 
 tested. 
 
 Paul Hellstrom, Chief of the Government Biological Insti- 
 tute at Luela, has undertaken the experiment whereby he ex- 
 pects to harden oats, barley and other grains so as to make them 
 sufficiently hardy to withstand a considerable degree of frost. 
 Green houses have been erected, which are in reality cold stor- 
 age houses, in which the plants may be subjected to the lowest 
 temperatures they can stand without being frozen. In this way 
 the seed that matures from the most hardy plants will be used 
 for propagation. By repeating this operation, and gradually 
 lowering the temperature, it is expected that after five or six 
 years' freezing, the nature of the grains will have been so ma- 
 terially changed that they will stand several degrees of frost 
 without damage. The experiment looks reasonable and should 
 meet with success, but it will require very delicate handling in 
 order to regulate the temperatures sufficiently close for the pur- 
 pose required. 
 
 The possibilities along this line, not only in propagating 
 grain, but in propagating other hardy plants and fruits are un- 
 
564 PRACTICAL COLD STORAGE 
 
 limited, and the experiments referred to will be watched with a 
 great deal of interest. This matter is mentioned here as a sug- 
 gestion to those who are interested in the production of hardy 
 fruits and plants. 
 
 MANUFACTURE OF PARAFFINE. 
 
 The application of mechanical refrigeration in the manufac- 
 ture of paraffine was the first use of mechanical refrigeration in 
 connection with a manufactured product. Paraffine wax is ex- 
 tracted from paraffine oil by cooling same to the correct tem- 
 perature to cause the wax to crystallize. In this way paraffine 
 wax of varying densities or melting points may be extracted. 
 The mechanical details of the apparatus may be any arrangement 
 which will present a surface at the correct temperature which 
 may be immersed in a tank of paraffine oil. A revolving surface 
 from which the paraffine may be scraped off as it revolves is 
 desirable. 
 
 COLD STORAGE AND FREEZING TEMPERATURES. 
 
 The temperatures given opposite the various goods named 
 below may fairly be stated to give the average of the best present 
 practice. In some cases comparatively little is known of the cor- 
 rect temperatures at which the various products should be stored, 
 as no tests have been made. For those goods with which the 
 author is familiar, embracing the more important of the perishable 
 products which are cold stored, temperatures are given which he 
 believes to be correct as applied to average practice. For many 
 of the special or uncommon goods the best obtainable authority 
 has been consulted. Owing to the small amount of accurate in- 
 formation available until recently, the present list shows some 
 marked changes from the temperatures regarded as correct a few 
 years ago. No doubt future changes will be made, but hardly to 
 the same extent. 
 
 Arbitrary temperatures are given for each commodity; but 
 the condition of the goods, length of time to be stored, conditions 
 of air circulation, humidity, etc., are factors in determining the 
 best suitable temperature. The following list of products and 
 temperatures should be considered as a guide only, subject to 
 change to meet varying conditions under which goods are stored : 
 
MISCELLANEOUS 
 
 565 
 
 COLD STORAGE AND FREEZING TEMPERATURES FOR VARIOUS PRODUCTS. 
 
 Products 
 
 Apple butter ' 42 
 
 Apples '. 3 o 
 
 Asparagus 33 
 
 Bananas 45 
 
 Beans (dried) 4c 
 
 Beer (bottled) 45 
 
 Berries, fresh (few days only) . 40 
 
 Buckwheat flour 42 
 
 Butter j^ 
 
 Butterine 20 
 
 Cabbage 33 
 
 Canned fruits 40 
 
 Canned meats 40 
 
 Cantaloupes (one to two months) 33 
 
 Cantaloupes (short carry) 40 
 
 Carrots 33 
 
 Caviar 36 
 
 Celery 32 
 
 Cheese (long carry) 35 
 
 Chestnuts 34 
 
 Chocolate dipping room 65 
 
 Cider 32 
 
 Cigars 42 
 
 Corn (dried) 45 
 
 Corn meal 42 
 
 Cranberries 33 
 
 Cucumbers 38 
 
 Currants (few days only) 32 
 
 Cut roses 36 
 
 Dates 55 
 
 Dried beef 40 
 
 Dried fish 40 
 
 Dried fruits 40 
 
 Eggs 30 
 
 Ferns 28 
 
 Field grown roses 32 
 
 Figs 55 
 
 Fish, fresh water (after frozen) 18 
 Fish, not frozen (short carry) . . 28 
 Fish, salt water (after frozen) . 15 
 
 Fish (to freeze) 5 
 
 Frogs legs (after frozen) 18 
 
 Fruit trees 30 
 
 Fur and fabric room 28 
 
 Furs (undressed) 35 
 
 Game (after frozen) 10 
 
 Game (short carry) 28 
 
 Game (to freeze) o 
 
 Ginger ale 36 
 
 Grapes 36 
 
 Hams (not brined) 20 
 
 Hogs 3° 
 
 Hops 32 
 
 Deg. F. Products 
 
 Deg. F. 
 
 Huckleberries (frozen, longcarry)20 
 Japanese fern balls 31 
 
 Lard 
 
 40 
 
 Lemons (long carry) 38 
 
 Lemons (short carry) 50 
 
 Lily of the valley pips 29 
 
 Livers 20 
 
 Maple sugar 45 
 
 Maple syrup 45 
 
 Meat, fresh (ten to thirty days) 30 
 Meats, fresh (few days only)... 35 
 
 Meats, salt (after curing) 43 
 
 Mild cured pickled salmon 33 
 
 Nursery stock 30 
 
 Nuts in shell 40 
 
 Oatmeal 42 
 
 Oils 45 
 
 Oleomargarine 20 
 
 Onions 32 
 
 Oranges (long carry) 34 
 
 Oranges (short carry) 50 
 
 Oxtails 30 
 
 Oysters, iced (in tubs) 35 
 
 Oysters (in shell) 43 
 
 Palm seeds 38 
 
 Parsnips 32 
 
 Peach butter 42 
 
 Peaches (short carry) 50 
 
 Pears 33 
 
 Peas (dried) 45 
 
 Plums (one to two months) .... 32 
 
 Potatoes 34 
 
 Poultry (after frozen) 10 
 
 Poultry, dressed (iced) 30 
 
 Poultry (short carry) 28 
 
 Poultry (to freeze) o 
 
 Raisins 55 
 
 Ribs (not brined) 20 
 
 Salt meat curing room 33 
 
 Sardines (canned) 40 
 
 Sauerkraut 38 
 
 Sausage casings 20 
 
 Scallops (after frozen) 16 
 
 Shoulders (not brined) 20 
 
 Strained honey 45 
 
 Sugar 45 
 
 Syrup 45 
 
 Tenderloin, etc 33 
 
 Tobacco 42 
 
 Tomatoes (ripe) 42 
 
 Watermelons (short carry) 40 
 
 Wheat flour 42 
 
 Wines 50 
 
566 PRACTICAL COLD STORAGE 
 
 THERMOMETERS. 
 
 Correct temperatures being the most important matter to be 
 considered in the successful refrigeration of perishable goods, 
 it follows that some accurate instrument must be used for meas- 
 uring same. The mercury thermometer graduated to the Fah- 
 renheit scale, with the freezing point of water at 32 F., is the 
 most common, and in fact practically the only instrument in use. 
 The accuracy of some thermometers cannot be depended upon. 
 The ordinary cheap themometer where the figures are stamped 
 on the scale and with graduations separate from the stem are 
 inaccurate sometimes to the extent of five degrees to ten de- 
 grees. It does not pay to buy cheap thermometers for cold 
 storage purposes. Often those given as advertising matter are 
 in use. Some years ago an eastern firm sent out a large number 
 of such thermometers as prizes. One of these was used for 
 reading outside weather temperatures. It was finally discov- 
 ered that the mercury bulb and stem were imperfect and not 
 correctly graduated and the readings were more than twenty de- 
 grees out of the way. This is exceptionally bad, but it is fre- 
 quently the case that thermometers are two, three or four de- 
 grees incorrect, and in fact more of the cheap thermometers are 
 two or three degrees off than there are that are accurate. No 
 matter what kind of a thermometer a cold storage man has he 
 will generally swear by it even though it be several degrees too 
 high or too low. Of course where a number of thermometers 
 are in use it is not probable that any one of them could be very 
 much off without it being found out. On receiving a new lot 
 of thermometers it is a good scheme to hang them up side by 
 side in the cold storage room with a thermometer which has 
 been in use and known to be fairly accurate. Then, if any one 
 of the new thermometers is incorrect it may be returned to the 
 manufacturer. Thermometers are not expensive, even the high- 
 class ones. At a cost of from $15 to $24 per dozen special cold 
 storage thermometers graduated, say from zero to 50° F., may 
 be obtained. The best ones have the graduations (scaled to 
 read to ?4 of a degree) etched on the stem and the figures on the 
 metal or enamel scale. In this way if they are correct when 
 tested they cannot become incorrect without being broken. 
 These thermometers cost more than those which are not etched 
 
MISCELLANEOUS 567 
 
 on the stem, but are more reliable. It is important that a ther- 
 mometer for cold storage rooms should be graduated with one- 
 quarter degree marks. Then a slight variation in temperature 
 may be quickly noticed. Some thermometers are only gradu- 
 ated on one degree or two degrees divisions, in which case it is 
 difficult to notice a variation of less than one-half a degree to 
 one degree. It is a good plan to gather up thermometers not in 
 use and have one certain place for hanging them in a cold stor- 
 age room. Then they may be compared and if any of them are 
 injured or inaccurate from any cause it will be discovered. In 
 any case some systematic method should be used and above all 
 things do not buy cheap thermometers. Buy them by the dozen 
 or half dozen and keep extra ones on hand so that when break- 
 age occurs you will not be tempted to go to the nearest store 
 which sells thermometers. 
 
TOPICAL INDEX 
 
 569 
 
 TOPICAL INDEX. 
 
 A 
 
 Page. 
 
 Absorbents 1 74 
 
 Absorption, ammonia system 20 
 
 Air, apparatus for purifying 160 
 
 Air, circulation 19,117 
 
 and evaporation, forced 146 
 
 and humidity 133 
 
 and temperatures for eggs 205 
 
 benefits from 124 
 
 Cooper system of 142 
 
 cost of operating forced 147 
 
 crude forced 137 
 
 false systems of 142 
 
 forced 118 
 
 for eggs in cold storage 204 
 
 gravity 131 
 
 in ice cold store 120, 440 
 
 in storage of furs and fabrics. .402 
 
 improved system of 131 
 
 methods of piping that hinder... 125 
 
 objections to forced 133 
 
 saving of space by forced 147 
 
 system of forced 138 
 
 theory of 140 
 
 undesirable forced 135 
 
 Air, cooler for ventilation 158 
 
 for ventilation, treating 156 
 
 drying .178 
 
 leakage 152 
 
 leakage in insulation 97 
 
 non-conducting properties of 45 
 
 purified by circulation 122 
 
 required for ventilation, quantity 
 
 of 161 
 
 spaces as insulation 92 
 
 washing for ventilation 159 
 
 water vapor in 168 
 
 Ammonia, direct expansion system.. 25 
 
 refrigerating machines 19 
 
 system superior to ice 452 
 
 vs. ice and salt systems 31 
 
 Apple industry, influence of cold stor- 
 age on 286 
 
 scald, influence of delay in stor- 
 ing after picked, on 314 
 
 scald, influence of temperature 
 
 on 311 
 
 scald, influence of wrapper on. .315 
 scald, varieties most susceptible 
 
 to 316 
 
 storage, experiments in 288 
 
 Apples, behavior of when removed 
 
 from storage. . ._ 305 
 
 catalog of varieties of 319 
 
 cultural conditions of 317 
 
 decay of ' 306 
 
 delay in the storage of 295 
 
 experiments in storage of 229 
 
 factors influencing the keeping 
 
 quality of 29° 
 
 frozen 299 
 
 function of cold storage house 
 for 287 
 
 Page. 
 Apples, importance of good fruit for 
 
 -storage 306 
 
 in cold storage 286 
 
 in cold storage, comparison of 
 
 varieties of 316 
 
 influence of cultural conditions 
 
 on 302 
 
 influence of storage temperatures 
 
 on 298 
 
 influence of type of packages on 
 
 storage of 304 
 
 influence of wrapper on storage _. 
 
 of 300 
 
 scald on 308 
 
 shipping 429 
 
 temperatures for storing 27, 299 
 
 Apparatus, insulation testing 72 
 
 for purifying air 160 
 
 Asphalt as water-proofing material. . . 107 
 
 Auger, ice 469 
 
 Axe, ice house 478 
 
 B 
 
 Bananas, in cold storage 560 
 
 shipping 428 
 
 Beef, shipping fresh 424 
 
 Beer, temperatures for storing 29 
 
 Beets, cold storage of 560 
 
 Blankets, charges for storing 406 
 
 Brace, channel 476 
 
 Breaking bar, ice 477 
 
 Brick preservative, Cabots' for water 
 
 proofing 109 
 
 tests on water proofing 1 1 1 
 
 Brine, chloride of calcium 187, 456 
 
 circulation, Coopers' Gravity Sys- 
 tem 452 
 
 coolers ". 189 
 
 density of chloride of calcium. .. 190 
 
 from common salt 188 
 
 method of making chloride of cal- 
 cium 192 
 
 over salt, advantages of chloride 
 
 of calcium 1 90 
 
 pipe covering, materials for.. 6 1,104 
 system for creamery, Cooper's 
 
 gravity 279 
 
 table for making chloride of cal- 
 cium 192 
 
 tank insulation 98 
 
 British thermal unit _ 41, 438 
 
 Butchers box, gravity brine system 
 
 in 540 
 
 refrigerators 539 
 
 Butter 425 
 
 air circulation in storage room.. 233 
 
 "air struck" 225 
 
 creamery 231 
 
 flavor and aroma 227 
 
 for cold storage, cooling. 549 
 
 for cold storage, preparing 227 
 
570 
 
 TOPICAL INDEX 
 
 Butter, freezing 225 
 
 humidity of storage room for... 232 
 
 in cellars J 8 
 
 in cold storage 224. 
 
 ladle 230 
 
 packages for 226 
 
 packages, mold in 232 
 
 packed in cans 226 
 
 paste salt for covering 232 
 
 preparing jars for storage of 229 
 
 protection from air 225 
 
 separator vs. gravity 227 
 
 specific heat of 232 
 
 storing in jars 228 
 
 storing in tubs 229 
 
 storing long period 55 : 
 
 temperatures for storing 26, 224 
 
 tubs, paper liners for 230 
 
 ventilation of storage room for.. 233 
 
 Butterine 230 
 
 C 
 
 Cabbage in cold storage 557 
 
 temperatures for storing 28 
 
 Cabot's brick preservative for water 
 
 proofing walls 109 
 
 Calcium chloride as an absorbent. ... 175 
 
 Calking bar, ice 477 
 
 Canal chisel, steel ice 478 
 
 wood handle ice 477 
 
 Candling room, egg 217 
 
 refrigerated egg 221 
 
 Cantaloupes in cold storage 561 
 
 Carbonic acid gas machines 19 
 
 Carpets, cold storage of 405 
 
 Carrots, cold storage of 561 
 
 Cars, temperatures in refrigerator. .. .424 
 
 ventilated 422 
 
 Cases for eggs 209 
 
 Cave cold storage 17 
 
 Celery in cold storage 559 
 
 Cellars 17 
 
 ice 118, 490 
 
 storing vegetables in 556 
 
 Chaff as insulation 55 
 
 Channel brace 476 
 
 Charcoal as insulation 60 
 
 Chloride of calcium, as an absorbent. 175 
 
 breaking up 186 
 
 brine 187, 456 
 
 brine, density of 190 
 
 brine, method of making 192 
 
 brine over salt, advantages of.. 190 
 
 brine, properties of solution 193 
 
 brine, table for making 192 
 
 preparing and handling 185 
 
 preventing frost on pipes by.... 178 
 
 process, Cooper's 182 
 
 uses of 177 
 
 Charges, for cold storage 29 
 
 fish freezing and storing 395 
 
 storing blankets 406 
 
 storing clothing 406 
 
 storing furs and fabrics 406 
 
 storing lap robes 406 
 
 storing overcoats 406 
 
 Cheese, and forced circulation 133 
 
 author's remarks on storage of. .267 
 
 cold storage of 235 
 
 conditions under which to store 
 
 col d cured 247 
 
 curing of 235 
 
 during curing, influence of paraf- 
 fining on shrinkage of 250 
 
 effect of temperature on quality 
 of cold cured 261 
 
 Cheese, experiments in cold curing... 
 
 humidity of curing room for. . . . 
 
 in curing, shrinkage of 
 
 in experiments, scoring of 
 
 influence of paraffining on qual- 
 ity of 
 
 influence of temperature on 
 shrinkage of 
 
 quality of cold cured 
 
 refrigeration for cold curing. . . 
 
 results of storage, cold cured... 
 
 ripening or maturing of 
 
 shipping 
 
 shrinkage in cold cured 
 
 temperatures for storing 
 
 temperatures for curing 
 
 test of cold cured 
 
 truck 
 
 Cherries, cold storage of 
 
 Chisel, canal ice 
 
 ice 
 
 starting ice 
 
 Circulation, Cooper system of air.-. . . 
 
 Cooper system of brine 
 
 crude forced air 
 
 false systems of air 
 
 forced air 
 
 gravity air 
 
 in ice cold store, air 
 
 methods of piping that hinder air. 
 
 objections to forced air 
 
 of air 19, 
 
 of air, benefits from 
 
 of air in butter room 
 
 system of forced air 
 
 undesirable forced air 
 
 Cloaks, cold storage of 
 
 Clothing, charges for storing 
 
 Coats, cold storage of 
 
 Cold cured cheese, conditions under 
 which stored 
 
 effect of temperature on quality 
 of 
 
 quality of 
 
 results of storage 
 
 shrinkage in 
 
 test of 
 
 Cold curing of cheese 
 
 Cold rooms, doors in 
 
 variation in temperature in 
 
 ventilation of 
 
 windows in 
 
 Cold storage, and freezing tempera- 
 tures 
 
 and ice house combined 
 
 and ice house, plan for 
 
 benefits of 
 
 classes of goods placed in 
 
 commercial aspect of local 
 
 for fruit growers 
 
 for nurserymen 
 
 development of 
 
 for retailers 
 
 house cooled by ice and salt.... 
 
 house, cost of construction 
 
 industry, importance of 
 
 moisture given off by goods in. . 
 
 of apples 
 
 of bananas 
 
 of beets 
 
 of cantaloupes 
 
 of carpets 
 
 of carrots 
 
 of celery 
 
 of cheese 
 
 of cherries 
 
 of cloaks 
 
TOPICAL INDEX 
 
 571 
 
 Gold storage, of coats 405 
 
 of currants 561 
 
 of dried fruit 561 
 
 °* ^p. j 94 
 
 of fabrics 396 
 
 of fabrics, air circulation in.... 402 
 
 of fabrics, humidity in 401 
 
 of fabrics, ventilation in 403 
 
 of fish 384 
 
 of florists' goods 562 
 
 of fruits 560 
 
 of furs and fabrics 396 
 
 of heads 405 
 
 of lemons 560 
 
 of melons 560 
 
 of onions 559 
 
 of oranges 560 
 
 of pears 332 
 
 of plums 561 
 
 of potatoes 558 
 
 of pumpkins 557 
 
 °| r "P 405 
 
 01 silk 399 
 
 of skins 405 
 
 of squashes 557 
 
 of stuffed animals 405 
 
 of trophies 403 
 
 of trunks 405 
 
 of turnips 557 
 
 of vegetables 553 
 
 possibilities in development of... 21 
 
 probable demand for 22 
 
 Prof. Nyce's system of 174 
 
 rates 29 
 
 rooms, deodorizing 544 
 
 rooms, height of 32 
 
 rooms, small 25 
 
 rooms when empty, care of 410 
 
 rooms, white washing 544 
 
 slow cooling of goods for 546 
 
 stowing goods in 547 
 
 Cold stores, keeping clean 410 
 
 Cooper system for 370 
 
 cost of construction of small.... 368 
 
 designing of 32 
 
 designs for small 363 
 
 earnings of 29 
 
 equipment of 22 
 
 geometry of 32 
 
 ice 119 
 
 organizing and operating 21 
 
 proportions of 32 
 
 rural sites for 542 
 
 uses of absorbents in 174 
 
 Cold water paint 417 
 
 Cold weather ventilation 162 
 
 Composite insulation 71 
 
 tests of 78 
 
 Compressed air machines 19 
 
 Conduction of heat 4° 
 
 Conductivity of substances, table of 
 
 heat -_. . 42 
 
 Conductors of heat 4 1 
 
 table of poor heat 43 
 
 Construction of ice houses 493 
 
 small cold stores, cost 368 
 
 Convection of heat 38 
 
 Cooler for ventilation, air 158 
 
 brine I ^9 
 
 Cooling, butter for cold storage 549 
 
 of goods for cold storage, slow. 549 
 
 pipes on ceiling 125 
 
 pipes, radiation to 126 
 
 room, ice . II 9 
 
 room, mold in 55° 
 
 Cooper's chloride of calcium process. 182 
 
 Cooper's gravity brine system for 
 
 creamery 279 
 
 system, cost of construction 24 
 
 system, diagram of 458 
 
 system for cold stores 370 
 
 system of air circulation 142 
 
 system of refrigeration 453 
 
 system of ventilation 161 
 
 Cork, as insulation 60 
 
 pipe insulation 104 
 
 Corrosion of pipes 188 
 
 Cost of construction, cold storage 
 
 house 24 
 
 small cold stores 368 
 
 Cost, harvesting ice 463 
 
 insulation ■. 113 
 
 operating cold store 30 
 
 operating forced air circulation . 147 
 Covering, materials for brine pipe. 61, 104 
 
 Crab, hoisting 483 
 
 ice hoist 479 
 
 Cream and milk, cooling of 283 
 
 Creamery, butter 231 
 
 gravity brine system for. ...... .281 
 
 ice handling machinery for 280 
 
 ice house, model 506 
 
 refrigeration 269 
 
 refrigeration, ice vs. refrigerating 
 
 machine for 271 
 
 refrigerator 272 
 
 refrigerator, construction of 275 
 
 Cream, transportation of 278 
 
 Crusher, ice 457 
 
 Currants, cold storage of 561 
 
 Curing of cheese, cold 235 
 
 D 
 
 Dairy products, in refrigerators 537 
 
 products, shipping 425 
 
 Dairy refrigeration 269 
 
 ice vs. refrigerating machine for. 271 
 
 Danish ice houses 504 
 
 Decay of apples after removal from 
 
 storage 306 
 
 Designing of cold store 32 
 
 Designs for small cold stores 363 
 
 Deodorizing a cold storage room.... 541 
 
 Dexter system 448 
 
 Direct expansion, ammonia system.. 25 
 
 Direct tankage system 450 
 
 Disc fans 135 
 
 Doors, for cold rooms 151 
 
 special refrigerator 151 
 
 Drains in ice house 525 
 
 Dress suits, charges for storing 406 
 
 Dried fruits, in storage 561 
 
 temperatures for storing 28 
 
 Drying air 178 
 
 E 
 
 t Earnings of cold store 29 
 
 Egg candling, booth, construction of .218 
 
 room 217 
 
 room, refrigerated 221 
 
 Egg case fillers 210 
 
 Egg cases 209 
 
 Egg rooms, white washing 544 
 
 Eggs, and lemons, storing 555 
 
 causes of musty 197 
 
 difficulties in storing 26 
 
 freezing in bulk 552 
 
 freezing point of 196 
 
 Eggs in cold storage ._ 194 
 
 absorbents as applied to 207 
 
 air circulation for 204 
 
572 
 
 TOPICAL INDEX 
 
 Eggs in cold storage, consistency of.. 200 
 
 effect of humidity on 201 
 
 evaporation of 203 
 
 in oats, packing 214 
 
 must or mildew on 197 
 
 packages for 208 
 
 packing for 213 
 
 temperatures for 195 
 
 tests on evaporation of 208 
 
 trays for 213 
 
 ventilation for 206 
 
 Eggs, in refrigerator cars, shipping. .420 
 kept in cold storage, estimated 
 
 value 194 
 
 shipping 425 
 
 storing 214 
 
 temperatures for storing 26 
 
 testing 216 
 
 Electric fans 135 
 
 Elevator, endless chain ice 481 
 
 ice 32, 529 
 
 planer 470 
 
 single gig 485 
 
 Evaporation, and forced air circula- 
 tion 133, 146 
 
 of eggs in cold storage 203 
 
 of eggs in cold storage, tests on. 208 
 of frost on pipe coils. 163 
 
 Experiments, advice regarding 30 
 
 in apple storage 288 
 
 in cold curing of cheese 238 
 
 in grain growing 563 
 
 in peach storage 355 
 
 with insulation for ice houses . . 496 
 
 Freezing, and storing fish 383 
 
 and storing poultry 551 
 
 butter 225 
 
 eggs in bulk 552 
 
 fish by mechanical refrigeration. 389 
 
 fish with ice and salt 387 
 
 fish with ice and salt, directions 
 
 for 391 
 
 point of eggs 196 
 
 walls 450 
 
 Frost, from refrigerating pipes, remov- 
 ing 411 
 
 on pipes by use of chloride of 
 
 calcium, preventing 178 
 
 Frozen apples 299 
 
 Fruit, cold stores, designs for small . 363 
 
 growers, cold storage for 360 
 
 influence of cold storage on fla- 
 vor and aroma of 349 
 
 ' trees, operating plant for storage 
 
 of 381 
 
 trees, storage of 372 
 
 when removed from storage 350 
 
 Fruits, hardy 563 
 
 in cold storage ;. . . .560 
 
 shipping t 426 
 
 Furs and fabrics, circulation in storage 
 
 of 402 
 
 cold storage of 396 
 
 humidity in storage of 401 
 
 storage charges for 406 
 
 ventilation in storage of 403 
 
 F 
 
 Fabrics, air circulation in cold stor- 
 age of 402 
 
 cold storage of 396 
 
 humidity in cold storage of 401 
 
 ventilation in cold storage of... 403 
 
 Fans for ventilation 155 
 
 farm ice houses 493, 498, 502 
 
 Field ice planer 469 
 
 Fillers for egg cases 210 
 
 Fireproof insulation 99 
 
 Fish after frozen, deterioration 393 
 
 storing 392 
 
 Fish, cold storage of 384 
 
 freezing and storing 383 
 
 freezing and storing, charges for. 395 
 freezing by mechanical refrigera- 
 tion 389 
 
 freezing, directions for ice and 
 
 salt 391 
 
 freezing, ice and salt 387 
 
 preparing for freezing 390 
 
 shipping 425 
 
 Fisher system 442 
 
 Flavor and aroma of butter 227 
 
 Floats, ice 475 
 
 Florists' goods in cold storage 562 
 
 Flour, temperatures for storing 28 
 
 Food preservation 12 
 
 Forced air circulation, and evapora- 
 tion 146 
 
 cost ■ of operating 147 
 
 crude t 137 
 
 objections to . . .* 133 
 
 saving of space by 147 
 
 system of 138 
 
 undesirable 135 
 
 Fork bar, knob handle three-tined ice. 478 
 
 ring handle ice 477 
 
 Freezing, and cold storage tempera- 
 tures 564 
 
 Gays' system of piping 129 
 
 Geometry of cold storage houses 32 
 
 Gig elevator 485 
 
 Grain growing, experiments in 563 
 
 Granulated cork as insulation ....... . 61 
 
 Grapple, Jack 481 
 
 Gravity air circulation 131 
 
 Gravity brine system, Cooper's. _ 453 
 
 Cooper's, temperatures obtainable 
 
 with 456 
 
 for creamery 281 
 
 for creamery, Cooper's 279 
 
 Gravity butter 228 
 
 Grocers' sundries, temperatures for 
 storing 28 
 
 H 
 
 Hair felt, as insulation 64 
 
 for brine pipe insulation 104 
 
 pipe insulation 104 
 
 Handling goods for storage, trucks 
 
 for 543 
 
 Hardy, fruits 563 
 
 plants 563 
 
 Harness, ice plow 474 
 
 Harvesting ice 462 
 
 cost of 463 
 
 Harvesting, marking out ice for.... 471 
 
 Heads, cold storage of 405 
 
 Heat, character of 438 
 
 conductivity of substances, table 
 
 of relative 42 
 
 conduction of 40 
 
 conductors of 41 
 
 convection of 38 
 
 leakage 34 
 
 of butter, specific 232 
 
 radiation of 38 
 
 transmision, table of co-efficients 
 
 of 49 
 
 table of non-conductors of 44 
 
TOPICAL INDEX 
 
 573 
 
 Heat, table of poor conductors of.... 43 
 
 theory of 38 
 
 through walls, transmission of . . . . 50 
 
 transmission of 38 
 
 transmission through insulation.. 85 
 variation in transmission of.... 46 
 
 units 41 
 
 Height of cold storage rooms 32 
 
 Hemlock wood as insulation 70 
 
 Historical 17, 118 
 
 Hoist, ice 479 
 
 Hoisting, crab 483 
 
 tongs 481 
 
 Humidity 167 
 
 and air circulation 133 
 
 and air circulation for eggs in 
 
 cold storage 204 
 
 as affecting eggs in cold storage2oi 
 for eggs in cold storage, table of 
 
 correct 203 
 
 for storing nursery stock 377 
 
 in butter room 233 
 
 influence of quantity of goods 
 
 on 545 
 
 of curing room for cheese 244 
 
 on keeping quality of pears, in- 
 fluence of 335 
 
 regulation of 545 
 
 table of relative 173 
 
 Hydrometer, brine 191 
 
 Hygrometers 1 69 
 
 I 
 
 Ice and salt, for freezing fish 387 
 
 lowest temperature obtainable 
 
 from 439 
 
 mixture 439 
 
 systems, operating. ... 459 
 
 vs. ammonia systems 31 
 
 Ice and snow, refrigerating value of. 489 
 
 Ice, as a refrigerant 18, 436 
 
 auger 469 
 
 boxes and refrigerators 532 
 
 boxes, Bohn system 533 
 
 boxes, circulation of air in 532 
 
 calking bar 477 
 
 cellars 118, 490 
 
 chisel 46 5 
 
 chisel, starting ,.484 
 
 cold storage, circulation of air 
 
 in 44° 
 
 cold storage, early systems of..44 I 
 
 cold storage, moisture in 439 
 
 cold store : 119 
 
 cold store, air circulation in.... 120 
 
 cold store, moisture in 120 
 
 cooling room 119 
 
 cooling systems, overhead 121 
 
 cost of harvesting . 463 
 
 creamery refrigeration with 27.1 
 
 crop 462 
 
 crusher 457, 529 
 
 elevator 539 
 
 field, care of 465 
 
 field, removal of snow from 466 
 
 first trade in 18 
 
 floats 475 
 
 fork bar 47? 
 
 for cold storage 18 
 
 for harvesting, marking out. . . .471 
 
 handling machinery 457 
 
 handling machinery for cream- 
 ery 280 
 
 harvesting 462, 475 
 
 harvesting, preparation for 464 
 
 Ice house, and cold storage combined. 527 
 and cold storage, plan for 530 
 
 Ice house, and refrigerator combined. .277 
 
 axe 478 
 
 construction of 119 
 
 drains in 525 
 
 evolution of 490 
 
 farm 493, 498, 502 
 
 filling farm 500 
 
 for retail trade 512 
 
 model creamery 506 
 
 ventilation of 526 
 
 with snow, filling 492 
 
 wholesale 519 
 
 Ice houses 489 
 
 Ice houses, commercial 5*3 
 
 construction of 493 
 
 Danish 5°4 
 
 experiments with insulation for. 496 
 
 filling 494 
 
 for storing 437 
 
 insulation of 493 
 
 waste of ice in 492 
 
 Ice in house, meltage of 529 
 
 packing 484 
 
 waste of 495 
 
 Ice lift 479 
 
 Ice machine refrigeration for cream- 
 ery 271 
 
 Ice marker 47° 
 
 Ice pits 1 r8, 491 
 
 Ice planer 469 
 
 Ice plow, field 473 
 
 hand 472 
 
 harness 474 
 
 rope 474 
 
 with swing guide 473 
 
 Ice, purity of lake 462 
 
 refrigerating value of 437 
 
 refrigeration from . 435 
 
 refrigeration, principles of 435 
 
 refrigeration temperatures from.. 43 5 
 
 saw 476 
 
 scraper 466 
 
 slide and table 480 
 
 snow 469 
 
 stacking 492 
 
 storing 462 
 
 table with slide 480 
 
 temperature of melting 438 
 
 thickness of 463 
 
 tools 486 
 
 Impurities and moisture, relation be- 
 tween 123 
 
 Income from cold store 29 
 
 Insulating papers 67 
 
 Insulation _ 36, 7 2 
 
 air leakage in 97 
 
 air spaces as 92 
 
 application of 5 1 
 
 brine pipe 61 
 
 chaff for 55 
 
 charcoal for 60 
 
 composite 37.71 
 
 cork for 6° 
 
 cost of "3 
 
 fireproof 99 
 
 for ice houses, experiments with. 496 
 
 for street pipe line 105 
 
 hair felt for - 64 
 
 heat transmission through 86 
 
 importance of efficient 5 2 
 
 materials for 53 
 
 materials, test of 4° 
 
 mineral wool for 57 
 
 moisture in 9° 
 
 water proofing of 106 
 
 nails in 7* 
 
 of brine tank 98 
 
574 
 
 TOPICAL INDEX 
 
 Insulation, of ice houses 493 
 
 of pipe 104 
 
 quilt for 65 
 
 requirements of 53 
 
 sawdust for 55 
 
 shavings and sawdust as 543 
 
 shavings for 56 
 
 straw for 55 
 
 superintendence of construction 
 
 of 115 
 
 testing apparatus 72 
 
 tests of 37- 73 
 
 tests of composite 78 
 
 types of 92 
 
 various constructions 93 
 
 wood for 69 
 
 Introduction 10 
 
 j 
 
 Jack grapple 481 
 
 Jackson system 447 
 
 Jars for butter storage 228 
 
 Ladle butter 230 
 
 Lake ice, purity of 462 
 
 Lap robes, charges for storing 406 
 
 Leakage of air 152 
 
 Lemons and eggs, storing 555 
 
 Lemons, in cold storage 560 
 
 shipping 428 
 
 temperatures for storing 28 
 
 Lift, ice 479 
 
 Lime as an absorbent 175 
 
 Line marker 472 
 
 Liners for butter tubs 230 
 
 Linseed oil for water proofing walls, r 09 
 
 Local cold storage, advantages of . . . .360 
 
 commercial aspect of 362 
 
 M 
 
 Machinery, for ice handling 457 
 
 refrigeration 19 
 
 Marker, ice 470 
 
 Marker, line 472 
 
 plow, ice 472 
 
 Materials for insulation 53 
 
 Measuring iron for ice 469 
 
 Meat, shipping fresh 424 
 
 Meats, temperature for storing 29 
 
 Mechanical refrigeration for fish 
 
 freezing 389 
 
 Melons in cold storage 560 
 
 Meltage of ice in house 529 
 
 Milk 425 
 
 and cream, cooling of 283 
 
 transportation of 278 
 
 Mill shavings as insulation 56 
 
 Mineral wool, as insulation 57 
 
 slabs or blocks 58 
 
 Miscellaneous 542 
 
 Moisture and impurities, relation be- 
 tween 123 
 
 Moisture, and ventilation 163 
 
 given off by goods in cold stor- 
 age 123 
 
 in ice cold storage 120, 439 
 
 in insulation 96 
 
 on pipe coils 163 
 
 Mold, in butter packages 232 
 
 in cooling room 550 
 
 Moth, effect of cold on 408 
 
 Musty eggs, causes of 197 
 
 N 
 
 Nails in insulation 71 
 
 Nurserymen, cold storage for 375 
 
 Nursery cold storage, plan of 378 
 
 Nursery stock, buildings and appa- 
 ratus for storing 375 
 
 humidity and temperature for 
 
 storing 371 
 
 methods of storing 374 
 
 operating plant for storage of.. 381 
 Nuts, temperatures for storing. ... 2S 
 Nyce system 174, 446 
 
 O 
 
 Oats for packing eggs in cold stor- 
 age 214 
 
 Oleomargarine 23c 
 
 Onions in cold storage 559 
 
 Operating a cold store 21 
 
 costs of 30 
 
 Oranges, in cold storage 560 
 
 shipping 428 
 
 temperatures for storing 28 
 
 Organizing a cold store 21 
 
 Overcoats, charges for storing 406 
 
 Overhead ice cooling systems 121 
 
 Oysters, shipping 426 
 
 P 
 
 Packages, for butter 226 
 
 for eggs in cold storage 208 
 
 on keeping quality of pears, in- 
 fluence of type of 342 
 
 on storage of apples, influence of 
 
 type of 304 
 
 Paint, cold water 417 
 
 for refrigerating pipes 417 
 
 for water proofing walls, lead. . 109 
 
 Painting metal surfaces 543 
 
 Papers, insulating 67 
 
 Paper, requirements of insulating.... 69 
 
 value of insulating 68 
 
 Paraffine, manufacture of 564 
 
 Paraffining cheese, influence on qual- 
 ity of 262 
 
 on shrinkage of cheese during 
 
 curing, influence of 250 
 
 Paste salt 232 
 
 Peaches in refrigerator cars 358 
 
 Peach industry, influence cold storage 
 
 on 353 
 
 Peach storage, difficulties in 354 
 
 experiments in 355 
 
 results 356 
 
 Pear industry, influence of cold stor- 
 age on 332 
 
 Pears, experiment in storage of 333 
 
 in cold storage 332 
 
 Pears, influence of, delayed storage 
 
 on keeping quality of 336 
 
 humidity on keeping quality of .335 
 temperatures on keeping quality 
 
 of 340 
 
 type of packages on keeping qual- 
 ity of 342 
 
 wrapper on keeping quality of.. 346 
 
 Pears, results from storage of 352 
 
 snipping 429 
 
 Perishable products, shipping 419 
 
 table of temperatures for ship- 
 ping .' 432 
 
 temperatures for 419 
 
 Pine wood as insulation 70 
 
 Pipe coils, moisture on 163 
 
TOPICAL INDEX 
 
 57E 
 
 Pipe covering, granulated cork as.. 61 
 
 insulation I04 
 
 line insulation ! ! ! ] 105 
 
 Pipes, corrosion of !88 
 
 paint for refrigerating ! 4 i 7 
 
 removing frost from refrigerat- 
 
 „. . In £ •, 411 
 
 Piping, Gay's system of 120 
 
 methods of I25 
 
 on ceiling ...125 
 
 side wall, with screen 127 
 
 side wall with screen 127 
 
 St. Clair system of 130 
 
 Pitch and cork pipe covering 61 
 
 Planer, elevator 47 o 
 
 field ice 4 6g 
 
 Piant growth, regulation by refrigera- 
 tion 5 6 2 
 
 Plants, hardy .' .' 563 
 
 Plow, field ice 473 
 
 hand ice 4 72 
 
 rope, ice 474 
 
 swing guide with ice 4 73 
 
 Plums, cold storage of 361 
 
 Pork, shipping fresh 425 
 
 Potatoes, in cold storage 558 
 
 in cold weather, shipping 421 
 
 temperatures for storing 28 
 
 Poultry, shipping fresh 425 
 
 storing and freezing 551 
 
 temperatures for storing 28 • 
 
 Preservation, food 12 
 
 Preservatives, Cabot's brick, for wa- 
 ter proofing 109 
 
 Process butter 228 
 
 Psychrometers 169 
 
 Pumpkins, cold storage of 559 
 
 Purifying air, apparatus for 160 
 
 Q 
 
 Quilt insulation 65 
 
 application of 66 
 
 Quinces, shipping 429 
 
 R 
 
 Radiation of heat 38 
 
 to cooling pipes 126 
 
 Rates for cold storage 29 
 
 Refrigerant, temperature of 134 
 
 Removing goods from storage 548 
 
 Refrigerating pipes, paint for 417 
 
 removing frost from 411 
 
 Refrigerating, value of ice and snow. 489 
 
 Refrigeration, application of 20 
 
 applied to the silk industry 563 
 
 for retailers 536 
 
 from ice 435 
 
 importance of 10 
 
 regulation of plant growth by.. 562 
 
 uses of 11 
 
 Refrigerator 18 
 
 and ice house combined 277 
 
 Refrigerator cars 4 21 
 
 over-loading 4 2 9 
 
 peaches in 358 
 
 shipping eggs in 420 
 
 temperatures in 424 
 
 Refrigerator, creamery 272 
 
 Refrigerators, and ice boxes 53 2 
 
 dairy products in 537 
 
 for butchers 539 
 
 meat in 5 38 
 
 temperature in 537 
 
 Retailers, refrigeration for 536 
 
 Root cellars 17 
 
 Rope, ice plow -. . . . 474 
 
 Rugs, cold storage of 405 
 
 S 
 
 Salt, for covering butter 23; 
 
 brine from common i8i 
 
 Sawdust, as insulation 55, 541 
 
 for packing ice ce 
 
 Saw, ice 47C 
 
 Scald, apples, influence of delay " iii 
 
 storing after picked on 314 
 
 apples, influence of wrapper on.. 31 = 
 
 on apples 30 j 
 
 on apples, influence of tempera- 
 ture on 3 r j 
 
 varities of apples most susceptible 
 
 to ^it 
 
 Scraper, ice , . . . , 4 g^ 
 
 snow scoop 46 ? 
 
 Screen and side wall piping 127 
 
 Separator butter ' 227 
 
 Shavings as insulation 56, 543 
 
 Sheet cork as insulation 61 
 
 Shellac for cold storage rooms 417 
 
 Shipping, apples 42 g 
 
 bananas 428 
 
 butter ' 425 
 
 cheese 425 
 
 dairy products 435 
 
 eggs 425 
 
 fish 42 6 
 
 fruits 425 
 
 lemons 42 8 
 
 meats ,424 
 
 milk 425 
 
 oranges 42 g 
 
 oysters 42 fi 
 
 pears 42g 
 
 perishable products 4.19 
 
 perishable products, table of tem- 
 peratures for 432 
 
 quinces 42 g 
 
 use of weather reports in 4.29 
 
 vegetables 429 
 
 Shrinkage, in cold cured cheese 246 
 
 of cheese in curing 244 
 
 of cheese, influence of tempera- 
 ture on 248 
 
 Silk, cold storage of 399 
 
 industry, use of refrigeration in.. 563 
 
 Single gig elevator 4.85 
 
 Site for a cold store 54.2 
 
 Skins, cold storage of 405 
 
 Slide and table, ice 4.80 
 
 Sling psychrometer 170 
 
 Snow and ice, refrigerating value of. 489 
 
 Snow ice 469 
 
 Snow in ice house, packing 492 
 
 scraper 468 
 
 Specific heat of butter 232 
 
 Spruce wood as insulation 70 
 
 Squashes, cold storage of 557 
 
 St. Clair system of piping 130 
 
 Stacking ice 492 
 
 Stevens system 445 
 
 Storage, handling goods for 546 
 
 removing goods from 548 
 
 Storing, and freezing poultry.". . . . .551 
 
 eggs and lemons 555 
 
 butter, long period 551 
 
 ice 462 
 
 products, space required for.... 545 
 various products in same room. 550 
 
 vegetables in cellars 556 
 
 Stowing goods in cold storage 547 
 
 Straw as insulation 55 
 
 Strawberries, cold storage of 561 
 
 Street pipe line insulation 105 
 
 Stuffed animals, cold storage of 405 
 
576 
 
 TOPICAL INDEX 
 
 Superintendence of construction of 
 
 insulation 115 
 
 Swing guide, marker plow with 472 
 
 T 
 
 Tamarack wood as insulation 70 
 
 Tankage, system of direct 450 
 
 Temperature, in cold room, variation 
 
 in 127 
 
 in refrigerators 537 
 
 of melting ice 438 
 
 of refrigerant 134 
 
 Temperatures, cold storage and freez- 
 ing 564 
 
 cold storage and freezing, table . 565 
 
 in refrigerator cars 424 
 
 for curing cheese 242 
 
 for perishable products 419 
 
 for shipping perishable products, 
 
 table 433 
 
 obtainable with Cooper's system.. 456 
 on keeping quality of pears, in- 
 fluence of 340 
 
 Temperatures for storing, apples.. 27, 299 
 
 beer 29 
 
 butter 26, 224 
 
 cabbage 28 
 
 cheese 27 
 
 dried fruits 28 
 
 eggs 26', 205 
 
 flour 28 
 
 grocers' sundries 28 
 
 lemons 28 
 
 meats 219 
 
 nursery stock 377 
 
 nuts 28 
 
 oranges 28 
 
 potatoes 28 
 
 poultry 28 
 
 Testing apparatus, insulation 72 
 
 Testing eggs 216 
 
 Tests, insulation 37,' y^ 
 
 of cold cured- cheese 260 
 
 of insulating materials 48 
 
 of water proofing materials. ... no 
 evaporation of eggs in cold stor- 
 age 208 
 
 Thermometers 566 
 
 Tongs,_ edging-up 485 
 
 hoisting 48 1 
 
 Tools, ice 486 
 
 Transmission of heat through insula- 
 tion 85 
 
 variation in 46 
 
 Transportation of milk and cream.... 278 
 
 Trays_ for egg storing 213 
 
 Trophies, cold storage of 405 
 
 Truck, cheese 547 
 
 for handling goods 546 
 
 Trunks, cold storage of 40s 
 
 Tubs, paper liners for butter 230 
 
 Tubs, storing butter in 229 
 
 Turnips, cold storage of . . . .' 557 
 
 U 
 
 Units of heat 41 
 
 V 
 
 Vacuum, non-conducting properties of. 45 
 refrigerating machines 20 
 
 Variation in temperature in cold 
 
 room 127 
 
 Vegetables, in cellars, storing. .,. . . .556 
 shipping 429 
 
 Ventilated cars 422 
 
 Ventilation 117, 149 
 
 air cooler for 158 
 
 and moisture 163 
 
 apparatus for purifying air for. 160 
 
 cold weather 162 
 
 Coopers' system of 161 
 
 fans for -. . 155 
 
 for eggs in cold storage 206 
 
 in storage of furs and fabrics.. 403 
 means for handling air for. . . . 153 
 
 methods of. washing air for 159 
 
 - of butter room 233 
 
 of cold rooms 124 
 
 of ice house 526 
 
 practices to avoid in ..152 
 
 pressure and exhaust method of. 153 
 
 quantity air required for 161 
 
 treating air for 156 
 
 W 
 
 Wall piping 127 
 
 Walls, freezing 450 
 
 water proofing of 106 
 
 Warehouse receipt, form for 407 
 
 Water proofing, materials, tests of... no 
 
 of walls and insulation 106 
 
 structural method of 112 
 
 Water vapor in air 1 68 
 
 Weather reports in shipping, use of. 429 
 
 Wetting down ice field 465 
 
 Whitewash, applying 413 
 
 Government formula for 415 
 
 lime for 416 
 
 preparing 4 r 4 
 
 Whitewashing 412, 541 
 
 machines 415 
 
 preparing storage rooms for.... 413 
 
 Wickes' system 444 
 
 Windless ice hoist 479 
 
 Windows for cold, rooms 151 
 
 Winter storing -of nursery stock.... 3 72 
 
 Wood for insulation 69 
 
 Wrapper, on keeping quality of pears, 
 
 influence of . . . 346 
 
 On storage of apples, influence of. 300 
 
PRACTICAL COLD STORAGE 
 
578 
 
 PRACTICAL COLD STORAGE 
 
 Stevenson's %g£ Door 
 
 FOR REFRIGERATING APARTMENTS 
 
 FASTENS AND TIGHTENS ITSELF 
 
 A perfect seal at top, bottom and corners, where others always fail. 
 Has patent adjustable, flexible door irame. 
 Cannot stick, leak or wear out. . , - , , 
 
 Works from either side, gives clear doorway, includes lock. 
 Made for cement or asphalt floors. Has beveled threshold where trucks are used. 
 These doors are shipped with their door frames, hinges and fastener complete, 
 ready to be set in place, screwed fast and used. As shown in the following diagrams, 
 the door makes an overlapping contact, with a soft hemp gasket in the joint, and is 
 held to its seat against the front of the door frame by powerful elastic hardware. 
 The thick portion of the door fits loosely, so tnat considerable change of size, form 
 and position due to wear, swelling, etc., does not make it leak or bind. 
 
 Where all old style doors when they work badly or leak must be eased, thus 
 forever destroying their fit, a slight re-adjustment of our patent door frame restores 
 our door to its original perfection of fit and freedom in a 
 minute at no expense. As these doors do not stand in the 
 doorway when open it can be six inches 
 less in width than for old style doors— an 
 important economy in refrigeration. 
 
 As constructed in this 
 year, 1905, the opening in 
 wall to receive these door 
 frames should be V/% inches 
 wider and 4 inches higher 
 than the size of the door- 
 way in the clear. Follow 
 construction numbered 1 
 and 2. For overhead track 
 doors this rough opening 
 should extend 13^ inches 
 above the lower edge of 
 the track. Door frames 
 are secured with lag screws %x4 inches, inserted through front casing at A. 
 Figure S shows door frame with full standard sill and head used on all 
 sizes of door frames. Suited only to walking through. 
 
 Figure B shows our wooden beveled threshold, which connects lower 
 ends of door frame and forms a part of it, let down into floor. No jolt, no 
 feather edge, no splinters. For warehouses. Accommodates trucks. 
 
 Figure C, cement floor, shows lower ends of door frame extending 3 
 inches below the surface of the floor and connected by angle irons extending 
 across doorway from one side to the other below the surface. 
 
 Doors for abattoirs and beef houses, with port in head of door frame to 
 
 accommodate overhead 
 track. 
 
 Special doors on a mod- 
 ified plan for intermittent 
 or continuous freezers, per- 
 fectly tight and perfectly 
 free, regardless of tem- 
 perature, moisture or 
 accumulation of ice in 
 any degree. 
 Combined self-closing ice door and chute of two styles, ice counters. 
 Fireproof metal covered doors, made the same as above and covered all over 
 door and all over door frame with metal sheets, lock seamed in the most approved 
 manner. 
 
 Form of specification : To guard against infringers and substitutes for our work, 
 
 specifications should read, "Cold storage doors and door frames with self-tightening 
 
 hinges and fastener, complete, to be furnished by Stevenson Company, Chester, Pa." 
 
 Patents are granted or applied for on every valuable feature of this work. 
 
 Infringers will be prosecuted. 
 
 ym. 
 
 STEVENSON COMPANY, Chester, Pa., U.S.A. 
 
PRACTICAL COLD STORAGE 579 
 
 OUR STANDARD TYPE ABSORPTION 
 
 REFRIGERATING MACHINERY 
 
 FOR COLD STORES 
 
 Our facilities for turning out complete 
 
 POWER HOUSE AND REFRIGERATION EQUIPMENT 
 
 for 
 
 COLD STORES 
 
 are unsurpassed by any house in the world. Our Standard 
 
 Absorption System is the most efficient for 
 
 producing low temperatures 
 
 WE MAKE 
 
 BOILERS VALVES AND FITTINGS 
 
 STACKS COILS AND PIPING 
 
 TANKS CONDENSERS 
 
 SHEET IRON WORK EXCHANGERS 
 
 WRITE FOR CATALOGUE 
 
 Henry Vogt Machine Co. 
 
 LOUISVILLE, KY., U. S. A. 
 
580 
 
 PRACTICAL COLD STORAGE 
 
PRACTICAL COLD STORAGE 
 
 581 
 
 Do You Seek Economy? 
 
 RESULTS OBTAINED FROM TRIUMPH COMPRESSORS 
 CONFIRM THE FACT THAT VALVES CONTAINING FEATURES OF 
 REGULATION AND SAFETY ARE PRODUCTIVE OF 
 
 THE MOST EFFICIENT RESULTS 
 
 lOO-TON REFRIGERATING CAPACITY 
 
 DURABLE — SUBSTANTIAL— ECONOMICAL 
 
 The Triumph Ice Machine Co. 
 
 AMMONIA 
 FITTINGS 
 
 OUR TEXT BOOK FREE 
 
 DIRECT 
 EXPANSION 
 
 f GENERAL OFFICES AND WORKS | 
 
 CINCINNATI, OHIO j 
 
 THE TRIUMPH ELECTRIC CO. 
 
 MANUFACTURERS OF 
 
 TRIUMPH GENERATORS AND MOTORS 
 
 "ALWAYS THE STANDARD OF EXCELLENCE" 
 
 t OO K. W. DIRECT-CONNECTED GENERATOR 
 
 Our Electrical Machinery is Particularly Adapted for Cold Storage Duty 
 
 Bulletins CS 221 and 241 will acquaint you with full details of oonstruotion 
 
5S2 
 
 PRACTICAL COLD STORAGE 
 
 Featherstone Foundry and 
 Machine Co. 
 
 348 North Halsted Street, Chicago, III. 
 
 Featherstone Double-Acting Ammonia Compressors 
 Consolidated Single-Acting Ammonia Compressors 
 
 Atmospheric Ammonia Condensers fc Everything Required for 
 Double-Pipe Ammonia Condensers X an Ice Making or 
 Double-Pipe Brine Coolers J Refrigerating Plant 
 
 SEND FOR OUR CATALOGUE 
 
 High-Grade Semi-Steel Flanged Valves and Fittings 
 
 Drop Forged Bessemer-Steel Flanged Unions 
 
 Boyle Inions 
 
 Featherstone Foundry and Machine Co. 
 
 348 North Halsted Street, Chicago, III. 
 
PRACTICAL COLD STORAGE 
 
 583 
 
 De La Vergne 
 Machine Co. 
 
 New York 
 
 Standard Horizontal Machine 
 
 HORIZONTAL and VERTICAL 
 
 REFRIGERATING AND 
 
 ICE MAKING MACHINES 
 
 5 TO BOO TONS 
 
 "Hornsby-Akroyd" Oil Engines 
 
 UP TO 125 H. P. 
 
 KOERTING GAS ENGINES 
 
 65 TO 3,000 H. P. 
 
 MAIN OFFICE AND WORKS, FOOT OF EAST 138TH ST., NEW YORK 
 
 BRANCH OFFICES 
 
 philadelphia, pa., glrard bldg. 
 Boston, Mass., Tremont Blog. 
 Pittsburgh, Pa., Times Bldg. 
 
 Cincinnati, Ohio, Neave Bldg. 
 Chicago, III., Security Bldg. 
 St, Louis, Mo., Wainwright Bldg. 
 
584 PRACTICAL COLD STORAGE 
 
 (Ear lumbal? 
 
 Ixh auat §team 5Krf rigsraiutg Harirto 
 
 Practically Eliminates the Fuel Cost in the Operation 
 of a Refrigerating Plant 
 
 Uses Low Pressure Exhaust Steam from Any Source 
 
 Specially Adapted for the Refrigeration of 
 
 Cold Storage and Freezing Warehouses, Creameries, 
 
 Cheese Factories, etc. 
 
 Noiseless : Simple : Durable : Economical 
 
 HENDRICK BRINE COOLERS 
 
 and AMMONIA CONDENSERS 
 
 Carbondale Machine Company 
 
 CARBONDALE, PA. 
 
 NEW YORK CHICAGO BOSTON BALTIMORE PITTSBURG 
 
 r - 
 
 Remington Machine Co. 
 
 BUILDERS OF 
 
 jRrfrtrjerattng 
 iUarijtorg 
 
 w^w 
 
 Wilmington 
 Delaware 
 
 if 
 
 SMALL 
 MACHINES 
 
 SPECIALTY 
 
PRACTICAL COLD STORAGE 
 
 585 
 
 Rempe Company^ 
 
 c7W anufacturers of 
 
 wrought r^rxfj q 
 
 Iron Pipe K^r kJ JL J— /O 
 
 In any desired 
 continuous 
 length or shape 
 
 For Ice and Refrigerating Machines 
 
 Pipe Welding by Electricity 
 
 > 
 Z 
 
 en B 
 
 o 
 
 z 
 
 Ammonia Receivers, Oil Intercepters 
 Ammonia Fittings of All Kinds 
 Return Bends and Manifolds 
 oAttemperators of all kinds 
 
 GALVANIZED COILS a Specialty 
 
 Corner Sacramento and Carroll Avenues 
 CHICAGO, ILL. 
 
586 
 
 PRACTICAL COLD STORAGE 
 
 Coils of All Kinds 
 
 BENDS and MANIFOLDS of Every Description 
 
 For Ice and Refrigerating Machinery. 
 Large Pipe Bends Especially. 
 
 Anhydrous Ammonia and Carbonic Acid Gas 
 Cylinders. 
 
 SEAMLESS CYLINDERS. 
 The Harrisburg Copper Coil Feed Water Heater. 
 
 No Superior. Also 
 
 The Open Heater and Purifier. 
 
 WROUGHT PIPE. Send Us Your Inquiries. 
 
 Harrisburg Pipe £&> Pipe Bending Co. 
 
 HARRISBURG, PA. 
 
 We use a special extra 
 heavy pipe made to 
 withstand the bending 
 strain. Write for prices 
 
 Philadelphia 
 PipeBendingWorks 
 
 MANUFACTURERS OF 
 
 COILS AND 
 BENDS OF 
 WROUGHT 
 IRON PIPE 
 
 SEND FOR CATALOGUE 
 
 OFFICE AND WORKS 
 
 4151 N. Fifth St., Philadelphia 
 
PRACTICAL COLD STORAGE 587 
 
 The Whitlock 
 Coil Pipe Company 
 
 MANUFACTURERS OF 
 
 WROUGHT IRON 
 
 COILS 
 
 FOR ICE AND REFRIG- 
 ERATING MACHINES 
 
 ALSO 
 
 IRON : BRASS : COPPER 
 
 COILS 
 
 i^OF ALL KINDS ^"» 
 
 FOR HEATING AND 
 COOLING' 
 
 we Whitlock Coil Pipe Company 
 
 HARTFORD, CONN., U. S. A. 
 
PRACTICAL COLD STORAGE 
 
PRACTICAL COLD STORAGE 
 
 589 
 
 The Solvay Process Co.'s 
 
 Chloride of Calcium 
 
 FUSED . . . (75% Test) . in Drums 
 
 GRANULATED (75% Test) . in Barrels 
 
 GRANULATED (98% Test) . in Barrels 
 
 FLUID . . . (40% Test) in Tank Cars 
 
 Practically Chemically Pure .. Composition Guaranteed 
 
 Makes the Strongest Brine for the Least Money 
 
 The Best Drier for Cold Storage Rooms 
 
 Carbondale Chemical Company 
 
 CARBONDALE, PA. 
 
 NEW YORK CHICAGO BOSTON BALTIMORE PITTSBURG 
 
 SLAGEL'S 
 
 Arm? (Eaktum GUjlorite 
 
 The Brine that Saves Your Pipes 
 
 NON-ACID, STRICTLY NEUTRAL, DRY, 
 CLARIFIED, REFINED 
 
 Made to give value received. The quality is right. 
 Write us for price and samples. 
 
 We guarantee it superior to any made in this section. 
 We have no sole selling agents. 
 
 ACME CALCIUM WORKS 
 
 Box 98 POMEROY, OHIO Phone 117 
 
590 PRACTICAL COLD STORAGE 
 
 I 
 
 Madison Cooper Co. 
 
 Watertown, N. Y. 
 
 Sfofriggrattttg iEttgtogrg 
 and Arrfrtterta 
 
 Plans, Specifications and Estimates Furnished for 
 
 From the simplest farm cold storeto the largest modern ware- 
 house equipped with the most approved machinery and devices 
 for obtaining the best results economically. Complete plants 
 installed and turned over to the owners in full operation. 
 
 The Cooper Systems 
 
 GRAVITY BRINE CIRCULATION 
 
 POSITIVE FAN VENTILATION 
 
 FORCED AIR CIRCULATION 
 
 PREVENTION OF FORMATION OF FROST 
 ON REFRIGERATING PIPES 
 
PRACTICAL COLD STORAGE 
 
 591 
 
 The Standard Paint Company 
 
 100 WILLIAM STREET, NEW YORK 
 CHICAGO OFFICES, 188-190 MADISON STREET 
 
592 PRACTICAL COLD STORAGE 
 
 Cabot's Insulating "Quilt" 
 
 The Scientific, Sanitary and Perfect 
 Insulator that 
 
 "Carries Its Own Dead- Air Spaces" 
 
 Send for Sample and Catalogue 
 SAMUEL CABOT, Sole Manufacturer, Boston, MaSS., U.S.A. 
 
 SPECIAL 
 
 fans for Air Circulating Systems 
 
 IN COLD STORAGE 
 
 Of galvanized steel, housed in wood housings. Fitted with 
 self-aligning and ring-oiling bearings. These fans are light 
 running. Gives greatest efficiency with the least power. 
 Designed for continuous operation. Made in seven sizes, 
 from twelve to sixty inches. Special sizes to order. 
 
 Madison Cooper Company 
 
 WATERTOWN, N. Y. 
 
 Muz look 
 
 II.... X 70 ^.f^i^*.*— *•**+■ PONTAINING a complete list of Ice 
 
 Stt attO fliPinQftttttOtt ^ Machine Builders, Ice Factories, 
 
 Cold Stores, Packing Houses, Breweries, 
 Dairies, Creameries, Meat Markets, Ho- 
 tels, Restaurants, Confectioners, and all 
 establishments using Mechanical Refrig- 
 eration in the United States and Canada, 
 PRICE 
 
 tA Directory of the Bound in Cloth. - $5.00 
 
 t air i • r* u p. Bound in Flexible Morocco, 5.50 
 
 ICC Making, (-.Old OtOrage, Sent to any address on receipt of price 
 
 Refrigeration and Nickerson & Collins Co., Publishers 
 
 Auxiliary Trades 315 Dearborn Street, Chicago 
 
PRACTICAL COLD STORAGE 593 
 
 insulating f npn 
 
 Standard of the best cold storage architects and engineers 
 because it is thicker, stronger and more durable than any 
 other insulating paper made. It has stood the test of 
 time — the only test. 
 
 Ask for samples and book 
 on "Thermal Insulation" 
 
 F. W. Bird C&, Son, Makers 
 
 ESTABLISHED 1817 
 
 EAST WALPOLE, MASS. 
 
 NEW YORK CHICAGO WASHINGTON 
 
 Canadian Factory and Office, Hamilton, Ont. 
 
594 
 
 PRACTICAL COLD STORAGE 
 
 THE RECOGNIZED AUTHORITY 
 
 IN ALL MATTERS RELATING TO 
 
 A Monthly Review of the Ice, Ice Making, Refrigerating, 
 Cold Storage and Kindred Trades 
 
 The oldest publication of its kind in the world, and the only medium through 
 which can be obtained all the reliable, technical and practical information relating 
 to the science of mechanical ice making and refrigeration. Ice and Refrigera- 
 tion is invaluable to any one owning, operating, or in any way interested in, ice 
 making or refrigerating machinery. 
 
 It has won the confidence of all classes of the trade throughout the world by 
 its absolute independence and impartiality. It aims to be a thoroughly represent- 
 ative paper, catering to no particular class, but striving to become indispensable 
 to all. It is not shackled by any pet theories, and no man or class of men has 
 any private pull with it. Its columns are open to the entire trade; to any one who 
 has anything of interest or value to say. 
 
 SUBSCRIPTION PRICE 
 In U. S., Canada and Mexico, . . . $2.00 per year 
 
 In all other countries, $3.00 per year 
 
 Payable in advance 
 
 Remit by postofBce or express money orders, or by bank draft on 
 
 Chicago or New York 
 
 NICKERSON £& COLLINS CO., Publishers 
 
 315 Dearborn Street, Chicago, U. S. A. 
 
PRACTICAL COLD STORAGE 
 
 595 
 
 SHEET CORK 
 INSULATION 
 
 RACTICAL tests and experience have demon- 
 strated that granulated cork is the most perfect 
 commercial insulation on the market at the 
 present time. Modern methods in building 
 construction demand a more suitable form of 
 insulation. We now manufacture cork boards 
 consisting of granulated cork compressed in sheets of con- 
 venient size and thickness. 
 
 Acme Sheet Cork. This form of insulation is com- 
 posed of small granules of natural cork compressed in molds 
 and baked at a high temperature, without the addition 
 of any foreign cements. 
 
 Impregnated Sheet Cork. This form of insulation is 
 composed of small granules of natural cork, molded and 
 thoroughly impregnated with a waterproof substance, which 
 surrounds each separate particle of cork. This prevents 
 the absorption of moisture, deterioration or disintegration. 
 Cement plaster will adhere firmly to the surface of our 
 materials, which makes the finish of the room desirable 
 and sanitary. 
 
 We are prepared to furnish plans and specifications for 
 the complete installation of our products. 
 
 Samples or models will be furnished upon application. 
 We solicit your inquiry. 
 
 Armstrong Cork Company 
 
 INSULATION DEPARTMENT J* PITTSBURGH, PA. 
 
 V. 
 
596 PRACTICAL COLD STORAGE 
 
 Books on Cold Storage, Ice 
 Making and Refrigeration 
 
 Compend of Mechanical Refrigeration 
 
 By Dr. J. E. Siebrd. Sixth edition. Price, prepaid, cloth, $3.00. Morocco, $3.50. 
 The only work treating- on all the various branches of theoretical and applied 
 refrigeration, and will be found to contain a large amount of information which 
 would be looked for in vain elsewhere. 
 
 Practical Cold Storage 
 
 By Madison Cooper. Price, prepaid, cloth, $3 50. Morocco, $4.50. A complete 
 treatise upon the theory, design and construction of buildings and apparatus for the 
 preservation of perishable products, approved methods of applying 1 refrigeration and 
 the care and handling of eggs, fruit, dairy products, etc. It is a volume 9%x6% 
 inches in size, containing 600 pages printed on heavy half-tone paper, profusely illus- 
 trated with diagrams, sectional views and half-tone cuts. 
 
 Machinery for Refrigeration 
 
 By Norman Selfe. Price, prepaid, cloth, $3.50. To the ice or cold storage man 
 who wants to produce the best results with the least primary investment of capital, 
 the smallest cost of maintenance and the lowest working expense, this work will 
 prove of great value. 
 
 The Modern Packing House 
 
 By F. W. Wilder. Price, prepaid, cloth, $10.00. Morocco, $12.00. The only work 
 of the kind ever published. A complete treatise on the designing, construction, 
 equipment and operation of a modern abattoir and packing house, according to 
 present American practice, including formulas for the manufacture of lard and 
 sausage, the curing of meats, etc., and methods of converting all by-products into 
 commercial articles. 
 
 Indicating the Refrigerating Machine 
 
 By Gardner T. Voorhees. Price, prepaid, cloth, $1.00. Morocco, $1.50. Treats 
 of the application of the indicator to the ammonia compressor and steam engine, 
 with practical instructions relating to the construction and use of the indicator, 
 and reading and computing indicator card. 
 
 Refrigeration Memoranda 
 
 By John Levy. Price, prepaid, flexible leather, vest pocket size, 75 cents. Con- 
 tains a number of useful memoranda and tables in plain everyday engine-room lan- 
 guage. All algebraical formulas have been excluded with the idea of placing the 
 ook in the hands of the man at the throttle in such shape that he may understand 
 it without sitting up all night to figure it out. 
 
 NICKERSON CS, COLLINS CO. 
 
 PUBLISHERS 
 
 315 Dearborn Street 
 
 CHICAGO, U. S. A. 
 
PRACTICAL COLD STORAGE 
 
 597 
 
 INSULATION 
 
 WE MANUFACTURE AND CONTRACT 
 FOR THE ENTIRE INSULATION OF 
 COLD STORAGE PLANTS WITH 
 
 Lith 225 Linofelt 
 
 Wjcf'jTRIFJ 
 Au-TiAqvA Czmeivt 
 
 i" ' LlXTOFELT 
 
 ' " *1"a Jtrijv 
 Z"Zirir 
 WfujiRim Strips 
 
 XLtNOFSLT 
 
 %' I &.G Soahds 
 
 <£_DouBI.E W.P PjlPJSR 
 %'T5.aB0ARDS 
 
 "tixf'TtmRim Jhlipj 
 
 Jee Jforjz jG.' 
 
 OUR INSULATION CAN BE INSTALLED 
 SOLID OR WITH AIR SPACES. WE CAN 
 ALSO GIVE YOU ANY FINISH DESIRED 
 
 Union Fibre Company* 
 
 WINONA, MINN., U. S. A. 
 
 Chicago Sales Office, Room 304, Great Northern Bldg. 
 
598 
 
 PRACTICAL COLD STORAGE 
 
 BF a square foot of 1 inch 
 Hair Felt costs 20 per 
 ■* cent, more than the same 
 amount of any other 
 insulation and gives you 
 100 per cent, better results, which 
 would you choose as the most 
 economical ? 
 
 Poor insulation requires larger refrig- 
 erating apparatus and what is saved 
 in insulation is more than expended 
 in machinery. 
 
 The use of Hair Felt insures perma- 
 nent economy, means thinner walls 
 and partitions, and saves space that 
 can be used for storage purposes. 
 
 Nature's Insulation is carefully select- 
 ed cattle hair, thoroughly washed and 
 air dried, and when once put up the 
 old reliable Hair Felt is there to stay. 
 Vermin, fire and moth proof. 
 
 Write for samples, testimonials and 
 information as to how you can save 
 that 100 per cent. 
 
 Baeder, Adamson & Co. 
 
 Philadelphia, Pennsylvania 
 
PRACTICAL COLD STORAGE 
 
 599 
 
 Table of Insulation Tests 
 
 The figures show the total heat transmission per hour, per square foot, at a difference in 
 temperature of 66° Fahrenheit between inside and outside of tester. The British Thermal 
 Unit 'B. T. U." is the amount of heat required to raise i pound of water i° Fahrenheit. 
 
 %-inch D. k M. Boards 
 
 W. P. Paper . 
 
 Viudi D.&M. Boards 
 
 4-inches Mill Shavings 
 
 X-inch T). & M. Boards. 
 
 W. P. Paper . 
 
 K-incn D. &. M. Boards. 
 
 5.16 B.T.U. 
 
 7.20 " 
 
 J$-inch D. & M. Boards. 
 W. P. Paper . 
 4-inches Mill Shavings 
 W. P. Paper . 
 J6-ioch D. & M. Boards 
 
 " J 8.13 " 
 
 : M. Boards, -, 
 
 ' I 
 
 3ork — 1 Inch L 
 
 . (Sheets) [ 
 
 : M. Boards. ) 
 
 X-inch D. & M. Boards. 
 W. P. Paper 
 3-inch Sheet Cork— 
 W. P. Paper 
 
 V-ioch D. & ] 
 
 8.56 
 
 Jj-iDch D. & M. Boards. 
 
 14 Half-inch Air Spaces 
 Waterproof Papers . 
 
 V 8 -meh D. & M. Boards, 
 
 Jg-inch D. & M. Boards. 
 W, P. Paper . 
 4-inches Mineral Wool 
 W. P. Paper . 
 >8-IdcIi D. & M. Boards. 
 
 %-lnch D. & M. Boards. 
 
 Half-Inch Air Spaces 
 P. Papers . 
 
 %-lnch D. & M. Boards, 
 
 X-inch D. & M. Boards 
 W. P. Paper . 
 1-inch Sheet Cork . 
 W. P. Paper . 
 K-ineh D.& M. Boards 
 %-inch '!').& M. Boards 
 ^C^Z. W. P. Paper . 
 1-inch Air Space 
 W. P. Paper . 
 %-iuuh D. 4 M. Boards 
 
 Jtf-inch P. & M. Boards, 
 
 W. P. Paper . 
 
 Jtf-iuch )». A. M. Boards 
 
 8.69 
 
 9.54 
 
 12.77 
 
 19.78 
 
 25.17 
 
 } 30.42 
 
 The above figures show results of a test of Cold Storage insulating materials recently 
 made. The figures prove that with three Inches of HAIR FELT not only more insula- 
 tion can be obtained, but the best Insulation that ca n be had. 
 
 BAEDER, ADAMSON & CO., Makers 
 
 PHILADELPHIA CHICAGO 
 
 NEW YORK BOSTON 
 
600 
 
 PRACTICAL COLD STORAGE 
 
 Send for a copy of our Booklet, "Nature's Insulation" 
 
 Every cold storage man should have a copy 
 
 BAEDER, ADAMSON & CO., Makers 
 
 Philadelphia Chicago 
 
 New York Boston 
 
WM. H. BOWER, 
 
 ' General Manager. 
 
 PHILA., PA. 
 
 GEORGE R. BOWER, 
 Sec'y and Treas. 
 
 Sty? Ammonia 0k. 
 
 OF PHILADELPHIA 
 
 Manufacturers and Distillers of Ammonia 
 
 26° Aqua Refined and Purified 
 
 FOR ABSORPTION MACHINES 
 
 ANHYDROUS 
 
 STRICTLY PURE 
 
 BOILING POINT— 30° F. 
 
 ESTABLISHED AS THE 
 STANDARD 
 
 ALWAYS DRY 
 
 "EVER THIRSTY FOR 
 HEAT UNITS" 
 
 DISTILLED FROM PURE AMMONIA °f OUR 
 OWN MANUFACTURE 
 
 
 Lrfrf 
 
 
 OTfrmjJ 
 
 
 
 <&l \M 
 
 
 
 j&ES 
 
 
 ^jb\ 
 
 
 A 
 
 
 Specify B. B. 
 Shipments Immediate. 
 
 Pamphlets Free, in English, German or Spanish. 
 
 OUR AMMONIA MAY ALSO BE OBTAINED FROM THE FOLLOWING : 
 NEW YORK CITY— 100 William Street, Roessler CB, Hasslacher Chemical Co. 
 
 BUFFALO-Seneca Street Keystone Warehouse Co. 
 
 BOSTON— 45 Kilby Street .... Charles P. Duffee 
 
 PITTSBURG— Duquesne Freight Station . Pennsylvania Transfer Co., Ltd. 
 WHEELING, W. VA — . . ' '. Wheeling: Warehouse and Storage Co. 
 
 BALTIMORE— 301 North Charles Street Baltimore Chrome Works 
 
 WASHINGTON— 1227 Pennsylvania Avenue • • Littlefield, Alvord CB, Co. 
 NORFOLK— .... • The Nottingham ffl, Wrenn Co. 
 
 ATLANTA-Century Building ... Southern Power-Supply Co. 
 
 SAVANNAH- • • ■ Benton Transfer Co. 
 
 JACKSONVILLE— Atlantic Coast Line Avenue S. E. W. Acosta 
 
 NEW ORLEANS— Magazine and Common Streets . Finlay, Dicks (S. Co.. Ltd. 
 
 CLEVELAND- 
 CINCINNATI— . . • 
 CHICAGO— 16 North Clark Street . 
 MILWAUKEE— 136 West Water Street 
 KANSAS CITY— 717 Delaware Street 
 INDIANAPOLIS- 
 LOUISVILLE— 
 LIVERPOOL— Adelphi Bank Chambers 
 
 The Cleveland Storage Co. 
 
 Pan-Handle Storage Warehouse 
 
 F. C. Schapper 
 
 Central 'Warehouse 
 
 O. A. Brown 
 
 Central Transfer and Storage Co. 
 
 Louisville Public Warehouse Co. 
 
 Peter R.McQuie £8. Son 
 
mmamgg ^ 
 
 The WERLIIN 
 
 Anhydrous Ammonia Purifier 
 
 PATENT APPLIED FOR 
 
 3lr? a«ij 
 ftrfrigrnitfttg 
 
 
 Descriptive Booklet 
 
 LOUIS 
 WERLIIN 
 
 Inventor and 
 Manufacturer 
 
 2815 Grays 
 Ferry Road 
 
 Philadelphia 
 
t 
 
 Choose! 
 
 Expert 
 Advice 
 
 Two Ways to Learn 
 
 Ho^ to Buy Refrigerating Machines 
 
 » 
 
 The prospective purchaser has two ways of 
 determining the most desirable type of ice 
 making or refrigerating rnachine. He can 
 learn at the " dear school of experience " or 
 he can get our advice. During our years of 
 experience we have built practically', every 
 type of machine. We have,, made tests of 
 each, as well as of the machines made by 
 others. Our standard type — single-acting 
 with vertical compressors — is the result. . 
 Don't waste your money. Use our experience. 
 It is yours for the asking. Write for catalog B 
 
 York Manufacturing Co, 
 
 MAIN OFFICE AND WORKS, YORK, PA. 
 GENERAL WESTERN OFFICE, CHICAGO 
 
 Branch Offices: Boston, New York, Philadelphia, Pittsburg, Cincinnati, 
 St. Louis, Houston, Tex., San Francisco, Atlanta ■> 
 
 V. 
 

 m 
 
 ill 
 
 •I ML 
 
 T 
 
 liilltlltH 
 
 HHHT 
 
 ■ '.' WiffimWn 
 
 
 Hull 
 
 111