TD i45M^i°3™""'""""l"-ibrary Engineering wori< in towns and small citi lllllllllllllllllllllllllljlllllllllllllllll 3 1924 004 644 252 The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004644252 ENGINEERING WORK TOWNS AND SMALL CITIES BY ERNEST McCULLOUGH M. WEST..SOC. ENG. ? Formerly Coniulting Engineer, Merchants Association, San Francisco; lately Ejigineer Munidpal Engineering and Contracting Company, Chicago, etc., etc. Author pf "The Vrooman Act/' "Municipal Public Works," "The Business of Contracting," etc., etc. TECHNICAL BOOK AGENCY GO. I 1906 CHICAGO. U. S. A. 1906 COPYRIGHTED, IMS BY ERNEST McCULIiOUGH Rogers Sf Hall Co., Press, Chicago THIS BOOK IS AFFECTIOISTATELY DEDICATED TO MY PARENTS PREFACE «b I Lolcl every man a debtor to bis profession ; from tlie ivLicli, as men of course do seek to re- ceive countenance and profit, so ougbt tbey of duty to endeavor tkemselves by -way of amends to le a lielp and ornament tliereof . ' Francis Bacon. The author hopes that, through Engineering Work in Towns and Small Cities, he may, in some part, pay his debt to the profession of which he is proud to be a member. The first chapter is essentially an extended preface. Chicago, III., July, 1906. TABLE OF CONTENTS. Chapter I — The City Engineer and His Duties 9 Introduction — Surveyors — Engineers — Duties Defined by Ordinance — Consulting Engineers. Chapter II — Roads and Streets 19 General Discussion — Parked Roadways — Grades — Grade Ordinance — Pipe Laying Regulations. Chapter III— Walks, Curbs and Gutters 29 Materials for Walks — Curbs and Corners — Materials and Plans for CrQss Walks — Gutter Specifications. Chapter IV — Street Pavements 38 Local Considerations — Pipe Laying — Street Cars — Roads — Gravel — Macadam — Oil— Tar — ^Armored Macadam — Bitulithic Pavements. , Chapter V — -Street Pavements (continued) S2 Cobbles — Stone Blocks — Wood — Bituminous Rock — Asphalt — Bi-ick — Costs. Chapter VI — Sanitation 68 Dangers of Filth— Bacterial Action — Garbage Disposal — Street Clean- ing — Definitions of Terms. Chapter VII — Drainage , . . . . 71 Gutters — Flumes — Pipes — Inlets and Catch Basins — Materials for Drains and Sewers. Chapter VIII — Sewerage 79 Vested Interests — Plans — Separate, or Sanitary System — Combined System — Grades — Flush Tanks — Manholes — Depths — Cleaning — Sewer Ordinance — Sewage Disposal — Mechanical Separation — Chemical Precipitation — Filtration — Septic Tanks — Sedimentation. Chapter IX— Water Supply 98 Purification — Filters — Sources of Supply — Pumps — Qu'antity of Water — Waste — Meters — General Use — Design^ — Pressure Regulators — Materials for Pipes — Copper Sulphate Process — Thawing Frozen Pipes. Chapter X— Concrete 112 Cement — Standard Cement Specifications — Concrete Aggregates — Cinder Concrete — Mixing^Plastering — Proportions — Formulas for Proportions — Mixing Machines — Concrete Building Block Specifica- tions — Coloring — Retempered Mortar. dhi Chapter XI — Building Department 139 National Building Code — Suggestions for Sanitary Code — Plumb- ing Ordinance. Chapter XII — Miscellaneous Data 150 Lighting — Cost of Street Lights — Fire and Police Alarms — Storage of Gasoline — Some Details of City Bridges — Surveys and Resurveys — Additions to Cities — Value of Old Plants — Municipal Ownership of Water Works — Franchises— Sinking Funds. 7 TABLE OF CONTENTS— Conttotted. Chapter XIII — Contracts and Specifications • 170 Contracts vs. Day Labor — I^ursing ot Local Labor — Essentials of Contracts — Rules of American Public Worlts Association — Concrete Pavements — Brick Paving Specifications of National Brick Makers' Association — Wood Paving, Brooklyn — Chicago Paving Specifica- tions — Stone CuVb . and Gutter — Macadam— Asphalt — Wood — Brick- Granite Blocks — Miscellaneous Provisions^Chicago Sewer Specifi- cations — ^A Good Pipe Sewer Specification — Wrought Iron — Steel — Cast Steel — Cast Iron — Timber— Hydrants, Water Pipe, Etc. — Pipe Laying — Lumber in Trenches — Gravel and iSlacadam Roads — Na- tional Standards — Sewer Adjustment — ^Bitulithic Pavement — Con- crete — Cement Sidewalks. Chapter XIV— Office Systems 238 Filing System in Providence, R. I. — Hartford, Conn. — Columbus, Ohio— Springfield, Ohio— Office of W. D. Sell, Charleston, W. Va.— Ernest McCullough, Chicago — W. Newbrough, Evanston, Wyo. — Tuttle & Pike, Kansas City, Mo. — Certificates and Plats for Architects. Chapter XV— City Engineers' Records , 268 Map Mounting — Duplicating Processes — ^Hektograph Recipe — Scheme for Colors — Hints on Making . Drawings — Lettering and Numbering of Plats and Records — ^Job Book — Specification Plats — ^Positive Cop- ies — Sutveys and Resurveys — Index Map — Recorded Plats — Build- ing Permits — Licensed City Surveyors — Property Records — Depart- ment Records — Street Openings — Contour Map — Plotting Contours — Stadia Slide Rules — Diagrams — Sub-surface Maps — Postal Card Rec- ords — Monuments and Benches — Levels and Profiles — Grade Studies — Forms of Procedure — Finals — House Numbering — Records for Very Small Places — Contract Drawings. Chapter XVI— Field Worb 301 Standard Tapes — Measurements — Monuments — Sutveys Along Side- walks — Marking Points — The Resurvey of City Lots — Four Cases and Methods — Bench Marks — Setting, Stakes for Work— iVarious Methods for Setting Sewer Grades — Marking Sewer Connections — Setting Out Buildings — Sidewalk Grade Surveys — Stadia Surveys — Surveying Curved Roads and the Calculations for Same— Locating Buildings — General Observations. Chapter XVII — Engineering Data , 328 Rules and Formulas for Street Work — Sewers and Drains — ^Water Works — Beam Calculations — Strength of Materials — Strains in Framed Structu'res — Retaining Walls — Archest-Culverts — Formulas for Reinforced Concrete Beams, Floors, Walls, Arches, Columns and Foundations — Logarithms — Mensuration — Tables. Appendices: A. Machines for Mixing Concrete I B. Trenching Machines VI C. Bibliography X D. Trade Literature and Specification Index XXXV Alphabetical Index XLVII CHAPTER I. THE CITY ENGINEER AND HIS DUTIES. "It is in men as in soils, where sometimes there is a vein of gold whidl the owner knows not of." — Swift. This book is written for two classes of officials in towns and cities having a population of less than twenty thousand inhabitants and it may be found useful in some larger places. Elected officials and those who have had no technical educa- tion belong to the first class. They come into intimate relations wfth men who have charge of engineering work, are interested in it, oftentimes direct it and therefore may be benefited by reading this book. The second class is composed of engineers and surveyors hold- ing the position *of town or city engineer. Especially those with little or no previous experience in municipal engineering. To meet the requirements of the two classes the book has been divided. Both will appreciate the chapters preceding those on office work. The chapter on bibliography and that on the fil- ing of fragmentary literature will likewise interest both. So, it is believed, will the appendices. The chapters on field and office work and engineering data are intended solely for engineers. The hori-technical reader will Hardly apprecia'te them. It is hoped the plan will be successful. In larger cities engi- neers have other sources of information and this book will hardly interest them. The writer hopes that for places having less than ten thousand inhabitants this book will be a satisfactory manual of municipal engineering. " . The sources of information available to men in larger Cities and which it is hoped every engineer will at some tiirie br Other consult, are given iii the chapter on bibliography. The books and periodicals there mentioned have all been freely drawn upon by the author who takes this means of acknowledging the assistance 10 ENGINEERING WORK IN he has received. To make a separate acknowledgment in each case would require too many small type notes. The publishers do not like the expense, the printers hate them and readers cordially detest them. Besides, so much of the information is common knowledge it would be difficult and will nigh impossible to know whom to credit. In a few cases acknowledgment has been made. Not all the matter, however, is reprint. Much of it is ■ the accumulation of many years' experience in this kind of work. It is believed some is here printed for the first time, as it has been picked up in the field, over the drawing board, at engineers' con- ventions, and in conversation with experienced and practical men. Perhaps it has all been printed before. If so it is in widely scat- tered publications and therefore not accessible to the majority of engineers. The author is not claiming originality for afl that appears in these pages. He simply has tried to put in convenient form some odds and ends of professional knowledge which may be - appreciated by the men whom it will benefit. It may be inferred from the residence of the writer that the work is simply compiled and that his knowledge of conditions in small towns is second hand. For over five years he served as town engineer, street superintendent and member of the Board of Health in a far western city of less than two thousand inhab- itants. For two years he served as city engineer, street commis- sioner and building inspector in another western city of nearly three thousand inhabitants. In the West (the real West of today) a place of two thousand can be compared with places of six thou- sand in the eastern States, and a place of three thousand with one of eight to twelve thousand in the East, so far as the class, char- acter and amount of work is concerned. In his consulting and contracting experience the writer has had much to do with towns and cities ranging from five hundred inhabitants to many thou- sands. This book, therefore, does not contain simply impressions of an engineer from a large city. When he tells how to drain a street he does it because he has been out in rubber coat and boots in storms showing "dagos" how to take care of the water. When he tells how to stake out work it is a description of methods he has used and found good. , Such an introduction the author feels is due his readers. To- day there are many books compiled in libraries by men of little " TOWNS AND SMALL CITIES. 11 experience. Readers are clamoring for something "practical," and as this book is intended for men who pride themselves on being practical they should know they are getting first hand informa- tion—supplemented, of course, with selected matter from good authorities. The book hinges about engineering work and therefore about the engineer. For the average engineer employed by the average town and small city the author would like to make a plea. Three classes of men are engaged for such work and receive appointments by the council. The first consists of men who are not engineers. They are surveyors and sometimes of the kind called "land butchers.'' Their work is of a kind not calling for the refinement and niceties of city work and they are apt to be careless and good humored over mistakes. City surveying re- ' quires measuring with steel tapes and turning angles on tack points. A "row of apple trees" is too vague a limit of accuracy for city work. As the pay of surveyors seldom approximates that of engineers, surveyors will take the position of town or city sur- veyor, or engineer, at a much lower salary than an engineer will accept. If the surveyor is a bright man who will work hard and study hard he may develop into a good enough man for the place. Such men, however, do not always develop that" way. The second class consists of men who principally follow sur- veying for a living but are anxious to become engineers. They have no technical school education but are largely self educated and have received some earlier training on railroads, or with large corporations. If appointed town or city engineer before their ambition weakens they develop into first-class men. It is becoming increasingly difficult for an engineer without a technical school education to succeed. In a specialty, however, a self-taught man has an excellent chance. Some of the finest engineers the writer has met in small places are of this class. Their work is their hobby and they read and study all the time and put into practice as much as they can. A town possessing a man like this should keep him. The third class consists of men educated at good technical schools. They may have considerable experience before accepting the ■ position, or they may not. Their training, however, teaches them how and where to acquire needed information and if con- 12 . ENGINEERING WORK IN tent to remain in the small place and grow up with it the town will be the gainer by keeping such a man as long as he is content. ^s he is well educated and up to date he must be paid properly and treated with consideration to keep him contented while his classmates are winning success in larger fields. While the engineers honored with appointments as engineers in the small places have been above graded by their educational opportunities and natural inclinations toward study they can, in each grade, be classified like all men into ranks ranging from very wise men down to something a degree worse than a plain fool. But if occasionally a town picks up one of the latter the whole profession should not be judged by him. It is assumed the councilmen will realize the importance of -having a good man in the position and make careful selection. Unfortunately this is not always the case. It is usually customary to fix the pay a little lower even than a second rate "land butcher" would take and then hunt for an engineer to accept it. That men can be found to accept such pay and the treatment so often associated with poor pay, should not militate against engineers in general, but it does. One important fact seems to be forgotten. The engineer is in this line of work to stay. It is his means of livelihood. If given the . least encouragement he will apply himself to study and research and as the years go by his value can not be estimated. His death or removal will be little short of a public calamity. The councilman on the other hand is elected for a short term. He may, or may not, be re-elected. After he returns to private life he loses interest in the engineering work and after awhile forgets all he ever learned in his brief tempestuous term as a city father. Under such circumstances his interest in the best good for the people who elected him should lead him to be careful in selecting the engineer. When he does ^elect a good one he should treat him at least as considerately as he does the town attorney, whose word is law — and occasionally poor law. The attitude of the average councilman toward the average engineer was shown when a national organization of public works officials was started a few years ago. One elected official fought against admitting engineers to membership. "They are our serv- ants," he said, "and we do not want them arguing with us in TOWNS AND SMALL CITIES. 18 open meetings." His position was supported by many, but the engineers won out and were admitted. Today the membership is almost entirely of engineers. The elected officials are such a short time in the work that they do not feel like joining the society. An English councilman said : "Our surveyor is a man. with very big ideas ; he is always bringing forward some large scheme just as though he must do it to justify his occupation here." {Goodrichi "Disposal of Town's Refuse.") The remark has a pathetic ring to it. The town had an ent ergetic and' ambitious man who rushed with enthusiasm into his work and was checked by the complacent, and tolerant air of his superior officers. There is another side to this. An engineer is seldom tactful. So much of his work can be approached in a direct manner he is apt to be impatient when questions of policy come up. There are two ways of getting results in mathematical operations. The only proper way is to figure correctly and the result proves itself. Some- times an engineer has been known to make a result come to where it should by a process known as "fudging." That is, he starts from the answer and with the assumed, or actual, conditions works to it by short cuts and empirical rules to save time and trouble. While the same result, or at least a satisfactory result, may be obtained, it is not workmanlike. It is therefore in the code to do everything right and in the most direct and accurate manner possible:. The city father, on the other hand, has to answer to his con- stituents and must evade objections of men in the council whose constituents represent interests opposed to his own. Policy must govern nearly all he does. He has to plan ahead and can often see a point the engineer fails to see. Policy forbids him taking the engineer into his confidence. To a man who has some interest to forward and who is unable to pursue direct methods it is the extreme of exasperation to run up against a "rule of three idiot," as the writer heard a young engineer designated in one place where he was called into consultation. Therefore it is that many councilmen in the smaller places wish as an engineer a man who will really be the surveyor to the council. His duty ds to set stakes where ordered, in the manner ordered and not until ordered. If they can get such a man they 14 ENGINEERING WORK IN take delight in ordering him around and they disparage all engi- neers because of the example in their own place. When a real engineer is placed in such a position there is a great deal of unnecessary friction. In addition to this the aver- age property owner sddom likes an engineer. He is considered to be an unnecessary expense and it has been seriously proposed in. many places to drop engineers altogether and let contracts to men who will set their own stakes and work on honor. The places that have tried it never seemed satisfied. Why employ an engineer? Engineering News once said, "The fact that a competent engineer can make a little money go much farther than it would go without his advice and aid is one which the general public is slow to comprehend. The average man con- gratulates himself upon the dollars he saves by dispensing with an engineer's services and knows nothing of the dollars lost in exorbitant prices or in work poorly executed." Boswell says, "The true, strong and sound mind is the mind that can embrace equally great things and small." The giving in once in a while to the opinion of a competent engineer is one of the small things that will really be a great thing for the city in after years. To have things started well is half the work. A cheap, incompetent man means untold expense in the future. A good man may mean that the city will- always have pride in its appearance and in the character, with resulting- economy, of its public work. "Before a man can speak on any subject it is necessary to be acquainted with it," says Locke. A councilman can hardly get a thorough knowledge of municipal engineering between the date of his nomination and election so it is hardly seemly for him to give too full instructions to the engineer. If the engineer is not competent then the councilmen appointing him fail in their duty to the people whose affairs they administer. Use care in selecting the engineer. Pay him as much as the town can afiford and dp not pay less than the rates current for such work in the vicinity. Deal with him as if he knew his busi- ness. If he shows himself incompetent fire him. If intelligent but merely lacking in tact let some one finish his education in policy. The policy of the councilman looks oftentimes to the engineer like "fudging." If he can be shown that it is simply TOWNS AND SMALL CITIES. IS another process for attaining a right end and is not wrong he will be all right An engineer' is a creature of mathematics and com- mon sense. If he is strong on mathematics and shy on common sense he is a poor engineer. But he must have enough mathe- matics to: get correct results. Much' of the trouble — and the writer has found no place free from it — comes from an indefinite understanding of the duties of the engineer. The following ordinance is recommended as being now in satisfactory use : ORDINANCE NO...... An Ordinance Creating the Position of City Engineer and Defining his Duties and Fixing the Compensation of Himself and Assistants. The Common Council of does ordain as follows : Section 1. — That the position of City Engi- neer is hereby created in the , who ' shall be appointed on of each year Snd hold office for one year from the date of his ap- pointment, or until his successor is appointed and qualifies, unless he is sooner removed for cause or by reason of abolishment of the office by ordi- nance. ■ Section 2. — He shall be a Civil Engineer of not less than five years' practical experience _ as such, and if a graduate of the State University, or of some technical school of equal grade, in the civil engineering course^ his course of study shall count as two years' practical experience. A Land Surveyor of not less than five years'' practical experience as such, but with less than two years' experience in engineering surveys and construction work, shall be eligible for appoint- ment provided he graduates in municipal engi- neering from a correspondence school. Section 3. — The City Engineer shall make all the surveys, maps, profiles, estimates of cost for improvements, and plans for public improvements ordered by the City Council, set all grade and line stakes for such work, supervise the repairs on sti-eets, the repairs and cleaning of sewers, pre- pare all specifications for public work when so ordered, see that the building and plumbing ordi- • nances and regulations are enforced and generally ■ do all work that may be required b;y the Council of a" civil engineer in connection with public im-' provements. 16 ENGINEERING WORK IN Section 4. — He shall preserve monuments and bench marks and establish new ones when nec- essary, upon orders from the Council, properly describing and recording the descriptions in rec- ord books and on plats. Section 5. — He shall make suitable records in books and on plats, said records to be so com- plete that any competent engineer can from them and by their means retrace- and check all work done by him. Said records to be and remain the property of the city and be turned over to his successor in office and a certified list of same be given to the City Clerk at the same time. Before any bills for work done by the City En- gineer will be allowed the City Clerk must certify that the proper entries have been made in the record book for said work. Section 6. — ^He shall prepare all ordinances that require phraseology of a technical nature for the doing of work under his direction or to describe work done and give same to the City Attorney to put into legal form. Section 7. — The compensation of the City Engineer shall be He shall furnish hds own office and all instru- ments, tapes and tools required and pay for re- pairs on same. The city shall pay for all papers, books and stationery actually used by him upon the city work. Section 8. — He shall be free to select his own assistants and shall be held responsible for their work. No assistants can be appointed with- out an order from the Council and the compen- sation shall be fixed in said order. Section 9.^-Nothing in this ordinance shall operate to interfere with, or abridge, the right of the city to employ designing and consulting engineers and architects for special work or to advise with the City Engineer and supervise work he is in charge of, whenever the Council deems it for the best interests of the city to employ said specialists in certain classes or. kinds of work. Section 10.' — This ordinance shall take effect and be in force on and after It may be taken for granted that a consulting engineer will be needed occasionally. Sometimes the city engineer asks for one. This seldom happens, however, for a confession of incom- TOWNS AND SMALL CITIES. 17 petency is often thought to be implied when an engineer makes such a request. Why this is so is one of the things no man can explain. It is common for physicians and surgeons to call in spe- cialists for consultation. No important case goes into court with- out an imposing array of counsel. The engineer, alone, is discred- ited if he asks for the advice of a more experienced man at the expense of his employers. No objection is made if he pays the bill out of his own pocket. When selecting an engineer for special work the city engineer is generally able to recommend a man. It is assumed here that if the city engineer is worth his salt he will be a member of some of the local, or state, or national engineering societies and be a subscriber to one or more of the good technical papers or maga- zines. He will then be in a position to know the names and stand- ing of the leading specialists. Avoid selecting men employed by large corporations having interests in the vicinity, even if they do the work cheaply, or donate their services. It is not always wise to employ a man representing patented or special articles. An unbiased man may recommend those v^ry things, but it is better so than to have a man do it who is finan- cially interested. Some men may object that the foregoing ordinance gives too much to one man. Every man of common sense knows that few towns pay a street commissioner enough to live on; hence he must neglect the public work while he makes enough on the side to support his family. In many small places he owns teams and numerous relations are carried on the pay roll as drivers of the teams. The small pay never attracts good men and none of them know anything more about the street work than they pick up by themselves. Reading a book or paper to learn what others have done never enters their mind. The fees of the building and plumbing inspector seldom amount to as' much as a good man can earn by working for wages so good men seldom fill the position and the inspection is a farce. Sewers are never cleaned. When plugged the obstruction is moved. That is all. The cost in the aggregate is high. There is seldom enough surveying to pay a good man to give the records much attention. In fact it is often a loss for a man 18 ENGINEERING WORK IN- to hold the position, but he .takes it to prevent too severe compe- tition. The positions can all be combined and held by one good man, whose .heart will be in his work ; for the city can pay one good salary that will be less than the aggregate of several small ones paid to men who do not earn them. The engineer will then have some incentive to make a record asd win the respect of the people. CHAPTER II. ROADS AND STREETS. "Best kills better.'' — German Proverb. "How often we see all lost because, forsooth, improvement waiteth on perfection. I say, Alas." There are no set rules to follow in establishing grades and improving streets. The streets are to look well, are to serve as avenues of travel and are spaces in which the public may lay drains and conduits. They are to be improved at the lowest possible cost to attain these ends. All other considerations are matters of detail. In the work of improving streets experience counts for much and a knowledge of what others have done is helpful. When grade is mentioned it is generally the longitudinal slope that is meant. By slope is generally meant the fall of the sidewalk or roadway toward the gutters. When cross section is mentioned it means the shape of the street from property line to property line. Business streets should have, if possible, a level- cross section, or one nearly level. That is, the curbs on each side should have the same elevation on a line across the street making a right angle with the street line. It is generally easy to accomplish this as the business portion of a town is, as a rule, laid out in the first place in the most level part of a tract of land. To effect proper drainage the sidewalks slope toward the gutters and the roadway is high in the center to shed water to the gutters. The shaping and crowning of the roadway depends upon the width of the street and the material used for paving, as some smooth, impervious pavements require very little crowning. When one side of a street is slightly higher than another considerable study must be given it to secure the proper crown. For a sidling street some men have the crown nearest the high side. Sometimes they make a straight slope across the street. This, however, is objectionable, as all the water has to pass over the street and may injure the pavement. The writer prefers to have the 19 20 ENGINEERING WORK IN crown somewhat to one side, for the slope is then exactly the same to each gutter, simply being longer on the lower side. An old rule, and one in general use, for light grades is to make the crown on macadamized roads one-fortieth of the distance between curbs. For asphalt one-fiftieth, and for brick, stone and wood one-sixtieth. The reason asjphalt has the grealer crown is that water injures it and should therefore be taken off quickly. Some towns are laid out on a hillside with contour roads and streets. Methods for improving them vary considerably, being influ- enced by the difference in elevation of the sides of the thoroughfares. When the difference is slight the curbs may be set at different elevations. When somewhat greater the sidewalks can be made narrow with a terrace to the curb. A still greater difference will permit of a terrace between the sidewalk and curb and one between the sidewalk and the property line. A greater difference may call for a sidewalk level with the curb and a straight slope from it to the property line. A still greater difference will call for only one narrow sidewalk on the lower side of the roadway. In improving contour streets on hillsides an attempt should be made to get the improvement at the lowest possible cost consistent with appearance. The roads should wind and the slopes should be sodded as though in a park. Considerable swing should be made to go around trees rather than cut them down. Business streets are improved from property line to property line. A common rule is to put two-fifths of the width in sidewalks and have three-fifths between curbs. Like all rules it is not to be blindly followed. A wide sidewalk is a good thing and a very wide roadway costs more for repairs than it is apt to be worth. A wagon seldom occupies more than nine feet in width. Eight feet is the ordinary over all width. Eighteen feet between curbs will permit two wagons to pass with ease. Twenty-seven feet allows one wagon to stand at one side and permits two to pass it. Thirty- six feet will allow a wagon at each curb while two pass between them. It is seldom therefore that a business street needs to be more than thirty-six feet wide between curbs. As repairs are computed by the square foot it is well to consider that street repairs are expensive and sidewalk repairs are low. For a single street car track allow ten feet and for a double track allow eighteen feet additional to above widths. TOWNS AND SMALL CITIES. 21 It is a common matter today for small cities and towns to have in residence districts a roadway not exceeding twenty-five feet wide in the middle of the street. Each side has a curb and the ground slopes up from the curb to the property line. The sidewalk on each side is six feet wide and set one foot from the fence. For a sixty- foot street this gives thirteen feet on each side between the curb and sidewalk on which to plant trees and grass. Such a street is said to be parked. Great Falls, Mont., is a good example of a city so improved. Mr. C. W. Swearingen, for ten or twelve years city engineer there (now in Havre), had hard work to introduce such parking. Now the people are proud of their parked streets. In the writer's opinion it is the best method for residence streets. It is low in first cost and in cost of maintenance. It is beautiful in appearance. It also affords space in which to put sewers, water pipes, and underground conduits on each side without tearing up the street surface. Sometimes a town has streets with very steep grades. The writer in 1893 prepared plans for the improvement of a street having a 31 per cent grade (a rise of twenty-one feet in one hundred), by winding a sixteen-foot roadway from side to side. The roadway had a grade of only 11 per cent and there were many slopes to plant with grass and flowers. A narrow sidewalk was placed on either side with steps at the turns in the road. In Burlington, Iowa, there is such a roadway and within the past year Wm. Barclay Parsons of New York proposed the same treatment for some of the steep streets in San Francisco. In some European cities steep streets have been treated in such a manner. In establishing grades two things are to be considered — drainage and traction. Any slope will cause water to move, but for macadam roads a minimum grade of one foot in two hundred is advisable. For pavements the roadway may be level from one end of the bloclc to the other, but it should not be .level if any grade can be obtained. For streets having a very light grade or no grade, a slope for surface water is obtained in the gutter by making what Is known as a summit somewhere in the block. With a level street it will be in the middle. At the summit the bottom of the gutter may be at nearly the same elevation as the curb. At the ends of the block or at the catch basins the curb may stand a foot above the bottom of the gutter. 22 ENGINEERING WORK IN -It having been shown that water can run off a level street, it is necessary to see the limiting effect of traction. Street grades should be limited between the lightest possible for eiBcient drain- age and the steepest a horse can ascend with ease. The steepest grade should not exceed, if possible, a seven-foot rise in one hun- dred feet. Heavier grades,- as .well as extremely light ones, should be adopted only after most careful study. Calling the load a horse will pull on a level surface 100, then on a grade of — 1 in 100 a horse will pull 90 per cent. 8 " " 81 4 " " 52 5 « « 40 10 " " . 25 The above table shpws that the steepest grade on a street regulates the loads that can be hauled over that street. In many cities located on rivers the grades on the bridge approaches de- termine the wagon loads throughout the whole business district. In the establishment of grades no block can be dealt with alone. It is necessary to study a district in order that the effects of the grade on one block may not be harmful. In the chapter on surveys a method is discussed for engineers, but a reference here may do no harm. Briefly, it is best to study the ground care- fully and determine the streets designed to carry the main drain- age. These streets having been determined, take up the entering streets gne after another and see what grades can be fixed on them so the drainage plan will work freely. The street it is intended to improve may be among the last streets studied. The writer has known of cities going to an expense of many hundreds of thousands of dollars because such a study was not made in the beginning. Whenever a petition came in the engineer was instructed to set grade stakes for one block at a time and take into consideration only the conditions in that block. Sometimes a town is so located that grades can be established one block at a time. This is rare, however, and a careful study is best. Such work is, of course, somewhat expensive, but once done it is done for all time and the records, if kept, will De serviceable. Avoid a "penny wise and pound foolish" policy in such matters. Future growth must be considered. TOWNS AND SMALL CITIES. 23 In establishing grades, the question of the expense of improv- ing the street to the grade must be taken into account. This has to be figured as all other business matters are figured. When several possible grades are under consideration the best grade may be the most expensive in first cost if the street is an im- portant business street. If it is a side street, or cross street, or unimportant residence street, the property owners should have a voice in the matter and be permitted to exercise considerable in- fluence. Here the first cost will generally be the controlling factor. If any street, however, is apt to be an important line of com- munication or drainage, the question of first cost may be dismissed. The best grade is the one to obtain. It is to be borne in mind that in mentioning grades the writer means the official elevations at controlling points on the streets and the slopes connecting the official elevations. He does not mean the actual earth moving and such improvements. There is nothing in all the work of a municipal officer which requires more pure grit and courage than the work of establishing a grade preliminary to the improvement of a street. No matter how it is finally settled, he meets with the approval of a very few and makes enemies of many. Some of the enemies are vindictive and never let up. Until a regular grade is established each man has regarded the street in front of his own lot as so much of his own property and it is hard to persuade him that any one else has jurisdiction over it. He has sidewalked, drained and paved ( ?) it to suit hiinself, and, whether above or below the general level, is confident that his floor line is exactly where the grade should be. Whatever the procedure adopted for gradually bettering the condition of the streets, the first step is to provide for proptr drain- age. A dirt road can give fairly good satisfaction if it is roimded up in the center and kept well rolled and has gutters on each side to conduct surface water to a place wfiere it can be disposed of. Therefore, temporary grades can be established and gutters made. Sidewalks can be built on these grades. The appearance of the streets have as much to do with the growth or failure of a city as any other thing. Strangers get their first impression of a pface from the streets and nothing can be said in praise of the wealth or enterprise of the inhabitants, or of the 24 ENGINEERING WORK IN logical advantages of the business location of a city that will counteract the effect of a poor street as a first impression. First impressions are said to be most lasting, therefore the streets should be attended to first. The questions of sewerage and water supply can be left until the city has at least one good look- ing street. Better sewerage facilities and improved water systems will be demanded as a city grows. If it does not look prosperous and so impress visitors it will not grow. Before taking up a discussion of materials for paving, the writer wishes to offer an ordinance for the establishment of official elevations. Do not establish elevations on the center lines. Each paving material requires a different crown and the elevation along the middle of the street fixes the elevations of the curbs. When ma- terials are changed it means an increased or a lessened depth in the' gutters, or else the curbs must be reset. The property owners set their floor lines with reference to the curbs. If every change in paving materials or every change in the width of the roadway alters the curb elevation, the property owner will never be secure in his mind. Sometimes it is best to fix the official elevations at the property line and obtain the curb elevation from that. Sometimes it is best to establish the elevation on the curb. The writer prefers the first method. It gives the property owner a well established eleva- tion to which to build. Future -changes in the width of the side- walk or of the roadway or a change in the paving material have then no terrors. When that is done it is an easy matter to fix the elevations by ordinance so they can be always set. The ingenuity of the engineer will'be called into play to describe the elevations and the points where they are fixed. In order that elevations can be always referred to one plane of reference, an official base must be established. Then all points can be stated as being so many feet above or below the official base. It is usual to take the lowest point at which drainage is dis- charged and count it as having an elevation of zero or one hun- dred. If an elevation of zero is given, then there may be times when some work is done below that elevation, and this will necessitate minus elevations. The engineer can explain this to the non-technical TOWNS AND SMALL CITIES. 25 reader. It makes mistakes possible. It is better to assume that point as having an elevation of one hundred feet above city base, the base then being an imaginary plane. If- on the sea coast, the mean of lower low tides is a good point to assume as being one hundred feet above city base. ORDINANCE NO An Ordinance establishing a City Base, or Plane of reference for Elevations and fixing the elevation of a Primal Bench Mark. The Common Council of does ordain as follows : Section 1. — That the Official City Base, or Plane of Reference for elevations in the City of is hereby fixed at a point one hundred (100) feet below the low water mark at street and street as ascertained on in the year Section 2. — The cross cut in the top of the copper bolt set in the top- of the concrete monu- ment at the Northeast corner of the entrance to the City Hall on the ground floor is hereby de- clared to be the Primal Bench Mark of the City of and the elevation thereof is one hun- dred and ten feet and thirteen one-hundredths of a foot (110.13) above City Base. Section 3. — All official elevations hereafter established in the City of shall be de- scribed with reference to their elevation as com- pared with the official base in feet and decimal parts of a foot. No grade or official elevation shall be established other than by ordinance and in the manner described in this ordinance. Section 4. — This ordinance shall take eflFect and be in force on and after ORDINANCE No An Ordinance establishing official elevations on street between street and street.' The Common Council of does ordain as follows : Section 1.— The official elevations at the in- tersection of street and street are hereby fixed as follows, to-wit: At the Northeast corner feet ( ) above City Base. At the Northwest corner feet 26 ENGINEERING WORK IN (..,.) above City Base. At the Southeast and Southwest corners feet (....) above City Base. Section 2. — On street feet north of the north line of street feet (...._) above city base. Section 3. — At the intersection of street and street the official elevation at each corner shall be feet (....) above City Base. Section 4. — The elevations mentioned in the preceding sections of this ordinance are fixed at the property lines. Section 5. — The elevation of the curbs shall be fixed at the time the street is improved and the slope from the property line to the curb across the sidewalk shall not ^e less than one-eighth of an inch per foot {%") nor more than one-half of an inch (54") per foot. Section 6. — The shape of the cross section and the elevations thereof shall be fixed at the time the street is improved, depending upon the material used for paving. Section 7. — The longitudinal slope or grade of the street shall be on straight lines connecting the points where the elevations are fixed, as pro- vided in this ordinance; excepting that where the grade breaks- in the block between the inter- secting streets the roadway and curbs shall be on vertical curves of such length and kind that the allowable cross slope of the sidewalks will be maintained. Section 8. — The grades of the gutters shall be so fixed that the extreme height between the tops of the curbs and the bottoms of the gutters will not exceed one foot (!')• Section 9. — The official elevations of the cor- ners of intersecting streets, alleys, places, lanes and other public places and highways, intersect- ing said street at points between points on which the official elevations are fixed by ordinance shall be, and are hereby, fixed at an elevation being on a straight line connecting the two established points nearest said intersecting corners. Section 10. — All ordinances or parts of ordi- nances in conflict with this ordinance or any part of it, are hereby repealed as to the conflicting, portions. TOWNS AND SMALL CITIES. 27 i Section 11. — This ordinance shall take effect and be in force on and after In establishing elevations at street crossings and intersections try and make them level. If the intersecting streets have" grades of 3 per cent or more the crossing will have the appearance of pitching in toward the hill if made level. The best way to fix the intersection grade in that case is to make it equal to half the sum of the two grades but not to exceed three per cent. A town is justified in going to considerable expense to secure level cross sections in business districts where the grades are less than five per cent. The fbllowing extract from the 1904 report of the state fire marshal! of Ohio is interesting in so far as it relates to a proper regulation of pipe laying in streets: "Fires reported to the state fire marshal during 1904 as be- ing caused by gas explosion, gas leaks and by explosion, number ninety-four, but many fires reported as from unknown causes are doubtless properly chargeable to gas. "Gas leakage under the impervious pavements of cities is a subtle, uncontrollable, menace to property and to life as well. Many mysterious conflagrations presenting inexplicable phenomena are due to the presence in houses of gas which has entered through the cellar from a leaking main. "Gas companies anticipate a loss from leaks of 12 to 20 per cent of all the gas they force into the mains, it being cheaper to bear that loss than to open the streets and repair the pipes. A leakage of 187,000 cubic feet per mile per annum for four-inch mains is considered nominal. The report of the Massachusetts State Board of Gas and Electric Light Commissions showed that in 1899 the mains in use for gas distribution in that State averaged 4.81 inches in diameter and their leakage for the year was 162,334 cubic feet per mile. The gas companies of Massachusetts are re- quired to report their 'gas unaccounted for' which elsewhere is considered a confidential fact. "The authoritative tables of Field's Analysis of Gas Undertak- ings show that in the cities of England the gas leakage is about 500,000 cubic feet per mile of main per annum. "In small towns this gas escapes harmlessly through the earth, except when the ground is frozen, but under the asphalt and 28 ENGINEERING WORK IN stone pavements of the city it is at all times forced along the outside ef the main until it finds a fill around a service pipe, which, by reason of its being more open, offers a path of least resistance into the cellar of some house. If the ventilation of the cellar is not ample the gas, being lighter than air, accumulates in coal vaults or between the joists, where an accidental spark, the strik- ing of a match or the flame of a candle, will ignite it with or with- out explosion. If the amount of the escaping gas is large it may be found in layers next the ceiling of every story of the house." CHAPTER III. WALKS, CURBS AND GUTTERS. "That we trip fleetingly along." The narrowest sidewalk should be at least five feet wide. If in a business district it should, of course, be wider and extend clear from the curb to the building line. In the residence districts it is better to have a grass plot on either side. Wooden sidewalks are only temporary affairs and should not be allowed to remain after they commence to wear. The boards get loose and the nails work up. They trip the pedestrian in summer and squirt muddy water on him in wet weather. If used they should be made of planks two inches thick, not more than eight inches nor less than six inches wide, and be spiked with a 20-penny nail. The span between bearings should not be more than three feet so the walk will not be springy. The top of the spikes should be set at least one-quarter of an inch below the top of the plank. Narrow walks consisting of wide planks running lengthwise of the road should not be permitted. A number of cities in the United States have judgments to the amount of hundreds of thousands of dollars hanging over them because of damage suits by reason of defective sidewalks made of wood. In consequence no wooden sidewalks can now be put down in those cities. Cinder walks are very well liked, and in many districts too poor to afford permanent walks cinder sidewalks are put down. A plank is laid on edge on each side of ftie sidewalk space and the width between leveled off, after which cinders are put down in thin layers, each layer being wet and tamped. Stone flag sidewalks are out of date. They wear unevenly and get loose after i«uch travel. Brick sidewalks of ordinary building brick soon go to pieces and become rough and dangerous. Brick sidewalks made of vitri- fied paving brick set in cement mortar are more satisfactory, but 29 30 _ ENGINEERING WORK IN a brick pavement is old fashioned and little, if any, cheaper .than a cement sidewalk. The best sidewalk is the concrete and cement walk properly laid. They should be put down under good specifications and com- petent supervision. Property owners putting down such walks by private contract should be compelled tp comply with the city spe- cifications. The glare of the light colored cement sidewalk on & sunshiny day is objectionable but may be overcome. By the use of lamp- black or other pigments the color of the sidewalk can be greatly modified. A good strong ordinance should be passed providing for put- ting down concrete and cement walks. No one should be permitted to engage in the business until he can show he is experienced in the work. He should pay a good license and put up a bond to protect the city in case his sidewalks go to pieces inside of two years. If a sidewalk built by him begins to break up within two years his license should be taken away from him and his bonds- men should be made to rebuild the walk. Every sidewalk con- tractor in this material should have a name plate and stamp his name at distances not exceeding twenty-five feet on each piece of sidewalk he puts down, together with the year and month. His sidewalks will thus advertise his work. A good cement walk should last several generations. It is becoming common nowadays to have the names 'of streets set into sidewalks at corners, or into the curbs' if concrete curbs are used. The contractor easily arranges this by having letters made of metal, which are oiled and laid on the base before the finishing coat is placed. When the finishing is done the letters are taken out, which is an easy thing because of the oil, and the space filled with colored cement mortar. The names should be placed at the ends of the cross walks. Curbing is placed as a division line between the sidewalk and roadway. Charles Mulford Robinson, whom the Good Roads Magazine styles the "American authority on the city beautiful," has the fol-. lowing to say about curbing in a recent report to the city council TOWNS AND SMALL CITIES. 81 of Colorado Springs, Colo. : "It is necessary aesthetically as well as practically, with brick and block pavements; it is by no means appropriate artistically where pavements are of gravel or macadam; is not often essential where such a roadway is narrow; and here may be a positively bad thing practically, since it prevents surface water from reaching the turf and roots of trees that it might otherwise do much to help." In this connection Mr. Mulford was speaking of the parking of streets, mentioned in Chapter II. For such streets the writer agrees with Mr. Mulford. On macadam or gravel streets not parked, wooden curbs are often used. The best are sixteen inches deep and four inches thick. The grade, or official elevation, on the top of the . curb should be two inches below the elevations established by ordinance. This will allow wooden sidewalks to be laid to grade and be spiked to the top of the curb, resting on it. ■Zo- fy-g.I. Concrete Curb The. foe /i on/yusett' yy^eo pavement has no concrete 603a. o/f^i's on steep gm^e. Granite curbs are generally set in pieces from four to eight feet long. They go into the ground from six to twenty-four inches, projecting from six to twelve inches. They are generally six inches thick at the top and eight inches thick at the bottom. The top is dressed and so is the exposed face. If the climate is severe the curbs are sometimes placed on a cinder or brick foundation going below frost line. The tops of the curbs are set at the official elevations established by ordinance and sidewalks are laid flush with the tops. Stone curbs are going out of use nearly everywhere. The short pieces are hard to keep in line and the appearance soon 32 ENGINEERING WORK IN becomes bad. It is difficult to secure good stone and the monolithic concrete curb is more durable and presents a handsomer appear- ance, besides which it is usually lower in first cost. The shaping of corners presents considerable variety. The most handsome corner is one where the two intersecting curbs me.et in a circle having a radius equal to the width of the narrower walk. . This is an additional reason for using concrete curbing, as the forms can be made for any radius. When granite curbs are used the corners are generally of very short radius, for curved stones cost much more than straight pieces, whereas for con- crete there as no additional cost aftei* the forms are made. To save the expense of making too many forms some tovirns have a common radius of ten feet. But many cities use curves with a radius as small as three feet and some of only eighteen inches. The appearance of such corners is not good. They jut out into the roadway too far and for vehicles are not so good as the larger curve. There are three ways of making wooden corners. In one the pieces are cut into lengths of one foot with an inside bevel on each end. Placed on a curve \yith the ends of the pieces spiked together the comer looks- well but is weak until the sidewalk planks are spiked to it. Sometimes several 4-in. x 4-in. posts are driven in the ground on a circle four inches back from the face of the curb. The posts are about three feet apart. Four thick- nesses of one-inch boards are bent around these posts and spiked thoroughly to them as well as to each other. Or two planks are sawed on a curve and short vertical pieces four inches wide and slightly bevelled on the edges are attached vertically to them. When finished it looks like the inside form for a concrete curb. This is set in place and when the earth is filled back of it the appearance is good. The writer has visited cities where rounded wooden corners were made by driving, on a circle, 2-in. x 4-in. pieces into the ground touching each other and then bending a one-inch board around the outside. The top of the curb should not be more than one foot above the bottom of the gutter. If possible it should • not exceed ten inches. It is often necessary to have a shallow gutter at the middle of the block and a deep one at the catch basin in order to TOWNS AND SMALL CITIES. 33 make a good grade in the gutter. The gutter is said to have a summit where the curb is low. CROSS WALKS. It is usual to provide cross walks on streets not improved or on streets improved with gravel or macadam. *■ tV-*'- 11"*- It" -n- If -» Cross wa/Zr of Brick ■or Sfone show/ng P/onkee/ye . Some /irm fiayi&ueeitfor Cbncreie. /? form o-fffuH-er of" crass/nyj common/y' use J nvifh o.s/>ho/i\ I I I- I I I I 4 ■ ""*■ ■ -I 10 > K K 10 5i < n F/g.4- Wooo Cffosswo/Af on moeocfom or eatfh roat/'wHlt weoJcuri ont/ sfone puffer. For earth and gravel streets the cross walk is usually of wood. The form is generally the same in all places. Cross pieces six inches wide and four inches deep are spaced four feet apart across the roadway. For a distance of one foot on each end they are bevelled down to an edge. On this bevel is spiked a three-inch 34 , ^ENGINEERING WORK IN plank and across the level top 'v£ spiked other three-inch planks to make the width preferred in that particular place. Usually such a cross walk is six or eight feet wide on top at intersections with, and across, the main street, and on side streets is from three to four feet wide. The width in the bevel is of course no use for walking on and is only there to assist wagons up the slope. The crossing usually is shaped to the cross section of the roadway, except close to the gutters, and the stringers are set flush. The top planks, therefore, rest on the ro^d and the sloping planks are partly bedded in it. On a gravel or dirt road it is usual to place large broken stones under the planks and between the stringers to provide ven- tilation for the planks, at the same time acting as a support. A|t a distanc^ of three »r four feet from the curb the top planki change direction so ijhey will rest on it and the bevelled planks' are stopped. This gives a continuous walk across the street I' and leaves space for ^he gutter underneath. Ffer macadam streets the' cross walks may be of wood, stone, brick jor concrete. The widths are settled according to the fancy of th^ parties putting them^ in. No walk' should be less than three feet vyide and wider walks should be used on main streets. Wooden cross walks are like those above described. Brick cross walks are made of vitrified paving trick set on edge and grouted between the joints with cement. It is a good plan to set a two-inch plank on edge on each side of a brick walk to take the shocks of wheels. The top of the plank to be level with the top of the brick at the edge. The walk should be slightly crowned (about two' inches in a five-foot walk and proportionately less for narrow walks) to prevent water standing on it and to make it sightly in appearance. Concrete cross walks should be slightly crowried, as for brick cross walks, and they also should have a wooden plank on edge to take shocks. The writer prefers, however, in the case of con- crete cross walks to place an edging of stone blocks between the concrete and the plank. Concrete cross walks are very hand- some and look well if care is taken to prevent a break on the edge. Somehow concrete gbes to pieces rapidly after it starts. Stone cross walks may be constructed of ordinary stone pav- ing blocks, of large flat flags, or of rubble. Stone paving blocks TOWNS AND SMALL CITIES. 85 are the best and should be laid close together and be grouted in the joints with cement grout. Large stone flags are difficult to get, are seldom smooth and generally too expensive considering the lack of appearance. A rubble stone cross walk is made by smoothing off the space and tamping it hard. Set a thick plank on edge on each side and cover the space with a stiff cement mortar mixed one to three, about one inch thick. Bed in this stones from four to eight inches square on top and as nearly cubical in shape as can be procured without taking special pains to cut them. The top should be smooth as possible and the stones are to be pressed into the mortar below so they will form an even surface on top for the walk. After the stones are all set pour between the joints a thin soft mixture of one to three cement mortar until the spaces and joints are filled flush. When the mortar sets the top of the walk looks like mosaic work. Such a walk looks well if slightly crowned. It is very good looking and durable, while not so ex- pensive as either brick, cut stone, or concrete. The cross walk follows the cross section of the street until it gets within five or six feet of the curb. Then it goes on a • straight line for the top of the curb. Within about three feet it stops and ends at a" concrete curb as a sort of small retaining wall. This wall goes gradually down on a slope on each side until at a distance of about two feet each side of the walk it reaches the street surface. It has a recess cut in the top opposite a similar recess on the sidewalk curb. This is to receive the ends of planks serving to bridge the gutter, or iron plates that are sometimes used for the same purpose. Some cities have the cross walk come within one foot of the curb and have no bridge planlc or cover. Streets that are paved with any of the more durable and modern pavements have no cross walks. At the place "where the crossing comes the curb parallel with the sidewalk curb is put in place and the cross section of the street at the crossing point is altered so it makes practically a level crossing from curb to curb. It is seldom that with such crossings any covering is put over the gutter opening. The writer, however, always prefers the gutter coverings and to have the area larger than is customary where they are not used. 36 ENGINEERING WORK IN aUTTZRS, Gutters on earth roads are generally ditches of considerable depth in the outlying districts and are merely rounded edges of the roads with a depression of from six inches to one foot, in the more settled parts of town. For macadam or gravel roadways on parked streets the gut- ters should be nicely rounded depressions not more than foui: inches deep and from two to three feet wide nicely payed with cobbles or flat stones or paving brick. They make a good looking division between the roadway and the grass. On macadam or gravel streets not parked, the gutters where wooden curbs are used generally consist of a wide plank spiked to the curb at a slight angle. This plank is practically on a con- tinuation of the slope of the roadway toward the curb. It is better, however, to make a gutter three feet wide of stones grouted in the joints with cement mortar. The specification is as follows, for this as well as for the gutter in the parked roadway: "The gutter shall consist of stones not less than four inches nor pore than eight inches in any dimension, laid with the flat side uppermost in a bed of cement mortar composed of one (1) part of approved Portland cement and three (3) parts of clean coarse sand. Spalls shall be ^sed to partially fill the interstices and the upper sur- face shall be well formed and laid to the lines set by the engineer. The bottom shall be a circu- lar arc. After the stones are laid in place and the surface pronounced satisfactory by the engi- neer the contractor shall fill all the interstices with a cement grout composed of one (1) part of approved Portland cement and three (3) parts of clean coarse sand mixed with enough water to make it about the consistency of heavy oil. The grout shall be poured into the inter- stices from a spout and shall not be laid over the surface and swept in with brooms. The inter- stices must be well filled with the grout to make the gutter solid and strong, and to prevent the stones from being washed out' by a rush of water." For a gutter composed of brick or stone blocks the specifica- tions should provide for a bed two inches thick of cement mor- TOWNS AND SMALL CITIES. 87 tar in which the brick or the stone should be imbedded and the pieces laid together as closely as possible. They should be laid with the length in the direction of the street. Grout should be poured into the interstices as specified for the stone gutter. When brick, wood, stone block or asphalt pavements are laid it is usual to have the pavement continue to the curb with no special provision for a gutter. It is becoming the custom now to have a combined concrete curb and gutter for all streets except those paved with macadam or gravel. When macadam streets are tarred, or treated in a way that tends to preserve them, the concrete gutter may be used. Other- wise it is out of place on a macadam street. In towns where horses are standing at the curbs for hours at a time it is good policy to make gutters of vitrified brick, or stone blocks, about six or eight feet wide on all streets improved with gravel or macadam or paved with asphalt, tar or similar materials. The continual moisture and the almost continual pawing of iron shod hoofs make macadam and gravel and asphalt streets go to pieces in a short time. CHAPTER IV. STREET PAVEMENTS. "What doest thou, knave?" "Marry, good sir, I am an improver of ways." "An improver of ways? Speak plainly." "Aye and 1 will. 1 am a purrveyor of paving materials to_ his Satanic majesty. Many miles of ways hath he paved in his kingdom with my good intentions." — Old Play. It is an axiom in street paving, as in most other work that the material lowest in first cost is generally highest in cost of maintenance. Therefore get the best pavement the tax payers can afford. But it is sometimes better to put down some material to be replaced later by a better than to postpone an improvement in- definitely. Sometimes a cheap pavement arouses enthusiasm and causes an improvement boom where a more expensive pavement might be so ruinous to purses that it would actually retard all desire for improvement. It is easy to generalize and easy to give the experience of other cities. The average tax payer will not be inclined to take another person's word, but will judge for himself when it comes to spending money for improvements. Away from cities with good railroad communication the ques- tion of material for street paving is entirely local. Where one material can be laid down as cheaply as another the fancy of the individual may be indulged and the city streets be a patchwork if the people vote that way. When freight rates are high and first- class material is imported at great cost the question is a burning one. This should be remembered in reading articles on paving in magazines and other publications. The . writer in New York or London can not settle the question for the people of Timbuctoo nearly so well as the people of Timbuctoo can for themselves, after they have had a little education and have obtained some ideas on the comparative values of the different materials most used. Local considerations largely govern. One is the freight rate on the materials usually considered best and the proximity of ma- ss TOWNS AND SMALL CITIES. 39 terials, suitable for pavements, usually given a lower place. Another is the necessity for skilled supervision of certain pavements during construction. If the local engineer has not enough of the requisite scientific knowledge to know that a first-clacs job is being secured and the city can not afford to employ the man with the knowledge and experience, some materials must be barred out. Another is experience in maintaining certain pavements. If the city has not the proper men and can not afford them then another material will be barred out. Each place must study carefully all the local conditions and improve the streets in the best way possible in that particular locality with reference to the good of the community and the least legitimate cost. Any of the leading materials will make a first-class pavement under proper conditions. It only requires common sense and a proper regard for the value of the opinions of men trained in the work; and possessed likewise of common sense, so their experience is of value to those who employ them. No street will last forever without some sort of maintenance and system for repairing. Constant attention is required and there must be wise ordinances well enforced to keep the streets properly preserved, in a state to travel upon with comfort and satisfaction. In the case of macadamized streets it has been found by actual observation that the cost of maintenance is one-third greater after the putting down of street car tracks. On such a street a T rail can be used under proper specifications, but a provision should be placed in the franchise providing that some other form (preferably a grooved girder rail) shall be put in when the street is paved with wood, stone, brick, asphalt or other material better than macadam. It has been proven that street car tracks on a street shorten the life of any pavement placed thereon. When franchises are granted for street railways the manner of constructing the road bed should be carefully specified and the form of rail to be used should also be specified. The street railway company should also pay a part of the maintenance cost. If an electric road operated by a trolley is to use the streets the double trolley system should be used, as there will be fess danger from electrolysis. In the single trolley system the. return current goes back underground and at every possible opportunity it attacks metal pipes in the ground. When an electric road is to be built 40 ENGINEERING WORK IN the city should employ a competent electrical engineer to prepare the specifications for doing the work and havfe him send an inspector to see that the work is done right. No road should be built without the city taking some such means for protection. To avbid destroying a street by too frequent openings for water, light and sewer connections, some regulation of pipe laying is neces- sary. It is well enough to have specifications for the opening of the streets and the restoration of the surface, but the inspection is too often slighted. The best way is tb require all pipes (other than sewers) to be laid at definite depths and at definite distances from the property lines. On streets going in one direction the depths and distances will be different- from those required on intersecting streets. At least twelve months before the street is paved all water, gas and sewer connections should be made. The best plan is to require service pipes and drains to be laid every 25 feet on each side of the street to a point one foot inside the curb line. When connections are afterwards made to the houses no openings will be necessary in the roadway. Maps of all the pipe lines showing the location and depths of house connections should be kept in the office of the city engineer. See Chapter XV. The question of street paving materials is a burning one. It is not settled. When a town becomes a city of about: 20,000 inhabitants the Council awakes to the fact that some decision should be arrived at regarding the best material to use and committees are sent to cities near by to investigate conditions. They are usually met by the agent for some particular material and shown the work his company is doing. . In the meantime the city engineer formulates questions and sends them with stamped, addressed envelopes to all the cities he knows of, having about the population of his city. If half the papers come back he is pleased, for so much of this is done that few men care to bother with replies. The writer knew of one city sending out five hundred letters of inquiry and receiving twenty-seven replies. • From the data thus obtained the engineer makes out tables and prepares a report. Frequently he rushes into print with it. The writer has reports in his possession made from data thus obtained TOWNS AND SMALL CITIES. « and some men recommend one material and some men recommend •another, as most suitable for their particular case. Apart from strictly local considerations the following points are to be taken into consideration in selecting a material for street paving: Appearance, ease of traction, cleanliness, healthfulness, noise and cost. The ideal pavement is durable, noiseless, cleanly, healthful, easy to travel on and cheap. The ideal pavement has not come into use so far as the writer knows. The best we can do is to approximate to it, although there are men selling certain materials who have tables of percentages to prove their pavement is the ideal. The loads a horse can draw on a perfectly level roadway each day is given by Haswell as follows : Asphalt 6,095 pounds Stone block 3,006 " Ordinary stone block , ■ 1,828 " Hard macadam : 1,391 " Hard gravel 1,279 " Hard earth 1,193 " Worn stone block 1,137 " Cobble stone 730 " Ordinary earth 456 " Sand 228 " Brick had not come in as a paving material when that table was prepared; but it i^ close to asphalt. Wood should have been mentioned, but a properly constructed wood pavement is as good as asphalt. The following figures given by asphalt companies show the comparative cost of haulage on streets paved with various materials. There is little reason to doubt their close agreement with observa- tion, even if presented by parties advertising a particular material. Cost to move one ton one mile by horse power (estimate made in Indiana) : •Asphalt , 2-7 cts. Block stone pavement (average) 5.3 cts. Macadam in good order 8.0 Cts. ' ^ " Gravel road 8.8 cts. Earth road, hard and dry 18.0 cts. Macadam with ruts 26.0 cts. 42 ENGINEERING WORK IN Wet sand 38.0 cts. Earth road with ruts and mud 39.0 cts. Dry sand 64.0 cts. It will be noticed that there is no mention made of brick or wood in the above table. The cost is practically the same as for asphalt. 7?fBLE I, Values of Pavements. fpe-qrranged from Bak&rh Jfoaas ffNoPffvE^MEhJTS . PEffCENTuec assigned fo gua/i-f-y. Qualities. < ^1 11 1! 1 1 < 1 , ^. ECONOMIC Loyv -f/rsT cast ■Low cosf of/na/hfenonee ■ Ease of tracHon Qooe/ roai-hoiof Eaee of cfeaniny /5 20 /o /& 'I lo 9 9 8 3 1 3 /5 e 1 2I 3 3 6 Tofctf SANITARY Np/'se.le&sn&se ffeaffhfufnesi €0 15 /O 44 to /o 44 37 13 5 32 /5 6 32 /£ 6 35 2 ,7 To/a/ ACCEPTABILITY. ^ee fmm mud and dasf Com/brfoS/e. /b use /Von odsorSeof ofheaf Z5 /a 3 ? 1 16 9 la I 21 3 3 2 2/ / 9 6 Tofa/ GffflND TOTffL. /S Joo 13 77 II 70 10 6S \ 61 e ,5S 9 S3 Table I has been taken from Baker's Roads and Pavements, with a slight rearrangement of the columns. No changes have been TOWNS AND SMALL CITIES. 43 made in the figures, however. The table has been made from reports received from many cities, most of them of considerable size. Other men give values considerably different and the writer has found that the values assigned vary with the. average sizes of the places from which reports are received and the completeness of the reports. The town also from which a favoriible report was received on oiie pavement may have been close tn a city where there were many first-class contractors laying it. The town con- demning it may be far away from good contractus. The table, however is interesting. Mr. T. J. McCarthy, assistant city engineer of I (olyoke, Mass., received a great many inquiries about the experience of that city with various materials and prepared Table II to send to inquirers. It will be noticed that he tells the kinds of foundations used for different materials. This is an important point. The sub- surface should be thoroughly compacted and the writei believes it should in all cases be underdrained with the tile leading to the near- est manhole or catch basin. All modern pavements should have a concrete foundation. As natural cement may be hurt by frost, the cement used should be Portland where the weather conditions are severe. The writer is opposed to pavement foundations of brick, or old gravel or macadam. EARTH ROADS. A town first tinkers with the old earth roads ^yhen people get tired of mud. It buys a road machine, which has to be rebuilt every spring because no care is taken of it between while, and buys a road roller. The streets are rounded this year according to the ideas of one man who knows little about it and next year of a man who knows less. A well rnade, well kept and thoroughly rolled earth road is very satisfactory in dry weather. It is pleasant to use when not dusty or muddy. Seeing that it is either the one or the other all the time, earth roads are counted as not just the thing for progressive places. GRAVEL ROADS. Gravel is the first improvement tried. The ideas of men differ exceedingly as to what constitutes a good gravel for road work. • In fact, their ideas differ as to what may be termed gravel / One 44 ENGINEERING WORK IN kind is very fine and has sharp edges and angles. It is never found rounded like marbles or cobblestones and is pretty fair material to use on streets with little travel. Although the writer gives a form I I I it O ^SS9c/ssa^sffto/^/ 'SSSl/Uat/efi ''/S 'Ssse///t/osi-\ '■apeuB ' 9sn fj 9peu^ •jIDsA J9ct 9yuOU3^iJ/OU/ JO ^ •p/^/^^^n <5 ^ Q^ <.VoC>IOtOVO'ON ocioo>oW)p9 0) ^10 00 CO rt'fc) O lO O O to OlQ o o o t I I I N.CD 00 O NOT w ^ ^ cvi cvi cj ~i ■< tvi o ^!5C5' I® 55 GO 65 over it or, after awhile, plow it in, when it covers the whole area to a depth of several inches. Engineering News, April 6, '1905, had an editorial on the sub- ject, and the following facts were presented in favor of a systematic land disposal. The proposition is %p bury all garbage on tracts of land far removed from habitations, under six inches of earth. By putting six inches of earth over the garbage a thickness of nine inches can be placed over the area. Then an acre of ground Will take 32,670 cubic feet of garbage or, say, 6t)0 tons. If we take the average annual production of garbage pei 1,000 inhabitants at 75 tons, a city of 25,000 inhabitants would produce 1,875 tons of garbage per annum, which could all be disposed of on a field a little over three acres in extent, or a tract of thirty acres would last such a city for ten years. A knowledge of the nitrifying and purifying properties of fresh soil assure one that such a plan can be adopted without offense. It is well known that even such highly offensive substances as spoiled meat and the bodies of dead animals, when buried in the earth with a cover of only a few inches of fresh soil, give off no offensive odor and are gradually resolved into their original elements, without offense. Garbage, however, contains only a very small percentage of animal refuse. In a cubic foot of average garbage from an American city, from 70 to 80 per cent is water. When the water is removed it will be found that the bulk of the remainder is vegetable matter, rubbish and bones. Of grease and animal matter there will be not to exceed 5 per cent as a rule. It is conceded that all the vegetable matter in garbage will decay without offense under a very slight cover of earth, and it will be seen that the actual quantity of animal matter buried in the soil, even if we applied garbage to a depth as great as a foot, would be no considerable amount. It will also be evident that when the actual composition oi. garbage is consid- ered, that while 600 tons to the acre may seem like a large amount to apply to land, it is so largely composed of water and vegetable matter that it can not possibly injure the land for agriculture by over-fertilization, especially if it is buried under a depth ot at '.east six inches of earth. The present way of covering a tract of land and then plowing it at infrequent intervals can not be too strongly condemned. The 66 ENGINEERING WORK IN way to do the work is to excavate trenches one foot deep and two to three feet wide. Commence with one at one side of the field and make it, say, 500 feet Jong. Place the garbage in this trench and spread it to a thickness of about nine inches A trench of the size mentioned will hold about twenty tons of garbage. To cover this garbage excavate another trench alongside and use the fresh earth. Engineering News then figured out on the above "basis for a city of 25,000 inhabitants. For the purposes of this book we wjll figure it in a different way. Assume one pound of garbage per day per capita. For 1,000 people this will be half a ton. This is an extreme figure, but we will use it. Assuming that a trench 500 feet long, one foot deep and from two to three feet wide, will hold twenty tons of garbage, we will require only twenty-five feet of trench per day for 2,000 people. Thij will be less than three cubic yards of earth to handle. As the soil on which such a plan can be best worked is easy to handle with pick and shovel, one man can be kept on the ground alb the time. He can dig the new trenches and cover the old ones and assist the teamsters to unload. When it is seen that he is over- worked another man can help him. Before winter sets in calculate the number of trenches required to hold the winter garbage and have them excavated early. They need not be covered, for the garbage will freeze, but as warm weather approaches some earth can be brought in from a borrow pit and an inch or two can be spread over the trenches until the dirt piled alongside has thawed enough to be used. As the city grows it will pay to dig longer and perhaps nar- rower trenches. Then each evening a regular road grader and ele- vator can be drawn down the side of the trench used that day and excavate a new trench while covering the old one. There are plows used in the Western States for breaking new ground. They cut a broad, deep furrow in a cut and cover style. Such plows might be used to advantage when the work becomes so heavy that manual labor would be too expensive. After some considerable area is covered the earth should be harrowed and when a season, is over it would be advisable to leave such land fallow a year. It might be harrowed early in the spring and the following fall plowed and the next spring be used for vege- I TOWNS AND SMALL CITIES. 67 tables. If a town owned twenty acres of land it could use one or two acres per year in this manner and the land would be properly fertilized once in ten years or so with the -garbage. The sludge from the sewage disposal plant could be placed with the garbage. The best way to get rid of straw and manure is to spread them over the ground in thin layers to let moisture do its work. Occa- sionally, in a long dry spell, it can be burned. As the odor of burning straw is offensive when mixed with stable wastes the writer recommended to one town the purchase of hay choppers. The dry straw and manure, free from lumps, were then chopped up and spread over the ground to rot and enrich the soil. Ashes and tin cans are not garbage and should be separated from it. Ashes make good filling for Vacant lots, when clean. Tin cans and wires are a nuisance, and about the only thing to do with them is to .use them also for filling, together with the ashes. They are not a menace to health at any rate, but are unsightly when piled on vacant lots. When dumped into hollows and ravines and gradu- ally covered with ashes rust sets in and they are not troublesome in a few years when excavating is done on the spot. The writer recommends ashes in connection with tin cans and metal because the ashes from the average American home contain a great deal of unburned coal with a high content of sulphur. When wet this assists greatly in rusting and decomposing the metal. Garbage should be collected in tight cans and hauling them through the streets will not be offensive. In Oakland, California, garbage is put in metal cans having tight fitting covers. Each can holds ten gallons and weighs, when filled, about fifty pounds. All the cans are brought empty, after being sterilized at the crematory, to the back yards and the full can is put in a specially constructed wagon and taken to the crematory. The great thing in favor of such a method is that the cans are regularly and thoroughly cleaned, the covers are never removed until the can reaches the place of final disposal, there is no leaky, bad smelling wagon traveling through the streets, and the wagon used is specially made for the work, so there is no rattling of the cans. The use of ground for garbage disposal will hardly be consid- ered after the town has become a large city, for the hauling of garbage long distances is expensive. The best method, when it 68 ENGINEERING WORK IN can be afforded is to install a first-class creniatory and burn all garbage and waste organic matter. It is the only sanitary way. In England, where the character of the refuse is somewhat different from American refuse, a great many plants for burninsj refuse are combined with power plants to raise steanj. Th& cost, of burning garbage is thus reduced, as some of the expense can prop- erly be charged to the fuel account of the power plant. The cost of the power plant is also reduced, as the garbage has a distinct fuel value, although slight. Analyses bi American garbage and refuse seem to indicate that few of our cities can do much along this line. There- fore, little has been attempted in the production of power from the incineration of garbage, i It may pay in very large cities, but in smalt places it is doubtful. Waring gave the 'percentages of different substances in garbage as follows: Rubbish 7 per cent. Water 71 Grease , 2 " Tankage 20 100 percent. The tankage amounted to 20 per cent or, say, 400 pounds in one ton. It yielded, upon treatment, 13 pounds of ammonia, 13 pounds of phosphoric acid and 3 pounds of potash. All of the grease was merchantable, so that while there was ten times as much tankage as grease, it only yielded, after expensive treatrrtent, 29 pounds of acids. A table given in the same book shows the garbage to vary in different cites from one-quarter to nine-tenths of a pound per capita daily. The idea of reducing 'garbage is dying hard. Some years ago it was all the r^ge, but today little is heard of it. There may be money in reducing garbage. We all know there is gold in sea water. The riglit kind of process must be efficient and cheap to get gold out of garbage or out of sea water. The largest item of cost in the disposal of garbage is the haul, which varies from 25 to 75 cents per ton mile. i For reduction only certain kinds of garbage are worth consid- ering. As they occupy a small percentage of the bulk, it means hauling one hundred pounds of material to pick over and sort a&d TOWNS AND SMALL CITIES. 69 then run through an expensive process to obtain at the end two pounds of grease and not quite three pounds of different a<:ids. No reduction works in America have paid without a subsidy of some sort and none can pay in a city of less than two hundred thousand people. Garbage contains more water and less grease in summer than it does in winter. It changes in composition from day to day, so a reduction plant must be located in a ilirge place, where a cer- tain amount of- the right kind of garbage can be depended on. Garbage is sometimes picked over even at incinerating plants, but no man can afford to pay pickers. They must do it themselves, like rag pickers in the alleys. In New York City a contractor did it, ~%ut this book is not written for places approaching New York in size. There are many garbage burners in the market that can be placed in the chimneys of ordinary kitchen stoves. The hot air going up the pipe carbonizes the garbage without odor and the refuse can then be burned in the fire box of the stove. A proper system for a small town should make it compulsory on every householder to provide himself with one of these carbon- izers or with a tight garbage can in the back yard. Beside the garb^ age can shotfld be one for ashes, rags, paper, etc. There should be heavy fines for mixing thp contents of the two cans, or barrels. Ashes should be hauled away at least once each week. Garbage should be hauled away at least twice each week in cold weather and once each day in summer. The garbage should be taken to a Jot and buried as already described or taken to a garbage incinerator and utterly destroyed. There are many fairly good devices in the market, but a city needs expert advice on the subject before investing, owing to the number of poor furnaces now advertised. Streets and alleys should be kept clean. Paper and rags are not only unsightly, but they^re a dangerous fire risk. Horse drop- pings should be taken care of also, especially on streets paved with impervious material. Street sweeping pays and so does frequent street sprinkling. It is bad to have poison-laden dust blown into eyes or nostrils. Dust is bad, also for store keepers. In a small place, the best a council can do often is to provide the land for the dump and men to look after it. Have a scavenger TO ENGINEERING WORK IN whose business it will be to look after papers, etc., on the streets and then advertise each year for bids for carrying the garbage from the houses to the dump. Pass an ordinance fixing the maximum rate to be charged householders for taking away their garbage and grant the exclusive^ privilege to the man who will do it for the lowest price, and pay the city 5 per cent of the gross receipts for the privilege. This will insure the citizens getting good service and they can not be ove'rcharged. Such work should be under the control of the Board of Health. As soon as there are paved streets the street cleaning depart- ment should be enlarged. The one man and cart, with a spear to pick rags and papers, will develop into a corps of "white wings, ' constantly in evidence. Constant cleaning is better than a sweeping once a night or once a week. The cost of cleaning paved streets varies from 12.5 to 20 cents per 10,000 square feet. The greatest expense in street cleaning, as in garbage disposal, is the haulage. It is good policy, therefore, to bear this in mind in designing sewers for a combined sewer system, or when design- ing storm water drains. The sweepings from the paved streets can often go directly into the sewers when they have a constant flow of a certain depth. This nlatter, however, is discussed in the follow- ing chapter, A definition of terms loosely used by laymen seems necessary. Garbage consists of solid, organic household wastes and the organic wastes of living; non-putrefactive matter and street sweepings being termed refuse. Sewage consists of liquid household wastes and con- tained excreta. CHAPTER VII. DRAINAGE. "A plague upon this dirty water!" A distinction is made by engineers between drainage and sewerage. Drainage applies solely to the disposal of surface and sub-soil water. That is, to water which can be put in any stream without dangef of polluting it.^ Sewerage, having to do with liquid wastes, containing putrefactive matter and matter containing germs and micro-organ- isms harmful to the human system, has to be considered apart from drainage. In the majority of cases the drainage of a town offers few diffi- culties. The whole practice is simple. Keep the water on the surface as long as possible in easily controlled channels and dispose of it in the most convenient stream or river. It is only harmful when allowed to collect in low lying places, where it will become stagnant and provide a breeding place for harmful insects and germs. The first step in drainage is to provide broad, deep gutters along the sides of streets, before or after grades have been established. Before the grades are established the gutters are merely ditches. After the grade has been established the gutters can be made of stone, as described in a previous chapter, or of brick Jr other mate- rial that will not wash' readily. On steep hill side streets, where an earth ditch would wash badly, and on streets where a great deal of excavation must be done before a gutter can be made on the official grade, temporary wooden V flumes are used. Sometimes wooden flumes with rectangular cross sections are used where a V flume would be too small. Great care has to be exercised in making the joints in wooden gutters. Underneath there should be laid a piece of wood for each section to be nailed to. On each side there should be a post driven deep into the ground, spiked to the flume. 71 7a / ENGINEERING WORK IN Across from post to post, underneath the flume, should be a board about six inches wide, and on each post there should be a piece one foot wide, projecting like a wing. The space should be filled with fine gravel or broken stone, tamped hard. If water then follows the ground alongside the flume it will be turned into it wherever such obstructions are met. The flume boxes should be not more than sixteen feet long. Ten feet makes the best length. When surface water is taken underground it is a source of expense and causes trouble whenever the, conduit is choked. There- fore, keep it as long as possible on the surface and arrange the drainage system so the streams will be divided at every street inter- section and sent in different directions to guard against too great an increase in flow and consequent difficulty in handling. Much of the rain-fall is absorbed as it falls. As a town becomes more closely built over and the area of paved streets increases, a less quantity of water is absorbed and proper underground conduits must be provided for drainage. When the town becomes a city then a portion of the sewerage system will have to be of large sewers, suMcient in size to take care of surface and subsoil water, m addition to the sewage. This is discussed in the next chapter. The slope of the streets and the crown placed on them form part of the drainage system of every town. In carrying the water' across the streets it must go underground. It is not good to have a gutter continue across a street intersection with a bridge over it, or a culvert only fifteen or sixteen feet long under the roadway. It is not nice looking, nor convenient or healthful. In some text-books on roads and municipal work the authors condemn the practice of having a small catch basin at the- end of a block with a pipe across underneath the intersecting street. The writer, however, has built them that way and found no objection to their use. Sometimes nothing else can be done. In irrigated sections, where small ditches flow in the gutterways, it is the only way water can be carried across a street. In such cases, the benefit of a sidling street is great. A dif- ference of one foot in elevation between curbs is seldom noticeable without an instrumental determination, while it does permit of easy drainage. ' The depth the pipe is placed below the surface depends upon the material. There should be not less than one foot of sand on top; TOWNS AND SMALL CITIES. 73 therefore, such a conduit is best placed under a, cross-wallc. If in a climate where the temperature varies in wide limits, the conduit should be of iron or reinforced concrete. Otherwise, of double strength vitrified pipe. At the higher end put a small catch basin in the gutter. The bottom should be about two feet below the bottom of the pipe and there should be a metal bucke.t fitted inside so it will permit of easy cleaning. The pipe should run across the street and at the lower end be turned up into the gutter at an angle instead of termi- nating in a vertical well. The end can come up under the Cross- walk, over the gutter. The well at the tjpper end should have a grating over it. As horizontal openings are easily clogged with paper, rags and leaves, the grating should have vertical openings. The 'writer has often placed the wells under the cross-walk and put the grating at an angle of forty-five degrees oyer the end of the well, leaning against the top of the walk. When the water rises it has a tendency to Uft obstructions and flow underneath into the well. When combined sewers are used to carry both storm water and sewage, catch basins are a necessity on all streets. Rather, inlets are necessary; for there is a difference. On streets that are not paved, or are simply improved with some material that wears and furnishes silt and dirt to go into the sewers, the inlets must be of a form that will allow the. storm water to enter the sewer and will leave the dirt in a basin, to be cleaned out after a storm. An inlet may therefore be simply an opening into a pipe that conducts the water to an underground conduit or it may be a part of a silt well or catch basin. Silt wells and catch basins are fine in theory. Practically, they are too often a delusion and a snare. If cleaned after every storm they are proper adjuncts to a sewer system. If left without clean- ing, as is too often the case, they are a nuisance and a danger. The writer knows of cities where thousands of catch basins have not been cleaned in twenty years. Some places the statement is made that the average time between cleanings is three years. He is, therefore, strongly of the opinion that when a street is paved with wood, brick, stone, asphalt or bitulithic material, catch basins 74 ENGINEERING WORK IN should be abolished and, a simple inlet provided, with a running trap at the lower end, the inlet pipes to terminate in manholes. The writer has raised storms of protest in places where he has advocated this. His only answer has been to refer the objectors to the street or sewer cleaning departments for figures. It has been found that in the majority of cities little attention is paid to thor- ough cleaning, of silt wells and catch basins because, of the great expense involved. The most that is done is to poke an opening under the trap when the basin is obstructed during a storm. The usual form of basin is a square or circular well of brick or concrete with a pipe leaving it near the top. A brick or concrete wall, or metal plate, as a partition across the well. at the top, the bottom of the partition being a few inches lower than the bottom of the pipe, forms a trap. The dirt is washed into the basin with tjie water and . is sup- posed to remain in the bottom while the water goes under the trap wall, through the pipe into the sewer. When the cleaning of the catch basin or silt well is omitted, or ^s an Infrequent occurrence, the dirt from only the first storm is retained in the basin. The dirt in after storms goes to the sewers. i If the sewers are designed with a minimum flow of three feet per second they will carry the material to the point of disposal. If it has to be dredged and taken away from time to time, dredging is cheaper than shoveling: into wagons and hauling away. A simple inlet therefore on streets ■ having good impervious pavements, with a running trap near the sewer, serves all the purposes of an efficient inlet. The writer is' anxious to collect all the information he -can on this subject of catch basin and silt well cleaning and will appreciate all data sent him. Readers will please bear this in mind when annual reports are issued. If any reader cares to investi- gate conditions in his own town and report to the writer, such kindness will be gratefully acknowledged. Before leaving this subject the writer wishes to add that such practice is only advisable where the sewers permit the material to be carried readily to the point of disposal. They must have suf- ficient grade to always have a self-cleansing flow and must be in good condition. , The practice of having the street refuse go directly into the sewers should not be allowed where it is possible to clean TOWNS AND SMALL CITIES. 76 the streets by some cheap method and where catch basms can be kept clean at low cost. If the sewers are properly designed for such work it will be found that the cost of keeping them clean will be less than the extra cost of cleaning streets and catch basms with shovels and teams. Silt wells, where used, should always have a metal bucket a few inches in diameter smaller than the well. Lying on the top rim there should be a cone shaped ring having the largest diameter a trifle smaller than the well and the smallest end a trifle smaller than the diameter of the top of the bucket. This will prevent material fall- ing between the bucket and the sides of the well to bind it in place. When the ring is lifted ihe bucket can easily be hoisted and emptied into a wagon. The bottom of the well can then be cleaned and the bucket and ring replaced. ^n dfiproraef fenn of ih/e.f- Connachco af- Corners. TH/s c/oes OKay wi'^ one iasin artef crasst'nq of sire&ts ^ (hasnKilk} ""J-y ie. a/most /er*/. N '^'''»«, y F/^.5 Many forms of inlet covers are on the market and it will seldom pay an engineer to get up plans for a local foundry, for the manufactured article can be shipped anywhere the freight rates are not excessive. Where the freight rates make it costly to buy from factories the engineer can design inlet covers for the local foundry to make. 76 ENGINEERING WORK IN It is usual to~p]ace the inlet on the curve of the curb half way between the cross walks. This means carrying the gutter around the corner and makes a depression for wheels to settle into when a Vehicle is rounding the corner. The writer prefers to have a vertical inlet grating at each Cross walk and a pipe following the curb to a point half way between the cross walks. At this point the two pipes can meet in a well having an iron grating cover. From this well an outlet pipe can run to the manhole in the center of the street intersection. Even if a silt well is not located here it is a good idea to have a chamber admitting of easy inspection and with the bottom shaped to permit of a proper junction of flow. With such an arrangement at street intersections all cross walks can go over the gutters on a level with the curb and the gutter around the corners need be only three or four inches high, simply enough to assist in guiding a wheel if a vehicle comes too close. Such a street intersection looks well if the curbs are joined on a circle of large radius. '' Wood is a material often used for first temporary underground drains. Wooden boxes should be square and set on edge, liiaking a diamond-shaped conduit. This is a gobd .form that will always have a self-cleansing flow. The use of wood is justified when the town needs the drains badly and is short of funds. It is justified when it is impossible to predict the direction or extent of future growth of populatior in a town likely to be subject to periods of boom growth, and the direction and location of main drains may be subject to change Wood should not be used when sewage is carried. Neither should it be used when a pipe twelve inclie$ or less in diametei will do the work. Vitrified pipes are most commonly used. When put less than five feet in the ground they should be of double strength. Pipes up to three feet in diameter can be obtained from almost all manu- facturers. They are smoother and have greater capacity than' brick sewers of^equal diameter. Brick is generally cheaper than vitrified pipes in all diameters exceeding thirty inches. . Ordinary house brick shbuld not be used, however. Use only vitrified or clinker brick for the lower half and a good hard brick for the upper half. The thickness of brick TOWNS AND SMALL CITIES. 77 sewers up to three feet in diameter may generally be one ring of brick (4f4 inches), although some engineers use two rings for all sewers over two feet in diameter. From three to six feet, two rings generally sufifice. Three rings, up to eight feet. Four rings, up to ten feet, and generally one additional ring for each pine inches or less increase in diameter. Concrete was once used for sewer^ and drains, but fell into dis- favor. Within the past five years it has come again to the front— ^ this time to stay. More is known of concrete today and better work is done, with better materials than' was the case thirty years ago. Concrete sewers built in place are not so good as those built on the bank and lowered into place when thoroughly seasoned. The interior of a concrete sewer is theoretically smoother than the interior of a brick sewer, but if -constructed in place with removable forms it is not always possible to get good workmanship. Con- tractors do not like to build them, for it is a gamble moving the forms. The writer prefers for concrete sewers to have them built on the bank and placed in position in sections after thorough curing or to build the lower half of well cured blocks and the upper half on forms. The forms should.be left in place a long time and con- siderable filling should be in place a few days before the forms are removed. In this respect brick sewers have an advantage, 'fpr the forms can be removed almost immediately after the, last brick is in place and settling is taken care of in the joints. Brick sewers, however, are inferior to properly constructed concrete sewers in other respects and the bricklayers' unions are becoming so' hard to deal with that the writer believes brick sewers are apt to almost disappear in a few years. An empirical rule for the thickness of concrete sewers is to make the minimum thickness five inches wfien no steel reinforce- ment is used and four inches when it is used. For sewers not rein- forced the thickness should be in inches equal to the diameter in feet, plus one inch. For reinforced sewers the thickness should be in inches equal to the diameter in feet, minus half an inch, due regard being paid to the minimum thickness above mentioned. The reinforcement around the pipe should be equal in area to one per cent of the area of the concrete, taking a longitudinal section. 78 ENGINEERING WORK IN The longitudinal reinforcement should be one-third of one per cent of the area of the ring or cross section. However, for larger sewers careful calculations should be made. , When the word sewers is used drains of course are understood for the foregoing matter relates to both. CHAPTER VIII. SEWERAGE. "The welfare , of the people is the supreme law." Sewerage generally waits until water supply has been attended to. Modern sewerage syst-ems contemplate water carriage of wastes and if the town has no public water supply sewers are not needed. Drains are all the people need. The subject of sewerage can, however, be as well taken up after drainage as to wait until water supply is discussed. At the time the plan for surface drainage is prepared, plans for a sewer system should likewise be adopted. It should not be a matter oF haphazard growth, but should be gone at properly. Be- cause a complete plan is prepared it does not mean it will all be constructed at one time, but simply that as sewers are put in they will be of the right size and put in the right place. In a growing place the work is never complete, but sewer building is going on all the time. Plans prepared must take this into consideration. Laterals can generally be planned of the right size, but the mains will be rebuilt or replaced by larger ones as the city grows. Having complete plans in advance fixes the lines of the main drainage and insures economy. As the grades on streets govern location of drains as well as sewers, a complete plan at the beginning of things shows where it will be possible to keep surface water and sewerage separate and where it will be best to combine them. It has unfortunately happened many times that for lack of proper attention to this matter of getting plans early many private sewers have been built by well-to-do people. When a proper plan is at last prepared it has been found imppssifile to use these sewers in a general system and expensive lawsuits and vexatious delays resulted. Vested interests always cause trouble. If a good plan for sewer- age and drainage had been prepared early enough the private sewers 80 , ENGINEERING WORK IN t ... could have been constructed in a manner and in locations satis- factory to the council, and when a public system was installed they could have been purchased and thus been a benefit instead of a draw- back when the city got around to that part of the work. The term ^'sanitary sewers" is applied to small pipe systems designed to carry off household wastes alone, without surface or sub- soil water. Such a system is also known as the "separate"' system of sewerage. It is the only system to use in very small places, and can in fact be kept apart from a storm water system until a city is quite large. An ideal method of sewering and draining cities is to have two distinct systems, one for sewerage, and one for drainage. This is costly, however, when a certain limit in sizes of mains is reached, so when a point is reached in the devolpment of a city requiring the drainage water to be taken underground the combined system should be installed.' By keeping the surface water in gutters for as long a time as possible, a distinct saving in sewer . construction is effected. By having two entirely separate systems many expedients can be adopted to save cost. Storm water sewers are large and are only needed when a storm comes. They can, therefore, be placed at shallow depths. The writer installed one system by making shallow semi-circular conduits inside the curb line and sidewalks were built over them. At regular intervals gratings placed in the curbs admitted water to the storm sewers. A small place contemplating the building of a combined system at the start may go without sewers for many years, for large sewers cost money. In planning sewers for a sanitary system it is necessary to have the pipes large enough to flow half or three-quarters full with a velocity of about two and one-half to three feet per second. They will then keep themselves clean. If built of too large a size to carry a flow of constant depth at the proper velocity the sejliment in the sewage will be gradually deposited until the sewer is choked. A small channel is left at the top, sufficient in size to carry the constant flow arid-no more. If this sewer is intended to carry storm water it will be found to be choked with decaying matter and refuse when the storm comes and the street is flooded until the sewer is cleaned. TOWNS AND SMALL CITIES. ^ «1 In addition to the choking up of the drain and thus rendering it unfit for its purpose as a storm drain, the continual deposit of excremetitious matter is a menace to health. The large empty spaces invite accumulations of noxious gas, and odors, annoying in every way, get out into the open air. It is commonly believed -that a sewer can not be too large, but more trouble is caused by sewers too large than by those barely large enough which occa- sionally prove too small in time" of big storms* A small sewer is annoymg once in a while and occasionally causes damage to property by reason of its inability to carry off a large rush of water in a short time. A sewer too large is always dangerous, not alone to' the pocketbook but to health. When sewers become choked it is usual to flush them with a hose attached to the nearest hydrant. Takfc a 15-inch pipe as an example. Disregarding decimals, the area is 177 square inches. The area of a stream of water from a 2V2-inch hose is 5 inches. For flushing purposes it is useless. If there are no flush tanks on the line a wagon is sometimes used. Such a wagon usually has a tank containing from six hundred to one thousand gallons of water and with a twelve or fifteen inch opening at the bottom with a flap cover. This wagon is driven over a convenient manhole and the flap opened. The water goes in with a rush and such flushing is really efficient for some distance. The minimum grade has already been referred to as one sufficient to produce a velocity of from two and one-half to three feet per second. A lighter grade will produce such a sluggish flow that solid matters can not be moved and so remain to clog the pipe. Too steep a grade produces so rapid a flow that solid matters often arestranded because the flow is not deep enough to float them. Eitjier extreme is bad. A maximum velocity should be about eight feet. When the grade ■ of the street is such that a greater velocity will be obtained the sewer should be run on a grade to secure not more than five feet per second and when it gets too near the surface drop a manhole to a- greater depth and, start another section of sewer from the bottom of it. This stepping of the sewer down hill can be accompalished by vertical drops in manholes or by the uge of tumbling chambers, where the sewage falls over a flight of stone or concrete steps. In the separate system small pipes must be used and it often 82 ENGINEERING WORK IN happens that a three or four inch pipe would be amply sufficient for the work. Such small pipes, however, choke , too easily and are difficult to clean. Therefore, the smallest size should be six inches. The writer has found from experience that it is unwise to make any line of six inch sewer more than six hundred feet long. The late Colonel Waring was an extreme advocate of six-inch pipes and has left his impress upon the minds of many text book compilers. His real argument was economy. The difference in cost between a six and eight inch pipe is small and the cost of excavation, laying and backfilling in each case is the same. For the slight difference, the eight inch pipe is preferable. Until the population has grown sufficiently to keep a constant cleansing flow in the pipes a flush tank is a necessity in some localities. Flush tanks are generally considered a necessity in separate systems. ' A flush tank should be capable of discharging from 60 to 300 gallons of water in less than one minute into a sewer and should " be adjusted to discharge at least once each day. There are many patterns on the market. In general their advantages may'be summed up as follows : The sudden discharge of a large volume of water into a small pipe momentarily compresses the air in front and forces it out at every opening. This creates ^ temporary vacuum which is filled with fresher air from the outside and thus simplifies the question of ventilation. The frequent volumes of cool water thrown in, together with the consequent changing of th" air tends to keep the temperature of the sewer at a safe point. Disease germs can not multiply to any extent in a temperature less than sixty degrees Fahrenheit, and the ordinary temperature ot a sewer seldom falls below sixty degrees. Flush tanks therefore, serve a useful. purpose by cooling the sewers to some degree and by making a steady temperature impossible. Articles occasionally become stranded in a sewer and the sudden discharge of water m large quantities into the pipe starts them to moving This tendency of sewers to fill up until they obtained a cleansing flow was the primary reason for the adoption of flush tanks. The other benefits were noticed after they were in common use. In all sanitary sewers having a slow velocity of flow a TOWNS AND SMALL CITIES. 83 confervoid growth attaches itself to the sides juSt below the line of constant flow. The flush tank helps, loosen this growth also. C^^ Shape Sewer, /} si-rong form of COnc/u/'/" /r? genera/ use, . //7Specf/on /?a/es —a/so ca//ee^~/.gir?p /?o/es — ore a/so occas/ono/fy set en a s/onffrom a Y tnsi-&ae/ of a 7". F/^.3 /n3p&Gf-/o/7 /tola. In a sanitary, or separate system, manholes are placed at the end of each block and at the junctions cif sewer« and at changes in grade. They are thus frequently six or seven hundred feet apart. Inspection holes are often placed between manholes. They are simply pipes terminating a foot or so below the surface and arranged so they can be opened to inspect the sewer if a stoppage occurs. Sometimes the inspection holes are placed at an angle for the easy introduction of a rod for cleaning. As sanitary sewers 84 ENGINEERING WORK IN are not intended to carry silt or heavy solids a saving can be made in manholes. No~ catch basins, inlets or silt wells are needed on the streets. Occasionally roof water is admitted to them with the idea of giving them a thorough cleansing in time of storm. The introduction of rain water should be carefully regulated, however, or the sewer system may be taxed to do its work. A surface drainage system requires manholes and so does a combined system at frequent intervals. Where the grade of a street is less than 3 per Cent (three feet in one'hundred feet) man- holes should be placed about one hundred and fifty feet apart. On a five per cent grade they can be five hundred feet apart. For ease and convenience of cleaning, however, they should never be more than three hundred feet apart on sewers more than twelve inches in diameter. In {Cutting down a sewer system attention should be paid to depth. , For a residence district the depth should be such that cellars can be readily drained. Therefore, in making - a survey it is well ^ to take elevations on the floors of all houses and measure the depth of the cellar. The sewer should be deep enough to allow a drop of one foot in one hundred feet from the bottom of the cellar to the top of the sewer. When profiles are made of streets the profile of the bottoms of cellars should be marked also. It will generally be sufficient to allow a depth of seven feet below the street grade for the tops of sewers in residence districts and a depth of at least ten feet in business districts. A depth of twelve feet is better in a business district. Sometimes in flat sections there is a discussion as to whether to put in a long sewer on a slight grade or construct several outlets with many short mains and short laterals. Such matters had better be left to the engineer who plans the system, presuming, of course^ that he has been selected for his proven ability in such work. Baumeister says : "In general, the question of a system of complicated sewers is not solved by laying a number of equally important lines, but by leading the drains to a common center. It is cheaper to build a -single system of nx capacity than n systems of x capacity." In the separate as well as in the^ cornbined system all sewers should summit at manholes in order to provide ventilation. If a dead end can not be avoided it is a good plan to have a manhole or inspection hole there with a perforated cover. Underneath the TOWNS AND SMALL CITIES. 85 cover a pan should be suspended to catch dirt and dust. Sometimes an iron pipe connects the end of the sewer with a leader up the side of a house to get a high altitude in order that the warm sewer air in ascending will create a current throughout the system. Today in many states the laws forbid the pollution of stre?ims 'with raw sewage. This calls for some preliminary treatment and as it costs money and the filter beds, etc., occupy considerable area it is advisable to reduce the amount of sewage to a minimum. This is another argument in favor of the separate system. However, the liquids can sometimes be separated satisfactorily and therefore it is not necessary to run two systems side by side after the constant flow of sewage is large enough to . half fill a twelve-inch pipe. An egg-shaped sewer can be built with a section small enough at the bottom to carry the constant flow of sewage and the top afford space for the rush of storm water. The egg-shaped sewer should be laid at a grade which will give the smaller section a cleansing velocity when flowing six inches deep. This gives also a s_ewer that a man can enter to clean when necessary. The lirnit on size of an egg-shaped sewer may be said to be about ten feet in height. After a sewer of greater capacity is required the circular section can be resumed or the horseshoe section adopted. At a point where it is desired to separate the sewage from the storm water a separator can be placed and the storm water taken to the usual place of disposal while the sewage goes to the treatment works. Such a separating chamber prqvides for taking care of all the water flowing to a certain depth in a- sanitary sewer. When it exceeds this depth the surplus flows away in the storm sewer. The matter is generally arranged by providing for a certain amount of dilution of the sewage. This may be taken at from three to four. That is, when the volume flowing in the sewer exceeds the ordinary flow three or four times the excess can be taken away in an overflow. Sewers should be so laid that the bottoms of house connections enter at the middle of the sewer. This permits a flow of half the depth, without eddies that would otherwise be caused by the side pipes. In connecting two sewers of different diameter it is custo- mary to have the tops inside at the same elevation. This prevents deposits in the smaller sewer when the larger sewer is flowing deep.' All junctions of sewers should be made in manholes and the 86 ENGINEERING WORK IN bottoms should be shaped to the bottoms of the sewers and with curves having a radius equal to about twice the diameter of the en- tering pipe. House connections should always be made by "wyes" attached to the pipes at an angle. No connections at right angles should be permitted. An inspector for the city should inspect every connection made. Sewers need cleaning at intervals even when equipped with flush tanks. The cleaning should be done in the fall before winter rains and snows commence and in the early spring before the April rains. Some lines will be found always clean so they can be omitted. Sewers large enough for a man to enter are cleaned with scrapers and shovels, the material being taken up the manholes in buckets and put in wagons to carry away. Sometimes they are "hydraulicked" by pushing a hose through while it is flowing under heavy pressure from a hydrant or fire engine. The process of clean- ing a system should commence at the lower end and proceed toward the last lateral. Then the system should be gone over again, This time commencing at the top and working down to clear out all accumulations. Small pipe sewers are sometimes cleaned by putting in a wooden ball having a diameter a little less than that of the pipe. This ball floats until it meets an obstruction when it is stopped and the water dammed up until enough accumulates to force the obstruction on or wash it out.. Sometimes a scraping is necessary in pipe sewers, especially when there is a heavy confervoid growth. A small wooden float, weighted so it will remain an inch or so beneath the surface is attached to a string and dropped down an inspection hole or man- _ hole. It floats to the one below where an attendant catches it and then a small rope is tied to the string and hauled through. A heavier rope is attached to this and when the man at the lower end has orie end of the rope the scraper is attached to the other end and dragged through. A string is tied to the end of the scraper so the rope can be again hauled through without having to work the float a second time. The scraper should go through twice. The writer has used as a scraper a heavy chain several feet long. The first three or four feet has steel wire twisted in each link until it resembles a bottle cleaning brush. The long part of the chain dragging behind loosens silt in the bottom. By hauling the TOWNS AND SMALL CITIES. 87 chain down the sewer' it helps dam the sewage and the pulHng is comparatively light. As the material in the bottom is loosened the extra rush of water helps clean it out. The passage of the scraper is bound to force some material into the house connections. If it goes in the direction of the fibw this will, not be so serious as if it were dragged against the current. After the scraper goes through a gunny sack filled with hay, excelsior or shavings should be pulled through. Then the water in all the houses along the line should be turned on to clear out the .obstructions in the connections. When going over the system the second time from the top to the outlet the chain can be inside the sack. If sand deposits in the sewer the scraper should be simply a long heavy chain and it should be hauled through several times, both with and against the current. There are many sewer cleaning devises now on the market and it will pay to investigate them if any trouble is encountered. Some- times jointed rods are used and they are very convenient. In March and April, 1904, the Sanitary Section of the Boston Society of Civil Engineers held a discussion on "The Cleaning and Flushing of Sewers." The full discussion was printed in the October, 1904, number of the Journal of the Association of Engineer- ing Societies. Copies can be procured from the Secretary of the Association, Boston, Mass. The same number contains a paper on "The Disposal of Municipal Refuse." The copy of the Journal re- ferred to costs twenty-fivex cents and it is worth several times that price for the opinions and-experience of the twenty-five eminent engineers who took part in the discussion generally come higher. SEWER CONNECTIONS. After a sewer system is constructed, it is a source of consider- able expense unless care is taken to regulate connections. Plumbers and drain-layers, if left alone, have a happy-go-lucky way of con- necting houses to the sewers in the streets. If properly looked after no harm is done. The following ordinance from Havre, Mont, (prepared by C. W. Swearingen, city engineer), is a good one for towns and cities of less than 10,000 inhabitants. It is simply 88 ENGINEERING WORK IN a drain-laying ordinance, and does not touch upon matters properly contained in a plumbing ordinance : An Ordinance to. Regulate the Construction, Al- teration and Repair of Sewers and House Drains in the City of Havre, Montana. Be it Ordained by the City Council of the City of Havre, Montana: Section I — Supervision. The construction, re- pair and rriaintenance of all sewers, drains, and cess pools, whether public or private, shall be under the supervision and control of the city engineer. Section II — License. No person, firm or cor- poration shall engage in or conduct the business of sewer connecting and house draining, or ex- cavate any trenches for sewer pipe or open, un- cover, or in any manner make connection with, or lay any sewer or drain, or attach to, modify or repair any appurtenances to sewer connections with the sewer in the streets or alleys or with any private sewer or drain in the city of Havre with- out holding the proper licerrse for such work from the City Council of the city of Havre, Mont., excepting only persons operating under special contract with the city for such work. Section III — Application for License. The ap- plication for license shall be presented to the City Courreil and endorsed by the city engineer; and no person, firm or corporation shall receive such license who does riot have an established place of bthiness within the corporate limits of the city of Havre, and who shall riot first have, furnished the city engineer satisfactory evidence of his or their responsibility and qualifications to ply their trade in acordance with, the requirements of this ordinance and the engineer's rules for the conduct of such work. Se;ction IV — Bond. After favorable action ,by the City Council granting a license, and before the same shall be issued, the applicant or appli- cajits shall 'file with the city clerk a bond in the sum of fifteen hundred dollars ($1,500), which bond shall be approved by the mayor and the city attorney, conditioned upon the protection of the city of Havre against all loss or damage which may occur on account of such licensee through any carelessness or negligence in either TOWNS AND SMALL CITIES. 89 the execution or protection of his work, or by reason of any unfaithful or inadequate work done by such person, firm or -corporation, or by his or their employes, and that said licetjsee as such will also conform to the conditions and requirements of the city for his or their govern- ment, or in default thereof will submit to such penalties as are or may be prescribed by the city engineer. Section V — License Fee. The license fee of a drain layer shall be forty dollars ($40.00) per annum, payable in advance, and no license shill be granted for a greater or less period than one year. Section VI — Use of License. No person, firm or corporation engaged in the business of sewer connecting and drain laying shall allow his or their names to be used by any other person directly or indirectly, either to obtain a permit ' or to do any work under his or their license or bond. Section VII — Permit. Before commencing the construction, modification or repair of any sewer, drain or cesspool the drain layer shall first ob- tain a written permit from the city engineer, and such permit shall be upon the ground at all times during the progress of work and must be shown ' any officer in authority on demand. Section VIII — Applicafion for Permit. All ap- plications for permits must be made in ^writing upon the proper blanks for that purpose, and signed by the owner or his authorized agent, and when it is required they shall be accompanied by a plan showing the whole course of the drain which is to be constructed, together with the size of same, the location o'f all branches, depth of drain below the floor of building," and such other information as may be required by the, en- gineer for, the proper direction of the work. , If the drain is to be connected with a sewer built by private parties, or to pass through property not owned by the applicant, the written consent of the owner must be procured and filed with the application before the permit is issued. Section IX — Fee for Connection. A fee of five dollars ($5.00) will be charged and collected by the city engineer for each connection, to cover the cost of setting grade arid filing in the engineer's 90 ^ ENGINEERING WORK IN office a plan of the work as completed. All moneys collected for sewer connections shall be covered into the city treasury to the credit of the Sewer Maintenance Fund. Section X — Barricades. Excavations in streets and alleys shall be made in such manner as to impede travel as little as possible, and the en- gineer may determine and limit the time such ex- cavation may remain open, and when unneces- sarily delayed he may direct that the number of workmen be increased to hasten the work -to such an extent as he may deem necessary. Red lights shall be maintained upon all unfinished work at night, from dark to sunrise, and suf- ficient barricades shall be in place at all times until the work is completed. Section XI — Refilling of Trenches. All trenches shall be refilled in a careful and workmanlike manner, and tamped or puddled so as to replace as nearly as possible all excavated material, and leave the surface in as good condition as before the commencement of work. Special care shall be observed with trenches within streets and alleys, and all surplus ma- terial must be removed when work is completed, and any refilling of trenches necessary to main- tain the highway- in good condition for a period of one year shall be done by the drain layer. Section XII — Size of Drains. No drain or sewer pipe shall be less than four (4) inches, internal diameter, and all sewers and drains shall be of sufficient size to accommodate the property they are intended to serve. Section XIII — Pipe. All pipes shall be first quality, salt glazed, thoroughly vitrified earthen- ware, sound and well burned, smooth and- thor- oughly glazed exterior and interior surfaces. All connections shall be laid to a uniform grade. Changes in the direction of the sewer shall be made by bends and suitable fittings,' Pipes shall not be cut or chipped except by permission of the inspector, and shall be done under his super- vision. Each pipe shall be carefully bedded as laid, the joint filled with fresh mortar com- posed of one part Portland cement and two parts of clean, sharp sand. The pipe shall be covered with fine earth or sand, free from rocks, and thoroughly packed to prevent the slightest set- TOWNS AND SMALL CITIES. 91 tlement of the drain. A swab shall be drawn through the pipe as laying progresses to clean the mortar joints and exclude objectionable material from entering the sewer. The swab shall be re- moved from the pipe by the drain layer at the completion of the work of sewer connection. Vitrified pipes shall not approach within two feet of any building, cellar, vault, or areaway, from which poifit cast iron pipes shall be used. In case soil pipe has been previously laid to said point by the plumber, the drain layer shall con- nect the two pipes in a careful and workrrianlike manner. Section XIV — Separate Connection, Every building shall be separately and independently > connected with the sewer; provided, however, that when, in the opinion of the engineer, it is deemed advisable to connect two or more build- ings or a line of tenements with the same sewer, the main drain or lateral shall terminate in a man-hole not less than two and one-half feet in diameter at the bottom and two feet at the top; the inverts shall be carefully formed in the con- crete foundation and the top shall have a tight cast iron locking cover. Section XV — Cess Pools. Cess pools shall not be constructed on property abutting on sanitary sewers, and the use of old cess pools shall be dis- continued when public sewers are constructed. Where cess pools are permitted they shall not be located within twenty-five feet of any dwelling, and shall not be less than six (6) feet square and twelve (12) feet deep, lined top and bottom and sides with .two- inch plank placed clo::e together, forming a tight chamber with a vent reaching six (6) feet above the surface. Section XVI — Storm Water. Where rain water leaders are connected with the sewers pro- vision must be made to secure against the en- trance of any objectionable material into the sewer. Section XVII— Improper Use. Entrance into the manholes or opening the same for any pur- pose whatever except by the engineer or other persons duly authorized, is strictly prohibited. No one shall throw or deposit, or cause or per- mit to be thrown or deposited in any vessel or receptacle connected with the public sewer, gar- J2 ENGINEERING WORK IN bage, hair, ashes, fruit, vegetables, peelings, re- fuse, rags, sticks, cinders, or any other matter or thing whatever, except human excrement, urine, the necessary closet papeV, liquid slops,' and drainage of such character. Section XVIII — Inspection. The city engineer may adopt such rules as he may deem necessary to provide for proper inspection of the work, and no work shall be covered until it has been' approved by the inspecjor, who will endorse a certificate of final inspection upon the perrnit issued for that particular work or connection. Section XIX — Penalty. Any person, firm or corporation who shall be found guilty of violating any of the provisions of this ordinance,^ or who shall fail or neglect to comply with any of such provisions, shall, on conviction thereof, be fined not less than five dollars ($5.00) nor more than one hundred dollars ($100.00) for each offense, and ten dollars ($10.00) for each day such per- son shall continue in violation thereof. Wilful violation of said regulations or of the directions of the city engineer or his inspector shall be cause for temporary suspension of the license of the offender by the city engineer pend- ing final suspension by the city council, in addi- tion to any other penalties that may be imposed under this ordinance, and such suspension 'shall operate until such penalties are paid and until license is restored by the City Council ; nor shall such suspension give the offending party the right to the return of any money paid for .such license. Section XX— All ordinances and parts of or- dinances in conflict with the provisions 'of this ordinance -are hereby repealed. Section XXI — This ordinance shall take effect and be in force from and after its passage, ap- proval and publication. Pa'ssed by the City Council this 5th day of June, 1905. Approved by the Mayor this 5th day of June, 1905. L. Newman, Mayor. Attest; R. E, Hammond, Acting City Clerk. TOWNS AND SMALL CITIES. ' S3 SEWAGE DISPOSAL. It is not enough to have a system of sewers installed and leave the disposal of the sewage to a place outside the city limits, as luck will have it. It is no longer safe to discharge sewage into rivers and streams, for the population of the country is increa-sing' rapidly, and all streams are used for water supply. A case was decided a few years ago in which a city was enjoined from discharging sewage into the stream from which its own water supply came. The decision was severely commented on by a certain class of people who believe no m^n . should be restrained in doing things to him- self But people" residing along a stream should not be placed in danger because the people higher up desire to save expense. For such the courts give ample protection and the trend of decisions is more and more severe and confining, until it is Jikely in a few years not the slightest contamination of any water / course will be per- mitted. Modern sanitary science has shown more diseases to result from impure .drinking water than from lack of sewerage facilities and the sources of supply ql drinking water must be protected. Seepage through the soil does much to purify the wastes of living, Gases escape into the atmosphere, but are seldom of a harmful nature. The liquids percolating through the soil and removed from beneficial oxygenizing agencies do more harm. If the soil is of a proper kind and the sources of well supply are not too near the surface the liquids may be purified. If they reach underground sheets of water close to wells they may not be diluted enough to be harm- less. They may rise through springs into the bottoms of rivers and be rendered innocuous by dilution. When delivered, however, in quantities into a river near its sur- face, together with all the waste matter in a putrifying condition, the result is anything but good, and, in fact, in times of sickness, is absolutely dangerous. Cities on the sea -coast and on tidal rivers have often been envied because their sewage could be discharged directly into the ocean and be rendered innocuous by dilution. Fish farming and oyster culture, however, are interfered with by such action. The tides bring back wastes the people want to get 94 ENGINEERING WORK IN rid of and the day is not far distant when all sewage will be puri- fied even before discharging into the ocean and its tidal tributaries. It costs money to handle large quantities of sewage. This is one of the strong arguments in favor of the separate system of sewerage, which provides a minimum amount of liquid; for storm water is taken care of in other channels. There are four methods in general use for the disposal of sewage. Briefly described they are as follows, it being remembered that' many modifications of each kind exist. MECHANICAL SEPARATION. This method separates the solids and fluid matter by straining. The liquid is discharged into a stream or lake comparatively color- less and with slight odor. It is not rendered harmless, however, by this method. Two modern modifications of this oldest of processes are — 1st. Irrigation with the efHuent. 2nd. Filtration of the elHuent. CHEMICAL PRECIPITATION. The sewage is run into tanks and chemicals used to precipitate the solids and clarify and purify the effluent. In both the preceding methods there is a material left, known as "sludge," which is a costly nuisance. Sometimes it is spread over land, allowed to dry and then plowed in. Sometimes it is dried and burned in kilns. Sometimes farmers take it as fertilizer and occasionally makers of fertilizers will take it as a gift. It is almost impossible to sell the stuff and few places can handle it at low cost. BROAD IRRIGATION. The sewage is run on land for irrigation. The land is used for raising fruits and vegetables and truck gardening generally. Some- times land can be rented for the purpose and sometimes it is owned by the municipality and rented to truck gardeners. Properly planned and executed this has, in some places, proven a cheap and efificient method of disposal. But there are many people who object to eating anything grown on a sewage farm. Occasionally such farms have been nuisances. In combination with septic methods of sewage treatment broad TOWNS AND SMALL CITIES. ,95 irrigation will be, and in some places is, successful. - It can only be used to advantage, however, where land is comparatively cheap. FILTKATION. This is an artificial 'scientific improvement upon broa,d irriga- tion, and is used in connection with mechanical separation, chemical precipitation, sedimentation, septic processes, or alone. As a final treatment for septic sewage, continuous or percolating, filter beds are at present the favorite. Otherwise intermittent filtration is best. Filter beds may be from two to five or six feet thick, composed of porous material in graded layers. For filtering material there are in use earth, sand, . broken stone, burnt clay, pieces of brick, shells, coke, cinders, gravel, glass, etc. The best material is one that will not break dovyn into dust and clog the bed, will "be suf- ficiently porous to have a beneficial straining action and present enough surface to support good colonies of bacteria. A filter bed works in two ways — 1st; It mechanically separates matter in suspension and, 2nd, it contains oxygen in the interstices of the material, which, aided by bacteria, oxidizes organic matter. It should have plenty of air and then the two -classes of bacteria men- tioned in the chapter on Sanitation can exist. When the filter is clogged only the putrefactive bacteria can exist. With intermittent filter beds the sewage is retained until the bed is full, when it is drawn off suddenly in order to cause a rush of air into the open spaces. In some systems filling is immediately recommenced. In others the beds are allowed to rest for about one-third the length of time sewage stands in them in order to absorb oxygen The writer believes that sedimentation and filtration, in com- bination with irrigation, will be the best solution of the sewage dis- posal problem. It is not always that the right conditions obtain, however, so the application is comparatively limited. The septic tatik then becomes a necessity. SEPTIC TANK. On this process the newspaper and magazine scientists" have become hysterical. A comparatively recent patented method utilizing 96 ENGINEERING WORK IN mysterious "bugs'' for the protection of man it has been an adjunct of the fairyland of science and entrancing to conteinplate. The writer believes that patents on the septic tank process are worthless, as its action has been known many years. Patents on appliances connected therewith to regulate flow, etc., are perfectly safe. Tanks can be, and have been, built without many things often urged upon councils. Good contact filter beds depend almost wholly upon aerobic bacteria and dispense with putrefactive processes. The septic tank is a tank with, or without, a roof wherein the sewage is held for a time to permit the anaerobic, or putrefying bacteria to throw down the solids and convert them into liquids. There is some precipita- tion in connection, but no chemicals are used. The action is pre- cisely the same as the action going ,on in a tight cesspool and privy vault. A small amount of sludge accumulates in the bottom and this sludge can be removed at any time for disposal. It dries into a fine dust and is harmless. It is really an ash such as is left after combustion. The liquid flows to filter beds where aerobic bacteria comr plete the work of purification. Where a high degree of purification is desired there should be three sets of filters, but in many plants only one filter is used after the preliminary treatment in the tank. The real value of the .septic tank lies in the fact that it destroys suspended matter without forming any great amount of sludge. It also acts largely to prevent a coating over the bacteria beds of cel- lulose matter more or less impervious to water. It also forms substances easily acted upon by the nitrifying bacteria. There is a further advantage, in that in all systems of filtra- tion there comes a time when the filter is clogged to a certain extent and the anaerobic bacteria increase too rapidly while the aerobic bacteria diminish. The beds then become offensive. The septic tank does much to prevent this by furnishing an ideal place for the anaerobes to work. A septic tank in connection with a filter and subsequent use of the effluent for irrigating kitchen gardens and lawns, is ideal for country resideijces and houses with grounds. A complete bacterial purification plant consists of a silt box, or detritus tank, to retain heavy inorganic matter; a s'eptic tank, with pump chamber; a sludge bed, and filter bed, or beds. Although TOWNS AND SMALL CITIES. 97 such a plant will remove 99 per cent of harmful micro-organisms the remainder can do damage, so final treatment over a farm dr on sandy soil, is advisable before allowing the effluent to run into a stream used as a source of water supply. SEDIMENTATION. Although it was stated at the beginning of the section on sewage disposal that there were four methods of sewage disposal with many variations on each, some readers may think that se4i- mentation can not properly be treated as a variation. Sedimenta- tion processes required tanks with a very slow velocity in which sludge settled and was periodically cleaned out. It was a process for simplifying the treatment of the liquid sewage. The septic tank really developed from the sedimentation tank. CHAPTER IX. WATER SUPPLY. "Where the vast aqueducts, carrying the purest and most necessary gift of God, reared their arched heights on Roman plains." — Anon. One of the first questions asked by a possible resident, or manu- facurer, who may locate in a growing town, is in regard to the water supply. He wants to locate in a place where he can get a plentiful supply of water for manufacturing purposes and for protection in case of fire. If there is a plentiful supply of water he also in^quires about a sewer System, for one is needed to carry off the waste. Water is needed for drinking, manufacturing purposes, laun- dries and baths, street sprinkling, sewer flushing, irrigating lawns, fire protection, etc., and if it is not good for all of these uses it is not a good commercial water. It may be all right for, cooking and drinking yet unfit for manufacturing, or vice versa. It is diffi- cult to get a water perfect in all respects, but good water of an aver- age quality can generally be obtained in sufficient quantity for any sm^ll place at no great expense. If it is polluted or impure it must be purified, if it is found to be impossible to get a better supply by going a little farther. Great' attention is now paid to the purity of water in the United States. Good sources of supply are difficult to procure and some artificial purification is rendered necessary, for people today will not take readily the water their grandfathers would have been satisfied with. ^ There are two systems of filtering in vogue, the first called slow sand filtration, and by some the English system. The other, rapid filtration or the American system of mechanical filtration. In the slow sand filtration system the water is led into filter beds where it percolates slowly through the filtering medium. On the surface of the sand slime is formed. A felted slimy mass of algse, and various bacilli, accumulates in this cultivation bed and here the main purification of the water takes place. It is therefore necessary, TOWNS AND SMALL CITIES. , 99 for the proper working 6f the sand filter, that this jelly layer be formed, and the process of purification goes on by the action of the nitrifying organisms until the filter becomes clogged by the sus- pended impurities and the flow of water gets scanty. It is then cleansed and put in shape for further use by skimming oflf the sur- face layer and putting on a fresh coating of sand. The water is turned in again and allowed to waste until a new jelly has formed when the effluent is turned into the city mains. In some places a lot of the old sand is put back with the new in order to hasten the formation of the jelly. Great numbers of filter beds are re- quired, as the work is done intermittently in order that the beds may be kept in. the highest possible state of efficiency. The system of slow sand filtration is therefore expensive and is better suited to very large cities than to smaller places. The mechanical system of filtration is an American invention and consists of tanks containing finely pulverized quartz as a filter- ing medium. A chemical coagulent is added to the water in small quantities to form the jelly and it is not therefore necessary to wait ■ so long for the filter to get into action. When it requires cleaning the flow of water is reversed in the filter and by machinery the sand is stirred up until the water running out is clear. The water is. set running the right way again, the coagulent added, and in a short time the filter is working at its full capacity. For a small town it is better than the slow sand filtration method and it may be better in larger places, but more experiments will have to be made before a positive opinion can be given. The primary idea of a filter was a strainer where the suspended matter was taken out. When the matter was thoroughly understood it was found there was a bacterial action also and the ordinary household filter instead of being a protection was an absolute danger, for it cultivated colonies of dangerous bacilli. A household filter in which the filtering medium is a baked clay or porcelain is the only kind to use. Dealers often say the way to clean them is to take out the porcelain once a week and wash it. Such advice is dan- gerous. The only way to clean it is to boil it by placing in cold water after washing and putting in a pot on the fire and allowing the water to come to a boil and boil brisky until the porcelain is hot. Then let it cool slowly. If the porcelain is cracked get a new one. Lake water is a doubtful source of supply. Ground well water 100 ENGINEERING WORK IN is sometimes safe to use, but is generally unsafe if taken from ground close to a large commvmity. The well in the thickly settled community is usually dangerous and the open well can not be condemned in too strong terms. If a well is used it should be closed and the water pumped from it for ordinary use. Driven wells are frequently used as a source of supply for a town and they are good if the quality of >vater is all right. For this reason when deciding to adopt the driven well system a careful examination should be made chemically and biologically of the water and an examination made as to the possible sources of supply of the sand and gravel bed into which the wells are driven. A large cistern may be constructed with several wells driven in the bottom of it. Water is theti pumped from the cistern or the wells may be driven in a regular series and connected with a main pipe from which the water will be pumped.- When the quantity required is not great, the best system is by pumps, with a standpipe, or tank, containing at least twenty- four hours' supply. The tank furnishes the pressure except in case of fire when it is better to disconnect it and let the pump force the water directly into the supply main. Ordinarily the pumps need only be used to keep the tank filled and there should be some sort of ■electrical indicator in the pump house so the engineer need not pump too much and cause the tanks to overflciw. With a town of over 3,000 inhabitants a direct pumping system may be preferable, with several standpipes in different parts of town, if it is very hilly or broken. The standpipes will be supplied by the force main and each supply its own district. There should be standpipes or tanks to supply districts ordinarily supplied by' direct pumping, in case of the pump being required to work in other districts when a fire breaks out and more pressure is needed. Each district can thus be as independent as though in different cities. With a large city a gravity system may be less expensive than a pumping station, but it will require careful figuring in any event With a gravity system reservoirs are generally used instead of tanks and standpipes. It is well to remember that when surface water from streams and lakes is stored in reservoirs that the reservoirs must never be covered, but should always be exposed to the light and air. When water from wells and underground sources is stored TOWNS AND SMALL CITIES. - 101 in reservoi/s it must be covered to exclude all light. This to prevent the growth of algs. Artesian wells are good enough in their way when no othef source of supply is available, but it is seldom that a well can be obtained of sufficient flow to si;pply even a small place, A town considering the proposition of obtaining water from artesian wells must proceed slowly and carefully; in order that after the hole is bored and the pipes laid, the volume of water to depend upon will justify the expenditure of the money spent to secure itT^ Salt water is used in sea side cities to sprinkle streets and has been found to be very much superior to fresh water for the purpose. It has been found of doubtful benefit in extinguishing fires, as a building well soaked with it never dries thoroughly. A pumping plant should generally be in duplicate so in case of breakdowns there will be no stoppage of the supply. This is not so important where the plant does not have to work more than a few hours each day or for a d^y or so in the week. For small towns, and generally throughout the west where fuel is scarce, the gas or oil engme connected to a power pump is coming rapidly into favor. The writer has recommended their use and believes they are the best thing in many cases for the service. They are useful in larger places also where there may be isolated districts to serve of limited area. In such places a separate pumping station with ele- vated tank can be placed and the water pumped from the main to this tank, which communicates with the pipe system in the small district as an independent supply. Again they may be used in towns where the water - company has a contract to furnish a certain high pressure in case of fire and the pumps do not work constantly. The pumps may supply tanks or standpipes at a sufficient elevation to furnish a good pressure for domestic use. The smaller gas or oil, engine may pump from these tanks sufScient to fill a smaller tank at a higher elevation which can be connected with the main system of pipes in case of fire, a check valve preventing the backing of the water into the lower taiik. As' this tank for fire purposes may not be used once in six months and ihight contain water enough to last a half dozen fire streams an hour or two a small engine will do the work at a minimum of attention and expense. In some favorably situated - places good tank capacity is fur- I 102 ENGINEERING WORK IN nished and large windmills are used. There is an oil or gas engine in reserve to use when the wind fails. A good windmill will cost nearly as much as an engine of the proper size. There is a great deal of economy resulting, however, when conditions are favorable. Producer gas engines are coming rapidly^ inta. use and well repay investigation. Electricity is used as much today as steam power in many cities having electric plants. , QUANTITY OF WATER. It is not safe to figure on less than thirty gallons per capita per day,, and the amount in a manufacturing town may reach sixty to eighty gallons per day per capita. Estimates based on the total population. Some American cities use much more, A leading authority has carefully investigated the use of water in American cities and his conclusions are that 60 per cent of the water is not accounted for. In Europe where there is more careful and judicious oversight it is stated that fully 90 per cent of the water is accounted for. Too little care is exercised in laying water pipes. In the opinion of the writer (from actual experience) it pays to set stakes for the water and gas pipes as much as it pays, because it is absolutely necessary, for sewers. Settling strains play havoc with joints. For convenience in making joints it is usual to elevate water and gas pipes. When this is done the trench to the tops of the pipes should be filled with sand, flushed in with water to give the pipes a solid bearing. Waste exists all through the system by reason of careless work in putting the pipes in place and also by reason of faulty work in making house connections. - The writer has- seen plumbers con- necting houses when the main was of thin wrought iron and there being a leaK under the saddle they beat around it with their hammers until the flow stopped — not adding anything to the excellence of the nearest joint in the main, which may have been defective at first. Waste also exists in the interior plumbing of the house and when a water works system is installed there should be a first-class ordinance passed to regulate this work and all cocks and faucets should be of a certain standard of excellence. But a very large part of the waste exists by reason of the householder being careless because he pays so much a month no matter how much he uses. TOWNS AND SMALL CITIES. " 103 The only re;nedy is the introduction of meters. An immediate saving in running expenses is noticed. There is not always a reduc- tion in revenue, but there is a saving of cQst and a consequent increase in actual profits. The careful economical citizen does his best to reduce his water bill and after he becomes accustomed to the meter finds that he does not have to skimp, as the minimum meter charge allows him plenty of water for every ordinary pur- pose. Wherever the meter system has been introduced it has been favorably received and its use extended. There has existed oftentimes a prejudice in the mind of the consumer against a meter for fear it will register in favor of the company, but a little reflection will show him that as it wears much water must pass through it without being registered, so if the new meter registers in his 'favor it will be apt to do so as it grows older. In some places a tank is placed in the water complany's office which contains exactly ten cubic feet of water at ordinary temper- ature. A house meter is attached to the supply pipe and water meas- ured into the tar^)c before the eyes of the consumer and he can read the result himself. With a meter geared to 99 per cent there is no fear of the test not satisfying him and he can go with the man and see that same meter installed in front of his house on the supply pipe. A report by the board of water commissioners of Hartford, Conn.,- said : "Meters act as mechanical inspectors of plumbing and as such are less objectionable to consumers than individual in- spectors, as well as being more effectual and reliable." It is possible to obtain in almost every city reliable house meters at moderate prices and their general introduction will reduce the cost of living and do away with enormous waste. As a guide to the possible use of water for various purposes thq following from the 1905 report for the city, of Battle Creek, Mich., is interesting: Per cent. Paid for by meter (12.2c per 1,000 gallons, average) . . 53 $23,000 Paid for, not metered 5 2,200 Parks, public buildings, not schools 8 3,500 . Schools, including lawns 6 2,600 Drinking fountains for horses 5 2,200 Flushing sewers 0.5 200 104 ENGINEERING WORK IN Blowing off hydrants 0.5 200 Wetting down new trenches 8 800 Fires 4.5 3,029 Slip of pumps 3 1,300 Urider registration of meters; 6.5 8,800 Leaks 6 2,600 Totals 100 $43,429 ^ The percentage of taps metered in 1905 was 88, or 3,879 out of 3,723. The average daily water consumption and waste per capita was 52 gallons. The meter rates range from 7 to 13 cents per 1,000 gallons, with a minimum annual rate of $3.00. All new water takers are required to put on meters, and all who change pipes or fixtures or added thereto. The writer thinks some guessing was done in apportionment. The fire use seems much too great. In a number of municipally owned plants water is apparently sold to the consumers at a low price because rates have been low- ered and many departments of the city get water free. To be businesslike all departments using water should be charged lor it and a sinking fund established to maintain the plant. In an interesting circular prepared by the Pitometer Company there is a discussion on the ■ subject of waste through underground pipes, although waste is carefully looked after above ground in the matter of salaries, cost of fuel, etc. The fact that what one city uses is not a criterion for another place is mentioned, and the following is quoted: "The water used by 2,553 families in Providence, R. I., was measured for one year. Five persons counted to a family, make a • total of 12,765 people. By actual measurement : 167 families used but 6.15 gallons to a person. 237 361 445 446 463 435 " 8.20 " 10.25 " 13.30 " 14.35 ' 16.40 " " " " 18.37 " " ■ " And yet we find Ainerican cities publishing the information, year TOWNS AND SMALL ,CITIES. 105 after year, that their works are actually supplying 150 to 300 gallons each day to each person in the city! The question is then taken up of the Chicago water supply, which in 1903 amounted to 160 gallons per capita. Estimating the actual consumption at more. than three times the highest average in the above table, or at 60 gallons, we have left a per capita of 100 gallons, or a total loss of 187 million gallons per day actually raised by pumps from the lake. Cities and private companies in England allow no such waste. By constant care, and by inspections judiciously made, as a regular part of administration, they keep the per capita consumption down to very different figures. For instance : In Liverpool, for all pur- poses, 38.346 gallons per capita, of which only' 23.18' per capita is set down for domestic uses of all sorts. There is no restriction of use by the consumers, day or night. In Manchester, 35.67 gallons per capita, of which 19.67 gallons is used for domestic purposes, 16 gallons for trade. In Birmingham, 29.52 gallons per capita. In London, 42.43 gallons per capita. These figures can be duplicated to any extent, but, it will be said, "This is in England." Let us take the city o'f Providence, R. I., again : In 1892 the per capita had increased to the alarming extent of 65J4 gallons per capita. In 1894 this had been reduced to 51J^ gallons by taking pains to discover where this great loss was made ! These figures include all the water delivered . from the works for all purposes. In the town of Ealing, England, with a population of 25,000, the per capita was reduced from 43 gallons per capita to 30.75 gallons per capita, by an eight weeks' campaign of the inspectors ! Losses through defective mains or service pipes tend to increase in amount rapidly. The history of the Chicago works shows this fact very clearly. Thirty-five gallons per capita was the original estimate of the engineer who designed the plant. In 1860 the .actual per capita was 43 gallons; in 1870 this had increased to 73 gallons; in 1875 to 100 gallons ; in 1890 to 138 gallons ; in 1900 it had reached 200 gallons; while in 1903 we find a per capita of 160 gallons after deducting all metered water." Much of the difference is caused by leaky and defective mains and connections. ^ It has to be admitted, however, that sometimes water is stolen outright. ' Nearly every man experienced in water 106 ENGINEERING WORK IN works maintenance can tell of 'private connections made by tunneling to street mains, and of by-passes around meters. It pays to install meters on every connection and also on mains, to divide the city into districts. A careful investigation from time to time will locate all losses closely and remedies can be applied. If pumps register a certain amount of water delivered to the mains and meters register a certain amount used, there must be a better way of accounting for differences than by estimating uses for publib purposes. Twice the writer has been called upon to devise means of pro- curing a large supply in towns bonded to the limit, and yet suffering from a shortage of water. A careful investigation revealed such losses that when the piping system was put in good shape and all connections metered, the per capita consumption as shown by pump- ing records, was cut almost in two. Other engineers have had similar, experiences. GENERAL USE. Good fire hose will cost at least 80 cents a lineal foot. The life of fire hose is not long and when it^s observed how rapidly elective pressure is lost by long streams no argument is required to show that large mains are an advantage in a water worKs systein. The following table is' instructive: FIRE STREAMS. Presspres required at nnzzte and at pump, with quantity and pressure of water necessafV to throw water various distances through different sized nozzles, using 2 1*2 n4 under, dust Stone 2H inch, irith most small stone Gtara), K lnc» 4~flc^eenedout-^ r- screened out.-. /-screened out -\ #- and under •^ 1 ■i 1^ i i 1 1 4 i 8 B 1 1 V § •a 1 3 V 1 o i t 3 i" a u 3 3; i 1 6 1« 2.0 4.0 1.40 0.44 0.89 1.4i 0.45 0.90 1.53 0.47 0.93 1.34 0,41 o.at 2.5 5.0 1.19 0.46 0.91 1.21 0.46 0.92 1.26 6 4g 0.96 1.10 0.42 0.83 3.0 5.0 1.11 0.51 0.85 1.14 0.52 0.87 1.17 0.54 0.89 1.03 0.47 0.78 3.0 6 1.01 6.46 0.92 1.02 0.47 0.93 1.06 0.48 0.97 0.92 0.42 0.8« 3.0 7.D 0.91 Oi.42 0.97 0.92 0.42 0.98 0.94 0.42 1.05 0.84 0.38 0.89 4.0 7.0 0.83 0.51 0.S9 6.84 0,51 0.90 0.87 0.53 0.93 0.77 0.47 O.B) 4.0 8.0 0.77 "6.47 0.93 6 78 48 6.95 0.81 0.49 0.98 0-71 0.43 o.sa (From paper on "'Concrete" by Chas. MatchemO When the best concrete obtainable is wanted the proportions should be fixed by the cement mortar. The following extract from specifications recently prepared by the writer for a reinforced concrete chimney illustrates this; "The concrete shall be mixed as follows: One bag of cement shall be considered to be one cubic foot and the cement mortar shall be mixed '^ in the proportion of one part of cement by meas- urement with. two parts of clean sharp sand by measurement. If mixed by ^hand the sand and - cement shall be mixed dry until an absolutely uniform color is obtained and then water shall be • added to make a paste the consistency of thick cream." "The voids in the stone having been first ascertained, enough cement mortar shall be used to completely fill the voids. If the voids exceed one-third the mass they are to be reduced by TOWNS AND SMALL CITIES. 129 means of screened gravel or small stone to the required amount. Sand shall not be used to reduce the voids in the stone. The percentage of cement mortar in the concrete shall not exceed thirty-three (33) per cent, nor be less than twenty-five (35) per cent." The foregoing is for a certain piece of work. It can be varied. It is better always to prescribe the cement mortar and determine the voids in the stone. A great many men want rules for estimating quantities of ag- gregates when the voids are not known, but must be assumed. There are several rules in common use, but it must be remembered they are only true for certain proportions of voids and are simply good for purposes of estimating. Assume an example where the mixture is 1 to 8 gravel and cement. Assume that bank gravel contains 20 per cent of voids. There /are 37 cubic feet in one yard. Add to this 20 per cent and the total equals 32.4 cubic feet. By one rule one-ninth of this is cement. By another rule one-eighth is cement. Count 3.8 cubic feet per barrel and this gives practically one barrel of cement per yard of concrete. Some men count the cement as one-ninth of the mass provided all the voids are filled. Others claim that the 20 per cent of voids in the gravel, can be filled with fine sand and this sand will contain voids that cement will fill. Therefore they count the cement as being simply one-eighth of the mass. Assume a mixture of'l cement, 3 sand and 5 broken stone. The stone contains 40 per cent of voids. The sand contains 35 per cent of voids> As the voids in the sand are less than the voids in the stone and the proportion of cement is fixed, we will neglect them. Multiply 27 cubic feet by the percentage of voids in the stone and add this to 27. Divide by the sum of the parts of sand (3) and stone (5), a total of eight. Multiply by 3 .and divide by 27 to get the cubic yards of sand. Multiply by 5 and divide by 37 to get the cubic yards of stone. To get the number of barrels of cement divide the cubic feet of sand by 3, as there happens to be three times as much sand as cement. This result divided by 3.8, the cubic feet of cement per barrel, gives the number of barrels of cement, 130 ENGINEERING WORK IN The above rule fixes the cement as a proportion of the sand, as fixed in the specifications. Some men would have divided the large amount first obtained by the sum of the cement, sand and stone, making 9 instead of 8, and proportioned the aggregates in that manner. A general rule used by a number of men is credited to Mr. Fuller; It is simply to add the number of parts, thus : 1 plus 3 plus 5 equals 9, and divide'by 11, to get th« number- of barrels of cement. If the barrel is assumed to hold 3.8 cubic feet, multiply by 3.8 to get cubic feet, and multiply by 3 to get cubic feet of sand, and by 5 to get cubic feet of stone. If the cement barrel contains less than 3.8 cubic feet of cement the rule is worthless. It is assumed also for a certain percentage of' voids in sand and stone. The rule first above given can be used with any percentage of voids or with any size cement barrel. Hand mixing is being supplanted by machine mixing and there are a number of machines in the market. The writer classifies themTis follows: 1st. A stationary receptacle without inside deflectors. Snd. A stationary receptacle having fixed deflectors. 3rd. A stationary receptacle with movable deflectors. 4th. A movable receptacle with stationary deflectors. 5th. A movable receptacle with movable deflectors. .. 6th. A movable receptacle without inside deflectors. The machine mixing of concrete is required in all good work today, so a man doing extensive work and not using a mixer is behind the times. The proper kind of machines does the work cheaper than by hand and the mix is more thorough. CONCRETE BLOCK SPECIFICATIONS The following specifications for the manufacture of hollow con- crete building blocks are proposed as a standard by a Committee on Standard Specifications of the National Association of Building Block Machinery Manufacturers. DEFINITIONS. SAND— Such material as will pass through a screen with }4-inch mesh and is retained on screen with a No. 40 mesh. This TOWNS AND SMALL CITIES. 131 applies to river sand, bank sand or screenings from a stone crusher. GRAVEL — Material obtained either from a bank or a river of such size as is retained on a screen having a j4-inch mesh. CRUSHED STONE — Such stone from a crusher as is retained on a 54-'nch screen. BANK GRAVEL — Such material as is obtained from a pit or river containing both sand and gravel. AGGREGATE — Any material such as broken stone, gravel or such fragments psed with cement and sand mortar in making con- crete for the purpose of reducing the cost and adding to the strength. VOIDS — ^The space existing between particles of sand, crushed stone or materials of which an aggregate is composed. CEMENT — Any Portland cement which will pass the tests required by the American Society for Testing Materials. QUALITY OF SAND, Sand suitable for concrete work must not be finer than the above described ; must be sharp and gritty ; not soft or loamy ; must be free from loam or other foreign material, and must not contain any perceptible amount of clay, or other soluble matter. Some authorities concede that clay to the extent of 10 per cent in sand or gravel is not harmful. This committee is of the opinion that any perceptible amount of clay is unsafe. Crushed stone must be reasonably free from dust and must be retained on the same size screen as the bank sand, viz., J^-inch- Gravel or crushed stone must be free from loam, dust or other foreign material, and must contain no .soft or rotten stone. DETERMINATION OF AMOUNT OF CEMENT TO BE USED WITH AGGREGATES. A theoretically correct concrete should consist of sand and gravel or crushed stone or a combination of them, containing any amount of cement equal to the voids in such combination. In other words, interstices should be filled with cement. To state 'this in another way, if the concrete is made up of sand and gravel, such proportion of cement should be used with the sand as is equal to the voids in Jhe sand, and such quantity of this resulting mortar of sand and cement should be used wjth the crushed stone or gravel as will fill all the voids in the crushed stone or gravel. 132 ENGINEERING WORK IN Restating this in a few words, the cement should fill the voids in the sand and the resulting mortar should fill the voids in the aggregate. DETERMINATION OF VOIDS. To determine tlie voids in the sand, or the material to be used as an aggregate, what is known as the "water test" is employed. In preparing for -this test the sand or gravel must be perfectly dry. Sand has a greater volume when wet. A receptacle holding a known amount, such as a quart jar, is filled with the material to be tested, sand, for example, and into this receptacle is poured as much water as the sand or other material will absorb. The water should be measured. The amount of water absorbed indicates the voids, and also indicates the exact amount of cement which it is necessary to use in order to produce a solid concrete. In making hollow blocks if no gravel or other coarse aggregate is used, the result of this test sho'uld give the proportions of sand ■ and cement to be used in block manufacture. Average sand will absorb 35 to 35 per cent of water, indicating from 25 to 35 per cent of voids, also indicating that the proportion to one part of cement to from three to five parts of sand are required to make a solid concrete. The proper selection of sand and aggregate material is im- portant. Care should be taken that the particles vary so in size as to reduce the voids ' to the smallest amount possible. With .this careful selection the amount of cement required to produce good work is greatly reduced. MIXING. After the materials are selected they should be mixed together dry until thoroughly incorporated, or in other words, until the mass IS of an absolutely uniform color. Water should then be applied and the thorough mixing repeated. The amount of water should be in all cases as great as possible without causing the materials to stick to the molds when the stone is removed. A little more care in the treatment of the face plates of any machine will enable the manufacturer to use a wetter concrete than is usually employed'. Only such size batches should be mixed at one time as can be used up within thirty minutes from the time the water has been added. TOWNS AND SMALL CITIES. 133 MANUFACTURING. The concrete should be placed in the mold^n small quantities and tamping should begin immediately upon the placing of the first shovelful, and continue until the mold is full. The material should be tamped with a tamper having a small face, and short, quick, sharp blows should be struck. In faced blocks the face should be composed of two parts sand and one part of cement, the same being mixed in the manner described above. Owing, however, to the excess of cement used in facing, and owing, further, to the fact that the cement is what makes the concrete sticky, the facing can not be used as wet as the balance of the block is made. Great care should be taken to tamp the con- crete thoroughly into the facing so as to unite the two into one solid stone. In the wet process the amount of water used is such as will produce a plastic, or flowing, condition in the concrete, but not enough to wash the cement from the other material. When placing the material in the molds the entire mold is filled with one pouring. No stone having transverse ties or webs cracked should be used, or even allowed to cure. Should a slight crack occur in moving the green stone, throw the material, back, and make it. over. In no case use a cracked stone in a building. CURING. All stone made by the medium wet or medium dry process should be made under cover, ancl kept under cover for at least ten days, protected from the dry currents of air. If shed room is not available to store a ten days' output, the blocks should be car- ried out after the initial set has taken place, and covered with canvas, hay or other covering, which will retain moisture, and at the same time keep the dry air from circulating around the block. Under no circumstances should blocks be made under the direct rays of the sun, nor should blocks made by this process be exposed to either sunshine or dry winds while curing. The blocks should be gently sprinkled as soon as possible after making, that is, just as soon as the cement has set sufficiently so that it will not wash. Blocks should be kept wet from ten days to 134 ENGINEERING WORK IN two weeks, and should never be removed from the yard for the purpose of using in a building until they are from thirty to sixty days old. This is very important. A green block will surely crack in the building on account of shrinkage. , LAYING. In laying cement stone a soft mortar composed of one-half cement mortar and one-half lime mortar should be used. This mortar should be made with fine sand free from stone and should be buttered on the ends of the stone before laying. The' stone should be laid in the mortar and work down. Do, not leave end joints open until after the building is completed, because when the end joints are filled at this time shrinkage in mortar is liable to loosen it, causing the mortar to fall out, leaving openings through the wall. The spreading of mortar is very important, because if mortar is unevenly spread so that it is thicker under one portion of the stone than under the other, a leverage is created, which under the weight of the wall above is liable to produce a crack in the stone. COLOKING. In using coloring matter with concrete, the color should always be mixed with the cement dry, before any sand or water are added. This mixing should be thorough, sa that the mixture is uniform in color. After this mixing the- combination is treated in the same way as clear cement. The writer wishes to add to the above that the mortar recom- mended is, in his opinion, too rich in lime and the excess of lime will create an efflorescence in the face of the block. Very few concrete block buildings look good in the joints. , There is today on the market a material known as Bricklayers' Cement, manufactured in Louisville, Ky., that is excellent for cement block joints. It is made by grinding 15 per cent of hydrated lime with calcined cement stone to a powder that leaves only 5 to 8 per cent on a sieve of 10,000 meshes per inch, thus securing a perfect mixture in proper proportions, much better than any dry mixing attempted by hand. TOWNS AND SMALL CITIES. 135 All blocks should be thoroughly wet on the sides to which the mortar is applied. Not simply wet with a brush passed hastily over, but soaked like brick are soaked. - Unless this is done the blocks will absorb the moisture from the mortar like dry bricks and there will be no perfect bond. The writer has found nothing equal to retempered mortar for cementing concrete building blocks. It is very slow setting and the adhesiveness being somewhat destroyed by the retempering an addition of from ten to fifteen per cent of hydrate of lime restores it. Retempered mortar works nearly as well under the trowel as lime and cement mortar mixed half and half. Being so slow setting, it takes readily the weight of the stone wall and variations in thick- ness make little difference. It is not so much a difference in thick- ness as it is a difference in density of the mortar. A thoroughly worked retempered mortar is creamy and when spread is of fairly uniform density and if care is taken to make the thickness uniform the slow setting while the wall is settling prevents the leverage spoken of in the proposed standard specifications. _The specifications for mixing coloriHg matter are excellent, but they do not go far enough. Coloring matter containing acids will attack, the akaline sub- stances in cement and destroy it. Be careful, therefore, in select- ing the coloring pigment and do not be too free in coloring con- crete work. All the materials used weaken cement except ultra- marine. This seems to add somewhat to the strength. To make a gray surface more pleasing to the eye than the natural cement color, use not to exceed one pound of lampblack to a bag of cement or four pounds per barrel. The writer has attended cement conventions and listened to papers on coloring cement work and has mingled with men who have related to him many different kinds of experiences with color- ing matters. His only personal experience has been with lamp- black and with Pikron. It is unwise to use more lampblack than mentioned above and he does not think it well to use more than half that amount. Pikron was* used by him on the Pacific Coast fifteen years ago to get a better gray than lampblack yielded safely. 136 ENGINEERING WORK IN It was mixed with the water and made it look like ink. He^ has seen no advertisements of this material in several years. What follows on the coloring of cement is not from the writer's experience, but is culled from many sources. For green use 5 lbs. of ultramarihe, and for blue use 6 to 7 lbs. of ultramarine per bag of cement, or four times those amounts respectively per barrel. One authority says 2 lbs. of Excelsior Carbon Black per bag or 8 lbs. per barrel will make a good black. Another says use from 10 to 11 lbs. of manganese dioxide per bag or from 40 to 45 lbs. per barrel. Use 6 lbs. per bag or 24 lbs. per barrel of Roasted Iron Oxide for brown. Yellow Ochre makes yellow when 6 lbs. per bag or 34: lbs', per barrel are used and it makes buff when the quantities are nearly doubled. An ordinary red can be made with frbm.e to 10 lbs. per bag, or from 24 to 40 lbs. per barrel of Red Iron Oxide. A bright red can be obtained with 6 lbs. per bag, or 24 lbs. per barrel of Pom- peiian Red. So-called white cement is often merely plaster of Paris. At Sandusky a white cement is made that is claimed to be a true Portland. The cement, however, constitutes such a small portion of the concrete that care must be taken to use_white aggregates when trying to approximate to a pure white. A pure white can not be obtained. The writer has seen some marvelously good work, however, when white cement was used with marble chips instead of stone and marble dust instead of sand. He has seen good results obtained with light colored stone, per- fectly clean water, marble dust and screenings instead of sand and a final dusting of marble dust before the concrete was dry. RETEMPERED MORTAR. It is common to see a clause in specifications forbidding the use of mortar that has commenced to set. Today, however, it is well known that retempered mortar has a Value. If allowed to set for about half an hour and then worked very vigorously for ten or fifteen minutes the time of ultimate set is prolonged. , There is no decrease in strength until after the second or third re-working. There is sometimes a slight loss in adhesiveness. This TOWNS AND SMALL CITIES. 137 U. restored by adding 10 or 15 per cent of hydrate of lime to the mortar. It is a difficult matter to make fresh concrete join to old work. The ordinary way is to clean the old surface and thoroughly wet it. Then put the new concrete against it. The writer prefers to wash the cleaned surface with a one per cent solution of sulphuric acid and then put on a layer of retempered mortar, after washing off with clean water the acid wash. The retempered mortar is slow setting and interposes betwen the . old, hard set concrete and the new, quick -setting concrete, a layer of material that will join to both. It forms, as it were, an elastic joint during the time the new concrete is setting. Ill repairing the surface of sidewalks retempered mortar is good. First cut the broken place down half an inch or more with square edges. Then clean the space with a wire brush and wash it with a ope or two per cent solution of sulphuric acid. Mix a batch of rich mortar, about one to one, cement and sand, and allow it to stand thirty minutes. Then- with a hoe and shovel work it vigorously and thoroughly until it is like a smooth working dough. Wash off the acid with clean water and put the retempered mortar in the space. It must be more vigorously trowelled than is usual for such work. After a little experience a mason can make such repairs in a way ' that will defy detection. PROPORTIONING AGGREGATES TO FILL VOIDS. In the proposed standard specifications for building blocks it is stated that voids in materials can be determined by using a small amount and pouring in water. In the opinion of the writer the amount is too small. His method is as follows: Use a box containing about five cubic feet and fill it flush with the stone, or largest sized aggregate. - Pour in water gently in order that no air will be trapped and measure the water as it goes in. The amount of water used deter- mines the amount of finer rhaterial netessary to exactly fill the voids. Empty the box on a platform and spread the material in a thin layer, allowing the water to run off. Then cover it with the next smaller size of aggregates as determined l^ the amount of water used to fill the voids and turn the whole mass over with shovels 138 ^ ENGINEERING WORK IN until well mixed. Then shovel it into the box, tamping it so the whole amount will go in. Should it more than fill the box screen the remainder to separate the sizes and remove from the box enough of the smaller size material to permit the surplus of the screened large material to, go in. In this way all the coarser material will be in the box and enough of the smaller material to pack the voids. Fill the box again with water. This amount of water repre- sents the amount of the next, smaller sized material necessary. Take for example that stone, gravel and sand are being used. The first aggregate tested for void was the stone. The second- test was the stone and gravel. The third test is for stone, gravel and sand. The material necessary to fill the voids, after screening surplus, must be placed on a memorandum. The amount was 'found by using water, but when placing in the box it will be found that on account of the sizes of the smaller sized aggregate some will not pack in like sand or cement. Having filled the box again with water empty on the platform and spread the aggregates. Cover them with the amount of sand indicated by the water test and turn over thoroughly until mixed. Then place in the box in small amounts and tamp into place. Having filled the box, after screening surplus as above directed, and ascertained the amount of stone, sand and gravel, pour in a measured quantity of water again until the box is filled. This last amount of water represents the amount of cement paste neces- sary to finally fill all the voids. By proceeding in the above manner with graded sizes of ma- terials the voids can be reduced as low as 7 per cent. This means a saving in cement. A lean concrete thus made will be remarkably strong in compression. In drawing up specifications the amounts of each size of aggre- gates used can then be specified and the mixing will do the rest. In using a revolving drum concrete mixer put the' coarsest aggre- gates in first. CHAPTER XL BUILDING DEPARTMENT. "The house founded upon a rock." The writer has prepared building ordinances for towns and intended in this chapter to present one as a guide. Not as a model ordinance, but one that would do as it has done in other places. The idea was given up when the .Building Committee of the National Board of Fire Underwriters, New York City, made a final report. ' It is in the shape of a complete building code and designed to cover conditions in towns and villages as well as in cities. A copy will be sent upon request, accompanied by ten cents postage, to all city oihcials. Perhaps others may also obtain copies, but that can be found out by writing to the Secretary in New York City. The Code looks somewhat voluminous, but the writer would urge that it be passed in its entirety, for no one can foretell what the little place may become. There is nothing in it that will be likely to meet with more opposition that is commt)n with ordinances prepared for the good of the many, with no hidden motives. The passage of this ordinance in all the towns and cities of the United States will tend toward a desirable uniformity of insurance rates and a desirable uniformity in building construction generally. When people herd together in thickly settled communities three things are to be guarded against: Insanitary surroundings. Risk of fire. Risk of danger to life because of cheaply constructed buildings. . A gpod health department to care for the disposal of wastes will do much for the protection of health. A good fire department is necessary and does much to avoid great losses by fire. A fire department, however, can be much less 139 140 ENGINEERING WORK IN costly than it now is, if proper attentioji is paid to the -erection of buildings. A poorly constructed building may cause incalculable damage by reason of being a fire, trap. It also prevents the fire department doing good work because of fear that it may fall while the fire is being fought. Firemen are brave and take great risks, but they are not going to take needless risks more than other men. A single badly built structure increases insurance rates for many blocks in its vicinity and lowers rents for as great a distance. In this chapter a plumbing ordinance is inserted, although it might be thought such an ordinance belongs in the chapters on Sanitation or Sewerage. It is put here for the reasor that th; department having charge of the erection of buildings can better supervise plumbing work than another department. The writer wishes to add that the ordinance appointing the city engineer can be amended when the building and plumbing ordinances are passed' by appointing him ex-o£ficio Commissioner of Buildings and Inspector of Plumbing. If the place grows in size so that departments are created that section of the ordinance can be amended. Or a section can be attached to the building and to the plumbing ordinances, to the effect that until such oflficers are appointed the city engineer will be such officer ex-officio and so act until the appointment of his successor in such work. PLUMBING WORK. Every city official interested in sanitary betterment should pro- cure copies of the following works of Wm. Paul Gerhard, C. E. : Recent Practice in the Sanitary Drainage oi Buildings, No. 93, Van Nostrand's Science Series. Price, 50 cents. House Drainage and Sanitary Plumbing, price 50 cents, being No. 63 of Van Nostrand's Science Series. The Disposal of Household Wastes, price 50 cents, being No. 97 in Van Nostrand's Science Series. ' In No. 93 the following suggestions for a Sanitary Code appear. These can be compared with the ordinance given in Chap- ter VIII, from Havre, Mont., and that ordinance can be amended if thought best before passing, in order to incorporate some of these suggestions that may not appear therein. TOWNS AND SMALL CITIES. Ml A — ^RULES AS TO HEALTHFUL BUILDING CONSTRUCTION. 1. It shall be considered unlawful to erect, or cause to be erected, a new building upon any site which has been filled up with house refuse or any kind of animal or vegetable matter, unless such matter shall have been properly removed from such site. 2. It shall be considered unlawful hereafter to erect, or cause to be erected, any new buildings or structures of any kind upon any damp or wet site, unless such site shall have been effectually drained by means of suitable, properly laid earthenware tile pipes. 3. It shall be considered unlawful to lay such drain pipes in such a manner as to communicate directly with any drain carrying foul'sewage, or with a sewer or cesspool. 4. The drainage of the subsoil of buildings shall conform to the following regulations and requirements : a. The subsoil drains shall be laid, if possible, at a depth of not >less than two feet .below the cellar floor. b. They shall be laid with open joints, protected against entrance of dirt or vermin by collars of clay or by paper or muslin wrapping. c. They shall be laid on a true grade, with perfect alignment and with a continuous fall toward the outfall. d. The outfall shall be either directly into the open air or into a ditch or road gutter. Mr. Gerhard has the following note: If connection must necessarily be made with a sewer, arrangements shall be made for perfect, disconnection, and the water seal of the trap must be maintained, even in the driest seasons, by suitable arrangements, approved by the inspector. The writer changed somewhat the wordings of paragraph d above. Section 5, following, has been changed also by the writer. 5. It is recommended that all cellar floors be made of con- crete, not less than six inches thick, and that when the building is in a damp location that the concrete shall have incorporated in it a waterproofing medium or shall be treated otherwise with some waterproof compound.. The cellar may be made tight by putting 'over the whole floor surfade, before laying the concrete, a thick- ness of felt or tarred paper mopped with hot asphalt or hot tar or with some compound of each, and upon that a second layer also mopped with the same material. It is recommended that every wall of new buildings be pro- 142 . ENGINEERING WORK IN vided with a dampproof course of proper material, placed above the level of the ground, and also that the walls, to the height of the damp course, be treated with a waterproof compound or have incorporated in them waterproof material, or that on the outside of the wall, against the earth, there be placed several thicknesses of felt or tarred paper mopped as provided for floors. It is recommended to whitewash the cellar walls of all build- ings at least twice a year. 6. Buildings without basement or cellar shall be placed on brick or stone piers or posts, and the floor of the first story shall be raised so as to be at least two feet above the surface of the ground. There shall be a free circulation of air underneath the floor, and between it and the surface of the ground. B — ^RULES AS TO CONNECTIONS BETWEEN HOUSE DRAINS AND STREET SEWERS. 1. It shall be considered unlawful to connect, or cause to be connected, any private drain with a street sewer without first obtain- ing a permit from the proper authorities. 2. It shall be considered unlawful hereafter to construct any drain for any building and to construct the same to any street sewer, unless the drain shall in its plan and construction conform to the following requirements: a. Each building shall have a separate connection with the street sewer. b. Wherever junction pieces have been built into the sewer, they must be used for making said connection, unless special per- mission is obtained to cut the' sewer. c. No pipe, or other materials for drains,' shall be used until they have been examined and approved by the authorities, or their duly appointed superintendent or inspector. . No house drain to be larger than five inches inside diameter, except by special per- mission. d. No street shall be opened until the junction .piece in the sewer has been located by the superintendent. e. If no junction pieces are built into the sewer, a connection shall be made by inserting into a brick sewer (or concrete sewer — McC.) a junction pipe of proper size, and cut slant to an angle of forty-five degrees by the manufacturer. ~ Great care must be TOWNS AND SMALL CITIES. 143 taken not to injure the sewer, and all rubbish shall be carefully removed from its inside. f. In connecting a house drain with a pipe sewer, a Y junction (if none can be found — McC.) must be inserted in the line of the sewer, and the main sewer left in good condition. g. In all Cases the trench must be opened to the point of con- nection without tunnelling, so as to allow of an easy inspection. Note — The above is an important provision if any thought is taken that there is danger of future settlement injuring the street surface. Thought must be taken of that as well as regard being had for easy inspection. — McC. h. In opening any streTet or public way, all materials shall be placed where they will cause the least inconvenience to the public, and the whole enclosed with suflBcient barriers, and properly lighted at night from the beginning to the end of the work. i. The least inclination of the house drain shall be 1 in 60, unless a written permit is obtained to lay a house drain to a lesser grade. k. When the course of the house drain is not the same as that of the junction piece, it must be connected therewith by a curve of not less than ten feet radius. All changes of direction to be made with curved pipe, and in no case must a pipe be clipped. 1. Every joint shall be laid with gasket and cement, and bedded in hydraulic cement at least four inches in depth. m. The ends of all pipes not to be immediately connected shall be securely closed, water tight, and guarded against entrance of earth, with imperishable materials. The inside of every drain, after it is laid, must be left smooth and perfectly clean throughout its entire length, and true in line and grade. n. The back-filling over drains, after they are laid, shall be puddled or rammed, all water and gas pipes protected from injury or settling, and the surface of the street made good within forty- eight hours after the completion of that part of the drain lying within the public way. o. No privy vault or cesspool shall be connected with the - hou^e drain or sewer. A PROPOSED PLUMBING ORDINANCE. The following ordinance is in use in several places : An Ordinance to regulate the plumbing and drainage of build- ings in the of 144 ENGINEERING WORK IN The Common Council of does ordain as follows : Section 1. That all the work of installing new plumbing and drainage work in buildings erected, or to be erected, in the ■• . and repairs and additions to, and alterations of the plumbing and drainage of all buildings in said city, shall be done in accordance with the provisions of this ordinance, and of Ordinance No known as The Building Code. Sec. 2. All connections of plumbing and drainage of build- ings with the public sewers shall be made in acordance with the provisions of this ordinance and Ordinance No. . . . ., known as the Drainlaying Ordinance. HOUSE DRAINS. Sec. 3. House drains shall be of first quality, salt glazed vitrified fire clay, with perfectly smooth interior and exterior sur- face, .except for three inches at the joint ends, inside the socket and outside where the pipe fits into the socket. The pipe shall have what are known as extra wide and deep sockets. House drains of tile shall terminate five feet from the building line and from that point to the inside of th£ house shall be of first quality cast or wrought iron pipe. Where said pipe comes in contact with the -earth it shall be coated with some approved process or rustless coating. The joints of tile drain pipes shall be filled with cement mortar with one inch of cement dipped, hemp gasket ^riven in and the joints of iron pipes shall be well caulked with lead and made air and water tight. The house drain shall not be laid below the cellar floor, except where absolutely necessary, and in this case it shall be laid in a trench and shall be surrounded with concrete. The trench shall be filled and closed after the drain is thoroughly inspected and pro- flounced tight. All connections in horizontal pipes to be made with Y branches. VENTILATION. Sec. 4. (a) When connections are made to old and improperly constructed or ' foul street sewers, or to cesspools or vault^, the house drain shall be trapped, near the jJoiht whei'e it leaves the building, hy a running or half S trap, which shall hot be larger TOWNS AHD SMALL CITIES. 145 in diameter than the house drain. This trap shall be placed in an accessible position, protected against freezing, and must be pro- vided with an inspection hole, and a tightly closing cover. (b) There shall be a fresh air inlet pipe, entering the house drain just inside the main trap, of a diameter not less than four inches, and opening at any convenient place out of doors, approved by the inspector; provided, however, that when the said, trap is not required the fresh air inlet shall be omitted. (c) When connection is made to well constructed sewers, having a self-cleansing flow and adequately ventilated, the above trap shall be omitted and the plumbing so arranged that in every house connected with such a sewer there shall be an uninterrupted flow of air passing from the sewer up the house drain and soil pipe and out at the roof. (d) All soil and waste pipes shall be run in as straight a manner as possible up to and at least five feet above the main house roof. Soil pipes to be enlarged to six inches and waste pipes to four inches above the roof. The upper terminus shall not be located within five feet of a window, ventilating shaft or chimney flue. The outlet above the roof shall not be capped by either a return bend, ventilating cap, or movable ventilator. (e) ^ Extensions of soil or waste pipes shall not be constructed of sheet metal or earthenware, and no soil, waste or vent pipe shall stop in any brick or earthen chimney flue, serving as a ventilator. GENERAL PIPING. Sec. 5. (a) No soil pipe shall be larger than four inches, and no waste pipe larger than two inches inside diameter (their ex- tensions above the roof excepted). (b) Waste pipes for fixtures to be in size as follows : Inches inside diameter. Wash Ijowls 1J4— 1^ Bath tubs IH— 2 Pantry sinks 1 J4 — 1 J^ Kitchen sinks IJ^ — 2 Laundry tubs IJ^ — 8 Slop sinks 2 — 3 Urinals '. 1^—3 Row of basins, tubs or urinals 2 — 3 146 ENGINEERING WORK IN No deviation from these sizes permitted unless specially author- ized by the Inspector of Plumbing. (c) All soil and waste pipes shall be kept outside of walls or partitions, and the system arranged in such, a manner that it may at all times be readily examined and repaired. (d) Every fixture in the house shall be separately and effectu- ally trapped by a seal retaining trap placed close to the fixture, and arranged so as to be safe against back pressure, self siphonage, loss of seal by evaporation or siphonage. (e) Wherever vent pipes are used, the branch vent pipes for water closet traps should be not less than two inches in diam- eter. All other traps to have vents the same area as th-e trap. The size of the main vertical lines of vent pipes will depend upon the height of,the building and should also increase with the number of branches which they receive. Where back air pipes are carried through the roof, they must be enlarged to four inches, to prevent clogging in winter time. All horizontal air pipes must be so graded as to discharge the "water from condensation into a trap or waste pipe. T-branches on upright vent lines must always be set at such a height above floor that the branch vent can not act as an overflow pipe in case the waste should be stopped up. (f) No branch waste pipe for tubs, sinks or basins to be larger than one and one-half inch diameter. (g) Connections of lead pipes with iron hub pipes shall in all cases be made with heavy brass ferrules properly soldered to the lead and well caulked to the iron pipe. (h) All joints between lead pipes, whether for supply or waste pipes, to be wiped soldered joints; cup joints not to be made any- where. Joints between lead pipes and brass fittings to be wiped solder joints; joints between lead pipes and brass couplings may be cup joints. (i) Vertical iron pipes shall, be as follows : Not to exceed two stories in any building can have standard iron pipe; not to exceed three stories . shall have heavy iron pipe ; below, the pipe shall be extra heavy. (j) All rain water conductors which are carried up within the walls of a building shall be of iron pipe. Connections with such TOWNS AND SMALL CITIES. 147 rain water pipes along their vertical course, for the discharge of sewage or waste water therein, will not be permitted. Rain water conductors shall be trapped if they open at the top near windows, ventilating shafts or flues. GENERAL PROVISIONS. Sec. 6. (a) Every water closet shall be adequately flushed with water from a special flushing cistern arranged directly above it, except that where a cistern is liable to freeze other methods may be permitted, provided that thorough and sufficient flushing is secured. Every water closet apartment shall have direct means of ventilation into the open air. Pan closets shall not be permitted in any building. The outlets for single water closets shall not be larger than three inches in diameter. (b) No opening shall be provided in the house drain for the purpose of receiving the surface drainage of the cellar, unless special permission is previously obtained and the directions fol- lowed. (c) It shall be unlawful to throw or. deposit, or cause or permit to be thrown or deposited, in any vessel or receptable con- nected with a public sewer, any garbage, hair, ashes, fruit or vegeta- bles, peelings, or kitchen refuse of any kind, rags, cotton, cinders, or any other matter or thing whatsoever, except faeces, urine, the necessary closet paper, and liquid house slops. (d) Waste pipes from refrigerators or other receptacles in which provisions are stored, shall not be directly connected with a drain, soil pipe or other waste or sewer pipes, but shall be made to discharge over an open tray, provided with a waste pipe and seal- retaining trap. (e) Drip pipes from safes, under any kind of plumbing fix- tures, must not have any connection with any soil, waste, or drain pipe. (f) Overflow pipes from water tanks shall not be connected to any soil, waste, or drain pipe. (g)" No steam exhaust shall be directly connected with any soil or waste pipe or drain communicating with a street sewer. (h) An approved form of grease trap must be placed on every sewer connection leading from dwellings, hotels, restaurants and buildings in which a sink is located. For one sink the grease trap 148 ENGINEERING WORK IN shall be not less than eighteen inches in diameter and it shall be increased proportionately to the number and size of sinks. The minimum dimension for a restaurant or hotel shall be thirty-six inches in diameter. The grease trap may be constructed of vitri- fied ironstone tile pipe with a six-inch Y attached and so set that the Y will point upward and be connected to the main drain by means of a manufactured curved pipe (chipping of pipes to make a bend is prohibited) in such a manner that a trap will be formed. The depth below the bottom of the outlet hole shall be equal to the diameter of the grease trap basin. The inhet shall enter thq grease trap basin above the level of the top of the outlet and shall ter- minate in a right angle bend two inches below the curve forming the trap in such a manner that there shall be at least two inches seal. Across the middle of the basin shall be a thin Jron plate, the bottom of which shall be six inches below the bottom of the inlet and the top of which shall be two inches higher than the bottom of the inlet. This plate shall be between the inlet and outlet open- ings. The grease trap may be covered with wood or any other material and shall have the grease skimmed off every day. The basin shall be cleaned as often as directed by the Inspector of Plumbing, but not less. than once in seven days. (i) When the grease is unusually plentiful from any kitchcH the Inspector of Plumbing can order placed, at the expense of the owner of the biuilding, a grease strainer, of approved design, in addition to the grease trap. This strainer to be qleaned whenever directed, but not less than once in seven days. (j) Livery stables and barns with floors for cleaning vehicles, etc., shall be provided with sand boxes of approved pattern and same must be kept in efficient working condition. (k) Before granting a permit to install the plumbing work in any building the Inspector of Plumbing shall carefully examine the plans. He shall cut out all superfluous pipes arid see that the arrangements are as simple as possible, consistent with the best practice. He shall prepare, or procure from competent authorities, drawings illustrating all the standard connections and arrangements pemitted and keep same on file in his office for the inspection of the public. Copies of said drawings shall be furnished at the actual cost of reproducing to all registered plumbers upon request. (1) AH materials used shall be of first quality and the In- / TOWNS AND SMALL CITIES. 149 spector of Plumbing is authorized to make such tests as he lees proper in order to determine the quality of tl;ie said materials. (m) Before the fixtures are placed in connection with the pipe system, and before the soil pipe and iron house drain are con- nected with the outside drain, the outlet of the house drain and of all its branches shall be closed tight and the pipe filled with water to its top, and every joint shall be carefully examined for leakage, and all joints shall be securely closed before connections are made with said pipe system. The water test shall be applied before the pipes are built in or covered if there are any places where they require to be hidden. The water shall remain in the piping system for at least twelve hours. Sec. 7. The plumber shall give the Inspector of Plumbing at least twenty-four hours' notice when he is ready to test the piping system. It shall be the duty of the Inspector of Plumbing to see that the pipes are filled with water within that time or forfeit to the plumber five dollars for each and every twenty-four hours' delay beyond that time. (The rest of the sections of this ordinance can be filled in to suit local conditions. They should fix the officers, the fees, the penalties, etc.) The writer believes a provision like the following should appear in every sanitary code or in every plumbing ordinance: Section — . Whenever a public sewer is laid past a house it shall be unlawful to maintain any cesspool or privy vault for more than sixty days thereafter within two hundred feet of said sewer. Such cesspools and privy vaults shall be cleaned out and refilled with clean earth and the building shall have sanitary closets and sinks installed and connections shall be made with the said sewer. CHAPTER XII. , MISCELLANEOUS DATA. "Reading maketh a full man." LIGHTING. The cost of street lighting does not seem to vary by any known rule. Investigation shows such wide differences in the same locality that sometimes hints of collusion between councilmen and officials of the light company may be warranted. The policy of the private company is of course to "charge all the traffic will bear,'' and as rates are often fixed by simple comparison of rates in near-by cities there is danger of innocent and unsuspecting men of honest intention being hoodwinked by -showings from places where the administration of aflfairs is not so fair and honest as in their town. Yet there is also the danger of the lighting company being unin- tentionally wronged by a comparison unjust and too one-sided. But if the rates are fixed too low the company goes into the counts and shows its books whereupon the judge is liable to fix the rates. Owing to this some cities have a pleasant' little way of fixing the rates at the point which is one notch higher than the litigation point and thereby secure a low-priced service — which is apt to be very costly in reality, considering service and breakages, or pretended breakages, or by the fixing of a schedule by the company which does not inure to the benefit of the city. No just comparison can be made without a full knowledge as to the number of hours of burning. A contract between the light company and the city should be specific and in detail and should be submitted to some man who has a knowl- edge of the business and the technical terms used, before it is signed. Claims of a lessening of cost under municipal ownership are not always borne out on investigation, as municipal book-keeping leaves much to be desired. Many men do not seem to consider that municijial works are as liable to deterioration by time as private works and therefore do not write off depreciation every year. X50 TOWNS AND SMALL CITIES. 151 The invariable fault is to fall back on taxation to make up deficits, pay bonds, etc. While this is perhaps correct, the amounts the taxi)ayers have to pay on account of the bonds and other expenses incurred by reason of municipal ownership should show on the books of the plant as items of expense. The cost of lighting with arc lights varies from $55 to $136 per year and the schedules and average hours of burning vary as much more. But it may be stated that in detailed examination of the schedules it does not show that the hours vary as the cost exactly. For a small town kerosene lamps on posts have been used with only fair satisfaction, until a gas plant or electric plant has been put in. But it is not necessary to wait for a general plant to be put in as there, are several makes of incandescent mantle gasoline lamps in the market which give excellent satisfaction. The burner has to be heated before the gas is lighted and some have a small separate alcohol lamp for the purpose while others have an attach- ment on the burner. The lamps are made in several styles for street use and many prefer them to gas or electric light. From one of the circulars of a firm making gasoline incandes- cent mantle lamps the writer has taken a table showing the com- parative cost of lighting a room 20x60 feet floor area and with ceiling of ordinary height. It is given below and has not been changed in any way. A few remarks might be made in this con- nection, however, as to the statement of cost so the reader can figure the matter out himself. A 16-candle power electric lamp is con- sidered sufficient in most cases for a floor area of 100 square feet, therefore it is possible the cost of the electric light service might be less than the figures given. Three-fourths of a cent per hour is a usual charge. A 16-candle power gas jet is more likely to consume 6 feet per hour, although the usual flow of an ordinary burner is 5 feet. One dollar per 1,000 feet of gas is cheap gas. The information as to cost of carbine for acetylene gas gives no information to the non- technical reader. In the city of Wabash, Ind., the cost of a lercandle power acetylene jet in 1900 was yi cent per hour with discounts off of from 10 per cent to 30 per cent for consumption of from 600 to 2,000 hours. The cost of the oil lamp with central draught, the writer believes to be a trifle low and he can not vouch in any 152 ENGINEERING WORK IN manner for the figures relating to the incandescent gasoline lamp, except to state that he knows where electric lights have been taken out and these lamps used instead, with better satisfaction and a remarkable saving in expense. The number of hours had best be investigated also in the table as the writer has not looked into it in any way except as to *the cost explained above. It is always* best to examine closely all tables and statements made in catalogues, as errors sometimes creep COMPARATIVE COST. For Lighting a Room 30x60 One Hundred Hours Per Month for One Year. Eighteen incandescent electric lamps, 16-candle power, 288 candle-power, 21,600 hours at J4 cent per hour, cost $162.00. Eighteen gas jets, 16-candle power each, 288 candle power, 5 feet per hour, per jet at $1 per 1,000 feet, cost .^ 108.00 Twelve Acetylene gas jets,. 20-candle power each, 240-candle power, carbide at $90 per ton, cost . . 100.00 Three central draft oil lamps, 75-candle power vcach, 225-candle power, one gallon of oil per burner, 10 hours, at 6 cents, cost 21.60 Three incandescent gas lights, 100-candle power each, 300-candle power, one gallon of gasoline per burner, 60 hours, 6 cents, cost 3.60 The following table from the Municipal Journal and Engineer, June, 1905, was compiled by the Mayor of Syracuse, N. Y., from statistics gathered prior -to the re-letting of the contract for that city : Municipal Cost or Per Arc Average Capitali- City. - Population. Private Light Fuel Price zation of Plant. Per Year. Used. Coal. Plant. 'Albany 93,920 Private $117.80 Coal $2,000,000 Alleglieny 138,018 Municipal 68.59 Coal $1.88 Atlanta 96,550 Private 75.00 Coal 2.50 Baltimore 531,313 Private 99.92 Coal 8.20 2,700,000 Boston 594,618 Private 124.10 Coal 10,500,000 Bridgeport 77,635 Private 83.00 Coal Chicago 1,873,880 Municipal 76.00 Water Cincinnati 332,934 Private 96.00 Coal 3.75 700,000 Cleveland 414,950 Private 54.36 Coal 2.76 1,650,000 Columbus 136,487 Municipal 66.00 Coal 1.76 31,000,000 Dallas 44,159 Private 73.56 Coal 1.30 2,500,000 Denver 144,688 Private 64.36 Coal 8.73 1,650,000 TOWNS AND SMALL CITIES. '163 Municipal Cost or Per Arc Average Capitali- City. Population. Private Light Fuel Price zation of Plant. Per Year. Used. Coal. Plant. Detroit 309,653 Municipal 85.00 Coal 1.40 485,000 Elmira 37,106 Private . 73.00 Coal 8.00 Fall River 114,004 Private 90.00 Coal 3.00 8,250,000 Grand Rapids 91,630 Municipal 61.651 Coal 2.58 849,600 Hartford 87,863 Private 80.00 Coal 3.00 Indianapolis 196,033 Private 109.50 Coal 4.15 850,000 Jersey City 219,468 Private 70.95 Coal 2.85 45,000 Kansas City 173,064 Private 70.00 Coal and water 4.00 1,900,000 Louisville 215,408 Private 74,00 Water Lowell 100,150 Private 97.50 Water Lynn 72,350 Private 65.00 Coal 3.00 Memphis 113,669 Private 84..00 Coal Minneapolis 214,112 Private 120.45 Coal Nashville 82,711 Municipal 98.55 New Bedford 68,955 Private 85.00 New Haven 114,600 Private 94.00 Coal 5.00 New Orleans 300,625 Private 45.00 Coal 1.79J^ 200,000 New York 3,766,139 Private 98.55 Coal 845,000 Omaha 113,361 Private 82.18 }4 Coal 3.75 1,000,000 Paterson 113,267 Private 77.00 Coal 3.26 Portland, Ore. . . . 98,655 Private 146.00 Coal 85,338,000 Providence 189,742 Private 94.50 .Coal Reading 85,051 Private 101.00 Water Richmond 86,148 Private 63.60 Coal 3.80 5,000,000 Schenectady 43,538 Private 109.50 Coal 1.75 Scranton 107,026 Private 85.00 Coal 2.91 Seattle 92,020 Private 34.00 Water St. Joseph 110,479 Municipal 72.12 Coal 1.25 800,000 St. Paul 172,038 Private, 66.00 Water St. Louis 612,279 Pfivate 95.00 Coal 1.60 102,000 Toledo 145,901 Private 98.00 Coal 2.00 10,000,000 Trenton 76,766 Private 83.00 Coal 2.05 Troy 75,567 Private 118.62 Water and coal 2,000,000 Utica 60,097 Private 116.18 Coal 2.50 2,000,000 Washington 293,217 Private 85.00 Coal 3.00 Wilmington 81,300 Private Coal- ^ 5.00 Worcester 128,552 Private 108.00 Coal 4.75 600,000 YonkerS 52,701 Private 109.50 Coal 800,000 The cost for gas and electric lighting and for telephone service , is not always'lower in a large city than in a small one. It is apt to be more costly, for maintenance in a rapidly growing city or in one covering a large extent of territory is greater per seryice than in a steadily growing city of moderate size. More is kndwn about acetylene gas than was known a few years ago. Before any city determines upon gas or electricity or any other form of lighting to be owned as a municipal enterprise a long and careful investigation should be made and estimates obtained by a competent man, or by competent men. In relation to the placing of lights a report mide in St. Louis (1899) by the board of public improvements was against the use of 154 ENGINEERING WORK IN electric lights in the residence districts and in favor of incandescent mantle gas lamps (not gasoline, but city ^as). The cost was found to be practically the same. In the business district a large volume of light, which will in some measure illuminate the buildings as well as the streets is needed, while in the residence districts an even distribution of light by small units is found to be wanted. Small units of light have an econemical advantage for lighting long blocks with few street intersections. Incandescent electric lamps in the residence districts are objectionable on account of the wiring strung overhead and across intersecting streets, and electric arc lights in residence districts are an annoyance to the residents of the immediate vicinity. Trees in a residence district also interfere with a proper distribution of light from an electric lamp. In many European cities the number of gas jets in out-of-the- way courts, narrow squalid streets and other places where in the United States it is thought a waste of good money to put lights, always attracts the attention of the traveler. Upon inquiring the reason he is told that one gas jet is equal to a policeman and very much cheaper, as a preventative of crime. In some cities of the United States it has been found that a bright light at each end of a block does more toward clearing a neighborhood of the unfor- tunate creatures of the half world than a nightly raid of the police. FIRE AND POLICE ALARMS. 'There is only one standard alarm system in the United States, and when a town becomes a city the agents for the system soon give all the information about it that any man can want. It is too costly, however, for the small town, and for such places the writer has found the simple magneto telephone to be as efficient as anything and very cheap. The operation of such a system is as follows : The city is divided into districts, seldom exceeding six on account of the number of rings required, and each district has a number. As many telephones as the city can afford _to pay for are put in locked boxes on poles with a notice painted on the box telling where the key may be found. In many of the saloons, stores, hotels and other public places and in the residences of the members of the fire department may be placed telephones or simply alarm bells. When any person notices a fire it is only necessary to go to the nearest telephone box, open it TOWNS AND SMALL CITIES. 155 and proceed to ring the number of rings which will indicate the district in which the fire is discovered. The alarm should be rung, say three times, and then the aurophone put to the ear so inquiries may be answered. They will come in at once from every tele- phone on the line and one answer is made to all, giving the exact locality of the fire by the house owner's name, or number and street. The companies are supposed to have sufficient organization for every member to know exactly where to report. The chief should at once repair to the fire and the various captains and other desig- nated officers to the places where the hose carts and ladder trucks and engines are housed. Some members who have apparatus at their residences or places of business proceed to the fire, while others whose duty it is will stop to rouse certain individuals who have no alarms. BUILPING REGULATIONS. The following extract from the 1904 report of the State Fire Marshal of Ohio is instructive: FIRE LOSSES FROM GASOLINE EXPLOSION. "The reckless use of gasoline in Ohio caused S95 fires during 1904 ; 396 in 1903 ; 473 in 1901. The many appalling accounts of persons being burned to death by explosions of this product of petroleum does nqt seem to have taught the people a proper appre- ciation of its power to destroy. They are, perhaps, not aware that the vapor arising from gasoline when mixed in a proportion of over 7 per cent with the air is one of the most dangerous explosives. The liability of powder to explode in handling is but slight if com- pared with that of gasoline. "At the ordinary temperature of a dwelling, gasoline continu- ally gives off inflammable vapor, and a light, a spark or a lighted cigar within a distance of ten feet from the material may ignite it through its vapor which explodes. The vapor from one pint of gasoline will, in the absence of free ventilation, make 200 cubic feet of air explosive. It depends upon the proportion of air and vapor whether it becomes a burning gas or an explosive. The danger does not lie so much in the devices for its use as in having it about. The widespread practice of using it for cleaning purposes is reckless indeed, for aside from its making the surrounding air 166 ENGINEERING WORK IN explosive the friction from rubbing textile fabrics in it may pro- duce an electrical spark which will ignite it and set the room ablaze. A recent circular from the National Board of Fire Underwriters carries expert advice relative to the handliilg of gasoline devices." SOME DETAILS OF CITY BRIDGES. (An abstract in Engineering News of a paper read by Willis Whited, assistant engineer, Department of Public Works, Pitts- burg, Pa., and printed in the Proceedings of the Engineers' Society of Western Pennsylvania:) City bridge floors should, wherever practicable, be paved, if the traffic is heavy enougTi to justify it. Plank floors are expen- sive to keep in repair, besides being rough and unsightly after they are somewhat worn; they are also apt to break througli and injure horses' legs. A durable, cheap floor consists of reinforced concrete slabs placed on the stringers, or cross beams, and covered with asphalt paving. This is somewhat heavier than plank floor, and rather more expensive, but the cost of maintenance is so much less that in the long run it is more economical. It has the, further advantage that it is waterproof and prevents the drainage from the roadway, which is quite corrosive, from rusting the steelwork under- neath. Other good methods of constructing' floors are by buckled plates, and by beams covered with flat plates; these, like the rein- forced concrete slabs, can be covered with any suitable paving ; they also furnish a better support for street rails if they are re- quired. If a plank floor is used, white oak or yellow pine are good for joists. The flooring may be laid in two thicknesses where the traffic is very heavy; the plank rots more quickly, but is not so apt to break through. If the traffic is light, a single thickness of plank is better and the plank should not generally be inore than about 8 inches wide. I have so far been able to find no wood to compare with white oak for this purpose. Good white oak, however, is becoming very scarce in this part of the country. For paving, asphalt can be used if there are no street car tracks and the grade does not exceed 4 or 5 per cent, and the traffic is heavy enough to keep the asphalt in good order. Asphalt being only 3 inches thick is lighter than any other paving. Some varieties of asphalt requiring no binder are only 2 inches thick (the binder being TOWNS AND SMALL CITIES. Wi 1 inch thick). If asphalt paving is used where there are street car tracks it is generally best to put a row of stone blocks on each side of the rails. Where the grade exceeds 4 or 5 per cent and the traiific is very heavy, block stone is, perhaps, the only suitable material. Where the traffic is light, brick may be used. Wood blocks, which are better if creosoted, make an excellent pavement where the grade is not too heavy; they are much lighter than brick or stone and about as durable. They will stand a very heavy traffic and can be used next to street rails. All these pavements should be laid on concrete foundations, which may be reinforced if required to be laid as slabs. Masonry bridges should, of course, be paved the same as ordinary streets. ' The sidewalks may be built of white oak planks,^ which should be kid crosswise' on the bridge and about % inch apart, and should be dressed to uniform thickness. If the spaces between them are wider than 54 inch people can see through them to the ground or water beneath, and some nervous people can not bear that. If the planks are laid lengthwise it is almost impossible to wheel a baby carriage across the bridge; besides, the ends lift up and people stumble over them. If pflank sidewalks are laid, it is well to protect the curbs with steel angles, about 4x3x5^ inches, with the 3-inch leg turned down to form the curb and the 4-inch leg horizontal on top of the sidewalk plank, and secured to it by J^-ihch lag screws about 3 feet apart through the horizontal leg only. If they pass through the vertical' leg, it is very difficult to -get the curb angle loose to permit the putting in of new sidewalk planks owing to the fact that the screws rust firmly in the oak plank in a short time. Cement is the best material for sidewalks with which I am acquainted. It can be laid as reinforced concrete . slabs faced with mortar, or on buckled plates. Asphalt was formerly much used, but it is not so durable as cement, costs about as much, and, if any steel work comes up through, it contracts away from it, leaving a place where damp dust lodges and corrodes the steel work very rapidly. Cement, on the other hand, adheres closely to the steel and protects it from corrosion. If the' sidewalk is of cement, which seldom occurs except where the roadway is paved, a cement curb is almost always the best. It is hardly ever necessary to face it with ^teel. 158 ENGINEERING WORK - IN It is very important to thoroughly drain the spandrels of masonry bridges, especially where they cross over streets. They should be drained by means of pipes leading down through the piers into sewers. The ba,cking of the arches should be made thoroughly waterproof, preferably by a coating of strong cement mortar; asphalt is not durable in such places, and any leakage or drainage through the haunches of an arch produces dirty icicles in the winter, and unsightly incrustations in summer. (Note. — The wffter wishes to say that he believes some prep- aration that sinks into the pores of the cement is better. He has used Szerelmey Stone Liquid for waterprooiing and found it excel- lent. It is an English preparation, having been on the market fifty or more years.) The railing of ar bridge should be of sufficient height for pro- tection, but not so high but that a person can readily see over it. It ^ is sometimes well to incline it considerably inward at the top to prevent children from climbing over it, or it may be well to make the body of the railing of vertical parallel bars for the same reason. There should be no openings larger than about 6 inches wide, other- wise small children might crawl through. If a stone railing is built the same rule should be observed as to openings, and the prpjecting coping at the top will prevent children climbing over it; the inside should be dressed so as not to injure, the clothing of pedestrians ; it is well to finish the top with a slope of about 30 degrees so J)oys ■ can not walk on it. All railings, of course, should be of tasteful design, and not only be, but also look, substantial. Although very often done, it is seldom necessary to put a railing on the curb line; its principal service there generally is to furnish a roosting place for loafers. SURVEYS -AND RESURVEYS. Many of our towns have been settled so long and there has been so little care exercised in preserving monuments that the original stakes have disappeared and a "happy-go-lucky" way of establishing lines for fences and buildings has <;rept in which leads to trouble between neighbors. Sometimes the trouble flares out and the whole town is stirred from center to circumference over the matter and the merits and demerits of various surveyors discussed with acrimony. It is apt to get to such a pass that it is impossible TOWNS AND SMALL CITIES. 159 to relocate the original lines with certainty. The longer such a state of affairs continues the worse the confusion and the prospect of costly law suits are promising at some future time when land has increased considerably in value. The causes for such a state of affairs are many. Sometimes the original survey was faulty. This is often the case, for the original survey was made when land was cheap, with imperfect instruments and by careless methods; sometimes by men illy trained. When the original stakes disappeared surveyors coming after who were called upon to survey a lot had to start from some lence corner or building claimed to be correct by some and the correctness of which was denied by others. If these surveycrs had been commissioned to survey the whole town and their records kept carefully the troubles would not be so great. But the surveys were isolated ones made at a cost satisfactory to the lot owner and the price seldom large enough to enable a man to do all the work that was really neces- sary to do a correct job. When the owners between the later re- surveys finally get pinched there is trouble. When the need of some proper definition of boundaries is realized and a complete re-survey decided upon, it should be made by a competent engineer who has had previous experience in that class of work and who has some legal knowledge. For his work must be done so if courts and juries follow over the lines they will say it has been as well done as it possibly could be. It is a risky think to disturb long established possession and only the most con- scientious and careful work will do. An axiom in settling disputes over" lines is that monuments govern "distances and distances govern bearings. Such decisions were given in former days when compass lines were so often run and there was known to be errors in that class of work. This setting of a monument was something any man could do and it was supposed almost any one could measure a line as he wished, but the turning of angles was a matter requiring skill and in matters of skill men often make mistakes. It is now conceded, however, that with the modern methods of laying out work the measuring of a line is a more skillful matter than the turning and reading of an angle and later decisions give the proper weight to both operations. Although there has been a change in that respect, there has been none respecting monuments and they must govern above every- 160 ^ ENGINEERING WORK IN thing — unless positive proof can be given that they have been ahered or changed in location. Of several calls in a description the certain govern the uncertain, even to the rejection of the uncer- tain. When a town has been laid off without any permanent monu- ments and the original stakes have rotted and disappeared the sur- veyor who comes in and tries' to lay off that town mathematically, without paying proper attention to long established possession is foolish. Each block has to be treated by itself and the surveyor must recognize what he terms inaccuracies. The city of course is entitled to the full street width, but it is doubtful if any buildings can be removed from the street if they are not an obstruction. They can be permitted to remain until they become a nuisance or until rebuilt, when the city can assert its claim to the portion of street they occupied. Rights never run against the public. A re-survey made under such circumstances often gives crooked streets of varying width, where the original plat showed a straight street of even width, but if none of the points can be* positively identified then it is impossible to lay the place off as it was claimed to be first laid off. The only way to prevent a recurrence of expense and trouble is to finally and definitely fix the lines by permanent monuments, well identified, and record the maps. If the town has been monumented and the buildings have been put up without surveys there is no doubt that they must come to the right lines, as the monuments govern, and if in existence at the time the buildings were erected there could be no excuse for -not building exactly on the proper lines. Because the original owner was too stingy to employ a surveyor he should not be allowed to unsettle the lines of a whole neighborhood. All subdivisions of land within the town limits should be sub- ject to the approval of the Council before the plats are filed. The Council should prescribe the maximum and minimum grades, the direction of the lines and the width of the streets. When the owner submits his plats for the approval of the Council they should show proper connections with adjacent city monuments and show monu- ments at all street intersections and changes of direction. The elevation of all corners above city base should be also shown in red ink. In laying out land into additions to cities it is common for Streets to intersect so there are many triangular lots. These gore TOWNS AND SMALL CITIES. 161 lots should not be left to private ownership, for they are seldom built upon properly. There should be an ordinance passed provid- ing that gore blocks shall have no lots with acute angles and that lots at the acute end of a gore block should have a frontage at the end of not less than twenty feet. The point thus cut off the lot to be added to the street intersection. Such a provision will give the city a great deal of space that can be improved in a way that will enhance the appearance of the streets. The ordinance should provide also that the city can park or otherwise improve with statuary, fountains, etc., any part of the intersection space thus added to the natural intersection space made by the junction of the two streets. The ordinance should also pro- vide that in districts where the roads are curved or practically laid out on contour grades that angular lots shall have no acute angles, but that where otherwise an acute angle would come the street lines of the intersecting streets shall be joined with a curve of twenty-five feet radius. While some greedy land owners may object, the ultimate benefit is so great that it helps the value of the property. The writer once prepared an ordinance for the governing of additions to towns and cities, but could not get the city council to adopt it. He believes it would be a good ordinance to adopt, for the rectangular system of street layouts has been overdone in the United States. Every city should have a civic center and there should be radiat- ing streets for convenience in going from one part of the city to the other as well as for beauty. In many places no improvements can be made in the layout, at an expense within the present reach of the people, but the laying out of additions to the city can be regulated and in future years when the city is rich enough to condemn prop- erty to make new streets and avenues there will be a comparatively small area to deal with. ORDINANCE NO An Ordinance to Regulate the Subdivision of Lands within the Corporate Limits of and to Govern the Laying Out of New Additions to Said City. The City Council of does ordain as follows: 162 ENGINEERING WORK IN Section 1. No street, alley, lane, avenue, thoroughfare or public higliway shall hereafter be adopted to be placed upon the official maps of the City of dr recognized as existent as other than a private thoroughfare in said City except the plat of such shall have been first submitted to the City Council of said City for adoption as a public street, lane, alley, avenue, thoroughfare or public highway and none shall be so adopted unless in the platting the sec- tions of this ordinance hereinafter following shall have been fully complied with, and for reference all such shall be hereinafter designated as roads. Section 2. All acre property within the cor- porate limits shall be and is subject to the re- quirements of this ordinance. Section 3. No 'additions to said City now outside the present corporate limits shall be received within the corporate limits by extension of said limits to include same unless all roads therein conform to the requirements of this ordi- nance. Provided, however, that nothing herein contained shall prevent them being considered as private roads and omitted from all official maps and from all consideration in public improve- ments. Section 4. No cuts shall exceed twenty feet in depth to allow roads to be' constructed on a grade of five per. cent and no fills shall exceed twenty feet to permit roads to be constructed on a grade of five per cent, except that cuts and fills on sidehill roads are not limited as to height and depth to permit roads to be constructed to a grade of five per cent. Section 5. Where roads can be laid out on a maximum grade of five per cent and the depths of cuts and fills to obtain said grade shall not exceed ten feet the land shall be laid out on the rectangular system. Section 6. Where the requirements of Sec- tion 5 can not be fully complied with the roads shall be laid out in the most practicable manner to accomplish the desired result as to maximum grade, which shall not exceed a limit to be fixed in each case by the City Council. Section 7. Main roads shall be 100 feet wide and shall follow the section lines as nearly as TOWNS AND SMALL CITIES. 163 *' practicable, each section giving one-half of the said road. Section 8. Secondary roads shall be not less than seventy feet wide and shall go through' the centers of the sections as nearly as practicable. Section 9. Only main and secondary roads shall be laid out on north and south and east and west lines, all other roads in the subdivision to be laid off at an angle of approximately forty- five degrees with said main and secondary roads. Section 10. Tile subdivision of the prop- erty shall be made as, though the main and sec- ondary roads did not exist and shall be laid over same so that they shall be cut at an angle through the said subdivision. In the subdivision no roads shall be less than fifty feet wide and no alley shall be less than fifteen feet wide. There shall be an alley through the length of every block. No blocks shall be longer than seven hundred feet and the least depth of lots for building jpur- poses between road and alley lines bounding same shall be one hundred and twenty-five feet. Section 11. Where acute angles would occur by reason of the joining of two straight roads the angle shall be cut oflf and added to the road intersection by ah isoceles triangle with a base for building front of twenty-five feet. Where two curved contour roads meet with an acute angle the side lines shall be joined with a circular curve having a radius of twenty-five feet, joining the said side lines, on tangents, the additional space thus made being added to the said road inter- section. Section 12. When by reason of the joining of roads at acute angles the projection of the side lines would leave islands in the intersections having any frontage of less than fifty feet, said island shall be the property of. the public to be added to the said road intersection or to be im- proved as a parking or place for statuary, but not for buildings having walls and roofs. Section 13. When by reason of the laying out of main roads to a grade of not to exceed five per cent the connecting roads shall be waste- ful of land if laid out on such a grade a departure may be made from the system upon express per- mission of the Council after a report upon said subdivision by the City -Engineer. If necessary cross connecting roads may be laid out on steeper 164 ENGINEERING WORK IN grades provided they are of such width that a zig- zag roadway twenty feet wide may be constructed within said width with a grade not to exceed seven per cent. i Section 14. No main or secondary road shall have a grade to exceed five per cent, but shall be deflected where necessary in order to maintain that maximum witKTn the limits of cut and fill provided in this ordinance. Etc., etc., etc. EVALUATION OF OLD PLANTS. ^ There comes a time in the history of almost every place when the idea of purchasing an existing plant has to be considered. At such a tim& the wisest course is to send for an outside competent man to make an estimate of the proper, price to be paid. There are three values to an old plant of a private company; • First — The value to the company as an investment. Second — The value of the plant by reason of the material in it. Third — The value of the plant to the community. This third value may be nearly what the company places as the income producing value, and again, it may be far lower than the actual value of the material in the plant. The value to the community depends upon the efficiency of the plant. If it has been well designed and cared for and" all extensions made have been , under the direction and with the approval of the council, or board of public works, then the people may pay the price the company asks. Otherwise there is a serious economic loss possible by reason of the duplication of an already efficient machine. But if the plant has not been well designed and the extensions show that a niggardly policy has been pursued and there is evident a lack of judgment in the management of many of the small though important details it is possible the people have no system to purchase ; it is simply a plant and a poor one. It may happen the plant can be taken at a proper valuation and remodeled to do all the work required of it at a less cost than an entirely new plant would cost. All these are matters to be determined at the time of examination. The person employed to examine the plant has first to deter- mine, as near as can be, the original cost. To this he must add the cost of all extensions. He must ascertain the exact indebted- TOWNS AND SMALL CITIES. 165 ness of the company and the state of the indebtedness. The yearly interest charge and cost of operation. The revenue from private consumers and the revenue from the city. The life of the franchise and the length of life left in all existing contracts, if any. And generally, the value of the plant to the community, the general features of design, the present condition, and cost of making it adequate to serve the town if purchased. The value of the material should also appear, but it is not of such importance as the other items, for the deterioration must be naturally an esti- mate for much of the plant. With such information before them the people can act intelli- gently when it comes to voting on bonds. The embarrassing features of a purchase by the city are the value to place on any existing long term contracts the city may have with the company, and whether the city should pay anything for the franchise right, which has been obtained from the city. These questions require expert advice. MUNICIPAL OWNERSHIP. The writer has not changed his ideas on the subject of mu- nicipal ownership in the United States since he first declared him- self thirteen years ago. In this book he does not intend to argue the question, for it has no place in such a book. Municipal ownership of water works is almost a necessity, regardless of administrative defects, for the supply of water is then under absolute control of the citizens so long as they have any bonding ability left. A private company does not always afford the fire protection needed, although a fair showing of plants will possi-. bly reveal that under private ownership there are more purification plants than under municipal ownership. The hope of saving should not influence in the public owner- ship of waterworks, for sometimes it is so expensive a luxury that although taxes, interest and profits are not considered in the items of expense attendant upon operation, the people are extremely likely to pay more for their water than the private company charges. In general tfie items of expense entering into the operation of a municipal plant will be the same as those entering into the opera- tion of a private plant. However, it is not best to figure on any profit, for the business is a co-operative enterprise and the product 166 ENGINEERING WORK IN should be sold at cost. Taxes can not be figured in on a public plant, but insurance must be. The interest and sinking fund on the bonds should be charged as an item of expense, but no interest charged on the investment after the bonds are paid up. The money is permanently invested. It is not fight either to figure into the cost of operation a fund to provide for future extensions. These will be met by the future residents when needed. As the noted Irish member of parliament said, "Do not be so careful to take care of posterity. It has done tjothing for us and our grandfathers let us paddle our own canoe.'' Every thinking man realizes that it is not well to tax ourselves in this generation for the whole cost of an enterprise which will benefit the next generation as well. It' is proposed also that all annual extension work should be borne by general taxation, for there is a good return to the city at large and the amount needed is difficult to estimate in figuring up expenses pf operation for the succeeding year in order to fix charges. So then we have to consider as legitimate cost of running a municipal plant the interest and sinking fund to pay off the bonded indebtedness, the writing off each year of the depreciation, the making of repairs, the maintenance of the whole system and the cost of fuel, labor, administration, insurance, etc. The revenue from the works should be from two sources ; gen- eral taxation and private consumption. The consumers of the product should not pay the entire expense, for they are the pro- gressive element whose property has been improved. The owners of unimproved property should pay a part of the cost. Every enter- prise of a public nature in the town increases the value of all property and the unimproved property increases in value in a greater ratio than improved property. So if it is a lighting plant the city should pay for its own lights from general taxation and in case of a waterworks plant, for the water it uses or has a right to use. This is the true theory at the bottom of hydrant rental and payment for water for public use when dealing with a private com- pany. It is not right to make a contract at a flat rate with a water company for hydrants for ■ a term of years. The council should annually get all the information regarding cost of the company's ■TOWNS AND SMALL CITIES. 167 plant, cost of operation and the revenue for the year past. Then fix the rates on an equitable basis for the consumers of water and guarantee to the water company a proper return on its invest- ment by making up the deficiency by the payment of an annual sum on account of general benefit, fire protection and public use. In return for this require the water company to put in hy- drants whenever and wherever ordered by the city, the sum of money paid by the city being independent of the number of hy- drants. The city should own the hydrants and pay for their erection, connection with the water mains and maintenance. It is a grave mistake to pay a certain sum per month or year for each hydrant, as it operates to keep many districts out of the reach of fire protection because of the increased cost of extra hydrants. Yet thp people in these districts have their share of the taxes to pay for fire protection, general benefits and public use of water. The tax rates in badly governed cities and also in cities owning • all sorts of public utilities are high. Care must be taken that in owning public utilities the bonded indebtedness and the consequent tax rates do not become too much of a burden. In shifting from indirect to direct taxation there is not always economy. It may be that the opponents of municipal ownership on general principles may be correct and that wise laws well and intelligently enforced are better than municipal ownership. FRANCHISES. Upon the subject of municipal control volumes could be writ- ten. It is best for any small place having applications for fran- chises for street car lines, telephones, electric lighting, gas lighting, etc., to employ some competent person to prepare the terms on which the franchise will be granted and then advertise the fran- chise under these terms for sale to the highest bidder. The in- numerable details can hardly be touched upon here, and new fea- tures become known daily. SINKING FUNDS. Two tables, or rather One table in two parts, here given, will help in the calculation of sinking funds. 168 ENGINEERING WORK IN TABLE IIL ANNUAL PAYMENT PER DOLLAR INVESTED, TO REPAY ORIGINAL OUTLAY AT THE END OF A GIVEN NUMBER OF YEARS. Life of Plant. , (years) Rates of Interest on Installments— jf. B% 4^ ^ e% 8!« 10 9 .08723 $ .08330 $ .07950 $ .07587 9 .06903 11 .07808 .07416 .07039 .06679 .06008 12 .07046 .06656 .06283 .05928 .05269 18 .06403 .06015 .05646 ' .05296 ,04652 14 .05863 .05467 .05103 .04759 .04130 15 .05376 , .04994 .04634 .04296 .03683 16 .04961 .04582 ,04227 .03895 .03298 17 .04595 .04220 .03870 .03544 .02963 18 .04271 .08899 .03555 .03236 .02670 19 .03981 .03614 .03275 .02962 .02413 20 .03722 .03368 .03024 .02718 .02185 LIFE OF PLANT IN YEARS. Deprecia- tion of plant. Rates of Interest on Installments— )<. Si 4!< ^ 6^ 8% I' .3 4 5 6 7 8 9 10 11 46.90 31.00 2345 18 93 16 90 13.72 12.05 10.77 9.72 8.88 816 41.04 28.01 21.60 17.67 14.99 13.02 11.62 10.34 &.37 ' 8.58 . 7.91 36.73 25.68 2010 16.62 14.21 12 42 11.04 9 95" 9.05 831 7.68 33.40 23.79 18.85 15.73 13.53 11.90 10.62 9.60 8.76 8.07 7.47 28.55 20.91 16.88 14.28 12.42 11.01 9.90 9 01 8.26 • 7.64 7.10 The first shows the annual payment per dollar invested to re- pay the original outlay at the end of a given number of years. The following example shows how it is used. A given equip-- ment of machinery, costing $35,000, is estimated to have a useful life of fourteen years. At the end of that time it will have a scrap value of $1,000. The money earned by the plant receives interest at 4 per cent, payable annually. What annual charge must be made to extinguish the principal by the time the machinery must be TOWNS AND SMALL CITIES. 1C9 renewed? The sum to be made up is $35,000 — $1,000=$34,000 in fourteen years. The first part of the table gives for fourteen years and 4 per cent, the payment $0.5467 per dollar. The annual depre- ciation debit is, therefore, $24,000x.05467=$l,312.08. In addition to this, of course, interest must be paid on the $2S°,000 investment; the rate of interest is not necessarily the same as the 4 per cent above used, since it depends on the conditions under which the capital was borrowed.- The second part of the table gives the term of amortization or "life of plant" for various percentages of depreciation and various rates of interest. The following example shows how it is used. A system of water pipes for city distribution cost $125,000. Besides the interest on the bonds, the system is charged annually with $2,500 (2 per cent) depreciation. In what time will the sum thus accumulated, earning 5 per cent interest, paid annually, be sufficient to pay for the bonds at par? From the second part of the table we find, for 2 per cent depreciation and 5 per cent in- terest, the figure 25.68 years. This represents the time required to wipe out the debt at par. If there has been, for example, a premium of 4 per cent paid, there requires to be paid back 104 per cent, and for this the table does not suffice directly. This part of the ques- tion is taken up in the chapter on Engineering Data, for it re- quires a knowledge of mathematics and the use of logarithms, so an engineer is a good person to call upon to figure the matter. The tables are copied from those printed and distributed by Messrs. Charles C. Moore & Co., Engineers, of San Francisco, Cal., and printed in Engineering News March 2, 1905, from which the above descriptions of use were taken. CHAPTER XIII. CONTRACTS AND SPECIFICATIONS. "The better the description, the better the deed." — E. C. Easy. It is unwise to attempt to do any work without plans and specifications being prepared in advance, with estimates of cost. Complete specifications are plain descriptions, with the necessary drawings, in detail, of the work to be done, and should form a part of the contract. Nothing should be taken for granted. Do not bind the contractor so he will lose control of his men and do not be too trustful in dealing with him. Use common sense. As a rule it is better to do all public work by contract than day labor. It will be found most satisfactory in the end, although a very few places have found it otherwise. It is not economical for the municipality to furnish paving and other material and contract simply for labor. In such cases inspectors are apt to be lenient in passing imperfect material in order to save loss. The only way is to have the contractor fur- nish everything under rigid inspection before it goes into place. The council should not attempt to dictate to the contractor whom to employ and whom not to employ. It is not just to the contractor nor acting honestly with the people taxed for an im- provement to compel the contractor to employ only" home labor. It is well to help home labor and give it the preference, all things being equal, but if the contractor is limited to such help the cost of the work is increased. The men thus encouraged become inde- pendent and lazy and good men are scarce and hard to deal with. A contractor generally prefers to get all bis labor in the town in which the work is being done, if he can. Special labor protection clauses as a rule are seldom needed. For economical work there must be good, clear specifications, honest advertising and letting of contracts, with competent super- vision and severe penalties for non-performance and shirking of .work. 170 TOWNS AND SMALL CITIES. 171 It too often happens that in small towns and cities contracts and specifications are copied from other cities where conditions require certain clauses. An unreasoning copying does not always work well. Mr. Wait says there are four essentials to a contract. They are as follows : 1st — Two parties with capacity to contract. 3d — ^A lawful consideration; a something in exchange for its legal equiv- alent; a quid pro quo. 3d — A lawful subject matter, whether it be a promise, an act or a material object. 4th — Mutuality; a mutual assent, a mutual understanding, a meeting of the minds of the parties. Without these four elements no contract is binding in law. Dr. Waddell says : "The esentials of a well drawn contract that comes within the province of the engineer are as follows : 1. — A proper and customary form. 2. — ^A full and correct description of all parties to the argeement. 3. — A thorough and complete preamble. 4. — A statement of when and under what conditions the contract is to become operative. 5. — The limit, if any, for duration of contract. ' 6. — An exhaustive statement of what each party to the contract binds himself, his executors, administrators, successors, ~ or assigns, to do or refrain from doing. 7. — A clearly defined enunciation of the consideration which each party is to receive; this is the essential raison d'etre of the instrument. 8. — The forecasting of all possible eventualities that would materially affect the agreement, and a full statement of everything that is to be done in case of each eventu'ality. 9. — Penalties for failure to comply with the various terms of the agree- ment. 10. — Provision for possible cancellation of contract. 11. — -Provision for settlement of all business relations covered by the contract ' or resulting therefrom in case of cancellation, taking into account all possible important eventualities. ■* 12. — Mention of the place where the agreement is drawn or of the place where it is to be put in force, so as to show the state under the laws of which the validity of the contract is to be determined, should suit be necessary to enforce It. 13. — Methods of payments, if any are to be made. ^ 14. — Provision for extra compensation and the limitations connected therewith. 15. — Provision for possible changes in contract. 16.. — Provision for transfer of the contract, or for subletting. 17. — Provision for settlement of disputes. 172 ENGINEERING WORK IN 18.— Provision' for satisfactory and sufficient bond, if any be needed. 19, — Provision for defense of lawsuits, if such provision be necessary. 80. — Definition of names used in contract, such as "Engineer," "Com- pany," "Contractor" or "Trustee." 21. — Dating of contract. 22. — Proper signatures with the necessary seals, if the latter be required. 23. — Witnesses to the signatures, or execution before a notary public. The American Public Works Association was formed in 1904. The object is to have a clear understanding of all that enters into a contract; between city officials and contractors for public work. This association asks that the following rules be observed in preparing contracts" and specifications : 1. — When state or municipal statutes conflict with association rules, the latter shall be waived. ■> 2. — When work is done on a percentage basis, security should be given to guarantee estimate and faithful performance of the work. 3. — ^Designing engineer shall not compete for work advertised to be let under his plans and specifications. 4. — No bids shall be asked until money to pay for the work has been provided. 5. — Bids shall be opened and read in public. 6. — No bids shall be submitted after time named in advertisement. 7. — No bids shall be withdrawn after time set for opening of bids. 8. — Illbgibility, or ambiguity, shall invalidate a bid. 9.-^Bidders shall not be permitted to change prices stated in bid. 10. — Bids shall state specifically make of apparatus or machinery proposed, and same shall be specified in contract. 11. — When all bids are rejected new bids shall not be made on the same specifications without readvertising. 12. — The amount of certified check required shall be stated in advertise- ment calling for bids. 13.— *-Bid bonds may be substituted for certified checks. 14.^Checks or bid bonds shall be returned to all but successful bidder as soon as award of contract is made, 15. — Award of contract shall be made within thirty days after bids have been opened or checks returned to bidders. 16. — Bond shall not exceed 25 per cent of contract price. 17. — ^Twenty days shall be allowed contractor in which to furnish satis- factory bond, 18. — In event of discrepancies between the drawings and specifications, decision of the engineer shall be final, 19, — All instructions regarding work shall be given by the engineer or his as^stants. ' '20. — Extra work shall only be done on written order of engineer when authorized by contractee at a price to be agreed upon. 21. — In deducting material not required only the value of- same shall be deducted. TOWNS AND SMALL CITIES. 173 22.— Changes in construction shall not be made to lessen quantities of material in transit or in process of manufacture unless contractor be paid for all actual loss occasioned. 23. — When a specific make of machinery or apparatus is specified in contract same shall be furiiished in accordance with manufacturer's plans and specifications submitted with bid. 24. — Engineer or his authorized assistants shall at all times have access to the work and materials for purpose of inspectiii, and have notice of concealed work before it is covered. 25. — In event of emergency work contractor 3I: all notify engineer and engineer shall furnish inspector. 26. — Work done in regular progress of the contract and ordered torn down' for purposes of inspection, if found to be in accordance with the specifications shall be at cost of contractee. 27. — Engineer shall give written notice to contractor when work or ma- terial has been rejected. 28. — Monthly estimate shall be made on or before the fifth day of each month. 29. — Monthly estimate shall be based on the contract price and shall in- clude all material delivered and labor performed. 30. — Ten per cent of monthly estimate shall -be retained by contractee until work is completed. 31.^ — Time shall be allowed contractor for' delay caused by strikes, acci- dents, or other causes beyond his control. 32. — When work is completed engineer shall accept or reject same within s reasonable time. 33. — Contractor is released from all future responsibility when contractee takes possession of plant, whether settlement has been made or not, unless otherwise agreed. 34. — When work is accepted the 10 per cent retained shall be paid in final settlement, and bond shall be released and returned, except where a time guarantee has been agreed upon. 35. — ^Arbitration shall be resorted to in all cases before applying to the courts. It will lengthen an already lengthy document too much to add the foregoing nineteen rules in the specifications and contract, so it will be enough to put in one paragraph, "Work to be done under the Rules of the American Public Works Association." It will be a good idea also to put that statement in the advertise- ments for bids in order to attract the best contracting firms. The above rules seemed to be necessary in view of the many •absurd restrictions put upon contracting, especially in small places where the city attorney and city surveyor feel frightened over the " prospect of having dealings with an outside man or firm. Engineering News notes with approval the following clause from specifications sent to the editors for comment : 174 ENGINEERING WORK IN "The number ,of working days named in the proposal will be estimated in the comparisons of bids at the rate of five dollars ($5) per day." The following specifications for work are given as useful studies of good examples in several places : CONCRETE. The first good pavements of concrete were laid in Richmond, Ind. Mr. H. L. Weber, the city engineer, in a paper before the Ohio Engineering Society gave the following: SPECIFICATIONS. Section 1. — The Contractor shall furnish all the labor, tools and materials necessary for the completion of the cement work and accessories as herein specified; also furnish all labor and materials required for protecting and re- pairing adjacent structures, maintaining public travel on 'the street or inter- cepted roads, walks and streets; all labor and materials required for any of the operations, principal or collateral.^ mentioned or implied herein. All materials and labor shall be subject to the inspection and acceptance of the Engineer and Superintendent in charge. SUB-GRADE. Sec. 2. — Excavate to the full width and depth below the top of the grade stakes, as shown by plans. Tfie material excavated shall be delivered by the Contractor to such lots or tracts of land abutting upon the improvement tRat may require filling. After such lots are filled, the remaining material shall be delivered to such points as the Board of Public Improvements or Engineer may designate, provided the haul does not exceed one thousand yards, other- wise said material shall belong to the Contractor, to be disposed of. SUB-DRAINS. '' Sec. 3. — Sub-Drains shall be laid of three or four (3" or 4") inch common drain tile, eight (8") inches below the sub-grade as shown by the plans. The tile shall be laid to a true grade and line, with close fitting joints, with clean gravel packed around and over them to the top of the trench. The tile shall be connected to su'ch outlets as the Engineer may determine. All junctions to be made with "Y" and "T" branches, and all deflections with curves of vitrified sewer pip& TREES, ROOTS, ETC. Sec. 4. — Trees shall not be injured, but roots of trees, which in any way interfere with the construction of the walk and its maintenance in proper manner, shall be cut away_ as the Engineer may direct. The pavement shall be properly fitted around all fixtures in the walk. RELAYING, ETC. Sec. S. — ^Where the material in any walks that now exist on the street shall be accepfable to the Board of Public Improvements, they shall be relaid to the grade and line established; the price therefor shall be determined by adding 10 per cent to the actual cost of the work as determined by the Engineer. TOWNS AND SMALL CITIES. 175 , FOUNDATION "A." Sec. 6. — Upon the sub-grade shall -be placed clean, coarse gravel, eight (8") inches in thickness after being thoroughly wet and rammed, and to a uniform depth of four to six (4" to 6") inches below the finished grade. FOUNDATION "B." Sec. 7. — Upon the sub-grade, prepared as shown by the cross section and as above specified, there will be placed a six (6") inch layer of rubble, or field cobble stone, the refuse of Quarries, old bowlders taken from the old bowlder curbing (if too large they shall be broken if used), or coarse gravel. Upon this layer shall be placed sufficient gravel to fill the interstices, and form a foundation with a total depth of eight (8") inches, after being leveled off and settled by flooding and ramming. Upon this bed will be placed a layer of good, clean gravel, two (8") inches in depth, to be properly spread, packed, and smoothed, to receive the concrete cu'rbing. CONCRETE. Sec. 8. — Upon the foundation place the concrete, four to six (i" to 8*) inches thick after being thorou'ghly rammed; it shall be uniformly one (I'O inch below the finished grade. The facing shall be placed in the templets forming the curb, backed up with concrete thoroughly rammed to place. The concrete shall be composed of one part cement, two parts sand, and four (4) parts gravel; the gravel can contain the sand, and two (2) parts clean screened, crushed lime stone. The proportioning of the cement, gravel and stone shall be done by placing a templet of the proper size upon a platform and placing therein the sand, gravel or stone by actual measure- ment in the proper quantities, leveling off the form with a straight edge; over the top evenly spread the cement in the proper proportions; remove the templet, ttfrn the mass at least twice thoroughly, or until it is thoroughly mixed, add clean water from sprinkling can and thoroughly mix to make a concrete of such consistency that when deposited and rammed to place shall envelop every particle of sand with the cement, and every particle of gravel or stone with mortar. This result must be obtained to the entire satisfaction of the Engineer. The concrete shall be laid in. blocks of the following dimensions: Six by seven (6'x7') feet for seven (7) foot walk; six by six (6'x6') feet for six (6) foot walk; and six by five (6'x5') feet for five (5') foot walk, with ex- pansion joint separated by two pieces of three-ply tarred paper, at each 33 feet of line, an(l intermediate joints with dry sand, as the Engineer may direct. WEAKING surface. Sec. 9. — Before the concrete has set, deposit the wearing surface, which shall be one (1") inch in thickness, composed of one part cement and two parts clean, coarse, washed sand, if the nature of the material require it; or one part cement, one part sand, and one part clean, crushed stone screenings. First mixed thoroughly in a dry state, then add sufficient clean water, and thoroughly mix into a medium soft mortar. Deposit this upon the concrete . and trowel down to insure a perfect contact, then level with a straight edge from the grade strips. When sufficiently hard, float and trowel to a smooth continuous surface. Avoid dusting the surface with dry cement. 176 ENGINEERING WORK IN TOWNS AND SMALL CITIES. 177 The surface, except a marginal draft two inches wide aroufld each plate and five inches along curb line, shall be pitted with a brass roller acceptable to the Engineer. The wearing surface shall be cut in blocks the same siz.e as the concrete base. As soon as the work has properly set, all templets to be removed and edges plastered to the full depth of templets, if required by the Engineer. All walks shall have a rise of one-fourth inch per foot from the curb to the lot line. Strips properly staked shall be set on both sides of the walk to keep straight, being careful that the grade and fall are correct. Any walk not properly laid, must be taken up and relaid by the Contractor. CEMENT CURB^ GUTTER AHD CROSSWALKS. Sec. 10. — The cement curb, gutter and crosswalks shall be constructed in place, under the direction of the Engineer, upon a bed of gravel, eight to ten (8* to 10") inches in depth, after being flooded with water and. com- pactly rammed to an even surface. Upon the sub-grade will he laid the found- ation A or B as shown by plan. The curb and gutter or crosswalks will be composed of concrete, formed by intimately mixing, dry, one (1) part Port- land cement, two (2) parts coarse, clean sand, washed if necessary, three (3) parts of clean, medium sized gravel, and two (2) parts of clean, screened lime stone, crushed to pass through -d screen of one and one-half mesh, to which add sufficient clean water to form a concrete, that, when placed in the templets and thoroughly rammed, free mortar will appear on the surface. The ramming of the concrete in the forms shall be done with the proper tamping bars and othei" tools to insure a compact homogeneous mass, with full square corners. The stone shall be sprinkled before it is added to the mortar. The proportions given being intended to form a con- crete in which every particle of sand shall be enveloped by cement, and every particle of gravel and stone enveloped by mortar, this result must be ob- tained to the satisfaction of the Engineer. All exposed surfaces shall be covered with a finish coat one (1) inch in thickness, composed of one part cement, one part of finer clean stone screenings, and one (1) part of clean, coarse sand. The facing shall be placed in the templets forming the curb backed Up with concrete and thoroughly rammed to place. The top facing of curb and gutter shall be thoroughly troweled to insure perfect contact. When suffi- ciently hard, float and trowel to a smooth true surface. The curb to be constructed with the top edge to the established grade of the street; the upper and lower face corner to be rounded to a radius of one inch. The curb shall be six inches thick at the top, and the gutter eight (8") inches thick, and twenty-eight (28") inches wide, and constructed in seven-foot sec- tions, alternately. . When the intervening sections are constructed there shall be a strip of tarred paper placed in the joints, as the Engineer may direct. The proportioning of the cement, sand, stone and gravel shall be done by placing a templet of proper size upon a platform, and placing therein the cement, sand, stone and gravel in the proper quantities by actual measure- ment, leveling off the templets with a straight edge. Wrought iron protections will be built in all comers and places designated. 178 ENGINEERING WORK IN ROADWAY PAVEMENT. Sec. 11. — ^The sub-grade will be thoroughly rolled, leveled and re-rolled until it is true to grade and cross-section of the finished roadway, and from eight to twelve (8''to 12^0 inches below the surface of the street, as the case may be. If found necessary for sub-drainage, upon the sub-grade, place three to four (3" to 4") inches of gravel, thoroughly wet and consolidated by rolling or ramming, or both. Upon this gravel foundation will be placed a layer of concrete from four to five (4" to 5") inches in thickness and finished to a true crown and grade, parallel to the finished street surface and three to four (3'' to 4:") inches below the same. This will constitute the foundation for the cement roadway. When sufficiently strong to sustain the roadway paving, the surface of the concrete foundation will be covered with a coating of fine sand, raked off with a flat board rake, by hand, so as to remove all sand except that which may remain in low places and voids in the concrete foundation. Upon this will be placed a layer of thin tar paper (or other suitable paper) or material to act as a separating joint. Upon this will be laid' the concrete pavement two to three (3" to 3") inches thick, in sections the full width of the street and feet in length, with expansion joints next the gutters and ends. This roadway concrete will be composed of one part cement, two parts sand, three parts gravel, and two parts crushed stone, mixed with water to form a rather wet mixture. Upon this will be placed the wearing surface, one inch thick, composed of one part cement, one part clean, sharp sand, and one part clean stone or granite screenings, mixed with water to form a rather wet facing mixture. The wearing surface will be deposited in two layers, one-half inch thick, the first to be thoroughly rammed to insure perfect contact; the second applied immediately after, and thoroughly troweled and worked over, and made to conform to the finished surface of the street by the use of the proper forms. When sufficiently hard, the surface to be floated and steel troweled, and. lastly, raised with a cork float, and when flnished-must be true to ^ grade and cross-section. All concrete must be machine made, or thoroughly mixed by hand, as the Engineer may direct. CEMENT. Sec. 12. — (Note: The writer advises in this section the Standard Cement Specifications of the American Society for Testing Materials, instead of those used in Richmond, Ind.) SAND. Sec. 13. — ^The sand shall be clean, coarse river or bank sand, acceptable to the Engineer. • WATtR. Sec. 14. — None but clean, clear water shall be used, which must be fur- nished by the Contractor. TOWNS AND SMALL CITIES. 179 As soon as a section is finished it shall be protected by placing mu'slin or canvas thereon, and in dry weather it must be kept moist for five days by thorough sprinkling. STREET CROSSINGS. Sec, 16. — Where drive ways, alley crossings, or street crossings occur in the line of walk, the walks will be made of special construction as shown by plans, or as directed by tiie Engineer. Letters shall be placed as directed by the Engineer. WORK SUSPENDED. Sec. 16. — ^Any work not finished in the time specified, shall, be discon- tinued for the season, upon notice from the Board of Public Improvements, and not again commenced until said Board shall order the Contractor to begin work. No work shall be laid in freezing weather. STEPS. Sec. 17. — ^At points where it will be necessary to construct platforms, steps, or other appurtenances, along any building in order to harmonize said building to the established grade, the outride line of said appurtenances shall be feet from the curb line, and parallel therewith, and con- structed as shown by plans and detail drawing. In Bellefontaine, Ohio, a pavement that had been down for thirteen years was inspected by a committee from Richmond, Ind. The committee reported that although the pavement was extremely durable it was unpopular because so slippery in all seasons. The committee reported that in their opinion it was because the surface was finished with a steel trowel, whereas in Richmond after steel trowelling the surface was trowelled with a cork trowel. The corrugations and ridges left in the Bellefontaine pavement was another objection. The Bellefontaine specifications were as fol- lows: CEMENT PAVEMENT. Section 1. — The lower strata of the cement pavement or grout must be four inches thick, composed of one part of best Portland cement equal to the Buckeye Portland cement to four parts of clean, sharp gravel and sand, in which the proportion of the sand is about one-half that of the gravel. This must be thoroughly mixed by a screw mixer and so much water thor- oughly incorporated during the mixing process as will show on the surface of the concrete after it has been -well rammed to place, which must be done as expeditiously as possible after the mixing, and the concrete must be made solid and complete at once after being dumped in place. Sec. 8. — After the lower strata has been placed and before it has thor- oughly set, then the top, two inches thick, composed of equal parts of the Portland cement and coarse, sharp sand and gravel, sifted to the size of a pea, then wet mixed and rammed the same as the grout, a very thin layer of pure cement must be well rubbed into the concrete surface, first to insure adhesion, then the entire coat must be added before the concrete is set. 180 ENGINEERING WORK IN Sec. S. — The entire concrete and top must be separated carefully and regularly into blocks five feet square and the edges neatly finished, and the surface grooved in continuous lines from side to side every four inches, the grooves being V shaped, thfee>sixteenth inches deep and one inch wide, to be troweled smooth, the entire pavement being carefully built to the grade givn by the engineer, must present a true crown, as represented on the cross section prepared for the same. Sec. 4. — A row of blocks on one side to have joints sloping in euch manner that they can be raised without disturbing the other blocks. Sec. S. — Curbs, one part cement to three parts sand, six inches wide of same material, to be raised on each side to a level with the sidewalks as per engineer's plan. Sec. 6. — The whole worb, when completed to be covered two inches deep with wet sand and kept in that condition for one week after completion of the contract. Sec. 7.-T-The above specified work, when completed is to be first-class in every particular and is to be guaranteed by the contractor to last a relative time longer than any brick paving, as the contract price exceeds the contract price of the brick or any like material of which there may be a competitive bid. Sec. 8. — All work to be in strict conformity to the plans, specifications and cross-section of the improvement and to be carried out under the general requirement as hereinafter specified. BRICK. The following specifications were adopted for brick pavements at-the Sixteenth Annual Convention of the National Brick Makers' Association : sub-structure or grade. Earth in excavation to be removed with plow and scraper, or other device, to within two (2) inches of sub-grade, then brought to true grade with the roller, the weight of which should not be less than five (5) nor " more than eight (8) tons. If the earth is too hard to receive compression through the weight of the roller, then loosen the remaining two (2) inches with a pick and cart away. . ^ Earth in embankment must be applied in" layers of eight (8) inches in thickness and each layer thoroughly rolled, and in both excavation and em- bankment the sub-grade must have a uniform density. If the ground is a spouty clay, tile drainage should be provided to carry off this accumulation of wet. CURBING. If cement is used it should be completed, if stone, all should be hauled and distributed and set before the grading is finished, ana may then be used as a guide to finish the sub-grade. It should range in thickness from four (4) to six (6) inches, twenty (20) to twenty-four (24) inches deep, the business and street traific gov- erning the same, and lengths not shorter than five (5) feet, except at clos- TOWNS AND SMALL CITIES. 181 ures.' Neatly dressed on top with a square or rounded outer edge and four (4) inches down on the inside. The outer surface to be too! dressed to the depth of the face exposed and to the depth of the thickness of the brick and sand c^ishion. The intersection at street corners and alleys should be circular, with radius of four (4) and three (3) feet, respectively. (Note — In this connection the writer wishes to call attention to his remarks earlier in this book, on having a large radius at intersections.) UARGINAL CURBS. Should always be of a hard and durable character, of stone, and from fourteen (14) to eighteen (18) inches deep, dressed on top and five (6) inches down on the face next to the brick. Set to accurately fit the curvature of the cross-section of the street, on six (6) inches of concrete and backed up with the same within six (6) inches of the top. CONCRETE FOUNDATIOlt — CBVSHEO STONE. Should be of approved quality of hard rock, with no fragment larger than will pass through a two (2) inch ring and none smaller than will pass through a one (1) inch ring in their longest dimensions, free from all refuse and foreign matter. (Note — It will be seen from these specifications that a dense concrete is not called for. The stone is ranged - between two sizes that will assure at least 30 per cent of voids. In the following paragraphs it will be seen that only half enough sand to fill the voids is called for. To get a dense concrete smaller sizes of stone should be permitted.) SAND. Must be clean, sharp and dry, and thoroughly mixed in its dry state until the whole mass shows an even shade, with an approved brand of either hydraulic or Portland cement.. If of hydraulic, the proportion of mixture should be of one part of cement and two parts of sand;^ if of Portland cement, one part of cement and three parts of sand. (Note — By hydraulic cement is meant natural cement, for Portland is also an hydraulic cement. — McC.) To the above mixtures should be added sufficient clean water to mix to a plastic mass, fluid enough to rapidly subside when attempting to heap to a cone shape. To this mixture add four (4) and five (5) parts, respec- tively, of damp crushed stone, or clean, screened gravel, and turn the whole mass over not less than three (3) times, or until every fragment is thor- oughly coated with the cement mixture. For the reception of this mixture the grade should be set off in five (5) foot squares, with » stake at each comer. Tops of each should be at the surface of the concrete, which must be tamped until free mortar appears at the surface. Occasional sprinkling in extreme hot, dry weather is beneficial. After thirty-six hours the cushion sand may be spread. ^ SAND CUSHION. Sand should be clean and free from loamy matter. It need not neces- sarily be sharp. It should be two (2) inches thick before the compression of the brick by rolling. The sand should be spread by the aid of a tern- 182 ENGINEERING^ WORK IN plate, the whole or one-half the width of the street, made to conform with the true curvature of the street cross-section. BRICK. The brick should all be hauled and neatly piled inside of the curb line before the grading is finished, or, if allowed by the engineer, delivered on the street in wagons and carried from the pile or wagon on pallets or with clamps, and not wheeled with barrows. They should be first-clas^ and thor- oughly vitrified, showing at least one fairly straight face, with rounded edges^ with no greater radius than 3-16 of an inch. They should not be less than aj4x4x8, or more than 3^x4x9 inches, free from cracks,\ with but slight lamination and at least one edge with but slight kiln marks allowed. ^ Such brick or blacks shall be submitted to a test of an hour in the National Brick Manufacturers* Associations* standard rattler, and under the conditions prescribed by that association, and if the loss by abrasion during such test exceeds 20 per cent of the original 'weight of the brick tested, then such brick or blocks shall be rejected. BRICK LAYING. Brick should be laid perpendicular to the curb. Broken brick or block can only be used to break joints in starting courses, or in making closures. The brick sliall be laid on edge, close together, in straight lines across the roadway between gutters. Gutters shall be constructed as directed by the engineer. After the brick are laid " they shall be thoroughly inspected and all warped, spalled and soft brick removed and replaced by more perfect ones, and those found with the bad face up should be turned down. TAMFING AND ROLLING. After the inspection is thus completed the edge of the pavement shall be tamped to grade next to the curb, to the width of six (6) or eight (8) inches out from the curb, with a hand tamper. The entire pavement shall then be rolled with a five (6) ton steam roller uiitil all brick are thoroughly bedded and the whole surface assumes a practical plane conforming to the gradient and curvature of the roadway. EXPANSION CUSHION. An expansion ctfshion must be provided for, one inch thickness next to the cilrb, filled two-thirds its depth with pitch, the top third being filled with sand and a like cushion at right angles with the street, at intervals of fifty feet THE FILLER. The filler shall be composed of one part each of clean, sharp sand and Portland cement. The sand' should be dry. The mixture, not exceeding oge- third bushel of the sand, together with a like amount of cement, shall be placed in the box and mixed dry, until the mass assumes an even and un- broken shade. Then water shall be added, forming a liquid mixture of the consistency of thin cream. From the time the water is applied until the last drop is removed and floated into the joints of the brick pavement, the same must be kept in con- stant motion. TOWNS AND SMALL CITIES. 183 The mixture shall be removed from the box to the street surface with a scoop shovel, all the while being stirred in the box as the same is be- ing thus emptied. The box for this purpose shall be 3}^ to 4 feet long, 2T to 30 inches wide and 14 inches deep, resting on legs of different lengths, so that the mixture will readily float to the lower corner of the box, which should be from 8 to 10 inches above the pavement. This mixture, from the moment it touches the brick, shall be thoroughly swept into all the joints. Two such boxes shall be provided in case the street is twenty feet or less in width; exceeding twenty feet in width three- boxes should be used. The work of filling should be thus carried forward in line until an advance of from fifteen to twenty yards has been made, when the same force and appliances shall be turned back and cover the same space in like manner, except that the mixture for the second coating may be slightly thicker than the first. To avoid a possibility of too great thickening at any point, there should be a man with a large sprinkling can, the head perforated with small holes, splinkling gently the surface ahead of the sweepers. This should be done in the application of each course here specified. After the joints are thus filled flush with the top of the bricks and suffi- cient time for evaporation has taken place, so that the coating of sand will not absorb any of the mixture, one-half inch of sand shall be spread over the whole surface, and in case the work is subjected to a hot" summer sun an occasional sprinkling, suflicient to dampen the sand, shall be followed, for two or thrfee days. The grouting thus finished must remain absolutely free from disturbance or traffic of any kind for a period of ten days. WOOD. , Wood paving specifications, Brooklyn, N. Y. : 3. — The wearing surface shall be composed of longleaf, all heart, yellow pine blocks, treated as hereinafter describedi All blocks shall be of sound timber, free from bark, sapwood, loose or rotten knots, or other defects which shall be detrimental to the life of the block or interfere with its lay- ing. No second growth timber will be allowed. 2. — The blocks are to be treated throughout with an antiseptic and water- proof mixture, at least 50. per cent of which shall be dead oil of coal tar. commonly known as creosote oil. The remainder to be resin or some other ' s:milar and suitable waterproof . material. All portions of each individual block shall be thoroughly treated with the mixture, and after treatment the" specific gravity of the blocks shall be greater than that of water. 3. — After treatment the blocks sha.l show such waterproof qualities that, after being dried in an oven at a temperature of 100° for a period of 24 hours, weighed, and then immersed in clear water for a period of 24 hours and weighed, the gain in weight shall not be greater than 3 per cent. 184 ENGINEERING WORK IN CHICAGO SPECIFICATIONS. The following paving specifications were in use in Chicago during 1905: CURB STONE. The curb stone must be of the best quality of ,. . . stone, straight and free from cracks, seams, sand pockets or drill holes. Buff-colored sand- stone will be rejected. The top edge must be of full thickness, square, and neatly bush-ham- mered. The face must likewise be dressed to a depth of twelve (12") inches from the top. The back side of the stone must be "pointed" to a depth of at least two (2") inches so as to leave the top of the stone five (5") inches in thickness throughout. The ends shall be dressed smooth and square to a depth of eighteen (18") inches from the top, so as to make close joints. The bottom of the stone must be straight and parallel with the top. ' Where sandstone is used the upper roadw;ay corner shall be rounded to a radius of one and one-half (IJ^'O inches. The stones, after being dressed, shall be not less than five (5") inches thick, three (3') feet deep or four (4') feet long. In no case shall the lengths of the stone on the top and bottom differ by more than one (1') foot. The curb stone shall be set to the established grade in a continuous line on each side of the street, feet from and parallel with the center line thereof, except at all intersections of streets and alleys, where the curb shall be returned to the street line. All grades and lines will be given by the Engineer. The stones are to be firmly set upon blocks of flat stone six (6") inches in thickness, and at least eight by twelve (8"xl2'') inches in size. Oolitic limestone and sandstone shall not be used for blocking. At each street intersection there shall be furnished and set four (4) and at each half intersection two (2) circular corner stones cut to a radius of two (2') feet, unless otherwise ordered by the Engineer. These stones must be bush-ham nlered on top, and on the face for a distance of eighteen (18") inches down. No extra charge will bfe allowed for circular corner stones. All curb stone now set on the street, that is not at the proper line or grade, must be placed in proper position. The' curbing shall be back-filled to the top, and the filling at that point shall be four (4') feet wide and shall have a slope of one and one-half (i;^) horizontal to one (1) vertical. The full quantity of filling shall be put in front and back of each curb stone as it is set, and must be thoroughly rammed with a proper rammer at ;the same time, so that the curbing will be firmly held in place. No lines or grades will be given for the setting of curb stones until the same shall be dressed according to specifications. COMBINED CURB AND GUTTER. In making the combined curb and gutter Portland cement shall be used and ordinarily will be subjected to the following inspection and tests: (Note — The writer advises here the Standard Cement Specifications, Chapter X, instead of those used in Chicago.) Samples of cement which it is proposed to use in the work shall be sub- TOWNS AND SMALL CITIES. 185 mitted to the Board of Local Improvements in such quantities and such time and place as to make all the required tests. The Board of Local Improvements reserves the right to reject, without recourse, any cement which is not satisfactory, whether for reasons mentioned in these specifications or for any good and sufficient cause. All cement to be used in the combined curb and gutter must be delivered on the work in approved packages bearing the name, brand or stamp of the manufacturer. It shall be thoroughly protected from the weather until used, in such manner as may be directed. . The granite screenings used in making the concrete shall be clean, dry, free from dust, loam and dirt, and when delivered on the street shall be de- posited on a fiooring, and kept clean until used. The crushed granite shall be clean, free fr6m dust and dirt, broken so as to measure not more than one (1") inch in any dimension, and when deliv- ered on the street shall be deposited on a flooring, and kept clean until used. The granite concrete combined curb and gutter shall be constructed at the established grade and in a continuous line on each side of the street ( ') feet from and parallel with the center line thereof, except at all intersections of streets and alleys, where it shall be returned to the street line, and at such intersections there shall be formed the necessary circular stones built to such radii as the Engineer may direct. All grades and lines will be given by the Engineer. The combined curb and gutter shall rest on a foundation of cinders which must be six (6") inches in thick- ness after being thoroughly flooded and compactly rammed to an even surface. The curb and gutter shall be made of concrete formed by intimately mix- ing one (1) part ot cement with two- (8) parts of fine granite screenings; to this mixture shall be added fotu* (4) parts of crushed granite and the whole thoroughly mixed together, after which just sufficient water to wet the mass shall be added, so that when it is rammed in place a film of mois- ture shall appear on top. All exposed surfaces shall be covered with a finish- ing coat of mortar three-eighths (H") inch in thickness, composed of one (1) part of cement thoroughly mixed with one and one-half (.lyi) parts of the fine granite screenings. Before the concrete sets the curb and gutter shall be cut into sections not exceeding six (6) feet in length. The gutter flag must be eighteen (18") inches wide apd five (5") inches thick; the curb must be seven (7") inches thick throughout, except at the upper face corner, which is to be rounded to a radius of one and one-half (I'/i") inches. The height of the curb above the gutter flags will be of varying dimensions, averaging not less than ( ") inches. The contractor or contractors shall build without extra charge all "inlets" necessary to properly connect the combined curb and gutter with the catch- basins, and such steps on the gutter flags at the crossings as the Engineer may direct. The curb and gutter shall be back-filled to the top, and filling at that point shall be four (4') feet wide and shall have a slope of one and one-half (1%) horizontal to one (1) vertical. The full quantity of fiUing shall be put in front and back of each section of curb and gutter as it is built, and must be thoroughly rammed with a proper rammer at the same time so that the curb and gutter will be firmly held in placa 186 ENGINEERING WORK IN CURB WALL REPAIRS. Wherever curb walls on the line of this improvement are found to be defective, they must be torn down and rebuilt , to such a depth from the top as the Engineer may direct. In this rebuilding the contractor or contractors will be allowed to use all the old material previously therein contained which may be suitable, but must also furnish any and all new materials which may be necessary to bring the wall to the line and grade given by the Engineer, and finish it in a good and workmanlike manner. The roadway side of the wall to a depth of ( ') feet from the top of the masonry shall be plasteered at least one-half (}4") inch thick with a mortar composed of one (l5 part of approved Portland cement and two (2) parts of clean, coarse, sharp sand; the sand and cement to be first thoroughly mixed dry and then sufficiently moistened with water to form a thick mortar. The mortar must be used immediately after mixing, and no mortar which has once set shall be used. The price bid per lineal foot of curb wall repairing and plastering must include all costs of the removal and replacing of cap planks, sidewalks, lamp posts, etc., and all necessary earth excavation. ^ FREFARATION OF SUB-GRADE. Where filling is required it shall be of earth or cinders, free from ani- mal or vegetable matter, and shall be deposited in layers of not more than two (2') feet in thickness, and shall be thoroughly compacted. All necessary filling to bring the street to sub-grade and to properly back-fill the curb, shall be deposited on the street before any curb is set. In all cases where curb is set the back-filling shall have a berme of at least four (4') feet behind the curb, at the top thereof, with a slope of one and one-half (IJ^) horizontal to one (1) vertical. Where cutting is required the earth must be excavated to such depths as may be necessary to bring the roadway to the proper sub-grade after having been thoroughly compacted. The earth shall be excavated back of the curb for a distance of four (4') feet level therewith; otherwise the contractor or contractors will not be allowed to remove the earth from the sidewalk area. The contractor or contractors shall remove all spongy material or other inferior or vegetable matter that may be in the way of making this improve- ment. All approaches connecting said street with other streets or alleys inter- secting shall also be cut and filled so that the same shall have a slope of not less than one (!') foot in twenty (20') feet, and shall be secured from settlement adjoining the pavement. The roadway shall be brought to sub-grade by cutting or filling as may be necessary; said sub-grade shall be eleven (11") inches below and parallel with the top of the finished pavement after having been thoroughly compacted and secured from further settlement by flooding, ramming, or rolling, or all, as may be deemed necessary by the Engineer. The contractor or. contractors will bid with the express understanding that be or they must use all necessary precaution in preparing the sub-grade 90 TOWNS AND SMALL CITIES. 187 as to support the pavement permanently, and so that the pavement shall re- main at the original grade for a period of ten (10) years. This clause will not be waived' on account of any trenches or holes made in the street prior to the laying of the pavement by any corporation or private party. The price bid for cutting or filling must include all cost of bringing the Sub-grade to its proper position and compacting and securing the same from settlement. (To the above point the specifications are the same for all pavements.) MACADAM. CRUSHED STONE. All crushed stone used in this improvement shall b& the best of its kind, dry, clean, free from dust and dirt, and shall be practically uniform as to sizes and quality, and as nea** to a cube in form as possible. MACADAM. On the sub-grade as formed and compacted, shall be spread a layer of crushed limestone broken so as to measure not more than four (4") inches and not less than two and one-halt iZYz") inches in any dimension. This layer shall be, covered with limestone screenings, in such quantity as to com- pletely fill all interstices, then flooded and rolled with a ten (10) ton steam roller until thoroughly compacted. This layer shall not be less than ( ") inches in depth at the center and not less than ( ") inches in depth at the sides. The above shall be covered with a layer of medium limestone broken so as to measure not more than two and one-half iZYz") inches and not less than one and one-half (15^") inches in any dimension. This layer, shall be covered with limestone screenings in such quantity as to completely fill all interstices, then flooded and rolled with a ten (10) ton steam roller until thoroughly compacted and brought to a true and uniform surface. This layer shall be not less than four (4") inches in depth at the center and not less than two (2") inches in depth at the sides. The above shall be covered with a course of crushed granite broken so as to measure not more than two (3") inches and not less than one and one- half (1^") inches in any dimension. This course shall be covered with bonding gravel of such quality as may be approved by the Board of Local Improvements, and in such quantity as to completely fill all interstices, then thoroughly flooded • and rolled with a ten (10) ton steam roller. On this layer shall be spread one-half OA")' inch of granite screenings which shall be rolled into said layer. The above layer shall not be less than four (4'J inches in depth at the center and not less than two (2") inches in depth at the sides, after having been brought to a true, uniform and u'nyielding surface. Each course above specified shall be built continuously and the stone for the same shall be spread immediately on being dumped. In no case shall depressions be brought up with screenings. The surface of the pavement shall be built to conform to the lines and grades furnished by the Engineer. 188 ENGINEERING WORK IN CROSSWALKS. In the macadam pavement as above described crosswalks six (6') feet in width, extending from curb line to curb line, shall be built of vitrified shale paving brick; there shall be four (4) crosswalks at each street inter- section, two (2) at each half intersection. and one (1) across each intersecting alley wing. The brick shall be true and uniform, five (5") inches in depth, from three to four (3" to 4") inches in width and from nine to twelve (9" to 12") inches in length. They shall be laid on a bed of one (1") inch of sand, so as to break joints, and in parallel courses. The spaces between the ends and sides - of the brick must not exceed one-eighth (J^'O'inch, and shall be filled with clean, sharp sand, and the brick rammed to a true and uniform surface. No broken or cracked brick will be allowed to remain in the crosswalks. Where ordered by the Engineer a header composed of sandstone curbing four (4") inches thick by twenty-four (24") inches in depth, and of the re- quired length, shall be set at the ends of the crosswalks in such position as directed. The crosswalks, gutters and their appurtenances sha!l be formed and constructed where and as directed by the Engineer, and without , extra cost over and above the price paid per square yard for the pavement. (If some other material is to be used instead of macadam omit, all under the headings, Crushed Stone, Macadam, and Crosswalks, and substitute the following specifications for concrete founda- tions, etc.:) CONCRETE FOUNDATION. On the sub-grade as above prepared shall be laid a foundation of Port- land cement concrete to a uniform thickness of six (6")" inches. CEMENT. (Note — Previously given.) SAND. The sand used in making the concrete shall be clean, dry, free from dust, loam and dirt, of sizes ranging from one eighth (J^") inch down to the finest, and in such proportion that the voids as determined by saturation shall not exceed thirty-three (33) per cent of the entire volume, and it shall weigh not less than one hundred (100) pounds per cubic foot.' No wind-drifted sand shall be used. The sand when delivered on the street shall be deposited on flooring and kept clean until used. CRUSHED STONE. The crushed stone used in making the concrete shall be of the best quality of limestone, clean, free from dirt, broken so as to^ measure not more than two (2") inches and not less than one (1") inch in any dimension. The stone when delivered on the street shall be deposited on flooring and kept clean until used. MIXING AND LAYING OF CONCRETE, The concrete shall be mixed on movable tight iron platforms of such size as shall accommodate the manipulations hereinafter specified. TOWNS AND SMALL CITIES. 189 The cement, sand and stone shall be mixed in the following proportions: One (1) part of cement, three (3) parts of sand and seven (7) parts of crushed stone. The sand and cement shall be thoroughly mix.ed dryi to which sufficient water shall be added and then made into a stiff mortar. The crushed stone shall then be immediately incorporated in the mortar and the mass thoroughly mixed, adding water from time to time as the mixing progresses, until each particle of stone is covered with mortar. The concrete shall be removed from the platform with shovels and depos- ited in a layer on the roadway in such quantities that after being rammed in place it shall be of the required thickness and the upper surface shall be true and smooth and ( ") inches below and parallel with the top of the finished pavement. During the progress of the work the sub-grade must be kept moist. The concrete shall be sprinkled so as to prevent checking in hot weather, and shall be protected from injury at all times, and shall lay * at least seven days before being covered with the wearing surface, or a longer time if deemed necessary. (The foregoing specifications for sub-base and foundation apply for all classes of wearing surface. From this point they are as follows for the different materials:) ASPHALT. ASPHALTIC CEMENT. The asphaltic cement hereinafter specified shall be made of refined Trinidad Lake Asphalt, obtained from the island of Trinidad, or of an asphalt of 'equal quality for paving purposes, and heavy petroleum oil. The oil shall be mixed with the asphalt in such proportions as are suitable to the character of the asphalt used. BINDER COURSE. Upon, the concrete foundation as above specified, shall be laid a ^'binder" course, composed of clean broken limestone of a size known as "small con- crete," and asphaltic cement. The stone shall be. heated and thoroughly mixed with asphaltic cement in the proportion of fifteen (15) gallons of asphaltic cement to one (1) cubic yard of stone, the mixing shall be contin- ued until each particle of stone is thoroughly coated with the asphaltic cement. The binder shall be spread on the base above described, and, while in a hot and plastic condition, shall be rolled with a five (5) ton steam roller until it has a uniform thickness of one .and one-half (l^^'O inches. The upper surface shall be parallel with and two (2") inches below the final sur- face of the pavement. Binder that has been burned or has become chilled shall be removed, from the line of the work. WEARING SURFACE. Upon this binder course shall be laid a wearing surface, which shall be composed of asphaltic cement seventeen (17) partsj' sand seventy-three (73) parts, and pulverized carbonate of lime ten (10) parts. The sand and asphaltic cement shall be heated separately to a temperature of three 190 ENGINEERING WORK IN hundred (300°) degrees Fahrenheit. The pulverized carbonate of lime shall be mixed with the sand, and these ingredients then mixed with the asphaltic cement at the above temperatute, in an apparatus which shall effect a perfect mixture. The mixture at a temperature of not less than two hundred and fifty (350°) degrees Fahrenheit shall then be carefully spread by means of hot iron rakes in such a manner as to give a uniform and regular grade, and to such a depth that after having received its ultimate compression it will have a thickness of two (2") inches. The surface shall be compressed by rollers, after which a small amount of hydraulic cement shall be swept over it, and it shall then be thoroughly compressed by a fifteen (15) ton steam roller; the rolling being continued as long as it makes an impression on the surface. Where necessary to make the gutters impervious to water, a width of twelve (13") inches next to the curb shall be coated with hot pure asphalt, and smoothed with hot smoothing irons in order to saturate the pavement with excess of asphalt. WOOD. SAND CUSHION. Upon the concrete foundation shall be ^read a layer of sand in such quantity as to insure, when compacted, a uniform thickness of one (1") inch. On surfacing said layer of sand the contractor or contractors shall Use such guides and templets as the Engineer may direct. WEARING StIRFACE. ^ Upon the sand cushion as above specified shall be placed blocks of southern long leaf yellow pine. The blocks shall be four (4") inches in depth and four (4") inches in width, and shall not be less than five (5") inches nor more than ten (10") inches in length, with the fiber of the wodd running in the direction of the depth. The blocks shall be made of sound timber and shall be square-edged, free from bark, -shakes, loose or rotten knots, red heart or dead timber, and other defects which will interfere with the proper .laying of the same. No second growth timber will be accepted. After the blocks have been inspected and found satisfactory, thfey shall be placed in an air-tight chamber where, by means of superheated steam and the use of the vacuum pump the sap in the blocks shall be vaporized and the moisture in them removed. When the blocks are thoroughly dry the wood preserving oil shall be admitted into the chamber and subjected to a pressure which shall be maintained until twelve (12) pounds of the oil shall have been forced into each cubic foot of timber and until the oil shall have impregnated the timber through the entire depth of the block and to the satisfaction of the Board of Local Improvements. The wood-preserving oil shall be Kreodone-Creosote paving oil, or any creosote paving oil which shall in the opinion of the Board of Local Improvements be equal thereto in quality for this putpose. The blocks shall be laid in parallel courses across the roadway at an angle of 45° with the center line thereof, except on alley wings where they TOWNS AND SMALL CITIES. 191 shall 'be laid perpendicular to the center line thereof. The courses shall break joints alternately. The blocks must be driven tightly together. Unless otherwise provided gutters shall be formed by setting four -courses of blocks adjacent to the curbs and parallel thereto." Spaces for expansion shall be con- structed as follows: The joints running parallel with and at the gutters shall be one (1") inch in width, and at intervals of one hundred_(100") feet along the roadway the joint running across the same shall be one-half i%") inch in width. These expansion joints shall be filled with bituminous cement. The blocks shall be firmly bedded in the cushion of sand and the surface of pavement brought to a uniform contour in accordance with the profile of the Engineer by rolling them with a five (5) ton asphalt roller. The joints shall be filled with bituminous cement or pitch which will resist the solvent action of the wood-preserving oil, and which will not be brittle at 0°^ F., nor flow at 200° F. The cement shall be applied at a tem- perature of not less than 30D° F., or at a higher temperature if necessary to render it fluid enough to properly run into and fill the joints. The blocks must be thoroughly dry before the cement is applied. Extra care must be taken and extra material must be used at the gutters and around catcU- basins, manholes, etc., in filling all joints in both the, paving and along the curbing to effectually prevent the leakage of water into the sub-roadway. The contractor or contractors shall provide the Board of Local Improve- ments, or its representative, with a duplicate delivery ticket for -each and every barrel, load or tank of paving cement delivered on the work. This ticket must be signed by the consignor of the cement, and be of a form approved by the Board of Local Improvements. Immediately after the spreading of the paving cement, and while it is still hot, the same shall be covered to a depth of not less than one-quarter WO of an inch with clean, dry torpedo sand. The cementing and top dressing must be completed each . day to within twenty-five (25') feet of the face of the blocking. If the blocks that have been laid should become wet before being cemented or top-dressed, they must be taken up and reset, without compen- sation therefor, should the Engineer so direct. On streets having curbwalls the space between the walls and the blocks shall be filled with a mortar composed of one (1) part Portland cement and three (3) parts of clean, coarse, sharp sand. HEADERS. At the end of each intersecting street and alley wing there shall be pjaced a "Header," extending from curb to curb, and so dressed as to conform to the crown of the pavement. The "Header" shall be constructed of three by twelve (3''xl2") inch oak plank, properly supported by six (6") inch split cedar posts, three (3') feet in length, firmly set in the ground and spaced not more than five C5') feet apart. AIJ "Headers" shall be constructed by the contractor or contractors without extra charge. CROSSWALKS. Unlesg otherwise directed by the Engineer there shall be formed in the 192 ENGINEERING WORK IN pavement four (4) crosswalks at each street intersection, three (3) at each half intersection and one (1) near the middle of each long block. A gutter nine (9") inches in the klear width shall be constructed at the ends of the crosswalks by setting sandstone curbing in the roadway nine (9") inches from and parallel with the curb line. The sandstone curbing must Ee four (i") inches thick and twenty-four^ (34") inches deep, and the length of the curbing shall be within three (30 feet of the width of the abutting sidewalk space; pfovided, however, that ^e minimum length of said curbing shall be six (6') feet. The crosswalks, gutters and their appurtenances shall be formed and constructed where and as directed by the Engineer, and without extra cost over and above the price paid per square yard for the pavement. BRICK. SAND CUSHION. Upon the concrete foundation shall be spread a layer of sand in such quantity as to insure, when compacted, a uniform thickness of one (I'O inch. On surfacing said layer of sand the contractor or contractors shall use such guides and templets as the Engineer may direct. WEARING SURFACE. Upon the layer of sand as above specified shall be placed the brick of such quality and in sifch manner as hereinafter specified. aUALITY OF BRICKS. ' The brick to be used shall be of the best quality of vitrified paving brick. Salt glazed bricks will not be received. The dimensions of the brick used shall be the same throughout the entire work in any particular case, and shall be not less than eight (S) inches in length, four (4) inches in depth, and two and one-half (25^) inches in thickness, with rounded edges to a radius of one-quarter (.%) of an inch. Said brick shall be of a kind known as repressed vitrified paving brick and shall be repressed to the extent that the maximum amount of material is forced into them. They shall be free from lime and other impurities, shall be as nearly uniform in every respect as possible, shall be burned so as to secure the maximum hardness, so annealed as to reach the ultimate degree of toughness ' and thoroughly vitrified so as to make a homogeneous mass. The bricks shall be free from all laminations caused by the process of manufacture, and free from fire cracks or checks of more than superficial character or extent. Any firm, person or corporation bidding for the work to be done shall furnish specimen brick, which shall be submitted to a ''water absorption" test, and if such brick show a water absorption exceeding three (3) per cent of their weight when dry, the bid of the person, firm or corporation so furnishing the same shall be rejected. Such "water absorption" test shall be made by the Board of Local Improvements of the City of Chicago in the following manner, to-wit: Not less than three (3) bricks shall be broken across, thor- oughly dried, and then immersed in water for seventy-two (72) hours. The TOWNS AND SMALL CITIES. 193 absorption shall then be determined by the difference between the weight dry and the weight at the expiration of said seventy-two (72) hours. Twenty or more specimen bricks shall also be furnished by each bidder for submission to the "abrasion" test by the Board of Local Improvements. Such test shall be made in the following manner, to-wit: Such specimen brick or a sufficient number to fill fifteen (15) per cent of the volume of the rattler shall be submitted to a test for one hour in the machine known as the "Rattler," which shall measure twenty (30) inches in length and twenty-eight (88) inches in diameter, inside measurement, and shall be revolved at the 'rate of thirty (30) revolutions per minute. If the loss of weight by abrasion during such test shall exceed twenty (20) per cent of the original weight of the brick tested, then such bid shall be rejected. All brick shall have a specific gravity of not less than two and one-tenth W (2.10) as determined by the formula — Specific gravity equals where WW" W equals weight of brick dry, W equals weight of brick after being im- mersed in water for seventy-two (72) hours, and W" equals weight of brick in --water. All brick used must be equal in every respect to the specimen submitted by the bidders to the Board of Local Improvements for test. HOW LAID. All brick shall be delivered on the work in barrows, and in no case will teams be allowed on the street before the wearing surface is rolled. Broken bricks can only be used to break joints in starting courses and in making closures, but in no case shall less than half a brick be used. The bricks shall be laid on edge, close together, in straight lines across the roadway, between gutters, and at right angles to the .curbs and perpen- dicular to the grade of the street. Gutters shall be constructed as directed by the Engineef. The joints shall be broken by a lap of not less than three (3") inches. On intersections and junctions of lateral streets the bricks shall be laid at an angle of forty-five (45°) degrees with the line of the street unless otherwise ordered by the Engineer. The bricks when set shall be rolled with a roller weighing not less than five (5) tons until the bricks are well settled and made firm. Or, if the En- ^neer shall direct, the bricks, when set, shall be thoroughly rammed two- or more times. The ramming to be done under a flatter, with a paving ram- mer weighing not less than thirty (30) pounds, the iron of the rammer face in no case to come in contact with the pavement. After rolling and ramming, all broken brick foutid in the pavement must at once be removed and replaced by sound and perfect brick. * PITCHING OS GROUTING AND TOP DRESSING, When the brick are thoroughly bedded, the surface of the pavement must be true for grade and crown. The surface of the pavement shall then be swept clean, and the joints or spaces between the brick shall be completely filled with a paving pitch which is the direct result of the distillation of 194 ENGINEERING WORK IN "straight run" coal tar, and of such quality and consistency as shall be ap- proved by the Board of Local Improvements, The pitch must be used at a temperature of not less than 880 degrees . Fahrenheit. When the brick are thoroughly bedded, the surface of the pavement must be true for grade and crown. The surface of the pavement shall then be swept clean, and the joints or spaces between the bricks shall be filled with a cement grout filter composed of limestone 65 per cent, furnace slag 25 per cent, and potters' clay 10 per cent, to be made as follows: The above mate- rials in the proportion stated shall be mixed together and ground into an impalpable powder, and theo burned in kilns unttil jeduced'to clinker, after which it shall again be ground into an impalpable powder. Equal portions of said grout and clean, sharp sand shall then be thoroughly mixed, and suifi- cient water added to bring the mixture to such a consistency as will allow it to run to the bottom of the joints between the brick. After said joints are filled to the top, the surface shall be finished off smoothly with steel brooms. After the spaces between the brick have been filled with the pitch or grout as above specified, the surface of the pavement shall then receive a ' one-half (J4") inch dressing of -sand evenly spread over the whole surface. Where ' cement grout is used as a filler the pavement must be kept clear of traffic for a period of four (4) days — or as touch longer as the Engineer may direct-^fter the application thereof. HEADERS. At the end of each intersecting street and alley wing there shall be placed a "Header," extending from curb to curb, and so dressed as to conform to the crown of the pavement. The "Header" shall be constructed of three by twelve (3"xl8") inch oak plank, properly supported by six (6") inch split cedar posts, three (3') feet in length, firmly set in the ground and spaced not more than five (5') feet apart. All "Headers" shall be constructed by the contractor or contractors with- out extra charge. CROSSWALKS. Unless otherwise directed by the Engineer there shall be formed in the pavement four (4) crosswalks at each street intersection, three .(3) at each half intersection and one (1) near the middle of each long block. A gutter nine (9") inches in the clear width shall be constructed at the ends of the crosswalks by setting sandstone curbing in the roadway nine (9") inches from and parallel with the curb line. The sandstone curbing must be four (4") inches thick and twenty-four (24") inches deep, and the length of the curb- ing shall be within two (8) feet of the width of the abutting sidewalk space; provided, however, that the minimum length of said cu'rbin^ shall be six (6') feet. The crosswalks, gutters and their appurtenances shall be formed and constructed where and as directed by the Engineer, and without extra cost over and above the price paid per square yard for the pavement. TOWNS AND SMALL CITIES. 195 GRANITE BLOCKS. SAND CUSHION. Upon the concrete foutidation shall be spread a layer of sand in such quantity as to insure, when compacted, a u'niform thickness of two (2") inches. ^ On surfacing said layer of sand the contractor or contractors shall use such guides and templets as the Engineer may direct. GRANITE BLOCK. Upon the sand cushion shall be set syenite or granite paving blocks hav- ing a uniform grain and texture, without lamination or stratification, and free from an excess of mica or feldspar. The blocks shall measure from three and one half (S^A") to four (4") inches in width, eight (8") to ten (10") inches in length, and five (5") inches in depth, and be so dressed as to have substantially rectangular plane sur- faces, so that when the l)locks are in place the joints at the ends and sides shall average one-fourth (.'A") inch in width. Soft or weatherworn stones obtained from the surface of the quarry, and stones which wear to a polish under traffic, shall not be. used. The blocks shall be laid in uniform courses across the roadway between the gutters (except at the injtersections of- the streets where they shall be laid at an angle of forty-five (45°) degrees with the center line thereof) and the space between the blocks, when in place, shall in no case be less than one-eighth (Ji") inch nor more than three-eighths (H") inch. Each course shall consist of blocks of the same width, and be so laid that all longitudinal joints shall be broken by a lap of at least three (S") inches. The gutters shall be formed as directed by the Engineer. The spaces shall be immediately filled to within two (2") inches of the top of the blocks with dry gravel free from loam and dirt, and the blocks rammed to a true surface and firm bed with a seventy-five (75) pound ram- mer of approved shape. No cr-acked or chipped blocks shall remain in the pavement. After ramming, the spaces between the blocks are to be completely filled with a paving pitch which is the direct result of the distillation oi "straight run" coal tar, and of such quality and consistency as shall be approved by the Board of Local Improvements. The pitch must be used at a temperature of not less than 880 degrees Fahrenheit and be spread in such quantity so as to apply two (2) gallons to each square yard of- pavement. The spread- ing must be done in sections if the Engineer so directs. The contractor or contractors shall provide the Engineer, or his repre- sentative, with a duplicate delivery ticket for each and every load or tank of paving pitch delivered on the work. This ticket must be signed by the consignor of the pitch, and be of a form approved by the Board of Local Improvements. Immediately after the spreading of the paving pitch, and while it is still hot, the blocks shall be covered to a depth of not less than three- quarters (J4") inch with dry roofing gravel. This gravel must be entirely free from sand or loam, and not to exceed one-half (Ji") inch in size. All 196 ENGINEERING WORK IN gravel must be clean, washed, dried and heated enough to prevent the chilling of the pitch. The tarring and top dressing must be completed each day to within five (50 feet of the face of the blocking. HEADERS. At the end of each intersecting street and alley wing there shall be placed a "Header," extending from curb to curb, and so dressed as to con- form to the crown of the pavement. The "Header" shall be constructed of three by twelve (3"xl2") inch oak plank, properly supported by six (6") inch split cedar posts, three (3') feet in length, firmly set in the ground and spaced not more than five (5') feet apart. All "Headers" shall be constructed by the contractor or contractors without extra charge. CROSSWALKS. Unless otherwise directed by the Engineer there shall be formed in the pavement four (4) crosswalks at each street intersection, three (3) at each half intersection and one (1) across each and every alley wing and one (1) at the middle of each long block. The crosswalks shall consist of three (3) rows of granite flagstones spaced eighteen (18") inches apart. The flagstones shall be of the best quality of granite, free from sand pockets, drill holes, seams, or other defects, eighteen (18") inches wide, five (5") inches in thickness, and not less than three (3') feet in length, except where shorter stones may be necessary to- make closures, and shall be ''bush-hammered" on top, and the sides. and ends pitched and dressed to a line so as to make tlose joints. They shall be firmly bedded in sand and well rammed to a uniform surface. A gutter nine (9") inches in the clear width shall be constructed at the ends of the crosswalks by setting gfanite curbing in the roadway nine (9") inches from and parallel with the curb line. The granite curbing must be four (4") inches thick and twenty (20") inches deep, and the tength of the curbing shall be within two (2') feet of the width of the abutting sidewalk space; provided, however, that the minimum length of said curbing shall be six (6') feet. The crosswalks, gutters and their appurtenances ' shall be formed and constructed where and as directed by the Engineer, and without extra cost over and above the price paid per square yard for the pavement. MISCELLANEOUS. * DEPOSITS FOR SEWER WORE. Contractors bidding under these specifications will be required to deposit, and it is hereby understood and agreed that upon the award of the contract for the work under these specifications, the contractor or contractors will deposit—. (1) The sum of three ($3,00) dollars for adjusting — and building (if necessary) of two (2) lineal feet rise of additional brick masonry— of each ■ and every manhole on the line of this improvement. (2) Ten ($10.00) dollars for the adjusting — and building (if necessary) TOWNS AND SMALL CITIES. 197' of two (2) lineal feet in rise of additional brick masonry — of each and every catch basin on the line of this improvement. (3) Thirty-five ($35.00) dollars for the building, complete, of each new City of Chicago standard catch basin which may be required, (4) Seven ($7.00) dollars for the furnishing and- setting of each City of Chicago^ standard cast-iron catch basin or manhole cover which may be required. (5) Fifty (50) cents per lineal foot of City of Chicago standard nine (9) inch tile pipe; and (6) Two ($3.00) dollars for each lineal foot in rise of brick masonry required on manholes or catch basins beyond the first two (2') feet above mentioned. In consideration of such deposit the contractor or contractors will receive' a voucher in the amount of whatever part of such deposit may have been used in the above construction, and in like manner as hereinafter specified on page 6, under "Manner of Payment." Any balance or excess of deposi^ will be returned to the contractor or contractors. EIGHT HOURS TO CONSTITUTE A DAy'S LABOR. In the prosecution of the work under these specifications eight (8) hours shall constitute a day's labor, and any contractor or contractors -who shall compel or allow laborers or employes to work more than eight (8) hours in one day shall be liable to have this contract forfeited, as provided by Section 1687 of the Revised Code of the City of Chicago. Provided, howfever, that in case of emergency the contractor or contractors may, by and with the written consent of the Board . of Local Improvements, allow laborers and employes to work extra time. CHARACTER OF WORK. All work shall be executed in the best and most workmanlike minner, and no improper materials shall be used but all materials of every kind shall fully answer the specifications, or if not particularly specified, shall be suitable for the place where used and satisfactory to the Board of Local Improvements. EXTRA WORK. ■No claim whatever will be made by the contractor or contractors for extra material or work, or for a greater amount of money than is herein stip- ulated to be paid, unless some changes in or additions to said work, requir- ing additional outlay by the contractor or contractors, shall first have been ordered in writing by the said Board of Local Improvements, said writing to be attached to the contract for the making of said improvement and stating that such work is not included in the contract, what the extras are, and that such are necessary for the proper completion of the work, or for the secutity of the work previously done, and the reason therefor; provided, however, that at the discretion of the Engineer in charge of the work he may order "extras" to the maximum amount of $200.00 in the execution of this contract without the authority of the Board of Local Improvements. PATENTS. All fees for any patented invention, article or arrangement or other 198 ENGINEERING WORK IN appurtenances that may be used upon cir in any manner connected with the construction, erection or maintenance of the work, or any part thereof embraced in the contract and these specifications, shall be included in th^ price stipulated in the contract for said work, and thq contractor or con- tractors must protect and hold harmless the City of Chicago against any and all demands for such fees or claims. USE OF FIRE HYDRANTS. # Contractors desiring to use water from public hydrants will be- required to make application for same to the proper bureau*, and conform to the rules and regulations provided in such cases by City ordinances and the rules of the Department. TIME FOR COMPLETION. The contractor or contractors shall bid with the express understanding that the work to be performed under these specifications shall be commenced not later than thirty (30) days from the time of awarding the contract- for same, and shall be completed on or before , and that the said time specified for completion of the work is an essential con- dition of this contract. Provided, however, that if the contractor or contractors is or are delayed by the City of Chicago in the commencement of the work, or in case the work is suspended by order of the City authorities, then the time of such delay or suspension shall- be added to the time for the com- pletion of this contract. ' ■• WATER mains; HOW PROVIDED FOR. When the water main shall not have been laid in any street ordered im- proved and it has been ascertained that there are not enough houses to pay the City of Chicago a revenue of ten (10) cents per lineal foot for every foot of said water main, then the contractor or contractors to whom may be awarded the contract for improving such street, shall advance the money necessary to lay said water main, and the money thus advanced for doing said work shall be returned by the City of Chicago from any moneys not otherwise appropriated when it is shown that a revenue of ten (10) cents per lineal foot of water main is being derived therefrom; provided, that if the money so advanced by the contractor or contractors is not paid back to him or them within two (3) years from the date of the advancement thereof, interest at the rate of five (5) per cent per annum shall be allowed after the expiration of two (2) years until paid. ALIEN LABOR PROHIBITED. It is hereby understood and agreed that said contractor or contractors sjiall not employ, nor permit to be employed by his or their sub-contractors, any pei^son or persons other than native-born or naturalized citizens of the ■ United States. CONNECTION OF OPENINGS. It is hereby understood and agreed that the contractor or contractors shall furnish without extra compensation all labor and materials necessary to connect and fit the new pavement with all openings on the line of said pavement in connection with water, sewer, gas, electric conduits, etc., after the same have been brought to the proper grade, and in general everything necessary to render the work fully complete and ready for use. TOWNS AND SMALL CITIES. 199 DAMAGES AND OBSTRUCTIONS. All loss or damage arising out of the nature of the work to be done, or from any detention or other unforeseen or unusual obstruction, or from difficulties which may be encountered in the prosecution of the work, or from the action of the elements, shall be sustained by the contractor or contractors, who will be required to replace all pavements, etc., without cost to the City of Chicago. UABILITY OF CONTRACTORS IN THE MATTER OF OBSTRtJCTIONS AND DAMAGE TO WATER, GAS OR DRAIN PIPES. The Board of Local Improvements reserves the right to take whatever old blocks, planking, granite blocks, or any other old material from -the street, and the contractor or contractors will be required to carefully set aside all such material and deliver the same to the City of Chicago, or dis- pose of it as may be directed by said Board of Local Improvements. The contractor or contractors shall be required to remove at his or their own expense all obstructions, such as stone, old blocks, debris, trees, etc., that may be in the way of making the improvement. The contractor or contractors shall remove all su'rplus materials and debris from the street as the work progresses, so that the public may have the use of the street as soon and as fast as completed. The contractor or contractors will be required to remove all sidewalks in the way of said improvements in a careful manner, and preserve and replace the same in as good condition as found before removal, at his or their expense. The contractor or contractors will be held responsible ior any damage to the water, gas or drain pipes in addition to the penalty prescribed by ordinance, ^ During the progress of said improvement the contractor or contractors will be required to keep free and unobstructed any railway along the entire length of the work, keeping all stones, carts, material and all obstructions of whatever sort away from the tracks of such railway so that cars may be run along the same, and said railway to be used in its customary manner without hindrance, and said contractor or contractors will be held liable for all damages resulting from any failure to comply with this stipulation. If in the prosecution of said work it shall be necessary to dig up, use or occupy any street, alley, highway or public grounds of said City of Chicago, the contractor or contractors shall erect and maintain strong and suitable barriers, and during the night-time lights, such as will effectually prevent any accident or harm to life, limb or property, in consequence of such digging up, use or occupancy of said street, alley, highway or public grounds; and the contractor or contractors shall be liable for all damages occasioned by the digging up, use or occupancy of any street, alley, highway or public grounds, which may jesult therefrom, or which may result from the carelessness of such contractor or contractors, or his or their agents, employes or workmen, or assigns. SWORN STATEMENT REQUIRED. ^ No final estimate or final payment shall be made herein by the City of Chicago or any of its officers or agents until the contractor or contractors. 200 ENGINEERING WORK IN shall deliver to the Board of Local Improvements "a statement in writing, setting out fully the amount, kind and quality of the several materials delivered upon, u'sed and incorporated into the work herein required to be done; said statement to be gworn to by said contractor or contractors before a Notary Public or other officer authorized to administer oaths. It is further agreed that the Board of Local Improvements shall have a reasonable time in which to verify the accuracy of such sworn statement before such estimate or final payment is made. I INSPECTION. Inspectors will be appointed whose duty shall be to point out to the contractor or contractors any neglect or disregard of these specifications; but the right of final acceptance or condemnation of the work will not be waived thereby. '* i The Board of Local Improvements shall have authority to order the dismissal of any employe on the work who refuses or neglects to obey any of its instructions relating to the carrying out of the provisions and intent of these specifications, or who is incompetent, unfaithful, abusive, threatening or disorderly in his condu'ct, and such person shall not be again employed on the work. Upon all questions concerning the execution of the work in accordance with these specifications and the measurements thereof, the decision of thjC Board of Local Improvements shall be final. Ordinarily one inspector will be employed on the , setting of the curbing, one on the foundation and two on the laying of the pavement; but if on account of a disregard of the speci- fications on the part of the contractor or contractors additional inspectors should be required, such additional inspectors shall be employed by the Board of Local Improvements as it may deem necessary to insure faithful com- pliance with the contract, and the pay of such additional inspectors shall be charged to said contractor or contractors at the rate of $3.50 per day and deducted from the amount due him or them on settlement. If at any time during the progress of the work any rejected materials fliou'ld be found in the street, or any portion of the work being improperly done, such material shall be removed and replaced by proper material and workmanship at the expense of the contractor or contractors.* Notice of any imperfections in the worlc to any foreman or agent in charge of any portion of the work shall be considered as notice to the con- tractor or contractors. CHANGES. Should the Board of Local Improvements deem it proper or necessary in the execution of the work to make any alterations which shall increase or diminish the quantities or the expense, such alterations or reductions shall not vitiate or annul the contract or agreement hereby entered into, but the fiaid Board of Local Improvements shall determine ' the value of the work so added or omitted, such value to be added to or to be deducted from the contract price, as the case may be. PAYMENT IN BONDS. In case the contract shall provide for payment of the party or parties to whom it shall ,be awarded in bonds, issued as provided by statute, said TOWNS AND SMALL CITIES. 201 bonds shall be' taken for a sum equal to their par value at the time of delivery. CONTRACTS PAYABLE FROM ASSESSMENTS ONLY. The work to be done pursuant to this contract shall be done under the direction of the Board of Local Improvements of said City of Chicago, and it is expressly understood that in no case will the said Board of Local Improvements or the said City of Chicago, or any officer thereof, be liable for any portion of the expenses or for a»iy , delinquency of persons or property assessed. MANNER OF PAYMENT. If the rate of progress shall be satisfactory to the Board of Local Im- provements, and when it shall appear that all claims for labor as aforesaid shall have been satisfied, estimates will be issued to said contractor or con- tractors during the making of said improvement, for eighty-five (85) per cent of the value of the work done and in place, at the time of issuing such estimates, and estimates for the balance or remainder will be issued upon the final completion and acceptance of the work. The assessment and vouchers drawn, or bonds issued against the same, and interest thereon, and all vouchers or bonds for work issued to the con- tractor or contractors, and interest thereon, shall be paid only when the assess- ment levied, or which may hereafter be levied, for said improvement, shall be collected as provided by an Act of the General Assembly of the State of Illinois, entitled, *'An Act Concerning Local Improvements," approved June 14th, 1897, in force July 1, 1897, and that said vouchers or bonds, and interest thereon, shall be payable only from such special assessment, and out of no other assessment or fund whatever, and that all vouchers or bonds for a part of any installment, and interest thereon, shall only share pro rata with the vouchers or bonds, and interest thereon, for the remaining part thereof. In case the City of Chicago should become the purchaser of any special assessment certificates at any sale for the delinquent special assessments, in default of other bidders, such purchase shall not be deemed a collection of such special assessment, and no act of the City of Chicago done or suffered, shall be construed as a collection of any special assessment or part thereof, until the money due thereon shall be actually paid into the treasury of the City of Chicago. It is uriderstood that the reserve, costs, etc., shall be paid out of the first installment. It is hereby understood and agreed that the material furnished and used and the workmansliip employed in the construction of the said pavement shall be of such character and quality as to insure the same to be free from all defects, and in continuous good order and condition satisfactory to the Board of Local Improvements, ordinary wear excepted, for a period of ten (10) years from and after the completion and acceptance of the same; and as a guarantee of the faithful performance of these specifications, the quality of the material furnished and the proper construction of said improvement, the contractor or contractors hereby agree to keep and maintain the said improvement, without additional charge or cost to the City of Chicago, in 202 TOWNS AND SMALL CITIES. such order and condition as will be satisfactory to the Board of Local Im- provements, ordinary wear excepted, for the period of ten (10) years from and after the completion and acceptance of the same, which keeping and maintaining shall include repairs or the entire reconstruction of the same, the necessity for which may be occasioned by or through the use of -faulty or inferior material or workmanship, or from any other cause whatsoever; provided, however, the contractor or contractors shall not be required to keep or maintain any part of said improvement, under this guarantee, which after its completion and acceptance shall have been removed for the purpose of laying or repairing any gas, sewer, water or other pipe in accordance with a permit granted by the City of Chicago for such purposes, except as here- inafter provided. Should the said pavement be ciit or removed for the purpose of laying or repairing any gas, sewer, water or other pipe by parties having first ob- tained a permit from the City of Chicago therefor, the contractor or con- tractors agree to, within five (6) days after notice so to do from the Board of Local Improvements, relay, repair and repave said pavement in strict ac- cordance with these specifications and with such material and in such manner as will leave the whole pavement in as good and durable condition as it was before the same was cut or removed, the cost thereof to be paid for by the City of Chicago out of its general fund at the following rate: Five ($5.00) dollars for each cut or removal of one (1) square yard or, less in area; and for each cut or removal in excess of one (1) square yard in area, five ($5.00) dollars for the first squ'are yard thereof, and three ($3.00) dollars for each square yard and fraction of a square yard additional to the first square yard. If the contractor or contractors shall fail, neglect or refuse to repair, keep and maintain the said pavement in good order and condition in accord- ance with these specifications, within five (5) days after notice so to do from the Board of Local Improvements, the said Board of Local Improvements may proceed to do, or cause to have done, the work necessary to comply with the same, and collect the cost and expenses thereof from the contractor or contractors or his or their bonjdsmen. ' DIRECTION AND SUPERINTENDENCE. The contractor or contractors shall perform all of said work under the direction and superintendence of the Board of Local Improvements of the City of Chicago, and to its entire satisfaction, approval and acceptance. All material to be incorporated in the work, all labor performed, and all appli- ances, tools and methods used, shall be subj ect to the inspection and ap- proval or rejection of said Board of Local Improvements,- and the said Board of Local Improvements reserves the right to finally decide all ques- tions arising as to the proper performance of said work, and as to whether the rate of progress thereon is such as to correspond with the conditions of these specifications; and if the work shall not be begun at the time herein stipulated, or if the rate at which work shall be performed shall not, in the Judgment of the Board of Local Improvements, be such as to insure its progress and completion in the time and manner herein stipulated; or if said work shall be wholly or in part improperly constructed, then to declare the contract for said work forfeited, either as to a portion or the whole of TOW his AND SMALL CITIES. 203 said work, and to re-let the same, or to order the entire reconstruction of said work if improperly done; and in such case of default, or in any case of default, to adjust the difference of damage or price (if there be any) which, accofding to the just and reasonable interpretation of these specifica-. tions, and the contract as a whole, the contractor or contractors should in the opinion of the said Board of Local Improvements pay to the City of Chi- cago for any further failure to properly commence and prosecute, or to proper- ly construct said work,^in all respects according to the conditions hereinbefore; specified, or for any other default; and it is hereby understood and agreed, that for the amount of damage or price determined by said Board of Local Improvements to be paid to said City of Chicago by said contractor or con- tractors for any such default, or for any money paid out by said City of Chicago on accoutit of said contractor or contractors in consequence of any default, there shall be applied in payment thereof a like amount of any money that may be due and owing to the contractor or contractors on account of said work so far as there may be any such money, and so far as the same shall be sufficient; and if there shall not be sufficient amount retained from said contractor or contractors then and in guch case the amount to be paid to the said City of Chicago in consequence of such default shall be a just claim against said contractor or contractors, and be recovered from him (ir them at law, in the name of the City of Chicago, before any court of com- petent jurisdiction. In case the said > Board of Local Improvements shall deem it necessary to declare any portion or section of said work forfeited, it i^ expressly stip- ulated and u*nderstood that such declaration of forfeiture shall not in any manner relieve the contractor or corftractors from the covenants and condi- tions of the contract for said work, but the same shall be and remain valid- and binding on said contractor or contractors. « contractor's default. The said work shall be prosecuted with such force as the Board of Local Improvements shall deem adequate to its completion within the time speci- fied, and if at any time the contractor or contractors shall refuse or neglect to prosecute the work with a force suiiicient, in the opinion of the said Board of Local Improvements, fo^ its completion within said specified time, or if in any event the contractor or coiitractors shall fail to prof'eed with the work in accordance with the requirements and conditions of these speci- fications, the Board of Local Improvements shall have full right and author- ity to take the work out of the hands of the contractor or contractors and to employ other workmen to complete the unfinished work, and to deduct the expense thereof from any money that may be due and owing to the con- tractor or contractors on account of the work, or to re-let the same to other contractors. In case the contractor or contractors shall abandon or in any way or banner fail to complete said work in the time herein specified, the City of Chicalo is hereby authorized arid empowered to pay to any laborer or laborers who may have been employed by such contractor or contractors upon the above specified work, out of the funds due said contractor or contractors, uopn the estimates of the Board of Local Improvements, at the time said 204 ENGINEERING WORK IN Board of Local Improvements shall, declare said contract forfeited, any and all sums of money which may be found to be due and owing to such con- tractor or contractors undpr said contract, and without giving any notice whatsoever to said co-itractor or contractors of the intention sD to do. And in every such -case the City Comptroller is hereby authorized and empowered to ascertain the amount or amounts so due and owing to any su'ch laborer or laborers, from said contractor or contractors in such manner and upon such proof as he may deem sufficient, and without giving any notice of such proceedings to said contractor or contractors; and the amount or amounts ao found by him to be due and owing to such_ laborer or laborers shall- be final and conclusive as against said contractor or contractors, and may there- after be paid over by said City of Chicago to su'ch laborer or laborers. And no estimate will be issued to said contractor or contract'^r*! until all claims for labor on this contract shall have been satisfied, said sums of money being payable out of the proceeds of the special assessment levied, and out of the proceeds of any special assessment which shall hereafter be levied fof said improvements, when collected. The contractor or contractors shall make no claim against said City of Chicago in any event, except from the collections of the special assessment made or to be made for said improvement, and to take all risks of the invalidity of any such special assessments, the City of Chicago not to be liable in any event by reason of the invalidity of special assessments, or any of them, or of the proceedings therein, or for failure to collect the same. ASSIGNMENT PROHIBITED. No part of the work herein specified shall be assigned or sub-contracted without the written consent pf the Board of Local Improvements and^ in no case shall such consent relieve the contractor or contractors from the obligations hereifi entered into by the same, or change the terms of this agreement. In the interpretation of these specifications the decision of the Board of Local Improvements shall be anal. The undersigned hereby certi that he ha read the foregoing speci- fications, and that h prdposal. for the work is based on the conditions and Fequirements embodied therein and should the contract be awarded to h he agree to execute the work in strict accordance herewith. Name Residence Name Residence Name Residence REMARKS. ' On the outside front page of the specifications is a description of the work to be .done, together with an e'stimate of all the quantities of all the materials to be used and the work to be done. Then follows the Instructions to Bidders, of which a sample is here given from the Granite Block Specifications ; TOWNS AND SMALL CITIES. 205 INSTRUCTIONS TO BIDDERS. It is the intention of these specifications to provide for this improvement in a complete, thorough and workmanlike manner. The contractor or con- tractors to whom the work is awarded shall furnish all materials, labor and appurtenances necessary to properly complete the work in accordance with these specifications, and anything omitted herein which may be reasonably interpreted ' as necessary to such completion — the Board of Local Improve- ments being the judge — is to be merged in the prices bid for the improvement. No bid will be accepted, which does not contain an adequate or reasonable price for each and every item named in the schedule of quantities. Bidders must satisfy themselves by personal examination of the location of the proposed work, and by such other means as they may prefer, as to the accuracy of the estimate of quantities, and shall not at any time after the submission of an estimate, dispute or complain of such estimate of the engineer, nor assert that there was any misunderstanding in regard to the nature or amount of the work to be done. Bidders must present satisfactory evidence that they have been "-regularly engaged in the business of laying granite block pavements, or are reasonably familiar therewith, and that they' are fully prepared with the necessary capital, materials and machinery to conduct the work to be contracted for to the satisfaction of the Board of Local Improvements. Bidders must state in their proposals the name and place of quarrying of the granite they propose to use; and if the granite specified has not pre- viously been tested and accepted by the Board of Local Improvements the bidder shall furnish such ~ sample blocks in ample time .so that the said Board of Local Improvements may make the tests it may deem necessary. AH bids must be made subject to the rights of* the owners of a majority of the frontage, to contract for the improvement as provided for in Sections 80 and 81 of an Act of the General Assembly of the State of Illinois, en- titled "An Act Concerning Local Improvements," approved June 14, 1897; in force July 1, 1897. No bids will be accepted from any persons or firms who may be in arrears to the City of Chicago upon debt or contract, or who may be in de- fault, as su'rety or otherwise upon any obligation to said City~ of Chicago, or behind specified time on any previous work. Companies or firms bidding for the work herein described, must state in the proposals the individual names and places of residence of the persons comprising, or officers of, such com- pany or firm. The Board of Local Improvements expressly reserves the right to reject any or all bids, or to accept bids 'separately as to curbing, filling, grading or paving, or to accept any bid in the aggregate. SEWER SPECIFICATIONS— CITY OF CHICAGO— 1903. INSTRUCTIONS TO BIDDERS. The contract of which these specifications are a part is drawn under an ordinance which was heretofore passed by the City Council of the City of Chicago, providing for the said improvement, and it is understood that the contractor shall carefully examine the said ordinance, as under the laws of 206 ENGINEERING WORK IN the State of Illinois the improvement as completed must comply with the terms and provisions of the ordinance providing for the aaid improvement. It is the intention of these specifications vttf *provide^ for this improve- ment in a complete, thorough and workmanlike manner. The contractor to whom the work is awarded, shall furnish all materials, labor and appur- tenances necessary to complete the work in accordance with these specifica- tions, and anything omitted herein that may be reasonably interpreted as nec- essary to such completion is to be merged in the prices bid for the im-> provement. No bid will be accepted which does not contain an adequate or reasonable price for each and every item named in the schedule of quantities. Bidders must satisfy themselves by personal examination of the location of the proposed work, and by such other means as they ma^ prefer, as to the accuracy of the estimate of quantities. Bidders must present satisfactory evidence to the Board of Local Improve- ments that they have been regularly engaged in the business of building sewers, or are reasonably familiar therewith, and that they are fully prepared with the necessary capital, materials and machinery to do the proposed work. All bids must be made subject to the rights of the owners of a majority of the frontage, to contract for the improvement as provided for in Sections 80 and 81 of an Act of the General Assembly of .the State of Illinois, en- titled "An Act Concerning Local Improvements," approved June 14, 1897. in force July 1, 1897, and the amendments thereto. No bids will be accepted from any person' or firms who may be in arrears to the City of Chicago upon debt or contract, or who may be in default, as surety or otherwise, upon any obligation to said City of Chicago or behind specified time on any preyiou's work. Companies or firms bidding for the work herein described, must state in the proposal the individual names and places of residence of the officers or persons comprising such company or -firm. The Board of Local Improvements expressly reserves the right to reject any or all bids, or to accept bids separately as to different sections of the work, or to accept any bid in the aggregate. A list of the sewers to be constructed is given in the form of proposal, "Letting No ," and the proposal, with all information, special notation, etc., shall be considered a part of these specifications. The plans and drawings showing location and dimensions of sewers to be constructed, prepared by the Board of Local Improvements of the City of Chicago, and on file in its office, with all notes, dimensions, figures and cor- rections thereon, shall be considered a part of these specifications, and in event of any discrepancy between plans and specifications, the judgment of the Board of Local Improvements oi* its authorized agent shall be decisive thereon. , NATURE OF THE WORE. The contractor shall, for the contract price per lineal foot for the sewer proper, furnish all the material and all tools and do all the work prescribed in these specifications, and shown on the plans attached, including foundation and all necessary work and material for building of outfall, shall make the requisite excavation for building the sewer, and its appertaining structures and connections, shall do all the ditching, diking, pumping, bailing and drain- TOWNS AND SMALL CITIES. 207 ing, all sheeting and shoring; shall make all provisions necessary to main- tain and protect all buildings, walls, fences, trees, gas pipe, water pipe, con- duits, sewers and other structures of whatever nature; shall provide all bridges, fences or other means of maintaining travel on intersecting streets, and on streets or roads in which the trenches are excavated; shall maintain the same in good and safe condition so long as may be necessary; and then shall remove such temporary expedients and restore such ways to their proper condition; shall provide watchmen, fences, red lights and all other precautionary measures necessary to the protection of person and property; shall provide all centers and forms; shall construct all foundations, all brick, tile pipe, concrete, stone and timber work; shall set in place all iron work, and refill all trenches; and shall put in complete working order the sewer or sewers awarded him, and shall do each and all to the satisfaction of the Board of Local Improvements. The contract price is to include the cost of the removal of trees, roots, timber or masonry structures or other obstacles, and the deWy or damage occasioned by same, whether any of these obstacles are shown on the plan or not. EXCAVATION. The ground shall be excavated in ^pen trenches, except where tu'nnel- ing is considered necessary or proper by the Engineer, in such direction as is required, to the width and depth as may be necessary for the proptir con- struction of sewer according to plan. The trenches must he of sufficient width to admit of ample room within the lines of the sheeting to permit of the work being constructed in the manner and size specified. Wherever the nature of the ground will admit of it the bottom of the excavation is to have the shape and dimensions of the outside of the lower half of the sewer. Jn order to secure this the con- tractor is to provide a pattern or form made with two segments, one to fit the outside and the other the inside of the invert. It is to* be firmly and securely set to the proper grade, as given by the Engineer, and is to remain unmoved in its position until after the masonry is laid. The bed .for the sewers is then to be brought to the required shape, by trimming, with suit- able tools, to a line stretched from the outside of the masonry to the form- If the character of the ground met with in excavating is such that the external form of the sewer can not be preserved, the excavation shall be made to conform as nearly as possible tg the external shape and dimensions of the sewer, and the space between the external sewer lines and the bottom and sides of the excavation as made, shall be filled with dry earth by the contractor. Where streets are paved all surplus material excavated must be removed from the trencli and the streets as fast as excavated by the contractor at his own expense. The sidewalks must in no case be obstructed, and the con- tractor shall make provisions at all cross streets for the free passage of vehicles and foot passengers, either by bridging or, otherwise. The excavation of the trench shall not advance more than 600 feet ahead of the completed masonry or pipe work, except where, in the opinion of the Engineer, it is necessary to drain wet ground. Where, rock is encountered in excavating the trenches, it is to be re- moved by drilling and blasting, or otherwise, to the level of the outside 208 ENGINEERING WORK IN of the bottom of the sewer. Whenever a water main, gas pipe or other con- duit crosses the line of the trench, the rock on each side of the pipe, for the distance of, two feet, is to be removed without blasting. Where blasts are made the trench is to be carefully covered with suitable brush or timber or matting to prevent danger to Ufe and property, and the contractor must secure a special permit for blasting. Before the sewer is 'built all irregu- larities of the rock are to be filled with sand and gravel, well rammed into its place, without extra compensation. For all rock excavation, in addition to his price per foot of sewer, the contractor is to receive a compensation of three dollars per cubic yard. In estimating the number of cubic yards, the necessary width of the trench at the surface of the rock, by the depth from the surface of the rock to the bottom of the invert of the sewer, is to be 'considered the dimensions of the rectangular section upon which estimates of quantities are to be based, no allowance being made for excavation beyond these boundaries and no deduction made for the portion which comes on the quarters of the invert that may not be removed. Boulders, one-quarter cubic yard and over in size, will be measured as rock excavation. Hardpan and boulder clay shall not be classed as rock, although it may be more economical to remove the same by blasting. No claim for an amount of money beyond the contract price of the work will be entertained or allowed on account of the character of the ground in which the trench or other excavations are made, except for the rock cutting heretofore specified. The contractor must assume the risk of meeting quicksand, hardpan, boulder clay, rubbish, unforeseen obstacles, underground conduits, railroad tracks, pavements, etc. All .water, gas, or other kinds of pipes or conduits are to be carefully supported and protected from injury by the contractor, either until the sewer is built and the backfilling finished, or, if it is necessary, until the proper person shall remove or change them. Nothing in this contract shall be so construed as to relieve any person or corporation, owning or using any pipes, conduits or tracks from the obligation to maintain and protect such pipes, conduits and tracks without any expense to the City of Chicago or to the contractor building said sewer. When existing sewers have to be taken up or removed, the contractor must provide and maintain temporary outlets and connections for all private or public drains, sewers, or catchbasins, and he mu'st take care of all sewage and storm water which will be received from these drains and sewers, and discharge the same; and for this purpose he must provide and maintain at his own expense an efficient pumping plant and temporary outlet, and be prepared at all times to dispose of the water and sewage received from these temporary connections until such times as the permanent connections with the new sewers are built and in service, which permanent connections shall be made by the contractor -in a careful and workmanlike manner. All paving, graveling, macadamizing, planking, sidewalks, culverts, and crosswalks, or any street paving or walk whatever, are to be carefully removed before the excavation is made, and kept separate from other exca< vated material, and carefully replaced after sewer is completed. TOWNS AND SMALL CITIES. 209 Tunnels shall be of such width and height as the Engineer may direct, and shall be excavated in conformity with the cross-section to be furnished by him. SHEETING AND BRACING. ' To secure the protection of the work,- the streets adjacent, buildings, or other improvements, the contractor must furnish and put in place at his own expense such shores, braces, sheeting, etc., as may be necessary for the safety of the work or the public. The sheeting and bracing shall be removed as the work progresses, in such manner as to prevent the caving in of the sides of the excavatign, or any damage to the masonry. The Board of Local Improvements may order the sheeting and bracing left in, when in its opinion it is necessary for the protection ofj tlie work; in such cases only will a charge be allowed for the same at the rate of $18.00 per thousand feet B. M. The contractor shall at his own expense shore up and restore, and make good, as may be necessary, all fences, buildmgs, walls, conduits, or other properties which may be disturbed during the progress of the work, and the said contractor will be held responsible for all damages which may happen to neighboring properties, or in any other way from neglect of this pre- caution. The price paid per lineal foot of sewer shall include the cost of all ex- cavations, all temporary supports and braces that inay be necessary to secure a safe prosecution of the work until the permanent structure is complete; such temporary supports must in all cases be removed by the said contractor at his own expense after or concurrently with the completion of the per- manent structure. FOUNDATIONS. Whenever the ground is sufficiently firm and unyielding, the masonry or pipes are to be laid directly on the bottom of the excavation; but whenever this shall not be the case and such foundation is not shown on the plan, it shall be built of masonry, concrete, or of plank and timber, as the Board of Local Improvements may direct. The contractor will be allowed extra compensation for this work at prices named below for the different kinds of foundations required. The following are the prices to be paid for foundations, timbering, sheet ing, etc. : $18.00 per 1,000' B. M. for plank and sheeting. $ 8.00 per cubic yard for brick masonry. $ 7.00 per cubic yard for concrete. PROTECTION AGAINST WATEK. The contractor shall do all pumping and bailing, build all drains, and do all other work necessary to keep the trench and sewer clear of ground water, sewage, or storm water during the progress of the work, and until the cement mortar is sufficiently set to be safe from injury. To this end in wet trenches he shall keep a channel open on each side of the work dur- ing its construction, which shall be maintained so as to catch the water 210 ENGINEERING WORK IN from the sides of the trench and to conduct it to a sufficient sump or bale hole in front of thte work. BACKFILLING. After the arching is completed on any length of sewer, and before 'the centers are struck, the trench is to be filled to a height of not less than one foot above the arch. On brick sewers the spandrels are to be well con- solidated by .thorough ramming wherever the ground is of a nature to admit it. As soon as the mortar and masonry are sufficiently set, the trench is to be sufficiently filled to prevent liability ot injury to the banks, road surfaces, adjacent pipes, railroad tracks, sidewalks, or other property, public or private. The surplus material taken from the trench is to be removed entirely from the street, or disposed of in su'ch a manner as directed, so as to save the city from all damages or expense on account thereof. The backfilling shall in all cases be left with a smooth and even sur- face and a sufficient crown. Where required the backfilling shall not be left unfinished more than 600 feet behind the completed masonry or pipe work. Ditches shall be opened and connected to the inlets of the catchbasins, hereinafter provided for, so "as to provide for the adequate drainage of the surface of the adjacent lands and ditches. ' . ^ FILLING. The sewers shall in all cases be covered with earth to a depth of not less than three feet, and where the trenches do not furnish sufficient ma- terial the contractor shall supply such deficiency at his own expense. When additional filling is required to be placed over the sewer for its protection, the contractor shall furnish and spread earth, cinders or clean ashes, free from animal or vegetable matter, in such a manner and in suffi- cient quantity, so that after it is thoroughly compacted the embankment shall be of uniform grade and cross-section, and of the dimensions shown or specified in the plans or proposal sheet. The number of cubic yards stated in the proposal sheet is approximate only. RESTORATION OF SURFACE OF STREET. In all streets or parts of streets that are paved, graveled or macadamized, all the backfilling is to be well rammed with suitable tools in layers not exceeding twelve inches in depth, provided the grpund is clay, stiff loam, or of a. tenacious nature. If the ground is sand or gravel, the backfilling is to be puddled in such a manner as directed. After being puddled or rammed to the required height, the pavement shall be relaid carefully and thoroughly in a manner adapted to its peculiar, character, and to the satisfaction of the Engineer. When the work is completed all surplus material, earth, rubbish, etc., mu"st be removed and the' surface of the streets included in this contract must be left in as good condition, in all respects, as it was before the commence- ment of the work, and it must be maintained in such condition during a period of one year after acceptance of the work, CENTERS AND PATTERl?S. The centers, patterns and templets necessary in the construction of the work are to be furnished by the contractor at his own expense. TOWNS AND SMALL CITIES. 211 The centers upon which the arch is formed must be strong and accurately made, and shall in no case be used utitil ^ approved by the Engineer, and when in his opinion either the templets or centers become unfit for use they shall be removed from the work and new ones supplied by the. con- tractor; on curves they must correspond to the radius of the curve. MASONRY. Unless Otherwise noted on the proposal sheet, all brick sewers, the in- ternal diameters of which are 2}4 feet or less, shall be built of one ring of brick; all brick sewers, the internal diameter of which exceed 2>^ feet and not more than 6 feet, shall be built of two rings of brick; all brick sewers,- the internal diameters- of which exceed 6 feet, and are not more than 10 feet, shall be built of three rings of brick; and a!I brick sewers, the internal diameters of which exceed 10 feet and are not more than 15 feet, shall be built of four rings of brick. The most perfectly formed bricks and those with the smoothest surfaces are to be used in the inside of the sewer, the smoothest edge of the brick being laid to the face. The courses are to be laid in line and kept perfectly straight in the direction of the sewer and parallel to the rise of the same, and shall be laid as stretchers, breaking joints with those in the adjacent coutses. Every brick must be laid separately in full mortar joints on hot-' tom, side and end. No joint shall exceed one-half (54) of an inch in thickness, and all joints on face shall be trowel-srruck. The mortar joints on the inside of the sewers, below the center line, are to be carefully struck when laid, and those above to be scraped smooth with the bricks immediately after the centers are struck. The refuse mortar to be scraped off and re- moved entirely from the sewer before it has time to harden. All inverts or bottom courses are to be laid to line from templets, accurately made, and correctly set to the lines and grades furnished. No work in masonry shall be done when the thermometer is below twenty-five (25) degrees F., without permission from the Engineer, and then 'under conditions for protecting it from frost, approved by him. UANHOLES. All manholes are to be circular in section and three feet internal diam- eter. They are to be built with two rings of brick, giving a thickness of eight inches to the wall. The bricks in the inside ring are to be set verti- cally. The outer ring may be built of bats as far as broken bricks on hand will go, otherwise whole bricks are to be used. On sewers three feet in diameter and greater the manholes shall be supported by the arch invert "of the sewer without additional foundation. On .sewers less than three feet in diameter the invert of the sewer through the manholes shall be built of two rings of brick and on each side thereof shall be built ct solid brick foundation twelve inches thick, making the entire founda- tion four feet and six inches in diameter. The top of the manhole is to be two feeti in diameter, being drawn in by means of six header courses the diameter being decreased two inches for each course, and an iron cover set thereon. On unpaved streets, the tops of the covers of the manholes are to be at the surface of the streets; on paved streets, one-half inch lower. 212 / ENGINEERING WORK IN The cost of all manholes shall be included in the price paid per Hneal foot of sewer. CATCH-BASIMS. All catch-basins are to be circular in section and four feet in internal diameter. They are to be built of two rings of brick upon a floor of two- inch pine plank closely jointed. The bricks in the inner ring (excepting the top .and bottom header courses) are to be set vertically. The outer ring may be built of bats as far as broken bricks on hand will go, otherwise whole bricks are to. be used. The brick work shall be seven feet two inches deep; the top of the catch-basin shall be two feet in' diameter, being drawn in by means of eight header courses, the diameter being decreased three inches for each course, a top header course,, being laid flush with the course below and an iron cover set thereon. The catch-basins are to be connected to the sewer with nine-inch pipe and trapped - with nine-inch half-traps, the bottom of the traps to be set three feet and six inches above ^^ the floor of the basin. The top of the cover shall be set at the grade given by the Engineer; and when so directed the contractor shall set a piece of nine-inch pipe in the side of the basin at the prop,er elevation to receive the water from the ad j acent ditches. The cost of all catch-basins shall be included in the price paid per lineal foot of sewer. COVERS. AH covers used shall be of good quality of cast iron, the curb shall weigh not less than 350 pounds and the lid shall weigh not less than 120 pounds, and shall be of the same size and pattern as iron covers now in use by the Bureau' of -Sewers, in the City of Chicago, provided that if the catch- basins are built in the parkways, lighter covers may be used weighing not less than 140 pounds. FIFE LAYING. Each pipe is to be laid on a firm bed, and in perfect conformity with the line and levels given by th'e Engineer. The ends of the pipes are to abut close, against each other in such a manner that there shall be no shoul- der or want of uniformity of surface on the interior of the drain. The joints are to be as uniform as possible in thickness and thoroughly filled with mortar; ^where the pipe Js laid in running sand the joints must be caulked with oakum. Each joint is to be wiped clean of mortar on the inside before another length of pipe is laid. JUNCTION OP SEWERS. The junction of two or more sewers must be made in strict conformity with the plans. The work mu'st be done with special care and in a perfect manner and the brick at the joining edges must be shaped smoothly to proper curves and the two sewers joined with a thorough bond, the cost of all junctions to be included in the price per lineal foot of the main sewer. When connections are made with sewers carrying water, special care must be taken that no part of the work is built under water; a flume or dam must be put in and the new work kept dry until finished. TOWNS AND SMALL CITIES. §13 SIDE JUNCTIONS. ^ Intersections or lateral sewers, whether of brick or pipe, and all junc- tions for catch-basin drains are to be built into the sewers at such places as are shown on plans. Six-inch junctions for house drains to commence ten feet from street corners and to be placed thence twenty-five feet apart through the blocks, or as otherwise shown on the plans, shall be built into the sewers in a thorough and workmanlike manner. Whenever required the brick intersections are to \fe strengthened by backing up the angles with piers of masonry. The junctions are to be bricked off at the ends, thoroughly closing them. The pipe junctions are to be closed by_ laying the brick against the end of the pipe. In no case are the bricks to be placed inside the pipe. All dead ends of the sewers are to be closed with eight inches of brick work. OUTLETS. The outlets for main sewers are to be built in accordance with plans and specifications supplied for each case. The terminations or intersections of sub- mains and laterals with main and sub-mains respectively, are to be made through brick or pipe junctions previously built. If for any cause the junc- tion previou'sly made_ in the sewer, with which the contractor is to con- nect, is to be changed in size or position, or a new one is to be built, the contractor shall, without extra price, do all the necessary labor of any kind, growing out of said change. MATERIALS. All materials, of" whatever nature, required in the construction of the sewers, catch-basins and manholes,- shall be new and of the best quality, and shall be furnished by the contractor. BKICKS. The bricks shall be the best quality for the purpose for which they are intended, uniform in quality, sound and hard burned, free from lime and cracks, and to have a clear ringing sound when struck, whole and with edges full and square, and of standard dimensions; they shall be of compact^ tex- ture, and after being jfhoroughly dried and immersed in water for twenty- font hours shall not absorb more than 15 per cent in weight of water. PIPE. ' The pipe shall be straight, smooth and sound, thoroughly burned, well glazed, free from lumps or other imperfections, and with the least possible variation from the specified dimensions or true cylindrical shape. All straight pipe must be straight in the direction of the axis of the cylinder, with the ends cut at right angles with the axis of the pipe and the inner and outer surfaces of each pipe must be concentric. The thickness of the pipe shall be: For 18-inch pipe, 1% inches; for 15-inch pipe; lyi inches; for la-inch pipe, 1 inch; and for 9-inch pipe, 7/i inch, with a limit of variations not exceeding J^ of an inch either way. When double strength pipe is specified, the stand- ard of thickness shall be one-twelfth of the internal diameter of the pipe. The curves, slants and Y junctions must conform to all the foregoing re- quirements as regards quality, form and workmanship, and the thickness shall be equal to that of pipes of the same caliber into which the Y may be 214 ENGINEERING WORK IN jointed. Alii slant junctions and branch junctions shall be molded for an angle of thirty-four degrees with the sewer with which they are to connect. CEMENT. The cement shall be fresh made, of some satisfactory and reliable brand, and of such quality and uniformity as has been demonstrated by the Board of Local Improvements of Chicago to be of superior quality and thoroughly adapted to the construction of sewers and similar work, and shall be approved by the Engineer. Natural cement shall be so finely ground that 90 per cent of the whole will pass through a sieve- of 100 meshes to the lineal inch, and when treated ; in the usual manner for tensile strength, shall give results comparing favor- ably with the best brands of American Natural Cement.' The cement, when tested in the usual manner, shall take an initial set in not less than 10 minutes. Portland cement shall be of some brand of reputation known and estab- lished by use. It shall be ground so that ninety-two (93) per cent will pass through a standard sieve of 100 meshes to the lineal inch, and when mixed, one part cement and three parts sand, shall show a tensile strength of two hundred pounds per square inch in seven days — one day in air and six days in water — and an increase of not less than 20 per cent in strength ^t the end of twenty-eight days, and an additional increase of 15 per cent at the end of three months. As ample time is required for making tests, the contractor shall submit samples of the cement he desires to use and one or more brands may be approved by the Engineer, any of v/hich the contractor may use. If large quantities of Portland cement are to be used in this work the contractor shall deposit and store the cement in a suitable warehouse, where it shall remain under the supervision of the Board of Local Improvements antil after it has been tested and accepted by the Engineer. MORTAR. The mortar for brick work shall be made by carefully measuring and thoroughly incorporating one part of natural cement with two parts of clean* sharp sand in dry state, mixed with clean water^ to the proper consistency, and shall be used while fresh, arid the use of mortar which has -set and then been retempered will not be allowed. The mortar used in laying pipe sewers shall consist one part of natural cement and, orie part of clean sand mixed and used as above specified, all to be furnished by the contractor without extra charge. CONCRETE. AI! concrete shall be composed of one part Portland cement, three parts clean torpedo sand and six parts of broken stone. The stone shall be of good quality, graduated in size, angular in shape and free from dirt or clay. All stone must be broken, so as to pass through a ring one and one-, half inches in diameter. The cement and sand shall be measured and shall be thoroughly mixed dry, until the mixture is of a uniform color, and shall be wet with as little water as will render it proper for use, and thor- oughly worked. . The stone shall be added and the whole shall be mixed until TOWNS AND SMALL CITIES. 215 each stone is thoroughly coated with mortar. The stone shall be wet or washed, if required, before it is added to the mortar. INSPECTION OF WORK AND MATERIALS. All. materials, of whatever nature, shall be inspected upon the ground when delivered, by an inspector appointed by the Board of Local Improve- ments, who shall, upon finding defective or poor material of any kind, .mmediately report the same to the Engineer in charge of work, and the contractor shall, when notified by said Engineer or inspector, at once re- move said defective or poor material from the line of the work. Inspectors will be appointed whose duty it shall be to report to their superiors any neglect or disregard of these specifications by the contractor; but the right of final acceptance or condemnation of the work will not be . waived thereby, nor by any other act of the City of Chicago by its officers or agents relating thereto. If at any time during the progress of the work any rejected or inferior materials should be. fo'und in the street, or any portion of the work should be improperly done, such material and work shall be removed and replaced by proper material and work at the expense of the contractor. Notice of any imperfections in the work or material to any foreman or agent in charge of any portion of the work in the absence of the contractor shall be con- sidered as notice to the contractor. The contractor shall execute the work only in the presence of the Engi- neer or Inspector during the usual working hours of the day, unless other- wise directed by the Engineer; but the presence or superintendence of the said Engineer or Inspector shall in no way relieve the contractor of the re- sponsibility of his work, or be Sny warrant for him to furnish bad material or poor workmanship. The contractor shall notify the Engineer 48 hours before beginning work on this contract Njf his intention to do so, and in case of a temporary suspen- sion of the work, he shall give a similar notice before resuming work. The contractor will be required to dig all stake holes necessary to give the lines and levels for the work in time for the daily visit of the Engineer in charge at su'ch time as he may appoint, and shall furnish and drive all stakes as directed. The contractor shall furnish all necessary facilities, should it be deemed advisable by the Board of Local Improvements to make an examination of any work already completed. If the work is found defective in any respect the contractor shall defray the expense of such examination and of satis- factory reconstruction. If the work is perfect, such expense will be allowed, for. All the work shall be executed in the best and most workmanlike man- ner and no improper material shall be used, but all materials of every kind shall fully answer the specifications, or if not particularly specified, shall be suitable for the place where used and satisfactory ■ to the Board of Local Improvements. ^ Whenever the word "Engineer" is used, it is understood to mean the Board of Local Improvements, any member of the Board, the Engineer of the Board, or in his absence his duly appointed assistant or inspector rep- resenting him, limited to the special duties imposed on each. 216 ENGINEERING WORK IN EXTRA WORK. The actu'al length of each sewer to be built may be more or less than the corresponding length given in the proposal sheet or plan, but no varia- tion will be made in the rates on that account. No extra or customary measurement of any kind will be allowed in measuring the work under these specifications; but the actual length, area, solid " contents or number shall be considered and the length shall be measured on the center line of the work whether straight or curved. The contractor will be_paid the con- tract price for each unit of work done, which price will include the cost of all work herein described, including all junctions, manholes and catch- basins, with their connections. , No claim whatever will be allowed the contractor for extra work or ma- terial, or fot a greater amount of money than is herein stipulated to be paid, unless some change in or addition to said work, requiring additional outlay by the contractor, shall first have been ordered, in writing by the Board of Local Improvements, said writing to be attached to the contract for the making of said iinprovement, and stating that such work is not included in the contract, what the extras are, and that such are necessary for the proper completion of the work, or for the security of the work previously done, and the reason thertsfor. The Board of Local Improvements reserves the right to' make any change in the plans and specifications that it may deem desirable or necessary, which change may increase or diminish the quantity of material or labor or the expense, and such change shall not violate or annul the contract or agreement hereby entered into, but the contractor shall furnish the neces- sary labor and material to complete the contract as amended. The value of the work so added or omitted shall be added to or deducted from the con- tract price as the case may be, and the determination of such value shall be based on the rates and prices named in this contract, when such rates and prices can be equitably applied, otherwise the value shall be determined by mutual agreement between the Board of Local Improvements and the contractor. If, for any cause, the Board of Local Improvements finds it necessary or desirable to suspend operations for any considerable length of time, it is to be done by the contractor on due notification, and he will not be entitled to any damages of any kind or nature whatsoever because of such detention. He will, however, be allowed further time in the completion of his contract, equal to the delay caused by the suspension of the work. All loss or damage arising out of the natu"re of the work to be done, or from any detention or other unforeseen or unusual obstruction or diffi- culty, which may be encountered in the prosecution of the work, or from the action of the elements, shall be sustained by the contractor. GUARANTEE. It is understood and agreed that all labor and material shall be of such char- acter that the entire work, including the restoration of the surface of the street, shall be and remain in good condition during the entire period of one year from the acceptance of the work, and the coutractor hereby agrees to keep in perfect repair, during such period, the whole of his work, except in TOWNS AND SMALL CITIES, 217 cases where the repairs may be rendered necessary by causes clearly beyond his control. In the event that any pavement, sidewalk, crossing or other surface which may have been disturbed in the prosecution of the work shall not be restored by the contractor within a reasonable time after the completion of the work and the acceptance of the same by the Board of Local Improve- ments, or if any such pavement, sidewalk, crossing or surface shall, because of the settlement of the back-filling, be in bad condition during the period of the year after the acceptance of the work, or if any of the contractor's work shall be foutid defective or incomplete during such period, and the contractor shall neglect to repair such defective work within 15 days from the date of a notice from the Board of Local Improvements directing him to niake such repairs, then the City of Chicago may make such repairs and restoration of the street at the expense of the contractor and shall deduct the cost thereof from any money belonging to the contractor in the control of the City. STREET PERMIT. Before beginning work on this contract, the contractor shall obtain from the proper officer a street opening permit and shall deposit with the Commissioner of Public Works a sum of money sufficient to pay for the cost of any repairs or restoration of the surface of the street for which the contractor shall be liable under the terms of this contract. At the expira- tion of one year after the completion of the work and the acceptance of the same byi the City, the money so deposited, or an;^ balance thereof, shall be returned to the contractor, all charges against and deductions from such deposit being made in accordance with the terms of this contract. DIRECTION ANp SUPERINTENDENCE. (Note — See street specifications for Chicago.) contractor's DEFAULT. (Note — See street specifications for Chicago.) labor claims. In accordance with an ordinance passed by the City Council March 10,_ 1879, the Board of Local Improvements reserves the right to refuse to issue a voucher and to direct that no payment shall be made to the contractor in case it has reason to believe that the said contractor has neglected or failed to pay any su'b-contractor, workman or employe for work performed on or about any of the sewers included in these specifications, until said Board is satisfied that such sub-contractor, workman or employe has been fully paid. After full completion of the work to the satisfaction of the Board of Local Improvements, it reserves the right, in accordance with said ordinance of the City Council, to refuse the payment of 15 per cent reserve, or any amount due said contractor, until it is satisfied that all sub-contractors, work- men and employes of said contractor have been fully paid. The Board also reserves the right, after ten days' notification to said contractor, in accordance with the provisions of said ordinance, to apply all money due, or that may become due u'nder the contract for sewers included 218 ENGINEERING WORK IN in these specifications, to the payment of such sub-contractors, workmen or employes of said contractor, without other or further notice to hira of its intentions so to do. . The failure of the Board of Local Improveijients to comply with the provisions of the ordinance in regard to unpaid sujjrcontractors, workmen or employes, shall in no wise affect the liability of the contractor or his .sureties, to the city or to the persons, who are or who may have been in his employ. MANNER OE' PAYMENT. (Note — See street specifications for Chicago.) -^ CONTRACTS PAYABLE FROM SPECIAL ASSESSMENT ONLY. (Note — See street specifications for Chicago.) TIME FQR COMPLETION OF WORK. The wqrk to be performed under these specifications shall be commenced within fifteen (15) days after the time of, signing the contract for same, and shall b.e completed on or before :.,.... and the said time specified for completion of the work is an essential con- dition of this contract. Provided, however, that if the contractor is delayed by the city in the commencement of the work, or in case the work is sus- pended by order of the city authorities, then the time of such delay or suspen- sion shall be added to the time for the completion of this contract. After the date specified for the completion of this contract, the Super- intendent of Sewers shall liave the right to issue permits to any person to make connections with the sewer herein provided for, although the work may not ha/e been fully completed and accepted, and the issuance of any such permits shall not entitle the contractor to any additional allowance or relieve him from any responsibility. ASSIGNMENT PROHIBITED. No part of the work herein specified shall be assigned or sub-contracted without the written consent of the Board of Local Improvements, and in no case shall such consent rfelieve the contractor from the obligations herein entered into by him, or change the terms of this agreement. LIABILITY OF CONTRACTOR IN THE MATTER OF BARRIERS AND DAMAGE TO PERSONS OR PROPERTY. If, in the prosecution of said work, it shall be necessary to dig up, use or occupy any street, alley, highway or public grounds of said city, the contractor shall erect and maintain such strong and , suitable barriers, and also during the night time stich lights, as will effectually prevent the hap- pening of any accident or harm, to life, limb or property, in the consequence of- such digging up, use or occupancy of said street, alley, highway or public grounds, and the contractor shall be liable for all damages of every '^kind and nature occasioned by reason of his failure to comply with any of the provisions mentioned in this paragraph. Said contractor shall also be liable for any damage to persons or property occasioned by the negligence of such cont/^actor, his agents, employes, workmen or assignees, TOWNS AND SMALL CITIES. 219 USE OF VACANT LOTS The contractor will not be allowed to occupy or use any vacant lot as a de-^ pository for stone, sand, gravel or other material, without written permission of the owner or agent of the land, <> copy of which shall be filed with the Board of Local Improvements. KAILSOAOS. All railroads not required to Bb taken up must be kept in running order where practicable. No allowance will be made for delays or otUer damages occasioned by the necessity of keeping the railroads in constant running order, or for removing or replacing the same when it is necessary to do so. EMfLOYES. The contractor shall employ capable superintendents "or foremen to represent him on the work, and they shall receive and obey orders from the Engineer. The Board of Local Improvements shall have authority to order the . dismissal of any employe on the work who refuses or neglects to obey any of its instructions relating to the carrying tfut of the provisions and intent of these specifications, or who is incompetent, unfaithful, abusive, threatening or disorderly in his conduct, and such person shall not be again employed on the work. i PATENTS. (Note — See street specifications for Chicago.) USE OF FIRE HYDRANTS. (Note — See street specifications for Chicago.) SWORN STATEMENT REQUIRED. (Note — See street specifications, Chicago.) ACCEPTANCE OR REJECTION OP BIDS. All bids will be made subject to the rights of the owners of a majority of the frontage to contract for said work, as provided for in Section 80 of an Act of lihe General Assembly, approved June 14, 1897, and in force July 1, 1897, and the amendments thereto, and up6n the express condition that when a bid is accepted by the City of Chicago and the owners of a majority of the frontage fail or neglect "to avail themselves of the provisions of said Section 80, if such original bidder fails or refuses for fifteen days after the first posting or publication of the notice award, or in case a contract be made by the owners, and default by them, then, within ten days after notice that such owners are in default, to enter into a contract, then the certified check deposited with the Board of Local Improvements with such bid shall be thereby forfeited to the City of Chicago. No bids will be accepted from any persons or firms who may be in arrears to the City of Chicago upon debt or contract, or who may be in default as surety or otherwise, upon any obligation to said city, or behind specified time on any previous work. Companies or firms bidding for the work herein described must state in the proposals the individual names and places of resi- dence of the persons comprising such company or firm. The Board of Local Improvements expressly reserves the right to- reject 220 ENGINEERING WORK IN any or all bids, or to accept bids separately as to any part of the work, or to accept any bid in the aggregate. The undersigned hereby certifies that he has read the foregoing specifi- cations, and that his proposal for the work is based on the conditions and requirements embodied therein, and should the contract be awarded to him he agrees to execute the work in strict Accordance herewith. Name ' , Residence Nai^e Residence Name Residence ' PIPE SEWERS. A good specification for laying pipe sewers from Engineering News: Only one man under each inspector shall be allowed to lay tiles on the main sewer, and only one on house connections; and no tile shall be laid except in the presence and according to the directions of the Inspector. Tile pipes shall , be so laid as to be evenly supported throughout the whole length of the barrel, with no weight resting on the bell. If the trench is dug deeper than the grade of the barrel no spalls, shims or lumps shall be used to raise" the pipe to grade, but an even bed shall be formed of sand or approved fine material properly tamped. Joints sball be made as follows: (1) Line with mortar the lower third of the entire circumference of the bell; (2) insert the pipe to be laid and, a jute gasket freshly dipped in neat grout; (3) bring the pipe to grade and line; (4) caulk the gasket tightly into the joint; (5) fill the joint with mortar mixed rather stiff, using a rubber mitten; (6) tamp mortar into joint with an approved tool until it is solidly filled; (7) smooth on mortar, using a rubber mitten, until its surface makes a bevel of not more than 60 degrees with the pipe; (8) protect the cement (preferably with burlap), and fill laround the barrel of pipe with sand or similar material, tamping solid with an approved tool; (9) remove burlap and cover joint and pipe with fine material; (10) clean out and point joint on inside of pipe. On pipes less than 13 inches in diameter cleaning out may be done with a bag, stu'ffed so as to tightly fill the tile, drawn through each length of tile as it is laid. All pipes must have the lower third of the joint completely filled with cement; pipes larger than 18 inches shall have the lower half pointed, and larger than 24 inches the whole of the joint, using neat cement on the top half if necessary. (Note. — The writer fails to see the necessity for specifying a gasket in sewer pipe joints except when the sewer is laid in water or in running water. In sucli case mud might get in or the cement be washed out of the joint. The gasket should be dipped in neat cement grout. When the trench is dry and it is reasonably TOWNS AND SMALL CITIES. 221 certain the mortar can set before any water can get in through the joints he prefers to have the joints filled with a stiff mortar. All sewer pipe should have extra wide and deep sockets no matter whether it is double or ordinary strength shell.) STRUCTURAL MATERIAL. WROUGHT IRON— All wrought iron shall be uniform in character, fibrous, tough and ductile. It shall have an ultimate tensile resistance of not less than 48,000 pounds per square inch, and elastic limit of not less than 24,000 pounds per square inch, and an elongation of 20 per cent in eight inches when tested in small specimens. STEEL — All structural steel shall have an ultimate tensile strength of from 54,000 to 64,000 pounds per square inch. Its elastic limit shall be not less than 32,000 poutids per square inch, and test specimens, ruptured in tension, must show a minimum elongation of not less than 20 per cent in eight inches. Rivet steel shall have an ultimate strength of from 50,000 to 58,000 pounds per square inch. CAST STEEL — Shall be made of open hearth steel containing one-fourth to one-half per cent of carbon, not over eight hundredths of 1 per cent of phosphorus, and shall be practically free from blow holes. CAST IRON — Shall be of good foundry mixture, producing a clean, tough, gray iron. Sample bars five feet long, one inch square, cast in sand molds, placed on supports four feet six inches apart, shall bear a central load of 430 pounds before breaking. Castings shall be free of serious blow holes, cinder spots and cold shuts. Ultimate tensile strength shall be not less than 16,000 poutids per square inch when tested in small specimens. TIMBER — All timber used shall be of good, sound material, free from rot, large and loose knots, shakes, or any imperfection whereby the strength may be impaired, and to be of the size and dimensions called for in the specifications and plans. OTHER MATERIALS— Hints as to proper specifications for brick, cement, sand, stone, etc., are to be found in the specifications in this book. HYDRANTS, WATER PIPE, HOSE— To be in accordance with National Board standards, and latest edition of the New England Water Works Asso- ciation. GAS PIPE — To be in accordance with specifications of the American Gas Light Association. SPECIFICATION FOR LAYING WATER PIPE. (First, specify the hydrants, pipe, valves, etc., and all accessories and materials and labor. Specify the doing of the work in full accordance with the plans -and drawings forming a part of the specifications. Second, specify all the items likely to complicate the opening of trenches in the streets.) All parts liable to draw shall be firmly secured by straps and bolts. In addition to this, a firm blocking shall be set behind all caps, curves, hydrants. 222 ENGINEERING WORK IN and branches, said blocking to be tightly wedged and have a large surface a^^ainst the undisturbed earth. When laid the spigots of the pipe shall be so adjusted that there shall be a uniform^ space all around and if any pipe does not allow sufficient space it shall be replaced by one of proper form and dimensions. ■ The minimum dimensions of joints shall be as follows: - Size of Pipe. Depth of Joint. Space. 4" to 6" 8" 0.4" 8" to 14" 3.5" 0.4" 16" 4" ~ 0.5" The pipes shall lack one-quarter of an inch of being driven full into bells, and gaskets of clean, sound hemp yarn, braided or twisted and tightly driven, shall be used to pack the joints. The lead shall be pure, soft lead of the best quality, suitable for caulking, and securing a tight and permanent joint. Joints shall be first cleaned and wiped perfectly dry. The melting pot shall never be more than fifteen feet away from the joint to be poured, and the joint shall be run full at one pouring. Competent, experienced mechanics must be employed to do the caulking. The caulking must be faithfully executed so the joint will be tight and secute without overstraining the metal in the bell of the pipe. After caulking the lead shall be flush with the face of the socket. All pipes and casting shall be carefully cleaned before laying, and again after laying. Open ends shall be plugged when work is left at night or during a lay-off, at noon hour or other time. After removing plug, interior of pipe shall be inspected before "commencing work. Care must at all tim^ be exercised to prevent earth, sand, mud or rubbish from being left in pipes or castings. Care should be taken to give the pipe a solid bearing throughout its entire length. If the earth excavated from the trench can' be deposited firmly around and over the pipe to secure it from after settlement, it can be used and must be tamped and moistened as tamped until at least one foot in depth covers the pipe. One or more feet in length at each end of the pipe, depending upon the size, shall be left unfilled until the rest of the pipe has been so -cov- ered, to allow examination of the joint and for necessary recaulking in case the joint has been disturbed by the filling. The joints shall then be covered by filling and tamping in the same way. After the pipes have been covered with one foot of filling as specified, the remainder of the trench shall be filled in any practicable manner and so tamped or flooded that there will be no settlement of the street surface. No stones or rock fragments shall be permitted in the filling within six inches of the pipe. ' If the earth removed from the trench can not be replaced properly in the opinion of the engineer in charge the trench shall be filled under, around and for six inches on top with sand, thoroughly rammed and afterward com- pacted by flooding with water. (Note — Here should follow specifications for restoring street surfaces.) TOWNS AND SMALL CITIES. 223 LUMBER LEFT IN TRENCHES. In small places it is not customary to leave lumber in trenches. The writer has had inquiries as to why it is done. If the ground has any tendency to slide, the filling in the trenches will settle too slowly to oppose any force to the squeezing in of the banks. When there are water pipes or gas pipes or any underground conduits that may suffer if joints are opened, care must be taken to prevent their alignment being disturbed. If the street is not very wide and the foundations of the buildings on either side, do not get below the bottom of the trench there is apt to be settle- ment. In such cases it is customary to require the contractor to leave bracing and timbers in place to act as retaining walls until the filling settles and can take care of the pressure. Too many cross braces can^hot be left in, for it will interfere with the settlement of the earth. Lumber for such purposes does not have to be first- class. Care is to be taken that the contractor does not persuade the man in charge to leave too much in place. As a usual thing he gets a good price for such material and is anxious to leave it and be paid for it as it is likely to be left on his hands after the work is done. It can be used only for similar work. SPECIFICATIONS FOR GRAVEL ROADS. (For the preparation of the earth foundations ideas can be found in fore- going specifications. The same may be said of the cleaning up specifications.) Upon the earth foundation thus prepared spread a layer of clean gravel four inches thick. None of the gravel shall exceed two inches in any dimen- sion and it shall be graded from that size down to sand in such proportions that a minimum of voids shall be left. It is to be spread in an even layer and sprinkled and rolled until it ceases to niove under the roller. If it does not compact readily a thin coating of clay or loam shall be placed over it and washed into the interstices. On top of this lower layer shall be placed a layer of clean, sharp gravel, free from pieces round like marbles> and from which all pieces exceeding three- quarters of an inch in all dimensions shall be excluded. This layer shall be sprinkled and rolled like the lower layer but instead of clay or loam being used as a binder if it does not compact, it should be bound with fine "sand or rock dust. MACADAM. For macadam roadways the writer often uses the following specifications : First specify the rock to be used. It is well to test rock from different local quarries in a rattler, etc., and thm name in the speci- 224 ENGINEERING- WORK IN fications all the rock that passes the tests satisfactorily and also allow any other rock that will pass the tests. Then specify the preparation of the roadway and require the rolling to be done with a roller of not less than five tons weight and to be rolled and sprinkled alternately until a wagon with two inch tires carrying not less than one ton can be drawn over without cut- ting or very appreciable settlement. Upon the earth foundation shall be spread the macadam in three layers. The lower layer when compacted shall constitute one-half the thickness of the finished 'roadway. No stone in it shall exceed in any dimension one-half the thickness of the said layer. Not to exceed twenty per cent of the stone shall be small enou'gh to go through a half-inch mesh and be retained on a one-eighth inch mesh. The remainder of the stone shall be fairly uni- form in varying sizes between the extremes permitted. After the lower layer is spread with rakes and forks it shall be rolled and sprinkled alternately until it ceases to move under the roller, fine stone dust or sand, or both stone ^ust and sand being added from time to time to fill the interstices and assist in holding the material' firm. When rolled until a wagon with two inch tires and loaded with not less than one ton, can be taken over it without causing the stone to be displaced, or making an appre- ciable rut, the spreading of the second layer may be commenced. The second layer when compacted shall cons<'itute one-third the thickness of the finished roadway. No stone in it shall exceed in any dimension one- half the thicknpss of the said layer. Not to exceed twenty per cent shall be small enough to pass a half-inch mesh and be retained on a one-eighth inch mesh. The remainder of the stone shall be fairly uniform in varying sizes between the extremes permitted. The second layer shall be rolled, sprinkled, spread and bound in the same manner as required for the first layer. The third layer "shall complete the total thickness of the pavement. No piece of stone in it shall exceed in any dimension one-half the thickness of the said layer. Not to exceed twenty per cent shall be as fine as stone dust or siich as will pass a one-eighth inch mesh. The remainder to range uniformly between the extreme sizes permitted. ' This third, and final, layer shall be spread, sprinkled, rolled and bound as specified for the two lower layers. The surface of the roadway shrfll present a uniform and smooth appear- ance and conform to the lines and levels of the engineer in charge. The engineer before accepting the work can cover the roadway with water and the contractor shall pick and refill all depressions that contain more than one- half inch in depth of water and if a depression containing in the center one-half inch of water, be less than four feet across then such hole must be picked and refilled, under the direction of the engineer. For heavy traffic on a business street the thickness can be twelve inches. No particular object is gained in making it more. On residence streets with extremely light travel and a good soil TOWNS AND SMALL CITIES. 225 six inches is ample if drainage is taken care of. Streets with medium traffic can have eight or nine inch macadam. (Engineers do not think much of gravel roads except where nothing better can be procured, and for parks. Some engineers per- mit clay to be used as a binder. Good specifications and directions for the construction of earth, grravel and macadam roadways are given free of cost to all in- quirers by the Bureau of Road Inquiry, Department of Agriculture, Washington, D. C.) NATIONAL BOARD STANDARDS. There have, from time to time, been issued by the National , Board of Fire Underwriters, standard specificaticSns covering various types of fire-protecting apparatus and appliances, among which are the following: • National Electrical Code, as recommended by the Underwriters' National Electrical Association, together with a list of electrical fittings. Automatic Sprinkler Rules. Underwriter Fire Pumps. Specifications for Hydrants. Specifications for Water Pipes. Specifications for Hose. Fir-e Doors and Shutters. Wire Glass and Fratning of Same. Watchmen's Clocks. Signalling Systems. Fire Pails, Waste and Ash Cans. Chemical Fire Extinguishers, both Hand and Stationary. Fuel Oil Storage. Kerosene Oil Systems. Gasoline Lighting. Gasoline Stoves. Acetylene Gas Generators. Gasoline Engines. Any of the above standards can be obtained from the National Board of Fire Underwriters, No. 32 Nassau street. New York City, upon application. ' MISCELLANEOUS SPECIFICATIONS. The writer would urge upon all men hav.ing much to do with the drawing of contracts and specifications to procure a copy of "Contracts and Specifications," by the late Prof. J. B. Johnson. 226 ENGINEERING WORK IN The book contains a course of instruction in the law of contracts as applied more particularly to engineering work. The references to the items to be remembered in drawing up such papers is full, and a valuable collection of specifications is given for all classes of work. The book has been a standard for some years. Dr. J. A. L. Waddell informs the writer that his lecture on "Contracts" and his lecture on "Specifications," which were deliv- ered before a' number of our leading technical schools, have been revised and extended. With the addition of a chapter on "The Law of Engineering Contracts," by John Cassan Wait, the lectures will be printed in book form during the year 1906. The writer advises engineers to keep track of work advertised in technical papers and procure, when possible, copies of specifica- tions. All such information should be card indexed. SEWER ADJUSTMENT SPECIFICATIONS. It is customary in constructing sewer systems in unimproved streets to have the tops of manholes, catch basins, inlet covers, etc., left flush with the surface of the ground. When the street is after- ward paved all these covers are brought flush with the pavement or brought to grade. For the doing of such work the following supplemental specifications are used in Chicago in connection with street paving contracts : ADJUSTMENT OF SEWER MANHOLES AND CATCH BASINS. The contractor shall, for the prices bid per unit, lower, raise and adjust to the " proper grade and line all covers to the sewer manholes and catch basins; shall furnish and set new .iron covers where needed; shall build new catch basins and shall furnish and lay tile pipe to connect said basins to the sewers. NEW CATCH BASINS. All catch basins are to be circular in section and four feet in internal diameter. They are to be built of two rings of bricl; upon a floor of two- inch piiie plank, closely jointed. The bricks in the inner ring (excepting the ' top and bottom header courses) are to be set vertically. The outer ring may be of ba^s as far as broken bricks on hand will go, otherwise whole bricks are to be used. The brick work shall be seven feet two inches deep; the top of the brick work shall be two feet in internal diameter, being drawn in by nine header courses, and an iron cover set thereon. The. catch basins are to be connected to the sewer with nine-inch tile pipe and trapped with nine-inch half-traps, the bottom of the traps to be set three feet and six inches above the floor of the basins. TOWNS AND SMALL CITIES. 227 The price bid per new catch .basin shall include the cost of the catch basin complete including the iron cover and not to exceed sixteen feet o£ tile pipe. ^ OLD MANHOLES. The covers of the .manholes shall be taken off and the upper courses of the brickwork removed if they be defective or if it be necessary to set the covers at a lower grade; if it be necessary to raise the covers more than six inches the upper header courses shall be removed until the internal diameter of the - brick work shall be two feet and six inches and the man- hole shall be built up with new brick work to the proper grade arid an iron cover set thereon, using the old cover if it be in a suitable condition. The price bid per manhole shall include the cost of all the above work and material, including not to exceed two feet of new brick work, excepting the new cover, if furnished. ' OLD CATCH BASINS. The covers of the catch basins shall be taken off and the upper courses of the brickwork removed and the brickwork built up and cover set as specified for old manholes. The catch basins shall be cleaned out, and all open joints filled with fresh mortar. When necessary the new brickwork shall be drawn over to one side so that the cover shall occupy its proper position with ref- erence to the curb. When the catch basin is not located in the line of the gutter a nine-inch inlet pipe shall connect the catch basin with a suitable brick inlet constructed next to the curb. The price bid per catch basin shall include the cost of all the above work and material, including not to exceed two feet of new brickwork, excepting the new cover and tile pipe, if furnished. COVERS. The contractor shall set all covers to the correct grade in a bed of mortar on top of the brickwork above specified.' After the foundation for the pavement is laid the covers shall be reset to the exact grade, if necessary, without extra cost. All new covers shall be of a good grade of cast iron. The curb shall weigh not less than 350 pounds, and the lid, if -of iron, shall weigh not less than 120 pounds, provided that if the catch basins are to be built in the parkways lighter covers may be used, weighing not less than 140 pounds. When so directed by the Engineer the contractor shall furnish oak lids for the new covers. The covers and iron lids shall be of the size and form of the iron covers and lids now in use by the Bureau of Sewers in the City of Chicago. The oak Hds shall be constructed of two pieces of three- inch oak plank securely fastened to one and one-half inch oak cross pieces with sixteen quarter-inch boat spikes. The price bid per new cover shall include the cost of the lid and the setting of the cover, and shall be in addition to the price for adjusting the manhole or catch basin. MASONRY. The bricks must be clean and thoroughly wet before being laid; the most perfectly formed bricks and those with the smoothest surfaces are to 228 ENGINEERING WORK IN be u'sed in the inside courses, the smoothest edge of the brick being laid to the face. No joint shall exceed one-half of an inch in thickness, and all joints on face shall be trowel -struck. If it be necessary to build more than two feet of brickwork in adjusting the coyer of any manhole or catch basin, such excess shall be paid for at the rate of two dollars per lineal foot. PIPE LAYING. Each pipe is to be laid on a firm bed, and in perfect conformity' with the line and levels given. The ends of the pipes are to abut close against each other in such a manner that there shall be no shoulder or want of uniformity of surface on the interior of the drain. The rings are to be placed centrally around the joints of the pipes. " The joints between the rings and the pipes are to be as uniform as possible in thickness and thoroughly filled with mortar. Each joint is to be wiped clean of mortar on the inside before another length of pipe is laid. The price bid per lineal foot of pipe shall include the cost of all material and labor, including excavation and backfilling, and shall be paid for all inlet pipes and all outlet pipes in excess of sixteen feet for each basin. MORTAR. The mortar shall be made by carefully measuTing and thoroughly incor- porating one part of natural cement with two parts of clean, sharp sand in dry state, and mixed with clean water to the proper consistency, and shall be used while fresh, and the use of mortar which has been set and then retempered will not be allowed. The mortar used in laying pipe sewers shall be of pure cement, mixed and used as above specified, all to be furnished by the contractor without extra charge. BRICKS. The bricks shall be of the best equality for the purpose for which they ^ are intended, uniform in quality, sound and hard-burned, free from lime and cracks, and to have a clear, ringing sound when struck, whole and with edges fu'Il and square, and of standard dimensions, viz.: 8x4x3^4 inches; they shall be of compact texture, and after being thoroughly dried and immersed in water for twenty-four hours shall not absorb more than fifteen (16) per cent in weight of water. PIPE. The pipe shall be straight, smooth and sound, thoroughly burned and vitrified, well glazed, free from lumps or other imfierfections, and with the least possible variation from the specified dimension or true cylindrical shape. All straight pipe must be straight in the direction of the axis of the cylinder, and the inner and outer surface of each pipe must be concentric. BACK-FILLING. The earth must be carefully replaced around all: manholes and catch basins and over all tile pipe laid under this contract in su'ch a manner that no further settlement will take place, and it must be thoroughly rammed with suitable rammers or puddled with water, or both, as the Engineer may direct. TOWNS AND SMALL CITIES. 229 DRAINING INT£RSBCTING STREETS. Whenever the grade of the new pavement is such as to interfere with the drainage of intersecting streets into existing catch basins, additional brick inlets shall be built at the outer edges of the new pavement and con- nected to the catch basins with nine-inch tile. The price bid per lineal foot of tile pipe shall include the cost of this work including the brick inlet. IRON INLET GRATINGS. When so directed by the Engineer, the contractor shall furnish and set a cast-iron grating seventeen inches by twenty-four inches, of the form and dimensions shown on the standard plan of sewer manholes and catch basins in the office of the Engineer of the Board of Local Improvements. The grating is to be supported by a cast-iron frame and brick foundation and connected to the catch basin by means of a nine-inch pipe in the manner shown by said drawing. The price bid per grating shall include the cost of all material and labor above specified, except the tile pipe. OLD IRON COVERS. All old iron covers for manholes and catch basins that are not needed on the work shall be delivered by the contractor to the city. OLD PIPE CONNECTIONS. The pipe connections from the old catch basins to the sewer shall be examined at the expense of the contractor, and if found defective shall be put in good condition at the expense of the city. BITULITHIC PAVEMENT. The following specifications were used in Cincinnati in 1904-5 : EARTH FOUNDATION. The earth foundation or sub-grade will be brought to an even surface, parallel with the grade proposed for the pavement, by making the necessary excavation or embankment. Soft or spongy earth, or other material not firm, will be removed, and the space filled with stone or with extra concrete, .as specified for pavement base. The sub-grade surface will be compacted by rolling and ramming. Any portion not accessible to the roller shall be thor- oughly compacted by ramming. When this shall have been done,, the sur- face shall be true, smooth and ' eight inches below the finished surface for the pavement. Excavation shall be paid for at the price bid per cubic yard, and crushed stone or concrete per cubic yard at the price bid for same. All excavated material shall belong to the contractor. PAVEMENT BASE. Upon the earth foundation prepared as specified shall be laid a layer of crushed granite boulders or hard limestone that after its ultimate com- pression by rolling and ramming shall have a depth of six inches. The surface of the layer of stone will be true, exactly parallel with and two inches below the surface proposed for the finished pavement. The crushed stone shall 230 ENGINEERING WO'RK IN be sound and clean, the fragments being uniformly graded in sizes from a material that will pass a three-inch screen to material that- will stand on a one-inch screen, and the various sizes shall be laid in strata, each stratum passing through a screen having perforations With a diameter not to exceed one inch larger than the diameter in the screen through which the material refused to pass. The layer of crushed sJ;one prepared as specified will be coated with War- ren's No. 1 Puritan brand semi-liquid composition, or material of the same chemical and physical properties, said bitumen to be sufficiently flexible to unite freely with the cold stone. On top of this composition shall be spread a heavy coating of Warren's No. 24 Puritan brand hard bituminous cement, or material of the same chemical and physical properties, thoroughly binding the pavement base and making it readily _.unite with the bituminous concrete wearing surface. One gallon of bituminous cemfent will be used to each square yard of surface. On this prepared pavement base shall be laid the wearing surface, which shall be composed of carefully selected hard crushed stone, mixed with bitumen "and laid as herein specified. WEARING SURFACE. After heating the stone in a rotary mechanical drier to a temperature not to exceed 250° F., it shall be elevated and passed throu'gh a rotary screen having six or more sections with varying si^ed openings, the maximum of which shall be 1^ inches and the minimum 0.1 inches diameter. The sev- eral sizes of stone thus separated by the screen sections shall pass into a bin containing six sections or compartments. From this bin the stone shall be drawn into a weigh box resting on a scale having seven beams. The stone from each bin shall be accurately weighed in the proportion which has been previously determined by laboratory tests to give the best results-; — that is, the most dense mixture of mineral aggregate, and one having inherent sta- bility. From the weigh-box each batch of mineral aggregate, composed of different sizes accurately weighed as above, shall pass into a "twin pug," or other approved form of mixer. In the mixture shall be added a sufficient quantity of Warren's Puritan brand bituminous waterproof cement, varied from No. 19 to No. 24, or material having the same chemical and physical charac- teristics to suit the stone used, in sufficient quantity to thoroughly coat all the particles of stone and to fill all voids in the mixture. The bituminous cement shall, before mixing with the stone, be heated to between 200° and 250° F., the amount used in each batch shall be accurately weighed and used in such proportions as has been previously determined by laboratory examination to give the 'bfSt results and to fill the voids in the mineral aggregates. The mixing shall be continued until the combination is a uniform concrete. In this condition it shall be hauled to the street and there spread in the prepared foundation to su'ch a. depth that, . after thorough compression with a. steam road roller, it shall have a thickness of two inches. The proportioning of the varying sizes of stone and bituminous cement shall be such that the compressed mixture shall, as closely as practicable, have the solidity and density of solid stone. SURFACE FINISH. After the rolling of the wearing surface tnere shall be spread over it a TOWNS AND SMALL CITIES, 231 thin coating of Warren's quick-drying bituminous flush coat composition, or material of the same chemical and physical characteristics, the purpose of this coating being to thoroughly fill any unevenness or honeycomb which may appear in the surface of the mixture. There shall then be rolled into the surface a thin layer of stone chips for the purpose of presenting a gritty surface which will not be slippery, the size of the stone chips to be subject to the special direction of the Engineer. The- stone chips will be of the same quality as stone specified for the wearing surface. The roller used for compacting the earth foundation or sub-grade, for compressing the pavement base and wearing gurface, also for rolling the stone chips, shall be operated by steam power and give a weight pressure of not less than 650 pounds per lineal inch of roller. Each layer of the work shall be kept free from dirt so that it will unite with the succeeding layer. PORTLAND CEMENT CONCRETE. When, on rolling the sub- foundation, it is found impossible to make the street sufficiently solid to hold up the roller, the contractor shall be required to furnish a Portland cement concrete foundation, to be laid under the fol- lowing specifications: The concrete shall consist of mortar and crushed stone, gravel or slag, which will vary in size from ^ inch to 3 inches, mixed in such proportions as will provide a solid concrete. The mortar shall consist of one part of Portland cement to three parts of clean, sharp, coarse sand, and shall be used with crushed stone in predetermined proportions to give a firm, solid concrete. As soon as the concrete is well tamped, and before it becomes set, there shall be scattered over the surface of the concrete a suf- ficient quantity of clean broken stone of such size as will pass a IJ^-inch or 2-inch opening on a rotary, screen. Sufficient of the stone to be u'sed to about half cover the concrete. This stone shall then be tamped so as to become well bedded into'the surface of the concrete, leaving a rough surface to the founda- tion of the pavement. The object of this binding course of crushed stone is to afford a rough surface to the concrete to enable the bitulithic wearing surface to more firmly adhere to the same. If the fine crushed stone does not -provide the best proportions of fine- grained particles, they must be supplied by the use of not to exceed 15 per cent of hydraulic cement, pulverized stone or very' fine sand. ' MATERIALS. The bituminous cement shall be prepared by selecting bitumen which has been distilled from coal and passed in a gaseous state through water and puri- fied by water, removing therefrom all matter soluble in water, and only that bituminous material shall be used which condenses from the gaseous state in water. The material selected shall be mixed in fixed proportions so as to give and produce a uniform condition as to the quantity of free carbon. The bituminou's cement shall not be adulterated with any class of asphalt, coke- oven coal tar, water-gas coal tar, or any of the products of petroleum, and shall be especially refined and distilled at temperatures never rising above 450° F., using such forms of mechanical steam, and air agitation as will accom- plish uniformity of results, and remove, as far as possible, napthalene and Other matters most susceptible to atmospheric influences, *232 ENGINEERING WORK IN The bituminous cement shall be ,of such quality that when three ounces is placed in a glass dish three inches in diameter in the sun for two years it shall be decreased less in its . penetration (taking the penetration of 1/16 inch below its surface) than the best quality of Trinidad Lake asphalt paving cement for the same original penetration at 79° F. The bituminous cement shall be of such character that when nine parts of the cement are mixed with 92 parts of sand which will pass a 20-mesh sieve and stand on a 30-mesh sieve, and placed in water, it shall -show no discoloration at the' end of three months when placed subject to the chemical influence of the sun during parts of the day, and shall be firmer, as shown Jby testing on an ordinary cement tester at the' end of six months, than a Trinidad asphalt cement submitted to the same condition will show at the end of two weeks. The mineral ingredients shall be so arranged as to sizes that they will have inherent stability independent of the bitumen so as to stand a weight of at least three tons &r\. a four-wheeled vehicle with three-inch tires without the bitumen. The pure bitumen used in the wearing surface shall be of su'ch softness that it will not be harder in penetration at 70° F. than a Trinidad asphalt paving cement, composed of 100 parts refined Trinidad Lake asphalt and thirty parts petroleum residuum, at 18° Beaume. GUARANTEE. The price bid per square yard to include -repairs necessary to maintain the pavement in good condition, satisfactory to the Board of Pub'.ic Service, for a period of five years fro:^ the date of acceptance by the city. GENERAL. Under these specifications it is intended to get a wearing surface which 5s two inches in depth over all, and it shall be the option of the' bidder to use a bituminous binder course to level u'p the foundation or to level it up with a part of the wearing surface mixture. The binder course, if used, shall be fine particles of stone or gravel not to exceed one inch ia diameter, thoroughly coated with Warren's Puritan brand bituminous waterproof cement - No. 19 to No. S4, or material with the same chemical and physical charac- teristics. The attention of bidders on the bitulithic pavement is called to the agree- ment on file with the Council of the City of Cincinnati, under date of October 3, 1904, and bidders are hereby notified that the sum of 25 cents per squ'are yard will be retained from the contract price, and that the city will pay the same direct to Warren Brothers Company for the patent rights and service therein granted. CONCRETE SPECIFICATIONS. f CEMENT — The cement may be any brand of American or foreign Port- land cement which will meet the requirements of these specifications. (Note — If the work is such that natural cement or Puzzolan, etc., cement may be used, they can be substituted in the above for Portland, or may be placed in addition to Portland, thus competing with it.) CONDITION OF DELIVERY — It must be delivered in original packages, labeled with the brand and the name of. the manufacturer. These packages TOWNS AND SMALL CITIES. 233 may be either barrels or bags, but must be well protected in either case from air and moisture. Any broken packages may be rejected or used at the option of the Engineer in charge of the work. TIME OF DELIVERY— The contractor shall furnish the cement upon the work at least ten days before it is needed to be used, in order that time may be given to make the necessary tests. HOUSING — It shal) be stored in dry, well ventilated buildings for work of any magnitude, and for work of less importance it shall be safely stored and protected from moisture in any form. TESTS OF CEMENT— The cement shall be tested in accordance with the specifications prepared by the American Society for Testing Materials, and the methods proposed by the American Society of Civil Engineers. ' SAND — All sand used for mortar shall pass a No. 10 sieve, and 80 per cent of it shall be retained upon a No. 74 sieve. It shall be a silicious sand, as sharp as can be obtained within reasonable limits of cost. . It shall be free from all vegetable and organic matter and shall not contain more than 10 per cent, by weight, of clayey or loamy material. (Note — An addition of clay and (so-called) loam to sand has been found in many instances to produce an actual increase in strength. The supposition is that it is because of the voids being more perfectly filled than if the sand was clean and sharp. The specifications for the materials for concrete blocks prohibit clay or loam. The reason is that the evenness of color, so desirable in building blocks, is liable to be impaired if the aggregates are not perfectly clean.) STONE — The aggregate shall consist of crushed trap rock, granite, hard limestone, or other material equally hard and durable which shall meet the approval of the Engineer. The broken stone shall be free from vegetable or organic matter in any shape and free from mud and dust or from lumps of clay or clay covered fragments. When sand is to be used in the concrete the stone shall be screened to pass through a inch ring and retained on a screen of inch apertures. The stone shall be thoroughly wet before mixing with the mortar. When it is desired to use screenings with the crushed stone the proper ^proportion of sand to be used shall be determined by analysis. GRAVEL — Gravel shall be composed of clean pebbles of hard and durable stone, of sizes not exceeding two inches in diameter, free from clay and other impurities except sand. When containing sand in any considerable quantity the amount per unit of volume of gravel shall be determined accurately to admit of the proper proportion of sand being maintained in the concrete mixture, CINDERS — Cinders used for concrete shall be from coal, reasonably free from .sulphur, and shall contain no ashes or unconsumed coal, organic matter or clay or dirt of any description. WATER — ^Water shall be clean and reasonably clear, free from sulphuric acid' or strong alkalies. MIXING BY HAND — (1) Tight platforms , shall be provided of sufficient size to accommodate men and materials for the progressive and rapid mixing of at least two batches of concrete at the same time. Batches shall not exceed 234 ' ENGINEERING WORK IN one cubic yard each, and smaller batches are preferable, based upon a multiple of the number of sacks to the barrel. (2) Spread the sand evenly upon the platform, then the cement upon the sand, and mix thoroughly until of an even color. Add all the water necessary to make a thin mortar and spread again; add the gravel (if used) and finally the broken stone, both of which, if dry, should be first thoroughly wet down. Turn the mass over with shovels or hoes, or both, until thor- onghly incorporated and all the gravel and stone is covered with mortar; a minimum of four complete turnings is required. (3) Another approved method, which may be permitted at the option of the Engineer in charge, is to spread the stone or gravel, or both if used, on the board as many inches in tliickhess as there are parts in the mixture. Over this place the sand evenly and on top of the sand the cement evenly over the whole. Turn the whole mass twice dry; turn it twice while apply- ing water with a rose nozzle sprinkler, and give, it a fifth turning when • loading into thtf wheelbarrows or carts, or into the work. MACHINE MIXING — Mixers u'sed instead of hand work shall be batch mixers of the revolving drum type so arranged that the materials shall be .placed in measured batches in, the mixing receptacle and shall be discharged in . thoroughly mixed batches. The minimum number of revolutions of the ; mixing drum shall be twelve for each batch. CONSISTENCY — The concrete shall vary in consistency according to .the requirements , oi the work. If rnixed fairly dry it shall be tamped after depositing until the moisture flushes to the surface and the concrete quakes. Xlie preferable consistensy shall be when the concrete is so moist that >t quakes like jelly .and requires very little tamping. LAYING — (1) Each course should be left somewhat rou'gh to insure bonding, with the next course above; and if it be already set, shall be thor- oughly cleaned and doused with all the water it will absorb readily before the next course is placed upoji it. At the option of the ' Engineer the contractor may be required to treat the face of old work with an acid wash and put on an inch of retempered mortar before laying fresh concrete on it. The plane . of courses shall be as nearly as possible^ at right angles to the line of. pressure. (2) An uncompleted course shall be left with a vertical joint where the work, is stopped, and the concrete shall not be allowed to assume a- slope.; (3) The work should be carried up in sections of convenient .length and kept as nearly as possible on the same plane all over the work, and com- pleted without intermission. , EXPANSION JOINTS — In exposed work expansion joints shall be pro- vided at intervals of thirty to fifty feet. A temporary vertical form or par- tition ,of plank shall^ be set up and the section behind completed as though , it were .the end of the structured The partition will be removed when the next section is begun and the new concrete placed against the old without, any mortar flushing. Locks shall be provided if directed or called for by the plains. (2) In reiififorced concrete structures the length of the sections may be nmterially increased, or expansion joints may be entirely omitted, at the option of the Engineer. ^ a- ' ■ ' DEPOSITING — Concrete shall be deposited within five minutes ^Tter. it is "mixed and shall be kept continuously mixed until deposited. No concrete TOWNS AND SMALL CITIES. 235 having attained an initial set shall be used, but retempered concrete may be used under the direction and personal supervision and instruction of the Engineer in charge. FACING — Facing may be accomplished in one of two ways: (1) The material next the face may be spaded back with a. flat shovel or flat fork, to permit the mortar to flow to the face; (8) about one inch of mortar as used in the concrete, but without the stone, shall be placed next the forms imme- diately in advance of the concrete. Either method may be used at the option of the Engineer, the contractor being permitted to use the, least costly method that gives a satisfactory result. FREEZING WEATHER— In freezing weather work may be proceeded with at the option of the Engineer in charge, provided that the water be warmed, but not boiled, the sand and other aggregates be heated, but not hot enough to blister the skin of the hand. On work where an efflorescence will not be objectionable, salt may be added to the warmed water in the following proportions: The difference in temperature between freezing point and the temperature likely to be encountered before the concrete sets shall be the amount of salt, expressed iii percentage of the amount of water by weight, to be used. The salt shall be thoroughly dissolved in the water before mixing the concrete. Exposed concrete shall be covered with straw, hay, sawdust or cloth at night when the temperature is expected to drop below freezing point. FORMS — (1) Forms shall be substantial and unyielding, properly braced or tied together by means of wire or rods. (3) The material used on faces shall be of dressed lumber and on the backings may be of undresSfed lumber, secured to the studding or uprights in horizontal lines. (3) Planking once used in forms shall be cleaned before being used again. (4) Face forms shall be coated with soft soap, or with crude oil, at the option of the Engineer in charge, to prevent concrete from adhering. (5) In dry btit not freezing weather the forms shall be drenched with water before the concrete is placed against them. (6) On face work forms shall be made carefully to prevent leakage of water through them, and care shall be taken to prevent the formation of ridges or depressions showing the marks of the forms. (7) The forms must remain in place at least forty-eight hours after all the concrete in that section has been placed, except that when a fairly dry mixture, well tamped, has been used, the forms «ay be removed earlier.. In freezing weather they must remain until the concrete has had time to thor- oughly set. FINISHING — After forms are removed small cavities are to be pointed up and projections smoothed off. The entire face shall then be washed- with mortar made of one part of cement to two parts of sand, mixed to the consistency of cream and applied with a whitewash brush. USUAL SPECIFICATIONS FOR CONCRETE SIDEWALKS. All cutting and filling necessary to bring the foundation to subgrade as given by the engineer in charge of the work, must be done by the coni- 236 . ENGINEERING WORK IN tractor. When necessary the foundation must be consolidated by wetting and hy rolling or ramming to give it proper stability. Soft and spongy places not affording a firm foundation must be dug out and refilled with sand or gravel, and well compacted by ramming, and foundation brought to within four and one-half (.iyi") inches of the grade. (NoTE^ — The writer believes that under the sidewalk should be placed two or three inches of cinders well compacted, or about one inch of sand if the subsurface is a clay and there should lie drains laid from the cinders or sand to the nearest manhole or catchbasin. 'This is not necessary if the soil be a porous one.) On the surface thus prepared shall be placed a layer of hydraulic cement concrete for four (4) inches in thickness, composed of one part approved Portland eement, two parts best clean, coarse, sharp sand. After mixing dry, five parts of broken stone, of a size not larger than two and one-half (2^) inches in any dimension, shall be added and then water added 'in ju:st sufficient quantity as will give a surplusf' of moisture' when rammed 's Zhd.'fldd. le^b 7 S.W 4 OF N.E.I4. OF SeC.I&-49-33 I ' //? /A/'s square ft>e. 06'ove. Su^cf/Wsions pre phi-t-e-c/' I The.if are here on^i^erf /or f^e. sca/e YirouJ^ 6e too The most satisfactory method for taking care of the tubes, considering economy and ease of reference, is to have a framevork built in the office much like the studding in house framing. In each vertical post drive wooden pegs at a slight angle long enough to hold about two or three tubes on each pfeg. In order that prying TOWNS AND SMALL CITIES. 249 visitors may not become too interested in work going on in the office it is good practice to number every job consecutively and place only the number on the label pasted on the tubes containing work in hand. The first class of drawings will usually be on paper or tracing cloth. The second class usually consists solely of blue prints. The second class will be indexed in the permaneiT,t index record, so far as the original drawings from which the prints are made are con- cerned. An additional- index for work in hand is therefore a sim- ple matter. '^ A book with plain pages and having an alphabetical index is usedr Each job is numbered consecutively and a record entered in the book, commencing with the first page. Usually a page is given to each job. First the number of the job is placed at the upper outside corner of the^age. Underneath is placed the name and address of the party for whom the work is being done, and such other items (including dates) as may be considered necessary to keep the record compact and fairly complete. Below this put a list of^the drawings used for the work, together with their index and filing numbers. In the aphabetical index forming part of the book it is simply necessary to put in the name of the employer (client), together with the job number and page of the record. The cost of the tubes is so small that it pays to keep all the drawings, together with specifications, contracts, etc., in these same tubes and file them away when the job is done. If any question afterward arises the ability to produce such papers when~ wanted is a valuable asset. The writer usually seals the tubes and puts them where the dust can not accumulate and where there will be small danger of fire. An engineer should have a fireproof safe, or rather, a good sized vault, in his office and keep all the records in it. If he can not do this, but must carry them to a vault for storage each night, he will find rolls and flat portfolios better than shallow drawers and standard filing cases. Metal protected filing cases may, of course, be purchased if the engineer can afford it. (Note — The writer wishes to add to the original letter by saying he uses shallow drawers in the office under the drawing board to hold plain sheets that have been cut ready for use and also to hold drawings re- ferred to during the day. In a vault shallow drawers have a place. They should never hold more than twenty-five sheets, however, as it is a difficult 250 ENGINEERING WORK IN job to look for anything when there are more. The best device of this kind he has seen was one where there was a piece of heavy pasteboard as a false bottom. In the bottom of the drawer near the front was a large hole. When the drawer was pulled out the hand was pushed under the false bottom and it was raised and carried forward until the front rested on the top of the drawer thus permitting an easy examination of the sheets. Within the past few years a iiling system has come into use whereby the drawings have eyelets attached to them on one side. A case is u'sed with a door that comes down flat like a ladies* writing desk. Fastened to this door are two rods over which the eyelets go. When the door is swung to its vertical position the drawings hang by these rods and are .very convenient for refer- ence. Such a scheme requires little room.) FIELD AND OFFICE BOOKS. To avoid duplication of numbers all books used are numbered consecutively, transit iooks being indicated in the index by "T," level books by "L" and books used in the office by "O." The letter and number placed on the back, where it can be seen when the book is on a shelf, indicates to the searcher the book wanted. (Note — The writer uses generally a book ruled in quarter-inch squares, or in ten ^qu^res to the inch, for all his work except work of a fairly regular kind, like railroad or canal surveys. There is no vertical ruling in red lines, so this enables him to use the book for all classes of work. If he happens to be so placed that he can not get hold of such a book he prefers, to use a book ruled like a level, book.) >, Office books are two in kind. One kind is about the same in size as a field book, but costs much less, and when possible all pages should be ruled in squares. The other office books are usu- ally about 8^ inches wide and 14 inches high. The pages are also ruled in squares. The squares may be eight or ten to the inch. (Note — It should have been stated that the larger hooks are used alto- gether for structural work and static calculations. The smaller books for surveys, hydraulic calculations, etc. For figuring paper it is easy to purchase loose sheets for 20 cents a pound, ruled on both sides in quarter-inch squares.7~ When doing any work it is wisest to do it in a book instead of on slips of paper to be thrown away. A slight degree of care used to indicate at the top of the page the work done thereon, and a careful indexing of the book will often save considerable annoy- ance and expense afterward. The writer, for this reason, when in the field prefers to do his figuring on pages of the field book rather than on separate pads; if it can not be done without interfering with the notes on an opposite page, then he figures in the back of the book. TOWNS AND SMALL CITIES. 251 In any scheme for indexing plats, etc., the letters "T," "L" and "O" are kept for th& books. The books are not numbered with the number of the piece of work, for frequently one book may be f^ "V tl _.0 (D>AJOiS^{8 OOSCL— -liiJQ — ■>*- l*> Cvl :*, Ui ^ ^ ^ S ^ I is !^ to LOZ3Q=>UJ>-cO 'i- J»1? R CM 1£ o 1^ t I puOjpoo/y[ CM ■^ ^i- to ^ N ro 5 !2 10 00 > r^ U ■^ s: * "^ 15 <^ * i ^ 5- ^ ^ C/) PI ^ f- - *« s ii 1^ ? 'H 0) ^ IJ » ■ i^* SfH t^ S ^ .- WffsH/Ncro/)/ St. - 258 ENGINEERING WORK IN benches. On the index map place the number in the proper loca- tion. On the small cards also put the numbers ^own in the proper locations. Red ink is generally used for elevations and eome other color for survey poii^ts. On the back of the card write the descrip- tion, exact location and elevation. The cards are filed in large envelopes in a box serially. When a survey is to be made in any part of the city a glance at the map on the wall gives the number of the card covering that part. The card is removed from the case or envelope and placed in the back of the field book. This renders it unnecessary to do any copying when in a hurry. As the same information is on a card in a regular card index there is no danger of serious loss if the map card is lost while in the field. LOOSE LEAF INDEX SYSTEM FOR NOTES. ETC. .In the course of time sketches, notes of observation, trade secrets, useful, wrinkles and formulas accumulate and should be so preserved that' they will be immediately available when wanted. It is a good plan to carry a loose leafx book with ruled pages and make such memoranda and notes on the loose sheets. Each item should be placed under a heading, so it can be found with certainty whgn wanted, and it is a good plan to put at the top of the sheet all the headings under which the subject will be looked for when wanted. When back in the office the sheets should be taken from the covers and filed alphabetically in a box of the proper size. Where several headings are indicated, make out blank sheets for each subject, containing that subject at the top and underneath a state- ment as to the heading under which the information is filed. These auxiliary sheets are to be filed alphabetically. It can be readily seen that such a system is self-indexing and calls for no additional work in recording, provided only one subject is entered on each page. The engineer has thus a constantly ex- panding self-indexed hand-book of data. / It is, of course, not one he can carry with -him in his pocket, but it is one he can easily refer to in the office. TRADE LITERATURE. (In the 4ast chapter the writer has placed a part of his article which relates to the filing and indexing of fragmentary literature. In that chapter TOWNS AND SMALL CITIES. ' 259 is a Hit of dealers in articles required by city officials and the list lias been prepared in order that readers will know who can supply their wants. As all catalogues should be preserved for futuTe reference the place for a description of filing methods seemed to be in such a chapter.) EVERYTHING IN ITS PLACE. The writer is strongly opposed to roll top desks, or desks con- taining more than one drawer, in an office. That is, in the office of an engineer having assistants. He prefers a flat top table with one shallow drawer, where the man using it can put pencils, etc. and where he can leave small things of his own at night. This table can have some shelves at one end on which to place things needed during the day, but everything can go to its place at njght.' A large metal cash box is convenient, and one can be placed on each table so that books, memoranda, etc., used during the day can be locked in that box and be put away for the night. To keep the drawiijg boards and tables free from dust, and to protect papers tacked down, a linen or muslin cover should be hung over each every evening at quitting time." The following article is re-printed entire from Engineering News of July 20, 1905, being a reprint from The Transit, published by the Engineering Society of the University of Iowa. All the illustrations have been redrawn for this book. METHODS OF FILING RECORDS IN A CITY SURVEYOR'S OFFICE. BY FRED GABELMAN, C. E. -In some of our larger cities .the lot and land line surveys are made by engineers in private practice, the city engineering depart- ment devoting its entire time to public improvements, doing nothing whatever with these surveys. Since no department of the public service is directly responsible for the maintenance of monuments, there is consequently no uniform system of monumenting street and other lines, hence every engineer or firm of engineers, doing this , kind of work must have its own system of street and land line monuments and references to the same, which in fact is a very valuable part of the firrri's assets. If a firm has records of and references to all the s.ection, land 260 ENGINEERING WORK IN and street monuments and lines in the city, and is called- upon to make from three to twenty surveys per day, it must have these records and references, very full and complete, and must Tiave a very systematic and flexible method of indexing the accumulated and rapidly accumulating information in order that the preliminary notes for making any survey may be prepared quickly, and with the assurance that all the information which bears directly or indirectly upon the location of the tract of land to be surveyed is known and noted. QpfOEfi CAffO . Va/e ^lyen hy _ On eucc'^ of ^ _ /fdifress _ _ fo 6e cam/i/e^ej^ ^ OnlerM, Soajr /^t •fO-Zfc/Vh. C/iffD. (Tlhe cards used iy Me f/'rrr? are pnnfe^f^ It was the writer's privilege to be associated with Tuttle &. Pike, civil engineers of Kansas Gity, Mo., for eight years as chief "draughtsman and as chief assistant, and while serving in this ca- pacity the following system of filing records was largely developed, the writer being instrumental in the evolution of' some of the prin- cipal features of the system. This system embraces the following records : 1. Recorded Plats.' 2. Forty-Acre Plats. 3. Section Books. 4. Field Note Books. 5. Certificate of Surveys. TOWNS AND SMALL CITIES. 261' 6. Miscellaneous Maps. 7. Bench Marks. RECORDED PLATS. Copies are made of all- plats of record in the office of the Re- corder of Deeds for Jackson County, Mo., the county in which Kansas City is located. These copies are made on tracing cloth and are exact copies of all the information on the original plats. They are all of a uniform size, the border line is 15xl8j4 inches and the trimming line is 16^x20 inches. The same letter is used in all the titles, thus securing uniformity for all plats. The plats made in each year are numbered in the order of their date of filing for record, the year being placed in the upper left hand corner of the plat and the numerical number for that year in the upper right hand corner. The tracings are filed flat in drawers in a filing case in numer- ical order with reference to the year and year number. The years mclusive of the plats in each drawer are printed on the label card on the front of the drawer. Copies are made of. all plats that are filed for record each month, thus keeping the file up to date. "Positive" prints (that is, prints with white background and blue lines) are made of these plats as they are called for and sold to real estate firms, abstractors and others; quite a number being regular subscribers for prints of all plats filed for record. For field and office use, positive prints, made on best linen ,paper, are used. They are folded uniformly so that they are 4x95^ inches. The title, section, township, range and 40-acre number are printed on one end, thus : Beacon Hill 16 — 49 — 33 7 and filed numerically with reference to section number and 40-acre number in each section in a document filing case. The section numbers inclusive are printed on the label card on the front of each file., FORTY-ACRE PLATS. Plats are made on tracing cloth to the scale of 100 feet to the inch for each qtiarter quarter-section of all the sections within the 262 ENGINEERING WORK IN city limits of Kansas City, Mo., showing all the additions on same that are of record (see Fig. 1). The plats are 19j4x20 inches. The addition names are arranged numerically with reference to date of record and printed in the upper left hand corner (the number to right of the year refers to the year number). The street names are put on the margift, and the lot numbers on the rear of the lots, so as to leave room for indexing surveys and for recording the measurements, angles ani other information on the face of the plat. The plats are called "Forty-acre Plats." They are num- bered from 1 to 16 for each section, as shown in Fig. 2. This makes the plats self-indexing, as one can find any quarter quarter- section in any section at once. The tracings are filed fiat in draw- ers in a filing case in numerical order with reference to sections. For ofBce use positive prints are made on heavy parchment paper and bound with a loose leaf ring binder, so that at any time, as new subdivisions are made, they can be platted on the tracings and new~^ prints inserted in the binder. There are three books; Each binder has four 1-inch rings. The surveys are in- dexed in red ink on these prints, also all measurements, angles, etc. For field use positive prints are made on linen paper. These prints are duplicate copies of all field work compiled in the Forty- Acre record books in the office, so that the field man can see at a glance what has been done in the quarter quarter-section |n which he is working. SECTION BOOKS. All references to section lines, land lines and street lines are compiled in field note books that are called "section books.'' There is one book for each section. Bach book is divided into parts of ten pages each to correspond with the 40-acre plats of the section. The first ten pages are used for reference to section corners, quarter- section- corners and measurements and angles between said corners. An outline sketch of the section is drawn on the second page (see Fig. 2), showing the 40-acre numbers, and the street names on the 40-acre lines, also measurements between 40-acre lines. The next 160 pages are used for reference and ties to street lines, ten pages being used for each 40-acre number, pages 11 to 20 ior 40-acre No. 1, pages 21 to 30 for 40-acre No. 2, etc. This makes the book self-indexing as, for example, the ties to street lines in 40-acre TOWNS AND SMALL CITIES. 263 No. 4 would be- on the pages in the 40's, ties to street lines in 40-acre No. 12 on the pages in the 120's, etc. The first page of each set >< 1 \l -1 N ■- 1 1 ' I .5 t Q ft I iT 5 , il f5 'i \i ■? f: .1 '2. ^5 I ;! ■^ ^ V ^ ^ t ^ (5 ^ ^ h - ' i^ * ii! Q^?!§ 1^ 1^1 > If 8 ^5l *»; SO «) ^ Sr <0 I ^ ^ 1 • •< ^\ V ilzn ■' ^ e ill -| cji .|4'|.. 1.. |« |.. 1.. p^'i ,. 1. I -|. if^ I II I < « II Q brff^Er Op£ning //kco/TD. 280 ENGINEERING WORK IN (or future department.) The third way is a combinatton of book with cards. The plat shows the two sides of the street from one corner , to another, including one crossing at the end of the block. Plat on the street thus put down, the sewer, or the water or gas pipe, etc., and then plat in the right place the connection when it is made. Mark the date, etc., and number of the index card and all. information that will help. In this connection remember the • plat is to be on the left hand page and the other page can be used for notes. ' The card index should be by streets and contain -all partic- ulars that will be necessary in determining the location of the con- nections made. These cards to be in the colors selected before for the departments in question. Triangle or Straight Edge EN6.NEW&. The cards are filed alphabetically by streets. File them reg- ularly in the direction of the house numbers. The permit book has numbered stubs so that is all that is needed for number reference to permit. CONTOUR MAP.. The City Engineer should have a contour map on a scale of 400 feet to- an inch. The lines in black should show only- the TOWNS AND SMALL CITIES. 281 outlines of the blocks and need not be marked with dimensions. Upon this map should be platted all elevations determined at any time, and when enough are platted the contours can be drawn in, selecting any interval the judgment of the engineer dictates. For interpolating contours the writer has used foi; years a method described by him in Engineering News,- May 10, 1900, a cut of which he is enabled to reproduce by the courtesy of the editors. The elevations are written at the proper points and a dotted line is drawn connecting two points qn which the elevations have been determined, and whidi are platted in their relative posi- tions. A piece of ruled paper, marked as shown, is laid at any angle and one end is at one of the points. That is, the figure on the slip of paper is the same as the elevation of that point. A triangle is then laid on the plat so that the edge passes through the other point and the number on the slip ■ that corresponds to that elevation. The triangle is then moved along another triangle, or a straight edge, and at each contour interval decided upon a dot is marked on the line connecting the two points. • In the issue of June 31, 1900, of the same paper, Mr. H. F. Bascom, C. E., describe3~a method, original with himself, which is superior. He lays a strip of ruled paper along a line connecting the two points. This piece of paper has no figures marked on it. He then lays on top of it another strip having graduations, such as above described. This last strip is placed at an angle so that one graduation touches the elevation on one point so marked and 282 ENGINEERING WORK IN the oiher end of the strip intersects a line that intersects the marked elevation of the second point. By following lines to the edge he plots his contour points. This is shown in the illustration. For a ready method of covering a large area preparatory to a study for sewerage and . drainage nothing can compare with the Stadia method and a contour map. The old time tedious calculations >for reducing stadia readings have been superseded by diagrams and slide rules. Messrs. W. and L. E. Gurley, Troy, N. Y., sell for 75 cents the Cox Stadia Computer, which the writer has used for a number of years with great satisfaction. The Cox Stadia Slide Rule, 10 inches long, costs $4.50, and a 80-inch rule costs $12.50. The Webb (cylindrical) Stadia Slide Rule is about 10 inchfes long and is so made that it is equal to a straight slide rule four feet long. The price is $5.00. All instru- ment dealers sell them. Stadia diagrams can be readily made, but being l&rge, are confined to ofifice use. The computers above mentioned can be carried to the field. The formula for horizontal distances i&: Rod reading x Cos'', a. Use a large sheet of bristol board and along the lower edge draw a line twenty inches long divided into twenty parts. Divide each part into ten. From the left hand end describe an arc with a radius of twenty inches. Number the di- visions on the bottom line, commencing with at the left end and ending with 200 at the right end where the circle begins. By the above formula compute the horizontal distance , for a rod reading of 300 feet and for every degree up to about twenty. Plot each distance as found on the bottom line and erect a perpendicular to intersect the arc. From the vertex at the left draw an inclined line through the intersection on the arc and produced to intersect a perpendicular erected from the 300 point on the bottom line. Such a diagram is shown in the accompanying illustration. Calculations can be made for quarter degrees or for every five minutes if desired and also plotted. Through each inch point on the bottom line erect a perpendicular in black ink. At each tenth point erect a perpendicular in fine red ink. Lines can also be placed on such a diagram to give elevations, but it is tedious plotting them. The writer uses another diagram for elevations. He first obtains the horizontal distances on such a diagram as above described and for elevations makes a diagram on TOWNS AND SMALL CITIES. 283 cross section paper, ruled in squares. The vertical scale is ten times the horizontal scale on Diagram 2. A pin is inserted in the lower left hand corner and a thread attached to it. On the right hand side angles are marked by taking the tangents from a table of tangents. On the left hand side the elevations are marked. Stretching the thread to cover the angle, the horizontal distan,ce is read on the bottoth and followed up a vertical line to an inter- section with the thread when a glance to the left will give the difference in elevation. S/ogtvin S. Nei^hfs. / fv 'If rs- ? 7' ?• " ;l 1 ' 5- .' _- ''• ' ' ' ' , ' 5 ' ' ,T '' Z ^ . - -- /■ o o o 4o a a B M SB Sraoin DiUGftHMs. ^/a^n/r? i. /&rao8taf disf. 2 »*3 f .5 .r .73 3 10 II i£ 13 1+ 15 l« 17 .5 ♦ .J 5 s s •s 7 .s -8 •* 3 •^ ro .75 2. AS -S 'IS 3 .iS .s !ts 4 .-&5 .5 .75 5 //ofizonf-o/ i/''st = /fatyreen/zhf K els'- A « * fflwj&fe <^i/^;E. In obtaining the horizontal distance from Diagram 1, an arm is made one inch wide and about twenty-four inches long. It is graduated along the upper edge like the bottom line of the diagram and under the point is some reinforcement of heavy paper. A fipe needle is put through the point on the arm and on the lower line of the diagram. _An assistant calls off the angle and the arm is swung to it. The rod reading is called off and is read on the arm. At the point of intersection with a vertical line the eye 284 ENGINEERING WORK IN drops to the bottom and there the horizontal distance is at once read off. Such diagrams have a value that ordinary slide rules and computers do not have. The latter are graduated for a fixed relation of the stadia wire inter-fal to distance. It occasionally hap- pens that stadia wires (liXed^wires are the worst offenders) will change interval for some reason or other and instead of the ratio being 1:100 it may be 1:98 or 1:103 or some other ratio equally a nuisance to compute. The change in the interval is sometimes caused by the wax softening. This has happened to the writer several times until now he uses adjustable wires. The interval he tests three time's each day on measured lines. When the ratio changes (with fixed wires) it is only necessary to' ascertain the new ratio on a measured line and make an arm" to use for it instead of the arm that is regularly, graduated for the constant ratio of 1 :100. While on the subject of diagrams attention may be called to ■n«l^- Eng.News. the following figure illustrating a rapid method of assessing cost of work on frontage. This' the writer has used often for esti- mates. The cut is from one that appeared in Engineering News illustrating an article on the subject by the writer some years ago. MUNICIPAL SUBSURFACE CONSTRUCTION MAPS. Under the above title The Engineering Record of April 1, 1905, printed an article by Hubert S. Wynkoop, .Electrical Engi- neer, Bureau of Electricity and Gas, Brooklyn, N. Y.. with a plat which has been redrawn for this book in order that the details can be seen clearly. A reduction of the original cut would not have been clear. - TOWNS AND SMALL -CITIES. 285 He explains the map and gives the reasons why it is necessary to have such records. To engineers and contractors operating in towns aad cities fairly well supplied with modern conveniences his reasons are good. To men in small places where the work of tearing up streets may -be said to have hardly commenced his article would hardly appeal. Sometime in the history of every town the underground pipes, conduits, wires, drains, etc., become a great annoyance and expense. All for lack of a little care and forethought, or perhaps because of downright stinginess on the part of the first officials, who would not pay the cost of having maps made. , The writer in his contracting experience has many times been obliged to lower water pipes, etc., when putting in sewers, because no one knew when the plans were drawn, how deep the obstructions were in the ground. The writer, when making surveys for water- works and sewer systems, bores down where pipes, etc., are known to be and puts the information on the profile. If the location of the obstruction is not known, then of course no borings can be made to ascertain the depth, and digging trenches across at every corner is too expensive. The lack of definite knowledge often interrupts public work for long periods when obstructions are encountered and blocks the street until enough information can be obtained to permit the work to proceed. Or until the company owniiig the obstructions can be settled with. In many^ cities troubled with sewers backing up the trouble is found to be with pipes run through the sewers by work- men employed by gas or water companies, and even the city. . Mr. Wynkoop says : "Let no town deem itself too small to undertake such a work (i. e., having complete records prepared). Who can predict what degree of future greatness lies in store for the little town? As to these maps, I advocate then, for cities, large beginnings; for towns and villages, small beginnings; but for each city, town or village at least a beginning.'' Today a contractor desiring to open a Philadelphia roadway makes application for a permit, stating the character and extent of the proposed work and suggesting an approximate location. When the permit reaches him it is accompanied by a sketch drawn to scale and indicating the locations of existing construction as well as the definite location assigned for the proposed work. The 266 ENGINEERING WORK IN 'i k ^ , 1 •| ~%s - ^ •— .5T-- - \ ■■" *,!" ■6;z — 5 *" 1 ' 1 ds,^ "5 .p; and 30 and the points of reversed curve is 14° 51'. 360° : 14° 51' : : 628,32 : X therefore the length of the curved front of lot 30 from the corner to P. R. C. is 25.92 feet. 318 ENGINEERINO WORK IM To check : Curvefi front of lot 32.. 25.49~feet Curved front of lot 26 ' 51.58 feet Curved front of lot 30 25.92 feet Total length curve _ 102.99 feet Total included angle is 59°. 360° : 59° : : 628.32 : 102.97 (check). The lines drawn on the diagram indicate the method of pro- cedure for the next curve. Care must be taken to check all calculations by measurement on the map. In recording the map the dimensions of the lots as found are placed on it, and the radii of all curves drawn to an intersection, with the length of radius marked, together with central angle. It would be a great help to future engineers if all Lat. and Dep. measurements were tabulated on the map." ■ A. I / C = long chord, c = chord. ■;^D=defl. fore'. T = R tan Sin. D =-^ R = T cot -g- R = Sin. U E = R ex. sec.-^ Chord defl. = '^ R No. of c = -Tj- c I -g- tan— Tan. defl. = }i Sin. D =- chord defl. ch( The foregoing tells how the calculations are made for lot lines when curved roads are run in. The writer has never seen the subject taken up in text books, i To stake out the work the front line is run in after the lengths TOWNS AND SMALL CITIES. 319 of the side lines are calculated. Having the Lat. apd Dep. of each of the two corners on the street it is an easy matter to calculate the bearing and distance. Thus a crooked traverse line is run on each side of the street and the lot corners set in that way. For filling in, the accompanying formulas are used to get lengths, of chords, sub chord?, etc., and the lot corners being the B. C. and E. C of the curves bounding the lot a check is had on each. The writer uses chords of from five to ten feet in setting out the curves and the carpenter when building the fence drags a garden hos^ or large rope around them. He can then Set pegs as close together as he wishes. It will be nfaticed the exact curved length is "given. It is done because in future resurveys some men will use a longer chord length than others. To calculate the length of the angular front of a lot or bldck the writer generally uses a table of secants. The width of the lot is the base, the front is the hypotenuse. The difference in the bearing between the straight width and the slantHEront is the angle. Miiltiply the width by the secant of the angle to get slant front. To get the difference in the lengths of the side lines multiply the tangent of the angle hy the width. Given, the slant width of a lot and the angle at the base of the triangle imultiply by the sine of the angle to get the difference in the length of the side lines and multiply by the cosine to get the straight width across. " ' If the engineer has no table of secants he can use the follow- ing formula : 1 Secant= Cosine oi he can divide the straight width by the cosine of the angle to get the slant front, the hypotenuse. The writer has frequently made surveys of tracts of land by" the stadia method and laid out in several places base lines with stakes set one hundred feet apart, connecting his instrument sta- tions to these base lines by careful tape measurements. The base lines are generally measured on the slope as described earlier in this chapter. Very careful study is made of the most difficult parts of the tract and in some cases parts of roads are laid out on the ground at the time the topographical map is made. All the data having been 320 ENGINEERING WORK IN obtained the contour map is made and the subdivision platted on it, the lots, etc., being calculated as already described. The points on the base lines are connected to the lots and several parties can be set to work staking out the lots when necessary. Periodic discussions arise in engineering papers over curved roads, as much trouble is experienced in _ relocating them. All the trouble can be obviated if the man who does the original work is careful to give full notes. He should place on the map the in- formation already mentioned and in addition put on the center line of the road. This is best tabulated on the map outside the plat. He should give full notes for a traverse line consisting of the long chords of each curve and the chords of reverse curves With B. C. and E. C. and P. R. C. plainly designated. At distances closely approximating five hundred feet he should put in some form of monument. He can not err in putting down plenty of information. The tabulated information will have a column giving each sta- tion number and a column for the Lat. and Dep. respectively, of the point. Then the bearing and length of the line. Then three col- umns headed respectively, B. C, P. R. C. and E. C, and a column giving radius of curve and whether to the right or left. This, of course, for the center line. The Lat. and Dep. being on the lot corners, it is no trouble to calculate the bearing and distance to any lot corner from any point on the center line of the street. In one place where the, writer did considerable work the streets were all irregular and he had the Lat, and Dep. calculated for every corner in the place before he left. Until an engineer tries such a method he can not realize what a convenience it is. A useful survey was made with the stadia in a town laid out with irregular roads and where the original notes were lost. The maps on record contained no notes and the lots were simply numbered. Encroachments by fences were numerous. A tracing was made of the maps on file and enlarged to a scale of fifty feet to an inch. Then a stadia survey was made of fence lines and buildings and platted on the same scale. The trac- ing was found to fit on some individual blocks but did not fit as a whole so the adjustment of the street lines was made block by block. The stadia map was inked in and one block after another of the enlarged tracing was pricked through on it after as careful an adjustment of the lines as was possible. Some of the fences were TOWNS AND SMALL CITIES. 821 undoubtedly correct and others as surely wrong. Latitude and de- parture squares' having been ruled on the stadia map center lines were fixed as closely as possible and a set of notes computed. They were then run out on the ground. At each angle point measure- ments were made to each side of the street and the points shifted until they were fitted. Then an accurate taped survey was made of these adjusted points and a map made and adopted as official. It took time and patience and when finished was perhaps as nearly correct as such a survey, made after so many years, could be when few original fences were left. Many of the stakes in existence were claimed to have been changed by interested property owners as the man who made the map simply put down the widths of the roads and numbered the lots and blocks. The original map, how- ever, was carefully made to scale. A transit used for stadia surveying should have a horizontal circle graduated from to 360, preferably to the right (in the direction the hands of a clock move) so that 90 represents East; 180, South; 370, West. Occasionally the O represents South, 90 West, etc., but the principle remains the same. It is convenient if the compass circle is graduated to correspond, for the needle then checks the vernier reading. Set the instrument on a carefully referenced point and set vernier "A" (the vernier at the eye end of the telescope), at O. Let the needle swing and move the whole instrument until the needle also indicates O. Then clamp. Unclamp the upper plate and direct the telescope to some point as a foresight and begin taking the sights. In the book put down "Set up on Sta. O," and , write a description, all on the left hand page. On the right hand page it is advisable to have a series of concentric circles spaced about ten to the inch, the center of the circles representing the sta- tion. Graduations to single degrees can be marked on the outer circle. This is very handy for sketches and when such a book is used it is good policy to use one page for each station. Sketching is not necessary but is a wonderful help when there are many fences, buildings, etc., to be noticed. The writer for some years used "positive" blue prints on thin paper for this purpose and car- ried a bunch to the field with him, pasting one in each page of fiis field book. Lately, however, a field book for such work has been made and is sold by Engineering News. 322 ENGINEERING WORK IN The columns on the left hand page are as follows: Horizontal angle (from zero). Vertical angle (plus or minus). Rod reading. Needle reading about every fifth and sixth shot. The above are filled in the field and the sketches made. The latter are filled in the office. Magnetic bearing (calculated). Total elevation above datum. Horizontal distance. The manner of calculating distances and elevations has been described in a previous chapter. In platting, a large paper protractor is used with the center cut out. The writer draws two fine lead pencil lines on the map through the initial point and lays the protractor down so that they intersect the four ninety degree points on the protractor. The upper edge of the protractor is pinned to the board. A piece of paper is glued to the O point on a scale and a fine needle put through it and inserted in the sheet at the station. The scale can thus be swung around in a circle. If the protractor is graduated from to 360 the angle readings in the field are used. If it is graduated into quadrants then the calculated magnetic bearings are used. • First the bearing is called off and the scale swung to it. Then the horizontal distance is called off and platted. Next the total elevation above datum is marked at the point. After all the shots from that station are platted the protractor is shifted to the next. In working in the field a reading is taken to a new station and carefully read. Vernier "B" is also read when the station reading is made. The last entry at the old station is the one to the "forward station. The instrument is carried to the forward station, vernier "A" is set at the reading found for vernier "B" at the station just left and the backsight taken. The rod reading should be the same as the forward reading but the sign of the vertical angle will be different. If the reading does not agree calculate what the difference will amount to and act as seems best. Ustjally there will be a slight difference and a mean of the' two readings will give an accuracy that will be as close as one requires for such work. The first entry at the new station is the check reading to the old. The telescope is not reversed as the above description shows. TOWNS AND SMALL CITIES. 323 In shifting the protractor on the map the procedure imitates closely the field method. Through each station point two lines are drawn at right angles and the protractor fitted to them. Sometimes it is well within the limits of accuracy to plot station points as side shots are plotted. Generally it is best to make a traverse survey set of notes of the stations polygon and plat it by latitudes and departures. Errors will then be confined to each station point and will not be cumulative. If that is not done it is well to plat the stations polygon in any convenient way before plotting the side shots. If errors have crept in on the lines tfiey can be adjusted before a lot of work has been done. When carefully done the limit of error will be well within the limits of plotting. An error of 1 : 900 is not particularly good work in running the polygon. It should be nearer 1 : 1500 or 1 : 2000 and can be readily attained without much loss of time. As wire intervals sometimes change a steel tape should be carried and once in a while a line should be measured with the tape and checked with the stadia rod. If the wires are adjustable then adjust them. If they are fixed wires, merely make a note of the new interval and remember it when making the calculations in the office. An engineer in private practice does not need an umbrella, a recorder, an observer, etc He can do all the work himself with one or two active intelligent rodmen, using a self reading leveling rod or a specially made stadia rod. Several firms in the United States make good patterns of stadia rods on wood and some make them- on a tough oiled painted paper to be glued on a board. A few make them on canvas to be tacked on a board. The writer has used several such rods of different patterns and they were all good. Generally he uses one of his own pattern as illustrated. It is made from ten to fifteen feet long in sections with hinges, on the back so it folds into short lengths. On each side is a common door bolt at each joint to hold it straight when extended. A line is scribed down the back from top to bottom and a point is marked on the back at the bottom to show the rodman when it is- on a point. There is a nail here to protect the foot. The rodtiran either carries a rod level to insure the verticality of the rod or has a small plumb bob hung on the back. He stands directly behind a24 ENGINEERING WORK IN the rod and is careful not to permit his hands to obscure a sight of any part of the rod. When the instrument man sets up his instrument he measures the height from the ground to the telescope axis and directs the Each device repre- sents one-tenth of a foot. Even tenths on right. Odd tenths on left. No figures. Horizontal ruling represents black. Di- agonal ruling, red. Red diamond at half foot mark. Black numbers, one-tenth high, at each even foot Red numbers, one- tenth high, at each odd foot. Numbers are in space opposite device. With this rod the nearest foot can be read on short sights and closely estimated on others. Every reading is made on a corner as well as on a point which is advantageous at different hours of the day. STADIA ROD. middle cross wire to that height on the rod for each sight. He reads, however, only the upper and lower stadia wires. For work requiring long sights and great accuracy is not required, an ordinary level rod- can be used and held upside down by the rodman. The TOWNS AND SMALL CITIES. 325- upper wire is then directed to the top of the rod and the lo*er wire gives the direct rod reading without any figuring, mental or otherwise. It takes very little practice to become proficient in reading an inverted rod. A specific use for the stadia is when a city council wishes grades recommended on certain streets and the time is limited. A stadia survey can be made in a very short time and a profile platted from the contour map sufficiently accurate for the in- , tended purpose. The writer has often done this. The stadia offers an excellent means of surveying a tract of land for grading estimates. This, however, is treated in text books on surveying. With a good transit in good adjustment having a well divided vertical arc, elevations can be taken that check wonderfully close with a level. The writer at first triangulated a tract of land he proposed surveying by the stadia method and determined his instrument points, or at least enough for control. He no longer does this except on a very extensive survey. He also ran levels with a wye or dumpy level and established benches and turning poihts. He seldom does this any more, for the angular elevations check so well that the time might as well be saved. If his elevations do not close reasonably when his work is completed he will go out with a level and get the exact elevations on the stations and use them, thus confining his errors to each station. In calculating his elevations in the office he first carries them through -from station to station and checks on the starting point, where the field work of course closes. Any error within allowable limits is then distributed over the Nations in proportion to the lengths between them and these corrected elevations used in computing the side shots. GENERAL NOTES. No city engineer should be content with a limit of error in measuring, exceeding 1 : 5000, practically one foot in a mile. That is really too great, for good work done should approximate 1 : 10,000. For long lines the writer prefers to measure on the slope to tack heads so that the tape is thus supported its entire length. This eliminates the error due to sag and miscalculation 326 ENGINEERING WORK IN as to level of tape. Erfors may creep in when calculating but care must be taken to guard against them. • There are a number of formulas for correction of sag, etc. If an engineer wishes to apply them he can do so but it is easy to remember that the correction of sag in an ordinary tape is practi- cally equal to 0.25 of an inch times the length measured in feet. Subtract this from the measurement, for the correction due to sag on an ordinary 100-foot tape is 0.25 of an inch. If no correction is made for sag the tape will be short and consequently the dis- tance recorded will be greater than the true distance. The expansion per unit of length for one degree rise in tem- perature or the contraction of one degree fall in temperature is 0.000006. The standard temperature is 60°. The difference 4n temperature between the standard and that at which the measure- ment is made, multiplied by the length in feet times 0.000006 gives the correction for temperature. The normal pull on a tape at which the most uniform results will be obtained varies from ten pounds for fifty feet length to sixteen pounds for one hundred feet. It is a good idea to write the maker when a new tape is purchased and obtain all the infor- mation he will give in regard to normal tension, etc., for the tape. A discussion last year in Engineering News developed the fact that there are several ways of doing simple things. An inquirer asked for the best method of surveying a street for the purpose of locating accurately the buildings on each side. One method recommended was to run a line approximately down the center of the street and set transit points 800 feet apart. Each point is occupied in succession and with a 100-foot tape as many corners as possible are measured to, the angles to the points being taken at the same time with the transit. For wide streets with the houses set far back, each corner is located by angles (without taping), from at least two transit points. This approximates the plane table method. As houses are built with square corners a sketch is made of each ground plan and all the measurements taken. The two front corners are plotted from the „ survey and the buildings drawn in from the measurements on the sketches. Another method was to measure a base line on one side of the street close to the fence and set stations 100 feet apart. Set the TOWNS AND SMALL CITIES. 327 transit on each and turn a right angle across the street and measure across to set a base line on that side. The stations are all num- bered. After completing the transit work measure on each base line, marking the plus for each fence corner and opposite each house corner. Measure from the plus the right angle distance to the house corner. Record this in the form of a fraction in white chalk on each object, the numerator being the plus and the de- nominator being the right angle distance from the base line. The engineer follows the men making the measurements and makes his sketches and such other measurments as are necessary. In this method no diagonal measurements are made. A third method was similar to the first, but two base lines were run. One was in front to get all the front fences and corners of buildings and the other in the rear of the lots to get the back corners. In the course of his experience in city work the writer has had to make a number of such surveys. Sometimes it was while in the employ of other men and acting under their instructions. He has therefore used each of the above methods and his preference is for the first. He considers it the neatest and most expeditious, both in field and office. If the nearest foot is close enough (and it generally is), a stadia survey will do the work with the fewest men and in the short- est time. More data is apt to be collected also, for the method is so simple and easy. ' CHAPTER XVII. ENGINEERING DATA. "A little steeling maketh the whole concrete kin." In this chapter the writer proposes to place a lot of odds and ends of material that he trusts will be of value. He will appreciate very much all assistance his readers will give in the future to make the chapters on Office Work, Field Work and Engineering Data more valuable in later editions. Copies of special reports, good ordi- nances, forms of procedure, plats, formulas, etc., are especially wanted. Their receipt will be acknowledged and due credit given if used. STREET WORK. All grade ordinances should definitely fix the points where the elevations are established. The engineer is supposed to prepare all such matter carefully in his office before writing the ordinance. The writer thinks it best to have a vertical, curve connect all changes of grade where they occur between intersecting streets. This will avoid the appearance of a break. He usually plots his grade line on a large scale and. connects the inclinations with a parabola. Fig. 1 is from Baker's Roads and Pavements. Professor Baker recommends that there should be from 10 to 15 feet of curve for each foot of change in elevation in one hundred feet. Fig. 3 shows a method of calculating a parabola. It is used in forming a diagram for the cross section of a pavement between curbs. Another method for describing the parabola is shown in Fig. 3. Divide the distance between the ends of the curve into any number of parts and place the numbers at the points as shown, commencing at each end. Multiply the two numbers at each point together. TOWNS AND SMALL CITIES. The P/f/rffBOL/r ,^^'r Verheo/ curve .-"'i '"^ 329 EUy.A =. ^=/l£ Rg.t AC -, Hivide. ho/f v/i^f/i o/ roae/way /t?to n ports. ~f'^ ~ Hl'sfnnce e/ov^n /b surfyce /ro/n //he AB = X af- / =2^JcatZ or4-X. = 3*0: eif3 orSx, -a — — - — ~ ^ 1 10 i 2 ».-•■; e ^ ' 5 ■ t i ' 4 V ' ■ i 3 > - J 330 ENGINEERING WORK IN Divide the total rise by the product of the two numbers at the middle point. Multiply the result successively by the products of the numbers at the other points. The results give the ordinates of the parabola. This method is also good for constructing a parabola for any purpose, such as finding the bending moments in beams uniformly loaded, the flow of a jet of water, etc. It is a good plan in preparing the -grade ordinance to first plot the profile with the proposed grades; fix the vertical curve and take the elevations from the profile at intervals varying from fifteen to twenty-five feet and describe each in the ordinance. When the curb is put in there will be no breaks, for the, slight angular point at each change can be adjusted on slight curves extending a few inches each way. Some care taken in the office work is well repaid. - Figs. 4 and 5 illustrate exaggerated diagrams given to con- tractors at a time the streets are improved. The curbs are sup- posed to be set first. With the use of boning rods the foreman can then fix the curve of the cross section exactly and the engineer does not have to be always on hand to give stakes. The rods are simple in construction and use. Take a common lath three or four feet long and nail it to a piece of board about four inches wide and six inches long. Wrap a piece of white paper around the top of the lath. Set the base piece on top of the curb on one side of the street and place on it a brick or stone to hold it in place. Another lath of exactly the same length is held on the opposite curb to sight over. The third lath is divided into feet and inches and usually has a movable sight on it. Such a sight may be a piece of paper tied on so it can be moved up or down readily. The cheap yard sticks given away. by stores are useful for the purpose instead of graduating a lath. This rod is held so the graduations read from the top down. The fixed rod is placed on one curb and the foreman takes his rod to the other and holds one end of a tape. An assistant takes the graduated rod and the other end of the tape and measures each distance successively as called off. When a distance is measured the movable sight is set the proper distance down and the rod held on a stake. This stake is driven until the foreman sighting over the target can see the top of the opposite stake. In this way points can be set every ten feet, more or less, along the line of the street after the curbs are seL The diagram is TOWNS AND SMALL CITIES. 331 usually given on a piece of cross section or profile paper and the foreman can read the distance down at any desired distance frorii Si^hf/'ftff //he. /hree feet above curS. If ^ 24'0" J i»- Tier ^Ti'd" 1>^-3'o"-i^Si3l'-^V(f^)f-Vo'-i^%'li'-tf-Vcf-i^ Maaraiim /fi Mtee /oyere. QuHers J'o"»v/i/e. '3"efeep. F/ff.S 6.e -'2r'c 3^ *^^ «.e &A I I ' 6 e I 23ea/'gn ofc/vas seaf-zof? of o sfreef" Aar/h^ curds af"] eft'fferent e/eyaHor?$. Moke //h7i'f- o-f s/ope. foranyporf'/'on of /Ae Cross se^f/bn, /0Ji Vtde //o//or>^ lyjieefer m Snj.^etvs. the curb. He does not therefore have to measure to the points marked if there is anything to prevent it. He can set stakes as close together as he wishes, 332 ENGINEERING WORK IN Common custom approves of the parabola as the best form for the cross section of a street. It is easy to put in for one thing. In some places instead of using the boning rods the engineer sets a stake the height of the crown. At half the distance to the curb set a stake with its top one-fourth the height below the crown. That is half -way between the gutter and the crown the height is three- fourths the crown. Some engineers prefer two flat slopes from crown to gutter with a slight rounding at the intersection. Some prefer a segment of a circle. It is almost entirely a matter of taste, although the writer believes the parabola is best. In an earlier chapter some rules were given for crown heights. Custom varies. In Boston, for macadam the rise is one-half- inch per foot in width. For granite block, three-eighths of an inch. For asphalt or brick, five-sixteenths of an inch. In New York for asphalt, one-quarter of an inch and for brick or granite, three- eighths of an inch. In Chicago a minimum of two per cent and a maximum of five per cent of half width for asphalt, brick or granite. For macadam a minimum of foiir per cent and a maximum of eight per cent of the half width. In Omaha the custom is to decrease the crown as the longi- tudinal slope increases. This is sensible and is now used in other places. The following formula for the crown of asphalt paved streets was originated by Andrew Rosewater, city engineer of Omaha : C = W (100— 4p) ^ 5,000, where C = crown of pavement in feet. W = distance between curbs in feet. p ;= %' of longitudinal grade. The crown for brick, wood or stone is five-sixths of the Crown for asphalt, as such materials are not harmed by water standing on them. The above formula is for a level cross section. Reference has been made to winding roadways on extremely steep streets. To study such a problem, make a contour map of the street on a scale of forty or fifty feet to an inch. For turning space at each side there should be about twenty feet. Draw on each side a line parallel with the side lines and twenty feet distant from them. Draw a series of equilateral triangles between these twenty- foot lines. The sides of the triangles crossing the street indicate closely where the roadway may be located. The roadway should TOWNS AND SMALL CITIES. 383 be sixteen, feet wide and the lines of the triangles cross it. That is, at the bottom the point of the triangle will be on the down hill side of the road. It will cross the roadway diagonally until at the other side of the street it will be on the up-hill side. Draw in the lines of the roadway in this way and when the twenty-foot strip is reached, carry, the roadway lines across it at a right angle with the side of the street. This wiil then give plenty of space for a turn. Along the center line of the roadway as laid out thus, make a profile and then fix the grade, giving not to exceed three per cent on the turn. It is best to make it level. If there is a grade on the turn, make it on a curve with a radius of sixteen feet. If the steep street is winding around a hill side instead of going straight up, the above procedure must be modified to suit condi- tions. The foregoing is only a suggestion, for every case demands special treatment. Page after page of formulas can be given treating of intersec- tion elevations. Few of them are worth bothering with. Therfi will be slight necessity for any if the elevations are fixed at the side lines instead of on the center lines of streets. In a preceding chapter the treatment of intersections approached by streets with steep grades has been discussed. The writer has often employed with benefit, models to illus- trate his ideas to property owners and councilmen. A model of a hill-side street, showing the appearance before improvement (which every one will recognize), side by side with one showing the com- pleted work, will 'sometimes advance proceedings several months and avoid many headaches and discussions. The most simple way to make such a model is to transfer con- tours to pieces of board and saw the pieces with a scroll saw,^ to the shape indicated by the contour. The pieces are nailed together and present the appearance of steps. The steps can be filled with wax or cement or putty and given a smooth surface. A plaster-of- paris mold is taken of it and can be used as a mold for the con- struction of a light model of papier mache. Sometimes the original is colored and fixed up, but it is heavy. Sometimes cross sections are made of light wood and pieces of cardboard fastened to them and the whole frame covered with paper which is colored. Such a model is light, but fragile. The minimum grade in gutters should be about six inches in one hundred feet or what is called a five-tenths grade. 334 ENGINEERING WORK IN On streets level, or nearly kvel, the following formula is used for putting in summits : = (i) - i&) where x = distance of summit from higher inlet L = distance between inlets. R = grade of gutter (per cent). D ^= difference in elevation of inlets. A graphical method is often used in the office. ' Make two scales having the same number of divisions per inch as the scale of the map, but figured according to the per cent of grade instead of feet in distance. One scale begins at the right end with the elevation of the inlet at that end of the block. The other scale begins at the left end with the elevation of the inlet at that end. The scales are then numbered to correspond to the rise or fall. One scale is marked on the top edge of the strip and the other on the lower edge. Place the scales on the map with the gradu- ated edges touching and with the ends placed at the inlets having corresponding elevations. It will be seen that at some point be- tween the inlets the elevations on the scales correspond. This is the point where the summit should be placed, and the elevation of the summit is read off the two scales. It is not necessary to make new scales for each block. Two can be made on bristol board and the figures placed on them lightly with lead pencil when required. * In a long block two summits are occasionally required when it is impossible to get a grade as good as five-tenths per cent with one summit. This will call then for an inlet near the middle of the block and the elevation and position can be calculated by the formula or fixed graphically. An experienced engineer can locate a summit with a glance at a contour map or profile. In an earlier chapter the subject of tarred and oiled roads was discussed. Since that chapter was put in type more information has become available. The Bureau of Road Inquiry, Washington, D. C, has experimented in some Southern cities with tar. The results so far as cost and satisfaction go, have met expectations. A full account with data has been published in an interesting bulletin dis- tributed free to all inquirers. TOWNS AND SMALL CITIES. 335 DRAINAGE AND SEWERAGE. The following table is taken from the catalogue of a sewer-pipe company and is so common a feature in such publications that it can hardly be new to the readers of this book. The formula used in calculating it is an old and simple one, no longer used except for tile drainage and second quality sewer pipe used for drainage purposes. The table gives fairly reliable results, however, and is useful for pipe culverts. CABRTma CAFACITY--GALLONS PEB UIITUTE. I in. 2 in 3 in. 6 in. Q in. I foot 2 feet 3 feet SIZB OF fall fall fall fall fall fall fall fall ' Pipe. P*i P*^ P'^iL ^l. per per per per icon. 100 ft. 100 ft. 100 ft. loaft. 100 ft. 100 ft. 100 ft. 3 inch. 9 12 IS 22 27 31 44 54 4 " 20 28 35 SO 62 7> 101 124 6 " 63 89 III 156 194 224 317 389 8 " 140 198 246 348 432 499 706 864 9 !! 196 277 339 480 595 687 971 1180 lO " 261 369 457 648 803 928 1310 1610 12 " 432 612 758 1070 1330 1530 2170 2660 '5 !! 800 1130 1400 1980 2450 2830 4010 4910 i8 " 1320 i860 2310 3260 4040 4660 6590 8080 20 " 1720 2500 3060 4330 5305 6130 8660 106 10 24 " 2910 4IIO 5035 7I9I 8810 10270 14520 17790 '7 !! 4020 5680 6960 9840 12050 13920 19680 24 no 3° 5380 7618 9320 13180 16 140 18640 26350 32280 33 6950 9840 12050 17040 20865 24090 34070 41730 36 " 8800 12450 15210 21563 26410 30500 43130 52820 The standard formula is the Chezy formula. V = c i(Ts where V = velocity in feet per second. c is a co-efficient found by means of Kutters' formula. r is the hydraulic mean radius found by dividing the area of the water (cross section) by the wetted perimeter. s is the fall in feet divided by the length in feet. Old hydraulicians tried to secure a simple formula which would be generally applicable. It was found that there was a fairly . con- stant relation sxisting between slope, area and velocity, for watei ENGINEERING WORK IN is inclined to run down hill and the law of its flow is known. Friction modified the flow so the area of the stream was a factor /^t --y^fs-^. This ^ives wid//> /vr any ^iven difference in /eve/ vrh/ch j'&t will Just pass over wit/i head (/?) . //" there IS a ve/ocity of approach fh) must inc/ude the head necessary fo yive tha/ ve/ocity, which is (^) , if y is the ve/oci'ty of approach /n feet per second. In order to describe the pafh of the Jet Set off a 6 verti- co/iy =-k^ on any sca/e,Or>d 6 c horizontally =-gV9h di'u'de ad and dc into any egua/ numier of e^ua/ parts , jo/n a with the div/s/ons on dc,ond ver/ico/s through tie divisions on o'6. The intersections of these lines will f/ve the pareu- bo/ic path of the underside of the jet. from Co/ A^oore's Sanitary Engineering. TOWNS AND SMALL CITIES. 347 .3 S a. •s •-v ^^ u O si ^1 00; S X **• .3 'I X g a a - S- O fl) ta O •I .S § Q- ° s u § Id J1 o 1. •a 4> >• » be s ^ Bj (0 •c n » n S o ^CDlACDeOCDcDcDt- iH "H 1-1 i-H N ej CO CO oo N to 00 e4 a> to.e4 tx 00 •-■ « 00 cQ tk t-ooo>i-ie4eotot-ooa>OiHeo^iQt-co o o O i-l iH It rH tH iH r-l eoorHe4'<^;Doooe<$u3aoi-i< ■* ^ us 0>a>a»>-i«oO'4* ej a r- lo eg © CO us eg. i-j 00 «o 3 eg <2 K !9 i--05ejuSQOrHcopeoor-ous^coe400>oDf-*usio»«— ooosOrHejeneO'^iotoi^oo ^o«oejt-om«ei-ooooi-50'*eiooT«0525t-o i-ia>o;ou3a3cot-e3i-i^i-ioir-«oaoususoc]OF-i CO Ti* fvO) eiusoseoodcoodTHOcocodoocousmco i-i>Hi-ie4evicoeo^ususcot-t-oo03piH i| ;-g :-S :-S :-S • V : a : a eqe«ieise»5'*i^>oio«o«o«-t-ooooo5o>ooi-irH e-o ea r- CO oasK A iM o -^ o CO N r-, N 00 eg OS tk a> ^ OOOOOOOOOi— (rH*--3t-eiit-eoooTj McoTjt-;r'Ooa>a>OTHrHe?5C000000»W5rHO'*OQ0iafl»»O iHi-ii-((Meoo>-iNto r-ooo»-(cocDt-Oii-(e3cocot^osiHeoiftOi-*Oa^in«Dl^Q0 05i-(C0 iHi-iiHi-TirHeaMoae^eaeiNNCiimeomcocoeonsm^ cO'^a>05*ira«Dr-o6oJOi-!eiTin»co 04 tk CO 00 o'lM '<« CO 00 o eq tk CO oa 001 ^ o 00 o 01 Td CO •-< M iH iH ^ 64 e!m 04 CO n CO n CO « ^ ^ V ^ U3 lo la va TOWNS AND SMALL CITIES. Hit 111! 349 ■8 1 J S '1 s '5j?ssr8.ss.&ss2'aa II 1 1 CO *o 11 i! ••i-s 1 r ■-■MMMMnrJMioiqmmii- n o 66l1HMM«NC«NNC(f« eo SS*?'a!5'^s'^s&S!:; « OOo'oOmmmhmhmm ^ odoboo'oodoHHH ■^ s i 1 i : 1 : : : i : iiiiiiiiiiiii yi :r X iR y; x u u u u o o^ g U U fJ u u u H o a a a !SS V t/ V V tl V Ih tM • iiyii jai3j3AAja •^•riO'Ooo c ESTIMATES FOR SEWER WORK. The cost of hand digging in ordinary earth with labor at 15 cents per hour and foreman at 25 cents per hour is practically 20 cents per cubic yard for a trench six feet deep; 25 cents for eight feet; 30 cents for ten to twelve feet; 35 cents for fourteen feet; 40 cents for sixteen to eighteen feet; 45 cents for twenty feet deep. The above figures are actual cost without profit being added. Back filling will be additional and depends upon the method adopted for doing it. A team with driver, and man to assist holding the scraper, should scrape in about fifty yards in ten hours, Of easy 350 ENGINEERING WORK IH ; .oddd ^ UJPJOc «i;^ cocr>o - 1 1 % c5 ^^ giddo t % ine\J^-cJ ^■o'dd "e.^ ^-^. dodo to pood 5 pddd •^-<: e ^666 00 ^>. ■~ — — CJ ^ddd "% ^p'bdd ^1 ^^ =±t-S ^ddd ^1 O CNl Irt 00 d 0' d d !j ( ;^' U (010)0 1 1 1 J^P»t CM ^'% '"iZ'^ (Ti -: <" % °2S 00 ^ ^ 600 ■ ^ ^ — (M — ^% ul M odo ^ 5 in lom H (O IT) pdd CO ^ 000 CD (D *-% 0' dd o'^s OO 'OOO — ■ CM — •^^, cvi to rO do 6 1 - r : DOM© 1 t % "U , ^ to TOWNS AND SMALL CITIES. SSI material. Men with shovels and picks should backfill about teif yards each. On the same basis the excavation alone in tough clay will be practically 30 cents per cubic yard for six-foot trenches; 37 cents for eight feet; 45 cents for ten to twelve feet; 53 cents for four- teen feet; 60 cents for sixteen to eighteen feet; and 67 cents for twenty feet deep. , Hard pan, 50 cents per cubic yard for six-foot trench; 62 cents for eight feet; 75 cents for ten to twelve feet; 87 cents for fourteen feet; $1.00 for sixteen to eighteen feet; $1.12 for twenty feet deep. In estimating sewer work add to the above the cost per foot of pipe; one cent per inch of diameter for hauling, laying, cement, etc.; 25 per cent profit on the labor items and 15 per cent profit on the cost of material and laying. .Add the cost of backfilling at about 15 cents per cubic yard. The tables of comparative cost of tile and brick sewers are taken from the catalogue of the Blackmer & Post Co., and are said to be based on the following prices, with favorable conditions of soil and weather. Tile. — Labor 22^ cents per hour. ' Pipe layers, 30 cents per 'hour. Cement, 80 cents per barrel. Sand $3.00 per yard. Mortar for pipe, 1 cement, 1 sand. Brick. — Labor, 22J^ cents per hour. Brick, $6.00 per M. Bricklayers, 35 cents per hour. Hod carriers, 30 cents per hour. Mortar men, 28 cents per hour. Mortar for brick work, 1 cement, 3 sand. Prices today for such work would be more nearly as follow^: Laborers, 25 cents; mortar men, 30 cents; hod carriers, 35 cents; pipe layers, 35 cents ; bricklayers, $1.00 per hour. Sand and cement according to locality. Brick from $9.00 to $18.00 per M. A good mason will lay from three to four thousand brick per day. The accompanying tables of quantities of brick and mortar for round and egg-shaped sewers are believed to be correct : WATER TIGHT MORTAR. When laying pipe in a ditch having a flow of water it is cus- tomary to partly fill the joint with jute soaked in neat cement grout and fill the joint with a tnortar of 1 to 1 cement and sand. Over the joint when filled wrap a strip of cloth like a bandage to 352 ENGINEERING WORK IN keep the water frbm washing out the cement before it is set. The admixture of a very small amount of plaster of Paris is ad- vised by some, but the writer does not recommend it. A better way is to mix pine tar and cement to the consistency of putty and ram into the socket with a caulking tool. The work must be done rapidly and the paste must not be allowed to get mealy. The pine tar can be washed off the hands with kerosene. The following recipe for a water-resisting mortar was given in Cement, July, 1904 : In 2 lbs of water dissolve J4 lb. of salt ; add 1 lb. of potash lye ; heat to from 85 to 100 degrees F. ; mix 2 to 3 parts of cement to 1 part of sand; moisten with the. salty potash mixture while warm and apply the paste immediately, for it sets in less than one minute. Or some powdered wood charcoal can be mixed with the sand an 9» "5 141 70 27 41 58 78 100 '25 IS 80 90 lOO 110 12s 150 »7S 200 iA 21 62 83 107 >33 i(>3 196 »3l 363 505 27 30 «.I3 »4< »73 20S 245 330 427 792 lf> 183 1 p 83s 995 1 163 '344 '537 39 4> 48 54 60 III 472 593 728 876 ioj8 1214 1415 1616 503 ^'76 934 1107 1294 1496 1720 ''I 428 849 1023 1212 1418 "639 1876 2290 2827 341 459 594 748 918 1105 1310 «53' 1770 2027 2470 3049 354 tVs' 66 ' '4 1181 ,1 1637 1893 2167 2637 325s 120 '.... Reduction of Chimney Draft by Long Flues Total length of flues in feet. . 50 100 200 400 600 800 1000 2000 Chimney draft in per cent 100 93 79 65 58 5* 48 35 Examples. — 1. Given a head of 100 feet in five miles, required the discharge for various diameters of pipe. The head per 1,000 feet is here 3.78 feet. Following down the space in which this value occurs, we find that a 48-inch _pipe will give 109 cubic feet per second (read on the right) or 70,000,000 gallons per day (read on left). So, also, pipes of 36 inches, 24 inches, 16 inches, 8 inches diameter will discharge, respectively, 51, 17, 5.8, 0.91 cubic feet per second, or 33,000,000, 11,000,000, 3,750,000, 590,000 gallons per day. 2. Given a discharge of 10,000,000 gallons per day^ required the necessary head for different diameters of pipe. Following TOWNS AND SMALL CITIES. 357 horizontally along the line for which this dis.charge is marked at the left of the diagram, we find that a 36-inch pipe with" a head of 0.43 feet per 1,000 feet will answer. Also pipes of diameters 30 inches and 24 inches will give the required discharge if the heads be, respectively, 1.02 and 3.2 feet per 1,000 feet. 3. It is desired to limit the velocity in a cast-iron pipe line supplying power to 2.5 feet per second. The quantify of water required is 12 cubic feet per second. What size of pipe is neces- sary and what loss of head is involved? Noting the intersection of the line for 2.5 feet per second velocity with the ■ horizontal line for 12 cubic feet per second, we see that a. 30-inch pipe losing a head of 0.66 feet per 1,000 feet will answer the requirements. In the chapter on water supply a table is given of water pressures as reduced by hose. The following table is of the same nature, but deals with single and siamesed connections, such as are used in buildings for fire protection : TABLE OF REQUIRED HYDR.\NT PRESSURES (POUNDS). Hose diameter. 2%" 3" 3%" Hose lines, Single siamesed Single Slameaed Single Siamesed Smooth bore nozzle, 1 Vi" 2" IVi" 2" 1%" 2" Length of hose line 100' 121 139 92 101 84.5 88 150' 139 170 99.5 113 87.5 93.5 200' 158 201 107 125 91. 99. " 250' 176.5 232 114.5 137 94.5 104.5 300' 195 263 122 149 98 110 " • 400' 232 325 137 173 105- 121 Note. — From data derived from experiments by John R. Freeman (Transactions American Societv of CSvil Engineers, No^•em■ ber, 1899) ■The loss ot pressure in the 3-inch and 3V4-iuch hose probably represents unusually good conditions, and in practice may somewhat exceed the above Rgures. Not included in the, above are losses not exceeding 5 lbs. incurred in a Siamese connection. The table of Fire Stream Data is intended to be used in con- nection with calculations for heights of towers when such a system of supply is contemplated. The • other tables here presented may be useful in connection with water works design or extension. With a joint about 2J^ inches deep the weight of lead per running foot is equal to about one-sixth of the J diameter of the pipe in inches. If a 4-inch joint is used, the weight of the lead per running foot is equal to about one-fourth of the diameter in inches. 358 ENGINEERING WORK IN Kre Stream Data for 1-Inch Smooth Nozzle This Table also Serves for 1^-Inch Ring Nozzle . Height of Tower required to maintain Fire v Fire Jet Streams as shown in columns 3 and 3 through all ll =5S 2^-inch Rubber Hose Lines mentioned l|l Height Reach SO xoo SCO 300 409 500 Feet Feet Feet Feet Feet Feet Feet Feet 25 43 42 •47 67 V 82 94 106 "7 30 5< 47 161 77 84 99 "3 126 140 35 18 5> «74 92 102 "7 131 '47 ib3 40 64 55 186 106 "5 '33 '5' 16S 186 4S 69 58 198 119 129 149 'U 191 209 SO 73 61 2og >3i 142 •bS 1 88 211 234 55 76 64 2lS •45 .,8. 181 207 232 »57 60 79 67 228 iss 172 200 226 253 280 65 82 70 237 172 186 216 246 273 303 70 S' 72 245 184 200 232 264 294 327 75 87 74 255 197 2l6 248 282 3'7 349 80 89 7b 26j 211 230 264 300 338 372 8S , 9» 78 274 226 243 382 3 '9 338 359 398 90 92 80 279 «37 257 298 379 420 95 94 82 287 250 271 3«4 359 400 444 100 96 83 295. 264 287 33' 377 420 467 Fire Stream Data for 1^-Inch Smooth Nozzle Height of Tower required to maintain Fire _, u >;_. S Streams as shown in columns 2 and 3 through 2^-ineh Rubber Hose Lines -mentioned sill ll '0^. Height Reach 50 xoo 200 300 400 &°t Feet Feet Feet Feet Feet Feet Feet 25 44 44 188 - 72 80 100 119 237 '5^ 30 5» 50 206 86 q6 121 142 ibS 186 35 59 54 222' 100 112 140 'bS 190 218 40 6S 59 238 116 128 161 188 218 248 ■45 70 63 252 130 144 180 204 246 278 50 71! 66 265 J 44 160 201 227 274 310 55 ■80 69 279 .58 176 222 250 302 340 60 81 72 291 X72 192 241 273 327 370 6s 86 7'i 303 188 208 262 296 3S5 402 70 88 77 314 202 224 281 322 383 432 75 90 79 32s 216 240 302 345 4" 464 So 92 81 336 230 256 323 368 436 494 85 94 81 346 246 272 342 391 464 524 90 96 85 356, 260 288 =•5-1 414 492 nt 95 98 87 366 274 304 382 439 52? 58b 100 99 89 376 288 320 403 462 548 608 TOWNS AND SMALL CITIES. 369 Friction of Water in Pipes Friction losd in pounds pressure per square inch for each 100 feet of length in different size clean iron pipe, discharging given quantities of water per minute. GnlloTiB Size of Pipe— Inside Diameter. Hmute lin. IHin. 2 in. 2>^in. 3 in. 4 in. 5 in. 6 in. 8 in. 10 in. 12 in. 5 0.84 0.12 0.03 10 3.16 0.47 0.12 0.03 15 6.98 0.97 O.W o.oa 20 12.3 1.66 0.42 0.13 0.03 S5 19.0 2.62 0.67 0.21 0.10 SO 27.5 8.75 0.91 0.30 o;i2 0.03 85 37.0 5.05 1.26 0.42 0.14 0.05 40 48.0 6.52 8.15 1.60 0.51 0.17 ^ 45 2.01 0.63 0.27 0.07 60 10.0 2.44 0.81 0.35 0.09 0.03 75 22.4 6.32 1.80 0.74 0.21 0.06 0.03 100 39.0 9.46 3.20 1.31 0.33 0.12 0.05 125 14.9 4.89 1.99 0.51 17 0.07 150 21.2 ■7.0 2.85 0.69 0.25 0.10 0.02 H5 28.1 9.46 3.85 0.95 0.34 0.14 0.03 200 ij. ' 37.5 12.47 5.02 1.22 D.42 0.17 0.05 0.01 250 19.66 7.76 1.89 0.65 0.26 0.07 0.03 0.01 SCO 1 28.06 11.02 2.66 0.93 37 0.09 0.04 Gallons Sin. 4 in. 5-in. 6 in. Sin. 10 in. 12 in. 14 in. 16 in. 18 in. 20 in. 850 15.2 3.65 1.28 0.50 0.12 0.05 0.02 400 19.5 4.73 1.68 0.»5 0.16 0.06 450 25.0 6.01 2.10 0.81 0.20 0.07 0.03 500 30.3 7.43 2.70 0.96 0.25 0.09 0.04 0.017 0.009 0.005 600 10.6 3.45 1.72 6.348 0.13 0.05 0.024 750 5.40 2.21 0.53 0.18 0.08 0.038 JOOO 9.60 3.88 0.94 0.32 Q.IS 0.062 0.U36 0.02 1250 1.46 0.49 0.20 1500 2.09 0.70 0.29 0.135 0.071 1750 0.95 0.38 ?nno 1.23 0.49 0.234 0.123 2500 0.77 0.;862 188 0.107 !tnon • l.ll 0;515 267 0.15 0.09 3500 0.i697 0.365 0.204 0.124 4000 0,'91 0.47 0.264 0.158 4500 0:^93 0.33 0.20 5000 0.73 0.41 0.244 300 ENGINEERING WORK IN Contents in Cubic feet, U. S. gallons and weight of water per foot length for pipe of various diameters, also area in scjuare feet and inches, and circumference in inches. Diameter of Pipe in inches. Area in sq, feet or contents in Cubic feet per foot oflengtb. Contents in U.S. gallons per foot length. Weight of water in one foot length, in Area In sq. in. Circum- ference in inches. 1 .0055 .0408 .34 ;78 3.14 2 .0218 .1632 1.36 3.14 6.28 3 .0191 .3672 3.06 7.06 9.42 4 .0873 .6528 6.14 12.56 12.66 6 .lil6i 1.020 8.61 19.63 15.70 6 .1963 1.469 12.25 28.27 18.85 7 .2673 1.999 16.68 33.48 21.99 8 .3191 2.611 21.79 60.26 25.13 9 .4418 3.305 27.67 63.61 28.27 10 .5454 4.P8 34.04 78.54 31.41 11 .66 4.9.17 41.19 95.03 34.65 12 .7854 5.875 49.02 113.10 87.69 13 .9218 6.895 67.54 132.78 40.84 14 1.069 7.997 - 66.73 15a.94 43.98 16 1.227 9.18r 76.60 176.71 47.12 16 1.396 10.44 87.16 201.06 60.26 IS 1.768 13.22 110.31 254.47 66 61 20 2.182 16.32 136,19 314.16 . 62.83 22 2.640 19.76 164.79 380.13 69.11 24 3.142 23.50 196.11 462,39 75.39 26 3.687 ■27.58 230.16 630.93 81.68 SS 4.276 31.99 266.93 615.75 87.96 SO 4.909 36.72 306.42 706^86 94.24 32 6.686 41.78 348.64 804.26 100.63 34 6.305 47.16 393.59 907.93 106;81 36 7.069 62.88 441.25 1017.9 113.09 38 7.876 58.92 491.64 1134.1 119.38 40 8.727 65,28 644.76 1256.6 I2S.66 42 9.621 71.97 600.69 1385.4 131.91 44 10.659 78.99 6^9*16 1520.S _ 138.28. _ 46 11.641. 86.33 720:44 1661.9 144.61 48 U.666 94.00 784,16 1809.6 160.79 TOWNS AND SMALL CITIES. 361 s 1 ^ g i 1 1 ^ i g g n 1 S^il M s §' S' £f g' S3 s' S ^ 5- s" ;f s* 3 ^ 8 la a C4 in OD ■« t- s u -BT («)■ § s S •s: ffi S s s a iS H ,g s ^ rt s S' S s CO S s S' s sa' * » ;S i S S i ^ i g i o t s 1 o «3 § i i i 1 a ;« « to oo t- 1 u St ss HI ^ o 1 1 a T5 1 a s' to 3J 00- s «. a s ^ 1 fr^ S- 1 1 a i-t 1 1 s* 1 t-- rt 1 OS' B S s !« CT 3 s 2 ^ f; s « S s ^ M «* o to" «o 00- cT o ij 2- e-f » 5 »i s- S n s g s s s o o ^ 1 $ o m o s ■s S n ■* ^ ■s t- cf oT or o- ■ 11 Cj- a ^ i-i ? s s s S? g ^ ^ ff m 12 o s o s s CJ CO ■* « la Kf o- ti' ir^ » 00- cT a s' « •-I O cf S' n' 'flJ' 1 us 5 to g ?- o CO- 1 er oT la o ^ g 12 O s o p s r3 s f2 is" «9 g -00 rH «- CI- go" S tn '« «- * •* la o- S- ^ lO « ai CO 04 Ol t^ £ o K «. « (O S- s s s iS 3 s s g !-«■ IH *^ tH IH e) « CI e« 0« e4 " i,S' u> CO t- 00 o> s •H S n s a a c* eo s 8 ENGINEERING WORK IN Table Showing Flow of Water "pet Second through Glean Iron Pipes. Fall IQ feet per DIAMETERS. 100 ft. o( lin. 2 in. Sin, 4 in. 6 in. Sin. 10 in. 11 in. 12 in. pipe m.K eu. ft. CO. ft. en. fi. en. ft. en. ft. ca. ft. en. ft en. ft. -lu 1.265 .12 .878 .960 1.047 l.Illl 1.194 1.265 1.325 1.377 1.423 1.410 1.687 1.683 1.120 1.221 1.320 1.394 1.49(1 1.680 1.653 1.722 1 188 1.851 1.996 2.136 1.402 .14 1.489 .16 - .673 .611 .639 .659 .703 .737 .768 .808 .876 .931 1.634 .18 1.728 .20 .298 .314 .330 .346 .359 .377 .396 .444 1.846 .22 1.940 .24 2.g26 2 117 .26 .1235 .1298 .1335 .1465 ' .1562 .28 2.807' .30 .0630 .0692 .0749 a. 397 .SS 3^68 .40 .02684 4.662 .60 .02924 .08SS .177] .496 1.046 1.866 2.391 8.020 .60 .03274 .0916 .1928 .64e 1.676 2.069 2.63< 3.310 .10 .0349! .0995 .2146 ,68S 1.262 2.229 2.85f 3.601 .80 .00561 .03776 .1060 .233! .631 1.344 2. 388 8.06S 3.856 .M 00611 .04081 .llli .246C .672 1.424 2.6K s.m 4.072 1.00 .00677 .04321 .1190 .2582 .721 1.496 2.66! S.tii 4.30f ).30 .00781 i04849 .131S .289! .784 1644 2.932 3.16C 4.128 IM .0OH41 .06160 .1419 .3036 .868 1 182 3.210 4.01C 6.09t 1.6( .00886 .05460 .1607 .3231 ' .922 1.916 8.460 4.3W 6.482 l.St .00961 .06740 .1690 .S4IS .976 2.03S 3.679 4.67S 6.839 ,2.0C .00990 .66111 .1711 .3601 1:02! 2.166 3.866 6.261 6.160 8.O0 .01246 .07399 .2081 .4MKI 1.269 2.661 4.762 6,08( B& 4.00 .01492 .08734 .246S .6331 1.484 3.146 6.663 7.02! s.ot .01666 .1095 .2786 .6964 1 666 S.51il 6.704 8.244 9.961 «.O0 .01867 .1200 .S04S .6390 1.92G 8.847 7.O0 .01988 .1288 .8631 .6967 1.970 4.196 8.00 .02141 .02283 .02424 .02676 .02890 .1376 .1442 .1623 .1634 .1748 .3669 .3816 .4043 .4440 .4977 .1606 .I960 .9464 .•270 1.0060 2-144 2.274 2.399 9.00 10.00 , 12.00 - 14.00 . i 16.98 .03081 .I8BS .6181 .6436 1.0810 18.00 .03276 .1956 ' W.OO .03468 .2047 .6832 ... 26.00 .03897 .04316 .04987 .06648 .06320 .2276 .2483 .2833 .6523 30.00 ' > 40.00 ; 6».00 - 60.00 70.00 .06943 ' To find the velocity in feet per second necessary .to carry a given <]uantity of water in a pipe of given diameter, divide the quantity in cubic feet per selTohd by the area of the pipe !n square feet; the quotient will give the velocity. TOWNS AND SMALL CITIES. Table Showing Flow of Water per Second through Clean Iron Pipes., S6S Fall la DIAMETER. ( feet per 14 16 16 18 20 23 24 26 30 36 40 48 1«) in. In. in. ID. in. in. in. in. in. in. In. in. teetot cu. cu. cu. cu. cu. cu. cu. en. CU. cu. cu. cu. pipe ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. .02. 10.29 13.88 22.98 .03 7!78 8.99 10.24 to. 97 12.70 14.66 16.35 18.02 17.00 19.66 23.08 24.43 27.89 M 32.93 .OS ■7.'48 7.61 37. 00 .06 ..... 's.'ei ■4.61 e'.ii) 40.21 .07 ..1. a!26 s.'io 4.07 6.36 6.64 8.27 11.9(J 19.76 26 27 43.67 ,08 i.ii 'i.OT 2.43 3.37 4.35 6.62 7 13 8 70 12.84 20.86 38.14 46.81 .09 1.88 2.19 2.69 3.49 4.68 6.01 7.66 9.3G 13.48 22.30 39.80 49.06 .10 1.91 2.30 3.72 3.66 4.92 6.32 7.96 9.81 14.21 23.47 31.46 62.15 .11 2.02 2.43 3.88 3.88 6.16 6.62 8.34 10.44 16.06 24.91 33.36 64.95 .U 2.11 2.64 3.03 4.06 6.40 6.94 8.75 10.87 16.81 26.12 34.68 67.86 .13 2.18 2.66 3.18 4.33 6.62 7.24 9.U 11.41 16.47 27.20 36.31 60.07 .14 2.27 2 76 S.28 4.40 6.82 7.61 9.47 11.80 17.18 28.24 37.57 63.02 .15 2.36 2.84 3.39 4.61 6.06 7.78 9.80 12.26 17.94 29.19 39; 18 64.47 .16 2.44 2.94 3.49 4.76 6.27 8 03 10 13 12.70 18.68 30.29 40.64 66.63 .17 2.64 3.98 3.62 4.90 6.48 8.36 10.57 13.13 19.21 31.42 41.88 68.60 .18 2 69 3.11 3.69 6.03 6.65 8.65 10.77 13.46 19.61! 32.48 43.07 70.62 .19 2.67 3.21 3.81 6.17 6.92 8.35 11.10 13.84 20.32 33.40 44.38 73.75 .30 2.72 3.29 3.92 6.30 7.05 9.07 11.43 14.23 20.79 34.49 45.^30 74.44 .22 2.88 3.47 4.13 6.63 7.42 9.65 12.05 14. 9H 21.80 36.15 48.12 78.29 .24 3.02 3.63 4.32 6.87 7.79 10.01 12.61 16.69 23.83 37.74 60.48 81,68 .26 3.16 3.79 4.61 6.18 8.14 10.48 13.23 16.42 23.93 39.40 52,67 85,20 .28 3.29 3.96 4.68 6.38 8.48 10.91 13.79 17.07 24.86 40.86 56.04 88,46 .30 3.42 4.11 4.87 6.64 8.77 11.29 14.36 17.75 25.87 42.28 66.33 91,73 .SB 3.63 4.46 6.31 7.17 9.49 12.25 15.50 19.25 27.96 (5.95 61.09 100.40 .40. 3.99 4.78 '5 67 .7.65 in. 16 13.13 16.62 20.62 29.84 48.83 65.41 105.89 .60 4.46 B.37 6.39 866 11.43 14.78 18.71 23.13 33.66 54.89 73.09 119,34 .60' 4.9) 6.91 7.02 9.64 12.59 16.20 20.42 26.30 36.79 59.95 80.32 130.88 .70 6.37 6.45 7,66 10 33 13.66 17.63 22.05 27.12 39.66 65.17 86.70 148.09 .80 6.77 6.90 8.16 11.09 14.66 18.7823.61 29.20 12.39 69.80 92.58 153,49 .90 6.11 7.31 8.64 U.71 15.64 19.9325.07 31.00 45.23 74.33 98.00 1.00 6.44 7.70 9.10 12.37 16.47 21.0626.42 32.73 47.71 78.46 103.99 1.20 .7.00 8.39 9.95 13.65 17.99 23.07 29.03 36.18 53,91 82.84 1.40 7.60 9.16 10.87 14.76 19.49 24.6831.49 39.31 57.66 1.60 /8,17 9.81 11.63 16.84 21.03 26.97 J3.90 42.36 1.80 8.93 10.47 12.43 16.90 22.45 29.70 36.1(1 44.10 3.00 9.26 11.09 13.14 17. 8S 23.66 31.16 38.45 1 S.OO 11 .3S 13.66 16.17 21. 8« 28.86 4.00 13. 2S 16.84 18.77 To find the area of a requited pipe, clie quantity and velocity being given, divide the quantity in a stated time by the velocity in the'same . period; the quotient will be the required area, trom which the diameter may readily be calculated, 364 ENGINEERING WORK IN PRESSURE OF WATER. 4t S Jo s i. s it at 4/ = J5 X = B U. c ;: u. s ^ X B e X s" X c = S? B £? s _E is c I! •V S"" •0 = (A •0 sir. ■0 5'^ ■O s *. ■0 X sk X re it X K S 1- R it X u CL. "^ a. a. £ cu , 0.4 s> 22.1 )0I 43-7 151 654 201 67.' 251 108.7 2 0.9 S2 22.5 102 .442 "52 658 202 875 252 109.2 i 1-3 S3 229 103 44.6 153 66,3 203 87.9 253 109 6 4 17 54 ^JJ 104 45-0 154 667 204 S84 254 110.0 5 2.2 55 238 105 45 5 '55 67.' 205 88 8 255 110,5 6 2.6 56 24.3 106 45 9 156 67.6 206 892 256 iio.o 7 30 57 247 107 463 '57 680 !^ 897 257 111.3 8 3-5 58 2S 1 108 468 158 6S.4 901 258 111,8 9 3-9 .59 255 109 47.' 159 68.9 209 905 2'i9 11,2.2 10 4.3 (10 26.0 110 47.6 160 69.3 210 91.0 260 Hi 6 If 4« 5l 2fi.) 111 48.' 161 69.7 211 9> 4 3(H ■1131 12 5-2 62 26 8 112 485 162 70.2 212 91.8 262 1135 >3 5* fJ 27 3 113. 489 '63 70.6 2i3 92.3 263 1^:: M 6 1 64 'V 114 49.4 164 71.0 214 927 264 H *5 6s 28.1 un 49.S 'fi5 71.5 2'5 93.1 265 1»4.8 16 6.9 66 28 6 II& 50.2 166 7' 9 216 93.*^ 266 115.2 17 7 4 Jl 29.0 '17 507 167 72.3 1:2 94,0 267 115.7 18 78 68 294 118 51.1 16S 72.8 94 .1 268 I15.I ■9 8 2 09 299 119 51.5 .69 73.2 219 94.9 269 116.5 30 8.7 70 303 120 52.0 170 73.6 220 95-3 27C I17.0 21 9-1 71 30.' 121 5' J '7' 74.1 221 9^.7 271 117.4 ai 9.5 72 3<2 122 52.(= 172 74 5 222 96.2 272 117.8 23 lO.O 73 316 123 53.3 173 .749 22T 966 273 118.3 24 10.4 74 32.0 124 53 7 '74 75 4 224 97 274 118.T 25 10.8 75 32.5 "25 54 1 1-5 75-S "5 97-5 275 119.1 26 ■ 1.3 76 32.9 126, 546 1-6 762 2 26 97 9 276 119.6 27 11.7 'I 33.3 127 55.0 177 76.7 227 98 ! 277 120.0 aS 12.1 78 33.'^ I2S 55-4 '78 77.' 228 988 278 120,4 29 125 79 34.2 129 55.9 ir9 775 229 902 2T9 120.8 30 130 80 34.6 130 56.3 lHo 78 S 2 to 996 2R6 121.3 31 13.4 81 35.1 '31 5>.o 1S4 79-7 234 101.4 28J 123.0 I'i '^i 85 36.8 135 .58.5 '85 80.1 235 101.8 28s 123,4 36 k6 86 372 '.36 58.9 186 80.6 236 102.2 286 >?S.9 37 ]6.o 87 "y '37 59.3 '5' 81 237 192.7 287 124.3 38 'J* 88 38 1 '38 59.8 1 88 8.4 236 103 1 288 124 7 39 16.9 69 .385 '39 60.2 .89 81.9 239 '03.5 289 125-2 40 173 90 39.0 140 fio.6 190 !'-3 240 104 290 1 2,5,6 41 ,'Z' 9' 39-4 141 61.1 191 R2.7 241 104 4 291 126.0 42 18.2 92 39.f> 142 615 192 83.2 242 104.8 292 I26.S 43 186 93 40. 1 143 61.9 193 63.6 243 105 3 293 ■26.9 44 190 94 407 144 62.4 194 84 244 10S.7 294 127,3- 45 46 195 9'i 41.1 '45 62 S 19s 84 5 245 106,1 295 127.8 19.9 96 41.6 '46 63.2 196 84.9 246 106.6 296 128,2 ti 20.1 '2 42.6 "Z '•17 '97 853 247 107.0 297 128,6 20 8 98 424 148 64. 19S 8s.8 248 1074 298 129.1 49 21.2 99 42.9 '49 645 199 86.2 249 107,9 299 129,5 50 21.6 00 433 150 65.0 2«0 866 250 'o8..-( 300 129,9 TOWMS AND SMALL CITIES 365 HYDRAULIC WEIGHTS AND MEASURES. I U. S. Gallon ■ I Cubic Foot . 1 Acre-Foot •. , I Acre-Foot 1 Square^Mile-Inch ,. 1 Square Mile-Inch . 1 Square Mile-Inch . 1 Cubic Foot per Second 1 Cubic Foot per Second 1 Cubic Foot per Second 1 California Miner's Inch 1 Colorado Miner's Inch 1 Million U. S. Gallons per Day 1 Foot of Depth . Pound per Square Inch 1 1 Inch of Mercury at 32 . 1 Atmosphere (equals 29.922 Inches Mercury) , 1 Cubic Foot of Water per Second falling i ft vertical=0.1t&5 Horse Power (theoretical) I Cubic Foot of Water at 39.2° F weighs 62.4 Pounds. I U. S. Gallon of Water at 39.2° F. weighs 8.34 Pounds. =231 Cubic Inches. =7.48 U. S. Gallons. =43,560 Cubic Feet. =325,829 U S. Gallons =S3.33 Acre-Feet. =2,323,200 Cubic Feet. =17,377,536 U. S Gallons. =646,272 U. S. Gals, per day'(24 hrs ). =50 California Miner's Inches. =38.4 Colorado Miner's Inches =0.020 Cubic Feet per Second. =0.026 Cubic Feet per Second. =1.55 Cubic Feet per Second. =0.433472 Pounds per Square Inch. =2 307 Feel of Water. =1.1334 Feel of Water. =33.9 Feet of Water. ''Conservative Working Pressures for Good Grades of New Water Hose Inter- nal PBESSURESr POUNDS. Diam- eter 3-Ply 4-Ply 5-Ply 6-Ply 7-Ply 8-Ply 9-Ply IfrPly UPly 12Ply a in. 236 315 393 472 551 630 708 787 •866 945 % " 157 210 262 315 367 420 472 525 577 63U 1 " 127 169 212 254 296 339 381 424 466 508 IX " 102 131 169 203 237 271 305 339 373 .406 la " 91 122 152 183 213 244 274 305 335 366 IH •• 78 104 130 156 183 209 235 261 287 313 2 " 72 96 120. 144 168 192 216 240 264 288 2V " 64 85 107 128 149 171 192 214 235 256 2H " 68 77 96 116 134 154 173 192 211 231 3 • 53 70 88 106 123 141 158 176 194 2.1 , 3H " 45 60 75 90 106 121 136 151 166 181 .^ 4 •' 43 57 72 86 100 115 129 143 158 172 366 ENGINEERING WORK IN. BEAM CALCULATIONS. The town engineer is called upon to design many structures of a simple kind and a discussion of the underlying principles of beam formulas will be a useful review. After this we will take up the design of walls, culverts, etc. MOMENTS. When a weight rests upon an object it strains it in some de- gree. If the object ds lying on the ground supported throughout its entire length, the force is simply equal to the weight. When the object is a beam, for example, supported at the ends, the weight acts in two ways. First, it tends to shear the beain at each point of support and, secondly, it tends to bend the beam. The force exerted in bending is called a moment. The moment of a force is the product of the force into the arm with which it acts. Take, for example, a small piece of wood about one inch square, perfectly level, but with one end fastened mto a wall. The other end being free and unsupported. Cut a groove in the top and roll a ball in the groove. The nearer the ball ap- proaches the free end the more the piece of wood bends. If this piece of wood were larger, so that it could be termed a beam, it would be called a cantilever beam. (See Fig. 6.) If the load is in pounds and the distance from the wall to the load is in feet, the distance multiplied by the weight gives the bending moment in foot pounds. The distance may be (and gen- erally is) taken in inches and the bending moment is given as so many inch-pounds. With the above example the statement that the moment of a force is the product of the force into the arm with which it acts, may be plainly understood. In other words, the farther the load is placed from the point of support, the greater bending moment it develops. The arm is always perpendicular to the direction of the force. The accompanying diagrams, showing the usual cases occurring in the loading of beams, will help illustrate the definition of bend- ing moments. , ' The weight does not act directly to cause bending. It must act TOWNS AND SMALL CITIES. 367 through the arm or distance it (the weight) is away from the ■point where the bending moment is developed. In calculating the strams. on beams, the maximum bending moment is the one used. Weight tends to carry the beam, down vertically or in ■ the line of direction in which the weight acts. This action is resisted 'by the .supports under the beam. As soon as resistance is en- countered the beam may shear at the edges of the support; that is, be cut oflf like slicing butter with a knife, or it may bend at some point between the supports. The point may be where the load strikes or it may be somewhere else on the beam. Where the point may be depends upon several things. -Q t= "9-^ r.3.7 Fig. 6 illustrates the cantilever b€am fastened at one end and Joaded with a concentrated weight. It must be remembered that we can only use the concentrated weight alone in preliminary calculations or in explaining the action of forces. The weight of the beam can not be neglected in practice, so when using a concentrated weight we have of necessity- a concen- trated as well as a distributed load. This refinement, however, will be neglected in the following discussion for the sake of clearness. . Let W. represent a concentrated weight, L represents the distance between supports. , w represents a distributed weight. w' represents the weight of the beam, also distributed. In Fig. 6, the bending moment is M = W X L., The maximum bending moment is at the wall'.. It becomes less the nearer the weight the moment is taken. In the general discussion while the letter L is termed the distance between supports, in the case of the cantilever it is the distance from the support to the center -of gravity of the weight. Fig. 7 shows a cantilever beam with a distributed weight, or load. - ^ , , ;- Afofce or weight may be represented by a line, to any scale. The length of the line represents the amount and the direction in 368 ENGINEERING WORK IN which the force acts ifi shown by the direction of the line. Usually an arrow point is placed on the line to indicate direction. In the case of weights and the loading of beams it is understood the force acts downward, so the line is vertical. In Fjg. 6 calculate the bending moment. At the support draw a vertical line from the middle of the beam. This line can go up or down, but it is customary to draw it down, as the force acts in that direction. The length of the line will represent the bending moment. Connect the end of it to the center of the beam at a point directly under the center of gravity of the weight. This gives a triangle in which the bending moment at any point in the beam can be found by measuring the perpendicular distance from the center of the beam (base of the triangle) to the limiting line of the force diagram (the hypothenuse of the triangle). Apply this to Fig. 7. Here the total weight is multiplied by the distance from the support to the center of gravity of the load. That is, by half the length of the load. It is expressed thus: M = wX^ The maximum bending moment in this case is also at the point of support. A drawing can be made as in the case of Fig. 6, but the limiting line for a distributed load is a parabola instead of the hypothenuse of a triangle, and it begins at the extreme end of the load. This will be taken up when describing Fig. 15. There may be cases in which a cantilever beam has to carry its own weight (w'), a distributed load (w), and a concentrated load (W) as well. The bending moment, M, is equal to w'X L, plus w X L, plus W X L. Each is calculated separately and the results added. ^ nommnnnn Fig. 8 is a beam freely supported at both ends with a concen- trated load in the middle. We know by intuition that each support must carry half the load, so the maximum bending moment must be equal to half the load into half the span. That is, the expression is TOWNS AND SMALL CITIES. 369 4 which is the same thing. We have calculated the moment for two cantilevers,, but in this case the beam has two end supports, so the inaximum bending moment must be in the middle under the load. Fig. 9 shows a distributed load on a beam freely supported at both ends. We have already seen that the maximum bending moment for a distributed load is one-half that of the same load concentrated, so the expression in this case is M = wX-^ A distributed load has a tendency to arch. It is illustrated in the case of a brick wall. When calculating the load borne by the top of a window or door frame, the weight is not that included be- tween the vertical lines from the sides of the opening to the top of the structure. It is the weight *bf a triangle of wall having the three sides equal to the span of the opening. The bricks have a tendency to key together, aside from the adhesion caused by the mortar. Similarly with a distributed load of boxes, or bags, or rails. The question also arises in computing the pressure on the top of a culvert under a high fill. As the beam gives way the pieces com- posing the load adjust themselves until they form practically a beam and can be self-supporting over a considerable span. Tests of beams loaded with materials piled' haphazard on them are not reliable. The load should be piled in slender columns with well defined spaces between, so that when the beam bends the ma- terial can not heap and relieve the loading. In order to express this clearly and lead to a ready under- standing of Fig. 15, distributed loads in this discussion have been represented by lines of balls free to move and adjust themselves to the changing form of the beam as it bends. T ^ CL_i ' Fig. 10 differs from Fig. 8 in that the concentrated load is not in the middle. Calling half the length a, it can be proven that 370 ENGINEERING WORK IN 2 2 4 L as shown in the case illustrated by Fig. 8. A similar line of reasoning for Fig. 10 {fives the following expression: M = W xi^ for a concentrated load not at the middle.- Fig. 11 shows a beam haying two equal concentrated loads, equally distant from the center. In this case , , M = WXa . . No particular illustration is needed dn this case, as a careful fol- lowing of the preceding explanations will show how the formula is developed. However, the explanation of Fig. 14 will help throw light on it. Fig. 13 shows a combination wherein the concentrated load is distributed over a portion of the beam. Where a and b are equal, the formula is M - WXL WXI 4 8 When the distances from the points of support to the center of' gravity of the load are not equal the expression is j,_ WXaXb W Xl L 8 H IKREGULAK LOADINGS. After discussing reactions we will take up the calculation of •Xr--,---- -^ ^ I OlU ^1^^ fif.H- the location of the maximvim bending moment under irregular load- ings. The position, however, may be determined graphically. TOWNS AND SMALL CITIES. 371 Fig. 13 illustrates the method of drawing : triangles already described. The bending moment is calculated and represented by a line drawn vertically downward from the center of gravity of the load. The triangle is completed by drawing the hypothenuse. The bending moment at any intermediate point is found by meas- uring vertically downward from the middle of the beam at the point, to the hypothenuse. When there are several loads the bending moment is calculated for each and a triangle plotted for each, as shown in Fig. 14. It will be noticed that under each loal several triangles cross. The bending moment under each load is therefore equal to the sum of the distances from the center of the beam to the hypothenuse of each triangle. Connect the outside points thus found and draw in the exterior line. A perpendicular dropped to the outside diagram from any point gives the bending moment at that point. The maximum bending moment is at the point where the longest vertical line can be drawn from the center of the beam to the outside force diagram. Fig. 15 shows the force diagram of a distributed load. The maximum bending moment ( M ^ — - — \ , is set off at the point half way between the supports. A parabola is then drawn with a height equal to this bending moment and a base equal to the dis- tance or clear span. All measurements are made on a horizontal line through 'the middle of the beam. The reason for the parabola may be seen by a reference to Fig. 9 and Fig. 14. The distributed load can be represented by a line of balls and the force triangles plotted for each. These triangles of force can be worked into a force diagram which will assume the shape of a parabola. Having ascertained this, it is unnecessary to again go through this process and the parabola may be drawn directly when it is desired that the bending moment on a beam 332 ENGINEERING WORK IN uHiformly- loaded is required to be known at any other point than the middle. Fig. 16 hardly needs a detailed description. It shows how to ascertain the maximum and other bending moments in a beam loaded with a distributed and any number of concentrated loads. The maximum bending moment is at the point where the longest vertical line can be drawn between the parabola and the bounding, lines of the -other force diagram. The location can be calculated also if the graphical process is not used. /vf./7 W' FfflS In the preceding explanations all beams have been considered as simply r^tiiig upon the supports. Fig. 17 shows a beam loaded with a,, distributed load and having the ends fastened into the wall. B;y Calculations which would hardly be interesting in this review, it can be proven that for such a case the maximum bending moment is M = w X ^_ instead of M = w X -tl as in the case already mentioned. The diagram in Fig. 17 is constructed by drawing a parabola having M = w X -g-- Also A, A' parallel o to base and at a distance equal to M = w X _— • The vertical distances between the parabola and the line A A' are the moments for the corresponding points on the beam. In such beams there are points known as points of contra flexure. That is, instead of the beam bending in the middle and the ends raising slightly, the ends remain fixed and the beam bends in three points. At the middle it is concave on the top and on the bottom are two points distant 0.21131 of the span from each sup- port, where the beam bends downward, or is concave on the bottom. Fig. 18 shows a tied beam having a ' load concentrated at the middle. This diagram is drawn by drawing a triangle having TOWNS AND SMALL CITIES. 373 M = "W X -J-- Also A A' parallel to the base and at a distance of M = W X _-- The vertical distances between the triangle o and the line A A' are the moments for the corresponding points on the beam. The points of contraflex'ure are J4 L from the points of sup- port. In the case of Fig. 17 the maximum bending moment was for a distributed load. In the case of Fig. 18 we use a concentrated load, giving M = W X — plus the distributed load equal to the weight of the beam ; thus, M = w* X — - o It is important to remember the weight of the beam in all calculations. This weight is called the dead load. The superim- posed weight is called the live load. In a structure the weight of the structure is the dead load and the weights the structure is designed to carry constitute the live load. The method of finding the maximum bending moment for a beam carrying a distributed load together with a concentrated load has been given. Also the method of finding the maximum bend- ing moment caused by several concentrated loads. The most simple way of obtaining the moment in such cases is to reduce each con- centrated load to a distributed load and add these distributed loads together and calculate the maximum bending moment for the total equivalent distributed load, an easy matter. A distributed load gives a moment one-half that given by an equal concentrated load applied at the middle of the span. So for a concentrated load at middle of the span multiply by 3. At 0.333 of the span from a. support, multiply by 1.78. At 0.25 the span, by 1.5. At 0.20 the span, by 1.28. At 0.166 the span, by 1.111. At 0.143 -the span, by 0.98. At 0.125 the span, by 0.875. At 0.111 the span, by 0.79. At 0.10 the span, by 0.72. The foregoing method is used in mai>y offices and is a labor saver. A caution, however, must be given to users, that, as the maximum bending moment is not exactly equal to the sum of the separate bending moments, a beam calculated by this method will be larger than would be required if the more exact process were 874 ENGINEERING WORK IN followed. This caution is necessary however, only 'vhen the weights are very heavy. CONTINUOUS BEAMS. * The foregoing cases touch upon beams resting on two sup- ports and also the case of beams tied at each end. Continuous beams are beams that rest on more than two supports; for example, a beam across from wall to wall in a building and resting upon a post in the middle. It is then a continuous beam of two spans. If it had rested upon two intermediate posts it would be a continuous beam of three spans. Each span assists the adjoining span in nearly all cases, and there are points of contra-flexure in each span. A continuous beam of two spans uniformly loaded is no stronger than a beam of one span so loaded. A continuous beam of two spans loaded with a concentrated load at the center of each span is stronger than a simple beam. The bending moment in each span is one-fourth less than if the beam were not continuous. When the beam is continuous over three spans and the load is uniformly distributed, the bending moment in each span is eight- tenths the load on a single span for a non-continuous beam. The bending moment on each span of a three-span continuous beam having concentrated loads of equal weight in the middle of each span is six-tenths the bending moment on a simple span. The foregoing remarks apply only to beams having two and three spans of equal length with equal loads on each span. REACTIONS. The loads on a beam tend to carry it downward. The supports prevent this action. The effort put forth by the supports is termed a reaction. It is said that the supports push up with a force equal to that exerted downward by the load. In Fig. 6 and Fig. 7 the reaction at the point of support is equal to the combined weights of the beam and the load. In Fig. 9 the reaction at each support is equal to one-half the total weight. In Fig. 13 the reaction at B is equal to the moment produced by the load multiplied by the distance a, divided by the span. The reaction at A is equal to the reaction at B subtracted from the TOWNS AND SMALL CITIES. 375 total load. The above operation can be reversed for a check. The reaction therefore at any support is equal to the load multiplied by its distance from the other support and divided by the span. The' reaction at the opposite support is the difference between the total load and the reaction first found. In the case of several loads, as in Fig. 14, find the moment for each about the opposite support and add together all thi^se moments. Divide by the length of the span and the reaction is ob- tained. To obtain the other reaction, add the loads together and subtract the first reaction from the sum. In dealing with concentrated loads in finding reactions, half the weight of the beam is afterward added to each reaction. The weight of the beam can therefore be neglected in the calculations, provided it is afterward added. If a beam projects from a wall and rests on a post. or end of a brace, like a balcony, for example, there will be two reactions. At the wall where the beam is fastened the reaction will be downward and at the support it will be upward, provided, of course, the load is outside the post. If between the post and wall the reactions are figured in the manner already described. Multiply the load by the total distance from its center of gravity to the wall and divide by the distance from the wall to the post. This gives the reaction at the post and this is plus, or acting upward. Subtract this from the load to get the minus, or downward reaction at the wall, or tied end. In the case of a load, as shown in Fig. 13, it is enough to siiri- ply take the weight of the whole object io be a concentrated load applied at its center of gravity and calculate accordingly. The length then of the load makes no particular difference. It is because of the reactions there are bending moments and shearing strains in beams, so we have to find the bending moments in order to find the reactions. SHEARING FORCE. if a beam is made of a tough material it will bend, as has been shown, whenever the ends rest on supports and the span between is free. If the material were soft it would .cut in two at the sup- ports, because of its weight and the weight of the load. This action is termed shear. It exists in a greater or less degree in each point in the length of the beam. 376 ENGINEERING WORK IN' In Fig. 6 the shear is equal to the total load and is the same at every point. The shear diagram is a parallelogram. In Fig. 7 the maximum shear is at the fixed end and is equal to the weight per lineal foot multiplied by the length. The shear at any point is equal to the weight per lineal foot into the distance to that point. The shear diagram is a triangle. In all beams the maximum shear is at one of the supports. When beams rest freely at both ends the shear is equal to the greater reaction or supporting force. ^ nnnnnnnnm m f/f./S In Figs. 19 and 30 the shear is equal to one-half the total load. In the shear diagrams the shaded parts represent the amount of shear and the following rules explain how the shear diagram is obtained. Calling the loads, the forces acting downward, plus, the re- actions, forces acting upward are called minus. Beginning with either reaction, put it down with its sign. Add to it, algebraically, the first load. This gives the shear for every point from the origin to that point. Add to this, algebraically, the next load and continue in this manner until the end of the beam is reached. At some point on the beam the shears become positive if they were first negative, or vice versa. r,i,.ii 21 the maximum shear W X In Fig. S2 the loads are A study of Figs. 31, 22 and 23 should make this plain. In Fig. L. equal and at equal distances from the ends. The maximum shear is therefore equal to the total load. Reference has been made to the calculation of the position of TOWNS AND SMALL CITIES. 377 maximum bending moment. The points of maximum bending moment occur where the shear changes sign. I— «--jL Jt-*-^ f — ^ ^ Q 'Jh ^ F,,,Z^ liUMMI nj.S3 A general rule for finding the bending moment at any point of any bearii is to add together the bending moment at the origin, the sum of the moments of all concentrated loads to that point, in- cluding the shear at the origin, .and the sum of the moments of the distributed loads about the same point. This rule can be checked by constructing a force diagram and measuring the bending moments at several points and then calculating them. When a beam is uniformly loaded and in addition carries a sin- gle concentrated load the position of the maximum bending moment is found by dividing the moment of the concentrated load by the distributed load. This may give a plus or a minus result, which will indicate the distance to the right or left. of the middle of the beam of the position of maximum bending moment caused by the combination of the loads. It is a good plan to consider the origin as being at the left in calculating the moment for the concentrated load. APPLICATIONS. A knowledge of the actions of forces in beams is useful in designing buildings, culverts, bins, retaining walls, etc., and as the engineer should be well posted in bridge work before designing anjrthing larger than a fifteen or twenty-foot span bridge, we need not touch upon the subject of moving loads. It will be suificient to take the length of the heaviest engine or wagon that will cross the bridge." Find the weight and distribute it ^ over the four wheels. Consider the two wheels on one side as concentrated loads and calculate the maximum bending moment for these loads in different positions on the beam. Design the beam for' the greatest moment found. The total jive load is gen- erally distributed in calculations. The expression, wl^ is often met It simply means that w is 378 ENGINEERING WORK IN the unit load, the load per foot or per inch. To get the total load it is necessary to multiply the unit load by the length.. Then in cases where the total load has to be multiplied by the length it really amounts to the unit load being twice multiplied by 1, or, rather, by 1'. We have seen that for a beam freely supported at both ends a distributed load causes a bending moment, M = -^— and when o, the ends are fastened, M = ^ In reinforced concrete floors, -la, wl' fastened firmly on four sides, it is allowable to use M = -— -. A floor is a slab composed of beams lying side by side. To calculate the strength of a floor we simply take a strip . one foot wide and use the load coming on that portion. A wall is a succes- sion of beams fastened edge to edge. If the beams are calculated as being vertical they are all cantilevers. If they are calculated as being horizontal their thickness depends upon the length of the beam between vertical supports. These supports may be columns or buttresses or ties in the rear. In olden days the ties in the rear were called counterforts but were of little service, for a severe load against the wall tore it from the counterforts. Today the use of reinforced concrete makes counterforts prac- tical and really useful. A retaining wall may be designed as a vertical slab held in place by counterforts at regular intervals. This will be taken up later. STRAINS IN STRUCTURES. It has been mentioned that forces may be represented by lines to some scale and the direction in which the forces act may be represented by the direction of the lines. An understanding of these principles has led to the development of Graphic Statics, or the art of calculation by drawing lines. Fig. 24 is the old familiar diagram of the parallelogram of forces. A B represents in amount and direction a certain force. B C represents in amount and direction another force. They act together at the point B. The line B D is called the resultant. To find it draw a line from A parallel with B C and draw a line to intersect it from C, parallel with A B. The line B D connecting TOWNS AND SMALL CITIES. 379 the opposite corners is the resultant in amount and direction that tends to move the object at the point B. The same result could be obtained in a neater manner by setting off the line A B from the end-C of B C and completing the triangle. Any number of forces can be thus connected, by joining one after another to the Ijnes already drawn, until we have a dia- gram lacking one side. A line drawn to fill this missing part of the diagram will represent in amount and direction the resultant of all the forces. ^fiSS Fig. 25 shows two common arrangements of braces. In each case draw a vertical line from the joint to represent the weight on the frame. From the end of this line draw Unes parallel to the pieces of frame work. The lengths of these lines measured on the same scale as that of the vertical line gives the amount of force each piece puts forth to resist the weight. The small horizontal lines in the diagram (A) represent the thrust of the feet of the braces against the abutments. The vertical line represents the total weight. Part is borne by one abutment and part by the other. The sum of these two portions represents the total weight. The portion of the vertical line (measuring downward) intercepted by a horizontal line, represents the part of the weight borne by the brace toward which that horizontal line goes. Fig. 26 contains several diagrams of interest. In (1) is shown a beam A C having a rope ABC, attached at each end and carry- ing a load L. To the right draw (2) which contains a vertical line a c representing the amount of the load. The lines a b and b c are drawn, respectively, parallel to A B and B C. They represent the tension in those portions of the rope. From b draw b d 380 ENGINEERING WORK IN pgirallelto A C. This; show? the compression in the beam A C. Only a portion of the load ;exerts compression on A C, for the whole load is finally carried by the supports on which the beam restsi The line ■a d shows the load on the support at A and c d shows the load on the support at C Tn (3) is shown a trussed beam A C loaded with a load L. There is a vertical strut B L under the load and from the ends of -the beam to the lower end of -the strut are ties A B and B C. On the right draw (4) in which a c represents the load drawn to scale. Draw a b from one end, parallel to A B and draw b c from the other end parallel to B C. They will meet in b from which point draw b d parallel to A C, which represents the stress on each half of the beam A. C. The loads on the supports are shown by. c d and a d. The trussed beam shown in (3) of Fig. 26 can be inverted, and instead of a strut L B there can be used a rod. The rods A B and B C can be replaced by rafters and we have a simple roof truss, in which the strains are reversed, being in tension where they were in compression, etc. Fig. 27 represents a roof truss of a more complicated form. The vertical line from the apex is a tie and the horizontal lines are ties; They are in tension and the inclined pieces are in com- pression. The truss is figured as . if alone, for no matter how many trusses there may be, when one is calculated the rest are similar, except at the ends, but there the walls will carry the load. The TOWN'S. AND SMALL CITIES. 381 load on a truss consist? of the weight of a strip of roof extending half way on each side to the next truss and from one support to- the other. That is a strip the width of the space between trusses and in length equal to the rafter lengths. Of course all the load, including the weight of the truss, -goes into the walls and sets up .reactions. But this is neglected ii^ com- puting strains in the members. The total load is divided^ into as many parts as there are supporting joints on the rafters, counting the two ends as one. In this roof there are four. One part cif the load is supposed to act at each joint and half of one part at each end where the roof rests on the walls. In the calculations- this part is not considered. Draw the vertical line A F. A B represents the load on one wall and E F the load on the other wall so far as the distributed loads go to the .joints. The part B C represents the load on the joint between B and C. That between C D the load at the apex etc. From B draw the line B b parallel with the rafter on the left and from E draw the line E e parallel with the rafter on the right. The lengths of these lines represent stresses on the portions of the rafters between the joints and the feet. From C draw the line C c parallel with the rafter-. 6ri the left and from D the line D d parallel with the rafter on the right. These lines represent stresses in the upper ends of the rafters. It will be noticed that the lines are lettered with capital letters and the inside spaces have small letters. In the stress " diagram these letters are at points. The line between two points represents the member between corresponding letters on the truss diagram. Referring again to the diagram, b c represents the stress on the strut on the left between the spaces b and c, and e d represents the stress on the strut on the right between the spaces d and e. The vertical line c d represents the stress on the vertical tie rod. G b the stress on the horizontal tie rod on the left side and G e the stress on the horizontal tie rod on the right side. As the vertical .line A F in the stress diagram represents, the total load of the roof so A G is the total reaction at support 'A and G F the total reaction at the point F. The stresses are' divided into tensile and .compressive. In making the stress diagram we commenced at -A and went to F, the capital letters denoting panel points. Following the lines in 382 ENGINEERING WORK IN the same order all stresses acting toward panel points are compres- sive and those acting away are tensile, the vertical weight line not being considered. From G to e is a tensile stress. From-b to A or from e to F compressive. The forces act from A toward the apex so following them in that direction it is easy to determine the nature of the strain in each member. The method of Graphic Statics is applicable to all forins of trusses, to retaining walls, arches, etc. With the elementary ideas set forth here any man with a little careful thought should be able to construct a diagram of forces for almost all simple forms of trusses. Sondericker's Graphic Statics ($2.00) is an excellent book for further study. Notice the words "stress" and "'strain." Stress' is a measure of a force. "Strain is the deformation caused in a piece by a stress. The two pages following show methods of calculation used gener- ally by engineers in designing fan and Fink trusses. RESISTANCE OF BEAMS. CENTER OF GRAVITY. The last section simply mentioned how to calculate the manner in which forces acted and their amounts. Before the question of re- sistance to the forces can be taken up a few definitions must be given of factors used. When a piece is acted upon as a whole the resultant of the forces must pass through the center of gravity of the piece. This is the point in which the whole mass of the body might be concentrated, without affecting the force of gravity existing be- tween the piece (or body), no attention being paid to the relative positions or distances of the body and other adjacent bodies. Parallel forces, (that is, forces acting in the same line) opposite in direction, balance at the center of gravity. A weight acting downward is met by a resultant at the center of gravity and the body is stationary. If the points of application varied ever so little there would be a moment set up tending to rotate the body about the center of gravity. If a piece of paper or other material is cut into any shape and suspended by a point and a straight line drawn across in the direction of the suspending liiie it will pass through the center TOWNS AND SMALL CITIES. 8»3 NOTES ON ROOFS AND LOADS FOR SAME ANGLES OF ROOFS AS COMMONLY USED tniHirUon ft. add 4 lbs. to the above loads per square foot. It is customary to add, 30 lbs. per square foot to the above for snow and wind when separate calculations are not made. PRESSURE OF WIND ON ROOFS (Unwin) a =Angle of surface of roof with direction of wind. F = Force of wind in pounds per square foot. A= Pressure normal to surface of roof =F Sin. ai.M Co>. trU B = Pressure perpendicular to direction of wind=F Cot. a Sin. a>.M Coi. a C = Pressure parallel to direction of wind=F Sin. a i.x Coi. i^ AngledfToofsa 5» 10^ 20° SO" 40° 60° 60° 70° 80° 90O A=PX ,125 .Si .46 .66 .83 .95 1.00 1.02 1.01 1.00 BfePx .m .21 .42 .ST .64 .61 .(0 .35 •vt .00 C = FX .01 .04 .15 .33 .53 .73 .85 .96 .99 1.0ft CARNEGIE HAND BOOK. 384 ENGINEERING WORK IN ROOF TRUSSES TABLES FOR FINDING STRESSES IN MEMBERS FOR ROOF TRUSSES •OF THE DIFFERENT TYPES AND PITCHES AS OPVEN BELOW AND OF ANY SPAN Rule— To find the stress in any member, multiply tha coefiScient given for that member by total dead load carried by truss (= span in feet X distance between trusses in feet X weight per square foot). If tha truss is acted upon by wind forces w other unsymmetrical loading, the stresses in the members must be calculated accordingly and combined wit^ the dead load stresses as found below. Ktoli (leptk s.b.d' Omitting the fibre stress the expression for the section modu- lus is, ? "■ which is correct, as may be ascertained by looking 6 at any handbook containing tables of the properties of sections. The fibre stress depends upon the material. The point k was unfortunately omitted in Fig. 30. It is supposed 392 ENGINEERING WORK IN to be midway between G and H where the dotted line is drawn. The dotted line parallel with G H and also shown on Fig. 31, where it is marked M A, requires explanation. This line represents the moment arm of the resisting forces in the beam. In a number of reinforced concrete theories put forth, the moments of the (^oncrete and in the steel are balanced around the neutral axis. That is, the fibre stress is multiplied by an arm equal to the distance from the neutral axis to the center of grav- ity of the section. Upon such an hypothesis the action is thought to be like a pair of scissors having a joint on the neutral axis. As the weight is applied from- the outside the action is repre- sented in -Fig. 30. This being the case the triangle that stretches may be represented by one having a height equal to the deptn of the beam and a width at the bottom equal to d e (Fig. 31). The triangle that compresses has a height equal to the depth of the beam and a width equal to c b (Fig. 31). These two triangles are super- imposed and when the forces that balance are struck out the form of strains left is like that shown in Fig. 31. In other words, the neutral axis is not a fulcrum around which opposing actions work, " but is merely the point where two opposing forces balance and therefore equate to zero. The moment arm is the. distance between the points where the force in each half of the beam is concentrated". As the section modulus is a guide to the strength of a beam and is constant for all conditions of loads, independent of the spans, a table of S once calculated is good, for all time. It does not vary in proportion to weight, so frequently the lightest beam having the proper value of S js the Jjest to use for the sake of economy. Let M equal the bending moment in inch-pounds and S equal the section modulus in inch units. Let s equal the allowable fibre stress. ThenM = Ss = R, and S= -^ s • ' Having shown by the calculation- of the section modulus of a rectangular beam how the shape is all that has to be considered, we may use any form by using th^correct value of S. We may use any material by using the right value of s. We may use any system of loading and change it as we desire by substituting for M its proper TOWNS AND SMALL CITIES. 393 value in terms of length or span, and of the loads, either con- centrated or distributed. PROPERTIES OF USUAL SECTIONS. Section. -TT^ Area. -V^S" Y- 6d e 3 •577d. J. ' 1 6y f' UyM.y'-(i-i)(y-^y i(istktj 1 T77f/77m J. id-hlb-t) U-hU-t) /2 Id^-yg-i) 6d. t k- 6- 2 96 "2^ ga6 /2 12 ^-> .76540! .049 U- hfi-t) ZslKhf 6b i 394 ENGINEERING WORK IN A few values of the moment of inertia and of the section modulus are here given for use in simple work. For other shapes the rekder js referred to the hand books of the Steel companies and many excellent books on design of structures. Godfrey's hand Book ($2.50) is good. \ BEAM FORMULAS. It has been shown that the greatest bending moment in inch- pounds equals the section modulus times the allowable fibre stress, and that the section modulus equals the bending moment in inch- pounds divided by the allowable fibre stress. If the quantities are in foot pounds then the bending moment equals one-twelfth the section modulus multiplied by the allowable fibre stress and the section modulus equals the bending moment divided by the fibre stress multiplied by- twelve.' After the foregoing explanations it is not necessary to give a number of 'rules and formulas, for anyone can deduce rules to apply to any shape of beam. The tables of strength of materials here following will enable them to be applied to any materials. The modulus of elasticity has been referred to already and it is the basis of comparison between materials as the section modulus is between shapes. The strengths here given are the ultimate strengths of the materials. For safe loads divide as follows : For wrought iron and steel divide by four; for cast iron, divide by four; for wood, by eight, and for stone by six. The usual fibre stress (safe) used for hard steel is 16,000 pounds to the square inch in tension, and for sqft steel from 10,000 to 13,500 pounds per square inch. DEFLECTION OF BEAMS. The elastic limit of a beam is sometimes confused with the modulus of elasticity. _They are different factors, however. All materials are tq some extent elastic. They will return to their original form when the load is removed. Finally, however, a load may be applied which will permanently lower their modulus of elasticity. The material then has taken what is called a "'set." It has reached its elastic limit, which is usually about six-tenths the ultimate strength. TOWNS AND SMALL CITIES. 395 ■ STRENGTH OF MATERIALS. Ultimate Resistance to Tension. In pounds per square inch. Metals and Alloys. Aluminum Bronze, average. 10 per cent. Al. and 90 per cent. Copper, . 85000 IX •; " 985< " " . 28000 Brass, cast 18000 ' wire, •..-... 49000 Bronze or gun metal 36000 Copper, cast 19000 sheet 30000 " bolts 36000 "^ wire, unannealed 60000 Iron, cast, 13,400 to 29,000 16500 wrought, round of square bars of 1 to 8 inch diameter, double refined, . 50000 to 54000 wrought specimens yi inch square, cut from large bars of double refined iron, 50000 to 53000 wrought, doublerefined, inlarge bars of about 7 square inches section, . 46000 to 47000 wrought, universal mill plates, angles and other shapes, . . . 48000 to 51000 wrought plates over 36" wide. . 46000 to 50000 The*modukis of elasticity of double refined bar iron is 25,000,000 to 27,000,000. Iron Wire, . " wire ropes. Lead, sheet, 70000 to lOOOOO ; 90000 3300 — JONES et LAUGHLIN HAND BOOK. 396 ENGINEERING WORK IN All beams bend even when strong enougli' to carry the load placed on them. A limit, however, is placed on the bending, or deflection, and when a beam is not strained beyond the elastic limit the deflec- tion in inches is as follows : W X L' X c Def. = EXI Where W = weight in pounds, L=: span in inches, c = a constant, E = modulus of elasticity, and I = moment of inertia. The following values of c are used : Beam supported at both ends, loaded in center 0.021 Beam supported at both ends, uniformly loaded 0.013 Cantilever loaded at, end 0.333 Cantilever uniformly loaded 0.125 In order not to crack plastering no beam should deflect more than one-fortieth of an inch per foot of span. The modulus of elasticity of steel is from 29,000,000 to 31^00,000 pounds. For cast iron about 15,700,000 pounds. For wrought iron about 26,000,000 pounds. For oak and pine (average), 1,300,000 pounds. For concrete from 2,000,000 to 3,000,000 pounds. COLUMNS. Columns may be in one of three classes as shown in Fig. 32. They may fail by bending or crushing, or both. The strength to prevent crushing depends upon the compressive strength of the material of which the column is made. The ability to stand without bending depends upon a factoi" called the "radius of gyration.'' The ability to stand without either crushing or bending depends upon the quality of the material and the design. A short column is stiffer than a long one of the same material. The first class of columns is fixed at both ends and is the strongest, considering the section. The one that is fastened at one end and hinged at the other, or with a pin end, is not so strong. The weak- est .form is a column with two pin ends. When the fixed column TOWhhS AND SMALL CITIES. 397 STRENGTH OF MATERIALS-Contlnued. AVERAGE. Steel. 65000 to 120000 Tin, east 4600 feiic, 7000 to 8000 s Timber, Seasoned, and other Organic Fiber. Taken largely from Trantwine's pocket book (edition o{ 1868.) Ash, English 17000 " American, 16000 Beech, " 15000 to 18000 Birch 15000 Cedar of Lebanon, 11400 " American, red , . 10300 Fir or Spruce, ....... 10000 Hempen Ropes, ..... 12000 to 16000 Hickory, American, ...... 11000 Mahogany 8000 to 21800 Oak, American white 10000 to 18000 Oak, European » 10000 to 19800 Pine, American white, red and pitch, Memel, Riga, 10000 long leaf yellow, . . 12600 to 19200 Poplar, 7000 Silk fiber 62000 Walnut, black, . . . . . . . 16000 Stone, Natural and Artificial. Brick and Cement 280 to 300 Glass 9400 Slate 9600 to 12800 Mortar, ordinary, 50 .s>-JON£S &-LAUGHLIN BAND BOOS. 398 ENGINEERING WORK IN bends it" has two points of contra jlexure if both ends are fast or one fioint if only one end is fast. Reinforced concrete columns must have the loading reduced when the length exceeds ten times the diameter. The length should never exceed 'fifteen times the diameter. - The extreme of length, however, is generally governed by the size of the column, which increases rapidly with height and consequently takes up valuable floor space. Wooden columns should follow the same general rule as rein- forced concrete. Steel and iron columns and struts need to be reduced for load after reaching a length of twenty times the least width and should never exceed fifty times the least width. Two One Two y fix.td pin pin ends. find. ends. Fig.ZZ Columns. A beam begins to act as a column in the upper half as soon as loaded. Therefore after a wooden beam has a span of twelve times the least width it should be braced laterally and a steel or iron beam should be braced laterally for the same reason after the span exceeds twenty times the least width. Usually, however, they are braced at closer intervals. RADIUS OF GYRATION. An eminent engineer once said : "The radius of gyration is one of the most happy ideas of the fathers of engineering termi- nology. It is a first-class name, for it is not a radius and has n6thing to do v^ith gyration." The radius of gyration seems to have been a stumbling block to many writers. The writer has never TOWNS AND SMALL CITIES. 399 seen a definition that was capable of ready comprehension by the average man. The term is one in common use, and is a factor used in the formulas for columns. It is to column formulas what the section modulus is to beam "formulas. The radius of gyration of any section ^s the square root of the moment of inertia divided by the section area, and is written r. Suppose a plank three inches thick and twelve inches wide is used as a column or strut. After a certain load has been placed on the end it begins to bend. To stiffen it a plate of steel half an inch thick is bolted to each of the sides. This makes a four-inch column of it. If the plates stiffen Jt sufficiently then the radius of gyration of that column is the distance from the neutral axis to the '' center of gravity (or area) of one of the added sections. In this case one and three-quarter inches. Take another example. A three-inch solid cast iron column is bending under a load. It is taken down, but as no other material can be had it is recast into the shape of a hollow circular column. It then holds the load perfectly, although no new material has been added, because the radius of gyration has been increased. Every section, except circles, has at least two radii of gyra- tion. . The least radius is the one used. COLUMN FORMULAS. For columns many formulas are used. The older formulas were extremely complicated, as they were generally deduced by reasoning upon a slight foundation knowledge of the properties of materials. Modern formulas are known as straight line formulas and are de- duced from experiments on full size columns. W = safe load in pounds. 1=: length of column in inches. r = least radius of gyration. b = breadth in inches of least side, or diameter of round column. p = working stress in lbs., per sq. in. of section. a = area in square inches. Steel Column — W = pXa p=- 17,100- 57 fAJ\ 400 ENGINEERING WORK IN WEIGHT OF A CUBIC FOOT OF SUBSTANCES. Names of Substances. Aluminum, cast .... " rolled Anthracite, solid, of Pennsylvania . " broken, loose " " moderately shaken " heaped, bushel, loose Ash, American white, dry Asphaltum .... Brass (Copper and Zinc), cast " rolled .... Brick, best pressed . " common hard *' soft, inferior . Brickwork, pressed brick " ordinary . Cement, hydr'c, ground, loose, American, Rosendale " " " " " ' Louisville ■" " '■ " English, Portland Cherry, dry . Chestnut, dry . Clay, potters', dry . ... " in lump, loose Coal, bituminous, solid .... " " broken, loose " " heaped, bushel, loose Coke, loose,. of good coal . . . _. '* " heaped bushel Copper, cast rolled Earth, common loam, dry, loose " . " " " " moderately rammed " as a soft flowing mud . Ebony, dry Elm, dry s . . Flint Glass, common window ..... Avera'ge Weight, lbs. 160 167 93 54 58 (80) 38 87 504 534 150 125 100 140 112 56 50 90 43 41 119 63 84 49 (74) 26 (40) 549 556 76 95 -108 76 35 163 157 Gneiss, common ; jgg JONES & LAUGHLIN HAND BOOS. TOWNS AND SMALL CITIES. 401 Wooden Column — First Case — Length not more than twelve times the diameter or least breadth. W = a X c. Where c equals one-tenth the strength in the tables of strength of materials. Case II. — Length more than twelve times the diameter. Yellow pine, p = 850 — 8.5 (^^ Oak and Norway fir. p = 760— 7.41 (-^^ White pine and spruce, p = 630 — 6 ( -r— ) Hollow Round Cast Iron — p - 7625 — 40(-^) Columns and walls and roof joints carry a load equal to that over an area measured half way to the next support in each diFCCtion. As a general rule the compressive strength of wrought iron and steel is equal to the tensile strength. Cast steel in compression is about 20 per cent stronger than in tensionr Cast iron is six times stronger in compression than in tension, a fact to be remembered in designing cast iron beams. Wood is generally about two-thirds as strong in compression as it is in tension. Stone and masonry generally ten times stronger in cortipressibn than in tension. BUILDING LOADS. The loads usually figured for buildings are as follows :• Roofs 40 lbs. per sq. ft. Floors of dwellings and offices 70 " " " " " churches, theatres and ballrooms 125 " " " " " warehouses 300 to 250 "~ " " " " for heavy machinery 250 to 400 " (( (( 402 ENGINEERING WORK IN WEIGHT OF SUBSTANCES-Continaed. Average Names of Substances. Weight, lbs. Gold, cast, pure, or 34 carat . , ... 1204 " pure, hammered ...... ISl? ' Grain, at 60 lbs. per bushel 48 Granite 170 Gravel, about the same as sand, whiph see. Gjrpsum (plaster of paris) 142 Hemlock, dry .' . .25 ■ Hickory, dry ' . . , ^ 53 Hornblende, black . . . . , . , .203 Ice / . . . 58.7 Iron, cast 450 " wrought, purest 485 " " average 480 "ore 175 Ivory 114 Lead 711 Lignum-vitae, dry 83 Lime, quick, ground, loose, or in small lumps . 53 " " " "■ thoroughly shaken . 75 " " " " per struck bushel . (66) ^ Limestones and Marbles 168 "• " loose, inlrregular fragments 96 Magnesium- 109 Mahogany, Spanish, dry 53 " Honduras, dry ... .35 Maple, dry 49 Marbles, see Limestones. Masonry, of granite or limestone, well-dre^ed . 165 " " mortar rubble 154 " dry " (well scabbl6d) . 138 " " sandstone, well dressed . . , 144 , Mercury, 33° Fahrenheit .... 849 Mica 183 Mortar, hardened 103 Mud, dry; close 80 to 110 " " wet, fluid,'' maximum 120 Oak, live, dry 59 ^JONES & LAUCHUN HAND BOOK. TOWNS AND SMALL CITIES. 403 BEARING PRESSURES. Ordinary stone 180 lbs. per sq. in. Good stone 300 " " " " Brick in lime mortar 150 " " " " Brick in cement mortar , -.200 " " " " Concrete equal to best stone. Rock in place will bear from 5 to 200 tons per sq. ft. Dry clay from 2 to 6 tons per sq. ft. Soft clay from 1 to 3 tons per sq. ft. Gravel from 6 to 10 tons per sq. ft. Sand from 3 to 6 tons per sq. ft. Usual earth, etc., from 0.5 to 1 ton per sq. ft. Feet of piers and masonry columns and walls should be stepped off at an angle of about sixty degrees with the horizontal to spread the load. Piles generally carry from 10 to 15 tons each. Loads as great as forty tons have been used. The Engineering News formula for the bearing load of piles is the best the author is acquainted with and is one in common use. Let p = safe load in tons. d := penetration in inches under last blow. W = weight of ram in tons. h = height of fall in feet. ♦!,<.„ „ 2Wh This formula, and the fact is true for all pile driving formulas, should be used only when the pile is moving at each blow but with a perceptible lessening of movement. It is not good when the pile refuses to go any further. A pile driven to "refusal" may be resting upon rock and thus be able to bear almost any load within the limits of the crush- ing strength of the wood, or it may have struck some small obstruc- tion and be shattered as well. A good rule to follow is to stop -driving when the pile stops moving, but do not continue driv- ing after the above formula shows it is driven enough to carry the intended load. A pile is a column and the radius of gyration is not considered in computing the bearing power, for the necessary stiffness is furnished by the earth in which it is driven. 404 ENGINEERING WORK IN WEIGHT OF SUBSTANCES-ContlnuGd. Average Names of Substances. Weight, lbs. Oak white, dry 60 " other kinds . . . . 33 to 45 Petroleum 55 Pine, white, dry 35 " yellow, Northern 34 " " Southern 45 Platinum ...)...., 1343 Quartz, common, pure 165 Rosin . 69 Salt, coarse, Syracuse, K. Y. . . , . . .45 " Liverpool, fine, for table use ... 49 Sand, of pure quarts, dry loose . . 90 to 106 '•' wellshakei: ..... 99 to 117 " perfectly wet . . . . . 13a to 140 Sandstones, fit for building 151 Shales, red or black . . '. . . .163 Silver ..." 655 Slate . . . . . . , . . .175 Snow, freshly fallen ■ I • • • • 5 to 13 " moistened and compacted by rain . 15 to 50 Spruce, dry 35 Steel 490 Sulphur 135 Sycamore, dry , .37 Tar J . . . 63 Tin, cast .459 Turf or Peat, dry, unpressed . . . 20 to 30 Walnut, black, dry . . . . ... .38 Water, pure rain or distilled, at 60° Fahrenheit 63>^ "sea 64 Wax, bees 60.5 Zinc or Spelter 437.5 Green timbers \isu.i11y weigh from one-fifth to onerhalf more than dry. ^ JONES & LAUGHLIH HAND BOOK. TOWNS ANB small CITIES. ,m STABILITY. Fig. 33 shows how the stability of structures is computed. F is a force acting against the structure abed, with an arm f 1. The line g h represents the weight of the structure drawn to any Rf.33 ^--■* scale and passing through the center of gravity g. The line f e is the force platted to the same scale in line with F. The line f i is the resultant. To insure stability the moment of the distance c 1 multiplied by the weight of the section, should be greater than the moment of the force multiplied by the length f 1. The latter is the overturning moment and the former the resisting moment. ■^ If the point where the resultant touches the base is coincident with c then the structure is on the point of overturning. If it passes outside the base beyond c, the structure will overturn. In pracice the distance c k should not be less than one-third of c d. The resultant will then pass through the middle third. The effect of lessening the distance c k is to lessen the stability of the structure, to increase the danger of crushing the toe and to increase the pres- sure on the foundation. Occasionally piles have to be driven under the toes of such structures as retaining walls and dams, when econ- omy in material demands that c k be sometimes less than one-third of c d. It has been said that the force diagram can be drawn to any scale. The angle of the resultant is the thing sought. No matter what the length of the lines, the angle will be the same so long as 406 S - ENGINEERING WORK IN _ i the lines are drawn in the right directions and of the right lengths. The scale can therefore be as large as the case seems to require. The upper corner is always on a vertical line drawn through the center of gravity of the structure and at a height equal to the point of application of the line of force. ' This method of calculating stability is used for towers, tanks, bins, chimneys, dams, retaining walls, etc. For retaining walls and dams the pressure is in the shape of a triangle at the back. The pressure at the top is zero and increases with depth. It acts at a point one-third up from the bottom, as all forces in a triangle act through the center of gravity, which occu- pies this position. A table of the pressure of water is given earlier in this ch'apter. A deviation from this statement as regards a tri- angular force against retaining walls will be mentioned later. The pressure against towers, chimneys, etc., is caused by the wind. It is a distributed load acting on a cantilever beam and instead of being in the form of a triangle the force diagram is a parabola. If the weight of the structure is insufficient to resist the over- turning moment the additional weight required must be supplied by the foundation. If the ratio of base to height is very small the foundation must be spread. The upward Teaction on the base is the action of a load on a cantilever beam in length equal to the, distance from the' edge of the structure to the'edge-of the foundation. There- fore the foundation is in the form of a truncated cone or pyramid. Sometimes for chimneys the depth of the foundation is equal to one-sixth the height of the chimney. The width of the foundation at the top is one-tenth la'rger than the base of the chimney. The width of the foundation at the bottom is one and one-half the top width. There is a tendency to pull the foundation over which is resisted by the weight. To enable this to be brought into play the structure must be anchored to the foundation and the force is con- verted into a pull. The foregoing remarks about chimneys are true also of towers' and tanks. Their strength is calculated by using the properties for hollow square or r^und beams, according to the shape the structure is given. If the structure is truncated the strength rhust be com- puted at the bottom of sections. Wind pressure should be computed as being about 50 pounds TOWNS AND SMALL CITIES. ' 407 per square foot of surface as that is what a hurricane will fre,quently produce. The total pressure on a column will be the wind pressure multiplied by the radius of the column and its height. That is, the pressure on a round column is one-half the pressure on a flat surface having a width equal to the diameter of the round column. To find the total pressure when the wind is blowing against one of the diagonals of a square structure multiply the pressure against one of its sides by 0.707. The pressure against a tower having a tank on top is due to a distributed load (the wind against the framework) and also to a concentrated load caused by the wind blowing against the surface of the tank. The distributed load on the frame work may be fre- quently neglected. There is a slight twisting strain set up when the pressure is against the corners of the tower. This is resisted by bracing the corners with short pieces. Fig. 34 represents a braced tower carrying a tank, and the stress diagram. The dotted lines represent cross braces that are not considered when drawing the stress diagram, for they are out of action when the wind is blowing from the direction in which we are now considering the force. The braces act alternately as ties and struts. A diagram for the wind from the opposite direction would be identical with the first, so only one is necessary, but the dotted counter braces would be considered and the solid ones omitted if the other diagram were drawn. First letter the framework on the outside for each panel. From the point a, draw a horizontal line to represent the sum of the forces 408 ENGINEERING. WORK IN at the joints and indicate the amount o'l ^ach force by divisions in the line, properly marked. From the same point draw a line down- ward parallel with the batter pQst on the side opposite to which the wind is blowing. ^ i From each joint mark, except the first, on the horizontal line draw a line parallel with the batter post on the opposite side of the tower. This will make the convergency toward the bottom in the stress diagram. From the first joint mark on the horizontal line draw a line parallel to the counterbrace to intersect the batter post line. From this intersection draw^ a horizontal line to intersect the batter line from the second joint mark. From this last inter- section draw a line parallel with the next brace, etc., and continue until all have teen connected. The last line dropped from the end of the top horizontal line will be vertical and represents the upward pull on the anchorage. The horizontal line at the bottom, completing the diagram represents the compression in the bottom horizontal brace, or girt. This, how- ever, will be much less because the posts are tied. The tower is also designed to carry the weight of the filled tank. RETAINING WALLS. A retaining wall may have both faces vertical or have one ~ vertical and the other battered. If the batter is slight it is imma- terial on which side it is placed. When appearance is considered it is usual to have the batter on the back and have the face plumb. This assists as well in inaking the wall safe, for the filling gets a better hold on the wall by friction. If the batter is great the best plan is to place it in front so ■ the excess of material will act as a stay. The weight of the earth on the sloping back assists somewhat in adding its weight to the wall to supply a resisting moment against overturning, but this effect is lost if the material becomes wet. Vauban's rule for converting a wall with two vertical faces, into one with a sloping face having the same resisting moment, is to so adjust the angle of the sloping face that the line will intersect the vertical face one-ninth of the height from the bottom. The procedure then is to mark a point one- ninth of the heighth from the bottom and put a line through it at any desired angle, even making the wall triangular in section if that TOWNS ANp SMALL CITIES. 409 r is wanted. By computing a wall with two straight vertical faces and afterward changing the front by this rule, a -considerable saving in material can be effected. Before discussing retaining wall theories the following rules in use generally by practical men are worth remembering. Width at top one-tenth the total height above the surface of the ground. Depth of footing at front edge of wall five per cent of the height. Depth of footing at back of wall, seven per cent of the height. Horizontal projection in front at toe of wall, below surface of ground, five per cent of height. This projection is often omitted. Width (thickness) of wall at surface of ground as follows: For dry rubble, half the height; for good stone masonry, one-third the height plus one; that is; for a wall twenty-one feet the width will be one-third, equal to seven feet, plus one, making a total thick- ness of eight feet. For first-class stone or brick masonry, one- third the height. For first-class, solid concrete, three-tenths the height. Nearly all experiments on retaining walls have been with small models and with such materials as shot, peas, dry sand, etc. Ex- periments on large walls have not been enough in number to be of much value. Some experiments made within the last few years would seem to indicate that the pressure against a Retaining' wall for dry or moist earth should not be represented by a triangle but by a parabola. This would indicate that for low walls the pressure may be greater than a triangular force diagram gives and for high walls the pressure, increases on a curve. As this curve gradually be- somes straighter there may be a depth- after which there is no increase in pressure, owing to some arching action in the filling.- It has been suggested that a bounding curve for pressures might be drawn by starting with a diagonal line representing the pressure for saturated earth and another representing the pressure for dry earth. Draw a parabola tangent to the saturated earth line with a width equal to one-half the dry earth pressure at a depth of thirty feet. This curve would then represent the line of maximum pres- sure shown by the straight line m t in Fig. 35. Experiments made on pressures in grain and sand bins of full size indicate that a parabolic line of pressure is correct for loose, 410 ENGINEERING WORK IN granular materials. Whether it applies, however, to earth is not fully known. Earth filling is often saturated, in which case it becomes a semi-fluid mass with an increased resultant pressure -approaching a triangle in proportion as it loses cohesiveness. In the table of weights of substances the . weight of earth is given in different conditions. As the voids become filled with water the spaces formerly without weight take the weight of the water with which they fill. The angle of repose also lessens rapidly. A number of theories have been proposed for the design of retaining walls but for plain gravity walls the empirical rules already ' given serve all purposes and agree closely with the best practice. Walls often have to stand pressures not foreseen, and sometimes forces that can not be calculated. Today, however, a number of walls are built of reinforced concrete and in order to determine the dimensions some idea ' of ' pressures must, be obtained. Theories of pressure are coming to the front in numbers and old ones are heing revamped. In the end the idea of the line of maximum pressure being a paratola may obtain, but until it is proven the theory of Mosely, found in Traut- wine's Civil Engineers' Pocket. Book, and a' score of other works, will be generally favored, as it is simple, and walls designed by it have proven safe. Other theories generally make thinner walls where gravity sections a're used but make little difference in the case of retaining walls designed as slabs. Fig. 35 is copied from Trautwine. The line m w represents the slope at which earth will stand. It is here assumed at one on one and one-half (generally termed -IJ^ to 1 slope) or an angle of 33° 41' with the horizontal. The difference between that and 90° (the angle o m t) is 56° 18'. As earth will stand at the first slope mentioned there n^ust be some slope steeper than that at which it will commence to fall toward the wall. The line of maximum slope is taken at one-half the last angle or 88° 09', represented by the line m t This is known as the line of maximum pressure. The triangle o m t is the amount of earth that will press against a wall with a vertical back. For a wall with an inclined back the weight of the triangle c m o should be added to the weight of the wall. The line y P represents in direction and length the weight of the earth backing. If the wall has a vertical back the line y P will TOWNS AND SMALL CITIES. 411 be horizontal. If the wall has a battered back it will be normal (at right angle) to the back of the wall. It is situated at a distance up of one-third the height of the wall as it represents a triangle of force through the center of gravity of which it passes. This tri- angle of force it is understood is widest at the bottom, for at the top of the wall the pressure is zero. It is therefore upside down as compared with the triangle of earth filling. Referring again to Fig. 33 the overturning moment is the product of the force into the arm f 1. In the retaining wall backed with earth there is a certain amount of friction between the back of the wall and the earth filling as the wall moves in overturning. This friction helps to prevent the wall overturning until it reaches & c 1 f — ^- / f 1 ^ / >f a point where the earth falls behind the foot, provided the wall holds ^together. To find the eflfect this friction has we draw;, a parallelogram of forces y P f x. (Fig. 35.) The angle y P f is 33° 41' or the angle at which dry earth or sand will slide down masonry. Then y P represents the perpen- dicular pressure of the earth and x P the friction against the back. The line f P is the resultant of these two forces and thia is what tends finally to make the wall overturn or slide or break or be forced into the soil. Through the center of gravity of the wall draw the line g h. The resultant f P will pass through this line at s. Complete the parallelogram s i n o and draw the restiltant s n. This passes 412 ENGINEERING WORK IN through the base at the point j which should be in the middle third. Trautwine says a j should not be less than one-fifth a m even with the best masonry and unyielding soil. While the middle third gives the best margin of safety a less distance can be used if too great crushing pressure is not thereby developed in the toe of the wall or in the soil under the toe. When the back is offsetted or stepped instead of having a straight slope the pressure of the earth will be normal to a slant line drawn from the bottom to the top across "the steps, The moment tending to overturn the wall is the pressure f P multiplied by the length of the arm a v. The weight of the wall multiplied by ^ the distance of its Center of gravity from the point a is ihe resisting moment. While the arm a v in Fig. 35 is shorter than the arm f 1 in Fig. 33 the force f P, being inclined, is greater than the force y P. For the purpose of calculating the pressure it is usual to con- sider a cubic foot of earth as weighing one hundred pounds. One ^euhic foot of masonry can be figured as .weighing one hundred and fifty pounds. In obtaining the center of gravity the triangle of earth c m o must be taken into account, for its weight rests upon a projection at the foot of the wall equal to c o. To assume a cross- section of a wall having the proposed height use the empirical rules already given. Or calculate the overturning moment of the wedge of earth and draw a parallelogram of the right size to resist it, with the resultant passing through the toe. This can. then be transformed by Vauban's rule into a section with an inclined' face. It is usual to consider thq section of earth as being a slice one foot thick and the same with the wall . section. " If the wall is surchargeid, that is, has a terrace on top, the procedure is the same. The line m t is produced to an intersection with the terrace slope, thus making the wedge heavier. Fig. 36 shows a section of a reinforced concrete wall designed as a cantilever. Patents have been obtained on it so an extended description is hardly required here. The section is the same through- out the length. The reinforcing rods are all vertical and at the top and bottom are horizontal rods to prevent temperature cracks. The center of ^gravity is that- of a compound section consisting of the wall and the earth filling resting on the slab at the bottom. TOWNS AND -SMALL CITIES. 418 The diagonal reinforcement at the foot is to prevent the wall being broken at those points by the moments. Such a wall can be made of timber in which case it is , palled a bulkhead. The face can be connected to the bottom slab by spikes and the front projection can be replaced by a brace. At the back the front slab will be tied to the bottom slab by a tie of wood or metal. In fact many bulkheads and wooden retaining walls have been built by putting similar frames a number of feet apart and fastening heavy plank to the uprights by spiking them to the back or merely placing them at the back and counting on the pressure of the earth to hold them in place. Such forms of walls are more economical of material than gravity walls, but wood is perishable. When built of stone or brick flf.36 the rear, ties would be termed counterforts, but tear off readily. When placed in front they are termed buttresses, which are not always economical and have gradually assumed a place of ornament rather than utility. Reinforced concrete, however, possesses all the desirable qualities of wood with the additional one of imperishability so walls of this modern material are coming rapidly into use. As generally designed they consist of a floor slab and a face slab like the letter L through- out the length of the wall. At regular intervals vertical ribs (count- erforts) in the rear attach the two slabs so they will act as one section. While a number of such walls have been built, no study 414 ENGINEERING WORK IN has been published of the rib spacing in relation to height of wall in order to reduce cost. At present the spacing is arbitrarily settled by ^ach designer. In the following discussion the weight of the wall will be neg- lected. This adds to the factor of safety, adds practically nothing to the cost and simplifies the calculations. Methods of calculatiiig strength of reinfoi;'ced concrete beams will be taken up in pages fol-' lowing. I H fyff.37 ■L •»! 3. .4. Fig. 37 shows a section of wall assumed to be one foot long. There is a strip of filling one foot thick back of it tending to over- turn it, and the overturning moment at the toe A must be resisted by the weight of the earth on the bottom slab. None of the earth tending to overturn the wall rests on the bottom slab and the parallelogram of earth on the slab is considered as the wall. The reinforced concrete wall in front merely retains the earth wall in place. The vertical pressure therefore considered in the resisting mo- ment is equal to w h 1, where w ^ Weight of earth, h ^height of wall, and 1 ^ width of slab, acting through center of gravity of the section h 1. Assume x as equal to one-tenth the height and take moments about the toe for overturning^ and resistance to overturning, as already shown for a gravity wall. TOWNS AND SMALL CITIES. 415 Figs. 38 and 39 show the ribs used to tie the face slab to the bottom slab. , The face slab is calculated as a slab made of beams lying on their sides and spanning between the ribs. The loa4 on each beam is a distributed 'load " between the ribs. The horizontal thrust against the wall has been foirnd by Mosely's theory or any other. It is at the bottom but acting through a triangle is concentrated to cause an overturning moment, at one-third the height. The pressure of the earth against the bottom one foot beam of the face "TvT JilI. -rib F/g.3S slab to bend it, is equal to one-half the force multiplied by the height of the wall. This gives the load in pounds per foot. Multiply by the length in feet to get the total weight or load on the beam. Then upe the formula ^ as the beam is a continuous one ■ and multiply this by 12 to get inch pounds bending moment. A triangle can be drawn having this bending moment as ' the base and the height of the wall as the altitude. Horizontal lines drawn 416 ENGINEERING WORK IN through this triangle at other points give the bending moments of the other beams. Be careful to note the difference between the over- turning moment of the wall as a whole and the bending moments of its component parts. As the bending moments decrease toward the top smaller rods may be used or the rods can- be spaced farther apart. This latter is best, for workrnen are apt to make mistakes when rods differing in size are on the job. The bottom slab consists of beams lying side by side and' span- ning between the ribs, being attached at the bottom. The greatest strain will occur if the whole structure tips forward and lifts the last beam on the rear edge off the ground. It then supports- a distributed load one foot wide equal in height to the height of the earth over it and equal in length to the clear span between ribs. This beam being continuous the bending moment can be calculated as before. The bending moment decreases as a triangle toward the front face of the wall so the bars can be spaced wider as the face is approached. The bottom slab is fastened at the front edge securely, for the wall tends to overturn at that edge. It is fastened to the rear end of the rib by the ties. When the wall tips as a whole tlTe bottom slab acts as a beam with a span equal to the width of the slab from front to back. .It has a distributed load tending to tear it from the bottom of the rib, at the middle. To prevent this short vertical bars attach the slab to the rib. The lengths of the bars are governed by their size and by the adhesive strength of the concrete. The face slab has a tendency to tear off the front edge of the ribs and for the purpose of calculation the slab is considered as a vertical beam having a span equal to the height of the wall. To resist the stripping force short horizontal rods are' set into the ribs through the slab. In both cases, however, these stripping forces are small. In the majority of walls the cohesion of the concrete will be amply sufiScient without reinforcing ties. The projection x has a width on top from the face to the outer end equal to x^ minus half the thickness of the face slab. This distance multiplied by the reaction under the face of the wall gives the bending moment tending to break the projection off at B. This is counteracted by putting bars across the base in the bottom TOWNS AND SMALL CITIES. 417 sufficient in number and size to resist the moment. Under the ribs the bars can be 1.5x long and half way between the ribs they can run across the base. They decrease in length-as they approach the ribs. The thickness of the front end of the projection equals the thickness of the slab. At the wall it is twice as thick. The top of the wall is tied to the rear end of the bottom slab by steel rods sufficiently strong. The concrete in the ribs protects these rods. In large walls where a material saving can be thus made in concrete, it is usual to have the rib open like a timber braced tie. In small walls the ribs are solid. The ties along the back edge of the rib are calculated by taking a moment at C tending to break the wall at that point by reason of the weight of earth on the floor slab attached to the rib, resisting the overturning moment. The weight of the earth is equal to that resting on an area equal to width of slab times span. The foot of the wall and the bottom slab should be set well into the ground." GRAIN AND SAND BINS. Reference has been made to experiments made to determine the line of maxirnum pressure in bins containing grain or sand. The experiments were made by Mr. J. A. Jamieson and his paper appeared in Engineering News, March 10, 1904. The editors of that paper gave the following formula (deduced by Mr. H. A. Janssen, of Hamburg), as having "been proven by Mr. Jamieson's experiments to be correct. V=: vertical pressure of grain per square foot of depth below the surface of the grain. w = weight of grain in lbs. per cubic foot. f^ coefficient of friction of grain against side wall. k = ratio of lateral to vertical unit pressure. R = ratio of area to perimeter of horizontal cross section of the bin. e = the base of the Naperian system of logarithms. V=^A-e'R"'' The formula may be simplified by reference to some practical considerations. 418 • ENGINEERING WORK IN Wheat weighs 50 lbs. per cu. ft. Jamieson finds k for wheat closely 0.6, while friction coefficient f, for ordinary bin walls averages about 0.4. We may therefore take the product fk to be 0.25. Further, for all square or round bins the ratio R is constant and equal to one-fourth the diameter. Using above values the formula becomes V = 50dAe'd*"\ The term in the parenthesis approaches unity as the depth of grain increases. Limiting value of vertical pressure is therefore. Vertical pressure in lbs. per sq. ft. = 50 times the diam. of bin in ft. The term in parenthesis reaches a value of 0.9 when depth of grain equals 3.3, times the diameter of the bin. For all ordinary cases therefore, we may use the limiting maximum pressure directly. The horizontal pressure is at all times 0.6 as great as the vertical pressure. The formula means that the size of the bin determines the amount of pressure, whereas it was formerly believed the height alone had to be taken into consideration as in the case of fluid pressure. The vertical pressure being found by the .formula, the horizontal or bursting pressure against the sides of the bin at that point is 0.6 the vertical pressure. The Hne of pressure is a curve, instead of a straight line as in the tfieory of the retaining wall already discussed. Part of the weight therefore goes into the walls and part goes to the floor. The pressures given must be increased for other materials of greater weifht. Using wheat weighing §0 lbs. per cu. ft. with an angle of repose of 28°, the coefficient of internal friction =: 0.538. TABLE OF COEFFICIENTS OF FRICTION OF WHEAT (jAMIESON.) Wheat on wheat 0.532 Wheat on steel trough plate bin 0.468 Wheat on flat riveted plate and tie bars 0.375 to 0.4 Wheat on riveted cylinder . . .-= 0.365 to 0.375 Wheat on cement concrete, rough or smooth.. 0.4 to 0.435 Wheat on tile or brick, rough or smooth 0.4 to 0.425 Wheat on cribbed wood .0.42 to 0.45 TOWNS AND SMALL CITIES. 419 The ratio values for sand are practically the same but the weight per cubic foot is double. BULKHEAD WALLS. Many city engineers in places located on rivers, lakes or other bodies of water are called upon to design bulkhead walls. For ordinary foreshore protection, a fill with a long gradual slope on the face, covered with large, carefully placed stones, is usual. For bulkhead walls, however, meaning thereby retaining walls with a front designed, to permit vessels to come alongside, the, engineer is not well provided with information, the literature being sparse and useful only to specialists. Mr. S. W. Hoag, Jr., described in Engineering News, May 18, 1905, a method devised by him and Mr. D. C. Serber for calculating bulkhead walls' in New 'York City." What follows is an abridgement of his article, illustrated with a copy of his drawing. The subject is clouded with much uncertainty and experience is a most useful guide. The conditioiis given are an approximate cross section of submerged or of non-submerged wall, submerged sections and non-submerged sections of rip-rap filling and of earth filling and a surcharge of 1,000 lbs. per sq. ft. The analysis is con- ducted on the following assumptions : ' Weight of rip-rap in air, 107 lbs. per cu. ft.; submerged rip-rap, 70 lbs., per cu; ft; earth filling in air, 110 lbs. per cu. ft; submerged earth filling, 66 lbs. per cu. ft. ; surcharge, 1,000 lbs. per sq. ft. of surface. Erect a perpendicular a d. Lay off the prism of maximum thrust for rip-rap by the 'plane of rupture a e. Prolong a e to n. Denote the corresponding prism for the superimposed submerged earth filling by the plane e k, prolonged to m. Neglecting the change in plane of rupture for non-submerged earth filling, the limit of surcharge to be considered at the Surface grade is contained be- tween the intercepts d and m. Consider everything below mean high water as submerged and everything above mean high water as non-submerged. v First — Determine the weight of the submerged earth filling c e k, and replace it with a corresponding- weight of submerged rip-rap. The top surface of the latter will then be c f k. 420 ENGINEERING WORK IN Second — Determine the weight of the non-submerged earth fill- Qroph/co/ /f/fa/ysfs of BuLHHEfio Walls. iT' f. wl..—t I t ' , 'Ml. 1 ' /^ *^af ing c d m k and replace it with a volume of submerged rip-rap of equal weight, and allow it to take its position upon the first TOWNS AND SMALL CITIES. 421 reduced volume of submerged rip-rap. This second volume will then be c d' h' 1' m k f. Third — Take the surcharge of 1,000 lbs. per sq. ft. and erect upon the top surface d' h' 1' m of this imaginary bank of sub- merged rip-rap, a prism of submerged rip-rap of such a volume as shall equal in weight the surcharge; the upper surface of this reduced volume will be d" h" 1" m'. The area a d" h" 1" m' m e a ■ represents in volume all of the back filling used in exerting pressure against the wall, reduced to one homogeneous material, namely, submerged rip-rap, weighing 70 lbs. per cu. ft. To avoid the complication arising from a consideration of two planes of rupture a e and e m, consider alone the plane of rupture for rip-rap a n, for all the backfilling has been reduced to rip-rap. This is done by shifting the material represented by the area e n m to a new position, to form part of the prism limited by the plane a n, making h" the new position for e, 1" 1"' the new position for k 1', and m' m" the new position for m n. The volume to be considered ■having the weights of submerged rip-rap, is now represented by the area a d" h" 1'" m" n a. The center of gravity of this area is at g' and combining the weight of the mass through g' with its horizontal component, the horizontal thrust on the back of the wall is 27,000 lbs., applied at the point p. Combining this thrust with the weight of the wall, represented by the vertical line 65,300 lbs., through its center of gravity, the resultant is 71,000 lbs. passing through the base at the point r. In determining the center of gravity of the wall section it is, of course, necessary to consider the reduction in weight due to displacement below mean high water, of the twoxmaterials, concrete and granite, which enter into its construction, the weight of the non-submerged portion above mean high water, the weight of the submerged rip-rap on the steps in the rear of the wall, the weight of the superimposed volume of non-submerged rip-rap and of earth filling. Older methods trace the pressures through the different ma- terials, the several resultants finally after combination giving the total amount of thru'&t on the wall with its direction. The method just described is shorter, simpler and, practically, just as accurate. 422 ENGINEERING WORK IN ARCHES. Arches today are generally built of reinforced concrete, but occasionally a brick or stone arch may be constructed. The arch starts with a depth for the keystone and this depth is called the crown thickness. AU formulas in general use are largely empirical, being averages of successful arch bridges put into con- venient form by which other arches can be calculated. One used by the writer for several bridges (taken from an old English work) is as follows : Where d is the depth of keystone, or crown thick- ness, and r is the radius of arch at crown. For a single arch d= v 0.12 r, and for a series of arches d= yo.l7 r. The foregoing rules, however, are intended to apply more par- ticularly to semi-circular arches under fairly high embankments. When the load is uniformly distributed the rise should be equal to about one-fourth the span,- which gives a form approaching a parabola. The ring then can be of uniform thickness. Otherwise it must be thicker at the haunches. All arches are supposed to have a curve of equilibrium located somewhere within the lines of the arch. The calculations are com- plicated and many empirical rules and methods are in use to enable arches to be designed, without going through the calculation of the equilibrium curve, of such proportions that this curve will lie in the middle third. The ellipse is considered the most handsome ci,rve in existence. The circle always has the appearance of an ellipse except when viewed from one point. The ellipse possesses certain properties of strength and equilibrium also which make it a good curve for an arch bridge. Therefore it is in common use. Ways of drawing an ellipse are given in many books. It is usual to construct an ellipse like a , compound railroad curve, with several Centers. But for arches having earth filling exceeding two or three times the thick- ness of the arch at the crown the semi-circular form is preferable. For arches having a very flat rise it is probably best to have- a segmental arch of reinforced concrete. The critical point in an arch is in the ring on each side of the Center -at a point equal to half the rise. This joint is on a radial line from the center from which that part of the underside of TOWNS AND SMALL CITIES. 423 the arch ring is struck. Fig. 40 shows a method proposed by Mr. Emile Low for drawing the arch ring in order to get the necessary additional thickness at the critical joint in the haunches. At the middle of the span draw a circle with a radius equal to the rise. From the same point describe an arc on each side with a radius equal to the half span. On this arc the point b will be on a hori- zontal line with the top of the arch ring. Draw the radius from the center to b. Drop a perpendicular from b and draw a horizontal line from a to intersect with it at c. Connect the points c and d with a straight line. Bisect it and produce it to an intersection with the perpendicular dropped from the center of the arch. This gives the radius with which to draw the arc c d on the underside. A ^nq.lfec F^g.^ radius from the same center but equal to the first plus the ' crown thickness is the radius used in striking the outer side of the arch. To get the radius for the sharper part of the underside from c to the bottom of the arch draw a- line from the end of the span to c, bisect it and get the radius by the intersection with the radius of the larger circle. This it will be seen gives the ring of uniform thickness to the point c. The depth of the arch ring for this construction is given by Mr. Low as follows : Let S = span of arch in feet. R := rise of arch in feet. , H ^ depth of surcharge over arch in feet. d = thickness of arch at crown in feet, then d = ^ y (S — R) 10 — 3H 424 ENGINEERING WORK IN Such an arch must be buih of first-class brick or stone masonry. For reinforced concrete Mr. Daniel Luten. (president of the National ' Bridge Company), states that this combination results in consid- erable ecbnomy over a segmental circular arch, but is too flat at the crown and too high at the haunches for an extremely light ring, such as might be used for reinforced concrete arches. He states, in Engineering Record, that it has been found that nearly all arches with elliptical intrados and thin arch. rings will show slight cracks at the intrados crown. A circular segment, on the contrary, will show cracks at the under surface at the haunches and will break away from the span- drels above the springings, showing that this curve is too flat at the haunches and too sharply curved at the crown for the earth loading. He proposes the curve shown in Fig. 41, in which the inner curve is a mean between the ellipse and a segment of a circle having the same rise and span, and the outer curve is a circle. In this figure the ellipse a b c is the same curve as the inner curve of Fig. 40; the circular segment a d c passes through the crown and the springing of the ellipse. The inner curve of the arch is then determined as a mean of these two curves by bisecting the vertical distances between. In order to facilitate laying it out, the curve is approximated by arcs of circles determined by trial after a sufficient number of points on the curve have been plotted. „ The outer curve is a circle having its center on the center line of the arch and a radius equal to the radius of the intrados TOWNS AND SMALL CITIES.. 425 at the crown plus two and one-half times the crown thickness. ■ This relation between -the radii of inner and outer curves results in an arch ring of a thickness varying approximately as the secant of the angle of inclination. Such a ring is believed to give better results for equilibrium than either an elliptical or a circular arch. Fig. 43 illustrates a method much in use for determining the thickness of the arch ring for arches of brick or stone masonry. The critical joint in each half span is at half the rise. Its thick- ness is determined as follows, where S is the clear span and R the rise, t is the thickness at the joint and d the crown thickness: _S^ R _S_ R . = 3; t: :4; t: :1.8d. : 1.6 d. ^ = 5; t = 1.4d. On squared paper the above values can be plotted and a line drawn so the thickness for other, ratios can be obtained. For an elliptical arch the number of centers used in determining the inner curve is equal to the ratio. When the ratio exceeds 5 it is best to use reinforced concrete. •' To determine the arch thickness throughout set out the inner curve and mark on it the length of the two critical radial joints. 426 ENGINEERING WORK IN Set off at the crown the thickness. Connect the upper end of this with the upper end of the joint on one side. Bisect this connecting line and produce the line bisecting it to a junction Svith the vertical line through the middle of the half span. This gives the radius of the outer circle of the arch ring. It stops at the critical joints, from which point the outer line is tangent to the outer curve. If the height is increased by resting the arch upon vertical abutments the thickness of tlje abutment will be 0.3 span and at the rear end Will rise until intersected by the outer arch line. For the thickness of the croWn ot reinforced concrete bridges Mr. F. F. Weld, gives the following in the Engineering Record : C = thickness of arch ring in inches at crown. S= clear span in feet. L ^ live load per square foot uniformly distributed. D =:: weight of fill over the crown per square foot. C=y/ 'E'-j- O.lS + 0.005L + 0.0025D. Example — To find thickness of arch at crown. Span 60 feet. Live load 200 lbs. per sq. ft.', or 15 ton steam roller. Fill over crown 3 feet thick. C = 7.7 + 6 + 1 ■+ 0.55 = 15.2 ins. For railroad bridges- add 50 per cent to the equivalent live load for impact. Having determined C lay out arch. Rise is preferably % to 1-10 the span but will usually be governed by local conditions. Thickness of ring at critical joint should be 1^4 to V/i C, depending upon curve of intrados. Steel reinforcement should be in two layers on account of reversal of stresses and made continuous over the entire span. Amount -in each layer should be equal to 0.4 of one per cent (total 0.8%). There should be shear members rigidly connected to longi- tudinal rods and extending from one layer to another. Mr. Weld is engineer for a firm manufacturing a special reinforcing rod with such ^hear members. The shear members are necessary, how- ever, at certain places on the arch and do no harm at all points as stated. With a well designed equilibrium arch the lower rein- forcement can be dispensed with near the haunches, below the critical joint and the upper reinforcement can be omitted at crown, TOWNS AND SMALL CITIES. 427 provided plenty of shear members are placed on each side of the joint. In this connection Mr. Luten says : "A concentrated load ap- plied to the crown of such an arch as that of Fig. 41 will require reinforcement along the inner surface at the crown and along the outer surface at the haunches. By using one series of reinforcing tnembers for both these regions and alternating the points of their crossing the arch ribs, the one system of rods can be made to rein- force the arch against all stresses. By distributing the points of crossing so that the rods will cross in the middle and thirds of the half arch, this reinforcement will provide also for all possible concentration of loads on the arch." The difference in the two plans consists in the fact that Mr. Weld places reinforcement on both sides of his arch ring and has shear members the whole length. Mr. Luten reinforces his arch from a short distance on the outside of each critical joint on the bottom across to the same place on the other side. The rods are continuous from the outside end on top to where -they cross the ring and go over on the underside. The top of the ring he does not reinforce between the places the outer rods cross to the bot- tom near the critical joint. He lightens h"is abutments by taking the rods down to the water level and, crossing them under the bed in a concrete pavement, thus tying the abutments together. Mr. Weld recommends that central piers should have a mini- mum of 1-12 the span and be battered for appearance and sta- bility. Fig. 43 shows an arch reinforced in a manner illustrating the ideas presented by Mr. Weld. Fig. 44 shows an arch reinforced in accordance with the ideas presented by Mr. Luten. Mr. Luten objects to the usual design of culverts with sides and tops figured as flat slabs, and makes a plea for the arch, this being more espe- cially applicable to railroad culverts or culverts under embankments having railroad tracks on top. 428 ENGINEERING WORK IN He gives the following (Eng. News, May 34, 1906) for de- , signing such culverts for spans up to 50 ft. and with not more than 10 ft. of fill over the crown. Crovj^n thickness = — 2^ — -|- -g- o\j o Outer circle drawn with center 1-10 of span below center of inner circle. Back of abutments tangent to outer circle and battered one in four. Square inches of steel required to reinforce one edge of arch for 1 ft. in width = g^ Where H is height of opening in feet, C is crown thickness in inches, and L is live load in pounds that can be concentrated on single track ovfer half span. If the arch is reinforced near both edges (double reinforce- ment), the steel near the other edge must be added to the area given by the formula. If reinforced by a single; series of rods, they should cross the arch rib at points one-third, one-half and two-thirds of the distancefrom springing to crown. The arch, of course, carries the weight of the loadf yet the observer only sees the underside of the arch. The road is carried on a straight line which is determined by the retaining walls (or spandrels) set on the outer edge of the arch. These walls are designed as regular retaining walls. The abutments can be figured as already mentioned if the rise begins at the level of the ground or the surface of the water. ' If the arch rests upon abutment walls their thickness will be gov- erned somewhat by the height of the embankment, for they will serve the double duty of retaining walls and arch abutments. The point where the curve begins at the top of the abutment wall is termed the springing. The horizontal thrust of the arch at the top of the springing is equal to the total weight on the arch, including the weight of the arch, divided by 1.414. The vertical force at the springing, tending to aid the stability is equal to half the weight of the arch and load. Calling H the height of l^e springing above the , ground, the overturning moment due to the thrust on the arch =: ^^H where TOWNS AND SMALL CITIES. 429 w is the weight per Uneal foot of arch and load, S is the span, and R is the risfe. The resisting moment is = — - — + ^L. where W a Li is the weight of the abutment per cubic foot, and t is the thrust against the abutment at the springing. The moments can be com- pared with those acting against the abutment as a retaining wall and the one producing the heavier abutmeKt will be used in the design. In adopting this method the support given the retaining wall by the arch can be taken into account, for the thrust of the fill will assist in counteracting the thrust of the arch. REINFORCED CONCRETE. Concrete is practically tfen times as strong in compression as in ' tension. Consequently if a concrete beam is designed to stand a certain bending moment it would have to be in shape like a capital letter T inverted, in which the short foot would be at the top and have an area one-tenth as great as the area of the top (or in this case the bottom). Such is the theoretical beam of "cast iron in which the bottom flange is six times the area of the top flange. Practical considerations in the foundry prevent the castings of an iron beam of such form, so it is common to dispense with the top flange and make the bottom flange and upright leg proportion- ately stronger. When both flanges are used the upright is supposed to take care of shear. Such a beam cannot be made of concrete for the modulus of elasticity is very low and the beam would probably break in han- dling. When designed as a rectangular beam the material is uni- form and being uniformly distributed the neutral axis would seek the center of gravity and prevent a proper distribution of stresses. Such a beam would be enormously large and heavy for the load it could carry. The ratio of the modulus of elasticity of steel and concrete is variously given as being from 1-iO to 1-15. This ratio is used in many formulas to determine the exact position of the neutral axis. After that it is of no practical significance. The reason for the variation of the ratio is that some men use concrete with a certain modulus of elasticity and some use it with another. The fact is that the modulus of elasticity of concrete depends greatly 430 ENGINEERING WORK IN upon the care used in making it and varies in the same beam, as has been shown by taking sections of beams and separately testing them. _ ' Having determined the neutral axis the upper part of the beam in compression is of concrete and the total moment is expended at two-thirds of the distance up from the neutral axis. The ex- treme fibre stress in compression of concrete is usually limited to 500 lbs. per sq. in. Having determined, the position of the neutral axis and" the. total compression in the concrete the location of the steel reinforcement in the lower part of the beam is found and the total tension on it. The area of the steel is proportioned accord- ingly'.' The -concrete below the neutral axis is practically useless except as a protection for the steel. In fact the design of a reinforced concrete beam is likened to a belly rod truss beam. The beam stands the compression and the steel rod under the middle strut takes the tension. On this hypothesis reinforced concrete beams might be designed in such a manner, having a strut of concrete under which to pass the steel rod and the spaces between could be open, the rod being, surrounded with only enough concrete to pro- tect it. Nothing has ' yet been discoyered that will so effectively protect steel as cement. If there is any economy in such beams they will some day be made. Roof frames have been made and retaining walls with open ribs have been made on this principle. " The Visintini beam is a trussed beam invented by an' Austrian engineer, in which the reinforcement' is placed in the form of a Warren truss and sur- rounded with concrete to protect the tension members, the com- pression members being of concrete and large enough to furnish the required compressive strength. Any truss or frame of wood can be imitated in reinforced concrete and the dimensions of a reinforced concrete frame will be very little different from those of a wooden frame, depending upon the percentage of reinforcement. Steel has an elastic limit. Concrete has practically none. The elastic limit of steel is about six-tenths the ultimate strength. This, however, is not strictly true, for in soft steel the elastic limit can be raised by working the metal. This is the reason twisted rods of soft steel are so much stronger than the same size plain rods, of the same material. Soft steel is preferable for TOWNS AND SMALL CITIES. 431 reinforced concrete work if the elastic limit is raised, for it is more reliable as a building material than hard steel. Many of the theories and formulas for reinforced' concrete are based on the ultimate strength of the materials composing it. This is wrong, as experiments have proven, for the moment the elastic limit of the steel is passed, the fnodulus of elasticity rapidly lowers until it approaclies that of concrete. Another mistake made in using the ultimate strength of the steel is that for all iron and Steel the modulus of elasticity is so nearly the same that the as- sumption of the right ratio between steel and concrete may more than make up the difference existing between the mildest of iron and the hardest of steel. Assuming for .example a steel with an ultimate strength of 100,000 lbs. per sq. in. and an elastic limit of 60,000 lbs. with a modiilus of elasticity of 30,000,000. Take also some medium steel having an ultimate strength of 63,000 lbs. and an elastic limit of about 35,000 lbs. and having a modulus of elasticity of 28,000,000. It is readily seen that basing the comparative strengths of the upper and lower sections of the beam on their comparative moduli of elasticity, while there exists such wonderful variations of strength- within comparatively slight limits of the moduli of elasticity, is wrong. All tests have shown that the elastic limit, and not the modulus of elasticity, of steel governs the strength of the beam, and as concrete has no elastic limit capable of practical Use, then the ultimate strength of the concrete must, be used. Our knowledge of the properties of reinforced concrete increases daily. We have had the results of so many experiments published that we do not longer need the formulas derived by mathematicians nor the strictly empirical formulas derived from experiments alone. The mathematicians served to show the way to experiment. Experi- ments did not always prove their deductions to be correct, for they of necessity must assume perfect conditions, — conditions not always possible in practice, because after all it 'depends upon the care used in fabricating the concrete and combining it with the steel. As the compressive strength is depended upon and such strength cannot be uniform unless all the voids are filled, con- crete used for reinforced concrete beams should be a 1 : 2 : 4 mixture. In such a combination"" the voids are assumed to be filled 432 ENGINEERING WORK IN perfectly. In the portion of the beam in which the rods are imbedded the stone should not, exceed half an inch in any dimen- sion. After the filling has covered the rods larger stone can be used, but not exceeding three-quarters of an inch. Crusher run is best. The concrete should be wet, very wet in fact, and care should be taken not to entrap air. The neutral axis has been irientioned and its location seems to be deemed of such importance in discussions that a little space de- voted here to it will be useful. tL, ^. F,^4^ ^^4^ F.g^7 Fig. 45 shows a beam of rectangular cross section, in which the small wings on each side represent an area of concrete fifteen times as great as the rectangle. These wings are the thickness of the steel reinforcement. The center of gravity of this com- pound section is supposed to show the position of the neutral axis. This- theoretically is the proper location if the two ma- terials are considered as forming a new r^aterial and the concrete below the neutral axis is depended upon to furnish some tensile strength. In a certain patented reinforcing bar having shear mem- ( bers the concrete is so bound together that the whole of the lower part of the beam is supposed to be in tension. Hence the published formulas of the company making this bar, indicate the neutral'axis where shown in this figure. Fig. 46 is the same beam in which the concrete is not relied upon for any tensile strength. The stress increases proportion- ately with the length of the moment arm so the diagram of the ' stressed concrete assumes a triangular form and the center of gravity of such a beam is nearer the middle. The triangular form of stress adds to the factor of safety. ' If the concrete below the neutral axis is relied upon for tensile strength the form will be a parabola instead of a triangle. The TOWNS AND SMALL CITIES. 433 parabola is the correct form until the beam is dangerously loaded and the concrete in the lower portion is filled with minute cracks. Until the cracks open enough to expose the steel the beam will hold until the' ultimate strength of the concrete and the elastic limit of the steel are both passed. The depth of the beam, or thickness of the slab is always measured from the top of the concrete to the center of the rein- forcement. The concrete below the steel arid at its sides is solely for protection to the reinforcement. Calculation^ in which a clear distinction is not made between the modulus of elasticity and the elastic limit, place the neutral axis in different positions. Its position varies in fact with the proportion of steel used and with the load imposed. Experiments show that the neutral axis in a beam not, stressed beyond a safe point is in, or very close to, the middle of the beam. Close enough for all practical considerations. It is best then to so design beams that the neutral axis is taken at the middle and enough reinforcement will consequently be used to produce a safe design. In the following argument the ultimate strength will not be considered, for it is the safe design of beams that is sought. In- stead of using 3,000 lbs. for concrete the ultimate fibre stress of 500 lbs. per sq. in. will be used. Instead of using an elastic limit of 50,000 the safe fibre stress of 13,500 lbs. will be used. This will be all right for a mild steel twisted. For a high carbon steel with a higher elastic limit a higher stress can be used, but it is advisable to make the safe fibre stress one-fourth' the elastic limit. A great many formulas contemplate using one-fourth the ultimate strength. This partly accounts for the low percentages of reinforcement so often used. Referring to Fig. 47 (and to the previous discussion on resist- ing moments in beams), the total compression in the concrete is evidently 500 H^ == 125 bd. To properly determine the- size of the beam this must be equal to the stress in the steel. Calling the area of the steel A, this gives 12,500A = 135 bd 125 or A = ig"Tfifi ^^ ^■^■^' °^ '^ equal to one per cent of the cross section of the beam. 434 ENGINEERING WORK IN Taking the neutral axis as oeing in the middle of- the beam, and considering that the compressive forces act through the center of gravity of the triangle forming the stress diagram of the. con- crete, the moment arm of the steel reinforcement is equal to 0.833d or to five-sixths of the depth. The ultimate resisting moment must of course equal the bend- ing moment, or R = M. R = 0.833d X 135bd — 104bd"; -J M 104b Taking all dimensions in inches this moment is in inch- pounds. A similar proceeding can be followed for steel having an elastic limit of 32,000 lbs., or for any other limit, and the amount of steel will be proportioned accordingly. Some economy can be- effected thus if the prices of steel permit. Mild steel is the most reliable and can always be purchased in the open market. Allowing 10,000 lbs. safe fibre stress the steel will be 1.25% of the area. Allowing 16,000 lbs. safe fibre stress the percentage of steel will be practically 0.8%. In using any steel the ends should be bent ap at a right angle when beyond the support. When using a hard steel '<■ should be deformed if the high fibre stress is to be depended upon. Otherwise use a low fibre stress. The writer prefers soft steel smooth rods with a fibre stress of about 10,000 lbs. If a higher- fibre stress is used then use soft steel twisted rods. There are a number of deformed rods on the market, some of soft steel and some of hard steel. The percentage it is safe to use depends upon the safe fibre stress of the steel. The deformations add to the ordinary adhesion of concrete to steel, the advantage of a mechanical bond. Whether this is in the long 'run a decided ad- vantage is not proven. ^ The adhesion of concrete to steel may be often destroyed when using steel having a high elastic limit unless some mechanical means are provided to assist the adhesion. When this reduction in the amount of steel is secured at the expense of using a material (hard steel) not considered reliable for general structural pur- poses, the safety of the structure may be questioned, especially if the TOWNS AND SMALL CITIES. 435 designer has used a factor of safety based on the ultimate strength. The. adhesion of concrete to steel is allowed at about 75 lbs. per inch of surface, with a factor of safety of four. That is, a one-inch square rod will offer a resistance of 4 X 75 := 300 'lbs. per inch in length of rod, to being pulled out. All rods should lap at least 25 diameters where spliced. When using too high a fibre stress in the steel there is danger of causing the imbedded rods to slip and the neutral axis will rapidly rise, thus throwing too much stress on the concrete. This is why the mechanical bond is thought to be helpful. It is best to design safely and not pay too much regard to extreme economy in material. When using a stress that will not be likely to over- tax the concrete the mechanical 'bond is always an advantage. The only warning concerning the use of deformed rods is not to ask too much of the bond tut to depend rather upon the adhesion. It is not advisable to use a depth of beam exceeding 1-12 the span. The breadth should not exceed two-thirds the depth. Thin- ner beams must be cross-connected at distances of not to excted twelve times the thickness to avoid bending. The shearing stresses in beams can be calculated and the beam designed for depth so the shearing stress will not exceed 50 lbs. per sq. in. When connecting slabs to supports, as in the case of the slabs fof retaining Walls, already considered, the ad- hesion of 75 lbs. per sq. in.' is the force depended upon for holding. There should be reinforcement in the web. To determine this construct the parabola of bending moments on the beam. Then when the reinforcing rods in the bottom have passed the point where they are or value in resisting bending moment, turn them upward it an angle of forty-five degrees to within about one 'inch of the top of the beam. This will generally mean that at the quarter point one-fourth of the rods will be turned up. .At one- sixth of the span one-third of the remaining rods will be turned up. At one-eighth there will be turned up one- fourth of the remaining rods. The outer rods should not be turned up but will continue straight to the end, where they will be bent into a hook. When beams are continuous over two or more spans the breaking load can be increased one-fourth. We can therefore cal- culate the amount of steel necessary to carry a load one-fifth less than if it was a beam of simple span. The saving of steel thus 436 ENGINEERING WORK IN effected in the bottom will be placed in the top of the beam ex- tending on each side of the supports to the quarter span points of the beam, where the rods will then be bent downward at an angle of forty-five degrees to within an inch of the bottom. This guards against contra flexure which otherwise would crack the beam — sometimes, however, without weakening it. It is a good plan to always reinforce against contra flexure when a beam is tied. /v^. 4-6 LI Whether the additional support is sought or not, by tying the end supports the effect is gained and the beam frequently has unsightly" cracks unless the contra flexure is considered. In many cities the building ordinances refuse to permit any advantage to be taken of the continuous beam action, but compel all beams to be designed as for simple spans. The usual formula wl* for a uniformly loaded beam is -'^ but if advantage is taken of the continuous beam action it becomes • — or ^L and in the case 10 12 wl' of. floors supported on all sides it is — The thickness of concrete to place under the rods in the bottom, or over the rods in the top should not be less than one and one-half times the diameter or thickness of the rod. The least thickness, irrespective of the size of tne rod, should be one inch. This thickness to be measured from the center of the rod. Round or square rods are superior to flats. The best shape is the T bar, but it is claimed a patent has been issued for the use of that shape. The rHore numerous the rods the better the re- inforcement, provided that no rod of less size than half an inch is used, and the least space between rods should be equal to the thickness or diameter. The spaces between rods should not ex- TOWNS AND SMALL CITIES. m ceed two-thirds the thickness or depth. So far as size is con- sidered an exception can be made for hard drawn wire, provided it can be stretched and held tight during the placing of the con- crete. The stretch should not be enough to place any initial ten- sion on it. Very small rods can be, and are, used but are apt to bend. Expanded metal and electrically welded fabric are extensively used. They are excellent materials. Sometimes the area of such reinforceiftent is not sufficient so it is often necessary to supple- ment it with rods. In all slabs reinforced with rods there should be rods of the same size crossing them to distribute the stresses. It is customary to have the interval between the distributing rods equal to 1.5d, where d is equal to the thickness or depth. In reinforced cinder concrete the safe fibre stress should be taken as equal to one-half that of good rock concrete. Fig 49 1 1 1. 1 1 \l li «^ -— -^^— ^ ■r^^ Fig. 49 shows a common form of culvert, for the usu^prac- tice is to make them rectangular. The tops are slabs tiecPto the sides and they carry the earth load and any other live load that may be imposed. The bottom in such a culvert is designed to help resist the thrust on the bottom at the sides. The sides are designed as beams supported at the top and bottom, the span being equal to the height of the culvert. Sometimes the sides are designed as retaining walls. In such a plan the bottom can be omitted or may be merely a pavement- for the bottom of the waterway. The top can then be depended upon to assist in resisting the overturning moment of the walls. In all reinforced concrete construction the work should be so done that every part will be connected firmly to other parts. The 438 ENGINEERING WORK IN force tending to separate, the joints should be figured and the rods placed in deeply enough to resist the shearing or tearing force. All rods should be turned up at a right angle when past the point of support. This should never be neglected, as anchor- age is essential. One argument in favor of deformed rpds is that the projections furnish anchorage along the length of the rod. CONCRETE ,'COLUMNS. Concrete columns may be of plain concrete. If expected to develop much strength they should be made of a 1 :3 or of a Ij :1 mixture of cement and sand. Mixed wet and deposited carefully in well made forms, with due care to prevent the entrapping of air, they are fully as rigid as reinforced columns if the length doe^ not exceed ten times the least diameter. They can be counted on to carry 700 pounds per square inch 'safely at that limit of length. Concrete columns strong enough to carry loads, and made of 1 : 3 : 4 concrete, should not be stressed more than 500 pounds per square inch. Concrete columns reinforced with steel have been made where the length has been equal to twenty times the least diameter. They can be and have been used, but it is better to keep to shorter columns of this material, for there is often so much carelessness in its manufacture. For slender columns the writer prefers to use steel angles sufficiently strong to carry the load and with connections to in- sure the load being transmitted to the steel. This metal is im- bedded in the concrete which is thick enough to protect it in case of fir? and therefore will add the necessary stiffness so the radius of gyration of the steel angles does not have to be taken into account. Some men arrange four angles in the form of a cross in the center 6i the column. This, however, is a bad arrange- ment, for we then have a steel column so fixed that the concrefje is divided into four sections and is of use only for fire protection. The writer prefers to arrange the angles facing outward and spaced so the thickness of concrete between the flat sides is equal to the' least. thickness of concrete outside the legs. This disposes of the steel in beiter shape and the interior concrete acts with the steel to give -sjiffness and at the same time it is connected with the concrete outside. The angles are tied together with heavy rods TOWNS AND SMALL CITIES. 439 wrapped aroUnd, with intervals between the wraps equal tc the space between the angles.. Or they can be latticed. Columns such as just described can be made with i:3:5 con- crete, as the concrete is not expected to carry any load. It must be put carefully in place, however, and be rather wet. The design of reinforced concrete columns having longitudinal rods is not well settled. ^Experiments made do not ju&tify great dependence upon them, as it is not known how tht stjel takes its share of the load or whether it takes any. If it does take any we do not know positively how much. Failures iir such columns have been along the line of reinforcement. Such reinforcement should be depended upon rather to prevent btnding. So long, however, as it is used at all, 30 long- will columur, be so designed that the steel will be expected to take part of the load. Here the modulus of elasticity comes in. Imagine a unit size of any material stretched to double its letif^tn. The force re- quired to stretch it is the modulus of elasticity. Therefore when we consider the compression of columns it plays an important, part in comparing relative extensibility. For ordinary concrete the ratio between the moduli of elasticity oi the concrete and the steel may safely be taken as 1 :15. If the concrete is stressed 500 pounds per square inch then the steel cati safely be stressed fifteen times this amount, or 7,500 pounds. It is usual to reinforce col- umns vertically with an area of steel in cross section of between 2.5 and 3.0 per cent. This steel is divided into small rods or sometimes half is placed in the corners in angles and half in small rods between. If it is all in small rods they are placed at equal distances round the column, if round, or in equal numbers on each side. The column is therefore secure against bending in any direction.'- There is a doubl& reinforcement as some steel acts in compression no matter which way the column bends. The angle at which con- crete shears is approximately forty-five degrees, so the rods are tied together with heavy wire at distances equal to the least width of the column, considering the width as measured .from center to center of opposite rods. The ties may be horizontal, or they may be angular, in which case the wire is generally wound round the^ rods. They should also be tied together from corner to corner at 440 ENGINEERING WORK IN the same intervals. The writer has used expanded metal sheets set radially like the spokes of wheels, tied to rods at the outer edges, and having expanded metal wrapped round the whole length. Assume part of the load carried by the concrete and part by the steel and assume the area of the steel at 3.0 per cent. Then the area of the concrete is a = A — 0.03 A, where a is the area of the concrete and A the total area of the section of the column. The total weight, W, to be carried by the column will be W = 500 (A — 0.03 A) + 7500 (0.03 A) X A. The total weight divided by 0.97 X 500 plus 0.03 X 7500 = 710 gives A = — — - This is the number of square inches of area in a section of the column. Multiplied by 4he percentages, the area of the concrete and of the steel, respectively, are found. The above argument can be carried out for any percentage of steel. Steel used in reinforcing columns should be hard steel preferably, in order to get the benefit of the higher modulus of elasticity. For columns made of -1 :2 :4 concrete the reinforcement longi- tudinally should not be omitted. The extreme fibre stress in the concrete should not exceed 500 pounds. When a length exceed- ing ten times the least thickness is used, the stress should be re- duced by the following formula: p = 600 — 6 /'-i- -Ki) where P = pressure per square inch on the concrete, 1 = length of column in inches, and d = least side (or diameter) in inches. Experiments have shown that when concrete columns are wrapped with steel rods or wire, a fibre stress of from 1,000 to 1,500 pounds can be used. The pressure on top of the column tends to "bulge" it outward and the wrappings of steel hold it in. In this connection it is necessary to say that there must be some compression before the spiral wrappings are called into effect. Such columns are usually made' round in cross section. A number of columns are built with spiral wrappings, for the reason that unless high unit stresses can be used, concrete columns will be too large. This means loss of light and space in a structure and too heavy a look to the framework. TOWNS AND SMALL CITIES. 441 Mr. Weld, engineer of the Trussed Concrete Steel Company, uses the following formulas for hooped columns: a = ?MJ^ aiid P = -S£_ S 32.5 d where d = diameter of core in inches a = cross section of hoop t" = the pitch, and S = allowed stress in the steel. 32.5 d = the hoop tension for each inch in height of the column, with 1,000 pounds safe working stress in the concrete. As the hooping steel will be either band or wire a high value may be used, say 80,000 pounds per square inch. The pitch should not exceed -g- D Having determined the thickness of the hooping steel the column can be designed, using 1,000 pounds per square inch in the concrete and 15,000 pounds per square inch in the steel. Longi- tudinal rods will be used as in the last example. They prevent bending in the column and the spiral wrappings are tied to them by wires. AH rods and wires should lap at least twenty-five diame- ters where spliced. When the length exceeds twelve times the diameter or least side, reduce the pressure per square inch by the formula: 1000 -'"(4) WALL AND COLUMN FOOTINGS. A plain concrete, stone or brick footing is secured by spread- ing the whole load over an area sufficient to keep within the per- missible bearing power of the soil. It is usually accomplished by stepping down so that a line drawn from the bottom of the wall or column, at -an angle of sixty degrees with the horizontal, will pass through the foot of each step. Sometimes the steps are omitted and the footing is made in the form of a truncated cone or pyramid. There is a waste of material in such footings and an in- crease of weight because of the foundations. Reinforced concrete footings are used wherever the saving in cost will justify them. When designing -footings it is best to calculate for both plain and reinforced concrete and compare the cost. 442 ENGINEERING WORK IN The breadth of the footing when reinforced is determined by the bearing powef of the soil. It is then designed like a beam having a span equal to the breadth of the footing and carrying a concentrated load in the middle. The load, however,- occupies a length on the middle of the beam equal to the width of the wall, or diameter or side of the column. The bending moment is thus found by which to proportion the beam. At each edge of the wall, or column, there is a shearing stress against which the footing must be designed. The projection from ,' // . >; \^\ £kff/r}p/e^ of /fe/nforcecf Foof/h£fs, / V the edge of the load to the end of the footing is calculated as a cantilever beam carrying a distributed load equal to half the weight imposed on the footing. The shear developed at the edge of the wall or column will be taken care of by the addition of concrete.- Allowing 50 pounds per square inch for shear in the concrete, and nothitig in the steel, determine the shearing strength of the beam already calculated as sufficient to carry the load. If found deficient in shearing resistance increase the thickness of the footing at the edge of the load, TOWNS AND SMALL CITIES. 443 This leads to some thought about the designing of short beams heavily loaded. As shown already, the length of a beam will bear some proportion to its depth. When the beam is less than ten or twelve times as long as it is deep the shearing stresses must be considered and -the rods be firmly secured to vertical or angular shear members. In the ckse of footings the shear members are not necessary, for the beam is supported its entire length. The loads coming through walls and columns are frequently excessively heavy, but if the bearing power of the soil is good the supporting beam (footing) may be short, consequently the shear must be figured. It is good practice to increase the width of the column or wall at the base, (on top of the slab) by an addi- tional width of fifty per cent to get a better footing slab. For wall footings the rods are cut in lengths equal to twice the wall width plus the projection from the wall to edge of foot- ing. Then half the. rods reach the edge on one side and the rods between reach the other edge. This carries the opposite ends of the rods past the middle of the span on each side -arid leads to some economy. When figuring the loads on a vvall, one foot in length is taken * as the width of the beam. When figuring the loads on a column the footing beam is taken at a width equal to the width of the column. This is equivalent to two reinforced beams under the columns, connected to each other at right angles. This means a square slab under the column containing two layers of steel reinforcement. Some designers place steel each' way under the width of the column and also diagonal rods to the cor- ners. Under the column there will be four layers of steel and at each edge qnly one layer. Tiis layer will not be continuous over -a square slab, but will occupy only the width of four beams, one at each corner and one at the middle on each side. There will be tri- angular spaces between containing no reinforcement. The writer usually has only two layers of steel. That is, he carries out the reinforcement in each direction clear to the edges so that the footing is a flat slab reinforced like a floor slab. The rods are cut in lengths equal to the projection plus twice the column width so that each alternate rod is at the edge of the slab. The diagonal reinforcement only comes into play in case the column 444 ENGINEERING WORK IN tips and the square reinforcement will take care of that if the foot- ing is a slab. The least depth of concrete under the rods in the footing should be four inches. The thicicness of the footing at the edge can be six inches, over the rods. It then slopes upward to the wall or column. As a simple beam the reinforcement is in the bottom. Con- sidered as a cantilever supporting upward forces, the reinforcement is in the top, for aJJ reinforcement goes in the tension side of beams. CEMENT TESTING. Every city engineer should have a cement testing outfit, but if the town cannot afford one he can make tests to satisfy him that the cement he is using is practically complying with the National standard specifications. In the chapter on concrete simple acid tests are given to de- tect the admixture of raw material. When a cement is unusually light in color and does not wear well the acid test may show that considerable raw material was added to it after manufacture. All things being equal, the finer a cement is ground the better it will be in concrete, or mortar. The first test, therefore, should be directed toward ascertaining the fineness. Obtain a scale that will weigh up to one pound by quarter ounces. Obtain from a reputable maker a 100 mesh sieve made of No. 40 wire, Stubbs' gauge, and examine it with a microscope to see that the interstices are uniform. Weigh out carefully three ounces of cement into the sieve. Holding the sieve in the right hand shake it rapidly but not violently at the rate of about twenty movements a minute, striking it gently against the ball of the left hand. It will require about ten minutes' shaking, but if 'a few coins or telephone slugs are put in with the cement the operation will be hastened. When the cement seems to have stopped going through the sieve, pour the residue carefully on to the scales. As 'the standard specifications call for not less than 92 per cent to go through a lOO-mesh sieve, this amounts to about, one-twelfth, or in three ounces to one-fourth of aij ounce of residue. Make the te^t several times, or with six ounces instead of three occasionally. TOWNS AND SMALL CITIES. 445 The specific gravity test is beyond the reach of the greater number of engineers. The soundness test and time of setting are tests readily made. The specifications in the preceding chap- ter tell what to expect. Foi: a Portland cement use about 20 per cent of water and conduct the operations in a room having a temperature close to 62 degrees F. Make a mortar of neat cement and water, mixing thoroughly for about five minutes under pressure, time to be estimated from moment of adding water and to be considered of importance. Make on glass plates two cakes each about three inches in diameter, half an inch thick and drawn down to fine -edges, and, cover them with a damp cloth or place them in a tight box not ex- posed to currents of dry air. At the end of the time specified for initial set apply the needle one-twelfth of an inch in diameter, weighted to one-fourth of a pound to one of the cakes. If an in- dentation is made the cement passes the requirement for initial setting. If no indentation is made it is too quick setting. At the the end of the time specified for "final" set apply the needle one- twenty-fourth of an inch iVi diameter loaded to^one pound. The cement cake should not be indented. The needles mentioned can be made by anyone. Take two pieces of wire eight or nine inches long and file one end of each to the size mentioned. A ball of lead the required weight is then fastened on the wire. The wires are applied by holding them vertically between the fingers, letting the small end rest on the pat. Expose the two cakes to air under a damp cloth for twenty-four hours. Place one of the cakes, still attached to its plate, in water for twenty-eight days; the other., cake immerse -in water at about 70° temperature supported on a rack above the bottom of the receptacle; raise the water gradually to the boiling point and maintain this temperature for six hours and then let the water, still containing the cake, cool. When making the boiling test it is important to keep the same depth of water over the cake. For the purpose have another vessel beside the one containing the cake, full of water and add water from time to time to the testing ves- sel, to supply losses by evaporation. The added water being also boiling will not affect the test. If the boiled cake shows evidences of cracking or distortion either reject the test or wait for the results of the twenty-eight- 446 ENGINEERING WORK IN day test of the cake in fresh water. The foregoing are the recom- mendations of the United States Army Engineers. --^ • The tensile test is the One that is always mentioned in speci- fications and on which great reliance is placed. Briquettes are made of neat cement and about 20 per cent of water, and of 1 cement to 3 sand with about 13J4 per cent of water. About one pound of cement is used and the mixture is thoroughly kneaded with the hands covered with rubber gloves. It is made into a ball and tossed from hand to hand for several minutes, after which it is pressed into the briquette molds firmly. Ramming it or tamping with a hammer is not always locked upon with favor, although these are customary methods for securing hard briquettes. The lowest priced tensile testing rnachine costs about sixty dollars. The writer, in a previous book some years ago, men- tioned the cross bending test as a fairly reliable substitute, and has made many tests with an ordinary water pail to apply the weight. He at first used bars one inch square and six inches long with a clear span over supports, of five inches. By experimenting considerably he finally made bars eleven inches long and one inch ■ square resting on supports ten inches apart. A pail is hung over the middle of the bar, or beam, and the weight to be poured into the pail is practically about one-tenth the required tensile strength. To make the beams use an iron frame such as printers use for forms. Have ten short pieces of steel or iron exactly one inch "square and five strips of % i"- by 1 in. iron and set of printer's quoins. Set the iron blocks and strips in the frame so that there will be made five recesses each one inch square and eleven inches long. Put the cement mortar into these recesses and when set remove them to a box where they can rest without distortion or without being exposed to currents of dry air. They should be thus kept under a damp cloth for twenty-four hours and then be placed in water until needed for the seven-day and twenty-eight-day test. The- writer breaks the five beams for each set of tests and takes the average as one-tenth of the required tensile strength. This gives an extremely close agreement with regulation tensile tests. The sand should be either the standard sand recommended by the, American Society or should be the standard crushed quartz. Still the very best sand used in the vicinity, carefully cleaned, will often do. TOWNS AND SMALL ClflES. 447 The cement should be brought on the site of the work at least ten days before it will, be vised in order to give time for a seven- day test. In- sampling cement, take every tenth barrel or every fortieth sack. Baking powder cans are excellent for taking samples to the testing laboratory. Carry them in a basket, or pail. About one pound should be taken from each sack. Make a briquette or bar from each sample and then average the remainder for a test briquette representing the average of the lot. Every book dealing with concrete contains considerable in- formation on cement testing.' The best book on the market today dealing with the subject is "Practical Cement Testing," by W. Purves Taylor ($3.00). Every engineer handling large quantities of cement should possess a copy. The subject of simple tests is fully treated in that work and the method of breaking beams in a cross-bending test is also fully gone into. USEFUL LUTES AND CEMENTS. Waterproof Compositions — Asphalt Fluid Coatings — Heat as- phalt in a steam jacketed kettle and. a mixture can be obtained with petroleum naphtha in which the part of asphalt not dissolved is held in suspension. Asphalt is entirely soluble in benzol or toluol, which are about the, cheapest of all the constituents of asphalt. Tar and pitch are sometimes used in this connection, but tar contains water, light oils, and free carbon, and does not wear as well as re- fined asphalt; and pitch contains free carbon, which is sometimes objectionable when thinned out with a solvent. The asphalt alone is Sometimes pervious to water, and this is improved by adding about one-fourth its weight of paraffin, and made better, if in addi- tion a little boiled linseed oil is added also. For thicker composi- tions, where. body is required, asbestos, stone powder, cement, etc., may be added as fillers. Oil-Proof Compositions — For, Small Leaks — Good glue or gela- tine, 2 parts ; glycerine, 1 part and water 7 parts. Apply warm and it stiffens quickly on 'cooling. A'hother very useful composition is a stiff paste of molasses and flour. A stiff paste of glycerin and litharge is oil-proof, acid-proof and water-proof. These form a chemical combination and set in a few minutes. By adding a little ■ill" 448 ENGINEERING WORK IN water the paste will set more slowly. It is mixed as required. Plaster-of-Paris wetted by itself, or mixed with asbestos, straw; hair, etc., is useful. A solution of silicate of soda made into a stiflf paste with carbonate of lime, gets hard in six to eight hours. Acid-Proof Compositions — The asphalt compositions already mentioned, compositions of melted sulphur with fillers of stone powder, cement, etc., also the following which withstands hydror chloric acid vapors : Rosin, 1 part ; sulphur, 1 part ; fire-clay, 3 parts. The lute "composed of boiled linseed oil and fire-clay acts well with most acid vapors. Compositions of glycerine and litharge are useful, especially when made according to the Davis formula: Litharge, 80 pounds; red lead, 8 parts; "flock" asbestos, 10 parts, fed into a mixer, a little at a" time, with small quantities of boiled oil (about six parts of oil being used). A particularly useful cement for withstanding acid vapors, being also tough and elastic, is : " Crude rubber, cut fine, 1 part ; linseed oil, boiled, 4 parts; fire-clay, 6 parts. The rubber is dissolved in carbon disulphide to the consistency of molasses and then mixed with the oil. The foregoing recipes were given by Samuel S. Sadtler, chem- ist, in a paper read on June 4, 1904, betore the Philadelphia Engi- neers' Club. Other useful formulas are found in Spon's "Dictionary of Work- shop Receipts." In a preceding section the writer has mentioned several methods of making water-tight joints in sewer pipes. In addition to the methods there described he has used a sulphur joint made of sul- phur and sand. The sulphur is melted with the sand to a consistency where it will pour. A dam is made at the joint and the cement poured in like the lead in a water pipe. It cools very rapidly and if properly done is successful. The number of men having the skill and patience to do a good job this way, is small. Mr. Potter, the well known sanitary engineer is the one who first advocated this cement. Two or more lengths of sewer pipe are cemented together on the bank and lowered into place in the trench. As the cement practically makes one piece out of the several joined sections the total number of joints is reduced so they do not leak so freely. Care must be taken to have a bed the pipes will rest upon evenly. Stone and Other Cements — For setting iron in stone the above TOWNS AND SMALL CITIES. 449 sulphur cement is good. From Mr. Sadtler the following recipe for stone cement is had : Zinc oxide, or magnesium oxide, 3 parts ; zinc chloride or magnesium chloride, 1 part. Water to make a paste. Powdered stone is generally used as a diluent. An iron cement is made as follows : Iron filings, 40 parts ; manganese dioxide or flowers of sulphur, 10 parts; salammoniac, 1 part; Portland cement, 80 to 40 parts; water to form a paste. SINKING FUNDS. In an earlier chapter a table has been given dealing with sinking funds. It was stated there that in the case of a pay- ment of a premium on the bonds the tables did not suffice. If the amount to be repaid is 104%, then the equivalent de- preciation is 2% -T- 1.04 = 1.9231, and to get this we must go to the formula from which the table was computed. n = number of years, term of amortization. r = rate of interest received. X = rate of depreciation charge, or annual sinking fund in- stallments in dollars per dollar. log L+i^ log (I + r) we obtain ■05 -f- .019231 ^^- .019231 n = — 019231 _ = 26.35 years. log .1.05 log 3.60 _ 0.55630 log 1.05 ~ 0.02119 The formula for rate of depreciation charge is (I + r)"-! The preceding formulas and the tables referred to in an earlier chapter are for interest compounded yearly. The following formula is for calculating sinking funds with interest compounded half yearly. A is the annual installment. The first payable one year after investment and the last one at the end of n years. 450 ENGINEERING WORK IN LOGARITHMS OP NUMBERS. No. 1 2 3 4 5 6 7 8 9 Diff. 10 0000 0414 0792 1139 1461 1761 2041 2304 3553 2788 3010 3322 3424 3617 3802 3979 4150 4314 4472 4624 4771 4914 5051 5185 5315 5441 5563 5682 5798 5911 0043 0453 0828 1173 1492 1790 2068 2330 2577 2810 3032 3243 3444 3636 3820 3997 4166 4330 4487 4639 4786 4928 5065 5198 5328 5453 5575 5694 5809 5922 1 0086 0492 0864 1206 1523 1818 2095 2355 2601 2833 3054 3263 3464 3655 3838 4014 4183 4346 4502 4654 4800 4942 5079 5211 5340 5465 5587 5705 5821 5933 2 0128 0531 0899 1239 1553 1847 2122 2380 2625 2856 3075 3384 3483 3674 3856 4031 4200 4362 4518 4669 4814 4955 5092 5224 5353 5478 5599 5717 5832 5944 3 0170 0569 0934 1271 1584 1875 2148 2878 3096 3304 3502 3692 3874 4048 4216 4378 4533 4683 4829 4969 5105 5237 5366 5490 5611 5729 5843 5955 4 0212 0253 0294 0334 0374 40 n 12 13 14 15 10 17 18 19 20 0607 0969 1303 1614 1903 2175 2430 2672 2900 3118 3324 3522 3711 3892 4065 4232 4393 4048 4698 4843 4983 5119 5250 5378 5502 5623 5740 5855 5966 0645 1004 1335 1644 1931 2201 2455 2695 2923 3139 0682 1038 1367 16T3 1959 2227 2480 2718 2945 3160 0719 1072 1399 1703 1987 2253 2504 2742 2967 3181 0755 1106 1430 1732 2014 2279 2529 2765 2989 3201 37 33 31 29 27 25 24 23 21 21 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 3345 3541 3729 3909 4082 4249 4409 4564 4713 4857 4997 5132 5263 5391 5514 5635 5752 5866 5977 3365 3560 3747 3927 4099 4265 4425 4579 4728 4871 5011 5145 5276 5403 5527 5647 5763 5877 5988 3385 3579 3766 3945 4116 4281 4440 4594 4742 4886 5024 5159 5289 5416 5539 5658 5775 5888 5999 3404 3598 3784 3963 4133 4298 4456 4609 4757 4900 5038 5172 5303 5438 5551 5670 5786 5899 6010 20 19 18 17 17 16 16 15 14 14 13 13 13 13 12 12 12 12 11 No. 5 6 7 8 9 Diff. /ONES & LAUGBLIN HANu HOOK. TOWNS AND SMALL CITIES. 451 C is total capital invested, r is one dollar plus six months' interest. n is the number of years from investment to the maturity of the sinking fund, when the latter will become equal to the capital originally invested. A _ r' — 1 C r*" — 1 LOGARITHMS. The following table of logarithms is inserted because it may be found useful in some of the operations above mentioned, as well as for others where the arithmetical work would be other- wise very tedious. The following instructions will refresh the memory as to the use of a table of logarithms : The log. of 2500 is 3.3979 [The log. of 3.5 is 0.3979 The log. of 250 is 2.3979|The log. of .25 is —1.3979 The log. of . 25 is 1.3979|The log. of .025 is —2.3979 The log. of 2587 is found as follows : Take from the table the log. for 2580, which is 3.4116. The tabular difference in the column on the right is 17. Subtract 2580 from 2587 and multiply the difference, 7, by the tabular difference, 17, and add the result 119 to log. 3.4116, which gives log. 3.41279 as log. of 2587. To insure that the product of the differences is correctly added compare this final log. with the next highes.t, 2590, in the table and, as it is 3.4133, the result found is correct. Conversely given, log. 3.41279 to find the number. An inspec- tion of the table shows that this log. is not in it, so we take the next lowest, which is 3.4116, corresponding to the number 2580. The difference between these two logs, is 119, which, divided by the tabular difference, 17, gives 7 as the figure to be added to 2580 in order to get the exact number corresponding to log. 3.41279. To multiply numbers add their logarithms and find from the table the number corresponding to the new logarithm thus found. To divide one number by another find the difference between their logarithms and the new logarithm thus found is the logarithm of the quotient. To perform an example in proportion add the logarithms of 452 ENGINEERING WORK IN LOGARITHMS OF NUMBERS-Contlnued. No. 1 2 3 4 5 6 7 8 9 Diff. 40 6021 6128 6232 6335 6435 6532 6628 6721 6812 6902 6990 7076 7160 7243 7334 7404 7483 7559 7634 7709 7782 6031 6138 6243 6345 6444 654? 6637 6730 6821 691) 6998 7084 7168 7251 7332 7412 7490 7566 7642 7716 7789 6042 6053 6064 6075 6085 6096 6107 6117 11 41 42 43 44 45 46 47 48 49 6149 6253 6355 6454 6551 6646 6''39 6830 6920 7007 7093 7177 7359 7340 7419 7497 7574 7649 7733 7796 6160 6363 6365 6464 6561 6656 6749 6839 6938 7016 7101 7185 7367 7348 7437 7505 7583 7657 7731 7803 6170 6374 6375 6474 6571 6665 6758 6848 6937 7024 7110 7193 7375 7356 7435 7513 7589 7664 7738 7810 6180 6384 6385 6484 6580 6675 6767 6857 6946 7033 7118 7202 7284 7364 7443 7520 7597 7672 7745 7818 6191 6294 6395 6493 6590 6684 6776 6866 6955 6201 6304 6405 6503 6599 6693 6785 6875 6964 6212 6314 6415 6513 6609 6702 6794 6884 6972 6333 6325 6425 6522 6818 6713 6803 6893 6981 10 10 10 10 10 9 9 9 9 50 51 52 53 54 55 56 57 58 59 60 7042 7126 7210 7292 7373 7451 7538 7604 7679 7752 7825 7050 7135 7218 7300 7380 7459 7536 7613 7686 7760 7832 7059 7143 7226 7808 7388 7466 7543 7619 7694 7767 7839 7067 7152 7235 7316 7396 7474 7551 7627 7701 7774 7846 9 8 ■8 8 8 a 8 7 8 8 7 61 62 63 64 65 66 67 68 69 7858 7924 7993 8063 8129 8195 8261 8325 8388 7860 7931 8000 8069 8136 8202 8267 8331 8395 7868 7938 8007 8075 8142 8309 8374 8338 8401 7875 7945 8014 8083 8149 8315 8380 8344 8407 7882 7952 8021 8089 8156 8322 8387 8351 8414 7889 7959 8028 8096 8162 8338 8393 8357 8420 5 7896 7966 8035 8102 8169 8235 8399 8368 8426 6 7903 7973 8041 8109 8176 8341 8306 8370 8433 7 7910 7980 8048 8116 8182 8248 8312 8a76 8439 8 7917 7987 8055 8122 8189 8354 8319 8383 8445 1 6 1 7 6 7 6 6 6 No. 1 2 3 4 9 1 Oi». ^JONES & LAUOHLIN HAND BOOK. TOWNS AND SMALL CITIES. 453 the two numbers that are to be multiplied together and subtract from this new logarithm the logarithm of the divisor, the num- ber corresponding to the final log. being the result wanted. To raise a number to any power multiply by the exponent of that power. That is, to square a number multiply its log. by two and the number corresponding to the new log. is the square of the first number. This applies to all powers. To extract the root of any number divide its log. by the index of the root and the number corresponding to the new log. is the required root of the number. This is true for all roots. No formula containing a plus or minus sign can be solved directly by logarithms; for adding logarithms is equivalent to multiplying their numbers and subtracting logarithms is equivalent to performing the operation of division with their numbers. MENSURATION. Several pages are here given of formulas useful in mensuration and trigonometrical calculations. A table of logarithms is useful when the formulas are complicated, for partial results do not have to be taken into account, as may be seen by performing an ex- ample in proportion by the help of logarithms. The tables of natural sines, cosines, tangents, etc., represent the functions of angles mentioned on the upper half of the page containing the Solution of Right-Angled Triangles, with a radius equal to unity. To use them the function is taken directly from the table and multiplied or divided or added and subtracted. Loga- rithmic tables of functions are tables of the logarithms correspond- ing to these numbers. Although the values are only given to each ten minutes of arc these tables will frequently be found useful. The two pages giving weights and gauges of steel will be useful for reinforced concrete designing. 454 ENGINEERING WORK IN LOGARITHMS OF NUMBERS-Contlnued. No. 1 2 3 4 5 6 7 8 9 DM. 70 8451 8513 8573 8683 8692 8751 8808 8865 8921 8976 9031 9085 9138 9191 9243 9294 9345 9395 9445 9494 9542 8457 8519 8579 8639 8698 8756 8814 8871 8927 8982 9036 9090 9143 9196 9248 9299 9350 9400 9450 9499 9547 8463 8525 8585 8645 8704 8762 8820 8876 8932 8987 9042 9096 9149 9201 9253 9304 9355 9405 9455 9504 9552 8470 8476 8482 8543 8603 8663 8722 8779 8837 8893 8949 9004 8488 8549 8609 8669 8727 8785 8842 8899 8954 9009 8494 8555 8615 8675 8733 8791 8848 8904 8960 9015 8500 8561 8621 8681 8739 8797 8854 8910 8965 9020 8506 8567 8627 8686 8745 8803 8859 8915 8971 9025 7 71 72 73 74 75 76 77 78 79 8531 8591 8651 < 8710 8768 8825 8883 8938 8993 9047 9101 9154 9206 9258 9309 9360 9410 9460 9509 9557 8537 8597 8657 8716 8774 8831 8887 8943 8998 9053 9106 9159 9212 9263 9315 9365 9415 9465 9513 9562 6 6 6 6 6 6 6 5 6 80 81 82 83 84 85 86 87 88 89 90 9058 9113 9165 9317 9269 9320 9370 9420 9469 9518 9566 9063 9117 9170 9322 9374 9325 9375 9425 9474 9523 9571 9069 9122 9175 9227 9379 9330 9380 9430 9479 9528 9576 9074 9138 9180 9232 9284 9335 9385 9435 9484 9533 9581 9079 9133 9186 9238 9289 9340 9390 9440 9489 9538 9S86 6 5 6 6 5 5 6 6 6 4 4 91 92 93 94 95 96 97 98 99 9590 9638 9685 9731 9777 9823 9868 9912 9956 9595 9643 9689 9736 9782 9827 9872 9917 9961 9600 9647 9694 9741 9786 9832 9877 9921 9965 9605 9652 9699 9745 9791 9836 9881 9926 9969 9609 9657 9703 9750 9795 9841 9886 9930 9974 9614 9661 9708 9754 9800 9845 9890 9934 9978 9619 9666 9713 9759 9805 9850 9894 9939 9983 9624 9671 9717 9763 9809 9854 9899 9943 9987 9628 9675 9722 9768 9814 9859 9903 9948 9991 9633 9680 9727 9773 9818 9863 9908 9953 9996 6 6 4 4 5 5 4 4 4 No. I 2 3 4 5 6 7 8 9 Dill. JONES & LAUGHLIH BAND BOOK. TOWNS AND SMALL CITIES. 455 SHEET IRON AND STEEU WEIGHT or SUPERFICIAL FOOT. BIRMINGHAM GAUGE. Wbioht IN Lbs. WEIOnTINLBS Oaugb. OAVas. lion.. Steel. lion. Steel. No. 1=.3 12.12 12.86 No 16=.065 2.63 2.68 " 2=.284 11.48 11.71 17=. 068 2.34 2.39 " 8=.259 10.47 10 «8 18=. 049 1.98 2.02 " 4=.238 9.62 9.81. 19=.042 1.70 1.78 " 5=.22 8.89 9.07 20=. 035 1.56 1.59 " C=.203 8.20 8.36 21=. 032 1.40 1.43 " 7=.18 7.27 7.42 22= .028 1.25 1.28 " 8=.165 6.67 6.80 23=.025 1.12 1.14 " 9=:.148 5.98 6.10 24=. 022 1. 1.02 '• 10=.184 5.42 6.53 25=. 02 .9 .92 "11=. 12 4.83 4.95 26= .018 .8. .82 " 12=. 109 4.41 4.60 27= .016 .72 .73 « 18=. 095 3.84 3.92 28=. 014 .64 .65 " 14=. 083 3.35 3.42 29=. 018 .56 .57 ''16i=.072 2.91 2.97 80=.012 .6 .51 TANK IRON AND STEEL. WEIGHT OF SUPERFICIAL FOOT. Thickness, in INCHSS. Weight IN I>B8. Thickness in Inches. Weight in Lbs. Iron,. Steel. Iron. Steel. ^=.03125 1.27 1.30 A= .3125 12.63 12.88 V^=.0625 2.62 2.67 f = .876 15.16 15.46 A=.09375 3.79 8.87. A= .4375 17.68 18.03 *=.125 5.05 6.16 V= .5 20.21 20.61 A=. 15625 6.32 .6.45 A= .6625 22.73 23.19 A=.1875 7.58 7.73 *= .625 25.26 26.77 X=.21875 8.84 9.02 f = .75 30.31 30.92 i = .25 10.10 10.30 i= .875 35.37 36.08 A=.28123 11.38 11.61 1 =1. 40.42 41.23 The loir temperatnie (as compaied with Iron) at which Steel Plates have to be finished, canses a slight springing of the roHs, leaving the plate thicker In the center. This, combined with greater densflr, causes Steel Plates, If kept up to full thickness on the edges, to weigh more than Iron. Itoth Iron and Steel over 7S Inches wide are liable to run even heavier than the weights given above. 456 ENGINEERING WORK IN WEIGHT OF BAR STCEL PER LINEAL FOOT. " ^ .« s s -o 3 gSSSSSSggSSSSS'SS ■a« TT lO iO »O00CSOjJ-«M«i0. t^OOOggj K 'SS s 8 * SaSS?SS&9SSS£ig'SSS 91 00 n -* ■V •* io.msDt-coQO»o^^cg2;S£;SgJ » s& a. :fi S8 in siseisssssBSssssffi? N^N CO 03 « -* '^kntocot>c»aoaoAO^ot*tfinr-o « £ S o» « g^SnSSSS^gS&SS^&S to 09 e« Ot e< eo CO W-^-^PiOiOWOt-t-QOOSO^Mj;*;; o S eg CI s s S $ S S g S S S SS S £ s s s s s g " - w ot 01 « Qt n eoa^ ■^»u^u3ooooo-- o a » 8S5 s e S s S S a S B S3 S 5 g s s ss s s s s « tH " " i-i 04 oioiotrcoo -e gg 13 § £ s S S S S g S !S g S S S5 S S Si ? s ^^^^T-i*t^o)G4«o)oec<9eoeo'V'«kaiO(9t>GO » ii s t- ^ £S § g s a s s s? s s 5 3 a s s s s ^ " -" ^^^0)0tC4C4&ie*9D9W'di 0,008727 en- circle. ^= ^=area. rf = diameter. ''^''!=0.7854rf» r =:radius. 1^= contents. rf=l,12838 VTJ Area. Sector of Circle =length of arc X half radius. Segments of Circle=area of sector less triangle, also for flat segments very nearly=|-V'o.388A"-)-j^ — ^JONES & LAUGHLIII HAND BOOK. 458 ENGINEERING WORK IN MENSURATION-Contlnued. Cylinder. 4 A=:ird' —d -> Sphere. F= nd» Pyramid and Cone. ^ =periphery or circumference of base X half slant height. I^=area of base + j^ perpendicular height^ Frustum. ./4 =sum of, peripheries or circumferences of the two ends Xhalf slant height+area of both ends. Frustum of a cone. V=inA (R'+r'-i-Jlr) Frustum of pyramid. V=\ A {B+ i^B3+6) • (^ being the distance of the two parallel end surfaces jffand*.) —JONES ft LAUGBLIN HAND BOOK. TOWNS AND SMALL CITIES. 459 MENSURATION-Continued. Triangle. A = ^ sX(s—a) {s—6) (s—c) if s half of the sum of the sides a, b, and c, or;:=baseXhalf perpendicular height. Polygons. Area of any irregular polygon- can be found by divid- ing the polygon info triangles and take the sum of the triangles' area. Area of any regular polygon No. of sides , . .,,,,». St — -X (circumscribed rad.)*Xsin. % Ellipse. A=7r«* No. sides. Parabola. A—^sA *Area of any Irregular Plane Surface. I— d— i— d— !jr— d-i— d-^- Divide the surface into any number, say n, parallel' strips of equal _widths, d, whose middle ordinates are represented by " h k k h h h 13 3 4 1-1 n then is, after Poncelet's rule, A=d2 A + ^^ d {a-h)+ ^ d {b-k\ 1 n/ but more exact after Francke's rule, A = d2 h-V-i^^d {,8a\ h-c)h) + ^^d(8 b -^ k-g k\ .3 I n-l n/ — ^JONES & LAUGHLIH HAND BOOK. 460 ENGINEERING WORK IN MENSURATION-Contlnued. Properties of the Circle. Circumference=Diam. X 3.1416 or 3|'. Diam. X .8862= Side of an equal square. Diam. X.7071— " inscribed " Diam. " X .7854= Area of circle. Radius X 6. 2832=Circu mf erence. Circumf erence=3. 5446'V^area of circle. Diam. = 1.1283v'area of circle. Length of arc =No. of degfrees X .017453 radius. Degrees in arc whose length equals radius=57° 2958. Length of an arc of l'=Radius x .017453. " " " 1' =Radius X .0002909. l"=RadiusX. 0000048. ir=Proportion of circumference to diam..=3. 1415926. jr» =9. 8696044. yS^=1.7724538. Log. 9r=0 4971499. —=0.3183001. TT ^=.002778. Trigonometrical Pormulas. General MQaivalenta. The diagram shows the different trigonometrical ex- pressions in tefms of the angle A. In the following formulae Radius=l. Cot A LAUGHLIN HAND BOOK. TOWNS AND SMALL CITIES. MENSURATION-Continued. Complement of anangle=its difference from 90" Supplement of an angle=its difference from 180' 1 __ ~cot. Sin.=- cos. , _, _ sin. _ 1 ■ ~cos. ~cot. Sec.=^Rad»+tan»=^=|i Cos. = |/(l_sin.'')=^=sin. X cot.=^ tan. Cosec. =-: — sm. Cot _S2!i__L sin. tan. Versin.=Rad. — cos. Coversin.= Rad. — Sin. Rad. =tan. x cot. = ^/sin. " +cos. » Solution of Right-Angled Triangles. Hypoth. ' =base« +perpend. ' Base* = (hyp. +perp. ) X (hyp.— perp. ) Perp. ' = (hyp. +base) X (hyp, — base). A Sm.=a-^ Cot. a=-4- Cos. «=-7^ Cos. ^=-4 Tan. «=4 cot.*_;^ c Cosec. a—-j- c Sec. »=-g b =90°— a A=B tan. a A=Csin. a B=:C COS. a- A cot. \ V(C+A)(C-A) C=v'y4»,+.ff«= - A . B ^ c sin. a COS. gy^ -JONES & LAUGHLIN HAND BOOK. 462 ENGINEERING WORK IN MENSURATION-Contlnued. 'Solution of Oblique-Angled Triangles. Value of any side C is : ^_A sin. c B sin. c C= sin. a sin. b cos. ^+sin. b cot. c B -=A COS. b+A COS. a+siri. a cot. c' (^=\/A'>+B'—2A B COS. c- B COS. a+Bsva. a cot. ^ Value of any angle a is : Sin. a= A sin. c A sin. * -o-^— =sin. (b+c) Sin. «=sin. ^ cos. ^+cos. b sin. f Cos. fl:=sin. b sin. ^ — cos. 6 Cos. ^ Cos. a=- Tan. «= 2.ff C A sin. £■ ^ sin. 5 B-rA COS. f C— .(4 COS. b •_ tan. *+tan. c Tan. rt='r T 7 — T ten. bxi.( at— 1 -JONES & LAUGHLIH HAND BQOi;, TOWNS AND SMALL CITIES. I TUieiR c IC 20' 30' 4C 60' 60' 1 2 3 4 0.00000 0.01746 0.03492 0.05241 0.06993 0.00291 0.02086 0.03783 0.05533 0.07285 0.00582 0.02328 0.04075 0.05824 0.07578 0.00873 0.02619 0.04366 0.06116 0.07870 0.01164 0.02910 0.04658 0.06408 0.08163 0.01455 0.03201 0.04949 0.06700 0.08456 0.01746 0.03492 0.(B241 0.06993 0.08749 80 88 87 86 es 6 6 7 8 0.08749 0.10510 0.12278 0.14054 0.15838 0.09042 0.10805 0.12574 0.14351 0.16137 0.09335 0.11099 0.12869 0.14648 0.16435 0.09629 0.11394 0.13165 0.14945 0.16734 0.09923 0.11688 0.13461 0.15243 0.17033 0.10216 0.11983 0.13758 0.15540 0.17333 0.10510 0.12278 0.14054 0.1583S 0.17638 64 es 83 81 60 10 n 13 14 0.17633 0.19438 0.21256 0.23087 0.24933 0.17933 0.19r40 0.21560 0.23393 0.25242 0.18233 0.20042 0.21864 0.23700 0.25552 0.18534 0.20345 0.22169 0.24008 0.25062 0.18835 0.20648 0.22475 0.24316 0.26172 0.19136 0.20952 0.22781 0.24624 0.26483 0.19438 0.21256 0.28087 0.24933 0.26795 79 78 77 76 76 15 16 17 18 19 0.26795 0.28675 0.80573 0.82492 0.84433 0.2n07 0.28990 0.30891 0.32814 0.34758 0.27419 0.29305 0.31210 0.33136 0.35085 0.27732 0.29621 0.31530 0.33460 0.35412 0131850 0.33783 0.35740 0.28360 0.80255 0.82171 0.34108 0.36068 0.28675 0.30573 0.82492 0.34133 0.36397 74 73 73 71 70 20 21 22 23 24 0.36397 0.38386 0.40403 0.42447 0.44523 0.38721 0.40741 0.42791 0.44872 0.37057 0.39055 0.41081 0.43136 0.45222 0.37388 0.39391 0.41421 0.43481 0.45573 0.37720 0.39727 0.41763 0.43828 0.45924 0.38053 0.40065 0.42105 0.44175 0.46277 0.38386 0.40403 0.42447 0.44523 0.46631 69 68 67 66 65 25 26 27 28 29 0.46631 0.48773 0.50953 0.63171 0.55431 0.46985 0.49134 0.51320 0.5R,'i45 0.55812 0.47341 0.49493 0.51688 0.53920 0.56194 0.47698 0.49858 0.52057 0.54296 0.56577 0.48055 0.50222 0.52427 0.54674 0.56962 0.48114 0.50587 0.52798 0.55051 0.57348 0.48778 0.50953 0.63171 0.55431 0.57735 64 63 62 61 60 80 81 82 83 84 0.57rS5 0.60086 0.62487 0.64941 0.67451 0.58124 0.60483 0.62892 0.fi,W55 0.67875 0.58513 0.60881 0.63299 0.65771 0.68301 0.58905 0.61280 0.63707 0.66189 0.68728 0.59297 0.61681 0.64117 0.66608 0.69157 0.59691 0.62083 0.64528 0.67028 0.69588 0.60086 0.62487 0.64941 0.67451 0.70021 69 68 67 66 65 85 38 37 88 89 0.70021 0.72654 0.75355 0.78129 0.80978 0.70455 0.73100 0.75812 0.78598 0.81461 0.70891 0.73547 0.76272 0.79070' 0.81946 0.71329 0.73996 0.76733 0.79544 0.82434 0.71769 6.74447 0.77196 0.80020 0.82923 0.72211 0.74900 0.77661 0.80498 0.83415 0.72654 0.75855 0.78129 0.80978 0.83910 M 63 63 61 60 40 41 42 43 44 0.83910 0.86929 0.90040 0.93252 0.96569 0.84407 0.87441 0.90569 0.93797 0.97133 0.84906 0.87955 0.91099 0.91315 0.97700 0.85408 0.88473 0.91633 0.94896 0.98270 0.85912 0.88992 0.92170 0.95451 0.98843 0.86419 0.89515 0.92709 0.96008 ■ 0.99420 0.86929 0.90010 0.93252 0.96569 1.00000 49 48 47 46 45 60- 60' 40' 30' 20' 10' 0' 1 COTMGSail 1 — CARNEGIE HAND BOOK. -464 ENGINEERING WORK IN a COTASGHIT O'. IC 20' 30' 40- 60' 60' ao 343.77871 171.88540 114.58865 85.93979 68.75009 57.28996 89 1 57 28996 49.10388 42.90408 88.18846 34.36777 81.24158 28.63625 88 2 28.6862!> 28.48160 24.54176 22.9(«77 21.47040 20.211555 19.08114 87 » 19.U81I4 18.07498 17.16984 16.84986 15.60478 14.92442 14.30067 86 4 14.80067 13.72674 13.19688 12.70621 12.25061 11.82617 11 .43005 85 E 11.48005 11.06943 10.71191 10.88640 10.07808 9.78817 9.61436 84 6 9.61 *SS 9.2.'>530 9.00988 8.77689 8.65S55 8.84496 8.14485 83 7 8.14435 7.95302 7.77035 7.69575 7.42871 7.26873 7.11537 82 8- 7.11687 6.96823 6.82694 6.69116 8.56055 6.43484 6.31875 81 9 6.31875 6.19703 6.08444 6.97676 5.87080 5.76937 «.67128 80 10 5.67123 6.67638 6.48451 6.89552 6.30928 6.22.5(« 5.14455 79 11 5.14465 6.(l6.')84 4.98940 4.91516 4.84300 4.77286 4.70463 78 12 4.70463 4.6RR25 4.57863 4.51071 4.44942 4.38969 4.83148 77 18 4.33148 4.27471 4.21983 4.16530 4.11256 4.06107 4.01078 76 J4 4.01078 8.96165 8.01364 8.86671 8.82083 8.77596 8.78205 75 16 8.78205 8.68909 3.64705 8.60688 3.66657 8.62609 8.48741 74 16 8.48741 8.44951 8.41286 8.87594 8.84023 8.80521 8.27085 78 17 8.271185 8.23714 8.20406 S.ni59 8. 13972 3.10842 8.077B8 72 18 3.07768 8.04749 8.01783 2.98869 2.96004 2.98189 8.90421 71 19 2.90421 ,2.87700 2.86028 2.82391 8.79802 2.77264 8.74748 70 SO 8.74748 2.72281 2.69a'i3 8.87462 2.65109 2.62791 2.60509 69 21 2.60609 2.58261 2.66046 2.58865 2.61715 2.49597 8.47609 68 22 2.47509 2.4.5451 2.43422 2.41421 2.39419 2.S7S04 8.35585 67 «i 2.85585 2.83693 2.81826 2.29984 2.28167 2.26374 8.24604 66 24 2.24604 2.22857 2.21182 8.19430 2.17749 8.16090 2.14461 66 SS 2.14461 2.12832 2.11233 2.09654 8.08094 2.06553 2.05030 64 28 2.05080 2.08626 2.02039 8.00569 1.99116 1.97680 1.962G1 63 27 1.96261 1.948.58 1.93470 1.92098 1.90741 1.89400 1.88073 68 88 1.88073 1.86760 1.85462 1.84177 1.82907 1.81649 1.80405 61 S9 1.80405 1.79174 1.77955 1.76749 1.75556 1.74375 1.73205 60 $0 1.78205 1.72047 1.70901 1.69766 1.68643 1.67680 1.66428 69 SI 1.66428 1.65337 1.64256 1.681H5 1.62125 l.«li'74 1.61)083 68 sa 1.60088 1.59U0a 1.57961 1.66969 1.65966 1.54972 1.68987 67 S3 1.63987 1.53010 1.52043 1.61Ub4 1.60133 1.49190 1.48256 6S 84 1.48256 1.47330 1.46411 1.45501 1.44698 1.43703 1.42815 55 SS 1.42815 1.41934 1.41061 1.40195 1.89336 1.88481 1.378.S8 64 86 1.87638 1.86800 1.35968 1.35142 1.84823 1.8.'i611 1. 82704 68 87 1.8271)4 1.81904 1.81110 1.30323 1.29511 1.28764 1.27994 52 88 1.27994 1.27230 1.26471 1.25717 1.24969 1.24227 1.23490 61 89 1.23490 1.22768 . 1.22031 1.21310 1.20693 1.19882 1.19175 60 40 1.19176 1.18474 1.17777 1.17085 1.16898 1.16716 1.16087 49 41 1.16037 1.14863 1.18U91 1.131)29 1.12.^69 1.11713 1.11061 48 42 1.11061 1.10411 1.09770 1.09131 1.08496 1.07604 1.0728)7 47 48 1.07287 1.06613 1.06094 1.06378 1.04766 1.04158 1.03553 46 44 1.03558 1.02962 1.023.55 1.01761 1.01170 1.00588 1.00000 45 60' ec 40' 80' 20* 10' 0' § TUGMT •1 CARNEGIE HAND BoOi: TOWNS AND SMALL CITIES. 465 o SIDE, c lO' 20' 30' 40' 60' ec 1 a 8 4 0.00000 0.0174S 0.034»0 0.05234 0.06976 0.00291- 0.02036 o.osrai 0.05524 0.07266 0.00S82 0.02327 0.04071 0.05814 0.07656 0.00873 0.02618 0.04362 0.06105 0.07846 0.01164 0.02908 0.04653 0.06395 0.08136 0.01454 0.03199 0.04943 0.06685 0.08426 0.01745 0.08490 0.n52.S4 0.06976 0.08716 89 88 87 88 85 S 6 7 8 9 o.osne 0.10453 0.1218r 0.IS917 0.15643 0.09005 0.IW4C , 0.12476 0.14205 0.15931 0.09295 0.11031 0.12764 0.14493 0.16218 0.09585 0.11320 0.1SOS3 0.14781 0.16505 0.09874 0.11609 0.13341 0.15069 0.16792 0.10184 0.11898 0.13629 0.1.5356 0.17O7« 0.10468 0.12187 0.18917 0.15648 0.17365 84 83 83 81 80 10 11 12 13 14 0.17S6S 0.19081 0.2O?91 0.22496 0.24192 0.17651 0.19366 0.21076 o.zzm 0.24474 0.17937 0.1S652 0.21360 0.23062 0.24766 0.18224 0.19937 0.21644 0.28345 0.25038 0.18509 0.20222 0.21928 0.2.Sfi27 0.25320 0.18795 0.20507 0.22212 0.28910 0.25601 0.19081 0.20791 0.22495 0.24192 0.25882 79 78 77 76 7S 15 16 17 18 19 0.2.'>882 0.27564 0.292»r 0.30902 0.32567 0.26163 0.27843 0.29R15 0.81178 0.32832 0.26443 0.28123 0.29793 0..S1454 0.33106 0.26724 0.28402 0.30071 0.31730 0.83381 0.27004 0.28680 0.30848 0.32006 0.33655 0.27284 0.28959 0.80625 0.82282 0.83929 0.27564 0.29287 0.80»02 0.82,')57 0.34202 74 73 78 71 70 90 81 S3 S3 84 0.84209 0.35837 0.37461 0.39073 0.40674 0.34475 0.S610S 0.87730 0.39341 0.40939 0.34748 0.86.S79 0.37909 0.39608 0.41204 0.!«i021 0.86650 0.8826S 0.89875 0.41469 0.35293 0.36921 0.38537 0.40142 0.41734 0.8.'i,'i65 0.37191 0.88605 0.40408 0.41998 O.S.VW 0.37461 0.89073 0.40674 0.42262 6S 68 67 66 65 SS S6 S7 S8 £9 0.42262 0.48837 0.45399 0.46947 0.48481 0.42525 0.44(198 0.45658 0.47204 0.48735 0.42788 0.44350 0.45917 0,47460 0.48989 0.43051 0.44620 0.46175 0.47716 0.49242 0.43318 0.44880 0.46483 0.47971 0.49495 0.48575 0.45140. 0.46630 0.48226 0.49748 0.43887 0.45899 0.46947 0.48481 0.60000 64 63 62 61 60 80 81 88 S3 34 o.snooo 0.S1504 0.52992 0.64464 0.E5919 o.Sbsm 0.51753 0.53238 0.54708 0.56160 0.60503 0.52002 0.53484 0.54951 0.66401 0.S0754 0,52250 0.68780 0.55194 .0.56641 0.51004 0.52198 0.63975 0.55486 0.56880 0.51254 0.52745 0.64220 0.55678 0.57119 0.51504 0.62992 0.54464 0.55919 0.57358 59 68 57 66 55 85 86 87 88 89 0.67358 0.58rr9 0.60182 0.61.^66 0.62932 0.57596 0.B9014 0.60414 0.61795 0.63158 0.67838 0.69248 0.60645 0.62024 0.63383 0.58070 0.59482 0.60876 0.62251 0.63608 0.68307 0.59n6 0.61107 0.62479 0.63832 0.58543 0.69949 0;61337 0.62706 0.64056 0.58779 0.60182 0.61666 0.62tl32 0.64279 64 53 52 51 50 40 41 42 43 «4 0.64279 0.6^606 0.66913 0.682U0 0.69466 0.64501 0.66825 0.67129 0.68412 0.69675 0.64723 0.66044 0.67344 0.68624 0.69883 0.64945 0.64262 0.67569 0.68. «B 0,70091 0.66166 0.66480 0.67773 0.69046 0.70898 0.65386 0.66697 0.67987 0.69256 0,70505 0.65606 0.66913 0.68200 0.69466 0.70711 49 48 47 40 45 60' ec «y sc ao> lO* O' 1 (XISIHI. CARNEGIE HAND BOOS. 466 ENGINEERING WORK IN 1 ' i»)3iins c 10' 20' SO* 40* 60' 60' 1 a 3 4 1.00000 0.99983 0.99939 0.99863 0.99766 1.00000 0.99979 0.99929 0.99847 0.99786 0.99998 0.99973 0.99917 0.99831 0.99714 0.99996 0.99966 0.99005" 0.99813 0.99693 0.9999S 0.99958 0.99892 0.99795 0.99668 0.99989 0.99949 0.99878 0.99T76 0.99644 0.99985 0.99939 0.99863 0.99756 0.99619 89 88 87 83 85 6 « 7 8 9 0.99619 0.99453 0.99255 0.99027 0.98769 0.99594 0.99431 0.99319 0.98986 0.98723 0.99567 0.99390 0.99183 0.98944 0.98676 0.99540 0.99357 0.99144 0.98902 0.98629 0.99511 0.99324 0.99106 0.98858 0.98580 0.99482 0.99290 0.99067 0.98814 . 0.98531 0.99452 0.99265 0.99037 0.98769 0.98481 84 83 83 81 80 10 il 13 13 14 0.98481 0.98163 0.97815 0.97437 0.97U30 0.98430 0.98107 0.97754 0.97871 0.96959 0.98378 0.98050 0.97693 0.97304 0.96887 0.98325 0.07992 0.97630 0.97237 0.96815 0.98272 0.97934 0.97566 0.97169 0.96742 0.98218 0.97876 0.97602 0.97100. 0.96667 0.98163 0.97816 0.97487 0.970BO 0.96693 79 78 77 76 75 15 18 17 18 19 0.96593 0.96126 0.95630 0.95106 0.94S52 0.96617 0.96046 0.95545 0.95015 0.944S7 0.96440 0.95964 0.96459 0.94924 0.94361 O.OfiiWS 0.96RS2 0.95S73 0.94832 0.94264 0.96385 0.95799 0.95284 0.94740 0.94167 0.96206 0.96715 0.95195 0.94646 0.94068 0.96126 0.95630 0.95106 0.94652 0.93S69 74 73 78 71 70 20 . 21 22 23 24 0.93969 0.93358 0.92n8 0.92050 0.91355 0.93869 0.9S2SS 0.92609 0.91936 0.91236 0.93769 0.93148 0.92499 0.91822 0.91116 0.93667 0.98042 0.93388 0.91706 0.90996 0.93565 0.92935 0.92276 0.91590 0.90875 0.93462 0.92827 0.92164 0.91472 0.90753 0.93358 0.'92718 0.92050 0.91355 0.90631 69 6S 67 68 85 25 28 27 28 2» 0.90631 0.89879 0.89101 0.88295 0.87462 0.90507 0.89752 0.88968 0.88158 0.87321 0.90383 0.89633 0.88835 0.88020 0.8n78 0.90359 0.89493 0.88701 0.87882 0.87036 0.90IS3 0.89363 0.88566 0.87748 0.86892 0.90007 0.89232 0.88431 0.87603 0.86748 0.89879" 0.89101 0.88295 0.87462 0.86603 64 63 63 61 60 80 81 83 83 84 0.86603 0.85717 0.84805 0.83867 0.82904 0.86457 0.86567 0.84650 0.83708 0.82741 0.86310 0.85416 0.84495 0.8S549 0.82577 0.86163 0.85364 0.84339 0.83389 0.83418 0.86015 0.85112 0.84183 0.83228 0.82248 0.85866 0.84959 0.84025 0.83066 0.82083 0.85717 0.84805 0.83867 0.82904 0.81915 69 68 57 68 '65 85 88 87 88 8» 0.81915 0.80903 0.79864 0.78801 0.77715 0.81748 0.80730 0.79688 0.78622 0.77581 0.81580 0.80558 0.79512 0.78442 0.77347 0.81412 0.80388 0.79335 0.78261 0.T7162 0.81242 0.80212 0.79158 0.78079 0.78977 0.81072 0.8UU38 0.78980 0.77897 0.76791 0.80902 0.7i9864 0.78801 0.77715 0.78804 64 63 62 61 60 40 41 42 48 44 0.76604 0.75471 0.74314 0.73135 0.71931 0.78417 0.75280 0.74120 0.72937 0.71732 0.76229 0.75088 0.78924 0.71B29 0.TB041 0.74896 0.18728 0.72537 0.71825 0.1E851 0.74703 0.78681 0.73837 0.71121 0.78661 O.74S09 0.78833 0.72136 0.70916 o.Tsm 0.74814 0.73135 0.71934 0.70711 49 48 47 48 45 ecK 6CV 40' sc 20" 10* C 1 SINB CARNEGIE HAND BOOK. TOWNS AND SMALL CITIES. 467 1 SIClllTS c IC 20' SO' 40' 60' 60' I 8 4 1.00000 1.00015 1.00061 1.00137 1.00844 1.00001 1.00021 1.00072 1.00158 1.00265 1.00008 1.00027 1.00088 1.00169 1.00287 1.00004 1.00034 1.00095 1.00187 1.00309 1.00007 1.00042 1.00108 1.00205 1.00333 1.00011 1.00051 1.00122 1.00224 1.00357 1.00016 1.00061 1.00187 1.00244 1.00382 89 88 87 88 8$ 6 6 7 8 9 1.00382 1.00561 1.00761 1.00983 1.01247 1.00408 1.00582 1.00787 1.01024 1.01294 1.00435 1.00614 1.00825 1.01087 1.01342 1.00463 1.00647 1.00863 1.01111 1.01891 1.00491 1.00681 1.009U8 1.01155 1.01440 1.00521 i.oon5 1.00942 1.01200 1.01491 1.00551 1.0O751 1.00983 1.01247 1.01543 84 83 83 81 80 10 11 12 18 14 1.01543 1.01878 1.08284 1.02630 1.03061 1.01695 1.01930 1.02298 1.02700 1.03137 1.01849 1.01989 1.02382 1.02770 1.03218 1.01703 1.02049 1.02428 1.02842 1.03290 1.01758 1.02110 1.02494 1.02914 1.03368 1.01815 1.02171 1.02562 1.02987 1.03447 1.01872 1.02234 1.02630 1.03061 1.03628 79 78 77 78 75 15 16 17 18 19 1.03528 1.04030 1.01669 1.05146 1.06762 1.03609 1.04117 1.04663 1.06246 1.06869 1.03691 1.04206 1.04757 1.05347 1.05976 1.03774 1.04295 1.04853 1.05449 1.06085 1.03858 1.04385 1.04950 1.05552 1.06195 1.03944 1.0*177 1.05047 1.05657 1.06306 1.04030 1.04669 1.05146 1.05762 1.06418 74 73 72 71 79 SO 81 W 8S S4 1.08418 1.07116 1.07863 1.08636 1.09464 1.06531 1.07235 1.07981 1.08771 1.09606 1.06645 1.07356 1.08109 1.08907 1.09750 1.06761 1.07479 1.08239 1.09044 1.09895 1.06878 1.07602 1.08870 1.09183 1.10041 1.06995' 1.07727 1.08503 1.09323 1.10189 1.07116 1.07853 1.08636 1.09464 1.10388 69 68 67 69 65 85 88 87 28 89 1.10888 1.11280 1.18233 1.13257 1.14S35 1.10488 1.11419 1.12400 1.13433 1.14521 1.10640 1.11679 1.12568 1.18610 1.14707 1.10793 1.11740 1.12738 1.13789 1.14896 1.10947 1.11903 1.18910 1.13970 1.16085 1.11103 1.12067 1.18088 1.14152 1.15277 1.11260 1.12233 1.13267 1.143SS 1.16470 64 63 88 61 60 80 81 88 83 84 1.18470 1.16663 1.17918 1.19236 1.20622 1.15666 1.16888 1.18183 1.19468 1.20869 1.16861 1.17075 1.18350 1.19691 1.21099 1.16059 1.17883 1.18569 1.19920 1.81341 1.18259 1.17493 1.18790 1.80158 1.21684 1.16460 1.17704 1.19012 1.20386 1.21830 l.lfififiS 1.17918 1.19236 1.20622 1.28077 68 CT 6S 65 S5 36 87 88 89 1.22077 1.2360? 1.85214 1.88908 Lssm 1.22327 1.23S69 1.85489 1.87191 1.88980 1.82679 1.24134 1.25767 1.27483 1.29287 1.22833 1.24400 1.28047 1.27T78 1.89597 1.23089 1.24669 1.26330 1.88075 1.29909 1.23347 1.24940 1.26616 1.28374 1.80223 1.23607 1.26214 1.26902 1.28678 1.80541 64 63 68 61 60 40 11 42 48 44 1.30541 1.32501 1.84563 1.38783 1.89016 1.80661 1.88888 1.84917 1.87105 1.39409 1.31183 1.331T7 1.85274 1.87481 1.39801 1.81609 1.33619 1.36634 1.37860 1.40203 1.81837 1.83864 1.35997 1.38242 1.40806 1.82168 1.84212 1.86363 1.88628 1.41018 1.88501 1.84563 1.36733 1.89016 1.41421 49 48 47 48 4S ec ec 40' 30* 20' IC C I COSEOIBIS S CARNEGIE HAND BOOS. 468- ENGINEERING WORK IN 1 COSEICAlira i C 10' 20' 80' 40' ec 60* 1 !9 3 4 oo B7.29869 28.65371 19.10732 14.88559 343.77516 49.11406 26.45051 13.10262 13.76312 171.88831 42.97571 24.66212 ,17.19848 18.23472 114.59301 38.20155 22.92559 16.38041 12.74560 85.94561 34.88232 21.49368 15.63679 12.29125 68.75736 31.25758 20.23028 14.95788 11.86887 57.29869 28.65371 19.10782 14.33559 11.47Sn 89 i? 86 85 6 6 7 8 9 11.47371 9.56677 8.20651 7.18530 6.39245 11.10455 9.30917 8.01565 7.03962 6.2m9 10.75849 9.06515 7.83443 6.89979 6.16607 10.43343 8.83367 7.66130 6.76547 6.05886 10.12752 8.61379 7.49571 6.68633 5.95536 9.88912 8.40466 7.83n9 6.51208 5.85539 9.B6677 6.20551 7.18530 6.89245 5.75877 81 88 82 81 80 10 11 .12 IS 14 6.7587? 5.24084 4.80973 4.44541 4.13357 6.66533 6.16359 4.74482 4.89012 4.08591 5.57493 5.08863 4.68167 4.33622 4.03938 B.48740 5.01585 4.62023 4.28366 8.99393 6.40263 4.94517 4.66041 4.tSi239 8.94952 5.82049 4.87649 4.50216 4.18238 8.90613 5.24084 4.80978 4.44541 4.13357 3.86870 79 78 75 15 16 17 18 19 8.86370 3.62796 8.42030 3.23607 8.07165 3.82223 3.69164 3.38808 3.20737 3.04584 3.78166 3.65587 3.35649 3.17920 3.02057 3.74198 8.52094 3.82651 8.15155 2.99574 S.70815 3.48671 3.29512 8.12440 2.9n85 3.66515 3.45317 3.26581 3.09774 2.94737 8.62796 8.42080 8.23607 8.07156 2.92380 74 78 73 71 70 20 21 82 23 24 2.92380 2.79043 2.66947 2.659S0 2.45859 2.90063 2.76945 2.65040 2.64190 2.44264 2.87785 2.74881 2.63162 2,52474 2.42692 2.85545 2.72850 2.61313 2.50784 2.41142 2.83342 2.70851 2.69491 2.49119 2.39614 2.81175 2.68884 2.57698 2.474rr 2.88107 2.79043 2.66947 2.65980 2.45859 2.36620 69 68 87 66 66 25 26 27 28 29 2.36620 2.28117 2.20269 2.13005 2.06267 2.85154 2.26766 2.19019 2.11847 2.05191 2.33708 2.25432 2.17786 2.10704 2.04128 2.32282 2.24116 2.16568 2.09574 2.03077 2.80875 2.22817 2.15366 2.08458 2.02039 2.29487 2.21535 2.14178 2.07356 2.01014 2.28117 2.20269 2.18005 2.06287 2.00000 64 68 ea 61 60 SO 81 S2 SS 84 2.00000 1.94160 1.88708 1.88608 1.78829 1.98998 1.93226 1.87834 i.&sm 1.78062 1.98008 1.92302 1.86990 1.81981 1.77303 1.97029 1.91388 1.86116 1.81180 1.76552 1.96062 1.90485 1.85271 1.80388 1.75808 1.95106 1.89691 1.84435 1.79604 1.76073 1.94160 1.88709 1.83608 1.78829 1.74345 69 68 67 59 55- 85 86 87 88 89 1.74345 1.70130 1.66164 1.624»r 1.68902 l'.6182S 1.68838 1.72911 1.68782 1.64894 1.61229 1.5T771 1.72205 1.68117 1.64268 1.60689 1.57213 1.71503 1.67460 1.63648 1.60054 1.56661 i.ToaiB 1.66809 1.63035 1.59476 1.56114 1.70180 1.66164 1.62427 1.58902 1.55572 64 63 62 61 60 40 41 42 43 44 1.65672 1.52425 1.49448 1.46628 1.43956 l.S.'SBR 1.61918 1.48967 1.4617S 1.48524 1.54504 1.61415 1.48491 1.45721 1.43096 1.58977 1.50916 1.48019 1.45274 1.42672 1.53455 1.50422 1.47551 1.44831 1.42251 1.52938 1.49933 1.47087 1.44391 1.41835 1.52426 1.49418 1.46628 1.48956 1.41421 49 48 47 46 45 ecy ec 40- 30' 20' IC C P 8ICASIS ^ -CARNEGIE HAND BOOK. TOWNS AND SMALL CITIES. 469 Decimals of a Foot for each t-64 of an Inch. 0' r 2" 3' 4" 5" 6" 7'- 8' 9" 10" IV .0 .0883 .1667 .2500 .8333 .4167 .5000 .."ssas .6667 .7500 .8333 .9167 & .0013 .0846 .1660 .2513 .3346 .4180 .5013 .5846 .6660 .7513 .8346 .9180 3^. .0026 .0859 .1693 .2528 .3359 ^4193 .5026 .5859 .6693 .7526 .8359 .9193 & .0039 .0872 .1706 .2539 .8372 .4206 .5039 .5872 .6706 .7539 .8372 .9206 A .0052 .0885 .1719 .2552 .3385 .4819 .5052 .5885 .6719 .7562 .8865 .9219 A .0065 .0898 .1732 .2565 .3398 .4232 .5065 .6896 .6732 .7665 .8398 .9233 A .0078 .0911 .1745 .2578 .8411 .4245 .5078 .5911 .6745 .7578 .8411 .9245 A .0091 .0924 .1758 .2591 .3124 .4258 .5091 .5924 6758 .7591 .8424 .9258 a .0104 .0937 .1771 .2604 .3437 .4271 .5104 .5937 .6771 .7604 .8437 .9271 A .0117 .0951 .1784 .2617 .3451 .4284 .6117 .5951 .6784 .7617 .8451 .9284 A .0180 .0964 .i79r .2630 .3464 .4297 .5130 .5964 .6797 .7630 .8464 .9297 a .0143 .0977 .1810 .2643 .8477 .4310 .5143 .5977 .6810 .7648 .8477 .9810 A .01^ .0990 .1823 .26.16 .3490 .4323 .6156 .5990 .6823 .7656 .8490 .9323 a .0169 .1003 .1836 .2669 .3503 .4386 .5169 .6003 .6836 .7669 .8508 .SS39 A .0182 .1016 .1849 .•2682 .3516 .4349 .5182 .6016 .6849 .7682 .8516 .9349 il .0195 .1029 .1862 ;2695 .3529 .4362 .5195 .6029 .6862 .7695 .8529 .9362 a .0208 .1042 .1875 .2708 .3542 .4375 ,5208 .6042 .6875 .rro8 .8542 .9375 u .0221 .1055 .1888 .2721 .R.'i.W .4388 .5221 .6055 .6888 .7721 .8555 .9383 A .0234 .1068 .1901 .2734 .3568 .4401 .5234 .6068 .6901 .7734 .8568 .9401 il .0247 .1081 .1914 .2747 .8581 .4414 .6247 .6081 .6914 .7747 .8581 .9411 A .0260 .1094 .1927 .2760 .8594 .4427 .5260 .6094 .6927 .7760 .8594 .9427 li .0!??S .1107 .1940 .2773 .3607 .4440 .6a?3 .6107 .6940 .7773 .8607 .9440 ii .0286 .1120 .1953 .2786 .3620 .44^ .5286 .6120 .6953 .7786 .8620 .9453 a .0299 .1133 .1966 .2799 .8883 .4466 .5299 .6183 .6966 .7799 .8683 .9466 H .0312 .1146 .1979 .2812 .3646 .4479 .6312 .6146 .6979 .7812 .8646 .9479 i! .0326 .115^ .1992 .2826 .3659 .4492 .6326 iel59 .6992 .7826 .8659 .94^ a .0339 .1172 .2005 .2839 .3672 .4505 .5339 .6172 .7005 .7889 .mm .9505 ii .0352 .1186 .2018 .2852 .3685 .4518 .5852 .6185 .7018 .7852 .8685 .9518 A .0885 .1198 .2031 .2865 .8698 .4531 .5365 .61« .7031 .7865 .8898 .9531 II .0378 .1211 .2044 .2878 .3711 .4544 .BS78 .6211 .7044 .7878 .8711 .9544 H .0391 .1224 .2057 .2891 .3724 .4557 .6391 .6224 .7057 .7891 .8724 .9557 » .0404 .1237 .2070 .2901 .3737 ,4570 .5404 .6237 .7070 .7904 .8737 .9570 a .0417 .1250 .txws .2917 .3750 .4683 .5417 .6250 .7083 .7917 .8750 .9583 —JONES & LAUCHLIN HAND BOOK. 470 ENGINEERING WORK IN Decimals of a Foot for each 1-64 of an Inch. 1 0' 1" 2" 3" 4' S" 6" 7" 8' 9- 10" 11" % .0417 .1250 .2063 .^17 .3750 .4583 .5417 .6250 .7083 .7917 .8750 .9533 13 .0430 .1263 :2096 .2930 .3763 .4596 .5430 .6263 .7096 .7930 .8763 .9596 a .0443 .1276 .2109 .2913 .3776 .4609 .5443 .6276 .7109 .7943 .8776 .9609 n .0456 .1289 .2122 .2956 .3789 .4622 .5156 .6289 .7122 .7956 .8789 .9622 A .0469 .1302 .2135 .2969 .3802 .4635 .5469 .6802 .7135 .7969 .8802 .9635 « .0482 .1315 .2148 .2982 .8815 .4648 .5482 .6315 .7148 .7982 .8815 .9648 » .0495 .1328 .2161 .2995 .3828 .4661 .5495 .6328 .7161 .7995 .8828 .9661 « .0508 .1341 .2174 .3008 .3841 .4674 .5508 .6341 .7174 .8008 .8841 .9674 a .0521 .1354 .2188 .3021 .3854 .4688 .5521 .6354 .7188 .8021 .8854 .9688 %k .0534 .1867 .2201 .8034 .3867 .4701 .5534 .6367 .7201 .8034 .8867 .9701 n .0547 .1380 .2214 .3047 .8880 .4714 .5647 .6380 .7214 .804T .8880 .9n4 ti .0560 .1393 .2227 .3060 .3893 .4727 .5560 .6393 .7227 .'8060 .8893 .9727 ii .0W8 .1406 .2240 .3078 .3906 .4740 .6673 .6406 .7240 .8073 .8906 .9740 ti .0586 .1419 .22B3 .3086 .3919 .4753 .^86 .6419 .7253 .8086 .8919 .9753 13 .0599 .1432 .2266 .3099 .3932 .4766 .5599 .6432 .7266 .-8096 .8932 .9766 » .0612 .1445 .2279 .3112 .3945 .4779 ,5612 .6445 .7279 .8112 .8915 .9779 K .0625 .1458 .2292 .3125 .3958 .4792 .5625 .6458 .7292 .8125 .8958 .0792 U .0638 .1471 .2305 .3138 .8971 .4805 .6638 .6471 .7805 .8138 .8971 .9805 Sf .0651 .1484 .2318 .3151 .8984 .4818 ,5651 .6484 .7318 .8151 .8984 .9818 « .0664 .1497 .2331 .3164 .3997 .4831 .5664 .6497 .7331 .8164 .8997 .9831 \l .0677 .1510 .2344 .3177 .4010 .4844 .5677 .6510 .7344 .8177 .9010 .9844 a .0690 .1523 .2857 .8190 .4023 .48S7 .5690 .6523 .7857 .8190 .9023 .9857 13 .0703 .1536 .2370 .3203 .4036 .4870 .B703 .6536 .7370 .8203 .9036 .9870 !i .one .1549 .2383 .3216 .4049 .4883 .5716 .6549 .7383 .8216 .9049 .9883 ^ .0789 .1562 .2396 .3229 .4062 .4896 .5729 .6562 .7396 .sm .9062 .9896 U .0742 .1B76 .2409 .3242 .4076 .4909 .5742 .6576 .7409 .8212 .9076 .9909 If .0755 .1589 .2422 .3255 .4089 .4922 .5755 .OuoV .7422 .8255 .9089 .9922 «l .0768 .1602 .2435 .3268 .4102 .4935 .5768 .6602 .7485 .8268 .9102 .9935 u .0781 .1615 .2448 .3281 .4115 .4948 .5781 .6615 .7448 .8281 .9115 .9948 u .0794 .1628 .2461 .3294 .4128 .4961 .B794 .6628 .7461 .'8294 .9128 .9961 « .0807 .1641 .2474 .3307 .4141 .4974 .5807 .6641 .7474 .8307 .9141 .9974 « .0820 .1654 .8487 .3320 .4154 .4987 .6820 .6654 .7487 .8320 .9164 .9987 1 1.0000 ^JONES & LAUGHLIN HAND BOOK. TOWNS AND SMALL CITIES. 471 Decimals of ari Inch for eacTi I -64th. Ads. Aths. Decimal. Fract'n Ads. Aths. Decimal. Fract'n 1 .015625 33 .515625 1 2 .03126 17 34 .53125 3 .046875 35 .546875 2 4 .0625 1-16 18 36 .5625 9-lS 5 .078125 37 .578125 3 6 .09375 19 38 .59375 7 .109375 39 .609375 4 8 .125 1-8 20 40 .625 5-8 9 .140625 41 .640625 6 10 .15625 21 42 .65625 11 .171875 43 .671875 6 12 .1875 3-16 22 44 .6875 11-16 13 .203125 45 .703125 7 14 .21875 23 46 .71875 15 .234375 47 .734375 8 16 .25 1-4 24 48 .75 3-* 17 .265625 49 .765625 9 18 .28125 25 50 .78125 19 .296875 51 .796875 10 20 .3125 5-16 26 53 .8125 13-18 21 .328125 53 .828125 11 22 .34375 27 54 .84375 23 .359375 55 .859375 12 24 .375 3-8 28 56 .875 7-8 25 .390625 57 .890625 13 26 .40625 29 58 .90625 27 .421875 59 .921875 14 28 .4375 7-16 30 60 .9375 15-l« 29 .453125 61 .953125 15 30 .46875, 31 62 .96875 31 .484375 63 .984375 16 83 .5 1-2 32 64 1. 1 -JONES & LAUGHLIH HAND BOOK. APPENDIX A. MIXING CONCRETE WITH MACHINES. In the chapter on concrete mention was made of the modern method of mixing with machines. It is commonly stated that concrete must be mixed so that all the voids in the stone will be filled with cement mortar and to make a good cement mortar all the voids in the sand must be filled with cement paste. When a concrete is so made it is perfect. The one drawback to such perfection is that the mixtures are generally specified as a 1:8:4 or a 1:3:5, etc., and if it happens that a propor- tion is specified so that all the voids can not be filled we see readily enough that the foregoing definition does not hold good. The definition of well mixed concrete must therefore be modi- fied to read : "So that all the grains of sand will be coated with cement paste and all the particles of stone be coated with cement mortar." Such perfection of mix can not be obtained by the use of shovels or any other tools, in the hands of men. A close approximation may be obtained by careful manipulation, but it is costly. Attention is directed to the following table taken from an article in Engineering News, August 27, 1903, by Clarence Coleman, United States assistant engineer: EFFECT OF TIME OF MIXING ON STRENGTH OF CEMENT-MORTAR (1 CEMENT TO 3 SAND.) . Mean teoiile strength of briquettes after Water , Days . , — Hontba » . Years , Time of per cent of 7, 28, S, e, 1, 2, nixing dry ioRredients lbs. lbs. lbs. lbs. lbs. lbs. 1 min 8 25 231.6 317 397 437 435 429 2 mins 8.25 274.4 366 425 447 468 43n 3 " 8.25 288.2 396 454 516 521 459 4 " 8.25 306.8 418 466 534 536 490 5 " 8.25 324.6 436 495 546 532 515 a " 8.25 335.0 446 528 554 559 481 7 " ; 8.37 344.8 446 500 509 585 530 8 " 8.50 387.2 471 530 571 663 511 9 " 8.75 362.2 469- 538 603 601 53V 10 '.' ....... 8.87 368.6 488 564 612 615. 524 The above table represents the results of tests made by Mr. i MIXING CONCRETE WITH MACHINES. Coleman to determine the effect of time in mixing by hand. It shows how much the time of mixing has to do with the strength of mortar and concrete. For example, a batch mixed one minute with a hoe in a cast iron box with inclined ends (the most perfect method of hand mixing) showed a tensile strength of 231.6 pounds per square inch in seven days. Another briquette from the same batch showed a tensile strength of 429 pounds in two years. A batch, however, that was mixed ten minutes showed a tensile strength of 368.6 pounds in seven days. The briquette from the batch mixed one minute had less than two-thirds the strength of the briquette mixed ten minutes. An average of briquettes from the ten minute batch broken after two years showed a strength of 524 pounds as against 429 from the one minute batch. The reason for the results shown in the above table is that the mortar mixed a short time was not so thoroughly mixed as the mortar manipulated a longer time. It would hardly seem that much argument is required on that score, yet the writer has met many men who think the addition of water will correct the defects of insufficient mixing and in some mysterious way distribute the cement properly. \ The cement must be properly distributed for two reasons: First, if every particle of stone is coated with sand-cement mortar and every particle of sand coated with cement paste the greatest opportunity is given the materials to consolidate and firmly bind. Second, stone goes to pieces when exposed to the atmosphere be- cause it contains elements attacked by other elements contained in the atmosphere, especially in the cities. Cement is practically acid proof and if thd stone and sand are thoroughly coated the concrete will not be apt to disintegrate as much as if particles of stone and sand were exposed to injurious elements. Concrete may be porous and allows a certain amount of moisture to go through, but if the stone and sand are protected from the water and the solvents it carrifes the porosity may not be harmful. In throwing the material around with shovels the process is simply an averaging one. It is impossible that the exact proportions of each aggregate are taken up with each shovel load. A few minutes' observation of men at work will show that streaks are common. If there are streaks the concrete can not be uniform APPENDIX A. throughout the mass and therefore can not have the strength it should have. If it does not have the strength and is streaky in composition it plainly does not have each grain of sand and particle of stone coated with mortar, therefore is open to destruction by the atmosphere. On pages 349-385, Report of the Watertown Arsenal, 1897, will be found reports of tests of piers made with well mixed hand made concrete and of piers made with machine mixed concrete. The average compressive strength of the hand mixed concrete was 989 pounds per square inch and the average compressive strength of ma- chine mixed concrete was 1,098 pounds, showing an advantage of 11 per cent in favor of machine mixing. Other tests made at the same place showed an advantage of 25 per cent. It must be borne in mind that the hand mixing was performed with greater care than is customary on ordinary work. On page 3,784, Report of the Chief of Engineers, U. S. A., 1904, is an interesting table showing a comparison of hand mixed concrete with cube mixed concrete used in a pier in Duluth Harbor. The hand mixed concrete was "first-class concrete,'' according to Government requirements. Forty-five briquettes of ^concrete (not mortar) were made and tested. For a seven-day test the cube mixed concrete was 47 per cent the stronger. On a twenty-eight- day test it was 23 per cent stronger. On a six months' test it was 16 per cent stronger. On a twelve months' test it was 13 per cent stronger. This showed that concrete gradually increases in iii MIXING CONCRETE WITH MACHINES. strength, so the difference in strength ultimately is not so great as at first. Structures, however, generally receive their full load within sixty days and often are tested with a test load much greater in a few days after completion. It is well to remember that ma- chine mixed concrete obtains its full strength much more quickly than -hand mixed concrete, and that hand mixed concrete is never so strong. The first concrete mixer the writer used was in 1888. It was a gravity mixer (so called), and he stopped using it and worked by hand, for the product was not always uniform. In 1891 he used a wooden cube and was greatly pleased with the quality of product turned out. Since then he has used a number of styles, but prefers the cube, because the principle is right and the concrete is uniform. A little thought will show why this type must be superior. Any machine designed to imitate the shovel action separates the ma- terials first and then combines and recombines them. Excellent concrete has been made with such machines and is being made every day. But the shovel and hoes likewise make good concrete if given enough time. In a cube, suspended on an axis, tly-^ugh diagonal corners the other intermediate corners are altern^telfAon either side of the median line, "^s the cube revolves the mass is moved, or slid, alternately from side to side and corner to corner, changing shape with every move. In addition portions- are carried up on the six sides until they, exceed the angle of repose; of the material, when it falls down toward the center. This falling is accomplished by a turning over at the upper edges and a folding on the mass below, rolling down in a thin sheet. As there are six sides, there are six commingling sheets, each lapping over a lower one at a different angle from the preceding and following sheet. Observing men have noticed that on a macadamized road "nig- ger heads" work to the surface. This is for the reason that when granular materials of differing sizes are disturbed the smaller particles work through the interstices of the larger and finally fill the space so the larger pieces have to be above. In a cube mixer this action is seen to perfection. The disturbance of the mass tends to make the smaller particles work into the voids, but as the cube turns they are prevented from going to the bottom, for APPENDIX A. the bottom is continually changing. The motion therefore compels a filling of the voids. It is for this reason the cube mixer is so rapid in mixing and turns out so uniform a concrete. The older cube mixers had to be stopped to load and dis- charge. Today there is an improved form of cube in the market that is rapidly coming to the front. It has an axis consisting of a loading and discharging spout on rollers, fastened to a frame that tilts to discharge. This arrangement makes the machine undoubt- edly the fastest batch mixer on the market, and as the concrete is_ good it is in the writer's opinion the best. An experiment was made in coloring mortar to demonstrate it. A batch of mortar was mixed in a cube and in a machine imitating the shovel action. A certain amount of coloring matter was put in each batch and the time of mixing was the same. In the cube mixed mortar the coloring was distributed in an absolutely uniform manner, show- ing no streaks. In the other batch a number of streaks were found inside as well as on the face. It has been charged that the cube can not mix mortar. The writer knows of many used for that purpose and giving satisfac- tion. Occasionally, but so rarely that the occurrence is notable, a material is encountered that gives trouble. By putting four to six half-inch rods through the cube parallel with the axis the trouble is entirely remedied. The cube in the form above described is manufactured and sold by the Municipal Engineering and Contracting Company, Chicago, Illinois. The writer has reserved a description of the mixer for an appendix in order to free himself from criticism for recommending any certain type of machinery in his book. The opinions expressed in this appendix are his honest opmions on the subject of concrete mixing machines after an extended ex- perience with many makes. To forestall criticism he admits that for two years he served as engineer for the above company and if charged with bias can only plead that it is an honest one. He feels he is benefitting his readers by this full mention of the mixer and if it helps his former employers he will be pleased. APPENDIX B. TRENCHING MACHINES. For the same reasons that impelled the writer to leave for an appendix a description of concrete mixers, a description of trenching machinery has been left to be treated in the same way. Every contractor for trench work has thought of some device for saving human labor, but the only practical machine with which the writer is acquainted (and he has seen every advertised machine and some that are not advertised) is made by the Munici- pal Engineering and Contiracting Company, Chicago, 111. While in the employ of the above company he supervised the excavating of many miles of sewer trenches in St. Louis and other places and was in daily touch for over two years with work done by the Chicago Sewer Excavator in many parts of the country. The machine is made in several sizes adapted for trenches to any depth down to twenty feet and for widths varying from twelve to sixty inches. The machines consist essentially of a traction engine with a long arm at the rear and over which two chains pass. To these chains are attached bars of iron, technically termed "buckets," holding cutters and plow points. To excavate a trench the arm is drawn forward as the ma- chine moves and the cutting points loosen the earth as the chains pass over the wheels on the arm. This is caught and carried upward by the buckets and thrown on to a cross traveling belt that delivers it alongside the trench. The dirt piled along the side is afterward scraped into the trench in any practicable way. Sometimes a backfilling conveyor is used with the machine. This backfilling conveyor is a belt on a carriage attached to, and traveling with, the excavator. The belt is actuated by a separate engine receiving steam from the excavator boiler and the cross carrier on the excavator throws the dirt on the belt instead of on the ground. By means of the long belt the dirt is carried back TRENCHING MACHINES. and dropped into the trench on the newly laid pipe. Any prac- tical man can readily see how valuable an attachment the back- filler is, where it can be used. The company also made, and still makes when ordered, a machine having a large wheel for excavating trenches, but such machines, no matter how well made, are not practicable in all grounds and the practical limit in depth is about seven feet. A wheel must of course be at least twice as many feet in diameter as the depth of any trench it can excavate. Some ground has a tendency to cave. If a wheel machine is used in such ground there must necessarily be a long space, equal i to the diameter of the wheel that can not be braced. The chain type of excavator working with a long narrow arm is ideal, as the trench can be planked up to the machine. The wheel type was a forerunner, but was found to be not so practicable for a variety of work as the machine now under description. For the contractor the company has interesting liteiTiture to show why it is to his interest to use such a machine. The writer wishes here to confine himself mainly to the reasons it is good for such work to be done by machinery in cities and towns. In the first place the labor question is an item. The majority of cities prefer to have money spent at home. It is seldom that a contractor can get enough men in any small or medium sized place, and he must therefore import laborers. It is a bone of contention always. The people feel nervous over so many poor men coming in, and fear vagabonds will be left for the town to support after APPENDIX B. the contractor is gone. The local merchants claim such immi- grants do them no good and that they take money away from the town. Each machine does the work of from fifty to two hundred men, and it is fair to assume the few men needed for each ma- chine can be readily obtained in the town. The money spent for labor is therefore spent at home on permanent residents of a good class. The local hardware stores, machine shops, the better hotels, etc., are the industries benefitted. The streets are free from large crews of rough- men, and the way the machines work is a ■matter of local pride. The trenching work is so quickly done that frequently there is accomplished in one summer as much a:s gen- erally takes two or three summers. Until the trenches are dug and refilled and compacted no street work can be done. It is a decided gain for any place to be able to put in sewers, water mains, electric conduits, etc., and have the work done quickly in one season so a chance can be had to fix the streets for winter. The machines will do fully seven hundred yards per day under the right conditions, and as they are being continually im- proved we shall some day hear of much larger records. Seven hundred yards means fourteen hundred feet of trench twenty-seven inches wide and six feet deep. It means over eight hundred feet of trench ten feet deep. It is a novel thing for the citizen to see from one to three blocks of sewer trench dug, pipe laid in it and trench backfilled in one day. The writer is rather enthusiastic over the subject of trench excavators of the type mentioned, for he knows them to be a success when properly handled. To insure their proper handling the company leases them and sends competent operators to take care of them.- The lengths of the buckets regulate the widths of the trenches and one machine can be used for different width trenches by simply changing the buckets, a few hours' work. The cut is made at one operation and to the full depth and width. No shovel- ing to stages or several handlings of the material. TRENCHING MACHINES. The modem housekeeper in these days of pneumatic house- cleaning companies does not dread housecleaning as did her ances- tors. The machine comes in the morning and goes away at night. All the house is cleaned and not a fte'al missed and no unneces- sary fuss made. The old style farmers' wife hated harvest time, for it meant Wg dinners and back-breaking work, overworked nervous systems and breakdowns. Today the harvest crew comes with tents and a cook wagon. The farmer's "wife makes the time a holiday. So it is with the modern city in these days of the perfected trench machine. It comes into town on a freight car. Is un- loaded in the morning. At noon it reaches the street where it is to start At one o'clock the whistle blows and at the rate of one to three blocks per day it rips up the streets and iills the trench behind it as it goes. About the time the citizen thinks he will take a day off to view the monster at work he learns it is gone. It gets to the end of the block, the cross walk is ' removed- for an hour and replaced. A water pipe or house connection is encountered. The machine digs up to it, the excavator arm is raised and the machine goes ahead until it clears the pipe. Then it is dropped and digs until the right depth is attained, when it backs up and digs under the pipe. It makes one think of the day of miracles. A rock is encountered an4 grappling hooks yank it out while the machine gOes ahead. Mr. F. C. Austin, the President of the Municipal Engineer- ing and Contracting Company, has done more to improve con- tractors' machinery, than perhaps any one single man in the United States, if not in the world. His study of trench machinery led him to make investigations along the line of machinery to make- canals and ditches with sloping banks for drainage and irrigation. Under the name of the F. C. Austin Drainage Excavator Com- pany he has put on the market the past year a 'machine capable of doing that work. From the work so far done with the ma- chine (which has been used for several years, and is now past tbe experimental stage) it is certain to be as successful in such work as the trench excavator has been in sewer and waterworks jobs. APPENDIX C. BIBLIOGRAPHY. ''Blessings be upon Cadmus, the ancient Phoenicians, or whoever it was that invented books."-i— Carlyle, The reading engineer is the man in demand today. There- fore, read. The man who reads good books adds to a knowledge of what he sees, a knowledge of the things seen and recorded by other men. If he possesses common sense, he is in a fair way to become a practical man. No man today is practical unless he is a student. All of us engineers know the loud-mouthed pretentious man who says, "I am a -practical man. I don't read any Tom-fool books written by professors. I know what I see and I don't let any man do my thinking for me." We all know him and how costly he has proven in the development and growth of Ameri- can cities. Such men work entirely by hypothesis. The average man does not understand what is meant by hypothesis. He styles it theory. Therefore, a theoretical man is a fool because an hypothesis is a guess and the man who works with guesses as his starting point is a fool, and if a guess is dignified with the name of theory, then all theoretical men are fools. Q. E. F. Men who read are called theoretical because it is known that theories are stated in books. The man who does not read is therefore styled practical. A theory is a statement of the law found to produce certain results. It is therefore a statement of practical facts. After men have observed certain phenomena for a long period of time, they are able to formulate a statement describing it, and this statement is the theory underlying the action, in other words, is the law of it. BIBLIOGRAPHY. An hypothesis, on the other hand, is merely a guess or a hazarded statement. If it precedes a study and the results of the study prove its correctness, then it may blossom into a theory. The man who works by true theory is a practical man. The man who works by hypothesis is theoretical, according to the common understanding of the word theory. It is the duty of every engineer to make his employers thor- oughly understand the difference between true and false theo- ries. Half the Councilmen in our cities believe our books are filled with stuff intelligible only to engineers. Get that idea out of their minds. Loan them books when advocating- certain projects. See that they read good books by the best authors. Show them how to skip the necessary mathematical parts and still get the benefit from the book. Let them understand fully that the man who reads does not always read mathematical and purely scientific books, but that the larger number of our en- gineering books are written by men of years of experience. The Councilmen should understand that the scholarly en- gineer has a better opportunity to become practical than the man who refuses to read, but prates about being "practical." The best definition of an engineer is that given by Welling- ton. "An engineer is a man who can do well with one dollar what any one can do badly with two." The only way he can do it is by adding to his own knowledge and experience, that of others in the same line of work. When Councilmen fully understand this, much of the dissatisfaction connected with the office of town or city engineer will disappear. There are several good books written for municipal officials who are not engineers. A great many written for engineers can also be appreciated by men without engineering education. In the following list the writer has endeavored to select books every engineer engaged in munidipal work should possess. He has also mentioned books that all officials should read. All the books mentioned should be on the shelves of every public library in the country. The list is not claimed to.be exhaustive. It is simply a list of books the writer can recommend. There are others- prob- ably as good. Others will come out before the ink on this page APPENDIX C. is dry. Of the making of books there is no end and a complete list can not be given. If this book endures the list will be changed every year and ten or fifteen years from now, perhaps, few on the present list will be deemed worthy of a place. Some will endure, but, as a rule, a technical book is of use only a few years. Some, however, the writer studied in school twenty years or more ago are up to date now. Prices are given, but no publishers' names, as they can be purchased from all booksellers. The Technical Book Agency can supply them, and the writer has been retained to advise oij the selection of books by that company. Any reader looking for some book on a particular subject can write the company aad Ms inquiry will be turned over to the writer for an opinion. A reader in a distant place wishing to secure an opinion on a widely advertised book that he can not personally examine, can secure the opinion of the writer without cost by writing to the company. It will be a pleasure to be of such service. In addition to the books meiitioned, all of the books in Van Nostrand's Science Series can be recommended. These books are handy in size for the pocket; cost fifty cents each, and are written by authorities in the subjects treated. A man making a special study of some subject can safely buy books in the Van Nostrand Science Series treating of the subject In reply to an inquiry in Engineering News as to the best twenty-five books for an engineer to have in his library, five engineers sent in their opinions. These letters have been printed in neat pamphlet form and can be procured on request. An engineer also wrote a letter to the Engineering Record, giving a list of books to cost one hundred dollars, and the letter is printed in circular form. Mr. M. N. Baker, Associate Editor Engineering News, read an address before the American Water Works Association on a list of books for the Water Works OfEce. It is a valuable paper for reference and has been reprinted in pamphlet foria, 'In 1901 the Society for the Promotion of Engineering Edu- cation appointed a committee of seven members to prepare a list of books on applied science a'nd technology suitable for the use of libraries. This list is also published in pamphlet form and can be readily procured. xi| BIBLIOGRAPHY. Of course, every book dealer hsrs lists, but the sbov« are mentioned because they are the recommendatiojis of men who have nothing to sell and give practical opinions. It is well to have those lists on hand for reference, The writer has tried to make the following list practical by giving the books in it his endorsement. Some he has com- mented on and others he has said nothing about. Their men- tion, however, is a recommendation. Every engineer should be a member of his state society. He should also, if possible, be a member of one or more of the national engineering societies. If he can not do this, then he should purchase and read their proceedings. The writer fails to see how a progressive engineer can do business without Engineering News (weekly, $5.00 per annum), or the Engineering Record (weekly, $3.00 per annum), either or both. They are published in New York. The frequent refer- ences to, and the number of extracts from these papers in the psiges of this book show how much he relies upon them in his own work. The Journal of the Association of Engineering Societies is published in Boston, Mass. It is a monthly and the subscrip- tion price is $3.60 per annum. It contains the cream of the papers read before the leading engineering societies. Engineering Magazine is a monthly, published in New York City. The subscription price is $3.00. It is a magazine of rather general character and is chiefly valuable because of the monthly index it contains of current engineering literature. For men who .make a specialty of municipal work and are not interested in anything else, there are two journals, both monthlies. Municipal Engineering is published in Indianapolis, Ind., and is ably edited by Charles Carroll Brown, who has an international reputation as a specialist in municipal work. The subscription price is $2.00 per annum. The Municipal Journal and Engineer is printed in New York and costs $3.00 per year. The editor is Professor Folwell, author of the standard Ameri- can college text'book on Sewerage and the standard American follege teKt-book on Water Supply, .Many special periodicals are published of interest to en- xiU . -APPENDIX V. gineers, but the Writer is trying to confine himself in this chap- ter to books and periodicals for municipal engineers. When the writer printed some pamphlets and sold them himself, he was astonished at the number of men who use postage stamps for transmittal through the mail instead of sending money orders. He was also astonished to see the number that took pains to buy stamps of the largest possible denomination. At one time he had on hand over one hundred dollars in stamps of denominations greater than ten cents. It was a loss, as they could not be returned to Uncle Sam and had to be disposed of to collectors. Common sense should teach a man that denominations of more than one or two cents are hard to dispose of. They can not be used for currency and few houses can use them for postage. One and two cent stamps can always be used some time. The mail-order houses generally advertise that all stamps received of denominations larger than one and two cents will be returned and no remittances exceeding one dollar will be accepted if in stamps. It is well to remember such, things in ordering books. Notwithstanding the fact that banks charge for cashing out- side checks, nearly all men who have a small bank account send a personal check without any addition for collection charges. On fifty-cent checks (of which the writer received a number) the collection charges sometimes amounted tottn cents, equal to twenty per cent discount. Money should be transmitted either by draft or money order. GENERAL WORKS. HANDBOOK OF STREET RAILROAD LOCATION.— By John P.. Brooks, Professor of Civil Engineering in State College of Kentucky. 16mo, 145 pages^ 108 figures. Mo- rocco, $1.50. HANDBOOK FOR STREET-RAILWAY ENGINEERS.— By H. B. Andrews, C. E. Second Edition. 3x5 inches, 203 pages, 41 figures. Morocco, $1.35. GENERAL WORK. THE CIVIL ENGINEER'S POCKET-BOOK.— By John C. Trautwine, Civil Engineer. Revised by John C. Trautwine, Jr., and John C. Trautwine, 3d, Civil Engineers. Eighteenth Edition, 80th Thousand, Revised and Enlarged, with more ■ than 370 pages of new matter and more than 250 new illus- trations. 16mo, 1,079 pages. Morocco, $5.00. CIVIL ENGINEERING: A TEXT-BOOK FOR A SHORT COURSE.— By Lieut.-Col. G. J. Fiebeger, U. S., Army, Pro- fessor of Engineering, U. S. Military Academy; Member of American Society, of Civil Engineers. 8vo, xiii-|-573 pages, 180 figures. Cloth, $5.00. A TREATISE ON CIVIL ENGINEERING.— By W. M. Pat- ton, C. E., Author of "A Practical Treatise on Foundations," late Professor of Civil Engineering at the Virginia Poly- technic Institute, etc, Second Edition, Corrected. 8vo, xviii-|-1.654 pages, 468 figures. Half leather, $7.50. The above two books on Civil Engineering are very good. In some points a good preliminary training in mathematics is necessary for a full understanding of the discussions. MUNICIPAL IMPROVEMENTS.— A Manual of Methods, Utility and Cost of Public Improvements for the Municipal Officer. By the late W. F. Goodhue, Civil Engineer, Mem- ber of the Western Society of Engineers and the Wisconsin Polytechnic Society. Third Edition, Enlarged. 12mo, viii-f- 207 pages, illustrated. Cloth, $1.75. Intended for municipal officials who have had no engineer- ing training or experience. LANDSCAPE GARDENING; Or, How to Lay Out a Garden. Intended as a general guide in choosing, forming or improv- ing an estate (from a quarter of an acre to a hundred' acres in extent), with reference to both design and execution. By Edward Kemp. 12mo, xxxii-f-464 pages, 204 figures. Cloth, $2.50. LANDSCAPE GARDENING AS APPLIED TO HOME DECORATION.— By Samuel T. Maynard, formerly Professor of Botany and Horticulture at the Massachusetts Agricul- APPENDIX C. tural CoUege* Botanist to the Massachusetts State Board of Agriculture, Secretary of the Massachusetts Fruit-growers' Association, etc. ISmo, xvi+SSS pages, 168 figures, includ- ing tnany full-page half-tones. Cloth, $1.50. These two books are of. value to park commissioners and improvement societies. MUNICIPAL PUBLIC WORKS.— By S. Whinery, Civil En- gineer. Cloth, $1.50 net (Postage, 13c). A good text-book for all city officials, as it discusses the inception, construction land management of public works. MUNICIPAL ENGINEERING AND SANITATION.— By M. N. Baker, Ph. B., Assoc. Editor Engineering News, etc. Half leather, $1.25 net (Postage, lie). A book all Mayors, Councilmen and members of improve- ment clubs should read. MATHEMATICS. HANDBOOK OF MATHEMATICS.— For Engineers and En- gineering Students. This book is peculiarly adapted to ref- erence work, but is also well suited for use as a text-book fof School or home study. By J. Claudel. From the Seventh French Edition. Translated and Edited by Otis Allen Kenj^n. Ooth. About 700 pages. 422 illustrations. Net, $3.50. PRACTICAL MATHEMATICS.— By F. Castle. 80 cents. A good book for beginners and for review. A MANUAL OF PRACTICAL MATHEMATICS.— By F, Castle. $1.50. More complete than the eighty-Cent book. GRAPHICAL CALCULUS.— By Barker. Cloth, $1.50. The writer considers this the best book on calculus for self-tutored men. . . MECHANICS. PULLEN'S MECHANICS.—Cloth, $1.50. A good book. Readily understood by any student having a knowledge of simple equations. ELECTRICITY. MECHANICS APPLIED TO ENGINEERING.— By Good- man. Cloth, $8.00. The best reference book. Some parts require a knowledge of calculus to thoroughly understand. When used as a text- book, It should be preceded by Castle's Practical Mathematics (SOc) or Pullen's Mechanics. ELECTRICITY. ELECTRICAL ENGINEERING FOR ELECTRIC LIGHT • ARTIZANS AND STUDENTS.— By W. Slingo and A. Brooker. 806 pages. Cloth, $3.50, Of this book the Electric Age says; "It is as complete as anything we have ever seen. It should meet with a hearty reception among electricians and students of electricity, for it is one of the most comprehensive books ever published. Every- thing that is necsesary to a clear understanding of electric lighting and kindred subjects is found in this volume, and we think that every individual of the classes mentioned would greatly further his own interests by possessing and studying this work." ELECTRICAL ENGINEERING IN THEORY AND PRAC, TICE.— By G. D. Aspinwajl Parr, M. Sc, M. I. E. E., A. M. I, Mech. Eng., etc. Cloth, 6x9 inches, $3.33 net. This is the latest book on the subject and has received high praise, It covers practically the same field as the work by Slingo and Brooker. It is intended as a text-book, and the mathematics used are of the most elementary kind. Examples to work are given at the end of each chapter. The books here mentioned on eleetrieity are books dealing almost wholly with electric lighting. If the municipal engineer is anxious to look into other phases of the subject, there are many books the writer can recommend. DRAWING. Uses of Drawing Instruments, the Construction of Plane INDUSTRIAL DRAWING — Comprising the Description and SYM APPENDIXC. Figures, Tinting, The Projections and Sections of Geo- metrical Solids, Shadows, Shading, Isometrical Drawing, Oblique Projection, Perspective, Architectural Elements. For the Use of Academies and Common Schools. By the late Prof. D, H. Mahan. Revised and Enlarged, and Chap- ter on Colored Topography Added by Prof. D. F. Thomp- son, of R. P. I., Troy. 2 vols, 8vo, xiii+209 pages, 30 plates.. Cloth, $3.50.. FREE-HAND LETTERING.— Being a Treatise on Plain Let- tering from the Practical Standpoint for Usie in Engineering Schools and Colleges. By Victor T. Wilson, M.> E., Assist- ant Professor of General Engineering Drawing, University of Illinoi's. 8vo, x-)-95 pages, 9 figures, 23 full-page plates. Cloth, $1.00. A complete work. FREE-HAND PERSPECTIVE.— For Use in Manual Training Schools and Colleges. By Victor T. Wilson, M. E., Assist- ant Professor of General Engineering Drawing in the Uni- versity of Illinois. 8vo, vii-|-357 pages, 139 figures. Cloth, $3.50. LETTERING FOR DRAFTSMEN, ENGINEERS AND STUDENTS.^A practical system of free-hand lettering for working drawings. By C. W. Reinhardt. Revised and En- larged Edition. Oblong boards. 32 pages, 50 illustrations, 10 plates. Price, $1.00. A first-class book by the Chief Draftsman of Engineering News. ROGERS' DRAWING AND DESIGN.— An Educational Treat- ise Relating to Linear Drawing; Machine Design; Working Drawings; Transmission Methods; Steatn, Electrical and Metal Working Machines and parts'; Lathes; Boilers and parts; Instruments and their use'; Tables, etc. 486 pages. Price, $3.00. LINEAR PERSPECTIVE 'SELF-TAUGHT.— A practical hand-book, giving the principles and practice of linear per- spective. By Herman T. C. Kraus, C. E. Illustrated. Price, $2.50. xviti SURVEYING. TECHNIC OF MECHANICAL DRAFTING.— By Chas. W. Reinhardt, Chief Draftsman Engineering News. -Cloth, ob- long; 8x11 inches; 43 pp.; 90 illustrations, 11 full-page plates. $1.00. Giving general instructions on the care and handling of draftsmen's instruments and materials, and containing chapters on Outlining, Outline Shading, Section Lining, Curved Surface Shading, Shading of Inclined Surfaces, Map Drawing, Character and Finish, etc., and containing 69 distinct conventions for Sec- tion Lining. SURVEYING. ELEVATION AND STADIA TABLES.— For Obtaining Dif- ferences of Altitude for All Angles and Distances, Hori- zontal Distances in Stadia Work, etc., with All Necessary Corrections. Together with Hydraulic Tables, Giving Ve- locities for Various Channels and Slopes. By Arthur P. Davis, Mem. Am. Soc. C. E., Hydrographer U. S. Geological Survey. 8vo. Cloth, $1.00. THE THEORY AND PRACTICE OF SURVEYING.— De- signed for the Use of Surveyors and Engineers Generally, but Especially for the Use of Students 'in Engineering. By J. M. Johnson, C. E., late Dean of the College of Mechanics and Engineering of the University of Wisconsin, formerly Civil Engineer on the U. S. Lake and Mississippi River Surveys, Member Inst. Civil Engineers, Member of the American Society of Civil Engineers. Sixteenth Edition, Revised and Enlarged. Small 8vo, about 900 pages, illustrated. Cloth, $4.00. HANDBOOK FOR SURVEYORS.— A Pocket-book for the Classroom and the Field. By Mansfield Merriman, Profes- sor of Civil Engineering in Lehigh University, and John P. Brooks, Professor of Civil Engineering in State College of Kentucky. Third Edition, Revised. 16mo, 246 pages. Mo- rocco, $3.00. PLANE SURVEYING.— A Text and Reference Book for Use of Students in Engineering and fo'r Engineers Generally. APPENDIX a By Paul C. Nagent, A. M., C. E., Professor of Civil Eft- gifteering, Syfacuse University. 8vo, xvi+577 pages, 320 flgares. Cloth, $3.50. THE ADJUSTMENTS OF THE ENGINEER'S TRANSIT AND LEVEL.— By Howard C. Ives, C. E., Assistant Pro- fessor of Civil Engineering in the University of Pennsylvania. Second Editions. Ifimo. Boards, 2Sc. PLANE SURVEYING.— By W. G. Raymond, C. E., Iowa State University. Cloth, $3.00. A standard American text-book. A TREATISE ON SURVEYING.— By W. M. Gillespie. Brought to date by Cady Staley, C. E. Two vols. $5,00. A splendid book for self-tutored men. A MANUAL OF FIELD AND OFFICE METHODS.— For the Use of Students in Surveying. By W. D. Pence and M. S. Ketchum. Cloth, $2.00. This book should be in the library of every civil engineer and surveyor. MANUAL OF LAND SURVEYING.— By F. Hodgman, C. K, M. S. Leather, $2.50. Deals fully with the legal points involved. Quotes court decisions, etc, A valuable book all engineers should possess. CONTRACT WORE. ENGINEERING AND ARCHITECTURAL JURISPRU- DENCE. — ^A Presentation of the Law Of Construction for - Engineers, Architects, Contractors, Builders, Public Officers and Attorneys-at'Law. By John Cassan Wait, M. C. E., LL. B. (M. C. E., Cornell; LL. B., Harvard). Attorney and Counselor-at-Law and Consulting Engineer; Member of the American Society of Civil Engineers; sometime Assistant Professor of Engineering, Harvard University. 8vo, ixxx-|- 905 pages. Cloth, $6.00; sheep, $6.50. THE LAW OF OPERATIONS PRELIMINARY TO CON- STRUCTION IN ENGINEERING AND ARCHITEC- CONTRACT WORK. TURE. — Rights in Real Property, Boundaries, Easements and Franchises for Engineers, Architects, Contractors, Builders, Public Officers and Attorneys-at-Law. By John Cassan Wait, M. C E., LL. B. (M. C. E., Cornell; LL. B., Harvard), Author of "Engineering and Architectural Juris- prudence." 8vo, lxiii-|-638 pages. Cloth, $5.00; sheep, $5.50. THE LAW OF CONTRACTS.— A Text-book for Technical Schools of Engineering and Architecture. By John Cassan Wait, M. C. E., LL. B. 8vo, xiv+331 pages. Cloth, $3.00. ENGINEERING CONTRACTS AND SPECIFICATIONS. By J. B. Johnson, C E. Cloth, $3.00. A book every engineer should possess. It has been menr tioned in a previous chapter HAND-BOOK OF COST DATA.— A Reference Book giving Methods of Construction and Actual Costs of Materials and Labor on Numerous Engineering Works. By Halbert P. Gillette, E. M., M. Am. Soc. C. E., M. Am. Inst. M. E., etc. Flexible leather; gilt edge; 4j4x7 inches; 640 pp.; illustrated. Price, $4.00 postpaid. A book that should be in the hands of every engineer and contractor. THE BUSINESS OF CONTRACTING.— By Ernest McCul- lough. 45 pages; paper cover.' 50 cents postpaid. A text-book on business methods. CONTRACTS AND SPECIFICATIONS.— Lectures delivered by J. A. L. Waddell, C. E., Author of "De Pontibus," before the Students of the Rensselaer Polytechnic Institute, with Notes on the Law of Contracts by John C. Wait, M. C. E., LL. B., Author of "Engineering and Architectural Juris- prudence," etc. (In preparation.) The lectures have, been reproduced without change, and it is hoped that it will form a useful text-book to perfect young engineers in the writing of these technical documents. Dr. Waddell stipulated that the price of the book should be kept as low as possible, so as to make its purchase no hardship for the students ; and this will be done. APPENDIX C. ARCHITECT, BUILDER, AND OWNER BEFORE THE LAW. — A summary of American and English decisions on the principal questions relating to building and the employ- ment of architects; with about 800 references, including also practical suggestions in regard to the drawing of building contracts and forms of contracts suited to various circum- stances. By T. "M. Clark, F. A. I. A. One 8vo vol. 387 pages, cloth. Price, $3.00. CONSTRUCTION (see also General Works). A HAND-BOOK FOR SUPERINTENDENTS OF CON- STRUCTION, ARCHITECTS, BUILDERS AND BUILD- ING INSPECTORS.— By H. G. Richey, Superintendent of Construction, U. S. Public Buildings. 16mo, v-|-743 pages, 357 figures. Morocco, $4.00. THE ARCHITECTS' AND BUILDERS' POCKET-BOOK.— A Hand-book for Architects, Structural Engineers, Builders, - Contractors, and Draughtsmen, and a valuable book of ref- erences for everything relating to the construction and equipment of buildings. By the late Frank E. Kidder, C. E., Ph. D., F. A. I. A. Fourteenth Edition, Rewritten. Twen- ty-fifth Thousand. 16mo, xviii-f-1400 pages, 1000 figures. Morocco, $5.00. A PRACTICAL TREATISE ON FOUNDATIONS.— Explain- ing fully the Principles Involved. Supplemented by Arti- cles on the Use of Concrete in Foundations. By W. M. Patton, C. E., late Professor of Civil Engineering at the Virginia Polytechnic Institute. Second Edition, Enlarged. 8vo, xxviii-|-546 pages, 135 figures. Cloth, $5.00. A standard American work. INSPECTION OF THE MATERIALS AND WORKMAN- SHIP EMPLOYED IN CONSTRUCTION.— A Reference Book for the Use of Inspectors, Superintendents, and Others Engaged in the Construction of Public and Private Work, etc. By Austin T. Byrne, C.E. Author of "High- way Construction." Second Edition. 16mo, xvi-|-540 pages. Cloth, $3.00. CONSTRUCTION. RETAINING-WALLS FOR EARTH.— Including the Theory of Earth-pressure as Developed from the Ellipse of Stress. With a Short Treatise on Foundations, Illustrated with Exarnples from Practice. By Malverd A. Howe, C.E., Professor of Civil Engineering, Rose Polytechnic Insti- tute. Member American Society of Civil Engineers. Third ■Edition, Revised ,and Enlarged. ISmo. Cloth, $1.35. ORDINARY FOUNDATIONS.— Including the Cofifer-dam Process for Piers. With Numerous Practical Examples from Actual Work. By Charles Evan Fowler, C.E. 8vo, xxvi-)-341 pages, 148 figures. Cloth, $3.50. A TREATISE ON ARCHES.— Designed for the Use of En- gineers and Students in Technical Schools. By Malverd A. Howe, C. K, Professor of Civil Engineering, Rose Poly- technic Institute. 8vo, xxv-|-351 pages, 74 figures. Cloth, $4.00. A TREATISE ON MASONRY CONSTRUCTION.— Contain- ing Materials and Methods of Testing Strength, etc.; Com- binations of Materials — Composition, etc.; Foundations — Testing the Bearing Power of Soils, etc.; Masonry Struc- ture — Stability Against Sliding, Overturning, Crushing, etc., etc., ftc. By Ira O. Baker, Professor of Civil Engineering, University of Illinois. Ninth Edition, Extensively Re- vised. 8vo, about 600 pages, 160 figures and 6 folding plates. Cloth, $5.00. The standard American text book on the subject. THE MATERIALS OF CONSTRUCTION.^A Treatise for Engineers on the Strength of Engineering Materials. By J. B. Johnson, C.E., late Dean jf the College of Mechan- ics and Engineering of the University of Wisconsin. Third Edition, Revised and Enlarged. Large 8vo, xv-|-795 pages, 650 illustrations, 11 plates. Cloth, $6.00. An excellent general book on materials. A TREATISE ON CONCRETE, PLAIN AND REIN- FORCED.— rMaterials, Construction and Design of Con- crete and Reinforced Concrete, with chapters by R. Feret, William B. Fuller, and Spencer B.. Newberry. By Freder- APPENDIX C. *ick W. Taylor, M.E., and Sanford E. Thompson, S.B., M.I.T., Assoc. M. Am. Soc. C. K, Mem. Am. Soc. for Test- ing Materials. 8vo, xl+589 pages, 176 figures. Cloth, $5.00. One ot the latest and best books on concrete. TUNNELING.-^A practical treatise. By C. Prelini, C.E. With additions by Charles S. Hill, C.E., Associate Editor "En- gineering News." 149 working drawings and figures. Sec- ond Edition, revised. 8vo, cloth, 311 pages. Illustrated. Price, $3.00. MODERN TUNNEL PRACTICE.— By David McN. Stauffer, M. Am. Soc. C. E., M. Inst. C. E., Vice-Pres. Engineering 'News Publishing Co. Cloth, 6J^x9J^ ins.; about 300 pp.; 135 illustrations and full-page plates. $5.00. THE CEMENT WORKER'S HANDBOOK— By W, H. Baker. Cloth, 4J^x6^ ins.; 86pp. $0.50. This small book has been compiled to meet the requirements of the com- mon workman, and covers more than fifty most im- portant subjects on cement and its uses in constfiietion. Contents: Commercial Hydraulic Cements; Mortars; Con- cretes; Cost of Masonry; Practical Notes on Cement work. CEMENT AND CONCRETE.- A treatise designed especially for American engineers, covering the manufacture, prop- erties and testing of cement, and the preparation and use of cement mortars and concretes. Special attention is given to the Costs of Cement and Concrete for different uses and under various conditions. By Louis Carlton Sa- bin. 504 pages, 161 tables of tests. Price, $5.00. REINFORCED CONCRETE.— By A. W. Buel and Chas. S. Hill. Cloth, 6x9 ins,; 434-|-x pp.; 311 illustrations and 5 folding plates. $5.00, Second edition, revised and enlarged (1906). The writer considers this the best hook on reinforced con- crete up to date of going to press. EARTH AND ROCK EXCAVATION.— A manual for engi- neers, contractors, and engineering students. By C. Pre- Hni, C, E. 8vQ, cloth. Illustrated. 357 pages. Price, $3.00. SANITATION. ROCK EXCAVATION, METHODS, AND COSTS.^By H. P. Gillette. 376 pages, 56 illustrations. Price, $3.00. EARTHWORK AND ITS COST.— By H. P. Gillette. 360 pages. Price, $2.00. STEAM POWER PLANTS, THEIR DESIGN AND CON- STRUCTION.— By Henry C. Meyer, Jr. 160 pages, 16 plates and 63 illustratians. Price, $8.00 net BRIDGE AND STRUCTURAL DESIGN.— By W. Chase Thomson. Cloth, 6x9 ins.; 88 pp.; 76 illustrations. $2.00. A good book for a beginner who has had little previous mathematical training. Good also for review for graduates of technical schools. More complete works are: DuBois, Strains in Framed Structures, $10.00; Johngon and Turneaure, Modern Framed Structures, $10,00; Merriman and Jacoby, Roof* and Bridges, 4 vols., $10.00; Ketchum, Mill Buildings, $4.00. For structural designing the designer makes considerable use of the hand books published by the various steel compa- nies. Lately, however, Mr. Edward Godfrey has published a book of tables for structural designers that is superior in many respects to the steel companies' books. The price is $3.50. It is bound in leather in the usual pocket book form. The un- usual arrangement of the tables and diagrams first attract at- tention. The author, however, has stated he put the tables and data most frequently used in the middle of the book where they will be most readily found. Other commonly used tables are in the front and back. Between these choice iocatioos are the tables not so often used. The arrangement therefore is not calculated to make the book popular as a treatise on the subject with begi|iners. For the experienced man, however, it is very valuable. SANITATION (see also Sewerage, Water Supply, Construc- tion). HANDBOOK OF SANITATION.— A Manual of Theoretical and Practical Sanitation. For Students and Physicians; for Health, Sanitary, Tenement'house, Plumbing, Factory, APPENDIX C. Food, and Other Inspectors; as well as for Candidates for all Municipal Sanitary Positions. By George M. Price, M.D., (Medical Sanitary Inspector, Department of Health, New York City, etc. Second Edition, Revised and Partly Rewritten. 12mo, xv+301 pages, 29 figures. Cloth, $1.50. A good book for the purpose. THE ECONOMIC DISPOSAL OF- TOWNS' REFUSE.— By W. Francis Goodrich, A. I. Mech. E. Demy 8vo, xvi+ 340 pages, 75 illustrations. Cloth, $3.50. An English book of considerable value in a full study of the' subject. A GUIDE TO S.fiNITARY HOUSE-INSPECTION; Or, Hints and Helps Regarding the Choice of a Healthful Home in City or Country. By William Paul Gerhard, C.E., Con- sulting Eflgineer for Sanitary Works. i6mo, 146 pages. Cloth, $1.00. See also mention of books by the same author in previous chapters. MUNICIPAL SANITATION IN THE UNITED STATES.— By Chas. V. Chapin. Cloth, $5.00. PRINCIPLES OF SANITARY SCIENCE AND THE PUB- LIC HEALTH.— By W. T. Sedgwick. Net, $3.00. One of the best books on the subject. MODERN PLUMBING, STEAM AND HOT WATER HEATING. — A new practical work for the plumber, the heating engineer, the architect, and the builder. Tenth edition, revised and enlarged. By James J. Lawler. Price, $5.00 net. HANDBOOK OF PRACTICAL HYGIENI— A short and concise laboratory guide for the sariitary analysis of air, water, soil, and the principal food materials; also a chap- ter on the ventilation of buildings. By D. H. Bergey, A.M., M.D., First Assistant, Laboratory of Hygiene, University of Pennsylvania. 170 pages. Price, $1.50 net. FIFTY CHARTS SHOWING HOW PLUMBING SHOULD BE DONE. — Shows every fixture, trap, ferrule, joint, pipe, xxvi SANITATION. vent, with proper sizeg, material and distances, for every kind of a plumbing job. Great aid in estimating. Shows customers how plumbing should be done and why it costs more than making wood boxes. A new editi6n for 25 cents by mail prepaid. THE DISPOSAL OF MUNICIPAL REFUSE.— By H. DeB. Parsons, Consulting Engineer, M. Am. Soc. C. E., M. Am. Soc. M. E. Cloth, $3.00. The-besjt general work on the subject. It is not so full as the general student would desire but as a book to read when studying the subject it can hardly be surpassed. GARBAGE CREMATORIES IN AMERICA.— By William Mayo Venable, M.S., Assoc. Am. Soc. C. E., Assoc. M. Am. Inst. E. E. Cloth, $2.00. This book deals almost entirely with incineration and is an up-to-date presentation of the subject. HEAT AND LIGHT FROM MUNICIPAL AND OTHER WASTE.— By Jos. G. Branch, M. Am. Soc. M. E., etc. Cloth, $3.00. This book is written almost wholly to advance the use of furnaces and appliances invented by Mr. Branch. He has writ- ten a good book, however, and one that will repay reading. In any study of the disposal of refuse the officials con- cerned should procure all the books on the subject and study them closely. The "one book man'' has no place in such a study and the ensuing discussion. All the books mentioned in this list under the head of SANITATION should be read and carefully studied. The fol- lowing books also will be very useful and in fact may be con- sidered indispensable. REFUSE DISPOSAL AND POWER PRODUCTION.— W. F. Goodrich. Cloth, $5.00. The above is an English book and treats fully of crema- tion. THE REMOVAL AND DISPOSAL OF TOWN REFUSE.— By Wm. H. Maxwell. Cloth, $6.00. APPENDIX C An English book treating the subject in the pfactical man- ner so common to English works. STREET CLEANING AND THE DISPOSAL OF A CITY'S WASTE.— By Col. Geo. E. Waring. Cloth, $1.35. This book deals almost entirely with street cleaning and says little of value about garbage disposal. The writer was one of the most emineflt of American sanitary engineers and died of yellow fever early in the Spanish War. ROADS AND STREETS. HIGHWAY CONSTRUCTION.— A Treatise on Highway Con- struction, Designed as a Text-book and Work of Reference for all who may be engaged in the Location, Construc- tion, or Maintenance of Roads, Streets, and Pavements. By A. T. Byrne, C.E. Fourth Revised and Enlarged Edi- tion. 8vo, xl-f-895 pages, 306 illustrations. Cloth, $5.00. A remarkably complete book. The best to buy if only one book can be afforded. A TREATISE ON ROADS AND PAVEMENTS.— By Ira Osborn Baker, C.E., Professor of Civil Engineering, Uni- versity of Illinois. 8vo, viii+655 pages, 171 figures, 68 Tables. Cloth, $5.00. A later book than the first mentioned by Byrne. Covers the ground thoroughly. STREET PAVEMENTS AND PAVING MATERIALS.— A Manual of City Pavements; the Methods and Materials of their Construction. For the use of Students, Engmeers, and City Officials. By Geo. W. Tillson, C. E., President Brooklyn Engineers' Club, Mem. Am. Soc. C. E. 8vo, xii+ 533 pages, 60 figures. Cloth, $4.00. A complete work on the subjects mentioned in the title. Valuable in cities rather than towns. THE MODERN ASPHALT PAVEMENT.— By Clifford Rich- ardson, Director, New York Testing Laboratory, Long Island City, N. Y., sometime Principal Assistant Chemist HYDRAULICS. in the U. S. Departftiertt 6f Aefkaltiife and Inspector of Asphalts and Cements of the District of Columbia; Mem- ber of the Committee on Roads and Materials, Am. Soc. for Testing Materials. 8vo, vii+SSO pages, 33 figures. Cloth, $3.00. A book every engitoeer should read before using asphalt. CITY ROADS AND PAVEMENTS.— Suited to Cities of Mod- erate Size. By Wm. P. Judsott, C.E. Cloth, $3.00 net. A good book to place in the hands of pavement investigat- ing committees. ECONOMICS OF ROAD CONSTRUCTION.— By H. P. Gil- lette. Cloth, $1.00, A very practical book on earth and macadamized roads. HYDRAULICS (see also Sewerage, Water Supply). DIAGRAMS OF MEAN VELOCITY OF WATER IN OPEN CHANNELS. — Based on the Formula of Ganguillet and Kutter. Prepared by Irving P. Church, C.E., Professor of Applied Mechanics and Hydraulics, College of Civil En- gineering, Cornell University. Paper, $1.50. THE GRAPHICAL SOLUTION OF HYDRAUUC PROB- LEMS.— Treating of the Flow of Water Through Pipes, in Channels and Sewers, Over Weirs, etc. By Freeman C. Coffin, Member of the American Society of Civil Engineers. Second Edition, Revised and Enlarged. 16mo, 85 pages and 36 full-page diagrams. Morocco, $3.50. HERING— TRAUTWINE. A GENERAL FORMULA FOR THE UNIFORM FLOW OF WATER IN RIVERS AND OTHER CHANNELS.— By E. Ganguillet and W. R. Kut- ter, Engineers in Berne, Switzerland. Translated from the German, with Numerous Additions, Including Tables, Dia- grams, and the Elements of 1,300 Gaugings of Rivers, Small Channels, and Pipes, in English Measure, by Rudolph Her- ing and John C. Trautwine, Jr., of the Society and Insti- tute of Engineers. Svo, xxiii+340 pages, illustrated by fig- ures and folding plates. Cloth, $4.00. APPENDIX C. A TREATISE ON HYDRAULICS.— Designed as a Text-book for Technical Schools and as a Manual for Engineers. By Mansfield Merriman, Professor of Civil Engineering in Le- high University. Eighth Edition, Rewritten and Enlarged. 8vo, 593 pages, 199 figures. Cloth, $5.00. The present standard American treatise. An excellent work. HYDRAULIC TABLES.— Showing the Loss of Head due to the Friction of Water Flowing in Pipes, Aqueducts, Sew- ers, etc., and the Discharge over Weirs. By Gardner S. Williams, M. Am. Soc. C. E., Professor of Civil, Sanitary, and Hydraulic Engineering, University of Michigan, and Allen Hazen, M. Am. Spc. C. E., Civil Engineer. 8vo, iii-f- 75 pages. Cloth, $1.50. HYDRAULIC DIAGRAMS FOR THE DISCHARGE OF CONDUITS AND CANALS.— By Charles Swan and Theo- dore Horton. Cloth; 6x9 ins.; 45 pp.; including 17 diagrams. Second Edition, enlarged. $1.00. Includes Conduits of eight different types of Cross Section and Canals of Rectan- gular and Trapezoidal Cross Section. SEWERAGE (see also Sanitation, Water Supply, Hydraulics). SEWERAGE. — The Designing, Construction, and Maintenance of Sewerage Systems. By A. Prescott Folwell, Member American Society of Civil Engineers; Professor of Muni- cipal Engineering, Lafayette College. Fifth Edition, Re- vised and Enlarged. 8vo, x-|-455 pages, ilftistrated. Cloth, $3.00. The present American standard text-book on the subject. SEWER DESIGN.— By H. N. Ogden, C.E., Associate Member American Society of Civil Engineers; Assistant Professor of Civil Engineering, Cornell University. 12mo, xi-|-334 pages, 54 figures, 5 plates. Cloth, $3.00. An excellent work of reference. SEWAGE AND THE BACTERIAL PURIFICATION OF SEWAGE.— By Samuel Rideal, D.Sc. (Lond.), Fellow of University College, London; Fellow of the Institute of Chemistry, of the Chemical Society, and of the Sanitary SEWERAGE. Institute of Great Britain; Vice-President of the Society of Public Analysts; Author of "Water and Its Purification," Disinfection and Disinfectants." 8vo, viii+a78 pages, 47 figures. Cloth, $3.50. An excellent book fully up-to-date on English practice. SEWAGE WORKS ANALYSES.— By Gilbert J. Fowler, M. Sc. (Vict), F.I.C., Superintendent and Chemist, Manchester Corporation Sewage Works. 12mo, viii-)-135 pages, ^llus- trated. Cloth, $2.00. Valuable to specialists. BRITISH SEWAGE WORKS.— And Notes on the Sewage Farms of Paris and on Two German Works. By M. N. Baker, Ph.B.,- C.E., Assoc. Editor Engineering News. Cloth, $2.00. A good book for all officials in cities contemplating the installation of sewage purification plants. TABLES AND. DIAGRAMS FOR MAKING ESTIMATES FOR SEWERAGE WORK.— By S. M. Swaab. Paper; ob- long, 4J^x7j4 ins.; 20 pp.; 16 plates. $0.50. Contents: Gen- eral explanation, method of using tables and diagrams, ex- .amples worked out, circular sewers, egg-shaped sewers, ex- cavation for one and two-ring brick circular sewers, exca- vation for circular sewers in full and- partial cradleSj exca- vation for one' and two-ring brick egg-shape sewers, and for egg-shape se\wers in full cradle, for sew;ers varying in diaineter from 1 ft. 6 ins. to 15 ft. PURIFICATION OF SEWAGE AND WATER.— By W. J. Dibden, F.I.C., F.C.S. Cloth, $6.50. A .necessary book for the complete study of the subject. Written. by an English authority. THE SEPARATE SYSTEM OF SEWERAGE.— Staley and Pierson.. Cloth, $3.00. The first book on sewerage that the eng;ineer in a small place should buj. THE CLEANING AND SEWERAGE OF CITIES.— Bau- meister. Cloth, $2.00. The second book engineers in sinall .places should buy. A European book with notes on American practice. Tddi APPENDIX C, SANITARY ENGINEERING.--By Col. E. C. S. Mocwe. aoth. $10.00. A book for the specialist and for the engineer who wishes to go thoroughly into the study of sewerage. An English work. TREATMENT OF SEPTIC SEWAGE— Rafter. Van No.s- trand Science Series. 50 cents. WATER SUPPLY (see also Hydraulics). WATER-SUPPLY ENGINEERING.-The Designing, Con- struction, and Maintenance of Water-supply Systems, both City and Irrigation, By A. Prescott Folwell, Professor of Municipal Engineering, Lafayette College, Second Edi- tion, Revised and Enlarged, 8vo, xjv+570 pages, illustrated with 95 figures and 19 full-page plates. Cloth, $4.00. PUBLIC WATER-SUPPLIES.— Requirements, Resources, and the Coristraetion of Works. By F. E. Turneaure, C,E„ Dean of the College of Mechanics and Engineering of the University of Wisconsin, and H. L. Russell, Ph.D., Pro- fessor of Bacteriology, University of Wisconsin. With a Chapter on Pumping-machinery by D. W. Mead, C.E., M, Am. Soc. C, E., etc. Svo, xiv4-746 pages, 231 figures. Cloth, $5.00. The present standards on American prjictice. Used as text books in the leading schools and for reference by practicing engineers. THE DESIGN AND CONSTRUCTION OF DAMS.— Includ- ing Masonry, Earth, Rock-fill, and Timber Structures; also the Principal Types of Movable Dams, By Edward Weg- mann, C.E., M. Am. Soc, C, E, Fourth Edition, Revisec) and Enlarged. 4to, xii-|-250 pages, profusely illustrated with T5 figures in the text and 97 pUtes, includJng folders and half-tones. Cloth, $5.00. A standard book, WATER-SUPPLY.— (Considered Principally from a Sanitary Standpoint.) By William P. Mason, Professor of Chejnis- WATER SUPPLY. try, Rensselaer Polytechnic Institute. Third Edition, Re- written. 8vo, vii+448 pages, 40 figures, 26 half-tone plates. Cloth, $4.00. THE FILTRATION OF PUBLIC WATER-SUPPLIES.— By Allen Hazen, Member of the American Society of Civil Engineers. Third Edition, Revised and Enlarged. 8vo, xii-|-331 pages, fully illustrated with line and half-tone cuts. Cloth, $3.00. TOWERS AND TANKS FOR WATER- WORKS.— The Theo- ry and Practice of Their Design and Construction. By J. N. llazlehurst, Member of the American Society of Civil Engineers. Second Edition, Revised and Enlarged. 8vo, x-f-325 pages, 61 figures Cloth, $3.50. WATER-FILTRATION WORKS.— By James H. Fuertes, Member of the American Society of Civil Engineers. l2mo, xviii-|-283 pages, 4$ figures and 20 half-fone plates. Cloth, $2.50. WATER-POWER.— An Outline of the Development and Ap- plication of the Energy of Flowing Water. By Joseph P. Frizell, Hydraulic Engineer, Member of the American So- ciety of Civil Engineers. Third Edition, Enlarged. 8vo, vii-f 646 pages. 251 figures. Cloth, $5.00. WATER AND PUBLIC HEALTH.— The Relative Purity of Waters from Diflferent Sources. By James H. Fuertes, Member of the American Society of Civil Engineers. 12mo, x-1-75 pages, 70 figures. Cloth, $1.50. ELEMENTS OF WATER BACTERIOLOGY, WITH SPE- CIAL REFERENCE TO SANITARY WATER ANAL- YSIS. — By Samuel Cate Prescott, Assistant Professor of Industrial Biology, and Charles Edward Amory Winslow, Instructor in Sanitary Bacteriology, Massachusetts Insti- tute of Technology. 12mo, vi-1-162 pages. Cloth, $1-2S. EXAMINATION OF WATER.— (Chemical and Bacteriologi- cal.) By William P. Mason, Professor of Cheffltstry, Rensselaer Polytechnic Institute. Third Edition, Revised. ISmo, v-1-155 pages. Cloth, $1.25. xxxiii APPENDIX C. THE MICROSCOPY OF DRINKING-WATER.-^By George Chandler Whipple, formerly Biologist and Director of Mt. Prospect Laboratory, Department of Water Supply, Brook- lyn, N. Y.; formerly Biologist of Boston Water Works. Second Edition, Revised. 8vo, xii+338 pages, figures in' the text and 19 full-page half-tones. Cloth, $3.50. WATERWORKS DISTRIBUTION.— A practical guide to the laying out of systems of distributing rriains for the supply of cities and towns. By J. A. McPherson, A. M. Inst. C. E. Cloth, $2.00. An English book. Very complete and practical. WATER AND ITS PURIFICATION.— By Samuel Rideal, D.Sc. Cloth, $3.00. ' .:■.,!.•>,/; An English work of great value. SOME DETAILS OF WATER-WORKS CONSTRUCTION. — By W. R.: Billings. 96 pages, 28 illustrations. Price, $2.00. Every city engineer should have this book^ WATER-WORKS FOR SMALL CITIES AND TOWNS.— Describing the methods of construction of the various por- . tions of a water-works piknt. By John Goodell. 281 pages, 53 illustrations. Price, $2.00. If a man can afford only one book on water-works con- struction, this is it. HYDRAULIC AND WATER-SUPPLY ENGINEERING.— A practical treatise. Relating to the hydrology, hydro- dynamics, and practical construction of water-works in North America. By J. T. Fanning. Fifteenth edition, re- vised and enlarged. New tables and illustrations added. 8vo, cloth, 650 pages, 180 illustrations. Price, $5.00. A standard for the past 30 years. Well worth the price. EARTH DAMS.— A Study, By Burr Bassell. Cloth; 6x9 ins.; 68 pp.; 31 illustrations. $1.00. Chapters: Preliriiinary Studies and Investigations; Outline Study of Soils; The Th'ebaud Dam, California; Different Types of Earth Dams; Statistical Description of High Earth Dams; Works of Reference. ELEMENTS OF WATER SUPPLY ENGINEERING.— By E. Sherman Gould. $2.00. Indispensable to the up-to-date, practical eng:ineer. APPENDIX D. TRADE LITERATURE AND SPECIFICATION INDEX. "The literary efforts of the ad. writer will take rank with the writings of »' Shakespeare, a Milton, a -Shelley — maybe." The following description of a method to keep track of trade literature is from an article by the writer in Engineering News, March 8, 1906: TRADE LITERATURE. A description of filing and indexing methods for the office of an engineer (or for any business man today) would not be complete without reference to the preservation of trade liter- ature. Some of it is of a high class and worthy of preserva- tion and careful indexing. The writer indexes by the name of the firm and by the prnicipal articles mentioned. Some of the pamphlets are in- dexed by all the articles referred to and sometimes a copy is made of the index of the pamphlet or catalogue itself. The ful- ness of the index depends upon the character and probable future value of the publication. A card index is provided for this material, which is en- tirely separate from all other indexes used in the office. Filing cases are used of the right size to take the matter readily, and they are numbered consecutively. Each pamphlet or catalogue is given the number of the case it goes into, and undernea!th is a serial number which tells at a glance the number of fi4in- phlets filed. While this latter is not absolutely essential, it adds to the convenience of reference to the publication, and it is also useful for statistical purposes. It is well to put in these cases all fragmentary literature obtained from all sources, such as clippings from papers and magazines, occasional volumes of society proceedings, etc. APPENDIX D. Clippings are usually pasted on sheets of paper and put into envelopes. Sometimes they are pasted into scrap books, put on the shelves with the filing cases and numbered with them. Sometimes, when a letter filing case is used they are filed alpha- betically in such a case. Ne separate cls^ssification is att«mpte4- The trade literature is coming in every day, and one book con- tains so many items it is impossible to make a classification on the shelves. It is best and simplest to xa»ks it in an icd^x. Pamphlet filing cases can be purchased that look well on a shelf, being made with book-imitation backs. They cost from $8 to $4 per dozen. The writer has used pasteboard eases, made "by paper boxmak«rs and bookbinders at a cost of from 15 to 20 cents each. They are 3 inches wide, 7 inches high, and at the open end are 11 inches long on th? bottom and 7 inches long on top. The pamphlets therefore are on their edges. For larger catalogues special sizes have to be made. The filing transfer cases ma.de for the Shannon system of filing let' ters are very good when purfhased without the attachments to which the letters are fastened when transferred. They con- sist of a case, open at one end, into which fits a piece of paste-- board, bent to form two sides and one end. The writer -h^s adopted, and intends holding to, cheap letter files that cati be purchased in any stationery store for from 15 to 20 cents each. He prepares them by removing the index sheets, putting in a division of cigar box wood to make two filing spaces, and placing them like drawers in a case made for them. The inside dimensions are lOxlS inches, and putting 9 division in the middle gives two compartments a trifle less than 6 inches wide by 10 inches long. Every catalogue that will go into such a space is put there. Sometimes a little trim' ming of edges i5 necessary. Generally the division is made so that one gide will be 6yi or 7 inches wide by JO i&cbes long. The other sids will take small catalogues. On the outside of the file is siarked the width of the divisipa, so the indexer can tell at a glanee whether the catalogue he is indexing will go into a certain file. It ean be seen tbsit serially numbered publieation$ do not follow in TRADE LITERATURE AND SPECIFICATION INDEX. order in filing cases. When a case is filled a small letter "F" is put on the outside, under the number. The odd sizes in which trade literature comes is a nuisance, but fortunately the large-sized publications, printed on extra heavy paper, seldom contain anything worthy of preservation. They seem to be gotten out to feed the pride of some one or Other and to make a job for the printer. Such expensive work is thrown away, except in so far as it tends to develop the art of printing and engraving. Few publications having pages exceeding 9x13 inches contain data of any kind that is valuable- The small pocket sizes are often crammed with useful material. SPECIFICATION INDEX. The writer presents here a selected list of names of the leading manufacturers of and dealers in materials and appliances, so his. readers will find an answer to the question, "Where can I get it?" They all stand high in their respective lines, and if the reader intends collecting a pamphlet library he can hardly find better -names to start with in securing catalogues. Three classes of men send to business houses for cata- logues. The first class always uses postal cards and 95 per cent ask for best prices and discounts. This class consists of men who send for everything that can be had for nothing. Practi- cally no business is ever secured from such, and many bouses as a restdt ignore postal card requests. The second class consists of men who are collecting pam- phlet libraries, and all the printed matter they, receive is in- dexed and filed. The majority may be in the long run good men, so a business house is willing to send them all the printed matter they produce. It is a courteous thing for a man to write a letter and enclose some postage stamps when he does not expect to make immediate use of the catalogues, but merely intends filing them. Some houses do not like inquirers to send stamps, but they all prefer letters to postal cards. The third class conaisls of men who are seeking informa- tion for immediate use. In such case it is advisable to grfve the dealer some idea of the situation and- he wiljl be glad to do all APPENDIX D. he can, supplementing his circulars oftentimes with personal letters and the sending of representatives with samples. No business man will send a representative to bother an inquirer if specially requested not to do so. AIR COMPRESSORS (see also Boilers, Engines, Pumping Engines) . THE MURRAY IRON WORKS CO., Burlington, Iowa. ANEROID BAROMETERS (see also Engineering Instru- ments) W. & L. E. GURLEY, Troy,. N. Y., U. S. A. ASPHALTUM. NATIONAL OIL REFINING & MANUFACTURING CO., 79 Dearborn St., Chicago, 111. ASPHALT MINERS AND REFINERS. GLOBE ASPHALT CO,, 405 Bakewell Building, Pittsburg, Pa.; Branch office, 310 Tajo Building, Los Angeles, Cal.; Mines, Goleta, C^l-! Refinery, Obispo, Cal. ASPHALT ROOFING AND PAINT. STOWELL MANUFACTURING CO., 459-61 West Side Ave., Jersey City, N. J. BAROMETERS (see Aneroid Barometers, Engineering Instru- ments) BLOWERS (see Fans and Blowers) BOILERS (see also Air Compressors, Engines, Pumping En- gines) THE MURRAY IRON WORKS CO., Burlington, Iowa. BOOKS (see also Scientific Books) TECHNICAL BOOK AGENCY, P. O. Box 691, Chi- cago, 111. BRICKS. WESTERN BRICK CO., Danville, 111. Shale, building, paving and impervious sewer brick. CABLEWAYS — Overhead (see also Manila Rope, Cordage, Tackle Blocks, Tramways, Wire Rope, Rope) BRODERICK & BASCOM ROPE CO., 805-9 N. Main St., • St. Louis, Mo. TRADE LITERATURE AND SPECIFICATION INDEX. CEMENT (see also Portland Cement, Portland Cement Man- ufacturers, Natural Cement) CEMENT DEPARTMENT, ILLINOIS STEEL CO., The Rookery, Chicago, 111. GERMAN - AMERICAN PORTLAND CEMENT WORKS. Office, Marquette Building, Chicago, 111. Works, La Salle, 111. Western Cement Co., Louisville, Ky. THE WHITEHALL PORTLAND CEMENT CO. Works, Cementon, Pa. Principal Sales Office, 1733 Land Title Building, Philadelphia, Pa. CEMENT STONE MACHINERY (see also Tools for Ce- ment Workers, Curbing and Gutter Machines) THE CENTURY CEMENT MACHINE CO., 181 W. Main St., Rochester, N. Y. The Hercules Cement Stone Machine makes hollow blocks, water tables, sills, lintels or ornamental stone of all sizes and designs up to 6 feet long. CESSPOOL OUTFITS (see Vault and Cesspool Outfits, COMPRESSORS (see Air Compressors) CONCRETE (see Concrete-Steel, Steel-Concrete, Re-enforced Concrete, Pipe, Contractors, Engineers, Dams, etc.) CONCRETE MIXERS. MUNICIPAL ENGINEERING AND CONTRACTING CO., 607-11 Railway Exchange, Chicago, 111. CONCRETE-STEEL (see Concrete) CONTRACTORS (see also Engineers) J. J. O'HERON & CO., 6 Wabash Ave., Chicago, 111. CONTRACTORS' TRENCH PUMPS (see also Pumps) , Edson Manufacturing Company, 355-7 Atlantic Ave., Bos- ton, Mass. CORDAGE (see also Cableways) Broderick & Bascom Rope Co.,' 805-9 N. Main St;, St. Louis, Mo. CRANES. Northern Engineering Works, Detroit, Mich. APPENDIX D. CRUSHING MACHINERY (see also Strieet Sweeping Ma- chinery, Pulverizing Machinery) E. H. Stfoud & Co., 30-36 La Salle St., Chicago, 111. CURBING AND GUTTER MACHINES (see also Cement Stone Machinery) THE CENTURY CEMENT MACHINERY CO., 18i W. Main St., Rochester, N. Y., have a machine that makes cement stone curbing and gutter on the job. DAMS (see also Concrete, Engineers and Contractors, Etc.) DITCHING MACHINERY (see also Excavating Machinery, Trench Excavators) F. C. AUSTIN DRAINAGE EXCAVATOR CO., Railway Exchange, Chicago, 111., U. S. A. MUNICIPAL ENGINEERING AND CONTRACTING COMPANY, 607-11 Railway Exchange, Chicago, 111. DRAIN TILE (see also Sewer Pipe) " DRAUGHTING INSTRUMENTS (see also Engineering In- struments) QUEEN & CO., Inc., lOlO Chestnut St., Philadelphia, Pa. DRAWING INSTRUMENTS (see also Engineering Instru- ments) W. & L. E. GURLEY, Troy, N. Y., U. S. A. J. C. SALA, San Francisco, Cal. DRAWING TABLES (see also Filing Cases) Economy Drawing Table Co., 1303 Utah St., Toledo, Ohio. ECONOMIZERS (see Fuel Economizers) ENGINEERS (See also Contractors) ERNEST McCULLOUGH, Specialist in Concrete and Mu- nicipal Improvements, Monadnock Block, Chicago, Hi ENGINEERS AND CONTRACTORS FOR CONCRETE- STEEL DAMS AMBURSEN HYDRAULIC CONSTRUCTION CO., 176 Federal St., Boston, Mass. ENGINESL (see also Air Compressors, Boilers, Pumping En. gines) THE MURRAY IRON WORKS Co., Burliflgton, Iowa. ENGINEERING INSTRUMENTS (see also Draughting In- struments, Drawing Instruments, Leveling Instruments, APPENDIX D. HOSE — Suction (see also Pumps, Vault and Cesspool Outfits) Edson Manufacturing Co., 355-7 Atlantic Ave., Boston, Mass. LEVELING INSTRUMENTS (see also Engineering Instru- ments) W. & L. E. GURLEY, Troy, N. Y., U. S. A. BAUSCH, LOME, SAEGMULLER CO., Rochester, N. Y. MACHINERY (look for kind wanted under proper head) MANILA ROPE (see also Cableways) Broderick & Bascom Rope Co., 805-9 N. Main St., St. Louis, Mo. MERCURAL THERMOMETERS (see alsp Engineering In- struments) W. & L. E. GURLEY, Troy, N. Y., U. S. A. METEOROLOGICAL INSTRUMENTS (see also Engineering Instruments) W. & L. E. GURLEY, Troy, N. Y., U. S. A. METERS (see also Water Meters) MINING PUMPS (see also Pumps) Edson Manufacturing Co., 255-7 Atlantic Ave., Boston, Mass. MIXERS, for Concrete and Mortar. MUNICIPAL ENGINEERING AND CONTRACTING COMPANY, 607-11 Railway Exchange, Chicago, 111. NATURAL CEMENT (see also Cement) ODORLESS VAULT AND CESSPOOL OUTFITS (see Vault and Cesspool Outfits) OFFICE SUPPLIES (see also Engineering Instruments) TECHNICAL BOOK AGENCY, P. O. Box 691, Chicago, 111. OPTICAL INSTRUMENTS (see also Engineering Instru- ments) W. & L. E. GURLEY, Troy, N. Y., \J. S. A. BAUSCH, LOMB, SAEGMULLER CO., Rochester, N. Y. PAINT (see also Asphalt Roofing and Paint) PAPER FOR DRAUGHTING (see also Engineering Instru- ments) xlii TECHNICAL BOOK AGENCY BOX 691 CHICAGO. ILL. PUBLISHERS OF AND DEALERS IN Scientific and Technical Books Inquiries as to the heSt books on emy technical subjedt will be cheerfully and promptly answered. Prominent men in all lines of engineering work are consulted by us, so inquirers can be assured of getting the beA advice. Libraries sele(5ted for technical men on the moit favorable terms. Any technical book published mailed on receipt of publisher's price. No discounts given on single books, for we sell only the lateA editions. Books sent for examination upon receipt of price, provided same are returned within two weeks in perfe(5t condition, when money will be refunded, less poAage. Slide Rules, Drawing Instruments and Office Supplies sold. TRADE LITERATURE AND SPECIFICATION INDEX. QUEEN & CO., Inc., 1010 Chestnut St., Philadelphia, Pa., U. S. A. PERIODICALS. CEMENT AGE, New York, N. Y. CEMENT AND ENGINEERING NEWS, Chicago, 111. CONCRETE, Home Bank Building, Detroit, Mich. THE CONTRACTOR, Security Building, Chicago, 111. JOURNAL of the Association of Engineering Societies, Boston, Mass. JOURNAL of Western Society of Engineers, 1737 Monad- nock Block, Chicago, 111. ENGINEERING NEWS, 320 Broadway, New York, N. Y., U. S. A. THE ENGINEERING RECORD, 114 Liberty St., New York, N. Y. . ENGINEERING WORLD, Chicago, III. MUNICIPAL ENGINEERING, Indianapolis, Ind. MUNICIPAL JOURNAL AND ENGINEER, New York, TECHNICAL BOOK AGENCY, P. O. Box 691, Chicago, 111., takes subscriptions for all Scientific and Technical Periodicals. PHYSICAL APPARATUS (see also Engineering Instruments) W. & L. E. GURLEY, Troy, ^. Y., U. S. A. BAUSCH, LOMB, SAEGMULLER CO., Rochester, N. Y. PIPE. REINFORCED CONCRETE PIPE CO., Jackson, Mich. PIPE JOINT COMPOUND. Alan H. Tripp, 118-120 Michigan St., Chicago, 111. PORTLAND CEMENT (see also Cement) CEMENT DEPARTMENT, ILLINOIS STEEL CO., The Rookery, Chicago, 111. CHICAGO PORTLAND CEMENT CO., Chicago Stock Exchange Building, Chicago, 111. SANDUSKY PORTLAND CEMENT CO., Sandusky, O. PORTLAND CEMENT MANUFACTURERS (see also Ce- ment) ALSEN'S AMERICAN PORTLAND CEMENT WORKS, 45 Broadway, New York, N. Y. xliii ARE YOU INTERESTED IN SAVING MONEY ON PUBLIC OR SEMI-PUBLIC WORK? ENGINEERING NEWS has for 30 years reached the leading: firms in America who have anything: to do with constructing: public or semi-public works, or for. furnishing: the supplies for the same. $30,000 CUT IN THE BOND ISSUE. "I desire to say that of the ten bidders for sewer work nine came from havingr seen our advertisement in the one issue of ENGINEER- ING NEWS, and the city has been enabled to cut their bond issue from *95,000 to $65,000." F. E. M., Cy. Engr.. Canton. PRICES WERE BELOV OUR EXPECTATIONS. "We feel much pleased with the result of our advertisement, as the prices came below our expectations. Most of the replies came through ENGINEERING NEWS." P. S. S, "The two advertisements for gravel roads in Atlantic Co., N, J., placed by me in your paper at a cost of $28.00 saved the county 826,992." J. J, A., Eng, RECOMMENDED BY ENGINEERS AND CONTRACTORS. • "We consult ENGINEERING NEWS for advertisements of pub- lie work. We should think that the weekly trade journals, which have their advertisements classified, would be used more by contract- ors. For this section (the Pacific States) we recommend ENGI- NEERING NEWS." R. B., Engineering Supplies. Los Angeles. "For information in regard to contracts we generally refer to ■ ENGINEERING NEWS. Although we read the daily papers, yet for general information in regard to contracts throughout the country we depend almost entirely upon ENGINEERING NEWS." E. W. P. Co., San Francisco, Write us when planning new work. When wanting: bids send us the advertisements; the rate is $2.40 an inch a time. The subscription price is five dollars per year, weekly. ENGINEERING NEWS 220 BROADWAY, N. Y. "THE COMPANION AND GUIDE OF THE ENGINEER IN EVERY CLIME." APPENDIX D. PULVERIZING MACHINERY (see also Street Sweeping Ma- chinery, Crushing Machinery) E. H. Stroud & Co., 30-36 La Salle St., Chicago, 111. PUMPS (see also Hand-Power Pumps, Contractors' Trench Pumps, Pumping Engines, Mining Pumps, Vault and Cesspool Outfits, Hose) • PUMPING ENGINES (see also Air Compressors, Boilers, En- gines) THE MURRAY IRON WORKS CO., Burlington, Iowa. REINFORCED CONCRETE (see also Concrete) ST. LOUIS EXPANDED METAL FIREPROOFING Co., Corrugated and Universal .Bars, St. Louis, Mo. ROAD MACHINERY (see also Steam Road Rollers, Hauling Engines) BUFFALO STEAM ROLLER CO., Buffalo, N. Y., U. S. A, ROOFING (see also Asphalt Roofing) ROPE (see also Manila Rope, Wire Rope) SCALES, for Engineers and Architects (see also Engineering Instruments, Tapes) LUFKIN RULE CO., Saginaw, Mich., U. S. A. SCIENTIFIC BOOKS (see also Books) W. & L. E. GURLEY, Troy, N. Y., U. S. A. SEWAGE DISPOSAL (see also Flush Tanks) PACIFIC FLUSH TANK CO., 184 La Salle St., Chicago, 111. SEWER EXCAVATORS (see also Ditching Machinery) MUNICIPAL ENGINEERING AND CONTRACTING COMPANY, 607-11 Railway Exchange, Chicago, 111. SEWER PIPE (see also Drain Tile, Pipe) MONMOUTH MINING AND MANUFACTURING CO., Monmoutl.', 111. STACKS— Steel (see also Steel-Plate Construction, Tanks- Steel, Feed Water Heaters) THE PETROLEUM IRON WORKS CO., Washington, Pa. STEAM ROAD ROLLERS (see also Road Machinery, Haul- ing Engines) xliv Ine First consideration i^cff £,**■"■ Quality or Product No mixture can be perfect in quality unless it is of absolute uniformity. In mixers, ^liavingr for mixing devices some form of paddles or blades, cutting through but not mixing the main mass at ttie bottom, it is obvious that the portions in motion and tliose in repose do not receive the same mixing. It is also a demonstrated fact that all forms of blades or scoops, in a mixingr chamber pocket some of the in^edients and this material is carried until the batch is discharged, when it slides out, unmixed, producing a streaky product. THE CHICAGO IMPROVED CUBE CONCRETE MIXER retains the entire batch, in mixing, in a single mass. It is all mixed together and the result must be perfect uniformity. The Chicago Cube has no insides except small breaker rods. The sides are perfectly smooth and cannot pocket the material. The rods break up any possible ball and ingredients cannot adhere to them, The cube does the work. , On account of superior quality of the nrixture, all concrete tested in the new Government Structural Material Testing Laboratory is mixed in the Chicago Cube Mixer. Sizes and Mountings for Every Requirement Write for Catalogue No. 36. Municipal Engineering and Contracting Company .General Offices: Railway Exchange, Chicago, U. S. A. New York Office: 150 Nassau St. TRADE LITERATURE AND SPECIFICATION INDEX. BUFFALO STEAM ROLLER CO., Buffalo, N. Y., U. S. A. STEEL PLATE CONSTRUCTION (see also Feed Water Heaters) THE PETROLEUM IRON WORKS CO., Washington, Pa. STREET SWEEPING MACHINERY (See also Crushing Ma- chinery) E. H. Stroud & Co., 30-36 La Salle St., Chicago, 111. WATER METER MANUFACTURERS. Bufifalo Meter Co., 290-396 Terrace, 233-239 West Genesee St., Buffalo, N. Y. WATERPROOFING COMPOUNDS. HARDESTY & HUME, Home Life Building, Washington, D. C. WEIGHTS AND MEASURES— Standard (see also Engineer- ing Instruments) W. & L. E. GURLEY, Troy, N. Y., U. S. A. WIRE GLASS. THE CONTINUOUS GLASS PRESS CO., 915 Pennsyl- vania Building, Philadelphia, Pa. WIRE ROPE — of every description (see also Cordage) Broderick & Bascom Rope Co., 805-9 N. Main St., St. Louis, Mo. SURVEYING INSTRUMENTS (see also Engineering Instru- Ments) BAUSCH, LOMB, SAEGMULLER CO., Rochester, N. Y. W. & L. E. GURLEY, Troy, N. Y., U. S. A. QUEEN & CO., Inc., 1010 Chestnut St., Philadelphia, Pa., U. S. A. J. C. SALA, San Francisco, Cal. TABLES (see Drawing Tables) TACKLE BLOCKS, for rope (see also Cableways, Manila Rope, Cordage, Traniways, Wire Rope) Broderick & Bascom Rope Co., 805-9 N. Main St., St. Louis, Mo. TANKS— Steel (see also Steel Plate Construction) Contractors Wanted flWe desire all contractors wanting work in the line of Land reclamation to write us. We are in constant touch with ditching projects, con- cerning which we have full information which can be handled no other way so successfully as with the Austin Drainage Excavator Land Reclamation is Revolutionized with the Austin Drainage Excavator There are nearly 100,000,000 acres of wholly unproductive swamp lands besides many million acres of arid lands in this country which can be reclaimed at small cost with this machine, and which will become the garden spots of the country. It constructs a ditch per- fectly true to grade, of practically any depth, width of bottom or width of top desired, slopes the banks to any angle and delivers the waste banks at a distance from the ditch, producing a wide berm, and accomplishes the entire work at a single operation. It removes every particle of loose earth from the ditch and trues the banks to exact specifications without disturbing the original strata of earth in the banks. It constructs a scientifically correct and permanent water-way, built to conform to nature's laws and immeasurably superior to any other style of construction. Once its merits are known, no other style of ditch building can successfully compete with this machine. Address Department No. A. F. C. Austin Drainage Excavator Co. General Offices: Railway Exchange New York Office: 150 Nassau St. Chicago, 111., U. S. A. APPENDIX D. THE PETROLEUM IRON WORKS CO., Washington, Pa. TAPES'— all kinds, for measuring (see also Scales) LUFKIN RULE CO., Saginaw,^ Mich., U. S. A. TOOLS, FOR CEMENT WORKERS (see also Cement Stone Machinery, Curbing and Gutter Machines) THE CENTURY CEMENT MACHINE CO., 181 W. Main St., Rochester, N. Y., has an excellent assortment of Cement Tools at lowest prices. TRAMWAYS, wire rope (see also Cableways, Rope) Broderick & Bascom Rope Co., 805-9 N. Main St., St. Louis, Mo. TRANSITS AND LEVELS (see also Engineering Instru- ments) BAUSCH, LOME, SAEGMULLER CO., Rochester, N. Y. QUEEN & CO., Inc., 1010 Chestnut St., Philadelphia, Pa., U. S. A. TRENCH EXCAVATORS (see also Ditching Machinery) MUNICIPAL ENGINEERING AND CONTRACTING COMPANY) 607-11 Railway Exchange, Chicago, 111. VAULT AND CESSPOOL OUTFITS— Odorless (see also Pumps) Edson Manufacturing Co., 255-7 Atlantic Ave., Boston, Mass. zlvi TYPEWRITERS ODELL. $7. 50 EXPRESS PREPAID TO ANY POINT IN THE U. S. A well made typewriter. Not a toy. Can be carried in a grip. Metal type. Perfect alinement. Good in2uii(plder. Splendid ma- chine for engineers who have small correspondence and who also wish to prepare neat specifications. A member of this company uses one and recommends it. POSTAL, $25. 00 F. O. B. FACTORY EQUAL TO, A $100 MACHINE Has universal keyboard. Good manifolder. Mr. Ernest McCullough has used one for three years past for all his correspon- dence and specied writing. His two latest books were written with the POSTAL. We use one in our office and can recommend it. WE CAN ALSO SUPPLY FINE ENGRAVED STATIONERY FOR ENGINEERS AND COMPLETE OFFICE EQUIPMENTS Tecnnical Book Agency p. O. Box 691 CHICAGO, ILLINOIS INDEX. Abutments for Arches 428 Accuracy in measurements 335 required in city surveying.. 11 Acetylene 151 Acid proof cement 448 test of cement 113 Adhesion of concrete to steel 434 Adjustment, sewer specifications 236 Advertising for bids 170, 173 Aerobes 64, 96 Air, danger from foul 62 Alarms, fire and police. ...... , 154 Algae 98 American Public Works Associa- tion \ 172 American Soc. C. E. methods for testing cements 115 for Testing Materials cement tests 115 system of filtration 98 Anaerobes 64, 96 Analysis of garbage 68 Anchoring rods in concrete 434 Appearance of streets help to city 23 Approaches to bridges 22 Aqueducts, capacity of. 110 Arches 422 Arching of distributed loads.... 369 Architects, requirements in sur- veys 267 Arch rings 425 Area of pipes ". . 360 of planes 459 I of beam sections, table 393 Arms of moments 366 of moments in beams 392 Armored macadam 50 Artesian wells ■- 101 Ashes 67 ■ Asphalt, cost of hauling on 41 load horse can pull on 41 pavements 56 paving, crown 20 paving specifications 189 water injurious ^to 20 Asphalted macadam 48 Assessment diac^ram 284 Avenues (see Streets, Roads). Axis (see Neutral Axis). Bacteria 96 Baker's values of pavements. 42 Bars for reinforcing 436 of steel, table of weights. . 456 twisted . .• 430 Base, plane of reference, official 24 Basin, catch 32 in gutter 73 Baumeister formula for sewer grades 343 Beams, best concrete for 343 cast iron 439 concrete 429 action in as column 398 continuous 374 deflection of 394 formulas 366, 394 moment of resistance 387 moment arm 392 « table of properties of sec- tions 893 resistance of , . 382 weight of •. 373 Bearing pressuTes 403 Benches and monuments 391 Bench marks 367, '308 records of 256 Bending moments 366 Bidders, instructions to 204 Bidding sheets 295 Bids, advertising for 170, 173 Bins for sand and grain.., 417 Bitulithic pavements 50 specifications 229 Bituminous rock 56 Blocks, concrete 130 granite paving 195 Blue prints 270 Boning rods, use of 330 Boom, paving 38 Books, field , 264 1 indexing field .344, 345 field and oflSce 350, 353 job 373 section , 263 for city officials, see Ap- pendix C. Borders on plats 269 Bradford separating weir 346 Breadth of concrete beam 435 Brick cross walks 34 number laid in one day 351 pavements 57 pavements, cost 59 pavements, crown 20 pavements, load horse can pull on 41 pavements, specifications . 180, 193 sewers .. ,. 76 sewers, spec^cations 311 sidewalks .". 39 Bridge approaches, grades on 22 Bridges, city 156 473 The Journal of JVestern Society of Engineers Is a high-grade bi-monthly illu^rated magazine of some eighty to one hundred pages in each •number, and contains the originaJ papers of en- gineering interest that have been presented to the Society, with the discussion of the same. These papers treat of subjects in aJl lines of en- gineering, 8u:e well illustrated, and should be of value to engineers, chemi^, scientific and busi- ness men everywhere. The Subscription Price is . Ss-oo a year. The ' circulation is about 1500 copies of each issue ; six times a year. The JOURNAL is a valuable advertising medium., as it goes eJI over the world and to a high cleiss of technical read- ers. Advertisements,-if of intereft to engineers, may be published in the JOURNAL. For rates or other information concerning the yournal of Western Society of Engineers address or call upon the Secretary, 1737 Monadnock Block .. Chicago INDEX. Building loads 401 ordinance 139 permits 275 locating by survey 336 Bulkhead walls 419 Burkli-Ziegler formula for storm drainage 341 Business street cross-section 19 c Calculations for concrete walls. . 413 for curved roads 315 Cans, tin 67 Capacity of aqu'educts. . .- 110 of pipes, diagram 354, table ij60 Carbonizers for garbage 69 Card index 240, 253, 271 Carloads, pieces of pipe in 349 Car tracks 20 Cases and tubes 246 Cast iron beams 429 pipe 109 weight and thickness 355 Catch basin 32, • 73 basin specifications 212 Cements and Lutes 447 Cement 112 cur^bs 32 pavement, speciiications .... 179 testing 113, 116, 444 walks 30 Center of gravity 382 Center line of street for grade. 24 Certificates of surveys 264 Cesspools :••■.• ^2, 149 Chambers, diversion in sewers. . . S5 tumbling in sewers . .^ 81 Chemical precipitation of sew- age 94 Chezy formula 335 Chimneys, stability of 406 tables of horse power and draught 356 Cinder concrete 121 walks 29 Cippoletti weir formula 354 Circle, formulas 457 properties of 460 Circulation in water mains....'.. 107 Cisterns, capacity of 361 City Engirieer, office fixed by or- dinance 15 records 268 City base, or plane of refer- ence 24 surveying, accuracy required 11 Classes of engineers 11 Clauses in specifications, general (see also materials) 196 Clay and lime 113 reproduction process 274 Cleaning catch basins 74 rods 83 streets ..62, 74 sewers' . , 82, 86, 87 Cloth mounted paper 269 Cobbles 52 ♦ load pulled by horses on pavement 41 Code, building 139 Colby's sewer computer 338 Color conventions 271, 287 Coloring cement walks 30 concrete 134, 135 drawings 271 Columbus office records '240 Columns 396 of concrete '. . . , 438 formulas 399 Combined sewers 73 Common sense 15, .39 Compressive strength 401 Compression of concrete 429 Computers for sewer work 338 Concrete I 120 anti- freezing mixture 237 for beams 431 blocks 130 coloring 135 colu'mns 398, 438 cross walks 34 culverts 437 curbs 32 footings 441 mixing 121 mixers (see also Appendix A) 130 mixtures 126, 431 pavements 59 pavement specifications 174 proportions 126 reinforced 429 retaining walls 412 sewers 77 sidewalk specifications 235 specifications 232 tar 49 under reinforcing bars 436 walks 30 water in 123 Concentrated weights 367 loads altered to distributed . . 373 Cone mensuration 458 Connections to drains and sew- ers 142 Connectin_g sewers 85 Construction plats 292 Consulting engineers 16 Contact beds 96 Continuous beams 374 concrete beams and slabs. . . 436 Contour diagrams 281 maps 277, 280, 294 - roads 20 Contraflexure in beams 372 CoAtracts and specifications 170 vs.- day labor 170 drawings for 299 Conventions on drawings.., 271 474 When You Want to Employ Competent Engineers; Draughtsmen Superintendents of Construction, Inspectors, Instrumentmen, Topographers, or any Engin- neering Assistant, Mechanical, Electrical, Mining or Architectural WRITE OR WIRE US. We can place at your disposal thirteen years accumulation of good men and will guarantee the one we recommend to be competent. All of our candidates are willing to . Report onTheir Own Merits You can find the man you want by coming to us. Most of the good engineers are our members. It proves they're good if they are our members. That's why we get them. Correspondence from Other Competent Men Solicited The Engineering Agency, Inc. OF CHICAGO Fulton Building, Pittsburg Established 1893 Monadnock Block, Chicngo For Competent Technical Men Only INDEX. Copper sulphate 110 Copying specifications 171 Corners of streets 32 Correspondence, indexing 242 Cosecants, table of 468 Cosines, table of 466 Cost diagram 284 as a factor in street grades 23 first and ultimate 3S~ of hauling 41 of hauling street sweepings 70 of improvements 20 of lights 150, 152 of pavements 69 of repairs near car tracks. . 39 of sewer work 349 Cotangents, table of 464 Councilmen 12 Counts and juries on surveys... 159 Cranes slide rule 338 Crossings over gutters 35 elevations : . 27 Cross section of street 19 walks 33, 35, 73 walks, specifications 194 Crooked roadways 332 Crown ; 19 setting out on street 332 for asphalt, brick, macadam, stone, wood 20 Crusher run stone 121 Culverts of concrete 437 formulas for size 340 Curb elevations 20, 24 height 21, 32 Curbing in general 30 specifications, concrete 184 specifications, stone 184 Curing concrete blocks 133 Curve formulas 318 vertical ._ 328 Curved road calculations 315 Cylinder mensuration 458 Danger from poor buildings 139 Day labor vs. contracts 170 Days, number of working 174 Dead ends 107 Defective sidewalks 29 Definition of grade 23 of terms in street work. ... 19 Deflection of beams 394 Deformed rods 434, 438 Decimals of a foot 469, 470 of an inch 471 Department records 277 Deposits in sewers 81 Depreciation of public works. . . . 150 Depth of concrete beams 433, 435 of drains 72, 80 of flow 80 of gutter 21, 32 of sewers ,..,,.. 84 Design for inlet covers 75 of roof 381 Detail drawings 270 Diagram for contours 281 of flow in pipes 337 for flow in sewers 339 of force 371 of pipe capacity 364 for stadia work 282 for street work 330 Dimensions of walls 409 Disposal of garbage , 65 of sewage 93 Diversion of flow in sewers. .85, 344 Distributed loads, arching in.... 369 Dock walls 419 Double circulation in water pipes 107 Drainage (see also Sewers, Drains). size of culverts 340 definition of 71 as a grade factor 21 important . , 23 of street intersections. .. .72, 76 good practice 71 under pavements 43 quantity to provide for 338 summits 334 ^ table 335 Drain connections 143 depth of , 72 house 144 under cross walks 73 Drawings, coloring of 271 of details 270 for concrete work 299 filing and indexing 247 hints on making 272 plain 272 standard sizes 241 Driving piles 403 Dry concrete 123 Durability of cement walks 30 Dust 69 on roads 46 stone for concrete 121 E Earth road, cost of hauling on.. 41 general 43 load horse can pull on 41 Education, technical a necessity. . 11 Egg shape sewers 85 Elastic limit 430 Elasticity, modulus of 388 Electric lights 151 records 277 Electrolysis 39 Electric .roads 39 Electrical thawing of pipes Ill Elevations from city base 24 on center lines vs. curbs. ... 24 on crossings 27 difference between curbs. ... 20 of curbs 31 475 The Monthly Journal CONCRETE is the leadmg authority upon Portland Cement and Concrete Construction. It covers all phases of the subject fully and is indispensible to engineers, con- tractors, architects and cement workers. This is the Concrete Age. New discoveries and de- velopments are bemg made each month. : : : : : Send ONE DOLLAR for a year's subscription. JUST PUBLISHED CONCRETE BUILDING BLOCK AND SIDEWALK CONSTRUCTION. CON- TAINING SAMPLE SPECIFICA. TIONS. ETC. $L00 : : Address Concrete Publishing Company 50 Home Bank Building DETROIT : : MICHIGAN INDEX. official ,. 23, 24 Ellipse, mensuratioii 459 Encroachments on roads 320 Ends of pipes 107 Engineers, careful selection of . . 12 consulting 16 plea for in small places 11 qualifications 15 three classes of 11 value of good 14 Engines for pumping 102 English system of filtration 98 Error in levels 309 in measurement 325 Essentials in contracts 171 Estimates for sewer work 349 Evaluation of old plants 164 Excavation tables 349 Excess of lime in cement 113 Expanded metal 437 Expansion in tapes 326 Expense of cheap men 14 Extras 172 F Factor of safety 432 Fanning ' drainage formula 341 Fat concrete 126 Fence encroachments 320 Fibre stress 391 in concrete • 430 Field and office books 250 books 241, 264 books, indexing 244, 245 work 301 Filing and indexing maps 244 cabinets 269 drawings 247 maps and plats 269 sizes for plats -. 272 surveyors' records 259 Filtering of water 98 Filtration of sewage 95 Filth 63 Fire alarms 154 from gas leaks 28 losses 155 streams^ 106 stream 'tables 358 Underwriters' building code. 139 use of water 106 Flexure of beams 372 Floors . . . ; 378 for bridges . . . . .^ 156 Flow of water in pipes, tables 362, 363 in sewers, diagram 338 over weirs 353 Flumes 71 Flushing sewers 81 Flush tanks 82 Fools as city engineers 12 Foot, decimals of tables 469, 470 Footings of concrete 441 Force diagrams S71 Forces, parallel 382 Formulas for arches 422 for beams 394 for bending moments 366 Chezy, for flow 335 for. columns 399 for concrete columns 440 for culverts 340 for curves 318 for deflection 396 Kutter's 336 for mensuration 467, 462 for pile driving 403 for reinforced concrete beam 433 for sinking funds 449 summit in street 334 for weirs 354 Foul flow '. . . . 344 Foundations for pavements. . .43, 188 under towers and chimneys. . 406 Foundries, standard castings. ... 75 Franchises fdr street railways. . . 39 Franchises 167 Francis* weir formula 354 Freezing of concrete 237 Freight, effect of on cost 38 Friction in pipes 359 Frozen pipes Ill Frustrum 458 Funds, sinking 167, 449 G Gallons per foot in pipes, table. . 360 Gaf1)age analysis 68 definition 70 disposal on land 64 carbonizers 69 hauling 62 reduction 68 Gas of decomposition 64 engines , - 102 limits 151 pipes and leaks 27 Gasoline lights 151 storage 155 Gates and valves 107 Grades (see also Elevations, Heights) 19 definitions 23 in gutters 333 examples of light and steep 31 ordinance for 25 measurement on 302 profiles for 330 for sidewalks _ 313 maximum and minimum in sewers 81 for sewers 342 for streets, proper method of study 22 on streets, maximum and minimum 22 temporary , 23, 71 vertical cuf ves 328 476 WATERPROOFING A. feature ot the remarkaUe gro-wtn oi tke con- crete industry is the necessity for some good method to secure 'watertightness. This has lately commenced to attract attention, Tvith the result that a numher of processes and materials are advertised. Xime may prove some to be good It has proven many to he had. THE TEST OF TIME has heen successfully home hy the English material SZERELMEY STONE LIQUID since 1870. It IS a colorless liquid applied "with a hrush. It enters into the pores and does not alter the color of the surface. The makers have pigments to mix -with it vt^hen the user desires a coloring that will not fade or sunhum. It improves the concrete and acts as a preservative THE CAUSE AND CURE OF DECAY IN STONE sent on request Sold in original imported packages. The British gallon is twenty per cent larger than the U. S. gallon. AmetJcan A^t8.,HARDESTY 6f HUME, Home Life Biag.,Waslimgtoii, D.C. Chicago Office, J. J. O'HERON &f CO.. 6 Wabasi Avenue, Chicago, lU. SZERELMEY 6? CO., LONDON, ENGLAND INDEX. Grade stakes in sewers SiO table, showing pulling effect S2 Grading surveys S25 Grain and sand pressures 409 Grain and sand bins 417 Granite block paving specifica- tions 195 curbs 31 Graphic statics 382 Gravel roads 41, 43, 59 specifications . ., 223 Gravity, center of 382 Grease traps 148 Growths in reservoirs 110 in sewers 86 Gutters 36, 71 crossings 35 depth 21, Sa grades 333 horses standing in 37 inlets 346 summits in 21, 33 formula 334 Gyration, radius of 393, 398 H Hard vs. soft steel 430 Hartford office records 240 Haulage of street sweepings 70 Healthful building construction.. 141 Height of curb 21, 32 Helotograph 270 Hillside roads 20, 332 Hose pressures 106, 365 Hooped concrete columns 441 Horsepower of chimneys 356 Hou'se connections . .' 85 drains ^ - 144 numbering 296 Household filters 99 Hydrant pressures 106, 357 specifications 221 Hydraulic weights and measures 365 I Ideal pavement 41 Improvement of streets 19, 333 plats 330 Index books 240 card, for records ... 240, 253, 271 •loose leaf 238 ' maps 256 Indexing: books 245, 262 correspondence 242 drawings 247 field notes 245 maps 244, 245 notes, reports, etc. . , 243 surveys 265 Inch, decimals of 471 Inertia, moment of 390, 393 Inks, transfer 270 Inlets (see also catch basins) . . 73 in gutters 345 Inquiries about paving 40 Inspecting sewer connections. . . 86 Inspection 17 holes 83 Inspector, building and plumbing 140 Instructions to bidders 204 Insurance rates 107 Interests, vested ..." 79 Intersections, drainage 76 Invert blocks, perforated, for sewers '. , , 342 Inverted siphons in sewers 343 Iron cements 448 column 401 pipe 109 plates, weight of 455 specifications 221 Irregular loadings 370 planes, area of 459 Irrigation in cities 72 with sewage 94 J Tamieson's experiments on bins. . 417 Janssen's formula for pressures 417 Joining curbs at corners 32 Job book 273 Junctions in sewers 85 marking 312 K Kerosene lights 161 Kutter's formula 336 L Laborers, nursing 170 Lake water 99 Land butchers 11 disposal of garbage 64 Lar^e sewers 81 Laying out cities., 161 Lead in pipe joints 357 Leaks in gas pipes 27 Lean - concrete .'. ...v 126 Level cross section for street. . . 19 for tapes 301 Licensed drain layers 89 surveyors 376, 301 Light grades 21 Lighting department records. . . . 278 of cities 160 Lime 112 excess of in cement 113 Limestone for concrete 121 Limit, elastic 430 of error in levels 309 Lines, accuracy in measuring. . . . 159 marking on buildings 305 Live loads 377 Loads, building 401 concentrated vs. distributed. 373 distributed, arching of 369 477 ESTABLISHED 1845 INCORPORATED 1900 Largest Manufacturers in A.merica of FIELD INSTRUMENTS for Civil, Hydraulic and Mining Engineers and Land Surveyors ANEMOMETERS, BAROMETERS DRAWING INSTRUMENTS, STANDARD WEIGHTS AND MEASURES, SCIENTIFIC BOOKS, =====^== ETC. . TRANSITS, LEVELS, COMPASSES, PLANE TABLES, CURRENT METERS, LEVELING RODS CHAINS AND TAPE LINES W. & L. E. GURLEY TROY, N. Y. Our Latest Illustrated Catalogue Mailed on Application INDEX. Loadings, irregular 370 Loads, live 377 on pavements 41 Local considerations 38 Locating buildings 326 Logarithms ^...450, 452, 454 Loose leaf index 258 Losses by fire 155 Lot surveys 267, S05 Lowering water pipes 343 Low*s arch formula 423 Lumber in trenches 223 Luten's arch formulas 424, 428 Lutes and cements 447 M McMath formula for drainage... 341 Macadam, armored 50 asphalted ....-, .- 48 cost of 59 cost of hauling on 41 crown 20 loads pulled by horses 41 general 45 specifications 187 tar 49 MacCarthy's values of pave- ments ' 44 Machines for digging trenches. Appendix B. Machines _ for concrete mixing. Appendix A. Magneto, telephone . .•• 154 Mains for water, size of 107 Maintenance of streets 39 Manholes S3 sewers entering 342 specifications' 211 Manure 67 Maps, border on 269 contour 280 filing and indexing 244 and plats, filing of 269 indexing 245 left and right hand 269 for indexes 256 of stadia 'survey 332 of underground conditions. . 284 Marks, bench 308 Marking drawings 273 sewer junctions 312 survey points 304 Materials, furnishing vs. con- tracts 170 for paving 39 strength of 395, 397 for water pipes 108 weight of 400, 402, 404 Mathematics and common sense. . 15 Maximum bending moment 367 street grade 22 Measures, hydraulic 365 Measuring, accuracy in 325 lines 159 on slopes and grades 302 with steel tapes SOI water 353 Mechanical filtration 98 separation of sewage 94 Mensuration formulas. ., .457 to 463 Meters, water , 103 Micro-organisms 63 Miscellaneous specifications 325 Mixing concrete (Appendix A) 121, 130 Mixtures of concrete 126 Models, use of 333 Modulus, section 390 of elasticity 388 Moisture in concrete 125 Moment arms 366 arms in beams .'. . . 393 bending 366 diagrams 371 of inertia 390, 393 of resistance 387 Monuments 303 records of 356 and benches 291 Moore's formula for sewer grades 342 Mortar 112 retempered 135 water tight 351 Moseley's retaining wall theory. . 410 Mounting paper 269 Municipal ownership 165 N Names of streets in walks 30 Neutral axis 389, 392, 429, 433 Nitrification 96 Notes, indexing 343 ownership of 268 Numbering houses 296 Odors in sewers 81 Oil proof cement 44/ Oiled roads 47, 334 Office and field books 250 systems 338 Official base for elevations 24 elevations 33, 34 Opening ■ pavements 40 streets . .' 278, 285 Ordinance, building 139 for street elevations 25 city engineer 15 for sewer connections 87 Overflows for sewers 343 Ownership, municipal 165 Paper, cloth, mounting 369 Parabola, area of 459 constructing 328 force diagram 371 478 The Chicago Sewer Excavator Is made in several sizes. The large size does the work of from 100 to 200 men. The smallest size from 73 to 150 men. They dig trenches from 14 to 60 inches wide, to depths of 20 feet, in a single cut. Widths and depths easily regulated. Trenches cut practically to grade and under favorable circumstances at the rate of from 60 to 100 cubic yards per hour. Supported on surface in advance of cut. No caving banks. Equipped for selftraclion. Travels between trenches under its ovvn power without dismantling, at the rate of two miles per hour. Begins work the moment it reaches new line of trench. Xne Cnicago Excavator Comparea -witn liana =^=^= Labor. == The Excavator is always on hand the DAY AFTER PAY DAY. It makes NO OBJEC- TION TO OVERTIME. It is better than a foreman for it is a PACEMAKER for the pipe layers. Pipe laying records nave been broken since these machines have been used. TOUGH GROUND, re- quiring the use of a PICK, is where the machine does most profitable work. Excavating in a SINGLE CUT, it is far cheaper in deep cuts than hand labor where the cost rapidly increases with depth. On many kinds of work it will be NINETY' PER CENT. CHEAPER than hand labor. For sale, or leased to responsible contractors. Write for Catalogue No. 136; MUNICIPAL ENGINEERING AND ' = CONTRACTING COMPANY RAILWAY EXCHANGE, CHICAGO. ILL. NEW YORK OFFICE. 150 NASSAU ST. INDEX. Parallel forces 382 Parking of streets 21 Pavements, asphalt 56 bitulithic 50 bituminous rock 56 brick 57 cheap '. ... 38 cobbles 62 concrete 69 crown for 20, 332 foundations 43, 188 ideal 41 stone 62 wooden 53 Paving, boom 38 bridges 156 inquiries .- 40 cost of hauling on 41 loads hauled on 41 materials, values of i.42, 44 specifications,-, asphalt 189 specifications, bitulithic 229 specifications, brick 180, 192 specifications, cement 179 specifications, concrete 174 specifications, granite- block. . 195 specifications, macadam .... 187 specifications, wood .... 183, 190 Permits for buildings 275 Pestilence 62 Pile driving 403 Pipes, capacities 360 crossing sewers 343 diagram 354 gas 27 laying regulations 40 laying, specifications 221 lead in joints 367 materials for , . 108 number pieces in carload... 349 specifications for 231 sewer specifications 212, 220 for water 108 table of capacities 335 table of cast iron 355 tables of flow 362, 363 Plain drawings 272 Plank sidewalks 29 Plans for 'covers 75 Plants, value of old 164 Plats ■ 241 for archite9ts 267 for construction work 292 and maps, filing 269 indexing 266 for street work 330 Plea for egineers 11 Plumbing, defective . .^ 102 "ordinance 143 work 140 Police alarms 154 Polygons, mensuration 459 Poor concrete 127 Population in cities 342 Portfolios 269 Portland cement 113 slag 113 Postal card records 289 card reports 296 Precipitation, chemical, of sewage 94 Pressures, bearing 403 in grain and sand bins 417 for .fire purposes 106 in hydrants 357 on walls 409 of water 364 in water systems 101 of wind 383, 406 Private sewers 79 Privy vaults 149 Procedure in work 295 Profiles for grades 330 and levels 291 Property owners' share in grades 23 records 276 Proportions for concrete 128 Providence records 238, 240 Public Works Association, Amer- .„ican 172 Pull on different grades 22 Pumps 100 Purity of water ■ . 98 Puzzolan lis Pyramid mensuration 458 Q .Quantities for sewers 347, 348 Quantity of drainage water 338 of water, per capita 102 .R Radius of gyration 393, 398 Railways in streets 39 Rainfall 338, 340 Rainwater in sewers 84 Raising water pipes 343 Rates for water 104 for lighting 150 Ratio of E, concrete and steel.. 429 heading and practice 17 Reactions 374 Records of benches and monu- ments < 256 of city engineers 238, 268 for departments 277 for city surveyors 259 in Hartford 240 in Providence 238 of property lines. . . ; 276 for small places 298 in Springfield 242 of surveys and resurveys. . . 274 Reduction of garbage 68 Refuse, . definition 70 Regulations for street openings.. 40 Reinforced concrete 125, 429 concrete beam formulas 433 concrete columns 438 179 It is necessary to read The Engineering Record to become well informed in the latest practice — both standard and special — in all departments of civil engineering. Published Weekly Domestic Subscriptions, $3.00 per Annum. Foreign Subscriptions, $6.00 per Annum. Club Rates Domestic Subscriptions in clubs of two or more, $2.50 each ; at least one of each two subscriptions in the club to be new. All Subscriptions Payable in Advance. SAMPLE COPY ON REQUEST. The Engineering Record 11^ Liberty Street .. New York U. S. A. INDEX. concrete sewers 77 concrete walls 412 Reinforcing steel 436 of web 436 Repairs to sidewalks . . .- 1S7 to streets 80, 39 on macadam roads . . -. 46 Reports on postal cards 296 Reservoirs 100, 110 Residence streets, improvements on 21 Resistance of beams 382 moment 387 Resultant of forces 382 Resutfacing of macadam roads. . 46 Resurveys 158, 274, 305 Retaining walls 408 Retempered mortar .' 136 Rich concrete 127 Roads (see also Streets). curved, calculations 316 earth and gravel 43 contour, on hillsides 20 macadam 45 oiled and tarred. .« 47, 334 specifications for gravel 223 winding 332 rollers 61 Roadway widths 20 Rods, use of boning 330 ' for reinforcing concrete.... 436 for sewer cleaning S3 for stadia work 323 twisted 430 Roof design 380, 383, 384 water •• 84 Rules, Am. Pub. Wks. Assn 172 for street improvements 19 slide, for sewer work 388 slide, for stadia work 282 s Safety, factor of 432 Sag in tapes 302 formulas 325 Salary for engineer 14, 17 Salt water 101 Sand and grain bins 417 filtration 98 road, hauling on 41 Sanitary code 140 sewers 80 Scraping sewers 86 Sea walls 419 Sedimentation of sewage 97 Secants, table of 467 Section books 862 cross, of streets 19 modulus 390 Table of beams 393 Selection of engineers 12, 14 Separate sewers 80 Separation, mechanical, of sewage 94 Separating sewage devices 85, 344 Septic tank 95 Servants, engineers as 12 Setting of concrete 126 stakes for work 309 out street crowns 332 Sewerage, definition 71 Sewage, definition 70 disposal 93 filtration 95 irrigation 94 per capita 342 treatment 85 Sewer (see also Drains, Drainage). adjustment 226 brick 76 cleaning 86 * cleaning rods 83 combined 73 computer 338 concrete 77 connections 86, 142 cost of 349 depths 84 deposits in 81 egg shape 86 flow diagram 339 flushing 81 growths in 86 large 81 at manhole 342 marking junctions 312 grades 81 overflows 343 plans .....; 79 records 277 sanitary 80 separate 80 setting grade stakes 310 siphons 343 sizes 80, 81 specifications 205, 226 on steep streets 81 tables of quantities 347, 348 tile 76, 351 velocity 342 ventilation 82, 84 vested interests 79 water carriage 79 in wet ground 343 wooden .^ . . 76 Shaping of corners 32 Shear 375 in concrete beams 435 Sheets for files 272 Sidewalks 19, 29, 137, 235, 313. ^i Sidling streets 19, 72 Silica cement 114 Sines, table of 465 Sinking funds 167, 449 Siphons, inverted 343 Sizes, standard for drawings.... 241 of sheets 272 of sewers 80 of water pipes.... 107 Skilled paving supervision 39 Slabs 378 480 OWL CEMENT A high grade Portland Cement Made expressly for the use of men whose years of experi- ence lead them to be exacting in their cement specifications. Such cement is therefore the best for beginners. GERMAN-AMERICAN PORTLAND CEMENT WORKS LA SALLE. ILL. Sales offices: Marquette BuSding, Chicago, 111., U. S. A. INDEX. Slag cement ....'. 113 Slide rules, stadia S82 rules, sewer 888 Slope . . . ^ 19 m drainage 340 on . pavements ' 333 Small places, records for 298 sewers 81 Smells 62 Smith-Francis weir formula .... 354 Soft vs. hard steel 430 Specifications and contracts 170 brick pavement 180 catch basins , 212 cement pavement 179 concrete 832 concrete curb and glitter.... 177 concrete blocks . . . ." 130 concrete sidewalks 235 crosswalks (see paving mate- rials). gas pipe 221 gravel road 223 hydrants, pipe, hose 221 iron 221 laying water pipe 221 manholes 211 miscellaneous 225 National Board Standards. . 225 pipe sewers 212, 220 sewers 205 sewer adjustment 226 steel 221 stone curbing 184 timber 221 paving, asphalt 189 paving, bitulithic : . 229 paving, brick 192 paving, concrete 174 paving, granite 195 paving, macadam 187 paving, wood 183, 190 Sphere, mensuration 458 Springfield records 242 Sprinkling roads 46, 69, 101 Stability 405 Stadia diagram 282 rod 323 slide rules 282 surveys 314, 322, 325 Stakes for sewers 310 setting for work 309 Standpipes 100 Standard drawing sheets 272 Statics, graphic 382 Steel colutans 401 hard and soft 430 pipe 109 plates, weight of 455 specifications 221 tapes .., 301 Steep streets 21 Stone blocks 52 pavements 41 cements 448 dust in concrete • . . • 121 cross walks S4 crusher run 121 curbing specifications 184 curbing 31 flags 29 paving, cost 59 paving, loads 41 paving, crown .20, 332 Storing gasoline 155 water lOO Strains in structures 378 Straw 67 Streets (see also Roads). appearance 23 car tracks in 20, 39 cleaning 62 rules for .improving 19 intersection drainage 76 lighting as protection 164 names in walks 30 oiled and tarred 334 openings in 40, 278, 286 parking 21 pavement crowns 332 records 277 sidling 19, 72 sprinkling 69, 101 winding 332 data for work 328 diagrams for work 330 models for plans 333 Strength, compressive 401 of concrete 126 of materials 395, 397 Stress, fibre 391 and strain 382 in concrete 430 Structures, strains in 378 Struts in concrete beams 430 Study in grades 22 Substances, weight of. .400, 402, 404 Subsurface maps 284 Sulphate, copper for water 110 Sulphut in concrete 121 joints 448 Summit in gutter j .21, 33, 334 Supervision, skilled, in paving. , 39 Surveys for architect 267 certificates/ 264 for encroachments 320 indexing 243, 265 of lots 305 and resurveys 158, 274 records of 259 marking points 304 map of stadia 322 Surveying, fees 17 C+nflin 314 Surveyors . .'.'.'.'Al, 'U,' 159, ' 276,' 301 Sweeping into catch basins 74 Systems for office 238 Table of bar steel 456 of carloads of pipe 349 481 T. FRANK QUILTY, Assoc. Amer.Soc. CE. ERNEST McCULLOUGH, M. W.S.E. Engineer. Mem.West.Soc.Eng. Consulting Engineer. JOHN J. O'HERON & CO. GENERAL CONTRACTORS 6 Wabash Avenue Chicago Contracts taken in any part of the world, A specialty made of work done on the "cost-plus-a-fixed-sum" method. This firm has an exceptionally good record in sewage disposal plants, sewerage and waterworks construction, tunnels for waterworks, etc., massive masonry and bridge foundations Contracts taken for waterproofing masonry structures by any specified process Chicago representatives for the well known " Szerelmey Stone Liquid," for waterproofing stone, brick and concrete. INDEX. of cast iron pipe 355 of chimney horsepower .... 356 of cisterns and tanks 361 of cosecants 463 of cosines -166 of cotangents 464 of decimals of a foot... 469, 470 of decimals of an inch....'. 471 of excavation in. trenches .. . 349 of fire streams 358 of flow in pipes .362, 363 of flow over weirs 353 of friction- in pipes 359 of hydrant pressures 357 of hydraulic weights and ^ measures 365 of pipe capacity 335 of pipe contents 360 of properties of beam sections 393 of pull on grades 22 of data' for roof design. .383, 384 of safe hose pressures 365 of secants 467 of sewer materials 347, 348 of sines 465 of steel and iron 455, 456 of strength of materials. 395, 397 of tangents 463 of water pressure 364 of weights of materials. . . . 400 402, 404 Tact a- prime requisite 13 Tamping concrete 123 Tangents, table of 463 Tanks, flush 82 gallons in 361 septic, 95 stability of 406 water 100, 108 Tapes, expansion - 326 levels for 301 standard 301 Tar for roads 47 concrete 49 macadam 49 Tarred and oiled roads 334 Taxation 151, 167 Technical education 11 Telephone, magneto 154 Telford road 46- Tension in concrete 429 Terraces on streets 20 Testing cement 113, 444 Thawing pipes Ill Theories of retaining walls 409 Thickness of arch ring 425 of cast iron' pipe 355 of concrete slab 433 of walls 412 Ties to survey points 304 Tile sewers 76, 351 Timber speciflcations 221 Tin cans 67 Towers, stability of 406 Track record maps 289 Tracks in roads 20 Traction as grade factor ....21, 22 Trade literature [see Appendix „D) , 258 Transfer inks 270 Trantwine's theory, of walls 410 Trench excavation table 349 Trenching machines. Appendix B. Triangle, mensuration 459, 461 Triangulation ■^ 325 Trigonometry 460 Trolley lines 39 Truss diagram 380 Tubes and cases 246 Tumbling chambers 81 Twisted rods 430 u Underground drains 72 maps 284 'Values of old plants 164 of pavements 42, 44 'Valves and gears 107 Vauban's rule for walls 408 "Vegetable growths in reservoirs . . . "Velocity in iron pipes 362, 363 in sewers (see Tables, Dia- grams) 81 'Ventilation of sewers 82, 84 Vertical curves 328 Vested interests 79 Visintini beams 430 Voids in concrete 127, 137 w Wagons for sewer flushing 81 Walks for bridges 156 cross 33 Walls 378 of concrete 412 for docks . . I 419 retaining 408 Waste of water 102, 105 Water crossing street 19 table of flow 362, 363 flow formula 335 from lakes 99 from wells 99 mains, size of 107 meters ' 103 pipes 108 pipes lowering 343 pressure 364 quantity of . . . .' 102 rates 104 supply 352 uses of 98 surface 72 tanks 100 tight concrete 127 I tight mortar 351 482 NEW YORK. 1835 SAN FRANCISCO. 1855 I C SALA INSTRUMENT MAKER San Francisco, Cal. SOLE MANUFACTURER OF THE McCULLOUGH TAPE LEVEL For 51 years " Sala instruments Lave teen standarcl on the Pacific coast. Earthquakes and fires Lave no tad effect and in the New San Francisco new customers will join -with old customers in support of the old house. Every transit and level tested ty Mr. Sala, personally, before shipment. A FuU Line of Field and Orxice Supplies always on hand. Maker at tbe large transit for tke re-gurvey of San Francisco in 1863. INDEX. tower 4a7 weight in pipes 360 Waterproofing 168 Waterproof cement 447 Waterworks records 277 Wear on macadam roads 46 Web reinforcement 435 Weight concentrated 367 of bar steel 456 of beam 373 of pipe 35S of steel and iron plates .... 46S of water in pipes Weights of materials 400, 402, 404 on beams 367 hydraulic 365 Weir formulas 354 in sewer 346 measuring 352 Welded fabric 437 Weld's arch formula. 426 column formula 441 Well water 99 Wells, artesian 101 in crowded districts > . 62 in gutters 73 Westrumite for sprinkling 47 Wet concrete 123 ground, sewers in 342 Wheat 418 Width of sidewalks 20, 29 of roadways 20 Winding of roadways 332 Windmills 102 Wind pressure 383, 406 Wooden columns 401 curbs 31 cross walks 33 pavements 53 Wo6d paving, cost 59 crown 20, 330 ' traction 41 specifications 183, 190 pipe 109 sewers .-.^ 76 sidewalks 29 specifications 221 Work setting stakes for 309 Working days . . .' 174 pressures of hose , , , , , 365 FINIS. 48S R etnforced Concrete Sewer and Water Pipe And Solid Concrete Catch Basins Are a Municipal Economy. ' Indorsed by all Leading Engineers. Why: They are permanent improTements. They harden and strengthen with age, They will never need any repairs. They are both frost and root proof. They are not only the best but the cheapest. Write us for Booklet and Particulars. Re-inforced Concrete Pipe Co, Jackson, Mich. Office : sSandsg Sun Building. Factory : South Park Avenue