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A&LY OARPEMTRY 
 
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 P. P. 28, 29, 31 
 
 A.H Payne sc 
 
THE 
 
 ENCYCLOP/EDIA 
 
 OF PRACTICAL 
 
 
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 COMPRISING 
 
 itlje Cljotcf, |)rmruation, ant) $trni0tl) of iilatmals, 
 
 EXPLANATIONS OF THE THEORY AND PRACTICAL DETAILS, 
 
 A COMPLETE SYSTEM OF LINES 
 
 FOR THE 
 
 CARPENTER, JOINER, & STAIRCASE BUILDER, 
 
 TOGETHER WITH AN ACCOUNT OF 
 
 THE IMPROVEMENTS EFFECTED IN ENGLAND AND ON THE CONTINENT, 
 
 AND ILLUSTRATIONS OF 
 
 THE MOST REMARKABLE EXECUTED WORKS. 
 
 EDITED BY 
 
 EDWARD LANCE TARBUCK, Architect. 
 
 Editor of “THE BUILDER'S PRACTICAL DIRECTOR;” Author of “A POPULAR ACCOUNT OF THE STYLES OF ARCHITECTURE," 
 being the Essay for which the Royal Institute of British Architects awarded the “Institute Medal" for 1 854 ; Articles contributed to 
 “THE BUILDER" on “The Present State of Architecture”, etc., etc 
 
 (Kljt Sigjit of Croiialotioii is rmruth. 
 
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 LEIPZIG AND DRESDEN: A. H. PAYNE. 
 LONDON: J. DAGGER, 
 
 07, PATERNOSTER ROW. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 , ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
P R E F A C E. 
 
 AN ENCYCLOPAEDIA OF CARPENTRY AND JOINERY, 
 complete in its several divisions, and embracing, not only illustrations of the works 
 of all times most remarkable for execution, but also a comprehensive survey of the 
 advances made in England and on the continent, together with a system of lines, is 
 unquestionably one of the requirements of our day. 
 
 It is sufficiently obvious, and generally allowed by practical men, 
 that the old books which have been so long in their hands are, in various respects, 
 extremely defective. Although many of these present the most recent improvements 
 known to their authors at the periods of publication, and contain much which is still 
 exceedingly valuable, few well-informed persons will venture to assert that the great 
 impulse latterly given to the science of construction, the extensive projects carried 
 out, and the admirable modifications effected in minor details, do not call for the 
 production of a new and comprehensive work. 
 
 In England, the rapid progress during the last few years of the 
 railway system and the vast development of commerce and manufactures have stimu- 
 lated research* and ingenuity, thus leading to advances in the theory and modifications 
 in the practice of Carpentry and Joinery. We stand, in truth, on the vantage-ground 
 of ages. All the various civilizations of past times have contributed to produce that 
 great result, — the actual present. Never, perhaps, in all history were the records 
 of those exertions which constituted the practical wisdom of people long buried 
 in dust and oblivion so ransacked to utilise our own efforts. But while searching 
 dili gently into antiquity we are in danger of underrating contemporary labours. 
 
9 
 
 PREFACE. 
 
 One of the principal objects of this serial will consist of an endeavour to diffuse 
 widely an accurate knowledge of many constructions of our own age, many “ in- 
 dustrious observations, grounded conclusions, and profitable inventions and dis- 
 coveries.” It must be acknowledged, we think, that there is not in this country 
 an appreciation commensurate with their importance of the thought and ingenuity 
 latterly displayed on the continent of Europe. The French and Germans especially 
 have greatly distinguished themselves, not only in the production of numerous 
 valuable books, but also in the execution of works equally remarkable for their 
 novelty and usefulness. In the former respect, indeed, there can be no doubt 
 that the French nation stands unrivalled. Professor Emy’s treatise on Carpentry 
 is the most elaborate which has ever appeared; and the volumes of Krai ft, 
 Rondelet, Blouet, Scanzin, and other accomplished men, are suggestive of in- 
 formation of the utmost value to many who are masters neither of the language nor 
 of the opportunity and outlay essential for its acquirement. 
 
 The aim of this Encyclopaedia is, therefore, to condense in one Text- 
 Book, of such moderate size as to be within the reach of all, results of experience 
 abroad and in England; thus truly constituting the most available and recent compen- 
 dium of the elementary principles and multifarious details in which the Carpenter and 
 Joiner are concerned. At a comparatively small cost, the student will be enabled to 
 obtain many of the advantages derivable from large and expensive works; and there 
 may be found precepts of which it is useful for the experienced professional man to 
 be reminded. Detailed illustrations of the latest improvements will be laid before many 
 hitherto deprived of an acquaintance with them, more especially that extensive and 
 most useful class to whom such subjects are of the very highest interest and import- 
 ance, and without whose practical aid no works could possibly be executed. With 
 this purpose kept steadily in view, every valuable production will be carefully 
 consulted, and the Editor’s personal observations in France, Germany and Italy 
 introduced. That clearness, so often neglected, which may enable the humblest 
 intellect to comprehend the principles laid down will be especially studied; and 
 it is hoped that, in this respect, the book will be found more valuable than many 
 of its predecessors. 
 
 In more respects than one, the Editor of an Encyclopaedia of (Car- 
 pentry and Joinery stands in a position of peculiar difficulty. He is exposed to the 
 criticism of two classes, the theoretical and practical men, who often look at the same 
 subject from very different points of view. The former are but too apt to regard the 
 hitter :is having ideas limited to routine operations ; while the practical man applies the 
 term theorist with something akin to a feeling of contempt. There is, however, a certain 
 
PREFACE. 
 
 3 
 
 neutral ground which it is proposed to occupy, — that spot where an intimate con- 
 nection takes place between the workman and the architect or engineer, the owner 
 of capital and those who derive support from that capital, and without whose co- 
 operation no progress whatever could be made. Notwithstanding this book treats 
 principally of practical operations, the theory of construction and the valuation of 
 materials and workmanship must not be altogether ignored. We desire to illustrate 
 continuously the relation between theory and practice. These are, so to speak, links 
 of a chain which, if separated, no, longer save the operative from absurd failures, or 
 support the theorist with facts to uphold his conclusions. It is hard to please both 
 classes. But, as we address chiefly practical men, as a combination of theory and 
 practice is essential to success, and as no one is qualified to form an opinion on 
 particular matters relating to an art or science before he has taken a survey. of its 
 totality, such parts of the theory as are necessary to comprehend details o£ con- 
 struction will be embodied in the work. 
 
 Our general plan will be fully explained in the first chapter. This is 
 a matter of justice to subscribersfcvho are solicited to take about thirty parts of a serial; 
 and it is only requisite to mention here that we shall aim at that precision, order, and 
 unity of arrangement which obviate the necessity of trespassing on the patience of 
 the reader. Practice comes before theory in the development of many branches of 
 knowledge, and the workman commences his labours at the bench ; but when an art 
 is matured and the theory defined, then, if the head is always to guide the hand, the 
 study of principles should, in a book, precede their practical applications. 
 
 In the series of Practical Examples instances are included of works 
 executed from the designs of some of the most eminent men in England and abroad; 
 and our best thanks are due to those architects who have, with such enlightened and 
 disinterested liberality, permitted the publication of copies of their working drawings. 
 The illustrations generally will be drawn to scales sufficiently large to serve as 
 practical guides; and they will be coloured, whenever it is deemed requisite, hi order 
 to facilitate their ready comprehension. 
 
 To the plates of Lines considerable study has been devoted. They 
 are contributed, together with the descriptions and the second chapter, by Mr. Henry 
 J. Collins, whose practical experience will, it is trusted, be an ample guarantee, alike 
 for the correctness of the principles defined and the simplicity of the methods recom- 
 mended. That intricacy in the drawings and the complicated explanations of them in 
 which many foreign authors have indulged, from the not altogether reprehensible aim 
 at extraordinary elaboration, will be carefully avoided. A glance, for instance, at the 
 work of Emv is enough to frighten many students and cause them to despair of compre- 
 
4 
 
 PUR PACK. 
 
 bending subjects which mav have appeared sufficiently clear to the veteran professor. 
 To enlarge on the importance of Practical Geometry is quite needless. Although a 
 lomr separate treatise upon it is not proposed, such advanced problems will he pre- 
 sented as are indispensable, the reader being supposed to be acquainted with the 
 regular definitions of points, lines, and the more elementary information. 
 
 We are quite aware of the severe criticism which it is probable this 
 Encvclopanlia will have to sustain. That labour which is attendant on the careful col- 
 lation of numerous publications will not be spared; for there is no book of this de- 
 scription which does not contain more of the results of former experience than what, 
 strictly speaking, is entirely original. At the same time, our own studies and practical 
 observations have been directed with a special view to give, not merely the weighty 
 opinions of others, but also to add, in however feeble a degree, to the general stock of 
 information and to facilitate its acquirement. The work must go forth to the world 
 in the hope that it will contain more to be approved than to be condemned, and that 
 whatever utility it may possess as a whole will be considered by an indulgent public 
 when noting defects ill the parts. • 
 
 K L. T. 
 
 » 
 
FIRST DIVISION. 
 
 CHAPTER I. 
 
 GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 MODES OF ACQUIREMENT AND PLAN OF THE WORK. 
 
 When commencing the study of that part of any useful art which is to be 
 learned from books, it is obviously of great importance to proceed in an orderly manner, and this 
 chapter is therefore devoted to the consideration of the mode which is best calculated to further 
 the proposed end without unnecessary waste of labour. A general view of the subjects of the 
 Encyclopaedia is thus involved; and it is proposed to treat; — - first, the general nature of the 
 system to be adopted in the acquirement of a knowledge of carpentry and joinery; secondly, 
 the union of theory and practice; and thirdly, the plan of the work, preceding its settlement 
 with a brief glance at other modes of procedure and of the reasons which have prompted 
 a departure from them. 
 
 In general education we begin by teaching that alphabet which may be stated 
 as at once the material on which our knowledge is erected and the medium of its communication. 
 The writers who have hitherto given to the world works on carpentry and joinery have, however, 
 rarely deemed it essential to observe that order in presenting the details of their subjects which 
 so greatly facilitates their mastery by the student. But it is only doing many of them simple 
 justice to admit that they have written with such ability and added so greatly to the information 
 which previously existed that the deficiency of method in their treatises is of slight import when 
 we counterpoise the weighty character of the matter wherever it may be found. It is never- 
 theless our ambition to endeavour to put the right thing in what is conceived to be its appro- 
 
it 
 
 GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 priate place. We think, for instance, it is very desirable that the materials with which an 
 artisan has to deal, and without which his vocation disappears, should be described before pro- 
 ceedin'; to the principles of construction; but, on examination, it will be found that the pecu- 
 liarities of the former have been treated by some authors at the end ot their works, .by others 
 in the middle, and by very few towards the beginning. 
 
 Before, however, materials can be applied by the carpenter and joiner with 
 economy and scientific precision, a general knowledge of the tools employed is certainly essential. 
 Prior also to commencing the serious labour of acquiring an elaborate art, the student will probably 
 be interested in having presented before him an outline, at least, of its origin and progressive 
 advance. It is also well understood that, in the arts now under consideration, little can be done 
 without some medium of expression in the form of representations on flat surfaces of the works 
 to be executed. An early comprehension, therefore, is necessary of the general principles which 
 guide the practical delineation of what are termed working drawings, a knowledge of geometry 
 and projection being thus essential. There is a special class of drawings, more strictly working 
 drawings than many others, technically, although not with very strict scientific precision, called 
 lines, the understanding of which and the ability to make them are of great importance to 
 the operative. These several matters appear sufficiently preliminary to demajid consideration 
 before starting with the series of subjects, which, taken with the above, constitute altogether the 
 explanations in words and by drawings of the several matters which it is the aim of this Ency- 
 clopaedia fully to illustrate. 
 
 There are, we should mention, two manners in which knowledge can be ob- 
 tained from books. First, the method of acquiring and subsequently advancing a new science, by 
 studying results in the order of time in which they were discovered or invented, together with the 
 way in which this was done, when, of course, the tod of classification is proportioned to their number 
 and complexity. So, when considerable advances have been made and there are ample materials 
 allowing the deduction of a theory, the above mode is really no longer suitable to the purpose. 
 The proper system then consists in presenting the results in their right order, independently of 
 the period of their discovery, to a student placed at the correct point of view to apprehend 
 them. This is called the scientific method in contradistinction to the historical first mentioned. 
 As the former supersedes the latter when an act is advanced from its state of immaturity to 
 some degree of completeness, a learner, with but a very ordinary intellect, may be put on an 
 eminence raised by the labours of men of genius who could not in their day rise to the sum- 
 mit: through coming last he thus commands, by a moderate amount of toil, a full view of the 
 rich results which in the course of centuries have been gradually accumulated. The scientific 
 will, of course, be the system followed in this work; but an idea may be formed of the historical 
 from the chapter on the progress of carpentry and joinery, which, although it is but a sketch 
 and we have not proposed to explain the presumed train of thought of the early inventors and 
 thus show how progress was made, the incidents, so far as they illustrate this being mentioned, 
 will suggest the probable development to those who will think for themselves. 
 
 It may possibly be urged that the usual form of an Encyclopaedia is to 
 arrange the contents alphabetically. But our object is to present in an uniform, progressive order 
 die elementary or simple and the more complicated subjects. This is, in fact, the true encyclopae- 
 
GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 7 
 
 (lical rotation.. An alphabetical order is no order at all, so far as the several matters are in them- 
 selves concerned, being dependant on the arbitrary influence of the first letters of words, which latter, 
 although they stand for ideas, have nothing in their commencing letters in common with the ideas; 
 and suclran arrangement is confusing to a person who wishes to acquire a consecutive acquaintance 
 with the principles and practice of an art. By the method we adopt the mutual relations of the 
 various parts will, it is hoped, he rendered clear; and the glossary given at the end of the work 
 will secure that advantage of the dictionary form which aids the acquirement of technical terms. 
 
 The summary of the classification to be given expresses in some degree the 
 divisions of the arts treated in their hearings with reference to one another, and to this great impor- 
 tance is attached. For, before concentrating his attention on any particular branch of a field of 
 inquiry, the learner should be enabled to take, as it were, a bird’s-eye view of its main ramifications. 
 In this manner it is proposed to obviate the idea too readily formed by the novice that his vocation 
 is more complicated and that there is greater difficulty in its mastery than is really the case; 
 while, at the same time, this effort is desirable inasmuch as it lessens the discouragement 
 often induced in one who knows that he is making some progress, but is doubtful where and 
 with what ideas he will finally terminate his course. To diminish unnecessary exertion is a 
 great object; and it is conceived that this end will be promoted by considering early the theory 
 of the useful arts treated, thus laying the. foundation which is essential in order to comprehend 
 the practice. Although the greafer part of this work will be occupied with the consideration of 
 practical matters, if the workman is to be enabled To give a reason for his proceedings, it is 
 necessary to consider the theory which governs them; and, as this is so strangely undervalued 
 by many, we deem it essential to make a few observations which may tend to dissipate the 
 prejudices existing on the subject. 
 
 An Encyclopedia of Carpentry and Joinery has for its proper scope the illu- 
 stration of the application of scientific principles to trades involving manual dexterity. The scien- 
 . tific carpenter belongs to a class standing between the theorist and the operative. He does not work 
 so much to advance science as to apply existing knowledge to actual requirements. The necessity 
 of some acquaintance with theory is obvious even from this consideration. But, as it has been 
 truly remarked, “a forbidding distance and awkward jealousy seem to subsist between the 
 theorists and the practical men engaged in the cultivation of mechanics in this country;” and 
 we deem it very desirable “to shorten this distance, and to eradicate this jealousy.” Every truly 
 practical man must admit his debt to science, which, as Tredgold observes, “substitutes certainty 
 for uncertainty, security for insecurity; it informs him how to raise the greatest works with con- 
 fidence, and how to produce stability with economy, or, in its own language, how to obtain a 
 maximum of strength with a minimum of materials.” He well knows that a knowledge of 
 scientific principles enables him to judge better respecting alleged improvements in practical 
 matters and of the utility of variations from usual forms. To succeed in practice it is essential, 
 either to have defined notions of the theory, or else a sort of intuitive natural acqaintance with 
 it, guiding our efforts to a successful result. In fact, experience and abstract speculation must 
 be combined. Taking, for instance, so apparently simple a matter as the form of the joint at 
 the foot of a rafter, it involves principles often entirely overlooked in the workshop, to say 
 nothing of the numerous other joinings in carpentry. Again, with reference to the general 
 
s 
 
 GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 outlines of framed work, a carpenter who has studied roofs without having previously mastered 
 the theory of the action of forces wants one of those fundamental requirements without which 
 he cannot hope to make much progress. It is not sufficient to assert that a roof will stand; the 
 question is why will it stand? Will it stand as well or better with less materials, or with a 
 different arrangement of them, and for what reason? It is easy to make a structure sufficiently 
 strom:'. The works of peoples in a comparatively early phase of their civilization evidence this 
 truth. Their roofs, to keep to our example, are exceedingly massive, so massive that they are 
 too strong, — absurdly strong. The difficulty is to make them weak enough; not too weak, for 
 this is as great a defect as a superabundance of strength. “The great caution,” says Ware, “is 
 that the roof be neither too massy nor too slight, for in architecture every extreme is to be 
 avoided; but of the two the overweight of roof is to be more regarded than too much lightness. 
 He will do the most acceptable service to his profession who shall show how to retrench and 
 execute the same roof with a smaller quantity of timber.” The medium is what is required; and 
 this can only be settled by one who combines experience Vitli theoretical knowledge. Practice 
 is often the l’esult of what existed years ago in books; and we must not lose sight of the credit 
 due to those who contributed to develope the theory. 
 
 As art is simply the practical application of the principles of science, to begin 
 a work on vocations so matured as those of the carpenter and joiner with the practice, and then go 
 hack to the theory, seems to us a species of retrogression. Th*e workman of course commences 
 his labours in the workshop; but, in treating an useful art in a book, by starting with the theory 
 the dependance of the practice upon it is rendered clear. Yet, on glancing at works similar to 
 this, it will be observed that such a method is the exception instead of the rule. The valuable 
 treatise by Emy commences with an account of tools, and then, materials are considered before 
 the several details in which they are employed; but placing the theory of the action of forces 
 at the end of the two volumes diminishes, in our opinion, the praise that is justly due for the 
 otherwise excellent arrangement. It is to be regretted that the work by Hassenfratz was never 
 completed, as it promised to exhaust the subjects, while, at the same time, they were treated in 
 an orderly manner; but the manual on carpentry by Le Page is as remarkable fox' the method 
 displayed as for the compression of information within so small a space, it being by far the most 
 complete treatise for its size which we have ever perused. Materials, the action of forces, and 
 the several descriptions of works, are consecutively considered, but practical geometry is placed 
 at the end. Ivrafft, as is well known, merely described his .elaborate plates and the executed 
 examples supplied by contemporary architects; but we must not dilate upon the numerous 
 foreign writers. Turning to English books, the celebrated article on carpentry in the Encyclo- 
 paedia Hritaiinica, by Professor Robison and Dr. Thomas Young, is as remarkable for the terse- 
 ness oi the language as the mode of treatment. Materials being elsewhere considered, the 
 article starts with an abstract of the doctrine of passive strength, leading to propositions relating 
 to flexure. 1 he elements of carpentry are next considered, including the action of forces, then 
 the various joinings, and finally illustrations of executed examples. The article on joinery by 
 1 rcdgold opens with some historical remarks, explaining next working drawings, projection, the 
 development of surfaces and miscellaneous problems, before the several practical matters; but 
 materials are placed last. '1 he treatise on which the last named author’s reputation mainly 
 
GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 9 
 
 rests consists of ten sections, all extremely valuable, but the book is not distinguished for 
 method, the structure and classification of woods forming the conclusion. The earlier works 
 of Nicholson consist chiefly of a collection of problems, but he afterwards adopted the divi- 
 sions of descriptive, mechanical and constructive carpentry. By descriptive he meant the modes 
 of delineating on planes the lines for different kinds of work by the rules of geometry; by 
 mechanical the consideration of the action of forces, the strains to which timbers are exposed, 
 and the relative strength of various framings; and constructive included the manner of reducing 
 timber to different forms and joining them to produce a construction in accordance with the 
 design. There is great merit in this classification; but it appears to us not incapable of improve- 
 ment. The terms descriptive, mechanical and constructive, seem somewhat vague and wanting 
 in scientific precision. They arc all phrases which may be applied with more or less latitude 
 to most of the operations in carpentry; for, in treating them in a book, it is a description 
 throughout; and mechanical and constructive intwine closely with one another. Two pieces of 
 timber cannot be joined without the combination being at once mechanical and constructive, 
 while the explanation is descriptive in a different sense from that intended by Nicholson. We 
 may treat of the principles of mechanics applied to construction, as our author has done, but 
 theory of construction is presumed to be a more appropriate word than mechanical carpentry; 
 and the application of the theory to roofs, domes, etc. will be shown under these headings. 
 Again, in the article on lines, which are what Nicholson means by descriptive carpentry, the 
 general principles which guide their delineation will be explained, and the practical application 
 of these principles distributed throughout the work. Our aim is to determine the mutual 
 dependanee of the several branches of carpentry and joinery, and to class them so that the 
 rational consideration of one shall follow another which precedes it, and be, in its turn, a 
 foundation for subsequent advances. The generality and simplicity of the various matters, or, 
 in some instances, their degree of difficulty or importance, determine the order in which they 
 should be taken; and it is surprising with what facility we then come to the different branches 
 of enquiry. That there are as many schemes as writers is partially true; but to continue a plan 
 believed to be defective is as wrong as the attempt, however unsuccessful, to eliminate another 
 is unquestionably a step in the right direction. We are quite aware that, in treating carpentry 
 and joinery, it is impossible to devise a method which shall be truly and absolutely scientific. 
 There must be something artificial and arbitrary about it, and an approximation only is to be 
 obtained; as the various matters are, from their nature, too intimately mixed to be completely 
 separated. The parts of roofs are often analogous to those of trussed floors and partitions, and 
 so on ad infinitum. Still the theory of framing applies to all and will be kept separate. 
 
 ii 
 
10 
 
 PLAN OF THE WORK. 
 
 FIRST DIVISION. 
 
 1. GENERAL VIEW OF CARPENTRY AND JOINERY. 
 
 2. INTRODUCTION TO THE LINES. 
 
 3. TOOLS. 
 
 4. SKETCH OF THE PROGRESS OF CARPENTRY 
 AND JOINERY. 
 
 SECOND DIVISION. 
 
 MATERIALS. 
 
 1. ON TIMBER GENERALLY. 
 
 2. DESCRIPTION OF KINDS. 
 
 3. FELLING, SQUARING AND TRANSPORT. 
 
 4. ON DECAY. 
 
 5. PRESERVATION OF TIMBER. NATURAL AND 
 WATER SEASONING. 
 
 fi. APPLICATIONS OF HEAT. 
 
 7. MISCELLANEOUS MODES OF SEASONING. 
 
 S. ARRANGEMENTS OF STRUCTURES TO PREVENT 
 DECAY. 
 
 THIRD DIVISION: 
 
 THEORY OF CONSTRUCTION. 
 
 1. GENERAL OBSERVATIONS. 
 
 2. PRINCIPLES OF FRAMING. 
 
 3. PIECES PULLED IN THE DIRECTION OF THEIR 
 LENGTH. 
 
 4. PIECES PRESSED IN THE DIRECTION OF THEIR 
 LENGTH. 
 
 5. HORIZONTAL PIECES SUPPORTED AND FIXED 
 AT ONE AND BOTH ENDS. 
 
 fi. INCLINED PIECES. 
 
 7. CURVED PIECES. 
 
 FOURTH DIVISION. 
 
 PRACTICAL CARPENTRY. 
 
 1. GENERAL OBSERVATIONS. 
 
 2. JOININGS. 
 
 3. FLOORS GENERALLY. 
 
 4. SINGLE, DOUBLE, AND FRAMED FLOORS. 
 
 5. PARTITIONS. 
 
 fi. ROOFS GENERALLY. 
 
 7. COVERINGS AND INCLINATIONS, 
 fi. ORDINARY FORMS OF ROOFS. 
 
 !». CURB ROOFS. 
 
 10. ROOFS ON THE PRINCIPLE OF THE ARCH. 
 
 11. ROOFS WITH TIMBER AND IRON COMBINED. 
 
 12. GOTHIC ROOFS. 
 
 13. DOMES. 
 
 14. BRACKETING, GROINS, SOFFITS, NICHES, etc. 
 
 15. CENTERING, 
 lfi. BRIDGES. 
 
 17. SCAFFOLDS AND KNOTS. MACHINES, etc. 
 
 18. ACCESSORY CONSTRUCTIONS. 
 
 FIFTH DIVISION. 
 
 PRACTICAL JOINERY. 
 
 SECTION I. 
 
 1. GENERAL OBSERVATIONS. 
 
 2. FRAMING AND GLUEING-UP. 
 
 3. MOULDINGS AND PROFILES. 
 
 SECTION II. 
 
 FIXED JOINERY. 
 
 1. FLOORS. 
 
 2. PARTITIONS, WAINSCOTING, SKIRTINGS, etc. 
 
 3. DOOR AND WINDOW FRAMES. 
 
 4. STAIRCASES AND HANDRAILS. 
 
 5. SKYLIGHTS. 
 
 fi. SHOP-FRONTS. 
 
 7. SUNDRY WORKS. 
 
 SECTION III. 
 MOVEABLE JOINERY. 
 
 1. DOORS. 
 
 2. SASHES. 
 
 3. SHUTTERS. 
 
 4. HINGING. 
 
 SIXTH DIVISION. 
 
 1. ON SPECIFICATIONS. 
 
 2. MEASUREMENT AND VALUATION. 
 
 APPENDIX. 
 
 CONCLUDING OBSERVATIONS. 
 GLOSSARY OF TECHNICAL TERMS. 
 INDICES. 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 11 
 
 The descriptions of the plates of “Practical Examples” and “Lines” will he 
 interspersed throughout the work, virtually not interrupting the progression sketched; the student, 
 who wishes to follow the filiation of subjects having only to turn over the pages devoted to the 
 above illustrations. This arrangement is, in fact, necessitated by publishing considerations; but we 
 should mention, that, although each plate, with some exceptions, will be described under a 
 separate heading, many will be alluded to when treating the general subjects, such as roofs, etc., 
 to which they relate, note of which is made in the index, so that the reader will be enabled 
 to refer to whatever information he may require. The second chapter, including such problems 
 in practical geometry as have special reference to the operations of the carpenter and joiner, 
 embraces projection, and the general principles essential to be understood before considering 
 the individual cases of lines relating to every description of works, the importance of staircases 
 and handrails necessitating their particular and lengthened consideration. 
 
 In the concluding observations at the end of the work a list of the contri- 
 butors and the authorities consulted will be given; and having now at some length pointed out 
 and prepared the ways, we shall at once enter upon them. 
 
 CHAPTER II. 
 
 THE LINES OF CARPENTRY AND JOINERY. 
 
 BY IIENRY J. COLLINS. 
 
 If we direct our attention to the important structures which the carpenter 
 has to erect, or to the elegant and elaborate workmanship of the joiner, it will be evident that, to 
 be proficient in their- business, these workmen have to be familiar with many of the principles and 
 processes of geometrical science. Without a knowledge of this kind, some of the most simple 
 examples of such works as groins, roofs, centering, bridges, viaducts, etc., would present insurmount- 
 able difficulties to the carpenter; and the joiner, if deficient in this respect, would not be able to 
 execute with exactness the varied and novel forms which are continually required. Such work, 
 by way of example, as that which is at once circular or elliptical on plan and in elevation, many 
 forms of skylights and domes, and especially the construction of staircases and handrails, must, 
 of necessity, require an acquaintance with modes of applying geometrical principles. 
 
 It is, of course, in the workshop and on buildings that practical skill in using 
 tools, judgment as to materials, and an acquaintance with constructive details generally, must be 
 gained. But there is also knowledge to be acquired which the workshop or the building will 
 not afford the opportunity for attaining. This may be obtained from books in hours of leisure, 
 especially that which appertains to the various geometrical methods necessary in the arts now 
 under consideration. 
 
 The department of geometry which relates more particularly to the various 
 mechanical arts has received more attention on the continent than in this country. In France 
 especially it has occupied the attention of many eminent scientific men, and has been made 
 a subject of independent study, as a branch of abstract science, under the name of Descriptive 
 Geometry. 
 
12 
 
 T1IK LINES OF CARPENTRY AND JOINERY. 
 
 L. L. Vallee defines descriptive geometry to he: — “The science which 
 teaches the means of representing with exactness geometrical proportions, and to make in these 
 proportions all possible delineations.” In another place, the same writer remarks: — “All our ideas 
 are not of such a nature that they can be communicated by means of spoken or written language. 
 This is particularly the case with regard to those which relate to the form and position of bodies; 
 so much so that, to assist us in explaining our meaning, it is necessary to have recourse to 
 representations which address themselves to the eye.” With the same ideas, the celebrated 
 Gaspard Monge, speaking with reference to descriptive geometry, says: — - “It constitutes a 
 language necessary to the man of genius who conceives a project, to those whose task it is to 
 direct the carrying of it out, and to those who have to execute the different parts.” With the 
 intention of exactly defining descriptive geometry, Monge remarks: — “It has two objects; the 
 first is to teach the methods by which we may represent on a sheet of paper which has only 
 two dimensions, viz. length and breadth, any object which has three, viz. length, breadth and 
 thickness. The second object is to show how we may ascertain, from an exact representation, 
 the true form of bodies, and deduce all the truths connected with their forms and positions.” 
 
 In the schools of France descriptive geometry receives a large share of 
 attention. W hat is taught embraces all that relates to those general principles and methods which 
 are universal in their nature. The special applications naturally follow; as those to carpentry and 
 joinery, shipbuilding, masonry, and other arts. So much of it as relates to the operations of the 
 carpenter and joiner, will be explained in the articles on projection and development in the 
 present chapter, and as Various methods have to be illustrated in the course of the work. 
 
 It is the case with studies of this nature that great advantage results from 
 thoroughly mastering the elementary principles. If properly chosen, the introductory problems have 
 a positive value for their own sake, but the studying them until they are perfectly comprehended 
 has the additional utility that it serves to prepare the mind for easily understanding the most 
 intricate examples. In the present instance, it is recommended that the part of this chapter 
 which relates to Projection and refers to Plates 3, 4, and 5, should be carefully gone through 
 ami well understood, and it is believed that the learner will then find no difficulty with any of 
 the plates that afterwards appear. Soffits, groins, roofs, etc., will be so treated in sets of plates 
 that when the learner has mastered the problems in projection he may at once proceed to the 
 study of any particular department. lie should then go through the series of examples illus- 
 trating t lie subject he has chosen, and these will be so arranged in each case that he will begin 
 with the most simple and proceed gradually to the more difficult problems. There will be 
 illustiated where required, some methods that might have been appropriately included in the 
 introductory chapter, but which it has been thought will be more useful if placed by the side 
 of their practical applications. 
 
 It may be well here to allude to the great assistance the learner may derive 
 in hi.- fii.-t studies from modelling any solid forms that may appear to present difficulties to his 
 mind. ( onnnon soap has been used for this purpose, on account of the ease with which it may be 
 'in to un\ nquired shape; but the carpenter, with his tools at hand, will find a piece of pine or 
 some other wood the most suitable material. When a question arises which relates to the 
 development of the surface of any solid, it can readily be made the subject of experiment. 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 13 
 
 If a representation of the solid has been modelled, by bending a piece of thin paper over any 
 part of it, the development of that part can be readily tested. Even when no particular difficulty 
 is felt, it will often be found that doing this will render the whole matter so perfectly clear and 
 simple that the learner will be amply repaid for the trouble be may have taken. It is the more 
 desirable to arrive at a thorough comprehension of the principle on which any method depends, 
 because, when this has been done, the workman becomes able to vary his mode of procedure to 
 meet special requirements, and thus often save much labour. 
 
 Our treatment of the lines will commence with a selection of problems in 
 practical geometry having particular reference to the requirements of the carpenter and joiner, and 
 which may he regarded as supplementary to what may be met with in the ordinary introductory 
 works on that subject. Projection and development will be next considered, and we shall 
 then proceed to illustrate soffits, groins, roofs, domes, skylights, sashes and frames, mouldings, 
 columns, staircases and handrails, etc. 
 
 In concluding these introductory observations, we will only further remark 
 that the example of a predecessor will not be followed in one respect; for we shall not ostenta- 
 tiously claim for every arrangement that may be thought to be in the slightest degree an improve- 
 ment , an exclusive merit for the invention. The results of experience and careful observation 
 and study will be given, and it will be left for others to judge whether this portion of our work 
 is an useful addition to what has already appeared. 
 
 MODES OF DESCRIBING ARCS OF CIRCLES. (Lines. Pi.ate 1.) 
 
 It is very often necessary to describe arcs of circles, and it is requisite 
 that the carpenter should he familiar with various methods, in order that he may be able to use 
 the one best suited to any particular case. The size of the work, its situation, or the means at 
 hand may render one method much more convenient than any other. 
 
 The span and rise of any arch being given, to find the centre from which to describe 
 
 the arch. (Fig. 1 .) Let A B be the span of the arch, and C D the rise. Produce the centre 
 
 line D C to e. From the centres D and B, with any radius, describe two arcs cutting each 
 other at / and g. Through the intersections / and g, draw a line cutting the line D e at h, 
 which is the centre from which to describe the arch A D B. 
 
 To describe an arc of a circle through any three given points. ( Fiq . 2.) Let A, B, C, be 
 
 the three given points. From the centres A and B, with any radius, describe two arcs cutting 
 
 each other at d and e. From the centre B and C, with any radius, describe two arcs cutting 
 each other at / and g. Through the points d, e, and /, g, draw lines intersecting at h. The 
 point h is the centre from which to describe the arc required. 
 
 To find the, centre ofi an arch of any rise and span, by means of a bevel. {Fig. 11.) 
 Let A B be the span and C D the rise. Continue the centre line C D to q and draw the straight 
 line A D. With a bevel take the angle ADC. From A draw the line A fi, making the angle 
 equal to the angle ADC. The intersection f of the lines A f and D e is the centre 
 from which to describe the arch A D B. 
 
14 
 
 TUI' LINES OF CARPENTRY AND JOINERY. 
 
 To draic an arc of a circle to any span and rise icith rods (Fry. 4.) Let A B be the 
 
 span, and C I) the rise. Let two rods or laths, as I) e and D /, be prepared, the length of 
 
 each to be not less than the span. Let them be fastened together at D, and, to keep them 
 steady in the position shown, let them be tied together by a third piece at y h. Drive a nail 
 or pin in at A, and also one at B. If the rods be kept steady against the pins at A and B, and 
 at the same time moved, so that a pencil held at the point D goes from I) to A and afterwards 
 from D to B, a true are of a circle will be described. 
 
 To draw an arc of a circle to any span and rise, hy means of a fiat trianyle. ( Fiy . 5.) 
 
 Let A B be the span and C D the rise. To obtain the form of the triangle: draw the 
 
 straight line I) B (Fig. 5.), and from D draw the straight line D c, parallel to A B and equal 
 to D B. Join e B. The triangle eDB is the one required, and it has to be. made of wood or 
 some other suitable material of a thickness proportioned to its size. The mode of using it is ex- 
 plained by Fig. ■’> a. The difference between this method and the one last described is, that in 
 this case three pins are required, viz. at A, D and B, instead of only two as before; and the 
 triangle must be shifted, after describing the arc from A to D, so that it touches against the pins 
 1) and B, to describe the remainder of the arc from D to B. 
 
 To describe a, semicircle, by means of intersectiny lines. ( Fiy. 6.) Let A B and C D be 
 the two diameters. Draw the lines ef,fy, yh, and he, parallel and equal to A B and CD. 
 Divide Ac, B /’, A i, and i B, each into a similar number of equal parts, in this case say five as 
 shown. From the point C draw the lines Ci, C>, C;t, and C 4. Then from the point D and 
 through the points i, - 2 , :t and 4 in the diameter A B, draw lines respectively intersecting those 
 of the corresponding numbers as shown. These intersections will be points in the circumference 
 of the semicircle, which has to be drawn through them. 
 
 Jo describe, an arc of a circle, by means of intersectiny lines (Fiy. 7.) Let A B be the 
 chord of the arc, and C D its versed sine. Through the point C draw the line ef parallel to 
 A B ; and from the points A and B draw A y and B h parallel to C D. Draw A C and B C, 
 and from the points A and B draw Ac and B/ perpendicular to AC and B C. Divide AD, 
 c C, and Ay, each into any similar number of equal parts, in this case say five, as 'shown. From 
 the point C draw the lines, Ci, C >, C t, and C i. Then from the points i, 2 , :i, and 4, in 
 the line AD, draw lines towards the corresponding points in the line e C, and intersecting re- 
 spectively the lines Ci, C 2 , Ci, as shown. These intersections are points in the required arc. 
 Repeat the process just described for the opposite half of the arc. Draw a line through all 
 the points of intersection thus obtained, and the whole will be completed. 
 
 Instrument for drawing arcs of circles, described by Dr. Young (Fig. 8.) In Dr. Thomas 
 ^ 01 mg’s “Lectures on Natural Philosophy and the Mechanical Arts” published in 1807, there 
 is mentioned a contrivance for describing arcs of circles which may be serviceable for some 
 purposes. It consists of a thin piece of elastic wood a a, which is bent to any required degree 
 of curvature by the action of the screw h in the centre, while the ends bear against the small 
 rollers cc. To answer properly it should be thicker in the middle than at the ends, and the 
 degree of tapering should be determined by experiment for each instrument. If made every 
 where of such a thickness that it assumes a circular form when in its utmost state of flexure, 
 it will retain a similar shape, without sensible error in every other position. 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 15 
 
 MODES OF DESCRIBING ELLIPSES. (I jines. Plate 1.) 
 
 With reference to the various modes that may he adopted for describing an ellipse, 
 it is important always to recollect that the true figure is of such a nature that no two parts 
 are similar, for ever so short a distance, except when on opposite sides. The curve contin- 
 ually changes from the flatter part of the sides to the quicker curve of the ends. It will 
 therefore be perceived that any mode of drawing an ellipse by means of arcs of circles forming 
 part of the curve must be essentially faulty in principle; and it will be found that the figure so 
 produced is very imperfect in its form and wanting in the gracefulness of curve which charac- 
 terises the true ellipse. A mode of describing a figure somewhat similar to an ellipse with arcs 
 of circles is explained, but all the other methods are to be preferred. 
 
 To describe a figure nearly similar to cm ellipse, with arcs of circles from four centres. 
 (Fig. 9.) Let AB be the transverse, and CD the conjugate. From the point A in the trans- 
 verse set off A e, equal to C /. Divide the distance ef, into three equal parts. From e towards 
 A mark the distance eg equal to one of these parts; and make fh equal to fg. On the base 
 gh describe the equilateral triangle gib, and produce the sides respectively to lc, k. From 
 the centre i, with the distance i D describe the arc /rDf; and from the centres /and g describe 
 the arcs at A and B as shewn in the figure. 
 
 To describe a true ellipse. {Fig. W.) Let AB be the transverse, CD the conjugate, 
 and e the centre of the ellipse. From the point C as a centre, with the radius A e, describe 
 arcs cutting A B at the points f and f. These two points are called the foci of the ellipse. As- 
 sume any point i, in the transverse, between the foci, and then with the radii iA and i B, and 
 from the centres / and f, describe arcs cutting one another at g, g, g, g, which are points in the 
 circumference of the ellipse. By assuming in this way a number of other points in the trans- 
 verse, between the foci, as •->, :t, and i, and describing arcs, a sufficient number of points may 
 be determined in the circumference of the ellipse to accurately define the curve which has to 
 be drawn through them. 
 
 To describe an ellipse, by means of a lath or a narrow strip of paper {Fig. 11.) The 
 following method is especially recommended to notice, as it is perfectly correct in principle, 
 and at the same time simple and available under almost all circumstances. The carpenter would 
 generally use a wooden rod for ellipses of the size he would require ; but by using a narrow 
 strip of paper, the smallest ellipses required on drawings may be described with the greatest 
 accuracy and facility. 
 
 Let A B be the transverse and C D the conjugate. According to the dimensions 
 of the ellipse to be described, let ef g h be a strip of paper, a lath, or a stout rod. Mea- 
 suring from the end e, mark the distance ef, equal to half the conjugate, and eg, equal to half 
 the transverse. Place the lath efgh in any position, so that the point f coincides with some 
 point in the transverse, and the point g with some point in the conjugate. The point e, at the 
 end of the lath, will then coincide with a point in the circumference of the ellipse, which has 
 to be marked by a dot. By continually changing the position of the lath, but at the same time 
 always keeping the points f and g respectively over the transverse and conjugate, a sufficient 
 number of points may be determined in the circumference of the ellipse to accurately define the 
 curve which has to be drawn through them. 
 
16 
 
 THE LINES OF CARPENTRY AND JOINERY. 
 
 To describe an ellipse, by means of a trammel. (Fig. 12.) This method is in principle 
 exactly similar to the one last explained, and if that has been understood the nature of this 
 will be easily seen. Let AB be the transverse and Cl) the conjugate; e,f,g,h, represents 
 the trammel which may be of any convenient size. The dark lines corresponding with the 
 transverse and conjugate represent a groove. The rod i k is fitted, in the same manner as a 
 beam compass, with a pencil and two points, which slide freely and can be fixed in any position 
 by a screw. The points should be equal in diameter to the width of the groove. Fix the pencil 
 in its place at I, and at a distance from it, equal to half the conjugate, fix the point m; also fix 
 the point n, at a distance from / equal to half the transverse. Place the rod as shown in the 
 figure with the points in the respective grooves. By moving the point m along the groove ef, 
 the pencil at / will be made to describe a true ellipse of the dimensions required. 
 
 To describe an ellipse, by means of a string. (Fig. 12.) Let AB be the transverse and 
 C D the conjugate. As in Fig. 10, find the two foci of the ellipse by describing arcs from the 
 centre C, with a radius equal to half the transverse, cutting the transverse at e and /’. Let a pin 
 be driven in at e and also one at f. Then let the ends of a piece of string be tied together, so 
 that when laid over the two pins and stretched tight, it shall form a triangle of which the vertex 
 is at C. If a pencil be held at the vertex of the triangle formed in this way by the string, 
 and if the pencil be moved round, as shewn at g, while care is taken at the same time to keep 
 the string stretched tight, a true ellipse will be described. This mode may be serviceable under 
 some circumstances, as it is quite correct in principle; but the difficulty of keeping a string 
 of any length always stretched to an equal degree of tightness tends to make it a little uncertain. 
 
 To describe an ellipse, by means of intersecting lines. (Fig. 14.) Let A B be the trans- 
 verse and CD the conjugate. Through the points C and D draw the lines ef and g It, parallel 
 and equal to AB. Also through the points A and B draw the lines eg and f b, parallel and 
 equal to CD. Divide Ac, B f, Ai, and i B into a similar number of equal parts, in this case 
 say five. From the point C draw the lines Ci, C-», C:t, and C 4 ; then, from the point D and 
 through the points i, i, i, and i, in the transverse, draw lines respectively intersecting those 
 of the corresponding numbers as shown. These intersections will be points in the circumference 
 of the ellipse, which has to be drawn through them. Repeat this process on the opposite side 
 of the transverse and the ellipse will be completed. 
 
 MISCELLANEOUS PROBLEMS. (Lines. Plate 2.) 
 
 To describe an ellipse round a given rectangle. (Fig. I .) Let ABCD be the rectangle. 
 Draw the centre lines ef, and g h, and from g mark the distance g k, equal to A g. Draw the 
 line A /•, which will be equal to half the transverse, and A l to half the conjugate of the ellipse 
 required. 
 
 I o find the centre and two awes of an ellipse (Fig. 2.) Let ABCD be the ellipse. 
 Draw any two parallel lines, as cp and gh, and through the centre of each of these lines draw 
 the line ik. I he centre of the line ik at l will be the centre of the ellipse. From the centre l 
 «ith any radius describe arcs cutting the circumference of the ellipse at m and n. Draw the line 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 17 
 
 m n, and through l, parallel to m n, draw the line C D, which will be one of the axes. Through 
 /, and perpendicular to C D, draw A B, which will be the other axis. 
 
 Through a given point ivithin an ellipse to draw a concentric ellipse. (Tig. 3.) Let 
 A B C I) be the given ellipse, E the point through which the required ellipse is to he drawn, 
 and E the centre. Draw the semi-diameter A F through the point E. Take any number of 
 points in the circumference as g, C, h, B, etc. and from them draw the semi-diameters, g F, C F, 
 h F, BF, etc. Join A g, g C, C h, h B, etc., and beginning at E, draw lines parallel to A g, etc. 
 as E m, mn, no, op, etc. The points m, n, o,p, etc. are in the curve of the ellipse which has to 
 be drawn through them. 
 
 To draw a line, from any point, perpendicular to the curve of an ellipse. (Tig. 4.) Let 
 A BCD be the ellipse; E, F, the two foci; and G the point from which the line is required 
 to be drawn. Join EG and F G, and bisect the angle EGF with the line hi, which will be 
 perpendicular to the circumference of the ellipse at the point G. 
 
 To draw a line, from any point, perpendicular to an arc of a circle. (Tig. 5.) Let A be 
 the point. Mark an equal distance on each side in the arc, as at h and c; and from the centres 
 b and c, with any radius, describe arcs intersecting at d. Draw the line d A, which will he 
 perpendicular to the arc as required. 
 
 11“ the point is on the extremity of the arc, as at E, mark two equal distances, as at 
 f and g, and from the centres E and g, describe arcs intersecting at It. With the same radius, 
 and from the centre f, describe an arc at i; and from the centre E with the distance f h de- 
 scribe an arc intersecting the last described arc at i. Draw the line i'E, which will be perpen- 
 dicular to the arc as required. 
 
 If the point is out of the circumference, as at K, describe from the centre K, with 
 any radius, the arc Im. From the intersections l and m as centres, describe arcs cutting each 
 other at n. Draw the line nK, which will be perpendicular to the arc as required. 
 
 To describe an hyperbola, by means of intersecting lines. (Fig. 6.) Let there be given 
 in position the double ordinate A B, the diameter D E, and the abscissa C D. Draw D f parallel 
 to AC, and A / parallel to CD. Divide AC and A/’, each into the same number of equal 
 parts, in this case say four. Draw the lines Ei, E i, and E:’>; and from the points i, i, and 
 j in the line A f draw lines to D, intersecting those of the corresponding numbers as shown. 
 These intersections are in the curve of the hyperbola, which has to he drawn through them. 
 
 Tig. 6 a is another illustration of the same curve, in which the width is greater in 
 
 proportion to the height. 
 
 To describe a parabola, by means of intersecting lines (Tig. 7.) Let there be given in 
 position the double ordinate AB, and the abscissa CD. Draw De parallel to AC, and A e 
 parallel to C D. Divide A C and A e, each into any similar number of equal parts, in this case 
 say four. Draw perpendicular lines from the points i, i, and ;t in A C; and from the points 
 i, and 3 in A e, draw lines to D, intersecting those of the corresponding numbers as shown. 
 These intersections are points in the curve of the parabola which has to be drawn through them. 
 
 Fig. 7 a is another illustration of the same curve, drawn by the same method , in 
 
 which the width is greater in proportion to the height. When very flat the curve is nearly 
 
 similar to an arc of a circle. 
 
 in 
 
ME LINES OF CARPENTRY AND JOINERY. 
 
 18 
 
 To describe a parabola, by means of tangents. (Fig. 8.) Let there be given in positio 
 the double ordinate A B, and the abscissa C D. Produce CD to E and make D E equal to 
 CD. Join AE and BE; and divide AE and BE, each into any similar number of equal 
 parts, in this case say eight. Number these divisions from A to E, and from E to B ; and join 
 the points which have corresponding numbers. The lines so drawn will be tangents to the 
 parabola, which has to be described so as to successively touch each line. 
 
 To describe a rampant arch, with arcs of circles. (Fig. 9.) Let A B be the span, and 
 A C the difference of the heights of the springings. It is necessary to have the half of a regu- 
 lar polygon, and in this case, to obtain seven centres, we will use the dodecagon, the half of 
 which has six sides. Divide AC into two equal parts, and describe the semi-circle C e A. 
 Divide the circumference into six equal parts, and produce AB towards D, making AD equal 
 to the extension of the semi-circle. From the centre of the line D B, raise the perpendicular 
 t, i, and draw Ci, and f \ parallel to A B. The point g will be the centre of the semi-circle 
 i, :s, etc. equal to the first. Join the points l, ■>, :t, etc. to form the half-polygon, and prolong 
 its sides respectively to h, i, k, /, m, and u. From the point i as a centre, with the distance l C, 
 describe the arc C h. From the centre 2 , continue the arc to i, and so on in this way from the 
 other centres i, 4, 5, n, and ", until the curve is drawn to B. This method produces a good 
 curve, and although the last arc may not always exactly coincide with B, the error in this 
 respect will be sufficiently trifling for it to be easily corrected. 
 
 To draw rampant curves by intersecting lines, etc. (Figs. 10, 11, 12, and 13.) As the 
 methods for drawing the ellipse and parabola have already been described, these figures require 
 no special explanation. 
 
 Fig. 10. — Mode of drawing a rampant ellipse. 
 
 Fig. I I. — A segment of a rampant ellipse. 
 
 Fig. 12. — A rampant parabola, by intersecting lines. 
 
 Fig. 13. — A rampant parabola, by tangents. 
 
 To draw an octagon, by cutting off the angles of a square (Fig. 14.) Let A BCD be 
 the given square. Draw the diagonals AD and C B, and the centre lines e f and g h. From the 
 centre i, with a distance equal to any half diagonal, as i A, mark on the centre lines the points 
 c, g, f h. Join eg, gf,fh, and he, and klmnopqr will be the octagon required. 
 
 To draw mi octagon in a square, so that an angle of the octagon shall be in the middle 
 of each sale of the square. (Fig. /•>.) Let A BCD be the given square. Draw the diagonals 
 A D and C B, and the centre lines ef, and g h. From the centre i, with a distance equal to 
 halt the width of the square as i g, mark on the diagonals the points k,l,m,n. Join eh kg, 
 g I, etc., and ekgljmhn will be the octagon required. 
 
 P R O J E C T I 0 N. 
 
 GENERAL EXPLANATION. (Lines. Plate 3.) 
 
 A great number of the geometrical methods employed by the carpenter 
 ami joiner are applications, in one form or another, of the principles of orthographic projection, 
 whirl) may perhaps be most readily understood by considering, first, the mode of representing 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 19 
 
 objects as they must actually appear to the eye. Suppose an object, A A Fig. 1 , to be seen from 
 the point E. Its image is conveyed to the retina hy a system of converging rays as r,r,r,r. 
 In the language of geometry, the image on the retina is a projection of the object. Also if a 
 plate of glass, as BB, is interposed between the eye and the object, and its outline, as it ap- 
 pears, traced upon the glass, this outline will be a projection of the object A A. The outline 
 b b is a perspective representation, or a perspective vieu\ The position of the eye, E, is termed 
 the point of sight. The lines r,r,r,r, which include the whole of the outline of the object, are 
 called rays, and taken together they are called a system of rays. As they converge to a point, 
 they are, according to the form of the object from which they commence, called either a pyra- 
 mid or cone of rays. The plane on which the outline is made, represented in this case by the 
 plate of glass BB, is termed the plane of delineation. The plane on which an object is supposed 
 to stand is termed the ground plane. 
 
 The art of producing representations of objects by means of lines or rays 
 converging to the point of sight is so important a department of projection that it is made a dis- 
 tinct subject of study under the name of Perspective. In perspective the representation of objects 
 is absolutely truthful, so far as they appear to the eve. But the apparent dimensions and forms 
 of objects are modified by any change of distance Or position, and therefore, while this mode 
 of representation affords a means by which the appearance of the varied forms of nature and 
 of art may be correctly imitated, it does not serve for the purposes of the mechanical arts. For 
 the works of the architect or engineer to be designed and executed, it is necessary that a system 
 of representation should be adopted which admits of the most accurate delineation of any 
 object, and by means of which the actual position, form, and dimensions of any work may be 
 defined. This is accomplished by substituting for the converging rays that have been just de- 
 scribed a system of parallel rays, as shown by Fig. 2. 
 
 This method of projection by parallel rays is very extensively applied to 
 the purposes of science and in the useful arts. The terms which have been explained in 
 connection with Fig. 1. apply equally to the parts of Fig. 2., except of course that the system 
 of rays no longer forms a cone or pyramid. When, as here shown, the rays are parallel and 
 they are perpendicular to the plane of delineation, the method is termed orthographic projection. 
 
 From what has been explained it will be understood, that strictly the 
 word projection is a general term which includes both perspective and orthographic projection. 
 But in ordinary language the extended signification is not adopted, and the word projection is 
 used to mean only that with parallel rays. 
 
 If the plane of delineation is horizontal and the projecting lines are vertical, 
 the representation produced is called a plan. Thus in Fig. 3. the outline h b on the plane of 
 delineation BB is the plan of the object A A; the actual plan being shown by the figure C ('. 
 If the projecting rays are carried down to the ground plane the figure produced is a plan simi- 
 lar to that just described, but it is also alluded to as the “seat of the object in the ground plane.” 
 
 If the plane of delineation is vertical and the projecting rays are hori- 
 zontal, and the external part of the object is shown, the representation is termed an elevation. 
 In this way the outline d d in the plane of delineation DD may be called the front elevation > 
 the actual front elevation being shown by the figure EE. Also the outline ff on the plane of 
 
20 
 
 THE LINES OF CARPENTRY AND JOINERY. 
 
 delineation FF may l>e termed the side elevation ; the actual side elevation being shown by the 
 figure G G. 
 
 Still adhering to this mode of representation, viz., with the plane of de- 
 lineation vertical and the projecting rays horizontal, if only the contour of any object is drawn, 
 the outline is termed a profile as at II. Also, if the object is shown as though it were cut 
 through, and the part in front removed, to explain the internal or constructive arrangement, 
 the representation is called a section as at I. The plane of section is almost always parallel 
 with the plane of delineation. 
 
 PliO.IEUTION OF POINTS, LINES, SURFACES, AND SOLIDS. 
 
 The operations that will now he the subject of illustration have for their 
 object the exactly defining by means of drawings, position , form, and magnitude. In many 
 cases so little difficulty is presented that the simplest means are sufficient, and any one may 
 easily give this kind of information with precision. But where complexity exists, it is necessary 
 that principles should he understood, and modes of procedure adopted, which require for their 
 comprehension a certain amount of systematic study. 
 
 NATURE OF LINES, SURFACES, AND SOLIDS. 
 
 Lines may be straight or curved. 
 
 Surfaces may he plane; or with a simple or single curvature, when the surface is 
 straight in one direction, as in the case of a cylinder or cone; or they may have a double or 
 compound curvature, as in the case of a sphere, an ellipsoid, etc. 
 
 Solids can he treated only by considering the nature of the surfaces which hound them. 
 
 POSITIONS OF POINTS, LINES, AND SURFACES. 
 
 In order to he able to clearly define the positions of objects which have 
 to he delineated, we will consider the ground plane to be a horizontal plane on which the object 
 is supposed to rest: the plane of delineation for the plan to he a similar horizontal plane above 
 the object, and of course parallel with the ground plane; the plane of delineation for the front 
 elevation to he a vertical plane in front of the object; and the two planes of delineation for the 
 sale elevations to he vertical planes, parallel with each other, and perpendicular to both the 
 ground plane and the plane of delineation for the front elevation. 
 
 The simplest problem that can he presented is to define the position of a 
 >inglc pomt. 1 he position and length of any straight line must be exactly determined if we 
 Inn r shown the points which are its ends. The position, length, and form of any curved line 
 will he precisely indicated if, besides the two points which are its extremities, there are given 
 a number oi other points which lie in that line, at certain distances between its ends. 
 
 Any plane surface may have its position, form , and dimensions defined if 
 die linos which bound it are in all respects correctly described. A curved surface may also be 
 made the subject of rigorous definition. If we suppose the surface to be marked with lines, 
 pi. K od according to some law, — the particulars of these lines, as well as of those which are 
 it' bound. nies, will enable us to know all that is required concerning that surface. And since 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 21 
 
 solids must be bounded by surfaces, the most exact information may in the same way be ex- 
 pressed with relation to them. 
 
 As it has been shown that it is by means of points that we may effect 
 all the operations in projection, it is necessary to consider what relates to defining the position 
 of a single point. To describe the situation of a point, we must state what its relative position 
 is with reference to some other point, or to any line that may be determined on. In Fig. 1, 
 Plate 4, let i, represent a point the position of which is to be defined. The ground plane 
 A BCD; the plane of delineation for the plan EFGII; the plane of delineation for the front 
 elevation ABFE; the plane of delineation for the side elevation BCGF; and the lines which 
 bound them, afford the means of clearly describing distances and positions. By way of making 
 these remarks more familiar, we will speak of dimensions in feet and suppose Fig. 1 d to be a 
 scale of feet. On any plane surface we can only represent two dimensions, thus on the plan 
 Fig. la we may show that the point is in a vertical line, which is ten feet from the line E F, 
 and four feet from the line F G, but we cannot show at what height in that vertical line the 
 point is situated. Also in the front elevation Fig. 1 b we may indicate that it is in a horizontal 
 line, which is fifteen feet above the line A B, and four feet from the line B F, but this repre- 
 sentation does not afford the means of showing how near to the plane A B F E, or how far 
 back from it, the point may be situated. The same remarks apply to the side elevation. Fig. I c. 
 Thus it will be seen that to establish the position of any point three dimensions are necessary, 
 and that to give these there must be two planes of delineation. There may be the front and 
 side elevation; or one elevation and the plan. In Fig. 1, — i shows what may be described as 
 “the seat of the point in the ground plane”. The other letters and figures of reference are 
 arranged with the intention thfflt, as far as practicable, the different views may explain each other. 
 
 The position of a line with reference to the planes of delineation and the 
 ground plane may be of two kinds. It may be parallel with one of the planes, in which case 
 its treatment is comparatively simple; or it may be not parallel with any one of the planes, in 
 which latter case more difficulty will be experienced. When an object is considered which 
 is not bounded by plane surfaces, but which, like an ellipsoid, is bounded entirely by a curved 
 surface, the nature of its position must be determined by the relation which a centre line, or 
 some arbitrary constructive or working line, bears to some one of the planes. 
 
 If a line lies in a plane parallel to any plane of delineation, that line and 
 its projection on that plane of delineation will be ecpial; and if any line lies in a plane which 
 is not parallel to any plane of delineation, the projected representation of that line on the plane 
 of delineation will be shorter than the line. 
 
 Plane surfaces that have to be represented may be in any one of three 
 positions with relation to the planes of delineation. This can be best understood if it is sup- 
 posed that the plane surface is produced until it intersects the ground plane and one of the 
 planes for the elevations. In Fig. 2, Plate 4, a circular surface is shown which is represented 
 as extended until it intersects the ground plane at hi, and the plane BCGF at ik. Thus the 
 plane hikf is seen to be parallel with one of the planes; and when the position of any object 
 is of this nature, all the representations, as the plan, and the front and side elevations, are 
 very simple. The line Ik in Fig. 2 a is the plan of the circular surface. Fig. 2b shows the 
 
THE LIKES OF CARPENTRY AND JOINERY. 
 
 22 
 
 front elevation of the same. In the same way as on the plan, the side elevation would be a 
 single line. 
 
 The position of the plane surface to be represented may be similar to a 
 that shown by Fig. 3, where the intersection hi is parallel to the line E F, but ik is not pa- 
 rallel tn FB. In this position, as in that just described, the side elevation of the circular 
 surface would he a single straight line. Fig. 3a represents the plan, and Fig. 3 b the front 
 elevation. 
 
 The student will meet with no particular difficulty in his endeavours to 
 represent objects in the two positions just described, but the third position requires processes 
 somewhat more complicated; and although there is nothing in the subject that will not be easily 
 understood after a little study, it may be well to suggest that the greatest help to the compre- 
 hension of the methods necessary for the third position, will be a familiarity with all that re- 
 lates to the first and second. In Fig. 4. a circular surface is represented as before, but in this 
 instance the intersection hi is not parallel with E F, and ik is also not parallel with F B. In 
 this position, no representation of the circular surface will be a straight line as in the preceding 
 cases. Fig. 4 a shows the plan, and Fig. 4 b the front elevation. 
 
 This statement of the leading ideas which relate to Projection has been 
 presented with the intention that the student should be first led to the consideration and com- 
 prehension of general principles, this being the course that is most likely to lead to good re- 
 sults and to save time and trouble in the end. 
 
 W e will conclude these remarks by referring to a few illustrations of the 
 projection of geometrical solids. It will be our endeavour, in all cases, to make the mode of 
 arranging the views and the letters and figures of reference Contribute to the explanation of 
 the methods. As far as practicable the same letters will be made to show the same parts in 
 the different views; and the system of marking the figures, as /, / a, 1 b, etc. will generally in- 
 dicate the order in which they have to be considered, and the way in which one representation 
 depends for its construction on another. In connection with the various practical matters that 
 have to be treated, further details relating to projection, with all necessary illustrations and 
 descriptions of methods, will be given. 
 
 Figs. J, 3 a, etc. Plate 4, represent a hexagonal prism, in the position ex- 
 plained by big. 2. Fig. ■>. shows the plan; Fig. 3a t lie front elevation; and Fig. 5b the side 
 elevation. 
 
 kigs. 6, 6 a, etc., Plate 4, show an octagonal prism, in the same kind of 
 position as that explained by Fig. 3. Fig. 6 ‘a represents a right section of the prism. Figs. 6‘, 
 t> /», and b r, respectively show the front elevation, the plan, and the side elevation. 
 
 kigs. /, 7 a, etc., Plate 4, show a cylinder, also in the same kind of po- 
 "iiion as that explained by Fig. 3. Fig. 7 a represents a right section of the cylinder. Fiqs. 7, 
 
 / b and / r, respectively show the front elevation, the plan, and the side elevation. 
 
 1 he next example is that of an object in the same kind of position as 
 that explained by bag. 't, Plate 4. As, in order to produce representations of this nature, it is 
 m i osary that the particulars of the position should be very clearly comprehended, we will 
 ina UM "* an introductory diagram. We will suppose the position of the object to be the 
 
THE LINES OF CARPENTRY AND JOINERY. 
 
 23 
 
 same, as that of the line ab in Fig. I, Plate 5. What has to be understood is the difference 
 that there is between the angle that the line a b makes with a c, which is its seat in the ground 
 plane, and the angle that the projected representation of the same line would make on the 
 elevations. It will be seen that the front elevation of the line a b would be as shown by the 
 dotted line b cl. It is obvious that the angle c cl b must be less acute than the angle c a b. Fig. I a 
 shows the plan of the same line a b, and Fig. 1 b the front elevation. The angle c a b, Fig. / c, 
 is the actual angle made by the line a b with its seat in the ground plane. The situation and 
 inclination of any object admit, of course, of being infinitely varied; but the principle explained 
 by the preceding remarks must always be considered when an object is in the same kind of 
 position as that shown by Fig. 4, Plate 4. 
 
 Figs. 2, 2a, etc, Plate 5, represent a square prism in the position just 
 described. Fig. 2 is an elevation in which the prism is represented at the angle which it makes 
 with the ground plane. Fig. 2a is a right section of the prism. The distances on the lines r r 
 and ss serve to construct the plan Fig. 2b in the manner shown. The horizontal lines from 
 Fig 2, and the vertical lines from Fig. 2 b, give the front elevation Fig. 2 c. And the distances 
 on the line tt, taken from Fig. 2b, applied in conjunction with the horizontal lines continued 
 from Fig. 2, in the manner represented, serve to produce the side elevation Fig. 2d. 
 
 DEVELO P M E N T. 
 
 The development of the surfaces of solid objects is in various ways im- 
 portant to the carpenter and joiner. It consists in drawing on a fiat surface a figure that shall 
 be exactly equal, in form and dimensions, with the surface of the solid. It may perhaps be 
 most simply explained by stating that if the development be truly drawn on a piece of paper 
 or other flexible material, it will, on being bent over the surface of the solid, be found to coincide 
 with it in every respect. It is intended to illustrate this part of our subject in detail in con- 
 nection with the different practical problems to which it relates; but, by way of introducing it 
 to the student, we will refer here to the elevations and developments of the five regular solids. 
 (See Plate 5.) If these developments, as shown, are cut out of pasteboard, which is to be cut 
 only half through where indicated by the dotted lines, they may by bending be made to re- 
 present the respective solids. If made rather large , the edges may be fastened together by a 
 needle and thread, which is the readiest way. 
 
 Figs 3, 3 a, and 3 b show the elevations, in two positions, and the development, of the 
 tetrahedron, which is a regular pyramid having four equal faces which are equilateral triangles. 
 
 Figs. 4, 4 a, and 4 l> represent the hexahedron or cube, with six equal faces which 
 are squares. 
 
 Figs. -5, 6 a, and 5 b indicate the octahedron, formed of eight equal equilateral triangles. 
 
 Figs. 6, 6a, and 6b show the dodecahedron, which consists of twelve equal penta- 
 gonal faces. 
 
 Figs. 7, 7 a and 7 b illustrate the icosahedron, composed of twenty equilateral triangles. 
 
24 
 
 THE TOOLE employed in carpentry and joinery. 
 
 CHAPTER III. 
 
 THE TOOLS EMPLOYED IN CARPENTRY AND JOINERY. 
 
 It is not our intention to enter at any length into the subject of this 
 chapter, as the workshop is the proper place for acquiring a knowledge yf tools. Generally 
 -peaking, the carpenter uses the axe, adze, socket-chisel and saw, together with the mortice- 
 gauge, auger, level, plumb-rule, square and chalk-line, the employment of the plane by the 
 joiner forming the chief distinction, so far as tools are concerned, between the two vocations; 
 the carpenter being occupied on the main constructive parts of buildings, and the joiner on 
 the fittings and finishings for safety, convenience and decoration. The bench, at which both 
 work, is about 2 ft. 8 ins. high by 2 ft. fi ins. wide, and 10 or 12 ft. in length. Below the top, 
 on one side, a vertical sideboard is fixed, and in this holes are placed diagonally to receive the 
 bench-pin , used to support at one end a piece of wood to be operated upon, the other extremity 
 being held by the bench-screw and cheek, which form a kind of vice. 
 
 Having premised thus much, we shall range the various tools under the 
 general headings of: — first, tools for striking and for cutting, through percussion or slight 
 pressure; secondly, tools for boring or piercing; thirdly, tools for sawing; fourthly, tools for 
 planing; and fifthly, tools for determining lines and surfaces. 
 
 STRIKING AND CUTTING. The hammer, with an iron head, and the 
 mallei, entirely of wood, require no explanation; but we may remark that the axe, with a blade 
 parallel to the handle, is used to chop timber vertically, the adze, with a blade at right angles 
 *o the handle, cutting it in a horizontal direction; and the hatchet is a species of small axe. 
 
 Of chisels there are various kinds, as firmer and paring chisels, the latter 
 having thinner edges than the firmers; among mortice chisels the socAef-chisel is adapted for 
 large timbers, and the sash-chisel for morticing sashes; the gouge has a concave face. 
 
 BORING. Awls, bradawls, gimlets, and bits of various kinds, are employed 
 lor piercing and boring wood. The first are used for small holes; and, in commencing the in- 
 cision, care must be taken to apply the chisel-shaped end at right angles to the grain of the wood, 
 so as to cut the fibres, instead of forcing it in by simple pressure. Of boring tools the bradawl 
 is the smallest; and the gimlet has a transverse handle to give the workman increased power. 
 Bit- are removable from a doubly-curved crank-shaped stock, so formed as to be suitable for 
 the large variety used, as countersinks, rimers, centre-bits, etc. Augers have transverse handles for 
 working with both hands, and the cutting points vary in shape; they are adapted for large 
 holes, preparing for the socket-chisel, etc. 
 
 SAB ING. The cross-cut-saw has a handle at each end and is used by two 
 men to cut large timbers across the grain. It is about 5 or 6 feet long. The rip saw, employed 
 to cut wood in the direction ol the fibres, has generally 8 teeth to 3 inches, the blade being about 
 inches long; and the half rip saw is about the same length, with 3 teeth to the inch. Hand 
 -aws, lor cutting thin pieces across the direction of the grain, have 26 inch plates, with 15 teeth 
 
TIIE TOOLS EMPLOYED IN CARPENTRY AND JOINERY. 
 
 25 
 
 to 4 inches, inclining more than those of the above; and for particularly thin boards, the panel 
 saw, with a very thin plate, 26 inch long, with 6 teeth to the inch, is adopted. Tenon, sash and 
 dovetail saws are so thin that it is neeessary to strengthen them by means of metal backs to 
 prevent buckling. The tenon saw is mostly used for cutting across fibres, and it has a blade 
 from 14 to 18 inches long, with about 8 teeth to the inch, and a sheet iron back. The sash 
 saw has an 11 inch plate, with 13 teeth to the inch, and a back usually of brass; and the 
 dovetail saw' has a similar back to a 9 inch plate, having 15 teeth to the inch. For circular 
 work the compass saw is employed; it has no back and is thicker on the cutting edge; the plate, 
 with 5 teeth to the inch, being about 1 4 inch wide at the end and 1 inch at the handle. To 
 cut a small hole the keyhole saw is used. There are other varieties of saws, as those with ex- 
 ternal frames, such as the w&od-cutted s saw r , the boiv saw, etc., but we shall conclude our brief 
 summary with some observations on the various forms of the teeth. 
 
 About 60° is an usual ancle for the teeth, the inclination beinc named the 
 pitch; and, with the exception of keyhole and compass saws, the teeth arc usually bent alter- 
 nately on the opposite sides of the plate, in order to clear the wood; this 
 is called the set of the saw. Peg or fleam, gullet, briar, and skip, are 
 terms applied to different teeth; and some examples are given in the 
 margin. In the valuable work entitled “Turning and Mechanical Mani- 
 pulation,” Holtzapffcl remarks that; — “It would be desirable if, in the 
 narrow taper saws with only one handle, we more frequently copied the 
 Indian, who prefers to reverse tlfe position of the teeth, so that the 
 blade may cut when pulled towards him, instead of in the thrust; this 
 employs the instrument in its strongest, instead of its weakest direction, 
 and avoids the chance of injury, 'flic inversion of the teeth, which in 
 India is almost universal, is with us nearly limited to some few of the 
 keyhole and pruning saws.” Saws for hard woods should have their 
 teeth closer and smaller than others for softer varieties; and if the teeth 
 of those used for the latter arc small, their intervals should be wider 
 in proportion, or they would speedily be choked up and prevented 
 
 ' \ \ ' fit V FM ' N 
 
 VwvVwWs/vV'A 
 
 
 
 
 working. 
 
 PLANING. The name of the tool called a plane is derived from the 
 
 object it is in general intended to serve, viz., to produce a flat or plane surface, although there 
 
 are convex, concave, and mixed varieties, such as moulding and grooving planes. Those with 
 
 flat under surfaces, having irons about 2 or 2 1 . 2 inches wide, are known as bench planes, 
 
 the section in the margin illustrating the various parts. A 
 
 plane- iron for cutting the wood is fixed in the plane stock, 
 
 the lower edge of the iron projecting beyond the under part, 
 
 » 
 
 or face, of the plane, which ought to be perfectly true. To 
 fix the iron a forked wedge is used, the angle varying from 
 from 20° to 60°, it being more upright in proportion to the 
 hardness of the wood to be operated upon. The opening, or mouth, of the plane is very nar- 
 row at the lower part, gradually widening above, and the shavings rise up through it when the 
 
 iv 
 
26 
 
 THE TOOLS EMPLOYED IN CARPENTRY AND JOINERY. 
 
 tool ie used. The projection of the plane iron may be very nicely regulated, or set, rank, or 
 fine, that is, projecting from the face in a greater or less degree. 
 
 The jack plane is employed to take off the rougher portions of the wood; 
 its stock is about 17 inches long by 3 inches wide and 3 inches high, and the tote, or handle, 
 is so placed as to give the utmost power in pushing the instrument forward. After the jack 
 plane the trying plane is used, and this is 22 inches long by 3 3 / 8 by 3 l / 8 inches high. The 
 Iona plane is 20 inches long by 3 : \ s by 3' 8 inches high, and it is used for shooting the edges of 
 floor boards, etc.; the jointer plane is 28' inches long. For rendering finished work .perfectly 
 smooth, the smoothing plane is adopted; and it is only 8 inches long by 3 1 / 8 by 2 3 / 4 inches high. 
 
 All the above are called bench planes. Rebate planes are for 
 forming rebates as in the margin, and there are various kinds: 
 they have no handles and the shavings are discharged through 
 an opening at the side instead of at the top; the dimensions 
 arc i) 1 o inches long by 3 deep, and the thickness varies from 
 1 o to l 3 j inch. Side rebate planes have the cutting edge at the 
 The side fi (lister is adapted to sink the edge of the stuff next the 
 operator ; while the sash fillister sinks the opposite 
 part. Ploughs are used for ploughing, or sinking 
 grooves , and they are ordinarily 7 3 / 8 inches long by 
 5 3 / t deep, with irons varying from */ 8 to 3 ;4 inch in 
 width. Toothing planes are for veneers, etc., and dado 
 grooving planes for grooves. To form mouldings and 
 beads, moulding and bead planes are used. They are 
 
 side of the iron and stock. 
 
 about 9 3 8 inches long 
 
 by 
 
 3 V 8 
 
 deep, the faces and 
 cutting edges being curved. With compass planes for 
 curved surfaces, we conclude the ordinary list. The 
 first diagram in the margin is the continental roughing- 
 
 o cj O O 
 
 out plane, the tote being for the 
 left hand while the right grasps 
 the back of the stock; below are 
 three varieties of French planes, 
 the last two being for concave and 
 convex surfaces., 
 
 DETERMINING 
 LINES AND SURFACES. We 
 
 next approach the tools in use for 
 setting out work, determining and 
 regulating forms, and marking the 
 requisite lines. 
 
 The plumb-rule is 
 
 employed to set-out work perpendicularly, and the form in the margin is adopted in France 
 to \eiih a vertical line. Differently formed squares are used by carpenters and joiners fo 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 27 
 
 setting right angles, those for trying-up, and setting-out work being respectively called trying 
 and setting squares. Reversing the blades of a square after drawing the lines suffices to prove 
 its correctness. The bevel is a species of square with a moveable blade to be set at an angle. 
 
 Bevels with fixed blades are often used; and the 
 diagram represents a useful French instrument, with 
 two right angles a.b.c., d.e.f, and one angle b.c.g. 
 of 1 35° or 45°. The mitre square is a bevel fixed 
 at an angle of 45°. To test edges the straight-edge 
 is employed; and two slips, or winding sticks, each 
 with two parallel straight edges, are used to de- 
 termine the level plane of the whole surface of a 
 piece of wood. Levels are of various forms, the most ordinary consisting of a rule 10 or 
 12 feet long, with a perpendicular piece fixed upright in the middle; in the centre of the 
 horizontal piece is a hole, and within this, when the former is perfectly level, a plummet, sus- 
 pended from the top of tlie upright, freely vibrates. The spirit level is a very useful kind. 
 The gauge is adopted to mark a line on a piece of stuff parallel to its edge; and the mortice 
 gauge has a double 'tooth. We need only name the compasses, but on the sliding ride it would 
 be easy to write a long dissertation, were it our intention to consider fully all the carpenters and 
 joiner’s tools and instruments. Many indeed are still unmentioned, and there are some, as 
 pincers, screiv-drivers, cramps, hook-pins, side hooks, etc., which cannot be included under the above 
 headings; but it is apprehended that what has been said is sufficient in a book like the present; 
 and, as before remarked, the novice should seek in the workshop for more complete information. 
 
 a il 
 
 i 
 
 CHAPTER IV. 
 
 SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 BY E. L. TARBUCK.- 
 
 It is now proposed to trace the main outlines of the origin and progress 
 of carpentry and joinery. More especially shall we consider the manner in which the former 
 has gradually been so perfected as, in the language of Nimmo, to “constitute one of the most 
 beautiful and useful applications of the liberal sciences to the arts of life.” The summary thus 
 involved is deemed peculiarly appropriate in an Encyclopaedia addressed partly to artisans. 
 For an acquaintance with the advances promoted by men who were originally workmen may 
 encourage others in the dcvisal of new forms and useful combinations to meet the varied re- 
 quirements of an age in which so many fresh demands have arisen. Above all, many pre- 
 judicies tending to retard progression may be dissipated. It is but too common for operatives 
 to exaggerate the relative degree of perfection in their own country of the vocation to which 
 they :fre devoted. One of the main objects of this book is to familiarise English artisans with 
 the works of their brethren abroad; for the exertions of the latter must command respect 
 wherever they are clearly understood. The workmen of all nations ought to forget difference of 
 language and location in the brotherhood of art. They should regard one another, not with jealousy 
 
SKETCH OF THE ORIGIN ANI) PROGRESS OF CARPENTRY AND JOINERY. 
 
 2S 
 
 :mil opposition, hut Avith the candid spirit of open-hearted men, anxious only for that generous 
 rivalry whose contentions are prompted by the most friendly and honourable feelings of emulation. 
 
 ‘‘It had been more proper,” said Moxon, “for me to have introduced car- 
 pentry before joinery, because necessity did doubtless compel our forefathers to use the con- 
 venicncy of the first, rather than the extravagancy of the last.” The birth of carpentry dates 
 from the earliest ages of the world; and it is not too much to say that in the history of its - 
 progression, that of humanity may be traced. We can imagine man in a savage state, without 
 other than the shelter afforded by caverns or the shade of trees, feeling acutely the inclemency 
 of the seasons, the heat of summer, the cold of winter, — exposed to the burning heat of the 
 sun during the day, and in the night to pestilential vapours and damp. “The penalty of Adam, 
 the seasons’ difference” was full upon him; but necessity, or the urgency of want, is the mother 
 of industry and invention. Man, wrapping himself in leaves, had hitherto crept like the beasts 
 within groves and hollow trees, or into dark caves and holes scooped in the earth, perched 
 himself like the birds in nests built with less skill than those of the swallow and the stork, or, 
 putting together a few sticks covered with turf, jested in a shelter of which the beaver would 
 have been ashamed. But in the dawn of social impulses, noting the fall of the rain and the 
 sweep of the wind, deriving some rude ideas of stability from the contemplation of the material 
 world around and the structures of animals, instinct first guided the construction of rude habi- 
 tations which reason long afterwards perfected. Without factitious wants, simple in manners 
 and uncorrupted by luxury, primitive tribes long live contented with the least artificial dwellings. 
 But man may be defined as a building animal with progression for his rule. To this circum- 
 stance do we virtually owe the origin of the luxuries of the mind and body, which have now 
 be come necessities, - to it is due the art of building, the development of which has invariably 
 been the starting-point of civilization and the precursor of knowledge of all kinds. And the 
 art of the carpenter is the earliest of all arts; and in Egypt, in Greece, and in Rome, and again 
 in Mediaeval days, the glorious temples of stone, carved with that beauty and refinement, which 
 heaven-bent thoughts inspire may, in their main outlines, and even in many of their smaller 
 parts, be traced to the rough wood huts which were formed in the wild forests of old. 
 
 Seeking in the ancient classic authors for information respecting the early 
 development of carpentry, Homer, Herodotus, Diodorus Siculus, Strabo, Pausanius, Tacitus, 
 Pliny, and \ itruvius, among others, give us some ideas on the subject. The last named writer 
 has speculated at length respecting the probable formation of the early huts in Greece. From 
 his work we gather that progress was made in the manner illustrated by the three first dia- 
 gram- in our Frontispiece, the third rendering clear the derivation of the general outlines of the 
 Doric temple. In it the reader will notice a very remarkable feature. This is the peculiarly 
 framed covering, unquestionably the first great effort in constructive carpentry. So enthusiasti- 
 cally was it formerly admired that even Cicero was betrayed into the unphilosophical observa- 
 tion that, it a temple were to be erected in heaven where no rain falls, it would be requisite to 
 crown it with a pediment roof. AY e perceive in it the attainment of the degree of geometrical 
 Knowledge which teaches that triangular combinations give invariable figures, rendering frames 
 tead\ : '.md this principle has since presided in the design of the most elaborate and beautiful 
 compositions in carpentry. On glancing at the Frontispiece, it is hardly needful to explain how 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 29 
 
 the columns were ultimately deprived of their bark, rounded, smoothed, raised on stones, and 
 similarly crowned at the summit, and, to prevent their splitting, hound with ligatures at both 
 extremities, those to the beams being afterwards superseded by various forms of joints, laps, 
 or rebates, preceding mortices and tenons. It is probable that the buttress, solving the problem 
 of vertical stability, was early devised. But it was ultimately dispensed with in Greece, unless 
 the pilaster may be considered as its representative. The coverings of the. roof, cut into varied 
 projections at the eaves, suggested cornices, the projecting rafters and plates constituting the 
 modillions and bed mouldings, the cross beams forming triglyphs, and the horizontal pieces 
 below, the architraves, as shown on the fourth, fifth, and sixth diagrams. Thus we have the 
 complete entablature of the advanced orders, in fact the groundwork of modern stone archi- 
 tecture. Quatremere de Quincy strongly confirms these views of the origin of Greek archi- 
 tecture. A positive proof of their correctness is found in Lycia, where the forms of the ancient 
 wood buildings are still retained, the storehouses and cottages resembling temples. That trees, 
 or wood posts, originated stone columns seems sufficiently obvious. But Mr. Fcrgusson has 
 endeavoured to prove that “the pillar was originally a pier of brickwork , or of rubble masonry 
 and that “as the masons advanced in skill and power over their stone material, it came more 
 and more to resemble posts or pillars of wood.” ( Handbook of Architecture.) We doubt whether 
 any of our readers will find it possible to believe in so peculiar a reversion of the natural order 
 of things. It, in fact, involves the manufacture of a material by a comparatively barbarous 
 people prior to tbc use of one supplied directly by nature. There is nothing in history, whether 
 it be in words or in architectural remains, to indicate that masons existed before carpenters. 
 And we shall hereafter show that the substance which is easiest to work is first used, and that 
 the forms then necessarily adopted are repeated in materials, wrought upon with more difficulty, 
 but better adapted for duration. 
 
 No remains of the early wood* structures which, in various countries, ori- 
 ginated styles of architecture have been spared by tbe hand of time. We must rest contented 
 with theories and literary traditions, especially as many of the more durable edifices have dis- 
 appeared. While the location of Troy is a problem, we read in the verses of Homer, still 
 living three thousand years after they were first sung, of its walls, its towers, and the strugglings 
 within them of the old life. From the works of this poet it is evident that the principal build- 
 ings in his time were the palaces of princes. But the colossal monoliths of Egypt remain, as 
 do the elegant temples of Greece, and in these roots of modern architecture the character- 
 istics of their timber prototypes may be traced. The most ancient structures are generally 
 temples consecrated to the gods; the more modern are palaces dedicated to human pride. 
 Striking indeed must have been tbe contrast between the proud magnificence of these noble 
 erections and the squallidness of the miserable hovels in which the people lived I In the east 
 the earliest forms of buildings may still be easily traced; for in many parts customs are im- 
 mutable, continuing, as is tbe case in China, for centuries unchanged. An old usage in Bur- 
 undi, that no stone or brick buildings should be erected, except the king’s palace and religious 
 edifices or pagodas, has now become a law; but the former is chiefly of timber, decorated how- 
 ever with colour and gold in so sumptuous a manner, that we can form but little idea of its 
 barbaric splendour. As Mr. Fcrgusson remarks, the modern Yezidi house, illustrated by Layard 
 
SKETCH OJ' THE ORIGIN AND PROGRESS QF CARPENTRY AND JOINERY. 
 
 :io 
 
 :ind chietlv rtf' tiinlicr, is “an exact reproduction in every essential respect of the style of building 
 in the days of Senacherib.” Notwithstanding the three types of early buildings mentioned by 
 Qua tie mere, even the rock-cut architecture of all countries bears traces of its derivation from 
 structural examples. In Persepolis timber erections seem as it were petrified. Wood forms 
 characterise the style of Nineveh. In India they have suggested many of those in stone. So- 
 lomon’s edifices were chiefly of timber. Herodotus speaks of the bridge at Babylon, thrown 
 over the Euphrates by Semiramis 2000 P>. C., as consisting of wood beams on stone piers. The 
 same queen is said to have constructed a bridge of boats across the Indus, and the Persian 
 king Darius another, 1008 yards long, over the Bosphorus, which he traversed with 700,000 
 men. A similar bridge was also made by the latter monarch across the Danube. Bridges, 
 indeed, are among the earliest works in carpentry. In savage countries we still see the rough 
 trunk thrown over the stream; then two trunks, with the branches int wining, as noted by Mungo 
 Park in Africa; and sometimes suspension bridges of rushes or the hides of cattle, as in Peru. 
 Herodotus speaks of a very ancient bridge erected by Menes over the Nile in Egypt, and which 
 was probably of timber. Even in that country of stone it is evident how wood dictated many 
 of the forms in the temples and other edifices. The author last mentioned tells us of buildings 
 in which the columns were imitative of palm-trees. Timber originals clearly suggested the main 
 features of the oldest temples; and the constantly recurring circular moulding at the angles is 
 undoubtedly a carpentry form. As large trunks were difficult to obtain, we note as one of the 
 consequences the petrified bundle pillar of reeds, or sticks, tied together at the top and bottom. 
 These most probably originated flutes; and the superincumbent pressure, causing a slight swell- 
 ing in the centre, gave rise to the entasis of columns. Even flowers and leaves were copied 
 in stone. The capitals of columns are often imitations of buds and bells; and the palm, lotus, 
 papyrus and date leaves were continually introduced. 
 
 When architecture advanced in Greece, the lower parts of the buildings 
 were of massy stonework, as in ancient Mexico, the upper portions only being plainly copied 
 from wooden prototypes. Up to the Persian conquest of Cyrus the Lycians employed timber, 
 then substituting stone. This change occured at the same period in other parts of Greece, and 
 in India about A. 1). 5. In the time of Xenophon even the statues of the deities in the smaller 
 Grecian temples were frequently of wood. We should observe that in some Athenian struc- 
 tures, such as the Temple of the A inds and the Choragic Monument of Lysicrates, the roof 
 is entirely of marble. But in most countries it is of timber; and, till we can construct a vault * 
 capable of resisting the destructive effects of the atmosphere, the more perishable material must 
 be employed, excepting instances of the adoption of iron. The Arabs formed ceilings of wood, 
 and their columns are plainly derived from posts. In Roman architecture caissons, formed by 
 the intersection of beams, suggested the similar beautiful features in vaults. 
 
 An examination of the huts* of savage tribes existing in our own age 
 i' singular] \ confirmatory of the above sketch of' the early development of* workmanship in 
 "(io<l. Hassenlratz took some trouble to ascertain the actual forms of such structures. In 
 hi' book on carpentry lie has given thirty-three examples, of which, however, only sixteen or 
 ( ight< i n were copied from existing habitations, the remainder being compositions from the de- 
 i.iifi d si counts o! travellers. 1 he pyramidal form, as the simplest, is that generally adopted. 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 31. 
 
 Usually the plan is oblong, although sometimes circular, and the roof is either angular or 
 curved, as stiff’ or pliant woods were at hand. Often flexible pieces are bent into a semi- 
 circle and the ends fixed into the ground, as in the African krall, Fir/. 7. on the Frontispiece. 
 M any of the habitations nearly approach the modern rural cottage form. Others resemble pig- 
 sties and rabbit bins, and a fourth variety chicken houses. The Siamese elevate the floor of 
 their cabins some feet above the ground for protection from damp; and the summer huts of 
 the Kamschatdalcs are supported on posts, and have for entrance an inclined piece of timber 
 with rough steps, like those in chicken houses leading to the roosting place. More advanced 
 dwellings consist of the trunks of trees piled one above another, with others crossing at right 
 angles, thus forming the side and end walls. The Siberian and Russian huts, Figs 8 and 9, 
 
 illustrate this description. In California bamboos are employed, placed upright, with horizontal 
 
 cross pieces at intervals. Chinese structures, when compared with those of less advanced 
 
 nations, are indicative of the progress of civilization. A species of bamboo is much used, 
 
 'fhe outer part is hard and the inner spongy: and it is thus practically a cylinder which does 
 not admit of squaring; but it is strong, hard, durable, and bears a great weight. It is in their 
 bridges that the skill of the Chinese is chiefly displayed. The houses, consisting principally of 
 wood, look like birdcages; and we have given, in the tenth diagram, a section of the peculiarly 
 curved roof which is capable of resisting the most violent storms. 
 
 The roof coverings of primitive habitations generally consist of the bark of 
 trees, woven rushes, thick stubble, turf, and, in cold countries, of earth and the skins of beasts. 
 Dry leaves, as large as can be obtained, are often adopted. It was so in antiquity; for Pau- 
 sanius speaks of the temple of Delphi, mentioned by Homer, as being covered with laurel. Thatch 
 and shingles were used by the Romans till about 280 B. C.; and tiles are found in ancient 
 Buddjiist architecture on i-oofs with stone decorations repeated from earlier wooden prototypes. 
 
 One noticeable fact in connection with original huts is. remarked by Emy. 
 The wood is never assembled by means of mortices and tenons, and joints of any description 
 arc exceedingly rare. Ligatures of .strips of wood, fagots, reeds, or hide, suffice for attachment, 
 although pegs or pins are occasionally observed. Some mastic is often used to harden the 
 bandages, the cabins ultimately attaining a surprising solidity, effectually resisting the most 
 severe hurricanes. The saw was of course never employed. When invaded by the Spaniards 
 the Peruvians had only the hatchet and the adze. Homer alludes to the plane, auger, rule, 
 and hatchet with two edges, but he does not mention the saw, compasses, or square. In many 
 parts of Russia the saw is still ignored; but the economy promoted by its use is not of para- 
 mount importance where timber is so abundant. 
 
 Returning now to the point whence we diverged to the consideration of 
 the dwellings of uncivilized tribes, the Romans seem to have used timber to as great an extent 
 as modern nations. Vitruvius speaks of Tntestinum opus, or joinery; and architraves, cornices, 
 ceilings, doors, etc., were often formed of wood. Buildings were sometimes erected chiefly of it, 
 as many of the theatres and amphitheatres; and the Coliseum was probably boarded. Pliny 
 refords a remarkable instance of mechanical ingenuity displayed, in Julius Caesar's time, in the 
 structure erected by Curio for the funeral exhibitions in honour of his father. Two theatres, 
 constructed back to back, were so connected by machinery as to admit of being wheeled round 
 
SKETCH OK THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 .32 
 
 to form an amphiteatrc for the shows of gladiators in the afternoon after the theatrical per- 
 formances in the morning. Both the Greeks and Homans vised 1 mines when besieging cities, 
 and the art of the carpenter was thus involved, as well as in the raising of statues, and other 
 hcavv loads. The latter people first developed the construction of centres, the aqueducts and 
 immense cloaca', or sewers, demanding their use. Rondelet has given illustrations of the pro- 
 bable forms generally adopted. Although it has been hinted that the celebrated dome of the 
 Pantheon was raised on compressed earth, the idea is extremely improbable. We may mention 
 that the roof of the mausoleum of Theodoric at Ravenna is formed of a single block of 
 stone, 35 feet in diameter and hollowed to form a flat dome. The Greeks neglected bridge 
 bmldni"- oreatlv attended to by the Romans, who are said to have elected the hist one in 
 GreCcc, that over the Ctesiphon. At Rome the oldest wooden bridge of which we have any 
 record is that of Sublieius (from sublica, a pile), built about 600 B. C., in the reign of Ancus 
 Martins. According to Polybius, it was on this bridge that Horatius Coccles displayed such 
 undaunted bravery in the defence of the city against the army of Porsenna. The bridge de- 
 signed bv Julius Caisar to span the Rhine is very celebrated. His army traversed it within 
 
 ten days of the time they began carrying the 
 timber for its erection. Palladio, Alberti, Sea- 
 mozzi, and other architects, have attempted its 
 restoration from descriptions in the Commentaries; 
 and we have given the presumed section in the 
 margin. The inclined struts supported the bridge 
 against the force of the stream, and piling ar- 
 rested floating masses. In the following diagram 
 is a representation of Trajan’s bridge over the 
 Danube, copied from the basso-relievo on the 
 triumphal column erected to him in Rome. Each 
 arch was 100 feet in span; and it will be per- 
 ceived that the construction is of a very ingenious description, scarcely surpassed by any of 
 the moderns. Apollodorus was the architect of the bridge as well as of the column. 
 
 On Plate 17, Fig. 1, is a section, from the view preserved by Fontana, of 
 the roof of Constantine’s basilica of St. Peter. It is remarkable for its simplicity, was open and 
 gilt, and is valuable as a traditional imitation of the ancient Greek and Roman form of roof. 
 Fig. 2. is the roof of the Argentina Theatre in Rome, presenting a combination of remarkable 
 strength. That of the basilica of St. Paul beyond the walls is given in Fig. 3, the trusses 
 being double. The last figure is the roof of the church of St. Sabine within the same city. 
 
 1 1 is incontestibly a type of the early carpentry described by Vitruvius. We need only add, 
 with respect to the examples on this plate, that it would be as well if modern architects 
 more frequently displayed an amount of scientific knowledge equal to that indicated in these 
 ancient constructions. 
 
 At the same period that the Romans were almost exclusively using stone, 
 i lie nations of central and northern Europe, living in the midst of forests, drew almost entirely 
 from these their building material. In the latter part of the empire, centuries after the fulfilment 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 33 
 
 of Augustus’s boast that lie had reconstructed Rome of marble, timber was chiefly used in the 
 churches of Paris. This city had attained importance under Clovis, who, among other works, 
 erected the cathedral at Strasburg, the walls of which were formed of large trunks of trees sawn 
 down the middle and fixed in the earth, the intervening parts being filled with clay and coarse 
 mortar, and the roof was thatched. This system of construction long continued. Paris, Rouen, 
 Caen, and many large cities in England and Germany, were principally built of wood, while 
 little Italian villages were of stone. At present, in many parts of Russia the majority of the 
 houses are of timber. The palace of the Kremlin was first erected of this material, as were 
 also the Cathedral at Cherson and the Church at Kieff, the latter enduring till within the last 
 few years. Both of the last mentioned were built by Vladimir the Great in the latter part of 
 the tenth century. Norway still possesses numerous timber churches of high antiquity, those 
 at Hitterdal, Urnes and Burgund being peculiarly interesting. At Kittle Grinstead, in Essex, 
 is the oldest wooden church in England. As nations advance in civilization, and as the ground 
 becomes cleared of forests to adapt it for agricultural purposes, wood is gradually super- 
 seded, especially when its liability to decay and its rapid combustion are fully apprehended. 
 Brick and stone succeed timber, and tile and slate follow thatch. Strabo speaks of ceilings 
 being arched, or “camerated” in his time to save wood. Gibbon, referring to Santa Sophia in 
 Constantinople, remarks that; — “The memory of past calamities inspired Justinian with a 
 wise resolution that no wood, except for the doors, should be admitted into the new edifice." 
 But during the Middle Ages timber was very extensively used in building, Never before were 
 the professions of the carpenter and joiner so fully matured. In proof of this we scarcely need 
 cite the wonderful roofs, considered even now as master-pieces of construction and decoration, 
 in which the great requirements of internal height, spaciousness and strength were attained 
 with such consummate skill. 
 
 In the early Mediaeval period, while the feudal system was in full vigour, 
 massy stone structures for protection were absolute necessities* The feudal lord fortified him- 
 self in his castle on a solitary elevated spot. Ilis serfs built their hovels in the immediate 
 neighbourhood, to be near the stronghold, into which they might fly when menaced by the 
 jealous retainers of rival nobles. In the village thus formed a parish church ultimately rose. 
 Wandering guilts of skilled artisans supplied such edifices wherever they were required. In 
 the towns larger churches were raised by these men, who put forth their utmost strength in 
 the cities, whose magnificent cathedrals displayed the most wonderful and imposing results of a 
 special devotion to the service of the Church. The carpenter’s work was at first rude in the 
 extreme, as also was that of the joiner. But both were gradually perfected; and the latter dis- 
 played his skill in the doors, screens, thrones, roods, organs and pulpits. In many of these, 
 however, the forms were evidently suggested by prior works in stone. The merit they present 
 is chiefly due to the carver. His exuberance of invention is perfectly surprising, there being 
 scarcely any repetition in the decorations. Even the two sides of the same detail often differ 
 in design. From many of the modes of joining it is probable that the vocations of carpenter and 
 joiner were exercised, as at present, by the same person. The carver stepped in after the 
 general framework was contrived; and in the fifteenth century the enrichments to panels were 
 
 carved upon them, instead of being stuck on as previously. Doors were always important 
 
 v 
 

 34 SKKTCII OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 objects of the joiner’s craft. The early examples are not carved, but, in the Norman and Early 
 English styles, are strengthened and decorated with iron scrolls of fine design, especially during 
 the last mentioned, towards the end of which they fell into disuse, although tracery was scarcely 
 introduced. In the Decorated style panels superseded the richly .spreading ironwork; and in 
 the Perpendicular the former were most elaborately ornamented. 
 
 Tie-beam roofs were first used and were never entirely discarded. The 
 tics are nearly always cambered, and often introduced without the slightest necessity. Trussed- 
 r after roofs, with diagonal ties, followed the tie-beam; and they were often formed with cross 
 beams, halved and pinned at the intersection in the middle of the span, and also to the two 
 opposite rafters. The undersides were frequently lathed and plastered. Then came hammer-beam 
 roofs, suggested by the former mode of strengthening the feet of rafters, 
 as shown in the margin. Lastly collar-braced roofs may be named; and 
 these were generally plastered underneath. 
 
 Saxon roofs in England are represented on manu- 
 scripts as being frequently covered with shingles, tiles and slates. Nor- 
 man timber roofs, now rarely found, were of high pitch, the framing 
 often open, with a covering of lead. In the thirteenth century the roofs 
 were also steeply inclined, and are sometimes in the form of an equilateral triangle. More 
 ornament was introduced in the fourteenth century. The timbers are often moulded and carved; 
 and the principals are frequently in the form of a pointed arch, which was at first produced 
 by the introduction of braces under the cross beams. Ultimately the spandrels were pierced 
 with traeerv. It was between ljfitO and 1460 that hammer beam roofs were invented. Brandon 
 mentions that over Westminster Hall as the earliest remaining example, hut we doubt the fact. 
 These magnificent erections are the glory of the carpenter’s art. One may look up into the 
 mystic gloom of that at Westminster and be overwhelmed by the grand genius of the men, who 
 could design such wonderful timber combinations, never before or since even approached in 
 the union of science with the expression of sentiment. In the best examples the thrust of the 
 principals is kept low by the simplest means, and further counteracted by means of buttresses. 
 At M estminster Hall the arched rib is a remarkable feature. Consoles support principals, 
 about IS feet apart; demi-angels holding shields are carved on the ends of the hammer beams; 
 and above is a rich profusion of cuspedand traceried panelling. The length of the rafters is about 
 three-fourths of the entire span. Those to Eltham Hall are about four-fifths, the angles of roofs 
 generally during the Middle Ages varying from 60° to 90°. Towards the latter period of Gothic 
 architecture they were nearly fiat, having framed panels within, richly decorated with flowers 
 and shields. Many early roofs were altered to admit clerestory windows; and they were then 
 often framed in a somewhat similar manner to a double floor, with principals of curved timbers 
 to obtain doubly inclined planes. I lie slight lateral cohesion of the fibres of fir, now chiefly 
 used for roofs, and its liability to split, rendered it unsuitable for the Mediaeval carpenter’s re- 
 quirements. Admirably seasoned oak was adopted, the timbers being secured by means of oak 
 pins, and halved, morticed, tenoned and framed with the utmost exactitude, the mouldings cut 
 out of the solid, and no iron, not even a nail, was used. The purlins, instead of laying over 
 the principals, are usually framed into them; and the rafters are thus flush with the top of the 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 35 
 
 latter. Colour and gilding were often introduced within; and lead, weighing about 10 pounds 
 to the superficial foot, was commonly used outside. We should observe that stone roofs, con- 
 fined chiefly to porches, apses and vestries, are found dating from the twelfth century. The 
 church at Losches, in Touraine, is entirely covered with this material. Long after their epoch 
 the forms of Mediaeval roofs continued partially in vogue. That of the cathedral of Versailles, 
 commenced in 1743, may he cited; and, on glancing at a section of the roof at Hampton Court, 
 we at once perceive the origin of the form which Mansard has wrongly the credit of inventing. 
 
 There are still remains in England of timber domestic habitations of the 
 fourteenth century. Those at Wingham, in Kent, Salisbury and York may be mentioned; and 
 it was at this time that bargeboards, with pinnacles and hip knobs to gables were introduced. 
 In the fifteenth century wainscoting began to be employed in the principal apartments, the linen 
 pattern being a particular favourite. Of the ornamental timber and plaster style of Elizabeth’s 
 age, one of the earliest remaining instances is a house in the market place at Newark. The 
 fronts were usually nearly all window. Harrison quaintly remarks; • — “Of the curiousnesse 
 of these piles I speake not, sith our workmen are grown generallie to such an excellence of 
 devise in the frames now made, that they farre passe the finest of the old. It is a worlde to see 
 how divers men being bent to buildinge, and having a delectable view in upending of their goodes 
 by that trade, doo dailie imagine new devises of their owne to guide their workmen withall.” 
 We put some of these words in italics as a hint to the present generation. But it is to be 
 wished that amateurs would now confine themselves to writing and talking, instead of contriving 
 “new devises” quite “their owne.” In the interior of the above houses the ceilings are impor- 
 tant features. The girders of the superincumbent floor formed the chief divisions, and within 
 these ribs of oak and plaster subdivided the space. Where the joists are visible, as at the 
 Marquis of Granby public house at Colchester, they were chamfered and sometimes carved. The 
 staircases are often richly decorated. Exterior wooden galleries become very usual in the 
 early part of the seventeenth century. 
 
 On the revival of classical after the decline of Gothic architecture, car- 
 pentry and joinery occupied a full share of attention. Many houses, of which Emy has given 
 a French example on his title page, were erected entirely of timber. It was in Italy, however, 
 that the new style was first developed; and many natives of that country greatly distinguished 
 
 themselves in the arts now under consideration. Serlio, who was much employed in France, 
 
 illustrated, in his first hook, a remarkable method of constructing naked flooring with short 
 timbers, on which subject Dr. Wallis afterwards made some elaborate calculations. The 
 former also contrived many ingenious forms of roofs and modes of framing doors. Alberti 
 makes some useful remarks on timber and carpentry; but, without citing the long list of Italian 
 authors, Ave may mention Palladio as the most distinguished. In carpentry he is particularly 
 celebrated for his bridges, of which avc shall give some examples; for, as Tredgold remarks: 
 “Many of the designs of the present time are merely improvements of the principles ex- 
 hibited in his valuable work. He appears to have been the first among the moderns Avho 
 attempted a species of construction that Avould render numerous piers unnecessary, and so as to 
 avoid exposing any part of the timber Avork to the shock of bodies carried doAvn by the current. 
 
 The bridge he erected over the torrent of Cismone, near Bassano, Avas of this kind, and the 
 
:U) SKETCH OF TIIF ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 span i OS foot.” The system of framed voissoirs m wood bridges is also attributed by the same 
 author to Palladio. Square scaffolding, used at the cathedral at Cologne from 1248, was suc- 
 cessfully employed by Domenico Fontana in 1586 to raise in front of St. Peter’s in Pome the 
 obelisk brought from Egypt. Some views of the method adopted are given in the work on 
 scaffolding and machines, perhaps the most valuable book of its kind in existence, published in 
 1743 , and bearing Zahalgia’s name. The praises of this last mentioned person were recorded by 
 Caylus and sung by the Passeroni; for he was originally a working carpenter, and was ulti- 
 mately made superintendent of the works at St. Peter’s. Fontana has preserved the form of 
 
 the scaffolding used by Michael Angelo in the 
 construction of the vaults to the nave of that ca- 
 thedral; and, on glancing at the section in the 
 margin, it will be perceived that it satisfies all 
 the requirements of resistance and stability. The 
 second figure, also from Fontana, is the centering 
 of the dome. As we shall give details of the fol- 
 lowing, it is here needful only to mention the 
 ingenious rolling scaffold for the repair of the 
 vaulted nave, and the flying scaffold for that of 
 the dome of St. Peter’s, both designed by Pietro 
 Albertini in 1776, together with the contrivance 
 of Companarino in 1756 for the restoration of the 
 dome of the Roman Pantheon. As Cresy justly 
 remarks, it “rivalled all others in the beauty of 
 its design and the delicacy of its execution.” 
 
 Before speaking of the ad- 
 vances made by the French in carpentry and 
 joinery, we have a few observations to make on some works executed by other continental 
 nations besides the Italians. At Schaffhausen, in Switzerland, one of the boldest timber bridges 
 ever designed was commenced in 1758 and finished in three years by Ulric Grubemnan, a vil- 
 lage carpenter of the canton of Appenzel. It was burnt by the French in 1799, after having 
 been repaired and raised in 1783 by the carpenter Spengler. In the middle of the stream was 
 a stone pier; and the two arches of the. bridge were respectively 193 and 172 feet in length, 
 the breadth of the roadway being 18 feet. John, the brother of Ulric, was also celebrated for 
 his skill. lie erected a bridge at Kniehenaw; and the brothers conjointly designed and super- 
 intended the formation of the bridge near Witten gen, and some other structures. Price, in 
 his I intis! i < m-penter , had suggested the use of arched ribs similar to those employed at Sehaff- 
 hausen twenty lour years previous to its erection. But it does not appear that Grubenman was 
 aware ol the existence of the book; and it is not improbable that he had never seen Palladio’s 
 work, ami was ignorant ol the construction of Trajan’s bridge. Between 1807, and 1809, several 
 I*' idges were erected by Wiebeking, a Bavarian engineer, who greatly improved the general 
 s '"‘ m "1 construction with curved ribs. The bridges at Freysingen, Ettringen, and Bamberg 
 an among his works, the latter having a span of 206 feet. Ritters, a Lucerne carpenter, 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 37 
 
 constructed a bridge at Mellingen. Another celebrated carpenter, Styerme of Wurtemberg, in- 
 vented and applied to roofs, domes and bridges an ingenious system of framing, which we shall 
 hereafter explain, as well as that of Laves, the Hanoverian architect. A master carpenter of 
 Germany designed the extraordinary roof, 235 feet in span, of the Riding House in Moscow. 
 According to Rondelet it was never executed, although given as such by Ivrafft, whose ob- 
 servations are repeated by Tredgold. 
 
 It is to the French, however, that credit is chiefly due for the modern 
 improvements in carpentry. An illustrious race of architects ably seconded the efforts made by 
 the Italians on the rise of modern civilization. So celebrated indeed did many of them become 
 that they were called to different parts of Europe to design and superintend the erection of 
 various edifices, Blondel, De Cottc and Boffrand, in particular, being much employed in Ger- 
 many. Bellidor, Gautier, .Tousse, Regemorte, Cessart, Gauthey, Perronet, Pitot and Couplet 
 advanced more or less the science of constructing hydraulic erections, the last four giving much 
 attention to centering. Bellidor, an artillery officer, pointed out in his Hydraulic Architecture its 
 theory, before neglected by practical men. Gautier’s large volume indicates ancient and modern 
 bridges. Perronet’s work On Bridges is a magnificent production. Pitot's remarks are very 
 valuable; and Couplet, among other matters, refers to portable bridges. Derand is another 
 French author who has treated carpentry with great clearness and given some useful illustra- 
 tions. Perrault, the celebrated designer of the Louvre and a physician by profession, published 
 in the latter part of the seventeenth century a collection of machines for raising heavy weights. 
 Much of value relating to the carpenter’s and joiner’s arts is found in the works, some of them 
 quite recent, of D’Aviler, Bullet, Briseaux, Blondel, Douliot, Desorge, Derand, Mesauge, Des- 
 fourneaux, Roubo, Jansen, Normand, Coulon, Pierrot, Krafft. Rondelet, Emy, Scanzin, and Blouet. 
 
 Numerous useful manuals have also been published, of which those of Protot 
 de Reims, Nosban, Le Page and Hamus, and Biston may be mentioned. From Roubo’s celebrated 
 book on joinery, which forms part of the series of Arts and Trades and appeared in 1771, we 
 learn that the art first began to assume importance in France in the reign of Louis XIII. In 
 1788, Hassenfratz and Monge were charged by the Academy of Sciences to produce a complete 
 work on carpentry, but the first volume only by the former has appeared (1804.) Krafft 
 succeeded in bringing together in one volume, published in 1 805, some of the most remarkable 
 pieces of carpentry executed before and in his -time. The departments of Rondelet’s Art of 
 Building (1814) relating to carpentry and joinery are very valuable; and Blouet, in his Supple- 
 ment, to Rondelet (1848) has surveyed construction “from the point of view of art.” Of Emy’s 
 elaborate 'Treatise on Carpentry we have before spoken. 
 
 But the French are still more distinguished for their executed productions. 
 Perceiving the defective height of the roofs in his time and the manner, in which they seemed 
 to crush the buildings beneath them, J. II. Mansard extensively employed the curbed roofs 
 to which his name has been given. We pointed out the example at Hampton Court; and 
 Krafft has shown that many were built in France in the latter part of the fifteenth century, 
 before Mansard’s time. The dome of the Invalides in Paris, one of the most remarkable works 
 of the age, and of which a detail will be given, was designed by Mansard; and the domes of 
 Jousse and Fourneau are also ingenious contrivances. In wood bridges the French are not 
 
 O o 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 :i8 
 
 behindhand, as may be inferred from the list of authors previously cited. . That of the Cite, 
 in Paris, and those by Aubrey and Molard, consist of combinations of iron and timber; and we 
 may mention Migneron, Emmery, Bruyere, Ezel, Morand, Coffinet, and Scanzin as having 
 executed remarkable works. 
 
 AVe are not exactly following the order of time, and propose now to refer 
 to the valuable improvement by Philibert Delorme, which has been the fruitful mother of suc- 
 ceeding inventions. This architect published A complete Treatise on the Art of Building, and, 
 in 1561, a work entitled New Inventions to build well at little Cost. The consumption of wood in 
 France had become so extreme that alarm was felt in contemplation of the comparative failure 
 of the supply. What with the requirements for combustion, for buildings', and the navy, for 
 the purposes of which latter no substitute for timber could be devised, it was deemed essential 
 to impose laws regulating its sale and giving to the government a primary right to choose its 
 provision. Economy was thus of the first importance; and it became desirable to contrive a 
 method of building civil edificies with timbers of smaller dimensions than those hitherto adopted. 
 This was the origin of the speculations of Delorme. His invention consisted in the construction 
 of roofs and domes, in which the largest timbers were used, with a series of arched ribs, formed 
 of planks, three or four feet long, one foot wide and one inch in thickness, bolted together 
 
 and fixed at their feet on strong level plates. Horizontal 
 rings of thin boards, with edges curved, were placed at 
 intervals in the height to steady the meridian-like rings and 
 prevent change of curvature. As the pressure is directly 
 downward, outward thrust on the walls is avoided; and 
 the ribs spring from the latter at intervals of about three 
 feet, each consisting of two or three planks, unbent, but cut 
 to the requisite curve. The beauty of the method is very 
 striking, and the internal space and effect obtained by it 
 sufficiently obvious. 
 
 But, strange as it may seem, this 
 construction had few partisans until the execution of 
 the cupola of the Halle aux Bles in Paris, which was 
 undertaken by Roubo under the direction of M. M. Legrand and Molino, the latter a self- 
 educated carpenter. Ever since the system has been extensively adopted. It was successfully 
 applied by Air. Sydney Smirke to the central compartment, 38 feet span, of the Pantheon 
 Bazaar, London; and, in this Encyclopiedia, an instance will be given in which an iron rib 
 i> introduced between the planks forming the principals of the roof over the Swiss Church, 
 London, with the working drawings of which we have been favoured by the architect, Mr. 
 fieorge Vulliamy. 
 
 As is generally the case with inventions, it has been attempted to 
 dimmish the credit due to Delorme. Serlio, who died in 1552, is reported to have observed 
 similar construction in repairing the palace of Tournelles. The domes of St. Mark and Della 
 Salim- at \ enice, the former completed in 1085, are also mentioned.. With reference to these 
 structures we may observe, in the first place, that there is no reason to presume Delorme was 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 39 
 
 aware of their formation; and, in the second, they materially differ from the forms given in 
 his work. The original assemblage, and the connexion of the ribs by cross keys, are, in 
 their simplicity and beauty, truly the production of a master mind. Rondelet has exaggerated 
 the expense; for Emy has demonstrated that the method w r as the cheapest devised at the time 
 in cases where large timbers could not be produced. 
 
 Various modifications have been made on the system of Delorme, and 
 we shall illustrate that of Lacase; but it was reserved for Emy to remodel the old mode of 
 procedure. Observing the waste of material in cutting the planks, the great labour involved 
 in comparison with roofs of the ordinary forms, and the extra strength requisite to provide 
 for the effects of cross strains, as the lateral cohesion of the fibres constitutes the strength of 
 the ribs, he invented the disposition shown in our three first plates of Practical Examples. As 
 we shall again refer to these, it is only needful here to mention that, whereas in the system of 
 Delorme the planks forming the principal are cut to the curve, in Emy’s they are bent in the 
 direction of the fibres on templets to the proper form. The number of joints is therefore di- 
 minished, and the cost of workmanship and the quantity of material wonderfully decreased. 
 As the planks are bolted together and prevented separating by iron straps and radiating struts 
 in pairs, so notched as to secure the ribs, they can, in few circumstances, yield under less 
 than a crushing force. 
 
 We shall next glance at the progression of that important branch of 
 carpentry which relates to the stress and strength of timber. And it must be confessed that 
 its present scientific state is due to engineers rather than to architects. More especially is it 
 owing to persons unconnected with the arts now under consideration, except through pursuing 
 general science. This is the case Avith respect to most of the men whose names Ave have 
 shortly to mention. Du Hamel, Muschenbroeck and Varennes Avere physicians; and, although 
 English Avriters have latterly contributed to mature our knowledge, they cannot even be com- 
 pared Avith the foreigners. Long ago it Avas remarked in the Edinburgh Review, Avhen criticising 
 an Italian author, that: — “While Ave give ourselves infinite trouble to pursue investigations 
 relating to the motions and masses of bodies which move at immeasurable distances from our 
 planet, Ave have never thought of determining the forces necessary to prevent the roofs of our 
 houses from falling on our heads.” Galileo, Wortzius, Grandi, Mariotte, Leibnitz, Bernouilli, 
 Euler, Lagrange, Parent, Bellidor, Muschenbroeck, Perronet, De la Hire, Couplet, Lamande, 
 Minard, Desormes, Lamblardie, Pitot, Parent, Bulfinger, Varignon, Coulomb, Du Hamel, Buffon, 
 Girard and Rondelet, form a long list, against Avhich the shorter one consisting of the names 
 of the Englishmen, Emerson, Gregory, Hutton, Wallis, Banks, Hooke, Robison, Young, Rennie, 
 BarloAV, Tredgold and Hodgkinson, is to be balanced. 
 
 In the Dialogues of Galileo, published in 1633, and the materials of 
 Avhich Avere first derived from observations in the dock-yards of Venice, this celebrated philo- 
 sopher endeavoured to connect Avith geometry, upon pure principles of mathematics, the strength 
 of beams, considering it Avith reference to their size and general forms. The defects of Galileo’s 
 hypotheses Avere exposed in 1680, by the actual experiments of Mariotte. He Avas one of the 
 first members of the Academy of Sciences. A collection of his Avorks Avas published in tAVO vo- 
 lumes at Leyden in 1717, and another edition at the Hague in 1740. Leibnitz, theorising only, 
 
40 
 
 SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 rather retrograded than otherwise in his endeavour to advance beyond the above authors. His 
 ideas appeared in the Leipzig Adz in 1684. James Bernouilli, however, Avho first investigated 
 the intricate problem of the elastic curve, continued in an onward direction. ( Complete works, 
 two volumes, Geneva, 1744.) as did afterwards Eider and Lagrange. The former was the first 
 modern who investigated with attention the compression of columns ( Berlin Memoirs, 1757, 
 Petersburg/! Commentaries, 177X.); and both say much on what they called the absolute and rela- 
 tive elasticities of wood, but neither experimented. It was during the first few years of the 
 eighteenth century that the last named authors first gave to the world the results of their 
 inquiries. In the Memoirs of the Academy of Sciences (1707, 1708.) are found the results of 
 many researches by Parent, which were greatly confirmed by Bellidor in bis Science for Engi- 
 neers (1729), which latter work contains a very complete series of experiments. Muschenbroeek 
 differs from the last named authors in his System of Natural Philosophy ; but the men 
 who have chiefly contributed to establish the correct theory of the strength of materials arc, 
 together with Rondelet (Art of Building 1814.), I)u Hamel and the naturalist Buffon. The 
 French Government, so much more liberal to scientific men than our own, supplied funds to 
 the two latter, as it afterwards did to Girard, for the prosecution of experimental researches. 
 The latter gave the results of observations on the flexure of fir and oak in bis Analytical Trea- 
 tise on the Resistance of Solids. His deductions are conjoined with the hypotheses of Mariottc 
 and Leibnitz; and the experiments, although made since, are less to be relied on than those of 
 Buffon. These latter were protracted during two years, and they are published in The Memoirs 
 of the Academy of Sciences (1768. 1740. 1741. 1712. 1768.) The experiments of Du Hapiel ap- 
 peared in his works On the Cultivation of Trees (1769) and On the Preservation and Transporta- 
 tion oj II oocl (1767) In the proper place we shall present some of these author’s conclusions, 
 our sole object now being to give the student an idea of the progress of the theory of construc- 
 tion. Buffon s experiments on pieces of oak, of a larger size than those previously chosen, are 
 peculiarly valuable; and Rondelet’ s are probably still more satisfactory. 
 
 As before noticed, it is only of late years that much of value lias been 
 done in England to determine the strength of timber; and Robison remarked that, “it is singu- 
 lar no writer has treated of it in the detail which its difficulty and importance demand.'’ The 
 theory of this author (Encyclopaedia Britan nica, and System of Mechanical Philosophy, with notes 
 l>y Sir Dand Brewster, 1X22.) is chiefly founded on the investigations of Leibnitz; and Barlow’s 
 conclusions agree less with it and Muschenbroeck’s experiments than with those of Buffon. The 
 results of experiments made in the government dockyards do not constitute the least useful 
 portion oi Barlow’s book On the Strength and Stress of Timber (1867.) To Dr. Thomas Young we 
 arc indebted for the development of the laws of flexure in his Lectures on Natural Philosophy. 
 He did not support them by experiments; but Tredgold gave a practical character in adding 
 to die doctors speculations. ( Elementary Principles of Carpentry, 1X20.) 
 
 It may be useful to note that, among others, Muschenbroeek, Pitot, Parent, 
 Knnddet, Emerson, Rennie, Barlow and Tredgold, experimented on the absolute strength, or 
 < uhesive force, of wood; and \arignon, Bellidor, Parent, Buffon, Du Hamel, Lamblardie, Girard, 
 Knnddet, Barlow and I redgold, on its transverse strength. Galileo, Wortzius, Grandi, Mariotte, 
 Leibnitz, Euler, \ arignon, Bernouilli, Lagrange, Robison, Young, etc., considered the abstract 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 41 
 
 theory. Again, Mariotte, Parent, Varignon, Bellidor, Lamblardie, and Girard, endeavoured 
 to determine the resistance of timbers by the simple consideration of their dimensions; while 
 others, as Du Hamel, etc., have also sought to settle their strength when combined. Mariotte, 
 Parent, Varignon, Bellidor, Du Hamel and Muschenbroeck experimented on small pieces of 
 wood, and Button, Lamblardie' and Girard on those of large dimensions. That the results of 
 various experiments should greatly differ is not surprising when we remember the differences 
 in the sizes of the pieces of wood employed, as well as the variations in texture of the same 
 kinds of timber, the fractures hastened by the occurrence of knots, and the peculiarities caused 
 by diversities of soil and other circumstances. 
 
 Coming next to that department of geometry which relates to the lines 
 for works in carpentry and joinery, are again found the French, in the advanced rank. To the 
 celebrated Gaspard Monge we owe the formation of descriptive geometry into a distinct system. 
 In 1705 he published a work under that title; and, on the basis then laid, it has been applied 
 to the industrial arts, such as carpentry, joinery, masonry, and also to fortification, dialling, per- 
 spective, etc. Before Monge’s time there was very little method in the requisite delineations. 
 The various solutions, invented for the purpose of the moment, were, in general, applicable to 
 it alone, and often extremely laborious and complicated. And the great merit of Monge consists 
 in having indicated the theory of descriptive geometry, besides sketching a philosophical system 
 of the mechanical arts and pointing the direction in which this object should be followed. He 
 long taught in the military school of Mezieres the science he had created; and it has since be- 
 come an important department of instruction in the Polytechnic and normal schools in France. 
 In 1739, Frezier published his Cutting of Stones and Wood, entering with great minuteness 
 into the several subjects of masonry, carpentry and joinery. Mathurin Jousse, Nicholas 
 Fourneau, Ausseur, and others, have also composed treatises on the cutting of wood, the 
 work of the second, a skilful carpenter, being of a particularly practical character with respect 
 to finding the lines. 
 
 The English books on the practice of carpentry and joinery, published 
 about the period of the above works, are chiefly remarkable for their extreme brevity. In this 
 respect they are very unsatisfactory and contrast strikingly with the foreign productions. Their 
 authors, in fact, were destitute of the broad views and thorough knowledge of practical details 
 so fully manifested by their continental brethren. In the reign of Charles the Second, in 1977, 
 two years before the first stone of St. Paul’s cathedral was laid, the earliest English book in which 
 joinery was considered appeared from the pen of Moxon, a Fellow of the Royal Society. It 
 came out in monthly parts, and was entitled Mechanick Exercises, or the Doctrine of Handyworks. 
 The technical words in use, the tools, and some manual operations, are superficially touched 
 upon, the book being oi very slight practical utility. One- might naturally expect to find some 
 remarks on the formation of sash windows, which were only then becoming common, but they 
 are not even mentioned. Godfrey Richards’ Palladio, published in 1716, six years after the 
 completion of St. Paul’s, is the first book in which carpentry is treated. In addition to remarks 
 by Richards, a rule is given for finding the length of hips and valleys, with the back or hip 
 mould. We can form an idea of the then state of things from the flourish with which this 
 invention was heralded. It is stated to have been “never yet published by any architect, 
 
 VI 
 
42 
 
 SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 modern or antique; a curiosity worth the regard even of the most curious workman; exactly 
 demonstrated in the rules and designs by that ingenious architect Mr. William Pope, of Lon- 
 don." \ discovery by Newton, altering the whole aspect of science, could hardly have been 
 introduced in more flaming terms than this rule for finding the length of hips and valleys. 
 Halfpenny’s Art of Sound Building appeared in 1725. It included lines for groins, angle 
 brackets, and an imperfect endeavour to facilitate the construction of handrails. In this latter 
 respect Price made a decided advance. His British Carpenter, published in 1733, must have 
 been very welcome to operatives. This author is generally very correct in his ideas, displaying 
 much discrimination in framings and joints, and he laid down numerous principles which have 
 been quietly appropriated by other writers. The method of covering a dome by boards bending 
 from the base upwards, and the lines for handrails and raking mouldings, are very ingenious. 
 A dome, designed by Price, still attracts attention, together with a bridge in which curved 
 ribs are employed. We have alluded to Schaffhausen, and may mention that the well known 
 bridge by Bludget at Portsmouth, U. S., is a close copy, on a large scale, of Price’s design. 
 Oakley, in his Magazine of Architecture (1730), kept to the sense of his title, transferring much 
 from other authors, particularly from Halfpenny. The Carpenters Companion (1733) by Smith 
 contains some sound practical advice together with tables of scantlings and thirty-three plates. 
 Many of the latter are very useful, but there is nothing new in the lines. Hoppus’s Builder’s 
 Repository includes information which, as before remarked, Oakley derived from Halfpenny. 
 Batty Langley’s Builders Complete Assistant ( 1 7 3 s ) presents some improvements in handrails. 
 He was, however, too apt to appropriate the ideas of other authors, labouring under the de- 
 lusion that nearly everything in his book was his sole “invention.” Of one of these “inven- 
 tions” no one has hitherto been ambitious of seizing the credit. And certainly no person be- 
 fore Langley’s time ever conceived and worked out the system of Gothic architecture which 
 is now the chief corner-stone of his fame; but unfortunately the celebrity thus acquired is not 
 of a description to be ardently desired. He kept a kind of school, and his pupils, all carpenters 
 and joiners, Avere excellent workmen. Such assemblages present many advantages; and, long 
 after Langleys time, Wyatt endeavoured to promote an union among superior operatives. 
 The Builder’s and Workman's Treasury and The Builders Jewel are also works by Langley, 
 who does not appear to have been extremely diffident with respect to the titles of his pro- 
 ductions. Salmon dilated on stairs, handrails and raking mouldings in his London Art of Build- 
 ing, which appeared about the same time as the last mentioned books. r I'he British Architect, 
 and Designs in Carpentry (1759) by Swan contain some noticeable ideas, among others the 
 formation of boards laid horizontally to line domes. Ware’s Complete Body of Architecture (1756) 
 is chiefly tilled with ornamental classic designs. Pain's numerous Avorks on carpentry and 
 joinery, ranging betAveen 1774, and 1791, contain much which is useful, particularly the mode of 
 lining a eylindric soffit in a circular wall. His staircases are also good; but many of the lines 
 arc extremely unintelligible as well as erroneous in principle. 
 
 1 he above authors appear to have worked with little or no idea of the 
 successful labours ot their continental brethren. As is remarked in the Encyclopaedia Britan- 
 "" 7 , ’ Much of Avhat has been given as neAv in English Avorks had been long known on the 
 continent; but there does not appear to have been much, if any, assistance derived from these 
 
SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 43 
 
 foreign works by any writer prior to Nicholson,” who, we may add, acquired sufficient know- 
 ledge of French to translate mathematical works, and, at one time, visited France. Mathematics 
 was his favourite study; and it is to the department of this science relating to the application of 
 geometry to construction that his improvements are chiefly confined. The two first works he 
 wrote, The Carpenters Guide and The Carpenters and Joiners Assistant , were both published 
 in 1792. These were followed by twenty-five valuable books on almost every department 
 of building. 
 
 . Peter Nicholson was unquestionably a man of considerable ingenuity and 
 
 great industry, devoted to his vocation with such disinterestedness that he died in absolute 
 poverty. The last years of this remarkable man were chiefly occupied in teaching drawing; 
 and we can picture him, with kind patience and all the enthusiasm of his youth, dilating to 
 stupid pupils on the mysteries of geometry and projection. We can picture this, — we can 
 recall his great services, and rightly blame the government, which was interceded with, but 
 did nothing, for the old man. Musing by his comfortless fireside on what he really had achieved 
 to advance the practical knowledge of architecture, we can pardon occasional forgetfulness of 
 the authors to whom he owed many of his ideas. He had dressed their conceptions in new 
 forms, better suited to the comprehension of some workmen, and he truly believed all to be 
 his own. In the Architectural Dictionary he has stated what lie conceived to be his sole in- 
 ventions. Their value excuses the apparently complacent tone; and those who would criticise 
 his works by a not altogether applicable standard should recollect how powerfully they have 
 been instrumental in diffusing, among artificers in particular, a correct knowledge of the prin- 
 ciples and practice of the arts of construction. 
 
 There are still many matters on which we are inclined to dilate, more 
 especially the timber works latterly executed in America, many of which are exceedingly 
 remarkable; and the consideration of the extensive use of iron conjointly with wood would 
 occupy great space. But Ave have endeavoured to indicate the main features in the progress 
 of carpentry and joinery, believing that no art can be fully understood without some acquaint- 
 ance with its history. Freely translating and condensing the eloquent words of Emy, it may 
 be permitted to conclude with them, and the reader who has read thus far will probably 
 endorse their truth. 
 
 If it is considered how much the progress of the art of fashioning wood 
 has contributed to the well-being of mankind, we rest convinced that the art of the carpenter 
 has been one of the first to arrive at comparative perfection, and that it has stimulated the 
 progress of many other vocations, in order to obtain the tools and machines which its inventions 
 have required. Its dignity is not misplaced when, as the father of architecture, it is now 
 claimed in the noble rank of the Fine Arts; for the forms observed in the finest stone edifices 
 are virtually due to the happy imitation of early timber constructions. In truth, architec- 
 ture, in its turn, has borrowed the help of science in displaying to the carpenter the immense 
 resources of his art to produce the boldest and most elegant combinations; but in constructions, 
 in which carpentry does not form a principal portion, of building, securing the foundations 
 by consolidating the soil, dividing the height into stages to multiply space, or forming a roof 
 for protection, it still provides the means for raising and distributing the materials, to sustain 
 
44 
 
 SKETCH OF THE ORIGIN AND PROGRESS OF CARPENTRY AND JOINERY. 
 
 the different workmen, and to facilitate the Construction of vaults. In the transport and erection 
 of grand monuments, it is carpentry which supplies mechanics its principal material for the 
 application of power to move gigantic masses; and it is to its supports that ancient edifices 
 owe the continuance of their duration. 
 
 Carpentry plays no less important a part in naval architecture, since it 
 constitutes its principal portion. To it also is due the origin, models, means of raising, and 
 the design, study and execution of iron buildings. Even now a scientific knowledge of the 
 art of carpentry is hardly less needful to the constructor in iron than to the constructor in wood. 
 
 In grand erections of every description we almost always observe the 
 prominence of carpenters. Their skill in accurately delineating objects before they are executed, 
 the constant use of a multitude of tools, cordages and machines, as powerful as they are simple, 
 and the bodily vigour which the practice of the art maintains, render them admirably adapted 
 for tasks in which judgment must be sure and rapid, and promptitude of execution conjoined 
 with strength and skill. 
 
 The profession of the carpenter is truly one of the finest in the art of 
 building. In the knowledge requisite to practice it as a master, and the intelligence necessary 
 in the humblest workman, it yields to no other vocation, standing as it does in the foremost 
 rank of utility in the execution of edifices as well as in their design. 
 
SECOND DIVISION. 
 
 MATERIALS. 
 
 CHAPTER I. 
 
 ON II M ?> E R G E N E R A L L Y. 
 
 DEFINITIONS. Trees are defined by Evelyn to be “such ligneous and 
 woody plants as are bard of substance, procere (tall) of stature; that are thick and solid, and 
 stiffly adhere to the ground on which they stand.” That part of trees which possesses a certain 
 amount of firmness and strength, rendering it suitable for mechanical purposes, goes under the 
 general denomination of timber; and wood is a synonymous term, although perhaps not so fully 
 expressive as timber of size and adaptation for construction. 
 
 ADVANTAGES. On the great value of timber for constructive pur- 
 poses, whether in engineering, architecture, or ship building, little need be said, “since it is 
 certain and demonstrable that all arts and artisans whatsoever must fail and cease if there 
 were no timber and wood in a nation; for be that shall take his pen, and begin to set down 
 what art, mystery, or trade belonging any way to human life, could be maintained and exer- 
 cised without wood, will quickly find it will appear that we had better be without gold than 
 without timber.” (Evelyn.) 
 
 The abundance of trees, their convenient forms, the ease with which they 
 may be cut, the facility and economy of the application of their substance, from its lightness, 
 tenacity, elasticity and duration, indicate them- certainly as the earliest, and, even now, in 
 many respects, and under many circumstances, the most appropriate material for a great 
 variety of constructions. 
 
 Noah “made himself an ark of gopher (cypress) wood”; and the utensils 
 discovered at Nineveh and the Egyptian mummy cases show that in far antiquity the choice 
 of wood most appropriate to the purpose and least liable to decay was intimately studied. In 
 England, King Arthur’s round table, the coronation chair in Westminster Abbey, and other 
 ancient remains, prove a similar discrimination conjoined with mechanical skill. 
 
 Stone resists alternations of moisture and dryness better than timber, and 
 is less liable to alterations of form, but it is inferior in facility of transport, and is not less 
 'fragile. It is evident that timber can be employed in numerous cases where stone is unsuitable ; 
 for it may be placed in a vast variety of positions and inclinations, combined to form convenient 
 compartments, and joined with the utmost facility, .\bove all, its lightness renders it a very 
 
ON TIMBER GENERALLY. 
 
 40 
 
 desirable material; and the rapidity with which wood structures can be raised and separated 
 into divisions in height and length, especially works of a temporary character, is not the least 
 of their advantages. For many parts of buildings, intended for long duration, as partitions, etc., 
 wood is oftentimes the preferable material. With respect to cost, Hassenfratz has calculated 
 that a wooden house is half as expensive as one of brick or stone. Belmas observes that in 
 France iron roofs are four, five or six times more costly than those of wood, and that their 
 superiority in point of duration is only felt after so considerable a lapse of time as to be quite 
 inappreciable; The substitution of iron for wood was considered by the same author as often 
 quite inexcusable, except when the latter is excessively dear; as, of course, an immediate return 
 of interest on the capital invested is, in most cases, of primary importance. The liability of 
 timber to combustion is, however, a forcible objection; but, with respect to roofs, they are 
 usually the last part of a building which is burnt. As we remarked in The Builder's Practical 
 Director: — ”In case of fire, iron columns become so heated that they first crumble and then 
 melt rapidly, or they are split by the water from the engines; and good solid timber posts can 
 be more reckoned on for their time of duration, greater confidence being then felt on entering 
 a burning edifice, iron columns giving way suddenly, the water accelerating their destruction, 
 but doing good to those of wood.” 
 
 PHYSIOLOGY. There are two great classes of trees, the Dicotyledo- 
 nous , or Exogenous, and the Monocotyledonous, or Endogenous. 
 The diagrams in the margin illustrate their differences, the two 
 lower ones being horizontal, or transverse, and the upper longi- 
 tudinal, or vertical sections. In the Exogenous class there are, 
 as 
 
 in a concentric manner round the centre, or pith, and increasing 
 in diameter to the outer part, or bark. There are also fine di- 
 visions, radiating from the pith to the bark, and called lesser 
 transverse septa, but it is often necessary in order to perceive 
 
 them to make use of a microscope. In many woods larger 
 
 rays arc readily observed. These are called larger transverse 
 l-.rngenous, („■ Endogenous, or septa, or silver grain, from their light, glossy, silvery appearance. 
 
 Dicotyledonous. .1 fonocotyledonous . 
 
 They give a very ornamental, flowered, satiny lustre to many 
 woods. ( )ak may be distinguished from chesnut by its having the silver grain which is absent 
 in the latter; but the word is often applied to both the larger and smaller septa. The term 
 
 medullary is also given to the rays from the pith to the bark, which apparently constitute the 
 
 chief strength of the wood, are seen in what is called the grain, and materially aid the deter- 
 mination of the different varieties of exogens. We may mention that Alder, Beech, Oak, 
 Plane and Sycamore, have larger transverse septa; while Ash, Cedar, Chesnut, Elm, Larch, 
 Mahogany, Pines, Poplar, Teak and Walnut, are not so distinguished. 
 
 Sap-wood is called alburnum, the hard or perfect inner, or heart-wood, the 
 duramen, and the outer layer formed every year the liber. On this last substance, the name 
 of which is the Latin for a book, the ancients wrote. The epidermis is the outer tissue of the 
 bark, often observed to be cracked; and- bole is the technical phrase for the trunk. A secretion, 
 
 perceived in the transverse section, separate rings, disposed 
 
ON TIMBER GENERALLY. 
 
 47 
 
 supposed by some to form the wood, is called cambium. Common sap is that which rises from 
 the root; the returning fluid is the proper sap. The bark, or outer cuticle, consists of four parts, 
 called the epidermis, the cutis, the cellular, and the liber, the last being inmost and the chief 
 seat of the vital action. Round the pith, in the centre of the tree, is the medullary sheath, con- 
 sisting of ducts and spiral vessels communicating with the stalks; the woody layers are placed 
 next; and the medullary rays, before mentioned, consist of cells lengthened across the grain, 
 binding the wood together, while permitting the passage of fluids. The trunk is the main 
 stem of a tree, branches spring from this, boughs from the branches, and twigs, bearing leaves, 
 from the boughs. 
 
 Such is the general nomenclature, enabling us to comprehend what we 
 are talking about, and to form clear ideas on the subject. The pith governs the section of a 
 tree; the distance between the concentric layers is seldom equal, or the form strictly circular, 
 # exposure to the sun and air affecting their shape. While trees are growing, the outer layers 
 are the weakest, and the inner, or heart-wood, the strongest, but as they approach -maturity a 
 corresponding uniformity is established: oriental trees are, we believe, hardest towards the bark. 
 Sap-wood of course contains the juices which ferment and nutritive matter subject to decay. 
 As its vessels lose their juices they become converted into heart-wood; and the woody tissue 
 gives firmness to the parts of the trunk. Sap-wood is lighter, softer and more even in colour 
 than heart- w T ood. The division between the two is usually distinct; and the relative quantity 
 of sap-wood greatly varies. In box wood there is very little; in snake wood it engrosses tw r o- 
 thirds of ,the diameter of the trunk. Occasionally there is a striking contrast between the sap 
 and heart-woods, as in ebony, the black part being the heart-wood; that of oak is dark brown. 
 In w’hat are called white woods, as poplar and willow, there is no distinction in colour between 
 the heart and sap-woods. The pith is sometimes very preponderant, as in the elder, rendering 
 the wood almost valueless. 
 
 Chemically speaking, oxygen, hydrogen, and carbon are the ultimate 
 elements of wood. It may be stated as a compound of woody fibre, gum, starch, sugar and 
 vegetable acids; and on the variation in the combination of these the peculiarities depend. 
 
 Du Hamel was of opinion that wood is formed by a deposition of the cam- 
 bium; Linmeus derived it from the pith; and other naturalists have suggested a change of the liber. 
 
 Our remarks have hitherto applied to the Exogenous class of trees. We 
 have now a few observations to make on the Endogenous, or Monocotyledonous class. The term 
 Endogenous means produced within, and Exogenous produced without, thus separating the classes 
 by distinguishing their modes of growth. Monocotyledons again have one, and Dicotyledons two 
 seed lobes, or seminal leaves. The Endogenw include bamboos, palms, annuals and herbaceous 
 plants. They are not considered as proper woods, those trees only being deemed to produce 
 such which have two sets of fibres, the growth being external and consisting in annual additions, 
 or rings. If the reader glances at the section at the commencement of this article, he will 
 perceive that in the Endogens there are not the distinctions which characterise the Exogens, the 
 substance of the former appearing to be made up of ducts and fibres, mixed in cellular tissue, 
 without apparent central pith, and there being irregular dots, tolerably distinct in the centre, 
 but closely compressed round the circumference. Although this substance is very inferior to 
 
Is 
 
 ON TIMBER GENERALLY. 
 
 that of the Exorjemr for constructive purposes, palms are often used in their native countries 
 lor joists and beams; and the inhabitants of the Isthmus of Darien extract certain hard 
 
 fibre> from palms and use them as nails. 
 
 SOIL. CULTIVATION. Evelyn observes in The Sylva: — “This is a 
 '■eneral rule, what trees soever they be which grow tolerably either on hills or valleys, arise 
 to oreater -taturc, and spread more amply on the ground; but the timber is far better, and ol a 
 finer grain which grows upon the mountains, except only apple and pear trees. 1 he timber ol 
 those trees which grow in moist and shady places is not so good as that which comes from a 
 more exposed situation, nor is it so close, substantial and durable. 
 
 Stiff clay soils arc very congenial to oak trees, but the ground should 
 be well drained, or the accumulation of water will induce early decay. That oak is the strongest 
 and most durable which has grown on a soil raising it slowly, as its wood thus acquires great 
 consistency. But, under peculiar circumstances and in a favourable soil, some oak trees with, 
 timber fitted for considerable duration arrive at maturity in a very few years. We may also 
 mention that oak derived from falling acorns, and beech from the mast which lies in the wood, 
 are more to be depended on than those transplanted. With respect to firs, their various quali- 
 ties are eminently dependant on the characteristics of the soil on which they grow. Those, the 
 timber of which is of a red colour, are usually found on cold, stiff earths, and those on light and 
 f-andy lands have not the strength, duration, and solidity of the above, their colour being almost 
 white. Honduras mahagony flourishes on low, marshy ground; alder on a damp, boggy soil, 
 and many other trees will succeed in earth quite unsuited for agricultural purposes, the annual 
 fall <>f leaves being a species of manure, gradually accumulating a suitable soil. In most low, 
 watery land, however, the wood of trees is soft, with loose texture, and too much bark; while 
 in deep, well drained dry soils, it is compact, bard, dries rapidly and lias little bark. 
 
 Emy makes some valuable observations on the manner in which timber 
 is affected by the soil on which it grows. In general, he says, marshy ground bears trees whose 
 timber is light and spongy in comparison with those grown on good, elevated land. Sap does 
 not acquire the qualities essential for the formation of durable wood in low, clayey ground, 
 where the roots are nearly always half drowned. Timber from such sources is not adapted for 
 the carpenters purposes. Oak, for instance, from a watery soil is more fitted for joiner’s than 
 for carpenter’s work, because it has less strength and stiffness, and is softer and easier to work 
 than oak from a dry and elevated locality; and it is less subject to cleave and crack when 
 employed in objects of small size. Watery earths are proper for alders, poplars and willows; 
 and although some other trees flourish in fresh, humid ground, oaks, elms and chesnuts attain 
 perfection only in a dry soil, composed of good earth retaining after rain only the humidity 
 requisite for vegetation. It is the same with all resinous trees: they do not fully succeed in a 
 marshy soil. Generally, sandy ground agrees with them best, and some species flourish most 
 in the neighbourhood of the sea; such as the maritime pine, as useful for its resinous products 
 :ls l° r hs wood. In Hue, trees which grow in poor and stony soils, and generally in all which 
 oppose the free spread ol the roots, or which do not fully supply the essentials necessary 
 lor their formation, attain little height, grow slowly, and produce rough wood, often knotty 
 and stunted, difficult to work, and ft only for the most ordinary purposes. 
 
ON TIMBER GENERALLY. 
 
 49 
 
 The following catalogue of the soils in which different trees flourish 
 
 will be found useful. 
 
 NAME OF TREE. CHARACTERISTIC OF SOIL. 
 
 ACACIA LIGHT, DEEP, DRY, SANDY. 
 
 ALDER WET, MARSHY. 
 
 APPLE MOST TOLERABLE SOILS. 
 
 ASH MOIST. 
 
 BEECH RICH, MOIST. 
 
 BIRCH RATHER STONY. 
 
 CEDAR SANDY f , ELEVATED. 
 
 CHESNUT .... LOAMY GRAVEL. 
 
 BOX ...... DRY; WARM ASPECT. 
 
 ELM MARLY. 
 
 LARCH ELEVATED; NEITHER MARSHY NOR CLAYEY. 
 
 LAUREL ..... LIGHT; WARM ASPECT. 
 
 MAPLE THIN. 
 
 OAK MOST TOLERABLE SOILS. - 
 
 PEAR DO. 
 
 PINES SANDY, ELEVATED. 
 
 POPLAR . ... RICH, MOIST. 
 
 WALNUT MOIST SOILS; RICH, DEEP. 
 
 WILLOW .... MARSHY. 
 
 YEW MOST TOLERABLE SOILS. 
 
 GROWTH. SIZE. AGE. It is generally allowed that trees which rise 
 
 slowly yield more excellent timber than those whose growth is rapid. There are two divisions 
 of the process of increase; first, that in which the trunk is gradually elongated; and second, 
 when it has attained its full altitude and the branches augment in length and spread. The 
 rate of development varies considerably in different trees: oaks spread most rapidly when 
 thirty years old. 
 
 Of course, the upward growth and the spread of trees is dependant, not 
 only on the nature of the soil, but also on the degree of openness of the surrounding space, 
 whether or not it allows room for free development. It would appear, however, that a tree 
 closely environed by others often attains its full altitude more rapidly than one which is iso- 
 lated. This is explicable if we consider the energy of growth as concentrated in one direction 
 and precluded from spreading out in branches. The tree naturally rises towards the light and 
 air, as a plant near the window in a room will spread in a similar direction; and thus the 
 densest forests contain the loftiest trees. Cropping the branches has also great influence on 
 the upward growth. 
 
 We have given on Plate 16. two diagrams from Hassenfratz, representing 
 the height and size of the trunks of oaks with relation to the number of years of growth. In 
 Fig. 1. the line 5, 10, 20, 30, 40, 50, 60, indicate the years; and the lines 5 a, 10b, 20 c, 30 d, 
 40 e, 50 f, 60 g, mark the corresponding heights. The curve a, b, c, d, e, f, g, is called by 
 Hassenfratz the late of elongation of the trunk. The most rapid upward growth appears to 
 take place during the first ten years; then gradually diminishes until thirty years, after which 
 
 Carpentry. yxi 
 
50 
 
 ON TIMBER GENERALLY. 
 
 the dimunition is very considerable. In Fig. 2. the law of increase in volume is shown by the 
 curve a, f>, c, <1, e. The line 0, 20, 40, 60, indicates the years, and the lines 20 a, 40 b, 60c, 
 SO </, the circumferences. 
 
 There are many instances of trees attaining a very unusual size. We 
 have met with a description of a cypress at Alexo, in Mexico, 76 feet in girth; that of another 
 at Santa Maria del Tuli is said to be 118 feet. A vine is mentioned in ancient times from the 
 wood of which a statue of Jupiter and columns for a temple dedicated to Juno were formed. 
 The great doors of the cathedral at Ravenna are of vine tree planks, some of which are 12 
 feet long and 15 inches broad. ( Evelyn ) Olearius noticed vines near the Caspian sea with 
 enormous trunks; and Strabo mentions a vine trunk 12 feet in circumference. The vine at 
 Hampton Court is said to be the largest now in existence. A cedar in the island of Cyprus 
 was 18 feet in diameter and 130 feet high: and the trunk of the lai-ch of Tiberius was 120 feet 
 long and only 2 feet in diameter. 
 
 The following are about the mean heights in feet, of the trunks of various 
 trees. Acacia 12; Alder 44; Ash 38; Beech 44; Birch 47; Box 15; Chesnut 44; Elm 44; Fir 
 57; Oak 44; Northern Pine 47; Plane 44; Sycamore 31; Walnut 47; Yew 15. 
 
 The age of trees of the Exogenous class may often be settled by obser- 
 vation of the rings, one of which is generally formed every year after the first year’s growth. 
 In temperate climates there is tolerable certainty in this test. Cedars, planes, oaks and limes 
 have thus been determined to be at least one thousand years old ; and yeAv trees are said to 
 have lived three times this period. 
 
 It is established that, of all organic structures, trees have the utmost 
 longevity. The 600 years of Pliny’s vine is as nothing to the yew in Brabourn church-yard, 
 in Kent, 3000, and that at Hedsor, Bucks, 3240 years old, the last named being 27 feet in 
 diameter. Lawson believed that some fruit trees lived 1000 years; Pliny mentions the oaks in 
 the Hereynian forest as coeval with the world; and box, hornbeam, walnut, white-thorn, cedar, 
 cypress and ebony, all live a vast number of years. “The gigantic baobabs of Senegal”, says 
 Emy, “have a great many hundred layers. Adanson has proved that, among those he has ob- 
 served, several were six thousand years old. They had without doubt seen under their shade 
 an innumerable series of generations of different animals. These vegetable products are more 
 ancient monuments than the pyramids of Egypt, and the antiquities of India. They may serve 
 to illustrate the history of the globe; and, perhaps, some day we may find trees still more ancient 
 in countries where travellers and naturalists have not yet penetrated.” 
 
 FIBRES. We have next to make some observations on the mechanical 
 structure of wood and may commence by briefly considering its fibrous nature. 
 
 The fibres of timber appear to be connected by a species of glutinous 
 cement, weaker than the fibres, and it is thus explicable why wood is more easily broken in a 
 transverse direction; for then the cement is acted upon, while in pulling a piece asunder it is 
 the fibres which resist. Mariotte considered fibres as so many bent springs, never breaking 
 till entirely unbent, their utmost force not being exerted till they were stretched to a certain 
 extent. 1 his supposition was in advance of that of Galileo, who supposed the fibres to resist 
 'Gth their utmost force and to break at once, ignoring their elasticity. 
 
ON TIMBER GENERALLY. 
 
 51 
 
 Fibres differ more in their separation and density than in size, being- 
 small and wide apart in soft woods, as deal, alder, etc., and closer in the hard woods, such as 
 mahogany and ebony. This explains the necessity of varying the character of edge tools. 
 The grain of wood depends on the direction and mixing of the fibres; and curls are consequent 
 on the filling in of spaces between the fork, or spring, of branches. Knots are the springs of 
 branches, often undeveloped; and, in soft woods especially, they are harder than the principal 
 substance. They often fall out of boards of pine and white deal, while they are retained by 
 the turpentine in yellow deal. Clean stuff is that without knots, or sapwood; free stuff is clean, 
 and planes without tearing; frowy stuff is of soft texture witli brittle fibres; curling stuff has 
 knots surrounded with curls; cross-grained stuff’ has its fibres in the opposite direction to the 
 surface, and this arises from a twist in them while growing. The grain may be popularly ex- 
 plained as lying in the direction in which the wood admits of being split in thicknesses. Felt 
 grain is when wood is split in the direction of the centre of the tree; the position in the direc- 
 tion of the annual plates is the quarter grain. If two pieces of timber are connected with their 
 fibres parallel, they are said to be joined sideways; if the respective fibres are at right angles, 
 the joint is perpendicular or transverse; and when it is perpendicular to both pieces, as in heading 
 or butting joints, the fibres are brought together endways: in oblique joints the fibres are 
 oblique to one another. 
 
 In cases where the fibres lie oblique to a strain exerted on a piece of 
 timber they are extremely apt to slide, and the strength is proportionately diminished. Rut 
 generally, force applied to timber acts on the fibres in one of two ways, by producing either 
 tension or compression. In a beam exposed to a transverse strain there is, however, what is 
 termed the neutral axis , in which the fibres are neither in a state of tension nor compression; 
 but we shall hereafter have more to say on this subject. 
 
 Woods vary considerably in the disposition of their fibres. Those of fir 
 are straight, and it breaks abruptly; but the crooked fibres of oak do not separate so suddenly, 
 as they stretch very sensibly, but the texture is found to be greatly deranged. Softness of 
 texture is often due to the crookedness of fibres and the consequent existence of vacuities; and 
 thus, although the fibres themselves may be very tenacious, crushing soon takes place through 
 their being bent, as in the case of a post swelling before fracture. We see the above exempli- 
 fied in the comparison of oak and fir. Fir carries twice as much as oak as a post, although 
 oak will suspend much more than fir; and this is attributed to the curvature of the fibres of 
 oak. In general, as Parent remarked, the force requisite to tear a body asunder is often about 
 equal to what will crush it; and we may mention that, according to this author, about sixty 
 pounds on every square line is necessary to crush oak. 
 
 COHESION. WEIGHT. Cohesion, or attraction of cohesion, is simply 
 that force which keeps together the particles of which bodies are composed and prevents their 
 separation. Of its nature, or what it is in itself, we cannot hope to know anything beyond the 
 fact of the existence of the law. It must not be confounded with adhesion , w r hich latter word is 
 expressive of the force of contact of different bodies. According to the modifications of cohesion, 
 we have the varieties of hard, soft, tough, elastic ivoods, etc. It is desirable to explain some 
 of the terms in use. 
 
52 
 
 ON TIMBER GENERALLY. 
 
 Direct cohesion , or force of direct cohesion, are phrases employed to express 
 the degree in which the fibres of wood adhere to one another. Ultimately, the unknown cause 
 cannot be more plainly defined than by reference to what is understood under the term corpus- 
 cular attraction. The cohesive force is technically limited to the power necessary to separate 
 fibres in the direction of their length; and this, as before observed, often approximates closely 
 with the force requisite to crush them. The term absolute is also applied to this description of 
 cohesion; and primitive has a similar meaning. Tenacity is the general term for the quality in 
 bodies which prevents their being easily torn asunder; and woods are stated to be less tenacious 
 when dry than when green, although usually weaker in the latter case and strongest when 
 thoroughly dried and seasoned. Tough woods present the utmost degree of flexibility and 
 strength, observable in those which bend most under a given weight. They are useful where 
 sudden shocks have to be sustained, as in machines; but it has been remarked that “tough 
 woods, cross the grain, such as elm, or ash, are 7, 8, or 10 times weaker than straight; and 
 wood that easily splits, as fir, is 10, 18, or 20 times weaker.” Hard, cross-grained, tough woods 
 are very difficult to work; but those which are called brittle, (liable to break into fragments) 
 may often be easily manipulated, and are preferable when there is much work to put on them. 
 Stiffness is the force which resists change of form, and woods remarkable for it are especially 
 useful when straightness is desired. Hardness is simply the opposite to softness; and it depends 
 more on force of cohesion than on density. Hard woods are adapted for work in which a fine 
 surface is required. The degree in which a hard body gives way to any stroke is proportioned 
 to the weight of the modulus of elasticity (the measure of the elastic force); and therefore a 
 table containing this weight indicates the comparative degree of hardness of woods. It is 
 chiefiy the elastic force of timber which resists the strains in carpentry. As noted in our brief 
 history, we are indebted to Dr. Thomas Young for some valuable researches into the subject of 
 the modulus of [elasticity. By its means the comparative stiffness of woods is ascertained; and, 
 as Tredgold remarks: — “For instance, its weight for cast iron is 18,240,000 pounds, and its 
 weight for oak is 1,714,000 pounds. Hence it appears that the modulus for cast iron is 10.6 
 times that of oak, and therefore a piece of cast iron is 10.6 times as stiff as a piece of oak of 
 the same dimensions and bearing.” Elasticity is simply the power of resuming a former shape 
 when a disturbing force is withdrawn. Contractibility applies to dimunition in bulk; and we shall 
 hereafter have much to say on the shrinkage of timber. Extensibility or dilatibility is the oppo- 
 site ol contractibility, or compressibility. All wood is a tissue of cells, or tubes, having more 
 or less porosity; and its weight thus depends on its density, or closeness of texture. Mechanical 
 compression may be applied, reducing some woods fully one-third or fourth of their original 
 size, when, of course, the hardness and density are proportionately increased. “This,” saysHoltz- 
 apffel, “lias been practised for the compression of treenails for ships, by driving the pins through 
 a metal ring smaller than themselves directly into the hole in the ship’s side; at other times (for 
 railway purposes) the woods have been passed through rollers, but this practice has been dis- 
 continued, as it has been found to spread the fibres laterally, and to tear them asunder; an injury 
 which does not occur when they are forced through a ring, which condenses the wood at all 
 parts alike, without any disturbance of its fibrous structure, even when tested by the microscope; 
 after compression the wood is so much harder that it cuts very differently, and the pieces almost 
 
ON TIMBER GENERALLY. 
 
 53 
 
 ring when they are struck together; fir may be thus compressed into a substance as close as 
 pitch-pine.” Under the patent of Messrs. Ransome of Ipswich, pieces of oak are driven by 
 means of a screw-press into an iron ring, exposed for about twelve or sixteen hours in a tempe- 
 rature of 180° before they are set at liberty, and are thus compressed two-thirds of their bulk, 
 recovering, on being wetted, three-fourths. The author above cited mentions Iron-bark wood 
 from New South Wales as the densest, and the Cortica, or Anona palustris from Brazil as the 
 lightest he has met with among true woods. Specific gravity is the term which indicates the 
 comparison made in weight between two or several bodies, and pure distilled water at 62° is 
 the ordinary standard employed. Poplar, willow, and soft firs, average about half the weight of 
 water; and box- wood, iron wood, and some others exceed its weight and sink. The specific 
 gravity of water being taken at 1, platinum, the heaviest known substance, is 22 times this; and 
 other bodies rank as 2, 3, and so on up to the above: decimals are almost invariably used. 
 
 Button observed in the course of his experiments, that pieces of wood 
 taken near the root were the strongest and heaviest, and he recommended the valuation of 
 timber by its weight, which, he says, is greatest when thick annual rings are formed by a tree 
 growing vigorously as it advances to maturity. A comparative equality seems, however, to be 
 approximated when the tree is mature, after healthy growth. Buffon also asserts that the heart 
 of a sound tree is the strongest part; but Muschenbroeck maintains it is the weakest, and that 
 the weakness increases as the tree grows older. The latter opinion appears to be now most 
 general. We believe that the heart-wood is most compact and preferable in trees which have 
 not attained maturity; but, when they are declining, it is less hard, and to be depended on than 
 that near the circumference. The north side of trees is also less durable and weaker than that 
 towards the south; that to the south-east is usually the strongest. Too little attention is gene- 
 rally given to these circumstances. As the heaviest wood is nearly always the strongest, that 
 of the trunk is obviously preferable to the branches; and the part in the middle of the former 
 is by many preferred to that near the root, or the springing of the branches. Barlow says that: 
 “In healthy trees, or those which have not already passed their prime, the density of the 
 butt is in some cases to that of the top in about the ratio of four to three, and that of the 
 centre to the circumference as seven to five. That the contrary has place if the tree is left 
 standing after it has acquired full maturity; viz, the butt will in this case be specifically lighter 
 than the top, and the centre than the outward part of the trunk within the bark.” 
 
 The following Table gives the specific gravity of various woods, that of 
 water being taken at 1000. 
 
 ACACIA G76.2 CHESNUT (HORSE) . . 657. 
 
 DO. (FALSE) . . . 791.2 CHERRY 74t. 
 
 ALDER 654.9 CHERRY (SMALL) . . 714.3 
 
 APPLE 735.7 CYPRESS 655.5 
 
 ASH 787.3 ELM 700.3 
 
 BEECH 720.4 Do. (YOKE) 759.8 
 
 BIRCH 701.9 LARCH 656. 
 
 BOX 919. LAUREL 695. 
 
 CEDAR 603.3 MAPLE - 628.8 
 
 CHESNUT 685.1 MULBERRY 754.6 
 
54 
 
 ON TIMBER GENERALLY. 
 
 OAK 
 
 . 905.1 
 
 PLANE (WESTERN) . . 
 
 719.5 
 
 FEAR (WILD) . . . 
 
 705.7 
 
 PLUM 
 
 701.9 
 
 PINE (WILD) . . . 
 
 . 020.7 
 
 SERVICE 
 
 910.4 
 
 PINE (WHITE) . . . 
 
 . 080.5 
 
 SYCAMORE 
 
 673 9 
 
 Do. (CULTIVATED) . 
 
 . 509.7 
 
 WALNUT 
 
 050.2 
 
 PLANE 
 
 . 622.5 
 
 WILLOW 
 
 448.9 
 
 Do. (EASTERN) . . 
 
 So that it 
 
 . 537.9 
 appears, 
 
 according to this Table, that Box has 
 
 the utmost spe- 
 
 cific gravity, and that Willow i 
 from the several experiments of 
 
 is the lightest wood. The results given are the mean, deduced 
 Hassenfratz and those of the physicians Muschenbroeck, Du 
 Hamel, Cossigni and Varennes do Fenilles, who all appear to have given great attention to the 
 subject, but, in many instances, differ very considerably in their conclusions: the mean between 
 all may therefore be tolerably correct, at least sufficiently so for most purposes. As Hassen- 
 fratz remarked: — “When we compare the results to which learned men have arrived, one 
 is at first astonished at the little agreement found among them; but, after refecting on the 
 causes which produce differences, surprise ceases, and we are, on the contrary, astonished 
 at what coincidences exist in their conclusions. Variations of weight in the same kinds of 
 timber depend on the nature of the soil, the meteoric situation, the latitude, the degree of hu- 
 midity and dryness of the wood, the part of the trunk x>r branches whence the piece was taken, 
 and the age of the tree.” 
 
 BENDING TIMBER. We shall hereafter touch on the other methods 
 of bending timber, but may notice in this chapter the process adopted before trees are felled. 
 Shakespeare speaks of the wind making “flexible the knees of knotted oaks,” and man has 
 compelled trees to grow in the most extraordinary directions. Searching for branches bent 
 naturally to a desired curve occupies a considerable time, and cutting the timber to it involves 
 much waste. It is to the demands of naval architecture that the art of bending wood is princi- 
 pally due, as in it curved pieces are absolutely necessary. In civil architecture also they are 
 continually required, more particularly in roof's and centering; and the cabinet-maker constantly 
 uses curved pieces of wood, either cut or bent to shape. It is evident that timber cut to a 
 curve against the grain cannot have the same strength as that in which the fibres are continuous 
 and parallel with the curve, as in the case of a bent piece, which, on the other hand, has gene- 
 rally a greater or less tendency to return to its original form. 
 
 Living woods have a natural elasticity which varies according to their 
 kinds, ages and sizes. Ot course the largest and oldest are the least flexible. When young 
 
 and growing they are therefore sometimes bent into va- 
 rious forms, and so confined, by means of cords, as to 
 continue in a certain curve and shape. The suppleness 
 and elasticity of young trees are peculiarly favourable 
 for such operations; and we give in the margin two 
 diagrams illustrative of the methods adopted. When 
 the trees are relieved they retain the artificial shape. 
 
 The bending of trees while grow- 
 ing has been objected to on account of its retarding their growth, and deteriorating the quality 
 
ON TIMBER GENERALLY. 
 
 55 
 
 of the wood, but there does not appear to be sufficient grounds for these conclusions. It is 
 doubtful whether there is much difference between the quality of wood thus artificially curved 
 and that which grows straight. But the real inconveniences consist in the long period which 
 must necessarily elapse before the trees become of sufficient dimensions for use, and the space 
 which those thus treated occupy in plantations. 
 
 DEFECTS IN TREES. CHOICE IN THE FIELD. We shall only 
 briefly glance at the diseases to which trees are subject, and the more prominent defects which 
 should command attention. 
 
 Wind and cold, and above all,- hard frosts, are extremely prejudicial to 
 trees, and certain insects also do them considerable damage. In the Hartz forest, about 1769, 
 1,500,000 trees were rendered by insects comparatively valueless; and the inhabitants of the 
 surrounding country found themselves menaced by almost total ruin. The remedy consists in 
 immediately felling the trees most invaded, and depriving them of their bark, which is to be 
 burnt; but the. best mode is to prevent the evil, as far as possible, by destroying the insects as 
 they appear, before they have time to lay their eggs. 
 
 Trees covered with moss or ivy are to be regarded with suspicion. The 
 
 * 
 
 former is to be rubbed or scraped off with care, so as not to injure the tree; and the roots of 
 ivy are to be dug up: if however it has been long on the tree, the exposure consequent on 
 removal must be taken into consideration, as permanent injury and decay is thus often induced. 
 
 The decline of trees is usually first indicated by the decay of upper- 
 most branches and their cessation to give forth leaves. As Emy observes: — “Wood has a 
 duration not possessed by other organised bodies. Vegetables which do not produce wood soon 
 dry up and fall into dust; animals putrify almost immediately after they cease to live, whatever 
 may be the cause of death; while wood endures ages after the cessation of vegetable life in the 
 tree whence it has been cut. But it is subject to alterations which should be understood, either 
 to prevent them completely, at least to retard their effects, or, above all, to be enabled to reject 
 for construction parts which give signs of immediate deterioration.” 
 
 Where hollowness is suspected, it is a good plan to bore the tree with 
 an augur, frequently drawing it out and examining the substance detached. Evelyn remarks 
 that: — “Hollowness is contracted when, by reason of the ignorant and careless lopping of 
 a tree, the wet is suffered to fall perpendicularly upon a part, especially the head, or any other 
 part or arms, by which means the rain is conducted to the very heart of the stem and body of the 
 tree, which it soon rots. In this case, if there be sufficient sound wood, cut it to the quick, and 
 close to the body, and cap the hollow part with a tarpaulin, or fill it with good stiff loam, horse 
 dung and fine hay mingled, or with well tempered mortar, covering it with a piece of tarpaulin.” 
 
 The general signs of decay are too obvious to escape careful attention. 
 When wind-shaken, there are “certain ribs, boils and swellings in the bark, beginning at the 
 foot of the stem, and ascending the body of the tree to the boughs.” Excrescences and large 
 scars speak for themselves; and black or red spots on the bark are suspicious. In general those 
 trees are to be preferred for felling whose trunks are most regular, as well in circumference as 
 in straightness from end to end, the diameter decreasing in regular proportion without swellings; 
 and the bark should be uniform in its texture. It is as well to make a regular survey at stated 
 
ON TIMBER GENERALLY. 
 
 56 
 
 times of forests, and, at the first sign of decline, no time should be lost in felling a tree before 
 its <r 0 od qualities have become too deteriorated. All appearances of knots, tumours, scars, and 
 dead branches, are very suspicious. 
 
 The roots of trees should be particularly observed. “Those of largest 
 roots (a sign of age) are longer lived than the shorter; the dry than the wet; and the gummy 
 than the watery: the sterile than the fruitful.” {Evelyn). Alberti recommended that all the timber 
 for a particular building should be brought from the same forest; but of the value of this 
 suggestion our readers must judge. Trees growing on the outskirts of forests are usually better 
 than those in the central parts, as they have more light and air. Those against walls become 
 stunted on the side towards them. 
 
 CLASSIFICATION OF WOODS. Woods may be scientifically classi- 
 fied by minute observations of their botanical characteristics, or, more simply, by dividing them 
 into hard, soft etc. The system adopted by Tredgold seems to us of very little practical 
 utility to the carpenter. He separated the various woods into two classes, viz., those with and 
 without larger transverse septa; and the former again into two divisions, and the latter into 
 three, according to the distinctness and texture of the annual rings. The practical carpenter 
 rarely troubles himself about the annual rings, and the larger and smaller transverse septa; it is 
 the qualities of timber with which chiefly it is requisite he should be conversant. Therefore it 
 is that we are inclined to accept Emy’s division of woods into four classes; — the hard, resinous, 
 white and soft, and hue, woods. Oak stands foremost in utility in the first class, and it is per- 
 haps the most valuable of all timbers. In the second class are the pines, uniting great length 
 with lightness and elasticity: in this country they are more extensively employed for purposes 
 of construction than the timber of any other trees. The woods in the third class, as poplar, 
 alder, etc., are of short duration and little used in building. Those in the fourth class, as box, 
 pear, etc., have fine, close fibres, and are adopted for ornamental purposes, turning, etc. The 
 following is a brief classification; but in the next chapter we shall adhere to the alphabetical 
 order as most convenient for reference. 
 
 Hard woods. Ash. Beech. Chesnut. Elm. Walnut. Oak. 
 
 Resinous woods. Cedar. Cypress. Larch. Pine. Yew. 
 
 • White and soft woods. Acacia. Alder. Aspen. Birch. Laurel. Linden. 
 
 Maple. Poplar. Willow. Yoke-elm. 
 
 Fine woods. Apple. Box. Cherry. Medlar. Pear. Plum. Service. 
 
DESCRIPTION .OF PLATES OF PRACTICAL EXAMPLES. 
 
 57 
 
 DESCRIPTION OF PLATES OF PRACTICAL EXAMPLES. 
 
 PLATES 1. 2. 3. ROOF EXECUTED AT MAR AC, FRANCE. A. R. EMY, ENGINEER. 
 
 In our Sketch of the Origin and Progress of Carpentry and Joinery we 
 traced the progression of ideas which ultimately led to the invention of the remarkable and 
 novel form of construction shown on these three Plates, and which is, in fact, the latest grand 
 development of the carpenter's art. It is said that M. de Saint Phar proposed in 1811, to con- 
 struct the arch of a bridge with bent planks; but, at all events, it was Emy, a colonel of 
 engineers, who first practically carried out the idea in the riding house here illustrated. In 1819, 
 lie suggested the adoption of the system for the roof of a riding house at Libourne, and ob- 
 tained permission in 1825, to realise his ideas at Marac, the roof at the former place being 
 executed in 1826. 
 
 On Platt 1. the transverse section of the roof at Marac is given. The 
 span is about 65 feet. Below, the small figures show the forms of the irons, etc., used to bring 
 together and fix the planks. 
 
 Plate 2. contains a portion of the longitudinal section, together with the 
 plan of the riding house. On the latter the principals, about 10 feet apart, are indicated 
 by the dotted lines. 
 
 On Plate 3. are the enlarged details, drawn to so large a scale that little 
 description is needful. Figs. I. and 2, are front and side elevations of the lower portion of 
 principal. Figs. 3. and 4. are sections, and Fig. 5. is the plan. 
 
 The semicircular principals are formed of deals, about 2 inches thick, 
 5 inches wide, and 40 feet in length. The bent timbers have not more than two or three joints, 
 and there are not above ten or twelve to each principal. As will be perceived, the bolts and 
 straps hold the whole firmly together; and, in addition to these, the radiating notched binding 
 pieces, firmly bolted on the convex and concave sides of the curved principals, and also the 
 timbers above, increase the stability of the framework. The whole rests on stout plates, placed 
 low down on the walls, there being scarcely any outward thrust. 
 
 As 'Emy remarks, there is not in the formation of these roofs any difficulty 
 above the capacity of the most ordinary Carpenter, a manifest improvement on the method of 
 Delorme. In the construction of the bent timbers there are no mortices and tenons; the timbers 
 are first curved, and very few workmen are then required to raise them. We need not here 
 expatiate on the peculiar advantages of this system, as they are explained in the chapter before 
 mentioned; but we shall give on a future occasion a detail of the scaffolding employed. 
 
 PLATES 4.0. SUN FIRE OFFICE , THREADNEEDLE STREET , LONDON. DETAILS OF WINDOWS 
 AND DOORS. C. R. COCKERELL R. A., F. R. S, ARCHITECT. 
 
 We are peculiarly happy in being permitted to lay before our readers 
 details of works executed under the supervision of so justly celebrated an architect as Professor 
 Cockerell. In these will at once he perceived the careful study, delicacy of taste, and originality 
 which are stamped on all his works. At least they will he observed so far as the present sub- 
 
 Carpentry. VIII 
 
DEVELOPMENT OF THE SOFFITS OF ARCHES. 
 
 5S 
 
 jcct admits of their introduction. It is needless to say much in explanation of details so fully 
 indicated. We would draw the reader’s attention to the arrangement at the sill of the window, 
 and to the simplicity of the architrave. The latter on both sides of the door is executed in 
 cement; and the contrivance shown on the section, by which an appearance of greater height on 
 one side is gained, is also to be noted. 
 
 PLATE 6. THE RECTORY , GRAVELEY. BAY WINDOW. R. R. ROWE , ARCHITECT. 
 
 This window was designed for an eastern aspect over a clear, cold country, 
 and is an excellent example illustrating the employment of double sashes. The arrangement of 
 the shutters, often so difficult a matter, is singularly compact and convenient. As will be per- 
 ceived, there are folding shutters to the two side windows, and lifting shutters to those in front. 
 The front elevation is not given, as that of the side, and the section and plan, are sufficiently 
 explanatory. The ceiling of the bay is panelled and is lower than that of the room: dotted lines 
 on the plan indicate the panels. 
 
 DEVELOPMENT OF THE SOFFITS OF ARCHES. 
 
 The term soffit, which is derived from the Italian soffitto, a ceiling, 
 serves to define the under surface of any arch or vault, and also applies to the under sur- 
 face of any projection. 
 
 Before describing the methods required for developing the soffits of dif- 
 ferent kinds of arches, we will allude to a general; principle that has to be considered. It will be 
 always found that the comprehension of any rule will be very much facilitated if its relation to 
 the known properties of some simple geometrical solid is clearly understood. As will be ex- 
 plained, the soffits of arches may be classed in three divisions, viz,: those which agree with 
 parts of the surface of cylinders; those which agree with parts of the surface of cones; and 
 winding soffits. 
 
 SOFFITS WHICH AGREE WITH PARTS OF THE SURFACE OF CYLINDERS. 
 
 (Lines. Plate 6.) 
 
 Let A B C, Fig. I. be an arch, which is semicircular in the plane of a 
 section at right angles with i& sides. DEFG, Fig. la, represents the plan of the arch, and 
 the line oi the supposed section just mentioned is shown by the dotted line hi. It will be evi- 
 dent that the underside or soffit of the arch must coincide with a portion of the surface of the 
 (•Hinder l /inn, shown by faint shading on the plan Fig. la. The extended plan or develop- 
 ment of this soffit would be of the form shown by Fig. / h. To render more obvious the nature 
 <it this stretching out of the soffit, it is represented with tin arrangement of panelling. 
 
DEVELOPMENT OF TIIE SOFFITS OF ARCHES. 
 
 59 
 
 On the cylinder shown by Fig. 2. are marked the kinds of arches which 
 may coincide with portions of the surface of cylinders. Thus a is an illustration of a semi- 
 circular arch cutting at right angles through a parallel wall. The part marked b represents the 
 case of a similar arch which is oblique with the face of the wall. By c is shown a semicircular 
 arch, as before, hut cutting through a wall which is circular on plan. And by d is represented 
 a similar arch, also in a circular wall, but cutting through it in an oblique direction. 
 
 To develope the surface of a cylinder. {Fig. 2.) Let EFGII represent the cylinder 
 the surface of which is required to be developed. As the ends of this cylinder are square with 
 the sides, the development of the curved surface will be a rectangular figure. The dimension, 
 one way, will be equal to the height of the cylinder as i k {Fig. 2 b). The width in the other 
 direction l • l will be equal to the circumference. When there is the opportunity this will be 
 most correctly measured by taking the girt with a string. Otherwise it may be calculated at 
 3' 7 times the diameter, which will give the true circumference very nearly. When only a part 
 of the circumference lias to be measured, as from p to q , {Fig. 2a) it will be generally found 
 most convenient, in practice, to do it by dividing the part of the circumference to be measured 
 into a certain number of equal parts, and then, with the compasses or otherwise, marking the 
 same number of equal distances on any straight line, as at rs, {Fig. 2b). It must however be 
 always borne in mind that, although this last method is convenient and must very often be used, 
 it can never be absolutely exact, as the distances taken by the compasses must always be less 
 than the actual length of the corresponding parts of the circumference. The greater the number 
 of the divisions, and the shorter the lengths taken by the compasses, the more this source of 
 inaccuracy is diminished. 
 
 Having obtained the circumference of the cylinder by either of these 
 methods, and produced the figure iklm, Fig. 2b, if two circular portions are added, as at 
 nn and oo, equal in diameter to the ends of the cylinder, the development of the whole will 
 be completed. 
 
 7o develope. a line drawn on a cylinder. {Fig. 3.) Let ABCD be the cylinder, and 
 E F the line of which the development has to be made. Draw a plan of the cylinder, as 
 Fig. 3 a, and divide the circumference into any number of equal parts, in this case say sixteen, 
 and from the points thus marked in the circumference, draw the lines g,l,p, etc., to the line EE, 
 as shown on the elevation ABCD. Draw the horizontal line E g, and lines parallel to it from 
 the intersections of the last drawn vertical lines with the line E F. Draw the development, 
 Fig. 3 b, of the whole of the curved surface of the cylinder, and produce across it the hori- 
 zontal lines, l, 2, s, 4, 5, a, ~, s, and 9. Draw the vertical lines g, h, i, k, etc., as shown in Fig. 3b, 
 at distances corresponding with those on the plan. Through the respective intersections of the 
 vertical and horizontal lines draw the curved line E F E, which is the required development of 
 the straight line E F on the elevation. 
 
 / o develope the soffit of a semicircular arch which cuts obliquely through a straight wall. 
 {Fig. 4.) In this as in the following examples the term semicircular arch is intended to signify 
 one that is semicircular on a line of section at right angles with its sides. (See the line hi, 
 Fig. 1 a.) The intersection of an oblique arch of this kind with the face of the wall would 
 be an ellipse. 
 
On 
 
 DEVELOPMENT OF THE SOFFITS OF ARCHES. 
 
 Let A B, Fig. 4, represent tlie plan of the wall, and CD the oblique 
 opening. Continue the oblique line C in the direction e, and from the angle f, draw the line fg, 
 :it ri-dit angles with C c. Draw a centre line hh, in the middle between the sides C and D of 
 the arch. From the centre i describe the semicircle klf. This semicircle has to be developed 
 along the line kg, and the remarks already made in explaining Fig. 2. apply here. In this dia- 
 gram the semicircle is shown divided into eight equal parts. Set off these parts along the line 
 kg, and perpendicular to that line, and from the points 1, 2, 3, 4, etc., draw the lines shown. On 
 
 these mark respectively the distances 1 m, 2 n, 3 0 , 4 p, etc., taken from the plan, and through the 
 
 points thus obtained draw the curved line, which will be the development of one edge of the 
 
 soffit. For the other edge, take the distance p q, and mark it on each of the lines 1 , 2, 3, 4, etc., 
 
 in continuation of the distances 1 m, in, 3 0, 1 p, etc. Then through the points thus marked draw 
 a second curved line, and the development of the soffit will be completed. 
 
 To develope the soffit of a semicircular arch- which cuts directly through a circular wall. 
 
 ( Fig. o.) If the description of the last problem has been understood, this case requires but little 
 explanation beyond what is afforded by the figure. The only point to be observed is that the 
 distances nr, os, pt, etc,, are 4iot equal in this example, and therefore to obtain the second 
 curved line of the extended soffit, it will be necessary to take them separately. 
 
 * To develope the soffit of a semicircular arch which cuts obliquely through a circular 
 wall {Fig. 6.) Beyond the explanation given for Figs. 4. and 5. this example calls for 
 no remark. 
 
 SOFFITS WHICH AGREE WITH PARTS OF THE SURFACE OF CONES. (Lines. Plate 7.) 
 
 Let A B C, Fig. /, be an arch, which is semicircular on the face of the 
 wall, which has its jambs on the bevel, as shown by the plan, Fig. la, and which has the same 
 bevel continued equally round the arch to the crown. It will be seen that the soffit of this 
 arch will coincide with a portion of the surface of the cone D E F which is shown by faint 
 shading on the plan. 
 
 To develope the surface of a cone. {Fig. 2.) Let A B C represent the cone, the surface 
 of which is required to be developed. From the centre d, Fig. 2a, with the radius de, equal 
 to B C, describe the arc e f. On this arc set off a distance eg equal to the circumference of 
 the base AB of the cone. Draw the straight line dg, and the development of the curved sur- 
 lace of the cone will be made. Add the circular part hh, equal in diameter to the base, and 
 the whole will be completed. 
 
 To develope a line drawn on a cone. {Fig. 2.) Let A B C be the elevation of the 
 cone, and D E the line of which the development has to be made. Draw a plan of one half 
 of the cone, as Fig. 2a, and divide the semicircle into any number of equal parts, in this ease 
 >ay eight, from the points thus marked in the circumference, draw the lines f, h, i, k,l, m, 0 , etc., 
 to the base All of the cone. From the points thus marked in the base line AB draw lines 
 converging towards the vertex C, but stopping respectively at the straight line D E. From the 
 intersections thus obtained in the line D E, and from the points I) and E, draw the horizontal 
 lines 1, :t, 5, ii, -, etc. to the line A C. 
 
DEVELOPMENT OF THE SOFFITS OF ARCHES. 
 
 61 
 
 Draw the development, Fig. 3 b, of the whole of the curved surface of the 
 cone, setting off on the line corresponding with the base the distances f, g, h, i, etc., agreeing 
 with those on the plan. Mark on one of the edges, qf, points corresponding with those figured 
 1 , 3, 5, etc. on the line A C on the elevation. With the centre q, and the distances q l, q 3, q s, etc., 
 draw the arcs of circles shown. Draw lines from the points f, g, h, i, etc., Fig. 3 b, converging 
 towards the point q, but stopping at the arcs to which they respectively relate, as shown. Then 
 through the intersections of these converging lines with the arcs i, 3, 5, etc., draw the curved 
 line D E D which is the required development of the straight line D E on the elevation. 
 
 To devefope the soffit of a semicircular arch, which has its jambs on the bevel, and which 
 has the same bevel continued equally round the arch to the crown. The arch to cut directly through 
 a straight wall. (Fig. 4.) Let AB represent the plan of the wall and CDEF the opening. 
 Continue the lines C D and E F so that they intersect each other at the point g. As already 
 explained by Fig. 1 , etc., the semicircular arch over the opening CDEF will agree with part 
 of the surface of a cone, of which D F is the base, and g the vertex. On the base line D F 
 describe the semicircle D h F, and divide the circumference into any number of equal parts, in 
 this case say eight. From the centre g, with the radius g I), describe the arc D i, which will 
 be the development of part of the base of the cone. To fnark on this arc the extended length 
 of the arch, set off along it the points i, 2, s, 4, etc., corresponding with the distances i. 2 , 3, 4, etc. 
 on the semicircle D h F. The line D s is the development of one edge of the soffit. To com- 
 plete the whole, draw the line gs, and from the centre g, with the radius g C, describe the arc 
 C k. The figure DCL is the development of the semicircular arch CDEF. 
 
 To develope the soffit of a semicircular arch, which has its jambs on the bevel, and which 
 has the same bevel continued equally round the arch to the crown. The arch to cut directly through 
 a circular wall. (Fig. 5.) Let A B represent the plan of the wall and CDEF the opening. 
 Continue the lines C D and E F so that they intersect each other at the point g. Draw the 
 straight line C F. Describe the semicircle C h F and divide the circumference into any number 
 
 <4 
 
 of equal parts, in this case say eight, and from the points i, 2 , 3 , 4 , etc., in the semicircle draw 
 perpendicular lines to the base as shown, and from their intersections with the base line draw 
 lines converging to the point g, as represented by the figure. From the centre g, with the radius 
 g C, describe the arc C k and set off upon it the distances 1 , 2 , 3 , 4 , etc., taken from the semicircle 
 C h F. F rom the points thus marked in the arc just described, draw a second set of lines con- 
 verging to the point g, as shown. From the point at which the first set of converging lines 
 intersect the circular lines of the plan, viz. mm, nn, 00 , etc. draw horizontal lines to intersect 
 the line C g. With the centre g, and from the points thus marked in the line C g, describe arcs 
 intersecting at R and R the converging lines to which they respectively relate, and through the 
 points thus ascertained, draw the curved lines as shown in the' figure. CDS, 8, is the develop- 
 ment of the semicircular arch CDEF. 
 
62 
 
 DEVELOPMENT OF THE SOFFITS OF ARCHES. 
 
 WINDING SOFFITS. (Lines, Plate 8.) 
 
 Any surface that winds cannot be developed with perfect correctness, and 
 therefore the class of soffits that we now have to consider must present some difficulty and 
 uncertainty. At the same time hy the method that will be explained, an approximation may be 
 arrived at that will be sufficiently near to the true development to serve all practical purposes. 
 
 Let A 11 C Fig. 1. be an arch which is semicircular on the face of the wall, 
 which has its jambs on the bevel as shown by the plan (Fig. / a), but which has its soffit level 
 at the crown. It will be seen that the soffit of this arch will coincide with a portion of the 
 surface of the solid marked DEF, on the plan, and of which a side elevation is represented by 
 Gill K, Fig. 1 b. It is by investigating the nature of this solid, and by ascertaining the mode 
 of obtaining an approximate development of its surface, that we shall arrive at an understanding 
 of the method to be adopted to develope the soffit of an arch similar to the one shown by Fig. I. 
 
 Referring to the plan Fig. 1 a, it is to be observed that the base of the 
 solid is the triangle DEF. The elevation of the end DE (as shown by Fig. 2.) is a semicircle; 
 while the tapering end F, is equal in height to the semicircle D E, as is shown by II K, Fig. I b. 
 The impossibility of developing the surface of this solid with strict accuracy will be perceived 
 when it is understood that, while the surface is straight in the line from I to K (Fig. 2b), in the 
 line from KtoH, and on the lines 3 , 3 , — ■>, ■>, and i, i, it is rounding from G to I, and hollow in 
 the direction shown hy the dotted line from I to H. 
 
 Fig. 2. shows the elevation of the semicircular end, with the distance be- 
 tween I) and L, divided into four equal parts. Lines corresponding with these points of division 
 arc represented on Fig. 2a and Fig. 2l>. The surface of the solid is thus divided into a number 
 of parts of each of which we can ascertain the precise dimensions. By means of these dimen- 
 sions we may find successively the approximate development of each of the divisions marked 
 by these lines. 
 
 To develope the soffit of a semicircular arch which has bevelled jambs but is level at 
 the crown. The arch cutting directly through- a straight wall (Fig. 2.). Let A B, represent the plan 
 of the wall, and C D E F, the opening. Continue the lines CD and E F, so that they intersect 
 each other at the point g. As already explained by Fig. I, etc., the semicircular arch over the 
 opening will agree with part of the surface of the solid of which DF,(?, is the plan of the base. 
 Gn the line 1)F, describe the semicircle D h F, and divide the circumference into any number 
 of equal parts, in this case say ten. From the points thus marked in the circumference of the 
 semicircle draw perpendicular lines to intersect DF as shown, and from these intersections 
 with 1) I, draw other continuing lines converging to the point g. Also from the points 1,2,3, and 4 
 in the semicircle, draw the lines k,l,m, and n, parallel to D F. 
 
 From the point g and perpendicular to D g, draw the line gp, and set off 
 upon it from g, the distances gk, g l, g m, etc., respectively equal to the heights ilc, i /, im , etc. 
 
 From the centre D, with a radius equal to the extension of the portion of 
 the semicircle between I) and 1 , describe an arc at ,<?. From the centre Jc, in the line gp, with a 
 radius equal to gl, describe an arc cutting the last described arc at s. The intersection of these 
 two arcs is a point in one edge of the development of the soffit. To obtain a second point in 
 
PROJECTION AND DEVELOPMENT OF AN OBLIQUE CONE. 
 
 63 
 
 the edge of the development: from the point thus last obtained, with a radius equal to the ex- 
 tension of the part of the semicircle between i and 2, describe an arc at u; and from the centre 
 /, in the line gp, with a radius equal to the distance gv, describe an arc cutting the last de- 
 scribed arc at u. The intersection of these two arcs is a second point in one edge of the de- 
 velopment. Repeat this process from the other centres and with the other distances until all 
 the points in the development of the edge of one half of the soffit are obtained. Then take the 
 distances tw, vx, etc., and mark them on the corresponding lines for the other edge. Draw a 
 line through nil the points thus obtained, as shown, and half the development will be completed. 
 Using the line os, as a centre line, make a second half similar to the one just drawn, and the 
 whole will be completed. 
 
 PROJECTION AND DEVELOPMENT OF AN OBLIQUE CONE. 
 
 (LINES. PLATE 9.) 
 
 Cases occasionally occur in which a knowledge of the mode of developing 
 the surface of an oblique cone is indispensable; and the obtaining on a larger scale, by means 
 of projections from the cone, the ellipse, the parabola, and the hyperbola, as represented on the 
 plate, will serve as an excellent exercise for the student, besides possessing a direct utility. 
 
 If the descriptions that have been given, referring to Plates 2 and 3 of 
 Soffits, have been understood, little difficulty will be experienced in performing the operations 
 involved in what is shown on the Plate now under consideration, especially as care has been 
 taken to put upon it such writing as is likely to contribute to its clearness. 
 
 To develope the curved surface of an oblique Cone. {Fig. 1.) Let ABC, be the ele- 
 vation of the oblique cone. On the base A B, describe the semicircle A 1 B, and divide the 
 circumference into any number of equal parts, in this case say eight. Produce AB to i, and 
 from the vertex of the cone let fall the perpendicular C i. With i as a centre describe arcs 
 from the points i, 2, p. etc., in the semicircle, intersecting the base line AB; and from these 
 intersections draw lines to the point C as shown. 
 
 Lay down the centre line c b, Fig. 1 a, equal to C B in the elevation. 
 From the centre b, with the distance B 1 , describe arcs on each side of the centre line. Then 
 from the centre c, with the distance C 7, describe arcs intersecting the last described arcs at 7 
 and 7. These intersections are points in the development of the great circle which is the base 
 of the cone. From the points thus obtained with a distance equal to 7, i>, in the semicircle, 
 Fig. I, describe other arcs as shown: and from the point c with a distance equal to (A, describe 
 arcs intersecting the last described arcs at r, and which intersections are other points in the 
 development of the base of the cone. This process is to be repeated, taking for the radius 
 
PROJECTION AND DEVELOPMENT OF AN OBLIQUE CONE. 
 
 64 
 
 respectively the distance C's, C i, etc., until the whole of the base has been developed, and the 
 points a a, in the development, agreeing with the point A in the base, have been obtained. 
 Draw a curved line through all these points in the manner represented, and join c a, and ca, and 
 the development will be completed. 
 
 On Fig. /. is indicated by lines, respectively marked with the names, 
 where the sections are taken which give the curves shown by the other figures. 
 
 Fig. I a, Avhile illustrating the development of the whole of the curved 
 surface of the oblique cone, represents the development of the great circle A B, which is the base 
 of the cone: the development of the small circle de; the development of the ellipse fe; the 
 development of the parabola eg; and the development of the hyperbola dlu 
 
 The projections of the cone have next to be considered. Fig. I b indicates 
 the section of the cone taken on the line dh, which section gives an hyperbola. 
 
 Fig. 1 c, shows the section of the cone taken on the line e g, which section 
 
 gives a parabola. 
 
 Fig. 1 d, represents the section of the cone taken on the line fe, which 
 section gives an ellijAse. 
 
 Fig. 1 e, indicates the section of the cone taken on the line de, which 
 
 section gives a circle. 
 
CHAPTER II. 
 
 DESCRIPTION OF WOODS. 
 
 ACACIA (Robinia pseudo-acacia.) The common, false, or bastard acacia 
 is a native of America where it goes under the name of locust tree. It grows rapidly, forms 
 heart wood very early, attains a great size, and is an ornamental tree. The average size of the 
 trunk, according to Hassenfratz, is 2 feet in diameter and 32 feet in length. 
 
 True acacia, as Acacia tortuosci, yields small timber, sometimes very hard, 
 and flourishes in most countries. The wood is of a darkish-red colour, is heavy and adapted 
 for ship building. Acacia verek is a hard white wood. 
 
 The common acacia, or locust tree, is of a greenish-yellow colour, with light 
 red fibres, and is hard, heavy and susceptible of a fine polish. For fencing, tree-nails for ships, 
 sills, wall plates, and the general purposes for which oak is used, it is admirably adapted. Its 
 lateral strength is superior and it is harder’, and more elastic than oak. Stewart says: — 
 “Acacia is very little known in England, but it is highly prized in North America, and said 
 to be superior to the laburnum; being close-grained, hard and finely veined, it is more valued 
 by the cabinet-maker than any other wood whatever. Pursh, in his Flora, asserts that, being 
 nearly incorruptible, it is equally useful for posts and gates. At New York it has been found 
 upon repeated trials, that posts of acacia for rail fencing stand w r et and dry next the ground 
 better than those of any other wood in common use, almost as well as posts of swamp cedar. 
 Gate posts of this timber on an estate near Baltimore have remained fresh for nearly a cen- 
 tury. Most of the houses which were built at Boston, in New England, on the first settling 
 of the English there, were made of this timber, and, in 1782, were as firm and sound as 
 when erected. Among those who use the wood, it is reckoned better than the best white oak 
 for the axle trees of carriages.” Acacia was first adopted for ship building in Virginia, and 
 it is now employed all over North America for tree-nails, etc., its scarcity confining its more 
 extensive use. For mill-rollers and cogs of wheels it is very suitable. 
 
 ALDER ( Retain alnus). The long-leaved alder grows to the height of 
 about 30 feet, and the white, or common alder, to about 35 or 40. Its texture is close and 
 fine, the colour reddish-yellow, and the wood is soft, working easily. For cabinet work and 
 turnery it is well adapted, and also for casting models. If buried in a watery soil, alder will 
 endure an indefinite period. A great portion of the buildings at Ravenna are on alder piles, 
 
 Carpentry. IX 
 
DESCRIPTION OF WOODS. 
 
 as is also the celebrated bridge of the Rialto in Venice. Vitruvius remarks that, if ground “be 
 infirm, soft and marshy to the bottom, then it must be dug and emptied, and piles of alder, 
 olive or oak scorched are to be driven in by machines very close together. 
 
 Alder is good for water-pipes, pumps and sluices; pipes of it have been 
 observed sound after 130 years usage; that which lays in bogs becomes black like ebony. The 
 wood is also, adopted for wheels, handles of tools, trays, etc. But when exposed to damp it 
 speedily rots, and is also much subject to worms when dry. Britton says it was formerly 
 used for scaffolding. The roots and knots are finely veined. 
 
 APPLE TREE (Pyrus mains}. Apple trees often attain considerable 
 dimensions and live between two and three hundred years. The wood is close, hard, of a 
 reddish-brown colour, and tolerably straight and free from knots. It should be well seasoned 
 previous to use, but is always apt to warp and split. Pear tree is superior in toughness to 
 apple, but the latter excels sycamore and chesnut in hardness. The wild apple, or crab tree, is 
 used by mill-wrights. 
 
 ARBOR VITrE, is much employed in America for carpenter’s work. 
 It is soft, of a fine textiu-e and red colour. The height of the tree is between 40 and 50 feet. 
 
 ASH (Fra admits excelsior). The common ash is indigenous in Europe 
 and Northern Asia. It attains a great size, and the trunk is usually very straight. The young 
 wood is the best, as it is flexible and works easily, but becomes hard and tough after the sea- 
 soning process. It is said that ash joists are so elastic that they bear a greater weight than 
 any other English wood. This timber is not durable if exposed to damp or alternate dryness 
 and moisture. It is much subject to worms which speedily attack the wood when full of sap. 
 The old wood is darker than the young, which latter is of brownish white. 
 
 Ash is an admirable wood for machines, implements, ship blocks, etc., on 
 account of its great elasticity and toughness; in the latter respect and in strength it is superior 
 to oak. For buildings generally it is not sufficiently durable. The mountain ash has a hard, 
 fine-grained wood. 
 
 BEECH ( Faaus sylvatica.) Pliny mentions beech as one of thirteen spe- 
 cies of trees bearing mast or acorns. Buckinghamshire and Sussex beeches are said to be 
 the best in England. The colour is considerably varied by the character of the soil. Brown 
 beech is usually tough. The lighter description is named white beech, and this is the hardest 
 but least durable. The timber is smooth, hard, the transverse fibres very visible, and the an- 
 nual rings are lighter on one side than the other. As the growth is rapid, the specific gravity 
 i' slight, and the wood is very liable to decay. Emy remarks: t— “Beech has been a long time 
 abandoned for purposes in carpentry because of its splitting and liability to the attacks of 
 worms; but it is believed that a means has been found to remedy these defects in choosing for 
 the felling period the commencement of summer when the sap is in flow. After felling it is 
 left a year to dry, and is then squared and. immersed in water during five or six months. These 
 measures are certainly not sufficient to render beech equivalent to oak, but may at least fit it 
 lor secondary works in carpentry for which a very long duration is not necessary.” In a green 
 'tato beech is often adopted for foundations, piles for docks, sea-walls, etc.; but it should be 
 entiiely submerged in water, as it will not bear being alternately wet and dry; and the least 
 
DESCRIPTION OF WOODS. 
 
 67 
 
 dampness at the ends of beams is especially to be apprehended. Evelyn says: — “If the timber 
 be altogether under water, it is little inferior to elm, as I find it practised and asserted by ship- 
 wrights.” Its splitting, cracking, and the speedy injury done by worms, are objections to beech 
 in a dry state. Emy’s views are somewhat in accordance with those of Du Hamel, who observes 
 that water seasoned beech is least subject to worms. Ellis recommended the felling of beech a 
 fortnight after midsummer, and immersing the planks in water for ten days, afterwards drying 
 them thoroughly. Sometimes it is exposed to smoke when taken from the water. 
 
 On account of its uniform texture and closeness, beech is suitable for 
 tools and frames of machines. A great quantity is brought to London in boards and planks. 
 Large types for printing are often made of it, as are also keys and cogs of machinery, lasts for 
 shoes, pattens, brushes and toys. For furniture this wood is in great requisition. 
 
 BIRCH (Betula alba) The common birch is a species of alder. It will 
 not endure exposure to worms, but is tough and compact, with the colour sometimes hand- 
 somely diversified: it is tinged with red, and the grain is rather fine. In a green state it works 
 more easily than after seasoning. Birch is much used in turnery and for furniture. 
 
 BOXWOOD {Buccus sempervirens). The fine grain, polish and warm 
 yellow colour of this wood are well known. That from Turkey is imported from Constanti- 
 nople and Smyrna, in logs from 2 to 6 feet long and 2 1 / 2 to 14 inches in diameter. It is softer, 
 paler and more curly than the European boxwood. At Boxhill, Surrey, and in Gloucestershire, 
 there is much boxwood; but the greater portion of the European is imported from Leghorn 
 and Portugal. Boxwood is hard, heavy, very durable, takes a fine polish, and, when planed, 
 is as smooth as polished metal. We may mention that among its applications are those to 
 wood-engraving, for rules and scales, chessmen, screws, pins for blocks and pullies, lathe- 
 chucks, musical instruments: its saw-dust is good for cleaning jewellery. 
 
 CEDAR ( Pinus cedrus). There are numerous kinds of cedars, and we 
 might consider them under Pine, but it will perhaps be found most convenient to keep this 
 separate heading. 
 
 The Pinus cedrus, cedar of Lebanon, or great cedar, was celebrated in 
 antiquity and is one of the finest of trees, growing to an immense size; not however equal to 
 the Wellingtonici gigantea: a portion of one is in the Crystal Palace, and is 103 feet high 
 and 33 in diameter. Although the cedars growing on Mount Lebanon are as majestic as 
 formerly described the valuable qualities of their timber are not now remarkable. It is red- 
 dish-white in colour, light and spongy. From the looseness of the nomenclature of pines it is 
 probable that there may be some mistake in the identification of the pinus cedrus with the 
 timber, which was considered so durable as to be employed by Solomon in his temple, lauded 
 by Pliny as observed 1178 years old in the temple of Apollo at Utica, and described by 
 Vitruvius as used in most of the temples of antiquity. 
 
 Pinus cedrus is resinous, of a straight grain, easily worked, and not liable 
 to be attacked by worms. The colour is yellowish-brown; the wood is lighter than any other 
 resinous kind; and the trunk sometimes grows to the height of fifty feet. 
 
 The lofty Deodara, a native of the Himalayas, or Indo-Tartaric mountains, 
 is similar to the cedar of Lebanon in appearance, and possesses the excellent qualities for which 
 
68 
 
 DESCRIPTION OF WOODS. 
 
 the latter was famous. It lias a hard, fine grain and considerable duration when exposed to 
 the weather. Bridges of this timber have endured 500 years; and the Hindoos use it for 
 most constructive purposes. 
 
 The brown-berried cedar ( Juniperus oyycedrus) is indigenous in the Levant, 
 the south of France and the north of Spain, and is also called the Juniper of those countries. 
 Its wood has been presumed to be the celebrated cedar of antiquity. 
 
 Bermudian cedar [Juniperus Bermudiana) is another species, valuable for 
 internal work; and the Virginian cedar ( Juniperus Virginiana) is red and yields the wood so well 
 known as used for enclosing the lead for pencils: it is indigenous in North America, the islands 
 in the West Indies and Japan. This wood is exceedingly durable, and not subject to worms: 
 its applications range from drawers to ship building. There are other description of cedars, 
 but we have named the principal. 
 
 Vitruvius mentions that the finest cedars in his time grew in Africa and 
 Candia. Herrara says that Cortes erected a palace in Mexico containing 7000 cedar beams, 
 averaging 12 feet in circumference and 120 feet in length. Sesostris of Egypt built a vessel of 
 cedar. From its hardy character it might probably be easily naturalised in most countries. At 
 present very few remain in Mount Lebanon. 
 
 CHERRY TREE (Cerasus). The wood of this tree is close-grained, hard 
 and of a reddish colour. Emy says that this last may be increased in intensity by soaking the 
 wood in lime-water for twenty-four hours. It is much used for furniture and Tunbridge wares. 
 The above author mentions that in countries where the small cherry-tree is allowed fully to 
 develope itself, the wood is excellent for carpentry, and is much used by joiners. 
 
 CHESNUT [Fagus castanea). Chesnut resembles oak, but, as Sir H. Davy 
 remarked, it may be distinguished from it by oak having the larger transverse sepa absent in 
 chesnut, in which latter also the pores in the alburnum are small, requiring glasses to distinguish 
 them, while those of the oak are large and more thickly set. If, again, a nail is driven into 
 oak before it is thoroughly dried, the surrounding part of the wood is blackened, but this 
 is not so in chesnut. 
 
 T he horse-chesnut (y Fsculus hippocaslum ) is not related to the Spanish or 
 street chesnut first named, which last it is which so closely resembles oak: horse-chesnut is soft, 
 with little durability when exposed and quite unsuited for purposes in which strength is required. 
 It is even and close in grain, and is used in turning and for water-pipes, for which latter purpose 
 it must be quite covered with earth. 
 
 The Spanish chesnut is a magnificent tree with a wide spread of foliage, 
 large leaves and smooth bark. It attains a great age; and near Sancerre, in France, there is a 
 ehesnut-tree which tor six hundred years has been known as the great chesnut: it is presumed 
 to be a thousand years old. 
 
 lliere is little sap wood in chesnut; and thus the wood of young trees is 
 believed to lie more durable than that of oak. Acording to Marshall, chesnut hop-poles are 
 superior to those oi any other wood; and that which is young is, from its elasticity, very often 
 UM'd (or hoops for churns and tubs, and also for rings for the masts of ships, the old wood 
 living tun shaky and brittle for these purposes, and indeed for any where the load or resistance 
 
DESCRIPTION OF WOODS. 
 
 69 
 
 is variable. For posts and pales chesnut is excellent, and also for pumps and pipes to convey 
 water. It works more easily than oak and does not shrink or swell after seasoning. Generally 
 speaking, chesnut, if not from old trees, may be used on most of the occasions on which oak 
 is adopted; and during the Middle' Ages it is said to have been employed in the roofs of halls 
 and chapter houses, while others consider that the timber believed to be chesnut is in reality 
 oak. Emy says: — “That which confirms my opinion that there was much less chesnut em- 
 ployed in ancient carpentry than is commonly imagined is, that this wood is very subject to be 
 worm-eaten within, while the exterior shows no sign of destruction, so that probably it would 
 not have endured so long as oak.” Evelyn also remarks of chesnut that, — “contrary to oak, 
 it will make a fair show outwardly when it is all decayed and rotten within; but this is in some 
 sort recompensed, if it be true that the beams made of chesnut tree have this property, that, 
 being somewhat brittle, they give warning and premonish the danger by a certain crackling.” 
 Bellidor observes that chesnut beams soon rot if the ends are enclosed in a wall. There has 
 been much controversy about the roof of Westminster Hall, whether or not it is of chesnut, and 
 also respecting that of Notre Name in Paris. Rondelet doubts whether the last mentioned is 
 chesnut, and asserts that both D’Anbenton and Buflfon believed it to be of oak. The roof of 
 Westminster Hall is really of oak. Evelyn says that a great part of the ancient houses in 
 London were built of chesnut; and Fitzstephen, referring to the time of Henry II, speaks of a 
 forest of fine chesnuts at the northern part of the city. At Greenwich there are still remaining 
 many old houses built of chesnut, undoubtedly obtained from the park. The soil most suitable to 
 chesnut seems to be a loamy gravel; and Sir II. Davy notes that moist earth is least favourable. 
 There is a chesnut in North America which apparently differs in species from those on this 
 side the Atlantic: it is much employed as a framework for veneers. 
 
 CYPRESS (Cupressus sempenirens). This is very durable, is supposed to 
 be the ancient Gopher, and was used by the Egyptians for mummy cases and by the Athenians 
 for coffins. It is said that the bridge built by Semiramis over the Euphrates was of this wood. 
 The old doors of St. Peter’s in Rome were of cypress and were found to be quite sound, when, 
 after six hundred years duration, they were replaced by brass gates. The wood is of a yellowish 
 red colour of fine grain and harder than pine. “It is certain that it never cleaves but with great 
 violence, and the bitterness of its juice preserves it from all worms and putrefactions.” (Evelyn.) 
 
 DEAL. See Pines. 
 
 EBONY (Diospyrus ebenum). There are various colours of ebony, the 
 black being the most common; and it is imported from the Mauritius, East Indies and Africa. 
 For cabinet-work, handles of doors, etc., ebony is well adapted: the African stands best. 
 
 ELDER ( Sambucus nigra). This is a wood of a fine yellow colour ad- 
 mitting a polish when old. It is cross-grained and tough, and is sometimes adopted for rules. 
 
 ELM ( Ulmus ). Of five English species, the campestris is the most durable 
 and hardest, and is employed for coffins. The major, or Dutch elm, is an inferior wood; the 
 glabra, or wych elm, is much used by wheelwrights; and the suberosa, or cork barked elm, com- 
 mon in Sussex, is not of good quality. Nearly forty places in England are called after the elm. 
 
 The colour of the heart wood is reddish-brown, darker than oak; and the 
 sap wood is yellowish-white. Elm warps and twists much in drying, is cross-grained, porous, 
 
70 
 
 DESCRIPTION OF WOODS. 
 
 and shrinks both in length and breadth. When constantly wet, it is a most lasting timber; 
 and we have in our possession a specimen as firm as ever, used for the piles of old Lon- 
 don Bridge. Elm is also durable when dry; but alternations of dryness and moisture pro- 
 duce rapid decay, while planking under water has been known to last seven centuries. Its 
 specific gravity is not much less than that of oak; and its toughness and strength are very 
 remarkable. The agricultural carpenter and the carriage-builder find elm very suitable for their 
 purposes; but for pumps, and water-pipes iron has been substituted. A long period should be 
 allowed for the seasoning process, but, after all, this wood is said to be more liable to the 
 attacks of worms than any other: when to all outward appearance quite sound, it will, on being- 
 struck, frequently crumble to pieces. On account of its cross-grain and liability to warp, elm 
 is not suitable for floors or roofs; but it stands the driving of bolts and nails better than 
 other woods. 
 
 Evelyn thus sums up the utility of Elm: — “It is a timber of most singular 
 use, especially when it may be continually dry or Avet, in extremes; therefore proper for water 
 works, mills, the ladles and soles of the Avheels, pipes, pumps, aqueducts, pales, ship-planks 
 beneath the water line; and some that have been found buried in bogs has turned like the 
 most polished and hardest ebony, only discovered by the grain; also for Avheel wrights, handles 
 for the single hand-saw, etc. Rails and gates made of elm are not so apt to rive as oak; the 
 knotty for naves, hubs; the straight and smooth for axle-trees; and the very roots for curiously 
 dappled works; it scarce has any superior for kerbs of coppers, feather-edge and Aveather-boards, 
 blocks for the hat-maker, trunks and boxes to be covered with leather, coffins, dressers, and 
 shovel-board tables of great length, and a lustrous colour if rightly seasoned; also for the caiwer 
 by reason of the tenor of the grain and toughness, which fits it for all curious works of fruitages, 
 foliage, shields, statues, and most of the ornaments appertaining to the orders of architecture; 
 and, for not being much subject to warping, I find that, of old, they used it even for hinges and 
 hooks of doors, but then that part of the planks which greAv toward the top of the tree Avas, in 
 Avork, to be a 1 ay ays reversed; and, for that it is not so subject to rift, Vitruvius commends it 
 both for tenons and mortaises.” 
 
 FIR. See Pine. 
 
 HOLLT (Hex cequifolium). A whitish, fine-grained, tough Avood, closer 
 in texture than any other in England. It is useful to the cabinet-maker, turner, joiner, and 
 Avood-engraver. 
 
 HORNBEAM ( Carpinus betulus). This is hard, heaA-y, tenacious and 
 close-grained, suitable for mallets, cogs of wheels, planes, etc. 
 
 HORSE-CHESNUT. See Cliesnut. 
 
 JUNIPER WOOD. See Cedar. 
 
 LABI RNUM (Cytisvs laburnum). Turners make much use of this Avood, 
 aa hich is hard, compact, and also durable Avhen exposed. 
 
 LARCH ( Pinus Larue) This is a kind of pine, pf a yellowish-white, 
 01 1 (, ddi>h-browu colour, according to the soil. It is not so knotty as fir, and is excellent for 
 girdu> and principal timbers. Larch gn-es rapidly, is remarkably durable, Avhether sheltered 
 01 t '' x l , ° i<J d. and in ancient times it Avas highly A-alued. Much AA r as formerly employed in the 
 
DESCRIPTION OF WOODS. 
 
 71 
 
 buildings in Venice. Larch pipes are used in Provence to irrigate the land. The Swiss cover 
 their houses with larch shingles, about one foot square and 1 / 2 inch thick, and also line the 
 interior with polished pieces. In two or three years the resin brought out by the sun stops 
 the joints in the roof, which is thus quite water-tight. As larch rarely cracks, it is suitable for 
 paintings: according to Pliny the wood was thus used in ancient times, and Raphael also adopted 
 it. For the arches of timber bridges Wiebeking preferred larch to fir. Riga and Memel are 
 easier to work, but the surface of larch is better, and it is excellent where there is great wear, 
 as on floors. It is very liable to twist and warp, but, when properly seasoned, stands well, and 
 in many parts of England is gradually superseding fir. For posts, pales, and other exposed 
 works, larch is excellent, as it fails only when other woods would do so. The American larches 
 have no turpentine, but are believed to be equal to those in this country. The knots of larch 
 
 do not decay, nor does it shrink so much as deal, and, as its fibres cross, it is little liable to 
 
 split with the grain. 
 
 LIGNUM VIT^E (Guaiacum). A hard and heavy wood, soft when cut, 
 but gradually hardening. It is used in machinery; and, as it splits with more difficulty than 
 any other wood, is therefore always prepared with the saw. 
 
 LIME ( Tilia ). This is of a creamy white colour, and a light, fine, soft 
 wood, admirably adapted for carving from its non-liability to split. Grinling Gibbons used it 
 extensively in the ornaments at St. Paul’s cathedral, etc., and Virgil praised it in ancient times. 
 
 For cabinet making, musical instruments, etc., lime is very suitable, and it is said to make 
 
 tolerable floors. * 
 
 LOCUST-TREE. See Acacia. 
 
 MAHOGANY (Swietenia mahogani.) It was in the repair of Sir Walter 
 Raleigh’s ships at Trinidad that mahogany was first used, and in this country for a candle box 
 for Dr. Gibbons, being presumed useless for other purposes on account of its exceeding hardness 
 and spoiling the workmen’s tools. There are only tln'ee species. That common in England is 
 from the country about the Bay of Honduras, Campeachy and the West Indies, the wood from 
 the islands being called Spanish mahogany; but it is probable that differences of soil alone cause 
 those of the woods. The Spanish mahogany has no large septa, the annual rings are not clear, 
 it warps very little, and is harder and closer grained than the Honduras, which is coarse, spongy 
 and soft. Spanish mahogany logs are 10 or 12 feet long and 2 feet square, and Honduras from 
 12 to 18 feet long and 2 to 6 feet square. The grain of the latter is irregular, with black or 
 grey spots, the best kind being most free from the grey spots, and of a golden colour with 
 beautiful veins, while the Spanish, ‘before it is oiled, is of a lighter colour, the pores seemingly 
 filled with chalk, although generally darker afterwards. The colours are brought out by oil, 
 varnish and alkaline preparations. 
 
 The trunk of mahogany has frequently a length of 40 feet, 6 feet in 
 diameter. Of all woods it is the most valuable for furniture. In this country the expense limits 
 its adoption, but in Jamaica it is used for floors, joists, etc. For ships of war it is well adapted 
 as shot does not splinter the wood. Doors, handrails of stairs, and veneers are some of the 
 purposes for which it is in constant requisition. Honduras holds glue admirably, and is thus 
 often adopted as a ground for veneers of the more valuable kinds. The permanence of form 
 
72 
 
 DESCRIPTION OF WOODS. 
 
 of mahogany renders it valuable for founder’s patterns, and it is used for parts of machinery, 
 hut it must he very carefully dried and seasoned; then the wood is not liable to be attacked by 
 worms, but it does not bear exposure in this climate. The mahogany from Africa and the 
 East is of an inferior quality. 
 
 MAPLE (Acer pseudo-platanus). It is light and is not subject to twist 
 or warp. This is the common English maple, and its colour is of a yellowish brown. 
 
 Acer saccharinum, the sugar-maple, or birds-ey e-maple, is remarkable for 
 the beauty of its well-known grain, or embryo-buds, which form different figures according as 
 the wood is cut. It comes chiefly from Prince Edward’s Island in America, the wood is much 
 used for veneering, and, if sawn nearly parallel with the concentric rings, the marking is much 
 enhanced in beauty. It endures under water, and is used by wheelwrights in America after 
 undergoing three years seasoning. Turners work maple so thin that it is nearly transparent. 
 In ancient times a kind of maple was much valued for tables. 
 
 OAK (Quercus). Of all trees used for constructive purposes oak is un- 
 doubtedly the most valuable. It is the king of the forest, its Latin name, robur, is expressive 
 of strength, and it combines in an eminent degree that firmness and duration which have given 
 to the expression “heart of oak” its significant meaning. So highly was this wood esteemed 
 in ancient times that there was a law concerning the gathering of acorns which fell beyond the 
 grounds of a person to whom the tree belonged. The colour is a fine brown, the heart of 
 mature age and sound quality weighs as much as 60 pounds per cubic foot, and when green 
 80 pounds; and the tree attains a great age and size, one felled in Monmouthshire, having been 
 improving four hundred years, was then perfectly sound, contained 2426 cubic feet of timber 
 and fetched £ 500. 
 
 In England there are two kinds generally known, the Quercus robur, or 
 common oak, and the Quercus sessiflora, or sessile-fruited oak. 
 
 The Robur is found in most temperate parts of Europe; that in Sussex 
 is generally considered the best in England. The leaves have strongly marked irregular sin- 
 uosities with very short footstalks, while those to the acorns arc long. The colour is brown of 
 a reddish tinge, and the wood has a straight grain tolerably free from knots, is hard, will not 
 bend easily, but may he readily cleaved; it resembles Dutch wainscot, and is admirable for 
 joists and other parts of building where stiffness is requisite. “For economical uses,” says 
 Evelyn, “it far excels all the kinds in the known world.” 
 
 I he Sessiflora is considered to be the common oak of Durham, or about 
 the northern parts of England, although there are many near Dulwich and Norwood, and they 
 arc found in most temperate parts of Europe. It has been supposed to be the old Druidical 
 English, or naval oak. The sinuosities of the leaves are more regular, but not so marked as 
 in the A obur, and they have long footstalks, those to the acorns being short. The wood is also 
 d.ukci in colour than that of the Robur, the medullary rays, or silver grain, are wider apart, 
 and tin; glossy smoothness of the grain causes it to resemble that of chesnut. Unlike the Robur, 
 " difficult to split, but it is more elastic, heavier and harder. With respect to the general 
 inferiority ^ ie sessile-fruited to the common oak, although contended for by many, it is pro- 
 bable that there is, alter all, little to choose, as diversities of soil must cause great differences in 
 
DESCRIPTION OF WOODS. 
 
 73 
 
 both kinds. From its strength, hardness, elasticity and toughness, the sessile-fruited oak is 
 admirably adapted for ship-building, and it is said that most of the old Gothic roofs in 
 this country are formed of it, a circumstance denied by Gwilt. Tredgold says, “that it is both 
 heavier and more difficult to work than the Robur,” Avhile Cresy observes, that “the wood is of 
 a softer quality, and consequently yields more readily to the tools of the workman.” As before 
 remarked, peculiarities of soil modify the character of wood, and both authors are probably 
 correct, the management of trees also making much difference in the quality of their timber. 
 Tredgold speaks of the Sessiflora bending considerably more than the Robur. 
 
 The red oak of Canada (Quercus rubra ) is of rapid growth, producing 
 light and spongy timber. It is not called red oak on account of the colour of its wood, but 
 because of the change in the appearance of the leaves before they fall. The white oak ( Quercus 
 alba) approaches nearest in quality to the English kinds. For ship and house-carpentry it is 
 well suited; and the wood is tough and flexible. 
 
 Wainscot oak, or Dutch Wainscot, was supposed by Lindley to be a variety 
 of the Sessiflora. It grows in Germany, and is floated down the Rhine in immense rafts to Hol- 
 land, whence it reaches this country. Clapboard is a kind of oak from Norway. Dutch wainscot 
 is without the white streaks which cross clapboard, and thus the two may be easily distinguished. 
 Clapboard is the inferior wood; and both are softer than the English oak, and well adapted for 
 fittings. Dutch wainscot is said to be less liable than English oak to warp and twist. It should 
 be cut opposed to the beat to secure a variegated appearance, but wood cut in the same direction 
 as the beat is less liable to split or warp and makes better mortices. The holm, or evergreen oak, 
 (Quercus ilex), has tough, hard, heavy wood; it is plentiful in the south of Europe. The live oak 
 ( Quercus virens) is an American kind, common in the southern states, and much employed for 
 ships; the timber is compact, dense and finely grained. The Italian oak does not endure so 
 long as the English, and the Austrian is less valuable, although taller than that in England. 
 The cork tree is Quercus suber. 
 
 From the Baltic, Germany, America, Styria, Istria, Italy, and some 
 other countries, much oak is imported into England, and used in the dockyards; but it is doubt- 
 ful Avhether any can be so fully depended on as the English kinds. 
 
 Of oak generally we may remark that, on account of the cost, its use has 
 become more restricted than formerly, as it Avas once adopted in this country for most of the 
 purposes for Avhich fir is noAV employed. When constantly dry it will last a thousand years; 
 and that of a broAvn colour is to be preferred, as the red is of inferior quality. Oak trees are 
 rarely mature before 100 years, but they should be felled a little before rather than after this 
 period. In the process of seasoning the wood shrinks, warps and tAvists very much, but is 
 admirably fitted for situations of alternate dryness and moisture, perhaps better than any other. 
 The outer ring decays first in damp situations in the timber of trees cut before or at their 
 prime; those cut afterwards decay from within. Evelyn says; — “That Avhich is turned and 
 a little Avreathed (easily to be discovered by the texture of the bark) is best to support burthens, 
 for posts, columns, summers, etc., for all Avhich our English oak is infinitely preferable to the 
 French.” Again; — “It is doubtless of all timbers, hitherto known, the most universally useful 
 and strong; for though some trees be harder, as Box, Cornus, Ebony, and divers of the Indian 
 
 Carpentry. " x 
 
74 
 
 DESCRIPTION OF WOODS. 
 
 woods, vet we find them more fragile, and not so well qualified to -support great incumbencies 
 and weights, nor is there any other timber more lasting which way soever used.” As the 
 strength of oak is dependant on its density, and the smaller the pores the more durable the 
 wood, those kinds in which the septa are smallest and not very distinct are the strongest. 
 Among the uses for which oak is eminently suitable we may mention wet, dry, and exposed 
 works, spokes of wheels, staves of casks, tree-nails, wall plates, sills, king-posts, door-cases, ground 
 floor joists, frames, furniture, and works of great strength, or much exposed to the weather. 
 
 OLIVE ( Olex Europa.) It was much used by the ancients in roofs and 
 to tie walls together, and is durable when protected. 
 
 PEAK ( Pyrus communis). This is harder and tougher than lime. Emy 
 Bays; — “Its wood is heavy, of a fine, close texture and red colour, and it rarely splits. When 
 worked it should be perfectly dry, since it shrinks in seasoning a twelfth part of its volume; 
 they use it in the carpentry of machines, for wheelwrights and also for the stocks of tools. The 
 wood of the cultivated is softer than that of the wild pear tree.” The latter, however, is 
 chiefly adopted. 
 
 PINES ( Pinus ). The varieties of pines, or firs, a family of cone-bearing 
 trees, is very great, and, consequently, somewhat confusing to the novice. Cedar and Larch, 
 both kinds of [tines, are considered under their alphabetical headings. 
 
 RED OR YELLOW FIR ( Pinus sylvestris). This is a native of Scot- 
 land, Denmark, Norway, Sweden, Lapland, Russia, Prussia and Poland. The timber is further 
 distinguished by the [torts whence it comes, as Memel, Riga, Dantzic, etc.; and a great quantity 
 is brought from the Baltic to this country in logs and deals under the name of red wood, 
 that from Scotland being little used. Riga comes under the denomination of masts and spars, 
 the former from 18 to 25 inches in diameter, and 70 to 80 feet long; spars applies to timber of 
 less diameter: baulks are the largest square bars that can be cut from wood. This is generally 
 considered the best timber from the Baltic, and the Russian from Cronstadt is inferior. Much 
 of the red wood is floated to the ports deprived of its bark. The trees from Norway are not 
 
 above 18 inches in diameter, and there is consequently much sap-wood; hut the heart is found 
 
 to be more durable than the timber from larger trees. Yellow deals and planks come from 
 Christiana, Stockholm, Gefle, and other parts of Russia, Sweden, Norway, and Prussia. Memel 
 includes Dantzic and Riga, and Norway includes Swedish. As remarked by Gwilt; — “foreign 
 timber has an advantage too seldom allowed to that which is grown at home, the former being 
 always in some degree seasoned before it arrives in this country, and therefore never used in so 
 unseasoned a state as the latter timber usually is.” The character of the soil greatly modifies the 
 ■quality of fir, a stiff cold earth producing the red colour, and more solidity and strength than is 
 observable in the white fir from light sajidy land. On this subject we find some remarks by 
 Mr. Farquarson in Hunter’s edition of Evelyn’s Sylva. “It is generally believed that there are 
 
 two kinds of fir trees, the produce of Scotland, — viz., the red, or resinous large trees, of a fine 
 
 grain and hard solid wood; the other, a white-wooded fir, with a much smaller proportion of 
 resin in it, of a coarse grain, and a soft spongy nature, never comes to such a size and much 
 more liable to decay. At first appearance this would readily denote two distinct species, but 
 1 am convinced that all the trees in Scotland under the denomination of Scotch fir are the same, 
 
DESCRIPTION OF WOODS. 
 
 75 
 
 and that the difference of the quality of the wood and the size of the trees is entirely owing to 
 circumstances, such as the climate, situation and the soil they grow in. The finest fir trees 
 appear in the most mountainous parts of the Highlands of Scotland, in glens or in sides of 
 hills, generally lying to a northery aspect, and the soil of a hard, gravelly consistence.” The 
 Scotch fir in plantations in England is not very valuable; it thrives only on a dry gravelly 
 ground. The extraction of pitch, tar, and turpentine is not considered injurious to firs, and 
 some have asserted that they are improved by the process. The colour is of a reddish-yellow 
 of different degrees of brightness, and there are no larger transverse septa; in the best descrip- 
 tion the annual ring's do not exceed one tenth of an inch in thickness. The Scotch fir sometimes 
 attains a great size, one at Dunmore containing 300 cubic feet. 
 
 From the lightness and softness of fir, and the ease with which it may 
 be worked, it is now the most extensively used of all woods for building purposes. It will not, 
 however, bear much strain, except in the direction of the length of the fibres, as the lateral 
 cohesion of the annual rings is but slight. Its durability is often very great; and Brindley 
 thought that “red Riga deal, or pine wood, would endure as long as oak in all situations.” In 
 Venice, and also in Amsterdam, most of the houses are built on fir piles, 13,659 being used 
 under the Stadt-House in the last mentioned city. Du Hamel observed some piles in a church 
 centuries old in excellent preservation. From its lightness and stiffness, fir is admirably adapted 
 for scaffolding, girders, joists, rafters, and framing generally. In the roof of an old castle it has 
 been observed in perfect condition, in fact as if just imported, 300 years old. The inferior de- 
 scription chokes the saw, has thick annual rings and abounds with soft resinous matter. Swedish 
 timber, although the toughest, thus chokes the saw. Railway sleepers and fences of good fir 
 are found durable; and for masts it is in particular requisition, especially the Riga. This 
 latter is softer than the Norway timber; and generally fir from cold countries is superior to that 
 from warmer climates. For joiner’s work fir is easier wrought, aud is almost as durable as oak, 
 besides being much cheaper. No wood agrees better with glue, the brightest in colour are the 
 best, and those which are spongy and porous in the grain are to be avoided. Holtzapffel says 
 that; — “In Norway, when they desire to procure a hard timber with an over-dose of turpentine, 
 they ring the bark of the branches just before the return of the sap; the next year they ring 
 the upper part of the stem; the third year the central; and, lastly, the lower part near the 
 ground. By these means the sap, or turpentine, is progressively hindered from returning, and 
 it very much increases the solidity and durability of the timber. The roots of some of the red 
 deals so abound in turpentine, that the Scottish islanders, the natives of the West Indies, and 
 of the Himalayas, use splinters of them as candles. The knots of deal, especially white deal, 
 are particularly hard; they are altogether detached from the wood in the outer planks, and often 
 fall out when exposed in thin boards.” We may add that the Kamtschatdales convert the 
 succulent, soft, white bark into bread. 
 
 WHITE FIR ( Pinns abies). That called the spruce of Norway is best 
 known, and comes from Christiana in planks and deals, obtained from trees of 70 or 80 years 
 growth, cut into three lengths of about 12 feet each, each length containing three planks, or 
 deals. Planks are 11 inches wide, deals 9 inches, and battens 7 inches. Deals are sold in Eng- 
 land by the 100 of 120; they are 3 inches thick; and if cut into two are called u'hole deals , into 
 
7G 
 
 DESCRIPTION OF WOODS. 
 
 lour, s/it denis, and into five, five rut stuff. The colour is a yellow, or brownish white; they are 
 said to unite with glue better than the yellow; the knots are tough; and the wood should be 
 well seasoned, as it is extremely apt to shrink and fly. If purchased as dry deals in the timber 
 yard, the shrinkage is about one ninetieth part. Those should be chosen which are straight 
 grained, and free from knots. White deal is preferable for panels, and yellow deal for styles 
 and framing. Both are unadapted for exposed situations. Swiss deals, known as Belly-boards, 
 are much used for sounding boards. 
 
 AMERICAN PINE ( Finns strobus). This is a noble tree, often rising to 
 the height of 250 feet. It is sometimes called the Weymouth, or white pine, is much used in 
 America, on account of being soft and light, for furniture, wainscoting, picture frames, and is 
 the favourite material for the figure heads of ships. Its clean, straight grain, and uniform texture, 
 render it very suitable for joiner’s work; and it is also much employed for masts. It stands the 
 weather tolerably well if perfectly seasoned, but it is not suitable for large timbers, and is very 
 subject to dry rot. The colour is brownish-yellow and the annual rings are not very clear. 
 
 YELLOW PINE ( Pinus variabilis), is used in America for house and 
 ship building. The New York (Pinus mitis ) is durable, having a large proportion of turpentine; it 
 is also called here the yellow pine. Quebec yellow pine lasts well in dry work, but there is little 
 dependance to be put on what is called the lower port timber. Newfoundland red pine (Pinus 
 rubra) is much used in ship building. The silver pine (picea) endures longer, according to Wiebe- 
 king, in air than in Avater; it is stiff and white and used in ship and house building. The Pitch 
 pine ( Resinosa ) has much resin, but is not very durable; and the Chester pine (Pinaster) endures 
 longest in water. Generally, the American fir is softer than that from the Baltic, but it is freer 
 from knots, and is well suited for mouldings and panels; it is often distinguished as pine. The 
 general nomenclature of the varieties of pine is very loose and confusing to the student. 
 
 PLANE (Platanus occidentalis). The plane is one of the largest American 
 trees, and is abundant about the Ohio and Mississippi. Pliny speaks of one at Lycia within 
 which eighteen persons dined together. The wood is grown in England; it is durable in water 
 and is used by the joiner and cabinet maker. 
 
 POPLAR (Populus). Of the five species common in England, the Abele, 
 or great white poplar, is perhaps most often used. The wood works easily, is light, durable 
 when dry, does not burn readily, nor easily split, and is suitable where there is not much wear, 
 and great strength is unnecessary. 
 
 ROSE-WOOD (Mimosa jacaranda). It comes from the East Indies, 
 Africa, Brazils, and the Canary islands, the best being from Rio Janeiro. The colours vary from 
 light hazel to deep purple, and the wood is heavy, often very close in grain, and is much used 
 by the cabinet maker. 
 
 SYCAMORE (Acer pseudo-platanus). It is sometimes called Great Maple. 
 A durable wood when dry, but very liable to the attacks of worms. It was once used in Eng- 
 land for floors, and is now adopted for turnery and furniture. 
 
 I'EAK, OR AFRICAN, OR INDIAN OAK (Tectona grandis). This is 
 a strong durable wood, used for all purposes in India. The African Oak is much employed 
 ior ships, but splinters when struck by shot; it does not belong to the same genus as the Indian. 
 
DESCRIPTION OF WOODS. 
 
 77 
 
 Teak is very tough, is little liable to dry rot, and is used, among other purposes, for the frame- 
 work of railway carriages. 
 
 WALNUT ( Juglans regia). The heartwood is greyish-brown and the 
 sap-wood greyish-white. Walnut does not warp or crack, is compact, solid, and works readily. 
 It is less liable than any wood, excepting cedar, to be attacked by worms. For wainscoting, 
 gun-stocks, cabinet work, and furniture, it is well adapted; and it was formerly used in building, 
 but is too flexible for beams. 
 
 WILLOW (aScAV). It will endure for light timbers, as rafters, if pro- 
 tected, and is perhaps the lightest and softest of English woods. For cricket bats, hoops for 
 tubs, and turnery, it is well adapted. 
 
 YEW ( Taa'us baccata). Emy says this wood is one of the heaviest grow- 
 ing in Europe, but is good for constructions in carpentry when of sufficient size. The colour is 
 a finely veined red, and the wood is used for furniture and bows. 
 
 PATENT WOOD. We may conclude this chapter by mentioning the 
 Patent Wood, or Fibrorts Slab, combining many of the properties of wood and superior to it for some 
 purposes, especially when it is necessary to glue up boards in order to cover a surface. In this 
 case the slabs can be supplied in single pieces of any length or width, admitting of being bent to a 
 curve; the usual sizes kept in hand being 13 feet by 7. The immense saving of labour must be suf- 
 ficiently obvious, as the slabs may be procured for from 2d, to Is, per square foot, according to the 
 thickness and surface finish. W e can hardly consider it perfectly uninflamable, as, on experiment, 
 a very decided flame was produced on the specimen in our possession; but, although very dense, 
 it works readily, and can be bent to any form. It is said not to split, wind, or shrink, is unin- 
 fluenced by atmospheric changes, and is proof against dry rot. Its chief applications are to 
 linings, panels and partitions; for the last it is peculiarly suitable, as it does not readily conduct 
 sound. By Mr. Sydney Smirke, the eminent architect, it has been introduced in the large panels 
 of the dome in the new Reading Room of the British Museum; and he has summed up its ad- 
 vantages as consisting in: — “1st, The entire absence of damp; 2nd, the possession of a surface 
 on which we can gild and paint at once without fear, and which is not liable to be disfigured by 
 the showing through of the ceiling joists, as is invariably tbe case with plaster. The quality 
 possessed by these slabs of submitting to be bent spherically is very peculiar and in that 
 respect greatly superior to wood.” 
 
 
 -V, 
 
 \a -* ‘ 
 
78 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATE 7. MILTON CLUB HOUSE, LONDON. DETAILS OF LANTERN. 
 
 WILLIAM WRIGIIT. ARCHITECT. 
 
 This club house, situated on Ludgate Hill in the City, was designed by 
 the above mentioned architect; and the lantern illustrated is admirably adapted for its situation, 
 much constructive knowledge being also displayed in the several details. Coupled fir girders, 
 each set having a curved wrought iron Hitch, G inches by 3 /i with 3 /4 inch bolts, support the 
 binders, 10 by 5 inches, carrying the lantern and the joists of the fiat: the timbers below the 
 oak sill are 13 by 4 inches. As will be perceived, the binders tail over beyond the girders 
 about 16 inches; and they are inserted into the wall at the other end, there resting on a York 
 stone template: this projection is rendered necessary by the desirability of obtaining the splay 
 formed by the recessed mouldings, facilitating the entrance of light. The arched arrangement 
 below is probably the most happy that can be combined with a circular lantern, on account of 
 its strictly harmonious effect. 
 
 To economise space only portions of the plan and section are given, but 
 the construction will be fully apprehended with the aid of the enlarged detail. We may remark 
 that drawings intended to be placed in the hands of builders can hardly be drawn to too large 
 a scale, if truly accurate and careful execution is to be secured. We believe that failure in this 
 latter respect is less often due to deficiency of skill on the part of operatives than to the small- 
 ness of drawings often placed in their hands, and the consequent absence of clear and unmis- 
 takeable detailment of parts sometimes exceedingly complicated: these may be obvious enough 
 to the draughtsman, who has considered the matter throughout, and understands what is re- 
 quired, without being so to one who looks at the drawing for the first time, and has probably 
 only a very brief specification to elucidate the construction. In the course of our experience 
 we have observed that it is the practice of the most eminent architects to furnish working de- 
 tails drawn to so large a scale that it is almost impossible to mistake the character of the 
 smallest parts. 
 
 SCANTLINGS. 
 
 Girders 10 X 4 Inches 
 
 Binders 10X5 „ 
 
 .Joists to Flat • 6 X 2 1 / 2 „ 
 
 Ceiling Joists 5 X 2 „ 
 
 Pieces under Sill 13 X 4 „ 
 
 Sill (Oak) 5 X 31/a „ 
 
 The sills are screwed with coach-head screws, and there are six to the 
 light, which last is ot iron, with a copper fillet below and 5 pounds lead flashing. It is always 
 desirable to raise a sill fully above a roof or flat; and in this instance 9 inches is the height to 
 the top of the sunk part of the sill. Inch boarding for lead; gutters one foot wide at the 
 narrowest part. 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 79 
 
 PLATE 8. VICAR'S BUILDINGS, CAMBRIDGE. DETAILS OF SKYLIGHT. R. R. ROWE , ARCHITECT. 
 
 This skylight is placed over the principal staircase of the above buildings, 
 and combines economy with a satisfactory internal effect, produced by very simple means. Wet 
 is effectually excluded, a point of much importance in designing skylights, and one oftentimes 
 difficult to attain. We would draw the reader’s attention to the ingenious contrivance at the 
 lower part of the skylight. The rafters of the roof below the skylight are secured with remark- 
 able firmness to the uprights and to the plate. The following extract from the architect’s speci- 
 fication embraces all requisite further information. 
 
 “The skylight to be framed in the best manner, with top-rail 4 , / 2 by 
 8 inches, bottom-rail 1 1 by 2 inches, styles b’/o by 3 inches, eight bars, each 3 by 2 inches, 
 three principal bars, each 5^2 by 3 inches, supported upon studs 4 by 4 inches, grooved for inch 
 louvre boarding: inch wrought cheeks, chamfered wall-pieces, ridge, brackets, mouldings, beaded 
 plate, etc., to be fixed in the best manner, according to the detail drawing. Four pieces of 
 perforated zinc, each 3 feet 9 inches by 9 inches, to be neatly fixed with zinc nails outside the 
 louvre opening to prevent the admission of birds and snow.” 
 
 THE RECTORY , GRAVE LEY. DETAILS OF ROOFS AND LANERN. R. R. ROWE, .ARCHITECT. 
 
 These roofs are tiled, and combine the requisite extra proportionate amount 
 of strength with an ornamental internal effect. The enlarged detail A, merits particular atten- 
 tion. On the right, in the attic, a bookcase is shown: the moulded cove above forms a very 
 appropriate finish. 
 
 SCANTLINGS. 
 
 Wall Plates 
 
 Principal Rafters 
 
 Common Rafters 
 
 Purlins 
 
 Ridges 
 
 Ceiling Joists, suspended to the Purlins where necessary 
 
 6 X 4 Inches. 
 8 X 4 
 4X2 
 
 7 X 3 V 2 
 
 7 X l'/ 4 
 3 X 2 
 
 
 Principals, Collars and Wood Corbels 8 X 6 
 
 Turned Pendants from Collars 6 X 6 
 
 Ridge Tree 6 X 6 
 
 Purlins 5 X 5 
 
 Circular Braces (thick) 3 
 
 This last roof, supporting the lantern, is placed over the principal stair- 
 case: there are two pair of principals, wrought and stop-chamfered. 
 
 “All the timbers exposed to view are to be wrought, and the feet of the 
 rafters where projecting to be planed over and cut to a profile pattern which will be given. 
 The staircase lantern lights are to be strongly framed, and are to have two inch sashes, fixed 
 and flashed with 6 pounds lead, in the best manner for conveying away condensed water and 
 excluding wet.” ( Extract from Specification.) 
 
80 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 At the side, details of the staircase are given, comprising sections of the 
 string and step, and also of the handrail. These require no explanation, as they could hardly 
 be defined clearer than as drawn to the scale furnished. 
 
 PLATE ,9. KINGSTON HOUSE. SKYLIGHT ON FLAT. N. E. STEVENS, ARCHITECT. 
 
 This skylight is in the form of a parallelogram, with sloping top and 
 pedimcnted ends. Half of the plan and of the longitudinal section are shown, together with 
 the end elevation and transverse section, and details of the angle upright, half-styles and soffit, 
 which last is of one and a quarter inch framing with effective mouldings: the arrangement of 
 the panels is indicated on the plan. 
 
 We have put the above four skylights together, as they form an useful 
 series (two on flats and two combined with roofs), very suggestive, and applicable, with slight 
 alterations, to a great variety of purposes. 
 
 LINES FOR GROINS. 
 
 1 he term groin is applied to the intersection of two or more vaults. The 
 nature of the groin must obviously depend on that of the intersecting vaults, and we will there- 
 fore refer to the most useful terms employed in defining the forms of vaults and arches. 
 
 The point at which the vertical face of the pier ends and where the arch 
 commences, is called the springing of the arch, as at a, Fig. 1 , Plate 10. The part of the pier 
 from "hich the arch springs is termed the abutment, as a b. The distance between the abut- 
 ments is the span of the arch, as ac. The highest part of the underside of the arch, as at d, is 
 called the crown of the arch; and the height of the crown above the level of the springing, as 
 <1 e, is termed the rise of the arch. Usually the springings on the opposite sides of the arch are 
 on the same level; but if one springing is on a higher level than the other, then the term 
 rampant arch is employed. 
 
 Arches are described as semicircular, elliptical, etc., according to the curve 
 to which the) aic formed, and vaults are also distinguished by various terms, according to the 
 nature of the solids with which their concave surfaces would coincide. Thus a cylindrical vault 
 '\<>ii1d agre c with part ol the surface of a cylinder; a cylindroidic vault would coincide with part 
 of the mu f.ic o of a cylindroid, or a solid of which the ends are ellipses instead of circles, as in 
 the case of the cylinder. A spherical vault agrees with part of the surface of a sphere. The 
 
LINES FOR GROINS. 
 
 81 
 
 term annular vault is applied when the plan is contained between two concentric circles; and 
 a conic vault has its concave surface agreeing with part of a cone. 
 
 We ascertain the mode of working out the various necessary problems 
 relating to groins by considering that the vaults coincide, in the way just explained, with the 
 surfaces of certain geometrical solids. In the most simple example of groined arches, viz., that 
 of the intersection of two equal semicircular vaults, the problem is that of the intersection of 
 the surfaces of two equal cylinders, as shown by Fig. 2, Plate 10. If the two vaults are equal 
 in height, but unequal in span (one being semicircular), the problem is that of the intersection 
 of a cylinder with a cylindroid. If the vaults are of different heights, and the smaller vault is 
 
 of a cylindric form, the groin is called a Welsh groin, and the problem is that of the intersection 
 
 of two cylinders of unequal diameters. 
 
 Fig. 3 is a plan, and Fig. 3 a is a section, showing a groin formed by the 
 intersection of two equal semicircular vaults. The diagonal lines in Fig. 3, from the angles of 
 the piers, indicate the intersections of the vaults, which in this case are straight on the plan. 
 
 On the plan Fig. 4, at a a, is shown a similar example of equal semi- 
 circular vaults; but the vault at b h, is of a greater span and rise than those at a a, and the 
 
 intersections at c c, become consequently curved on the plan. The intersections at c c, are 
 examples of what have been already alluded to as Welsh groins. 
 
 If it is desired that the lines of intersection shall be straight on the plan, 
 as at a a, Fig. 5, it is necessary that the smaller vault should be not semicircular but of a form 
 to be specially ascertained for each example. A groin of this kind is described by the term 
 under pitch groin. Figs, o a and 3 b are sections further illustrating this case. 
 
 If a coved ceiling is intersected by small arches for windows, or for 
 other purposes, groins are produced which are, according to circumstances, either under pitch 
 groins or Welsh groins. The intersecting arches arc called lunettes. 
 
 These and other kinds of groins may be built of brick or of stone, when 
 the geometrical methods relate to the forms of the vaults and to the construction of the 
 centering; or similar groins may be formed with ribs of wood which form the cradling for lath 
 and plaster. We will first direct attention to the problems which relate simply to the forms of 
 the vaults, without reference to the mode of construction, and which therefore are required 
 equally for the “ centering for groins ” and for the “ ribs for plaster groins.” Under the respective 
 headings there will then be explained the methods which specially relate to each of the two 
 modes of construction. 
 
 The form of one vault and the plan of the intersection being given, to find the form 
 of the second vault (Lines, Plate 11.) 
 
 Fig. I illustrates the case when the main vault is semi-circular; the inter- 
 sections are to be in the planes of the diagonals; the cross vault is to be of the same height 
 as the main vault, and its form is required. 
 
 The form of the cross vault must coincide with an oblique section of a 
 semi-cylinder which corresponds with the main vault. The cross vault will therefore be semi- 
 elliptical, and its form may be delineated by means of the trammel, or by any of the other 
 
 Carpentry. X I 
 
82 
 
 LINES FOR GROINS. 
 
 methods of describing ellipses already given. In the present instance the mode of ascertaining 
 the form of the cross vault by the method of ordinates will be explained. 
 
 Let A A, Fig. 1, be the plan of the main vault of which the form is re- 
 presented by the semicircle B C D. Let E E be the plan of the cross vault, of which the form 
 is required to be shown; and let FG and HI represent the plan of the intersections. Divide 
 the semicircle BCD into any number of equal parts, in this case say eight, and from the points 
 1 , 2 , 3 , etc., in the semicircle, draw lines perpendicular to BD to intersect the diagonal F G. 
 Let the line kl be at right angles with the sides of the vault EE. From the points of inter- 
 section in the diagonal F G draw lines parallel to the sides of the vault E E to intersect the 
 line k I, and continue these parallel lines a little distance beyond the line k I. Then, on these 
 lines and from the line kl, respectively mark the heights taken from the semicircle BCD. 
 The points thus obtained will be in the curve of the required arch which has to be drawn 
 through them. 
 
 Fig. 2 shows a problem of a nature similar to the last, but in this case 
 it is the form of the cross vault which is given, and this is semi-circular. As before, the arch 
 to be obtained must be a semi-ellipse. This example is made to illustrate the mode of finding 
 the second arch by a system of intersecting lines. This will in practice be generally found 
 a more expeditious method than that with ordinates, while like that mode it is applicable to 
 every form of arch; to groins which are oblique on plan; and to arches which are rampant, as 
 well as to those with level springings. 
 
 Let A A, Fig. 2, be the plan of the cross vault, of which the form is re- 
 presented by the semicircle BCD. Let E E be the plan of the main vault, of which the form 
 is required to be shown; and let FG and III represent the plan of the intersections. Draw 
 the straight line CI), and divide it into any number of equal parts, in this case say four, and 
 from the centre k draw lines through the points i, 2 , and 3, in the straight line C D to the 
 circumference of the semicircle. Draw the line D l, perpendicular to B I). From the point 
 C, and through the points just obtained in the semicircle, draw lines to intersect D l in the 
 manner represented. 
 
 Let the line mn be perpendicular to the sides of the vault EE; and from 
 the points m and n raise the perpendiculars mo and no, similar to D /; and mark on these per- 
 pendicular lines the heights i, 2 and ;t, corresponding with those on D /. Draw the centre line 
 p<l, perpendicular to w/i-and equal to k C; and from the point q draw lines to the points i, i 
 and i, in the lines m o and n o. Draw the straight lines rn i/ and n q, and divide them each into 
 the same number of equal parts as has been done with the line CD. Then from the point p and 
 through the points just marked, in the lines rnq and n q, draw lines respectively intersecting the 
 other radiating lines in the same way as in the semicircle BCD. These intersections will be 
 points in the curve of the required ai’ch which has to be drawn through them. 
 
 Fig. J shows the application of the method with intersecting lines to 
 groins which are oblique on the plan. 
 
 I'ig. 4 indicates the mode of finding the form of the smaller vault of 
 an under pitch groin. 1 he larger vault, of which the plan is shown at A A, being semicircular, 
 and the plan of the intersections being defined by the straight lines at B B, the smaller vault 
 
LINES FOR GROINS. 
 
 83 
 
 must be of the form represented at C C. This figure is made to show the method with ordinates, 
 and also that with intersecting lines. 
 
 Figs. 5 and 5 a illustrate the application of both the method with inter- 
 secting lines and the method with ordinates to rampant arches. In this case, as with the other 
 examples, it is required that the cross vault shall be of such a form that the plans of the inter- 
 sections shall he straight lines as represented in Fig. 5. The main vault is semi-elliptical as 
 shown at A A, and the form of the cross vaults will be as represented at B B. When applying 
 the method witli ordinates in cases of this kind, in the way shown on the figure, it is the base 
 line of the given arch and the base line of the rampant arch which are to he divided into the 
 same number of equal parts. When it is the base line that is thus divided, the curve will he 
 more accurately defined if the divisions near the springing are again subdivided into several parts. 
 
 The forms of tiro intersecting vaults being given, to dratc the plan of the intersections. 
 (Lines. Plate, 12.) 
 
 Fig. 1 illustrates the intersection of two unequal cylindric vaults, producing 
 a Welsh groin, of which the plan is required to he drawn. Let A A he the plan of the given 
 main vault of which the form is represented by the semicircle BCD. Let EE he the plan of 
 the cross vault of which the form is represented by the semicircle EG II. Produce the line 
 i P to k. Divide the semicircle FGH into any number of equal parts, in this case say eight, 
 and from the points thus marked draw lines parallel to EH, intersecting the line E k, at i, 2 , :t 
 and 4. Produce the line ?'D to /, and on the line D l mark the heights i, 2 , 3 and 4, respectively 
 equal to those on the line F k. From the points thus marked on the line D 1 draw lines parallel 
 to D B to intersect the semicircle B C D. From the points thus marked in the semicircle BCD 
 draw lines perpendicular to D B, as shown. Then from the points already marked in the arch 
 E F G draw lines perpendicular to F H, to intersect the lines last drawn in the manner ex- 
 plained by the figure. A line drawn through the points thus obtained will be the correct plan 
 of the intersection of the vaults. 
 
 Fig. 2 shows the application of the method just explained to a Welsh 
 groin which is oblique on the plan. 
 
 Figs. 3, 3 a and 3 b refer to the mode of procedure for obtaining the plan 
 of the intersection of a Welsh groin in connection with an ascending vault. 
 
 Fig. 3 is a longitudinal section through the crown of the ascending vault. 
 
 Fig. 3a is a plan showing the piers and the intersections. 
 
 Fig. 3 b is the diagram explaining the method of drawing the plan of the 
 intersections. Let A A he the plan of one half of the main vault of which the form is shown 
 
 by B C. Let D be the plan of the cross vault of which the form is shown by E F G. Draw 
 
 the centre line F li and on it mark any number of points, so arranged that those nearest the 
 
 crown of the arch are a less distance apart than those near the base line, in the manner re- 
 
 presented in the figure. Through the points so marked draw lines to intersect the curve, and 
 parallel to the line E G. On the line C i, mark from i heights respectively equal to those on 
 the line h F . Through the points so marked on the line C i draw lines to intersect the curve 
 and parallel to the line B?. From the points thus marked in the curve between B and C draw 
 lines perpendicular to B i, as shown. Then from the points already marked in the curve EFG 
 
S4 
 
 LINES FOR GROINS. 
 
 draw lines parallel to the sides of the vault D, to intersect respectively the lines last drawn in 
 the manner explained by the figure. A line drawn through the points thus obtained will be the 
 plan of the intersection of the vaults. 
 
 Fig. 4 is a section and Fig. 4 a is a plan illustrating the intersection of 
 a conic vault with a cylindric vault; the method shown being applicable to a Welsh groin 
 formed by a conic vault as well as to the particular ease explained. In Fig. 4 the quarter 
 circle at A represents half the elevation of the conic vault. This quarter circle is shown divided 
 into four equal parts. Vertical lines let fall from the points thus marked in the curve to the 
 base line give the widths i, 2 and a, which have to be marked on each side of the centre line on 
 the plan. The diagonal lines on Fig. 4a indicate the plan of the intersections of the two vaults. 
 
 Fig. 5 represents the geometrical method to be used when it is required 
 that while the cross vaults should converge towards a point on the plan, as in the last example, 
 it is desired that they should be level at the crown. A vault of this kind, instead of agreeing 
 with the surface of a cone, would coincide with a solid of a similar nature to that illustrated by 
 Fig l a in Plate 3 of Soffits, to which, and the remarks concerning it, the reader is referred. 
 
 Let A A be the plan of the cylindric vault, of which the form is repre- 
 sented by the semicircle BCD; and let EFGH indicate the plan of the cross vault, of which 
 the form at the widest opening is represented by the semi-ellipse E I F. Produce E H and 
 F G respectively to intersect each other at k. Produce F D to l. Divide the semicircle BCD 
 into any number of equal parts, in this case say eight, and from the points thus obtained be- 
 tween C and D draw lines parallel to BD to intersect the line D /. From the point F and 
 perpendicular to E F draw the line F m and mark on it, from F the heights l, 2 , and a, re- 
 spectively equal to those on the line D l. From these points in the line F m draw lines parallel 
 to EF intersecting both sides of the arch as shown. From the points thus marked in the curve 
 E I F draw lines perpendicular to E F to intersect E F and from these intersections in E F 
 draw lines to the point k. Then, from the points already marked in the semicircle BCD draw 
 lines perpendicular to BD to intersect respectively the converging lines just drawn, in the 
 manner shown by the figure. Lines drawn through the points thus obtained will be the plan 
 of the intersection of the two vaults. 
 
 CENTERING FOR GROINS. 
 
 In constructing the centering for groins it is the practice to form and fix 
 flie centering tor the main vault quite independently of and without reference to that for the 
 cross vaults, kig. 1 , Plate 13, is a plan which illustrates the arrangement in the case of a 
 semicircular main vault which is intersected by a cross vault of a semi-elliptical form and of 
 equal height with the main vault. The plan of the boarding of the main vault is show r n at A A, 
 k ig. 1 , while the elevation of the corresponding rib is represented by Fig. 1 a. 
 
 I he centering for the cross vaults, at the intersection, is formed by short 
 i ib> ( ailed jack ribs, which arc fixed on the boarding of the main vault as represented at B B, 
 
LINES FOR GROINS. 
 
 85 
 
 Fig. 1, and at B, Fig. 1 a. On these ribs the boarding is placed in the manner shown at C C, 
 Fig. 1, and C, Fig. / a. The geometrical methods required relate first: to making a mould by 
 which the line of intersection may he marked on the hoarding of the main vault, in order 
 that the jack ribs may be correctly placed; and secondly: to forming a mould by means 
 of which the hoarding for the cross vault may be cut so as to fit truly to the boarding of 
 the main vault. 
 
 In some cases the line of intersection for placing the jack ribs may be 
 marked with sufficient accuracy without using any geometrical process. Thus in Fig. 1 , the 
 lines required to be marked are those indicated by the dotted lines cl cl and e e. If two long 
 straight edges are fixed in a vertical position at cl and cl, a third straight edge held against them 
 horizontally would afford the means of marking the line of intersection at f. By shifting the 
 position of the third straight edge the line of intersection may he marked in this way for some 
 distance on each side of f towards the springing^, but this method will not enable the workman 
 to mark the line of intersection near the springing, because as that is approached the straight 
 edges will be found to be, of necessity, insufficient in length. Another method is to have one 
 vertical straight edge fixed at cl, and a horizontal one fixed at f, with one end touching the 
 vertical straight edge at cl. A third straight edge, placed against the two just mentioned, may 
 he moved so that the line of intersection may he marked with accuracy from the point f to the 
 springing cl. The line thus marked will coincide with the surface of the hoarding of the cross 
 vault. To mark the line for the jack ribs a proper allowance must be made for the thickness 
 of the boarding. 
 
 When the lines for the jack ribs are marked on the boarding by either of 
 these methods, or by means of the moulds that we shall next refer to, the next thing to do is to 
 fix a straight piece of wood in a temporary manner in the direction shown by the line gg, Fig.J, 
 so that its under edge shall be level, and the thickness of the hoarding lower than the crown f. 
 This straight edge, in conjunction with the lines marked on the boarding, will afford the means 
 of fixing the jack ribs with great certainty. 
 
 The mode of applying the mould for marking the position of the jack ribs 
 is shown at li h, Fig. 1 , where it is represented as bent down over the boarding of the main vault. 
 The mould for the boarding has to he of such a form that if bent down over the boarding of 
 the cross vault its edge w r ould coincide with the line of intersection as show r n by ii, Fig. 1. In 
 the case of the mould for the jack ribs, and in that of the mould for the boarding, the problem 
 is that of the development of a line drawn on a cylinder. For an illustration of this general 
 problem the reader is referred to Fig. 3 in Plate 1 of Soffits. If one vault is of a conic 
 form the problem is that of the development of a line drawn on a cone. The mode of working 
 out this general problem has been explained by Fig. 3 in Plate 2 of Soffits. 
 
 To produce the mould represented by Fig. 2 a, which is that required for 
 marking the position of the jack ribs, divide the semicircle between A and B, Fig. 2, into any 
 number of equal parts, in this case say four. Make a development of this part of the semicircle 
 as shown by the line a b, Fig. 2 a. On this line draw the perpendiculars shown, at distances 
 corresponding with the divisions in the semicircle. On these perpendiculars mark the distances 
 he, u, 22 and 3 * 3 , corresponding with the distances marked in a similar manner on the plan. 
 
80 
 
 LINES FOR GROINS. 
 
 Through the points thus marked draw the curved line ci23a, which will be the edge of the 
 mould required. 
 
 To produce the mould represented by Fig. 2 b, which is that required 
 for cutting the ends of the boarding, draw the line ed, which is to be the development of the 
 portion of the semi-ellipse which is between D and E, (Fig. 2). On this line, at distances cor- 
 responding with the divisions in the semi-ellipse, draw perpendiculars as shown. On these per- 
 
 pendiculars mark the distances ee, 1 1 , 22 , and 33 , corresponding with the distances marked in a 
 similar manner on the plan. Through the points thus marked draw the curved line c 1 2 3 d, 
 which will be the edge of the mould required. 
 
 Plate 14 contains further illustrations of the modes of obtaining the 
 
 moulds for the jack ribs and for the boarding; and if the remarks already made have been 
 
 understood no explanation will be required beyond what is afforded by the figures. 
 
 Figs. 1 and 1 a indicate the method for finding the mould for marking 
 the position of the jack ribs when the groin is oblique on the plan. 
 
 Fig. 2 shows the plan of a Welsh groin, and the mode of finding the 
 form of the mould Fig. 2 a, which is that for the jack ribs, and also that represented by Fig. 2 b, 
 for the boarding. 
 
 Figs. 3, 3 a, and 3 b illustrate the case of a rampant gi-oin. Fig. 3 a 
 
 shows the lines for the moulds for the jack ribs, and Fig. 3 b represents the lines of the two 
 
 moulds for the boarding. 
 
 Fig. 4 is an example of a cylindric vault intersected by one which is 
 
 level at the crown while its sides converge towards a point on the plan. Fig. 4 a gives the 
 
 lines for the mould for the jack ribs. 
 
 TUBS FOR PLASTER GROINS. 
 
 Fig. 1, Plate If), is an elevation and Fig. la is a plan illustrating the 
 most common mode of constructing groins which have to be finished with plaster. The laths 
 for the vaulting are supported by straight ceiling joists, fixed to curved angle riba and to 
 curved main ribs. 
 
 Fig. 2 is an elevation, and Fig. 2 a is a plan showing another arrange- 
 ment where the cradling is composed entirely of curved ribs. 
 
 Whichever of these two modes of construction may be adopted, the geo- 
 metrical methods which specially require to be understood relate to the form of the angle ribs 
 A A. Whenever one of the vaults is cylindric, and the line of intersection is straight on the 
 plan, it is obvious that the form of the angle rib must agree with an oblique section of a cylinder 
 and therefore be elliptical. When this is the case, after having ascertained the span and rise 
 of the angle rib, its curve may be described by any of the methods already given for drawing 
 ellipses. Or, whatever the form of the intersecting vaults may be, if their intersection forms 
 3 straight line on the plan, the form of the angle rib may be obtained by the method of ordi- 
 nates, or by a system of intersecting lines. As both these methods have been explained at 
 
LINES FOR GROINS. 
 
 87 
 
 length, in referring to Plate 2 of Groins, it will he necessary only to point out that Figs. 3, 3 a, 
 and 3 b, exemplify their application to finding the mould for the angle rib. 
 
 By referring to Fig. 1, Plate 16, it will be perceived that to coincide with 
 the surfaces of the intersecting vaults the angle rib must be bevelled at the part nearest the 
 springing. Fig. 1 a is an elevation of one half of the rib. In this figure the rib is represented 
 in the oblique position shown by the plan, and its apparent length is consequently reduced. 
 Fig. lb is an elevation of the whole of the rib showing its true length. 
 
 The bevelling the under edge of the rib so as to range with the vaults, 
 in the way described, is termed edging, and the degree of bevel must be ascertained by drawing 
 a plan showing the position and thickness of the rib. The best method is to make the rib in 
 two thicknesses. Having marked on each of these, by means of the mould, the curve for the 
 line of intersection, it is then necessary to take the distance ah from the plan and mark it on 
 the springing line of the rib at each end beyond the curve already described. The mould must 
 then be moved in a horizontal direction so as to allow a curved line, similar to the one already 
 produced, to be drawn from each of the points last marked, in the manner represented by Fig. 1 b. 
 
 Figs. 2, 2 a, and 2 b, Plate 16, relate to the geometrical methods necessary 
 to form the rib at the intersection of a Welsh groin. 
 
 On the plan, Fig. 2, the curved line a a represents the plan of the inter- 
 section. On each side of this line, at a distance equal to half the thickness of the rib, a line 
 is drawn. These two lines represent the inner and outer curve of the rib. If a line be drawn 
 from the point b to c, and then a second line parallel to b c, and touching the outer curve of the 
 rib as at d d, these two lines will indicate the thickness of stuff required to form the rib. 
 
 To find the moulds for this rib: from any points, as i, 2 , 3 and F, in the 
 semicircle E F G, draw lines perpendicular to E G, and meeting the curved line of intersection 
 act. From the points thus marked in the curved line aa, draw lines perpendicular to be, in the 
 manner represented by the figure, and on these lines mark heights respectively corresponding 
 with those marked i, i, a and F, in the semicircle above the line E G. Through the points thus 
 marked draw the curved lines eh and dh which will be similar to each other, and will be the 
 form of the mould required. 
 
 For the mould to bend under the rib so as to mark the true curve for 
 the centre of the rib: draw the line cli. Fig. 2b, which is the development of either of the 
 curved lines eh or dh (Fig. 2 ) and on it mark the points i, > and 3, agreeing with those in the 
 curved line. Fi’om these points in the straight line eh draw perpendicular lines, and on them 
 mark distances respectively equal to the distances from the points i, > and :s, in the straight line 
 c b, (Fig. 2) to the curved line a a. Through the points thus marked draw the line i k, and the 
 curve for the required mould will be obtained. * 
 
CHAPTER Ilf. 
 
 FELLING, SQUARING AND TRANSPORT. 
 
 FELLING. As the object is to obtain the largest quantity of durable, 
 hard and serviceable wood, the proper time for felling trees is when they are most free from 
 sap. As may be gathered from our observations in the first chapter of this Division, during 
 the months of spring, and autumn, the sap is either rising or returning. Consequently it is 
 in midwinter when no sap flows, or in midsummer, when the sap is spent in the leaves, 
 that, as Evelyn would say, “a felling should be celebrated.” At those periods the trunk is least, 
 charged with the fermentable matters which induce decay in timber. In winter the roots are 
 inactive, but in spring and autumn, when they are preparing sap, there are no leaves to absorb 
 and expend it; and the trunk is thus so charged that, if cut, the juice will often flow out, as in 
 the instances of the birch and maple. But there seems to be a virtual pause in vegetation from 
 about the middle of June to the middle of August, as is evidenced by the adherence of the 
 bark; for when the sap is in transit, as it passes immediately below the bark, the latter can 
 easily be separated from the trunk. It also appears that there is more sap wood in spring than 
 in autumn, so that, although both periods are to be avoided for felling, autumn is the preferable 
 time. Gwilt remarks that, — “Much difference of opinion prevails respecting the proper season 
 for felling trees, some being in favour of midwinter, and others of midsummer. It is, however, 
 a (picstion which principally turns upon the quantity and value of the soft or outer wood in the 
 trunk of the tree to be felled, called sap by the forester and carpenter. This sap, or outer wood, 
 being the only portion of the trunk in which the sap or juices of the tree circulate, if no value 
 lie set upon it, it seems of little consequence when the tree is cut down, because the mature 
 timber, which is the really valuable part of the wood, is impermeable to the sap in its ascent 
 through the soft wood, and is therefore in the same state in every season of the year. On the 
 other hand, where much value attaches to the soft or outer wood, or where, as in the case of 
 comparatively young trees, the greater part of* the trunk consists of sapwood, they should be 
 felled when the sap least circulates. The season in that case is doubtless midwinter, which, 
 ••"•tens paribm, is certainly the best season for felling timber. The next best season seems to 
 be midsummer, because the sap is then chiefly confined to the young shoots, to the circum- 
 icicnce of the soft wooo, and to the bark. The worst season would appear to be the spring, 
 juM before the development of the buds, when the tree is fullest of sap, and receiving fresh 
 supplies ot it from the root; and in autumn, immediately before the fall of the leaf, when there 
 
FELLING, SQUARING AND TRANSPORT. 89 
 
 is a superabundance of sap, from its being as it were thrown out of employment by the fall of 
 the leaf.” ( Encyclopaedia of Architecture.) 
 
 The timber of trees cut after they have attained maturity is brittle, while 
 those which are more mature are too full of sap. In the former case the heartwood will be 
 weak on account of decay having commenced; in the latter the sap will be too liable to ferment, 
 notwithstanding the seasoning process. There is also a considerable difference in the working 
 of wood according to the time of felling. Holly cut in winter works toughest; and it is the 
 same with pear and service wood cut in summer. Hawthorn works mellow if cut in October, 
 and box if cut in summer; and the latter is hardest if felled about the spring. The common 
 fault is to fell trees before the growth is completed. When mature, the heart-wood is of equal 
 strength and weight; but, if otherwise, it is the central wood only that is fitted for constructive 
 purposes, the decrease of hardness being in somewhat of an arithmetical proportion in the ap- 
 proach to the sap-wood. 
 
 Before felling a tree it is desirable that the natural juices which ferment 
 and cause decay should be allowed to escape from the capillary vessels, or the wood will long 
 remain green and moist. By depriving the tree of a ring of alburnum in early summer the 
 continued ascent of sap is stopped; and if the tree be felled after the sap which has risen is 
 expended in leaves, the trunk must be tolerably clear. Some cut gashes in the trunk; but there 
 are objections to this practice, as also to the partial cutting of trees, leaving only such a thickness 
 of trunk as may suffice for support, the ascent of sap being thus in a certain measure prevented. 
 
 The practice of barking trees while yet standing is of very great antiquity. 
 As the bark of oak is very valuable for tanning, but as, if the tree were felled in the winter it 
 would be difficult to remove the bark, and it is deteriorated when the leaves have expanded, the 
 trees are often reserved till about April or June when the rising sap loosens the hark. Buffon 
 advised stripping the bark in spring, and felling the tree in autumn, the sap-wood being thus 
 partially dried and hardened. In many forests in Germany it is usual completely to bark the 
 trunks of trees a year before they are felled. According to Count de Gallowin, a Russian 
 admiral, barked wood is not so readily bent by ordinary means as that which is felled without 
 being deprived of its bark. This merits serious consideration, especially as oak is so frequently 
 barked, and this timber is chiefly used for ship building, often necessarily in curved forms. 
 
 We may however altogether conclude that, “when a tree has an incision 
 made through the sap-wood at its trunk, it soon dies, and no further change takes place; and 
 the barking of trees, when in full growth and vigour, and letting them stand a twelvemonth 
 after the operation, is admitted, not only to improve the quality, but to increase the quantity, 
 at the same time that it seasons the wood; time, however, is the best seasoner, and no artificial 
 method can equal the natural process, which is that of getting rid of all the juices in so regular 
 a manner, that dissipating them does not too rapidly shrink and crack the timber.” 
 
 With respect to the general times for felling recommended by various 
 authorities, Vitruvius preferred between October and February, and Napoleon Bonaparte fixed 
 on between the 1st November and the 15th March, as the time for the timber used for naval 
 purposes (Du Hamel). Certainly, if the texture and strength of wood is considered, the winter 
 must be the preferable time. 
 
 Carpentry. XII 
 
90 
 
 FELLING, SQUARING AND TRANSPORT. 
 
 Du Hamel seemed to think it of little consequence at what period of the 
 year trees are felled. In Italy, indeed, they fell in summer and the timber is found to be very 
 durable. It is the same in Spain; but as these are both hot climates, promoting a rapid desic- 
 cation of the sap, it would appear that they are exceptional cases. Hartig, a learned German, 
 speaks strongly against felling in spring or summer. M. Rainn recommends the end of the 
 month of May, or the beginning of June; and Emy says that oaks cut in the summer were 
 observed after three years to be quite unfit for building: he advises the winter as the preferable 
 season. But, as before remarked, different trees must be felled at different periods to obtain a 
 particular quality of wood. The same season is not desirable for all, and moreover it is of 
 great importance to settle the age at which the utmost quantity of serviceable timber can be 
 obtained. The simple rule is to fell a tree when its increase ceases; but it is difficult to deter- 
 mine this period with exactitude. We before alluded to the observations of Hassenfratz on oak 
 (Chapter 7, Division 2.) when speaking of the growth of trees, and may again refer the reader 
 to the diagrams, Figs. 1, and 2. on Plate 16, showing the proportionate increase in height and 
 circumference; between 60 and 100 the tree spreads, and the trunk increases chiefly in circum- 
 ference. Evelyn recommends “about the age of fifty, or between that and sixty years of age.” 
 Daviler, speaking of oaks, says they should not be felled under 60 or above 200; and Belidor 
 preferred 100 years. Tredgold observes that poplar .should be cut between 30 and 50 years of 
 age, and ash, elm and larch between 50 and 100. Scotch pine and Norway spruce are usually 
 felled between 70 and 100 years. 
 
 Ellis says that beech felled in the middle of summer is least liable to the 
 attacks of worms, and he recommends a cut to let the sap exude before felling. Oak cut in 
 spring or autumn is said to be most liable to dry rot. The winter is decidedly the only proper 
 season for soft woods, as poplar, willow, lime, etc., while more latitude is permissible with 
 regard to the hard, such as ash and beech, whose heartwood only is valuable. Wood at first 
 grows rapidly and its texture is soft; then it becomes strong and firm; in the third period it 
 weakens and decays. Loudon remarks that the middle term is the proper for felling. Vitruvius 
 agrees with Cato that the fruit should be ripe; and the former writer preferred the autumnal 
 tail. Elm is good felled between November and February, and Theophrastus said that the 
 proper period for fir, plane and pitch is when they begin to bud. 
 
 s Ql ARING, etc. It is a common practice to leave the timber of a tree 
 foi six months before squaring, but it should not, as is usual, lie on the ground, or on pieces of 
 wood beginning to decay, as the rotten will affect the sound. Iron stands, or stones, should 
 be adopted, and the air allowed to circulate freely round each trunk. Squaring trees at once is 
 lx lioM d b\ num to pie\ent the tendency of the timber to split; and for large pieces to be used 
 as posts boring from end to end is a similar precaution. Wood, however, should not be cut 
 up into small scantlings before it is tolerably seasoned, or it will be very apt to split and warp. 
 It h >uld lir about a ycai in scantlings before it is employed, and that cut into thicknesses for 
 i i " or k seasons most easily, as the surfaces on which the air acts are increased. For thin 
 
 about t\\(l\o months seasoning suffices, but two or three years are required for thick 
 pieces. After cedar, rosewood, mahogany, and other foreign woods are cut into planks, they 
 care full_\ dried, as in the form of logs much moisture is retained. “Timber which 
 
FELLING, SQUARING AND TRANSPORT. 
 
 91 
 
 is cleft is nothing so obnoxious to rift or cleave as what is hewn; nor that which is squared as 
 what is round; and therefore where use is to be made of huge and massy columns, let them be 
 bored through from end to end. It is an excellent preservative from splitting, and not unphilo- 
 sophical,- though to cure the accident painter’s putty is recommended; also, the rubbing them 
 over with a wax cloth is good, or, before it be converted, the smearing the timber over with 
 cow-dung, which prevents the effects both of sun and air upon it, if, of necessity it must lie 
 exposed. But besides, the former remedies, I find this for the closing of the chops and clefts 
 of green timber, to anoint and supple it with the fat of powdered beef broth (?) with which 
 it must be well soaked, and the chasms filled with sponges dipt into it. This is to be done 
 twice over. Some carpenters make use of grease and saw-dust mingled; but the first is so 
 good a way that I have seen wind-shock timber so exquisitely closed, as not to be discerned 
 where the defects were. This must be used when the timber is green. We spake before of 
 squaring; and I would now recommend the quartering of such trees as will allow useful and 
 competent scantlings, to be of much more durableness and effect for strength than where whole 
 beams and timbers are applied in ships or houses, with slab and all about them upon false sup- 
 positions of strength beyond those quarters. For there is in all trees an evident interstice or 
 separation between the heart and the rest of the body, which renders it much more obnoxious to 
 decay and miscarry, than when they are treated and cemented as I have described it.” {Evelyn.) 
 
 On Plate 16, Figs. 3. to 14. illustrate various methods of cutting up-timber. 
 After having cut the several pieces, let fall a plumb line from the top, as in Fig. 5, and thus 
 the ends may be sawn at once in an uniform, corresponding manner. The smallest pieces, it 
 will be observed, are placed upwards. Fig. 3. shows the pieces in Fig. 5. before being cut. 
 As in Fig. 4. the ends may be sawed squai’e while in the round. Figs. 7. and 8. show methods 
 of obtaining a number of planks of about the same size. In Fig. 9. four methods are indicated, 
 and Fig. 10. is the system adopted by M. Moreau, a timber merchant of Paris. Fig. 11. is a 
 modification of the last method. In Fig. 12. square pieces are obtained. Fig. 13. is the mode of 
 obtaining the size of the strongest beam that can be cut from a round tree. Divide the diameter 
 of the circle into three parts; raise perpendiculars from the points within the circle in opposite 
 directions till they touch the circumference; and, on uniting the points in a rectangle, we have 
 the strongest form of beam. Of course it does not contain the greatest quantity of timber which 
 can be cut from a tree, as a square is the largest rectangle which can be inscribed in a circle. 
 
 This appears to be the most appropriate heading under which to lay be- 
 fore the reader an abstract of some remarkable observations communicated by T. A. Knight Esq. 
 to the Royal Society. {Philos. Trans. Vols. 91. and 107.) 
 
 When old trunks decay the wood will always split more or less, the 
 cracks being towards the centre, the wood contracting less in proportion in diameter than in 
 circumference.” “It is usual,” Knight says, “to cut oak as much as possible into what are 
 called quarter-boards, which are so named because the tree is first cut into quarters. In a per- 
 fect board of this kind the saw exactly follows the direction in which the tree most readily 
 divides when cloven; in this case the laminae of the silver grain lie parallel with the surface of 
 the board, and a board thus cut, when properly laid in the floor, is rarely or never seen to de- 
 viate from its true horizontal position. If, on the contrary, one be sawed across the silver grain, 
 
92 
 
 FELLING, SQUARING AND TRANSPORT. 
 
 it will, during many years, be incapable of bearing changes of temperature and moisture without 
 becoming warped, nor will the strength of numerous nails be sufficient entirely to prevent the 
 inconvenience thence arising. That surface of a board of this kind which grew nearest the 
 
 centre of the tree will always show a tendency to become convex, and the opposite side con- 
 
 cave, if placed in a situation where both sides are equally exposed to heat and moisture.” Some 
 experiments were next tried on ash and beech boards, “cut in opposite directions relative to 
 their medulla, so that the convergent cellular processes crossed the centre of the surfaces of 
 some of them at right angles, and lay parallel with the surfaces of others; by which means was 
 marked the comparative extent of their expansion and contraction when they were subjected to 
 various degrees of heat and moisture. Both were placed under perfectly similar circumstances 
 in a warm room, where those which had been formed by cutting across the convergent cellular 
 processes soon changed their forms very considerably, the one side becoming hollow and the 
 other raised, and in drying these contracted nearly 14 per cent, relative to their breadth. The 
 others retained, with very little variation, their primary form, and did not contract more than 
 3' 2 per cent in drying.” Tredgold gave in the Eicyclopcedin Britannica (Art. Joinery.) the 
 result of an experiment he made with resinous wood. Two pieces of 
 
 Memel fir were cut as A. B., C. I). in the margin. C. D. contracted 3. 
 
 75 per cent in width, becoming hollow on the outer part from the centre; 
 while A. B. remained straight, contracting only 0.7 per cent. As Tred- 
 gold observed; — “From these experiments, the advantages to be ob- 
 tained merely by a proper attention in cutting out boards for panels, etc., 
 will be obvious; and it will also be found that panels cut so that the 
 septa are nearly parallel to their faces, will appear of a finer and more 
 even grain, and require less labour to make their surfaces even and smooth. The results of 
 these experiments are not less interesting to cabinet-makers, particularly in the construction of 
 billiard— tables, card-tables, and indeed every kind of table in use. For such purposes the plank 
 should be cut so as to cross the rings as nearly in the direction A. B. as possible. We have 
 no doubt that it is the knowledge of this property of wood that renders the billiard-tables of 
 some makers so far superior to those of others. In wood that has the largest transverse septa, 
 as the oak, for example, boards cut as A. B. will be figured, while those cut as C. D. will be 
 plain.' Again, if flatness of surface is especially desirable, a piece of wood cut as A. B. is pre- 
 in able; and as < . I), where straightness of the edges is an object, because, as Knight remarks, 
 
 1 In* interior and older layers of wood are much more solid and specifically heavy than the 
 <\tnnal layers in the same tree; and the latter consequently contract more longitudinally in 
 di mi” than the former, and the edge of every board (that has been cut with surfaces nearly 
 parallrl with the line ol the converging cellular processes) which lay nearest the medulla in the 
 tree will therefore in drying become convex, while the opposite edge will become concave.” The 
 lihi( > ,it the edges of ( . D, will be found to shrink tolerably equal as they are equidistant 
 tinm the medulla; but in A. B., those at B. will contract less than those at A. The disposition 
 of wood to curve in its length is to be counteracted by so cutting it that the parts shall be, as 
 far as possible, of about the same ace. 
 
 O 
 
 TRANSPORT. \\ e do not deem it necessary to dilate on this subject. 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 93 
 
 Both Emy and Hassenfratz enter at very considerable length into the extraction of wood from 
 the forest and the various modes of transport by land and water. 
 
 On Plate 16., Figs. 15. and 16. are two very convenient and simple forms 
 of carriages for the transport of timbers, either short or of 
 any length. The cords behind Fig. 15. may be suspended 
 from the end of the horizontal shaft. Where there is a 
 river timber may be floated down it, and there is the 
 additional advantage that a seasoning process thus takes 
 place. In this way immense rafts are formed on the Rhine 
 of square pine logs, which are brought from the forests at the upper part of the river down to 
 Dort in Holland, where they are exported to this and other countries. The logs are placed 
 in layers to a depth of about six feet; and a length of 500 by a breadth of 250 feet is not an 
 unusual dimension of a raft. Rough plank floors are laid, there are often as many as 200 
 rowers, and the whole looks like a moving village, as the occupants live in huts fixed on the 
 l’aft, the timber forming which latter will often bring £ 20,000. 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATE 10 . EGYPTIAN HALL. LONDON. ROOF OVER REAR BUILDING. 
 
 GEORGE MAIR , F. S. A.. ARCHITECT. 
 
 From the taste displayed by this accomplished architect in his numerous 
 executed works, it is needful to remind but very few of our readers that he lays no claim to 
 the beauties displayed in the facade of this edifice, which at one period excited admiration under 
 the idea that it was a faithful reproduction of the architecture of that wonderful people on the 
 banks of the Nile; but we have now learned better things. 
 
 The sound constructive knowledge shown in the roof now under descrip- 
 tion will at once be perceived. In 1853, the old roof, indicated by dotted lines, was found to be 
 so defective as to necessitate its removal. There were then several objects to be kept in view, 
 calling for much skill on the part of the architect. Indeed, there is often more ability displayed 
 in alterations and additions, Avhen, of course, many unavoidable restrictions exist, than in the 
 erection of a new structure. In the present instance no window's were allowed in any of the 
 external walls, and ample light and ventilation were especially to be secured, together Avith 
 increased height, and great strength in the truss for exhibitional purposes. All these require- 
 ments are observed to be satisfactorily met in an economical manner. 
 
 Cast iron girders, proved by hydraulic press to carry five tons on the 
 centre, are laid across from wall to Avail, and timbers, each 13 by 7 inches, are placed on either 
 side of these and firmly connected by means of Avrought iron bolts. In this manner the Avhole 
 
description of practical examples. 
 
 weight of the roof is supported, - the rafters below and the strongly framed truss above. The 
 binder under the tie, supported at the ends by the girders, and at two points in the length by 
 wrought iron straps, 2' 2 by 1 2 inches, carries the ceiling joists with fillets as shown; and by 
 the form of the ceiling great height is gained in the middle of the room where most required. 
 Eight dormer windows on each side of the roof are introduced; these are glazed with rough 
 plate glass, and the room is brilliantly lighted. The ventilation is very successful: there is a 
 perforated grating in the ceiling, and the circular openings shown with louvres aid the escape 
 of vitiated air. 
 
 The plate comprises the transverse section, of which about three quarters 
 is shown (the other side being precisely similar), one halt of the longitudinal section, and de- 
 tails of the cast iron girders. 
 
 SCANTLINGS. 
 
 Lower Rafters 8 X 3 Inches. 
 
 Lower Plates 5 X 4 „ 
 
 Ties 8 X 5 » 
 
 Principal Rafters 7 X 4 „ 
 
 Common Rafters 5 X %*!% » 
 
 Purlins 7x4 „ 
 
 Ridge 4 X 3 l / 2 „ 
 
 Struts 4 X 4 „ 
 
 Plates 5 X 4 „ 
 
 Binders below Ties 8 X 4 „ 
 
 Ceiling Joists 4 X 2 */ 2 „ 
 
 Ceiling Joists to Dormers ... 3 X 2 „ 
 
 Sill (oak) 5 X 4 „ 
 
 Lower piece 8 X 4 „ 
 
 Head 4 X 3 „ 
 
 Moulded facia-board outside dormers, and inch i / i deal lining tvithin. 
 Countess slating to the roof, slate ridge, 3 / 4 inch slate slab over dormers, slate louvres to cir- 
 cular openings at end of building. 4 pounds lead step-flashing as shown, 5 pounds flashing to 
 the dormers, and 6 pounds lead to the gutters. Inch 1 / 4 gutter boards, and 2 inch drips. Rafters 
 12. Inches apart. 
 
 PLATE 11. MYDDELTON HALL, ISLINGTON. DETAILS OF ROOF. 
 
 WILLIAM LAMBERT, ARCHITECT. 
 
 It appears to us that there is a certain amount of originality displayed in 
 this combination. The laminated arched rib is, of course, on the principle introduced by Colonel 
 Emy (See Description of Plate /.), but its connection in the form of a bow-string truss with the 
 other portions ol the rool, and the important gain of increased central height is certainly in- 
 genious. ( )ur engraving is reduced from a very careful drawing by Mr. George Mortimer, 
 Irom whom we have the following particulars. 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 95 
 
 “The strains to which the various parts are subject are: — first, the head, 
 which is acted upon by a transverse strain, and is supported by blocks and struts resting on the 
 bow; secondly, the bow, which, if the bolts are properly screwed up, is compressed throughout 
 its length, and prevented rising at the haunches by the struts and blocks; thirdly, the tie, which 
 keeps the ends of the bow from spreading, is subject to tension, being supported by tie rods 
 from the head, which also keeps the crown of the rib from rising. The tie-beam is of red pine 
 in one length, the shoes firmly bolted on with the first four laminfe on each side, which were 
 then bent on cradles to the proper curve, and fresh lengths inserted as the work proceeded. 
 The laminfe were deals, 9 by 3 inches, fastened together by half inch bolts, 3 feet apart, and 
 by stout long screws, about 1 foot apart (See section at the right hand side of the bottom of plate). 
 Sometimes oak treenails are used instead of screws. The deals were 20 feet long, except at the 
 ends which were necessarily shorter. On the deals being bent round, breaking joint, the head 
 was placed in two lengths, halved at the centre of the bow, and the struts and tie-bolts fixed 
 simultaneously and screwed up until the tie cambered 5 inches. It Avas then raised from the 
 ground on to its bed (30 feet) by a single derrick composed of scaffold poles lashed together, 
 and a strong chain- fall secured round the centre of the truss and at each end, thus suspending 
 it from three points by chains united at the centre over the top of the bow. The cradling upon 
 which the bows w r ere bent prevented them from being thrown out of shape, as they Avere not 
 struck till truss was on its bearings. The ties of the king trusses spanning the intervening part 
 between the tw r o bows effectually prevented vibration at the top, Avhile the ceiling joists per- 
 formed the same office for the tie. The weight was about three tons. 
 
 Feet Inches 
 
 Chord of top of Bow r 55 „ 4 
 
 Versed Sine 6 „ 8 
 
 Radius 60 „ 9 
 
 When loaded with the roof, etc., the deflection was not quite one inch.” 
 
 SCANTLINGS. 
 
 Tie beneath Bow 12 X 9 Inches. 
 
 Head above Bow 9 X 9 „ 
 
 Struts between Bow and Head . 6 X 4 „ 
 
 Side Rafters 6 X 2 „ 
 
 Ceiling Joists 7 X 2 „ 
 
 Central Ties 9 X 3 „ 
 
 Principals 6 X 3 „ 
 
 Common Rafters 6 X H /2 » 
 
 Purlins 6 X 3 „ 
 
 King Post 9 X 3 „ 
 
 Struts 4X3 „ 
 
 Ridge 9 X H/a „ 
 
 The central span is nearly 21 feet 9 inches, and that of each of the sides 
 13 feet 14/ a inch; the length longitudinally is 53 feet between the Avails. The height from the 
 
96 
 
 THE decay of timber. 
 
 *** !; h :t ;zti 'zn 
 
 ".• . ,J " the tie rea.B .. a 4 met Yorit tempwe, Which 
 
 **»«**- 
 
 i ;;:,l ** . «. ** ^ m *» - ^ » * ** * »— **» 
 
 and the plan of the bow indicates the position of the bolts. 
 
 CHAPTER IV. 
 
 THE DECAY OF TIMBER. 
 
 DECAY GENERALLY. Alternations of dryness and moisture, too 
 - r ,. n t heat, constant moisture conjoined with an elevated temperature, too rapid or too dry a 
 current of air, arc among the predisposing causes of the decay of timber. To these may be 
 n i l.-d the action of insects, etc., and vegetable growths. If wood is desiccated rapidly by the 
 a] plication of dry air, or great heat, it will be apt to split, from the fibres being brought sud- 
 , ,lv together bv the rapid evaporation of moisture; and an elevated temperature in unven- 
 • . . I m.'io;izini s induces fermentation of the vegetable liquids in wood recently felled, the 
 ■ - - being rendered sufficiently evident by the close heat and disagreeable smell. Exposure 
 t. . the weather, and the continued action of the sun, wind, rain and frost, all have their 
 deteriorating effects. 
 
 Well seasoned timber unexposed to alternations of dryness and moisture 
 hen l.i -t nine hundred years, although it is apt to become brittle and to lose its cohesion 
 :i'l . Iuxtii'itv. The timber in the dome of St. Mark’s in Venice is still in good preservation, 
 
 bh' ;_di v 'on y, it- old. In the foundations of the old Savoy palace piles of chesnut, beech, 
 
 ' bn. and ■■ ik w re found to be quite sound after being nearly 700 years below ground; 
 
 may "h- rve the excellent state of the roof of Westminster Hall. It is observable 
 •' at in t - ut before their prime the outer portion is the first to decay, then the next layer, 
 
 "U gradually to the central part of the wood. This is due to the sappy character of 
 
 r r -iirf.i. . ; and if, prior to being thoroughly seasoned, paint is applied, the sap is 
 in ■■ I. thus contaminating the whole of the piece. In trees which have passed their 
 • ” ' 1 ' "’wood first goes, the outer portion often lasting a considerable time. If, therefore, 
 f *"' 'oner part should be most carefully examined. Dryness in excess produces 
 ■ • * ui rendering wood brittle and unfit to withstand the action of variable loads; but the 
 ordinary moi-mrc from a moderately dry atmosphere is not sufficient to induce decomposition. 
 
THE DECAY OF TIMBER. 
 
 97 
 
 Many woods constantly wet will last a long time; their decay in water is apparent from the 
 dissolution of a part of the substance and the formation of a coating of slime. The water ap- 
 pears to extract all that is soluble in it, and then what remains will endure a long period. 
 Afterwards, however, when taken from the water and dried, the wood is observed to be brittle. 
 T1 le inside planking of ships will often be found decayed when the outer part, constantly ex- 
 posed to the action of the water, is in good preservation. Alternations of dryness and moisture, 
 or wetness, seem to injure timber by the removal of a sensible portion at each change; and thus 
 a fresh surface is exposed to be in its turn removed. This is readily noticed in that portion 
 of piles which is about the change of level of the water. Woods full of resin, gum, or oil, are 
 very durable; and of course those impregnated with substances which are not soluble in water 
 are eminently adapted for works in it; for this reason oil and tar have been forced into woods 
 from one end so as to pervade the capillary vessels. Heat conjoined with moisture is probably 
 the most destructive of all conditions. The gelatinous matters, or albumen, in the sapwood 
 decompose, causing the rot. Putrefaction arises from moisture and the action of stagnant air. 
 If the wood is in a lower state of temperature than the moist air, the latter is condensed and 
 thus acts injuriously: the remedy consists in providing a current of fresh, dry air. The com- 
 mencing decay of unseasoned wood in damp and warm situations is indicated by its doated, 
 or stained appearance. Light seems necessary, together with air and moisture, for the con- 
 tinuance of vegetable growth; and cracks in wood, admitting air, are found to hasten decay. 
 All timber in air of a certain moisture and a temperature not under 45° gradually decomposes. - 
 The greater the heat the more rapid will be the decay where moisture prevails. In the bread 
 rooms of ships, warm moist cellars, and damp kitchens with constant fires, wood will be 
 found more or less in a rotten condition; and the action of close stoves in a moist at- 
 mosphere is especially injurious. Hassenfratz says: — “Among woods there are some which 
 decompose less readily on account of the resin with which they are filled; and next come the 
 hard woods: soft woods, such as willow, poplar, birch, alder, are those which decompose most 
 rapidly in the air. We have seen cedar and even wainscot doors retaining, after prolonged use, 
 their freshness at the time when they were made. There are many woods which endure longest 
 soaked in water, as for example the alder; it is therefore preferred in the formation of pipes for 
 running water. For want of alder elm is employed, and it endures a long time: these two 
 woods grow in moist soils.” 
 
 From the experiments of Dr. Prout it appears that wood is made up of 
 about equal weights of carbon and water, but the latter is not in its collective but its separate 
 state. The decomposition of a compound commonly occurs by the union of a foreign body 
 with one or more of the constituents of the compound, producing a change of form; and one 
 decomposing substance exercises its influence on all with which it may be in contact. In ad- 
 dition to fermentation and putrefaction (in common language the rot) the combustible elements 
 of bodies combine with the oxygen of the air, oxidation thus taking place, the change of wood 
 into humus being of this character. Sir H. Davy observes: — “In general, the quantity of 
 charcoal afforded by woods offers a tolerably accurate indication of their durability; those most 
 abundant in charcoal and earthy matter are most permanent, and those that contain the largest 
 proportion of gaseous elements are the most destructible. Amongst our own trees the chesnuf 
 
 Carpentry. , XIII 
 
THE DECAY OF TIMBER. 
 
 98 
 
 and the oak are pre-eminent as to durability, and the chesnut affords rather more carbonaceous 
 matter than the oak.” 
 
 WET AND DRY ROT. The decay of timber called the wet or dry rot 
 has been a subject of much dispute with respect to its causes and cure. I redgold thought there 
 was no real distinction between the two, stating that a free evaporation determines the wet rot, 
 and an imperfect evaporation, such as that in a confined place, the dry rot. It seems that in 
 the wet rot the gaseous products are evaporated, as in the open air, and the decay of a post 
 in water, and also of one in the ground, are considered cases of it; while in the dry rot a new 
 combination arises and a fungus appears. The dry rot is often produced by laying timbers 
 closely together. The fungus is known to the botanists under the names of Merulius lachrymans, 
 or Pohjporus destructor, or the genus Sporotrichum; and its spread is very rapid, it presenting 
 the appearance of a thick, tough skin of white leather. 
 
 Timber felled at an improper period is very subject to dry rot, and, as 
 trees often put forth vegetation after they have been felled, it is not improbable that a combi- 
 nation may take place between the acid matter in sap and the oxygen in the air, inducing fer- 
 mentation, leading to the dry rot. Gwilt believes that “imported timber is affected with the 
 seeds of decay long before its arrival here (fir more especially), and that the comparative warmth 
 and moisture of the climate bring more effectually the causes of decay into action, especially 
 where the situation is close and confined.” Certainly, the dry rot is always marked by the 
 grow th of fungi, and these never occur till decay has commenced, the wood being ultimately 
 left only connected by the fibrous portions which readily crumble into dust. 
 
 We shall conclude with some brief observations on the choice of timber, 
 and the avoidance of defective pieces, supplementary to what will be found in Chapter I. of 
 the present Division, on the selection of trees in the field. 
 
 CHOICE OF TIMBER IN YARD. Generally speaking, the wood 
 should be from a tolerably dry soil, I’cllcd at least three years and in the proper season. Its 
 straightness ought to be dependant on that of its fibres, not the result of sawing or cutting. 
 Pieces ot the straightest grain are to be preferred, but for knees and braces a curved direction 
 is ol course desirable. ( ross-grained fibres are to be rejected, and fractures will probably occur 
 near knots. Other things being the same, the heaviest woods are best, especially those least 
 changed in weight after soaking in water, as the fibres must necessarily be very close to pre- 
 vent the entrance oi moisture; and dense, hard woods, from the closeness of their pores, resist 
 the attacks of worms. 
 
 Respecting the age of timber we must refer the reader to Chapter I. of 
 dii' I)i\ ision. It causes a wonderful difference in the quality of wood, chesnut for example 
 b< ing tough and flexible when young, and brittle and often shaky when old. The fine yellow 
 deal which retains its colour a long while is best adapted for flooring boards, while the white 
 becomes Mack. 1 he best battens are free from knots, strakes, sap, and cross-grained fibres; 
 tin- next ha\e small, sound knots; and the third quality have the defects from which the others 
 ,n 1 hce. Reams laid side by side will endure longer if a space is left between them, allowing 
 the air to circulate and moisture to exude. “The greenest timber is sometimes desirable for 
 such as carve and turn, but it chokes the teeth of our saws; and for doors, windows, floors, and 
 
THE PRESERVATION OP TIMBER. 
 
 99 
 
 other close works, it is altogether to be rejected, especially where walnut tree is the material, 
 which will be sure to shrink. Therefore it is best to choose such as is of two or three years 
 seasoning, and that is neither moist nor overdry; the mean is best.” “For all cases that timber 
 is esteemed the best which is the most ponderous, and which, laying long, makes deepest im- 
 pression in the earth, or in the water, being floated; also, what is without knots, yet firm, and 
 free from sap, which is that fatty, whiter, and softer part called by the ancients alburnum, which 
 you are diligently to hew away.” “My Lord Bacon, (Exper. 658.) recommends for trial of a 
 sound or knotty piece of timber, to cause one to speak at one of the extremes to his companion, 
 listening at the other, for if it be knotty, the sound, says he, will come abrupt.” (Evelyn.) 
 
 CHAPTER V. 
 
 THE PRESERVATION OF TIMBER. 
 
 NATURAL AND WATER SEASONING. 
 
 PRESERVATION GENERALLY. The protection of wood from those 
 causes which produce decay is the general object of the various preservative measures. Immedi- 
 ately that timber is felled it should be removed to a dry, airy situation and be so placed that the 
 air may circulate freely around it, but the direct action of the sun and wind must be carefully 
 excluded, as well as all influences which unduly hasten desiccation. Of course, if the trunks are 
 roughly squared the air will act more thoroughly on the parts; but they should be partly sea- 
 soned before division into scantlings. If, previous to this operation, wood is not partially dried, 
 warping and twisting will probably occur, and the sudden exposure of surface induces a rapid 
 shrinkage, disturbing the fibres too suddenly. In order to avoid the latter, it was the practice 
 to lay planks in a running stream directly they were cut by the sawyer, thus preventing ex- 
 posure to the atmosphere; but, although the wood was found to work easily and warping rarely 
 occurred, still, as in boiling or steaming, its strength was deteriorated. The more gradual the 
 drying the better; and if it is slow, the wood, if of a tolerable quality, will be found to endure 
 a long time. The object of seasoning is simply to get rid of the moisture, sap, and other mat- 
 ters which are liable to fermentation, without disturbing the carbon, which is injured when there 
 is a great heat; and therefore gradual drying, evaporating the juices, or immersion in water, 
 which acts by washing them out, are probably the safest operations. Wood dried too quickly 
 becomes deficient in pliability as well as toughness, from the forced contraction of the outermost 
 pores, through which the moisture should gradually drain off. As before remarked, timber for 
 carpenter’s work should not be used in less than two years, and for joiner’s work than three or 
 
1 00 
 
 four after being 
 experiments on 
 growth, after an 
 comparative value of certain woods. 
 
 Cedar, perfectly sound. 
 
 Larch, sap quite decayed, but 
 the heart sound. 
 
 Spruce fir, sound. 
 
 Silver fir, much decayed. 
 Chesnut, very sound. 
 
 Ahele, sound. 
 
 Annals shows the results of 
 thirty to forty-five year 
 degree indicating the 
 
 Beech, sound. 
 
 Walnut, decayed. 
 
 Scotch fir, much decayed. 
 
 Pinaster, perfectly rotten. 
 
 Sycamore, considerably decayed. 
 
 Birch, worthless. 
 
 TI1E PRESERVATION OF TIMBER. 
 
 felled. The following statement from Young’s 
 inch and a half planks taken from trees of from 
 exposure to the weather of ten years; and thus in some 
 
 Oak if properly seasoned loses about two-fifths of its weight. The specific 
 gravity when cut is from 1000 to 1054; but after seasoning the weight is reduced from 70 or 
 74 lbs. per cubic foot to 60 or 63 lbs. The loss of one-third of the weight may generally be 
 considered to indicate the utmost attainable dryness, but the wood is then brittle. Oak reduced 
 to about 60 lbs. per cubic foot, or that which has lost about one sixth of its weight, is con- 
 sidered preferable for carpentry. 
 
 Rondelet thought timber generally should lose one-sixth of its weight in 
 seasoning to be fitted for the carpenter’s purposes; Tredgold believed one-fifth sufficient, and 
 one-third for the joiner’s requirements. 
 
 SHRINKAGE. Wood in the process of seasoning often warps and 
 twists and always diminishes in breadth. Warping, or winding, is simply the state in which 
 timber becomes convex on one side and concave on the other. The alteration in the direction 
 of the length of the fibres is rarely very perceptible, more especially in straight grained woods. 
 Rods split out of clean fir, or deal, have consequently been used as pendulum rods; and it is 
 said that, for this purpose, they are only inferior to some of the compensating pendulums. On 
 the other band the lateral expansion and contraction is so great that a rather wide piece of the 
 above mentioned woods, taken on the crossway of the grain, diametrically from the centre of the 
 tree, will be found a tolerable hygrometer. The softest woods are observed to shrink most 
 laterally, but there is a want of correct observation on the subject. White is less liable to 
 shrink than yellow deal. In teak the shrinkage is very slight; while rock-elm, according to 
 Mr. Eincham, gives half an inch to the foot, being about as much as any wood; and the dispo- 
 sition to shrink seems never entirely to disappear, even after very perfect seasoning. Wood 
 which splits in contracting is called shaken. While metals increase in size on the application 
 of beat, wood has quite a contrary property, increasing in cold weather and diminishing in hot. 
 1 bis is owing to the sap being condensed by cold, and, like other liquids, consequently enlarged, 
 as water is increased in volume by freezing. By observations of the above description it would 
 be easy to settle which woods have most sap. Foreign fir shrinks in the log about l / 30 part in 
 width after seasoning. W bite deal loses 1 / 70 part. According to Rondelet’s experiments, the 
 extent of expansion and contraction, produced in wood of a mean degree of dryness by the 
 ordinary atmospheric changes, was for fir from 1 / 75 to V360 part of its width, and for oak from 
 
THE PRESERVATION OF TIMBER. 
 
 101 
 
 VVi to 1 410 ; thus the mean variation in fir is 1 / 124 , and in oak , / 140 - The difference in width in 
 a fir board 1 2 1 / 2 inches wide would therefore be ^io °f an inch. It is obvious from this con- 
 sideration how necessary it is for the joiner to attend carefully to the chances of shrinkage in 
 framings; and we shall here draw attention to some particular details, as the statement of the 
 reason of certain practical observations may make more impression than if the latter were 
 mentioned separately. 
 
 We before remarked in Chapter 3. on the desirability of cutting wood 
 so that the parts of each piece may be about the same age. An instance of the ill consequences 
 resulting from neglect of this circumstance may be cited in the case of the curving of the stile 
 of a door hung with centres, and its rubbing against the jambs. We would beg the reader to 
 peruse again that portion of the above Chapter relating to the best modes of cutting wood so as 
 to avoid shrinkage in a direction which shall utterly spoil workmanship. It is because seasoning 
 does not affect the length of timber that we perceive in that which has not fully undergone the 
 above process and is used in architraves round doors and windows mitred together, that the 
 mitres are open towards the door and close on the outside, a sort of hollow being the result on 
 both sides of the frame. Of course the narrower the boards for flooring, etc., the more the 
 shrinkage is distributed. Panels must be allowed to be free in loose grooves, as, if restrained 
 from contraction by nails or mortices, they will split with great force. 
 
 Warping, arising from the irregular contraction of fibres, is much more 
 to be apprehended than the splitting of green wood cut into boards, etc. “Other mischiefs al- 
 most as fatal as decay also occur to unseasoned wood; round blocks, cut out of the entire cir- 
 cular stem of green wood, or the same pieces, divided into quarterings, split in the direction of 
 the medullary rays, or radially; also, though less frequently, upon the annual rings. Such of the 
 round blocks as consist of the entire section contract pretty equally, and nearly retain their 
 circular form, but those from the quarterings become oval, from their unequal shrinkage.” In 
 the formation of joints the expansion and contraction of timber is to be especially considered. 
 Dovetail joints ought never to be employed in carpentry, as the slightest shrinkage destroys the 
 strength of the combination; but in joinery the shrinkage of the parts of dovetails often has a 
 counterbalancing effect. Free room should be left for expansion or shrinkage, as if pieces are 
 too confined there is sure to be a split somewhere, the force in particular with which timber 
 expands being extraordinarily great. 
 
 NATURAL SEASONING. The simplest and most natural seasoning 
 process is to allow timber to dry in the open air. In this way the fermentable juices freely 
 exude and evaporate, thus removing facilities for the germination of fungi. The best remedy 
 for worms and the rot is a thorough circulation of air; and that which is stagnant is about 
 equally pernicious as stagnant moisture. Evelyn says: — “Lay up your timbers very dry, in 
 an airy place, yet out of the wind or sun, and not standing very upright, but lying along, one 
 piece upon another, interposing some short blocks between to preserve them from a certain 
 mouldiness which they usually contract while they sweat, and which frequently produces a kind 
 of fungus, especially if there be any sappy parts remaining.” The pile ought to be so elevated 
 as to admit a free circulation of air under as well as round it; and in dock-yards elevated sup- 
 ports of stone or iron are used, as if the timber is allowed to rest on decayed or damaged wood 
 
102 
 
 THE PRESERVATION OF TIMBER. 
 
 it will soon be corrupted. The rain must be carefully excluded, and the action of frosts is 
 injurious. It is of great importance to drain the ground and prevent the growth of vegetation 
 
 near the timber; and for this reason the ground is 
 often strewed with ashes and scales from a forge or 
 foundry, preventing the spread of vegetation. The 
 action of the sun and wind causes timber to crack 
 and fly. Painting the wood over with cow-dung 
 facilitaties equal drying and prevents cracking. 
 Rondelet recommends placing wood upright, after 
 it is roughly squared, immediately after felling, to 
 allow the juices falling down and thus obviate the 
 cracks often caused. Of course, when timber is 
 placed in houses to season, there must be numerous windows and louvres in the roof to promote 
 complete ventilation. 
 
 WATER SEASONING. This dilutes and washes out the sap, but the timber 
 is to be wholly submerged in running water, as otherwise the process will only be partial, and, in 
 fact, often destructive. Water seasoning is excellent for oak, and it is very generally adopted for 
 fir, which latter, on arriving in London is formed into floats on the Thames, but Gwilt seems to 
 think that dry seasoning is preferable. The colour of white woods is said to be improved by 
 water seasoning; but there can be no doubt that keeping timber in London so long in floats 
 promotes decay, as they are only partially sunk. Oak logs ought to be submerged about a year, 
 but less time Mill suffice for planks. Timber full of sap is greatly benefited by water seasoning. 
 According to Tachenius, the success of the Venetians in seasoning timber was entirely due to 
 sinking it in a green state in water and allowing it to remain there for many years. Timber 
 tor naval uses is often seasoned in salt water, but fresh should be used for that, intended for 
 civil purposes. Although it is Said that the action of sea water destroys the vitality of the dry 
 rot fungi, ships seasoned in it have been observed to be unhealthy on account of the hygro- 
 metric properties consequent on the absorption of salt. In Norway deal planks are seasoned 
 by being laid in salt water for three or four days when just sawed, and they are afterwards 
 diird in the sun without injurious effects. Du Hamel believed that water seasoned timber was 
 picfciable for joiners work, but thought that strength was lost. All wood should be carefully 
 dried after soaking, and the best way to do this is to place the pieces so that one end may be 
 
 much higher than the other. We cannot better 
 conclude tins Chapter than in the words of the 
 celebrated Evelyn, from whom we have frequent 
 occasion to quote, as his work is perhaps more 
 consulted than that of any other author on timber 
 trees. “Some there are yet who keep their tim- 
 ber as moist as they can by submerging it in 
 water, where they let it imbibe, to hinder the 
 cleaving; and this is good in fir, both for the better stripping and seasoning, yea, not only in 
 fii but in other timber. Lay, therefore, your boards a fortnight in the water (if running the 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 103 
 
 better, as at some mill-pond head), and there, setting them upright in the sun and wind, so as 
 it may freely pass through them (especially during the heat of summer, which is the time of 
 finishing buildings), turn them daily; and thus treated, even newly sawn boards will floor better 
 than many years dry seasoning, as they call it.” “Amongst wheelwrights the water seasoning 
 is of especial regard, and in such esteem among some that I am assured the Venetians, for the 
 provision in the arsenal, lay their oak some years in the water before they employ it. Indeed, the 
 Turks not only fell at all times of the year, without any regard to the season, but employ their 
 timber unseasoned; so that, though they have excellent oak, it decays in a short time, by this 
 only neglect. Elm, felled ever so green for sudden use, if plunged four or five days in water 
 (especially salt water) obtains an admirable seasoning, and may immediately be used. I the 
 oftener insist on this water seasoning, not only as a remedy against the worm, but for its ef- 
 ficacy against warping and distortions of timber, whether used within or exposed to the air.” 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATE 12. BRIDGE OVER THE SEINE AT IVRY, FRANCE. M. EMMERY, ENGINEER. 
 
 This bridge, which is erected at the junction 
 of the Marne with the Seine, and is now selected as one of the 
 best specimens of the use of curved ribs, consists of five arches, 
 of which one is shown, together with the springing of the next. 
 M. Emmery has published a very complete description of the mode 
 of carrying out the works, comprehending also much useful in- 
 struction with respect to bridges generally. 
 
 The span of the arches is about 75 feet and 
 the rise 1 / 7 nearly. As will be perceived, there are three bent 
 timbers, and the binding pieces sustain the platform of the road- 
 way. The details in the margin further illustrate the construction. 
 Plates of copper are placed between all those pieces of timber 
 which meet end to end, in order to avoid the indentation of the 
 fibres. The parts in the stone piers where the curved pieces abut 
 are cut perpendicularly to the tangents of the latter, and spaces 
 are left around to facilitate a free circulation of air and thus pre- 
 vent to a certain extent the decay of the ends. 
 
 It will be noted that the curved pieces are 
 not pierced for bolts, but are held together by means of iron straps, 
 and also by the cross pieces bolted at top and bottom through the 
 radiating binders. It must be acknowledged, however, that holts 
 passing through curved timbers are of the highest utility in pre- 
 venting sliding. At Marac both straps and bolts are employed, 
 but there are no cross pieces as in this bridge. M. Emmery had 
 
104 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 intended to form the arches in n manner which would have been preferable; ^ iz., by substi- 
 tuting for the thick pieces five planks, softened by means of steam and then bent to the curve. 
 M. Eustache, engineer in chief of bridges and roads in France, had previously suggested this 
 system, and applied it at Melun in the centering of a bridge where it was desirable not to inter- 
 pose any obstacle to the navigation of the river during the execution of the works. The reader 
 will be reminded of Emy’s method. In this, however, the arches are much larger than the last 
 mentioned, their object dissimilar, and the planks curved without the aid of humidity and heat. 
 The alteration contemplated by M. Emery was overruled by the proprietors, who feared its 
 success and the consequent risk of increased expense. 
 
 It is obvious that the centre of this bridge cannot yield without all the 
 other pieces giving way, and, from the skilful management towards the abutments, a very con- 
 siderable degree of stiffness is secured. It is a question whether the binding pieces would not 
 better answer their purpose of supporting the roadway if placed perpendicularly to it, as is done 
 in other examples, instead of radiating from the centre. Care should be taken in these bridges 
 to prevent the oscillations caused by the action of high winds, and the rapid movement of heavy 
 carriages. The inclined pieces at the two ends of each arch contribute to the increase of 
 steadiness. By making the bolts and straps which secure the curved timbers moveable, in order 
 that any decayed timbers may be taken out without interfering with others, the repair of timber 
 bridges is much facilitated, and they may thus be made to endure a considerable time. 
 
 BRIDGE OVER THE NEC EAR, NEAR STUTTGARD, WURTEMBURG. 
 
 Krafft has given details of this bridge, but he does not mention the name 
 of the designer. The span is about 03 feet; and the peculiar indentations, called in Germany 
 Ilange-Werk, are similar to that used in the bridges atMellingen and Feldkirch. Cresy remarks: 
 “Before the principle was adopted of jagging or notching the three timbers which form the 
 ribs, to enable them more firmly to lock into and abut against each other, it was the custom to 
 build up the arches with courses of solid logs of oak, in length from 12 to 15 feet, and about 
 Hi inches square; those were selected from the forest which had a curve most suitable to the 
 arch to which they were to be applied; and, in producing the requisite form, the timbers were 
 never cut across the natural grain; they were so laid that their abutting joints did not come 
 over each other, and were afterwards secured together by straps or hoops, which surrounded 
 them at every 5 feet distance. Much inconvenience resulted from this method, and an arch 
 constructed with bent timbers notched into each other is a rash improvement upon it; in one 
 instance the platform of the bridge was supported by the sides of the polygon, and in the other 
 b, tin' arc of a circle; both required that the abutments should not yield, but the strength of 
 an arch burned with bent timbers is far less likely to be interfered with than that consisting of 
 a number of limbers arranged along the portion of a polygon; for some of the sides lying hori- 
 zontally, and others perpendicularly, it is not possible to make them all bear equally, and resist 
 the effort occasioned by a load placed on the centre of the bridge.” 
 
 Hie conception of this bridge is certainly of an original character and its 
 composition very suggestive. The curved rib might be formed in many other ways. 
 
CHAPTER VI. 
 
 SEASONING TIMBER: APPLICATIONS OF HEAT. 
 
 HOT AIK. The practice of seasoning timber in drying rooms, made as 
 air-tight as is feasible and heated above the temperature to which the wood is ever likely to be 
 subjected, is not to be recommended, as the warm stagnant atmosphere retains the evaporated 
 moisture. But there would appear to be no objection to the admission of hot air in the lower 
 part of the room when it is permitted to escape above, carrying off the absorbed moisture. The 
 desiccation of timber is thus accomplished in one-third of the time essential in a natural at- 
 mosphere: a velocity of 100 feet per second is best for the hot air. 
 
 CHARRING AND SCORCHING. That wood only should be charred 
 which has been previously seasoned, as otherwise the moisture will be prevented escaping; when 
 only the external part is seasoned, the rot will make its appearance within; and again, charring 
 will not affect the centre which may be decayed without any appearance of surface deteriora- 
 tion. Charred wood lasts a long time, as evidenced in the instance of the temple at Ephesus 
 erected on piles thus treated. So Evelyn remarks, — “When wood is charred it becomes in- 
 corruptible; for which reason, when we wish to preserve piles from decay, they should be 
 charred on their outside. Oak posts, used in enclosures, always decay about two inches above 
 and below the surface. Charring that part would probably add several' years to the duration 
 of the wood, for that to most timber it contributes much to its duration.” 
 
 The common method of charring wood is to lay it on rough walls, en- 
 closing a space where the fire is lit, the wood being protected from the action of the outer 
 atmosphere: it is to be turned so that all sides may be submitted to the fire till the whole sur- 
 face to the depth of rather less than an inch is converted to charcoal. 
 
 Scorching the ends of posts or piles is an excellent preservative. 
 Semple, in his work on Building in Water , says: — “After your work is tied up, or even put 
 together, lay it on the ground with stones or bricks under it to about a foot high, and burn 
 wood (which is the best firing for the purpose) under it till you throughly heat, and even scorch 
 it all over; then, whilst the wood is hot, rub it over plentifully with linseed oil and tar, in equal 
 parts and well boiled together, and let it be kept boiling whilst you are using it; and this will 
 immediately strike and sink (if the wood be tolerably seasoned) one inch or more into the wood, 
 
SEASONING TIMBKR: APPLICATIONS OF HEAT. 
 
 I OH 
 
 rlu.-o all the | tores, and make it become exceedingly hard and durable, either under or over 
 wain ” Care mu>t be taken in scorching not to produce rents and cracks. Burning furze 
 ,tnov. etc., under wood, or smoke-drying it, destroys the seeds of worms, fungi and insects. 
 
 STEAMING AND BOILING. Timber which has been steamed or 
 hoiled is said not to shrink so much and to stand better, but it has less strength than that which 
 it. seasoned in the open air, or in cold water: it is also not so durable. About four hours is 
 the ordinary time occupied in the process, but the seasoning is probably more rapid in steaming 
 than in boiling. Mr. Hookey supposes “that the process of boiling or steaming dissolves the 
 pithy substance contained in the air tubes, by which means the latter fluid circulates more freely, 
 and the seasoning thereby proceeds with greater rapidity. 
 
 Boiling or steaming is resorted to as a preliminary to bending wood; for 
 that which has been boiled or steamed for some time, if immediately bent to a certain form 
 and so retained until it is quite dry, will spring back very slightly when relieved. There ap- 
 peal' to be much looseness of ideas respecting the exact time for which timber should be steamed 
 or boiled, and the precise difference between the curvature to which it is first bent and what 
 it ultimately assumes. In a future Chapter we shall allude to a new American process for 
 bending wood. 
 
 CHAPTER VII. 
 
 MISCELLANEOUS MODES OF SEASONING. 
 
 CHEMICAL AGENTS. Great attention has been given by scientific 
 men to the impregnation of timber with chemical antiseptic substances which coagulate the 
 albumen, and by filling the pores of the wood render their occupation by fungi almost impos- 
 -i Lie. Bituminous agents have been employed from a very high antiquity. It is said that the 
 mineral pitch, or patroleiun, from the Dead Sea was used by the Egyptians; and the state of the 
 wood of their mummy cases, and also of that found at Nineveh, demonstrate a more complete 
 process than the moderns, with all their science, seem capable of attaining. 
 
 It appears that the first patent granted in England for the preservation of 
 wood was taken out in 1737. by Alexander Emerson. He applied hot boiled tar mixed with 
 other substances. Patents to John Lewis, and Humphrey Jackson, follow; the first in 1754, for 
 the application of distilled plantation tar, and also for the preparation of a kind of varnish from 
 the juices of the American pitch pine; and the second, in 17H8, for boiling the wood in a strong 
 solution of calcareous earth in acid of vitriol, etc. In 1771), M. Pallas proposed a method of 
 mineralizing timber bv saturating it in green vitriol and precipitating the latter by means of 
 lime-water. An oil obtained from chips and refuse wood was used by Mr. Machnochie in 1803 
 b "as applied in a steam-tight chamber, and, the air being expelled from the pores of the wood 
 
MISCELLANEOUS MODES OF SEASONING. 
 
 107 
 
 the steam was admitted, ultimately condensed, and, after this process had been repeated more 
 than once, the timber was plunged in the oil. In 1822 Mr. .T. Oxford patented the use of 
 essential oil distilled from coal tar; and in the same year Mr. Bill impregnated logs with as- 
 phaltum: after five years insertion in the dry rot pit at Woolwich they were found to have 
 withstood the rot, other woods being destroyed in one-fifth of the time. 
 
 Sir Humphrey Davy had advised the application of corrosive sublimate 
 as an antidote to dry rot; and in 1832, Mr. Ivyan took out a patent for the preservation of 
 cordage, canvass, etc., by steeping them in a solution of bi-chloride of mercury (corrosive subli- 
 mate). Ultimately the process was applied to timber, the object being to convert the albumen 
 into an indecomposible substance. After being dissolved in water, the corrosive sublimate is 
 forced into the pores of the timber in closed tanks, force-pumps being used, and it thus com- 
 bines with the albumen. As its poisonous qualities destroy animal life, it is an effectual remedy 
 for worms and ants; but Kyanized wood is found to be more brittle and to have less specific 
 gravity and flexibility than that seasoned by non-chemical processes. At Kingstown harbour 
 Kyanized piles only resisted about a year. 
 
 In^l836, Mr. Mott used cresote for seasoning timber; in 1837, Mr. Mar- 
 gary took out a patent for saturating canvass, timber, etc., in a solution of sulphate of copper, 
 but the latter does not appear to be a very effectual agent; and in 1838, Mr. Hall employed 
 cresote, or essence of coal tar. In the same year that the last mentioned patent was granted, 
 Sir W. Burnett proposed the use of chloride of zinc as a preservative of canvass, timber, etc. 
 Burnetization, as it is sometimes called, has been advocated for remedying the failure of Kyan- 
 ization to protect timber exposed to the action of salt water; but we believe it is generally con- 
 sidered by scientific men as by no means satisfactory; in fact moisture quite destroys the efficacy 
 of chloride of zinc. 
 
 We come next to the method patented by Mr. John Bethell in 1838, 
 and which appears to be an excellent preservative process. The air and gases in timber 
 are withdrawn by means of air pumps , and oil of tar (commonly called cresote) is then 
 forced into the pores by means of hydrostatic pressure until the wood is impregnated with at 
 least 7 or 8 lbs. of oil, per cubic foot. This oil is found to set to a consistency like pitch, 
 effectually excluding moisture, and presenting after a few years the bituminized appearance of 
 wood observed in bogs. There is of course a certain danger to be anticipated from fire, and 
 the cresoted wood becomes exceedingly hard; but it is very successful in resisting the attacks of 
 every species of sea-worm (when it has absorbed about 10 lbs. of the oil per cubic foot), and 
 is perhaps more extensively used in railways for sleepers, posts, etc., than wood prepared by 
 any other process. It is said that cresoted timber gains strength, but loses it after about four 
 years exposure, and it is thus well adapted for buried timbers, as sleepers. We find the evi- 
 dence of Sir S. M. Peto, Mr. Rendel, Mr. Bidder, Mr. Hawkshaw and Mr. Brunei in its favour. 
 
 By the process patented by Mr. Payne in 1841, timber is impregnated 
 with alkalies, earths, or metallic oxides, a decomposition of them taking place in the pores of 
 the wood, insoluble substances being thus formed. The timber is rendered extremely hard, in fact 
 sometimes almost fossilized j and it is said that the softest woods may thus be rendered denser 
 and harder than the hardest in a natural condition, besides being practically incombustible, as 
 
MISCELLANEOUS MODES OE SEASONING. 
 
 lus 
 
 they will only smoulder. The timber however is rendered very brittle; and at Fleetwood it 
 
 speedily failed under the attacks ol sea-worms. 
 
 in 1840, a memoir on the preservation of wood wars read before the 
 French Academy of Seinin'* by the eminent chemist Dr. Boucherie. He proposed the appli- 
 cation of pyrolignite of iron (previously adopted by Mr. Bethell), or other earthy chlorides, 01 
 metallic salts, to render insoluble those fermentible juices which promote decay. The process 
 was one of aspiration, or a drawing-in of the solution by the pores of the timber as soon as 
 felled, as afterwards the absorbing power is greatly diminished when the vitality of the tree has 
 quite ceased. Two reports by M. M. Dumas and Arago, to the French Institute in 1840 and 
 Ibll. spread a knowledge of the invention which has since been considerably improved. The 
 vital energv of trees during growth was first availed of for the absorption of the preservative 
 liquid; and afterwards the logs were suspended perpendicularly, the Huid being poured in above 
 and left to sink by its own weight. Ultimately, the improved system of forcing the liquid by 
 simple pressure into the trunk at one of its ends was adopted. 
 
 Simple saturation, the sap remaining in the tree, was under various forms 
 (often assisted by considerable pressure) the mode of impregnating timber adopted before 
 
 Dr. Boueherie’s conception of entirely driving out the sap and supplying its place with 1 6 or 
 
 « 
 
 I „ of the pressure formerly necessary, the fibres of the wood being thus uninjured; as in the 
 old system the preserving liquid is forced at right angles to the fibrous tubes, while it now ap- 
 pears that no lateral connexion exists between them, and that therefore the proper way is to 
 inject fluids in the ends of logs. 
 
 Pyrolignite of iron, at first preferred, is at present superseded by a solution 
 of sulphate of copper and water, in the proportion (by weight) of 1 of the former to 100 of the 
 latter. As the success ot the process depends on the degree of permeability of the timber, that 
 felled between November and May may be injected in May; otherwise, if cut in May, or be- 
 tween Max and the end of November, it should be prepared within three w eeks of the felling. 
 
 1 he method of application is very simple. “Soon after the tree is felled 
 
 a saw-cut is made in the centre, through about 9 (0 of its section. The tree is then slightly 
 
 raised by a lever or wedge at its centre, and the saw cut is partially opened. A piece of string 
 is then placed round tbe saw-cut, close to the outer circumference of the tree, the support is 
 dien withdrawn, and the saw-cut closes on the string, thereby making a water-tight joint. An 
 augur-bole is then bored obliquely into the saw-cut, a wooden tube is driven into the hole, the 
 
 conical end of which is attached to a flexible pipe, which is in connexion with a cistern or 
 
 II (, ' n|r > al an elevation of from Bt I to 4i> feet above the tree intended to be preserved.” To 
 a l*H.' process on a larger scale the pipe is introduced at one end of the log. “When the 
 
 1 im< let operation, the sap runs out from the ends in a clear stream, showing the amazing 
 quaniitx of this fluid which it contains, in fact, the preserving fluid will traverse a tree 12 feet 
 l'".-'! 1 "'ll 1 ! (>s< pressure than is required to force it laterally through a plank three-quarters 
 "* 111 ' IH ^ * n fhickness. As the sap is forced out, the preservative fluid follow’s it, and its 
 i’ 11 " Ul ° " ^ u ‘ ( ' n 'l s °f the wood is ascertained by a chemical test. Thus the sap and fermenting 
 
 ( oinplctely expelled, and the timber impregnated throughout its length xvith the 
 preserving fluid.” 
 
MISCELLANEOUS MODES OF SEASONING. 
 
 109 
 
 A small apparatus costs from £ 10 to £ 15; and proprietors may thus 
 make use of refuse trees, in fact rendering them equal to many first class timbers for perma- 
 nent construction. Beech, Poplar, Willow, etc. are in this way available for many novel pur- 
 poses; and the best trees for the operation are the least costly, as Alder. Elm, Poplar, Beech, 
 Birch, Scotch Fir, etc. 
 
 The system is applied to the timbers used in a great many of the French 
 railroads, hitherto with perfect success; and it is calculated that the state saves by it at least 
 one million of francs annually on the telegraph lines. M. M. Avril, Didion, Mary, Leroux, 
 Lochet, Dupony, and other eminent engineers, have reported most favourably respecting the process. 
 
 Those readers who desire further information on the various chemical 
 processes for the preservation of timber are referred to l he Mechanics Magazine, vol. xxxix, 
 p. p. 346—350; The Penny Magazine for 1844, p. 135; The Encyclopaedia Britannica, art. “ Ship 
 Building The Mechanics Magazine, vol. xxxvi., p. 406; and Minutes of Proceedings of Institute 
 of Civil Engineers, vol. xii, in which latter is a list of patents granted. 
 
 PAINT. The protection afforded to the surfaee of wood in exeluding 
 influences which promote decay by means of metallic oxides is well understood; but we hardly 
 need say that if the wood is not well seasoned internal decay is promoted by the pores being 
 filled with paint, thus preventing the escape of the natural juices. Many woods in some situ- 
 ations last longest without paint; and in oak and fir the frizzly, wiry fibres are often more instru- 
 mental than paint as a protection from the effects of rain and the heat of the sun. Paint was 
 repudiated in the Middle Ages for the wood-work of churches, etc.; and Semple, in his Treatise 
 on Building in Water, notices an instance of field gates made of fir unpainted and in a perfectly 
 sound state, while others of the same wood and age covered with paint were rotten. Tredgold 
 says that he uniformly observed sanded to be much more durable - than common painting. 
 Chapman proposed as a good paint for wood, to grind up with any cheap oil sub-sulphate of 
 iron, (or the refuse of the copperas pans) thinned with coal tar oil in which a small portion of 
 pitch is dissolved. 
 
 PITCH. TAR. Charred timber intended for exposure to the weather 
 is often pitched over, set fire to, and turned about as it burns. Stewart recommends for paling 
 and weather-boarding, a mixture of six pounds of melted pitch, one pound of red ochre, one 
 pound of grease and a little lamp-black, to be applied hot when the wood is perfectly dry; or 
 eight pounds of tar, two pounds of fine sand, with a little red lead and soot; and to preserve 
 exposed framework joints, one pound of pitch, a quarter pound of grease, and as much powdered 
 chalk as will make the boiling mixture of a proper consistence: the joints are to be covered 
 when hot, and then secured with pins. The use of pitch of course needs the utmost care on 
 account of its rapid combustion. In Holland the gates, port-cullises, draw-bridges, sluices, etc., 
 are coated with a mixture of pitch and tar on which small pieces of cockle and other shells, 
 beaten almost to powder and mingled with sea sand and the scales of iron, are sprinkled; and 
 this is found, as Evelyn remarks, “to incrust and arm them in an incredible manner.” 
 
 Coal tar is a cure for the rot, a remedy for worms generally, and, in 
 particular, for the formidable Teredo navalis, or pile worm, so especially destructive to fir and 
 alder. Semple recommends a mixture of linseed oil and tar in equal parts, well boiled together 
 
.110 
 
 MISCELLANEOUS MODES OK SEASONING. 
 
 an ,l kept boiling when using it to scorched wood while yet hot; this will sink an inch or more 
 into the wood, closing the pores, and rendering it very durable in or out of water. 
 
 SUNDRY METHODS. We 1 iave vet to mention a few modes of preser- 
 vation which do not come under the above headings, or may be conveniently placed separately. 
 
 As remedies for worms, Gwilt recommends the saturation of timber with 
 any of the oils; Evelyn thought nitric acid, or sulphur, immersed in aqua-fortis and distilled, 
 excellent; and lime, oil of spike, oil of turpentine, or of juniper, or linseed, are all preservatives, 
 as is also soaking the wood in an infusion of quassia, as worms will not touch any thing which 
 is bitter. For the Teredo navalis, lime, sulphur, colocynth and pitch mixed are one remedy; and 
 various poisonous ointments are employed. The essential oils exterminate ants: arsenic is also 
 used. Oil is an excellent preservative of timber; and that of whalers and vessels employed in 
 the oil trade endures longer than the timber of other ships: staves from tallow casks make ex- 
 ceedinglv durable fences. Wood impregnated with linseed, or any other drying oil, resists 
 moisture, besides becoming harder. 
 
 Salt seems an antidote to decay; for in the salt mines of Hungary and 
 Poland the wood pillars which support galleries last for ages, while thosq. of brick or stone 
 crumble on account of the mortar decaying. But, although salt protects timber impregnated 
 with it, if there is any moisture the wood will be constantly wet. 
 
 Washing timber with charcoal and water is a preservative from the dry 
 rot, as charcoal is the greatest anti-putrescent known. 
 
 Stewart, speaking of the Alhambra, at Granada in Spain, says that: — 
 “The Spaniards attribute the durability of the timber to its being coated with a composition 
 consisting of Safne glue and garlic, well pounded in a mortar; these being mixed together, with 
 the addition of vermillion, are boiled over a gentle tire, until the glue becomes as thin as water; 
 too much or too little boiling deprives it of its viscous quality. Planks cemented with this com- 
 position arc said to adhere so firmly as to break at any other part except at the joint. Garlic 
 being noxious to worms, the Moors evidently mixed it with their cement in order to prevent their 
 depredations; it is not improbable that it was mixed with the gypsum used in the Alhambra, 
 which may account for the stucco work remaining uninjured either by spiders or insects.” 
 
 \ arious methods have been from time to time proposed to render timber 
 incombustible, but we shall not enter at length into the subject. 
 
 By Payne’s process, before described, wood may be prevented burning, 
 but it slow ly smoulders. I)r. Boucherie’s system reduces the inflammability of wood. Mr. Bushell 
 proposed to render timber fireproof by means of a coating of soluble glass, or silicate of potash, 
 which melts when heated and thus constitutes a species of protecting glaze. Evelyn speaks of 
 ‘a wash made of alum ; and the means generally adopted may be summarily stated as pro- 
 tecting the wood by causing it to imbibe saline solutions, covering it with thick and incom- 
 bustible mastics, or enveloping it with plates of metal: in none is the end fully attained. 
 
Ill 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATES 13. 14. SUN INSURANCE OFFICE. THREADNEEDVE ST., LONDON. DETAILS OF 
 FRAMINGS. C. R. COCKERELL, R. A., F. R. S, ARCHITECT. 
 
 These are given, independently of the larger details to which they relate, 
 as valuable and suggestive examples of framings, displaying much of that careful study for 
 which Professor Cockerell is so celebrated. The darker parts indicate wainscot; the rest is of 
 deal. Parts of doors, fanlights and partitions, architraves, plinth, console, etc., are comprised. 
 They require no explanation; but we would draw attention to the hanging of the entrance door, 
 and the mode of folding back; and also to the absence of the usual hackneyed forms of mould- 
 ings. The other points are mentioned on the Plates. It would be well if all architects be- 
 stowed the amount of consideration evinced in these details, instead of loosely describing such 
 parts in specifications, and leaving the mode of workmanship entirely to the builder. 
 
 PLATE 16. ORDINARY WINDOW FITTINGS, ARCHITRAVES, ETC. 
 
 These examples illustrate the ordinary forms commonly used. Such are 
 deemed absolutely requisite in a work addressed, like the present, to a great variety of readers; 
 and the usual kind are often, after all, most practically useful, meeting as they do wider re- 
 quirements, and serving as bases for more elaborate combinations. 
 
 There is one window with lifting, one with folding, and another without 
 shutters. The plans and sections' of the sills are given; the heads of the windows somewhat 
 resemble the plans, of course taking away the weights, etc., and adding lintels. It may be 
 useful here to specify some particulars relating severally to these windows. 
 
 The frames are described as deal cased, with inch outside and inside 
 linings. Inch 1 4 (or inch) deal (or wainscot) pulley pieces, 3 / 8 inch parting beads, and inch 1 > 
 (or inch 1 4 ) head; 1 2 or 3 ,, inch back. Ovolo, astragal and hollow, or moulded sashes, 1 1 2 to 
 2 1 2 inches thick, with circular or square tops and single or double hung. Brass cased pullies 
 to the inch 1 2 and *2 inch, and brass axle pullies to the 2 1 2 inch sashes. White Hax, patent 
 lines, or patent wire lines, and lead or iron weights. Common, or spring roller, sash fastenings. 
 The bottom beads ( 7 8 or inch thick rounded) are often tongued into the oak sill, and the 
 
 side beads rebated on to pulley styles. Where there are no shutters, there may be inch 
 
 rounded and rebated linings and soffit, and inch 1 4 moulded (or square) window back; with inch 
 rounded capping. 
 
 Lifting shutters may be inch 1 5 (or inch 1 2 ) moulded and bead butt (or 
 
 flush), hung in deal casing as above, with screw bolt, flush rings, lines, weights, ete., and inch 1 4 
 
 (or inch 1 2 ) moulded architrave, 5 or fi inches girt. 
 
 Folding shutters may have inch 1 4 proper boxings 5 inches wide, moulded 
 architrave, and inch return linings. The back linings on splay tongued to frame are often 
 moulded or beaded. Inch 1 4 one panel moulded soffit. Inch narrow beaded back and elbows. 
 Inch 1 /' 4 moulded and bead butt front shutters on splay; and inch (bead butt and square) 
 
112 
 
 ARRANGEMENTS IN STRUCTURES TO PREVENT DECAY. 
 
 hark flaps; the front shutters to he hung with 2 inch hutts and the back with 2 inch flap 
 hinges. Each window to have an iron spring bow shutter bar (3 feet 6 inches long), and two 
 gilt shutter knobs. 
 
 Casements will be described on a future occasion. 
 
 CHAPTER VIII. 
 
 ARRANGEMENTS IN STRUCTURES TO PREVENT DECAY. 
 
 Drainage and a thorough introduction of air into all parts of a building 
 are probably the best preventives of decay. Air bricks should be plentifully introduced, and a 
 current of dry air allowed to be constantly in contact with all woodwork. Then, when per- 
 fectly dry and in a moderate temperature, it will endure an indefinite period. Moist air when 
 in contact with wood of a lower temperature is condensed on it causing the rot; and Ave have 
 already spoken of the effects of combined heat and moisture. 
 
 No preservative precautions Avill avail if a building is inefficiently drained. 
 Areas are to be formed wherever practicable, and no earth should be [tiled up against Avails. 
 The building is to be raised, — not a fall around made by sloping earth towards the Avails. 
 Concrete prevents damp rising; and it is to be used in the foundations of all suspicious sites. 
 Air, or dry drains round buildings are very excellent but expensive contrivances; but a damp- 
 course ought never to be omitted. It may consist of asphalte 3 ' 8 inch thick, coarse slate slab, 
 bedded in pure cement with 1 .> inch course also above, cement alone 3 / 4 or inch thick, gas-tar, 
 or lead. If the lowest floor is boarded, dry rubbish and lime should be sprinkled beneath, the 
 vegetable mould having been removed. Sometimes the undersides of the boards and joists are 
 charred, or washed Avith charcoal and Avater; and this practice is often adopted on the side of 
 Avainscoting next Avails: the dry rot can then scarcely occur. 
 
 Care should be taken to alloAV the Avails and principal timbers of a build- 
 ing ample time to dry thoroughly before they are Covered in; by this means they also get 
 settled to their ultimate bearings, cracks and other defects in finished work being avoided. It 
 mu-t be sufficiently obvious that, if enclosed Avith joiner’s or plasterer’s Avork Avhile yet damp, 
 durability can hardly be expected ; and before joinery is fixed the plaster should be quite dry. 
 I In present practice is to run up houses Avith the utmost rapidity, and plaster and paint them 
 at omc. As f nvilt remarks: “I' or this the architect has been blamed instead of his employer, 
 
 aaIkisc object is generally to realize letting or to enjoy occupation as early as possible. After, 
 how (nor, the walls and timbers of a building are once thoroughly dry, all means should be em- 
 plo\cd to exclude a fresh accession of moisture, and delay becomes then prejudicial.” 
 
 I imber should be thoroughly seasoned before it is introduced into a build- 
 in^, as it must bo remembered it is from the ends that much of the moisture exudes, and 
 
ARRANGEMENTS IN STRUCTURES TO PREVENT DECAY. 
 
 113 
 
 these being usually covered are often the first to decay. Seasoning in the frame, once common, 
 has long been abandoned in ship building. Walls ought in fact to be tolerably dry before any 
 timbers are built in them, as the damp brickwork and the lime cause rapid decay, more espe- 
 cially if road scraping is employed instead of sand. Thus it is that lintels, bond, and the parts 
 of joists next walls, are so often completely rotten. The use of bond timber at all is objection- 
 able and it is now forbidden in the New Metropolitan Building Act. Dry lime does not seem 
 to injure timber; it certainly protects it against worms. Evelyn says: — “Timber that you have 
 occasion to lay in mortar, or which is in any part contiguous to lime, as doors, window-cases, 
 groundsils, and the extremities of beams, etc!, have sometimes been capped with molten pitch, 
 as a marvellous preserver of it from the burning and destructive effects of the lime; but it has 
 since been found rather to heat and decay them by hindering the transudation which those 
 parts require.” 
 
 Rooms should not be floored till the carcase is completed; but it is as 
 well to roughly plane the boards about a year before they are used; thus the sap will be quite 
 expelled and the seasoning perfected. The authority last cited advises; — “to prevent all pos- 
 sible accidents, when you lay your floors, let the joints be shot, fitted, and tacked down only for 
 the first year, nailing them for good and all the next; and by this means they will lie staunch, 
 close, and without shrinking in the least, as if they were all one piece; and upon this occasion 
 I am to add an observation which may prove of no small use to builders, that if one take up 
 deal boards that may have lain in the floor a hundred years, and shoot them again, they will 
 certainly shrink without the former method.” Wood for joiner’s work should always be cut up 
 into about the required thicknesses some time before being used, in order to allow it proper 
 time to dry and shrink; even in old wood, if the surface is renewed the extent of variation is 
 nearly the same as in new wood. 
 
 Painted floor cloth, completely covering a floor, is extremely injurious, 
 and some authors have even objected to carpets. It is as well to paint doors, windows, etc., 
 once in the carpenter’s shop before fixing, as the imbibition of moisture in a damp building and 
 from brickwork is thus in a measure prevented. Mahogany is often a cheaper article than deal 
 on account of the constant painting the latter requires. 
 
 Carpentry. 
 
 XV 
 
THIRD DIVISION. 
 
 T II E O KY < ) F C O N S T R UCTI O N. 
 
 CHAPTER l. 
 
 OBJECTS. We intend to sum up in this Division, as clearly and briefly 
 lips ill mil- power, the main features of the Theory of Carpentry, omitting much extraneous 
 matter with which the subject has been overloaded, while not leaving anything unnoticed which 
 I' n :dl \ nbsohitelv essential to he understood, or which may form a fitting introduction to a 
 more lengthened and elaborate consideration of the subject. Perplexing mathematical disqui- 
 sitions will l>e carefullv avoided, an ordinary comprehension of arithmetic and geometry being 
 sufficient to understand the views stated. 
 
 MECHANICS is the science which treats of the application of the laws 
 of motion and forces. Of its two divisions, statics and dynamics (relating to bodies in rest and 
 in motion), we have principally to do with the former, that is, the passive strength, equili- 
 brium. compression, mutual pressure, and resistance of beams, etc., their flexure, or bending, 
 under a weight being also involved. This Chapter is devoted to the consideration of those 
 matters which should in the first place he understood: in the second the general principles of 
 Valuing are treated; and the remaining Chapters comprise the practical consideration of the 
 strength of beams in various positions. 
 
 < )n the utility of an early comprehension of the theory of the useful 
 oi- non under treatment we have before remarked. Manv have a feelino - of fitness, or in- 
 Him perception, acquired by long experience, of the strength of various combinations; but 
 b"' olt'11 t nl-. and even when it exists a knowledge of principles, and of the reasons of pro- 
 ■ 1 1 hit', ran hardly tail to he of the very highest interest and importance. As is remarked in 
 di" /;„•'/<•/. If,-, tannin, “The many volumes called Complete Instructors, Manuals, etc., 
 
 'b' ' 111111 b humbler flight, and content themselves by instructing the mere workman, or some- 
 " - 1 ' 1 1 b*' nia-tcr-hiiilder a few approved forms of roofs and other framings, with the rules 
 drawing them on paper, from thence forming the working draughts which must guide the 
 uid the chisel of the workman. Hardly any of them offer anything that can be called a 
 prmciph . applicable to many particular eases, with the rules of this adaptation.” The carpenter 
 
GENERAL OBSERVATIONS. 
 
 115 
 
 has, — first, to determine the strength of his materials and what is the amount of strain they 
 will safely hear; secondly, the disposition of the different timbers so as best to distribute the 
 strain; and thirdly, the forms of the joints and other connexions, 'flic fii’st and second will be 
 considered in this Division, but the reader is requested to peruse that portion of C hapter I, Di- 
 vision 2, which relates to Fibres, Cohesion and Weight-, and the third will be treated in Division 4. 
 
 STRENGTH is the property by which bodies resist breaking. Stress, or 
 strain, is the force exerted on a body tending to break it. Thus, a pillar is equally strained in 
 all its parts by a direct load, and its strength is the resisting force. A strain is often produced 
 by the weight of the parts of a combination in addition to any other with which it may be 
 loaded; and in this way its size is practically limited. For instance a projecting beam becomes 
 less able to bear its own weight in proportion to the extent of projection; and if the latter is 
 increased beyond a certain point the beam will break ■ 
 
 Four cases of strains may be distinguished, i. A body may be torn 
 asunder by a force applied in the direction of the length of its fibres, when its cohesive strength 
 is estimated in proportion to the area of the transverse section taken at its smallest part, and 
 the weight requisite to destroy it is set down as its resistance of tension. 2. A body may be 
 compressed and ultimately crushed by a force acting in the direction of the length of the fibres, 
 opposite to that last mentioned. The repulsive, strength, as this is sometimes called, differs in 
 various woods. Oak is more cohesive than fir. but the latter is less compressible, or has more 
 repulsive strength, than the former: oak is therefore best for ties, king posts, etc., and fir for 
 straining-pieces, struts, story posts, etc. d. A body may be broken across by a strain acting 
 in a transverse direction to , its fibres, or obliquely or perpendicularly to its length, as in joists, 
 levers, etc.; resistance to cross strain is a phrase applied. 4. A body may be wrenched or 
 twisted, as the axle of a wheel; but into this subject we shall not minutely enter. 
 
 RELATIVE STRENGTH. As the term absolute is applied to the force 
 requisite to pull a beam asunder in the direction of the length of its fibres, so its relative strength 
 
 depends on its position. If a beam is fixed at one end A, and 
 is weighted at the end C, the strain at a point B is measured by 
 
 multiplying the weight by the distance B (': and if the weight is 
 
 distributed along B (.’, the stress at B is precisely the same as if 
 the load were concentrated at this point, which is the centre of 
 gravity of the weight. The strength of a beam fixed at one end 
 and loaded at the other is just half that of another double its 
 length and supported at both ends. In the last 
 the strain at B, caused by a load acting at 
 is as the weight multiplied by A B, C D and 
 divided by A D; and the strain at (' is as 
 the weight multiplied bv A C, ( D, and 
 divided by A D. The strain produced by a 
 weight at the centre 1» is one quarter of the strain which the same weight would cause at the 
 
 end of a beam of similar length with one end fixed. A beam will bear double the load dis- 
 
 tributed over its unsupported length that it will concentrated at the centre; and its resistance 
 
GENERAL OBSERVATIONS. 
 
 when the end- are firmly fixed is to that when they-aa^e only supported as three to two. “It is 
 w i ll known that the transverse strength of a beam is directly as the breadth and as the square 
 
 of the depth, and inversely as the length; and 
 the variation of the results of some experi- 
 ments from this law can only have depended 
 on accidental circumstances. If we wish to 
 
 find the number of hundredweights that will 
 break a beam of oak supported at both ends, 
 supposing them to be placed exactly on the 
 
 " ■ ■" r m 
 
 T“ 
 
 - 
 
 5a 
 
 middle, we may multiply the square of the depth in inehes by 100 times the breadth, and divide 
 hv thr length; and we ma\ venture in practice to load a beam with at least an eighth as much 
 a this, or, in case of necessity, even a fourth. And if the load be distributed equally through- 
 out the length of the beam, it will support twice as much; but for a beam of fir the strength is 
 somewhat less than for oak. A cylinder will bear the same curvature as its circumscribing 
 pri-m, anti it may be shown that its strength, as well as its stiffness, is to that of the prism as 
 one fourth of its bulk is to one third of the bulk of the prism.” 
 
 STIFFNESS in a beam is its resistance to flexure or bending. In car- 
 pentrv comparative stiffness is more important than comparative strength, for the simple reason 
 that timbers are more rarely exposed to strains which break than to those which bend them. 
 N v mat increase the scantling of a frame, thus adding to its strength, without proportionally 
 inert-using its tlijf'nes*, or resistance to change of form. In proportion to the deflection, or sag- 
 ging, of a beam, and its length is its stiffness; and the curvature should not be allowed to in- 
 crease above * 1 | #u th of the length, or 1 to th of an inch to the foot. To find the deflection of a 
 beam of fir loaded in the middle, multiply the cube of the length in inches by the load in 
 ( "iiml , and divide by the cube of the depth, and by ten million times the breadth. A beam 
 "t oak bend rather more than one of fir. Elastic bodies resume more or less their original 
 form after the operation of a force, which is not the case with those which are ductile. The 
 modubi . or measure of elasticity (■‘w Division 2., Chap. T., Cohesion) of different woods is as 
 t •• 1 1 " w - : Beech St 100 , Box r>( loO, Elm 8000, Fir 10,000, Oak 5000. Or. Young says: — -“For 
 
 b' :,m ' similarly fixed, stiffness is directly proportional to the breadth and the cube of the depth, 
 oel imcr.-elv to the cube of the length. 1 1ms a beam or bar two yards long will be equally 
 '"d "ch a beam one yard, provided that it be either twice as deep or eight times as broad. 
 
 ' "'b 'd a beam can be firmly fixed, by continuing them to a sufficient distance, and 
 
 1 " pmg them down by a proper pressure, the stiffness will be four times (?) as great as if the 
 "'b 'hiiplv supported. A hollow substance, of given weight and length, has its stiffness 
 "• ol\ proportional to the square of the diameter; and hence arises the great utility of tubes 
 " -"'ini '- i- required, the property being still more increased by the expansion of the sub- 
 tan.-, • than the ultimate strength.” The problem of the elastic curve (that assumed in bending) 
 
 N l in\. .-tig.iti-d l»\ James Bernouilli. M e only need say here that it can never be a 
 
 "" 1 giudualU more incurvated its it recedes from the point where the straining 
 
 O' 'pplii d. At this point it Inis no curvature, which hist is greatest in the middle, 
 decreasing towards the props where also there is no curve. 
 
GE NER AT. O F. S E RVATTON8 . 
 
 117 
 
 NEUTRAL AXIS. This is intimately connected with the subject of our 
 last remarks. When a beam bends, it is evident that the upper fibres are compressed and the 
 
 lower extended; and when the latter are forced beyond their 
 cohesive distance a fracture takes place, which fracture is clearly 
 one of tendon. In speaking of the strength of a beam we mean, 
 therefore, its resistance to compression on the concave, and to 
 extension on the convex side. But it will be observed that there 
 is a line, drawn dark, where neither of the two last operate, and 
 where, if a hole were bored, the beam would be just as strong 
 as before: this was first called by M. Fourier the neutral axis. 
 The force of compression is about equal to that of extension; 
 and the position of the neutral axis is determined by experi- 
 ments which show that in rectangular fir beams the fibres exposed to compression are in 
 proportion to those in tension as 5 to 3; and thus the neutral line is at 5 / 8 ths of the depth when 
 they are broken while resting on two supports, and at 3 / 8 ths when fixed at one end. In the 
 second diagram the matter is further explained. The fibres are more extended as they approach 
 B from A, and are more compressed in approaching C from A; A is the neutral point or axis 
 of rotation, and points between A and B, and A and C, are the centres of tension and compression. 
 
 CENTRE OF GRAVITY. This is the point about which a body ba- 
 lances itself and remains at rest. The centre of gravity of any irregularly shaped body may be 
 ascertained by observing the point where, when suspended in any direction, 
 the lines intersect one another. In cones it is one-fourth of the height from 
 the base; in triangles it is in a line drawn from the vertex to the centre of the 
 base, and at a distance of one-third from the last; and in cylinders, or prisms, 
 it is at the middle of the length. The direction of pressures is determined by 
 the consideration of the centre of gravity. Cresy remarks: — “Rectangular 
 .pieces of timber have their centres of gravity in the centre of their dimensions; 
 a piece of timber 12 inches by 12 inches contains 144 square inches, and its 
 centre of gravity will he 6 inches from each side; if the piece be broken by 
 any load, its fracture will terminate at the upper surface, or 0 inches above 
 the centre of gravity. The area 144 multiplied by C>, gives 864 as the lateral 
 strength, which may he applied in comparison with any other scantling of 
 different dimensions on wood of the same quality: saw this piece of timber down the middle; 
 the centre of gravity remains the same; if the sides are in the same vertical position, the area 
 of the section of each is 72, and this multiplied by 6, the distance of the centre of gravity from 
 the upper surface, makes half the product obtained before the timber was sawn; it is apparent, then, 
 that, the depth remaining the same, the strength varies as the thickness; should the position of 
 these latter timbers be reversed, that is, placed fiat instead of on edge, the centre of gravity 
 then is only 3 inches below the upper surface; the area of the end 72 being multiplied by 3, 
 we obtain only 216 as the product, which is only half the strength which it had placed edge- 
 ways. The scantling which has the greatest strength is not all square, but that with the same 
 area, which has its centre of gravity farthest from the top; a pieee of timber 14 by 10 inches 
 
Ms 
 
 DESCRIPTION OE PRACTICAL. EXAMPLES. 
 
 -• | unre to I in inches, and contains less than a piece 12 X 12, or 144 square inches; but the 
 , , nt re of gravity of the first is 7 inches from the top, and 140 multiplied by 7 produces 980, 
 wliii li exceeds 144 X 6 = 864. This is further illustrated by a plank 10 inches in depth 
 ,nd 1 inch in thickness; the sectional aera, 10 inches, multiplied by 5, the distance in inches of 
 ill, centre of gravity from the upper edge, the product is 50: the same piece placed flatwise 
 must onlv he multiplied by 1 ., inch; the product then is only 5, consequently the plank when 
 placed mi edge is ten times stronger than when placed flatwise. A beam or piece of timber 
 whose section is that of an equilateral triangle, when subjected to lateral pressure, is twice as 
 strong, when resting on its broad base, as when placed on edge, the centre of gravity of this 
 figure being at 1 , of its height measured from the base, or 2 from its apex: the lateral strength 
 of Mjuare beams is as the cubes of their breadth or depth; the lateral strengths of any beams 
 whose sections arc similar, are as to the cubes of similar sides of the section. In cylindrical 
 beams, the lateral strengths are as the cubes of their diameters: in rectangular beams, the lateral 
 strengths are to each other as the breadths and squares of the depths, the strength varying as 
 the breadth multiplied into the square of the depth. (Encyclopaedia of (aril Engineering.) 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PI. ATE 17. ANCIENT ROOFS IX ROME. These have already been men- 
 tioned at Page 52, and wc have only a few further observations to make. 
 
 1 lie first figure is a section of the roof of the basilica of St. Peter, erected 
 in die reign of die emperor ( onstantine, adjoining and covering part of the circus of Nero where 
 the apostle is said to have suffered martyrdom. The site of the basilica is now occupied by the 
 
 celebrated cathedral of St. Peter. When demolished, the timber of the roof was found to be 
 
 in so excellent a state of preservation that it was used in that of the Farnese palace. 
 
 1 ig. 2. i> the root of the Argentina Theatre. The iron stirrups are dis- 
 I"" 1 ^ nm< ^ and materially aid the support of the machinery which was suspended 
 below. Altogether this roof is well worthy of attentive study. It was executed in Hr. 
 
 ^ hu ot the roofs of the basilica of St. Paul beyond the walls is given in 
 1 " 1,1 1 rcdgold's Elementary Principles of Carpentri/ another will be found. That which 
 
 u, have chosen was of fir and is the oldest of all. It was destroyed A. I). 816 in the ponti- 
 
 b- ate of I -co III. The tie is about 86 feet in bearing, and is in one piece of timber. 
 
 I ig. I. the i oof of the church of St. Sabine, closely resembles the modern 
 kmg-po„ roof. I, was constructed about A. D. 425, and is remarkable as being the first known 
 example of the suspension of the tie-beam from the king-post by means of an iron strap. 
 
 PI. I TEs IS, I!/. 
 
 CIIFRCU OF ENGLAND TRAINING 
 
 INSTITUTION. HIGIini RY. 
 
 F. W. PORTER. ARCHITECT. 
 
 state that they 
 
 formed 
 
 i opt i 1 \ to undei stand and appreciate these details, it is necessary to 
 no part of the original design for the Training Institution. We before 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 119 
 
 remarked on the difficulties inherent on alterations, and that greater skill is thus often displayed 
 than in the erection of entirely new structures. In this instance the junction with the main 
 
 building is shown on the right of the transverse section (Plate 18) and adjoining it was an 
 
 oblong space surrounded by boundary walls. The conversion of' this into a gymnasium by 
 simply roofing it was the problem presented to the architect. As the boundary walls are low 
 and incapable of supporting a heavy weight, a row of cast iron columns was introduced where 
 indicated. These support one side of the main roof, and the tops of the rafters on the other 
 side resting on the wall, all outward thrust on the latter being counteracted bv means of a tie 
 rod connected with each column. The longitudinal section (Plate 19) shows the treatment 
 adopted at one end. Sashes are introduced; and the truss is so contrived that only a down- 
 ward pressure exists, the old wall being unaltered, save by the introduction of a stone corbel. 
 
 The intelligent reader will at once recognise the careful study which has 
 
 resulted in the scientific construction shown on these two plates. There is an airy lightness in 
 
 the roof which is peculiarly striking on noting the economical means by which it is attained. 
 With the least possible waste in cutting the timbers into shape, a remarkably graceful curve is 
 produced. Above, the skyl ight is a very effective feature, affording, together with the side 
 windows, a brilliant light, while its formation is particularly simple. Below, at the springing of the 
 curve, a combination will be observed well worthy of attentive consideration. Filling in such a 
 spandrel as that shown with an iron plate, connected with the timbers by means of bolts, is very 
 usual; but it appears to us that the strap, extending outside along the sloping top and down 
 the vertical piece, not only considerably increases the strength of the framework at the very 
 point where most required, but that it is an original conception on the part of Mr. Porter. Cer- 
 tainly, a similar design has not attracted our attention. The manner also in which the hori- 
 zontal timber at the top of the roof below the skylight is connected with the sloping side by 
 means of the small under-piece, notched in, secured by the bolts and strap, and gracefully 
 rounding the oval, is as peculiarly happy as sound in a constructive point of view. Altogether, 
 we could wish to sec more frequently designs conceived expressly for a definite purpose, instead 
 of being blindly copied from existing examples, in order t*> save the trouble of exercising indi- 
 vidual thought. 
 
 On Plate 18 the transverse section and enlarged sections of portions of 
 the principals, together with other details, are given. The figures on the transverse section 
 illustrate the mode of setting out the work. 
 
 SCANTLINGS. 
 
 Principals 
 
 Purlins 
 
 Cross pieces under Skylight 
 
 Sill 
 
 99 
 
 99 
 
 Centre post framed into collar of truss and ridge of 
 
 Skylight 
 
 Cross pieces over columns and under side lights . . . 
 
 sills : 
 
 
 Inche 
 
 7 X 2’ 
 
 | / 
 
 2 »9 
 
 9X4 
 
 99 
 
 5 X 3 
 
 99 
 
 f 
 
 4 X 3 
 
 99 
 
 11X3 
 
 99 
 
 3 X 3 
 
 99 
 
1 20 
 
 PRINCIPLES OF FRAMING. 
 
 Head? . . . 
 
 Lower Rafters 
 Purlins . • 
 
 Plates . • • 
 
 7 X 3 Inches. 
 7X5 ,, 
 
 1 X 2 1 / 2 „ 
 
 4X3 „ 
 
 Inch ' , boarding throughout; 2‘ inch roll; countess slating; Hartley’s 
 llcnl g la,>, i |6 inch thick in 2> 4 inch fixed skylights, and »/§ Inch in 2 inch sashes > 
 
 hung with strong brass butts. The bolts to principals are throughout l /s inch in diameter, 
 the east iron spandrils 1 2 inch thick and the wrought iron straps 2 ! /s k y 3 « inches, those to 
 I mi-lin.- Leinir I 1 , by 1 8 . The longitudinal section, details of trusses, etc., on Plate 19, are 
 figured and need no comment. 
 
 CHAPTER II. 
 
 PRINCIPLES OK FRAMING. 
 
 COMPOSITION AND RESOLUTION OF FORCES. There will be 
 little difficulty in apprehending these two processes which it is essential in the first place to 
 under'tand. We shall make use of diagrams, the various lines representing forces and the 
 directions in which they act. Plate 2<l is throughout alluded to in this Chapter. 
 
 In Fig. I. a body at A is supposed to be pressed, or urged onward by a 
 li>rcc which suffices to push it as far as B. But, at the same time, another force is applied, in 
 i direction at right angles to the first, and sufficing to carry the body to C. As the forces are 
 <>f equal intensity, A B is equal to A C. The body, if perfectly free, would be found to move 
 in the direction of the diagonal AD, stopping at 1). On drawing the parallel lines BD, CD, 
 i Mjuarc is found to be the result. This is called the square of forces. 
 
 But, suppose the forces acting on the body A are unequal, that in the 
 direction of B being twice the intensity of the other. It is evident that the figure when com- 
 pleted will he more oblong as one force exceeds the other. In Fig. 2., the force A B is sup- 
 1""' '! ke *"100 the intensity of AC. flic result is a parallelogram. This is called the paral- 
 lelogram o / forces. 
 
 I he single force A I), which is the result of the action of the two forces 
 \ l>. \ , acting in opposite directions, is technically named the resultant. And the process of 
 
 ’.'img u. that is, cd ascertaining one force equivalent to two or more components, is called the 
 <q f overs. A 1 ) is also named the diagonal of the square, or of the parallelogram. 
 
 Again, finding two or more forces equivalent to a single force, in other 
 word- retiring the force acting in the direction AE (Fig. 3), and of the intensity AD, into the 
 two forces, or components, A B, AC, is called the resolution ‘of forces. 
 
PRINCIPLES OF FRAMING. 
 
 121 
 
 pentry. 
 
 APPLICATIONS. This very simple matter is easily applied to car- 
 We often have to find whether two forces are sufficiently strong to act as one force 
 would in the direction of the diagonal, or one force is required equivalent to two. 
 The figure in the margin, illustrating the meaning of a buttress or shore when 
 there is an outward pressure at A requires no explanation. Turning to Plate 20, 
 Fig. 4. represents a piece of framework, say of a roof. We wish to determine 
 the force acting on the rafters. Let fall from A the dotted line A B repre- 
 senting in integers (say number of pounds) the weight pressing, or hanging 
 from A. I) raw tire lines A C, AD, and connect, parallel to them, the lines 
 BC, BD; the lengths AC, AD will represent in proportion to AB the 
 weights pressing on the respective rafters, or by which they arc strained or 
 compressed. The fact of one rafter being longer than the other has no in- 
 fluence on the strain, the directions remaining the same; but of course there 
 is the compression to be considered, and one beam double the length of ano- 
 ther will be compressed twice as much: the scantling should therefore be increased. To find the 
 horizontal pressure at the base of the rafter, draw the line C F which represents it, as A C does 
 the force pressing at the base of the rafter. In the last described figure the angles of the rafters 
 are equal, as most usual in roofs, but in Fig. 5. they are shown unequal, and A D sustains a 
 greater portion of the weight than A C. The more open the angle, the greater the pres- 
 sure sustained by the rafters; and Fig. 6. explains the evil effects of too great obtuseness. In 
 Fig. 7 the effects of increasing or diminishing the angles are further illustrated by the dotted 
 lines; in either case power is lost. The form of the framing is altogether changed in Fig. 8, 
 but the principles we have defined still apply. AC, AD, represent the great strains caused in the 
 support of the small weight AB. The position is disadvantageous: the upper piece is stretched 
 by the weight hanging from it, and the lower, acting as a strut, is compressed. In Fig. It 
 the combination is greatly improved with respect to strength; the forces arc about equal. 
 But Fig. 10. is the most preferable form; as in the two former instances there was a tendency 
 to tear asunder, while the present is a case of thrust, which is preferable to a strain. This 
 form is much employed in roofs, bridges, etc., and also for cranes to raise heavy weights, for 
 
 which last Fig. 1 1 is another example. If the 
 figures are reversed, as in the margin, the same 
 principles apply; the pieces are on the stretch. 
 Fig. 12 illustrates a mode of finding the pres- 
 sure of an inclined beam, especially with re- 
 lation to the joint. A is the centre of gravity 
 of the beam. Draw the dotted line B C, perpen- 
 dicular to the horizontal beam below, or parallel 
 with the sifte wall, and draw also BD perpen- 
 dicular to the latter, or parallel with the former. 
 Then set off from B in integers (say pounds) 
 the weight resting on the beam D E, this being represented by B C, and join B E, indicating the 
 direction of the pressure against the abutment E. Connect C F, the line being parallel with the 
 
 Carpentry. 
 
I o ) PRINCIPLES OF FRAMING. 
 
 1 1 < >r, . nr , 1 beam below. This last gives, in proportion to B C, the weight pressing at D, and 
 BI th( pressure «.f the inclined beam at E. Of course the horizontal pressure at E is equal 
 (bat at I). In all calculations respecting the strength of combinations in carpentry, when 
 tic- meet in a point they are reduced to three, by substituting for any two that may 
 i" i.iki'ii their resultant force,' combining this with another, and thus proceeding throughout. The 
 ' 1 1 1 , 1 \v i n l! is I ) r. \ oung - rule for distinguishing between a brace, oi stmt, and a tie, a matter of 
 onsidcrablc importance, “ lake notice of the direction m which the piece acts fiom which the 
 .-train proceeds. Draw a line in that direction from the point on which the strain is exerted, 
 ind li t it- length (measured on some scale of equal parts) express the magnitude of this action 
 in pounds, hundreds, or tons. From its remote extremity, draw lines parallel to the pieces on 
 
 A 
 
 A. ' 
 
 \\ // 
 
 
 " N 
 
 — 
 
 
 
 which the strain is exerted. The line parallel 
 to one piece will necessarily cut the other, or 
 its direction produced. If it cut the piece itself, 
 that piece is compressed by the strain, and it is 
 performing the office of a strut or brace; if it 
 cut its direction produced, the piece is stretched, 
 and it is a tie. In general, if the straining piece 
 is within the angle formed by the pieces which 
 are strained, the strains which they sustain are 
 of the opposite kind to that which it exerts. If 
 it be pushing, they are drawing; but if it be 
 within the angle formed by their directions pro- 
 duced, the strains which they sustain are of the 
 same kind. All the three are either drawing or 
 pressing. If the straining piece lie within the 
 angle formed by one piece and the produced 
 direction of the other, its own strain, whether 
 compression or extension, is of the same kind 
 with that of the most remote of the other two, and 
 opposite to that of the nearest.” In the diagrams 
 on Plate 20 the joints are mostly supposed to 
 be flexible or compass joints: strains on joints 
 will be hereafter considered. . 
 
 TRIANGLES. A truss is a com- 
 bination of framework capable of being resolved 
 into two or more triangles, and the timbers should 
 act as directly as possible on one another. The 
 basis of all framework consists of triangular 
 forms, for the simple reason that the triangle is 
 the only figure which is incapable ' of change 
 without altering the proportions of its sides, and 
 gles, or tearing apart. Struts and ties are em- 
 
PIECES PULEEI) IN TIIE DIRECTION OF THEIR LENGTH. 
 
 123 
 
 ployed to divide frames and thus wonderfully increase their strength, as, for instance, in the 
 squares in the margin (on opposite page), which cannot support pressure prior to the addi- 
 tion of braces, preventing racking at the angles, these being supposed fixed. The next figure 
 is a very strong triangular frame constantly used; and in the following swing-gate we perceive 
 the effect of the division into two triangles. So in roofs, the same principle is illustrated. 
 Polygons of beams are often employed; and by increasing their number, the dimensions of the 
 sides of each being kept very small, a sort of continuous wooden arch is obtained. 
 
 CHAPTER IH. 
 
 PIECES PULLED IN THE DIRECTION OF THEIR LENGTH. 
 
 GENERALLY. The absolute, or cohesive, strength of a beam is esti- 
 mated by the force, or weight, acting at the ends and pulling in the direction of the fibres. 
 These will resist separation in proportion to the area of the section standing at right angles with 
 the extending force. Of course, the power requisite to tear a beam asunder suddenly must be 
 much greater than what the same beam will bear in gradual operation for a length of time. 
 That ability of resisting a moving body, or the description of strength which has sometimes 
 been called resilience , is estimated in proportion to the strength and toughness, or to the stiffness 
 and the square of the toughness. The absolute strength of a beam is reduced to one-half, and 
 the stiffness to one-eighth on doubling its length; but the resilience is doubled on account of the 
 space through which the beam will continue to resist being quadrupled; and the same weight 
 must Tall from twice the height, or a double weight from the same height, to overcome the total 
 resistance. It is not often that the absolute strength of timber beams is of paramount impor- 
 tance, and that it is necessary for the carpenter to enter into calculations on the subject. With 
 respect to ties in roofs, etc., it is indeed rare for failure to occur from their tearing asunder in 
 the direction of the length of the fibres; and whenever this is at all apprehended iron rods 
 should be employed. Nevertheless it would be unpardonable did we omit to indicate in this 
 Work the means for arriving at the absolute strength of wood. 
 
 RESULTS OF EXPERIMENTS. The experiments which have been 
 made differ much in their results; and in former Chapters the causes of variations which were 
 naturally to be expected have been indicated. Rondelet gives the absolute strength of oak as 
 110 pounds avoirdupois for every Goljn °f an inch area. Parent and Pitot say 8,640 pounds is 
 the utmost strength of a square inch of oak. Muschenbroeck set it down at 17,300 pounds; 
 and from some experiments made at Woolwich it was found to he 9,000 pounds at a specific 
 gravity of 774. The experiments of Muschenbroeck and Emerson appear to be very generally 
 referred to as standards, and we shall therefore lay them before our readers, together with some 
 others, concluding with those of Rondelet. 
 
124 
 
 VIKCKS PILLED IN THE DIRECTION OF THEIR LENGTH. 
 
 Uefore iriving the results of some of Muschenbroeck’s experiments we 
 mav observe that thev are not always consistent with one another; for, in the Essais de Physique, 
 l„. observes that a sound piece of oak - of an inch square was torn asunder by 1,150 pounds, 
 , ll( | ( ] iat ;m oak plank 12 inches across and one inch thick supported 189,102 pounds. Thus 
 tl„ cohesion of a square inch is about 15,760 pounds instead of 17,300 as before mentioned. 
 Ik. tubers experiments give about 16,000 for the absolute strength of a square inch; as a rod, 
 <>m quarter inch square, was torn asunder by 1,000 pounds. 
 
 I \B1 E Gl 17. Vo 77// ABSOLUTE STRENGTH OF A SQUARE INCH OF VARIOUS WOODS, 
 
 I.' DEDUCED FROM MUSCHENBROECK’S EXPERIMENTS. 
 
 WOODS 
 
 POUNDS. 
 
 WOODS 
 
 POUNDS 
 
 Alder . . . 
 
 . . 1 3,91)0 
 
 Oak 
 
 17,300 
 
 A . sh. . . . 
 
 . . 12,000 
 
 Orange 
 
 15,500 
 
 Beech . . . 
 
 . . 17,300 
 
 Pitch Pine .... 
 
 7,650 
 
 Cedar 
 
 . . 4,800 
 
 Plum 
 
 1 1,800 
 
 Cypress . 
 
 . . 6,000 
 
 Pomegranate . 
 
 9,750 
 
 Elder . . . 
 
 . . 1 0,000 
 
 Poplar 
 
 5,500 
 
 Elm . . . . 
 
 
 Quince 
 
 6,750 
 
 Fir . . . . 
 
 . . 8,330 
 
 Tamarind .... 
 
 8,750 
 
 Lemon . 
 
 . . 9,250 
 
 Walnut 
 
 8,130 
 
 Locust . . . 
 
 . . 20,100 
 
 Willow 
 
 1 2,500 
 
 Mulbery . . 
 
 . . 1 2,500 
 
 
 
 The experiments of Emerson do not appear to have been made with the 
 a refulness which characterised Muschenbroeck’s proceedings. As the former does not give the 
 ultimate -trength of the various woods, but only the weights which may safely be entrusted to 
 them, it i- difficult to compare his results with those of the latter; but, as will at once be re- 
 markcil, the degree ol tenacity indicated by Muschenbroeck is considerably higher than that 
 allowed by some other inquirers. 
 
 / I/.// OIV/NG THE WEIGHTS WHICH MAY BE SAFELY SUSPENDED FROM ONE SQUARE 
 IN ( ll of VARIOUS WOODS, FROM EMERSON'S EXPERIMENTS, 
 
 WOODS 
 
 POUNDS. 
 
 WOODS. 
 
 POUNDS. 
 
 Alder . 
 
 4,290 
 
 Fir (Red) . . . 
 
 . 5,000 
 
 Ash . 
 
 6,070 
 
 Hazel 
 
 . 4,760 
 
 Asp . 
 
 4,290 
 
 Holly 
 
 . 5,000 
 
 Beech . 
 
 6,070 
 
 Oak 
 
 . 7,850 
 
 Birch . 
 
 4,290 
 
 Plane 
 
 . 5,000 
 
 ( berry 
 
 4,760 
 
 Plum 
 
 . 7,850 
 
 Crab . 
 
 5,000 
 
 Walnut .... 
 
 . 5,360 
 
 Elder . 
 
 5,000 
 
 Willow .... 
 
 . 4,290 
 
 Elm . 
 
 6,070 
 
 Yew 
 
 . 7,850 
 
PIECES PULLED IN THE DIRECTION OF THEIR LENGTH. 
 
 125 
 
 TABLE GIVING THE ABSOLUTE STRENGTH OF ONE INCH SQUARE , FROM 
 ANDERSON’S EXPERIMENTS. 
 
 WOODS. 
 
 POUNDS. 
 
 WOODS. 
 
 
 POUNDS. 
 
 Alder 
 
 
 Elm 
 
 
 4,450 
 
 Ash 
 
 . 6,300 
 
 Fir 
 
 
 2,928 
 
 Beech 
 
 . 6,300 
 
 Oak 
 
 
 6,1 14 
 
 - We come 
 
 next to the results of experiments made 
 
 by 
 
 Rondelet and given 
 
 in his Jj Art tie Batir. As Gwilt 
 
 remarks: — “They 
 
 are worth more than 
 
 all 
 
 which has hitherto 
 
 been done in this country; and 
 
 our surprise is great that in most of the 
 
 various treatises on 
 
 timber and carpentry, some whereof have resulted 
 
 from no mean hands, 
 
 more importance has 
 
 been given to theoretical instruction than to that which might have been 
 
 deduced from experi- 
 
 ments. The treatises indeed on mechanical carpentry almost seem to have 
 
 been written more 
 
 with the view of perplexing than of assisting the student.” 
 
 
 
 TABLE GIVING THE COMPARATIVE ABSOLUTE 
 
 STRENGTHS OF VARIOUS WOODS .46' DE- 
 
 DUCED FROM RONDELET’S 
 
 EXPERIMENTS ON 
 
 PIECES 19,188 ENGLISH LINES SQUARE. 
 
 WOODS. 
 
 PO UNDS. 
 
 WOODS. 
 
 
 POUNDS. 
 
 Alder 
 
 . 2,080 
 
 Lemon .... 
 
 
 1,400 
 
 Apple 
 
 . 1,187 
 
 Lime 
 
 
 1,407 
 
 Apricot . . . . 
 
 . 2,040 
 
 Maple (Foreign) . 
 
 
 2,094 
 
 Ash 
 
 . 1,800 
 
 Mulbery .... 
 
 
 1,050 
 
 Beech 
 
 . 2,480 
 
 Oak 
 
 
 1,821 
 
 Birch 
 
 . 1,980 
 
 Pear 
 
 
 1,680 
 
 Box 
 
 . 2,324 
 
 Pine 
 
 
 1,041 
 
 Cedar 
 
 . 1 ,740 
 
 Plane 
 
 
 1,916 
 
 Citron .... 
 
 . 1,460 
 
 Do. (Oriental) . . 
 
 . 
 
 931 
 
 Cherry .... 
 
 . 1,912 
 
 Do. (Occidental) . 
 
 
 1,031 
 
 Chesnut .... 
 
 . 1,944 
 
 Plum 
 
 
 1,770 
 
 Do. (Horse) . .- 
 
 . 1,231 
 
 Poplar 
 
 
 950 
 
 Ebony .... 
 
 . 2,321 
 
 Service 
 
 
 1,642 
 
 Elder 
 
 . 1,500 
 
 Sycamore .... 
 
 
 1,564 
 
 Elm 
 
 . 1,980 
 
 Walnut .... 
 
 
 1,120 
 
 Fir 
 
 . 1,250 
 
 Do. (American) . . 
 
 
 1,020 
 
 Larch .... 
 
 . 1,460 
 
 Yew r 
 
 
 2,285 
 
 RULES TO FIND THE ABSOLUTE OR COHESIVE STRENGTH OF TIMBER. 
 
 Reduce the sectional area to lines, and multiply this product by the 
 Tabular Number opposite the description of wood in the last Table; dividing then by 19,188 
 gives the greatest weight the piece can bear. As one-tenth of this last is the utmost that can 
 with safety he entrusted to timber, dividing by 10, or cutting off the final figure of the quotient 
 obtained, gives the load that should not be exceeded. The last table has been selected on which 
 to base the formula because we believe it to be at least as satisfactory, if not more so, than any 
 
PIECES pressed in the direction of their length. 
 
 126 
 
 ntli. , . Kmerson givo the following rule: — Square the diameter in inches, and multiply by 
 
 s* ; tiic product gives the load in cwts. which may safely he entrusted to fir. 
 
 TORSION. We may conclude this Chapter by briefly touching on the 
 w reaching or twisting of bodies. It concerns chiefly the axles of wheels, and frequently oc- 
 curs in masts and the rudders of ships. 
 
 If a cylinder is powerfully twisted the particles' in the outer circle lose 
 their cohesion, and those in the inner circles give way. The resistance offered by a homogeneous 
 body to a simple twist is equal to two-thirds of the force requisite to separate it laterally or 
 one-third of that necessary to cut it by a square edged tool. In the instance of two cylinders 
 wrenched apart, the amount of the forces exerted at the moment of fracture is as the squares 
 of the diameters of the cylinders. “With respect to torsion, the stiffness of a cylindrical body 
 varies directly as the fourth power of the diameter, and inversely in the simple proportion of 
 the length; it does not appear to be changed by the action of any force tending to lengthen or 
 
 to compress the cylinder; and it may very possibly bear some simple relation to the force of 
 
 cohesion, which has not yet been fully ascertained; but it appears that, in an experiment of 
 Mr. C avendish, the resistance of a cylinder of copper to a twisting force, acting at its surface, 
 wa- about of the resistance that the same cylinder would have opposed to direct extension 
 or compression.” {En cyclop. Brit.) 
 
 CHAPTER IV. 
 
 PIECES PRESSED IN THE DIRECTION OF THEIR LENGTH. 
 
 (iF.NKKALIA . Pitots experiments and those of Parent showed that the force 
 h qui'ite in ciu-h a piece of timber is nearly equal to that which will tear the fibres asunder; 
 and an upright beam, such as a post, should therefore support the weight found by the formula 
 given in the last ( hapter. 1 he rule however is by no means universal, as woods of soft texture, 
 although with very tenacious fibres, are crushed with comparative ease, the softness being owing 
 to tin undulated instead of straight character of the fibres, and to the existence of vacuities. 
 
 1 1 m "thu cii cumstance, constituting a remarkable difference between the two cases, 
 
 nv Inch must be taken into consideration. The post is flexible, and apt to bend under a weight. 
 A different mode of procedure must therefore be adopted to ascertain its strength. When an 
 "pngl,! piece of timber is above six or seven times the width of the base in height, it usually 
 ' n ' <n l 11 '" 1 1(1 hectare. It the height is ten times the side of the base, the bending 
 i lii.ibh, and it it i.s laised to one hundred times, no weight whatever can be supported. 
 
 It thus appears that the relation between the section of the base and the 
 Im.gli. of a column is an important element in any calculations respecting its ability to carry 
 
 ‘ R,v ™ " eifjl,t ’ as ,he ,noraent Hexu >’ e begins the strength diminishes. The resistance to com- 
 pression has also to be considered. 
 
PIECES PRESSED IN THE DIRECTION OF THEIR LENGTH. 
 
 127 
 
 FLEXURE. With respect to flexure we have not so much to consider the 
 force requisite completely to destroy the utility of a post as the prevention of the first bending. 
 Tredgold says: — “The strain will he directly as the weight or pressure; and inversely as the 
 strength, which is inversely as the cube of the diameter. The strain will also be directly as the 
 deflexion, which will be directly as the quantity of angular motion, and the number of parts 
 strained; that is, directly as the square of the length, and inversely as the diameter.” We 
 shall endeavour to put the matter a little clearer for the benefit of those of our readers who may 
 not have given much attention to the subject. 
 
 It is by bending that a post commonly gives way. One not above seven 
 or eight times the width of the base in height will rarely bend under less pressure than that 
 which suffices to crush it. If the post be about eight times its diameter in height, it gives bv 
 bending in the middle; if less it expands in the middle and splits. A height of ten times the 
 width of the base is about the safest rule; or the post may be as many inches in thickness as it 
 is feet in height. But circumstances often arise under which an adherence to these rules is 
 practically inconvenient. If, therefore, posts are in height about ten times the diameter or width 
 of the base they should not (according to deductions from Rondelet’s experiments,) be entrusted 
 with more than 5 pounds per 1.066 line; if fifteen times the base, 4 pounds; and if twenty times 
 the base, 3 pounds: at the same time the stability must be secured and the bases extended. With 
 reference to stability, the diameter of the base may vary in proportion to the height as 7 to 10. 
 The author last mentioned found that the strength of a post diminished in the proportion of the 
 number of times the width of the base is contained in the height of the post; and, taking for 
 the unit of comparison the force of I’esistance of a cube the dimension of which is represented 
 by 1, the progression decreases in the following manner. 
 
 For 
 
 a cube the 
 
 hei 
 
 ght 
 
 of which 
 
 is 1 , the strength 
 
 is 1 
 
 or 
 
 24 
 
 24 
 
 For 
 
 a piece the 
 
 height 
 
 of which 
 
 is 12 
 
 55 
 
 5 
 
 "IT 
 
 55 
 
 20 
 
 24 
 
 
 >5 
 
 
 
 55 
 
 24 
 
 55 
 
 1 
 
 2 
 
 55 
 
 12 
 
 24 
 
 
 55 
 
 
 
 55 
 
 36 
 
 55 
 
 1 
 
 3 
 
 55 
 
 8 
 
 W 
 
 
 55 
 
 
 
 55 
 
 48 
 
 55 
 
 1 
 
 6 
 
 55 
 
 4 
 
 24 
 
 
 55 
 
 
 
 55 
 
 60 
 
 55 
 
 1 
 
 12 
 
 55 
 
 2 
 
 ~ 24 ‘ 
 
 
 55 
 
 
 
 55 
 
 72 
 
 55 
 
 1 
 
 ~2T 
 
 55 
 
 1 
 
 24 
 
 Rondelet says that his rule agreed with experiments by M. M. Perronet, 
 Lamblardie and Girard, quoting a confirmatory passage from the last named author. 
 
 COMPRESSIONS. We before remarked on the differences between fir 
 and oak. The former having cross-grained fibres is often found to carry three times as much as 
 the latter, although the cohesive strength of oak renders it superior as a tie. Previous to dis- 
 uniting, fir diminished one-half, and oak more than one-third by compression in experiments 
 made by Rondelet. The results of these showed that the weights requisite to crush pieces too 
 short to bend were, for oak 49.72 pounds every of a square inch at the base, and for fir 
 i 56. 1 6 pounds. All bodies are more or less compressible, many recovering their original form 
 if the disturbing force is withdrawn. But a proportionately less force is requisite to increase 
 
I os necks pressed in the direction of their length. 
 
 .lilutation which ha, proceeded to a certain amount; and when a post is overloaded, if it does 
 I)0n( | on 0 „ c ,idc and then break, it swells sensibly on both, small openings, or longitudinal 
 .| v>< (ir shivers, make their appearance in the direction of the fibres, and it will not afterwards 
 fc,. ar „ne-halt the previous weight. The power to resist compression seems to depend chiefly 
 on the force of lateral cohesion, and a sort of internal friction; and the crushing consists in the 
 separation "f a wedge in an oblique direction. Dr. Young says: — “It the adhesion were 
 .imply proportionate to the section, it may be shown that a square column would be most easily 
 crushed when the angle of the wedge is equal to halt of a right angle; but it the adhesion is 
 increased by pressure, this angle will be diminished by half the angle of repose appropriate to 
 the substance. The consideration of the oblique direction of the plane of easiest fracture would 
 induce us to make the outline of a column a little convex externally, as the common practice 
 ha- been: for a circle cut out of a plank possesses the advantage of resisting equally in every 
 section, and consequently of exhibiting the strongest form, when there is no lateral cohesion; 
 md. in the case of an additional resistance proportional to the pressure, the strongest form is 
 afforded by an oval consisting of two circular segments, each containing tw'ice the angle formed 
 hv the plane of fracture with the horizon. If we wish to obtain a direct measure of the lateral 
 adhesion, we must take care to apply the .forces concerned at a distance from each other, not 
 Locator than one-sixth of the depth of the substance, otherwise the fracture will probably be 
 rather the consequence of flexure than of detrusion.” As we once before remarked, the ancient 
 Greeks had perhaps a more correct and delicate perception of the strength of columns than 
 other people seem capable of attaining; and the experiments of our most skilful engineers do 
 not give result, that can be compared for accuracy with the clear manner in which the Grecian 
 architect, distinguished the limits of their Doric order. The poets were scientifically correct 
 in calling them unbending; for the fracture is one of detrusion, taking place with less force than 
 will suffice to produce flexure. 
 
 A slight lateral support will often prevent a wooden post from bending, 
 and ihu, materially aid its duration and power of withstanding pressure. Transverse bridles, 
 arranged in an appropriate manner, are thus of the highest utility in staying the middle and 
 preventing the crippling of story posts, quarters, struts, etc., the prevention of bulging always 
 rendering compression more difficult. A fir pillar, one inch in section and twelve inches in 
 length, wa, loaded* with three ton, and instantly snapped when pressed with a force of sixteen 
 p"und, on one side. Another pillar loosely inclosed in an iron pipe, and thus protected laterally, 
 b"re four toil' and a half without any injurious consequences. The pressure should be pre- 
 ■■i,' ly in the direction of the axis and perfectly uniform; otherwise one side will be more com- 
 pr« "cd and thus become shorter than the other which does not sustain so great a weight. 
 
 KkSl LIS OI EXPERIMENTS. Parent says it requir.s rather more 
 than sixty pound, on every square line to crush sound oak. Rondelet states that from 6,000 to 
 T.imio per square inch are required to crush cubes of fir an inch in length, this last being re- 
 flueed one-halt; and for oak from o-OHO to 6,000 pounds, the length being reduced more than 
 one- third. 
 
PIECES PRESSED IN THE DIRECTION OF THEIR LENGTH. 
 
 129 
 
 TABLE GIVING PERRO NET'S PROPORTIONS FROM EXPERIMENTS ON SHORT PIECES. 
 
 WOODS. 
 
 
 
 WOODS. 
 
 
 Ash . . . 
 
 • • • 7V.s 
 
 
 Oak 
 
 12 Vs 
 
 Elm . . . 
 
 . . . 7 
 
 
 Poplar 
 
 7 a / 5 
 
 Fir. . . . 
 
 • • • 9 a /i 6 
 
 
 Willow 
 
 9 *5 
 
 TABLE GIVING 
 
 THE RESULTS 
 
 OF 
 
 GEORGE RENNIE'S EXPERIMENTS. 
 
 
 WOODS. 
 
 
 POUNDS. 
 
 
 Elm, 
 
 one inch cube, 
 
 crushed by ... . 1,284 
 
 
 Oak (English) „ 
 
 5 5 
 
 .... 3,864 
 
 
 Do. 4 
 
 ins. long „ 
 
 55 
 
 .... 5,147 
 
 
 Pine (American) „ 
 
 55 
 
 . . . . 1,606 
 
 
 White Deal „ 
 
 55 
 
 .... 1,928 
 
 
 TABLE GIVING THE COMPARATIVE VERTICAL STRENGTH OF VARIOUS WOODS , AS DE- 
 
 DUCED FROM RONDELETS EXPERIMENTS 
 
 ON PIECES 19,1 SS ENGLISH LINES SQUARE. 
 
 WOODS. 
 
 POUNDS. 
 
 
 WOODS 
 
 POUNDS 
 
 Alder . . . 
 
 ... 780 
 
 
 Lemon 
 
 858 
 
 Apple . . . 
 
 . . . 903 
 
 
 Lime 
 
 717 
 
 Apricot . . 
 
 . . . 1,255 
 
 
 Maple (Foreign) . . 
 
 843 
 
 Ash . . . 
 
 . . . 1,112 
 
 
 Mulberry 
 
 1,031 
 
 Beech . . . 
 
 ... 986 
 
 
 Oak ...... . 
 
 807 
 
 Birch . . . 
 
 . . . 861 
 
 
 Pear 
 
 816 
 
 Box . . . 
 
 . . . 1,444 
 
 
 Pine 
 
 804 
 
 Cedar . . . 
 
 . . . 720 
 
 
 Plane 
 
 830 
 
 Citron . . . 
 
 . . . 871 
 
 
 Do. (Oriental) . . . 
 
 874 
 
 Cherry . . 
 
 . . . 986 
 
 
 Do. (Occidental) . . 
 
 941 
 
 Chesnut . , 
 
 . . . 950 
 
 
 Plum 
 
 843 
 
 Do. (Horse) . 
 
 . . . 689 
 
 
 Poplar 
 
 680 
 
 Ebony . . 
 
 . . . 1,062 
 
 
 Service 
 
 981 
 
 Elder . . -. 
 
 . . . 789 
 
 
 Sycamore 
 
 968 
 
 Elm . . . 
 
 . . . 1,075 
 
 
 Walnut 
 
 733 
 
 Fir . . . 
 
 . . . 851 
 
 
 Do. (American) . . . 
 
 701 
 
 Larch . . 
 
 . . . 902 
 
 
 Yew 
 
 1,375 
 
 RULES TO FIND THE VERTICAL STRENGTH OF TIMBER. 
 
 We will take the last Table by Rondelet as the basis of calculation and 
 must refer the reader to the progression given in this Chapter under Flexure showing the de- 
 crease in the bearing strength of upright posts. 
 
 Bring the sectional area of the base of the post into lines. Look to the 
 Table for the vertical strength, and reduce it, in accordance with the progression (see Flexure) 
 proportionately to the height of the post. (Supposing this last to be about 12 times the width 
 of the base, take 5 / 6 ths, — thus oak 807 =: 672 1 / 2 ). 
 
 Then divide the area in lines of the section of the post by the Tabular 
 
 XVII 
 
 Carpentry. 
 
| 30 HORIZONTAL PIECES SUPPORTED AND FJXED AT ONE AND BOTH ENDS. 
 
 Number (of lines m,|,cr of rcetion) the Table is taken at (19,188). Multiplying this quotient 
 bv the reduction of the vertical strength (672' .1 gives the Irreaktng weight, one-tenth of which 
 i.» the load to be safely entrusted. 
 
 If the breaking weight of an oak post is known, we may readily obtain 
 that of a similar one of fir in the following manner. As the vertical strength of oak (807) is to 
 ; t , breaking weight, so is the vertical strength of fir (851) to its breaking weight. 
 
 CHAPTER V. 
 
 HORIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 SUPPORTED AT BOTH ENDS. Beams supported at both ends di- 
 minish in strength in proportion to the increase of bearing; and in those whose length is the 
 same between the supports, the strength is as the width and the square of the depth. The 
 bending of a beam laid transversely and supported at both ends is to be considered; ac- 
 cording to the amount of this, timber is termed stiff or flexible: in two pieces equally stiff the 
 bending will be in proportion to their lengths. When the quantity of timber is the same, a 
 beam is strong according to its depth; but if this last be too great with relation to the breadth, 
 the beam will lie liable to overturn. Tredgold says that, dividing the length in feet by the 
 -quare root of the depth in inches, and multiplying the quotient by 0.6, gives the least breadth. 
 To settle the weight which may safely be intrusted to timber it is necessary to find that which 
 will break it; and, for perfect safety, not more than one-tenth of this last should be taken. The 
 reader may here reperuse with advantage the remarks in Chapter l , Division 3, and some rules 
 and results of experiments will be given. We may quote from Dr. Young that the resilience 
 (before alluded to) of a timber beam is measured by “the distance through which it recedes or 
 is bent previous to fracture; and it may be shown that a weight which is capable of breaking it 
 by pressure would also break it by impulse if it moved with the velocity acquired by falling 
 from a height equal to half the deflection. Thus, if a beam or bar were broken by a weight of 
 |imi pounds, after being bent six inches without alteration, it would also he broken by a weight 
 oi 10H pounds falling from a height of 3 inches, or moving in a horizontal direction with a 
 velocity of lour feet in a second, or by a weight of one pound falling from a height of 300 
 indies. 1 his substitution of velocity for quantity of matter has, however, one limit beyond which 
 the velocity must prevail over the resistance, without regard to the quantity of matter; and this 
 limit is derived from the time required for the successive proppgation of the pressure through 
 the dillercnt parts of (lie substance, in order that they may participate in the resistance.” 
 
 SI RROK I ED A'l SEVERAL POINTS. If a beam is firmly connected 
 " dnee fixed points, two below and one above, it will support a greater weight between any 
 than it their was no connection with the remote point; and if firmly fixed at four points, 
 twn above and below, it will be about double the strength in the centre as when the remote 
 < onnexions are removed. \\ here beams are laid over numerous intervening points of support, 
 

 HORIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 131 
 
 the strength between these is considerably greater than when short lengths are adopted. 
 Joists, purlins, rafters, etc., should therefore be used in as long lengths as possible and be 
 notched over the intermediate supports, instead of being framed between them. A joist in one 
 length supported in the middle is much stronger than when, the same scantling being retained, 
 there are two joists. 
 
 SUPPORTED AT ONE END, AND FIXED AT ONE AND BOTH 
 ENDS. If a beam is fixed at one end, and loaded at the other extremity, the strain is four 
 times more than in the case of the same beam supported at both ends with the weight sus- 
 pended from the centre; and if the beam is fixed at both ends and the weight acts in the middle, 
 then its strength is to that when it is only supported at the ends as three to two. A weight 
 distributed over a beam only strains it to the extent of one-half as when concentrated in the 
 centre. Those who have experimented, excepting Musehenbroeck, have concluded that the 
 strength of beams fixed at the ends is to when they are only supported as three to tw6; but 
 we may mention that theoretical men have stated the proportion as four to two. Professor 
 Robison says: — “There is a proposition which has been called in question by several very 
 intelligent persons, and they say that Belidor has demonstrated, in his Science des Tngenieurs, 
 that a beam firmly fixed at both ends is not twice as strong as wdien simply lying on its props; 
 and that its strength is increased only in the proportion of two to three; and they support this 
 determination by a list of experiments recited by Belidor, which agree precisely with it. Belidor 
 also says that Pitot has the same results in his experiments. These are respectable authorities, 
 but Belidor’s reasoning is anything but demonstration, and his experiments are described in 
 such an imperfect manner that w r e cannot build much on them. It is not said in what manner 
 the battens were secured at the ends, any further than it was by cheva/ets. If by this word is 
 meant a trestle, w r e cannot conceive bow they w T ere employed; but w r e see it sometimes used for a 
 wedge or key. If the battens w r ere wedged in the holes, their resistance to fracture may be made 
 what we please; they may be made loose, and therefore resist little more than wdien simply laid on 
 props. They may be (and probably were) w T edged very fast, and bruised or crippled.” Emerson 
 agrees with the conclusions of Robison as above; wdiile, on the other hand. Parent’s experiments 
 coincide with those of Belidor and Pitot, and these last results are n6w generally accepted. The 
 mode of fixing is a very important point, as it considerably influences the quantity of extension. 
 We may here remind the practical carpenter that it is generally not advisable to build joists so as 
 to be firmly fixed at the ends, as they endanger the stability of thin w r alls, forcing them up with 
 the strength of a long lever. If, however, the w T all is tolerably thick and the joist is allowed to 
 tail nearly through it, the rigidity of the floor will be increased. 
 
 BEAMS IN MORE THAN ONE PIECE. It seems desirable to open 
 this subject in the present Chapter, although it will hereafter be more fully considered. Sup- 
 pose tw T o beams to be placed as on next page, not cohering, each will bend under a sufficient 
 w 7 eight, but the extension of the fibres A B of the under beam does not prevent the compression 
 of the fibres A B of the upper beam. Both together are not above twice as strong as one, 
 instead of being four times such; and both will bend as much as either under half the load. 
 Uniting the two, so as to hinder sliding, tends to prevent bending. Glue may be used in small, 
 and joggling (as in the second figure) in large works, pieces of hard wood being driven in. 
 
 
J32 HORIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 Iron bolt» may l>e substituted; hard wood joggles are apt eventually to work loose. The mode 
 
 shown in the third figure involves more waste 
 IIT TZ "IJZZZn than the preceding example, and the indentations 
 
 are apt to tear up. Pieces joined by these, or 
 similar methods, often fall not far short of the 
 strength of an entire piece. The fourth figure 
 exhibits a very successful union of strength and 
 pliability. The thin planks have ftdl liberty to 
 slide upon one another; no bolts or joggles are 
 employed, and the slips are kept together by 
 straps. Coach springs are formed in this manner. 
 
 EXPERIMENTS. In laying these before the reader, he will as usual 
 perceive, considerable diversity between the results given by different inquirers. With respect 
 to fir and oak only we may here repeat that the former is stated by Button to be six-tenths the 
 trength of the latter; Parent makes it ten-twelfths; and Emerson two-thirds, which last may 
 probable he safely adopted as a mean. 
 
 We shall first record the experiments of Du Hamel, which tend to show 
 that the resistance of timber to a transverse strain is diminished in proportion as the stuff is 
 
 more compressible. 
 
 Sixteen bars of willow were taken, half an inch square, two feet long, 
 and. supported by props at the two ends, were then loaded in the middle. Four were broken 
 
 under loads of forty, forty-one, forty-seven, and fifty-two pounds; the mean being forty-five 
 pounds. 1 hen four of the bars were cut one-third through on the upper side, and the cut was 
 filled with a thin slip of wood harder than the specimens operated upon, and fixed in tight. 
 1 hese were broken by weights of forty-eight, fifty-four, fifty and fifty-two, pounds; the mean 
 being fifty-one pounds. Four other pieces were next cut half through; and these broke under 
 toads ot forty-seven, forty-nine, fifty, and forty-six pounds; of which the mean is forty-eight. 
 1 he remaining four being cut two-thirds through and subjected to pressure, forty-two pounds 
 was found to be the mean strength. 
 
 In experiments on willow battens, one and a half inch square and thirty- 
 ix inches long, five hundred and twenty-five pounds was found to be the medium strength. 
 
 Afterwards six bars of the above dimensions were cut one-third through 
 the cut being filled up in the manner before indicated, when the medium strength was found 
 to be five hundred and fifty-one pounds. 
 
 Six battens, cut half through, broke under a medium weight of five hundred 
 md tom -two pound'. Six other battens, cut through three-fourths, gave under five hundred and 
 thim pound' as a medium. A batten of the size before mentioned was cut three-fourths 
 thiough, loaded until nearly broken, then removed and a thicker wedge-like piece introduced 
 in the place of the thinner slip, thus straightening the batten by filling the vacuity left from the 
 i ompression; the bar bore five hundred and seventy-seven pounds. 
 
 \\ e will next detail some of the results of Button’s experiments to which 
 allusion has been made in our Sketch of the Progress of Carpentry. During two years this 
 
HORIZONTAL PIECES SUPPORTED AND FTXED AT ONE AND BOTH ENDS. 
 
 133 
 
 philosopher continued various experiments on small oak battens ; but, dissatisfied with the com- 
 plex variations which occurred, he ultimately adopted the largest beams he could conveniently 
 procure, some of them being 28 feet long and 8 inches square. In order* to secure as far as 
 possible uniformity in the results of the experiments, all the trees were felled in the same season, 
 squared the next day, and tested on the third; and it was observed that oak diminished greatly 
 in strength in the course of drying. One curious phenomenon occurred in the case of green, 
 wood. On laying a weight almost sufficient to produce fracture, a very obvious smoke issued 
 from the two ends and a hissing noise continued all the time the timber w 7 as bending, thus 
 indicating that the whole length was strained. 
 
 The early experiments made on five inch bars were considered by Buffon 
 as the standard of comparison, and he extended these in length, trying numerous specimens of 
 each length, in continuing his inquiries. It was found that two-thirds of the load which 
 sufficed to break a beam .very decidedly affected its strength, inducing fracture after a lapse 
 of about two or three months. Half the breaking weight produced a particular curvature 
 without increase, and at which the beam remained stationary for a short time; and one-third of 
 the breaking weight did not appear to produce any permanent change, as the beam recovered 
 its straightness evon after having been under the load for some months. But this was only the 
 case with seasoned timber. One-third of the weight which would suffice to break a seasoned 
 piece, or one-fourth of what would break it in a green condition, might be laid on for a very 
 considerable period without perceptible injury. 
 
 TABLE GIVING THE RESULTS OF EXPERIMENTS BY BUFFON ON BARS OF SOUND OAK, 
 
 FOUR INCHES SQUARE , AND FREE FROM KNOTS. 
 
 1 
 
 2 , 
 
 3 
 
 4 
 
 5 
 
 7 
 
 ( 60 
 
 5,350 
 
 3.5 
 
 29 
 
 { 56 
 
 5,275 
 
 4.5 
 
 22 
 
 8 
 
 ( 68 
 
 4,600 
 
 3.75 
 
 15 
 
 ( 63 
 
 4,500 
 
 4.7 
 
 13 
 
 Q 
 
 j 77 
 
 4,100 
 
 4.85 
 
 14 
 
 
 ( 71 
 
 3,950 
 
 5.5 
 
 12 
 
 10 
 
 1 84 
 
 3,625 
 
 5.83 
 
 15 
 
 ( 82 
 
 3,600 
 
 6.5 
 
 15 
 
 12 
 
 ( 100 
 
 3,050 
 
 7 
 
 
 ( 98 
 
 2,925 
 
 8 
 
 
 The first column indicates the length in feet between the supports. In the 
 second the weight of the piece of wood in pounds on the second day after felling is expressed, 
 that on two bars being given. The third column shows the number of pounds which will 
 rapidly break the bar. In the fourth column are the number of inches the pieces bent prior to 
 fracture. The fifth column indicates the time of fracture. 
 
 In the Table on the next page the results of experiments on pieces of other 
 sizes are shown. Along the top the number of inches square is given , the figures in the 
 first column expressing the lengths in feet. 
 
1 ;U HORIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 table giving rm: results or buffoN'S experiments. 
 
 
 i 
 
 5 
 
 6 
 
 7 
 
 8 
 
 7 
 
 5,3 1 2 
 
 1 1,525 
 
 18,950 
 
 32,200 
 
 47,649 11,525 
 
 8 
 
 4,550 
 
 9,787 
 
 15,525 
 
 26,050 
 
 39,750 10,085 
 
 9 
 
 1,025 
 
 8,308 
 
 13,150 
 
 22,350 
 
 32,800 8,964 
 
 ID 
 
 3,61 l 
 
 7,125 
 
 1 1,250 
 
 19,475 
 
 27,750 1 8,068 
 
 12 
 
 2,087 
 
 6,075 
 
 9,100 
 
 16,175 
 
 23,450 6,723 
 
 14 
 
 — 
 
 5,300 
 
 7,475 
 
 13,225 
 
 19,775 5,763 
 
 h; 
 
 — 
 
 4,350 
 
 6,362 
 
 1 1,000 
 
 16,375 5,042 
 
 18 
 
 — 
 
 3,700 
 
 5,562 
 
 9,245 
 
 13,200 4,482 
 
 20 
 
 — 
 
 3,225 
 
 4,950 
 
 8,375 
 
 11,487 4,034 
 
 22 
 
 — 
 
 2,975 
 
 — 
 
 — 
 
 3,667 
 
 24 
 
 — 
 
 2,162 
 
 — 
 
 — 
 
 3,362 
 
 28 
 
 — 
 
 1,775 
 
 — 
 
 — 
 
 I 2,881 
 
 It will he seen that this Table is at variance with the theory that the 
 relative strength of beams of the same section is inversely as their length, — that is, that a beam 
 °l ( he "anie scantling as another, hut only half its length, will support twice the weight which 
 may he entrusted to the former. If the reader glances down the column devoted to the five 
 inch bars he will perceive that the relative strength by no means decreases in the ratio now 
 adopted in proportion to the length of the pieces: the last column indicates the strength which, 
 m accordance with tho above theory, the five inch bars should have exhibited. 
 
 / AR/.E GIVING THE RESULTS OF BELIDOR'S EXPERIMENTS ON SOUND OAK BATTENS 
 
 
 1 A 
 
 J B 
 
 i C 
 
 D 1 E 
 
 Experiments 1st. Ends loose 
 
 1 
 
 1 
 
 1 
 
 IS 
 
 | 400 
 
 415 
 
 406 
 
 
 
 
 
 | 405 
 
 
 Experiment 2nd. Ends firmly fixed 
 
 
 
 1 
 
 1 600 
 
 
 1 
 
 1 
 
 1 18 
 
 600 
 
 608 
 
 
 
 
 1 
 
 624 
 
 
 Experiment 3rd. Ends loose 
 
 2 
 
 1 1 
 
 1 
 
 18 
 
 810 
 
 795 
 
 812 
 
 805 
 
 Experiment 4th. Ends loose. 
 
 1 
 
 1 
 
 j 18 
 
 1,570 
 
 1,580 
 
 1,580 
 
 
 
 
 
 1,590 
 
 Experiment 5th. Ends loose 
 
 1 
 
 2 
 
 36 
 
 185 
 
 195 
 
 187 
 
 — — — 
 
 
 
 
 180 
 
 
 Experiment 6th. Ends fixed 
 
 1 
 
 1 
 
 36 
 
 285 
 
 280 
 
 283 
 
 • 
 
 
 
 
 285 
 
 
 Experiment 7th. Ends loose 
 
 2 
 
 2 
 
 36 
 
 1,550 
 
 1,620 
 
 1,585 
 
 — 
 
 
 
 
 1,585 
 
 Experiment 8th: Ends loose 
 
 1 a / 3 
 
 2 1 /* 
 
 1 
 
 36 
 
 1,665 
 
 1,675 
 
 1,660 
 
 
 
 
 1 
 
 1,640 
 
HURIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 135 
 
 The columns A indicate the breadth in inches of the pieces experimented 
 on, B their depths, C their lengths, D the breaking weights in pounds, and E the mean weights. 
 
 These experiments are given in the Science ties Ingenieurs. They are 
 remarkably complete, and, as perceived in the column D, three pieces of the same size were 
 tried, and the average afterwards taken. 
 
 TABLE GIVING THE COMPARATIVE STRENGTH OF VARIOUS WOODS, AS DEDUCED FROM 
 RONDELETS EXPERIMENTS ON PIECES 19.188 ENGLISH LINES SQUARE. 
 
 Alder . . . 
 
 ... 644 
 
 Lemon 
 
 . 1,087 
 
 Apple . . . 
 
 ... 976 
 
 Lime 
 
 . 750 
 
 Apricot . . 
 
 . . . 1,096 
 
 Maple (Foreign) 
 
 . 1,094 
 
 Ash .... 
 
 . . . 1,072 
 
 Mulberry .... 
 
 . 981 
 
 Beech . . . 
 
 . . . 1,032 
 
 Oak 
 
 . 1,000 
 
 Birch . . . 
 
 ... 853 
 
 Pear 
 
 850 
 
 Box . . . 
 
 . . . 1,160 
 
 Pine 
 
 . 882 
 
 Cedar . . . 
 
 . . . 627 
 
 Plane 
 
 . 728 
 
 Citron . . . 
 
 . . . 1,192 
 
 Do. (Oriental) . . 
 
 776 
 
 Cherry . . 
 
 ... 961 
 
 Do. (Occidental) 
 
 . 853 
 
 Chesnut . . 
 
 ... 957 
 
 Plum 
 
 950 
 
 Do. (Horse) . 
 
 . . . 931 
 
 Poplar 
 
 . 586 
 
 Ebony 
 
 . . . 1,155 
 
 Service 
 
 . 965 
 
 Elder . . . 
 
 . . . 1,072 
 
 Sycamore .... 
 
 900 
 
 Elm . . 
 
 . . . 1,077 
 
 Walnut 
 
 900 
 
 Fir .... 
 
 . . . 918 
 
 Do. (American) . . 
 
 . 864 
 
 Larch . . . 
 
 ... 843 
 
 Yew 
 
 . 1,037 
 
 We shall give at the end of this Division a valuable and extensive Table 
 reduced to English measures by Mr. Gwilt from Rondelet’s 11 Art cle Bdtir. 
 
 RULES TO FIND THE STRENGTH OF TIMBER LAID HORIZONTALLY AND SUPPORTED 
 
 AT BOTH ENDS. 
 
 At the end of this Division will be found a Table giving the greatest 
 strength of oak timbers. From this therefore the strength of a piece of oak may be obtained 
 by inspection without calculation, thus saving much labour. The breaking weights are given 
 when concentrated at the middle of the beams; and they will bear twice as much distributed 
 over their total length. The safe weight to be entrusted is one-tenth of the breaking weight; 
 and the former is readily obtained by abstracting the final figure from the latter. The following 
 rule is for applying the table to other woods, thus widely extending its practical utility. 
 
 Look to the Table in this Chapter giving the horizontal strengths of 
 various woods, as deduced from Rondelet’s experiments, and take the number opposite the wood 
 whose breaking weight is desired, say fir 918, or chesnut 957. Oak, it must be remarked, is 
 taken at 1,000. 
 
 I 
 
 Next seek in the Table at the end of this Division what would be 
 
1 HORIZONTAL PIECES SUPPORTED AND FIXED AT ONE AND BOTH ENDS. 
 
 the breaking weight of a beam of oak of similar scantling to that of fir or chesnut, whose 
 strength is desired. 
 
 Then, as the horizontal strength of oak (1,000) is to that of fir (918) or of 
 chesnut (957), as the case may be, so is the breaking weight of a beam of oak oi a certain 
 scantling to that of a beam of fir or of chesnut. 
 
 Taking the tenth of the result last obtained, by cutting off the final figure, 
 gives the load which may with safety be entrusted. 
 
 A useful rule may be deduced from Buffon’s experiments, assuming the 
 strength of a beam laid horizontally to be nearly as the breadth and the square of the depth, 
 and inversely as the length. Taking the length in feet and the breadth and depth in inches, 
 and. knowing that a beam seven feet between the points of support and four inches square 
 (Sec Buffon’s second Table in this Chapter), is broken by 5,312 pounds, it may be concluded 
 that a piece one inch square and one foot in bearing will break under 581 pounds. Then, sup- 
 posing b, <1, /, to represent the breadth, depth and length, we have for the strength of any other 
 piece of oak the simple formula: — 
 
 581 — Breaking Weight. 
 
 Under Relative Strength in Chapter 1, Division 3, another rule is men- 
 tioned; and in the same Chapter under Stiffness is one for finding the deflection of a beam 
 of fir loaded in the middle. If we have the cohesive value of a rod one inch square, the fol- 
 lowing formula given by Cresy ascertains the breaking weight of a beam loaded at the centre: 
 “Multiply the breadth by the square of the depth, and again by four times the constant value: 
 then this product, divided by the length in inches, will give the weight required.” For constant 
 values, take Oak at 1072, Teak 2151, Riga Fir 1590, Memel Fir 1635, Scotch Fir 1746, Larch 
 1896, Chesnut 1350, Elm 1620, Beech 1556. 
 
 Rondelet. says: — “It results from a vast number of experiments and 
 calculations made to find the relation between the absolute strength of oak and that which it 
 pos-'Csses when laid horizontally between tw r o supports, that the most simple means consists in 
 multiplying the surface of the size of the piece by half the absolute strength, and dividing the 
 product by the number of times its vertical thickness is contained in the length behveen the 
 supports.” (L'Art ile Bdtir.) 
 
 CHAPTER VI. 
 
 INCLINED 1' 1 E C E S. 
 
 GENERALLY. Experience demonstrates that an inclined piece of wood 
 1" ■ - .--t length in proportion as it recedes from the perpendicular. If we take a piece of wood, 
 first placing it upright as A B, and then incline it gradually in the direction of C toward D, 
 11 ' '"' "g’h decreases as it approaches D; or is as AB is to AE, or as the radius is to the sine 
 of the inclination. 
 
I 
 
 INCLINED PIECES. 
 
 137 
 
 4 
 
 The wide application of this statement to carpentry will at once be 
 
 B 
 
 A 1 
 
 perceived; in roofs, partitions and framings of various de- 
 scriptions, struts, etc., placed as in the diagram continually occur. 
 In Chapter 2, of this Division, will be found a rule for dis- 
 tinguishing between a strut and a tie. Barlow remarks: - 
 “Beams fixed at any angle of inclination have the strain upon 
 them diminished in the ratio of rad. : cos. I (I being the angle 
 of inclination), or their strength is increased in the ratio of cos. I 
 to radius; whereas it has commonly be said to increase in the 
 ratio of cos.' 2 I to rad. 2 , and some writers have even made it as 
 cos. 3 I to rad. 3 . It also appears that it is not the angle at which 
 the beam is originally fixed, but that to which it is deflected, 
 that must be adopted in our computation; and that, in many 
 
 cases, a beam fixed at an angle of inclination upwards will be broken with a less weight than 
 an equal beam fixed horizontally.” 
 
 RULE TO FIXE THE STRENGTH OF A STRUT AND THE LOAD WITH WHICH IT 
 
 MAY BE ENTRUSTED. 
 
 We must refer the reader to Chapter 4, of the Division, as we here adopt 
 Rondelet’s conclusions, as given in the Tables of the decreasing progression of the strength of 
 upright posts and the vertical strengths of various woods deduced from pieces BUSS lines square. 
 
 Reduce the sectional area of the strut into lines, and divide by the tabular 
 number (of lines super of section), the last mentioned table is taken at (19.188), giving a quotient. 
 
 Reduce the vertical strength in accordance with the progression given 
 proportionately to the length of the strut (supposing this last to be twelve times the width of 
 the end, take five sixths, — thus oak 807 = 672' 2 ), and multiply this by the quotient before 
 obtained, giving a product. 
 
 Then, as the length of the strut in feet is to its horizontal inclination in 
 feet, so is the product last obtained to the breaking weight. 
 
 One-tenth of this last is the weight to be safely entrusted to the strut. 
 
 TABLE SHOWING THE GREATEST STRENGTH OF OAK TIMBER LYING HORIZONTALLY. 
 
 With the liberal permission of Messrs. Longman and Co., the eminent 
 publishers, we are fortunately enabled to lay before our readers the following Table, previously 
 mentioned, from Mr. Gwilt’s valuable Encyclopaedia of Architecture; a work which should be in 
 the hands of all anywise interested in its varied contents. 
 
 The column A shows the length in feet of each piece of timber, B the 
 proportion of depth to length, and C the breaking weight in pounds avoirdupois. The weights 
 are concentrated in the middle of the bearings. 
 
 Carpentry. XVIII 
 
/ | i.l l ,s//0H7.V(; I HI- GREA TEST STRENGTH OF OAK TIMBER LYING UORfjZONTABL 1 . 
 
 | A V 
 
 C 
 
 A 
 
 14 
 
 * il 
 
 A 
 
 B | 
 
 ‘ C 
 
 A 
 
 b| 
 
 11 
 
 C 
 
 A 
 
 B 
 
 C 
 
 A | 
 
 B i 
 
 C 
 
 3 1 '*" inchea 
 
 tquarc. || 
 
 4.204 in 
 
 ?ht*8 
 
 square. 
 
 4.264 in. 
 
 X S.528 in. 
 
 5.330 in. 
 
 X 8.528 in. 
 
 0.390 in. 
 
 K 7 
 
 402 in. 
 
 6.3‘JO in. X 11 
 
 .726 in. 
 
 
 12 045 
 
 2 M2 
 
 7 
 
 16.221 1 
 
 5.685 
 
 8 
 
 22.242 
 
 7.106 
 
 10 
 
 32,225 
 
 5.21s 
 
 10 
 
 33.400 
 
 9.771 
 
 10 
 
 52,512 
 
 
 s 7 17 
 
 
 lo 
 
 12.72s [ 
 
 7.106 
 
 10 
 
 25.460 
 
 8.52S 
 
 12 
 
 26.174 
 
 7.462 
 
 12 
 
 27,482 
 
 11.72 
 
 12 
 
 43,176 
 
 
 T 1 ' • 
 
 1 26 1 
 
 12 
 
 10. 169 
 
 8 52s 
 
 12 
 
 21.942 
 
 9.949 
 
 14 
 
 22,111 
 
 8.705 
 
 14 
 
 23,244 
 
 13.68 
 
 14 
 
 36,533 
 
 3 pis i-i 
 
 , 689 
 
 1 974 
 
 1 1 
 
 8*696 
 
 9.949 
 
 M 
 
 17.713 
 
 11 37 
 
 16 
 
 19,106 
 
 9.949 
 
 16 
 
 20,067 
 
 15.63 
 
 16 
 
 31,537 
 
 3 730 ■ 14 1 
 
 1 980 
 
 
 16 1 
 
 7,6 15 
 
 1 1 .37 
 
 16 
 
 15,291 
 
 12.79 
 
 18 
 
 16,757 
 
 11.19 
 
 is 
 
 17,596 
 
 17.59 
 
 18 
 
 27,631 
 
 i 264 1 6 
 
 1 290 
 
 6 396 
 
 Js 
 
 6,702 
 
 12.79 j 
 
 IS 
 
 13.410 
 
 14.21 
 
 20 
 
 14,877 
 
 12.44 
 
 20 
 
 15,321 
 
 19.54 
 
 20 
 
 24,546 
 
 •l 700 I'* 
 
 ; 7 : | 
 
 7 106 
 
 2o 
 
 5,95 1 
 
 1 1.21 
 
 20 
 
 11,902 
 
 15.63 
 
 22 
 
 13,338 
 
 13.68 
 
 22 
 
 13,986 
 
 21.50 
 
 22 
 
 22,003 
 
 5 330 '•o 
 
 3 •> 17 
 
 7.M7 
 
 99 
 
 5.333 
 
 15.63 
 
 22 
 
 10,677 
 
 17.06 
 
 21 
 
 12,057 
 
 14.92 
 
 24 
 
 12,652 
 
 23.45 
 
 21 
 
 19,883 
 
 5 M '.o *>0 
 
 OQQ 
 
 *v52^ 
 
 24 
 
 4.S20 
 
 17.06 
 
 24 
 
 9,562 
 
 18.4S 
 
 26 
 
 10,965 
 
 16.17 
 
 26 
 
 11,572 
 
 25,11 
 
 26 
 
 18.092 
 
 5 3 4 M» 0 1 
 
 2 711 
 
 3 23s 
 
 26 
 
 4.386 
 
 18.48 
 
 26 
 
 S,772 
 
 19.90 
 
 28 
 
 10,053 
 
 17.41 
 
 28 
 
 10,534 
 
 27.36 
 
 28 
 
 16,554 
 
 i; 09s id 
 
 2.447 
 
 9 949 
 
 2S 
 
 1,014 
 
 19.90 
 
 2S 
 
 8,026 
 
 21.32 
 
 30 
 
 9,225 
 
 18.65 
 
 30 
 
 9,668 
 
 29.31 
 
 30 
 
 15,221 
 
 7.-U*2 : 2*> 
 
 2,257 
 
 10.66 
 
 30 
 
 3,686 
 
 21.32 
 
 30 
 
 7,480 
 
 
 
 
 
 
 
 
 
 
 j 7 334 ' 30 
 
 2,076 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3.198 iu. 
 
 .‘2ii4 in. 
 
 t.204 iii 
 
 X 
 
 x330 in. 
 
 5.330 iu. square. 
 
 5.330 in. 
 
 X 0.594 in. 
 
 6.396 in. X 
 
 >.52S in. 
 
 (>.396 in. 
 
 Xl 
 
 2.702 in. 
 
 “I i — 1 
 
 2.132 6 
 
 16,326 | 
 
 ! 
 
 3.553 
 
 sl 
 
 16,224 
 
 1.441 
 
 10 
 
 19,890 
 
 7.994 
 
 10 
 
 35,803 
 
 7.106 
 
 10 
 
 38,158 
 
 10.66 
 
 10 
 
 57,285 
 
 2.812 8 
 
 12.030 
 
 4.441 
 
 III 
 
 12.730 
 
 5.330 
 
 12 
 
 16,359 
 
 9.594 
 
 12 
 
 29,445 
 
 8.528 
 
 12 
 
 31,407 
 
 12.79 
 
 12 
 
 47,083 
 
 j 3.553 10 1 
 
 3.547 I 
 
 5.330 
 
 12 
 
 10,469 
 
 6.218 
 
 1 1 
 
 13,839 
 
 11-19 
 
 14 
 
 24,919 
 
 9.949 
 
 14 
 
 27,341 
 
 14.92 
 
 14 
 
 37,854 
 
 1.201 12 
 
 7.852 1 
 
 6.218 
 
 1 > 
 
 8,856 
 
 7.106 
 
 16 
 
 1 1,946 
 
 12.79 
 
 16 
 
 21,493 
 
 11.37 
 
 16 
 
 22,936 
 
 17.06 
 
 16 
 
 34,404 
 
 4.97 1 1 1 
 
 6,642 
 
 7.106 
 
 16 
 
 7.645 
 
 7.994 
 
 isl 
 
 10,173 
 
 14.39 
 
 18 
 
 18.853 
 
 12.79 
 
 18 
 
 20,110 
 
 19.19 
 
 IS 
 
 30,164 
 
 
 5J21 
 
 7.994 
 
 18 1 
 
 6.702 
 
 s.863 
 
 20 
 
 9.29s 
 
 15.99 
 
 20 
 
 16,737 
 
 14.21 
 
 20 
 
 17,852 
 
 21.32 
 
 20 
 
 26,719 
 
 6.390 IS 
 
 5,027 1 
 
 S.883 
 
 20 
 
 5*951 
 
 9.771 
 
 22 
 
 8,334 
 
 17.59 
 
 22 
 
 15,002 
 
 15.63 
 
 22 
 
 16,001 
 
 23.45 
 
 22 
 
 24,003 
 
 7 106 20 
 
 1.162 
 
 9.77 1 
 
 22 
 
 5,333 1 
 
 10.66 
 
 24 
 
 7 531 
 
 19.19 
 
 24 
 
 1 3,556 
 
 17.06 
 
 24 
 
 14,460 
 
 25.58 
 
 24 
 
 21,689 
 
 1 7.S17 22 
 
 1.000 ; 
 
 10 66 
 
 21 
 
 4,820 
 
 1 1.55 
 
 26 
 
 0,863 
 
 20.7s 
 
 26 
 
 12.336 
 
 18.48 
 
 26 
 
 13.158 
 
 27.72 
 
 26 
 
 19.377 
 
 S.528 21 
 
 3,615 
 
 1 1.55 
 
 26 
 
 4,396 
 
 12.44 
 
 28 
 
 6,270 
 
 22.39 
 
 28 
 
 11,287 
 
 19.90 
 
 28 
 
 12,125 
 
 29.85 
 
 28 
 
 18,060 
 
 9.238 26 
 
 3*289 
 
 12.44 
 
 <28 
 
 4,013 
 
 13.32 
 
 30 
 
 5,765 
 
 23.98 
 
 30 
 
 10,378 
 
 21.32 
 
 30 
 
 11,070 
 
 3 LOS 
 
 30 
 
 16,000 
 
 1 9.919 2S 
 
 3.010 
 
 13.32 
 
 30 
 
 3,766 
 
 
 
 
 
 
 
 
 
 
 
 
 
 10.660 30 
 
 2,767 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 3.198 ill. X 5-330 in. | 
 
 1.264 in. X 6 396 in. 
 
 5.330 in 
 
 X 0 396 in. 
 
 5.330 in. 
 
 X 10.000 in. 
 
 6.396 in 
 
 X 9-591 in. 
 
 7.462 in. square. 
 
 2.664 6 
 
 20,418 
 
 4.264 
 
 . 
 
 20,152 
 
 5.330 
 
 10 
 
 23,869 
 
 8.883 
 
 10 
 
 39,782 
 
 7.994 
 
 10 
 
 42,964 
 
 6.218 
 
 10 
 
 35,746 
 
 3.553 8 
 
 15.103 
 
 5.330 
 
 10 
 
 16,4)13 
 
 6.396 
 
 12 
 
 19,630 
 
 10.66 
 
 12 
 
 32,717 
 
 9.594 
 
 12 
 
 35,334 
 
 7.162 
 
 12 
 
 31,911 
 
 4.111 10 
 
 11,934 
 
 6.336 
 
 12 
 
 1 3.086 
 
 7.462 
 
 14 
 
 16,374 
 
 12.44 
 
 14 
 
 27.677 
 
 11.19 
 
 14 
 
 29,891 
 
 8.705 
 
 14 
 
 27,123 
 
 5.330 ! 12 
 
 9,815 
 
 7.462 
 
 14 
 
 11,071 
 
 8.528 
 
 16 
 
 14,294 
 
 14.21 
 
 16 
 
 23,888 
 
 12.79 
 
 16 
 
 25,791 
 
 9.949 
 
 16 
 
 23,413 
 
 6.21S 11 
 
 8.303 | 
 
 8.529 
 
 16 
 
 9,557 
 
 9.594 
 
 18 
 
 12,568 
 
 15 99 
 
 18 
 
 20,648 
 
 14.39 
 
 18 
 
 22,623 
 
 11.19 
 
 18 
 
 20,530 
 
 ! 7.106 16 
 
 7.167 
 
 , 9.594 
 
 is 
 
 s.379 
 
 10.66 
 
 20 
 
 11.157 
 
 17.77 
 
 20 
 
 18,595 
 
 15.99 
 
 20 
 
 20,0S4 
 
 12.44 
 
 20 
 
 18,224 
 
 7 ''•'1 Is 
 
 6.2S3 j 
 
 10.66 
 
 20 
 
 7.43S 
 
 11.73 
 
 22 
 
 10,001 
 
 19.54 
 
 22 
 
 16,669 
 
 17.59 
 
 22 
 
 1 s.002 
 
 13.6s 
 
 22 
 
 16,335 
 
 ' S>S3 20 
 
 5,57S 
 
 11.73 
 
 22 
 
 6, Otis 
 
 12.79 
 
 24 
 
 9,037 
 
 21.32 
 
 24 
 
 15,063 
 
 19.19 
 
 24 
 
 16,267 
 
 14.92 
 
 24 
 
 14,761 
 
 1 9.7711 22 
 
 5.010 1 
 
 12.79 
 
 21 
 
 6,023 
 
 13.86 
 
 26 
 
 8,223 
 
 23.10 
 
 26 
 
 13,706 
 
 20.79 
 
 26 
 
 1 1,802 
 
 16.17 
 
 26 
 
 13,436 
 
 i 10.660 24 
 
 4.519 
 
 13.86 
 
 26 
 
 5.4S2 
 
 14.92 
 
 28 
 
 7,524 
 
 24.87 
 
 28 
 
 12,551 
 
 22.39 
 
 28 
 
 13,544 
 
 17.41 
 
 28 
 
 12,637 
 
 11.548|26 
 
 4,111 
 
 14.92 
 
 28 
 
 5.017 
 
 1 5.99 
 
 30 
 
 6,918 
 
 26.65 
 
 30 
 
 11.531 
 
 23.98 
 
 30 
 
 12,453 
 
 IS. 65 
 
 30 
 
 10,940 
 
 12.436 28 
 
 3,759 
 
 15.99 
 
 30 
 
 1.013 
 
 
 
 
 
 
 
 
 
 
 
 
 
 13.324 30 
 
 3,459 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3.198 111. X O STOln. 
 
 4.264 in. X 
 
 7. 402 in. 
 
 5.330 in. X 
 
 7.462 in. 
 
 0.390 in. square. 
 
 6.390 in. X 10.06 in. 
 
 7.462 in 
 
 X 8.528. in. 
 
 3.198 1 6 
 
 1 
 
 1 24.489 
 
 4.974 
 
 8 
 
 28,224 
 
 6.21S 
 
 10 
 
 27,847 
 
 5.330 
 
 10 
 
 28,643 
 
 8.883 
 
 10 
 
 47,738 
 
 7.106 
 
 10 
 
 44,577 
 
 1.264 | 8 
 
 is. 136 
 
 6.218 
 
 10 
 
 22,277 
 
 7. 162 
 
 12 
 
 22,901 
 
 6.396 
 
 12 
 
 23,556 
 
 10.66 
 
 12 
 
 39,261 
 
 8.528 
 
 12 
 
 36,643 
 
 6.330 lo 
 
 1 1.321 
 
 1 7.162 
 
 12 
 
 is, 321 
 
 s.705 
 
 14 
 
 18,313 
 
 7.462 
 
 14 
 
 19,927 
 
 12,14 
 
 14 
 
 33,212 
 
 9.949 
 
 14 
 
 29,806 
 
 6.396 12 
 
 11.77S 
 
 8.705 
 
 1 1 
 
 13,499 
 
 9.949 
 
 16 
 
 16,721 
 
 8.528 
 
 1 16 
 
 17.101 
 
 14.21 
 
 16 
 
 28,670 
 
 11.37 
 
 16 
 
 26,746 
 
 7.462 1 1 
 
 j 3,363 
 
 9.949 
 
 16 
 
 13,379 
 
 11.19 
 
 18 
 
 1 1,663 
 
 9.594 
 
 Is 
 
 15,082 
 
 15.99 
 
 is 
 
 25,135 
 
 12.79 
 
 18 
 
 24,060 
 
 3.52s 16 
 
 | SJ61 
 
 11.19 
 
 Is 
 
 11,730 
 
 12.44 
 
 20 
 
 13,017 
 
 10.66 
 
 20 
 
 13,389 
 
 17.77 
 
 20 
 
 22,315 
 
 14.21 
 
 20 
 
 21,838 
 
 1 9.59 1 j 1 s 
 
 1 7,510 
 
 12.1 1 
 
 20 
 
 10.113 
 
 , 13.68 
 
 22 
 
 11,667 
 
 11.73 
 
 U-> 
 
 12.001 
 
 19.54 
 
 22 
 
 19,973 
 
 15.63 
 
 22 
 
 18,667 
 
 10.660 20 
 
 6,631 
 
 13.6s 
 
 2> 
 
 9,334 
 
 14.92 
 
 21 
 
 10,544 
 
 12.79 
 
 24 
 
 10, s 1 1 
 
 21.32 
 
 21 
 
 18,075 
 
 17.06 
 
 24 
 
 16,870 
 
 11.726 22 
 
 ! 6.001 
 
 14.92 
 
 24 
 
 l s,427 
 
 16.17 
 
 26 
 
 9,595 
 
 13.86 
 
 26 
 
 9,857 
 
 23.10 
 
 26 
 
 16,447 
 
 18,18 
 
 26 
 
 15,418 
 
 12.732 24 
 
 5,422 
 
 16.17 
 
 26 
 
 7.675 
 
 17.41 
 
 28 
 
 8,778 
 
 1 1.92 
 
 2s 
 
 S.710 
 
 24.87 
 
 28 
 
 15,050 
 
 19.00 
 
 28 
 
 11,046 
 
 13. 838 26 
 
 1 4,934 
 
 17.11 
 
 2s 
 
 ' 7,022 
 
 1S.65 
 
 30 
 
 8.072 
 
 15.99 
 
 30 
 
 8,302 
 
 26.65 
 
 30 
 
 13,638 
 
 21.32 
 
 30 
 
 12,915 
 
 1 1.021 2s 
 
 1.51 1 
 
 ls.65 
 
 20 
 
 6.457 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 15.090 30 
 
 4,150 
 
 || 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TABLE SHOWING THE GREATEST STRENGTH OF OAK TIMBER LYING HORIZONTALLY. 
 
 139 
 
 A 
 
 B 
 
 C 
 
 A 
 
 B 
 
 C 
 
 A 
 
 B 
 
 C 
 
 A 
 
 B 
 
 C 
 
 A 
 
 B 
 
 c 
 
 A 
 
 B 
 
 C 
 
 7.462 in. X 9-594 in. 7.462 in 
 
 X 13.858 in. 
 
 8.528 in. X 12.792 in. 
 
 9.594 in. X 1L72G in. 
 
 10.66 in. X * t .726 in. 
 
 11.726 in. X 12.792 in. 
 
 7.994 
 
 10 
 
 50.125 
 
 12.61 
 
 10 
 
 72,403 
 
 10.66 
 
 10 
 
 76,381 
 
 9.771 
 
 10 
 
 78,848 
 
 9.771 
 
 10 
 
 87,520 
 
 1 0.66 
 
 10 
 
 105,023 
 
 9.594 
 
 12 
 
 41.221 
 
 13.86 
 
 12 
 
 59,546 
 
 12.79 
 
 12 
 
 62,817 
 
 11.73 
 
 12 
 
 64,780 
 
 11.73 
 
 12 
 
 71,978 
 
 12.79 
 
 12 
 
 86,374 
 
 11.19 
 
 14 
 
 35.644 
 
 16.17 
 
 14 
 
 50,371 
 
 14.92 
 
 14 
 
 53,139 
 
 13.68 
 
 14 
 
 54,800 
 
 13.67 
 
 14 
 
 60,889 
 
 14.92 
 
 14 
 
 73,067 
 
 1 2.79 
 
 16 
 
 30.103 
 
 18.48 
 
 16 
 
 43,483 
 
 17.06 
 
 16 
 
 45,872 
 
 15.63 
 
 16 
 
 47,305 
 
 15.63 
 
 16 
 
 52,548 
 
 17.06 
 
 16 
 
 63,074 
 
 14.39 
 
 18 
 
 20,394 
 
 19.72 
 
 18 
 
 2M24 
 
 19.19 
 
 18 
 
 40,219 
 
 17.59 
 
 IS 
 
 41,476 
 
 17.59 
 
 18 
 
 45,985 
 
 19.19 
 
 18 
 
 55,301 
 
 15.99 
 
 20 
 
 23,432 
 
 
 
 
 21.32 
 
 20 
 
 35,715 
 
 19.59 
 
 20 
 
 36,820 
 
 19.54 
 
 20 
 
 40,911 
 
 21.32 
 
 20 
 
 49,093 
 
 17.59 
 
 22 
 
 21,003 
 
 8.52S 
 
 in. 
 
 square. 
 
 23.45 
 
 22 
 
 32,004 
 
 21.50 
 
 22 
 
 33,004 
 
 21.50 
 
 22 
 
 36,67 1 
 
 23.45 
 
 22 
 
 4 1,006 
 
 19.19 
 
 24 
 
 18,979 
 
 
 
 
 25.58 
 
 24 
 
 28,920 
 
 23.15 
 
 24 
 
 29,825 
 
 23.45 
 
 24 
 
 33,13S 
 
 25.58 
 
 24 
 
 38,765 
 
 20.79 
 
 26 
 
 17,270 
 
 7.106 
 
 10 
 
 50,92 1 
 
 27.72 
 
 26 
 
 26,356 
 
 25.40 
 
 26 
 
 27,138 
 
 25.40 
 
 26 
 
 30,155 
 
 27.72 
 
 26 
 
 36,185 
 
 22.39 
 
 28 
 
 15,802 
 
 8.528 
 
 12 
 
 41,878 
 
 29.85 
 
 28 
 
 24,851 
 
 27.36 
 
 28 
 
 24,830 
 
 27.36 
 
 28 
 
 27,491 
 
 29.85 
 
 28 
 
 33,109 
 
 23.98 
 
 30 
 
 14,530 
 
 9.949 
 
 14 
 
 35,426 
 
 31.98 
 
 30 
 
 22,149 
 
 29.21 
 
 30 
 
 22,832 
 
 29.21 
 
 30 
 
 25,369 
 
 31.98 
 
 30 
 
 30,443 
 
 
 
 
 
 16 
 
 30.581 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 11 . 0 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 T.4G2 in 
 
 . X 10.66 in. 
 
 12.79 
 
 18 
 
 26,812 
 
 8.5*28 in 
 
 . X 13.858 in. 
 
 9.594 in 
 
 X 12.TO2 in. 
 
 10.66 in. X 12.792 in. 
 
 1 1.726 in. X 13.858 in. 
 
 
 
 
 14.21 
 
 20 
 
 qq ftnq 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 S.9S3 
 
 10 
 
 55,738 
 
 15.03 
 
 22 
 
 21,342 
 
 11.55 
 
 10 
 
 82,746 
 
 10.66 
 
 10 
 
 85,929 
 
 10.66 
 
 10 
 
 95,476 
 
 11.55 
 
 10 
 
 1 1 3,776 
 
 10.66 
 
 12 
 
 45,804 
 
 17.00 
 
 24 
 
 19,280 
 
 13.86 
 
 12 
 
 68,052 
 
 12.79 
 
 12 
 
 70,670 
 
 12.79 
 
 12 
 
 78,521 
 
 13.86 
 
 12 
 
 93,572 
 
 12.14 
 
 14 
 
 38,757 
 
 18.48 
 
 26 
 
 17,345 
 
 16.17 
 
 14 
 
 57.576 
 
 1 4.92 
 
 14 
 
 59,782 
 
 14.92 
 
 14 
 
 66,424 
 
 16.17 
 
 14 
 
 79,155 
 
 14.21 
 
 16 
 
 33,449 
 
 19.90 
 
 28 
 
 16,051 
 
 18.48 
 
 16 
 
 49,627 
 
 17.06 
 
 16 
 
 51,406 
 
 17.06 
 
 16 
 
 57,340 
 
 18.48 
 
 16 
 
 68,328 
 
 15.99 
 
 18 
 
 29,226 
 
 21.32 
 
 30 
 
 14,760 
 
 20.79 
 
 is 
 
 43,628 
 
 10.19 
 
 18 
 
 45,247 
 
 19.19 
 
 18 
 
 50,274 
 
 20.79 
 
 18 
 
 60,910 
 
 
 20 
 
 26,142 
 
 
 
 
 
 
 
 2 1 .32 
 
 
 
 21.32 
 
 20 
 
 4 1,631 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 19.54 
 
 22 
 
 23,325 
 
 8.52S in. X 0.594 in. 
 
 8.528 in. X 14 924 in. 
 
 23.45 
 
 22 
 
 36,004 
 
 23.45 
 
 22 
 
 40,005 
 
 11.726 in. X 1 1-924 in. 
 
 21 32 
 
 21 
 
 21 087 
 
 
 
 
 
 
 
 >5 58 
 
 2 1 
 
 32 535 
 
 95 5§ 
 
 91 
 
 3(i 1M 
 
 
 
 
 23.10 
 
 26 
 
 10’ 1 30 
 
 7.994 
 
 10 
 
 57,285 
 
 12.44 
 
 10 
 
 89,111 
 
 27.72 
 
 26 
 
 29,606 
 
 27.72 
 
 26 
 
 32X90 
 
 12.44 
 
 10 
 
 122,528 
 
 21.97 
 
 28 
 
 17,557 
 
 9.594 
 
 12 
 
 47,093 
 
 14.92 
 
 12 
 
 73,279 
 
 29.85 
 
 28 
 
 27,090 
 
 29.85 
 
 28 
 
 30,100 
 
 14.92 
 
 12 
 
 100,769 
 
 26.65 
 
 30 
 
 16,144 
 
 1 1.19 
 
 14 
 
 39X54 
 
 17.41 
 
 14 
 
 61,996 
 
 31.98 
 
 30 
 
 24,908 
 
 31.98 
 
 30 
 
 27,676 
 
 17.41 
 
 14 
 
 85,241 
 
 
 
 
 
 
 
 
 16 
 
 
 
 
 
 
 
 
 19.90 
 
 16 
 
 
 
 
 
 12.79 
 
 16 
 
 34,403 
 
 
 1 1 
 
 
 
 
 
 
 
 l j ',0 1 0 
 
 7.462 in 
 
 . X 11-726 in. 
 
 14.39 
 
 18 
 
 30.170 
 
 22.39 
 
 18 
 
 46,923 
 
 9.594 ii 
 
 . X 13:858 in. 
 
 10.66 in. X 13.858 in. 
 
 22.39 
 
 18 
 
 64,518 
 
 
 
 
 15.99 
 
 20 
 
 i i o 
 
 
 
 
 
 
 ' 
 
 
 
 
 
 
 
 9.771 
 
 10 
 
 60,264 
 
 17.59 
 
 22 
 
 24,003 
 
 9.594 in. square. 
 
 11.55 
 
 10 
 
 93,089 
 
 11.55 
 
 10 
 
 103,633 
 
 11.726 
 
 11 . X 15.99 in 
 
 1 1 73 
 
 12 
 
 4<) 
 
 10 19 
 
 9 ] 
 
 21 ()M(i 
 
 
 
 
 13.86 
 
 12 
 
 70,458 
 
 13.86 
 
 12 
 
 S5.U65 
 
 
 
 
 13.68 
 
 14 
 
 42,622 
 
 21.95 
 
 26 
 
 19*737 
 
 7.994 
 
 10 
 
 61,447 
 
 16.17 
 
 14 
 
 64,763 
 
 16.17 
 
 14 
 
 72,037 
 
 13.32 
 
 10 
 
 131,280 
 
 15.63 
 
 16 
 
 36,792 
 
 23.45 
 
 28 
 
 17,960 
 
 9.594 
 
 12 
 
 52,992 
 
 18.48 
 
 16 
 
 55,906 
 
 18.48 
 
 16 
 
 62,118 
 
 15.99 
 
 12 
 
 107,968 
 
 17.59 
 
 18 
 
 31,808 
 
 25.05 
 
 30 
 
 16,605 
 
 1 1.19 
 
 14 
 
 45,402 
 
 20.79 
 
 18 
 
 49,117 
 
 20.79 
 
 18 
 
 54,463 
 
 18.65 
 
 14 
 
 91,333 
 
 19.54 
 
 20 
 
 28.637 
 
 
 
 
 12.79 
 
 16 
 
 38,704 
 
 
 
 
 
 
 
 21.32 
 
 1G 
 
 78,842 
 
 21.50 
 
 22 
 
 24,719 
 
 8.528 in. X 10.66 in. 
 
 14.39 
 
 IS 
 
 33,935 
 
 9.594 ii 
 
 X 11.924 in. 
 
 10.66 in 
 
 . X 11-924 in. 
 
 23.9S 
 
 18 
 
 69.126 
 
 23.45 
 
 21 
 
 23 196 
 
 
 
 
 15 99 
 
 20 
 
 30 1*>.5 
 
 
 
 
 
 
 
 
 
 
 25.40 
 
 26 
 
 21,307 
 
 8.883 
 
 10 
 
 62,651 
 
 17.59 
 
 22 
 
 27*003 
 
 12.44 
 
 10 
 
 100,250 
 
 12.44 
 
 10 
 
 1 1 1,389 
 
 1 1 .726 in. X 17.056 in. 
 
 27.36 
 
 28 
 
 18,928 
 
 1 ft 60 
 
 1 2 
 
 52 348 
 
 19.19 
 
 24 
 
 24,401 
 
 1 4.92 
 
 12 
 
 82,447 
 
 14.92 
 
 12 
 
 91,609 
 
 
 
 
 29.31 
 
 30 
 
 17,758 
 
 1 2.44 
 
 14 
 
 44/283 
 
 20.79 
 
 26 
 
 22,205 
 
 17.41 
 
 14 
 
 69,745 
 
 17.41 
 
 14 
 
 77,495 
 
 14.21 
 
 10 
 
 148,784 
 
 
 
 
 14.21 
 
 16 
 
 38.227 
 
 22.39 
 
 28 
 
 20,317 
 
 19.90 
 
 16 
 
 60,207 
 
 1 9.90 
 
 16 
 
 66,896 
 
 17.06 
 
 12 
 
 122,362 
 
 
 
 
 15.99 
 
 18 
 
 33,516 
 
 23.98 
 
 30 
 
 18.681 
 
 22.39 
 
 18 
 
 52.77 1 
 
 22.39 
 
 IS 
 
 58,653 
 
 19.90 
 
 14 
 
 103,511 
 
 
 A * -■ in. 
 
 17.77 
 
 20 
 
 29,754 
 
 
 
 
 
 
 
 
 
 
 22.74 
 
 16 
 
 89,355 
 
 
 
 
 19.54 
 
 22 
 
 26,669 
 
 9.594 in. X 10.66 in. 
 
 10.66 
 
 in. square. 
 
 10.66 in. X 15.990 in. 
 
 25.58 
 
 IS 
 
 78,344 
 
 10 66 
 
 10 
 
 66 830 
 
 21 32 
 
 24 
 
 24 inn 
 
 
 
 
 
 
 
 
 
 
 
 
 
 12.79 
 
 12 
 
 55,964 
 
 23.10 
 
 26 
 
 21,930 
 
 8.983 
 
 10 
 
 71,607 
 
 8.883 
 
 10 
 
 79,564 
 
 13.32 
 
 10 
 
 119,345 
 
 11.72 in. X IS. 122 in. 
 
 14.92 
 
 14 
 
 46,497 
 
 24.87. 
 
 28 
 
 20,066 
 
 10.66 
 
 12 
 
 58,891 
 
 10.66 
 
 12 
 
 65,435 
 
 15.99 
 
 12 
 
 98,152 
 
 
 
 
 17.06 
 
 16 
 
 40,138 
 
 26.65 
 
 30 
 
 18,144 
 
 12.44 
 
 14 
 
 49,818 
 
 12.44 
 
 14 
 
 55,453 
 
 18.65 
 
 14 
 
 83,030 
 
 15 10 
 
 10 
 
 1 57,537 
 
 19.19 
 
 18 
 
 34,992 
 
 
 
 
 14.21 
 
 16 
 
 43,010 
 
 14.21 
 
 16 
 
 47,783 
 
 21.32 
 
 16 
 
 7 1 ,675 
 
 18.12 
 
 12 
 
 129,561 
 
 21.32 
 
 20 
 
 31,241 
 
 8.528 in 
 
 X 11.426 in. 
 
 15.99 
 
 18 
 
 37,705 
 
 15.99 
 
 is 
 
 41,895 
 
 23.98 
 
 18 
 
 62,841 
 
 21.1 1 
 
 14 
 
 109,600 
 
 23.45 
 
 22 
 
 9^ 003 
 
 
 
 
 1 7.77 
 
 20 
 
 qq 1 -tq 
 
 a ■» 
 
 20 
 
 
 
 
 
 
 16 
 
 94,611 
 
 
 
 
 
 
 
 
 
 
 
 
 25.58 
 
 24 
 
 25,305 
 
 9.771 
 
 10 
 
 69,975 
 
 19.54 
 
 22 
 
 30,003 
 
 19.54 
 
 22 
 
 33,337 
 
 11.721 
 
 in. 
 
 square. 
 
 27.18 
 
 18 
 
 82,350 
 
 27 72 
 
 26 
 
 23 0G8 
 
 1 1 73 
 
 1 0 
 
 57 5^o 
 
 •>1 3) 
 
 2 1 
 
 97 ] 1 9 
 
 0 1 q ) 
 
 0 1 
 
 
 
 
 
 
 
 
 29.85 
 
 28 
 
 21,070 
 
 13.67 
 
 14 
 
 48,711 
 
 23.10 
 
 26 
 
 24,671 
 
 L 1 . 0 Zt 
 
 23. 1 0 
 
 26 
 
 27,412 
 
 9.771 
 
 10 
 
 96,272 
 
 12.792 in. 
 
 square. 
 
 31.98 
 
 30 
 
 18,373 
 
 15.63 
 
 16 
 
 42,049 
 
 24.87 
 
 28 
 
 22,574 
 
 24.87 
 
 28 
 
 24,083 
 
 11.73 
 
 12 
 
 79,174 
 
 
 
 
 
 
 
 17.59 
 
 18 
 
 36,668 
 
 26.65 
 
 30 
 
 20,756 
 
 26.65 
 
 30 
 
 23,061 
 
 13 67 
 
 14 
 
 66,978 
 
 10.66 
 
 10 
 
 115,572 
 
 
 
 
 19.54 
 
 20 
 
 32,729 
 
 
 
 
 
 
 
 15 63 
 
 10 
 
 57,818 
 
 12.79 
 
 12 
 
 89,826 
 
 
 
 
 21.50 
 
 22 
 
 29,337 
 
 
 
 
 
 
 
 17.59 
 
 IS 
 
 51,193 
 
 14.92 
 
 14 
 
 79,709 
 
 
 
 
 23.45 
 
 2*1 
 
 26,017 
 
 
 
 
 
 
 
 19.54 
 
 20 
 
 45,002 
 
 17.06 
 
 16 
 
 68,708 
 
 
 
 
 25.40 
 
 26 
 
 24,124 
 
 
 
 
 
 
 
 21.50 
 
 22 
 
 -10,338 
 
 19.19 
 
 18 
 
 00,329 
 
 
 
 
 27.36 
 
 2S 
 
 22,073 
 
 
 
 
 
 
 
 23.45 
 
 24 
 
 36,407 
 
 21.32 
 
 20 
 
 53,557 
 
 
 
 
 30.20 
 
 30 
 
 20,295 
 
 
 
 
 
 
 
 25.40 
 
 26 
 
 33.0S7 
 
 23.45 
 
 22 
 
 48,006 
 
 
 
 
 
 
 
 
 
 
 
 
 
 27.36 
 
 28 
 
 30,350 
 
 25.58 
 
 24 
 
 43,380 
 
 
 
 
 
 
 
 
 
 
 
 
 
 29.21 
 
 30 
 
 27,906 
 
 27.72 
 
 26 
 
 39,475 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 29.85 
 
 28 
 
 36,119 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 31.98 
 
 30 
 
 33,211 
 
1 4(1 fable showing the greatest strength of oak timber lying horizontally. 
 
 | A | B | C 
 
 1 A 
 
 B 
 
 C 1 
 
 1 A 
 
 B 
 
 ' c 1 
 
 A 
 
 
 C 
 
 A 
 
 B 
 
 C 
 
 A 
 
 B 
 
 C 
 
 | 12 192 In X 13.858 in. 1 
 
 I 13.859 In. X 17 056 in. 
 
 14.924 in X 19.1881,1. | 
 
 15.99 in. X 21.326 in. 
 
 17.05(iin. X 
 
 23.452 in. 
 
 1 S. 122 i 
 
 > X 
 
 25.584 in. 
 
 
 ! iioi 
 
 1 0 
 
 104 |?(i 
 
 15 99 
 
 10 
 
 200,501 
 
 1 7.77 
 
 io 
 
 238,692 
 
 19.54 
 
 10 
 
 280,064 
 
 21.32 
 
 10 
 
 324,62 1 
 
 1 I..10 10 12-1.1 10 
 
 1 7 00 
 
 1 *7 
 
 136 153 
 
 19.19 
 
 12 
 
 1(54.895 
 
 21.32 
 
 12 
 
 196,365 
 
 23.45 
 
 12 
 
 230,330 
 
 25.58 
 
 12 
 
 256,975 
 
 l.l.Sb IZ lUi.UO 
 
 
 1 1 
 
 114 364 
 
 22.37 
 
 14 
 
 1 39,492 
 
 24.87 
 
 14 
 
 166,0(52 
 
 27.36 
 
 14 
 
 190.810 
 
 29.85 
 
 14 
 
 225,814 
 
 Hi 1 1 11 1 s0..t.> 1 
 
 I 00 74 
 
 in 
 
 396 
 
 25.58 
 
 Id 
 
 120,415 
 
 28.43 
 
 16 
 
 143,350 
 
 31.27 
 
 16 
 
 1(58,772 
 
 34.11 
 
 16 
 
 194.956 
 
 1 s. I s J •> 1 74,5 1 2 
 20 T9 1 s j 65,350 
 
 1 25.58 
 
 18 
 
 9L941 
 
 28.78 
 
 18 
 
 105,575 
 
 31.98 
 
 18 
 
 125,686 
 
 35.18 
 
 18 
 
 147,171 
 
 38.37 
 
 18 
 
 170,933 
 
 1! 71*2 in. X H 924 In. 
 
 13.S58in.X , ‘ > -122 in. 
 
 14.924 in.X'20-251in. 
 
 15.99 in. X 
 
 22.386 in. 
 
 17.050 in-X 24. 51S in. 
 
 111.188 in. square. 
 
 
 15 in 
 
 ]() 
 
 175 s3(5 
 
 16.S8 
 
 10 
 
 212,517 
 
 18.05 
 
 10 
 
 250,626 
 
 21.32 
 
 10 
 
 292,795 
 
 15.99 
 
 10 
 
 257 787 
 
 
 IS 12 
 
 12 
 
 1 1 1.01 1 
 
 20.25 
 
 12 
 
 174,057 
 
 22.38 
 
 12 
 
 206,127 
 
 2 • > . 5 s 
 
 12 
 
 240,800 
 
 19.19 
 
 12 
 
 212.107 
 
 IT II 11 yl >l*ll 
 
 21 II 
 
 14 
 
 121,332 
 
 23.(53 
 
 14 
 
 147.331 
 
 26.12 
 
 14 
 
 1 74,365 
 
 29.85 
 
 14 
 
 203,702 
 
 22.37 
 
 14 
 
 1 (9,347 
 
 
 o J Hi 
 
 It; 
 
 1 05.00 1 
 
 27.00 
 
 Id 
 
 127,104 
 
 29.85 
 
 16 
 
 1 50,5 1 7 
 
 34.1 1 
 
 16 
 
 175,812 
 
 25.58 
 
 16 
 
 150, SlS 
 
 ■>) M) is 70,38-1 
 
 27.18 
 
 is 
 
 92.5S8 
 
 29.38 
 
 18 
 
 111,411 
 
 33.58 
 
 18 
 
 131,770 
 
 38.37 
 
 18 
 
 154,174 
 
 2 s. 78 
 
 18 
 
 135,711 
 
 1 12 792 In. X 15 (, 9in. 
 
 I I3.85S in. X 19.18s in. 
 
 14.924 in. X -L32I) in. 
 
 15.99 ii 
 
 . X 23-452 in. 
 
 17.056 in. X 
 
 25.584 in. 
 
 lil.ISS in. X 20.254 in. 
 
 | p 32 10 143 214 
 
 : 15 99 
 
 10 
 
 1 11.179 
 
 1 7.77 
 
 10 
 
 212,776 
 
 19.54 
 
 10 
 
 262,561 
 
 21.32 
 
 10 
 
 305,525 
 
 16.88 
 
 10 
 
 272,108 
 
 15 qg | » ] | 7 tv; 
 
 19 io 
 
 12 
 
 153.115 
 
 21.32 
 
 12 
 
 173,218 
 
 23.45 
 
 12 
 
 215,935 
 
 25.58 
 
 1.2 
 
 251,360 
 
 20.25 
 
 12 
 
 223,788 
 
 |sr. r » 14 ( )U (>3fi 
 
 J 22.37 
 
 ] l 
 
 129,528 | 
 
 24.87 
 
 14 
 
 150,991 
 
 27.36 
 
 1 1 
 
 182,668 
 
 29.85 
 
 14 
 
 2 1 2,559 
 
 23.63 
 
 14 
 
 189,310 
 
 o | q*> 1 1 ; si; hi ii 
 
 1 :25.5s 
 
 1(5 
 
 1 1 LSI 3 j 
 
 2S. 13 
 
 Id 
 
 133,733 
 
 31.27 
 
 Id 
 
 157,685 
 
 34.1 1 
 
 16 
 
 183,421 
 
 27.00 
 
 16 
 
 163,419 
 
 23 9s| is 75,411 | 
 
 1 2‘.78 
 
 18 
 
 OS, 035 1 
 
 3 1 .98 
 
 
 1 17,306 
 
 35.18 
 
 18 
 
 138,254 
 
 38.37 
 
 is 
 
 100,277 
 
 29.38 
 
 18 
 
 143,281 
 
 j 12.792 in. X17-0j8in. 
 
 l3.S58in.X20.254 In. 
 
 11 924 in.X22.386in. 
 
 15.99 in X 24.518 in. 
 
 IS. 122 ill. 
 
 square. 
 
 19.188 in X21 326in. 
 
 14 - M 10 • 152,7(52 
 
 1(5.88 
 
 10 
 
 100.522 
 
 18.65 
 
 10 
 
 233,917 
 
 20. 13 
 
 10 
 
 274,195 
 
 15.10 
 
 10 
 
 229,907 
 
 17.77 
 
 10 
 
 286,430 
 
 17 0(5 12 1 25«(*:J 1 1 
 
 20.25 
 
 12 
 
 101.021 
 
 22.38 
 
 12 
 
 192,378 
 
 24.52 
 
 12 
 
 225,750 
 
 18.12 
 
 12 
 
 187,107 
 
 21.32 
 
 12 
 
 235,565 
 
 1*1.90 II 10(5,279 1 
 
 23.63 
 
 1 1 
 
 13(5.721 
 
 2(5.12 
 
 1 1 
 
 162,737 
 
 28.60 
 
 14 
 
 190,751 
 
 21.14 
 
 14 
 
 159,973 
 
 24.87 
 
 11 
 
 196,074 
 
 22.74 10 01.711 
 
 27.00 
 
 io 
 
 118,026 
 
 29.85 
 
 1(5 
 
 1 10,483 
 
 32.(59 
 
 Id 
 
 164,852 
 
 24.16 
 
 16 
 
 142,094 
 
 28.43 
 
 1(5 
 
 171,010 
 
 25. 5S IS 70,238 | 
 
 29.38 
 
 18 
 
 103,481 
 
 33.58 
 
 18 
 
 112.372 
 
 36.78 
 
 18 
 
 114,538 
 
 27.18 
 
 18 
 
 121.077 
 
 31.98 
 
 IS 
 
 150.823 
 
 i 12.792 in. Xl''-‘1‘42>n. 1 
 
 1 l3.05Sin. X 
 
 ‘21.326 in. 
 
 1 1.924 in. X 23452 in. 
 
 17.056 in. 
 
 square. 
 
 18.122 in. X 19.188 in. 
 
 10.188 in. X 22.386 in. 
 
 1 5710 f 10 1 162,310 I 
 
 17.77 
 
 10 
 
 205,531 
 
 19.54 
 
 10 
 
 246,136 
 
 1 1.21 
 
 10 
 
 203,684 
 
 15.99 
 
 10 
 
 213,165 
 
 1 8.65 
 
 10 
 
 300,763 
 
 Is. 12 12 1 23^487 i 
 
 2 1 
 
 12 
 
 170.130 
 
 23.45 
 
 12 
 
 201,5 10 
 
 17.0(5 
 
 12 
 
 167,513 
 
 19.19 
 
 12 
 
 200,131 
 
 22.38 
 
 12 
 
 247,344 
 
 21 1 1 1 1 112,921 
 
 1 2-1.S7 
 
 1 1 
 
 144.920 
 
 27.36 
 
 14 
 
 170,490 
 
 ! 19.90 
 
 1 1 
 
 141.70(5 
 
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CHAPTER VC. 
 
 C U ]{ y E D 1? I E C E S. 
 
 GENERALLY. In the case of a curved rib, as for instance one sup- 
 porting the carriage way of a bridge, the pressure on the central topmost part lias a tendency 
 to cause the portions of the rib to rise at two intermediate points between the centre and the 
 abutments on either side. It is said that the utmost strain on a curved rib as above does not take 
 place when the weight acts exactly in the middle. Where it occurs has not been precisely 
 determined, although calculations have been made on the supposition that it is one-third of the 
 span of the rib from one abutment. Tredgold has given a valuable praetical rule on the subject; 
 and in Barlow’s Essay on the Strength and Stress of Timber, from which we have taken the 
 liberty of quoting, are tables transmitted to the officers and commissioners of His Majesty’s navy 
 showing the strength of oak scantlings naturally and artifically bent, etc. It would appear that 
 boiling or steaming with a view to bending timber does not improve its strength and rigidity, 
 and there* is always a tendency to return to the original form. 
 
 On the subject of naturally bent trees we remarked in Chapter T, Division 2. 
 In these, we believe, there is a more permanent set. It is in ship building that curved pieces of 
 timber are chiefly employed, and it is therefore not deemed essential to dilate on their strength; 
 the curved struts, etc., in Gothic roofs should have their scantlings increased above those which 
 would be adopted for straight pieces. 
 
 BENDING TIMBER. An invention by Mr. T. Blanchard, of Boston, 
 America, seems destined to effect a remarkable revolution in the use of bent timbers; and, as 
 it may probably modify some of the calculations in use, we shall mention it under this heading. 
 
 An English company has been formed to carry out this invention, and 
 we witnessed some lai’ge timbers bent with the most complete success at Messrs. Collinge’s 
 factory in Lambeth. The wood, having been properly steamed, is fixed on all sides in an 
 apparatus so as to prevent any alteration of form in the way of bursting, crippling, etc. End 
 pressure is then applied, and the wood is forced into a desired curve, the cross grain being 
 thrown into right angles, the knots following the bend, the juices forced out, and the cavities 
 filled with the interlacing fibres. In the ordinary bending process, the outer fibres being ex- 
 tended and the inner compressed, the whole is weakened, but In the American end pressure 
 method, the condensation and bending taking place simultaneously, the capillary tubes, of use 
 only when the tree is growing, are forced into each other, and the density, non-liability to com- 
 bustion, prevention of the depredations of insects, impermeability to damp, durability and hard- 
 ness, are vastly increased. The timber is neither spread nor flattened; and although the inner 
 part is contracted, the outer is not, as herefore, disintegrated and expanded, (Sec Chapter T, Divi- 
 sion 3, Neutral Axis.) the fibres being, as it were, firmly knitted together. Seasoning also is at 
 
CURVED PIECES. 
 
 142 
 
 the same lime effected l>v driving out the juices, thus obviating the locking up of capital during 
 ili.- Inn- process of natural drying. As Mr. Charles Mayhew remarked, one of the architectural 
 id\ antagC' of the American process is that, — “in its application to all circular, wreathed, or 
 misled work, it not only preserves the continuous grain of the wood, which is now usually and 
 lahurinuslv done bv narrow strips of veneer «glued on cores cut across the grain, with many 
 unsightly joints, ill-concealed at best; hut it will materially reduce the cost of all curved work, 
 tvhirli now varies, according to the quickness of the sweep, and will give the artist greater free- 
 dom in his design, by allowing him to introduce lines which are how cautiously avoided in order 
 to prevent the cost of their execution.” The same architect also stated his opinion that, from 
 the rigiditv and -trength of the wood being much increased, t lie necessity of using east iron 
 would in many cases he superseded. Sir William Hooker, of Kew, has expressed his conviction 
 that, from the present expensive method of cutting and shaping timber being superseded, a 
 'living of from one-fourth to three-fourths of the material will he effected; and that additional 
 strength i- gained at the very point where it is most required, at least. 74 per cent. The wood 
 appears to have no inclination to return to its original form, owing to the complete change in 
 the relation of its fibres; and bent pieces, cut into slips, are found to exhibit throughout a firm 
 and l i autiful continuous sweep of fibres. With reference to cost, by the adoption of this method, 
 the expense of ships must he reduced at least twenty-five per cent, besides increasing their 
 durability by avoiding the use of cross-grained wood. 
 
 A Roman Catholic cathedral in the United States has its domc*formed of 
 wood bent by this process. For Gothic roofs it is peculiarly appropriate, as well as involving 
 a e.msiderable economy in the manufacture of looking glasses, picture frames, and cabinet work 
 gene rally. We observe the names of Rennie, Fairbairn, and other eminent men, among the 
 supporters of the invention; and, if time does not indicate some subsequent deterioration in the 
 limber subjected to this process, it is one of the most valuable scientific advances which have 
 •been made in the present age. 
 
FOURTH DIVISION. 
 
 PRACTICAL CARPENTRY. 
 
 CHAPTER I. 
 
 GENERAL OBSERVATIONS. 
 
 The reader has now been placed at the point of view whence he may 
 enter with advantage into the consideration of the Practice of Carpentry, although much of it 
 has already been anticipated and treated at some length in each of the three preceding Divisions, 
 w e have done this because it is extremely difficult to maintain a perfect separation of the sub- 
 jects included in the headings given on the Tenth Page, and because of our belief that many 
 practical matters are better understood if explained when treating principles, which latter are 
 thus also more clearly illustrated. It is evident that the comprehension of the several con- 
 structive details now to be entered upon is facilitated by the preceding course; and the student 
 will perceive, as he advances, the application of the general principles hitherto laid down, and 
 which may be considered as the groundwork of what is to follow. 
 
 FORMS OF BUILDINGS. DRAWINGS. A square, or parallelogram, 
 is, generally speaking, the best form for a building, whether strength, duration, economy, or 
 convenience is considered. The execution is then of the simplest character with respect to the 
 several details. Circular forms are most expensive; and acute and obtuse angles in carpentry 
 are more costly, and admit of less strength in the connections, than right angles. Plane surfaces, 
 perfectly vertical or horizontal, are easiest to execute, and in most circumstances preferable with 
 regard to suitability. Again, rectangular rooms admit of the most convenient disposition of Fur- 
 niture, or whatever else may be placed within them, those of circular or polygonal forms, espe- 
 cially if of small dimensions, being rarely desirable. 
 
 In designing a piece of carpentry, such as a roof or partition, the simplest 
 procedure consists in first sketching the main timbers, considering them as so many lines without 
 breadth or thickness. A clear idea may thus be obtained of the nature of the various thrusts 
 and strains; and the lines can be easily erased and others substituted until a satisfactory equi- 
 librium is obtained. It is a waste of time primarily to draw the design out fair to scale, unless 
 the work is so devoid of complication that a correct notion of it may be formed before taking the 
 pencil in hand. In putting a new scheme on paper it creates confusion to indicate at once every 
 little detail, which, although a decided improvement, is nevertheless not absolutely essential for 
 the stability of a structure. Only those timbers which are thus requisite should engage con- 
 
GENERAL OBSERVATIONS. 
 
 ,, I, in making the first draught, and, the principal lines being determined so as to satisfy 
 
 f |„ requisite conditions, the smaller parts may he left until a scaled drawing is made. Even 
 t |,i, should he small, uniform with the section and plan of the building to which it relates. An 
 
 ,. n |., elevation, section or plan may next he drawn; and a scale of half or one inch to the 
 
 foot i> often convenient. On this all auxiliary matters requisite for the comprehension of the 
 
 detail -hould at least he indicated; and it is desirable to figure hearings, heights, scantlings, etc., 
 
 besides giving the last in the specification. The forms of the joints, modes of fixing straps, 
 holts, etc., should he represented so as to prevent the possibility of any mistakes, and the pro- 
 of some details considerably facilitates their comprehension. A scale ought to he put 
 <>n the drawings, and it is as well to write underneath what is intended, as it is sometimes in- 
 , o erectly drawn and thus misleads. It is the custom of some architects and engineers entirely 
 to omit figures on drawings, leaving it to the workman to measure every dimension; but the 
 practice is hardly to he commended. 
 
 PLAN. But few words are now requisite to elucidate the Plan sketched 
 at Page 10. Joinings arc first introduced as applying to all the works afterwards described, 
 and on account of the importance of accurately squaring, uniting and finishing the various parts 
 of framing. The duration of the oldest structures is not merely attributable to the careful choice 
 • •I materials and Scientific design, hut also to exactitude of workmanship; and, as Emy remarks, 
 “'flic smallest defect in the joints, or even some inappreciable inaccuracies, may, on being 
 multiplied in connection with the flexibility of the wood, allow a play injurious in proportion to 
 the extent of the piece of carpentry.” The consideration of floors follows that of the various 
 joinings, in accordance with the suggested advantage of taking primarily the subjects which 
 may form fitting introductions, or he, as it were, stepping-stones to others. Roofs, for instance, 
 are often kinds of floors placed at various angles. It is judged preferable to put partitions after 
 floors, although often easier to execute. To roofs, which next follow, much importance is attached, 
 the principles of which, if well understood, considerably aiding the comprehension of other sub- 
 jects which follow, such as centering bridges, etc. Domes naturally follow" roofs; and bracketing, 
 "fflts, etc., complete the list of main subjects relating to houses. Centering, bridges, scaffolds, etc., 
 occupy the succeeding Chapters; and in the final one on accessory constructions certain subjects 
 uming appropriately under this heading will he included. Throughout this Division such ge- 
 neral principles not disposed of in the Theory of Construction will occupy attention, together 
 with approved examples of the several works. 
 
 LINES. — PLATE 17. 
 
 ! o find the form of the curb when a circular^ arch intersects a flat ceiling. 
 
 I here is sometimes a necessity (as in churches) for a ceiling to he lower 
 m the crown of a semicircular headed window. In consequence of this the ceiling has to be 
 hollowed out. and a curb is required for the arris made by the intersection of the curved and flat 
 -ml." I '. I lie plate now to he referred to illustrates the mode of ascertaining the form of the curb. 
 
 /' 'O' 1 represents the elevation of the semicircular arch of the window. The 
 l' \< 1 ot the ceiling, as shown by the line aa, being a certain distance below the crow-n b. 
 
LINES FOR THE RIBS OF PLASTER NICHES. 
 
 J 45 
 
 Fig. 1 a is a section through the crown of the semicircular arch, the level 
 of the flat ceiling being indicated by the line a c, while the line b c shows the inclination of 
 the hollowed part. 
 
 By referring to Fig. 1 b it will be understood that the hollowed part of 
 the ceiling will coincide with part of the surface of an oblique cylinder, of which the diameter 
 bd is equal to the span of the semicircular arch. In this figure, as in the last, etc represents the 
 line of the fiat ceiling, and b c the inclination of the hollowed part. It will be seen that the line 
 a c corresponds with the curb of which we have to ascertain the form, and that, as the required 
 curve must coincide with an oblique section of a cylinder, it will be a portion of an ellipse. 
 
 Figs. 2 and 2 a illustrate the geometrical process for ascertaining the form 
 of the curb. In Fig. 2 a the arch of the window is represented by the semicircle e B e. The 
 distance AB shows the difference of level between the crown of the arch and the fiat ceiling; 
 and A C is equal to the distance from the face of the arch to the intersection of the inclined 
 hollowed part with the fiat ceiling. Divide the line A B into any number of equal parts, in 
 this case say eight, and through the points thus marked draw lines parallel to a A a, to intersect 
 the semicircle. Also divide the line A C into the same number of equal parts as A B and 
 through the points thus marked draw lines parallel to a A a. Then, from the points at which 
 the semicircle is intersected by the parallel lines, draw lines perpendicular to a A a, and respec- 
 tively intersecting the parallel lines between A and C, in the manner represented by the figure. 
 Through the points of intersection thus obtained draw the curved line a C a, which will be the 
 form of the inner line of the curb as required. 
 
 LINES FOR THE RIBS OF PLASTER NICHES. 
 
 In the construction of niches it is desirable that the arrangement should 
 be such that as few lines as possible are required, and the plates illustrating this subject re- 
 present those dispositions of the ribs which are the most simple in this respect. It will be per- 
 ceived that in many cases the back ribs may be placed so that they are all of equal and similar 
 curvature; while if another arrangement were to be adopted it would be necessary to ascertain 
 the form of each rib by a separate process. 
 
 To draw the ribs for a niche which is semicircular in plan and elevation. 
 
 ( [dues. — Plate PS.) A niche of this form corresponds with a quarter of a sphere, and Figs. 1, 
 
 / a, and J b serve to show that, with the arrangement represented on the plate, the ribs all coin- 
 cide with great circles. Fig. I corresponds with the side elevation of the cradling, — Fig. 1 a 
 with the front elevation, and Fig. 1 b with the plan. It will be readily seen that the same radius 
 which serves for the curvature of the curb will give the form of the front rib and also of 
 each of the back ribs. 
 
 Fig. 2 represents the front elevation of the cradling for a niche of the 
 torm referred to. Fig. 2 a is the plan of the same, and Fig. 2b is the section. 
 
 The upper end of each of the back ribs will require to be cut so as to fit 
 against the front rib, and the degree of bevel may be easily taken from the plan. Fig. 2 c is 
 
 Carpentry. " 
 
 XIX 
 
I INI s I'm; rilK BIBS OF PLASTER NICHES. 
 
 i it; 
 
 elevation -d the rib .narked d on the plan, and the distances ce and cf, taken from the plan 
 IM ,I m.-d-kt-tl on / Vo. 2c in the manner represented, give the amount of bevel required. 
 
 To draw the ribs for a niche, which is a segment of a circle on the plan and 
 
 which i' ri/iicin iilai in deration. (Lines. Plate JO.) 
 
 I 'ig. /. I a, and l b serve to show the way in which a niche of this kind 
 
 corresponds with a part of a sphere. These figures also indicate how, by making the ribs con- 
 „Tgr to a point at the back of the curb, the ribs may be made to be all similar and equal in 
 , .mature, and to coincide with portions of great circles. Fig. / corresponds with the side ele- 
 N.uion of the cradling, Fig. la with the front elevation, and Fig. 1 b with the plan. In this 
 , , 8e ,) R . >aJnt . ri ,dius that serves for the curb will be the proper one for the back ribs, but the 
 front rib will require a shorter radius. 
 
 Fig. 2 represents the front 'elevation of the cradling for a niche of the 
 form referred to. Fig. 2a is the plan of the same, and Fig. 2b is the section. 
 
 The lower ends of the back ribs will require to be cut so that they may 
 fit together in the way represented by Fig. 2. The degree of bevel may be measured on the 
 elevation. Fig. 2c is an elevation of the rib marked d in Fig. 2, and the distances ef and eg, 
 taken from the elevation. Fig. 2, and marked on Fig. 2c in the manner represented, give the 
 amount of bevel required. 
 
 . To draw the ribs for a spheridal niche, which is a segment of a circle on the 
 
 plan and in the deration. ( Lines. — Plate 20). 
 
 Figs. I, / a, and / o indicate the way in which a niche of this kind cor- 
 responds with a part of a sphere. These figures also show how the back ribs will be all of a 
 >imil.ur curvature, and agree with portions of great circles, if they are made to converge towards 
 a point on the plan coinciding with the centre of the sphere. Fig. / corresponds with the side 
 elevation of the cradling, — Fig. la with the front elevation, and Fig. I b with the plan. In 
 this case all the back ribs will be described with the same radius, but it will not be the same 
 a that required for either the curb or the front rib. 
 
 Fig. 2 represents the front elevation of tbe cradling for a niche of the 
 form referred to; the centre from which the front rib is described being at d. Fig. 2a is the 
 plan n| the same; the centre from which the curb is described being at e. The ribs are shown 
 to be placed at equal distances apart on the curb, and to be made to converge towards the 
 point c. I lie plan indicates the parts of the front rib at which the back ribs have to be fixed. 
 
 big. 2l> i> a section, on which is represented the geometrical construction, 
 
 by means of which the centre and radius for describing the curve of the back ribs may be found. 
 I In line ’ b. big. 2t>. i' the springing line, and parallel to it, at a height corresponding with 
 the centre in the front elev ation, is drawn the line fg. The line ac, Fig. 2b, is the line of the 
 h'ont <d the niche, and parallel to it, and at a distance corresponding with the centre e on the 
 I” n, i' drawn the line / //. I lie point /, obtained by the intersection of the two last drawn 
 hnes, i' the centre from which to describe the curve of the back ribs. 
 
 bigs. 2c and 2d represent the ribs marked K and L on Fig. 2a, and 
 'how how, by means of the respective widths taken from the plan, the required amount of bevel 
 may be marked on their upper ends. 
 
LINES FOR TIIF. RIBS OF PLASTER NK'IIES. 
 
 147 
 
 To draw the ribs for a spherical niche in a circular wall {Lines. — Plate 21.) 
 The principle to be applied in this case is similar to that already illustrated by the last three 
 plates. The niche corresponds with a portion of a sphere, and Fig. /, / a, and / b serve to show, 
 that if the back ribs are so arranged that on the plan they all converge towards the centre of 
 the sphere, they will all coincide with parts of great circles. 
 
 Fig. 2 represents the front elevation of the cradling for a spherical niche 
 in a circular wall. Fig. 2a is the plan of the same, and Fig. 2b is the section. 
 
 The upper ends of the back ribs must be cut to a bevel so as to fit against 
 
 the front rib. Fig. 2c is an elevation of the rib marked d in Fig. 2a, and the distance o f, 
 
 taken froin the plan and marked on Fig. 2c in the manner represented, gives the amount of 
 bevel required. 
 
 To draw the ribs fur an elliptical niche. ( Lines. — Plate 22.) 
 
 Figs. 1 , 1 a, and 1 b show the way in which a niche of this kind corres- 
 ponds with part of an ellipsoid. It will be perceived that when the back ribs are arranged 
 
 in vertical planes perpendicular to the face of the wall, all the required curves are portions of 
 circles as indicated by Fig. /, which corresponds with the side elevation of the cradling. Fig. / a 
 agrees with the front elevation, and Fig. / b with the plan. 
 
 Fig. 2 represents the front elevation of the cradling for an elliptical niche. 
 Fig. 2 a is the plan of the same, and Fig. 2 b is the section. 
 
 The curved edges of the back ribs must be cut to a bevel that will coin- 
 cide with the form of the niche. Fig. 2c is an elevation of the rib marked d in Fig. 2a, and 
 the distance e taken from the plan is the necessary difference between the radii for the curves 
 on the opposite sides of the rib. 
 
 CHAPTER It. 
 
 JOININGS IN CARPENTRY. 
 
 GENERALLY. The first consideration in forming joints is the object 
 to be attained. In other words, the peculiar strain acting at fhe point has to be taken into 
 account, as a joining very suitable for one purpose may be absolutely pernicious for another. 
 Great discrimination therefore is requisite in choosing the best possible form and placing it in 
 the best possible relative situation. 
 
 Many joints are preferred on account of their pleasing appearance; but 
 in this respect the carpenter must be carefully on bis guard. Strength is the primary object; what 
 is agreeable to (lie eye is secondary in a combination intended more for duration than beauty. 
 
 The expansion and shrinkage of the material employed must constantly 
 be borne in mind. In joinery the shrinkage of the various parts of a frame has often a counter- 
 balancing effect, and dovetail joints are common. These must be avoided in carpentry; for the 
 slightest shrinkage hastens the destruction of the combination. The bearing should have the 
 
JOININ’ OS IN CARPENTRY. 
 
 Ns 
 
 largest possible 
 We mentioned 
 the joints. In 
 airs of circles. 
 
 Mirhice; if otherwise, crippling or indentation of the fibres will probably occur, 
 at lbiu-e 1 03 M. Emmery’s expedient of introducing plates of copper between 
 Germany lead is commonly' adopted: M. Perrone t formed his abutments into 
 
 CLASSIFICATION. As ill the other branches of carpentry so it is in 
 joinings, the comprehension of the whole subject is much facilitated by a clear and comprehensive 
 classification of the several varieties. We adopt four main divisions. First, Pieces continued in 
 / ■noth. Secondly, Pieces increased in Depth. Thirdly, Piece s forming Right Angles. Fourthly, 
 Pieces forming Acute or Oh I me Angles. Some remarks on Ironwork conclude the Chapter. 
 
 PIECES COST /Xl'ED IS LENGTH. 
 
 FISHING BEAMS. This is the strongest method of lengthening by piec- 
 ing a beam. It consists in simply butting the ends together, and grasping the two by means 
 of others, placed on either side and secured by bolts, which last ought not to be inserted very 
 near the en ds. M. Perronet fished the stretchers, or ties, connecting the opposite parts of a center 
 which began to yield: this afforded a remarkable instance of the strength of fished beams. Six 
 counteracted a strain of 1 800 tons. Oak was adopted; and the stretchers were 14 by 11 ins. 
 To obviate the risk of the Lilts bending from their great length, the two side pieces were 
 scarfed triangularly into the middle piece, the scarfs being one inch deep, each face two feet 
 long, the bolt passing close to the angle. Ship carpenters constantly fish masts, yards, etc., 
 when broken; or they are spliced with a long bevel joint with a sharp edge at the end of the 
 piece, the edge being sometimes cut off, leaving an obtuse angle. 
 
 On Plate 21, Fig. I is the simplest form of a fished beam. The bolts 
 must be screwed up tight, as it is obvious that on them the strength mainly depends: shrinkage 
 of the timbers of course tends to destroy the efficacy of the combination. In Fig. 2 there is 
 not 'u much dependence on the bolts; but, as will readily be perceived, cutting into the beam 
 diminishes its strength and there is more labour than in the former example, as well as waste 
 of material. The underside is drawn with an acute angle, but it is best square on account of 
 shrinkage. In Fig. 4. keys are shown in the lower portion. Iler-e also there are the objection- 
 able indentations and increase of labour. An iron plate is placed on the upper part of Fig. 4. 
 
 SCARFING GENERALLY. The object of this description of joining is 
 similar to that above described, viz., to increase the length of ties, etc., of great bearing, when 
 one piece of timber of the requisite dimension cannot be obtained. But there is a decided dif- 
 ference between the two; for a fished beam, although stronger than one which is scarfed, has 
 an exceedingly unscientific appearance; and in the scarf clumsiness is avoided by making the 
 outer surfaces continuous, corresponding portions of each beam being cut away and the two 
 lapped together. 1 he projecting parts are called tables-, and steps is a term which, correctly 
 speaking, should be limited to horizontal tables. Occasionally tables are dovetailed; but, as 
 betore said, .this is not to be recommended, on account of the marked effect of a slight amount 
 "I 'hrinkage. Again, pieces of hard wood, called keys, wedges, or joggles, are let into openings 
 1* »' uit-il between two principal timbers with admirable effect in securing both together. We 
 m.i\ 1 1 ms divide scarfs into three classes: — first, those with horizontal or step tables, forming 
 
JOININGS IN CARPENTRY. 
 
 149 
 
 right angles; secondly, those with sloping tables , forming acute or obtuse angles; thirdly, kei/erf 
 scarfs, with horizontal or sloping tables. We shall group together scarfs without keys. 
 
 PRINCIPLES OF SCARFING. In the first place, we must premise that 
 
 two pieces joined, and intended to act as one would under tension, cannot resist to the 
 
 extent of a single piece. No scarf is so strong as two pieces of timber of the same scantling, 
 fished and bolted. The simplest scarfs are preferable. One table is not only easier of execution, 
 but. resists better than several; and the projection should not be increased to a great extent. 
 Iveys often add considerably to the strength of a combination; hut care must he taken not to 
 wedge too tight, and thus produce an injurious internal strain; and also to make the indents in 
 scarfs bear equally and fit accurately. With respect to the length of scarfs, this will depend on 
 the object in view, and the force causing the fibres to slide upon each other must be considered. 
 By adopting a long table the bolts may be increased in number, and the cohesive strength of a 
 
 compound piece is not diminished, hut the transverse is affected. For soft woods, as fir, a scarf 
 
 of a length of about four times the depth of the timber has been recommended when there are 
 indents and bolts; and for hard woods, as oak, twice the depth: if bolts are omitted, the scarfing 
 may be twelve times for soft, and six for hard woods. 
 
 SCARFS WITHOUT KEYS. On Plate 21 , Fig. 5 is the simplest form 
 of scarfing. It is obvious that the strength is quite dependant on the bolts. An iron plate 
 at top and bottom may be added, or there may be four plates, two above and below; but it will 
 still possess not above half the strength of an entire piece acting as a tie. The plates may be 
 differently disposed, as in Fig., 6, but this combination is hardly so strong as the first. By the 
 introduction of plates the inclination of the bolts to bend under a violent strain is much ob- 
 viated, their ends being so firmly secured; but the use of iron prevents the scarf being con- 
 sidered as a pure carpentry form. We have added some other varieties, Figs. 7 to 13. In 
 Figs. 7, 8, and 9, the dotted lines indicate thinner projecting portions, which, however, can hardly 
 he said to increase the strength. Figs. 9, 10, and 11 have sloping abutments; Figs 11 and 12 
 are adapted to resist a longitudinal strain; the last being a very simple combination in which 
 a piece of timber is let in below: Fig. 13 is a good form. It will be observed that the fore- 
 going examples have horizontal tables, and we shall next glance at some with tables at a 
 greater or less angle. 
 
 Fig. 14 represents perhaps the best form for an angular scarf without 
 keys. But it is not so strong as Figs. 5 and 6, or, as a tie, not half the strength of an entire 
 piece, as the joint is liable to fail under oblique pressure, and it is preferable for the bolts to 
 act on the surfaces of connection in a perpendicular direction. Scarfs with tables parallel to 
 the fibres of the wood also better resist a longitudinal strain: tearing asunder is however less 
 to be apprehended than the bending of the bolts. Fig. 15 shows the plates continued; but it is 
 noticeable in Fig. 14, as in Fig. 6, that the short plates are placed just where the greatest strain 
 takes place. Fig. 16 is a scarf greatly increased in length. In Figs. 17 and 18 tw r o other 
 forms are shown, but increasing the number of tables proportionately shortens the fibres, which 
 consequently resist less. Figs. 19 to 22 are more or less objectionable: the last is exceedingly 
 vicious; and placing the plates at the side, as in Fig. 21, weakens the joining. Where cross- 
 strains have to be resisted the square abutment on the upper sides of Figs. 23 and 24 is the most 
 
.101X1 N< is IN CARPENTRY. 
 
 i ;*o 
 
 preferable form , ns (So Xentral Axis, Chapter I, Division .%) the upper side is compressed while 
 t |„. | mV cr is extended, and in the former all oblique joints are to he discarded. The compressed 
 mid extended parts are divided by dotted lines. Making the joint as dotted in the lower parts 
 <»( Fie-. 2:1 and 24 would have diminished the power of resisting a cross strain. In applying 
 the torching examples, therefore, the reader must bear in mind that a joint for resisting a 
 longitudinal strain is unsuitable for a cross strain, and two varieties of forms have to be chosen: 
 when there is both a longitudinal and cross strain, the former should be most considered. Straps, 
 as in Fig. 23, are preferable to bolts for beams intended to resist a cross strain only, but they 
 must be fixed very tight. Bolts, of course, offer a great resistance to tension, but, if not of a 
 tolerable diameter, they will bend under the action of a considerable strain. On the continent 
 
 scarfs requiring a great amount of labour, its in the 
 margin, are often adopted, but they are greatly in- 
 ferior to the simple varieties. We may add that 
 the term trait <!e Jupiter is often applied to angular scarfs from their fancied resemblance to 
 forked lightning. 
 
 KEYED scares. Keys should be of hard wood with curled grain to 
 resist the indenting of opposite fibres. On Plate 22, Fig. I is the simplest form of keyed scarfs, 
 'flic tables are horizontal, their ends perpendicular, and the key is placed in the centre of the 
 combination, big. 2 is a better form. Were the key omitted there would be no occasion for 
 bolts, and the strength would be between one-half and one-third that of an entire piece. The 
 addition oT plates of course greatly increases the strength. If worked carefully, the pieces will 
 resist bending without the aid of bolts, but, on adding these, it is desirable previously to insert 
 a key in order to bring the joints to a bearing and the parts tightly together. Fig. 3 can be 
 executed with facility and is as strong as Fig. 2; bolts, however, must be employed. About 
 one-third the strength ot an entire piece will probably be a safe calculation for these three 
 scarfs, and the addition of plates increases the resistance. Figs. 4 and 5 have their abutments 
 at an acute angle with the horizontal surface of the table: the adoption of obtuse angles its dotted 
 in big. 4 is not to be recommended. In Fig. 5 two keys are shown together instead of one, 
 with doubtful advantage, big. (1 is an excellent example of a wedged step scarf of great strength, 
 which would be deteriorated were the keys placed as dotted. Figs. 7 and 8 are combinations 
 <>! straight and angular scarfs, big. 7 is a good form to resist a cross strain, the upper joint 
 being square and the lower angular: the plates are best continued. The labour of cutting the 
 kc\. as in big. S, is hardly worth while. In big. i) we have a scarf wholly sloping. The cir- 
 Mil.11 low, and that in big. 8 , are of continental derivation; but, as a general rule, square keys 
 mv least liable to play, shake and ultimately loosen: Fig. Ill is the best form of acute angled 
 '•••aiD with keys. Without plates it will be about equal to one-third the strength of an entire 
 l , ' ,<< ’ ^ Ml * 11111 equal to big. 1. Bolts should be square with the joints, and the angles in 
 big. in arc more easily splintered than those .in Fig. 1. Figs. I 1 and 12 are inferior to Fig. 10, 
 ilih"iigh 'tiling, and 1 igs. 13, 14 and In are least to be recommended. The remaining figures 
 arc good examples of French circular work. 
 
 It appears to us desirable to give bad forms as well as good; for, next to 
 pointing out that which is scientifically correct, is the utility of indicating things to be avoided. 
 
JOININGS IN CARPENTRY. 
 
 151 
 
 PERPENDICULAR TIMBERS. It must he obvious that many of (he scarfs 
 on Plates 21 and 22 are as appropriate for timbers placed perpendicularly as horizontally. 
 
 For instance, Fig. 5, Plate 21, is preferable for a post to 
 Fig. 14, as the joints of the last are more apt to splinter: 
 the ends may be angular. Again, Fig. 2 on Plate 22 is 
 more suitable for a pillar than Fig. 10. Square abutments 
 are to be preferred. The wood-cuts are forms for con- 
 tinuing posts in height: they arc taken from Krafft’s work. 
 
 We may remark in conclusion that keys and 
 bolts will invariably work loose if inserted in beams con- 
 nected with engines and having to resist intermittent strains. 
 They must therefore be dispensed with as much as pos- 
 sible, their use, strictly speaking, being only appropriate 
 in the case of the action of a steady, invariable force. 
 
 PIECES INCREASED IN DEPTH. 
 
 GENERAL PRINCIPLES. It is frequently necessary to increase the depth 
 of beams for various purpose's, and this is called building them up. However inclined we 
 may be to object to the phrase, it is now settled, and the invention of another which might 
 be more scientific would probably tend to produce confusion; besides it often happens that there 
 is more truth in the common sense acceptation of a term than in a rigorous scientific definition. 
 There are two modes of building beams, - viz., by lidding and keying ; and the difference be- 
 tween a built and scarfed beam consists that, in the former the pieces are laid on each other, 
 
 or joined tluepughout their length, while in the latter the lapping continues only a short distance, 
 being employed to increase the length. Built are stronger than scarfed beams, being generally 
 equal to a truss of the same depth; and the simplest methods are to be preferred. We have 
 noted the superiority of oak as a tie and that of hr as a post. Beams may therefore be greatly 
 increased in strength by making the parts stretched of oak and those compressed of fir. Built 
 beams placed horizontally will first be considered, and next those in a perpendicular position. 
 
 HORIZONTAL BUILT BEAMS. On Plate 23, Figs. 1 and 2 represent the 
 simplest and generally best form of built beams. Keys are inserted to prevent sliding. Fig. 1 
 is held together by bolts, and Fig. 2 by straps. It is obvious that the proper position of 
 both is near the keys, which are thus fully tightened and wedged-up. If the upper part of 
 Fig. 2 were slightly sloped on both sides towards the centre, the straps might be driven very 
 
 tight. The forms of keys shown in Fig. 3, and which are sometimes adopted in France, of 
 
 course involve much labour without corresponding advantage. So far as the various joinings 
 are concerned, the English are certainly superior to the continental artists. Beams arc often 
 built with a series of horizontal tables; Fig. 4 shows the most common form, and Fig. 5 is 
 another very usual. Professor Kobison remarks that a joggled beam, as Fig. 1, is stronger than 
 one scarfed, as Fig. 5, “in the proportion of the greater distance of the upper filaments from 
 the axis of fracture.” The form of Fig. 6 is not to be recommended, as failure will occur if 
 
JOININGS IN CARPENTRY. 
 
 ■ I i < r l 1 1 1 v injured or splintered. Making the angle as indicated to the right is also a bad practice, 
 inducing tearing-up. 
 
 By the adoption of Figs. 7, 8, and 9 a great increase of stiffness is often 
 obtained. Fig. I n, a French example, illustrates the introduction of scarfs. The piece at the 
 liutfom adds to die stiffness of the combination, as whenever it is desired to increase the rigidity 
 (if one piece of wood by the addition of another, this must be placed on the side which becomes 
 bv the strain. Fig. I 1 is tabled with keys; a wedge of hard wood is inserted with ad- 
 vantage at the upper part. Fig. 12 is an excellent English form. 
 
 Building beams with indents as in Fig. 13 and 14 is very usual; the for- 
 mer is preferable, as sliding is prevented. It will be perceived that the indents on both sides of 
 the centre of the beam incline towards it, that is where (if the timber is uniformly loaded) the 
 .'train acts, towards which the indents must invariably be directed. Fig. 15 is an application of 
 the 'Vstem to a curved beam; and Figs, lb and 17 are continental examples, two modes being 
 
 given in the former. Fig. 11 is preferable to Fig. 17. Beams are some- 
 
 times built as in the margin; also with several planks in lengths breaking 
 joint, as in Fig. 18. 
 
 VERTICAL built BEAMS are chiefly used for masts. On Plate 23, 
 Fig. 19 is a simple and excellent form, the two pieces acting well together - . Fig. 20 is one of 
 the connexions used with hooping in English dockyards, and Fig. 21 is adopted in France. 
 Bolts are employed for the latter, but they are apt to loosen, and we prefer the former. The 
 remaining figures arc foreign examples, some modified. Fig. 28 is a longitudinal section; the 
 transverse one being taken at A B. Elm joggles are often used, but very hard woods are apt 
 to work loose in acting on the softer fibres. 
 
 PIECES FOE MING RIGHT ANGLES. 
 
 PERPENDICULAR TIMBERS. On Plate 21, Figs. 1 to 3 show modes of 
 i "lim i ting an upright with a horizontal piece below. Fig. 1 is about the most common. 
 It i> cleai, however, that, il the projection and recess do not tit extremely accurately, the strain 
 "ill In "holly on the tenon, the horizontal sides being quite useless. Angles are therefore ofterr 
 bn turd as in fig. 2, the pressure being then more equable, provided care is taken in cutting the 
 i"int s( > *at the parts may meet closely. The joint drawn strong is preferable to that dotted, 
 ;m. il the lower piece is not very deep, it will be weakened by cutting too much into it; and a 
 '* UI P fint is liable to splinter. I he vertical piece must be kept quite perpendicular, 
 
 ■ i a li,_.it iiu filiation on one side will be very injurious. This may be obviated to some extent 
 by forming a circular joint, as in Fig. 3. 
 
 1 igs. 1 and .> illustrate what is called fox-tail ivedging, much employed 
 
 b> 'hip carpenters. Pieces made to fit very tight are often crippled in driving. In this joint 
 
 m0l *' C< 111111 h Rt the lower part than the tenon, forming in fact a descrip- 
 
 "" n . n| ,luvc,ai1 - l ' vo or more wedges of hard wood are next driven partly into the lower 
 
 | h , ' H ' n Axed into the mortice and forced down, the pressure at the 
 
 ,l "' ,n ° ltlCe Cailsln S thc wedges to rise in the tenon. By this operation the sides of 
 lorecd outward, and it is so firmly grasped that, if the wedges do not slip, the 
 
PIECES FORMING RIGHT ANGLES. 
 
 153 
 
 enon must break before the two pieces can be separated: the slope in the mortice ought to 
 be accurately calculated. 
 
 Figs 6 and 7 show methods of connecting a horizontal with a perpendi- 
 cular piece of timber. The quantity of insertion must be proportioned to the strain on the 
 horizontal piece; but, at the same time, the vertical piece must not be unduly weakened. Double 
 tenons may be used if the breadth of the timber is great. The pin tends to prevent the se- 
 paration of the pieces. It should be of some hard wood. 
 
 HORIZONTAL TIMBERS WITH THE END OF ONE TERMINATING AT A POINT 
 IN THE LENGTH, OR AT THE END OF THE OTHER. The usual mode of connecting binders with 
 girders will form a good illustration of the above. Fig. S shows the most common form of the 
 joint which is made with a mortice and tenon: the sloping upper part is called a tti.sk, and these 
 tenons have thus received the name of tusk tenons. The plane from which the tenon advances 
 is termed the shoulder; and the measure of the joints by transferring, in order that they may 
 fit one another, is taken with a counter gauge. 
 
 It will be perceived in Fig. 8 that a very firm support is afforded to the 
 binder. Care must be taken to commence sinking the mortice as near as possible to the upper 
 part of the girder; but, as the tearing off' of the tenon of the binding joint has to be guarded 
 against, the mortice must be brought a little down. The reason why the upper side of the 
 girder is to be preferred for morticing is obvious when we remind the reader that it becomes 
 concave. The strains are greatest at the top and bottom of the girder, lessening gradually to- 
 wards the middle where the mortice is shown deepest. Tenons may be inserted at about one- 
 third of the depth from the lower part, and be about one-sixth of the depth. Oak pins are 
 often driven in, and sometimes iron bolts. 
 
 Figs. 9 to 17 are from Emy’s Treatise. Fig. 18 illustrates the usual mode 
 of connecting joists with trimmers: the shoulders are square. The plans Figs. 19 and 20, from 
 Smith’s work, illustrate dovetails on wall plates. They are however objectionable forms, involving 
 too much labour, and being very apt to loosen. The same may be said of Figs. 21 and 22, 
 although they are certainly improvements. Fig. 23 is the best form for a dovetail, called by 
 the ’French queue cVhironde, or swalloics tail. Its simplicity is its recommendation; there is 
 comparatively little labour; and it is not so apt as the previous examples to work loose. Fig. 24 
 is lapped or halved. The insertion of a bolt will answer the same purpose as the dovetail 
 (although in a lesser degree) in preventing drawing out in a longi- 
 tudinal direction. This end is better obtained as in the sectional 
 elevation Fig. 25. The bolt will keep the pieces down; or, as 
 in Fig. 26, an angle may be formed; this however will probably 
 soon splinter. Sometimes, as in the plan Fig. 27, a wedge is driven 
 in. Or the parts may be as in Fig. 28, either as shown strong or 
 dotted. Dovetails arc cxeeedingly strong, because the tenon gradually 
 widens, preventing it drawing out through the space whence the di- 
 verging lines start; but the lower piece of timber must be well sup- 
 ported. If this is not the case, a mortice and tenon is preferable. 
 
 Figs. 29 to 34 represent the cogging, caulking, or cocking of 
 
 xx 
 
 Carpentry. 
 
PIECES FORMING ACUTE OR OBTUSE ANGLES. 
 
 154 
 
 tic-beams and wall-plates, the former being cogged down upon or over the latter. The indenting 
 parts must be carefully fitted. Fig. 32 is the preferable form, a groove being cut across the 
 tibres of the tie. The dovetail Fig. 33 will be formed to work loose. Figs. 35 to 37 are 
 plans of joints suitable for angles. 
 
 PIECES CROSSING. Pieces crossing one another may be simply lapped, 
 halved, or notched and dovetailed. Figs. 38 to 41 comprehend several illustrations. 
 
 Figs. 42, 43, and 44 show modes of erecting timber walls in Russia and 
 Switzerland. The pieces are let into one another alternately. 
 
 PIECES FORMING ACUTE OR OBTUSE ANGLES. 
 
 HORIZONTAL TIMBERS. On Plate 25, Figs. 1 to 6 represent examples 
 of pieces meeting otherwise than at a right angle. The first three are the best forms; Fig. 6, 
 although common, is very unscientific. The instances in which these angles occur are those of 
 wall plates and angle ties, the last especially to roofs. Probably the best form of connecion, 
 after all, is simply to carry the piece across as shown by the dotted lines in Fig. 3, and halve, 
 la]>, or notch the two together. Fig. 7 shows two pieces crossing one another. 
 
 FEET OF RAFTERS. The joint formed at the foot of a rafter is pro- 
 bably the most important in the whole range of carpentry. If the bearing is partial, the ill con- 
 sequences are soon perceived. If it is upon an angle, it will become crippled, or indent the 
 tie, causing settlement. The shrinkage of timber must be borne in mind, as the joint is thus 
 apt to become loose. By giving the foot of the rafter a sufficient hold, its fibres are all brought 
 into action; but ties are often made of such small scantling that this is difficult, more especially 
 as the rafter presses at the end of the beam where its extending effects cannot be allowed to 
 occur to any great extent without imminent danger to the stability of the whole combination; and 
 the tie itself cannot be lengthened on account of exposure to atmospheric influences, and con- 
 sequent decay. “Carpenters have therefore given up long tenons, and give to the tie of the 
 tenon a shape which abuts firmly in the direction of the thrust, on the solid bottom of the 
 mortice, which is well supported on the under side by the Avail plate. This form has the 
 further advantage of having no tendency to tear up the end of the mortice. The direction of 
 a joint between a rafter and a tie beam ought to be made precisely perpendicular to the true 
 thrust of the rafter; for, in the first place, unless Ave trust either to the friction, or to straps, the 
 bearing cannot be more nearly horizontal than this without danger of the rafters sliding out- 
 ward.-; and, in the second place, if avc made it more nearly vertical, we should lessen the ver- 
 tical pressure on the end of the tie beam immediately beyond the joint; a pressure which gives 
 firmness to the Avood, bv pressing its fibres more closely together, and increasing their lateral 
 adhesion, or rather internal friction. If, however, the tie beam Avere not deep enough to receive 
 the "hole of the rafter so terminated, Avithout too great a reduction of its depth, it Avould be 
 proper to make the joint a little flatter, or more horizontal, and to restrain the end from sliding 
 upwards by an iron strap fixed in a proper direction.” ( Encyclo . Brit., art. Carpentry.) 
 
 On Plate 24, Fig. 9 is a preferable form to Fig. 8, which last is cut too 
 di i p into the timber, and a tie of small scantling Avould thus be considerably weakened. In 
 1 >g- I' 1 there is a tendency to rise upwards, unless a bolt or strap is employed, or the dotted 
 
PIECES FORMING ACUTE OR OBTUSE ANGLES. 
 
 155 
 
 tenon is formed. By forming a tenon the tie is not weakened to the extent it would be were the 
 rafter to have a bearing throughout, as in Fig. 8, while a very firm hold may be obtained as in 
 Fig. 11, which is a very excellent joint. 
 
 In Fig. 12 the outer angle is too weak, and it is apt to splinter or break 
 away if, through any shrinkage of the other parts, the bearing were thrown in a great measure 
 upon it: continuing it a little distance into the tie would be preferable. Fig. 13 is the joint recom- 
 mended by Price in his British Carpenter. It has been repeatedly copied in various books as the 
 true joint. The angle of the tenon is rather oblique to the thrust, and what merit there is in this 
 joining has been greatly exaggerated. Fig. 14 is much better, and it may also be easier exe- 
 cuted. Fig. 15 is hardly so good as the one before mentioned. A very fair resistance is offered 
 by Figs. 16 and 17. Figs. 18 to 20 are more or less objectionable; and the remaining examples 
 are to be preferred. In Fig. 25 an iron strap is shown to a very good joint. One tenon, we 
 may observe, is preferable to two, whatever may be the thickness of the rafter, because of 
 the liability to unequal bearing on account of shrinkage, ill fitting, or careless workmanship. 
 The visible joints are generally most efficient in sustaining the actual pressure. 
 
 Both Robison and Tredgold, together with Perronet, are in favour of 
 curved joints. Dr. Young says: — “Any general curvature of the joint must be totally useless; 
 but a judicious workman will make it somewhat looser below than above, when there is any pro- 
 bability that the rafters will sink, taking care, however, to avoid all bearing too near the surface, 
 lest it should splinter, and, for these reasons combined, making the end a little prominent somewhat 
 above the middle of the surface which rests on the abutment.” Figs. 26 and 27 show curved joints. 
 
 JOINTS TO COLLARS, KINGS, RIDGES, ETC. Figs. 28 to 32 shew various 
 modes of connecting collars with principals by halving. Fig. 28 is the simplest and will pro- 
 bably be found to be stronger than any of the others, although the dovetailed joint Fig. 31 
 offers a great resistance to a strain tending to draw the pieces apart. Fig. 29 is a good form, 
 
 The butting of a principal, or strut, against a 
 king or queen post is preferable plain and perpendicular to one piece, 
 as in Fig. 33, and not as in Fig. 34, although Fig. 35 does not appear 
 so objectionable as the second. Fig. 36 illustrates the employment of 
 curved joints, against which we are decidedly inclined. Figs. 37 and 38 
 are not desirable forms, the last particularly, as the tenons will al- 
 ways be liable to break away. Fig. 39 shows a joint for a queen post 
 roof. In Fig. 40 the arrangement is preferable to that in Fig. 39, or 41. 
 Ridges may be fixed as in the margin: the third, fourth, fifth, and sixth 
 figures are from Rondelet. We add forms of joints for the foot of 
 a king post from Price, to be carefully avoided. Indeed, the bad joints 
 may be said to be almost as instructive as the good. 
 
 IRONWORK. 
 
 GENERALLY. The practice of introducing plates, bolts, and straps at the 
 joints of framing has been steadily increasing of late years until it has now become almost 
 
1 56 
 
 REMARKS ON TRONWORK. 
 
 universal. There can he no doubt that the strength and stiffness of joinings are thus consi- 
 derably increased; but we do not always perceive that attention to scientific principles without 
 which the employment of straps, bolts, etc., can be of little real utility. Where the use of ironwork 
 can he avoided, by the skilful formation of durable joints, fully answering the purpose of 
 holding’the parts of a frame together, the extra strength gained is hardly a sufficient excuse 
 for its introduction. 
 
 PRINCIPLES. In introducing iron straps or bolts, the direction of the strain 
 must first he determined. This is to be resolved {See Composition and Resolution of Forres, 
 
 < Inipter 2, IHvision 3.) into a strain parallel to each piece and perpendicular to it; and the strap 
 or holt should resist as nearly as possible in a parallel direction to the piece. The bolt at the 
 foot of rafter must not be too upright, or, as the roeff settles, it will gradually loosen; and, as the 
 rafter inclines to spread along the beam below, an oblique position is best for the strap or bolt. 
 The method is so to fasten the foot that it cannot draw from its place. It is not sufficient 
 merely to secure the rafter down, but the horizontal thrust must be met. A strap should be 
 notched square with the back of the rafter; and, by having an eye bolt through the tie, it allows 
 easy motion, following the rafter without danger of crippling. A branched strap should also 
 have a joint to allow freedom of action. Iron is generally preferable to wood for pins, on ac- 
 count of the large bore required by the latter material in order that it may be sufficiently strong, 
 while a piece of metal may be adopted of very small section. In the Middle Ages oak pins 
 were much used; but the timbers also were of this wood and of large scantlings, while at pre- 
 sent the smallest possible sizes are employed, and consequently it becomes necessary very care- 
 fully to avoid cutting into them at the joints. Price remarks truly that: — “If you use a round 
 bolt, it must follow the auger, and cannot be helped; by this helping the auger bole, that is, 
 taking off the corners of the wood, you may draw a strap exceedingly close, and, at the same time, 
 it embraces the grain of the wood in a much firmer manner than a round pin can possibly do." 
 
 EXAMPLES. On Plate 26 numerous examples of the application of iron- 
 work arc given. Figs. 1 and 2 illustrate the use of bolts; and in Fig. 3 a strap is substituted. 
 Iron plates are shown in Figs. 4 and 5. Fig. 4 is suitable for the foot of a rafter, and Fig. 5 
 for struts, a bolt being substituted for the timber king post. The plates are bolted down at 
 each end through the tie, and they are also indented. Figs. 6, 7, and 8 illustrate some of the 
 best forms of cast iron heads. In Figs. 6, 10 and II modes of connecting king posts with ties 
 arc shown; in Fig. 9 two nuts are inserted, one from the face of the post and another from 
 its side: in Fig. 10 a strap is substituted. Fig. 11 has a forked strap securing the struts. Fig. 12 
 'hows a form ol strap for connecting the queen post, collar and rafters. The remaining figures 
 hardly need explanation. 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATE 21. SYSTEM OF STYERME. The introduction of what Styerme 
 called pendant keys is the main feature of bis system. Such roofs are very suitable to carry 
 Hoois, heavy loads, machinery, etc., suspended; and the section given is suggestive in this 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 157 
 
 respcet. It is not improbable that the idea of the principle was derived from the Argentina roof 
 
 on Plate 17. In the margin are 
 two illustrations of the application 
 to bridges of Styerme’s system. 
 
 SYSTEM OF LAVES. 
 M. Laves was architect to the 
 King of Hanover: his system is 
 simple, light and economical, but 
 has not been extensively prac- 
 tised, the fact of its having been 
 patented on the continent ac- 
 counting in some measure for the 
 last circumstance. The reader 
 will call to mind our observations on the neutral axis of beams {Chap. I, Dir. .7.) As in Fig. 2, 
 Laves sawed his beams asunder and made the upper piece rather deeper than the lower, on the 
 supposition that the neutral axis is nearer the bottom, but Emy is of opinion that the two shonld 
 be equal, founding this conclusion on the results of experiments made in 1840, by order of the 
 French government, under the joint inspection of himself and M. M. Emmery and Riet. M. Laves 
 
 also published conclusions derived from many experi- 
 ments, tending to demonstrate the superior stiffness of 
 bis beams, and these conclusions were partly confirmed by 
 the commissioners. Figr. 1 is a roof executed in llano- 
 ver under the supervision of M. Laves, the diagram in 
 the margin showing one mode of fixing the ends. In Fig. 3 the principals of the roof are cut 
 
 and trussed instead of the tie; of course this might 
 be done to both. Figs. 4 are applications to posts, 
 not however to be recommended. Adjoining is a 
 bridge designed by Laves. 
 
 PLATE 2H. POoFS OF THEATERS IN PARIS. M. LENOIR, ARCHITECT. 
 
 PORTE ST. MARTIN. This roof is excellently 
 adapted for the required purpose, and the large 
 struts act in discharging the loads on the floors. 
 The side galleries are supported by very simple 
 means; and the reader will remark the general 
 application of the system of Styerme. There are 
 two floors well contrived in the roof: the details 
 A and B fully explain the construction of the 
 respective parts. 
 
 OPERA DES ARTS. This is a 
 rather complicated but very instructive example 
 of a theatre roof designed by the above named 
 architect. The various thrusts are well disposed 
 
I5S 
 
 FLOORS GENERALLY. 
 
 an d the timbers calculated to carry a great weight. Over the proscenium is a large roof for 
 fitting the scenery. 
 
 On the preceding page is a section of the roof of the Theatre des Italiens 
 in Paris, designed by M. Hertier. The arrangement of the double braced principals is very sug- 
 gestive, and the roof is of considerable strength. 
 
 CHAPTER III. 
 
 FLOORS GENERALLY. 
 
 DEFINITION. In its widest sense, the word Floor is applied to all the 
 rooms on the same level or story in a building. But, with a more restricted meaning, it refers 
 to the horizontal surface in houses, whether covered with boards or other materials, for walking 
 upon, to carry stores, etc., and also to the whole of the work called carcase or naked flooring , 
 serving to support the platform above and the ceiling below. Floors are, in fact, horizontal par- 
 titions, separating rooms on different levels, and supported by the vertical partitions which enclose 
 and divide rooms on the same level. 
 
 VARIETIES. The least expensive and complicated floors consist of a 
 series of beams, about a foot apart, laid across from wall to wall. They are now made much 
 deeper than wide in order to secure a certain amount of stiffness; but in the Middle Ages 
 squared timber was usually adopted to obviate the liability to twist and bend to which those 
 beams especially which are less in width than half their vertical height are peculiarly liable 
 unless counteracting means are adopted. At right angles to the beams, flooring boards are 
 nailed, forming the platform above, and laths are attached below for the ceiling. 
 
 Joists, joisting, floor of joisting, are technical phrases applied to timbers 
 supporting the boarding, except when the bearing is so great that it is requisite to introduce 
 larger pieces to carry the joists. r I hese latter are supported at the end by wall plates, the objects 
 of which are, first, to afford a means of securing the ends of the joists by cogging, and secondly, 
 to equalise the bearing on the wall. It is obvious that, if the joists were laid at once on the wall 
 (as is sometimes done on the continent) without the interposition of plates, the brick, or stone- 
 work, is borne upon very unequally, and irregularities of settlement are likely to occur, causing 
 unevenness in the floor, and cracks in the ceiling. Such floors, however, as the above, can- 
 nut meet all requirements. 1 he bearing, or load, may be so great, that it would not be 
 piudciit to trust to a single row of timbers. In the latter also the level character and finish 
 cl the ceiling f, an rarely be calculated upon with much certainty; and again, the passage 
 of sound is much facilitated. Accordingly, to obviate these defects, floors are made what 
 i< called double. limbers of large scantling are introduced supporting the joists for the 
 Homing boaid> above, and those for the ceiling laths below. These large pieces are placed at 
 more or less proximity, according to peculiarities of individual cases; and they are called 
 mt,,. Hi bunt mg joists. 1 1 ridging joists is the name given to the smaller timbers, which bridge 
 "\ci the binders at right angles, those below being ceiling joists. The space to be floored 
 
FLOORS GENERALLY. 
 
 159 
 
 
 
 may be so large that even the introduction of binders will not be sufficient. Still larger tim- 
 bers, called girders, are therefore employed. These may be considered as standing in the place 
 of walls, and the binders are framed into them. In such floors, there are four sets of timbers, 
 viz, girders, binders, bridging joists, and ceiling joists. Girders are often not sufficiently strong 
 to answer their required purpose, and they are trussed in various ways. Where sufficient depth 
 is allowed, girders may be strengthened to almost any required extent; and they ai’e sometimes 
 so strongly framed as to become a species of trussed partition. 
 
 Floors are occasionally constructed on a very peculiar system, consisting 
 in the employment of numerous short timbers. Serlio appears to be the first author who gave 
 designs for such constructions. This architect died in 1552. He described and illustrated the 
 method in the first book of his Architecture. It was suggested by an ancient amusement which 
 consisted in placing three or four knives so that their blades crossed, and being carried at the 
 handle ends, they thus supported one another. It is often difficult to obtain timbers of sufficient 
 length, not only for single but also for double flooring. Again, in polygonal and circular rooms, 
 there is great waste in cutting the wood. Some pieces must be much longer than others; while 
 
 the thickness of the floor is required 
 to be equal. Serlio therefore took a 
 hint from the crossed knives, and 
 framed timbers of different lengths 
 into one another. As is perceived in 
 the margin, by the exercise of a little 
 skill, short pieces, comparatively useless, 
 may thus be made available to con- 
 struct very strong and durable floors. 
 Such are common in Holland, and 
 the second is designed by INI. Mandar. 
 In Godfrey Richard’s Palladio are two 
 diagrams of floors of this description 
 executed at Somerset House, and al- 
 luded to as “a novelty in England.” 
 On Plate 29 we have put four exam- 
 ples of the system of Serlio. Fig. 4 
 is from a chateau de plaisance of the 
 King of Holland: and Figs. 4 A and 
 
 4 B are details of the connections. 
 
 Floors have been constructed of planks without any supporting joists or 
 timber work. Rondelet has described in his Id Art de Bdtir (Vol. 4, Page 154) a very extra- 
 ordinary floor of this description at Amsterdam, in a room 60 feet square. On Plate 29. Figs. 5, 
 one-half of the plan is shown, together with the section. The planks are of fir. As will be per- 
 ceived, the wall plates are of great strength secured by means of straps at the angles and rebated 
 for the boarding, of which there are three thicknesses of inch 1 /. 2 boards. The two lowermost 
 thicknesses are laid diagonally in reverse directions, and the third parallel to one side of the 
 
FLOORS GENERALLY. 
 
 1 60 
 
 room. The rise is about 2* 2 inches; and all the boards are nailed, grooved, and tongued together. 
 Trah'old observes: “This example shows how much may he accomplished by a well-disposed 
 
 bond, and firm connection of parts. The floor partakes of the nature of a thin plate, supported 
 round the edges.” We have great hesitation in differing from so respectable an authority. But, 
 in our opinion, this floor ought not to be considered in the light of a plate. Its stability is due 
 to the curved form, it being, in fact, a very Hat arch. That this was the principle the constructor 
 had in view will most probably be allowed by the reader who observes how admirably the thrust 
 is provided for by the formation of the rebates and the disposition of the straps. 
 
 ot fir; and the third is the floor of the grand antichamber of the chateau of the 
 
 It is impos- 
 sible to cite the 
 whole of the me- 
 thods ofconstruct- 
 ing Hoors. Pen- 
 dentives are some- 
 times introduced 
 with open work 
 below, variously 
 framed into com- 
 partments, in or- 
 der to produce 
 an ornamental 
 effect. 
 
 W e have ad- 
 ded in the mar- 
 gin a few curious 
 modes of con- 
 struction. The 
 Hrst is executed 
 in a granary at 
 Berne in Switzer- 
 land; the second, 
 in the Hospice in 
 the same city, is 
 Duke of Wurte tn- 
 
 berg at Stuttgard. 
 
 f i EXERAL REMARKS. Single, double, and framed flooring are the 
 time gi eat varieties; and there can he no doubt that, for ordinary purposes, they are peculiarly 
 suitable. Sometimes Hours of this general description are set out on corbels. Building tim- 
 bot> into a wall is more or less objectionable, and a thin one is liable to be much shaken. The 
 wood is very liable to rot, and a case recently occurred of the fall of a great mass of brickwork 
 "'v ing to tin de< «i\ of a plate at the lower part. It is thus preferable to build out sleeper walls 
 in basements to carry the plates supporting joisting. 
 
FLOORS GENERALLY. 
 
 161 
 
 Brickwork is often corbelled out for this purpose on each successive floor, 
 or iron corbels are introduced. Where flues are very numerous, iron ends are used at the ex- 
 tremities of the joists, when the hearing is interrupted to a great extent: girders decayed at the 
 ends are often renewed in a similar manner. 
 
 The extremities of the girders and binders used in floors are conti- 
 nually observed to be decayed, while the remainder, exposed to the air, is found to be 
 in excellent preservation. Whether or not mortar is near the beams there is a certain 
 humidity in the walls tending, sooner or later, to induce decay. One of the best re- 
 medies consists in leaving a space to which the air has free access all round the beam. 
 Emv suggests having holes bored through the stones so as to create a current. Setting the 
 ends of the timber out on corbels is a good practice, but not always feasible. In some ancient 
 edifices the timbers are continued entirely through the walls so as to expose the ends; but in 
 such cases care must be taken to protect them from the rain. Plates of lead, zinc, or copper, 
 are often adopted to separate the wood from the stone' or brickwork. On demolishing a part 
 of the chateau 'of Roque d’Ondres in France the ends of the oak beams built into the wall 
 were found to be enveloped in cork, and in perfect preservation, although upwards of six 
 hundred years old. In the church of the Benedictines at Bayonne the fir beams were on 
 examination found to be quite worm £aten, except the extremities, which were covered with cork 
 in the same manner as those of the chateau of Roque. These facts meritf particular attention. We 
 are indebted for them to Emy. As he remarks, — “We cannot doubt that the excellent preser- 
 ! ' vation of the extremities of these beams was solely due to the cork, of which the impermeability 
 is well known, since it is employed for vessels to contain all sorts of liquids, and to close bottles 
 containing spirituous liquors. This simple proceeding, the excellence of which is proved and 
 which is of slight cost, merits adoption, above all for edifices in which the carpentry is desired 
 to be of long duration.” 
 
 Floors should be kept about three quarters of an inch higher in the middle 
 of the room than at the sides. Ceilings also should rise thus much in the centre above the line of 
 the cornice. In very large rooms the rise should be rather more, from one to one and a half 
 inch, as there is sure to be more or less settlement. 
 
 It is a good plan to plane the upper edges of joists, as the floors are then 
 much smoother than when the joists are left rough as they come from the saw. Furring up 
 consists in laying slips on those parts of the joists which are below the general level, thus re- 
 moving irregularities. The }?hictice is not to be recommended, as the chips give way under 
 partial pressure, causing the disagreeable creaking noise produced when walking over them. 
 Furring down is nailing fillets on the lower edge of the joists to receive the ceiling laths . 4 
 Where the joists are very thick, such fillets aid the key of the plaster. For a similar motive the 
 laths should be narrow, if it is desired to have a perfect ceiling. The fillets are techni- 
 cally named furrings. 
 
 . 
 
 . 
 
 Carpentry. 
 
 XXI 
 
CHAPTER IV. 
 
 SINGLE, D0UB1 
 
 AND FRAMED FLOORS. 
 
 SINGLE FLOOKING. In this there is a series of single joists laid 
 at (lie ends on plates. It is sometimes made partly double, to hinder the passage of sound and 
 
 obtain a superior ceiling, every 
 third or fourth joist being about 
 one inch deeper than the others 
 and taking ceiling joists: in the 
 lowermost figure the ceiling is 
 quite independent of 1 the floor. 
 Single flooring is suitable for hear- 
 ings up to 25 ft, and, with the 
 same quantity of timber, is much 
 stronger than framed; but, if a 
 good ceiling is required, the bear- 
 ing ought not to exceed 15 feet. The joists should rest from 4 to 9 ins. on the walls, and 
 1 I ins. is their usual distance from centre to centre. Those of much greater depth than thick- 
 ness, or of protracted bearing, are apt to buckle, and this is obviated by strutting, the diagrams 
 exhibiting the herring bune kind skew nailed to the joists. It would improve the rigidity of the 
 ordinary combination to notch the struts slightly into the joists, or nail on triangular fillets for 
 abutments. Wrought strutting is of boards cut to fit accurately. Where the bearing exceeds 
 , 8 ft. strutting should be used, and another row 
 
 for every additional 4 feet. To prevent the trans- 
 mission of sound, sound boarding and pugging are 
 adopted, the latter consisting of coarse plaster 
 and chopped hay, laid about 1 , / 2 in. thick, on short 
 narrow boards, inserted between the joists and 
 resting on fillets about one inch broad and three- 
 quarters thick; sometimes laths about one or one 
 and a half inch wide, with intervals to key the 
 pugging, are adopted. In Paris flooring is fre- 
 < 1 1 1 < 1 1 1 1 \ constructed, as in the wood-cut, with laths, plaster and tiled floors. Stairs, fire-places 
 
 and Hues often interrupt the joists, and in such cases the two 
 outermost, called trimming joists, are made rather stronger than 
 the others, and a cross piece, or trimmer, is inserted, into which 
 the shorter joists are morticed. The operation is called trim- 
 ming; and it is customary to add one-sixth or one-eighth of 
 an inch to the thickness of the trimming joists and trimmer 
 
 r 9 .s .RJi ikisoufri' 
 
 '.TjiT'w t ilTi "nur 
 
 .. T — 
 
 
SINGLE, DOUBLE, AND FRAMED FLOORS. 
 
 1G3 
 
 for each joist supported. Ceiling joists ought not to be less than 2 ins. thick; and they are 
 
 put at the same distance apart as the 
 joists. As in the margin, by means of 
 boards, a panelled ceiling may be ob- 
 tained at small cost. 
 
 SCANTLINGS. It is difficult to lay down invariable rides, as no two 
 pieces of wood have precisely the same resistance. Tredgold has given various formulae, but 
 we deem it preferable to enumerate some scantlings sanctioned by practical experience, as it is 
 well known that few builders calculate the strength of joisting. The figures below are the 
 lowest that can, generally, be safely adopted; and, if the joists are less than 2 ins. thick, they 
 will split on driving the nails. The loading may usually be taken at 120 pounds per foot super, 
 if calculations are made. 
 
 Length. 
 
 Inches. 
 
 Length. 
 
 Inches. 
 
 5 Feet . 
 
 . . 5 
 
 X 2 
 
 15 Feet .... 
 
 9' 
 
 2 2*2 
 
 6 „ 
 
 . . 5 '/a 
 
 X 2 
 
 16 „ .... 
 
 10 
 
 X 27a 
 
 8 „ . 
 
 . . .. G 
 
 x 27 * 
 
 18 „ .... 
 
 11 
 
 X 2* 2 
 
 10 „ . 
 
 . . 7 
 
 X 2 Va 
 
 20 „ .... 
 
 12 
 
 X 2*/a 
 
 12 „ . 
 
 . . 8. 
 
 X 2 */ a 
 
 22 „ .... 
 
 12' 
 
 2 x 2 * 2 
 
 14 „ . 
 
 . . . 9 
 
 x 2 7 2 
 
 24 „ .... 
 
 13 
 
 X 3 
 
 Plates 4 X 3, 4 X 4, or 4 X 5 Inches. 
 
 DOUBLE FLOORS. These have binders supporting bridging and 
 ceiling joists. In what is called pully morticing a chase is made in the binders to receive the 
 
 tenons of the ceiling joists, which are then driven 
 up into place. Morticing the binder, especially 
 at the lower part, weakens it, but the upper part 
 may be cut into without danger, provided it is 
 filled with an incompressible substance, as it is 
 in a state of compression, while the lower part is in tension (See Page 117.) 
 
 SCANTLINGS. It is the practice with some to make binders half as 
 thick again as common joists. From 6 ins. bearing on the wall will suffice; and 5 or 6 ft. is 
 the ordinary distance apart. Binders adjoining walls are usually two-thirds the thickness 
 of the others, or a slightly defective timber is chosen. Plates may be 5 X 5, 6 X 5, or 
 7 X 5 ins. The following scantlings, deduced from our own observations, should rarely 
 be decreased. 
 
 Length. 
 
 Inches. 
 
 Length. 
 
 Inches. 
 
 5 Feet 
 
 . . 57 2 
 
 X 4 
 
 16 Feet 
 
 . . . . 11 X 67a 
 
 6 „ . 
 
 . . 6 
 
 X 4 
 
 ■ 18 „ 
 
 ....12X7 
 
 8 „ . 
 
 . . 7 
 
 X 5 
 
 20 „ v 
 
 . . . . 13X7 
 
 10 „ 
 
 . . 8 
 
 x 51/2 
 
 22 „ 
 
 ... 14 X 7 7/2 
 
 12 „ . 
 
 14 „ . 
 
 . . 9 
 
 . . 10 
 
 x 51/2 
 
 X 6 
 
 24 „ 
 
 ....15X8 
 
SINGLE, DOUBLE, AND 1 
 
 framed floors. 
 
 
 Ceiling Joists. 
 Inches. 
 
 Length. 
 
 Inches. 
 
 . 2 X 2 
 
 10 Feet . . . 
 
 . 4 X 2 */ 2 
 
 . V 2 X 2 
 
 12 „ ... 
 
 . 4V-2 X 2 Vo 
 
 . 3'/ 2 X 2 l / 4 
 
 
 
 U ',1 
 
 Length. 
 
 4 Feet . 
 
 G „ 
 
 DOUBLE FRAMED FLOORS. These have girders in addition to the 
 
 timbers last described. Bridging and ceiling 
 joists are carried by binders framed into the 
 o-irders. On Plate 24 numerous modes of con- 
 necting girders and binders are given. As 
 the -weight of the floor is concentrated at the 
 points where the girders rest, they should not be 
 
 placed over openings, such as doors and windows, unless on strong arches, or timbers throwing 
 
 the pressure on piers sufficing to carry the delectation of 
 the burdens. The air ought to circulate freely round 
 the ends, by the adoption of such contrivances as in the 
 margin; and we advise the use of stone instead of wood 
 plates. Sawing beams down the middle, reversing and 
 bolting together the two pieces is an excellent practice, 
 as a positive proof is afforded of the state of the inside, 
 and the timber becomes seasoned. A rolled wrought 
 iron flitch, uniform in depth with the girder, may be bolted in. 
 
 It is often dificult to procure timbers sufficiently large for girders, and 
 they are therefore frequently trussed, or converted into a sort of framework when the bearing 
 is much above 20 feet, the pressure being thus transferred to the walls and sagging prevented. 
 
 From the slight incli- 
 nation of the oak struts 
 in the two first diagrams, 
 great pressure is thrown 
 on the abutments, and, 
 unless these are very 
 strong, the combination 
 will fail Cambering de- 
 cidedly increases the 
 stiffness of a girder, and 
 it should be about half 
 an inch for every ten 
 feet, but the forcing is 
 apt to cripple the timber 
 and injure its natural 
 elasticity. The third and 
 I "nth figures arc very good trusses in which the posts and abutments are of wrought iron and 
 
 r — 
 
 
 
 
 
 
 1 — i? — 
 
 — i — 
 
 — 
 
 
 — 
 
 —LH q 
 
 
 
 
 
 
 Jd 
 
DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 165 
 
 the struts of wood, stiffer than the girder: below a plan is given. In the sixth figure an iron 
 head, abutments and rod are shown, rendering the truss very rigid, as a stronger material than 
 the timber is employed, which must be adopted effectively to truss a girder if its depth 
 cannot be increased. 
 
 SCANTLINGS. The following are about the lowest; and, as in those 
 previously given, fir only is meant. 
 
 Length. 
 
 
 Inches. 
 
 Length. 
 
 Inches. 
 
 10 Feet . . . 
 
 8 
 
 V* X 7 
 
 24 Feet .... 
 
 15 X 11 Vs 
 
 12 „ . . . . 
 
 10 
 
 X 7 
 
 26 „ .... 
 
 16 X 12 
 
 14 „ . . . . 
 
 11 
 
 X 7 1 2 
 
 28 „ .... 
 
 16 X 12'/, 
 
 16 „ . . . . 
 
 12 
 
 X 8 
 
 30 „ .... 
 
 16 X 1 3 r / 2 
 
 18 „ . . . . 
 
 13 
 
 X 8 V 2 
 
 32 „ .... 
 
 17 X 13'/ 2 
 
 20 „ . . . . 
 
 13 
 
 X 10 
 
 34 „ .... 
 
 18 X 14 
 
 22 „ . . . . 
 
 14 
 
 X 11 
 
 
 
 Distance apart about 10 ft.; and bearing 9 to 12 ins. 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATE 30. CARLTON CLUB HOUSE, PALL MALL, LONDON. SYDNEY 
 SMIRKE, A. R. A., F. S. A., ARCHITECT. This skylight is of a very simple, inexpensive descrip- 
 tion, and may serve as a model for those of similar character. The following arc the scantlings 
 
 of the timbers: — 
 
 Uprights 4 X 4 Inches. Sill 8 X 4 */ 2 Inches. 
 
 Binders 9 X 6 „ Head over Sashes . . 6 X 4 „ 
 
 Plate below Sill ... 4 X 4 „ Joists over Skylight . 5'/ 2 X 2 '/ 2 „ 
 
 “A. is a zinc valve, formed as an inverted cone, drawn up and down by 
 a line from below. The strong lines shows its position when down, or closed; the dotted lines 
 show it up, or open. When up, it is to admit air by the circular opening B. This opening is 
 to be continuous all round, the covering C being supported by standards at intervals. Fine 
 wire gauze is to be fixed outside the aperture B all round.” ( Specification .) The skylight is 
 covered with zinc. 
 
 SCHOOL AT TAMWORTH, FOR SIR ROBERT PEEL, BART. SECTIONS 
 OF ROOF OVER SCHOOL ROOM. This is also designed by the above distinguished architect, 
 and is a remarkably compact piece of construction of considerable strength. 
 
 Arched Ribs . . 10 X 4 ! / 2 Inches. Common Rafters ... 5 X 3 Inches. 
 
 Principals ... 8 X 4 1 / 2 • „ Plates 4 X 4 „ 
 
 Lower Rafters . 7 '/ 2 X 7 „ Ridge 9 X 5 „ 
 
 Collar .... 7 1 / 2 X 7 „ Purlins 7 X 7 „ 
 
 The remaining scantlings are on the Plate. 5 / 8 Inch bolts, tiled covering, 
 and plaster under battening; iron dowels 1 X 3 4 inch at junction of ribs with corbels. 
 
CHAPTER V. 
 
 P A R T I T IONS. 
 
 DEFINITIONS. In carpentry the word Partition applies to the framed 
 vertical timber work separating the rooms in- a building, and either lathed and plastered or 
 
 boarded. The term quartered partition is de- 
 rived from the use of small timbers called quar- 
 tering. In bricknogged partitions quarterings 
 about 3 or 5 ins. deep are placed from 18 to 
 27 ins. apart (taking two or three bricks), the 
 intervals being built up. Nogging pieces are 
 horizontal boards nailed to the quarters and 
 steadying the brickwork. In the accom- 
 panying diagram of a trussed partition, A is 
 the sill, B the head, C the intertie, D struts or 
 braces, F posts, G door head, H quarters or 
 quartering, I punchions: ashlering is the quar- 
 tering between the floor and rafters in attics, 
 used to cut off the angle. 
 
 GENERAL PRINCIPLES. If partitions are uniformly supported below, 
 there is little occasions for struts, and horizontal pieces may be disposed between to stiffen the 
 quarters. A partition often weighs from 14 to to 20 cwt., and it should rather be suspended 
 from the roof than rested on the floor below. As a general rule, however, partitions should be 
 self-supporting; and a simple mode of discharging the weight on the walls is to introduce two 
 struts, at an angle of about 40°, joggled above into a post; or a collar may be employed if there 
 is a doorway in the centre. Both methods are illustrated on Plate 31. Sometimes parabolic 
 arches of iron or wood are substituted for ordinary bracing. The timber should be well sea- 
 soned, the joints carefully fitted, and ample time allowed 
 for the partition to settle to its proper bearing before 
 being plastered; otherwise settlements will cause unsightly 
 cracks and defects. The adjoining diagram is an eco- 
 nomical form for story posts, etc. Filling in an ordinary 
 partition with plaster or rubbish hinders the passage 
 of sound. 
 
 SCANTLINGS. Quartering should not be less than 2 ins. thick, and 
 12 ins. is the usual distance apart. For a 2(1 ft. bearing, posts may be 4 X 2 , / 2 ins., for 30 ft. 
 •* ' •’> ins., and for 40 ft. G X 4 ins. Langley says the distance apart of principal posts 
 should be about 10 ft., and that of quarters regulated by the length of the laths, which will 
 otherwise be wasted. 
 
CHAPTER VI. 
 
 R 0 0 F S G E N E R A L L Y. 
 
 CLASSIFICATION. Roofs are the uppermost coverings of buildings; 
 and we may classify them on two different systems. First, by considering the external section 
 or outline; and secondly, the internal construction. In the former are: — roofs, whose outline 
 forms one prism or angle; next, those in which two or more triangles are involved, as in partly 
 flat or truncated, curb and M roofs; and lastly, those which are curved. At Page 10 roofs 
 are divided according to peculiarities of construction: some authors have separated them 
 into those which exert only a vertical pressure on the walls, and others in which there is an 
 outward thrust. There are varieties, as on Plate 32, many of which hardly admit of re- 
 duction under a comprehensive heading; but in most the principle of the king and tie is more 
 or less involved, pendants, or collars, supplying their place; or, as in the Norman roof, Fig. 1, 
 there is an arched arrangement, the rafters butting on joggled kings; large roofs and bridges 
 have thus been erected. A straining piece, acting somewhat as the key of an arch, divides the 
 king-post of the truncated roof, Fig. 2: Fig. 3 is an executed roof designed by Mr. R. R. Rowe. 
 Roofs circular on plan, and sometimes called revolved, or roofs of revolution, may be as Fig. 4; 
 and it is evident that in elliptical roofs, Fig. 5, the pressure is more unequally distributed than 
 in the former. In Fig. 6 the outline forms a double curve; Figs. 7, 8, and 9 are three of the 
 simplest sections, and Figs. 10, 11, and 12 are suggestive examples. 
 
 PRINCIPLES OF CONSTRUCTION. When the span of a roof is 
 very slight, a simple form called a lean-to, as in the margin, is used, the central dotted 
 line indicating the Avail; and, if the span is increased, the least complicated combination is shown 
 
 by the addition, the Avail being removed. If Ave suppose 
 A C to represent the pressure of the principal, and this 
 is resolved into A B, AD, it is clear that the outward 
 thrust is much greater than the downward pressure, the 
 _„B.. former being increased as the pitch of the roof is loAvered: 
 
 ! ft is also proportional to the length of a line perpendicu- 
 ~"*0 lar to the foot, and intersecting the vertical line dropped 
 from the apex, A E being elongated' as the angle of the 
 roof opens. The addition of the dotted collar is one of 
 the first steps in framework; but, by the substitution of the 
 tie beloAv, so proportioned that it can resist the strain without being too weighty, superior rigidity 
 is secured: the joint on the left side of the collar is called the carpenters boast. The simplest truss 
 Avhich has been devised is that on the top of the opposite page: the tendency to sag is obviated by 
 the bolt; and it may be shoAvn that, if the truss is three times the depth of the horizontal beam, 
 it Avill be about six times as strong as the latter alone, its stiffness being increased in a far higher 
 
HOOFS GENERALLY. 
 
 1 (iS 
 
 degree. In the next figure, it is evident that adding to the height does not proportionately 
 increase the strength of the combination. The stability of the abutments has to be con- 
 sidered: those of the dotted truss are evidently more liable to 
 
 Supposing 
 
 derangement than in that drawn strong, although in the latter 
 the tie is stretched more in the direction of its length; and, 
 therefore, the flatter the truss, the stronger must be the tie, the 
 feet of the principals having also to be securely indented, 
 bolted or strapped. The third cut is the ordinary queen post 
 truss with a tie having two points of support instead of one; 
 but a partial strain, as the suspension of a weight from one side, 
 is likely to destroy the efficiency of the frame, and counter- 
 acting means should be taken by the introduction of struts, etc. 
 the principals of trusses to be placed upright, their strength 
 will decrease as their length is increased; that is, the pressure 
 on a principal double the length of another is doubled. Con- 
 sidering the load as resting on the centre of gravity of a prin- 
 cipal, on completing the dotted lines, the horizontal pressure of 
 the principal at A is indicated by B A, that at C by B C, and 
 the vertical pressure of the centre of the principal by B 1), the 
 triangle Be/’ showing the direction and relative proportion of 
 the forces. 
 
 hen it is desired to have a ceiling higher than the springing of the roof, 
 
 the forms in the margin may be adopted. 
 
 I be strain on the two ties will be increased 
 
 according as they are raised, and that on the kiim 
 
 © 
 
 is also much greater than when the tie is 
 
COVERINGS AND INCLINATIONS OF ROOFS. 
 
 169 
 
 horizontal. Strong straps at the end of the king, and straps or bolts at the feet of the principals, 
 are requisite. The second section is designed by Price. 
 
 Openings in roofs for light or ventilation may be trimmed round as those 
 in floors. Some forms of dormers are added, together with the mode of framing wall plates, 
 dragon beams and angle ties to receive hip rafters. 
 
 GUTTERS should have proper bearers, and not be less than 1 ft. wide 
 at the narrowest part, having a fall of from 2 to 3 ins. in 10 feet, with drips 1 1 / 2 to 2 ins. deep, 
 at intervals of at least 1 0 feet, and cesspools 3 to 6 ins. deep and 1 1 2 to 2 feet long. The cuts on 
 the preceding page show the mode of obtaining their width from the section to put it on the plan, 
 the fall being set up from the lowest part. Tilting filets, used where walls, etc., rise above the roof, 
 in order to throw aside the water by slightly raising the covering, may be 3 to 4 ins. by 3 / 4 . 
 We hardly need warn the reader against V roofs, formed with two sides resting against the 
 outer walls of a building, with the gutter in the centre, total failure of the construction and 
 deluging a house with water being their apparent object. “As for those suspended over empty 
 space, Paxton gutters, and roofs springing from drooping, unsupported beams, instead of walls, 
 they are too contrary to common sense to have occurred before the nineteenth century.” ( Garbett .) 
 
 CHAPTER VII. 
 
 COVERINGS AND INCLINATIONS OR ROOFS. 
 
 COVERINGS. There should be few horizontal seams, or laps, as they 
 
 facilitate the entrance of rain which 
 rises up between the interstices, be- 
 sides diminishing the slope of the 
 roof; hence roofs covered with me- 
 tal, having seams running with the 
 inclination, require less slope than 
 when slate, tiles, etc., are adopted. 
 
 Thatch is one of the most 
 primitive roof coverings: its liability 
 to combustion is diminished by soak- 
 ing it in alum, size and water. Wood 
 is rarely adopted, except for tempo- 
 rary purposes, although shingles of 
 split oak, generally 8 to 12 ins. long 
 by 4 broad, thicker on one edge, 
 were formerly in extensive use. The 
 diagrams show methods of laying 
 boarding, either across or with the 
 inclination. Slates are employed, 
 either m split thin laminae, or in 
 slabs, with fillets or rolls covering 
 
 Carpentry. 
 
 XXU 
 
170 
 
 COVERINGS AND INCLINATIONS OF ROOFS. 
 
 the joints; and we need not describe the ordinary plain and pan tiles. Those on the foregoing 
 page, placed diagonally, were imported by an Italian to Madrid in 1805: some other forms are 
 added: and small channels are preferable. Of metals, lead, copper, zinc, and iron, are used, the 
 latter being galvanized. On account of their expansion and contraction, great care is requisite in 
 joining metallic coverings, so as to allow a play while keeping the joints water-tight. The 
 diagram A is a form of iron tiles, of exceeding lightness and duration, much used in France. 
 In the Palace at Westminster cast iron coated with zinc is adopted. Boarding for metals, 
 slate, etc., may be from 3 4 to 2 ins. thick, close joined, rough, wrought one or both sides, 
 grooved, etc. Battening for slating may be 3 / 4 to inch 1 / 4 thick, 2*/ 4 to 3 ins. wide, and 9, 12, 
 or 15 ins. from centre to centre. 
 
 INCLINATIONS. The inclination, or pitch, of a roof is the relation 
 between its width and height, depending on the destination of the building, considerations of 
 external and internal effect, the span, and, more particularly, the covering, and climate. It varies 
 from 25° to 65°, or from about one-fourth to nearly the actual span. The Persians, Arabians 
 and Egyptians made their roofs flat; Greek roofs vary from 12° to 16°; Roman are from 23° 
 to 25°: Gothic differ considerably, but the length of the rafters is often equal to the span; and 
 about the revival of classical architecture what is called the true pitch with rafters three-fourths 
 of the span was adopted. For slates the usual inclination is about 26°, or from one-third to 
 
 one-fourth of the span; plain tiles require a rather greater 
 inclination; hollow tiles much less than slates; and Roman, which 
 are alternately flat and round, more slope than hollow tiles. 
 
 High pitched roofs readily throw off rain and snow, 
 and are not so liable to be stripped by high winds: the pres- 
 sure is also more perpendicular, and there is less strain on 
 the walls. Low pitched roofs of course require less timber 
 and covering. The adjoining cut will be useful in enabling 
 the reader to perceive at a glance the effects of various 
 angles. In the Encyclopedic Methodique is a valuable table 
 of the slopes of roofs for various climates, part of which 
 is given by Gwilt. 
 
 CHAPTER VIII. 
 
 ORDINARY FORMS OF ROOFS. 
 
 DEI- INI I IONS OF PARTS. The diagrams represent the usual forms 
 "i long and queen post roofs, and we have lettered the respective parts. A is the tie-beam 
 restraining the opposite pressures, preventing the bulging out of the walls, and sometimes sup- 
 
ORDINARY FORMS OF ROOFS. 
 
 171 
 
 porting ceiling joists. The principal rafters, or principals, B, carry the timbers on which the 
 
 covering is laid, and also support the pur- 
 lins C, which connect the trusses, as the frames 
 are called. The common rafters, or spars, 
 D, are notched on the purlins in the middle 
 and on the pole-plates E, resting on the ends 
 of the tie-beams, and abut above against the 
 ridge, F. The icall plates G carry the ties, 
 distributing their pressure on the wall. The 
 principals abut on the king post H, which 
 supports the tie in the middle, and also takes 
 the pressure of the struts, or braces, I, sup- 
 porting the principals, and relieving the pres- 
 sure of the last on the joint below'. In wide spans queen posts, K, are adopted with a straining- 
 piece or collar, L, above, steadying the queens and re-acting against the pressure of the principals, 
 and with sometimes a straining sill, M, below', performing a similar office with respect to the 
 struts. Auxiliary rafters, sometimes named cushion rafters, or principal braces, are shown dotted 
 N, and serve to relieve the principal rafters w'hen the span is very wide or there is a great 
 strain. Hip rafters are those at the outer angles of a roof sloping off each w r ay, and also the 
 long one in the centre, the shorter ones being called jack rafters. Valley rafters are those to the 
 inner angles, or valleys. 
 
 F 
 
 KING POST ROOFS. In the margin some variations from the ordinary 
 king post roof are shown. Trusses generally should not exceed 10 feet apart; and king post 
 
 should be substituted for collar roofs when the span exceeds 
 25 ft; but the simplest form of kings must not be used for 
 spans above 35 feet. Purlins should be in as long lengths 
 as possible (See Page 131)-, and, when it is desirable for the 
 common rafters not to stand much above the principals, the 
 purlins are tenoned into the latter: both however are weak- 
 ened, and the practice is not to be recommended. In 
 Gothic trusses purlins are often supported by bracing below', 
 few' parts of a roof being more liable to failure. 
 
 SCANTLINGS. The following, based on our own practice, are for fir, 
 but the quality of the timber must be borne in mind; for that of inferior nature, add one-quarter 
 inch to each dimension. 
 
 Span. 
 
 Tie. 
 
 K : ng. 
 
 Principles. 
 
 
 Rafters. 
 
 
 Struts. 
 
 Purlins. 
 
 20 
 
 9 X 4 
 
 4 X 3V 2 
 
 4 X 3 \/ 2 
 
 3 
 
 X 2 
 
 4 
 
 X 3 
 
 6 
 
 X 4 
 
 22 
 
 9 «/ a X 4 V, 
 
 4V« X 3 1 / 2 
 
 4 l / 2 X 3>/ 2 
 
 3 
 
 X 2 Vi 
 
 4 
 
 X 3b 4 
 
 7 
 
 X 4 
 
 24 
 
 10 X 5 
 
 5 X 4 
 
 5 X 4 
 
 3' 
 
 2 X 2>/ s 
 
 4'/ 
 
 2 X 31/4 
 
 8 
 
 X 4 
 
 20 
 
 10 l / 2 X 5 
 
 5 X 4 1 / 2 
 
 5 X 4*/s 
 
 4 
 
 X 2!/ 2 
 
 4 1 / 
 
 2 x 4 
 
 8 
 
 X 5 
 
 28 
 
 1 1 X 5’/ a 
 
 5</ 2 X 5 
 
 5 </ 2 X 5 
 
 4 1 
 
 4 X 2 «/ 2 
 
 5 
 
 X 4' /4 
 
 8 
 
 / 2 X 5 
 
 30 
 
 11 X 6 
 
 6 X 5 
 
 6 X 5 
 
 4V 
 
 2 X 2 1/ 2 
 
 5 
 
 x 41/2 
 
 9 
 
 X 5 
 
ORDINARY FORMS OF ROOFS. 
 
 172 
 
 For Purlins: 
 
 Bearing 6 Feet 6 ^ Inches 
 
 „ ' 8 „ 7 X 4V 2 „ 
 
 „ 10 „ 8 X o „ 
 
 1 •) 9 X G „ 
 
 » 1 — )» 
 
 Plates may be 4 X 3, or 5 X 4 Inches, and Ridges 7 X 1‘ 2 to 12 X 2, /2 Inches. 
 
 QUEEN POST ROOFS. When the span exceeds 35 feet, a cpieen 
 post roof may he employed, unless stronger forms of kings, as in the two last diagrams in which 
 the tie has additional supports, are adopted: these points should not generally be allowed to 
 exceed 14 feet apart. The second diagram is suitable for a span up to about 45 feet, tor ad- 
 ditional bearings, or when great strength is required, small queens may be added as shown in 
 
 Spun. 
 
 l_ 
 
 Tic. 
 
 Queens. 
 
 Small Queens. 
 
 Principals. 
 
 | Strain^ Piece. 
 
 35 
 
 to 
 
 X 5 1 2 
 
 5 X 4 
 
 — 
 
 1 5 1 , 2 X 4 
 
 0 
 
 X 4 
 
 40 
 
 1 II 1 
 
 .4 x r, 
 
 5Vi X 4 
 
 — 
 
 r>Vs X 4 
 
 7 
 
 X 4 
 
 45 
 
 12 
 
 X 7 
 
 <; x 1 1 .4 
 
 — — 
 
 7 X 4 '/a 
 
 8 ’ 
 
 X 4 '/a 
 
 5o 
 
 13 
 
 X 7 
 
 7 X 5 
 
 0 X 3 
 
 7 , X 5 
 
 S 
 
 X 5 
 
 55 
 
 1 1 
 
 X S 
 
 8 X 5' /.4 
 
 7 X 3 
 
 8 X 5 '/a 
 
 9 
 
 X 5 1 , 
 
 I'm) 
 
 1 1 
 
 X 11 
 
 9 X (i 
 
 7 X 4 
 
 9V 2 X 6 
 
 10 
 
 X 6 
 
 65 
 
 15 
 
 X 10 
 
 10 X fi 
 
 S X 4 
 
 In 1 /., X 6 
 
 10 ' 
 
 .4 X 6 
 
 Strut’. 
 
 Rafters. 
 
 12 X 
 apart. 
 
 2' 2 ; PI 
 
 and the 
 
 3'/o X 3 
 
 4 X 3 4 1 ’ 4 X 2 «/* 
 
 4'/. X 3 4'/-. X 2 ‘A 
 
 4 W X 3V 4 43 m X 2 Vi 
 
 4 Va X 3 V 2 5 X 2 Vi 
 
 4 ‘/a X 4 5 X 2'Y, 
 
 5X4 5X3 
 
 1 urdns may be as given under King Post Roofs; Ridges 9 X 2 to 
 ates 5 .X 4 to G X 5 inches. In all case the trusses are presumed to be 10 feet 
 covering not heavier than slate. * 
 
 the woodcuts. When the bearing is very great and it is desirable to keep down the height, an 
 M or a truncated roof may be employed, of one of which latter, that over the Chapel at Green- 
 wich Hospital, the last diagram is an illustration. The clear span is 51 feet; and the scantlings 
 arc: tie 14" X 12", queens 12" X 9", struts 9" X 7", straining piece 10" X 7", lower 
 
 straining piece G" X 7 ‘, principals 10" X 7", and iron king 2 inches square. Added is a very 
 
 strong truss, suitable for bearings of about 70 
 feet. The tie may be 14" X 8", principals 
 14 ' X 8" and G"X8", collar 14" X 8" cen- 
 tral queens 8" XI", double queens 10" X4", 
 struts 8"X7" and G"X4", and kings G"X6". 
 The following dimensions should rarely be 
 diminished. 
 
 8 C A N T L I N G 8. 
 
CURB ROOFS. 
 
 173 
 
 DESCRIPTION OF PRACTICAL EXAMPLES. 
 
 PLATES 33. 34. 35. ROYAL COLLEGE OF SURGEONS, LONDON. THEA- 
 TRE ROOF AND SKYLIGHT. SIR CHARLES BARRY, R. A., F. R. S.. ARCHITECT. We would 
 draw our reader’s particular attention to the complete and elaborate delineation of this construc- 
 tion, with the working drawings for which we have been favoured by the celebrated architect. 
 The late George Stephenson remarked that a plan should explain itself. Some observations 
 on this subject will be found at Page 78; and the best we can say of these three Plates is that 
 further comment is needless. 
 
 PLATE 36. GALLERY FRAMINGS. This subject stands by itself in carpen- 
 try, and the four examples given are suggestive of the various modes of treatment. Figs. 1 and 3 
 are designed by Mr. William Wright; Fig. 2 is the gallery at the Swiss Church by Mr. George 
 Vulliamy; and Fig. 4 that at Romford Church by Mr. John Johnson. The scantlings not figured 
 are as follow. Fig. 2: — tie 9" X 5", principals 5" X 4", straining piece 5" X 4", binders 
 6" X 4", joists 3" X 2 , /o // , ceiling joists X 2 , / 4 // . Fig. 3: — bearer 9" X 8", binders 
 10" X 4", joists 3" X 2", girder below 9" X 4", plate 4“ X 3", template above 5" X 4 “ , 
 and 2' „ 6" long. 
 
 CHAPTER IX. 
 
 CURB ROOF S. 
 
 GENERAL PRINCIPLES. These roofs have four contiguous inclined 
 planes. They are very useful under some circumstances, diminishing the appearance of excessive 
 height, the springing of walls by outward pressure, and allowing the formation of successive 
 floors above the walls. But, as remarked in the Encyclopedic Methodique, a curb, or Mansard 
 roof is, in some respects, a chef-d'oeuvre of contradiction, as the upper part is inclined from 24° to 
 25°, while the lower is from 64 n to GG°; whence it results that one or the other is unsuited to 
 the climate or covering. It is further contended that it would be cheaper ultimately to carry 
 up the wall to meet the upper slope increased to the proper angle. The gutter is liable to be 
 
 blocked up with snow; and, from the sudden downward rush of 
 water, derangements constantly occur: the view into the street 
 also is impeded by the projection of the entablature. Metallic 
 coverings are often used above, and tiles or slates below. 
 
 The scientific structure of curb roofs is comprehended 
 in the theory of the polygon; and a simple experiment will easily 
 determine the equilibrium of the parts. Four principals may be 
 supposed to be connected by hinge joints, as shown in the margin. 
 If inverted, they will, by their own gravity, remain in a position 
 of equilibrio. The least shock, however, will be apt to destroy 
 
174 
 
 CURB ROOFS. 
 
 this; but the introduction of the collar stiffens the correct form of polygon already ob- 
 tained; and the lower pieces may be secured to plates, or a tie introduced. When the roof is 
 to be irregular! v loaded, proportional weights must be suspended from the reversed polygon, or 
 the centres of gravity of the pieces especially strained, when the form will of course be modified. 
 
 There are various methods in use to determine the profiles of citrbed roofs, 
 and it is desirable to indicate a few. In the first diagram the height of the triangle is equal to 
 
 its base, and the former is divided into two equal 
 parts at A, where a horizontal line is drawn; AB 
 is made equal to the half of A C, and thus the pro- 
 file of the curb is determined.^ In the next figure 
 A B is equal to A C, and D E and B F are each 
 equal to one-third of D B or D C. In the third 
 figure, devised by Bullet, the semicircle is divided 
 into three equal parts: and in the fourth figure 
 D’Aviler proposed to make A B equal to half A C, 
 and D E equal to half B D. In the fifth figure A B 
 is made equal to a sixth of the diameter, and, on 
 raising the perpendicular, the profile is determined. 
 In the Science (les Ingenieurs Belidor has given a 
 method which results in a good external effect, the 
 semi-circle being divided, as shown in the sixth 
 figure, into five equal parts. In the seventh figure 
 Ivrafft made AB equal to one-third of A C, and 
 D E equal to half B D. In the last figure a curb 
 is enclosed in an ellipse. Such construction is known 
 in f ranee under the name of ansede patiier; and, as this mode of drawing an ellipse is little 
 Known, we will describe it. Let AB be the transverse, CD the conjugate diameter, and CEB 
 an equilateral triangle. Make CF equal to CD; draw DG through F (settling, where it cuts 
 tin tiiangle, tltc profile of the curb) and GH parallel to EC: thus H and I are the centres 
 for describing the ellipse. 
 
 On Plate .17, are some excellent continental forms of curbed roofs. Fig. 1 
 i- exceedingly light and adapted for a gallery; in Fig. 2 there are floors lighted by dormers; 
 and 1 ig. 3 is suitable where a considerable amount of strength is requisite; ceiling joists may 
 • ,,la 'h'd below. Referring to Plate 31, there is a useful curbed roof. The lower pieces 
 are X 2' with window posts 5" X 3 '/ 2 ", and heads and plates 5" X 5"; 
 rafters 3' X 2 1 and ridge 9" X P/ 2 ". 
 
 common 
 
CHAPTER X. 
 
 ROOFS ON THE PRINCIPLE OF THE ARCH. 
 
 DELORME’S SYSTEM. The principle of this lias already been indi- 
 cated at Page 38; and the adjoining projection further illustrates it. The roof of the Halle 
 aux Bids in Paris, the most extensive example of its application, was completed in five months 
 
 in 1783, was burnt in less than two hours in 1802, and is now replaced 
 by an iron dome designed by M. Bellanger; but, although of the same 
 diameter, it has neither the lightness, nor elegance of the timber original. 
 The adjoining roof was 
 designed by Delorme; and 
 the other figures are il- 
 lustrative of the system. 
 
 On Plate 38 is a skilful 
 design by Mr. George Vul- 
 liamy, in which an half- 
 inch wrought iron flitch 
 is introduced between ribs 
 of four thicknesses of inch and a half deal, bolted 
 together. The arches shown at the side are 
 bracketed-out between the ribs, We may add the 
 upper principals are 5 X 4, purlins 6 X 4, rafters 
 4 ! / 2 X 2 , / 4 , struts 5 X 6, plates 4 1 / 2 X 3, ridge 
 9 X D/a, and ceiling joists 4 X 3 Inches. 
 
 LACASE’S SYSTEM is 
 explained by the woodcuts on the next page. The 
 middle one is the underpart of the ribs, and shows 
 the scarfing by which the pieces are connected; 
 the inner indicates the mode of fixing the horizon- 
 tal rings; and the outer figure is of the finished 
 construction. 
 
 Although Rondelet was of 
 opinion that this system united the advantages of 
 that of Delorme with less expense, it is evident 
 
KOOFS ON THE PRINCIPLE OE THE ARCH. 
 
 that 
 
 thc amount of timber required, and the consequent waste, is much the same, while Lacase’s 
 .,r C exceedingly flexible, and too much cut into to admit of great solidity. 
 
 EMY’S SYSTEM. (See Pa ges 39 and 57.) The first figure in the margin 
 is i he riding house roof at Libourne, France, the internal span of which is 68 feet, at 
 
 the springing of the roof 
 25 above the floor; the inner 
 figures are the chariots for 
 moving the ribs horizontally; 
 and the remaining diagrams 
 are double curved ribs, re- 
 commended by Emy, after 
 many experiments, for wide 
 spans; as the large roofs pre- 
 viously designed, such as 
 those at Moscow and Darm- 
 stadt, necessitating so enor- 
 mous a consumption of tim- 
 ber, can scarcely be consi- 
 dered satisfactory. 
 
 Of course, in plank ribs, if one springs the truss will be liable to fail 
 at that point; and the holes for the bolts, not only weaken the combination, but prevent the de- 
 sirable play between the layers: on account of shrinkage, the truss should be watched some time 
 alter fixing, and the ligatures tightened. Little contraction occurs in the length of the planks, 
 and that in the width will not perceptibly affect their strength. Brick and stone arches, fifteen 
 or twenty feet apart, and about one hundred feet in diameter, carrying purlins, etc., are often 
 used in I* ranee, one centre, running on wheels, serving for each arch. 
 
 VARIOUS METHODS. Arched ribs and parabolic curves are used 
 to steady roofs and counteract the effects of shrinkage. The first figure is the rib proposed for 
 the Riding house at Moscow, and the second is on the principle of Delorme: curved ribs are 
 preferable. 1 he first roof is on a system by Mr. Houldsworth, (rewarded by the Society of 
 Arts) with ribs simply sawn nearly to their ends. The next roof is executed over a Magazine 
 at 1 onion. Barns in Holland, Prussia, etc., are frequently constructed as in the following dia- ’ 
 giam. 1 he remaining roofs arc all very instructive; and the sixth example is applicable to dock 
 
ROOFS OF TIMBER AND IRON. 
 
 1 77 
 
 sheds, etc. We before explained the American process for bending timber, and its adoption 
 would often render roofs with curved timbers much less expensive. 
 
 CHAPTER XI. 
 
 ROOFS OF TIMBER AND IRON. 
 
 DESCRIPTION OF EXAMPLES. It is foreign to the object of this 
 Work to enter extensively into the consideration of the use of iron; and w 7 e shall therefore 
 confine the present Chapter to explanations of some illustrations in which that material is in- 
 troduced, having already touched upon its use in joinings. 
 
 Whenever the span of a roof is very protracted, or there is a considerable 
 outward thrust on the walls, or lightness is desirable, an iron rod is much more effectual than 
 a wooden tie. If rooms are required above, or a ceiling below, a tie may still be added. 
 The tearing asunder of timber in the direction of its length rarely, however, occurs. 
 
 On the following page are some useful suggestions; and we will here refer 
 to the roof on Plate 39 as a novel form of construction designed by Mr. F. W. Porter. The 
 collar rods are one inch square, worked with a fine worm where screwed, fitting the nuts 
 without joggling, the ends rivetted after the rods are well drawn home, and the worm run suf- 
 ficiently far to catch the stop nut at A, care being taken to prevent it showing beyond the face 
 of the nut. On the use of the strap, which is 3*/ 2 X '/ 2 in., at the junction of the principal and 
 upright, we remarked when describing Plates 18 and 19 (Page 119) by the same architect. The 
 scantlings are: — 
 
 Carpentry. XX11I 
 
17* 
 
 ROOFS OF TIMBER AND IRON. 
 
 Principals . . 
 
 Uprights . . 
 
 Curved Ribs . 
 Purlins . . . 
 
 Collars (double) 
 Plates . . . 
 
 Ridge . . . 
 
 8 X 5 Inches. 
 8X5 „ 
 
 8X4 „ 
 
 6X6 „ 
 
 6 X 2 */ 2 jj 
 6X4 „ 
 
 6x6 „ 
 
 Plate 40 contains two roofs in which 
 iron is introduced. 
 
 The first is designed by Mr. E. C. Robins, 
 and was executed under his supervision in 1852. 
 It combines exceeding lightness and great rigidity, 
 the bolts and straps being disposed with much 
 judgment. The following are the scantlings: — 
 
 Principals . . . 
 
 Purlins . . . . 
 
 Long Cross Ties 
 
 12 
 
 8 
 
 9 
 
 9' 
 
 4 
 
 5 
 4 
 
 X 5 
 X 4 
 X 5 
 X 4 
 X 4 
 X 5 
 X 2 
 
 Inches. 
 
 2V* X 
 
 Wall Plates . . 
 
 Pole Plates . . 
 
 Short Tie Struts 
 Common Rafters 
 Iron Straps . . 
 
 The idea of the next roof is avowedly derived by Mr. Rowe from that 
 previously described, in this Chapter, by Mr. Porter; but the reader will readily perceive the 
 skill displayed in phe modification to suit another purpose. For roofs of this description we 
 have been favoured by the architect with the scantlings below. 
 
 Principals . . . 9X6 Inches. Ridge . . . 6x4 Inches. 
 
 Purlins .... 6 X 6 „ Rafters ... 4 X 2 1 / 2 „ 
 
 Collars .... 9 X 6 „ Plates ... 12 X 6 „ 
 
 Plate 41 contains details of a system of roofing proposed by Emy. It 
 consists in the introduction of iron rods forming a series of triangles, counteracting the various 
 thrusts. 1 bis end is attained in the present example in a very complete manner; and we need 
 not remark on the beautiful simplicity of the combination. (Compare Page 122.) 
 
 CHAPTER XII. 
 
 G 0 I II 1 C K 0 0 F S. 
 
 DESCRIPTION OF EXAMPLES. We have opened this subject at 
 I age 44, and beg the reader again to peruse those remarks. Gothic roofs are there divided into 
 thnr-e with tie-beam s, trussed rafters or diagonal ties, hammer beams, and braced collars.' The first 
 
GOTHIC ROOFS. 
 
 179 
 
 are observed in all the phases of Mediaeval architecture; the second are common in the Early 
 
 English ( 13th century) and Decorated (14th century) styles; and as the latter was matured the 
 
 lower principals were cut into the form of a pointed arch. Ties are not often found in the 
 
 Early English period, collars with braces being substituted. Few original roofs remain; and 
 
 those in the Decorated style were generally superseded in the Perpendicular (15th century), 
 the weather moulding at the eastern side of the tower indicating the lofty pitch, which was 
 almost invariably diminished in the subsequent erection. Appended is a Decorated tie beam 
 roof; but, unlike the modern king post truss, the tie acts as a girder, carrying the timbers 
 above: the arched struts obviously increase the stability of the combination, 
 besides distributing the pressure downwards. Hammer beam roofs were com- 
 mon in the Perpendicular style, the earliest existing example being probably 
 that over St. Mary’s Chapel, Stourbridge, which has the ball flowers, peculiar 
 to the Early English and Decorated periods, carved on the beams. The date 
 is 1390, seven years before the erection 
 of that at West- 
 minster. ( See Page 
 •74.) The above dia- 
 gram will give an 
 idea of the manner 
 in which ties, usually cambered, were 
 employed, and also of the connexion of 
 the nave and aisle roofs. Roofs with 
 trussed rafters are shown in the follow- 
 ing cuts, collars being introduced in 
 wide spans. As in all Gothic roofs, 
 
 the plates are 
 usually very 
 thick ; and 
 the principals 
 are framed 
 into a piece 
 
 of timber laid cross the thickness of the wall, an upright sup- 
 porting, as well as controlling the outward thrust of the principal. 
 A vertical piece to support the ridge is frequently placed above 
 the collar; and the braces below were gradually increased in number 
 so as to suggest an arch, which latter was ultimately adopted. 
 The last of this diagrams indicate this progression, the two upper- 
 most being common in the Early English style: in the oldest 
 examples six, instead of seven sides are observed. Adjoining are 
 two usual forms of hammer beam roofs. The tension pieces above 
 and the struts below' counteract the outward pressure on the w'alls, 
 which is often too oblique, buttresses being often observed to have yielded after the plates have 
 
ISO 
 
 GOTHIC HOOFS. 
 
 decayed or -riven way. In the roof of Westminster Hall, of which a diagram is appended in the 
 <eC ond cur, die outward thrust is such that buttresses are indispensable. Below it is a section of 
 
 the roof at Hampton Court, a species of curb. It is a re- 
 markably skilful piece of construction, well tied together, with 
 the pressure distributed down the walls. Hammer beam roofs 
 should be designed so as to have little outward thrust, and, 
 when tints, are far superior to many of the other roofs common 
 in the Middle Ages, which are generally only suitable for 
 slight spans, or where great thickness of walling and strong- 
 buttresses can be introduced. The collars in hammer beam 
 roofs are often called wind beams, the ties cut short being the 
 hammer beams, the uprights on these queen posts , supported by 
 spandrel braces below and having collar braces cutting off the 
 angle formed by the collar and queen: pendants are sometimes suspended from the ends of 
 the hammer, or angels holding shields, books, etc., are carved at their termination. We add 
 one collar braced roofs, stout planking being introduced in the smaller diagrams. These roofs 
 
 were probably suggested by those with hammer beams, 
 there being a general distant semblance of outline, as 
 evidenced by a glance at the example at Hampton Court. 
 The hammer beam, again, was derived from trussed 
 rafter roofs, as shown in the woodcut at Page 34, thus 
 indicating a regular progression. {Compare the remark 
 at Page 6.) 
 
 With respect to the coverings of Mediaeval 
 roofs, tiles, slabs of stone, shingles, slate, and lead, were 
 church of St. Peter at York so early as A. D. 6G9. At 
 pre.-ent, slate is the most usual material, although tiling is very common, and lead is employed. 
 (See Chaplet' 7 of this Division.) 
 
 Although certain general forms of roofs, as above indicated, were common 
 hi the se\ oral styles of Gothic Architecture, the decorations are the most obvious means of 
 -tiling the date of examples respecting which no records exist. We have merely touched on 
 'h- -object, as this is not the place for antiquarian research, which has already been overdone. 
 ^ 11 ' M "' l| h on the modern Mcdiawalists has hitherto caused them to go back rather than for- 
 
 u.nd. and the philosopher sees demonstrated the stationary character of a school whose talk is 
 -ometimes of progression, but whose acts arc worse than retrogression 
 
 In Brandons Open limber Roofs of the Middle Ages, and Bloxam’s Prin - 
 ■ ij t tothic hc'/csiastical Architecture , much further information of the subject of this 
 Chapter will he found. 
 
 1 late 12 contains details of a roof designed by Mr. John Johnson, whose 
 nni ' n ' ’ 'f t't and accurate knowledge of Gothic art, displayed in the numerous churches and 
 other edifices erected under his supervision, as well as in his Reliques of Ancient English Archi- 
 .lie widely appreciated. I he scantlings, not figured, are as follow: — 
 
LINES FOR ROOFS. 
 
 181 
 
 NAVE ROOF. AISLE ROOF. 
 
 Principals . 
 
 ID 
 
 X 7 
 
 Inches. 
 
 Principals . 
 
 . 9x7 
 
 Inches. 
 
 Rafters . . 
 
 4 
 
 X 3 1 / 2 
 
 91 
 
 Rafters . . . 
 
 . 4 X 3' 
 
 2 91 
 
 Plates . . 
 
 7 
 
 X 5 
 
 * 99 
 
 Braces ... 
 
 . 7 x r> 
 
 99 
 
 99 
 
 4 
 
 X 3 
 
 99 
 
 Purlins ... 
 
 . 6 X 5 
 
 9’ 
 
 Purlins . . 
 
 11 
 
 X 6 
 
 
 Lower Plates 
 
 . 4X3 
 
 99 
 
 Ridge . . 
 
 1 1 
 
 X 2 
 
 99 
 
 Upper Plates 
 
 . 5X4 
 
 99 
 
 King (diametei 
 
 ’) 
 
 6 
 
 99 
 
 Uprights . . . 
 
 . 4X3' 
 
 2 99 
 
 Tie . . . 
 
 12 
 
 X 7 
 
 99 * 
 
 Tracery (thick) 
 
 U 
 
 ■2 99 
 
 Straps . . 
 
 2' 
 
 , X 3 8 
 
 ✓ 
 
 99 
 
 
 
 
 Lower Plates 
 
 6 
 
 X 5 
 
 
 
 
 
 LINES FOR ROOFS. 
 
 Figs. 1 and 1 a, Plate 23, explain the mode of finding the length and 
 backing of the hips of an ordinary roof which is rectangular on the plan. Fig. J gives the 
 pitch of the roof, and Fig. la shows the. plan of the hip A B, of which the length and hacking 
 have to he ascertained. From the point B draw the line B C, perpendicular to A I> and equal 
 to the rise of the roof. Join A C, and the line A C represents the required length of the hip. 
 
 To find the harking of the hip. Through any point, d, in A B, and at 
 rio-ht angles to A B draw the line e, f. From the centre J describe an arc as shown, touching 
 the line AC and intersecting the line AB at g. Join eg and f g, and the angle formed by 
 these two lines will coincide with that of the upper edge of the hip. A bevel is most readily 
 applied to the sides of the hip; therefore, draw any line as lih parallel to A B, and the angle 
 formed by this line and the line eg or f g, as represented on the figure, will be the angle for a 
 bevel to be applied to the sides of the hip. 
 
 Figs. 2 anil 2a exhibit the application of the methods just explained to a 
 roof of which all the angles on the plan are unequal, although two sides are parallel. The 
 position of the hips on the plan is ascertained by bisecting each of the angles. The letters of 
 reference are the same as in the last example and the same description applies. 
 
 Figs. I, la, lb, and le, Plate 2k, illustrate the case of a roof of which all 
 the sides and angles are unequal. As in the last example the position of the hips on the plan 
 is found by bisecting each of the angles. The triangular space marked in the middle of the 
 plan is to be made Hat, and the arrangement shown at once causes the sky-line of the roof to 
 be horizontal and renders unnecessary any winding of the inclined surfaces. The dotted lines 
 mm, nn, and o o mark the position of the principals, and Figs, la, lb, / e show their form. It 
 will be perceived that OAving to the irregularity of the plan of the roof the inclination of the 
 principals will be different on the opposite sides, although the slope of the slating w ill be every- 
 Avhere the same. Fig. 1 further illustrates the finding the length and backing of the hips, and 
 the explanation already given applies in this case. 
 
 Figs. 2 and 2a represent the lines for an octagonal roof, which hoAvever 
 call for no explanation beyond Avhat has been already given. 
 
LINES for roofs. 
 
 182 
 
 LINES FOR PURLINS IN CONICAL AND DOMICAL ROOFS. 
 
 / and la, Plate 2.'), illustrate the method for finding the correct cur- 
 vature and sectional form for the purlins in a conical roof. Fig. l a is the plan of one half of 
 the roof, and the right-hand portion of Fig. 1 shows half the elevation. The radius for the 
 curvature may he measured from the plan. The left hand portion of Fig. I explains the mode 
 of ascertaining what width and depth of material is required. Let abed represent the purlin. 
 Then through the points abed draw the square efgh. If the stuff he first cut to this section 
 and to the proper curve, the distances fb, ed, etc., may he readily marked with a gauge, and 
 the purlin he then finished to the required form. 
 
 Figs. 2 and 2a show the application of the same method in the case of 
 a roof of a domical form. 
 
 LINES FOR POLYGONAL ROOFS. — The problems which relate to polygonal 
 roofs arc, first, those which have reference to the finding the form of the angle ribs, when the 
 plan of die roof, and the right section of one of its sides are given; and second, those for finding 
 i lie covering of the roof, or the development of its surface, when the plan of the roof, and the 
 right section of one of its sides are given. 
 
 Fig. 3, Plate 25, is the elevation of a roof of which the plan is a hexagon, 
 as represented by Fig. 3 a. The curved line a'b, Fig. 3l>, is the right section of one side of the 
 roof. Divide this line into any number of equal parts, in this case say six, and through the 
 points thus marked draw horizontal lines, as shown on Fig. 3b, and from the same points let 
 tall perpendicular lines to the plan, as represented on Fig. 3 c. Take the distances a I, a 2, etc., 
 on the line a c, Fig. 3c, and mark them, from the centre line, on the respective horizontal lines 
 in Fig. 3 b. Through the points thus obtained draw the curved line a c, which will be the cor- 
 rect form of the required angle rib. 
 
 To produce the development of one vide of the roof: let the curved line 
 a b, Fig. 3b, be divided, as before, into any number of equal parts. Set off these parts on the 
 line a b, iig. 3d, and draw horizontal lines as shown. Then, from Fig. 3c, take the distances 
 ■> i, V-> — etc., and transfer them to Fig. 3d on each side of the line a b in the manner 
 represented. 1 hrough the points thus marked on the horizontal lines draw the two curved lines 
 a , i 1 2 1 r and the development of one side of the roof will be completed. 
 
 Polygonal roofs may be made in a great variety of forms, but the methods 
 explained will apply equally to all. Thus the roof represented by Fig. 4, of which the plan is 
 an octagon, would require no variation from the processes that have just been illustrated. 
 
 COVERINGS OF CIRCULAR ROOFS. — Fig. /, Plate 26, is an example of the 
 da>s ot roots to be now treated. I hey may be of many varieties of form in elevation, and they 
 dilicr from the polygonal roofs, just referred to, in being circular in plan. The surface of such a 
 figiuc as that represented by Fig. 1 cannot be developed with perfect exactness, but there are 
 two modes, by means of either of which a result may be arrived at, that will serve all 
 practical purposes. 
 
 iig. / a, 7 b, and / c illustrate the mode of covering a roof by means of 
 Ibis method consists in dividing the circle of the plan into a number of equal parts, 
 and pun ceding to find the development as though, instead of the roof being circular, its plan 
 
LINES FOR ROOFS. 
 
 183 
 
 were a polygon of many sides. What is required to be done is to find the development of one 
 side of a polygonal roof, in the manner already explained by Figs. 3, 3a, etc., Plate 23, and by 
 the remarks referring to those figures. 
 
 Fig. I, Plate 26, is the elevation of the roof, Figs. 1 a and 1 b represent 
 the supposed polygonal form, with many sides, and Fig. I c shows the development of one side. 
 
 The second mode, by means of which the form of the covering may be 
 ascertained, is that illustrated by Figs. 2, 2a, etc. The horizontal lines on the elevation, Fig. 2, 
 show the surface of the roof divided into a number of horizontal zones, each of which is sup- 
 posed to form a portion of a cone. Through the points marked in the curved lines by the 
 horizontal lines bounding each zone, lines are to be drawn to intersect each other and the centre 
 line as shown on the figure. The intersection of these lines marks in each case the vertex of 
 the cone of which the respective zone is a frustum. The problem therefore in the case of each 
 zone is to produce the development of the surface of a frustum of a cone. The mode of doing 
 this has been explained at length in connection with Figs. 2, 3, etc., Plate 7, to which the 
 reader is referred. 
 
 Fig. 2a is a plan indicating the boundaries of the circular zones. 
 Figs. 2b and 2c represent the development of the surface of the two upper zones, and Figs. 2d 
 and 2e show part of the development of the next two lower zones. 
 
 The coverings of domes are found by means similar to those now ex- 
 plained, as will be seen by referring to Plate 28, where the subject is further illustrated. 
 
 CHAPTER XIII. 
 
 1) 0 M E S. 
 
 DEFINITIONS. The word Dome (from the Latin domus, a house) is 
 applied to a roof of curved outline, circular, elliptical, or polygonal on plan, having sometimes 
 a lantern on the summit. Domes on a circular base may be spherical, spheroidal, ellipsoidal , para- 
 boidal, liyperboloidal, etc. Those which are lower than the radius of the base are termed suv- 
 based, or diminished, and the contrary surmounted. Again, cupola is a name given to those with 
 circular bases. The spherical is the most usual form, the plan being a circle and the section a 
 segment of one. The external and internal forms of domes are often dissimiliar; and we may 
 divide them constructively into those with or without horizontal ties. 
 
 GENERAL PRINCIPLES. The construction of timber domes is by no 
 means a matter very difficult of comprehension. As they usually rise nearly perpendicularly 
 from the walls, the outward thrust is rarely great; and, the chief tendency being to fall out- 
 wards, this may be counteracted by means of a strong band, timber ring, or iron chain or hoop 
 at the base: the liability to fall inwards is obviated by trussing. If a dome has to carry an 
 erection above, the framework must be proportionately strengthened, unless the superincumbent 
 structure is no heavier than the materials which would otherwise occupy the space were it 
 
184 
 
 DOMES. 
 
 omitted. Otherwise the downward pressure will induce failure by forcing (he upper part of 
 
 the dome inwards and the lower outwards. 
 
 Domes with horizontal tics naturally admit of the utmost strength; and, 
 when internal space is desired, the tie is elevated, thus acting as a 
 species of collar. Occasionally trusses arc placed at the outer dia- 
 meter of' the lantern with half trusses filled in, as shown in the 
 first plan. In others, as in the second plan, they radiate from the 
 centre. In the third and fourth plans other radiating forms are 
 given. The section below is of a dome designed by Styerme. It 
 is a remarkably light and graceful composition: the trusses radiate. 
 In dousse’s dome, which next follows, there are eight principal 
 trusses supporting the lantern, the 
 construction altogether bei g exceedingly simple. On Plate 43 
 are details of the dome of the Hotel des Invalides in Paris de- 
 signed by J. H. Mansard. 
 
 Although severely criticised 
 by liondelet, considerable skill 
 is displayed in this structure; 
 and the timbers are so com- 
 bined as to result in excel- jbj 
 lent equilibrium. 
 
 For domes without 
 
 horizontal ties, the systems of Delorme, Emy and Lacase, 
 previously explained, arc applicable. We add in the mar- 
 gin preceding some sections illustrative of the first named 
 method. For ribs of two thicknesses, each two feet apart, 
 the following scantlings are suitable. 
 
 24 Feet Diameter ... 8 X 1 
 
 36 
 
 60 
 
 ‘.Ml 
 
 108 
 
 Inches. 
 
 . 10 X V 2 „ 
 
 . 13X2\ S 
 
 . 13 X V , 
 
 . 13 X 3 
 
 To obtain greater strength the timbers are some- 
 times made double, as in the second figure, when the 
 scantlings may be reduced. It allows the formation of an 
 ascent to the summit between the ribs. In the third cut 
 there are two divisions. 
 
 I he design of domes admits of almost innumer- 
 able variations. In the f ollowing cut the framework resembles 
 centering, or a series of king and queen post trusses, ad- 
 mirably connected together with peculiar simplicity. The 
 central figure is Price’s dome, mentioned in our Sketch of the Progress of Carpentry. Oak was 
 
LIKES FOR RIBS OF DOMES. 
 
 185 
 
 recommended. The curved ribs rest on plates below, and are framed into a curb above carrying 
 
 the lantern: the purlins are so squared that the joints 
 of the small ribs are equal. As Price remarks, — “In- 
 all roofs land domes) of great extent, the wind is to be 
 prepared against, as strictly as the weight of the mate- 
 rials which cover them, because it hat so great a force 
 in storms of wind and rain; that is, it acts with more 
 violence than the. materials do, they being, what we may 
 
 call, steady pressure.' 
 
 LIKES FOR RIBS OF DOMES. 
 
 The geometrical processes required for the ribs of domes must be mainh 
 similar to those which have been already explained under the head of niches, and the reader is 
 referred to the remarks and illustrations relating to that subject. At the same time the greater 
 size of domes renders necessary several varieties of construction which call for some observa- 
 tions on the requisite lines. 
 
 For the method of making purlins of the proper form for conical roofs 
 and domes see Figs. I , 2, etc., Plate 25. 
 
 Figs. I .and la, Plate 27. illustrate an arrangement oi principal ribs, a 
 purlin, and jack ribs, for a spherical dome, in which all the ribs agree with great circles. 
 Fins. 2 and 2a show another form of construction, in which several purlins are introduced. 
 The explanations already given, and just referred to, will suffice for all the lines necessary 
 for these two examples. 
 
 Fig. 2 is a diagram representing, in elevation, an arrangement of ribs and 
 purlins for an ellipsoidal dome. Each rib will agree with a portion of an ellipse of which the 
 height of the dome will be the semi-conjugate, and the width measured on the plan the trans- 
 verse diameter. Each purlin will be elliptical in plan. Fig. 2 a is a plan showing the form of 
 the curb and the position of the ribs. This figure also represents a mode of proportionally 
 dividing the curb. The line a b is divided into a number of equal parts, and lines from the 
 centre of the ellipse are drawn through the points of division in the line ab to the curb line. 
 
 Fig. 4 is a diagram representing, in elevation, another arrangement of 
 ribs and purlins for an ellipsoidal dome. In this case the purlins will be elliptical in plan, but 
 the ribs will be semicircular. 
 
 Fig. 5 is a diagram showing, in elevation, a combination of ribs for an 
 ellipsoidal dome, in which one set of ribs will be semicircular as before, while another set 
 will be elliptical. 
 
 LINES FOR THE COVERINGS OF DOMES. 
 
 The geometrical processes to be used for finding the coverings of domes 
 have already been referred to in the article on covering circular roofs. See Plate 26, and 
 explanatory remarks relating to it. 
 
 The less distance there is between the ribs of domes the more truly boards 
 
 XXIV 
 
 Carpentry. 
 
LINES FOR THE COVERINGS OF DOMES. 
 
 1S6 
 
 n,. IV ho Kent over them to the required form. It would be best if at the widest part the 
 distance between the ribs were less than that usually made between Hour joists. That they may 
 be bent well to the form of the dome the boards ought to be rather thin. For the part of the 
 dome nearest the base the boards may be comparatively long and wide, but as the top is 
 approached it will be necessary, in order to diminish waste, to make them much shorter and 
 narrower. It is obvious that the greater the number of gores, or zones, and consequently the 
 narrower the boards are, the nearer will be the approach to a spherical form. 
 
 Figs. /, / a and / b, Plate 28, explain the mode of finding the form of 
 the gores which will cover the surface of an ellipsoidal dome. Fig. / is a plan, Fig. I a an end 
 elevation, and Fig. Il< represents one of the gores. By this method, with gores, which requires 
 no explanation beyond that given in the case of Figs. /, la, etc., Plate 26, the whole surface of 
 the dome may be covered by means of one mould. 
 
 Figs. 2 and 2 a illustrate the application of the method with zones to a 
 dome similar to the last. Fig. 2 is a half plan, and Fig. 2a is the end elevation. The inter- 
 sections of the lines a a, b />, etc., with the centre line mark the respective centres from which 
 the curves of the boards II, I, K, L are to be struck in the manner shown. 
 
 The boards for the widest part of a dome, as K and L, Fig. 2, will in 
 many cases require so fiat a curve, that owing to the great length of the radius it would be 
 impossible to strike the lines by means of a rod. Fig. 3 explains the method to be adopted 
 in this case. Let A BC represent the section of a spherical dome, and let C d show the width 
 of the lowest hoard. In the middle of the board between (J and d draw the horizontal line 
 ef, intersecting the axis of the sphere at g. Draw the line f A intersecting the axis of the 
 >pherc at //. Bv any one of the modes described in Chapter 2 describe an arc of a circle 
 through the points chf. This will lie the correct curve for the centre line of the board. 
 
 Fig. 1 is the plan of an annular vault. The part A represents its sectional 
 form. By continuing the lines b,c,d, etc., so as to intersect the centre line g h, the centres may 
 l>e ascertained from which to strike the curves of the boards K, L, M, N and O in the manner 
 represented, big. la is a smaller section showing more clearly the way in which the zones of 
 the annular vault coincide with portions of the surface of cones. 
 
 LINKS FOR PENDENTIVES. 
 
 II there is a room which is square in plan, which has vertical walls, and 
 
 "L" b has lur it- ceiling a surface coinciding with a part of a sphere (of a diameter equal to 
 
 "i '-teatrr than the diagonals of the room) then, the peculiarly formed arches produced by the 
 intei Met ion ol the vertical and spherical surfaces are called pendentives. Many varieties of 
 p< mlcntiv cs may be formed. 1 lie apartments may be square, oblong, or polygonal in plan; and 
 tin (rilings may be spherical, conical or ellipsoidal, flic known general properties of tho. solid 
 , ^ l< ' r, 'd |n g coincides afford the means of determining, in each case, the various 
 T 1 ' t< biting to the geometrical construction of the several parts. The geometrical pro- 
 
 blnns relating to pendentives have for their object the determining the correct springing lines 
 
 " n and also the defining the form, dimensions and position of the ribs. The remarks 
 
 ami illustrations already given in treating niches apply to these latter particulars, and it will 
 
LINES FOR PENDENTTVES. 
 
 187 
 
 be sufficient to observe in this place that in the case of conical ceilings the ribs will be straight; 
 with a spherical ceiling the ribs should correspond with parts of great circles; and with an 
 ellipsoidal ceiling the ribs would he all elliptical in form. What has more especially to be now 
 considered is the mode of obtaining the correct form of the springings. 
 
 Figs. I, / a, etc., Plate 29, illustrate the pendentives produced by the inter- 
 section of the vertical walls of a square room with a conical ceiling. The curved lines on the 
 walls from which the ribs spring will in this case be hyperbolas, and they may be described by 
 t lie method already shown on Plate 2, and explained in Chapter 2. The circles E, E, Figs. la 
 and lc, indicate the base of the cone with which the ceiling coincides. 
 
 Fig. / is a section in the plane of a diagonal. The springing lines A A 
 in this view are projected representations in which the height is correctly shown, while the width, 
 owing to the obliquity of the sides of the room, appears reduced. Fig. la is a plan in the cor- 
 responding position. Fig. 1 b is a section parallel with a side of the room, in which the form of the 
 springing line is truly represented. Fig. 1 c is a plan in the position corresponding with the last figure. 
 
 The springing lines, as shown by the curved lines A A A in Figs. / and 
 1 h, may be obtained in the following manner. From the point a, in Fig. I h, mark the dis- 
 tances a i, a ■>, and a w, taken from either of the plans, and draw the vertical lines intersecting 
 
 the inclined line of the ceiling at the point b, c and d as shown. From these points draw hori- 
 zontal lines in the manner represented. Then from the points i, ’ and :i in the plan draw- 
 
 vertical lines to intersect respectively the last drawn horizontal lines. These intersections be 
 and d are points in the curve of the. springing line which has to be drawn through them. 
 
 Figs. 1, la, etc., Plate 2(1, illustrate the pendentives produced by the inter- 
 section of the vertical w r alls of a square room with a spherical ceiling. The curved line on the 
 walls from which the ribs spring are portions of small circles of the sphere, while the ribs are 
 portions of great circles. In the oblique view of the springing lines presented by Fig. I, the 
 height is correctly shown, but the apparent width is diminished. This reduction of the apparent 
 width causes the springing lines in Fig. / to be represented as elliptical curves. The letters 
 and figures of reference in this plate are similar to those in the last; and the method of drawing 
 the springing lines in Figs. / and / b, by means of dimensions taken from the plan and applied 
 to Fig. 7 b , is the same as that which has been just explained in referring to Plate 29. 
 
 CHAPTER XIV. 
 
 BRACKETING, GROINS, SOFFITS AND NICHES. 
 
 SUMMARY. We enumerated these in our Plan at Page 10 for the sake 
 of presenting a complete general view of the subjects of the Encyclopaedia; but the information 
 which the carpenter requires relates almost entirely to the methods of finding the lines. The 
 subject has been fairly exhausted by Mr. Collins; and we refer the reader to the definitions and 
 explanations under the several headings in the Descriptions of the Plates of Lines as below. 
 
 For SOFFITS, see Page 58. For NICHES, see Page 145. 
 
 „ GROINS, „ 80. „ PENDENTIVES,, 187. 
 
 Bracketing is used to support cornices of great projection and save plaster. 
 
BRACKETING, GROINS, SOFFITS AND NIOFIES. 
 
 188 
 
 Wooden ribs, usually of I' - , in. deal for cornices, and I 1 2 to 2 ins. for entablatures, soffits, etc., 
 fixed to the ceilings and walls, about 12 or 14 ins. apart, with the profile cut roughly to that 
 ,,t the cornice, and within about one inch of its projection, this last space being- occupied by 
 ih, huh.-, nailed to the brackets, taking the plaster about 1 or 3 t in. thick. The skeleton 
 frame* placed at the mitres of the cornice are called angle brackets. Spandrel bracketing con- 
 -in- of a cradling between several curves, each being in a vertical plane and in the periphery 
 ot a circle of horizontal plane. Spheroidal bracketing is formed to receive the plastering of a 
 ■pheroid, spherical -bracket ing for a spherical surface, core bracketing for a cove, dome bracketing 
 tor dome, groin bracketing for a groin, and bracketing is'also formed for niches'. For entabla- 
 ture- to -hops, pendentives, etc., bracketing, or cradling, is fixed to take wood or plaster finish- 
 ing. What we call spandrels . the French, it may be remarked, name pendentives. A bracket 
 is also a support for shelves, etc. 
 
 We bring the above headings to a conclusion with the following method, 
 h\ Price, for finding a groin. 
 
 Erect a straight piece of a board on the corner of the pier whence the 
 groin -prings, and drive a nail at the meeting point of the groins; fasten on this one end of a 
 chalk line, straining it tight; slide it dfrwn the side of the said straight piece, and it will form 
 the groin »o as to stand perpendicularly over its line. 
 
 CHAPTER XV. 
 
 C E N T E R ! X G. 
 
 Wo shall not dilate at great length on the remaining subject of this 
 Division, as Centering. Bridges, Scaffolds, etc.; for, if the principles already defined have been 
 clenrh understood, little need be added to elucidate the above works. Centers may often be 
 considered as temporary bridges: and the latter are frequently constructed similarly to roofs, a 
 number of trusses being connected together; but there are many peculiar circumstances to be 
 taken into consideration, and these we shall brieflv explain. 
 
 DEFINITIONS. Arches of bridges, tunnels, vaults, etc., are supported 
 during construction bv a timber truss, frame, or rib, called a center or centre (from the French 
 verb a nicer or rnntrer, to build in the form of an arch). There are usually several frames, 
 from I iu III feet apart, variously trussed, tied and braced, connected together by bridging joists, 
 on which planks, or hu/gnays, are laid. 
 
 1 he following remarks applv chiefly to centering for bridges; but at 
 I tgc no much information, by Mr. Collins, will be found relating to the centering for groins, 
 im.re < -peciallv with respect to the various geometrical methods for finding the lines. 
 
 PRINT IPEES OF CONSTRUCTION. Three points have more espe- 
 tiallv to be considered in the design of centers. 
 
 k irst, they must afford an unchangeable support during the progress 
 ot the woik. Secondly, the expense must be slight, as they are only temporary erections: and 
 
CENTERING. 
 
 189 
 
 the timber should be injured as little as possible, in order that it may again he used. Thirdly, 
 they must admit' of being gradually and easily struck, or removed. 
 
 With respect to the first requirement, it is obvious that, as arches are 
 first built at the sides, the unequal pressure will tend to cause the center to rise at the crown 
 which it is thus often necessary to load; and, again, the pressure towards the latter as the arch 
 is completed being the greatest, it must be carefully secured, as well as the springing of the 
 centering towards which the pressure is distributed. The degree of sliding of the voussoirs and 
 the point at which they begin to act on the center are therefore primary matters for determi- 
 nation. Their friction and pressure on each other diminish the weight on the center: and ex- 
 perience demonstrates that a stone placed loose on an inclined ptfine will not slide until the 
 inclination is about 110°, and when it is connected by mortar or cement rarely under from 34" to 
 4fi°, according as the stone is hard or soft: but sometimes, as in the instance of the present 
 London Bridge, the archstones have slipped at 25°. Tredgold remarks that, generally for prac- 
 tical purposes, w y e may consider the pressure to begin with the joints at an angle of about 32° 
 with the horizon. This is called the angle of repose; and the pressure of the succeeding courses 
 above is proportionately increased. Couplet says that in a semicircular arch of uniform thick- 
 ness no voussoirs below 30° press on the center; and he adds that the weight to be supported is 
 not above four-ninths, or about one-half that of the arch. Robison, however, puts the pressure 
 down at two-thirds, and Pitot at eleven-fourteenths. When the voussoirs are at an angle of 
 45° the pressure on the center is about a quarter, and at (it! 0 about half the weight of the arch- 
 stones. Near the crown the weight of the stones is wholly carried by the center. These facts 
 indicate the points where the framework should be most strengthened. In elliptical arches the 
 pressure begins sooner than in those which are semicircular; and the Hatter the arch, the greater 
 the weight to be carried. 
 
 The timbers should be few in number, and be so disposed that the pressure 
 and strains are mutually counteracted. Principals are to be made to abut firmly end to end, 
 and intersect one another as little as possible. Sockets of cast iron are advisable at the angles; 
 and struts and braces are often used in pairs bolted together. The strains must be carried to 
 the points which can best support them - : and quadrilaterals are to be avoided, the strength and 
 stiffness depending on a series of triangles. As Robison remarks, the strain caused by one 
 piece on two others with which it meets at one point depends on the angles of intersection, and 
 these are greater as an obtuse angle is more obtuse and an acute angle more acute. All very 
 obtuse angles must be carefully avoided (See Page 122); but acute angles not necessarily ac- 
 companied bv obtuse ones are not so hurtful. To secure the utmost strength every timber 
 should be disposed so as only to be subject to a strain which either pushes or draws it in the 
 direction of its length; but cases occur in which this end cannot be attained, and interrupted 
 ties must be supported by something analagous to the king posts of roofs. Cresy says that, — 
 “Timbers which have great weights to support, and which are pressed in the direction of their 
 length, should be as many inches square as they are long in feet, or from a tenth to a twelfth 
 of their thickness in length: wdien drawn in the direction of their length, from a thirtieth to a 
 twenty- fourth: and bearers loaded at right angles, or perpendicular to their length, from a 
 twenty-fourth to an eighteenth.” 
 
190 
 
 CENTERING. 
 
 Tlie second requirement relating to the saving of expense in the con- 
 st ruction of centering was well met by Smeaton, the celebrated engineer, who designed his 
 centers suitably to the usual scantlings of timbers, thus economising both labour and material. 
 Speaking of the center of the Coldstream bridge, he observes: — “TV ith respect to the scant- 
 lin.rs I did not so much contrive how to do with the least least quantity of timber as how to 
 cut it with the least waste; for, as I took it for granted the center would be constructed of east 
 country fir, 1 have set down the scantlings such as they usually are in whole balks, or cut into 
 two lengthways.” (Smeaton' a Reports.) 
 
 Facility of gradual removal, the third requirement, is of very great im- 
 portance. Time must be allowed for the mortar to harden and the arch to settle; and the dis- 
 memberment of the center calls for much care and patience, although apparently a simple 
 operation. Double wedges, or blocks with wedge-shaped steps, are often used to support the 
 frames, and arc driven back when it is desired to ease the center, common mauls being employed 
 for small works, and a heavy beam, driven like a battering ram against the wedges, in large 
 ones, 'fhe contrivance adopted at Blackfriars bridge is shown on Plate 44, Fig. 1, A being the 
 striking wedge, the outer end of which is bound with iron: the pieces above and below, cut in 
 a zig-zag form to receive the wedge, arc of oak, and their surfaces are covered with copper. 
 The system common on the continent of slowly destroying the ends of the chief timbers is 
 inferior to the English method of removing the wedges introduced; as in the former it is diffi- 
 cult to allow the centers to rest securely, as is often desirable during the process of removal, 
 and lives are. occasionally sacrificed through the necessity of having men beneath. A gradual 
 withdrawing of the centering causes the joints of the masonry to close properly, and obviates 
 many evils consequent on a sudden removal. But “an arch built on a center perfectly suited 
 to its equilibration will not be in equilibrio when the centering is removed. It is therefore 
 necessary to form the centering in such a manner (by raising the crown) that it shall leave the 
 arch of a proper form. This is a very delicate task requiring a previous knowledge of the 
 ensuing change of form. On many occasions, if the centering were instantly struck, the arch 
 would give way. In any case, there is sure to be some ultimate settlement. Tbe sinking of 
 the bridge ol Neuilly was 14 inches during its progress, and It) 1 after the removal of the 
 centering. Dublin bridge, of 105 feet span, sank only 1 3 4 in., Blackfriars, of 100 feet span, 
 
 1 1 4 in., and A aterloo, of 120 feet span, l 1 in., after striking the centers. 
 
 In the Encydopcedia Britannica, art. Centre , the reader will find a masterly 
 resume of the whole subject. 
 
 DESCRIPTION OF EXAMPLES. Centers may be divided into those 
 w ith or without horizontal ties. Ihey are severally adopted according as it is desirable to leave an 
 open space below, which, in many bridges, is often necessary in order that navigation may not 
 In obsti uctcd. It is obvious that those without ties present the greatest difficulties in construction. 
 
 f>n Plate 44, bigs. 2 to 0 are forms of centers suitable for small openings. 
 Figs. 7 and S are adapted for tunnels. In Figs. 9, 10 and 11 stone offsets in the arch itself 
 Mi u>cd tor the abutments, of which practice we still see remains in ancient Roman works. 
 Eig. 12 is a form of centering for a rampant arch. Figs. 13 and 14 illustrate a method of 
 d< tu mining the position of a tie when used in the centering of an elliptical or semi-circular 
 
CENTERING. 
 
 191 
 
 arch. Draw the tangents A B, AC, and also, from the angle A, the line AD perpendicular to 
 the curve: E is the position of the tic. Then divide EB into two or three parts to determine 
 the position of the timbers F, G; and we have thus also the inclined strut. Binding pieces below 
 are so placed according as E C is divided into two or more parts. 
 
 On Plate 45, Fig. 1 illustrates Pitot’s system of centering. A stretcher 
 is extended at the angle where the archstones begin to yield, the extremities below are sup- 
 ported by struts, and a king post and principals placed above. This example is suitable for a 
 span of about 60 feet; and the rings, if of oak, may be 12 X 6 ins., stretcher, straining piece 
 and king 12 ins. square, lower struts 10 X 8 ins., upper struts 10 X 6 ins., and bridles 
 20 X 8 ins. Fig. 2 is the centering of the bridge at Moulins designed by Regemorte; and 
 Fig. 3 is that of Neuilly by Perronet. This last arch is 120 feet span with a rise of 30. The 
 scantlings are: — strut beams 17 X 14 ins., kings 15 X 0 ins., horizontal bridles 15x9 ins. 
 each half, eight horizontal ties 9 X 9 ins. Although the light appearance of this centering 
 may prepossess many, we have already mentioned its great settlement; and the footing of the 
 lower beams and the triangles generally are too oblique, the abutments insufficient, and the 
 whole deficient in strength and stiffness. Figs. 4 and 5 are also centers designed by Perronet. 
 Fig. 6 is that of the bridge at 'Orleans begun by Hupeau, executed by Perronet, and considered 
 one of the boldest ever constructed: the span is 100 feet. The pieces at A were inserted by 
 Perronet on the crown of the center rising and falling during the progress of the arch, thus 
 adding considerably to the rigidity of the frame. Fig. 7 is the centering of the bridge at Melun 
 by Eustache; and Fig. 8 is that of Briamjon. 
 
 We again refer to the woodcuts at Page 3(5 of the centering to the nave 
 and dome of St. Peter’s at Rome. 
 
 CHAPTER XVI 
 
 B R I D G K S. 
 
 GENERALLY. A bridge is simply an artificial elevated way, fixed, 
 moveable or floating, between two points separated by an intervening depression, whether a 
 river, canal, roadway, morass, ravine, etc. The science of bridge building, in stone, iron or 
 wood, is properly a branch of engineering; and we shall only glance at the prominent points 
 relating to constructions in the last named material, which is the simplest, cheapest, and most 
 used for wide spans, setting aside suspension bridges. 
 
 SPAN. Bridges should cross a stream at right angles to the current; 
 and the span will depend on the height of the banks, the rise and rapidity of the flood, and 
 the sizes of the timbers at hand: single arches are generally advisable up to about 35(1 feet span. 
 
 RISE. Telford and Wiebeking mention a rise of 1 in 24 as convenient; 
 and Smeaton says: — “If the ascents do not exceed 3 inches per yard they are no ways ob- 
 jectionable.” 1 in 12 appears to be the utmost permissible rise; and, as regards appearances, 
 Wiebeking names one-tenth of the span as a pleasing proportion for an arch. As the settlement 
 
BRIDGES. 
 
 192 
 
 is generally 1 in 72, if it is intended for a bridge to have a rise of 1 in 24 when completed, it 
 © » 
 
 must he framed with a rise ot 1 in lb. 
 
 WIDTH. With respect to the width of bridges, 18 feet clear admits of 
 
 carriages passing with safety; and 2 feet should be allowed for every foot passenger: thus, the 
 carriage way should be increased in the proportion 9, 18, 27, etc., and the footways 2, 4, 6, etc. 
 The roadways of Waterloo and Blackfriars bridge are 28 feet wide; and that of London bridge 
 i- 35 feet, with footways each 9 feet. Parapets may be from 3 ft. b ins. to 5 feet high: outside 
 braces are often used to steady them. 
 
 FLOORS. The Hours of foot bridges may be of planking 2 to 4 ins. 
 thick, pitched and sanded. The great duration of lead and copper will be found in the end 
 equivalent to their cost. For carriage bridges gravel mixed with tempered clay is laid on the 
 planking, and from 10 to 18 ins. deep in the middle and 9 to 15 ins. at the sides. Beliclor re- 
 commends paved bridges as the most lasting. Formerly it was common to lay paving on a 
 bed of sand; but its great weight and the percolation of the water; destroying the timber be- 
 neath, are objections: means may be adopted to carry off the water. 
 
 PAINTING, etc. All woodwork should be painted or pitched. Wiebe- 
 king soaked the mortices and tenons in hot oil, and applied twm coats of pitch and tar to all 
 principal timbers: he also formed small gutters near the lower extremities of the braces and 
 ribs to prevent water settling in the joints. 
 
 WEIGHT. The loading, framing and gravelled roadway of timber 
 bridges may be taken at about 350 pounds per foot super. 
 
 PILING. Stone is the best material for the abutments and piers; but 
 for the latter it is usual to substitute piling, consisting of squared timbers cut to a point at the 
 lower end and shod with iron to enter the ground, with a hoop at the upper part to prevent 
 splitting from the blow's of the monkey, or hammer. Flat piles, called pile planks, are about 
 1 ins. thick, ploughed and tongued together. Stilts is a name sometimes applied to piles with 
 the tops cut off below low water mark, having other piles built up above, and which latter, 
 decaying where alternately wet and dry, can thus be easily removed. The joinings are secured 
 by horizontal pieces firmly bolted: [dies are often morticed together with a dovetail joint. In 
 Smile piling the timbers are 9 to 15 ins. square, and from 2 to 5 feet from centre to centre, 
 driven in the direction of the current, and steadied by oblique braces. “When the river has a 
 considerable depth, a double rote of [dies is requisite, for it would be hazardous to depend upon 
 a single one: the lower range is driven about 3 feet apart, or from centre to centre, and a 
 capping piece, extending the whole breadth of the bridge, is laid upon the heads of each row; 
 an intertie crosses these, and on it is placed a third timber, extending the breadth of the bridge, 
 into which is framed the post, which carries the platform; these timbers are all well framed and 
 bolted together. l imber 12 inches square has sufficient strength to bear any weight to which an 
 ordinary wooden bridge is subject, though double rows of piles are often used: where many rows 
 are requisite, they must be protected by sterlings so contrived as to prevent ice or other floating 
 GhIic- from injuring them, and the best method of effecting this is to drive two rows of piles 
 " nding to a point, in front of the pier to be protected, and to plank them so as to resemble a 
 "edge; upon the top of this, which is level with the surface of the stream, is laid an inclined 
 
BRIDGES. 
 
 193 
 
 piece of timber against the pile, which may he strutted on to the heads of the piles forming 
 the wedge, and. by putting an iron edge to resist the ice, be made very efficient.’ (Cresys En- 
 cyclopaedia of Ctrl/ Enyineering.) To this work, and Tredgold’s Elementary Principles of Car- 
 pentry , we would refer the reader for additional information on the subject of timber bridges. 
 
 PRINCIPLES OF CONSTRUCTION AND CLASSIFICATION. The 
 simplest form of timber bridge is that on the principle of the flat lintel. To strengthen a timber 
 beam, without using a larger quantity of timber, we may make it deeper in the middle than at 
 the ends; and the best form for equilibrium is that shown in the upper figure adjoining, com- 
 posed of one piece, or several bolted or strapped together: 
 if there arc two pieces the lowest may be parallel above and 
 below, and the upper cut tapering as in the left hand side 
 division separated by the dotted line. (See Chapter 2, Divi- 
 sion 4.) Six modes are next suggested for supporting a single 
 beam; and a vast variety of bridges may be reduced to one 
 or the other of these principles. The simplest consists in 
 the introduction of struts or braces below; then come king or 
 queen post trusses, and other ordinary forms of roofs, used 
 either with or without the braces below; and lastly the varied systems of suspension may be named. 
 
 On Plate 46 are twenty-one diagrams illustrative of the principles of 
 bridge building now in vogue; and they will be found to form a very comprehensive series, to 
 which many most elaborate and complicated structures may be referred. In Figs. 1, 2 and 3, 
 and the wood-cut at Page 32 of Ciesar’s bridge over the Rhine, are modifications of the flat 
 lintel. Fig. 2 is a kind of latticed girder devised by Ithiel Town, an American Engineer. It is 
 suitable for spans up to 150 feet, and is much used on American railways; only small scantlings 
 are requisite. Fir planks about 12 ins. wide, and 3 ins. thick, united at the intersection by l 1 ._> inch 
 oak tree-nails, are used for the lattice, and its depth is in the proportion of about 9 feet to a 
 span of 78. The two ribs under each side of the roadway are connected by transverse timbers 
 about 12 feet apart, diagonal pieces are inserted below, and the lattices run into stone abutments. 
 Generally, the height of such trusses in America is about one-tenth of the span. The railway 
 bridge at Richmond, United States, 2900 feet long, with frames 10 feet deep, and spans of 
 from 130 to 150 feet, 60 feet above the water, cost only £ 24,200, a fact evincing the eco- 
 nomy of the system. 
 
 Fig. 3 is another American method of bridge building, that of Long. 
 
 o o O 7 O 
 
 It consists of a series of St. Andrew’s crosses; and a bridge on the Western railroad, United 
 States, was thus erected, 1260 feet long, in spans of 180 feet. The lower ties are 1 foot deep 
 by 5 inches broad, and the inclined braces and upper stringers 8 inches square, the heads and 
 sills being bolted together. 
 
 In Figs. 4 and 5 we have framing in which the tie takes the pressure, 
 thus relieving the abutments. The bridges at Schauffhausen (inadvertently compared in our 
 History to Price’s design) Landsberg, Zurich, and Wettingen are on this principle. 
 
 Figs. 6, 7, and 8 illustrate the transition to placing the thrust entirely on 
 
 Carpentry. . XXV 
 
BRIDGES. 
 
 104 
 
 tile abutments, as we may easily imagine a construction in which the tie in Figs. 4 and 5 is 
 removed. The straining piece A B in Fig. 8 should be equal to one third of C D. 
 
 In Figs. 9 and 10 is the principle adopted by Ritter in the Kandel bridge, 
 the pressure being on the abutments. 
 
 By the introduction of horizontal straining pieces, short timbers may be 
 made available, more particularly with polygons of beams, as in Figs. 11 and 12. Perronet 
 adopted polygonal arches. The angles are too obtuse for great strength; and variable loads acting 
 on bridges with short timbers and numerous joinings are apt speedily to produce derangements. 
 
 Next come continued curved ribs, either on the principle of Delorme, as 
 in Fig. 14, or on that of Kmy, as in Fig. 14. These last are in frequent use on railways. Care 
 must he taken to counteract vibration, on account of the elasticity of the ribs, and the bolts and 
 straps should he moveable, to facilitate the removal of decayed planks. At Page 104 a bridge 
 is described with an arched rib, depending on the abutments. Before Wiebeking’s time short 
 pieces of timber were used for curved ribs, but he adopted long lengths bent, and carried out 
 many remarkable works, as those at Freysingen and Bamberg. At Page 103 an excellent bridge 
 by Emmery is described and illustrated. 
 
 In Fig. 15 we have Palladio’s system of framed voussoirs; but, on account 
 of the shrinkage of the timbers, and the vibrations caused by variable loads, the lightness and 
 balance of the framing are continually endangered. 
 
 A curved rib when loaded at the centre yields there and at the two points 
 about midway between the centre and the abutments. Framed ribs, such as Figs. 16 and 17 
 and the wood-cut at Page 32 of Trajan’s bridge, have therefore been adopted for wide spans. 
 Fig. 17 is on a similar principle to the bridge at Schuylkill, America, designed by Wernwag. 
 'fhe span is 340 feet, the versed sine 38, and there are 31 radiating posts. Three double rows 
 of timbers, three deep, bound together with wrought iron, constitute the main ribs; the cross 
 pieces we have dotted would increase the rigidity of the combination. Fig. 18 is a good form 
 of framed rib with bent planks. 
 
 bigs. 19, 20 and 21 are on the suspension principle, ropes and timber 
 being used. The systems of Styerme and Lavesare described at Page 157. 
 
 ( )n Plate 47, big. 1 is the celebrated bridge over the Cismone, between 
 1 rent and Bassano, designed by Palladio, and constructed by a carpenter named Martino. Its 
 length is IDS feet, the transverse girders below are 12 inches square, and are strapped up to 
 tin' trusses out ot timbers 12 by 9 inches, and which form the parapet. Figs. 2, 3, 4, 5 and 6 
 are also designs by Palladio. 
 
 Figs. 7 and 8 are suggestive forms, together with Figs. 9 and 10, the last 
 example being >uitable for temporary purposes. Fig. 1 1 is also ingenious. 
 
 fig. 12 is illustrative of the suspension principle adopted by Burr in the 
 bridge executed over the Delaware in America. In this example there are five parallel rows 
 ot arches, with ribs of cut planks, 12 inches wide, 4 thick, and up to 50 feet in length, 3 feet 
 deep, breaking joint, and bound with iron straps. Horizontal ties, diagonal timbers, and iron rod 
 Mispenders arc introduced as shown. There are five arches, three of which are 300 feet in span. 
 
 1 ig. 13 is the bridge over the Brenta, at Bassano, designed by Palladio. 
 
BRIDGES. 
 
 195 
 
 Figs. 14 and 15 are horse bridges, the first at Vrach in Wurtemburg of 35 
 feet span between the piers, and a width of 7 feet 6 inches; and the second over a canal at Utrecht. 
 
 Figs. 16 and 17 illustrate a very ingenious and simple bridge designed by 
 Price, and which has attracted much attention. We give a brief description of it from his Car- 
 pentry. It is adapted to public and private uses by being so formed of small parts that it may 
 be carried to any assigned place, and there put together at a short notice. The bridge is sup- 
 posed to consist of two principal ribs made thus: the width of the place is spanned at once by 
 an arch rising one-sixth part of its extent; its curve divided into five parts, which are proposed 
 to be of good seasoned English oak plank, of three inches thick and twelve broad, their joint, 
 or meeting tending to the centre of the arch; within this rib is another, cut out of plank, as be- 
 fore, of three inches thick and nine broad, in such sort as to break the joints of the other. In 
 each of these ribs are made four mortices, four inches broad, and three high, and in the middle 
 of the said nine inch plank; these mortices are best set out with a templet, on which they have 
 been truly divided and adjusted. Lastly, put each principal rib up in its place, driving loose 
 keys into some of the mortices, to hold the two thicknesses together; while other help is ready 
 to drive in the joists, which have a shoulder inward, and a mortice in them outward, through 
 which keys being driven, the whole is kept together. On these foists lay the planks, gravel etc.; 
 and the bridge will be found suitable -for rivers thirty-six feet wide. In case the river is forty 
 or fifty feet wide, the stuff should be larger and more particularly framed. The planks ought 
 to be four inches thick and twelve broad; in each of these are six mortices, four of which are 
 four inches wide and two high; through these are driven keys which keep the ribs better to- 
 gether; the other two mortices are six inches wide and four high; into these are framed the 
 joists of six inches by twelve; the tenons of these joists are morticed to receive the posts, which 
 serve as keys. The wdiole being performed without iron, rusting, scaling and loosening of the 
 parts in the course of time is avoided, sound timber keeping tight and firm together. Although 
 some may imagine this timber arch is liable to give way when a weight comes on any particular 
 part, and rise where there is no weight, such objectors may be satisfied that no part can yield 
 or give Way till the keys are broken short off at once. 
 
 Fig. 18 is a bridge at Kehl on the Rhine; and Fig. 19 a curious example 
 at Savines, in the High Alps, 75 feet span, with a centre post 16 feet high, into which tw r o prin- 
 cipals are framed, the bridge being thus suspended. Fig. 20 is a remarkable bridge at Zurich 
 128 feet in span, roofed over, Figs. 21 illustrate a turning bridge spanning a Canal at Utrecht. 
 
 Plate 48 contains details of the bridge for carrying the turnpike road over 
 the Ouse at Littleport, designed and executed under the superintendence of Mr. R. R. Rowe, 
 Surveyor General of bridges in the Isle of Ely. It is an excellent model for structures of its 
 kind, being simple, economical and ingenious. 
 
CHAPTER XVII. 
 
 S C A F F 0 L 1) I N Ft, l^T G. 
 
 A Scaffold is a temporary structure for supporting workmen, raising ma- 
 terials, ete., during the erection or repair of buildings, and it may be either fixed or moveable. 
 For an account of Cenlcriufi see Chapter 15. 
 
 The Bricklayer's ordinary scaffold is formed of upright poles, generally 
 of fir, in or 5(1 feet long and 0 or 7 inches in diameter at the butt ends, which are fixed in the 
 ground. Additional height is obtained by lashing the poles together one above another, the 
 junctions being tightened by driving wedges between the cords. The uprights are called stan- 
 dards, the horizontal poles, parallel with the wall and fastened to the standards by cords, ledgers, 
 these last supporting cross pieces, at right angles to the wall and let into it at one end, named 
 jmfloqs, and which are generally of birch wood about 6 or 7 feet long; stout scaffold hoards for 
 working upon, hooped at one end to prevent splitting, arc laid on the putlogs. Shores are ob- 
 liquelv placed timbers used to support insecure buildings during repairs, etc. The building may 
 he considered as a post, the ground a beam, and the shore a brace, Planks, or beams, must be 
 used at both ends of shores to distribute the pressure; and they are tightened by wedges. 
 
 The Masons scaffold is erected independently of the walls, as no putlog 
 holes can be allowed in stonework. Two parallel rows of standards are raised; and round tim- 
 bers arc now superseded by square, joined with bolts and dog-irons. A travelling crane, running 
 along a tramway formed on the summit of the scaffold, is used to hoist materials. 
 
 Messrs. -Cubit t, the eminent builders of Gray's Inn Lane, have the credit 
 of first introducing into England scaffolding of squared timbers on an extensive scale at the 
 Huston Square Railway station: the parallel standards were 90 feet in total height. Such scaf- 
 folding, however, was used at Cologne Cathedral from its commencement in 1248, and subse- 
 quently on many occasions on the continent: in Paris it has been in constant requisition.. That 
 for the Nelson monument in Trafalgar Square was composed of 154 loads of unsawn timber; 
 it- height was ISO feet, the base 90 square, and the cost £ 240. 
 
 At 1 J age 36 are illustrations of the scaffolds for the dome and nave of 
 
 St. Peters at Rome which, together with that shown on Plate 49, and in the woodcut on the 
 
 opposite page, as used for their repair, are taken from Zabaglia’s work before mentioned. 
 1 he hist for the nave was raised complete and made to traverse the length. The height of that 
 for the dome was nearly Si) feet and t lie diameter ISO; the vertical pieces were suspended from 
 hooks inserted in the stonework. The revolving scaffold used for the repair of the Roman Pan- 
 theon, and shown on Plate 49 and in the following woodcut, was 143 feet in diameter. (See 
 /‘agi d>.) Emv observes that “it is the most ingenious that has ever been constructed,” and its 
 lightness and beauty can hardly he too much admired. The Italians, indeed, are the boldest 
 and most skilful scaffold builders in the world, although Sir Charles Barry has designed scaffolds 
 for the Houses of Parliament which may challenge comparison with any for security. 
 
 Gn Plate 50, Fig. J illustrates the scaffold devised by M. Dabrin, a master 
 
 • arpenter, for the repair of the church of St. Gervais in Paris; it is an excellent type of the 
 
SCAFFOLDING, ETC 
 
 197 
 
 fji oxr. 
 
 mason’s scaffold. Figs. 2 and 3 are hanging scaffolds designed by Zabaglia; Fig. 4 was used 
 for cutting the caissons of a chapel at Turin; Fig. 5 was designed by M. Mandar; Fig. 6, 
 although much used by painters, is very unsteady. A turning scaffold designed by Emy is 
 shown on Fig. 7; and we have added another more stable on the other side, Fig. 8. Fig. 9 is 
 
198 
 
 ACCESSORY CONSTRUCTIONS. 
 
 useful for many purposes. Below is Emy’s scaffold for the roof at Marac before described: 
 tlierc are neither mortices, nor tenons, the timbers being simply halved. The knots added 
 require no explanation. According to Emerson, a good hempen rope, one inch in circumference, 
 will hear 100 pounds. 
 
 CHAPTER XVIII. 
 
 ACCESS 0 R V CONS T R U C T 1 0 N S. 
 
 BRESSUMMEKS, OR BREAST-SUMMERS, are timber beams used 
 to support the breast, or front wall of a building when there is a wide aperture below. They 
 should have a bearing at both ends of at least 9 inches, and stone or iron templates are com- 
 monly adopted. Bressummers may be trussed as the girders shown in the woodcuts at Page 164; 
 and the scantlings must be determined by the rules given in the Third Division. They are 
 ordinarily 14 inches square, 14 by 12, or 14 by 9 inches. Those of large dimensions are often 
 sawn, reversed and bolted with 3 4 inch wrought bolts. A curbed flitch of wrought iron (' / 4 inch 
 thick), forged in the shape of an arch, may be inserted as shocvn on Plate 51, or it may be of 
 rolled wrought iron uniform in depth with the bressummer. By inserting a wrought iron plate, 
 sloping slightly upwards, as in the other figure, the shrinkage of the girder will be allowed 
 for, and the brickwork settle evenly. 
 
 Cast iron bressummers are objectionable, as, in case of fire, if they do 
 not at once crack, no dependence is to be placed upon them after being suddenly cooled with 
 water. Wrought iron is preferable in every respect, especially in case of fire. There is a great 
 increase of strength with an economy of nearly two-thirds of the material, and thus much less 
 weight to support. We may mention that, in calculating the strength of timber or iron bres- 
 'Uinmcrs, the weight of brickwork may be taken at about 100 pounds per cubic foot, timber 
 flooring, plastering, etc., at from 180 to 200 pounds per foot super, and the loading on floors at 
 120 pounds per loot super.: from 14 to 16 feet cube of stonework equal one ton. 
 
 LINTELS may be considered as small bressummers placed over doors, 
 windows, etc. Langley remarks: — “For the better disposing of the weight imposed on girders, 
 lintels should always be firmly bedded on a sufficient number of short pieces of oak, laid across 
 the walls. Smith recommends scantlings of 5 inches thick by 7 broad. A depth of as many 
 inches as there are feet in clear width of aperture has been named; and we advise 6 inches 
 deep in lower floors, and 4 1 2 in upper, the lintels being laid side by side in the breadth of 
 the opening, about 4 1 inches in width, and bearing 9 inches at each end on the walls. 
 
 BOND signifies a tie, and the term is applied generally to timbers cut 
 *'4 range with bricks and built in walls to assist in holding them together: it is sometimes dove- 
 tailed at the angles ot cross walls. Partitions with upright and vertical pieces of timber built 
 in the brickwork are called bricknogged. {See Page 106.) Chain bond is that serving the ad- 
 ditional purpose of attaching finishings. Fir bricks, about 4 by 2 3 / 4 inches, are inserted in 
 k w o i k at intenals to attach the finishings of doors, windows, etc. Smith advises the coating 
 ot all tunhei.- laid in walls with a composition of one pound of grease to four of pitch. 
 
ACCESSORY CONSTRUCTIONS. 
 
 199 
 
 By the Metropolitan Building Act, 18 and 19 Viet., C 12*2 — “no bond 
 timber, or wood plate shall be built into any party wall.” Tyerman’s patent hoop iron bond 
 will be found an excellent substitute for the ordinary wood bond. 
 
 BATTENS are scantlings from 5 8 to 2 inches thick and 1 1 / 2 to 6 inches 
 broad, often attached vertically to bond, wood bricks, plugs, or by wall books where there are 
 Hues, to walls, and from 9 to 15 inches from centre to centre, to take laths for plastering. 
 Battens 3 / 4 by 2 inches, 11 inches apart, fixed to flush bond or plugs, 12 or 14 inches from 
 centre to centre in the direction of the length of the battens, are common for laths, the damp 
 in brickwork thus not so easily showing and irregularities of surface being concealed. For 
 slating battens may be 3 4 , 1 and I 1 4 inch thick, 2' 4 or 3 inches wide, and 9, 12 or 15 inches 
 from centre to centre. 
 
 LATHS, often attached to battens, are thin cleft or split pieces of oak 
 or fir, used in slating, tiling and plastering. They are from 3 to 5 feet long and about one inch 
 wide. Single laths are 1 4 , double 3 / 8 inch thick, and there is lath and half. They should be 
 laid so as to break joint as much as possible. Thirty bundles go to the load at which they 
 are sold. Wrought nails should be used for oak, and cast may be adopted for fir laths. Heart 
 laths are chiefly used for roofing, and sap for plastering. 
 
 BOARDING for lead is from 1 to 2 inches thick, close jointed or with 
 edges shot; for slates from 1 / 2 to 3 /( inch, sometimes tongued; and for walls from 1 /., to 1 inch 
 variously jointed and finished. Weather boarding is usually feather-edged, that is made thinner 
 at one side than the other, and lapped from 3 / 4 to l'/ 2 inch; it may be rough, four boards 
 going to the three inch deal, wrought with edges shot, beaded, etc. 
 
 PALING AND FENCES. Enclosures may be fenced with oak posts 
 5, by 5, or 6, by 6 inches, 6 to 9 feet long and 9 or 10 feet apart, with 4, 5, or 6 feet cleft oak 
 
 piles, two or three arris rails, l 1 2 inch oak plant 12 inches wide at the bottom, capping at top, 
 
 with tenter books or nails, and gates to range, with hanging and lock stiles, and three hori- 
 zontal rails with paling or rounded bars. We have put on Plates 51 and 62 some ordinary 
 gates and palings. Plate 52 contains some excellent details of road gates designed by 
 Mr. William Wright and executed on the North Western Railway. 
 
 SPIRES AND TURRETS may be classed under the heading of this 
 Chapter. Three very suggestive examples arc given on Plate 51. 
 
 WOOD HUTS admit of innumerable variations in design. Those on 
 Plate 51 are perhaps as simple and inexpensive as any. They are suitable for camping and 
 other purposes: shelves etc. are shown. 
 
 C41SSONS AND COFFER DAMS. A passing mention of these will 
 suffice in this work. The former are large timber chests, used for building in water and so 
 
 contrived that the bottom may be detached from the sides. A level bottom or surface having 
 
 been prepared, and guide piles fixed, they are floated to the spot, weighted, sunk, anil then 
 built upon. Sometimes the caissons are rested on piles with the tops cut off level, as at a 
 railway bridge at Liege. 
 
 Coffer dams are water tight walls of piling to facilitate the execution 
 of works. The piles are sometimes driven close, at others with stout boarding between in 
 
20(1 
 
 LINES FOE MOULDINGS. 
 
 „ rooveti , and again dovetailed or notched together. In shallow water single piling is used, in 
 deep double, or"even four rows, clay, chalk or puddle being rammed between them. The sides 
 are braced to withstand the pressure of the water, which there is always great difficulty in 
 effectually excluding. 
 
 LINES FOR MOULDINGS. 
 
 TO ENLARGE .1 CORNICE OR OTHER ASSEMBLAGE OF MOULDINGS . — - 
 Let Fifj. I, Plate HI, represent the cornice which has to be enlarged, and let A B, Fig, l a, be 
 the proposed increased height. From the point b, Fig. I draw the perpendicular line ah, and 
 from the point a, with a distance equal to the required height AB, describe an arc, intersecting 
 the line be at c. Join a c. The points i, >, 3, 4 and 5, at which the line ac intersects the hori- 
 zontal lines of the mouldings, give the required proportionally increased heights, as shown on 
 the line A B, Fig. / a. To obtain the* proportionally increased projections of the several mould- 
 inas: from the point a draw the line ad at right angles to the line ac, to intersect the vertical 
 line ed which is let fall from the greatest projection of the cornice at e. From the various 
 points of projection draw vertical lines to intersect the line ad, in the manner represented, at 
 the points k, /, in, n, o, p and q. Transfer the distances thus marked on the line a d to the line 
 lb/, Fig. la, and from the points thus indicated draw vertical lines to mark the projection of 
 the various mouldings as shown. 
 
 TO DIMINISH .1 CORNICE OR ANY ASSEMBLAGE OF MOULDING Let 
 Fig. 2, Plate HI , represent the cornice which has to be diminished, and let A B be the proposed 
 reduced height. Draw the rectangle A def, letting its width be equal to the total projection of 
 the given cornice, and its height equal to the height of the given cornice. Draw the diagonal 
 line A e, and from the point B draw a horizontal line to intersect the diagonal A e at C. The 
 line BC is equal to the required diminished projection of the cornice. To obtain the pro- 
 portionally diminished height for each of the mouldings, draw horizontal lines from the profile 
 to intersect the line de as shown. On de construct the equilateral triangle deg, and from the 
 point g mark the distances g a and gb each equal to AB. Join a b and the line ah will be 
 equal to A B. From the points i, i and •> in de, draw lines to g, intersecting ab as shown. 
 I he points i, :i, i and •>, in a b, indicate the proportionally reduced heights of the mouldings 
 as required. To obtain the proportionately diminished projection of each of the mouldings, 
 draw vertical lines from the profile to intersect the line hi as shown. On hi construct the 
 equilateral triangle hik, and from the point k mark the distances kb and kc each equal to 
 B( . Join be, and the line be will be equal to BC. From the points rn, n, o, p, q, r, and s in 
 k i. draw lines to k, intersecting be as shown. The points in, n, o, p, q,r,s, in be, indicate the pro- 
 portionally diminished projection for each of the mouldings as required. Fig. 2a represents the 
 profile ul the reduced cornice, with the heights and projections as obtained in the manner described. 
 
 MOULDINGS TO BE BENT ON CIRCULAR WORK. The mouldings to which 
 dic.'C remark- refer are those which are intended to be fixed upon an inclined backing as repre- 
 sented by logs. ■) and Ha, Plate HI. It will be easily understood that if a moulding of this kind 
 l,<< ins 1,1 Fneular work, it must be made of a particular form in order that it may be bent truly 
 , ' 1< ‘ l H) 'ition required, logs, 4 and 4 a are diagrams to illustrate the principle which determines 
 
LINES FOR MOULDINGS. 
 
 201 
 
 the form of these mouldings. In these figures, proportion (which in an explanatory sketch is 
 immaterial) is sacrificed for the sake of greater distinctness and the moulding is drawn rather 
 large. A B Fig. 4 represents a cylindrical body round which it is required to bend the moulding 
 shown in section at C and C. It will be perceived that the surface represented by the line CD 
 must coincide with the surface of part of a cone, and if the two lines CD and CD are pro- 
 duced until they cut each other at e, the intersection so obtained will agree with the vertex of 
 the cone. And if from the centre e arcs of circles are described, as indicated by the dotted 
 lines, those arcs of circles will show the amount of curvature to which the moulding must be 
 worked. Fig. 4 a shows the necessary curvature of the moulding. 
 
 11AKIXG MOULDINGS. — Mouldings which are not horizontal in the di- 
 rection of their length are called raking mouldings. When a raking moulding has to intersect 
 a horizontal moulding of a given section, it is requisite, in order to produce a proper effect at 
 the junction, that the correct form of section for the raising moulding should be specially 
 ascertained. Figs. I and 2. Flats, .'{ 2, represent two pediments which illustrate one of the po- 
 itions in which raking mouldings occur. In Fig. / the raking moulding is straight, in Fig. 2 it 
 i. circular, but the method required for both cases is very nearly similar. In Fig. Ha, A re- 
 presents the profile of the given horizontal moulding. Divide the profile into any number of 
 equal parts, and from the points thus marked draw parallel lines at the inclination of the raking 
 moulding. From the points marked in the profile draw vertical lines as shown to any horizontal 
 line, as dr. If the widths on the line <1 e are transferred to the part B and measured in a direc- 
 tion parallel to the rake, and lines are let fall, perpendicular to the rake, in the manner shown, 
 the intersections so produced with the lines i, :i, etc., will give the form of a right section of 
 the raking moulding. In a similar manner the same widths on the line dr applied at ( , in 
 the manner represented, will give the form of a return moulding if one is required a t the upper 
 end. Fig. Ha illustrates the same method applied to another form of moulding. Figs, i and 
 4 a show the application of the same method in the case of a circular moulding. 
 
 .liYW/i II. I Its J'oil SIloF J 'JIOXTS. — Figs. and ■< a. Plate H 2, explain the 
 
 mode of finding the correct form for the angle bars of a shop-front when the section of a square 
 
 bar is given as at A. Divide the profile of the moulding of the bar into any number of equal 
 parts, and through the points thus marked draw lines, perpendicular to the line of the shop 
 
 front, to any line parallel to the line of the shop front, as cd. Also from the same points in 
 
 the given profile draw the parallel lines, i, ■>, :s, etc., in the manner represented. If the widths 
 marked on the line cd are transferred to the part E find lines arc drawn as shown, parallel to 
 the line of the mitre, the intersection of these lines with the parallel lines i, •>, :i, etc., will give 
 the form for the moulding of the required angle bar. 
 
 LINES FOR SKYLIGHTS. Plate 33. 
 
 Some of the methods already explained in treating roofs, as the mode 
 of finding the length and backing of a hip, etc*., apply equally to the corresponding parts of 
 skylights, and the reader is referred to the plates and remarks relating to that subject. 
 
 Figs. / and / a illustrate a conic skylight on an elliptic base. On Fig. I a 
 
 Carpentry. - XXVI 
 
202 
 
 LINES FOK SKYLIGHTS. 
 
 -hown a ^ood mode of dividing the curb into proportionate spaces. Draw the line a b, and 
 from its centre <■ draw the perpendicular line c d, making cd equal to ac and c b. Join da and 
 ,1b, and from the centre d with the radius dc describe the arc ecf. Divide the arc ecf into 
 the .-ame number of spaces that it is desired that a quarter of the curb shall be divided into. 
 Through the points thus marked in the arc. and from the point d, draw lines to intersect the 
 line ab. Through the points thus marked in ah, and from the. centre of the ellipse, draw lines 
 to intersect the line of the curb, and they will mark upon it the required position of the bars. 
 
 Figs. 2, 2 n and 2b explain the mode of finding the form of the curb in 
 rhe case of an octagonal skylight which springs from an inclined roof. On Fig. 2, ab is the 
 base of the octagonal pyramid with the upper part of which the skylight coincides, and defghi, 
 Fig. 2a, is i portion of the plan of the same. On Fig. 2, k,l and m are the points at which the 
 hips of the skylight intersect the roof, and from these points dotted lines are let fall to the plan, 
 to intersect the lines t o, go, ho, i o, etc., in the manner shown. The lines ep,pq, qr , r s. etc., 
 drawn through these intersections make the plan of the curb. To ascertain the true form of the 
 curb, as represented by Fig. 2b, draw horizontal lines to any distance from the points e, p, q, etc., 
 and also from the centre o. Take the distances a k, a l, and am, from Fig. 2, and mark them 
 on the centre line of Fig. 2 b. Through the points thus marked in the horizontal centre line 
 draw perpendicular lines to intersect the respective other horizontal lines as shown. Through 
 these intersections draw the lines ep, pq, qr, etc., Fig. 2l>, and the true form of the curb will 
 be obtained. 
 
 LINES FOR CIRCULAR HEADED SASH IN CIRCULAR WALL. - Plate 34. 
 
 The class of work now to be considered is that called double circular, it 
 being circular both in plan and in elevation. In the case of the circular sash of which the 
 elevation is represented by Fig. /, and the plan by Fig. I a, we will first explain the lines ne- 
 cessary foi forming the head ol the sash. Divide the quarter circle at F into any number of 
 equal parts, and let fall vertical lines to intersect the chord G on the plan, Fig. I a. From these 
 intersections draw lines perpendicular to the chord G as shown on Fig. / b. Draw any line, as 
 ' a a. parallel to the line G, and set off above it on the perpendicular lines, the heights a\, ai, 
 a . etc., taken from the elevation at F. T he points thus marked relate to the upper curve of 
 die sash head. In the same way mark the corresponding heights for the line of the under curve 
 ut the sash head. I hrough the points thus marked draw curved lines, as represented by Fig. lb, 
 and the face mould for the head will be obtained. 
 
 lu find the mould to bend on the upper surface of the head. On any 
 'tiaiglu line as b A hog. le, mark an extension of the quarter circle at F, by setting off along 
 di> - 1 1 . tight line distances equal to those marked i, 3 , etc. at F. From the points thus marked 
 'haw pei pendicular lines and on them mark respectively the distances b 1 , b i, b: t, etc., taken from 
 I ,g. lu at (i. A curved line drawn through these points, as shown by Fig. 1 c, will be the 
 di \i lopment ut one edge of the upper surface of the sash head. In the same way mark points for 
 the -e ond edge, and draw a curved line through them, and the required mould will be obtained. 
 
 / ig. I d represents the mould for the under surface of the head, obtained 
 
LINKS FOR AROHTVOLT IN CIRCULAR WALL. 
 
 203 
 
 in the same manner, except that the distance on the straight line is the developed length of the 
 under curve of the head. 
 
 To obtain the form of the veneers for the cod bar. Divide the semicircle 
 at H into any number of equal parts, and let fall perpendiculars to the plan in the manner 
 shown, and draw any horizontal line as ere, Fie/. I a. On any straight line as ccc, Fief. 1 e, 
 make an extension of the semicircle at II by setting off along the straight line distances equal 
 to the divisions in the semicircle. 'From the points thus marked in the straight line draw per- 
 pendicular lines, and on them mark distances respectively equal to those marked ci, ci, c 3 , etc., 
 at Iv. A curved line drawn through the points thus obtained will show the form for one edge 
 of the veneers of which the bar has to be composed. 
 
 To find the form of a radial bar. Let LL be the centre line of the bar. 
 Divide its length into any number of equal parts, and from the points thus marked let fall per- 
 pendicular lines intersecting the plan at M in the manner represented. Draw the horizontal 
 line d d as shown at M. From the points ddd in the line LL draw perpendicular lines as 
 shown, and on these perpendiculars mark distances respectively corresponding with those marked 
 d t, d>, d . i, etc., at M. A curved line drawn through the points thus obtained will be the form 
 of the convex edge of the required radial bar. 
 
 LINES FOR ARCHIVOLT IN CIRCULAR WALL. - Plate 35. 
 
 This plate illustrates the lines required when it is desired to form an 
 archivolt for a circular wall by means of a series of veneers. Fig. / is the elevation of the 
 archivolt. Fiq. / a is the plan of the circular wall; and Fig. i b represents the form the veneers 
 would present if stretched out on a flat surface. In Fig. 1 the semicircle is shown divided into 
 a number of equal parts, and from the points of division vertical lines are let fall to intersect 
 the curved line D D of the plan. In Fig. I b the distances on the springing line are made 
 
 respectively equal to those marked on the line D I) by the intersection of the vertical lines. 
 
 From the points thus marked in the springing line, Fig. / b, vertical lines are drawn, and on 
 
 them are marked the heights a i, a 2, a 3 , etc., respectively equal to the corresponding heights in 
 
 Fig. I . The line drawn through the points thus marked is the form of one edge of the required 
 veneers. The portion of the archivolt from E to F should, for part of its thickness, be cut out 
 of the solid, and be a continuation of the architrave below. Each layer of veneers should break 
 joint with those next to it. 
 
 Figs. 2, 2 a and 2b show the same method applied to the case of an 
 elliptic archivolt in a circular wall, and as the letters and figures of reference are similar to 
 those in Figs. I, etc., no special remark is necessary. 
 
 LINES FOR COLUMNS AND PILASTERS. - Plate 36. 
 
 Figs. 1 and / a represent a simple mode of drawing the curve for the 
 shaft of a column. In Fig. 1, as in the following figures, the amount of diminution is exagge- 
 rated in order to afford the means of showing more clearly the necessary lines. In this example 
 the distance a b, Fig. 1 a, is equal to the required diminution on one side of the column. From 
 
MXKS FOIt COLUMNS AND PILASTliUS. 
 
 204 
 
 t |, e |(um t /, the perpendicular be is drawn to intersect the semicircle. The distance be, Fig. / a, 
 .,nd the distance dr, Fig. /, are both divided into a similar number of equal parts, and hori- 
 Ji„,.s are drawn through the points thus marked in the manner shown. From the points 
 il,u> marked in the semicircle vertical lines are drawn respectively intersecting the lines f, g and 
 /, as represented. The line drawn through the points thus obtained is the required - curve, 
 w Inch i> part of an ellipse. 
 
 Fig. 2 shows a diminishing rule, with a plumb line attached, to be applied 
 to the shaft of the column. 
 
 Fig. 3 illustrates another method. The distance a b and the height of 
 the column are both divided into a similar number of equal parts. From the points of division 
 in <b lines arc drawn towards c, respectively intersecting the lines d, c and f as shown. The 
 line drawn through the points thus obtained is the required curve, which is part of a parabola. 
 
 Fig. 4 indicates a method nearly the same as the last, but shows how a 
 flatter curve mnv be obtained. Instead of the whole distance a b, any less distance as cb is taken 
 and divided into equal parts, flic proceeding then is precisely the same as explained for Fig. 3. 
 
 Fig. ■') represents the application to this case of the method for describing 
 an arc of a circle illustrated by Fig. 7, Flute l . 
 
 Figs. 6, 6a and 6 b show how the proper diminution of the flutes may be 
 drawn on an elevation. The semicircle Fig. 6a being correctly divided, the dotted lines, carried 
 to the line i as shown, mark the divisions at the base. Let the line ah, Fig. 6b, be equal to 
 the diameter of the base. On it construct the equilateral triangle abc as shown. From the 
 p"ini •' mark on the sides of the triangle the distances c\ e i, etc., respectively equal to the dia- 
 meter ol the column at the heights t, etc. Draw the parallel lines joining these points, then 
 die line.- • •, it, etc., Fig. 6b will be respectively equal to the diameters •>, i, etc., of the column. 
 
 * Li the line a b mark the points as shown, corresponding with the lines of the flutes at the base 
 l ,ni in die elevation, and from these points draw lines to c. These converedntr lines will mark 
 1,11 d |r hue.- • it, etc., the required proportionately diminished widths of the flutes which have 
 I" I" marked on the lines >, t, etc., on the elevation. 
 
 bigs. 7 and 7 a show tin easy mode of obtaining the divisions of the flutes 
 
 • m any pilaster. On any line a & set off on each side of the centre line, to any dimensions, 
 
 di-tanccs for the required number of flutes and fillets, making the widths of the fillets in correct 
 
 proportion o. those of the flutes. Then on the line ab construct the equilateral triangle abc. 
 
 1 ,l "' l ,u "" mark the distances rd and r e, each equal to the width of the pilaster for which 
 
 tensions of the flutes and fillets are required. Join de, and dr will be equal to the width 
 
 ' Ih I" 1 K,0,u ,lu ' points marked in the line ab draw lines to c, intersecting the line 
 Da- points thus marked in dr correctly indicate the required divisions. 
 
 hg. s indicates the way in which columns may be formed of staves. The 
 lVl 1 11 "" 0,1 d‘C diameter ol the column. A and B represent the bevels 
 
 required. 
 
I. INKS EOK JOINTS AND HINGING. 
 
 205 
 
 LINKS FOR BRACKETING. — Plate 57. 
 
 Fig. I. allows how a cornice bracket may be proportionately enlarged or 
 diminished. AAA represents the outline of the given bracket. Let lines be drawn through 
 the angles of the given bracket and converging to the point b. Let c indicate the proposed 
 diminished projection of the bracket. From the point c draw the lines c<l, tie, e /’, and f g, re- 
 spectively parallel to the corresponding lines of AAA, and intersecting one another on the 
 converging lines in the manner represented. The figure cdtrfg is the form of the required 
 diminished bracket. Also if h represents a desired increased projection of the bracket, lines 
 from h, respectively parallel to the corresponding lines of A A A, and intersecting the converging 
 lines in the manner shown, would give the form for a proportionately enlarged bracket. 
 
 Fig. 2 is a plan representing the arrangement of the brackets along a 
 straight wall, and also at an internal and an external angle. As shown, the angle brackets are 
 most conveniently made in two thicknesses, each piece being bevelled to the angle required for 
 correctly ranging with the other brackets. If a plan is made on which the position and thickness 
 of an angle bracket is represented, as at A, the distance be will show the required amount of bevel. 
 
 Fig 2 represents the form of a given square bracket. It is required to 
 find the form of the bracket for the angle of a square room. The line A B, Fig. 2a, represents 
 the angle, on the plan, of the required bracket. From the points c,d,e and g, Fig. 2, draw 
 parallel lines to intersect A B as shown. From the intersections thus marked in A B draw lines 
 perpendicular to AB, in the manner represented, and on these perpendicular lines mark re- 
 spectively the heights o c, i </, ■> e, if, taken from Fig. 2. The straight lines cd, de, ef, and fa. 
 Fig. 2 a, drawn through the points thus obtained, give the form of the required angle bracket. 
 
 Fig. 4 is a plan showing the arrangement of brackets when the walls form 
 obtuse angles on the plan. Fig. 4 a represents the form of the square brackets, and Fig. 4 b 
 illustrates the application of the method just explained for finding the form of the angle brackets. 
 
 Figs, o and o a show the same method applied to cove bracketing. In 
 
 this case the curved line edef etc., Fig. 2, is divided into a number of equal parts to obtain the 
 
 points for the requisite parallel lines. 
 
 LINES FOR JOINTS AND HINGING. - Plate 38. 
 
 The various forms of hinges and joints have been made the subject of 
 much ingenious contrivance. In this place we will indicate the general principles which de- 
 termine the design of these parts. To hang doors, shutters, etc., with perfect success requires 
 some amount of practical skill, and the example and instruction of an experienced workman 
 afford the means by which this must he, acquired. 
 
 b'ig. I shows how the proper bevel for the edge of a door may be ascer- 
 tained. The centre of motion is marked e. From <■ draw the line r a, and make the line ah at 
 
 right angles to ea; the line ah represents the proper bevel for (he edge of the door. 
 
 Fig. 2 shows the same method applied in the case of folding doors. In 
 rhis instance the line ca is drawn to the internal angle of the rebate, and the line cb to the 
 termination of the bead. 
 
UXF.S FOR JOINTS ANO HINGTNO. 
 
 •>ort 
 
 /■';<, s. 4 and i show the same system applied to circular doors. It is 
 
 n ,. ( , e .,. irv t h:„ the hovel of the edge of the door should he no more acute than the angle obtained 
 I,, t | 10 diagram, hut according to the design of the work it may, if desirable, be more obtuse. 
 
 Fig. H represents the form of joint and position of hinge commonly adopted 
 t, tr hanging one Hap to another. The dotted lines show one of the flaps thrown back. 
 
 /•’/>/. 7 shows the centre of the hinge placed at a certain distance from the 
 When the Hap is folded hack, it will be thrown from the joint a distance equal to twice 
 the length from the joint to the centre of the hinge. 
 
 Fig. <S' illustrates the formation of what is called a rule joint. It is ne- 
 eessarv that the knuckle of the hinge should be placed on the inside, in the manner shown, 
 because, when the centre of the hinge is somewhat within the thickness of the wood, there cannot 
 be any open .-pace seen at the joint when the flaps are at right angles. 
 
 Fill. !t shows how, by means of projecting hinges, one flap may be thrown 
 to a certain distance from the one to which it is hung. 
 
 Fir/. Ill indicates another mode by which the same result may be attained. 
 The door or shutter, being hung to the moveable stile A, can be thrown back in the manner 
 -houn bv the dotted lines. 
 
 Fiji. II explains the method of finding the place of the centre of the hinge, 
 when it i-. desired to fold the flap back to a given position. Let it lie necessary that the part A 
 lionld lie thrown hack to B. 1 )raw the line A B. and the intersection C w ill be the centre of the hinge. 
 
 Fiji. 12 illustrates the mode of finding the position of the centres for a 
 -wing door. Draw the line ah. From c, the centre of ah, draw the perpendicular c</, equal 
 to ■ ■' or r />. The point d is the required position of the centre. 
 
 Fiji, h'l explains a similar case, but in this instance the joint has to eor- 
 ivspond with a rebate on the opposite side. Produce da to c, and draw he at right angles to the 
 burnt the door. Make ed equal to ah. .loin l> a ; also join hd. From e, the centre of ha, draw the 
 perpendicular «•/. 1 he intersection /, with the line h d, will be the required position for the centre. 
 
 l ij}. 14 shows an arrangement by which the hinge is entirely concealed. 
 M:il,e hr equal to a /<, and draw the line a c. From any point d draw d e, perpendicular to a c. 
 1 he intersection r will be the centre of the hinge. 
 
 I' iji. l-i is a plan ot part ot it jib door, and illustrates the arrangement by 
 win. |, the difficulty resulting from the projecting base moulding is overcome. The hanging stile 
 ot the door is represented at A, and B shows the projecting base moulding, the line CD being 
 d" front line of the plinth. Draw the line *f- make ft, equal to ef\ join eg- and draw gh per- 
 pendicular to . The line gh represents the joint for the plinth and base moulding. The centre 
 
 *' "PP or P art °f the door ordinary butt hinges would be used; at the 
 
 bottom of the door a centre let into the floor would he required. The space marked K is ne- 
 ce sary lor the passage of the plinth etc. when the door is opened. 
 
 
 
FIFTH DIVISION. 
 
 PRACTICAL JOINERY. 
 
 S E C T I 0 N I. 
 
 1. GENERAL OBSERVATIONS. The distinctions between Carpentry 
 and Joihery have already been indicated at Page 24, and the latter term is peculiarly suitable, 
 as, while the strength of Carpenter’s work is mainly due to the relative position of the several 
 parts, the principles of mechanics being involved in considerations of weight and pressure, that 
 of the Joiner chiefly depends on the careful execution and firmness of the joinings. Again, as 
 distinguished in scale from carpentry, joinery is appropriately named by the French menuiserie, 
 or small work, and carpentry by the Italians grosso (large) leg name (joinery). We have in this 
 Division rather to illustrate the several works than to explain principles. As Tredgold remarks: 
 — “The practice of joinery is best learned by observing the methods of good workmen, and 
 endeavouring to imitate them;” but much which may be gathered from books has already been 
 anticipated in the First and Second Divisions, more especially in the latter on Materials con- 
 taining practical information of especial importance to the joiner, as a reference to Pages 91, 
 100, 101, 113, among others, will at once evidence. Indeed, together with the methods relating 
 to finding the various lines requisite for the execution of works, an intimate knowledge of the 
 properties of wood is absolutely essential to the joiner who would excel in his vocation. On 
 cabinet making, or the application of joinery to furniture, it is not proposed to dilate. 
 
 Joinery is here divided into three Sections. In the first the general 
 operations of framing, fixing and glueing-up the works which follow are explained; and it is 
 deemed preferable to consider separately in the successive Sections Fixed and Moveable Joinery. 
 The Lines will be found under their respective headings. 
 
 2. FRAMING, FIXING, AND GLUEING-UP. Work is usually pre- 
 pared in the shop before being fixed; and the rationale of much which follows will be clear to 
 the reader who bears constantly in view the two great principles of modern joinery: — first, to 
 reduce the wood to narrow pieces, thus distributing the shrinkage; and secondly, whenever 
 feasible, to fix it so as to be free to expand and contract. Variation of form chiefly occur cross- 
 wise to the direction of the fibres (Sec Page 100) of the wood, or in the width; and pieces so 
 cut are much less to be depended on than those taken lengthwise. On Plate 53, Fig. 1, E, F 
 is far more liable to warp than G H, the points A. B. 0. 1). remaining in the same relative 
 position. Again, on account of the slight variation in the length of the fibres, and in order to 
 equalise expansion and contraction, boards joined as in Fig. 2 should have the grain parallel 
 with the sides; as, if it runs in different directions, Fig. 3, one piece will probably split the other 
 restrained by it, A altering more at the end than B. 
 
 We shall now notice the principal general operations in joinery, after 
 sawing and planing, or forming the surfaces, and shooting, or making straight the edges of the 
 stuff, as the boards, planks and battens (See Page 76.) are called. 
 
PRACTICAL JOINERY. 
 
 *)|(s 
 
 Dordmliny is a method of joining angles by expanding pins fitting into 
 , l'ig. 1 1 There are three varieties. In what is called common, which is the strongest 
 in ,| cheapest, the ends of the joints show (Fig. 5), in lap, adopted for desks, drawers, etc., the 
 dovetails arc concealed, a straight joint appearing near the angle (Fig. (i); and mitre dovetailing, 
 the angle onlv showing, (Fig. 7) is suitable for work-boxes, tea-caddys, etc., in which careful 
 finish is a nreat object; the two last kinds are also called secret, or concealed, dovetailing. 
 
 Morticimj in joinery is illustrated in Fig. S. Oak pins are sometimes 
 driven through the cheeks of the mortice, or tapering wedges are introduced, forming a kind 
 „f dovetail and preventing the tenon pulling out. The thickness of single tenons is' usually 
 made about one-fourth that of the framing, with a width of not above fi\e times their thickness, 
 
 . if mo re, the tenons will probably bend in wedging. For wide rails of doors, etc., double 
 t. nom are adapted, tongues being also often inserted to add to the firmness of the joint. Double 
 tenons are sometimes formed in the thickness; but a single one is preferable and fits better. 
 
 I'/oiufliina or uroonnu are operations in constant use. As the upright 
 horizontal main pieces, or stiles and rails of framing are connected by mortices and tenons, so 
 the filling in, or panels, is fitted into grooves, as in Figs, ft, a small space allowing expansion 
 and contraction in the width of the panels. It is obvious from these last considerations, that 
 panels should be narrow and not very long, that is not above 15 ins. wide and ■'» feel 6 in . 
 long in work of the first character, the framing being in width about one-third that of the 
 panels, the thickness of these last about one-third that of tin; framing, grooves across the grain 
 one-fifth or one-sixth the thickness of the stuff, and with the grain one-third or one-fourth. 
 < treat care i> requisite in fitting panels so as not to rattle, yet allowing a certain freedom of 
 motion. They "ill probably split if glue or nails arc used; and the brads must be driven into 
 dn stiles and rails in fixing mouldings. Stuff may lie continued in width by any of the modes 
 indicated in Figs. 10 to 1 I, which are suitable when an extended surface is required at less 
 ■ ost than framed work. In Fig. 10 the edges are shot’, in Fig. 11 rebated’, in Fig. 12 matched’, 
 in l it;, PI ploiu/hed and tongued; in f ig. II varied modes arc shown, the last being chamfered 
 oil the faces, while some of the preceding examples are beaded one. or both sides. Methods of 
 /■ oi in/) untiles occupy the remainder of the Plate. Fig. 15 is a plain mitre joint; Figs. Mi and 
 IT arc for the angles of passages, the head taking off the sharp edge, and the joint being con- 
 ' ; di'd, which last object is otherwise attained in Fig. IS; Fig. 11) is for the internal amdes of 
 dados, skirtings, etc.; Fig. 20, the parts being drawn tightly together, is suitable for pilasters, 
 m 'l "'l"'' long joints running with the grain; l'ig. 21 is for rough work such as troughs; Fig. 22 
 I- mitre rebated; keys are inserted in big. 23; Fig. 24 is a strong American lap joint; and the 
 remaining figures exhaust the subjects: blockings may be added. 
 
 I .edffed , as distinguished from framed work, is shown in Figs. 1, Plate 54. 
 
 "I'"". 1 1 1 *.-• - 1 framing rails, or dumps, at the two ends of the stuff to prevent warping, the 
 ,l ' " ' 1 1'Onps being transverse to those of the boards. Either ploughed or grooved and 
 
 r o o 
 
 "ingned work i- adopted, the former being preferable; and, mortice damping consists in the 
 addition of tenons. 
 
 Scribing is fitting together irregular surfaces or edges, as- skirting to 
 1 * ' 11 ‘ , * lt ’ mouldings are scribed, as frequently done in doors and sashes. 
 
PRACTICAL JOINERY. 
 
 209 
 
 Mitring is adopted when scribing cannot be applied, as for the quirked mouldings in Figs. 4, 5, 
 and 6: Fig. 7 is an angle in one piece. Keys, or pieces of hard wood, are employed to join 
 curved, or curved and straight pieces, cross-tongues being inserted on each side of the key and wedges 
 introduced. (Figs. 8) Mortices and tenons, and screw bolts with nuts and washers, are also used. 
 
 The proper fixing of joiner’s work is particularly conducive to its finish 
 and durability. Skirtings, architraves, dados, etc., are secured to small pieces of wood called 
 grounds ; and, as these also guide the plasterer, much of the nicety of work depends on their 
 being accurately formed, and placed with faces and edges perfectly upright and horizontal. 
 Their thickness should be about one inch, or equal to that of the laths and plaster; and it is 
 usual to run a groove, or form a splay to key the latter. In boards above six inches wide the 
 splitting consequent on contraction may be obviated by either fixing them in the middle, leaving 
 the two outer edges free; or by fixing one edge and leaving the other at liberty. Sometimes, in 
 the case of many boards connected together, as table tops and similar work, buttons are screwed 
 behind them and slide in grooved framing, bearers, or supports. In dados and window backs 
 several boards, not framed, but simply joined together, are connected by cross-tongues, dove- 
 tailed pieces being also inserted at regular distances apart. The heading joints, which ought to 
 break , should be feather tongued. After this work is glued-up and quite dry, keys, about 2'/ 2 ins. 
 wide, are inserted in a dovetailed groove across the back of the boards, and about 2 ft. 6 ins. 
 or 3 ft. apart (if there is more than one), thus keeping the surface of the boards straight and 
 allowing freedom of motion. In Figs. 9, A is a' ground, B dovetailed pieces about 3 ft. apart, 
 and C is the key. The dado is as free to expand or contract as a panel in its frame, and 
 unsightly cracks are avoided by the joints being secured as described. The advantage of plough- 
 ing and tongueing several pieces together, instead of using one piece, is illustrated in the archi- 
 traves on Plate 55; and the grounds, which formerly were usually concealed, are often made 
 visible with obvious economy. The details by Professor Cockerell on Plates 13 and 14 may 
 here be referred to with advantage. 
 
 In glueing up, joiners adopt various methods more or less peculiar to them- 
 selves. When perfect flatness is desired, it is an excellent plan to saw up a wide plank in 
 several pieces, and change the sides in glueing them, as in Fig. I, Plate 56: the curving is thus 
 divided into four arcs (or as many as pieces), instead of being in one. So, in glueing-up deal 
 table tops intended to be veneered, the boards are first sawn into widths of about 4 ins., and 
 put together with an edge which grew nearest the heart of the tree adjoining one furthest from 
 it; and, after the glue has hardened, the boards are sawn between the joints, reversed, and again 
 put together: thus the slips are only two inches wide, and, their expansion and contraction being 
 mutually counteracted, warping can hardly occur. Figs. 2, 3, and 4 show modes of glueing and 
 blocking boards; and Figs. 5 are of an architrave. The straight fibres of wood are unfavourable 
 to circular work, which may be formed by cutting notches as in Fig. 6; but it is a better mode 
 to bend thin thicknesses on a mould, as in Fig. 7; or the method in Fig. 8 may be adopted, a 
 veneer being afterwards laid: in Fig. 9 the principle of changing the sides of the pieces is 
 further illustrated. The blocks dotted in Fig. 10 may be glued together and the curve afterwards 
 cut; but it is preferable first to saw the pieces to nearly the correct form before glueing. A section 
 and plan of a solid niche are given in Figs. 1 1 and 1 2 ; and the remaining illustrations are suggestive. 
 
 Carpentry. 
 
 XXVII 
 
PRACTICAL JOINERY. 
 
 2H» 
 
 above 
 
 joint" 
 
 centre. 
 
 Some 
 
 to lie 
 
 On Plate 57 are methods of glueing-up columns in narrow staves (not 
 , j„ width) with and without blocking; and on one figure the bevels are shown: the 
 hould be in the fillets. If additional support is requisite, a post may be placed in the 
 Small columns may be solid with a hole bored in the middle to prevent splitting, 
 examples of cornices, panelling, etc., are added. An Ionic or Corinthian capital, intended 
 carved, is allied with vertical joints to the abacus, and the leaves, etc., may lie ol squaie 
 
 bio. ks fixed to the bell. The set of details to the right arc from Rondelet. 
 
 Clued joints are often stronger than the wood, the adhesion, according to 
 Mi. Bevan’s experiments, being, under the most favourable circumstances, equal to a force of 
 7K> pounds per square inch; and the cohesive force of solid glue 4,000 pounds per square inch. 
 fh< adhesion is not proportioned to the quantity, but to the quality of the glue; and the pieces 
 ,,| wood should lie forced together, excluding all superfluous glue. Less glue is absorbed bv 
 dir horizontal fibres than by those placed in contact endways; but the former adhere best, and 
 th. Mue must lie allowed to soak into the latter. That of the best description is pale in colour, 
 ..Id. and from the whole skins of oxen, sheep, etc., the young animals furnishing an inferior 
 qualiiv. a." i" also what comes from the sinews, clippings of hides, hoofs, etc., from the tan yard. 
 It i> prepared by being broken into small portions and then just covered with water for about 
 twelve hours, the best swelling most, after which it is melted in a double vessel, the inner part 
 tm- the glue and the outer for water, by which means the operation is gradual, and, as the heat 
 cannot ri.-e above the boiling point of water, burning of the glue is prevented. It is thinned 
 bv additions of hot water, while simmering for one or two hours, until thoroughly melted so as 
 t,, mu in a line stream: soaking is sometimes omitted. Linseed oil and white lead mixed with 
 ■hie i' good for that to be exposed to the weather. Glue, we may remark, does not set in a 
 lie zinir temperature. Care must be taken often to turn five sides <?fa board exposed to hot 
 drv air, or to a (ire, as it will become concave, and the side exposed to moisture convex: in fact 
 mv different treatment of the two sides is apt to induce warping, flic edges of boards should 
 be wanned and the glue applied hot, as it rarely holds well when chilled. In curved work it is a 
 
 1 practice to saturate the convex side with glue after bending it, thus filling the extended 
 
 port'; and the glue must be allowed to harden before relieving the board. 
 
 Glueing thin leaves, or veneers of a valuable wood on that of inferior quality, 
 th. smaller being cut by hand with a thin saw and the larger by machinery, has latterly been 
 :id\ improved. 1 lie ground for veneering should be swelled out by wetting with size, and, 
 
 1 " ii>- thus . xpandetl, together with the glued veneer, curling is obviated. Of course the ground 
 111,1 t I" pcrlectly easoned, and glue of the best quality used. The work is afterwards weighted, 
 "i pressed, and ultimately smoothed with fine planes, scraped and polished. 
 
 M< >1 LDINGS AM) PROFILES. Mouldings are certainly the grammar 
 "t d' 1 oration, and in joinery are oftentimes, not merely ornamental, but eminently useful, \n 
 • ' mg joint", taking oil inconvenient and dangerous angles, and imparting that fitness and 
 t ' l h which arc special objects in the joiner’s art. Roman mouldings are usually parts of circles, 
 *' Ul 1:111 "* ellipses, and Gothic comprise almost every variety. We shall not enter into the 
 ' ' 1 ' L " > • 1 ' methods ol delineation, a.', generally speaking, the most graceful effects and play of 
 du .im I -hade are produced by drawing mouldings freely, or libera rnanu. On Plate 58, Fig. 1 
 
FIXED JOINERY. 
 
 211 
 
 is a fillet, or listel; 2 bend, or astragal; 3 ogee, talon, cyma. reversa, or inverted cyma; 4 cyma, cyma 
 recto, or cymatium ; 5 quarter-round, Roman ovolo, or echinus; 6 Grecian, or quirked oro/o (some- 
 times er/c/ moulding); 7 French ogee, or talon reverse; 8 cavetto, or hollow; !l scotia, or casement; 
 10 torus; II double torus, or torus and bead; 12 treble torus; 13 treble fillets; 14 reeds; 15 flutes ; 
 16 bead and quirk, or quirked bead; 17 bead and double quirk, or double quirked bead ; 18 Gothic 
 boutell; 19 chamfers, stopped in various ways; and 20 are combinations of mouldings. An ex- 
 cellent effect is often produced by bounding them in the manner indicated by the dotted lines. 
 
 SECTION II. 
 
 FIXED J 0 I N E R V. 
 
 1. FLOORS. Thei’e are two kinds in general use. In fabling floors 
 (Fig. 1 , Plate 59), an inferior description but useful when the stuff is liable to shrink, every 
 fourth or fifth board is nailed rather closer than the intervening full space for the others, which 
 are then shot and forced into their place by jumping upon them: the heading joints should fall 
 over joists. Straight joint floors (Fig. 2) are so named from the continuous direction of the 
 side vertical joints: each hoard is successively nailed, after being forced close to the adjoining 
 one with a flooring-cramp. Heading joints are straight, splayed (Figs. 4, ■>), rebated (Fig. 6), 
 ploughed or grooved and tongued (Figs. 7, S) with feathering or hoop iron, preventing the passage 
 of air and wet; and forking (Fig. 9) is often adopted for oak. Dowel ling (Fig. 9) consists in the 
 insertion of pegs of beech or oak (iron for wainscot) in place of the nails on the face, the edges 
 being thus not so weak as when grooved. In work without dowels, having plain joints, both 
 edges are nailed; but with dowelled or tongued Hoors it is sufficient to nail only one edge in a 
 slanting direction, concealing the nails: the edges of hoards laid folding must of course be square. 
 The stuff for floors varies from 3 / 4 to 2 ins. thick, and from 5 to 9 ins. in width, the narrowest 
 being preferable. Spruce, yellow and white deal floors are generally 1 or l l / 4 in. thick, battens 
 (5 ins. wide) 1 1 / 4 or l 1 and wainscot 1 or D/i in. In good work borders of narrow stuff are 
 mitred round the hearthstones, instead of scribing the boards, and the boarding is planed, after 
 laying, to an uniform surface. Parquetry, or marquetry, common on the continent, is inlaid work, 
 nailed, screwed, or glued down, on oak or fir boards; and several illustrations are given on Plate 59. 
 
 2. PARTITIONS, WAINSCOTING, DADOS, AND SKIRTINGS. 
 Partitions in joinery are from 1 */ 2 to 2 1 . 2 ins. thick, rough with edges shot, wrought, ploughed 
 and tongued, or panelled in various ways, as on Plate 60, in which wainscoting, or wall lining, 
 usually 1 to 1 1 / 9 ins. thick, with fascia and skirting, is illustrated. Dados, of which one mode 
 of fixing is explained at Page 209, may be considered as wainscoting, extending about 3 feet 
 high from the floor, 1 to 1 */ 2 ins. thick, capped with a bead or mouldings. They arc keyed or 
 tongued, and should be ploughed and tongued at the internal, and lap mitred at the external 
 angles. The simplest forms are given on Plate 60; and Plate 61 contains other examples, to- 
 gether with skirtings, placed round the margins of floors next the walls, and from 3 / 4 to 1 1 / 2 in. 
 thick, 4 to 18 ins. high, finished square, moulded, sunk, etc. They are fixed to narrow grounds, 
 
FIXED JOINERY. 
 
 2 1 2 
 
 with sometimes uprights and blockings, and scribed to the flooring boards, grooved in (to avoid 
 ..pen joints, harbouring dust, etc.), or a fillet is put behind. {See Hates la and 14.) 
 
 DOOR AM) WINDOAV FRAMES. Door frames, and also those 
 easements, or hinged windows, are either solid (technically proper door or window eases), or 
 I lies are hum: to linings. Plate 62 contains numerous illustrations. Proper door eases may he 
 I ->< 1 1 , j ns . (transom IX? ins.), rebated, beaded, etc., fixed to floor with wrought iron dowels, 
 or tenoned into stone or oak sill, or having lb, in. oak rounded step and inch tongucd riser for 
 entrances. For gates the frames may he 9 X M/a, 14 X 7 ins., etc. Doors hung in linings 
 i v, also Hat, dd) may have these (with the soffits) 1 to 2 ins. thick, single or double rebated 
 and rounded or beaded; inch framed grounds 4 1 /, or 6 ins. wide, and moulded architraves 9 or 
 12 ins. girt on one or both sides: the linings and soffits are often panelled, and have dovetailed 
 blockings. On the right of Plate 62 at the bottom is a peculiar form of door framing used in 
 tin- now Palace at Westminster, the joinery in which, we may remark, is the most elaborate 
 which has been executed in modern times. Casement frames (Plate 64) may be from 3 X 3 to 
 i; < 5 ins., rebated, beaded, chamfered, etc. For large windows the frames are often glued up 
 out of deals. The oak sills may be 1 X 3 to 6 X 5 ins., sunk, throated, weathered, beaded, 
 •j moved for galvanized iron tongues, or variously contrived, with drips and water bars, to ex- 
 hale wet. ''ashes hang on centres have a cut head, partly on the frame and partly on the sash. 
 Fanlights over doors are fixed in a frame continuous with that of the door, (wised frames for 
 'tihng sashes are illustrated on Plates 15 (.‘w Page III.) and 65; and the sills may be of the 
 dimensions named above, and of the forms shown on the last Plate. The sashes are hung by 
 means of cords passing over pullies tit the upper part of pulley pieces adjoining which the sashes 
 run. separated In rounded parting heads grooved into the former, the outer sash being kept in 
 place by the projecting outside lining, and the inner by the bead adjoining the inside lining, and 
 hicli i> also continued above the sill: when both sashes ar.e Jyung a parting slip, suspended from 
 above, separates the weights. These details are shown on Plate 65. On Plate 64, A are jamb 
 "anas, 11 elbows, (' the window hack, D the soffit, and F the architrave. The thickness of the 
 tutl varies from I to 1 1 2 in., and it is tongued or rebated together. ( See Plates 4, d, 6, 13, 
 14 , Id, 63, 64, 6d, 66, 67, 73, 74, 75, 76, 77.) 
 
 4. STAIRCASES AND HANDRAILS. The construction of staircases 
 ol the best description, wide, open, and without winders, is tolerably easy; but those which are 
 narrow, Jeep, and turn rapidly, call for the exercise of the joiner’s utmost skill. Although there 
 * 'bn' often much complication what is really essential to comprehend can be explained within 
 !'Oi"w limits; and the subject will here he exhausted without occupying much space, although, 
 in mam books, it lias been so expanded as to convey a fallacious idea of its extent and intricacy. 
 I " 11 ' od principles and constructive details will now be treated; and in the succeeding article, 
 b> Mr. Hem \ .1. ( ollins, methods of finding the lines are explained. These the Editor believes 
 to be more satisfactory and scientifically correct than any hitherto published, although each 
 't tirca-e builder often believes only in lus own system. 
 
 the poets of staircases may first be defined. A step or stair is the tread 
 in ^ r ‘ ” b»ifcthn. I he tiead is the horizontal surface, with the front edge, or nosing, square, 
 rounded, or moulded, a hue drawn touching the series of nosings being the line of nosings; and 
 
FIXED JOINERY. 
 
 213 
 
 the riser is the vertical piece. Straight steps of uniform breadth, parallel on plan, ai’e flyers-, 
 radiating steps, triangular on plan, winders'; broad steps, or landings, occupying the length of a 
 step, quarter spares, or paces-, and those taking up the whole breadth of the staircase half spaces, 
 or paces; the term landing is sometimes limited to a resting place leading to rooms. A\ hen 
 the first or bottom step is made to form a spiral line, or scroll at the outer end it is called a 
 curtail step: quarter rounds in a similar situation are often formed solid. The sets of steps, or 
 stairs, leading to quarter, or half spaces, or landings, are called flights, the whole between the 
 floors being the staircase. Well holes, or open newels , of various forms, are the spaces extending 
 downward between two or more sets of steps: they are sometimes closed to support the steps, 
 then becoming solid neicels. 
 
 With reference to construction, the woodwork, or framing, supporting the 
 treads and risers is •called the carriage, the principal parts consisting of rough strings, or two or 
 more timbers parallel to the adjoining side wall, inclined to the line of nosings, and supported 
 by cross pieces at one or both ends. When there is not a trimmer, a pitching or apron piece, 
 transverse to the rough strings, is firmly wedged into the side wall, below the top of the bottom 
 flight, to carry the rough strings and the joisting of the landings, the rough strings, however, 
 being sometimes continued to .the end wall. In stairs of two flights, with quarter or half spaces, 
 the timber which carries the joists is properly the apron, and that supporting the rough strings 
 the pitching piece, to which last the joists arc often tenoned or bridged: at a circular newel, 
 bearers, wedged into the wall, and uprights are used, dovetailed or tenoned together. The 
 flooring of the spaces is often feather tongued, glued and blocked on the bearers. Rough 
 brackets are boards of triangular form, nailed to the rough strings, and scribed to the tread and 
 riser. Rough hearers, placed under the nosings to support winders, are fixed at one end into the 
 wall, and secured at the other to the strings. (Plate 11, Fig. 11.) String boards (when curved 
 glued up in thicknesses, or got out of the solid) are those at the ends of steps into which they 
 are housed together with the winders, the face one, or outside string, being also sometimes 
 connected at the end with the newel; and, in bracket stairs, the string is notched, or cut, taking 
 the treads and risers extending over it, the faces of the outer ends of the steps being concealed 
 by ornamental pieces called brackets. The outside strings (Plate 11, Fig. 12) are usually 1 or 
 1 1 2 in. thick, and plain, framed, rebated and beaded, with sunk face, cut and mitred to riser, 
 moulded, glued in thicknesses on a cylinder, ramped, kneed, wreathed, etc.; while wall strings, 
 or those into which the opposite ends of the steps are housed, are 1 1 to 2 ins. thick, plugged, 
 ramped, writhed, kneed, etc. Treads and risers, bracketed, blocked, glued, tongued, and screwed 
 or nailed together, vary from 1 to 1 1 ,/ 2 inch in thickness, or there may be 2 ins. treads and 
 l 3 / 4 in. risers, the latter being rebated, tongued, feather tongued, etc., to the steps. (Plate 11, 
 Fig. Id.) Beaded apron lining 3 / 4 to 1 in. thick is used to cover the apron piece. The under- 
 sides, or soffits, of stairs are usually lathed and plastered, but may be boarded, panelled, etc. 
 
 Three kinds of staircases are in general use. Geometrical, or open newelled, 
 (Plate 68, Figs. 1, 2, il.) have a well hole down the centre, the steps being supported on one 
 side by the wall, and on the other by strings, each step being also carried by that below. The 
 parts next the wall are housed into the wall string, the winders being also wedged into the wall 
 at one end, into the string board at the other, and firmly screwed together: when carriages are 
 
FIXED JOINERY. 
 
 
 21 I 
 
 i|„. winders are fixed to hearers and pitching pieces. Dog-legged staircases (Fips. 4, .5.) 
 , 1:| v „„ w< .|| s< t | l( . balustrades of the successive fights being in the same vertical plane. The 
 , lit, anal angle of the steps is generally closed by the string, and not open to the end as in geo- 
 .;d staircases. Carriages, with hearers inserted in the wall and secured to the newel posts 
 ,„d -t rings, are adopted to take' the steps, Bracketed staircases are supported by carriages, land- 
 u, newels and notched strings, beyond which the treads and risers pass, having brackets mitred 
 the end> of the risers, and used, not for support, hut ornamentally, in concealing the rough ends 
 , ,1 ,| 1( -ieps, being fixed to the outside string hoard, which is. often moulded similarly to an 
 ; , n hitrave. The treads and risers, having been glued and blocked in the internal angles, the 
 t, |, i , rewed to the riser at the lowest part and roughly bracketed to the strings. All stair- 
 . i • , with cut strings nun la* bracketed, the best dog-legged and open-newelled being so, and 
 
 the geometrical generally. • 
 
 Having disposed of the constructive parts of the several kinds of stair- 
 < :i • (•', we mav now consider their proportionate disposition. 
 
 The relation between the height and width of a step has been touched upon 
 1 1 v Vitruvius, Scamozzi, and other authors. In the encyclopaedia Bntannico (he formula given 
 by P.hindel in his Come <f Architecture is recommended for staircases of easy ascent. “If a per- 
 iiii walking upon a level plane move over a space, 1\ at each step, and the height which the 
 ante person could ascend vertically, with equal ease, were H; then, if// he the height of a step, 
 uid p in width; the relation between p and h must he such, that when p = P. //=o; and when 
 
 11 //, p : o. These conditions are satisfied by an equation of the form h — II ^ 1 — qiT,)- 
 
 lllondel .I'sumes 21 inches for the value of P, and 12 inches for that of II; substituting these 
 
 values in our equation, it becomes h 
 
 (24 — p), which is precisely Blondel’s rule. We do 
 
 not think these the true values of 1* and H; indeed, it would be difficult to ascertain them; hut 
 th. \ are >o near, and agree so well with our observations on stairs of easy ascent, that they 
 ma\ he taken for the elements of a practical rule. Hence, according as h or p is given, we have 
 
 ., -I p, »»r p 24 — 2h. Thus, if the height of a step he six inches, then 24 — 12 
 
 12, the width or tread for a step that rises six inches.” A rise of 5 1 ., to 12 is, however, a 
 podcrahlr ratio; and. as the tread is widened, the riser is lessened. For inferior buildings 7 ins. 
 I- in usual rise to a 10 ins. tread; and for superior 12 ins. up to 15, with a rise of 4 to 6 ins. 
 II" rlM r :,, "l tread may he proportioned as in Figs. 10, Plate 71, a right angled triangle with 
 two equal sides, in which, A B being fixed as the width of the tread, AC is the height of the 
 riser, and (11 the inclination. 
 
 II"’ number of steps is adjusted in practice with what is called a story rod. 
 ‘ 1 1 ' 1 • 1 ' ‘ 1 1 into :, s many parts as there arc steps between the floors. Supposing the total height 
 to i ,c ‘ * * h. I tiS ins., there will he 2S steps (i ins. high; and, if there is an odd 
 1 1 1 1 ii 1 1 .I I cl niches, it is preferable to add rather than deduct one step. 
 
 /Ac width of staircases of the best, description is regulated by the space 
 'll"" 1 "- pci-'ons easily to pass, this is 4 feet in the clear for the steps; and none should 
 he Ins- than 2" feet ti ins. 
 
FIXED JOINERY. 
 
 215 
 
 Landings, or resting places, are to he disposed at intervals not exceeding 
 ten steps in superior staircases; .Alberti says not above nine: winders are to be avoided. The 
 best disposed staircases have only one revolution between the Hours; but where space is not 
 available this rule cannot be observed. 
 
 Handrails and Balustrades should be of sufficient strength and at a proper 
 height (from 2 ft. 4 ins. to 3 ft.) for the hand to move easily upon the rail, which must follow 
 the line of nosings, with an extra rise when turning, be, perfectly smooth, and of a section not 
 less than that out of a square of 2 1 / 2 ins.: some forms are given on Plate of Lines 42. To 
 enable handrails to follow the steps in the change of level and direction, they have to be ramped, 
 kneed, and wreathed (or writhed), the first term being applied to those concave on the hack, (or 
 upper) part, the second to those convex, and the third to those curved on plan at the same time 
 that they ascend or descend: a swan-neck is that portion, ramped and kneed, next a newel. A 
 mitre cap is the portion of the handrail over the newel, or principal vertical piece at the ends of 
 each fight, the intermediate uprights being the balusters: these last are usually I or IP, in. square, 
 two to each step, into which they are dovetailed; or*they are round, or made ornamental. Newels 
 are chamfered, framed, or turned; and the mitre caps are turned of such a form as to mitre 
 with the rail, which is of less width. Swan necked iron brackets are used to secure rails when 
 next to walls; and handrails are often grooved for iron cores (l'/ 2 X 3 8 in.) fitted to take iron 
 balusters, inserted at intervals, to which the cores are rivetted, and also screwed to the handrail 
 with screws in countersunk holes. Deal, wainscot, or mahogany, is used for handrails, newels 
 and balusters. In the veneered rails, now much employed, no heading joints show; and they 
 may be fixed firmer than cored rails. 
 
 Illustrations of the preceding remarks are given on Plates 68, 69, 70, 71, and 
 72, and for some of the figures we have drawn on suggestive foreign sources. The examples show 
 both ordinary and unusual dispositions; and only a few now need explanation. On Plate 71, 
 Figs. 1 illustrate a staircase described by M. Godefroi in a work, (published by the French Aca- 
 demy, entitled Ae Recueil des Machines. It is certainly ingenious and peculiarly suitable for a 
 very circumscribed space. There is one central string (or there may be several), and two persons 
 can pass, or one ascend with little exertion by using the respective steps for each foot. Figs. 2, 
 3, 5 and 7 show the solid steps much used on the continent: they are expensive and require 
 excellently seasoned wood, but, on account of their strength, are suitable for winders and other 
 purposes. The method, devised by the French, of fixing balusters outside the steps is given in 
 Figs. 4 and 5; and foreign modes of connecting steps and strings, the last always much thicker 
 than in England, in Figs, 5, 6, 7, 8, and 9. 
 
 LINES FOR STAIRCASES AND HANDRAILS. 
 
 Fig. J , Plate 39, is a plan of a dog-legged staircase. On this figure the 
 fronts of the risers are marked by firm lines, and the projection of the nosing is indicated by 
 dotted lines. Fig. I a is the elevation of the same stairs. 
 
 STORY ROD. — Fig. lb, Plate 39, shows the story rod. The number 
 ot steps being determined, the height from fioor line to floor line is marked on a suitable rod 
 
LINES for staircases and handrails. 
 
 2 1 fi 
 
 f rom the floors themselves, absolute correctness in this dimension being £hus secured. The dis- 
 f:ini C marked on die story rod is then divided into the same number of equal parts as there are 
 tr,.-. By thi~ means die exact height of a step is obtained, and the rod is of essential utility 
 in the fixing of the stairs. 
 
 PITCH BOAK1). Fig. 2, /’/ate 39, shows what is called the pitch 
 
 hoard. It is made of thin stuff, and is equal in height to the rise of one step, while its width 
 
 i i equal to that of a tread. 
 
 WALL ST KIM iS. — Fia. 3, Plate 29, which represents the wall string 
 t,i] the tii t tli'dit of the stairs shown by Figs. I ami la, indicates also the mode of using the 
 pitch board. The line ah is the edge of the board of which the wall string has to be made-. 
 At any di tance that may lie determined on, draw the line cd which is to coincide with the line 
 ut the no>ing>. I hc pitch board placed against tins line, as indicated at e and _/, will afford 
 the most ready means of marking the outline of the steps. 
 
 The position of the first winder in this wall string is shown at rn. Fig. 3. 
 l 'oi etting out on the wall strings the line? for the winders, the respective widths of the winders 
 
 inu t hi mea tired from the plan. The height w ill be, of course, a constant dimension. 
 
 FU,. '-In shows the wall string for the part marked HI on the plan; and 
 Fig. lb represents the continuation of the same from I to K. The distance from the nosing to 
 
 tie edge of tin wall string should be always measured on lines perpendicular to the line of the 
 
 edge, as at // and n, Fig. 3 a. 
 
 LASINGS. To gain a satisfactory effect the portions of strings, hand- 
 rail , etc., w hich are at different degrees of inclination are joined by curved lines, as at G, Fig. 3, 
 and K, Fig. 3 />, Plate 39, and these curves are described as easing*. Fig. 1 shows a convenient 
 method of producing a suitable curved line. The distances A B and B C are each to be divided 
 int" a imilai number of equal parts. Number the divisions from A to B and from B to C, 
 and join the points which have corresponding numbers. The lines so drawn will be tangents to 
 a parabolic curve, w hich has to be drawn so as to successively touch each line. 
 
 Fig. a explains another method. Make the distances A B and BC equal, 
 
 and from A erect the perpendicular A <1, and from C erect the perpendicular C e. Continue 
 
 the 1 hn< - till t hr v intersect one another. Their intersection will be the centre from which to 
 describe an are ol a circle joining the points A and C. 
 
 A RLA I HED S r l KING. Fig. I, Plate 40, is a plan of a staircase w hich 
 i- quii' a wreathed string; that is a string which, while it ascends w ith the stairs, forms the circum- 
 rM " ' "I 'be 'rmi-rvlindriral part of the well at bed. Fig. / a is the elevation of the same stairs. 
 
 I he steps are all of equal height, but the winders, at the well, are of a 
 " ol\ equal widih, which width is much less than that presented by each of the flyers above 
 dr|,i". b will he perceived that there is a tendency for the inclination ol' the string to 
 'duupdi changed at the part where the winders commence. The portion of the string 
 "" IM ,m "‘h 'teeper than the parts above or below, but it is desirable that the change 
 "I on hti.ifum diouhl he not suddenly but gradually made. This easing of the string is obtained 
 1 v " -'Hanging tiie widths ol the winders at the ends nearest to the well that their nosings 
 mm a e with a gracefully curved line. I he form of the string and the handrail must both 
 
LINES FOR STAIRCASES AND HANDRAILS. 
 
 217 
 
 he determined by the nosing line, and therefore it is very desirable that an easy sweep for 
 this line should be obtained. 
 
 Fig. 2 explains the mode of finding the proper nosing line. On any line 
 AB mark the distance c d, equal to the development of the semicircle bed on the plan. From 
 d raise a perpendicular, and on it mark the height d e, equal to the height of five steps. Join 
 c e. The diagonal ce is consequently the inclination of the string for the part marked bed on 
 the plan. Through e draw a horizontal line, and on it mark the distance ef, equal to the width 
 of two Hyers. From f raise a perpendicular, and on it mark the height fg , equal to the height 
 
 of two steps. Join eg. The diagonal eg marks the inclination of the spring for the upper 
 
 flight. Repeat this last process from eh, in the manner shown on the figure, and the line ci 
 
 will be the line of the inclination of the string for the lower flight. Ease off the angles e and e by 
 
 one of the methods explained on the last plate, and the line i kg will be the desired nosing line. 
 
 Fig. 2 a shows the mode of ascertaining the proper widths for the ends of 
 the winders and diminished Hyers by means of the nosing line just obtained. The curved dark 
 line is the nosing line, and the horizontal lines shown are respectively at the proper heights for 
 the steps. Perpendiculars let fall from the points at which the horizontal lines intersect the 
 nosing line mark the widths of the ends of the several winders and diminished Hyers in the 
 manner shown by the figure. The outline of the steps, thus obtained, must be drawn on a 
 veneer, taking care to also mark on it the centre line indicated on the figure by the vertical 
 dotted, line. The lower edge of the veneer may be cut to the form shown by the figure, but 
 it will be best to cut the step part after the veneer is blocked. 
 
 0 Fig. 2 b represents what is called the working cylinder, which is a framing 
 
 made to correspond with the form of the well. By means of the vertical centre line that has 
 been marked on it, the veneer may be correctly placed on this cylinder, so as to agree with the 
 position it is intended to occupy in the stairs. The veneer being securely fixed to the cylinder, 
 proper blocks may be glued over the whole surface. When the glue is dry the back of the 
 blocks is to be worked down to a uniform face, and some strong canvass is to be glued over it. 
 When this is dry the string may be removed from the cylinder, and cut to the proper form for the steps. 
 
 Fig. I, Plate 41, is a plan showing a staircase with a level landing round 
 a semicircular well. Fig. / a is the elevation of the same stairs. Fig. / b represents, to a larger 
 scale, the development of the steps and landing as required for the formation of the wreathed 
 string. The line a b, of the landing, in Fig. / b is the development of the semicircle a b. Fig. 1 . 
 
 Fig. 2, Plate 41, is a plan showing a staircase on a rectangular plan, with 
 winders in the two angles. Fig. 2 a is the elevation of the same stairs. This example requires the 
 adoption of the same method of ascertaining the nosing line, and then by its means finding the 
 respective widths of the winders, as is illustrated on Plate 40. On any line A B, Fig. 2 b, mark 
 the distance ed, equal to the development of the quarter circle k on the plain. From d raise 
 a perpendicular and on it mark the height de, ecpial to the height of four steps. Join oe. The 
 diagonal ce is consequently the inclination of the portion of the string that coincides with the 
 quarter circle k on the ]>lan. 
 
 . From e draw the horizontal line e f, equal in length to the width of two 
 
 Hyers. From / raise a perpendicular and on it mark the height fg, equal to the height of two 
 
 Carpentry. XXVIII 
 
*2 IS 
 
 lines for staircases and handrails. 
 
 M( . r ,| () j n , The line eg marks the inclination of the string for the upper flight. Kepeat 
 ,hU last process from <•//, in the manner shown on the figure, and the line ci will be the line of 
 inclination of the string for the lower flight. Ease off the angles e and c, and the curved line ilg 
 «ill he the desired nosing line. Fig. 2c shows how by means of this nosing line, and as explained 
 in the case of Fig. 2a, Flute 40, the correct widths for the ends of the winders may be obtained. 
 
 MITRE CAP. Figs. I, 2 and 3, Plate 42, represent sections of hand- 
 rail'. and illustrate the way in which the upper part of the rail may be made to coincide with a 
 portion of an ellipse. These sections show how by this means a certain degree of gracefulness 
 of form may be obtained. Figs, la, 2a and 3 a respectively explain the mode of finding 
 the proper outline for the mitre cap. 
 
 To pud the form of the mitre cap for the rail shown by Fig. I . Let the 
 circle A A, Fig. / a, represent the plan of the mitre cap, the diameter of which is to equal one 
 and a half times the width of the rail. Through the widest part of the section of the rail draw 
 the horizontal line hh, and from the points h,h, let fall perpendiculars to intersect the circle A A 
 at the points i,i. From the points i, i, draw lines to any suitable point as k. The lines i k and 
 i / will be those at which it is desired that the rail shall mitre with the cap. Mark any point in 
 the section, as e, Fig. /, and from it let fall the perpendicular e.\ to the line hh, and continue 
 the same perpendicular line to intersect the line ik at the point i as shown. Through the centre 
 / nf the circle A A draw the horizontal line B as shown. From the centre / describe an arc from 
 the point in the line ik to intersect the horizontal line B, and from the point thus marked in 
 the line B erect the perpendicular :: e, equal in height to the corresponding line in Fig. 1. The 
 point c. in Fig. / a, is one point in the required section of the mitre cap. Take other points%' 
 c. d. f and g, in the section of the rail and proceed in a similar manner to obtain corresponding 
 points in the section of the mitre cap. A line drawn through the points thus obtained will 
 be the required section. 
 
 Figs. 2 a and 3 a show the same method applied to other forms of rails. 
 •SCROLL AND CURTAIL STEP. — Fig. /, Plate 43, shows a good 
 iim-t hoi I of describing a scroll. 1 he width from A to B bein” - determined, the circle cd is to be 
 drawn of a diameter equal to one-third of the distance A B. As indicated by Fig. la, the dia- 
 n 1 ( 'ter oi this circle must be divided into three equal parts, and one of these parts again into six. 
 I rum die centre id the circle, in Fig. I, mark towards B a distance equal to one of these last 
 
 "I'taincd dimensions as shown by a thick line. From the point thus marked, which is one of 
 da (a ntres for describing the scroll, draw the perpendicular 1,2, equal in length to two divisions. 
 'I he end of this line is a second centre. Again, from the end of the last drawn line, in the 
 
 m ' mM< 1 ^'"" n ''•' ^ 1C figure, draw the perpendicular 2,3, making this line equal in length to three 
 
 tli visions. Repeat this process, making each new line longer than the last by one division until 
 a '"III. lent number of centres are obtained for the required number of revolutions. Each centre 
 M :l quarter revolution, and as in this example the outer spiral makes one revo- 
 
 ' 1,11,11 '' ^'df, m six quarter revolutions, six centres are shown. But a greater or less number 
 
 I 11,111 ' 1 " '"luiions maj be obtained by increasing or decreasing the number of centres. From 
 the centre first marked, indicated by 1 on the figure, let fall the perpendicular 1 e. From the 
 ‘ a ‘" e : <lia " lll( ' linc -t- <lravv the perpendiculars 3 g, 1 h, hi, and t ik, as shown by the 
 
LINES FOR STAIRCASES AND HANDRAILS. 
 
 219 
 
 figure. From the centre i, with the radius i e, describe the are ce. From the centre 2, with the 
 radius ie, describe the arc of. From the centre :t, with the radius -\f, describe the arc f g; and 
 so on till the point k is reached. From 1c mark the distance k/, equal to the width of the hand- 
 rail. From the centre «, with the radius « /, describe the arc Im. From the centre r>, with the 
 radius r, rn, describe the arc in n; and so on until the outer spiral is intersected. Draw the straight 
 lines / 0 and k 0 , and the scroll will he completed. 
 
 It may he considered an improvement of the form of the scroll if instead of 
 the straight lines commencing at / and k they are made to begin at the line gp. To gain this result 
 the scroll lines must be prolonged to the line gp by gentle curves as shown by the dotted lines at K R. 
 
 Fig. 2 illustrates the application of the method just explained to the pro- 
 duction of a scroll of which the external spiral makes one revolution and a quarter. Fig. 2 
 represents a spiral of one revolution. In these two figures the curves arc shown prolonged to 
 the line gp in a manner similar to that indicated by the lines RR in Fig. 1. 
 
 Fig. 4, Plate. 42, shows the lines for the curtail step. The plan of the 
 handrail and scroll being drawn, by any method, the position of the nosing, and of the riser and 
 string lines must be marked in the manner represented by the figure. Then, from the same 
 centres and in the same manner as for the scroll, describe the required outline of the riser for 
 the curtail step, the curved string line, and the nosing line of the cover board. HUH is the 
 handrail. B II B are balusters. RRR is the line of the riser. SSS is the curved string line; 
 and NNN is the nosing line. Fig. 4a is the elevation of the front of the curtail step. 
 
 Fig. I, Plate 44, illustrates another method of drawing a scroll. Let A B 
 be the given width. Divide the distance AB into ten equal parts; and from A draw the perpen- 
 dicular A c, equal to one of these divisions. Join Be. From d, the centre of A B, draw the per- 
 pendicular de as shown. Make <7 1 equal to de, and draw 1 g perpendicular to A B. From e, with 
 the radius cB, describe an arc cutting 1*7 at g. From g and perpendicular to Be, draw the line 
 g h, intersecting Be as shown. Through this intersection and from the point 1 draw the line 1 i. 
 Also from the point 2 and through the same intersection and perpendicular to the line 1 i, draw 
 the line ■>!. From the point 2 draw the line 2,3, parallel to AB, to intersect the diagonal 1 /. 
 From the point 3 draw the line 3, 1 , parallel to the line 1 , 2, to meet the diagonal 2 1. Continue 
 these lines round from diagonal to diagonal in the manner shown by the figure, and the points 
 1 , 2 , 3,4 , 5 and u will be the centres from which the spiral has to be described. From the centre 1 , 
 with the radius 1 B, describe the arc B g, and continue the arcs from the several centres till the 
 scroll is completed. The remarks made with relation to Fig. I, Plate 42, referring to drawing 
 the lines which determine the boundaries of each quadrant, the marking the width of the rail, 
 and describing the internal spiral, and the advantage of slightly easing the scroll line as shown 
 by the thick dotted lines, apply here and it is not necessary to repeat them in this place. 
 
 Fig. 2, Plate 44, explains the mode of describing what is known as Gold- 
 man’s spiral. AB shows the desired width of the scroll and AC is the diameter of the eye. 
 The distance C B is to be divided into a number of parts equal to four times the number of 
 revolutions and two more. In this example the number of revolutions is one and a half. There- 
 fore multiply D / 2 by 4 and add 2: the result is 8 , which is the number of parts the distance CB 
 is to be divided into. On the line D e mark the point f at a distance from D equal to half the 
 
22H 
 
 WKKATHED HANDRAILS. 
 
 ..iimbt-r nt* tlir last found divisions and one more, and also half the distance AC. The point f 
 ,| l0 ren ( I0 of the eve. Make / the centre of one side of a square, the sides of which are to 
 l„. ,. ftP h ,.(|ual to one of the divisions in CB, in the manner shown. From /' to the opposite 
 oioles of the square draw the lines f > and /a. From the points' 2 and :s, mark on the lines /a 
 nd divisions corresponding with the desired number of revolutions of the external spiral. 
 In rhi' ease. a> there are to he one and a half revolutions, mark one division and a halt', in the 
 in. inner represented, and from the points thus marked draw lines parallel to the sides of the 
 | mire as shown. Then the points i, 2 , 4 , 5 , and 0 are the centres from which to describe the 
 
 ftrC s forming the scroll. See remarks in explanation of Fig. /, Plate 44, and Fig. 1, Plate 43. 
 
 WKKATHED HANDRAILS. 
 
 I he lines for wreathed handrails have been generally considered to be of 
 extreme ditficuhv and complexitv. Some of the amount of study required for the comprehen- 
 sion of the principles of handrailing must be regarded as due to the nature of the subject; but 
 tin labours of the student have been often rendered still more tedious by the vagueness and 
 obscuritv of the explanations that have been given to him. If, instead of distracting our attention 
 it li unimportant variations of detail, we keep steadily in view the main principles on which the, 
 -c\eral processes depend, we shall succeed in divesting the subject of much of the difficulty that 
 to mam has appeared so formidable. 
 
 Many workmen, by long experience, have become so familiar with hand- 
 rail work that, although their systems of lines are imperfect or even unsound in principle, they 
 succeed by the guidance of a practised eye in producing a good result. It must not be expected 
 that all the practical details of handrailing can be completely understood without observing, in 
 the workshop, the modes of procedure adopted by skilful men; for without being instructed in 
 this wav no person could successfully execute even so simple a piece of joinery as a common 
 square framed door. I 11 this as in other cases the study of theory must be combined with 
 "b-cr\ ation of practice. \\ c will proceed to explain a system that shall combine a sufficient simpli- 
 c itv with all the certainty and exactness practicable, and which while admitting of universal appli- 
 cation shall not fail in the important consideration of economy of labour and material. Plates 4o, 
 le. and IT and the remarks referring to them are arranged with a view to present a general sum- 
 'd the whole subject, and to include explanations of till the principal matters that have to 
 vonsidered. Plates Is, 4i), and o() exhibit examples of the application to actual cases of the 
 piinciph s explained, and at the same time further elucidate what is previously treated. 
 
 I' ig. - />, Plate 40, illustrates the way in which the well of a staircase coin- 
 T- with a cylindrical suiace; and Figs. I, 2, and 3, Plate 43. show how handrails of several 
 1 " M,,S 1 :,< approximately agree with part of a hollow cylinder of which the internal diameter 
 < 1 1 1 . 1 1 - the width uf the well. It may be observed that these figures represent rails which are 
 -<|u:n «■ in their transverse sections, and it is to solids of this nature that all our remarks will relate. 
 It 1 . 1 shaped square rail is obtained it will be easy to reduce it to any desired moulded form. 
 
 HANDRAILING BY THE OBLIQUE CUT.- Fig*. 4, 4a, etc., Plate 43, 
 ex[ l mi in a vein i:d way, without entering into details, how a spiral solid may be cut out of a 
 
WREATHED HANDRAILS. 
 
 221 
 
 plank of a parallel thickness. ABCD is the cylinder with the surface of which the convex side 
 of the. rail coincides. EFGII is the edge of the plank from which the rail is to be obtained. 
 Fig. 4 a shows the plan of the required rail. The dotted lines produced from the plan and inter- 
 secting the lines of the plank indicate the dimensions in one direction and the position in the 
 plank of a cylindrical solid which will contain the rail. This solid when cut out of the plank 
 would present the appearance shown by Fig. 4 c. The upper and lower surfaces corresponding 
 with the faces of the plank, while the sides agree with the concave and convex surface of the 
 hollow cylinder ABCD. Fig. 4 <1 represents the same cylindrical solid with lines illustrating 
 the way in which the square rail is contained within its bulk. On Fig. 4 b, O O represents the 
 form of that part of the cylindrical solid which coincides with the plank face and which cor- 
 responds with an oblique section of a hollow cylinder. A mould made to this form, as it is 
 intended to he applied to the face of the plank, is called the Face Mould. The dotted lines PP 
 show where the same mould would be applied on the under side of the plank. It will be easily 
 understood that when, by means of the face mould, the necessary outline is marked in the proper 
 position on the upper and under faces of the plank, the required cylindrical solid can be at once 
 cut out with a saw. The distance q< j shows the amount of the obliquity of the cut. A flexible 
 mould corresponding with the development of the convex surface of the rail is termed the Falling 
 Mould. If this be applied on the convex surface of the cylindrical solid, as shown by the darker 
 tint on Fig. 4 d, the lines of the top and bottom edge of the convex side of the rail may be 
 marked. If the superfluous material be now cut away to the lines thus marked, and until the upper 
 and lower surfaces are made square with the convex side, the desired square rail will be produced. 
 
 HANDRAILING BY THE SQUARE CUT. — This system which con- 
 stitutes an important improvement is illustrated by Figs. 5, 5 a, etc., Plate 45. The edge of a 
 plank is represented by Fig. 5, and at I) and F are shown sections of a square rail. The dotted 
 vertical lines A G and C I being respectively through the centre of each section, and the dotted 
 line BII being in a similar way through the centre of the rail midway between the two ends. 
 The face of the plank is indicated by Fig. 5 a, and on it are represented three curved lines. The 
 dotted line abc corresponds with the centre line of a face mould on the upper face of the plank; 
 the line de f represents the position of a similar line supposed to be in the centre of the rail; and 
 the dotted line ghi shows the centre line of a face mould on the under side of the plank. It 
 will be perceived that these lines are precisely similar to each other in curvature; that they nearly 
 coincide at the point h, e, and b; and that at the*edge of the plank they differ from each only in 
 relative position, which is governed by the inclination of the plank. 
 
 The edge of the plank is again represented by Fig. 5 b, and the sections 
 of the square rail are marked by the dark tint. The oblique lines a, a, corresponding with the 
 side of the square rail, show the direction that the saw would be made to take according to the 
 oblique cut system. The lines b , b, represent in the same way the direction of the saw when the 
 square cut method is adopted. It will be seen that the spaces included between the lines b />, b b, 
 completely contain the square rail. Several advantages result from obtaining the wreath from 
 the plank by the square cut system. As is indicated by the figure, a considerable waste of ma- 
 terial is avoided; the sawing, being square through the plank, is obviously more readily accom- 
 plished than when it is oblique; there is a smaller quantity of stuff to remove in order to square 
 
W R R A TI I E D 1 1 A N D K A I L S . 
 
 
 tli.' rail ; anil from the outs being all square through the plank the various moulds may be all 
 inarkc.l together on the plank, so that by their disposition the material may be employed in the 
 |„ s| wav, both with reference to the direction of the grain and the most complete economy. 
 
 r; f f. ,• represents the face of the plank. The dark tint indicates the face 
 mould and the curved dotted lines a, a, show the amount of material that would be required for 
 the oblique cut. In this figure the width of the face mould at ee is equal to the width of. the 
 rail, and it- width at dd corresponds with the distance c a in Fig. bb. In fact the face mould 
 i> exactly the same as that which would be used for the oblique cut. As shown on the figure 
 tli. width •/</ is greater than the width cc; but there will be always sufficient material to contain 
 the finished rail if the face mould is made of a parallel width not less than either the width or 
 thickne— of the finished rail. A lien the face mould is made of a parallel width we have to 
 ascertain the form of its centre line and mark half the width on each side of it. If the centre 
 line of the face mould be correctly drawn, the width at d d may be made equal to or greater 
 than thr width or depth of the rail at the option of the workman. Some prefer to have a little 
 more material than is absolutely necessary; but as shown by Fig. bd a finished rail may be 
 included in a thinner plank and in a less width than would lie required for producing a 
 rail completely square. 
 
 Fig. be represents the solid obtained by the square cut and which includes 
 the required spiral rail. This does not at first sight have so satisfactory an appearance as the 
 cylindrical solid produced by the oblique cut; and we have now to consider haw the square cut 
 -olid may lie reduced so as to more nearly approach the form w r e require. The principle on 
 which we have to proceed will be most clearly illustrated if we suppose that we have tw r o simi- 
 lar lace moulds, each corresponding with the oblique section of the cylinder, and being of pre- 
 ei-cly the same form as would be required lor the oblique cut. Let us imagine the two face 
 mould.- to be respectively tacked on the upper and under surface of the solid in the proper re- 
 l.uiw positions, as shown by A and 1>. 11 the material be worked down to the form indicated 
 
 l'\ die lace moulds, and as shown by the dotted lines cc, cc, the sides of the solid will be made 
 of the proper cylindrical form. 
 
 In carrying out the square cut system some workmen do not use a falling 
 
 aI a ^’ "I' en one is required it is frequently applied to mark only the centre falling 
 
 ^' m <oint> ''ido of the rail. As is shown by the dotted lines on Fig. be the amount of 
 
 cylindrical surface on the convex side of the Ail is rather small, and it would sometimes be so 
 much so as to render the application of the falling mould a matter of difficulty. It may there- 
 fore be sometimes an advantage to allow a little more material for the convex side of the rail, 
 d'" ininasing the . \lindrical surface and facilitating the squaring. The increase of width wo.uld 
 require to be very trifling at cc, Fir,, be, but somewhat more at dd. 
 
 PROJECTION AND DEVELOPMENT OF THE FALLING LINE. 
 
 A falling would is produced by the development of the convex side of the rail; but several 
 ^ 11,1111 I' 11 •'< ul . 11 > .in determined by the form ot a line supposed to pass through the centre 
 "i <he width and depth of the rail, and which is called the centre falling line. This line may be 
 
 " l,: " lified in form » aeoording to the .judgment of the workman, and it will be there- 
 
 ° re M a<Uanta « € if we ( -'"»ider its projections and the mode of its development. 
 
WREATHED HANDRAILS. 
 
 223 
 
 Fig. /, Plate 46, represents the plan of a half cylinder, the semicircle being 
 divided into six equal parts. Fig. / d shows the development of the semicircle by measuring 
 alon<>- the line A B distances equal to those marked on the semicircle. The line A C, in this 
 figure, indicates a falling line of equal inclination throughout its length. From the points i, 
 etc., in the line A B, vertical lines ai’e drawn to the falling line. The intersections of the verti- 
 cal lines drawn from Fig. / with the horizontal lines produced from Fig. 1 d, in the manner 
 represented, mark the points in Fig. I a through which to draw the curved line A C, which is 
 one elevation of a falling line of an equal rate of inclination. Fig. / c, obtained by vertical lines 
 from the plan, Fig. 1 b, intersecting the horizontal lines as before, is the side elevation of the same line. 
 
 Fig. 2 c is a side elevation on which the falling line appears as two straight 
 lines. Corresponding with this figure, the falling line appears curved on the elevation Fig. 2 a, 
 and its development is as represented by Fig. 2d. 
 
 The elevations Figs. 3 a and 3 c, and the development Fig. 3 d, show a 
 falling line which in each view presents a curved appearance. 
 
 PROJECTION OF THE FACE MOULD. — RESTING POINTS. — 
 SPRINGING OF THE PLANK. From what has been started it will be understood that 
 the face mould must always coincide with some part of a section of a cylinder; the plane of the 
 section corresponding with the face of the plank; and the plank being supposed to be inclined 
 so that its face is as nearly parallel as practicable with the centre falling line. The curves of a 
 face mould must be necessarily always elliptical; and it has been suggested that they might be 
 described with a trammel. It L however believed that the use of this instrument would not be 
 found more convenient than the method with lines that will be explained. Our remarks for 
 the present will relate only to the finding the face mould for a single line. 
 
 The determining the form of the face mould is most simple when, as in 
 Figs. 4 and 4 a, Plate 46, the point d, over the middle of the development of the curved line of 
 the plan, is at a height above the line A B equal to half the distance B C. In this case the 
 plank would be inclined as shown by Fig. 4 l>, and finding the face mould would lie very easy. 
 The points A, d, and C, in Figs. 4 and 4 a, are called resting points, being points on which the 
 line may be supposed to rest. Much depends on the position of these points, and it is important 
 that their places should be accurately determined. A <1 B, Fig. 3, is the plan of the centre line 
 of the rail for which the face mould is required. BC is the height of one end of the line; and 
 AC is the inclination or pitch of the plank. The curve Ar/B being divided into any number 
 of equal parts, lines from the points of division and perpendicular to A B are drawn to the line 
 AB and prolonged to intersect the inclined line AC.' From the points thus marked in AC 
 perpendicular lines are drawn, and on them are marked distances respectively equal to the cor- 
 responding distances in the plan. The line A dC drawn through the points thus obtained is the 
 face mould line required. Fig. 3 a illustrates the nature of this method and shows how each 
 point in the curved line obtained corresponds with a similar point in the plan. 
 
 In Fig. 6 the height of the point d above the line A B is less than half the 
 height B C, instead of being exactly half the height of B C, as was the case with Figs. 4 and 4 a. 
 The position of the plank becomes changed in consequence, as shown by Figs. 6a and 6b. 
 The degree of transverse inclination which is given to the plank in order to make its face parallel 
 
WREATHED HANDRAILS. 
 
 224 
 
 with the three resting points A,r/, and C, is called the springing of the plonk. In Fig. 7 the case 
 j, varief i |, v ,he height of the point d above the line AB being greater than half the height BC, 
 ;,nd the plank must be accordingly sprung upwards as shown by Figs. 7 a and 7b. 
 
 In connection with this part of our subject it may be well to give some 
 attention to the section and development of a cylinder, as illustrated by Figs. I, / a, etc., Plate -17. 
 
 an elevation indicating the obliquity of the plane of section. Fig. / a shows the true 
 form of the section, which is an ellipse and corresponds in its nature with a face mould line; 
 while hi a. lb is the projected representation of the same. Fig. I c shows the development of 
 the edire of the sectional surface,' which corresponds in its nature with a falling mould line. By 
 studying these figures we may see how„by taking different portions of the same cylindrical sec- 
 tion, we may obtain face moulds corresponding with falling lines of various forms. Thus the 
 lower part of the section from A to B, is similar in its nature, both with reference to the falling 
 line and the necessary face mould, to what is illustrated by Fig. 6‘, Plate 46; while the upper 
 portion of the section from B to C is analogous to what is represented by Fig. 7, Plate 46. 
 
 The fact that different parts of the same section of a cylinder respectively 
 correspond with the face mould line required for the three positions of the plank illustrated on 
 Plate id bv Figs. 4, 4 a and 4 b, by Figs. 6 , 6 a, and 6 b, and by Figs. 7, 7 a and 7 b, should be 
 thoroughly understood, and it would be well for the student to familiarize himself with the 
 relation of various falling lines to their corresponding face moulds by working out a number of 
 projections, sections and developments of cylinders according to the methods explained. Fig. / d, 
 Plate \7 . further assists in illustrating what has been referred to. In this figure the portion of 
 the falling line from A to B is represented in elevation, in the position indicated by the plan, 
 
 and it will be seen that it corresponds with the case illustrated by Figs. 6, 6 a and 6 b, Plate 46. 
 
 b ig. / e indicates in the same manner how the portion of the section from B to C agrees with 
 the ease illustrated by Figs. 7, 7 a, and 7 b, Plate 46. 
 
 To determine the form of the face mould when the plank is required to be 
 
 " prang position. Let the plan of the centre line of the rail be represented by Fig. 2; and 
 
 on Fig. 2a let A be the position of the lowest resting point; let BC be the height of the top 
 resting point; and let L be the place of the middle resting point. Join A C; and from the point 
 h draw the line E/ at right angles to AC. From the points E and f let fall vertical lines to 
 die plan in the manner shown. From the point g, thus marked on the chord line of the plan, 
 
 '< t off die distance g h, equal to the distance E/, and draw the lines :s li and a i. From the point 
 
 ' produce the line fi at right angles to AC and make fk equal to the distance 3 h on the plan. 
 
 I In line A ( may be considered to be the chord of the required face mould line. Then the 
 
 point' A andC will be the two extremities of the desired curve, and k will be an intermediate point. 
 
 / o find any other intermediate point in the. face mould line, as one to correspond 
 "■a/, lie pm, It marked j on the plan. From the point •> draw the two lines >1 and 2 m, respectively 
 parulh'l to the lines . h and i i. From the point rn draw the vertical line mn to intersect the 
 Imo A ( . h-om the point a draw up perpendicular to A C and equal to the distance il on the 
 plan, p will be another point in the curvature of the required face mould line. In the same 
 manner other points njav be ascertained, to correspond with the points i, 4 , r>, etc., on the plan, 
 in tin m, mm i i ( pi evented. The curved line A opkqr C, drawn through the points thus found, 
 
AVREATHED HANDRAILS. 
 
 225 
 
 is the face mould line, which is part of the section of a cylinder, the plane of which would pass 
 through the points A, E, and C. 
 
 Figs. 3 and 3 a illustrate the same method as applied when the middle 
 resting point E is above the line A C. In this case the plank must be sprung upwards. So 
 .far as the letters and figures of reference are the same as in the last example the same descrip- 
 tion applies to this diagram. The line AopkqrC, Fig. 3 a, corresponds with the centre line 
 of the rail. To find the face mould line for the convex side of the rail: produce the line is, 
 Fig. 3, to the point s in the convex side, and from .s 1 draw si parallel to sh. Produce the line 
 E fk, Fig. 3 a, to v , and make the distance fu equal to the length of the line st in the plan. 
 The point u will be a point in the face mould line for the convex side of the rail; and other 
 points in the same line may be obtained in a similar manner. Thus from the point v, in Fig. 3, 
 draw the lines vw and vcc, respectively parallel to the lines s h and si. From w draw the vertical 
 line wy to intersect the line A C, which is to be produced as shown. From the intersection y 
 draw the perpendicular y z, and make y z equal to the distance vx on the plan. Then z will be 
 the point in the face mould which corresponds with the point v on the plan. A line drawn 
 through the various points thus obtained will complete the face mould indicated by the tint, of 
 which the concave edge corresponds with the centre line of the plan, while the convex side 
 agrees with the convex side of the rail. 
 
 The diagram Fig. 3 h represents the actual spring of the plank. The 
 distance fg corresponds with the distance sg on Fig. 3, and the height /E is equal to the dis- 
 tance /’ E on Fig. 3a. The distance E g is consequently equal to the length of the line sh on 
 
 Fig. 3. The lines it, tt represent the thickness and transverse inclination of the plank, and 
 
 the position of the rail in the plank is shown by the dark tint. The lines an, nu show the direc- 
 tion of the saw according to the method with the oblique cut, but the square cut system applies 
 to a sprung plank as well as when there is only the simple pitch to be dealt with. The plank 
 has to be cut square through as indicated by the light tint on Fig. 3c; and for reducing the 
 square cut solid thus produced to the cylindrical form the face moulds must be applied in an 
 oblique position corresponding with the amount of spring and as indicated by M and M, Fig. 3c. 
 
 HEIGHT OF THE RAH,. — LIFTING THE RAIL. — Over a level 
 landing the height of a handrail should be 40 inches, measured from the Hoor line to the top of 
 the rail. Over flyers, the height, measured from the middle of the breadth of each step, should 
 he 40 inches less the height of one step. If the height of the top of the rail were to be mea- 
 sured in the same manner, and made of the same dimension over winders, as is proper over 
 
 flyers, the apparent height would he less. This diminution of apparent height is more conspicuous 
 in proportion to the increased steepness of the ascent caused by a small diameter of well, and 
 a number of winders in the quarter. The protection from falling over the side of the stabs is 
 reduced in a corresponding degree. To overcome these defects the actual height of the rail over 
 the winders must be increased and doing this is called lifting the rail. If the rail is made of 
 the same height above the nosing line of the winders as it is over the middle of the breadth of 
 the flyers, a slight degree of lifting will be produced, which will often be sufficient; hut it is to 
 b e understood that the amount of lifting must be generally determined by varying circumstances 
 according to the judgment of the workman. Lifting the rail has the eft’ect of making the face 
 
 Carpentry. XXIX 
 
\V KE ATI l ED HAN DRA I ES . 
 
 221 ) 
 
 mould.- required for the upper and lower parts of a wreath differ from each other both in length 
 ,ml form, in eases in which but for the lifting the same face mould would have answered, by 
 re\i rsing, for both the upper and lower portions. 
 
 PITCH OF THE PLANK. — It will be easily understood that it is of 
 c-.-ential importance that the pitch of the plank, or the inclination at which it is supposed to lie, 
 Imuld l.e correctly determined. The face of the plank ought to be identical with the plane of 
 the section of the cylinder which gives the form of the face mould; and this should correspond 
 in a proper manner with the falling line of the rail. The pitch of the plank, and the consequent 
 lines f.»r ascertaining the form of the face mould, will be correctly determined if all the requisite 
 measurements are made to the line supposed to pass through the centre of the breadth and thick- 
 lies- of the rail. Thus on Fig. 2, Plate 47, the curved line oi 234 5 6 is the plan of the centre line 
 uf dii' rail, and the base line of the diagram Fig. 2a is made to correspond, in the manner shown, 
 with thi- plan of the centre line. The height of the upper resting point C being measured from 
 mie end of thi- line, the line A C indicates the correct pitch of the plank. It will be found that 
 l>v working to the centre line of the rail, in this way, the face mould lines produced are of the 
 proper form, and that owing to the inclination of the plank being correct the utmost economy 
 of material is practicable. 
 
 ELLIPTICAL STAIRS. — All the explanations given and all the me- 
 thod- proposed for stairs round a circular well are of such a nature that they will apply with 
 • qual correctness to the handrailing of stairs which are elliptical in plan. As with stairs of 
 which tin well is circular it is the elevations, sections, and developments of cylinders which have 
 to lx considered, so with stairs of which the well is elliptical in plan it is the elevations, sections, 
 and developments of cylindroids which determine all the particulars that have to be ascertained. 
 As will be seen by referring to Figs. 4, 4 a, etc., Plate 47 , the elevation and development of the 
 Idling line require no variation in the mode of treatment from what has been already illustrated, 
 and in the same way the remarks made in explanation of the face mould, etc., will apply 
 equally to elliptical stairs. 
 
 1 lie form of the falling line of the rail is governed by the dimensions of 
 d" ' ,f 'p at the well, and /' ig. 6 indicates the most desirable way of arranging the plan of the 
 I lie dotted line in the centre between the well and the wall line is divided into equal 
 I 1,1 • ;| nd 'I"’ !' neti of the steps are drawn perpendicular to this dotted line. 
 
 IKl L hORM ()h I HE HANDRAIL SPIRAL. — The properties of 
 1 '"in. Hu -plicre, the cylinder, etc., afford in numerous cases the only means by which we 
 
 in able to discover and work out the geometrical processes required for constructive purposes. 
 " , * 1 '' :, 'd 'I'" afforded we should be almost entirely without guiding principles, and use- 
 
 1 '"dd S, ai.cly exist, for the purposes of the art of handrailing we must employ the 
 I ' ' 1 h"" . and developments of cylinders. A squared handrail is usually defined to be 
 
 1 I ' n 'a I solid, of which the concave and convex sides exactly coincide with parts of a hollow 
 ' "I*!"' 1 :u ’d lower surfaces are so formed that all sections made by vertical 
 l ’' "" ' P a88 ’ n g through the axis of the cylinder are rectangular in form. It is however desirable 
 
 ^ ' c 1 that the true handrail spiral does not precisely agree with the form 
 
 di n has ju-t been described. \X hen the radius of the well is considerable, and the rise of the 
 
WREATHED HANDRAILS. 
 
 227 
 
 wreath is very trifling, the discrepancy between what may respectively be termed a cvlindric 
 spiral and a handrail spiral is almost inappreciable; but the difference becomes more and more 
 conspicuous as the radius of the well is diminished, and as the inclination of the wreathed hand- 
 rail is made more steep. In the case of a very small well, as one of two or three inches in 
 diameter, with say four winders in the quarter, a handrail squared exactly in accordance with 
 the generally accepted definition of its proper form would present an appearance similar to that 
 shown by Fig. 6, Plate il . A section taken at right angles to the inclination of the falling line 
 would be much narrower on the concave than on the convex side of the rail. The same result 
 would occur in a somewhat less degree if with the same size of well the inclination of the rail 
 were less steep, as indicated by Fig. 6 a. The peculiarity referred to would be distinctly per- 
 ceived if, by way of experiment, a hollow semi-cylinder of small diameter were formed and 
 models of handrails were cut out of it of different degrees of inclination. 
 
 An unsatisfactory result will also follow if the rail be shaped exactly ac- 
 cording to the ordinary definition of its form, when a straight rail over flyers joins a wreathed 
 portion of small radius. It will be understood that the developed length of the concave side 
 of the wreath must be less than that of the convex side, and that since the amount of rise must 
 be equal for the two sides the concave side must be of a steeper inclination than the convex 
 side. The junction of a straight rail with a scroll affords an example of what is alluded to. 
 
 By way of defining the form of handrail that it would be desirable to ob- 
 tain, we may suppose that a spiral plane winds round a cylinder in the manner represented by 
 A B, Fig. 7, which plane is to be considered as coinciding with the centre of the depth of the 
 rail, as indicated by the thick horizontal line in Fig. la. If we were to make a rail of such a 
 form that every section taken at right angles to the falling line (as shown by the line c cl, Fig. 7) 
 would be rectangular, we should produce a rail that would meet more satisfactorily every re- 
 quirement. A handrail as ordinarily defined differs from what we have described in being rect- 
 angular in the vertical section, as shown by the line ef. 
 
 These remarks are made with the view of calling attention to the fact 
 that in the only system by which the art of handrailing can be practised, viz. that of treating the 
 rail as part of a hollow cylinder, there is inherently a source of error that has to be guarded 
 against. It is suggested that only the convex side of the rail should be worked truly to the 
 form of the cylindric spiral, as ascertained by the use of the face mould; and that when the form 
 of the convex side is correctly determined, the upper and lower surfaces and the concave side 
 can be easily made to the shape that will be seen to be desirable. 
 
 When the following examples as well as the general explanations and 
 remarks already given have been understood it is trusted that the student will be sufficiently 
 master of the theory, and that only the observation of practice will be required. It may be 
 remarked that in the actual execution of handrail work many variations of detail will be per- 
 fectly admissible. Thus the mode of squaring the rail practised by one workman may differ 
 materially from that adopted by another, and yet the principle will be the same; and in the same 
 way with other details of practice. In illustrating the subject of handrailing we have acted on 
 
WREATHED HANDRAILS. 
 
 228 
 
 tlx- opinion that the object to be most desired is the complete mastery of the principles on which 
 tl„ art depends. The positions in which handrails have to lie placed are so various that no 
 pr.ietirable number of examples would include an illustration of every ease that could occur, 
 l, ut f | 1( . n ,an who really understands the several necessary processes can readily apply them 
 in all circumstances. 
 
 PLATE 4S. — HANDRAIL OVER LEVEL LANDING, WITH 
 I I \ KPS UP AND DOWN. — Fie/. I is a plan of the required rail. The centre line of the 
 rail shown in this figure is that to which we have chiefly to give our attention. At A, B, and li, 
 K shown the position on the plan of the butt joints of the rail. The joint at B is in the middle 
 , ,t ,|„. semicircle; those at A and h are removed (as must always be the ease) a few inches from 
 rhi commencement of the circular part. The chord lines front A to P> and from B to h , in the 
 ,-entre line, give the length of the base line for the face mould diagrams, and taken in conjunc- 
 tion with the rise of the rail determine the pitch of the plank. 
 
 Fhi. la shows the elevation of the steps, and the thick lines AC and C i 
 represent the centre line of the rail. 
 
 Fin. / h is the plan, placed in a position to correspond with the elevation 
 Fin. / <•; and Fir/. / d shows the development of the central falling line. The two elevations, in 
 conjunction with the development, make it easy to judge of the appearance of any handrail that 
 ma\ be designed, and if any objectionable effect appears likely to be produced, the curve of the 
 tailing line must be varied until a graceful form is obtained in the corresponding elevations. 
 1 he dotted lines sufficiently define the dependence of these diagrams on each other. On Fig. 1 d 
 the distance . : is the stretch-out or development of the semicircular part of the centre line of 
 the plan, while the distances .r ; and : g are each equal to the width of a step, and afford the 
 means of drawing the correct inclination of the straight part of the handrail. 
 
 In avoid unnecessary complexity in the diagrams, the falling line, as 
 -hown on /' i</. Id, is repeated on Fig. 2, but divested of the constructive lines which we no 
 longer require. On big. 2, which is to tw ice the scale of Fid. I, / a, rtc., there is drawn from 
 \. which i~ the lowest resting point ot the central falling line of' the. required wreath, the hori- 
 zontal line A B. BC is the height of the upper resting point above A; and the perpendicular 
 Inn. in the centre between A and B. from the point D to the falling line, gives the height of 
 E, which is the middle resting point. 
 
 I' iff- 9 - ■' (tud d a show how the dimensions that we have obtained enable 
 1,1 , ’ >< ei tain the form ol the face mould. I'hesc diagrams are precisely similar in nature to 
 / A j and In, Flail )7, and the explanatory remarks referring to those figures apply in 
 tin piosent instance. big. d is the plan ot the rail, and shows a few inches of straight rail at 
 da end of the w reath, l’hc chord line from a to b gives the length of the base line A B, Fig. da, 
 111 111,11111,1 I he point d, big. d, is in the middle of the length of the centre line on 
 
 the plan, and the perpendicular D E, Fig. da, is made to equal the height of this point in the 
 mantn-r indicated. The heights BC and D E are measured from Fig. 2. 
 
 I he part marked by the tint on Fig. da is the face mould. In the square 
 "" <ys,Pm ,1,ere are hvo (listin,,t objects to be attained by the use of the face mould; the first 
 bemg the marking on the face of the plank the form of the square cut solid that will contain 
 
WREATHED HANDRAILS. 
 
 229 
 
 the rail; the second being the reduction of the solid thus cut square out of the plank to a cy- 
 lindrical form. For the first of these objects we use the concave edge A AC which corresponds 
 with the centre line of the rail; and for the second we employ the convex edge which relates to 
 the convex side of the rail, and which is the same curve that would be required for the oblique cut. 
 
 To describe on the face of the plank the outline of the square cut solid: 
 with the concave edge of the mould mark the centre line A k C, Fig. 4; also mark the joint lines 
 Ao and Cjp. From any number of points in the centre line, with a radius equal to half the 
 width or depth of the rail (whichever is the greatest dimension) describe circles as shown. Draw 
 two curved lines touching these circles in the manner represented, and produce the joint lines 
 to the inner curve. The outline thus obtained gives the form of the smallest square cut solid 
 that will contain the rail, the thickness of the plank being equal to the width or depth of the 
 rail (whichever is the greatest dimension). As has been before remarked, some consider it an 
 advantage to allow a little more material towards o and p, because by doing so the correct 
 squaring of the rail is somewhat facilitated. The line oqp corresponds with the convex edge of 
 the face mould, and the plank may be sawn to this line, or to any intermediate curve. 
 
 The solid that has been cut square out of the plank requires to be reduced 
 to a cylindric form, and for this purpose we employ the face mould that we have obtained. It 
 is proposed that only the convex side of the rail should be made cylindrical by means of the 
 face mould, it being considered that for the formation of the upper and lower surfaces as well 
 as the concave side of the rail the eye of the workman will be the best guide. To reduce the 
 convex side of the square cut solid to a cylindrical form we must be able to place the face 
 mould upon the upper and lower faces of the solid in positions exactly corresponding with those 
 that would be required for the oblique cut. These relative positions will be governed first, by 
 the pitch of the plank, and secondly by the amount of its spring. If the plank were placed in 
 such a position that both its pitch and springing were correctly as required, and the centre line 
 or the line for the convex side of the rail were marked on its upper face, then the corresponding 
 line for the under face of the plank should be in such a position that vertical lines let fall from 
 the upper line would always pass through corresponding points in the lower line. 
 
 Let us consider the line A AC, Fig. -5, to be the centre line as marked on 
 the lower face of the plank. Fig. da shows the pitch and thickness of the plank; and the dis- 
 tance cb indicates how much the relative position of the face moulds is affected by the pitch. 
 This distance transferred to Fig. ■) gives the distance C b. Fig. 5 b shows the spring and thick- 
 ness of the plank (see Figs. 3 awl 3 a, Plate 47, and explanatory remarks referring to them) and 
 the distance h d indicates how much the relative position of the face moulds is affected by the 
 springing. This distance d b transferred to Fig. 5, as shown, enables us to place the line d e f in 
 its proper position on the upper face of the plank with relation to the line A AC on the lower 
 face. Having thus ascertained its relative positions, apply the face mould on the upper and 
 lower faces of the solid, and mark the centre line of the rail and also the line for the convex 
 side. The squaring may be then proceeded with. 
 
 A falling mould may frequently be dispensed with, but when it is desirable 
 that one should be used it is the line on the plan representing the convex side that must be 
 developed, and not the centre line. The mode of drawing the falling mould is illustrated by Fig. 6. 
 
SHOP FRONTS. 
 
 230 
 
 In tlio case of the example shown on this plate it is obvious that the upper 
 |,;n-t of the wreath precisely corresponds with the lower part in the nature of its curve. There- 
 f . , th, i, will he no lines required for the upper part, but it will be necessary to reverse the 
 ( mould. In cases where the upper and lower parts of the wreath are not similar in this 
 w ;i \ , two face moulds must he obtained, but no variation is required from the methods that 
 have been explained. 
 
 PLATE 49. —HANDRAIL OVER WINDERS. — This plate illustrates 
 th< application of the various processes that have been explained to a handrail over winders 
 round a semicircular well. Fig. I is the plan of the rail. Fig. 1 c represents the development 
 n| the steps in a plane coinciding with the centre line of the rail, as shown on the plan. The 
 thick line is the central falling line of the handrail, which is lifted over the winders. The dis- 
 tance m ,i. on the base line, is equal to the development of the semicircular portion of the centre 
 line on the plan. The two elevations Figs. 1 a and / b, obtained from the falling line by the 
 method already fully illustrated, serve to show the appearance the rail would present when 
 fixed in it place, and afford a guide for so modifying the curve of the falling line that the best 
 i fleet will be produced. The form of the face mould for the lower part of the wreath is repre- 
 -ented by f ig. 2, and for the upper part by Fig. 3. These last figures are drawn to a scale one 
 and a half times greater than those preceding. 
 
 PLATE 50. SCROLL OVER COMMENCEMENT OF WINDERS. 
 
 I hi plait illustrates the case of a scroll terminating a handrail over winders. In this instance, 
 i die winders arc at the bottom of the stairs, the handrail does not require to be lifted, and it is 
 made parallel with the nosing line. Fig. / is the plan. Fig. / c is the development of the een- 
 , 11 ^ killing line; and bigs. 1 a and 1 b are elevations indicating the appearance of the rail as 
 icw i d in two direction-, bigs. 2 and 3 show the lace moulds for the lower and upper portions 
 of the wreath to twice the scale of the other figures. 
 
 r>. SKYLIGHTS, 
 
 11 M | h\ I 1 _> to 2 1 ins. thick, rebated for glass, throated, chamfered or moulded in various 
 1 " 1 d 1 :l "ido Ira me, the mouldings not being continued round below, in order to allow the 
 
 1,1 1,1 11111 *db Lie curbs may he l 1 to 2 , / 2 ins., in two thicknesses, bevelled and chamfered. 
 L" 1 i v 1 1 1 ■" .tie disposed in various ways, sometimes sloping with the roof and fixed, sliding, 
 kim "M lung, "i'h rack stay-bar and hooks, or placed upright in fir solid frames and hinged 
 " r llU ".- (, n centres. (Sec P/ales 7, 8, Si, , 18, 1.9, 30, 33, 34, 33, 38.) 
 
 <>. SHOP FRONTS, ETC. 
 
 V e -hall here only touch on the works peculiar to shops, as so ,much 
 already explained relates to the subject. Sashes , moulded in various ways, vary from D.Ato 
 2 ins. m depth, and those of a superior description are faced with brass or zinc, having a 
 " ul wood ime, with moulding screwed on inside to take the glass. TJftwg 
 
 I i i" 2 iii'. thick, usually betid Hush and square, with iron shoes, lifts, stubbs 
 '■ :nr bistened with wrought iron, chamfered, jointed bars (2 l / 2 X 1 2 ins.) 
 
SUNDRY WORKS. 
 
 231 
 
 and thumb screws: those to sash doors have also plates, thumb screws and shoes. Revolving 
 shutters are of iron or wood, the latter varying in price from 3 to 4 shillings per foot super. 
 Stall hoards (below sashes) are wrought, framed, mitred at the angles, and may be 3 to 6 ins. 
 deep bv 4 to 12 ins. wide, moulded on the face outside and fixed with wrought iron L plates, 
 P/ 2 X 1 / a in., let in flush and having countersunk screws. Brass or zinc removeable mouldings, 
 to be obtained ready made in lengths up to about 30 feet, are generally placed outside. Show 
 hoards may be of l to 2 ins. deal, eross-tongued, etc., and fixed on framed bearers: where there 
 are windows below, 3 4 to I in. rebated, or eross-tongued, beaded sloping boarding is usually 
 fixed. Entablatures have I to 1 1 2 hi- Honduras mahogany friezes, housed into consoles at the 
 ends, with deal mouldings, put together with glued blockings, tongues, screws, etc.; and inch 
 cover boards, all fixed to strong fir cradling and backing. Pilasters, columns, etc., may be as on 
 Plate 57. Enrichments are often of papier macM, carton pierre, or carver’s compo. Counter top's, 
 usually of mahogany, may be 1 to 2 ins. thick, moulded on the outer edge and rounded on the 
 inner; and the fronts 1 to 2 ins. thick, panelled, the whole supported on wrought and framed 
 legs and bearers: 1 or l*/ 2 in. cross-partitions, dovetailed drawers on wainscot glued runners, 
 rebated into groove and sliding on bearers. The fittings, cases, etc., are varied in every con- 
 ceivable manner; and the Plates 73, 74 need no explanation. 
 
 7. SUNDRY WORKS. 
 
 Casings, outside, together with linings, or inside, coverings, vary from 5 8 
 to l 1 2 in. thick, and arc variously framed, rebated, tongued, matched and beaded. Cisterns 
 and sinks f 1 1 to 2 ins.) have rebated or tongued bottoms, and dovetailed sides; closet fronts 
 (1 to 2 ins.) have rebated, beaded, etc., fronts; fireplaces 1 to D/ 2 in. jambs and shelf: and 
 dressers 1 1 / 2 to 2 ins. eross-tongued, rounded tops, buttoned down, 1 to 1 1 / 2 in. framed ends, 
 potboards, sunk shelves, with bearers or cut brackets, or 1 to l l / 2 in. cut standards; 5 S in. 
 beaded facia and mouldings at top; 1 in. skirting below; and 3 4 in. matched and beaded 
 lining behind; dovetailed drawers on wainscot glued runners, with 1 in. fronts and bottoms, 
 3 4 in. rims, and wooden handles; framed and beaded legs (3 to 4 ins. square) and bearers, and 
 beaded rail in front 3 X 2 ins. Angle heads, used at external angles, flush with the plaster, 
 have a section of three-quarters of a circle, with a projection nailed to plugging or bond. Pews 
 (1 to l}/ 2 in.), secured to floor with angle irons, are panelled in various ways, with moulded and 
 grooved capping, seats (1 to l 1 4 in.) rounded on edge, supported by cut brackets, and book- 
 boards ( 3 / 4 in. with 1 2 in. rounded and tongued capping) on brackets. Free seats (1 f/ 4 to 1 1 . 2 in.), 
 have sloping backs, with chamfered styles and rails 4 ins. wide, and cut brackets 2 ft. 6 ins 
 apart: flaps should have strong joints, and be hung with flap or butt hinges. Mangers may have 
 2 ins. bottoms and 1 1 2 in. sides, tongued or rebated, with rounded capping; racks, rails 3 1 X 
 2 1 2 ins. with 1 , / 4 in. round bars; linings to walls of 1 in. stuff, tongued and beaded, with 3 / 4 in. 
 rounded capping; corn bins 1 to 2 ins. tongued bottom and sides, and ledged lid; inch 
 beaded rails with dovetailed and cut harness brackets, and framed and turned pins. Stall posts 
 may be 5 or 6 ins. square, stop-chamfered, with grooved and chamfered bottom, middle and top 
 rails 4 X 3 1 / 2 ins., the last rounded above, or there may be two middle rails 4 X 1 , / a ins.; 
 
 1 to 1 1 2 in. rebated or tongued and beaded boarding: skeleton framed gate to loose box with 
 
232 
 
 MOVEABLE JOINERY. 
 
 st vies, rails and brace 3 or 4 by 1' 2 ms-, and 1 a in. stuff 4' 2 ins. wide may be filled in. 
 Small bo.ies in walls to have 1 1 2 in. chamfered side linings and fronts, bond being introduced 
 above and below. 
 
 Ironmongery. Nails are wrought or cut; tacks are the smallest; brads 
 have a small projection on one side. Hinges are of cast or wrought iron, or brass; and there 
 are butts of various kinds, back Haps, cross-garnetts, hook and eye, parliament, H and PL hinges, 
 -wing-centres, etc. Of locks, there are stock, dead, iron-rim, mortice, etc.; and the handles, 
 finger-plates, etc., constitute the furniture. Latches are thumb, bow, mortice, pulpit, etc. Pullies 
 are brass-cased and axle; sash fastenings common and spring roller, with cranked for casements, 
 and espaniolette bolts. 
 
 SECTION II J. 
 
 M 0 V E A B L E J 0 I N E 11 V. 
 
 1. DOORS are internal or external and single or folding: jib doors are 
 partial!} concealed by being made flush with the wall and convassed or papered over. (See Plate 
 Lines H8.) Panelled doors are from 1 to 2 1 / 2 ins. thick, and are described according to the 
 number of panels and mode of finish. Thus, the panels may be plain and flush, square, cham- 
 fered. beaded or moulded in various ways (See Page 211) one or both sides, or square one side 
 and beaded or moulded the other, and so on. In bead butt work the two edges in the direction 
 "t the grain are beaded, while in bead flush the bead continues all round. It is as well to sto]> 
 chamfer- in order not to weaken the angles. Bolection mouldings project beyond the face of the 
 door: and raised panels have a margin sloped off all round, and which may be finished square 
 or moulded. A reference to Plates 53, 58 and 62 will fully explain the mouldings of doors. 
 
 < >n the last, \ is the bottom, B the top, (' the frieze and D the lock or middle rail; E is the 
 outside, h the middle, and G, wider than the others with a bead, the inunton; the panels are 
 1 ailed top, Iriezc. middle, bottom and side, according to their number. The dimensions ^usually 
 • dopted are 2 ft. lo ins. from the floor line to the centre of the middle rail, bottom and middle 
 rail- s in-.. and the remainder I 1 ins. wide, hedged doors [See Plate o4. Fig. /.) are the com- 
 monest of all. consisting merely of stuff (■• to 1 1 ._> in.) nailed to two or more ledges, and are 
 rough, m wrought, rebated, tongued and beaded. The addition of braces is the next improve- 
 mi'iit: but by adding a frame all round, covered outside or filled in with the boarding, we have 
 do br-t form of door, as the diagonals greatly increase the strength of the combination (See 
 / " 1 22 1, the stress being from the hinged joint. Again, doors covered on the outside do not 
 
 lodgment for wet presented by panels; and ornamental hinges are ample decoration. 
 
 I la -i dour- are illustrated on Plates 51, (32 and fi3: at the bottom of Plate 62 are sections of 
 "">-1 foim-. I he frames and braces are 1 to 2* 2 ins. thick, and of various widths, (say middle 
 ;,n 'l * >ot,oni n, '' > k and the remainder 5 ins.), stop-chamfered, with a covering, or filling-in, of 
 , m I in. boards, half plank or half deal widths, or battens, plain, rebated, ploughed and tongued, 
 f'cadi'd, chamfered, etc., either fixed vertically or angularly, on one or both sides. Gates to coach 
 
MOVEABLE JOINERY. ' 
 
 233 
 
 houses, etc., are usually thus formed with rebated and beaded meeting styles, saddle-back grooved 
 and rounded capping, and ivickets formed in one half; but they are occasionally panelled: small 
 gates are given on Plates 51 and 62. For sash doors the styles to the glazed part are diminished 
 in width, the lock rail haunched, and the sash may be as next described. 
 
 2. SASHES. Casement sashes are 1V 2 to 2?/ 2 ins. thick, and great care 
 is requisite so to hang them as to exclude wet; several modes, both foreign and English, being 
 being shown on Plate 6-1. Fanlight sashes are seldom above 1 1 / 2 in. thick; and they are either 
 fixed or turn on centres. Sliding sashes run on rollers, and may be so arranged as to run into 
 recesses in the wall, instead of passing each other, only one half of the window being thus 
 opened. TAfting sashes are either single or double hung, and vary from 1 to 2 1 2 ins. in thick- 
 ness. On Plate 65 the form of junction between the meeting bars of the sashes is shown, and 
 below it the franking, or connexion of the bars with a dowel. Other joinings are given, together 
 with sections of sash bars: A ovolo, B lamb’s tongue, C astragal and hollow, D various mould- 
 ings. The glass is fixed either with putty or a bead, and for sash doors should be bedded 
 in wash leather. 
 
 3. SHUTTERS are lifting, running, folding, or revolving. TAfting shut- 
 tei’s, illustrated on Plates 6, 15 and 66 (See Page III.), are hung similarly to sashes in one, two 
 or three heights, and fastened when up with screws, the lowermost resting on the hinged flap 
 which conceals them when down. Sometimes, as on Plate 66, they are made to pass above the 
 window. Running shutters go on rollers into a recess formed on one or both sides of the 
 window. The most inferior folding shutters are placed outside the window, hung to it with 
 parliament hinges, and fastened with bolts. All the above vary from 1 to 2 ins. thick , and are 
 framed similarly to doors, but usually flush on one side. Internal folding shutters fold into 
 recesses called boxings. The shutters showing on the face and hinged to the sash frame are 
 called front shutters, those behind, hinged to the front shutter and each other, back flaps: the 
 piece on the face forming the architrave, or a ground for one, is distinctively the boxing, or boxing 
 ground, and the piece behind the flaps the back lining. Boxings are l’/j to 1 1 / 2 in. thick, and 
 from 4*/ 2 ins. wide, framed, rebated, beaded and splayed; front shutters 1 to 2 ins. thick panelled; 
 and back flaps 3 / 4 to U/ 2 in. panelled; the soffit, elbows and window back are made to cor- 
 respond with the front shutters; and the back lining is plain, beaded or panelled: an iron shutter 
 bar fastens the shutters, but one of wood is adopted for kitchen windows. 
 
 Revolving wood shutters, formed of laths shod with iron, mentioned under 
 Shops, are often adopted for private houses. 
 
 4. HINGING. To enable a door to clear the carpet, and be close when 
 shut, the floor below is sometimes raised a quarter of an inch, and the hinges so arranged that 
 the door may rise slightly when opened: rising hinges with a spiral groove are adopted, and 
 the door is bevelled above next to the rebate as much in proportion as the hinge rises in a 
 quarter revolution. Of hinges generally there is a great variety and numerous modes of fixing 
 the same ones, sometimes, as in rule joints (Lines, Plate 38, Fig. 8.) being concealed, and often, 
 as to outside shutters (Fig. 9), having a considerable projection, when, of course, there is an 
 increased leverage. In the figure below A, on opening the door, no one can see through the 
 
 Carpentry. XXX 
 
i 
 
 MOVEABLE JOINERY. 
 
 joint ; in those on centres B, C, 1), E, the door moves very easily, but its too rapid closure may 
 hr obviated by a spring: in F the door clears the architrave. The next diagrams represent the 
 hinuimr and meeting of styles; and the remaining figures, together with the sliding doors, etc., 
 
 are instructive examples. 
 
 The following Plates relate to doors, sashes, hinging, etc. Practical 
 
 % 
 
8 I X T II 1) T Y I 8 I 0 N. 
 
 1. ON SPECIFICATIONS. 
 
 These consist of technical descriptions of materials, mode of work- 
 manship, dimensions, fittings and cost. Many will he found on previous pages; and in The 
 Builder’s Practical Director we have included lengthened specifications of nearly all kinds 
 of carpentry and joinery, together with a complete body of General Conditions, and minute 
 particulars of measurement and valuation. Full and accurate specifications are almost 
 of equal value with the drawings, on which it is difficult to show all that is requisite; 
 and extra charges are often due to omissions and indefiniteness in the descriptions. Again, 
 details should, whenever feasible, be given on drawings, and not abandoned to the caprice of 
 artisans by being only generally described. It is most convenient for general reference, as well 
 as to the surveyor who takes out the quantities, to group all the joinery under the headings of 
 the several rooms, not putting the doors, windows, etc., together; and the scantlings of timbers 
 should he described in the specification besides being figured on the drawings. 
 
 2. MEASUREMENT AND VALUATION. 
 
 Carpentry is generally measured and valued cubically, taking the extreme 
 lengths of the timbers including the tenons, and joinery superficially or running, dissected as 
 much as possible, and naming the thickness of the stuff; or the articles are numbered. In the 
 first named, taking the quantity of timber and pricing separately the labour is found to pay 
 best in light, and pricing the quantity at once, as fir in bond, fir framed, etc., in heavy work. 
 
 CARPENTRY. Timber in roofs, floors and partitions is measured 
 and valued per foot cube according to the labour; but the two latter, together with battening 
 for walls, slating, and rough boarding are often taken by the square of 100 feet. Centering 
 is valued by the square for use and waste, including striking and setting; but, when not more 
 than 47a ins. deep it is, with turning pieces, run. Scaffolding is let by the week, one-third of 
 the value of shoring being added for waste. Cradling, bracketing, ashlering, gutters and bearers, 
 
MEASUREMENT AND VALUATION. 
 
 236 
 
 ;, r0 measured by the foot super., and fences for farm buildings by the rod of 16 ft. 6 ins. run, 
 or solid as framed work: strutting, fillets, etc., are run. 
 
 JOINERY. Floors, and boarding to walls and ceilings are taken by the 
 s.jiiare, mitred boards to the first being run. Skirtings, chimney pieces, doors, gates, linings, 
 > ashes and cased frames (proper per foot cube) shutters, boxings, elbows, soffits, fittings to shops, 
 pilasters, columns, dressers, drawers, framed grounds, and closet fronts, per foot super. The 
 parts of staircases are also thus generally taken, girting the riser and tread, pricing winders 
 separately, running ramps and handrails, and numbering curtails, housings, caps, newels and 
 balusters. Skylights are taken at per foot super, or the bars and curbs are run. Water trunks, 
 gutters, fillets, blockings, runners, legs and rails are run, together with mouldings, measured 
 superficially if large. Cantilevers, brackets, pins, covers, holes, boxes, etc., are numbered. Iron- 
 mongery is charged with the work to which it appertains. 
 
 20 Per Cent profit is the usual allowance, d. in the shilling being 
 charged on a man’s wages, which are about 30 s. per week. It will be useful to add that 
 50 cubic ft. of timber, 400 ft. super of l 1 2 in. or 600 of 1 in. deal go respectively to the load; 
 120 deals to the hundred: one reduced deal is 12 ft. X 1 1 ins. X 1 , -/ 2 in. 
 
 / 
 
APPENDI X. 
 
 CONCLUDING REMARKS. It would be easy to swell out this Work 
 with long descriptions and varied illustrations of the numerous methods of doing the same thing; 
 but, although the subject is extensive, the book is comparatively small by condensation, — by 
 selecting an useful series of examples, and narrowing the text so as to instruct instead of con- 
 fusing the student. The Practical Examples are suggestive of almost every combination of 
 details. Peculiarities of situation and purpose preclude exact copyism; and the practitioner, 
 having acquired a knowledge of principles and modes of procedure, should apply his mind pro 
 re nata to the work in hand. So it is with the Lines. We venture confidently to say that, if 
 the reader has thoroughly mastered the course defined, he will easily do whatever is required. 
 
 On referring to the Glossarial Index the reader will at once be enabled 
 to ascertain the whole of the authorities adopted in the compilation of this Encyclopaedia; but 
 he will find the following works more especially useful. Truitt' de V Art de la Charpenterie, by 
 A. R. Emy. Traite Theorique et Pratique de VArt de Bdtir, by J. Rondelet, and Supplement, 
 by G. A. Blouet. Elementary Principles of Carpentry, by T. Tredgold. An Essay on the Strength 
 and Stress of Timber, by P. Barlow. The Encyclopaedia Britannica. Plans, Coupes et Elevations 
 de diverses Productions de VArt de la Charpente, by J. C. Krafft. Transactions of the Institution 
 of Civil Engineers. An Encyclopaedia of Civil Engineering, by E. Cresy. Roubo’s Treatise on 
 Menuiserie in Ees Arts et Metiers. Traite de. VArt du Charpentier, by J. II. Hassenfratz. 
 
 To the eminent architects Sir Charles Barry, Professor Cockerell, Messrs. 
 J. Johnson, W. Lambert, G. Mail-, F. W. Porter, E. C. Robins, R. R. Rowe, S. Smirke, N. E. 
 Stevens, C. Tebbutt, G. Vulliamy, and W. Wright, we again record our thanks for their contri- 
 butions of original working details; and we have also to acknowledge the able support and 
 general assistance afforded by Mr Henry J. Collins, the author of the Plates and Descriptions 
 of Lines. For the remainder of the Encyclopaedia the Editor is solely responsible. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 r A 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ✓ 
 
It is judged preferable to define various technics where they occur in the 
 course of this Encyclopaedia. The figures in the following 
 
 GLOSS A RIAL INDEX 
 
 point to explanations; and omitted terms will be found under the headings to which they relate. 
 The Practical Examples named in the Index of them are not here repeated; and the reader is 
 also referred to the Index of Pines for further references. 
 
 ABSOLUTE STRENGTH 1 15. 123 
 
 ACACIA 05 
 
 ADHESION OF GLUE 210 
 
 „ NAILS. To extract a sixpenny 
 nail driven one inch into dry oak 
 requires a force of 507 pounds, and 
 more than half a ton to extract it 
 by pressure when driven two inches. 
 The insertion of a nail overcomes 
 the cohesion as its extraction does 
 the adhesion of wood, which two 
 
 must not be confounded .... 51 
 
 ALDER • 65 
 
 ANGLE BAR 201 
 
 „ BEAD 231 
 
 „ BRACE 123 
 
 „ TIE 161) 
 
 „ OF REPOSE 189 
 
 ANGLES JOINING 208 
 
 APPLE TREE 66 
 
 APRON PIECE. See Pitching piece. 
 
 ARBOR VITJE 66 
 
 ARCH; KINDS AND PARTS 80 
 
 „ ; RAMPANT 18 
 
 ARCHITRAVES 111.212 
 
 Pages. 
 
 ARCIIIVOLT 203 
 
 ASH 66 
 
 ASHLERING 166 
 
 AUXILIARY RAFTERS 171 
 
 AXIS; NEUTRAL 51. 117 
 
 B. 
 
 BACK; THE UPPER PART; oi that opposite 
 
 the face or breast 212 
 
 BACKING OF A RAFTER OR RIB ; forming the 
 
 upper or outer surface 181 
 
 BALUSTERS AND BALUSTRADES . . . 215.225 
 
 BARGE BOARDS; inclined boards at gables. . 35 
 
 BATTENING FOR SLATING 170. 199 
 
 „ „ WALLS 199 
 
 BATTENS 75. 199 
 
 BAULKS 74 
 
 BEAD BUTT 232 
 
 „ FLUSH 232 
 
 „ ; ANGLE 231 
 
 BEADED WORK 208.211.232 
 
 BEARING; unsupported length; supported part . 
 
 BEECH 66 
 
 BELLY BOARDS 76 
 
 BENDING TIMBER 54. 106. 141. 209 
 
II 
 
 GLOSSARIAL INDEX. 
 
 Pages. 
 
 BEVEL; other than a right angle. 
 
 BINDERS 15S. 163 
 
 BIRCH 67 
 
 B1RDS-MOUTH; an interior angle so cut as to 
 admit of one piece of timber resting 
 firmly on the exterior angle of ano- 
 ther piece. 
 
 BLOCKINGS 269 
 
 ; GLUED 209 
 
 BOARD; LEAR; to take leadjwork over rafters at 
 gutters. 
 
 _ LISTED; reduced in width. 
 
 BOARDS; pieces of undefined length, more than 
 
 ■1" broad, and not more than 2* 2 " thick 75 
 
 ; FIXING 209 
 
 „ ; GLUEING UP 209 
 
 BOARDING FOR ROOFS 170. 199 
 
 „ „ WALLS 199 
 
 ; WEATHER 199 
 
 BOLECTION MOULDINGS 232 
 
 BOLTS 151 155 
 
 BOND 19S 
 
 „ ; CHAIN 198 
 
 BOOKS; nature of information to he acquired 
 
 from 3. 5. G. 7. 8. 9. 11. 
 
 ON CARPENTRY AND JOINERY. 
 
 .. ; ANCIENT 28 
 
 - : ENGLISH 8. 9. 25. 40. 41. 42. 43. 180. 190. 
 
 193. 109. 237. 
 
 - ; FOREIGN . 8. 37. 38. 39. 40. 41. 108. 237 
 
 BOXINGS 233 
 
 BOXWOOD 07 
 
 BRACED DOORS 232 
 
 BRACES 160.171 
 
 * ; COLLAR ISO 
 
 - ; PRINCIPAL 171 
 
 - ; SPANDREL 180 
 
 BRACKETING ... 187 
 
 ; LINES FOR ...... 188.205 
 
 BRACKETS; ANGLI |ss 
 
 FOR STAIRS 213.214 
 
 BREAKING JOINTS, is so placing them as not 
 to coincide with others. 
 
 BRE6SUMMERS 
 
 BRICKNOQG1NG ji 
 
 BRICK; FIR 
 
 BRIDGES 
 
 ; CLASSIFICATION 
 
 Pages. 
 
 BRIDGES ; CONSTRUCTION *193 
 
 ,. ; SPAN 
 
 191 
 
 ; RISE 
 
 191 
 
 ; WIDTH .... 
 
 192 
 
 ; PARAPETS . . . 
 
 192 
 
 „ ; FLOORS .... 
 
 192 
 
 ; PAINTING . . . 
 
 192 
 
 ; WEIGHT . . . 
 
 192 
 
 „ ; PILING .... 
 
 192 
 
 „ ; Aubrey 38 
 
 Delaware, U. S. 191 
 
 Burr 194. 
 
 Ettringen 30. 
 
 Cajsar’s 32. 193. 
 
 l'eldkirch 1 0 4. 
 
 Delorme 191. 
 
 I'rcysingen 30. 194. 
 
 Emmery 103. 
 
 Ivry 103. Kandel 191 
 
 F my 194. 
 
 Kchl 195. 
 
 Molard 38. 
 
 Kniehenaw 36. 
 
 Laves 157. 
 
 Landsberg 193. 
 
 Palladio 35. 191. 
 
 Littleport 1 95. 
 
 Long 193. 
 
 Mcllingen 37. 104. 
 
 Perronet 191. 
 
 Neckar 104. 
 
 Price 193. 195. 
 
 Richmond, U. S. 193 
 
 Ritters 30. 194. 
 
 Savines 195. 
 
 Styerme 1 50. 
 
 Schaffhausen 36. 193. 
 
 Town 193. 
 
 Schuylkill 194. 
 
 Trajan 32. 194. 
 
 SuMicius 32. 
 
 Wernwag 194. 
 
 Utrecht 195. 
 
 Wiebeking 36. 194. 
 
 Vrach 195. 
 
 Bamberg 30. 191. 
 
 Western railway, U. S. 
 
 Brenta 191. 
 
 193. 
 
 Cismonc 3\ 194. 
 
 Wittingen 36. 193. 
 
 Ctcsipbon 32. 
 
 Zurich 193. 195. 
 
 BUILDING BEAMS . . . . 
 
 151. 132 
 
 BUILDINGS OF ANIMALS AND MAN; dis- 
 
 tinction between 
 
 28 
 
 „ ; ARRANGEMENTS, 
 
 to prevent decay 
 
 
 112. 161. 161. 198 
 
 ; FORMS OF . . 
 
 143 
 
 BUTTING JOINTS 51. 148 
 
 c. 
 
 CABINET MAKING 207 
 
 CAISSONS 199 
 
 CAMBERING; forcing to a curve rising upwards 104 
 
 CARCASS; naked timbering 158 
 
 CARPENTRY AND JOINERY; distinctions be- 
 tween 24. 207 
 
 „ ; origin and progress of 27 
 
GI.OSSARIAL INDEX. 
 
 Ill 
 
 Pages. 
 
 CARPENTRY AND JOINERY; PRACTICAL . 143 
 
 „ ; precedence in building arts . . 29. 43 
 
 „ ; theory of 114 
 
 CARVING 33 
 
 CASEMENTS 212.233 
 
 CASING 231 
 
 CEDAR 67 
 
 CEILING JOISTS. See Joists. 
 
 CENTERS, CENTERING 188 
 
 „ ,. ; CONSTRUCTION 84. 188 
 
 „ „ ; LINES FOR ... 80 
 
 „ „ ; ORIGIN 32 
 
 „ „ ; Eustache 104. Briancon 101 . 
 
 191. Moulines 191. 
 
 Hupeau 191. Melun 191. 
 Perronct 191. Neuilly 191. 
 Pitot 191. Orleans 191. 
 Rcgemortc 191. St. Peter’s 36. 
 Blackfriars 190. 
 
 CENTRE OF GRAVITY 117 
 
 CIRCULAR WORK 209 
 
 „ „ ; LINES FOR 202 
 
 CIRCLES; ARCS OF 13. 17. IS 
 
 CISTERNS 231 
 
 CHAMFERS 20V 211 
 
 CHESNUT 68 
 
 CHERRY TREE 68 
 
 CLAMPING 208 
 
 CLAPBOARD 73 
 
 CLEAN STUFF 51 
 
 CLOSET FRONTS 23! 
 
 COFFER DAM 199 
 
 COGGING, COCKING, CAULKING . . . 153. 158 
 
 COHESION 51 
 
 COHESIVE STRENGTH 52.115 
 
 COLLAR 171 
 
 „ ; JOINTS TO 155 
 
 „ BRACED ROOFS 178. 180 
 
 COLUMNS; GLUEING-UP 210 
 
 „ LINES FOR 203 
 
 COMPRESSION 52. 127 
 
 „ ; CENTRE OF 117 
 
 CONE; projection and development of oblique . 63 
 
 CONTRACTION. See Shrinkage. 
 
 CONTRIBUTORS; LIST OF 237 
 
 CORNICES 210.211 
 
 „ LINES FOR 200 
 
 CORK ; PRESERVATIVE OF TIMBER BY USE OF 1 6 1 
 
 Carpentry. 
 
 Pages. 
 
 CROSS GRAINED 51 
 
 CROSS STRAIN 115 
 
 CRADLING 188 
 
 CUPOLA 183 
 
 CURB ROOFS 37. 173 
 
 „ TO SKYLIGHTS 202.230 
 
 „ AT INTERSECTION OF ARCH AND 
 
 CEILING 144 
 
 CURLING STUFF 51 
 
 CURTAIL STEP 213.218 
 
 CUSHION RAFTERS 171 
 
 CYPRESS 09 
 
 D. 
 
 DADO 211 
 
 „ ; FIXING 209 
 
 DEALS 69. 75 
 
 DECAY OF TIMBER. (See Seasoning and Build- 
 ings) 55. 96 
 
 DEVELOPMENT 23. 58 
 
 DOORS; KINDS AND PARTS 232 
 
 „ FRAMES 212 
 
 „ LININGS 212 
 
 DOMES 183 
 
 .. ; CONSTRUCTION 183 
 
 „ ; LINES FOR 185 
 
 „ ; Delorme 38. 175. 184. St. Mark and Della 
 
 Emy 39. 57. 176. 184. Salute, Venice 38. 
 
 Jousse 184. Halle auxBles 38.175. 
 
 Lacase 39. 175 184. Invalides , Paris 37. 
 
 Price 185. 184. 
 
 Styerme 1 84. 
 
 DOVETAILS 153. 208 
 
 DOWELLING 211 
 
 DRAGON BEAM 169 
 
 DRAWINGS 6. 19. 20. 21. 23. 143 
 
 DRESSER 231 
 
 DRIPS 169 
 
 DURATION. See Timber 
 
 DYNAMICS 114 
 
 E. 
 
 ERONY 69 
 
 ELASTIC BODIES 116 
 
 „ CURVE 116 
 
 ELASTICITY; MODULUS OF 116 
 
 xxxi 
 
IV 
 
 GLOSSARIAL INDEX. 
 
 ELASTICITY; MODULUS OF; table of 
 
 HI. HOWS 
 
 ELDER . . . 
 
 elevation . 
 
 ELLIPSES .. 
 ELM . . . . 
 
 15 
 
 I M VCLOPJEDIA OF CARPENTRY AND JOIN- 
 ERY; proper form of . . 
 
 „ „ ; scope of .... 
 
 ENTABLATURE 231 
 
 EXPERIMENTS AND TABLES OF THE 
 
 STRENGTH , etc., OF TIMBER 116. 123. 
 
 127. 128. 132. 137 
 
 16. 17 
 
 ■ages. 
 
 116 
 
 212 
 
 6!1 
 
 19 
 
 171 
 
 69 
 
 F 
 
 Pages. 
 
 FORCES; application of theory to practice . . 121 
 
 FORKING 211 
 
 FOX-TAIL WEDGING 152 
 
 FRAMES; DOOR 212 
 
 „ ; WINDOW 212 
 
 FRAMING; PRINCIPLES OF 120 
 
 ; TRIANGLES IN 122.232 
 
 „ JOINERY 207 
 
 FRANKING 233 
 
 FREE STUFF 51 
 
 FRENCH; modern improvements chiefly due to the 2. 1 1. 
 
 37. 38. 39. 41 
 
 ,FROWY STUFF 51 
 
 FURRING-UP 161 
 
 „ -DOWN 16 1 
 
 FACE MOULD 
 
 
 223 
 
 FALLING MOULD 
 
 
 222 
 
 LINE 
 
 
 222 
 
 FANLIGHT 
 
 
 
 FEATHER-EDGED 
 
 
 199 
 
 FELLING TIMBER 
 
 
 88 
 
 FELT GRAIN . 
 
 
 51 
 
 FIBRES. See Timber. 
 
 
 
 „ ; contract most crosswise 
 
 FILLETS; pieces of less scantling th 
 
 in battens. 
 
 207 
 
 ; TILTING 
 
 
 169 
 
 FIR BRICKS 
 
 FIR AND OAK. See Oak. 
 
 
 198 
 
 FIREPLACES 
 
 
 231 
 
 FISHING BEAMS 
 
 
 148 
 
 FIXING JOINERY 
 
 . . . 207. 
 
 209 
 
 FLEXURE 
 
 114. 116. 126. 
 
 127 
 
 FLOORING; SINGLE 
 
 . . . 158. 
 
 162 
 
 ,. ; DOUBLE . . . 
 
 
 163 
 
 „ ; FRAMED .... 
 
 . . . 159. 
 
 164 
 
 : PECULIAR . . 
 
 . . . 159. 160 
 
 ; PENDENTIVE . . 
 
 
 160 
 
 ; SERLIO’S . . . 
 
 . . . 35. 
 
 159 
 
 „ : FRENCH . . . 
 
 
 162 
 
 AT AMSTERDAM . 
 
 » BOARDS ; kinds and 
 
 modes of 
 
 159 
 
 fixing . . . 
 
 
 211 
 
 ELI SB: even or continuous with the 
 
 urfacc. See Bead. 
 
 FORCES; composition and resolution 
 
 of . . . 
 
 120 
 
 » ; square of .... 
 
 
 120 
 
 « ; parallelogram of . , 
 
 
 120 
 
 G. 
 
 GATES 199.212.232 
 
 GEOMETRY; DESCRIPTIVE II. 12 
 
 „ ; PRACTICAL; reason for advanced 
 
 or special problems only being given 4. 9. 13 
 
 GIRDERS 159. 164 
 
 „ ; TRUSSED 159. 164 
 
 „ ; CONNECTION OF BINDERS WITH 1 53. 1 6 1 
 
 „ ; PRESERVATION OF ENDS . . 161. 164 
 
 GLUE; adhesion, preparation, quality . . . . 210 
 
 GLUEING-UP JOINERY 209 
 
 „ AND BLOCKING 209 
 
 GOTHIC ROOFS 34. 178 
 
 GRAIN 51 
 
 „ ; CROSS 51 
 
 „ ; joining with reference to 207 
 
 GRAVITY; CENTRE OF 117 
 
 „ ; SPECIFIC 53 
 
 GROINS 80 
 
 ; LINES FOR 80. 189 
 
 „ ; WELSH 81. 84. 86. 87 
 
 GROOVED AND TONGUED. See Ploughed. 
 
 GROUNDS 209.211 
 
 GUTTERS 169 
 
 H. 
 
 HALVING 154 
 
 HAMMER BEAM 180 
 
 HANDRAILS; DEFINITIONS OF PARTS . . 215 
 
 „ ; LINES FOR 215 
 
 HANGE-WERK 104 
 
GLOSSARIAL INDEX. 
 
 V 
 
 Pages. 
 
 HEADING JOINTS 
 
 „ „ TO FLOORS 
 
 HINGING 
 
 ; LINES FOR 
 
 HIP ROOF; sloped off at the end. 
 
 „ RAFTERS 1C 
 
 „ ; LINES FOR 
 
 HOARDING; an enclosure of timber used during 
 building. 
 
 HOLLY 
 
 HORNBEAM 
 
 IIORSE-CHESNUT 
 
 HOUSING; insertion of one piece in another. 
 
 HUTS OF GREECE 
 
 „ „ SAVAGE TRIBES 
 
 „ ; DESIGNS 
 
 HYPERBOLA 
 
 INTERTIE 
 
 IRONMONGERY. See the details to which it 
 appertains 
 
 IRONWORK TO JOINTS 103. II 
 
 „ „ ROOFS 
 
 „ „ BRESSUMMERS 
 
 ,. „ GIRDERS 16 
 
 J. 
 
 JACK RAFTERS 
 
 JIB DOOR 206. 
 
 JOINERY AND CARPENTRY; distinctions be- 
 tween 24. 
 
 „ ; origin and progress of 
 
 JOININGS IN CARPENTRY . . . . 31. 144. 
 
 „ ; Pieces continued in length 
 
 „ ; „ increased in depth 
 
 „ ; „ forming right angles 
 
 ,, ; „ „ acute or obtuse 
 
 angles . . . 
 
 „ ; Collars, Kings and Ridges 
 
 „ IN JOINERY 
 
 JOINTS; LINES FOR 
 
 „ ; Heading, to floors 
 
 ,, ; Plates of copper and lead between 103. 
 
 ; ironwork to 
 
 Pages. 
 
 
 JOINTS; curved 
 
 
 
 
 
 51 
 
 JOISTS-; JOISTING . . . 
 
 
 
 
 158 
 
 211 
 
 „ „ ; SINGLE . . 
 
 
 
 
 162 
 
 
 „ „ ; BINDING . 
 
 
 
 158. 
 
 163 
 
 205 
 
 „ „ ; BRIDGING 
 
 
 
 158. 
 
 163 
 
 
 „ „ ; CEILING . 
 
 
 158. 163. 
 
 164 
 
 17i 
 
 JOGGLES 
 
 
 
 
 148 
 
 181 
 
 JUNIPER WOOD .... 
 
 
 
 
 70 
 
 70 
 
 K. 
 
 
 
 
 
 70 
 
 KEYS 
 
 . 148. 
 
 150. 
 
 151. 
 
 209 
 
 70 
 
 KEYED DADO 
 
 
 
 
 209 
 
 
 KING POST 
 
 
 
 
 171 
 
 28 
 
 : JOINTS TO . 
 
 
 
 
 1 55 
 
 
 KNEED 
 
 
 
 
 215 
 
 199 
 1 7 
 
 KNOTS 
 
 
 
 
 51 
 
 
 L. 
 
 
 
 
 
 
 LABURNUM 
 
 
 
 
 70 
 
 166 
 
 LAGGINGS 
 
 
 
 
 188 
 
 
 LAPPING 
 
 
 
 
 154 
 
 
 LARCH 
 
 
 
 
 70 
 
 . 155 
 
 LATHS 
 
 
 
 
 199 
 
 177 
 
 LEAR BOARD; for the lead w 
 
 ork of gutters. 
 
 
 
 198 
 
 LEDGED 
 
 
 
 208. 
 
 232 
 
 . 198 
 
 LEDGERS 
 
 
 
 
 196 
 
 
 LIGNUM VITA-1 
 
 
 
 
 71 
 
 
 LIME 
 
 
 
 
 71 
 
 
 LININGS; door 
 
 
 
 
 212 
 
 171 
 
 ., ; window .... 
 
 
 
 
 212 
 
 . 232 
 
 ,1 ; "'all ' 
 
 
 
 
 
 
 LINES; Contributed by Mr. II. 
 
 J. Collins 
 
 
 
 3 
 
 207 
 
 ,, ; Object in view . . 
 
 
 
 
 3 
 
 27 
 
 „ ; Necessity for their comprehension 
 
 
 
 1 1 
 
 147 
 
 ,, ; Mode of study 
 
 
 
 12 
 
 13 
 
 148 
 
 „ ; Claims to originality and utility 
 
 13. 
 
 212 . 
 
 237 
 
 151 
 
 „ ; Progress of knowledge 
 
 of 11 . 
 
 12. 4 
 
 1. 42 
 
 43 
 
 152 
 
 LINTELS .... 
 
 
 
 
 198 
 
 
 LOCUST TREE 
 
 
 
 
 71 
 
 154 
 
 LOGS 
 
 
 
 
 71 
 
 155 
 
 
 
 
 
 
 208 
 
 205 
 
 M. 
 
 
 
 
 
 211 
 
 J/ROOF; one shaped similarly 
 
 to the letter . 
 
 
 167 
 
 148 
 
 MAHOGANY 
 
 
 
 
 71 
 
 155 
 
 MANSARD ROOFS . . . 
 
 
 
 37. 
 
 173 
 
VI 
 
 GLOSSARIAL INDEX. 
 
 Pages 
 
 MAPLE 72 
 
 MARQUETRY 2,1 
 
 MASTS 74 
 
 MATCHED 208 
 
 MEASUREMENT 2: >5 
 
 MECHANICS 114 
 
 MEDIEVAL CARPENTRY 33. ITS 
 
 „ ROOFS 34. 178 
 
 MEDIEVALISTS: stationary character of the modern 180 
 
 MITRE CAPS 215.218 
 
 MITRING 208. 209. 215 
 
 MODELLING; assists comprehension of lines . 12 
 
 MODULUS OF ELASTICITY 52. 116 
 
 MORTICE AND TENON 153.208 
 
 ; PULLEY 163 
 
 „ : CHEEKS OF; the two solid parts at 
 
 the sides . . 208 
 
 MOULDINGS 200.210 
 
 „ ; LINES FOR 210 
 
 MILLIONS; the thick vertical chamfered, or 
 
 moulded, divisions of Gothic windows. 
 Ml’NTINS; the central vertical pieces of door 
 
 framings between the stiles . . . 232 
 
 N. 
 
 NEUTRAL AXIS 51. 117 
 
 NIC1IES; GLl'EING-UP , . 209 
 
 „ ; LINES FOR 145 
 
 NOGGING PIECES 160 
 
 NOTCH BOARD; one notched to carry steps. 
 NOTCHING 154 
 
 0 . 
 
 OAK 72 
 
 OAK AND FIR; relative properties . 111. 51. 115. 127 
 
 OBLIQUE CUT 220 
 
 OCTAGON IS 
 
 OLIVE 74 
 
 OPERATIVES; their status 2. 7 
 
 it ; advice to 27 
 
 ORTHOGRAPHIC PROJECTION IS 19 
 
 PAINT . 
 PALINGS 
 PANELS 
 
 P. 
 
 109. 113. 192 
 
 ' 199 
 
 . . 101. 20S. 21 1. 232. 233 
 
 Pages. 
 
 PARABOLA 17. 18 
 
 PARTING BEAD 212 
 
 „ SLIP 212 
 
 PARQUETRY 211 
 
 PARTITIONS IN CARPENTRY 160 
 
 „ „ JOINERY 211 
 
 PASSIVE STRENGTH • . . . 114 
 
 „ ; Pieces pulled in the direc- 
 tion of their length . 1 23 
 
 „ ; Pieces pressed in the di- 
 rection of their length 126 
 
 ,, ; Horizontal pieces sup- 
 ported and fixed at one and both ends 130 
 
 „ ; „ at several points 130 
 
 ,, , Inclined pieces .... 136 
 
 ,, ; Curved „ .... 141 
 
 „ ; Beams in more than one 
 
 piece . . . 131. 148. 151 
 
 PEAR 74 
 
 PENDENTIVES 160.186 
 
 „ ; lines for 186 
 
 PENDANTS 180 
 
 PERPENDICULAR TIMBERS . . 126. 151. 152. 153 
 
 PERSPECTIVE 19 
 
 PEWS 231 
 
 PHYSIOLOGY OF TREES 46 
 
 PILE PLANKS 192 
 
 PILASTERS 203.231 
 
 PILING 192 
 
 „ ; SINGLE 192 
 
 „ ; DOUBLE 192 
 
 PINES 74. 76 
 
 PINS 208 
 
 PITCH OF ROOF ; its inclination. 
 
 PITCH BOARD 216 
 
 „ OF PLANK 226 
 
 PITCHING, or Apron-piece 213 
 
 PITCH, TAR 113. 192. 198 
 
 PLAN 19 
 
 PLAN OF THE ENCYCLOPAEDIA 1. 9. 10. 114. 143. 
 
 144. 207. 237 
 
 ?> 
 
 PLANES 
 
 ; Why new adopted 9 
 19. 20 
 
 PLANE WOOD 76 
 
 PLANKS 75 
 
 PLATES; WALL .... 158. 160. 163. 164. 171 
 
 „ ; POLE 171 
 
 PLOUGHED AND TONGUED 208. 232 
 
GLOSSARIAL INDEX. 
 
 VII 
 
 Pages. 
 
 POINTS 20 
 
 POPLAR 76 
 
 PRACTICAL EXAMPLES eontribued by eminent 
 
 architects 6. 237 
 
 PRACTICE. See Theory. 
 
 PRESERVATION OF TIMBER. See Seasoning 09 
 
 PRINCIPALS 171 
 
 PROBLEMS. See Index of Plates of Lines. 
 
 PROJECTION 12. 18. 20 
 
 PROFILES 20. 200. 210 
 
 PROPER DOOR AND WINDOW FRAMES; 
 
 those solid 212 
 
 PULLEY PIECES 212 
 
 PUNCHIONS 166 
 
 PURLINS 171 
 
 PUTLOGS 106 
 
 a. 
 
 QUARTERS 166 
 
 QUARTERING 166 
 
 QUARTER GRAIN 51 
 
 QUEEN POST 171 
 
 „ „ ; SMALL 172 
 
 „ „ ; JOINTS TO 155 
 
 R. 
 
 RAFTER 171 
 
 „ ; joint at foot of 154 
 
 RAILS AND STILES; the horizontal and vertical 
 pieces forming the framework of a door. 
 
 RAMPANT ARCH IS 
 
 RAMPED 215 
 
 REBATE 208 
 
 „ ; MITRE 208 
 
 REPULSIVE STRENGTH 115 
 
 RELATIVE STRENGTH 115 
 
 RESILIENCE 130 
 
 RESISTANCE 115 
 
 RIDGE 171 
 
 ROOFS 167 
 
 „ ; CLASSIFICATION 167 
 
 • „ ; PRINCIPLES OF CONSTRUCTION . 167 
 
 „ ; COVERINGS 31. 169. 180. 182 
 
 „ ; INCLINATIONS 34. 170 
 
 „ ; ORDINARY FORMS 170 
 
 „ ; CURB OR MANSARD 37. 173 
 
 „ ; ARCHED 175 
 
 Pages. 
 
 ROOFS; TIMBER AND IRON 177 
 
 ,, ; GOTHIC 34. 178 
 
 „ ; CIRCULAR 167. 182 
 
 „ ; CONICAL 182. 167 
 
 „ ; DOMICAL 182 
 
 „ ; ELLIPTICAL 167 
 
 „ ; KING POST 171 
 
 „ ; LEAN-TO 167 
 
 „ ; NORMAN 167 
 
 „ ; POLYGONAL . . . • 182 
 
 „ ; QUEEN POST 171.172 
 
 „ ; REVOLVED 167 
 
 „ ; RAISED CEILINGS; with 168 
 
 „ ; Delorme 38. 175. Hampton 35. 180. 
 
 Emy 30. 57. 104. 176. Holland and Prussia 
 
 Ilouldsworth 176. 176. 
 
 Lacase 30. 175. Libourne 176. 
 
 Laves 157. Moscow 37. 176. 
 
 Styerme 156. Pantheon, London 38. 
 
 Darmstadt 176. Toulon 17(5. 
 
 Eltham 34. Westminster Hall 34. 
 
 Greenwich Hospital 69. 180. 
 
 Chapel 172. 
 
 „ ; SCANTLINGS. See Scantlings. 
 
 „ ; LINES FOR 181 
 
 ROPES; STRENGTH OF 198 
 
 „ ; KNOTS FOR 197 
 
 ROSE WOOD 76 
 
 ROT; WET AND DRY 98 
 
 RULES; Amount of flexure 116 
 
 „ ; Distinction between strut and tie . . . 122 
 
 „ ; The least breadth of horizontal timbers 130 
 
 „ ; Strain at particular points of horizontal 
 
 timber 115. 116 
 
 „ ; Cylinders 116 
 
 „ ; Centre of gravity . 117 
 
 „ ; Action of forces 121 
 
 ,, ; Absolute or cohesive strength, or resistance 
 
 to tension 125 
 
 „ ; Vertical, or repulsive strength .... 129 
 
 „ ; Horizontal strength, or resistance to cross 
 
 strain ... .... 115 116. 135 
 
 „ ; Inclined pieces (struts, braces, etc.) . . 137 
 
 S. 
 
 SASHES; LIFTING 111.212.233 
 
 „ ; FOLDING OR CASEMENT . .212.233 
 
vm 
 
 GLOSSARIAL INDEX. 
 
 SASHES; SLIDING .... 
 
 
 Papes. 
 . . 233 
 
 : ON CENTRES . . 
 
 
 . 212.233 
 
 ; FANLIGHT . . * . 
 
 
 . 212.233 
 
 : TO DOORS . . . 
 
 
 
 : LINES FOR . . . 
 
 
 . 201.202 
 
 SCAFFOLDING 
 
 
 . . 196 
 
 ; BRICKLAYER’S 
 
 and MASON’S 196 
 
 ; Albertini 36. Cologne 36. 196 
 
 Barry 196. Enston Railway Sta- 
 
 Cainpanarino 36. tion 196. 
 
 Ctibitt 196. Marac 198. 
 
 Dabrin 196. Nelson Monument 
 
 Kmv 197. 198. Pantheon, Rome 36. 
 Fontana 36. St. Gervais, Paris 
 
 Mandar 197. St. Peter’s, Rome 36. 
 
 Zabaglia 36. 197. Turin 197. 
 
 SCANTLINGS; the breadth and thickness of a 
 piece of timber: the term is also some- 
 times applied to timber less than five 
 inches square. The length of timbers 
 is not, as in masonry, considered in 
 the scantling. See Rules and Expe- 
 riments. 
 
 ; FLOORING. 
 
 : ; Single 
 
 : „ ; Double 
 
 ; „ ; Framed 
 
 ; ,. ; Ceiling Joists . . . 
 
 : PARTITIONS 
 
 : ROOFS. 
 
 : „ ; King Post 
 
 : „ ; Queen Post 
 
 ; ,, ; Arched 
 
 : DOMES 
 
 ; CENTERING 
 
 ; BRIDGES 
 
 : BRESSDMMERS and LINTELS 
 See Description of Practical Ex- 
 amples and Woodcuts. 
 
 SCAR! 
 
 196. 
 
 196. 
 
 196. 
 
 196. 
 
 SCARFS; PRINCIPLES . . 
 ; WITHOUT KEYS 
 „ ; KEYED .... 
 
 163 
 
 163 
 
 165 
 
 161 
 
 166 
 
 172 
 
 184 
 
 184 
 
 189 
 
 192 
 
 198 
 
 SCRIBING 
 
 S(, W>LI- 213.218 
 
 SEASONING; Preservation of Timber and Pre- 
 vention of Decay 99 
 
 f ; NATURAL . . 
 
 148 
 
 149 
 
 149 
 
 150 
 20S 
 230 
 
 112 
 
 101 
 
 Pages. 
 
 SEASONING; WATER 102 
 
 „ ; HOT AIR 105 
 
 „ ; CHARRING AND SCORCHING . 105 
 
 „ ; STEAMING AND BOILING . . 106 
 
 „ ; CHEMICAL AGENTS .... 106 
 
 „ ; PAINT 109. 113. 192 
 
 „ ; PITCH, TAR . . . .113. 192. 198 
 
 „ ; SUNDRY METHODS . . . 110.161 
 
 SECTION 20 
 
 SHAKEN WOOD 100 
 
 SHINGLES 169 
 
 SHOOTING, SHOT 207. 208 
 
 SHOP FRONTS AND FITTINGS 230 
 
 SHORES 121.196 
 
 SHOW-BOARD 231 
 
 SHRINKAGE . . . "91 . 100. 101 . 147. 207. 208. 209. 2 1 0 
 
 SHUTTERS ; LIFTING 1 1 1 . 233 
 
 „ ; FOLDING 111.233 
 
 „ ; RUNNING 233 
 
 „ ; REVOLVING 233 
 
 „ ; SHOP 230 
 
 SILLS 166. 212 
 
 SINKS 231 
 
 SKIRTING 211 
 
 SKYLIGHTS 230 
 
 „ ; LINES FOR 201 
 
 SLEEPERS; timber laid horizontally next the 
 
 ground 160 
 
 SOLIDS; GEOMETRICAL 22. 58 
 
 SOUND BOARDING AND PUGGING .... 162 
 
 SPANDRELS 188 
 
 SPAN ROOFS have two inclined sides. 
 
 SPARS 74 
 
 SPECIFICATIONS 78. 79. 94. 95. 111. 120. 165. 235 
 
 See Joinery throughout. 
 
 SPIRES 199 
 
 SPLAY; a sloping expanding side. This term is 
 properly applied to signify enlarge- 
 
 ment, slanted surfaces for other ob- 
 jects being called bevels, cants, cham- 
 
 fers, etc 233 
 
 SPRINGING OF PLANK 223 
 
 SPRUCE 75 
 
 SQUARE CUT 221 
 
 SQUARING TIMBER 90 
 
 STAFF BEAD. See Angle bead. 
 
 STABLE FITTINGS 231 
 
 STAIRCASES 212 
 
GLOSSARIAL INDEX. 
 
 IX 
 
 Pages. 
 
 STAIRCASES; PARTS OF 212 
 
 „ ; KINDS OF 213 
 
 „ ; STEPS, proportions 214 
 
 „ ; „ , number 214 
 
 „ ; „ , width . . 7 . . 214 
 
 „ ; LINES FOR 215 
 
 STALL BOARD 231 
 
 STANDARDS 196 
 
 STAVES 210 
 
 STATICS 114 
 
 STEP SCARFS 148 
 
 STIFFNESS 116 
 
 STILES AND RAILS; joining 208 
 
 STILTS 192 
 
 STORY POSTS 166 
 
 „ ROD „ 215 
 
 STRAIN OR STRESS 115 
 
 STRAINING PIECE 171 
 
 „ SILL 171 
 
 STRENGTH OF MATERIALS. See Experiments , 
 Passive Strength and Rules. 
 
 ,, ; Progress of know- 
 ledge of 39 
 
 STRUT 
 
 166. 171 
 
 STRUTTING; wrought and herring bone . . 162 
 
 STUFF 207 
 
 „ ; continued in width 208. 232 
 
 SUNK; recessed square from the surface. . . . 211 
 
 SWAN NECK 215 
 
 SYCAMORE 76 
 
 SYSTEM TO BE ADOPTED in acquiring a know- 
 ledge of Carpentry and Joinery . 5. 207 
 
 T. 
 
 TABLE TOPS; GLUE1NG-UP 92. 209 
 
 TABLES. See Experiments. 
 
 TABLED SCARFS 148 
 
 TABLING BEAMS 151 
 
 TEAK 76 
 
 TENON. See Mortice 153. 208 
 
 „ ; TUSK OF 153 
 
 „ ; SHOULDER OF 153 
 
 TENSION 115.117 
 
 THEORY AND PRACTICE . 2. 3. 6. 7. 8. 114. 207 
 
 „ OF CONSTRUCTION 114 
 
 TIE BEAM 170 
 
 TIMBER HOUSES. See Huts 33. 35 
 
 Pages. 
 
 TIMBER. <$'ee Trees 45 
 
 „ ; ADVANTAGES OF 45 
 
 „ ; BENDING 54. 106. 111. 209 
 
 „ ; CHOICE IN FOREST .... 53. 55. 96 
 
 „ ; „ „ YARD 98 
 
 „ ; CLASSIFICATION OF 56 
 
 „ ,; DECAY OF 96 
 
 „ ; DEFECTS IN 55 
 
 „ ; DURATION OF 45. 67. 69. 70. 73. 75. 96. 
 
 100. 106. 118. 141 
 ,, ; FELLING. See Description of Woods. 88 
 
 „ ; FIBRES 50. 51 
 
 „ ; FIREPROOF 110 
 
 „ ; PHYSIOLOGY OF 46. 97 
 
 ,, ; PRESERVATION OF. See Seasoning. 99. 112 
 
 „ ; SQUARING 90 
 
 „ ; TRANSPORT 92 
 
 „ ; WEIGHT 53. 100 
 
 TOOLS; classification, illustrations and uses of . 24 
 
 TORSION 126 
 
 TREES. See Timber 45 
 
 „ ; AGE .... 50. 72 
 
 „ ; ENDOGENOUS 47 
 
 „ ; EXOGENOUS 46 
 
 „ ; DEFECTS IN 55 
 
 „ ; GROWTH 49. 53 
 
 „ ; SOIL, CULTIVATION 48 
 
 „ ; SIZE 49. 50. 67. 68. 71. 72 
 
 TRAIT DE JUPITER 150 
 
 TRANSOM; a thick horizontal division separating 
 the compartments of windows, or a 
 
 door from the fanlight above. 
 
 TRIANGLES ; use in framing 122.232 
 
 TRIMMERS AND TRIMMING JOISTS . . . 162 
 
 TRUSS; a framed combination 171 
 
 TONGUED. See Ploughed. 
 
 TURRETS 199 
 
 V. 
 
 V ROOFS; those in the shape of the letter . . 169 
 
 VALLEY; the meeting part of the internal in- 
 clined sides of roofs. 
 
 „ RAFTERS 171 
 
 VALUATION ... 235 
 
 VAULTS 80 
 
 VENEERS 210 
 
 VERTICAL TIMBERS. See Perpendicular. 
 
XII 
 
 PLATES OF LINES AND EXPLANATORY TEXT. 
 
 
 Plates. 
 
 Pages. 
 
 
 Plates. 
 
 Pages. 
 
 INTRODUCTORY REMARKS . . . . 
 
 
 11 
 
 RIBS OF DOMES 
 
 27 
 
 185 
 
 MODES OF DESCRIBING ARCS OF 
 
 
 
 COVERINGS OF DOMES 
 
 28 
 
 186 
 
 CIRCLES 
 
 i 
 
 13 
 
 PENDENTIVES 
 
 29 
 
 187 
 
 MODES OF DESCRIBING ELLIPSES . . 
 
 i 
 
 15 
 
 do. 
 
 30 
 
 187 
 
 MISCELLANEOUS PROBLEMS . . . . 
 
 2 
 
 Hi 
 
 TO ENLARGE A CORNICE OR OTHER 
 
 
 
 PROJECTION (General Explanation). . . 
 
 3 
 
 18 
 
 ASSEMBLAGE OF MOULDINGS . . . 
 
 31 
 
 200 
 
 PROJECTION OF POINTS. LINES, SLR- 
 
 
 
 TO DIMINISH A CORNICE OR OTHER 
 
 
 
 FACES AND SOLIDS 
 
 4 
 
 20 
 
 ASSEMBLAGE OF MOULDINGS . . . 
 
 31 
 
 200 
 
 do. do. 
 
 5 
 
 22 
 
 MOULDINGS TO BE BENT ON CIRCU- 
 
 
 
 DEVELOPMENT 
 
 5 
 
 23 
 
 EAR WORK 
 
 
 200 
 
 DEVELOPMENT OF THE SOFFITS OF 
 
 
 
 RAKING MOULDINGS .... 
 
 
 201 
 
 ARCHES 
 
 
 58 
 
 ANGLE BARS FOR SHOP FRONTS . . 
 
 32 
 
 201 
 
 SOFFITS WHICH AGREE WITH PARTS 
 
 
 
 SKYLIGHTS 
 
 
 201 
 
 OF THE SURFACE OF CYLINDERS . 
 
 
 58 
 
 CIRCULAR HEADED SASH IN CIRCU- 
 
 
 
 SOFFITS WHICH AGREE WITH PARTS 
 
 
 
 EAR WALI 
 
 34 
 
 202 
 
 OF THE SURFACE OF CONES . . . 
 
 7 
 
 00 
 
 ARCHIVOLT IN CIRCULAR WALL . . 
 
 35 
 
 203 
 
 WINDING SOFFITS 
 
 s 
 
 02 
 
 COLUMNS AND PILASTERS 
 
 36 
 
 203 
 
 PROJECTION AND DEVELOPMENT OF 
 
 
 
 BRACKETING .... 
 
 
 205 
 
 AN OBLIQUE CONE 
 
 
 63 
 
 JOINTS AND HINGING 
 
 38 
 
 205 
 
 GROINS 
 
 10 
 
 SO 
 
 STAIRCASES AND HANDRAILS . . . 
 
 
 215 
 
 The form of one vault and the plan of the 
 
 
 
 Story Rod 
 
 
 215 
 
 intersection being given. to find the form 
 
 
 
 Pitch board . - . . . . 
 
 39 
 
 216 
 
 of the second vault .... 
 
 11 
 
 SI 
 
 Wall Strings 
 
 39 
 
 216 
 
 The forms of two intersecting vaults being 
 
 
 
 
 
 216 
 
 given, to draw the plan of the intersections 
 
 12 
 
 S3 
 
 Wreathed String . . . 
 
 40 
 
 216 
 
 CENTERING FOR GROINS 
 
 13 
 
 S4 
 
 do. do. ..... 
 
 41 
 
 217 
 
 do. do - 
 
 14 
 
 so 
 
 Mitre Cap 
 
 42 
 
 218 
 
 RIBS FOR PLASTER GROINS .... 
 
 15 
 
 86 
 
 Scroll and curtail step . . . 
 
 43 
 
 218 
 
 do. do. 
 
 16 
 
 87 
 
 do. do. . . . 
 
 44 
 
 219 
 
 lo find the form of the curb when a cir- 
 
 
 
 WREATHED HANDRAILS 
 
 
 220 
 
 cular arch intersects a flat ceiling . . . 
 
 17 
 
 144 
 
 Handrailing by the Oblique Cut .... 
 
 45 
 
 220 
 
 RIBS OF PLASTER NICHES 
 
 
 145 
 
 Handrailing by the Square Cut 
 
 iS 
 
 221 
 
 Niche, — semicircular in plan and elevation 
 
 is 
 
 145 
 
 Projection and development of the Falling Line 
 
 46 
 
 223 
 
 Ni. he. a segment of a circle on plan and 
 
 
 
 Projection of the Face Mould. — Resting 
 
 
 
 semicircular in elevation 
 
 U) 
 
 1 li 
 
 
 
 
 
 
 
 I oints. — Springing of the Plank 
 
 46 
 
 223 
 
 Niche. — a segment of a circle on plan and 
 
 
 
 do. do. do. 
 
 47 
 
 224 
 
 in elevation 
 
 20 
 
 146 
 
 Height of the Rail. — Lifting the Rail . . 
 
 47 
 
 225 
 
 Spherical Niche in a circular wall .... 
 
 21 
 
 147 
 
 Pitch of the Plank 
 
 47 
 
 226 
 
 Elliptical Niche 
 
 
 
 
 
 
 ROOFS . 
 
 
 1 A i 
 
 Elliptical Stairs .... 
 
 47 
 
 226 
 
 «lo 
 
 
 1S1 
 
 True form of the handrail spiral .... 
 
 47 
 
 226 
 
 
 24 
 
 181 
 
 Handrail over level landing, with flyers up 
 
 
 
 1 nrlins in conical and domical roofs 
 
 25 
 
 182 
 
 and down 
 
 4S 
 
 22^ 
 
 Polygonal Roofs . 
 
 
 
 
 
 
 
 
 
 1 v2 
 
 Handrail over winders. . 
 
 
 230 
 
 Core rings of circular roofs 
 
 Of! 
 
 
 
 
 
 
 
 l 
 
 Scroll over commencement of Winders . . 
 
 50 1 
 
 230 
 
xm 
 
 Plates. 
 
 1 
 
 2 
 
 3 
 
 4 
 
 (1 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 12 
 
 13 
 
 14 
 
 15 
 l(i 
 
 18 
 
 19 
 
 20 
 21 
 22 
 
 23 
 
 24 
 
 25 
 
 20 
 
 27 
 
 2s 
 
 29 
 
 30 
 
 30 
 
 31 
 
 32 
 
 33 
 
 34 
 
 35 
 30 
 37 
 
 PLATES OF PRACTICAL EXAMPLES AND EXPLANATORY TEXT. 
 
 A. R. EMY, ENGINEER 
 
 do. 
 
 do. 
 
 DETAILS OF WINDOWS AND DOORS. C R. COCKE- 
 
 do. do. 
 
 DETAILS OF BAY WINDOW. 
 
 do. 
 
 R R. ROWE, R. A., 
 
 DETAILS OF LANTERN. WILLIAM WRIGHT, 
 
 ROOF AT MARAC, FRANCE, 
 do. do. 
 
 do. do. 
 
 SUN FIRE OFFICE, LONDON. 
 
 RELL, R. A.. ARCHITECT 
 do. 
 
 THE RECTORY, GRAVELEY. 
 
 ARCHITECT 
 
 MILTON CLUB HOUSE, LONDON. 
 
 ARCHITECT 
 
 VICAR’S BUILDINGS, CAMBRIDGE. DETAILS OF SKYLIGHT. R.R. ROWE. ARCHITECT 
 THE RECTORY. GRAVELEY. DETAILS OF LANTERN AND STAIRCASE. R. R. ROWE, 
 
 R, A., ARCHITECT 
 
 KINGSTON HOUSE. DETAILS OF SKYLIGHT. N. E. STEVENS. ARCHITECT . . 
 
 EGYPTIAN HALL. LONDON. DETAILS OF ROOF AND SKYLIGHT. G MAIR. 
 
 F. S. A., ARCHITECT 
 
 MYDDELTON HALL. ISLINGTON. DETAILS OF ROOF. W. LAMBERT. ARCHITECT 
 BRIDGE OVER THE SEINE AT IVRY, FRANCE. M. EMMERY. ENGINEER . . . . 
 
 BRIDGE OVER THE NECKAR NEAR STUTTGARD, WURTEMBERG 
 
 SUN INSURANCE OFFICE, LONDON. DETAILS OF FRAMINGS. C. IL COCKERELL, 
 
 R. A.. ARCHITECT 
 
 do. d.o do. do. do. 
 
 ORDINARY WINDOW FITTINGS, SHUTTERS. ARCHITRAVES, etc 
 
 FELLING. SQUARING AND TRANSPORT OF TIMBER 
 
 ANCIENT ROOFS IN ROME. BASILICA OF ST. PETER. ARGENTINA THEATRE, 
 
 ST. PAOLO FUORI DELLE MURA, St. SABINE 
 
 CHURCH TRAINING INSTITUTION, HIGHBURY. DETAILS OF ROOF. F. W. PORTER, 
 ARCHITECT 
 
 do. 
 
 PRINCIPLES OF FRAMING 
 JOININGS IN CARPENTRY. 
 
 do. 
 
 do. 
 
 do. 
 
 FISHING BEAMS AND SCARFS WITHOUT KEYS . . 
 
 ,. .. KEYED SCARFS 
 
 ,. ,. BUILDING BEAMS 
 
 ,. ,. PIECES FORMING RIGHT ANGLES 
 
 ACUTE OR OBTUSE ANGLES. FEET 
 
 OF RAFTERS 
 
 „ ,, IRONWORK 
 
 SYSTEMS OF STYERME AND LAVES 
 
 ROOFS OF THEATRES IN PARIS. PORTE ST. MARTIN. OPERA DES ARTS. 
 
 M. LENOIR, ARCHITECT 
 
 FLOORS OF SHORT TIMBER AND PLANKS 
 
 CARLTON CLUB HOUSE, LONDON. DETAILS OF SKYLIGHT. SYDNEY S’MIRKE, 
 
 A. R, A., ARCHITECT 
 
 SCHOOLS ATTAMWORTH. DETAILS OF ROOF, SYDNEY SMIRKE. A. R. A.. ARCH- 
 ITECT 
 
 PARTITIONS AND ROOFS. WILLIAM WRIGHT. ARCHITECT 
 
 PECULIAR FORMS OF ROOFS 
 
 ROYAL COLLEGE OF SURGEONS, LONDON. THEATRE ROOF AND SKYLIGHT. 
 
 SIR CHARLES BARRY. IL A., ARCHITECT 
 
 do. do. do. do. 
 
 do. do. do. do. 
 
 GALLERY FRAMINGS AND SEATS 
 
 CURB ROOFS 
 
 Pages. 
 
 57 
 
 57 
 
 57 
 
 5S. 233 
 
 78 
 
 79 
 
 79 
 
 80 
 
 93 
 
 94 
 
 103 
 
 104 
 
 111 
 
 111 
 
 111. 212. 233 
 49. 90. 91. 93 
 
 32. 118 
 
 118 
 
 lls 
 
 120 
 
 148. 149 
 
 150 
 
 151 
 
 152 
 
 154 
 150 
 1 50 
 
 1 59 
 165 
 
 165 
 
 160 
 167 
 
 173 
 
 173 
 
 173 
 
 173 
 
 174 
 
PLATES OF PRACTICAL EXAMPLES AND EXPLANATORY TEXT. 
 
 Plates. 
 
 s Tin: SWISS CHURCH, LONDON. DETAILS OF ROOF AND SKYLIGHT. GEORGE 
 
 VULLLAMY, F. S. A., ARCHITECT 
 
 ' BEDFORD INSTITUTE. DETAILS OF ROOF. F. W. PORTER. ARCHITECT . . _. 
 
 I" SOUTHGATE ROAD SCHOOLS, DE BEAUVOIR TOWN. DETAILS OF ROOF. 
 
 E. C. ROBINS, ARCHITECT J 
 
 I" ST. CLEMENT’S SCHOOL, CAMBRIDGE. DETAILS OF ROOF. R.R.ROWE, ARCHITECT 
 
 II ROOF OF TIMBER AND IRON. A. R. EMY, ENGINEER 
 
 I- ROMFORD CHURCH. DETAILS OF ROOF. JOHN JOHNSON, F. S. A., ARCHITECT 
 I I HOTEL DES INVALID ES, PARIS. DETAILS OF DOME. J. H. MANSARD, ARCHITECT 
 
 CENTERING 
 
 is <io : . . . 
 
 I' ; TIMBER BRIDGES. PRINCIPLES OF FRAMING 
 
 * • <lo. 
 
 Pages. 
 
 1 75 
 
 177 
 
 J7S 
 1 78 
 
 178 
 180 
 184 
 
 190 
 
 191 
 
 193 
 
 194 
 
 I' 
 
 49 
 •i 0 
 
 51 
 
 52 
 
 53 
 
 54 
 
 55 
 
 50 
 57 
 5 s 
 59 
 • 0 
 01 
 02 
 
 03 
 
 04 
 
 05 
 00 
 07 
 os 
 09 
 
 70 
 
 71 
 
 72 
 
 73 
 71 
 75 
 70 
 
 LITTI.EPORT BRIDGE, ISLE OF ELY. R. R. ROWE, ARCHITECT . 
 SCAFFOLDING. DOMES OF ST. PETER’S AND PANTHEON, ROME 
 
 ild. 
 
 195 
 
 190 
 
 190 
 
 SPIRES, TURRETS, GATES. HUTS, GIRDERS . 
 RAILWAY GATES. NORTH WESTERN RAILWAY. 
 JOINERY 
 
 ARCHITRAVES 
 
 198. 
 
 WILLIAM WRIGHT, ARCHITECT 
 
 199.232.233 
 
 199 
 
 207. 208. 232 
 
 208. 209. 232 
 209. 212 
 
 209 
 
 „ MOULDINGS 
 
 FLOORING BOARDS. PARQUETRY 
 
 PARTITIONS, WAINSCOTING, DADOS 
 
 DADOS. SKIRTING | 
 
 DOOR FRAMES AND LININGS * . . , 
 
 DOORWAYS AS EXECUTED. WILLIAM WRIGHT AND R. R. ROWE, ARCHITECTS 
 
 CASEMENT FRAMES AND SASHES 
 
 CASED FRAMES AND LIFTING SASHES ’ ’ ’ 
 
 FOLDING SHUTTERS. BAY WINDOW, SYDNEY SMIRIvE, A. R. A., ARCHITECT 
 
 WINDOWS AS EXECUTED. CHARLES TEBBUTT, ARCHITECT 
 
 STAIRCASES : 
 
 210 
 
 210. 232 
 21 1 
 211 
 211 
 
 212. 232. 233 
 212. 232 
 212. 233 
 212. 233 
 212. 233 
 212 
 215 
 215 
 
 „ BALUSTRADES 
 
 SHOP FITTINGS 
 
 BAY WINDOW, STAPLEFORD PARK. P. W. WYATT. ARCHITECT 
 
 FRONTISPIECE 
 
 215 
 
 215 
 
 215 
 
 231 
 
 231 
 
 212 
 
 212 
 
 212 
 
 29. 29. 31 
 
 Printed by J F. Kltcber, Leipzig. 
 
Lines. Plate- /. 
 
lines Plain Z 
 
 Henry J. Col'lins. 
 
 A. H. Payne sc. 
 
Prarlical Examples, Hate Z. 
 
 » 
 
 ROOF EXECUTED AT MARAC, FRANCE . 
 A. R. EMY, ENGINEER . 
 
 E. L. Tar buck 
 
 AH. Payne sc 
 
hnrj /‘lute J. 
 
'•■W ' r t r ' r -J 
 
 ROOF EXECUTED AT MARAC, FRANCE 
 A. R. EM Y. ENGINEER. 
 
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 Henry J. Collins. A. H. Payne 
 
Lines _ Plate .5. 
 
 Henry J. Collins.' A. H Payne sc. 
 
SUN FIRE OFFICE. THREADNEEDLE STREET, LONDON 
 DETAILS OF WINDOWS 8 c DOORS. SEE PLATE 4. 
 
 C. R. COCKERELL. R A ARCHITECT. 
 
 E. L Tarbuck 
 
 A H Payne sc 
 

 
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 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Soffits, 1 . 
 
 Zin.es Fla/e 6' 
 
 
 • Henry J Collins . 
 
 A. H. Payne sc. 
 
 
THE RECTORY, GRAVELEY. 
 
 BAY WINDOW, WITH DOUBLE SASHES AND LIFTING AND 
 
 FOLDING SHUTTERS. 
 R. R. ROWE. ARCHITECT. 
 
 r*"> f f ' g r ' * i 3 i* i* — i Ve et. 
 
 I E L T a rib u. cli 
 
 A H Payne sc 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 
E. L. Tarim dk. 
 

Lines Plate 7 
 
 Henry J. Collins. 
 
 Soffits, Z . 
 
 A. H. Payne sc. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
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VICAR'S BUILDINGS. CAMBRIDGE. 
 DETAILS OF SKYLIGHT. 
 
 R. R. ROWE. ARCHITECT. 
 
 /‘rue// cai /:'■■// r/np/e.r //u/< Tl 
 
 E L Tarbuclc. 
 
 A H. Payne ec 
 
Soffits, 3. 
 
 Zints. PUue S 
 
 Fig. F 
 
 Ftg. /a- 
 
 -Fig. Z 
 
Lines — Plate 9. 
 
 Oblique cone. 
 
 Henrj-J. Collms . 
 
 AEPanie sc 
 
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KINGSTON HOUSE. 
 
 LOOKING UPWARD 
 
Groins, i. 
 
 Fuj.d. 
 
 Fig 4 
 
 Fig. 5. 
 
 Henry J Collms 
 
 AHPayne sc. 
 
OLD WA L L 
 
 Practical Examples Plate JO. 
 
 
 EGYPTIAN HALL, LONDON. 
 
 ROOF OVER REAR BUILDING, EXECUTED 1853. 
 GEORGE MAIR. F. S. A. ARCHITECT. 
 
 N. B. THIS ROOF WAS DESIGNED 
 TO REPLACE THE ORIGINAL ONE 
 SHOWN BY THE DOTTED LINES, 
 
 A STRONGER TRUSS AN D CR EATER 
 HEIGHT BEINC REOUISIT 
 
 JO J4 Jl 
 
 Feet 
 
 SECTION. 
 
 ROOT. 
 
 TR ANSVERSE 
 
 f 
 
 
 I 
 
 LONGITUDINAL SECTION (ONE HALF). 
 
 E. L.Tafbuck. 
 
 A. H. Payne sc. 
 
 4L, 
 
 

 MYDDELTON H A LL , ISLI N GTO N . 
 DETAILS OF ROOF. 
 WILLIAM LAMBERT. ARCHITECT. 
 
 Practical Exanyolcs Plate //. 
 
 iETartrack. 
 
 A.H.Payne sc. 
 
 

 
 
 
 -- 
 
 
 
 
 
 
 
 
 
 
 
 *• 
 
 
 
 
 
 
 
 
 
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Henry J Collins 
 
Practical Exam/ Per, Plan // 
 
 
 FANL1CHT 
 
 SUN INSURANCE OFFICE, 
 THREADNEEDLE STREET, LONDON. 
 C. R. COCKERELL. R. A. ARCHITECT. 
 
 DETAILS OF FRAMINGS 
 
 CORNICE 
 
 TRANSOM 
 
 CEILING OF 
 
 MOULDINGS 
 
 OF SWING DOORS 
 
 ENTRANCE 
 
 DOORWAY 
 
 ENTRANCE LOBBY. 
 
 ENTRANCE 
 
 DOOR - POST 
 
 CORNICE 
 
 DOOR SHUT 
 
 AND HANCINC 
 
 OF ENTRANCE 
 
 DOOR 
 
 N.B. THE DARKER 
 
 PARTS ARE 
 
 EXECUTED IN 
 
 WAI NSCOT. 
 
 fm ip 
 
 FOOT. 
 
 
 
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 1 
 
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A H Pay: 
 
SECTION 
 
 SECTION 
 
 PLAN 
 
 PLAN 
 
 CORNICE 
 
 
 plan or 
 
 CORNICE AND CONSOLE 
 
 SUN INSURANCE OFFICE, 
 THREADNEEDLE STREET, LONDON 
 C.R COCKERELL . R. A, ARCHITECT. 
 DETAILS OF FRAMINGS . 
 
 ravr 
 
 E L Tafbuck 
 
 rooT 
 
 ARCHITRAVE 
 
■miioc 
 
j / ucficao f'lcae 
 
 ORDINARY WINDOW FITTINGS; ARCHITRAVES , ETC. 
 
 
 SECTION 
 
 SECTION 
 
 PLAN 
 
 PLAN 
 
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Groins, 6. . 
 
 J-Jrlr.S, / KUe /, ). 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
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 E L Tartuck 
 
 A H Payne sc 
 
G R O I N S , 7. 
 
 Lines, rAare w 
 
 Henry J. Collins 
 
 AHPayne sc. 
 

Roman Roofs. 
 
 Practical li.ctnn jrlcs t Plat, 
 
 
 // 
 
NICHES, 
 
 
 O 
 
 c\< 
 
 
 
Tarbuck. 
 
 A H Payne sc 
 
 SECTION OF PORTION OF PRINCIPAL . 
 
 SECTION OF PORTION OF PRINCIPAL 
 
 CHURCHof ENGLAND TRAINING INSTITUTION, 
 HICHBURY PARK. 
 
 DETAILS OF ROOF OVER GYMNASIUM. 
 
 F W PORTER, ARCHITECT. 
 
 s/0 '* 0 " 
 
 „ 3 
 
 TRANSVERSE SECTION . 
 
 OLD BUILDING . 
 
 SECTION SHOWING MODE OF 
 CONNECTING PURLIN WITH 
 PRINCIPAL . 
 
 SECTION 
 
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 OF SASH BAR 
 CAPPINC . 
 
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CHURCH or ENGLAND TRAINING INSTITUTION 
 HICHBURY PARK. 
 
 EracttcaZ Example's, Ptatc A9. 
 
 2-A - ROLL 
 
 THE SASHES AT F 
 ARE HUNG AT TOP y 
 OPENING OUTWARDS . 
 
 INCH BOLT. 
 
 ANGLE IRONS AT E 
 OF BOILER PLATE 
 "A " THICK, S’ DEEP 
 ANDkT'LONG EACH 
 WAV _ ANGLE PLATES 
 AT ALL ANGLES, BOTH 
 AT TOP AND BOTTOM . 
 
 ABOVE SOCKETS, 
 OF GIRDERS 
 POST - 
 
 E. L. Tart) nek 
 
 A H. Payne 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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PRINCIPLES OF FRAMING 
 
 ■* r //ffSlsZO) X /Ci/ 
 
 E L Taxbuck 
 
 AH Payne sc 
 
Practical Fjcamples . Plaie 'll. 
 
 JOININGS IN CARPENTRY. 
 
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JOININGS IN 
 
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 PracUca7 Uu-anif/Jc^ Fktl<yJ!£. 
 
 Fig. 47. 
 
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Fig. 2. If. 
 
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Joinings in Carpentry. 
 
 Practical Uanzm/iles, Plate PJ. 
 
 E ,L Tar "buck 
 
 A H. Payne sc 
 

 
 
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 JOININGS IN CARPENTRY. 
 
 iMmmUl.uoh/it,.?. }),,}, 1 ? 
 
 
 Fig./fi Fin. 47. Fin M. Fin i.O 
 
 Fig. 40. 
 
 Fig. 42.. 
 
 Fig. 43. Fig. 44. 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
Joinings in Carpentry. 
 
 Practical JfcampZes, Plate&f: 
 
 53 54 53 36 ‘ 38 48 
 
 .E. L. TaTtmok 
 
 A H Payne so 
 

 R O O F S , 3 
 
 L we<f. -Plait QS. 
 
 

 
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ROOFS, 
 
 l/ineiijZYate k’o: 
 
Ironwork to Joinings. 
 
 Jr\ uj . JS 
 
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Prrzchfa.tllzani/ilcs. PZat&2. 
 
DOMES, 
 
 
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 AHPayne sc 
 

 
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LENOIR. ARCH ITECT. 
 
 
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Pendentives 
 
 
 
 
 
 
 
 
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Jj in e# , jP£a£es 30. 
 
 4 
 
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E L Tartuck 
 

 
 
 
 
 
 
 
 
 
Mouldings, i. 
 
 Lirvea, Plate , 3 / 
 
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r A MT I T I U N 5 AND ROOFS AS EXECUTED. 
 
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Roofs. 
 
 
 Practical 
 
 E&aTTijiles, Plate 3£ . 
 
 ■ TaT"buoli 
 
 A. H. Payne sc 
 
SKYLIGH T . 
 
 . L . TarbucX 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-Lines, Plate SJ. 
 
 Henry J Collins. ' AH Payne sc 
 
CIRCULAR SASHES. 
 
 J/in&sr f TlaLc 3^. 
 
 Henry J. QoIIltls 
 
Era,ctica/l/ Examfilw EUua.3-4. 
 

 
 
 
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BEDFORD WORKING MENS INSTITUTE. 
 
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enry -J. Collms 
 
OF OVER SOUTHGATE ROAD SCHOOL, 
 DE BEAUVOIR TOWN. J 
 
 PractzeaLExuuvzpJes, PlaE 40 
 
 TRUSSES 8 FEET APART. 
 A. FOR VENTILATION. 
 
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 CAMBRIDGE . 
 R.R.ROWE, ARCHITEC 
 
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TEL DES IN VALIDES, PARIS. 
 
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 L 
 
 TrcifUca I E jcartifil Plate 5 
 
J. Oollins. A. H. Payne so. 
 

J^raetical /4'xamjbh •> / J l(r/t . -1 '/. 
 
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TIMBER BRIDGES - PRINCIPLES OF FRAMING. 
 
 Fraciiad F 
 
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 Fig. £>. Fig. /#. 
 
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AND 
 
 Staircases 
 
 Handrails, 9. 
 
 Lines. Plate L7. 
 
 7 J Collins 
 
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 Practical FJaxtinfilej-, Flair 47. 
 
 Pitf- ^7 
 
 FYr/. /'9. 
 

R.ROWE, ARCHITECT. 
 
 PLAN. 
 

 
 
 
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Staircases and Handrails, 10 
 
 i 
 
 Henry J Collins AH Payne sc 
 
Staircases and Han d rails, . 
 
 Lines, Plate 4,9. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Staircases and Handrails, 12. 
 
 L ines, Fla £o . 
 
 HeiiTy J Collms 
 
 A.H.Payiie sc 
 
Practical Eacampl&y , Plate JP. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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W ' 6/^f £/ 
 
 37 677 
 
 77/ f’>i/ 
 

 
 
 
 
 
 
 
Joinery, 
 
 Practical P.ca/np lea, Plate .1 
 
 E. L. TartiuaE 
 
 JT'icfs . ,9. 
 
 A H FaYne eo 
 
J oi n e: ry. 
 
 ARCHITRAVES TO 
 
 DOORS,WINDOWS, ETC. 
 

 
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 A. H P ayne ec 
 
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PLAN OF PEDESTAL. 
 

J O I N E RY, 
 
 Practical Eaeam t files, Plat e oil. 
 
 E. L. T&Tbuok 
 
 A H Payne 
 

 F LOORS. 
 
 Practical Examples, Plate- ,19. 
 
 Be,. I 
 
 Fig. Z. 
 
 ;i i li II II II 11 11 II 
 
 -H H m H H H H H M- 
 
 Eg. 3. 
 
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 i ti o n s Wain scotinc* an d Dad o s . 
 
Fractical E' tx-am/il c.v, Flatc O'-/. 
 
 Dados and Skirtings. 
 
 E L Tart) Tick. 
 
Practical Ea-amjiles, Plate o'P. 
 
 Doors, Frames, Lin i n as a c . 
 
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Practical Haxcmftlea, Plate 6'4 
 
 Casement frames and sashes. 
 
 9 E . L T oLr’biiok 
 
 A H Pkyne so 
 

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Folding shutters, bay window Fractl£al rhk 00 
 
 AT BARLEY THORPE. 
 
 SYD N EY SMIRKE A . R . A . . ARC H I T E CT 
 
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 E L Tax tniols. 
 
CHARLES TEBBUTT, ARCHITECT. 
 
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T A I R C A S E S . T -rraczuxtc ajcamfues. 
 
Practical Pocamples, Plate 70. 
 

 
 
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S T A I R C AS E S . 
 
 rra oticai JL/scamplM, j'late //. 
 
 A H Rwn 
 
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E ET 
 
 Practical Ex/wtpJss. Plate 73. 
 

 CASES. 
 
 SECTION A. B. 
 
 I'ra often l If/tva m ft fay l J fn 1 1 ‘ 
 
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Bay Window, Stapleford Park 
 
 P. W. WYATT, ARCH ITECT. 
 
 Practical Ejca/nf,l«c, Plate 7t> 
 
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 Practical Eccam files, Platt' 77. 
 
 BAY WINDOW, STAPLEFORD PARK. 
 
 P. W. WYATT, ARCHITECT. 
 

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