In the preparation of this text on architectural drafting, the aim has' been to present the cultural aspects of the subject as well as the practical; to instill a love for and an appreciation of all that is good and beautiful in architecture, as well as to lay a practical foundation for those to whom a knowledge of architectural drafting would be a vocational advantage. To comprehend the difficulties encountered by the architect in estimating the loads of a modern office building, in calculating and providing for the thrusts of a Gothic structure, or for the strains of a dome such as St. Peter's, leads to broader knowledge and to a deeper and more enlightened appreciation of good architecture. It is quite as essential in the training of an architectural draftsman that he should acquire a thorough knowledge of construction and an understanding of the principles involved, as it is that he should become expert in the operations of drafting.

The authors have departed from the usual plan of presenting a series of plates to be copied. Mere copying leads to superficial knowledge and mechanical skill, instead of promoting self-reliance and originality. The principles set forth in the text are illustrated by drawings representing types of construction and design. After a drawing is thoroughly understood, the student's knowledge of the principles involved is to be tested by requiring him to solve either a similar problem or one that is a step in advance. This method leads the student into a broader and freer way of thinking and working. He should be taught to observe closely, to understand fully, to digest thoroughly, and to apply what he has acquired with originality.

Model drawing plates as well as problem plates are presented on hose-leaf sheets, from which may be selected a course of study that is adapted to local needs. It is believed that this plan will enable those instructors who prefer their own course of study, to use the text to advantage. Frequent additions will be made to the list of problem sheets and instructors are invited to correspond with the authors and to make suggestions freely.

The text has been adapted in its scope to the time available for a course of one or two years in secondary schools.

The authors tender their acknowledgements to The National Fire Proofing Company, who have kindly loaned material for reproduction.

In arranging this text, an elementary knowledge, of mechanical and free-hand drawing on the part of the students, has been assumed. For this reason, no description is given of those instruments which ordinarily would be included in a rudimentary treatise in either subject. Special emphasis, however, is laid upon a description of such tools and materials as are used to a greater extent by architectural draftsmen than by those in allied trades and professions.

The ability to sketch rapidly is of inestimable importance to the mechanic as well as to the architect. During the erection of a building, problems in construction are constantly arising. The foreman and superintendent may have occasion to discuss some detail of construction. In such discussions, sketches, rough but accurate, are frequently of the greatest assistance. These sketches are made on any available part of the structure. Should the architect appear upon the premises, the question is presented to him. He either approves a plan already discussed or suggests, also with sketches, an entirely new solution. Enter any house in course of construction and you will find on the unfinished plastered walls or sheathing rough sketches, reminders of just such discussions. The student, therefore, should be given practice in quick, freehand drawing. He should be able to supplement his statements with sketches. This may be accomplished by requiring him to render freehand all solutions to the problems given, either on cross-section paper, or, better still, in note books. The teacher should also illustrate his talks with quick sketches, that the student may have constant training in reading and interpreting drawings.

All building operations are regulated by local laws or ordinances. The authors have adopted the New T York City Building Code for this text as well as for all plates, not only because the requirements are ample and always on the side of safety but also because they form the basis of practically all other building regulations. It has been deemed expedient to dwell at greater length upon frame buildings than upon those constructed of brick, concrete, or steel, because the former are more easily comprehended, require a minimum of static computations, and have many details, particularly of interiors, in common with all classes of buildings, masonry or otherwise.

SECTION I - DRAFTING IMPLEMENTS

1. Architectural versus Mechanical Drawing. Architectural drawing is characterized by a freedom and "snap" totally alien to mechanical drawing. The latter must be absolutely exact, rigid, and drawn with a very hard pencil. Once having decided upon the shape of a piece of machinery, it must be worked up with a precision which admits of little originality in the design of its constituent elements. They must all be of a definite size and form, one part fitting into the other with a mathematical exactness. No such limitations hamper the architectural draftsman. However definite the problem in hand, he may exercise his originality in any number of ways. The designer has before him the entire field of architectural styles from which to choose: The Egyptian, the Greek, the Roman, the Rennaissance, the Gothic or the Art Nouveau. One style may appropriately be selected or a judicious combination effected; but even if the style or external adornment of the building has been decided for him, the draftsman can still show his initiative in the height of the rooms, in the proportion of the openings, in the color schemes of the exterior and the interior, in the construction, and in numerous other ways.

2. Architecture a Science. We have remarked upon the mathematical accuracy of mechanical drawing. The impression, however, must not prevail that architecture is inexact. Architecture is a science as well as an art and as such must be exact; but it is an exactness that admits of some freedom, provided of course, that it is exercised on the side of safety. To illustrate: The building laws of particular localities prescribe definite loads which every member of a structure must be capable of sustaining. Absolute accuracy must therefore obtain in the calculation of beams, girders and their supports; in the thickness of walls, etc. A larger factor of safety, however, may be assumed, which will necessitate an increase in the size and weight of the various members, with no detriment either to its stability or its design.

3. Architectural versus Free-hand Drawing. Architectural drawing combines the principles of both mechanical and free-hand drawing. The draftsman in the preliminary stages of a problem uses a soft pencil with which he does a considerable amount of sketching. In the gradual development of the design, he makes less use of freehand and more of mechanical drawing; in no stage of the work, however, entirely abandoning either.

The mechanical element in architectural drawing aids in the development of .manual dexterity, while sketching assists in the training of observation and memory.


SECTION II - THEORY AND PRACTICE OF DRAFTING

15. Methods. Architectural drafting may be studied by either the analytic or the synthetic method. In the latter, the order of procedure is first to draw a structure in its entirety and then to make a study of its details. For the synthetic method it is claimed that the student follows the same course he would pursue in an office and that he works with a clearer understanding than he would if he had to draw a number of miscellaneous, unrelated parts of a building. On the other hand, the adherents of the analytic method contend that the most uncouth and impracticable designs are made by students who know nothing of the construction of the various recurring elements of a structure, such as doors, windows, roofs, etc.

16. Synthetic-analytic Method. A happy medium may be found by combining the good points of each system in the synthetic-analytic method. The student should constantly refer to a complete set of plans as he draws details. A building, it should be remembered, is an aggregation of connected units; system and coherency must therefore prevail in its representation. The foundation should be considered first; then the superimposed walls, the crowning roof, the exterior finish, and finally, the interior embellishments should follow in consecutive order. These elements should be carefully studied by themselves and in relation to one another. The plans should be consulted for width of openings; elevations and sections for height of openings. Studied in this manner, the beginner soon acquires a proper conception of the elements when represented conventionally. Knowing them and their conventional representation, it will not be difficult for the student to combine them in original designs.

17. Plans. A plan is a horizontal section taken through a building at such a height above the floor as will show to best advantage the arrangement and construction. See Plate II. A plan reveals the outline of exterior walls and their thickness, the arrangement of rooms, means of communication, positions of all openings, fixtures and other appurtenances.

Plans include not only the plans of the various floors but also all elevations, sections, and details. It is a term applied to any set of drawings necessary to give a builder a clear understanding of the completed structure.

The most important drawing is the ground floor plan, for it determines in a great measure the arrangement of the rooms of all the other floors and consequently fixes the character of the elevations.

18. Sections. A section is the view obtained by cut- ting through a building vertically. Its purpose is to show the construction, arrangement and architectural treatment of the interior of a structure. If a building is cut through its center crosswise and vertically, the resulting section is known as transverse; see Plate II. A longitudinal section as illustrated in (d), is obtained if the building is cut through lengthwise and vertically. A section is marked by the same letters that identify the traces of the cutting plane on the plan. The section plane may be discontinuous, that is, carried in a zig-zag course through different rooms, if by so doing more information may be obtained.

19. Elevation. An elevation is a vertical projection of the exterior of a building or part thereof; see Plate II. It reveals the style of architecture employed, the height between floors, the size and position of the openings and the kind and dimensions of the materials. The front elevation of a building is sometimes referred to as its facade.

20. Details. Details are enlarged scale drawings of parts of a structure; see Plate II. They are used to elucidate those decorative and constructive features which cannot be shown with sufficient clearness and accuracy on small scale drawings. Detail drawings are either made full size or to a scale large enough to make them intelligible to the mechanic. The most common scales used for this purpose as well as those parts usually rendered to an enlarged scale are enumerated in Section I, paragraph 7.