This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Character of Line. The thickness of the line in drawing should be the same throughout its length, except occasionally in perspective rendering. The line may vary in different parts of the same drawing, and in different drawings, according to how much or how little detail is to be shown, but in every case the lines should be firm and clear. Those parts of an elevation which are nearest to the spectator should be drawn in heavier lines than the more distant parts. Thick lines generally tend to simplify the design. The outline of the curved mouldings, excepting those circular in section, should be drawn freehand, as they can be given more character in that way than if made with the compass.
The compass should be used in such a way that the point will not make large holes in the paper. The arms of the compass should be bent so that the pencil point and needle point will be perpendicular to the paper. Pencil lines should be made without a heavy pressure so as not to dent the paper. The ruling pen should be held like the pencil and used very lightly, for if too much weight is put upon the pen, the paper will be cut, and if the pen is pressed too hard against the T-square the blades of the pen will be closed and the lines become weaker. It is also necessary that the ink should always flow freely from the drawing pen. It should be renewed frequently and the pen should be cleaned each time it is refilled. If the ink refuses to flow, it frequently can be started by touching the end of the pen to the moistened finger, capillary attraction immediately starting the ink to flow.
Ordinary writing ink should not be used with the drawing pen. After the drawing is inked in, the pencil lines can be erased. The student will eventually become accustomed to making the important lines with the pencil and putting in many of the lines of the drawing immediately in ink, between limiting lines in pencil. But the drafts-man'should be very sure of himself and his drawing before using this method.
Shade lining, or indicating shadows by making the lower and right-hand edges of projecting planes in elevation heavier, see Fig. 4, is used in architectural drawing, especially in illustrations for publication. In office work, when it is desired to show the shadows, the latter are generally laid in washes. The brilliancy of the architectural drawing shown in many recent examples, especially from New York offices, is much increased by strengthening the outline of projecting members and ornamental parts, by accenting certain points, and by carrying through only certain important lines of mouldings, and drawing other lines only a short distance. Finished lines coming down on to projecting surfaces may be stopped short just before reaching the surface, giving effect of high light on those surfaces, as shown in Fig. 4; and lines at outer angles may be carried slightly across each other, giving a firm intersection, instead of stopping just at the junction. For plans the same holds good, as is shown in Fig. 5.
In an elevation, the planes toward the front may be drawn with dark lines and those farther back with lighter lines. Joint lines in masonry and the lighter lines of carving should be drawn in ink which has been diluted with water. The design for the National Maine Monument, page 9, shows a good method of lining an architectural drawing.
Fig. 4. Shade Lines.
Fig. 5. Junctions of Lines.
First Prize Design. National Maine Monument.
H. Van Buren Magonigle, Architect.
Architectural drawing is geometric. If the student is making the drawing of a model, he should try to think how the author of the model laid it out, and how he, the student, would proceed if he had the opportunity to lay it out. He will find that the model is represented on paper by the different projections such as the plans, sections and elevations. These are laid out to a certain scale; that is to say, one-fourth inch to the foot, which means that one-fourth inch in the drawing represents one foot in the model; or one-eighth inch to the foot, etc.
Definition of Plan. A plan of a building is a section cut by a horizontal plane through the walls, supports, etc., at such, a height so as to show the greatest number of peculiarities in construction, walls, doors, windows, supports, columns and pilasters, fireplaces, etc. It is possible to consider a plan as a horizontal impression that could be taken of the building in course of construction when it had arrived at a certain level in the height of a story. On the plan the construction is shown invariably by horizontal sections, but it is possible to project up all that is below and also to show what is above. In the first case the plan will show the architectural portions which project beyond the base of the walls or supports such as the base, steps, approaches, etc. In the other case it will show vaultings, ceilings, entablatures, cornices, etc. Sometimes it is desirable to show both - half of each - provided the parts shown are sufficiently interesting or necessary for explaining the entire scheme.
Definition of Section. The section is a plane cut through a building vertically, that is to say, it is the same thing perpendicularly that the plan is horizontally. This plane should be taken along the line of some main axis.
A single section rarely is sufficient to give all the interior of the building. It is accessary to have, as a rule, at least two, one a longitudinal section, perpendicular as a rule to the facade, and the other a transverse section, usually parallel to the facade. Very often a small section of the front alone is made. This should preferably be called a profile of the front.
Definition of Elevations. The elevations of a building are the projections of the building on vertical planes parallel to the side of the building of which an elevation is desired. Except in the case of complete uniformity, it is necessary to have several elevations in order to show the complete exterior of a building, such as the principal facade, side elevations, and rear elevation.