XIV. Detail of the Principal Doorway to the Basilica at Altamura, Italy.
"These two methods will aid one to tell from a drawing how the building will actually look when executed. It will give an idea of the scale of ornament, if a cornice looks just the right size on a certain building, the plate will tell you just how high that is. The T-square sketch is very valuable in cultivating the sense of proportion. Draw to scale such parts of the sketch as can be easily measured, and put in the remainder in proportion, and make these sketches at the scale at which you are used to working in the office. They will be of immense advantage in giving you a sense of absolute scale.
"There is such a thing as 'absolute scale,' and scale is not simply proportion. A drawing might be made in good proportion, and the building look well if executed a thousand feet long, and yet lose all its effectiveness if executed but one hundred feet in length, the relative proportions of the parts remaining the same. It is a fact that certain designs, which look well on paper, will not look well in execution, except at a large scale. Therefore it is valuable in making a sketch to put on it some of the measurements; and freehand sketches with measurements marked on them have a value in giving absolute scale.
"The back of a photograph is a very convenient place on which to make notes of the building itself, in regard to color, material, suggested changes, etc., and will be very useful in recalling the building to memory.
"Measuring buildings and drawing them out to scale is solid architectural work, and nothing else can take its place. It gives a realization of the actual size and appearance of things, and brings to notice the stone-jointing, sections of mouldings, vaulting, roofing, and construction in general. Measured work must be done very accurately, or else the results have no more value than approximate measures on sketches.
"The drawing should be made exactly as the building exists, without any change or improvement, or else the drawing will lose a great deal of its value as a basis for study. Many of Letarouilly's are nearly valueless as data for study because he has improved on the original, and thus his drawing does not represent the building as it actually exists.
"A good method of measuring buildings is to measure first the general dimensions and block out the building on paper at a small scale, then measure up windows, columns, etc., and set off full-size sections of all the mouldings with a strip of thin lead, such as may be had at any whole-sale lead store: only the thinnest sheet-lead will work, as the thicker leads are too stiff to bend. The large final drawings can then be made away from the building. It is important to draw out the building completely at a small scale, however, as it is very annoying when making the final drawing far away from the building to find that some important dimension has been forgotten.
"The ordinary tape stretches so much in long dimensions that it is inaccurate. It is best to get a tape with a metallic strip in it, and it should be at least fifty feet long in order to take dimensions over all, which is much more accurate than measuring with a short tape from point to point.
"The metric system is very convenient, but it is better for American students to use the English measure that they will have to use in practice, and take the tape over with them, for it is difficult to find them on the Continent. A sliding measuring-rod is nearly indispensable, and it will be most convenient to carry if it folds up to the length of the imperial drawing pad. Two large triangles are very useful in getting the projection of mouldings, as they can be held together to form a right angle."