Ever since man began to theorize about art he has assumed that the manmade dwelling place first made conscious artistic activity possible. This is true, for although the cave paintings were made at a time when men did not build dwelling places, prehistoric cave art is a solitary phenomenon. All pictorial and plastic arts are nowadays connected in some way with the man-built dwelling house.
Architecture forms a part of the subject matter of the great majority of paintings and drawings. More than this, a whole branch of painting has adopted the building itself as its subject. Although it had originally no other object than to reproduce the impression of splendor given by a town (splendid in comparison with untouched nature, then considered "raw"), the prominent architectural painters also included much of the otmosphere of contemporary life in their pictures. Today, architectural painting has been almost entirely replaced by photography.
Some knowledge of building technique is indispensable for anyone who depicts architecture, whether as a primary subject or as a background for figures, just as he needs a knowledge of the surface anatomy of human, animal, and plant life if he is to understand the forms he observes and reproduce them intelligently.
Architecture deals with man-made structures, but its methods are based on natural laws and natural conditions, in particular the laws of gravity and the nature of the materials used. The measurements are man made, adapted to man's size and ways of movement. Thus, ancient classical architecture was based on the golden mean.
When drawing buildings the human scale must be considered, or the figures will appear gigantic like Gulliver in Lilliput or minute like Gulliver in Brobdingnag.
A few basic measurements should be remembered to prevent elementary mistakes; or, rather than relying on numerical figures, it may be easier to retain in the memory a scheme like the one illustrated as a reference to scale. If these few proportions are borne in mind, the building will turn out properly as a whole.
The building material by its nature dictates certain proportions. A wooden beam cannot extend farther than twelve or fifteen feet unsupported; beyond that it would bend or even break. Used as a pillar, wood must have a certain thickness in relation to its length or it will bend in.
Other materials dictate other uses, but their peculiarities are much more obtrusive than those of the ideal building material, wood. Stone has a stronger resistance to pressure, but little tensile strength, and reinforced concrete is now used instead. Concrete gives resistance to pressure, and steel reinforcement adds resistance to strain.
The material used also dictates the construction technique. The opposed diagrams in the illustrations show how each material must be used according to its nature. The roof needs special consideration; it is often drawn quite incorrectly. Naive observation is not always enough. When the main structural forms are understood, it will be easier to understand the peculiarities of an unusual roof or to follow the logic of its construction.
The general structure of a building is determined, according to the laws of gravity, by horizontals and verticals. A building with leaning walls must fall sooner or later. The eye feels this unconsciously and seeks out horizontal and vertical relations, even when they are not structurally necessary.
The eye derives satisfaction if the axes of the windows lie vertically one above the other and the sills and lintels run in horizontal lines. If an architect disregards this convention he must introduce other optical lines of relationship to emphasize stability - for example, lines running right across the wall.