Nature and Need of Vertical Space Division
The design of the primary mass has now been considered under Rules 1a and 1b, and its horizontal divisions under Rules 2a and 2b. The next logical step is the consideration of the nature of the lines that cross the primary mass in a vertical direction. In the original planning of the primary mass it was found that the horizontal bounding lines and the horizontal divisions were parallel to the base line of an object and that the base line was necessary to ensure stability. Vertical lines are necessary and equally important to give the needed vertical support to an object.
So accustomed is the eye to vertical lines in tree trunks, tall buildings, and thousands of other examples that the upward eye movement in viewing an object, having a predominance of vertical elements, seemingly adds to its height.
The designer thus has a most useful device with which to increase the apparent height of an object that, for structural or other reasons, must in reality not have great height. [Chapter III] drew attention to the influence of horizontal lines on a project. Vertical lines on an object are found to produce an analogous effect vertically.
Architectural Precedent for Vertical Divisions
Gothic cathedral builders used the vertical line, repeated again and again in buttresses, pinnacles, and spires to give great apparent height to a building and to make it a unified vertical mass of great beauty. The modern church spire, together with the long, vertical interior columns, similarly affects our present day church edifices.
Plate 12
This idea of repeating the vertical bounding lines of the primary mass by cutting the mass into vertical spaces is also useful in breaking up or destroying the monotony of large unbroken surfaces. Pilasters may cut the front of a building into interesting spaces; piers may break up the regularity of a long fence; legs and panels may, each for the same purpose, cross a cabinet. While some of these may be structurally necessary and some not, they are all witnesses to the desire to produce beauty in design. As these examples are so numerous in the industrial arts, it is well to study in detail their proper adaptation to our needs.