[Figure 33], [Plate 14], is a common example of three vertical divisions in metal suggested by the needs of service. [Figures 35] and [36] are thin metal problems. The familiar pen tray is primarily a horizontal mass, so determined by its required service as a pen holder. The projecting handles form the outer divisions, and the spacing motive, Rule 3b, has been repeated in the raised projection, decorating the handles. The book rack in [Figure 36] is an example of the manner in which a nearly square mass, so designed for structural reasons, may, by Rules 3b and 2a, be broken into a fairly pleasing arrangement of divisions.
More Than Three Divisions
Rule 3c. In elementary problems, if more than three vertical divisions are required, they should be so grouped as to analyze into Rules 3a and 3b, or be exactly similar. The eye becomes confused by a multitude of vertical divisions and it is much better designing to keep them within the number stated in this chapter. There are instances, however, when this is impossible. Under such conditions the following treatment should be adopted:
Unless, as stated, a large number of vertical divisions may be grouped into two or three vertical divisions it is better to make all of the divisions of the same size. This does not fatigue the eye as much as would the introduction of a number of complex spacings. This solution enables the amateur designer to deal with complex problems with an assurance of securing a degree of unity.
INSTRUCTION SHEET
[Plate 15] is practically self-explanatory and shows the order in which the various divisions, so far considered, are to be introduced into the design together with the grouping of details within those divisions. Figure D introduces the additional element termed the appendage to be considered in [Chapter V].
SUMMARY OF DESIGN STEPS
(a) Construction of the rectangle representing the vertical or horizontal character of the primary mass with desirable proportions. Select the most prominent surface for this rectangle, preferably the front elevation.
(b) Subdivide this rectangle into two or three structural sections, horizontal and vertical in character. Make two or three trial freehand sketches on cross section paper for varied proportions and select the most pleasing in accordance with rules.
(c) Translate the selected sketch into a scale or full size drawing and add additional views to complete the requirements of a working drawing. Add additional structural elements: legs, rails, etc.
(d) For shop purposes, enlarge a scale drawing to full size, dimension and otherwise prepare it for actual use. See [Figure 102a], [page 68], for character of this change.
(e) Construct the project.
SUGGESTED PROBLEMS
Design a fire screen with two horizontal and three vertical major subdivisions.
Design a bookcase 4 feet 2 inches high with three horizontal and two vertical major subdivisions.
SUMMARY OF RULES
Rule 3a. If the primary mass is divided into two vertical divisions, the divisions should be equal in area and similar in form.
Rule 3b. If the primary mass is divided into three vertical divisions, the center division should be the larger, with the remaining divisions of equal size.
Rule 3c. In elementary problems, if more than three vertical divisions are required, they should be so grouped as to analyze into Rules 3a and 3b, or be exactly similar.
REVIEW QUESTIONS
1. What is the nature and need of vertical space divisions?
2. State the rule governing the use of two vertical space divisions and give illustrations in wood, clay, and metal.
3. Give the rule relating to the use of three vertical space divisions and furnish illustrations in wood, clay, and metal.
4. What is the treatment of more than three vertical divisions? Why?
Chapter V
APPENDAGES AND RULES GOVERNING THEM
Use of the Appendage
An appendage is a member added to the primary mass for utilitarian purposes. In the industrial arts, when an appendage is added merely for the purpose of decoration, it is as useless and functionless as the human appendix and, as a source of discord, should be removed.