An appendage in industrial arts may be, among other things, a plate rail, bracket, spout, cover, or handle, all of which are capable of service either for or with the primary mass. In architecture it may be a wing or ell added to the mass of the building. Simple as its design may seem, it is often so placed in relation to the main or primary mass that it does not seem to "fit" or to be in unity with that mass.
Designing an Appendage
Rule 4a. The appendage should be designed in unity with, and proportionately related to, the vertical or horizontal character of the primary mass, but subordinated to it.
Rule 4b. The appendage should have the appearance of flowing smoothly and, if possible, tangentially from the primary mass.
Rule 4c. The appendage should, if possible, echo or repeat some lines similar in character and direction to those of the primary mass.
Violations of Appendage Design
All of the foregoing rules are intended to promote the sense of unity between the primary mass and its appendages. If a mirror on a dresser looks top-heavy it is generally due to the fact that it has not been subordinated in size to the primary mass. Rule 4a. If the handle projects from the primary mass of an object similar to the handle on a pump, it has not been designed in accordance with Rules 4b and 4c. Again, if the appendage projects from a primary mass like a tall chimney from a long flat building, it has violated Rule 4a and has not been proportionately related to the character of the vertical or horizontal proportions of the primary mass.
Plate 16