Luckiesh, Matthew, 1883-1967 · New York, D. Van Nostrand company · leaf 295
267 COLOR IN LIGHTING … Fig. 112. Twelve snap switches are shown above the rotating contactor, of which the upper six control clear lamps as indicated by the numbers. The middle switches Si and S2 in the upper two rows control, respectively, the four lamps on the left and right.
Color
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
