155. The floor is the least important surface for illumination, and has no reflecting power of value. The walls vary in value according to their color and surface. With lights radiating upward, however, the ceiling possesses definite power, and should be considered.
156. Dark colors absorb light, while white and light colors reflect, and this must always be remembered; for upon the character of the decorations and furnishings of various rooms the quantity as well as the quality of light has serious influence.
POWER NECESSARY
157. While the list which we give herewith is based largely upon area, it may be taken as a basis of calculation for lighting equipment.
It is estimated that 300 square feet of a hallway requires four sixteen-candlepower, or eight eight-candlepower units.
In a room 20 x 20 feet, with furnishings of mahogany and green, broken up by bookcases and other furniture producing heavy shadows, it is estimated that twelve eight-candlepower lights are sufficient if worked into the frieze, and that a reading lamp of not less than thirty-two-candlepower be used as a drop light.
Assuming a room is 15 x 15 feet, and furnished in light tones, four eight-candlepower lamps are ample.