Light, photometry and illumination : a thoroughly rev. ed. of ''Electrical illuminating engineering'' (1912)
Barrows, William Edward, 1878-1960 · New York ; London : McGraw-Hill Book Co. · leaf 201
objects or surfaces such as the ceiling and walls of aroom. AVhen the ceiling, walls, or floor of a room are light incolor, the illumination will be increased by a greater or less amountdepending upon the distribution of light from the source orsources and the reflecting power of the different… … Fig. 109.—Representation of illumination values. they used for the tests was about 24 by 11.5 ft. and 10 ft. high.Dark green burlap and dark green rugs were used for the darkfinish, and light cream colored wrapping paper constituted thecovering for the light surface. The lamps were placed close…
Light · Photometry · Electric lighting
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