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 212
roduct of the lumens and the constant, divided by thewatts. The values of the effective lumens for some of the othertypes of electrical lamps and different gas lamps are given inTable 3G and 37. The effective lumens per watt were secured byaveraging the results obtained from various sources while… … Table 37Gas Lamps (Small Room, Light Ceiling)- „ ^ , Glassware orTvpc of lamp _ ^ reflector Consump-tion cu. ft. AVallsper hour Effective lumens per cu. ft. per hour Inverted lamp Prisroatic or opal (con-centrating).Inverted lamp Prismatic or opal (dis-tributing). Inverted lamp French roughed Ijall…
Light · Photometry · Electric lighting
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