This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
Tungsten lamps rates at 1.25 watts per horizontal candle-power, clear prismatic reflectors, either bowl or concentrating, large room; light ceiling; dark walls; lamps pendant; height from 8 to 15 feet .... .25
Same with very light walls........... .20
Tungsten lamps rated at 1.25 watts per horizontal candle-power; prismatic bowl reflectors enameled; large room; light ceiling; dark walls; lamps pendant; height from 8 to 15 feet ....... .29
Same with very light walls ........... .23
Gem lamps rated at 2.5 watts per horizontal candle-power; clear prismatic reflectors either concentrating or bowl; large room; light ceiling; dark walls; lamps pendant; height from 8 to 15 feet .... .55
Same with very light walls ........... .45
Carbon filament lamps rated at 3.1 watts per horizontal candle-power; clear prismatic reflectors either bowl or concentrating; light ceiling; dark walls; large room; lamps pendant; height from 8 to 15 feet ... .65
Same with very light walls ........... .55
Bare carbon filament lamps rated at 3.1 watts per horizontal candlepower; no reflectors; large room; very light ceiling and walls; height from 10 to 14 feet ............ .75 to 1.5
Same; small room; medium walls .......... 1.25 to 2.0
Carbon filament lamps rated at 3.1 watts per horizontal candle-power; opal dome or opal cone reflectors; light ceiling; dark walls; large room; lamps pendant; height from 8 to 15 feet ....... .70
Same with light walls ............ .60
 
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