Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 160
20 25 30 35 40 DISTANCE APART IN FEET Fig. 11.—Relativejillumination values for street lighting gas-filled lamps v. open arc lamps.Foot-candle curves of combined results given by two lamps placed 60 feet apart and15 feet high in fittings as shown. … Fig. 12.—Street lighting equipment. Cluster fitting employed with vacuum type lamps.New single lamp fitting for gas-filled lamps.
Lighting
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