Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 76
Feet from centre of beam. Fig. 1—Searchlights with Metal Filament lamps Showing effects of proper and improper focussing of lamps. … Fig. 2.—Incandescent electric lamp mountedin searchlight. Here we have the difference between215,000 maximum beam candle-power(Curve A) when the lamp is in focus ascompared to 17,000 candle-power (CurveB) when the lamp is J in rear of its properfocussing position. It is very importanttherefore that…
Lighting
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