Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 79
Fig. 1.—Showing variation in candlepower of lamps and effect of standards, S.Equidistant measurements taken at the circumference of a circle 2 ft. in radiusX 4 to give candlepower of lamp in a horizontal plane. Hailwood combustion lamp (clean). Oldham electric lamp (after six hours use).
Lighting
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