Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 440
Fig. 8.—Increase in Candle-power of Inverted Mantle by Employment of Globe.(A = Bare mantle. B = Mantle with clear glassspherical globe.) THE ILLUMINATING ENGINEER. 60 SO -40 JO 2010 o lo ao 30 -*o so 60 425 … 30 so 10 O 10 20 30 Fig. 7.—Polar Curves of Inverted Mantle with Spherical Globes of Increasing Obscurity. 50 -40 30 ZO 10 0
Lighting
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