Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 440
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 … so -44 30 ZO 10 O FiQ. 9.—Polar Curves of Upright Mantle with Three Globes with Opal Flashing. 426 THE ILLUMINATING ENGINEER. horizontal intensity on the left and givea greatly augmented flux in downwarddirections on that side. Silvered glass, although good as areflecting medium, has the…
Lighting
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
