Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 436
e lighton to the photometer screen, P. Withthis arrangement, the lamp under testremains immovable and the rays alwaysarrive upon the photometer disc normalto its surface, whatever be the angularposition of the mirror frame with regardto the lamp. The photometer box wasfixed, and balance was… … Fig. 2.—A view of the blackboard, illuminated by Uniflux Reflectors. The numberschalked on the board indicate the illumination provided.
Lighting
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