Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 272
has been repeatedwith greater precision. Although these sets of observationswere made without inter-related scale,it was noticed that, contrary to expecta-tion, for a given incident illumination,the brightness varied considerably withthe angle of emission, and hence the THE ILLUMINATING ENGINEEK… … Fig. 34.—Bristol board. (50 cleg.
Lighting
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