Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 25
Fig. 1.—Showing relative dimensions of original model and new smaller model. … Fig. 2. -Small model of photometer showing telephone receiver employed in regulation ofcomparison lamp. UNIVERSAL PHOTOMETER OF SMALL DIMENSIONS. volume is only about one-eighth thatof the first model. It can be veryconveniently carried in a travelling-bag, or even in a capacious overcoatpocket.…
Lighting
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