Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 517
Characteribic photometric curve. … Half-watt Reflector Fitting (concentrating type,detachable flange pattern), for interior orexterior use with One-watt lamps up to400 watts and Half-watt lamps up to 200watts. usual steel type, others are enamelled,and there are also cluster fittings. Ineach case the polar curve and the…
Lighting
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
