Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 266
d a reflecting powerof 86-4 per cent. An experiment shouldbe made with a thick layer of fine powderof a transparent substance to ascertainwhether it has any specular reflexion.There is no a priori reason (pace Lommel)why it should. A spoonful of tablesalt flattened down with a knife showsno general… … 0 10 20 30 40 50 60 70 80 90 Fig. 20.—Experiments on partial polish. * A New Method and an Instrument forDetermining the Reflecting Power of OpaqueBodies.- P. G. Nutting. Trans, of 111. Eng. Soc,U.S.A., Vol. VII., p. 616, Nov., 1912. f Trotter on illumination : its Distributionand Measurement.…
Lighting
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