Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 271
9075 tO +5 30 15 0 15 30 +5 60 75 90 Fro. 31.—Analysis of-Fig. 30. The eurve for e = 20° is not goodenough for reproduction. The curve … Fig. 32.—Bristol board. s = 40 deg. The differences are given in Fig. 33.With £ = 60° the increasing reflectingpower is very marked, as appears inFig. 34, which is plotted to half theradial scale of the other curves. Thedifferences from a circle of diameter 33are given in Fig. 35. Observations…
Lighting
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