Illuminating Engineering Society, Association of Public Lighting Engineers (Great Britain) · [London] · leaf 105
obtained direct from thefilament of an ordinary electric head-lamp without reflection. I think thatthis light is of very much less importancethan the beams defined under headings1 and 2, but it may have a useful psycho-logical effect ; the same may be said 94 THE ILLUMINATING ENGINEER (april 1921)… … Fig. 1.—Showing effecl of composite beam. The requirement of a well-definedupper limit t<> t In beam referred to underheadings I and 1 can only be fulfilled exactly on roads which are horizontalor of uniform slope. On a sudden down-ward grade the light will shine in theryes (if others in…
Lighting
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