Light, photometry and illumination : a thoroughly rev. ed. of ''Electrical illuminating engineering'' (1912)
Barrows, William Edward, 1878-1960 · New York ; London : McGraw-Hill Book Co. · leaf 226
Figs. 117 and 118.—Comparison between theoretical and actual curves. shown in Fig. 115. The equations of these curves are too com-plicated for practical purposes. The general case of polar curves yielding uniform illuminationis indicated by Fig. 116. The equation for curves of this natureis -_,…
Light · Photometry · Electric lighting
Internet Archive · Boston Public Library · Public Domain Mark 1.0. Free to use for anything.
