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 254
to its height above thereference plane (m being, therefore, small), and only points nearthe center of the tube are considered, K will remain nearlyconstant. Then if in Fig. 140 T, and T^ are two similar tubesspaced a distance d apart, and Eo denotes the illumination pro- ILLUMINATION CALCULATIONS… … Fig. 140. 1 -Illuminatioii from two tubes. If now a value oi d^h can be found that will give a constantvalue of Ep-T-Eo for all values of x-^h, the problem of so spacingthe tubes as to secure uniform illumination is solved. The exactsolution for this condition by calculus is rather…
Light · Photometry · Electric lighting
Internet Archive · Boston Public Library · Public Domain Mark 1.0. Free to use for anything.
