photometry
(fəʊˈtɒmɪtrɪ)
[ad. mod.L. phōtometria (1760), f. Gr. ϕῶς, ϕωτο- light, photo- + -µετρία measuring, -metry.]
Measurement of light; comparison of the intensity of light from different sources; the use of a photometer.
| [1760 Lambert Photometria 7 Optandum certe esset, ut excogitaretur Photometrum thermometro analogum, quod lumini expositum ejus intensitatem atque claritatem indicaret.] 1824 R. Watt Biblioth. Brit. s.v. J. H. Lambert, Photometry. 1830 Encycl. Brit. (ed. 7) Prelim. Dissert. 637/2 The eighteenth century created a new branch of optical science, destined to measure or compare the intensities of different lights, and therefore termed Photometry. 1865 Daily Tel. 24 Nov. 4/6 So far as photometry is concerned, the metropolitan [gas] companies have usually complied with the law. 1876 G. F. Chambers Astron. vi. i. 480 The subject of the photometry of stars..has received but little attention from practical astronomers. |