Church, A. H. (Arthur Herbert), 1834-1915 · London : Cassell · leaf 74
a paper disc, painted with vermilion, and add to it, by means of one of Maxwell's graduated white sectors, the above areas, or amounts of white (assuming the circle to be divided into one hundred degrees), each five parts of white added covering up five parts of vermilion. On rotating the compound… … Fifj. 12. containing fifty parts of white in the hundred : the com- pound disc, when at rest, is shown in Fig. 12. A similar sector of black will yield ten coi-responding shades of vermilion : a grey sector will yield a " broken " scale of ten tones. But by neither of the yjrocesses do we ob- tain…
Color
Internet Archive · Gerstein - University of Toronto · Public domain (published before 1931). Free to use for anything.
