Colour : a text-book of modern chromatics with applications to art and industry (1904)
Rood, Ogden N. (Ogden Nicholas), 1831-1902 · London : Kegan Paul, Trench, Trübner · leaf 201
re of blue and yellow still matches it perfectly. But, according to Helmholtz, this pure grey is really somewhat bluish, and it is owing to this circum- stance that it is able still to match the darkened yellow and blue, which is also really bluish. Pure grey has always ap- peared to the present… … Fig. 78.— Small White-and-Black Disk arranged so as to make a Grey by rotation. This •prey looks more bluish than the larger white disk ; 17 per cent, of an indigo disk is then mixed with the white. with a like .proportion of black. This compound disk was placed on the same axis with a white disk,…
Color
Internet Archive · Wellcome Library · Public domain (published before 1931). Free to use for anything.
