Published online by Cambridge University Press: 17 January 2013
The object of the following communication is to describe a method by which every variety of visible colour may be exhibited to the eye in such a form as to admit of accurate comparison; to show how experiments so made may be registered numerically; and to deduce from these numerical results certain laws of vision.
The different tints are produced by means of a combination of discs of paper, painted with the pigments commonly used in the arts, and arranged round an axis, so that a sector of any required angular magnitude of each colour may be exposed. When this system of discs is set in rapid rotation, the sectors of the different colours become indistinguishable, and the whole appears of one uniform tint. The resultant tints of two different combinations of colours may be compared by using a second set of discs of a smaller size, and placing these over the centre of the first set, so as to leave the outer portion of the larger discs exposed. The resultant tint of the first combination will then appear in a ring round that of the second, and may be very carefully compared with it.
page 283 note * See Note III. For a confirmation of Newton's analysis of Light, see Helmholtz. Pogg. Ann. 1852; and Phil. Mag. 1852, Part II.
page 283 note † Young's Lectures, p. 345, Kelland's Edition. See also Helmholtz's statement of Young's Theory, in his Paper referred to in Note I.; and Herschel's Light, Art. 518.
page 291 note * See however Encyc. Metropolitana, Art. “Light,” section 502.
page 291 note † Ib. sect. 516.
page 292 note * I have lately seen a passage in Moigno's Cosmos, stating that M. Plateau, in 1819, had obtained gray by whirling together gamboge and Prussian blue.—Correspondence Math, et Phys., de M. Quetelet, vol. v., p. 221.
page 296 note * Poggendorff's Annalen, Bd. xciv. (I am indebted for the perusal of this Memoir to Professor Stokes.)
page 296 note † Ib. Bd. lxxxvii. Annals of Philosophy, 1852. Part II.
page 296 note ‡ Ib. Bd. lxxxix., Ann. Phil., 1854, April.
page 296 note § Ib. Bd. lxxxviii. Moigno, Cosmos, 1853, Tom. ii., p. 232.