Page:A color notation (Munsell).djvu/91



(132) The last chapter traced a series of steps leading to the construction of a practical color sphere. Each color was tested

by appropriate instruments to assure its degree of hue, value, and chroma, before being placed in position. ‘Then the total sphere was tested to detect any lack of balance.

(133) Each color was also written by a letter and two numerals, showing its place in the three scales of hue, value, and chroma. This naturally suggests, not only a record of each separate color sensation, but also a union of these records in series and groups to form a color score, similar to the musical score by which the measured relations of sound are recorded.

(134) A very simple form of color score may be easily imagined as a transparent envelope wrapped around the equator of the sphere, and forming a vertical cylinder (Fig. 21). On the envelope the equator traces a horizontal centre line, which is at 5 of the value scale, with zones 6, 7, 8, and 9 as parallels above, and the zones 4, 3, 2, and 1 below. Vertical lines are drawn through ten equidistant points on this centre line, corresponding with the divisions of the hue scale, and marked R, YR, Y, GY, G, BG, B, PB, P, and RP.