18 Color Standards and Nomenclature. 



tone scale, on the plates running vertically, growing 

 from the full color, in the center, to a pale tint (at the 

 top) and a dark shade (at the bottom). For clearer 

 comprehension of these two distinct scales, each plate of 

 this work may be compared to a sheet of woven fabric ; 

 the chromatic scale (horizontal) representing the warp, 

 the luminosity or tone scale (vertical ) the woof. A third 

 kind of color scale is represented by adding progressive 

 increments of neutral gray to any color. This is shown 

 by the several series of Plates, of which the first (Plates 

 I-XII, with colors numbered 1-71) represents each step 

 in the spectrum scale unmixed with gray, followed by 

 five other series in which the same colors* are shown 

 dulled by gradually increasing increments of neutral 

 gray, the first (Plates XIII-XXVI, colors l'-7l') con- 

 taining 32 per cent., the second (Plates XXVII- 

 XXXVIII, colors l"-7l") 58 per cent., the third (Plates 

 XXXIX-XLIV, colors l'"-69'") 77 per cent., the fourth 

 (Plates XLV-Iy, colors l""-69"") 90 per cent., and the 

 fifth (Plates LI-LIU, colors l""\ 15'"", 23'"", 35'"", 

 49'"", 59'"" and 67'"") 95.5 per cent, of gray, the last 

 being in reality colored grays. Finally scales are shown 

 (on Plate L,III) of neutral gray (in which all trace of 

 color is wanting), and of carbon gray, a simple mixture 

 of lamp-black and Chinese white. It is not easy to find 

 a suitable name for these scales of reduced or "broken" 

 colors, but they may, for present convenience, be termed 

 reduced or broken scales. 



Full Color. — A color corresponding in intensity 

 with its manifestation in the solar spectrum. 



*The distinctions of color or hue diminishing in proportion to the increased 

 admixture of gray, each alternate color or hue, with its scale (vertical) of tones, is 

 omitted from the third and fourth series ; while in the fifth the color differentiation 

 is so greatly reduced that only the six spectrum colors (dulled by admixture of 95.5 

 per cent, ot neutral gray), together with purple (the intermediate between violet and 

 red) are given ; a yellow orange hue being substituted for spectrum orange because 

 it is more exactly intermediate in hue between red and yellow. 



