2 Color Standards and Nomenclature. 



number of colors they all fail to supply a ready or 

 convenient means of identifying- and designating the 

 colors— the principal utility of a work of this kind. It i s 

 in the latter respect that the present work is believed to 

 meet, more nearly than any other at least, this essential 

 requirement, and in this consists whatever originality 

 may be claimed for it. 



The "key" to the classification or arrangement here- 

 with presented is, of course, the solar spectrum, with its 

 six fundamental colors and intermediate hues, augmented 

 by the series of hues connecting violet with red, which 

 the spectrum fails to show. If, with the red-violets and 

 violet-reds thus added to the spectrum hues, the band 

 forming this scale be joined end to end a circle is formed 

 in which there is continuously a gradual change of hue 

 step by step, from red through orange-red and red-orange 

 to orange ; orange through yellow-orange and orange 

 yellow to yellow; yellow through green-yellow and yellow 

 green to green; green through blue-green and green-blue 

 to blue; blue through violet-blue and blue-violet to violet; 

 and violet through red-violet and violet-red to red— the 

 starting-point — with intermediate connecting hues. In 

 the solar spectrum, both prismatic and grating, but 

 especially the former, the spaces between the adjoining 

 distinct colors are very unequal ; therefore for the present 

 purpose an ideal scale must be constructed, so that an 

 approximately equal number of equally distinct connect- 

 ing hues shall be shown. Distinctions of hue appreciable 

 to the normal eye are so very numerous* that the 

 criterion of convenience or practicability must determine 

 the number of segments into which the ideal chromatic 

 scale or circle may be divided in order to best serve the 

 purpose in view. Careful experiment seems to have 



*According to Aubert more than 1000 hues are distinguishable in the spectrum, 

 though among them all the hues betweeen violet and red are wanting. 



