js-j 



CAPTAIN W. DE W. ABNEY ON THE COLOUR 



Column I. shows the wave-lengths; Columns II., III., and IV. the percentage 

 luminosity of the sensations (see fig. 6); Column V. the luminosity; Columns VI. , 

 VII., and VIII. the luminosity of the sensations in the normal spectrum. The 

 approximate areas of the three curves shown in Columns VI., VII., and VIII., and 

 graphically in fig. 7, are 747 '6, 344'3, and 5 '3 for the RS, GS, and BS respectively, 

 and the equation for white is 



RS GS BS W 



68-14 + 31-38 + -48 = 100. 



Columns VII. and VIII. have to be multiplied by and 7^-, or 2 '17 and 142 



I'.K.li 



48 



