222 Measurement of Colour and Determination of White Light. 



As nearly as possible this equation was reproduced. The 

 resultant colour was a bright yellowish green. Keeping the 

 centre of the slits as nearly fixed as possible, equation (6) of 

 Table V. was obtained. 



To test the sensibility of the eye and determine the range 



of error three components were combined to form a match to 



the original light. Two of the components were kept constant, 



the other was thrown out of adjustment, and a match reformed. 



The Argand burner was used as a source — 



For red : — 



31(22-l)+31-5(39-8)+65(69-7)=W. 

 30-l(22-l)+31-5(39-8)+65(697)=W. 

 30-9(22-l)+31-5(39-8)+65(69-7)=W. 



For green : — 



30-9(22-1 )+ 31 -5(39 9)+ 65(69-7) =W. 

 31 -5(22-2) 4 31 -2(39-9) + 65(69-7) = W. 

 31 -5(22-2) + 31 -2(39-9) + 65(69-7) = W. 



For red : — 



29(18) +33-5(34-9) + 63(59-5) = W. 



29(18) +-33-5(34-9) f 63(59-5) =W. 



29-l(18)+33-5(34-9)+63(59-5)=W. 



For green : — 



29(18)+33-6(34 : 9)+63(59*5)=W. 

 29(18) +34'9(34-9) + 63(59-5) = W. 

 29(18) +34-8(34-9)+ 63(59-5) =W. 



For violet : — 



For red : — 



20(22-2) +34(39-5) +56(68) =W. 

 20(22-2)+34(39-5)+66(68-4)=W. 

 20(22-2) +34(39-5) + 52(69-7) = W. 



29(17-9)+33-5(34-2)+63(59-3)=W. 

 28-2(179) + 33-5(34-2) + 63(59-3) = W. 

 28-5(17-9)+33-5(34-2)+63(59-3)=W. 

 29-2(17-9) +33\ r <(34-2)+ 63(59-3) =W. 



For green : — 



30( 17-9) + 33-5(34-2) + 63(59-3) = W. 

 30(17-9) +33-2(34-2) + 63(59-3) = W. 

 30(17-9)+32-6(34-8)+63(59-3)=W. 



