Minchin — Reflection of Light by Colored Papers. 447 



red, a — 0-0006562 mm 

 yellow, A. = 0-0005893 mm 

 green, a = 0*0005460 mm 

 blue, A = 0-0004862 mm 

 violet, A = 0*0004357 mra 



The slit in T r was adjusted for a match first with the total 

 light admitted at T, then with 0-5, 0*3, 0*2, and 0*1, the total 

 light. 



Table I gives the required width of T' in mm. for a match in 

 the different colors when T is 0"2 mm in width. All values 

 recorded are the average of eight readings. Data : 



Table I. 

 Width of T' in mm. 



For intensities of 



Color. 



Red 



Yellow . 

 Green __ 

 Blue ... 

 Violet .- 



1*0 



0-263 

 0*293 

 0-307 

 0-334 

 0-368 



0-5 

 0-146 

 0-165 

 0*171 

 0-183 

 0-189 



0-3 

 0*095 

 0-099 

 0-105 

 0-118 

 0-103 



0-2 

 0-071 

 0-079 

 0-082 

 0-090 

 0-105 



0-1 

 0-041 

 0-042 

 0-046 

 0-055 

 0*048 



