Minchin — .Reflection of Light by Colored Papers. 449 



Width of T' when T = 0*l mm . 



Intensities at T. 



Paper. Color , * , 



reflected. 0-1 0*2 0'3 0*4 0*5 



Red 1-424 ? 



-p. }] Yellow 1-302 ? 



Green 1-056 2-091 ? 



£ ieen Blue 1-450 2-278 ? 



Violet ? 



Width of T' when T = 0*l mm . 



Intensities at T. 



Paper. Color , K N 



reflected. 0*1 0*2 0*3 0*4 0-5 



Red 1-289 2-120 ? 



y. Yellow .._ 1-176 2-204 ? 



, g Green 0-683 1-299 2*029 ? 



g ieen Blue 0-782 1-280 1-912 2-129 2*710 



Violet Just a slight trace 



Width of T' when T = 0*2 mm . 



Intensities at T. 



Paper. Color , A , 



reflected. 0*1 0*2 0*3 0*4 0*5 



Red 1-847 ? 



-p, , Yellow ? 



Dark n 



, , Green ? 



Dlue Blue 4-667 



Violet ? 



Width of T' when T = 0"l mm . 



Intensities at T. 



Paper. Color , * * 



reflected. 0'1 0*2 03 0"4 0-5 



Red 1-213 2-061 ? 



T . , Yellow ... 1-088 1-980 ? 



hf Green 0-936 1*684 2*521 ? 



Blue 0*789 1*505 2*096 ? 



Violet 1*036 1-111 1-631 2*117 2'886 



Discussion of Data. 



Table II shows that approximately one half the incident 

 light was reflected by the mirror. Both Table I and Table II 

 show that as the violet end of the spectrum was approached 

 the width of T' had to be increased to procure a match. 



Because of the small amount of light reflected by the papers 

 it became necessary to cut down the intensity of the light 

 admitted at T. Each of the tables gives the greatest inten- 

 sities that could be used and allow the obtaining of a match. 



The deep red paper reflected red light only, to a sufficient 

 degree to allow of a match. 



Am. Jour. Scl— Fourth Series, Yol. XIX, No. 114. — June, 1905. 

 31 



