448 Minchin— Reflection of Light by Colored Papers. 



The lamp at T" was next placed at one side and a mirror 

 fixed at T' to reflect the light into the slit. Fig. 3 shows the 

 arrangement. 



The length of the light path was kept constant and the 

 angle of incidence was made 45°. The results are given in 

 Table II. 



Table II. 

 Width of T' when mirror is used. 

 Intensities at T. 



Color. , A v 



1-0 0-5 o-a 0-1 



Red 0-569 0*276 0'190 0'081 



Yellow 0-607 0-305 0'198 0-084 



Green 0'621 0-332 0-209 0-091 



Blue 0-685 0'381 0-238 0*109 



Violet 0*810 0-392 0*204 0*094 



The colored paper was substituted for the mirror and adjust- 

 ments of T 7 made as before. The following tables give the 

 results for the paper used : 



(The interrogation point denotes some light, but not suffi- 

 cient for a match. means no trace of color noticeable.) 



Width of T' when T = *l mm . 



Intensities at T. 



Paper. Color , * ■ x 



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



Red. 1*287 1*878 2*697 ? .. 



p, Yellow.__. ? ._.- .... __ .. 

 Dee / Green .... ? 



red Blue ? _. .. 



Violet 



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



Intensities at T. 



Paper. Color , * > 



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



Red 0-460 0*889 .. 1*680 2'009 



T . , . Yellow .... ? 



Ll S ht Green * .... .. 



rea Blue 2-235 



Violet .... ? 



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



Intensities at T. 



Paper. Color , -* v 



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



Red _. 1-903 ? 



n , Yellow 2-650 ? 



JJarK Green 1*810 ? 



green Blue 2*122 ? 



Violet. 2*418 ? 



* When T was narrow a little green was seen, but when T" was widened 

 for a match all trace of green disappeared. 



