where 



INTENSITY OF RELECTED AND EEFBACTED LIGHT. 



411 



2^8a:8ySfi--2f-^(Sf2-8a/^)sm(pcos^(pX j-2Isin2^ + - sinK^j 

 - 2^ • {8f'-8x"^) sin (p cos V X j -2Rsm2 ^ +- ^ sin K .r"! 



= - -2" sin ^ cos 2^ (1 - R) + 3 y sm ^ cos ''<^ \j-^-J^) 

 By adding this term to that which we have just found, the sum is 

 -2sm0(I-R)+- sm.^(^--^) - D I, ■ 



(0''+^^^^) |Tsin.^'+T,^^3^^^5^-i3Rsin0-I,| 

 (^/+^^5ir'A j5Tsin(^' + 5T,+ Tsin<^' + T,-F^sin0-I,| 



(^/+ ^(5ir,2cos^'+5y;siny)) sin^'x j -2 Tsin2-^' + ^ |^8inKa:,| 

 (,^/+ ^5^) j -T,(l-.— '^'cos/5y) + l^' .—'^'sin/rfyj 

 = Q,(a,-a)- 2 T sin 0' (sin 2^' -2 cos 2^')+ — ' ^sin (/)'(sin2^'-2cos2^')-D,T, 



= 2 



= 2 



+ 2 



+ 2 



