THE ABSOLUTE INTENSITY OF INTERFERING LIGHT. 327 



Integrating for y we obtain, 



ab\ fff , ( 27T / . n 

 Vlbratlon = ^ 9 d* { cos ^ (vt. - B 



_ cos Yt _ B + + cos (vt. -B - 



Integrating for x, it gives 



o> 6 s X 2 f 1 F" . 2 TT / 



47T 2 Dy IJO + /L ~X"V V 



^ 





-. 

 2 TT- D 



f^^ 

 < X 



t ,_- 



,_ 

 7T 2 Dq X 6 < X Z> _ X V 26 



sm ^- v ~ ^-^ sin 

 X o 



/a 6 2 X 2 . . ( 



intensity = (^ m ^- sm - cos 



sn C os 



sn 

 X 6 > + X b X 6 



/-/ J P+f 



VOL. XV. PART II. 



