118 Prof. S. Banerji on the Radiation of Light 



Thus, when x is large, 



#— 1 sin (%— rl 



J.w = V^ L cos (' c -i) + 8 — s~' J' 



T ,, /Tr. / *x 3 cos ( A -I)-i 



JiW = V - [ sin (— s)+ g - ~ir ~ J- 



Therefore 



2tt 27T 



k 2 sin -^ 0/r -</>')# ^ ^n 2 cosy(^ + (^) 



Z7T ^ Rl # 



27T 



K 2 COS— (yjr — (p')x 





2tt 



X* /J_3\ f B ^in-(^+^> ^ 



I 2 

 + terms involving higher powers of X . 



Taking Ri = o — p ^ 2 = 9 — T' we 0D ^ n (neglecting a 

 constant factor), 



-{Ci50(l + |)-Ci3(l + |)} 



-( •)--]■ 



Calculating the values of this expression for different 



values of ~, we construct the following table (Table I.). 



Plotting the values, we obtain a curve (fig. 1) representing 

 the distribution of intensity along any given diameter. The 

 fringes that appear on either side of the boundary are clearly 

 shown, the most remarkable feature being the extreme 

 rapidity with which the intensity falls practically to zero on 



