Propagation of Disturbance in a Dispersive Medium. 163 



Fi-. 1. 



Using an integral expression for J 2r , and writing x for ra 

 we have from (8), 



= I eos < ~ (.c<p — ctsm(p) \ dp 

 77 Jo L^ J 



7T 

 = l\\o*\K( X -\>)\d K , ..... (II) 



where 



.'o 



v _ s in (±tca) 



Ka 



312 



