144 PROF. H. M. MACDONALD ON THE DIFFRACTION OF ELECTRIC WAVES. 



e~* m for ( )* in the original expression, but, with a view to the special case where 

 n+\ is an integer, it is preferable to use the solutions K B+1/2 (t2) and K n +i /v ( iz); the 

 expressions to be approximated to are 2 1/! 77-"''V /2 K n+1/2 (tz) and 2 t >*Tr~'*z i '*K n +^( iz). With 

 the same notation as when n is an integer 



where R and (f> have the same values as when n is an integer. 



