104 APPLICATION OF THE PRELIMINARY RESULTS 



^ = 2 



' 



i (i _ m ) f 1 ** 



"" 'o 1 



. cos 





Writing now e""^ 1 "^" 1 in the place of cos (fiyv), we obtain 



provided we reject the imaginary quantities which may arise. 

 In order to transform this double integral let 



and we shall have 







J- ~ o~. I ~ I I T7^ ,Q2\ 1 "~o / I i 2 ) 



the integral relative to z being taken from z = to = . 



2+^ 



The value of 1 #, for iron and other similar bodies, is very 

 small; neglecting therefore quantities which are of the order 

 (1 g) compared with those retained, there results 



' 



where u and v may have any values whatever provided they 



