and Electromagnetic Theory. 341 



When p is little greater than 1, each polarization gives 

 approximately 



" 1 f-l R _l_ 8 , , 



Bi= 2-~i2"' Bs= 3 m^ 1] > 



A At 2 — 1 A 8 , a uvS 



1-e . At-^j-, A t - 15g 0,«-l).. 



Hence the values of the ratios 



B 2 :B 1= ~, and A 2 : A 1= || ^V-l. 

 "When /a is indefinitely great, 



T* '- 4 T* '_ 1 Tl"- 4 ti " 2 • 



*>! = ^— , I> 2 = — , 15!=— ±5 2 = — » 



OyU. //, /Lt , fX 



and for the means 



Bi= v B2= v' 



Since Aj + B, = J, A 2 + B 2 = ^, the ratios are 



B 2 : Bj= jg and A 2 : A 1= g. 



The formula for pressure %(§— B 2 ) gives for /x little greater 

 than 1 the value 



xU + IQ^ 2 - 1 ) 1 -} 



and for /x very great 



*13 2/a J 



The notion of interpreting the two sides of (14) in a 



similar way so as to count a term ^ — n f, \J f, dn fr d<f> 



with the terms of the other side in the mechanical rate of 

 working was rejected, cf. § 5. The consequences of such an 

 interpretation may be noted. The main term in pressure 

 when statical values are introduced, as for (20), is then 



|rjj W + A 2 ) -n"B*/p\ndn #, 

 and the new term means a back pressure from the dielectric 



