Vol. Ill, No. 7.] Magnetic Induction in Spheroids, 455 



[N.S,] 



but since an = . 



P 



we have 



SFi SFg _ . SF 



or or or 4 



12. From these, the cuustants can be determined, vtz. 



Qo{R) 



or 



A. (l + 4,rfc) ^ + (Bn - 'Lnk C" ) ^ =0, 



13. In particular, Aq= —'2vk Oologl 



1 + 

 1- 



^nd Gq= - 27rmi fl + h^r 



1 -f- 2/x^a 

 8 



cos^ 



-v 



v/1 



- ^' v^^O ^:-^" } ■ 



taken between limits. 



In order to simplify this, we shall assume that tlie wire is 

 wrapped round half the spheroid. This amounts to talcing /i 

 between the limits 1 and 0. 



In this case, "~T (''] f'l'""^-*) 



and C.= -2nmi\ 1 + — log^^^ — ^^-^ 



where uj, C], are axes of the outer confocal. 



If X be the total thickness of the layers of wire, 





ai = a + A, c, = c/l + — 



a.«-a« 



c* 



ell + ■ 



c 



J 1 tiearlj 



/. log-^^ i^logl 1 + - 



c + a 



