18 Mr Basset, On the Potentials of the surfaces formed by [Oct. 25, 
wade Ky aK) 3 ; 
enya eG) aye) ee (38); 
whence the attractions can be at once written down. 
Secondly, let R, R’ be the components perpendicular to the 
axis, then 
es | “F. (0) K,Q) I, (an) J, (06) a, 
R=] FQ) £0) K, Qn) J, Ae) dD 
and at the surface, 
dR dR’ _4nr 
i ae ae Mm. 
By (26) this becomes 
[ F (x) J, (A€) dn=— Tim PAR ero. | 
0 C 
Now — m= cos ae 
2 
ese, 
i na 
Therefore (39) becomes 
Aare (&° — 3) & 
BK (AE) dX = = - 
J, F005. 08) n= ea, 
ra? (a? — dae (a — 8) 
Age a I Pee Is Oa) J, (06) dadr 
Let u=[ oS aes Gee ae (Xa) da 
pas wept! OO Gee 
Now by (33 a) 
a 8 (Pa? J, (Aa) d 
K (A) | 2 os a = 
Let X= @, then 
K, (A) = sr | aera 
