II INDUCTION IN ROTATING SPHERES 43 Hence these conditions follow for :— In the matter of the shell √² 4 = 2w=3% дъ (a) for ρ (b) = r and p = R аф W = nzXn др Р Əz A solution of these equations is For φ = W n+1 D³(po³xe - naxa). მა nzxn Əz = Xn - 2(2n+1) X^ - 2n³X (§ 1, 4) == Əz Əz Determina- tion of the electric potential. = 2(n + 1) Xn Əz so that the equation for the interior is satisfied. Further, is the product of p+1 by a function of the angles and w, whence it follows that satisfies the boundary conditions. The value of the constant which must be added to the above expression to give the general solution depends in each case on the electrostatic influences to which the shell is subject. We may in any case charge the sphere with so much free electricity as will just make the constant zero, and this we shall in the sequel suppose to have been done. From we get at once W K 2 = K - - w = ய K - 1 a ρ n+1dx მ 1 n+1ǝy 2 όχι Əz nzxn+x- - dz 1 a Əz n+1əz =) + ・nzxn+y- nz Xn +2 Əz Əz Əz } Determina- tion of u, v, 20.