II 57 = INDUCTION IN ROTATING SPHERES Ωμ 2πα ° ' + Σπα - = k მუ k an Ω. Q_(-5)= −2+(5) 1 = Ω 2π + · Second form of the solution. This series leads to as accurate a result as we please, if only it be carried far enough; in fact it is only the develop- ment of the result in ascending powers of 2πa/k, as we may show in the following way. In the spherical shell the part of N, corresponding to X(-n-1 may be represented in the form (p. 52) d 1 (½ 2 x + x²x). Ωρ = 1+h² i dw h= = 4Rwi (2n+1)k If we again introduce the substitutions to be made in the case of a plane plate, develop 1 = 1-h²+h-h® + ..., 1+h2 and put for h its value 2πα τ k n we get Ω 2πα 1 δχτε 2πα + k n an k 1 3xx - (2x) = x + (2x) = Xrs k ns an θη 2πα 4 με + k from which development the preceding one follows when we use the relations Xrs d5 = Xrs, 22 Xrs - p² Xrs › an² n and sum for all values of r and s. L