110 II INDUCTION IN ROTATING SPHERES the direction of its motion.¹ Let the coordinates of the pole be 0, 0, c; then its potential is - 1 x= √§²+n²+(5+c)² 1 =- Thus the induced potential of the first order becomes for positive 01 - k 2πα όχας მუ = Σπα n ' +n† 8+0 1 Hence we get for the potential of the second order Ωρ = - 2πα (ΘΩ. k an = 2πα)² ((+c − r)n` _/ \_ ફ઼ + m k θη §2+n² n Σπα 2 1 ( n² = k §² + n² 1 2(5+ 2 §² + n² + c − r) - 12² } . r › In the same way the calculation may be continued. We get for the current-functions of the first and second orders α η × = 1 = 7, (1-1) = = + n² a α η kr(r+c)' - 2x (2) - ++² + cm² - where now r² = §² + n² + c². k) (r² − c²)(r+c)r' In the n-axis we have (since = 0) - Displace- thus 42 = - 2 a C 2π = (k) (r + c)r' a 1 k (r+c)r We may regard the point = 0, η - = 2παι k 0 as the centre of ment of the the distribution: thus it appears displaced through a distance induced distribu- tion. 1 a then becomes positive. 2 This result agrees exactly with that obtained by Jochmann.