ψ − qFt = ∫ FG − x3y3 Fr dx3,
F2 − x32 √ X3

(17)

elliptic integrals of the third kind.

Employing G. Kirchhoff’s expressions for X, Y, Z, the coordinates of the centre of the body,

FX = y1 cos xY + y2 cos yY + y3 cos zY,

(18)

FY = −y1 cos xX + y2 cos yX + y3 cos zX,

(19)

G = y1 cos xZ + y2 cos yZ + y3 cos zZ,

(20)