Drawing KM vertical and KN parallel to OC', then

(2) KM = A d[psi]/dt, KN = CR - A cos [theta] d[psi]/dt

= (C - A)R + A d[phi]/dt

so that in the spherical top, with C = A, KN = A d[phi]/dt.

The velocity of H is in the direction KH perpendicular to the plane

COC', and equal to gMh sin [theta] or An^2 sin [theta], so that if a

point in the axis OC' at a distance An^2 from O is projected on the

horizontal plane through C in the point P on CK, the curve described

by P, turned forwards through a right angle, will be the hodograph of

H; this is expressed by

(3) An^2 sin [theta] e^{([psi] + 1/2[pi])i}

= iAn^2 sin [theta] e^{[psi]i} = d/dt ([rho]e^{[pi]i})

where [rho]e[varpi]i is the vector CH; and so the curve described by P

and the motion of the axis of the top is derived from the curve

described by H by a differentiation.

Resolving the velocity of H in the direction CH,

(4) d.CH/dt = An^2 sin [theta] sin KCH = An^2 sin [theta] KH/CH,

(5) d.1/2CH^2/dt = A^2n^2sin [theta] d[theta]/dt.

and integrating

(6) 1/2CH^2 = A^2n^2(E - cos [theta]),

(7) 1/2OH^2 = A^2n^2(F - cos [theta]),

(8) 1/2C'H^2 = A^2n^2(D - cos [theta]),

where D, E, F are constants, connected by

(9) F = E + G^2/2A^2n^2 = D + G'^2/2A^2n^2.

Encyclopaedia Britannica, 11th Edition, "Gyantse" to "Hallel" Volume 12, Slice 7 · 第 15 / 53 题