The dynamical equations (4)...(9) can now be reduced to

X dq

(18) -- = - -- z - p^2z cot[theta] + q^2(x - [rho] sin[theta])

M dt

+ prx cot[theta] - g sin[theta],

Y dp dr

(19) -- = -- z - -- x - pq(x + z cot[theta] - [rho] sin[theta])

M dt dt

+ qrp cos[theta],

Z dq

(20) -- = -- x + q^2(z - [rho] cos[theta]) + p^2z - prx - g cos[theta],

M dt

dp

(21) -zY = A -- - Apq cot[theta] + qh3,

dt

dq

(22) -zX - xZ = A -- + Ap^2 cot [theta] - ph3,

dt

dh3 dr d

(23) xY = --- = C -- = -Cq --------.

dt dt d[theta]

Eliminating Y between (19) and (23),

/C \ dr dp

(24) (-- + x^2) -- - xz -- + pqx(x + z cot[theta] - [rho] sin[theta])

\M / dt dt

- qrx[rho] cos[theta] = 0,

/C \ dr dp

(A) (-- + x^2) -------- - xz -------- - px(x + z cot[theta]

\M / d[theta] d[theta]

- [rho] sin[theta]) + rx[rho] cos[theta] = 0.

Encyclopaedia Britannica, 11th Edition, "Gyantse" to "Hallel" Volume 12, Slice 7 · 第 25 / 53 题