C 416 ] 
T r x dC D 
follows Art. 1 2. which gives dt~ x = — = x 
2 7 r CD x <&D 
T 
(1 — A b x %uu) y and the inftantaneous varia- 
27Tg 
tion of the inclination of the earth’s axe to the ecliptic 
will be^rx — Kudu x(i — A b x — — x u u\ 
2 7T 2 Tg 
whole integral, when the fun arrives at the folftice, 
where we have r u = a y becomes 7 A a av. 
T 
A a‘ 
T T 
x x A bx = ( becaufe g 
2 -rrr 2 7 rg 
2 7r r 
-t) 
T , T 
\ A a a x x ( 1 — 
27 rr 
the formula to be made ufe of when the motion of 
the nodes is fenfible. 
A b x — — J j and this is 
27 rrA 
SECT II. 
Of the motion of the pole of the equator of 
the earth caufed hy the a&ion of the moon. 
1 6. Whatever has been faid in SeB. I. of the pre- 
ceffion, and of the ofcillation of the earth’s axe on 
the plane of the ecliptic, through the action of the 
fun, is equally applicable to the adtion of the moon ; 
it being requilke only to fubftitute every-where 
the moon inlfead of the fun ; L inftcad of S, and 
A inftead of s ; the time which the moon em- 
ploys in completing her revolution about the earth, 
inftead of the time the fun employs in performing 
