( *99 ) 
DEMONSTRATION. 
Suppofe fuch an oblong Figure as A a* fix’d to the 
Axis XI p at the Center C, but capable of moving freely 
round it towards P or towards /, yet fo as to be oblig'd 
to move with the Axis, when it is turned round. Sup- 
pofe now the Poles P and p to be fix’d, and the Body, 
thus conftituted, to be turn’d fwifdy round the Axis 
P/ ; then if the Angle AC P be oblique, and the Fi- 
gure A D a E be- oblong, the Parts A C and C a will ac- 
quire a Centrifugal Force, which will enlarge the Angle 
P C A, till it comes to be a right one. Befides this, a 
Velocity will be generated in the Motion, while A is 
going towards the Perpendicular a C, which will make 
it go farther on towards P, as to B, with a Motion which 
will after that be retarded, till the Centrifugal Force has 
Strength enough to fend it back again the contrary Way y 
and fo it will move continually with a reciprocal Mo- 
tion, like the Ofcillation of a Pendulum j and if a little 
of this Motion be loft at every Ofcillation, then the ob- 
long Figure AD^E will at laft move quietly about 
its lefier Axis DE coinciding with Pp. . 
If A a did not at firft exaClly coincide with F p, 
the Centrifugal Force will have the above-mentioned 
Effect ; and that this is not the Cafe in the Earth is 
more than probable, becaufe the. unequal IXifiribution 
of Sea and Land , befides' the Phenomena of the Tides 
?mift make the Axis of its Gravity, and confequently 
the Axis of its Revolution , to differ from the Axis 
of the oblong Spheroid, if the Earth had fuch a FT 
gure^ without confidering that every Earth-quake 
woFd alter fo nice an /Equilibrium, which once loft , 
w oidd never be recover’d again. 
