[ **> ] 
Fluid will be every-where in t^Equilibrio, if the 
whole Force that a&s at the Pole be to the whole 
Force that a&s at the Circumference of the Equator, 
as the Semidiameter of the Equator to the Semiaxis 
of the Spheroid ; and that the Forces with which 
equal Particles at the Surface tend towards the Sphe- 
roid, will be in the fame Proportion as Perpendi- 
culars to its Surface, terminated either by the Plane 
of the Equator, or by the Axis. Becaufe the centri- 
fugal Force with which any Particle of the Spheroid 
endeavours to recede from its Axis, in confequence 
of the diurnal Rotation, is as the Diftance from the 
Axis, it appears that if the Earth, or any other Planet, 
was fluid, and of an uniform Denfity, the Figure 
which it would aflume would be accurately that of 
an oblate Spheroid generated by an Ellipfis revolving 
about its Second Axis. 
Afterwards the Gravity towards an oblate Spheroid 
is accurately meafured by circular Arcs, not only at 
the Pole, but alfo at the Equator, and in any inter- 
mediate Places; and the Gravity towards an oblong 
Spheroid is meafured by Logarithms. The Gravity 
at any Diftance in the Axis of the Spheroid, or in the 
Plane of the Equator produced, is likewife accurately 
determined by like Meafures, without any new 
Computation or Quadrature, by (hewing that when 
Two Spheroids have the fame Centre and Focus ? and 
are of an uniform Denfity, the Gravities towards 
them at the fame Point in the Axis or Plane of the 
Equator produced, are as the Quantities of Matter in 
the Solids. 
This Theory is applied for determining the Figure 
of the Earth, by comparing the Force of Gravity in 
any 
