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* t 
Firft then I begin with the Conje&ures. 
Monf. Mairan fay?, that it is as reafonable tofuppofe 
the Earth (if it was once fluid) to have been an -oblong 
Spheroid at firft, as a Sphere:, and that, in fuch a Cafe, 
the Centrifugal Force of the feveral Parts of the Earth, 
arifing from its Revolution about its Axis, which might 
convert a Sphere into an oblate Spheroid, wou’d only 
change an oblong Spheroid into one lefs oblong. 
If the Earth was at firft’ a Fluid, (fuppofed ho- 
mogeneous, and of any given Form,) and left to 
thofe Laws, which we find to obtain at prefent} it muft 
put on a fpherical Figure, for the fame Reafon that 
Drops of Mercury, of Water, and other Fluids, put on 
fuch a Figure. And to fuppofe any Change made in 
that Figure from the Prefture of an external Fluid, filling 
up all Space, is contrary to what has been demonftrated 
by Sir I faac Newton in his Trincipia Lib . %. Prop. if, 
where he ftiews, That if any Portion of a Fluid be 
comprefs'd by the fame or any other homogeneous 
Fluids that Portion will not have its Figure alter'd 
by that Prejfure . 
And indeed we fee, that in the Receiver of the Air- 
Pump, Lumps of Butter, coagulated Oil, or Honey, 
Drops of Quickfilver or Water, &c. have the fame Fi- 
gure, whether the Prefiure of the Air a&s upon them, 
or be taken off by exhaufting the Receiver. 
That a fluid Subftance, of any Figure, will by the 
Gravity of its Parts become fpherical, is plain by the foF 
lowing 
DEMONSTRATION. Fig. I r 
Let A B C D E be a Portion of an homogeneous Fluid, 
whefe Parts tend towards one another, and whofe Figure 
is 
