( * 8 4 ) 
lumns/V and b a, there cannot be an ALquilihrium, till 
the Quantity of Matter in fe , becomes to the Quan- 
tity of Matter in b a, reciprocally as the Gravity at the 
Place a is to the Gravity at e and in that Cafe the 
Height g e will be reduc’d to k e, if k e : c a : : e B x 
e Z : a Ax C. And confequently the Surface of 
the Sea will go thro’ the Points i k b c, where b c under 
the /Equator is higher than i k towards the Poles, 
6KE.T). 
NB. That the Centrifugal Force will fill add to the 
Height of the Sea at b c, is plain from what we 
have faid before. And if we apply thefe ‘Prin- 
ciples to determine the differ eut Lengths of Pen- 
dulums, fwinging Seconds at Paris and at the Al- 
quator } from the Gravity at Paris, compar’d to the 
Gravity at the JEquator (in this Suppoftion of 
the APtion of Gravity and Figure of the Earth') a 
Pendulum muf be jhorter at the ALquator by more 
than io Lines , without confi dering the Centrifugal 
Force \ and if the Centrifugal Force be taken into 
Confederation , the P endulums muft be fhortened 
near a whole Inch. But this being about five Times 
more than agrees with Ob few at ion ; what proves 
too much , proves nothing at all. 
Having thus (hewn, that Monf. Mairari s Account 
of the A&ion of Gravity, on feveral Places upon the 
Earth’s Surface, can be of no Service for reconciling the 
Experiments made on Pendulums,, with the Figure of 
the Earth deduc’d from Monf. Cafifinfe Meafures : I 
proceed to fhew that his Demonftrations are founded up- 
on wrong Principles, And firft, in Relation to Gravity. 
This Gentleman has follow’d Sir Ifeaac Newton , in 
faying, that Gravity increafes in a duplicate reciprocal 
a Pro- 
