( *91 ) 
the Centrifugal Force acls, muft alter the Line of Ten- 
dency R P, and change the Diredion R P into R W, 
fome where between the Point P and the Center C j for 
if there be a heavy Body as a Plummet, hanging by a 
Thread in the Line S R, or S P, the Line of Tendency 
which has been fuppos’d perpendicular to the Curve 
ARD, without taking in the Effed of the Centrifugal 
Force ’ as foon as the Spheroid revolves about its Axis, 
the Body which wou’dfali in the Line S R, aded upon 
only by one Force, namely, that of Gravity, will now 
be aded upon by another Force, attne fame Tune pufh- 
in? it in the Line S s (which is the fame as R r) and 
confequently will move in the Line S v , diagonal of the 
Parallelogram s S R r \ or, which is all one, a Body plac d 
at R will have its Line of 'Tendency in R W, as 1 have 
already (hewn in my firft Differtation on this Subjed j 
only 1 did not fuppofe the Earth a Spheroid before the 
diurnal Motion, and therefore made ufe of the Line 
Z V inftead of the Line N R ; fothat it may be objeded 
that the Angle r SR will not be fo great in a Spheroid 
as in a Sphere, becaufe the Centrifugal Force which ads 
with the fame Obliquity (fince NRP = ZV C) is as 
much lefs in the Spheroid as N R is lefs than Z V: But 
I was aware of that, and therefore made the Angle 
R S r only of 5 Minutes, when it really appears to be of 
almoft fix Minutes, when the Earth is fuppos’d fphe- 
rical ; and therefore, without coming to give the exad 
Quantity of the laid Angle, one may eafily perceive, 
that Monf. CaJJini ’s Difference of the Axis and Equa- 
torial Diameter will produce a Figure, in which the 
Angle R S r, will not be lefs than of y Minutes. 
Such an Obliquity, caus’d in the Diredion of Gravity, 
will render the oblong fpheroidical Figure of the Earth 
impoflible, becaufe then Fluids wou’d not have the Lines 
of their Gravity perpendicular to the Horizons of the 
Vol. XXXIII. T t Places 
