( *97 ) 
Pendulums will be greateft at the Equator of the ob- 
long Spheroid, b'ecaufeg s — c is the greateft Quan- 
tity. 
Faflly, To compare the Lengths of Pendulums at 
the /Equator of the oblong Spheroid, thus found; with 
their Lengths at the Latitude of Paris upon the faid 
Spheroid — Let us exprefs the Excefs of Gravity at the 
./Equator, whereby it is greater than at ‘Paris (becaufe 
in this Figure, Paris is farther from the Center of the 
Earth, than the ^Equator, by tI? Part) by the Lei ter s, 
and the Excefs of the Centrifugal Force at the /Equator, 
above that Part of it which ads diredly againft Gravity 
at Paris , by l m n } the Gravity at Paris by g, 
and the Centrifugal Force at the /Equator by c j then 
g s ~~c will ff ill reprefent the diminilh’d Gravity, 
and anfwerto the Length of Pendulums at the /Equator, 
whilft g — c — l + m + n or g — c 4* / -|- m -f- n re- 
prefents the diminifh’d Gravity, and consequently the 
Length of Pendulums at Paris . If s be equal to Iff- m 
-f- n. Pendulums will be as long at the Equator as at 
Paris ; and if s be greater than / -{- ^ 4. Pendu- 
lums will be longer at the /Equator. But making all 
poflible Allowance, in Favour of Monf. Mairan’s Hy- 
pothefis, no Calculation will bring l-\~m + n to be 
greater than, or ever equal to /. Therefore Monf. 
Mairan'i Demonftrations, above-mentioned, are of no 
Force to prove the Earth to be an oblong Spheroid. 
And now , I think, I have anfwerd all that relates 
to the Figure of the Earth in Monf Mai rand Differ- 
tat ion \ in J hewing , That his Conjectures can neither 
be fup ported by thofe Phyfical Principles which Sir 
Ifaac Newton has Mathematically deduc’d from un- 
• queflioned 
