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<c Sir Ifaac Newton makes the Earth higher at the 
■ c Equator, and, confequently, flatted towards the* 
<c Poles, reckoning its Equatorial Diameter 34 Englifh 
“ Miles longer than the Axis j which he proves from 
the Principles of Gravity, and the Centrifugal Force 
“ that arifes from the Diurnal Rotation of the Earth* 
“ and, to confirm this, mentions feveral Experiments’ 
“ on Pendulums, which have been made fhorter to 
“ fwing Seconds, near the Equator, than in greater 
“ Latitudes.” 
i Thefe are the two Opinions which have divided 
Philofophers, and which we propofe to examine here. 
Monfieur Caffini , taking the Meafures above-men* 
tion d to be cxadl enough, not only to determine the 
Magnitude of a Degree of the Earth, correfponding 
with a Degree of the great Circle of the Heavens, but 
alfo to {hew the Difference in the Degrees of the Earth ; 
(reckoning thofe, that were foeafured in the South of 
France , to exceed thofe towards the North, by a 
certain Number of Toifes and Feet) demonftrates, that 
if the Degrees of the Earth are longer towards the 
Equator than the Poles, the Plane of the Meridian 
muff be an Ellipfe, whofe long Axis is that of the 
Earth. Here follows his firfl Demonftration. [See the 
French Memoirs for the Tear 1713 ] 
“ Let B D C R * be an Ellipfe that reprefents a 
“ Meridian of the Earth, whofe Poles B and C are at 
“ Ends of the great Axis B C, and whofe Foci E and 
“ F are taken at Pleafure. Now, to divide this 
“ Ellipfe into ‘Degrees, that is , to find feveral 
Points H, 1, V, fitch , that the Difiance, from the 
kC Pole to the Zenith , of every one of them, Jh all 
<( he of any given Number of Degrees. 
(C 
* Fig. 1. 
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