( z 94 ) 
Places where they are, {fuppofing the Horizons of Places 
to be Planes touching the Curve of the Earth in thofe 
Places) and Plumb Lanes wou’d be fo fa r out of the 
Perpendicular to Lines of Level, as to make an Angle 
eafy to be obferved, as 1 have fhewn in my former 
Paper. 
But if the fame Caufe be fuppos’d to act upon the Sea 
to make it level, as makes heavy Badies to fall (which 
certainly muft) then indeed Lines of Level will be per- 
pendicular to Plumb Lines, and the Level of the Sea, 
taken always for the Horizon of a Place, will not be a 
Plane touching the Earth, but cutting it towards the. 
Poles, and confequently the Water will be carried to- 
wards the ./Equator, as was before (hewn. 
Befides, theDiflference of the Action of the Centrifugal 
Force wou’d notbefo great between correfpondent Points 
of the fame Latitude in the Spheroid and in the Sphere * 
tor when the Line of Tendency R P is by the Centri- 
fugal Force chang’d into R W, the Point R upon the 
Spheroid does no longer correfpond in Latitude with 
the Point V upon the Sphere, but muft be taken nearer 
to V, fo that the Line R W may become parallel to 
V C, and R W A = V C A. 
If it be aliedged here, that Monf. Mairan fuppofes 
the Earth in Motion, and takes in the Effe&of the Cen- 
trifugal Force, when he makes the Line of Tendency 
to be R P j I anfwer, that if he had conftder’d the Earth 
as revolving upon its Axis, he wou’d not have made V C 
the Line of Tendency of a fpherical Earth in Motion, 
finceit is the Line of Tendency of fuch-an Earth at 
reft. 
In Monf. Mairan's Obfervation above-mentioned, he 
fays, Ct that we are not to compare the Centrifugal Force 
at the /Equator of an oblong Spheroid, with the Cen- 
trifugal force at the /Equator of a Sphere, or at the 
•/Equator 
