(24 9 ) . , 
« Center of the Earth, yet are they ftill perpendicular 
“ to their Horizons ; and, upon this Account, there 
« cou’d arife no Error in levelling of Lines, and in find- 
« ing the Rihngs and Fallings of the Ground. 
“ Upon this account alfo it will appear, that the 
“ Surface of the Earth is not fpherical, for if it were, 
« then wou’d all Lines, drawn from the Center, beper- 
« pendicular to the Surface of the Earth, fince it is the 
« known Property of a Sphere that >they muft be fo j 
« but I have already fnew’d, that it is not fo in the 
« Earth, and therefore it is plain, that the Earth is not 
« a Sphere. That therefore I may inquire more parti- 
te cularly into the Figure of the Earth, I will refume 
u my former Hypothecs, that the Earth iscompofed of 
cc an infinite Number of Canals, which communicate 
u with one another at the Center, and are all equipon- 
« derant, of which we will confider two, as O Q, and 
« O C, and let O CL be = r, O D = X and D C = jy, let 
« the abfolute Gravity be call’d and the C entrifugal 
« Force at the Equator n. O C is equal to V x a XJV z 
« the Weight of the Canal O Q_ is equal to the abfolute 
“ Gravity of the whole Canal minus the Centrifugal 
“ Force of each Particle contain’d in it, and becaufe the 
“ Centrifugal Force of each Particle is as its Diftance 
« from the Center, and therefore it encreafes in an A- 
“ rithmetical Progreflion, the greiteflof which is n ? 
« confequently the Sum of all the Centrifugal Force is 
“ equal to * n r , but upon the Hypothecs, that Gravity 
« is the fame at all Diflances from the Center, the ab- 
<c folute Gravity of the Canal O CL is / r, and therefore 
“ its real Weight upon the Center O (X is / r ■ — ■ J n r, 
« after the fame Manner, the abfclute Gravity of the 
“ Canal OCis/xV x* y * ; but the Sum of all 
“ the Centrifugal Forces of all the Fluids in the Canal 
O C, is equal to the Centrifugal Force of the Fluid in 
N in “ C D 
a 
