488 



ILLUSTRATIONS OF THE 



Note xxv. 



130 



Figure of the Earth, 



F 



tb 



428. That the earth is a fpheroidal body^ 

 comprefTed at the poles, or elevated at the equa- 

 tor, is a fad eftablifhed by many accurate expe- 

 riments ', and though thefe experiments do not 

 exadly coincide, as to the degree of oblatenefs 

 which they give to that fpheroid, they agree fuf- 

 ficiently to put it beyond all difpute, that the 

 earth, though folid, has nearly the fame figure 

 which it would affume if fluid, in confequence of 

 its rotation on its axis. 



Now, it is not at all obvious, to what phylical 



fe 



phenomenon is to be afcribed 



earth, as it 



fts at p 



ditions that rend 



the 



gure of equilib 

 Conftituted as 



The 

 f the 

 ffumption of the fi- 



h 



none o 



parably 



•iuni in any way neceflary to it. 

 t is, its parts cohere with forces 

 00 great to obey the laws of fta- 

 tical preiTure, or to aiTume any one figure rather 

 than another, on account of the centrifugal ten- 

 dency which refults from its revolution on its 



There is no neceffity that its fuperficies 



r 



Hiould be every where level, or perpendicular to 



the diredion of gravity, nor that every two co- 

 lumns. 



axis. 



<\' 



il 



ft 



\ 



P 



