Miftellanea Cwiofa. 5 5 



place another Globe within it ; and 1 doubt no c 

 but this will find Oppofers enough. I know 

 'twill be Obje&ed, That there is no Inftance in 

 Nature of the like thing ; that if there was 

 fuch a middle Globe it would not keep its place 

 in the Center, but be apt to deviate therefrom, 

 and might pofiibly chock againll: the Concave 

 Shell, to the ruin, or at leaft endammaging 

 thereof ; That the Water of the Sea would per- 

 petually leak through, unlefs we fuppofe the Ca- 

 vity full of Water ; That were it poflible, yet 

 it does not appear of what ufe fuch an inward 

 Sphere can be of, being {hut up in Eternal Dark- 

 nefs, and therefore unfit for the Production of 

 Animals or Plants ; with many more Objecti- 

 ons, according to the Fate of all fuch new Pro- 

 pofitions. 



To thefe, and all other that I can forefee, I 

 briefly Anfwer, That the Ring environing the 

 Globe of Saturn is a notable Inftance of this 

 kind, as havhig the fame common Center, and 

 moving along with the Planet, without fenfibly 

 approaching him on one fide more than the o- 

 ther. And if this Ring were turn'd on one of 

 its Diameters, it would then defcribe fuch a 

 Concave Sphere as I fuppofe our External one 

 to be. And fince the Ring, in any Pofition 

 given, would, in the fame manner, keep the 

 Centre of Saturn in its own, it follows, that 

 fuch a Concave Sphere may move with another 

 included in it, having the fame common Cen- 

 tre. Nor can it well be fuppos'd otherwife, 

 considering the Nature of Gravity 5 for fhould 

 thefe Globes be adjufted once to the fame com- 

 mon Centre, the Gravity of the parts of the 

 Concave would prefs equally towards the Cen- 

 tre of the inner Ball, which equality muft necef- 

 E 3 farily 



