PHYSICAL andLITERARY. 67 



its upward motion is fpent. And, indeed, 

 by prolonging the greater axis indefinite- 

 Iji an ellipfe coincides at laft with a 

 ftreight line ; and the motion in the for- 

 mer coincides with the motion in the 

 latter. Confidering then that gravity 

 and the vis iriyta are the two powers 

 which govern motion in the curve as well 

 as in the ftreight line, it muft follow, 

 that the law of motion is the fame iii 

 both. 



Of 



