30 a Mifcellanea Curio fa. 



A Difcourfe concerning Gravity, and 

 its Properties, wherein the T)e- 

 fcent of Heavy Bodies^ and the 

 Motion of Proje&s is briefly , but 

 fully handled : Together with the 

 Solution of a Problem of great 

 Vfein Gunnery. By E. Halley . 



NATURE, amidft the great Variety of 

 k Problems , wherewith She exercifes the 

 Wits of Philofophical Men, fcarce affords any 

 one wherein the Effect is more vifible, and the 

 Caufe more concealed, than in thofe of the 

 Phenomena of Gravity. Before we can go a- 

 lone, we muft learn to defend our felves from 

 the Violence of its Impulfe, by not trufting the 

 Center of Gravity of our Bodies beyond our reach j 

 and yet the acuteft Philofophers, and the fubti- 

 left Enquirers into the Original of this Moti- 

 on, have been fo far from Satisfying their Rea- 

 ders, that they themlelves (eem little to have 

 underftood the Confequences of their own Hypo- 

 thefes. 



Des Cartes his Notion, I muft needs confefs 

 to be to me incomprehenfible, while he will 

 have the Particles of his Cxleftial Matter, by 

 being reflected on the Surface of the Earthy 

 and fo amending therefrom, to drive down in- 

 to their Places thole Temftrial Bodies they find 



above 



