14 Matter and Motion. 



It follows from this, that when two 

 bodies move over unequal spaces in un- 

 equal times, their velocities are to each 

 other as the quotients arising from divi- 

 ding the spaces run over by the times. 

 If two bodies move over unequal spaces 

 in the same time, their velocities will be 

 in proportion to the spaces passed over. 

 And if two bodies move over equal spa- 

 ces in unequal times, then their respec- 

 tive velocities will be inversely as the 

 time employed ; that is, if A in one min- 

 ute, and B in two minutes, run over 10O 

 yards, the velocity of A will be to that 

 "of B as 2 to 1 . 



It appears, as far as human obervation 

 reaches, to be a settled law of nature, 

 that u all bodies have a tendency, attrac- 

 tion, or gravitation towards one another." 



The same force applied to two differ- 

 ent bodies, produces always the same 

 quantity of motion in each of them. For 

 instance, let a boat, which with its lad- 

 ing is one tun, be tied at a distance, to 

 another vessel, which with its lading is 

 twenty-six tuns ; if the rope that ties 

 tliem together be pulled either in the less 

 or bigger of these vessels, the 



