and acts equally, on all bodies according to their densi- 

 ties : it is perpetual, subject to no decay, needing no 

 reparation. But projection is a motion "given tcTt! .e. 

 body contrary to its nature: when given it would 

 always continue in a strait line, if nothing hindered if, 

 but cannot remove any obstruction without losing part 

 of its own force. Now the obstruction given by attrac- 

 tion must have the same effect as obstruction given by, 

 air or ether : it must continually lessen any projectile 

 force till that force is totally destroyed. 



f< A mortar elevated forty-five degrees, ejects a 

 at iirst in or near a right line, while the projectile 

 force is. vastly superior to the attractive, afterwards in a, 

 curve : for the moment the two. forces are in equiiibrio 3 

 in a segment of a circle : then in a curve less and less.. 

 bent, till it falls in a right line, to the centre of gra- 

 vitation. 



"This. is. the nature of all projectiles; nor ean any pro-, 

 jectile, thrown in any direction by any force of attrac- 

 tion, produce a circular motion : much less an elliptical 

 one, such as that of the earth. Besides, what physical, 

 reason can be assigned why the earth, being nearer the 

 sun in winter, the gravitating force does not increase; 

 and why the projectile does not increase in summer, 

 when it is farther from the sun, to the entire destruction 

 of one or the other. 7 



" A third motion also is supposed to be primarily im- 

 pressed on the earth, namely round its own axis. But no- 

 thing can be more plain than that a body so strongly at- 

 tracted by the sun as to keep it from flying off in a tangent, 

 must have its circular motion presently stopt ; as the 

 side ntxtthe.sun must be attracted most, the attraction 

 of all the planets co-operating theiejto. 



" To make this p-a'n, I hung a loadstone to a. small 

 string, and gave it as many turns as would continue its 

 revolving motion ten miuutes and a half, whew up iron, 



