ejsential to Matter, &c. 55

is there any thing more absurd than that a-ny number of degrees of celerity, abstractly

considered,

farther, I cannot help thinking still, that what is heresaid about the force of bodies is very evident to any one,even in the simple coarse way it is deduced in this pa-ragraph : great men have shewn it in a better way, anddemonstrative form. All sides, I think, grant that theresistance any body, as A, makes to be moved, is thefame with the resistance it makes to be stopt again :but if that were as the squares of the velocities, the bo-dy A would make four times the resistance to be mov-ed with 2 C, as it doth to be moved with i C; andnine times that resistance to be moved with 3 C; 16times that resistance to be moved with 4 C, &c. Butthis is extremely absurd; for, from the same reason thatA resists any change of its state of motion (or rest) at all,it resists equal changes equally: and, as I have said inthisN 0 ig, A moving with 1 C, is as much at rest withrespect to A moving with 2 C, as A moving with o C is toA moving with 1 C; or the changes from rest to motionare equal: and therefore contrarily, from motion to rest.

Besides, it is a standing theorem in mechanics, thatthe state os the center of gravity , rejiing , or moving uni-formly forward , is not changed from the aBion of bodiesamong themselves , or their snack oh each other. Nor isit less evident that 2 A moving with the celerity C,hath twice the force of once A moving with the famecelerity. Now supposing A moving with the celerity2 C, to encounter directly 2 A moving with once C>the center of gravity rests before the shock: but since(on this supposition) the contrary moments are as 4 and

E 4 24 the