( j8r ) ‘ 
will be as the Spaces defer ibed. But not therefore as 
the Squares of the Velocities . For in That Cafe, the 
Velocities themfelves are as the Spaces deferibed \ 
becaule the Times are equal. 
When a Body projected with a double Velocity , en- 
ters deeper into Snow or foft Clay , or into a Heap of 
fpringy or elaflick Parts, than in Proportion to its V 
locity ^ ’tis not becaufe the Force is more than pro- 
portional to the Velocity ^ but becaufe the "Depth it 
penetrates into a foft Medium, arifes partly from the 
Degree of the Force or Velocity, and partly from the 
Time wherein the Force operates before it be fpent. 
In the Colhfion of hard Bodies, his (1 think) agreed 
on all Hands, that ’tis demonft rated by Reafbn 9 and 
confirmed by Experience ; that when a perfectly hard 
Ball, moved with whatever Degree of Velocity , flrikes 
full upon another hard Ball, equal in Bignefs and 
Weight, and without any Motion in it * 5 if the Balls be 
unelaftick , they will both go on together the fame 
Way, dividing the Motion equally between them, with 
half the Velocity the nr ft Bali had originally : But if 
they be perfe&ly elaflick , the moving Ball will com- 
municate its whole Motion and Velocity to the quie- 
feent Ball, and it felf lie f ill in the others Place. 
Were it true now, that the Force of the moving Ball 
was as the Square of its Velocity ^ thefe Experiments 
would then lhew (which is infinitely abfurd) that the 
Force or vis inertia in the quiefeent Ball, the dead 
Force, was always proportional to the Square of the 
Velocity (which thefe Gentlemen affect fantaftically 
to call the living Force) of the moving Ball, whatever 
its Velocity were. Or the Force in Both might juft as 
reafonably be fuppofed to be as the Cube , or the qua - 
drato-quadrate, or any other Tower of the Velocity 
of the moving Ball, Which is turning the Nature 
Fffx of 
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