96 ESSAYS ann OBSERVATIONS 
two. It is faid, ‘‘ That when a body is 
“thrown up with a double velocity, and 
** confequently with a double force ; the rea- 
‘fon why it afcends four times its former 
“height, is plainly this, that the counter- 
‘action of gravity, while it has a double 
*‘ force to ftruggle with, has but half the 
“‘ time, in any given {pace, to produce its ef- 
“ fect.” The natural meaning of which is, 
that if a body, thrown up with any velocity, — 
rifes to a certain height in a given time; a 
body thrown up with double the velocity, 
ought to afcend to an equal height in half 
that time. This indeed would hold true, 
if the upward motions could be fuppofed u- - 
niform: but, as a body thrown up, happens 
always to be equably retarded, the real fact 
comes out to be very different. The body 
thrown up with the double velocity, rifes to 
triple the height of the firft body in an equal 
time, and to 2 of that height in half the 
time. Let the height to which the firft bo- 
dy rifes in any time, be called 1 yard; the 
height to which the fecond body afcends in — 
half that time, is 1 yard and 3. The for- 
mer pofition however, as it was only taking : 
a retarded motion for an uniform one, was — 
pretty 
