186 On the Measure of 
EFGH and the bodies are supposed to be 
put in motion before the spring is disengaged, 
there is, according to the prevailing theory, 
no motion produced by the spring.—There is 
merely a transfer of motion from C to D, and 
we have only the same motion after, that we 
had before, the action of the spring.—Is there 
not some inconsistency in supposing the spring 
to produce motion in one case but none in the 
other ? 
If instead of the mnequal pressure of a spring, 
an uniform pressure be applied, as in the 8th 
case, the various quantities of mechanical 
force expended at different periods of the ope~ 
ration, will, be more distinctly shown : for, 
the pressure being constant, each portion of 
space through which it acts will express the 
quantity of mechanical power which has been 
‘expended in that space. 
Tn its passage through a space =EH=3 EF 
(Fig. 8) an uniform resistance has. been 
opposed to A, which would bring it to rest in 
a space = EF. When it has arrived opposite 
to Hit has therefore lost. half its velocity ; 
and B having arrived opposite to I by the 
action of an equal. pressure through a, space 
= FL=i HF, has acquired the velocity ss 
. and ‘KG, 2 ee E Y, will i hati a So 
3 
