Moving Foree: 225 
In his definition of power (which I have 
quoted at page 129) he refers only to its 
effects in producing motion. But we havé 
seen that he understands the same measure to 
be the proper one, whether the force be ex- 
pended in producing motion or change of 
ficure, and he concludes that the effects of 
force “ cannot be so easily, distinctly, and 
fundamentally compared, as by having’ re- 
course to the common meastire; viz. mechanic 
power.” * 
If this principle be capable of such general 
application, it is desirable that it should be 
denoted by a distinct term, in order to 
obviate ambiguity or misapprehension. The 
compound term moving force has been com- 
monly applied, Ly various authors, to signify 
the action of moving pressure, as distinouished 
from qiiiescent pressure ; and from its general 
use in this acceptation, I have been induced to 
adopt it. 
It is sometinies indeed used for motive force, 
or the pressure uncembined with time or with 
the space through which it acts. But the two 
terms need not be confounded, and if moving 
force were defined to be “ moving pressure 
producing change of velocity; or change of 
figure in masses’ of matter,” it could not be 
* Philos. Trans, 1776, p. 4730 
Rf 
