Moving Force. 217 
of a patient enquirer; and I entreat that the 
too great length of this, I fear tedious, dis- 
cussion may be ascribed to my desire to merit 
the latter rather than the former appellation. 
I cannot help thinking that if this rejected 
_ principle had been first produced, not in oppo- 
- sition to, but as, what I believe it really is, 
an extension of the Newtonian doctrines of 
force, it would have been zealously cultivated 
and might have proved highly interesting to 
mathematicians, as well as of essential service 
to practical men, in explaining those variations 
of force, to the useful application of which 
their operations are chiefly directed. 
If we wish to trace the history of this mea- 
sure of force to its origin, we must go back to 
Galileo. It was first demonstrated by him 
that the spaces described by heavy bodies, 
from the beginning of their descent, are as 
the squares of the times, and as the squares of 
the velocities acquired in those spaces ; and he 
first distinctly explained all the phenomena 
of the motions of bodies uniformly accelerated 
or retarded by constant forces, in their simple 
and likewise in their compound actions. The 
law of continuity appears also to have origin- 
ated with him.—It is most extraordinary that 
both Mr. Robins and Mr. Maclaurin have 
Ee 
