<i 
Moving Force. 113 
“mechanics? Every new combination pre- 
‘sented to their minds must have involved them 
in new and repeated labours to ascertain its 
effects ; and these labours must have frequently 
terminated in a conviction that their time and 
pains had been wasted in examining old facts 
under new appearances. Such disappoint- 
ments have sometimes served indeed rather to 
stimulate than to damp their zeal for making 
farther discoveries. But if a good theory in 
physical science be understood to comprehend 
a distinct arrangement of what is known on 
the subject; or if it furnish the means of ap- 
plying the experience of one case so as to 
determine the result of another of the same 
kind, but different in degree, or under different 
circumstances; it cannot be questioned that 
such information must tend to shorten’ the 
labours, and smooth the path of the ingenious 
inventor ; and still more valuable must it be to 
those whose task it is to distinguish the curious 
from the useful, and to carry into execution 
the real but not the fanciful improvements. 
Neither does it appear that Mr. Atwood is 
supported in his opinion, by the history of 
useful discoveries in mechanics. If Huygens 
and Hooke had not been scientific as well as 
ingenious men, we might possibly have been 
P 
