344 Mr. Quinby on Crank Motion. 
stration, we shall always find the power and effect equal ia 
quantity, whatever be the machinery by which it is transmit- 
ted, with the exception of the difference occasioned by the 
adventitions causes above mentioned. But if we take as the 
power, that which might be, or ought to be applied in the 
given case, and find the effect less than the power, by a 
quantity, greater than is attributable to friction, &c. the re- 
sult proves a failure, not in the transmission, but in the ap- 
plication of the power. 
Art. XXIII.—Reply of Mr. Quinby, to the writer of the 
Examination of his principle of Crank Motion. 
TO THE EDITOR: 
Sir, —In the recent number of your Journal of Science 
and Arts, I observe what is entitled “ Examination of Mr. 
mane s principle of Crank Motion.” Inthis ‘‘ Examina- 
the writer first undertakes to prove that if the shackle- 
ee ‘mowed parallel to the piston rod, ‘+ there would be a loss 
of power.” His reasoning on this subject requires but one 
remark, If the principle he asserts were true, a machine 
might be made which would be a real “ perpetual motion,” 
which would supersede all other machines in the world, 
and blot out the glory of the inventors of the ship, and the 
steam engine, forever ;—for since P in descending, raises 
the greater weight W, (see his diagram,) through an equal 
— space, it is plain that with but one pound of power, 
e could drive both the bydeanlie works at Marly and the 
in Cornwall ! 
.- "The writer next undertakes to demonstrate, that in my rea- 
soning to prove that the principle assumed by Mr. Ward is 
incorrect, I committed an oversight, which ‘altogether des des- 
troys my “ demonstration of the Crank Problem.” But on 
this subject I may remark, that there is no connexion be~ 
tween strictures on the p rinciple assumed by Mr. West 
Zz ie Se —— this “ ae is, 
