320 A. B. Quinby on, Crank Motion. 
which this difference (if indeed it exists,) may be much more 
oy apes ane properly referre 
ect of the application of the rotative motion by 
the as it is now: known, and mathematically established, 
that it oceasions ‘no loss whatever of the acting power ;” and 
with respect to the smallness of the engines, it is obviously a 
circumstance insufficient to produce the difference stated. 
There must therefore be other causes on which this differ- 
ence depends. Bug what other causes, it will be asked, can 
be sufficient to produce the prodigious difference of. three 
fourths, in the performance of two similar engines? The an- 
swer is plain. It is, first, the injudicious or iment: oe 
tion of the coal consumed; and, secondly, the want of a 
stant and sufficient load in the buckets, during re time “the 
engine is in action. The latter, it is believed, is the chief 
cause on which the pe ae gopep 
ere is now one other thing to aa noticed before I pro- 
ceed further in my pice fe of this reply from the writer 
of the article in the North American Review 
e in the North American 
measure. of the e power of a steam-engine! 
[ now proceed in examining the reply from the writer in 
the North American Review. “ Before Mr. Quinby con- 
cluded,” says this writer, “that a very great blunder was 
made in these estimates, it would have, been well for him to 
_ have hunted up somé information on the subject.” 
In answer to this remark, it is now stated, that the more in- 
formation Mr. Quinby has hunted up on the subject, the more , 
he is confirmed in his original belief that “a very great blun- 
der was committed by those who made the estimates.” 
Tt has already been shown that one of the causes to which 
the difference is attributed does not exist; and the other, it is 
that he must also have peers that the Siplication of the rotative mo- 
tion by the crank occasions a loss of aé least one-third of the whole 
power. And this iaisan had, no dovbt, its full weight with the writer 
of the article i in the North American Review 
* 
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