A. B. Quinby on Crank Motion. 323 
article in the North American Review mean in his sentence 
that contains the words, ‘ no mechanical agent ned 
by the writer of the present eee that the utmost stretch of 
his mechanic and conceptive powers does not enable him to 
comprehend in what way any loss of power can take place. 
I shall now notice the charge made upon me for offering 
my opinion, that “the very frequent attempts to make a 
. ae engine are unnecessary and idle. 
It will be remembered by the scientific reader, that in my 
solution of the crank problem 1 demonstrated, that all the 
power applied at the upper extremity of thie’ shackle-bar* 
is transmitted by the crank to the appending machinery ; or 
which is the same, that the crank occasions no loss whatever 
of the acting power. Now this fact having been established, 
and it being known that no machine can ‘impart more power 
than is applied; and it being also known at the same time, that 
all the attempts that have been made “ to apply the action of 
the steam directly to a wheel,” or to construct rotary en- 
gines, have been instituted with the hope, and for the single 
purpose of obviating the very great loss of power which dif- 
ferent individuals have supposed to result from the application 
of the crank, it was certainly a fair, and tenable, and neces- 
sary conclusion, that all the attempts to construct pee en- 
gines are both unnecessary and idle ; and | have now no he- 
sitation in offering it as my deliberate and devidad opinion, 
that every attempt that shall ever be made to construct a 
rotary steam-engine will prove not only gingers 3 and idle, 
but unscientific ands illy. 
this writer, “ that it is not t for Mr. Quinby to set Rosie to 
the efforts of invention. It is the business of genius to con- 
quer difficulties which, to ordinary men like us, appear in- 
surmountable ; and it may even happen that some of these 
veer efforts, which, on the authority of Mr. Quinby’s opinion, 
are to be considered as unnecessary and idle, will, by being 
* In Europe this is called connecting-rod ; but on this continent, as 
oe as the writer is informed. itis univ ersally called by the name he 
ses. 
