A. B. Quinhy on Crank Motion. 323 



article in the North American Review mean in his sentence 

 that :^;ontains the words, " no mechanical agent whatever," 

 that the loss of power which he imagines, depends upon no 

 part whatever of the machine ? \i he means that it depends 

 upon no part whatever of the machine, it is frankly confessed 

 by the writer of the present reply, 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 

 rotary engine are unnecessary and idle.'' 



It will be remembered by the scientific reader, that in my 

 solution of the crank problem I demonstrated, that all the 

 power applied at the upper extremity of the 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 rotary en- 

 gines are both unnecessary and idle ; and I have now no he- 

 sitation in offering it as my deliberate and decided opinion, 

 that every attempt that shall ever be made to construct a 

 rotary steam-engine will prove not only unnecessary a.nd idle, 

 but unscientific and silly. 



It now remains to take some notice of the last paragraph 

 of the reply from the writer of the article in the North 

 American Review. " It may be obtserved, however,^' says 

 this writer, ''that it is not for Mr. Quinby to set bounds 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 maj even happen that sorr.e of these 

 very 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 

 far as the writer is informed, it is universally called by the name he 

 uses. 



