162 Steam-Engine— Physics, tf-r. 



When those who are acquainted with steam-engines of the 

 atmospheric kind only, are told that Morey^s cylinder revolves, 

 their imaginations may suppose a moving mass as large as the 

 enormous cylinders they have .been accustomed to see : but it 

 is not so ; the elastic force of steam requires machinery but of 

 comparatively small dimensions. 



The revolving engine makes up in activity what in other 

 engines is supplied by magnitude. 



We will take for example the engine working at the glass 

 manufactory, in this vicinity, the cylinder of which has one 

 foot stroke and nine inches diameter, and is at least a ten horse 

 power, working with fifty pounds — or, the engine now build- 

 ing for the Hartford boat. This engine will have two cylin- 

 ders of seventeen inches diameter and eighteen inch stroke ; 

 they will revolve fifty times a minute. The area of the piston 

 in each being 227 inches, steam at fifty pounds will give an 

 hundred horse power. 



This boat is seventy-seven feet long, twenty-one feet wide, 

 and measures one hundred and thirty-six tons. The engine, with 

 its boilers, will occupy sixteen feet by twelve, or one-eighth 

 only of the boat ; the cylinders being hung on the timbers of 

 the deck over the boilers. She is principally intended to tow 

 vessels up the river to Hartford. 



In towing, it is of importance that the engine admit of any 

 inferior velocity or power, till some momentum is had. An 

 engine working by atmospheric pressure does not admit of this. 

 And as the boat herself, at the moment of commencing the 

 operation, may have no steerage-way, by placing two blade- 

 rudders at the sides, behind the water-wheel, where a current 

 is occasioned by them, the boat is kept in her relative position. 



The application of the steam-engine to the towing of other 

 vessels was fully appreciated by the late Mr. Fulton, whose 

 conspicuous labours and enterprise . in the establishment of ' 

 steam-boats, the public duly honours. His active mind had 

 conceived of its utility ; and he would have obtained a patent, 

 had not the previous employment of steam in this way, and 

 the award of arbitrators on the question been in my favour ; 



