Mr. Cart-wright's Patent Steam Engine. $ 



circulate through the engine without mixture or diminution, 

 the ufing alcohol, after the firft fupply, can be attended with 

 little or no expence. On the contrary, the advantage will be 

 great, probably equal to the faving of half the fuel . When, 

 indeed, the engine is applied, as Mr. Cartwright occafionally 

 purpofes, both as a mechanical power and as a flail at the 

 fame time, the whole fuel will be faved. 



A farther advantage of this invention is its- applicability 

 to purpofes requiring only a fmall power, and for which any 

 other engine would be too complicated and expenfive. 



Plate I. reprefents a fedion of the different parts of the 

 engine. A is the cylinder, which is fupplied with fteam from 

 the boiler through the pipe a. B the pifton, in the aft of 

 goino- up. I the pipe which conduces the fteam into C the 

 condenfer, being a double cylinder, between which the fteam 

 is condenfed, and from thence paffes through b into the pump 

 D. The pifton D when going down prelTes the condenfed 

 water upon the valve c and (huts it, by which means the 

 water is forced to find a pafl'age through d into the air box E. 

 What air or elaftic vapour may have been driven along with 

 the water into E riles to the upper part of the box, where 

 acting by its elafticitv on the furface of the water, the latter, 

 fliutting the valve h, is forced through the tube/, and by this 

 means returned into the boiler. When the air is collected 

 in fuch quantity as to force the float g to fink to a certain 

 ' depth, the valve e opens, and allows a portion of it to efcape, 



F the fteam valve is opened by the return of the pifton B, 

 which raifes the rod attached to the under fide of F, while 

 at the fame time the valve G is fhut by its rod being prefled 

 againft the top of the cylinder. When the pifton B, prefled 

 down by the fteam introduced from the tube a through the 

 valve F, reaches the bottom of the cylinder, the valve G is 

 opened by its rod touching the bottom, while at the fams 

 inftant tbe fpring z ihuts the fteam valve F. 



HH two cranks, upon whofe axes are two equal wheels 



working in each other for the purpofe of giving a rectilinear 



B 2, direction 



