338 



Patent for certain Improicmcnts 



Table of the relative prcssrires per square inch, teniperatures 

 and expansiHrUy of steam at degrees of heat above the 

 Imliifg point rf water, hegnming ji'ith the temperature of 

 steam of' an elastic force equal to fve pounds per square 

 inch, and extending to steam able to sustain fortrf pounds- 

 on the Square inch. 



Pounds per 

 square Inch. 



Steam of an 

 elastic force 

 predomi- 

 nating over 

 the pressurc<( . ^ 

 of the atmo- 

 sphereupeu 

 a safety- 

 valve, 



requires to 

 be main- 

 tained by a 

 tJmpera- ' 

 turc equal 

 to abotit 



Degrees 

 of Heat. 



f227n 

 230^ 



2354 



L40. 



239', 

 2.50| 

 2591 

 2t77' 

 27.'> 

 278 

 .282 , 



Expan- 

 sibility. 



•51 

 G 



and at these 

 respective 

 degrees of 

 £ ^heat, steam ■{ 

 can expand 

 itself to 

 about 



times Its 

 volume, and 

 continue 

 eq\wl in 

 1 5 1' elasticity to 

 20 ! the pressure 

 25 oflheattno 

 30 sphere. 

 35 

 .■iO.. 



And so in like manner, by small additions of Icm.pcra- 

 tiire, an expansive power may be given to sLeam to enable 

 it to expand to fifty, sixty, seventy, eighty, ninety, one 

 hundred, two hundred, three huvidred, or move times its 

 •Volume, without any limitation but V/'hat is imposed by the 

 frangible nature of every material of which boilers or other 

 parts of steam-engines have been or can be made ; and pru- 

 dence dictates that the expansive force should never be car- 

 ried to the utmost the materials can bear, but rather be kept 

 considerably within that limit. 



Having thus fully explained my discovery of the expan- 

 sive power and force of steam, 1 shall proceed to describe 

 my improvements grounded thereon ; and in so dolns;, I 

 shall find it necessary to mention the entire steam-engine,; 

 and its parts, to which, as an invention well known, I nei- 

 ther can nor do assert any exclusive claim ; but at the same 

 time I must here observe, that, from the nature of my said 

 discovery, and its application, there can be no difficulty in 

 distinguishing my said iniprovements from the improved 

 engine, as to its other common and well known component 

 parts. 



1st. If the engine be constructed originally with the in- 

 tention of adopting rny said improvements, it ought to have 

 two steam-vessels of different dimensions, according to the 

 temperature or the expansive force determined to be com- 

 nnmicated to the steam made nse of in working the en- 

 gine ; for the smaller stoain-vessel, or cylinder, must be a 



measure 



