348 On the expanfive Force of the Steam of Water, &Tc. 



both important and new. The expence of movement in a. 

 fleam engine is compounded of the price of the fluid evapo- 

 rated and that of the fuel. The ufe of water requires no 

 farther expence than that of the fubftance employed as fuel ; 

 but it is poffible that fome other fluid, much dearer in itfelf, 

 may neverthelefs have fuch expanfion, that with an equality 

 of premire the faving in fuel may be greater than the price 

 of the fluid. If the refults from the fleam of alcohol be 

 compared with thofe from the fleam of water, it will be feen 

 that, at the fame temperature, the expanfive force of the 

 fleam of the former is always more than double that of the 

 latter. Much lefs fuel then will be neceflary to produce in 

 a fleam-engine the fame effecl by alcohol ; and if the ap- 

 paratus were difpofed in fuch a manner as not to lofe the 

 condenfed liquor, which would be attended with no great 

 difficulty, it might be ufed with much advantage in certain 

 cafes, and in engines of fmall dimenfions. But, according to 

 every appearance, there are other fluids lefs expenfive than 

 alcohol, which may have an equal or even a greater expanfion ; 

 and it would be a very ufeful object of refearch to determine 

 the mechanical eft'eft of which fleam is fufceptible, and to 

 give tables on that fubjeft, fimilar to that here prefented in 

 regard to water and alcohol. 



The refults given by experiments, of the expanfive force 

 of the fleam of alcohol at different temperatures, are ex- 

 prefled in the fame manner in the following table, as thofe 

 given by the experiments on the fleam of water. 



Tajllv 



