182 « [Assembly 



pelled by steam heated after being generated, is certainly capable 

 of convenient application to the steam engine. Enough, how- 

 ever, was obvious to them to enable them to report that the prin- 

 ciple is in itself true, and that the application of it to practical 

 use is well worthy of careful investigation. 



The experiments described by Mr. Frost, of which a sufficient 

 number were witnessed by the committee to enable them to as- 

 sert that there is no reason to suspect any fallacy in their results, 

 may be divided into two classes : 



1 . Those by which the expansive force and tension of steam, 

 heated after being generated, to which, in the remainder of this 

 report, tl\e name of dry steam will be given, and determined : 

 and 



2. Those by which the relations of dry steam to sensible and 

 latent heat, are investigated. 



In relation to the experiments of the first class, it is proper to 

 premise, that previous to the publication of the experiments of 

 Mr. Frost, it was held and admitted by all scientific men that 

 the vapor of water and of all other bodies did, like atmospheric 

 air, obey tlie law known by the name of the experimenter who 

 first investigated it, Guy Lussac ; and did, in conformity with 

 that law expand 4 loth part of their volume at the temperature 

 of freezing water, for every increase of 1° of Fahrenheit in their 

 temperature. The accuracy of this law, after being received 

 universally for near half a century, has recently been called in 

 question, even in its application to the gases, the experiments 

 under consideration seem to show that it is very far from being 

 true in dry steam. Guy Lussac appears to have been too hasty 

 in admitting the universal application of his law ; and even in 

 the cases whence he derived the inference that it was true of 

 a vapor of water, his experiments, as far as your committee have 

 been able to ascertain, did not extend to the particular points 

 which have been the chief subject of Mr. Frost's investigations. 

 The published results of Guy Lussac, derived from his experi- 

 ments on the vapor of water, extend from 32° F. to 212° F., and, 

 therefore cease exactly where Mr. Frost's begin. Tliere is, 



