32 LIFE OF SADI CARNOT. 



publish it, and bring himself out of his voluntary 

 obscurity. 



In fact (as his working notes prove), he per- 

 ceived the existing relation between heat and 

 mechanical work ; and after having established the 

 principle to which savants have given his name, 

 he devoted himself to the researches which should 

 enable him to establish with certainty the second 

 principle, that of equivalence, which he already 

 clearly divined. Thermodynamics was established 

 from that time. 



But these researches were rudely interrupted by 

 a great event the Revolution of July, 1830. 



Sadi welcomed it enthusiastically not, however, 

 it is evident, as a personal advantage. 



Several old members of the Convention were 

 still living, even of those who had become cele- 

 brated ; no favor of the new government was 

 accorded them. To the son of Philippe-Egalite 

 was ascribed a saying which, if it was untrue, at 

 least agreed well with the sentiment of his posi- 

 tion: "I can do nothing for the members of the 

 Convention themselves," he said, "but for their 

 families whatever they will." 



However it may be, some of those about him 

 vaguely questioned my brother as to his desires in 

 case one of us should be called to the Chamber of 



