H. V. RegnaulL 



271 



In 1841 he was appointed professor of physics in the 

 college of France. 



It was at this time that he began what became the great 

 work of his life. The experiments which constitute this 

 work were instituted at the request of the minister of 

 public works who proposed the following problem : To 

 determine the principal laws and the numerical da'a which enter 

 into the calculation of the work of steam engines. To the solu- 

 tion of this problem Regnault devoted himself with won- 

 derful ingenuity and patience during the interval between 

 1840 and 1852; and for years after the latter date, he was 

 occupied with problems growing out of the original one. 



The first installment of the results of his researches 

 appeared in the 21st volume of the Memoirs of the Aca- 

 demy of Sciences. These researches, extending through 

 a period of seven years, furnished the data for the most 

 accurate and important of his determinations, and form 

 his chief title to fame as a physicist. For this great work 

 he received, in 1848, the Rumford medal, for the greatest 

 advance made in physical science during the year. 



Previous to this, in 1847, he had been made chief 

 engineer of mines in France. His official duties, how- 

 ever, did not interfere with his activity in scientific 

 matters. Xot only did he continue to carry on his experi- 

 ments, but he also found time to complete and publish 

 his Cours filementaire de Chimie in four volumes. An 

 abridgment of this worl^, entitled Premiers Siemens de 

 Chimie, was printed two years later and translated into 

 several European languages. 



He was now at the summit of his reputation, and addi- 

 tional honors and duties were heaped upon him. He was 

 made foreign member of the Royal Society of London, 

 and corresponding member of the societies of St. Peters- 

 burgh and Berlin. From England he also received the 

 Copely medal. In 1850, he was made officer of the 



