JOSEPH HENRY, LL.D. 291 



ness, as he then wrought them out," says Professor 

 Gray, "his conception and his attractive illustra- 

 tions of the sources, transformation, and equiva- 

 lence of mechanical power, and given them fitting 

 publicity, Henry's name would have been promi- 

 nent among the pioneers and founders of the 

 modern doctrine of the conservation of energy." 



Henry always defined science as the " knowledge 

 of natural law," and law as the "will of God." 

 He fcmnd all things, even the storms, under the 

 " control of laws fixed, immutable, and eternal," 

 and rejoiced in believing that " a Supreme Intelli- 

 gence who knows no change " governs all. For 

 him there was never any conflict between science 

 and religion. 



In February, 1837. Henry went to Europe, accom- 

 panied by Prof. Alexander D. Bache, at the head 

 of the United States Coast Survey for eighteen 

 years. He became the friend of Faraday ; of Wheat- 

 stone, then Professor of Experimental Philosophy 

 in King's College, who was engaged in developing 

 his system of the needle telegraph ; of Arago, 

 Gay-Lussac, and other noted men. " At Kingjs Col- 

 lege," says Prof. Alfred M. Mayer, "Faraday, 

 Wheatstone, Daniell, and Henry had met to try and 

 evolve the electric spark from the thermopile. 

 Each in turn attempted it and failed. Then came 

 Henry's turn. He succeeded, calling in the aid of 

 his discovery of the effect of a long interpolar wire 

 wrapped around a piece of soft iron. Faraday be- 

 came as wild as a boy, and, jumping up, shouted : 



