The Three Secretaries 13? 



adopted by Wheatstone, for Ohm's law was at that time un- 

 known in England, as well as in America. 



Although Wheatstone in his controversy with Cooke, in 

 1841, claimed as his own the discovery that electro-magnets 

 may be so constructed as to produce the required effects by 

 means of a direct current, even in very long circuits, he sub- 

 sequently, in 1856, referring to the same early experiments, 

 wrote: "With this law and its applications, no persons in 

 England who had before, occupied themselves with experi- 

 ments relating to electric telegraphs, had been acquainted." 1 

 This can only be interpreted as an admission of Henry's 

 priority. 2 There was never, it is true, an acknowledgment 

 from Wheatstone of his indebtedness to Henry for advice 

 which enabled him to perfect his experiment in 1837; but, as 

 has been pointed out, it is a very significant fact that in 

 March, 1837. the magnet was discarded by Wheatstone; in 

 April his interview with Henry took place, and in April the 

 magnet was again employed and the success of the English 

 telegraph secured. 



The following summary is quoted from a well-known Eng- 

 lish authority : 



" It was only by Henry's discoveries that the electro-mag- 

 netic telegraph of Morse became possible, and Morse himself, 

 before he became involved in patent ligitation, freely acknow- 

 ledged his indebtedness to Henry. But Professor Henry, long 

 before Morse's telegraph came before the world, had sug- 

 gested the application of his electro-magnets to telegraphy, 

 and had even constructed a form of bell-telegraph for experi- 

 mental purposes which answered remarkably well. Henry, 

 however, had for his object 'the advancement of science, 



1 Cooke, William Fothergill, " The Elec- 2 The Electrical Engineer, January 13, 



trie Telegraph: Was it Invented by Pro- 1892, Volume XIII, page 30 (footnote) ; Pope, 



fessor Wheatstone ?" Part II, London, 1857, Franklin Leonard, "Life and Work of 



page 57. A series of controversial papers Joseph Henry," 1879, Journal of the Ameri- 



between Cooke and Wheatstone. can Electrical Society, Volume n, page 134. 



10 



