The Three Secretaries 137 



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 

 1 84 1, 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 iii 

 England who had loefore, occupied themselves with experi- 

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

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

 priority." 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 xili, page 30 (footnote) ; Pope, 



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



page 57. A series of controversial papers Joseph Henry," iS"]^, Journal 0/ the Ameri- 



between Cooke and Wheatstone. can Electrical Society, Volume 11, page 134. 



10 



