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graph, Mr. Morse, in an interview with Prof. Henry, at Washington, said, 

 according to his own account, "Well, Prof. Henry, I will take the earliest 

 opportunity that is afforded me in anything I may publish, to have justice 

 done to your labors; for I do not think that justice has been done you, 

 either in Europe or this country." 



Again, in 1848, when Prof. Walker, of the Coast Survey, made his 

 report on the theory of Morse's electro-magnetic telegraph, in which the 

 expression occurred, " the helix of a soft iron magnet, prepared after the 

 manner first pointed out by Prof. Henry," Mr. Morse, to whom the re- 

 port was submitted, said : " I have now the long wished for opportunity 

 to do justice publicly to Henry's discovery bearing on the telegraph." 

 And in a note prepared by him, and intended to be printed with Prof. 

 Walker's report, he says : " The allusion you make to the helix of a soft 

 iron magnet, prepared after the manner first pointed out by Prof. Henry, 

 gives me an opportunity, of which I gladly avail myself, to say that I 

 think that justice has not yet been done to Prof. Henry, either in Europe 

 or in this country, for the discovery of a scientific fact, which, in its bear- 

 ing on telegraphs, whether of the magnetic needle or electro-magnet order, 

 is of the greatest importance." 



He then proceeds to give a historical synopsis, showing that, although 

 suggestions had been made and plans devised by Soemmering, in 181 1, and 

 by Ampere, in 1820, yet that the experiments of Barlow, in 1824, had 

 led that investigator to pronounce " the idea of an electric telegraph to 

 be chimerical" — an opinion that was, for the time, acquiesced in by 

 scientific men. He shows that, in the interval between 1824 and 1829, 

 no further suggestions were made on the subject of electric telegraphs. 

 But he proceeds — " In 1830, Prof. Henry, assisted by Dr. Ten Eyck, 

 while engaged in experiments on the application of the principle of the 

 galvanic multiplier to the development of great magnetic power in soft 

 iron, made the important discovery that a battery of intensity overcame 

 that resistance in a long wire which Barlow had announced as an insu- 

 perable bar to the construction of electric telegraphs. Thus was opened 

 the way for fresh efforts in devising a practicable electric telegraph ; and 

 Baron Schilling, in 1832, and Professors Gauss and Weber, in 1833, had 

 ample opportunity to learn of Henry's discovery, and avail themselves of 

 it, before they constructed their needle telegraphs." And, while claiming 

 for himself that he was " the first to propose the use of the electro-magnet 

 for telegraphic purposes, and the first to construct a telegraph on the 

 basis of the electro-magnet," yet he adds, " to Professor Henry is un- 

 questionablt/ due the honor of the discovery of a principle which proves the 

 practicability of exciting magnetism through a long coil, or at a distance, 

 either to defied a needle or to magnetize soft iron." 



