426 WRITINGS OF JOSEPH HENRY. [1857 



STATEMENT IN RELATION TO THE HISTORY OP THE ELECTRO- 

 MAGNETIC TELEGRAPH.* 



(From the Smithsonian Annual Keport for 1857, pp. 99-106.) 



A series of controversies and law suits having arisen be- 

 tween rival claimants for telegraphic patents, I was repeatedly- 

 appealed to to act as expert and witness in such cases. This 

 I uniformly declined to do, not wishing to be in any manner 

 involved in these litigations; but I was finally compelled 

 under legal process to return to Boston from Maine — whither 

 I had gone on a visit, and to give evidence on the subject. 

 My testimony was given with the statement that I was not a 

 willing witness, and that I labored under the disadvantage 

 of not having access to my notes and papers, which were in 

 Washington. 



In the beginning of my deposition I was requested to give 

 a sketch of the history of electro-magnetism having a bearing 

 on the telegraph, and the account I then gave from memory I 

 have since critically examined, and find it fully corroborated 

 by reference to the original authorities. My sketch, which 

 was the substance of what I had been in the habit of giving 

 in my lectures, was necessarily very concise, and almost 

 exclusively confined to one class of facts, namely, those hav- 

 ing a direct bearing on Mr. Morse's invention. In order 

 therefore to set forth more clearly in what my own improve- 

 ments consisted, it may be proper to give a few additional 

 particulars respecting some points in the progress of discov- 

 ery, illustrated by wood cuts. 



There are several forms of the electrical telegraph; first, 

 that in which frictional electricity has been proposed to pro- 

 duce sparks, and motion of pith balls at a distance. 



Second, that in which galvanism has been employed to 

 produce signals by means of bubbles of gas from the decom- 

 position of water ; or b}'' other chemical re-action. 



* [Presented to the Board of Kegents of the Smithsonian Institution, on 

 their investigation (by a special committee) of certain publications touching 

 the origin of the electro-magnetic telegraph.] 



