PROCEEDINGS OF THE KE GENTS. 99 



The report was accepted and the resolutions were unanimously 

 adopted. The Board then adjourned sine die. 



APPENDIX TO THE REPOFvT OF THE COMMITTEE. 



STATEMENT OF PROFESSOK HENRY IN RELATION TO THE HISTORY OF THE 

 ELECTRO MAGNETIC TELEGRAPH. 



In the beginning of ray 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 having 

 a direct bearing on Mr. Morse's invention, and my paper in Silliman's 

 Journal was likewise very brief and intended merely for scientific 

 men. In order, therefore, to set forth more clearly in what my own 

 improvements consisted it may be proper to give a few additional 

 particulars respecting some points in the progress of discovery, illus- 

 trated by wood cuts. 



There are several forms of the electrical telegraph : first, that in 

 which frictional electricity has been proposed to j)roduce 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 decomposition of water. 



Third, that in which electro-magnetism is the motive power to 

 produce motion at a distance; and again, of the latter there are two 

 i kinds of telegraph, those in which the intelligence is indicated by the 

 motion of a magnetic needle, and those in which sounds and per- 

 manent signs are made by the attraction of an electro-magnet. The' 

 latter is the class to which Mr. Morse's invention belongs. The fol- 

 lowing is a brief exposition of the several steps which led to this- form 

 of the telegraph. 



The first essential fact, as I stated in my testimony, which ren- 

 dered the electro-magnetic telegraph possible was discovered by 

 Oersted, in the winter of 1819-'20. It is illustrated by figure 1, in: 

 which the magnetic ^'s- 1. 



needle is deflected by ^ 



the action of a cur- 

 rent of galvanism 

 transmitted through 



the wire A B. (See Annals of Philosophy, vol. 16, page 273.) 



A *■ 



