PROCEEDINGS OF THE REGENTS. 105 



I did not refer exclusively to the needle telegraph when, in my 

 paper, I stated that the magnetic action of a current from a trough is at 

 least not sensibly diminished by passing through a long wire. This 

 is evident from the fact that the immediate experiment from which 

 this deduction was made was by means of an electro-magnet and not 

 by means of a needle galvanometer. 



At the conclusion of the series of experiments which I described in 

 Silliman's Journal, there were two applications of the electro-magnet 

 in my mind : one the production of a machine to be moved by electro- 

 magnetism, and the other the transmission of or calling into action 

 power at a distance. The first was carried into execution in the con- 

 struction of the machine described in Silliman's Journal, vol. 20, 1831, 

 and for the purpose of experimenting in regard to the second, I ar- 

 ranged around one of the upper rooms in the Albany Academy a 

 wire of more than a mile in length, through which I was enabled to 

 make signals by sounding a bell, (fig. ^^- '• 



7.) The mechanical arrangement for 

 afiecting this object was simply a 

 steel bar, permanently magnetized, of 

 about ten inches in length, supported 

 on a pivot and placed with its north 

 end between the two arms of a horse- 

 shoe magnet. When the latter was 

 excited by the current, the end of the 

 bar thus placed was attracted by one 

 arm of the borse-shoe, and repelled 

 by the other, and was thus caused to 



move in a horizontal plane and its further extremity to strike a bell 

 suitably adjusted. 



This arrangement is that which is alluded to in Professor Hall's 

 letter* as having been exhibited to him in 1832 It was not, however, 

 at that time connected with the long wire above mentioned, but with 

 a shorter one put up around the room for exhibition. 



At the time of giving my testimony, I was uncertain as to when I 

 had first exhibited this contrivance, but have since definitely settled 

 the fact by the testimony of Hall and others that it was before I left 

 Albany, and abundant evidence can be brought to show that previous 

 to my going to Princeton in November, 1832, my mind was much 

 occupied with the subject of the telegraph, and that I introduced it in 

 my course of instruction to the senior class in the Academy, I should 



* See the Report of the Committee, page 96, and Proceedings of the Albany Institute, 

 anuary, 1858. 



