112 PROCEEDINGS OF THE REGENTS. 



circuit so closed by opening the first circuit, and thus interrupting the 

 current, when the needle would resume its ordinary position under 

 the inflaence of the magnetism of the earth. I informed him that I 

 had devised another method of producing effects somewhat similar. 

 This consisted in opening the circuit of my large quantity magnet at 

 Princeton, when loaded with many hundred pounds weight, by at- 

 tracting upward a small piece of moveable wire, with a small intensity 

 magnet, connected with a long wire circuit. When the circuit of the 

 large battery was thus broken by an action from a distance, the 

 weights would fall, and great mechanical effect could thus be pro- 

 duced, such as the ringing of church bells at a distance of a hundred 

 miles or more, an illustration which I had previously given to my 

 class at Princeton. My impression is strong, that I had explained 

 the precise process to my class before I went to Europe, but testifying 

 now without the opportunity of reference to my notes, I cannot speak 

 positively. I am, however, certain of having mentioned in my lectures 

 every year previously, at Princeton, the project of ringing bells at a 

 distance, by the use of the electro-magnet, and of having frequently 

 illustrated the principle of transmitting power to a distance to my 

 class, by causing in some cases a thousand pounds to fall on the floor, 

 by merely lifting a piece of wire from two cups of mercury closing the 

 circuit. 



The object of Prof. Wheatstone, as I understood it, in bringing into 

 action a second circuit, was to provide a remedy for the diminution of 

 force in a long circuit. My object, in the process described by me, was 

 to bring into operation a large quantity magnet, connected with a 

 quantity battery in a local circuit, by means of a small intensity 

 magnet, and an intensity battery at a distance. 



The only other scientific facts of importance to the practical opera- 

 tion of the telegraph not already mentioned are the discovery by 

 Steinheil, iu 1837, in Germany, of the practicability of completing a 

 galvanic circuit, by using the earth for completing the circuit, and 

 the construction of the constant battery in 1836, or about that time, 

 by Professor Daniell, of King's College, London. I believe that I was 

 the first to repeat the experiments of Steinheil and Daniell in this 

 country. I stretched a wire from my study to my laboratory, through 

 a distance in the air of several hundred yards, and used the earth 

 as a return conductor, with a very minute battery, the negative ele- 

 ment of which was a common pin, such as is used in dress, and the 

 positive element the point of a zinc wire immersed in a single drop of 

 acid. With this arrangement, a needle was deflected in my laboratory 

 before my class. I afterwards transmitted currents in various direc- 

 tions through the college grounds at Princeton. The exact date of 

 these experiments I am unable to give without reference to my notes. 

 They were previous, however, to the unsuccessful attempt of Mr. Morse 

 to transmit currents of electricity through wires buried in the earth 

 between Washington and Baltimore, and before he attempted to use 

 the earth as a part of the circuit. Previous to this time, and after the 

 abovementioned experiments, Mr. Morse visited meat Princeton, to 

 consult me on the arrangement of his conductors. During this visit, 

 we conversed freely on the subject of insulation and conduction of 



