IGO BIOGRAPHICAL MEMOIR OF JOSEPH HENRY. 



I soon savv', liowever, iiuit the application of this poorer was but an in- 

 direct method of employing tlie energy derived from the combustion of 

 coal, and, therefore, could never compete, on the score of ex])ense, with 

 that agent as a means of in-opelling machinery, but that it might be 

 used in some cases in Vvdiich expense of poV) er was not a consideration 

 to be weighed agrinst the value of certain objects to be attained. 



A great amount of labor has since been devoted to this invention, es- 

 pecially at the expense of the Government of the United States, by the 

 late Dr. Page, but it still remains in nearly the same condition it was 

 left in by myself in 1831. 



I also applied, while in Albany, the resxdts of my experiments to the in- 

 vention of the firstelectro-magnetic telegraph, in which signals were trans- 

 mitted by exciting an elecitro-magnet at a distance, by v> hich means bells 

 Avere struck in succession, capable of indicating letters of the alphabet. 



In the midst of these investigations I vras called to Princeton, through 

 the nomination of Dr. Jacob Green, then of Philadelphia, and Dr. John 

 Torrey, of New York. 



I airived in Princeton in iSTovember, 1833, and as soon as I became 

 fully settled in the chair v^hich I occupied, I recommenced my investi- 

 gations, constructed a still more pov.'erful electro-magnet than I had 

 made before — one which would sustain over 3,000 ]>ounds — and with it 

 illustrated to my class the manner in which a large amount of power 

 might, by means of a relay-magnet, be called into operation at the dis- 

 tance of many miles. 



I also made several modifications in the electro-magnetic machine be- 

 fore mentioned, and just previous to my leaving for England, in 1837, 

 again turned my attention to the telegraph. I think the tirst actual 

 line of telegraph using the earth as a conductor, was made in the be- 

 ginning of 183(3. A v/ire was extended across the front campus of the 

 college grounds, from the upper story of the library building to the 

 philosophical hall on the opposite side, the ends terminating in tvro wells. 

 Through this wire, signals were sent from time to time from my house to 

 my laboratory. The electro-magnetic telegraph was lirst invented by 

 me, in Albany, in 1830. Professor Tilorse, according to his statements, 

 conceived the idea of an electro-magnetic telegraph in his voyage across 

 the ocean in 1833, but did not until several years afterward — 1837 — attempt 

 to carry his ideas into practice; and when he did so, he found himself so 

 little acquainted with the subject of electricity that he could not make his 

 simple machine operate through the distance of a few yards. In this di- 

 lemma he called in the aid of Dr. Gale, who was well acquainted with 

 what I had done in Albany and Princeton, having visited me at the lat- 

 ter idace. He informed Professor Morse that he had not the right kind 

 of a battery nor the right kind of magnets, whereupon the professor 

 turned the matter over to him, and, witlithe knowledge he had obtained 

 from my researches, he was enabled to make the instrument vrork 

 through a distance of several miles. For this service Professor Morse 

 gave him a share of his patent, which he afterwards purchased from 

 iiim for 815,000. At the time of making my original experiments on 

 electro-magnetism in Albany, I was urged by a friend to take out a pat- 

 ent, both for its application to machinery and to the telegraph, but this 

 I declined, on the ground that I did not then consider it compatible 

 with the dignity of science to confine the benefits which might be de- 

 rived from it to the exclusive use of any individual. In this. ])erhaps, 

 I was too liistidious. In brielly stating my claims to the invention of 

 the electro-magnetic telegraph, I may say I was the lirst to bring the 



