380 MEMORIAL OF JOSEPH IIKNKY. 



approximation to the actual fads of electrical transmission; and 

 gives ii- mi account of the remarkable fact discovered by Henry 

 thai the magnetizing power of a current actually increases with the 



length of the c luctor, up t<> a certain point: nor of his other 



discovery, the "extra current" <>r the induction of a current upon 

 itself. Indeed it takes no cognizance of any of the numerous per- 

 turbations dependent on the m-sterious re-actions of electrical 

 '• induction." 



Note C. (From j,. J.'H.) 



till: ELECTRO-MAGNETIC TELEGRAPH. 



From among living eye-witnesses of Henry's early telegraphic 

 experiments in the years 1831 and 1832, the following may be 

 cited: 



Dr. Orlando Meads, a former student of the Albany Academy, 

 in an anniversary discourse commemorating the fiftieth rear of its 

 existence, thus referred to the scene- he witnessed a third of a cen- 

 tury before: "The older student- of the Academy in the years 1830, 

 1831, and 1832, and others who witnessed his experiments which 

 at that time excited so much interest in this city, will remember the 

 lone; coils of wire which ran circuit upon circuit for more than a 

 mile in length around one of the upper room- in the Academy, for 

 tin 1 purpose of illustrating the fact that a galvanic current could he 

 transmitted through its whole length so as to excite a magnet at the 

 farther end of the line, and thus move a steel liar which struck a 

 bell. Tin- in a scientific point of view, was the demonstration and 

 accomplishment of all that was required for the magnetic telegraph. 

 - - - Let us not forget that the click of the telegraph which i- 

 heard from every joint of those mystic wires which now link to- 

 gether every city, and village, and post, and camp, and station, all 

 over this continent, is lint the echo of that little hell which first 

 sounded in that upper room of the Academy."* 



On the same occasion, the Hon. Alexander \V. Bradford, also a 

 former pupil of the Academy, (who finished his course at the Insti- 

 tution and left it in 1832,) recalled the suspended lines of insulated 

 copper wire through which his teacher had demonstrated "the 

 magnetic power of the galvanic battery; and years before the inven- 

 tion of the telegraph, proclaimed to America and to Europe the 

 mean- of communication by the electric fluid. I was an eye- 



*"Historieal Discourse": on the Celebration <>f the Semi-Centennial Anni- 

 versary of the Albany Academy, June 23, 1863. Proceedings, etc. pp. i"., 26. 



