380 MEMORIAL OF JOSEPH HENRY. 



approximation to the actual facts of electrical transmission; and 

 gives us no account of the remarkable fact discovered by Henry 

 that the magnetizing power of a current actually increases with the 

 length of the conductor, up to a certain point: nor of his other 

 discovery, the "extra current" or 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 p. 



THE 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 year of its 

 existence, thus referred tp the scenes he witnessed a third of a cen- 

 tury before : " The older students 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 

 long coils of wire which ran circuit upon circuit for more than a 

 mile in length around one of the upper rooms in the Academy, for 

 the purpose of illustrating the fact that a galvanic current could be 

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

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

 bell. This 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 is 

 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 but the echo of that little bell which first 

 sounded in that upper room of the Academy." * 



On the same 'occasion, the Hon. Alexander W. 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 

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



*" Historical Discourse": on the Celebration of the Semi-Centennial Anni- 

 versary of the Albany Academy, June 23, 1863. Proceedings, etc. pp. 25, 26. 



