HENRY AND THE TELEGRAPH. 289 



uudeiiie all subsequent applications of the intermittent magnet, they 

 form indeed the indispensable basis of every form of the electro-mag- 

 netic telegraph since invented. They settled satisfactorily (in Barlow's 

 phrase) the "only question which could render the result doubtful"; and 

 though derived from the magnet, were obviously as applicable to the 

 galvanometer needle.* 



It is idle to say in disparagement of these successes, that in the 

 competitive race of numerous distinguished investigators in the field, 

 diligently searching into the conditions of the new-found agency, the 

 same results would sooner or later have been reached by others. For 

 of what discovery or invention may not the same be said? Only those 

 who have sought in the twilight of uncertainty, can appreciate the vast 

 economy of effort by prompt directions to the path from one who has 

 gained an advance. Not for what might be, but for the actual bestowal, 

 does he who first grasps a valuable truth merit the return of at least a 

 grateful recognition. 



1831. As an experimental demonstration of the telegraph — now made 

 possible, Joseph Henry, early in the year 1831, suspended around the 

 walls of one of the upper rooms in the Albany Academy, a mile of cop- 

 per bell-wire interposed in a circuit between a small Cruickshanks bat- 

 tery and an "intensity" magnet. A narrow steel rod (a permanent 

 magnet) pivoted to swing horizontally lilie the compass needle, was ar- 

 ranged so that one end remained in contact with a limb of the soft iron 

 core, while near the opposite end of the compass rod a small stationary 

 office-bell was placed. At each excitation of the electro -magnet, the 

 compass rod or needle was repelled from one limb (by its similar mag- 

 netism) and attracted by the other limb, so that its free end tapped the 

 bell. On reversing the current, the compass rod moved back to the op- 

 posite limb of the electro-magnet. This simple device the Professor was 

 accustomed to exhibit to his classes at the academy, during the years 

 1831 and 1832, in illustration of the facility of transmitting signals to a 

 distance by the prompt action of electro-magnetism, t 



This memorable experimental telegraphic arrangement involved three 

 very significant and important novelties. In the first place, it was the 

 first electro-magnetic telegraph employing an "intensity" magnet ca- 



* When urged by a zealous friend to secure an early patent on these valuable and 

 pregnant improvements, Henry resolutely withstood every importunity, seeiuiug to 

 feel that a. discoverer's position and aptitude are lowei'ed by courting self-aggrandize- 

 ment from scieutific truth ; a self-deny iug generosity which characterized him through- 

 out his life. Wliile such disinleresteduess cannot fail to excite our admiration, it may 

 perhaps be questioned whetlier in this case it did not, from a jiraetical point of view, 

 amount to an over-fastidiousness; whether such legal establisiiment of ownership, 

 shielding the possessor from (be occasional depreciations of the envious, and securing 

 by its more tangible remnn(U'ations tin'- leisure and the nutans for more extended re- 

 searches, would not have been to science more than a comjiensatiou for the supposed 

 sacriiice of dignity l)y ths ])liilosopher. Since the date of tlie American patents of 

 Wheatstone and of Morse (ten years later) several Imndred patents have been granted 

 in this country for ingenious improvements upon or modifications of tlie electro-mag- 

 netic telegraph, all of them necessarily dependent on Henry's original invention. 



tFor the testimonials of a few surviving eye-witnesses to the practical working of 

 Henry's experimental line in 1831, and 183"2, see "Supplement," Note E. 



S. Mis. 59 19 



