EDITOR'S TABLE. 



3 6 5 



EDITOR'S TABLE. 



PROFESSOR JOSEPH HENRY. 



IN" the death of Prof. Henry, Sec- 

 retary of the Smithsonian Institu- 

 tion, which occurred May 13th, Ameri- 

 can science has met with an irreparable 

 loss. Little needs to be said in eulogy 

 of a character so widely and familiarly 

 known, and so profoundly respected 

 and admired, as this venerable savant. 

 In Volume II. of The Popular Science 

 Monthly will be found an excellent 

 portrait of Prof. Henry, with a sketch 

 of his life, and an enumeration of his 

 most important scientific labors ; but 

 there are two or three features of his 

 career that are entitled to special recog- 

 nition, now that he has passed away. 



It is very well understood in the sci- 

 entific world that, more than any other 

 man, Prof. Joseph Henry is the scien- 

 tific founder of the system of modern 

 telegraphy, and this honor ought to be 

 equally conceded to him by the general 

 public. His earliest discoveries and his 

 most important scientific work were in 

 the field of electro-magnetic research, 

 entered upon within a very few years 

 after Oersted had announced the dis- 

 covery of the relations of electricity and 

 magnetism. Prof. Henry worked out 

 experimentally, and by the most elabo- 

 rate investigations, those laws and prin- 

 ciples of electro-magnetic action which 

 made the telegraph possible ; and not 

 only this, but he actually constructed 

 and operated an electric telegraph years 

 before Prof. Morse turned his attention 

 to the subject. The great contrivance 

 was of course bound to come, but no 

 consideration of this kind should be 

 permitted to detract in the slightest de- 

 gree from the honor of those by whom 

 it came. The scientific discoverer is 

 entitled at any rate to have his work 

 recognized, especially as he rarely gets 



anything else. It is the man who runs 

 in upon his discoveries and applies them 

 and brings them into notice that is usu- 

 ally credited in the popular estimation 

 with all the honor. In this case, Morse 

 has appropriated the glory that fairly 

 belongs to Henry. Morse originated 

 nothing by the current telegraphic al- 

 phabet that is, the combinations of 

 taps and clicks of the instrument, by 

 which letters are denoted. Electricity 

 had long been looked to as an agent 

 for the transmission of intelligence. 

 Many experiments had been made from 

 the time of Franklin to secure this ob- 

 ject, but none of them had succeeded. 

 Various contrivances had met more 

 recently with partial success, but Prof. 

 Henry's sounder of 1830 has gradually 

 displaced, and has now almost entirely 

 superseded, all other methods of elec- 

 tric signaling. Mr. E. K Dickerson, in 

 tracing out the history of telegraphic 

 invention, after stating the merits of 

 various previous contrivances, thus re- 

 fers to Henry's work : 



"Then came Prof. Henry, who, in 1830, 

 deduced from the hypothesis of Ampere 

 that magnetism was the circulation of elec- 

 tricity at right angles to the line connecting 

 the poles of the magnet the invention now 

 known as the compound electro-magnet. 

 In that year he constructed an electro-mag- 

 net that would sustain 1,000 pounds weight ; 

 and he answered the demonstration of Bar- 

 low, and proved that the electro-magnetic 

 telegraph was possible. In the same year 

 he set up an electro-magnetic telegraph at 

 Albany, over a line of a mile and a half in 

 length, using what is now known as the 

 ' polarized relay,' between the poles of 

 which a magnetic armature vibrated upon a 

 hinge, as the current of electricity was re- 

 versed the end of the armature striking a 

 sounder, and transmitting the intelligence 

 by sound. This was the first electro-mag- 

 netic telegraph (I use the popular phrase) 

 ever made ; and it was the first one possible 



