ADDRESS OF PROF. W. B. ROGERS. 83 



disappeared. This was Sturgeon's electro-magnet; and although 

 its lifting-power was small — limited at the utmost to a few pounds 

 — it had the merit of being in a practical sense the first electro- 

 magnet. 



After making many experiments with this instrument and with 

 currents variously applied, Professor Barlow, an English mathe- 

 matician and engineer, announced as his conclusion that the current 

 of electricity, under these circumstances, is so greatly retarded in 

 its progress through the wire that in a short distance it is rendered 

 incapable of accomplishing any decided mechanical effect. This 

 discouraging result was made public in the year 1825, when in 

 many quarters schemes began to be proposed for telegraphing 

 through the medium of electric force, and it seems for a time to 

 have satisfied the minds of practical and scientific men generally 

 that an electro-magnetic telegraph was impossible. 



During all this time America was comparatively silent. It is 

 true that Coxe had suggested a chemical telegraph, and Hare had 

 made numerous improvements in galvanic apparatus, but as yet no 

 representative of Franklin had entered the field of electrical 

 research. Soon, however, there appeared on the scene, first as a 

 country schoolmaster and a student in the Albany Academy, then 

 as a professor in this Academy, the man whose worth and scientific 

 labors we are assembled to commemorate, and who, in virtue of his 

 various discoveries in electrical science, may well be held entitled 

 to the honor of such a representation. 



Beginning his career of original experiment in 1827, Joseph 

 Henry early directed his thoughts to the improvement of electro- 

 magnetic apparatus, and especially to the development of increased 

 force in the soft-iron electro-magnet. He took up the rude instru- 

 ment of Sturgeon, experimented with it, studied the means by 

 which its efficiency could be varied and augmented, and at length 

 succeeded in so modifying its construction and its relation to the 



