ADDRESS OF PROF. W. B. ROGERS. 81 



His quick imagination led him at once to what may be called the 

 electrical construction of the magnet. To his thought each linear 

 current is but a magnetic element, and every magnet is but a con- 

 geries of such currents revolving around its axis; and he said to 

 himself, " I will construct a magnet with copper wires, and without 

 the metal hitherto supposed to be essential to this result, for I will 

 make the current revolve in a copper helix." He did so; sus- 

 pended the conducting helix, and found, as he had expected, that 

 its ends were attracted and repelled by the poles of the ordinary 

 magnet, and that when free to move it pointed like the compass 

 needle in obedience to the earth's directive power, and that in fact 

 this copper wire had the distinctive properties of a magnet. 

 AMPERE has been styled the NEWTON of electricity, and his 

 electro-dynamic theory of the action of currents and of magnets 

 has been thought worthy, so far as the logic of its demonstration 

 is concerned, of a place near the Principia of NEWTON. 



Electro-dynamic experiments were now rapidly multiplying and 

 numerous ingenious forms of apparatus were contrived to illustrate 

 the actions of currents on each other and of currents on magnets, 

 a class of phenomena which, from their novelty at the time, as well 

 as their intrinsic interest, some of my hearers will recall as having 

 been among the most surprising and fascinating of lecture-room 

 exhibitions. 



It was at this stage of discovery that another scientific genius, 

 FARADAY, who was destined to be the successor and perhaps more 

 than the equal of his great instructor, DAVY, leaving the chemical 

 labors in which he had already attained distinction, entered the 

 field of electrical research. After aiding DAVY in 1820 in repeat- 

 ing and extending OERSTED'S experiments soon after they had been 

 announced, he succeeded in producing, for the first time, the con- 

 tinuous rotation of a magnet around an electric conductor and the 



converse rotation of the conductor around the magnet, and a few 

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