The Three Secretaries 127 



to adopt ' henry ' as the name of this unit came from Professor 

 Mascart, the distinguished leader of the French delegation, 

 for among the French, some years ago, another name, the 

 ' quadrant ' or ' quad ' had been proposed, and since that 

 time much used ; that it was seconded by one of the leading 

 delegates from England, Professor Ayrton, who had himself, 

 a few years ago, proposed the word 'sec-ohm,' as being a 

 proper name for the unit of induction, a proposition which for 

 a time found much favor; and finally, that it received the 

 unanimous approval of the entire Chamber, thus furnishing a 

 testimonial of the highest order of the estimation in which the 

 work of Joseph Henry is held, and a recognition of his rank 

 as a natural philosopher which some of his own countrymen 

 have been somewhat tardy to appreciate and acknowledge." 



The discovery of magneto-electric induction in 1830 fol- 

 lowed that of the extra or self- inductive current, which, for that 

 matter, Henry always maintained should be considered to be 

 identical with magneto-electricity, 1 and in connection with 

 which he, first of all men, obtained electrical manifestations 

 from a magnet. 



"An electric current," writes Kennelly, "was in 1819 found 

 [by Oersted] to have magnetic properties. Here in 1830 

 the converse relation was first noticed, [by Henry] that a 

 conductor in motion through magnetized space developed 

 electrical properties. The propositions in these terms did 

 not receive full proof or recognition for some years, but Henry 

 seems to have been the first to observe an electrical cur- 

 rent induced by a magnet." 5 



Faraday made the same discovery in 1831 with the aid of 

 Henry's two forms of magnets, and was the first to print the 



1 The Electrical Engineer, March 9, 1892, American Inventions," in " The United States 

 Volume xvii, page 249. of America," edited by N. S. Shaler, New 



2 Kennelly, A. E., in chapter on "Typical York, 1894, Volume II, page 143. 



