992 Transactions of the American Institute. 



did not occur to him to try the effect of a longer circuit for his 

 secondary coil. In his beautiful series of experiments in 1831, 

 wherein he demonstrated the induction of currents, and, also, in his 

 ninth series, published in 1834, on the induction of a currrent on 

 itself, he contemplated no practical ajDplication of the principles 

 developed, and jesorted to no means of increasmg the power of 

 tlie induced currents, being content with mere exhibition of the 

 current itself by feeble manifestations. 



The credit of the first induction coil has generally been ascribed 

 by European authors to Prof. Callan, of Maynooth College, Ireland. 

 Prof. Callan's experiments and apparatus were, indeed, consider- 

 ably in advance of his European cotemporaries, but were subse- 

 quent to those of Prof. Page; and, in order more- fully to establish 

 the claim of Prof. Page to the first induction apparatus, and to give 

 eveiy discoverer, inventor and contributor his true chronological 

 position, a resume is here given of the progress of the subject of 

 induction since its first discovery b}^ Faraday, who, for the sake 

 of distinction, from static-electrical induction, adopted the term 

 *' volta-electric induction." In 1825, Faraday attempted to prove, 

 experimentally, volta-electric induction, and failed, although the 

 subsequent verification of his theory was made by similar experi- 

 ments and arrangements. [PMl. Trans. 1832, jp. 162.) In Novem- 

 ber, 1831, he read before the Royal Society an account of his 

 discovery of the induction of currents, showing that the passage of 

 a galvanic current in one wire induced a momentary current in a 

 contiguous wire, and that the movement of the wke, transmitting 

 a current, to and from another wire, also developed momentary 

 currents in the latter. In the same paper he also announced the 

 interesting discovery of the development of electricity by mag- 

 netism, the electric currents being produced by the development of 

 electro-magnetism in its cessation, and, also, by the motion of a 

 steel magnet to and from its keci^er — the latter being surrounded 

 by a coil of wire, connected with a remote galvanometer. With 

 the electro-magnet he obtained a slight spark by using charcoal 

 points, but failed to obtain the spark from the experiments with 

 the steel magnets. By using a very powerful loadstone he was 

 able to convulse a frog's leg, and he thought he produced a slight 

 sensation upon the tongue. This species he termed magneto-elec- 

 'tric induction. The currents in neither case were of sufiicient 

 intensity to produce a shock, although he used very large batteries. 

 It is a very remarkable circumstance that, in each experiment insti- 



