Faraday ' s Discoveries 



he never accepted an experimental result, until he 

 had applied to it the utmost power at his com- 

 mand. He raised his battery from ten cells to 

 one hundred and twenty cells, but without avail. 

 The current flowed calmly through the battery 

 wire without producing, during its flow, any 

 sensible^result upon the galvanometer. 



" During its flow, " and this was the time when 

 an effect was expected but here Faraday's 

 power of lateral vision, separating, as it were 

 from the line of expectation, came into play 

 he noticed that a feeble movement of the needle 

 always occurred at the moment when he made 

 contact with the battery; that the needle would 

 afterwards return to its former position and re- 

 main quietly there unaffected by the flowing 

 current. At the moment, however, when the 

 circuit was interrupted the needle again moved, 

 and in a direction opposed to that observed on 

 the completion of the circuit. 



This result, and others of a similar kind, led 

 him to the conclusion "that the battery current 

 through the one wire did in reality induce a 

 similar current through the other; but that it 

 continued for an instant only, and partook more 

 of the nature of the electric wave from a common 

 Ley den jar than of the current from a voltaic 

 battery." The momentary currents thus gen- 

 erated were called induced currents, while the 

 current which generated them was called the 

 inducing current. It was immediately proved 

 that the current generated at making the circuit 



