NEW CONCEPTIONS IN SCIENCE 



same as that of light, one hundred and eighty-four 

 thousand miles per second. 



If the ideas of Franklin seemed to fit in fairly 

 well with the discoveries of Volta and his im- 

 mediate successors, it was not the same with the 

 amazing performances of Faraday. Davy and 

 Arago had shown that an ordinary voltaic current, 

 passing in a coil about a soft iron bar, converts 

 the bar into a magnet so long as the current lasts. 

 Faraday reversed this, and found that simply by 

 pushing a bar of iron towards or away from a 

 magnet generates a current. The latter was so 

 small that though the great experimenter had his 

 finest instruments trained to detect any effect, if 

 there was one, it was days before he discovered 

 that the thing he sought was actually there. But 

 it was the seed of the oak. The modern develop- 

 ment of Faraday's device is represented in the 

 giant generators at Niagara Falls, where a line of 

 ten massive dynamos converts the equivalent of fifty 

 thousand horse-power into a current of electricity, 

 and sends it waving through the cables to Buffalo. 



No better example could be chosen to stimulate 

 the imagination and make it ask questions. Throw 

 off the "load" of these Niagara generators that 

 is to say, destroy the magnetic field, and at the 

 same time shut the water from the penstocks which 

 supply the power which turns them, and they will 



134 



