FARADAY'S DISCOVERIES LEADING UP 



TO THE ELECTRIC DYNAMO 



AND MOTOR 



[Michael Faraday was for many years Professor of Natural 

 Philosophy at the Royal Institution, London, where his 

 researches did more to subdue electricity to the service of 

 man than those of any other physicist who ever lived. "Far- 

 aday as a Discoverer," by Professor John Tyndall (his suc- 

 cessor) depicts a mind of the rarest ability and a character 

 of the utmost charm. This biography is published by 

 D. Appleton & Co., New York: the extracts which follow 

 are from the third chapter .Q 



IN 1831 we have Faraday at the climax of his 

 intellectual strength, forty years of age, stored 

 with knowledge and full of original power. 

 Through reading, lecturing, and experimenting, 

 he had become thoroughly familiar with electri- 

 cal science: he saw where light was needed and 

 expansion possible. The phenomena of ordinary 

 electric induction belonged, as it were, to the 

 alphabet of his knowledge : he knew that under or- 

 dinary circumstances the presence of an electrified 

 body was sufficient to excite,, by induction, an 

 unelectrified body. He knew that the wire 

 which carried an electric current was an electri- 

 fied body, and still that all attempts had failed 

 to make it excite in other wires a state similar 

 to its own. 



What was the reason of this failure ? Faraday 

 7 



