CONTENTS 



FRANKLIN, BENJAMIN 



LIGHTNING IDENTIFIED WITH ELECTRICITY 



Franklin explains the action of the Leyden phial or 

 jar. Suggests lightning-rods. Sends a kite into the 

 clouds during a thunderstorm; through the kite-string 

 obtains a spark of lightning which throws into diver- 

 gence the loose fibres of the string, just as an ordinary 

 electrical discharge would do 3 



FARADAY, MICHAEL 



PREPARING THE WAY FOR THE ELECTRIC 

 DYNAMO AND MOTOR 



Notices the inductive effect in one coil when the circuit 

 in a concentric coil is completed or broken. Notices 

 similar effects when a wire bearing a current approaches 

 another wire or recedes from it. Rotates a galvano- 

 meter needle by an electric pulse. Induces currents 

 in coils when the magnetism* is varied in their iron 

 or steel cores. Observes the lines of magnetic force 

 as iron filings are magnetized. A magnetic bar 

 moved in and out of a coil of wire excites electricity 

 ^therein, mechanical motion is converted into elec- 

 tricity. Generates a current by spinning a copper 

 plate in a horizontal plane 7 



HENRY, JOSEPH 



INVENTION OF THE ELECTRIC TELEGRAPH. 



Improves the electro-magnet of Sturgeon by insulating 

 its wire with silk thread, and by disposing the wire 



