A NEW SOURCE OF ELECTRICITY 



235 



thrust a magnet into the coil. Immediately there is a deflec- 

 tion of the needle, which indicates that a current is flowing 

 through the circuit. If the magnet remains at rest within the 

 coil, the needle returns to its original position, showing that 

 the current has ceased. Now let the magnet be withdrawn 

 from the coil ; the needle is deflected as before, but the defleo 



FiG. 106. The motion of a magnet within a coil of wire produces a 

 current of electricity. 



tion is in the opposite direction, showing that a current exists, 

 but that it flows in the opposite direction. We learn, therefore 

 that a current may be induced in a coil by moving a magnet back 

 and forth within the coil, but that a magnet at rest within the 

 coil has no such influence. 



A magnet possesses lines of force, and as the magnet 

 moves toward the coil, it carries lines of force with it. As 

 the magnet recedes from the coil, it carries lines of force away 

 with it. 



