MAGNETISM. 491 



other. Several, such as iron, nickel, and one or two other 

 metals, turn north and south when suspended on a pivot, hut 

 the great bulk of other bodies turn east and west, and are 

 called Diamagnetics. 



As we all know, the property of turning north and south 

 has been utilised in the Compass, without which modern 

 science would be paralyzed, and travel rendered impossible. 



It is worthy of notice that although the magnetic needle 

 of the compass turns to the north, it does not do so because it 



LOADSTONE. 



is attracted by the north pole, but because it is repelled from 

 the east and west. 



We have long known that if a current of electricity be sent 

 round a magnetic needle, the latter at once turns at right 

 angles to it. On this principle depends the Electric Telegraph. 

 When communication is made by using the handles, a current 

 of electricity is sent round the needles, and causes them to turn 

 at right angles until stopped by a little ivory pin, which pre- 

 vents them from overshooting themselves. 



There is a perpetual stream of electricity passing over the 

 earth from east to west, and in consequence all magnetic bodies 

 are forced to turn at right angles, just as is the case with the 

 magnetic needle. 



