398 MAGNETISM. 



When the north pole of one magnet is pre- 

 sented to the south of another magnet, these ends 

 attract each other; but if the south pole of one 

 magnet be presented to the south pole of another, 

 or the north pole of one to the north pole of 

 another, these ends will repel each other. 



From these criteria, it is easy to determine the 

 names of the poles of a magnetical bar, by ap- 

 plying it near a suspended magnet whose poles are 

 known. 



When a magnet is situated so as to be at 

 liberty to move itself with sufficient freedom, its 

 two poles do not lie in a horizontal direction, but 

 it generally inclines one of them towards the hori- 

 zon, and of course it elevates the other pole above 

 it. This is called the inclination, or dipping of the 

 magnet. 



Any magnet may be made to impart those pro- 

 perties to iron or steel. 



Of Magnetic Attraction and Repulsion. 



It appears at first sight that the attraction lies 

 only in the magnet, but experiment proves this 

 attraction between iron and it to be mutual ; the 

 iron attracting the magnet as much as the magnet 

 attracts the iron. Place the magnet and the iron 

 upon two separate pieces of cork, or wood, floating 

 upon water, at a little distance from each other, 

 and it will be found that the iron moves towards 

 the magnet, as much as the magnet towards the 

 iron ; if the iron be kept steady, the magnet will 

 move towards it. 



This attraction is strongest at the poles of a 

 magnet, and diminishes in proportion to the dis- 



