Magnetism. 25 



wood floating on water, or in any situation in 

 which it may turn freely, when the magnet will 

 arrange itself nearly in that direction, namely, 

 from north to south. To find the poles of a 

 magnet, place it under a smooth piece of glass, or 

 a piece of white paper, and sift or shake some 

 steel or iron filings on the paper or glass, and 

 you will find them arrange themselves in beauti- 

 ful curves, as represented in PL II. fig. 5. E E. 

 At each pole, however, the filings will take a 

 straight or rectilinear direction, as at A. B. and 

 those which happen to be situated at a small di- 

 stance from the poles will assume more or less of 

 the curve in proportion to their distance from 

 them. Some natural magnets are found to have 

 more than two poles ; in which case they may be 

 considered as two or more magnets united toge- 

 ther, and, in fact, have been sometimes separated 

 into so many distinct magnets. 



In England we call that the south pole of the 

 magnet which points towards the north, and that 

 is termed the north pole which is directed to the 

 south. The foreign philosophers, on the con- 

 trary, naii^e them according to the pole to which 

 they point. That is, the north pole of the mag- 

 net is that which is directed to the north or arctic 

 region, and the contrary. 



The principle of repulsion is also very strik- 

 ingly exemplified by the magnet; for if the same 

 pole of two magnets is presented one to the other, 

 that is, the north pole of one magnet to the north 



