400 FRAGMENTS OF SCIENCE. 



Now remove your needle from its loop, and draw it 

 from eye to point along one of the ends of the magnet ; 

 resuspend it, and repeat your former experiment. You 

 now find that each extremity of the magnet attracts one 

 end of the needle, and repels the other. The simple 

 attraction observed in the first instance, is now replaced 

 by a dual force. Repeat the experiment till you have 

 thoroughly observed the ends which attract and those 

 which repel each other. 



Withdraw the magnet entirely from the vicinity of 

 your needle, and leave the latter freely suspended by 

 its fibre. Shelter it as well as you can from currents 

 of air, and if you have iron buttons on your coat, or a 

 steel penknife in your pocket, beware of their action. 

 If you work at night, beware of iron candlesticks, or 

 of brass ones with iron rods inside. Freed from such 

 disturbances, the needle takes up a certain determinate 

 position. It sets its length nearly north and south. 

 Draw it aside and let it go. After several oscillations it 

 will again come to the same position. If you have 

 obtained your magnet from a philosophical instrument 

 maker, you will see a mark on one of its ends. Suppos- 

 ing, then, that you drew your needle along the end thus 

 marked, and that the point of your needle was the last 

 to quit the magnet, you will find that the point turns to 

 the south, the eye of the needle turning towards the 

 north. Make sure of this, and do not take the state- 

 ment on my authority. 



Now take a second darning-needle like the first, 

 and magnetise it in precisely the same manner : freely 

 suspended it also will turn its eye to the north and 

 its point to the south. Your next step is to examine 

 the action of the two needles which you have thus mag- 

 netised upon each other. 



Take one of them in your hand, and leave the other 



