244 



GENERAL SCIENCE 



pass from one pole to the other, but that the iron filings 

 are forced apart. Does this agree with the law of magnets? 



167. Care of Magnets. 

 If four bar magnets are 

 laid in the form of a 

 square so that opposite 

 poles, N and S, are touch- 

 ing, a complete circuit for 

 the lines of force will be 

 formed by the magnets and 

 there will be no external 

 magnetic effect. (This can 

 be proved by touching 

 them at various places 

 with a nail or by use of 

 iron filings.) This shows 

 that the steel of magnets 

 conducts magnetic lines 

 of force better than air. 

 For this reason, magnets 

 while not in use should 

 have their opposite poles connected by an iron conductor, 

 called an armature. This iron becomes a 

 magnet by induction and the magnetic 

 lines of force pass through 

 it. Magnets should not 

 be jarred or heated as both 

 tend to remove the align- 

 ment of the molecules and 

 thus destroy their mag- 

 netism. Like poles of two 

 good magnets should not 

 be placed very near each 



\\\ 



\S\\V\I 



f 



SHOWING LINES OF REPULSION OF Two 

 LIKE POLES OF MAGNETS 



How TO KEEP A 

 HORSESHOE MAG- 

 NET 



How TO KEEP 

 Two BAR MAG- 

 NETS 



