242 



GENERAL SCIENCE 



next to the first and so on out from the magnet until a 

 whole string of iron filings is formed. Since like poles 

 repel one another, the outer ends of these strings of iron 

 filings will have a brushlike appearance; the ends of 

 the strings being all of the same pole shove one another 

 apart. 



166. Magnetic Field about a Magnet. --The space 

 around a magnet which is affected by its force is called 



the magnetic field of the 

 magnet. This field is most 

 intense near the poles of 

 the magnet and decreases in 

 strength as it recedes from 

 the poles. At every point in 

 a magnetic field the force 



has a particular strength and acts in a certain direction. 

 If a very small compass is placed on the side of a bar 

 magnet near the N pole and then moved in the direc- 

 tion in which the needle of the compass points, it 

 will be found that the compass will take a curved path 



THE COMPASS FOLLOWS THE 

 LINES OF FORCE OF A MAGNET 



FIELD ABOUT A MAGNET 



toward the S pole of the magnet. In this way the whole 

 magnetic field may be mapped out. Each of the lines 



