374 FRAGMENTS OF SCIKV i 



act more powerfully on the particle than the more distant 

 one. Let S N, Fig. 2, be the magnet and n the particle 

 of north magnetism in its new position. &quot;Well, it is 

 repelled by N, and attracted by S. Let the repulsion be 

 represented in magnitude and direction by the line n o, 

 and* the attraction by the shorter line n m. The resultant 

 of these two forces will be found by completing the par 

 allelogram m n o p, and drawing its diagonal n p. Along 

 n p, then, a particle of north magnetism would be urged 

 by the simultaneous action of S and N. Substituting a 



FIG. 2. 



S I 



particle of south magnetism for n y the same reasoning 

 would lead to the conclusion that the particle would be 

 urged along n q, and if we place at n a short magnetic 

 needle, its north pole will be urged along n p, its south 

 pole along n q, and the ouly position possible to the 

 needle, thus acted on, is along the line p q, which, as you 

 see, is no longer parallel to the magnet. Verify this by 

 actual experiment. 



In this way we might go round the entire magnet, and 

 considering its two poles as two centres from which the 

 force emanates, we could, in accordance with ordinary me 

 chanical principles, assign a definite direction to the mag 

 netic needle at every particular place. And substituting, 

 as before, a bit of iron wire for the magnetic needle, the 

 positions of both will be the same. 



