84- Mr. J. P. Joule on the Effects of Magnetism 



For similar causes the interior of the bar will in general 

 receive the neutralization and reversion of its polarity before 

 the exterior, and hence we see in the tables that there is a 

 considerable elongation of the bar after the reversion of the 

 current; even when the effect upon the balance has become 

 imperceptible, owing to the opposite effects of the interior and 

 exterior magnetic particles. 



The bars employed in the preceding experiments were an- 

 nealed as perfectly as possible. The next series was made 

 with a bar of exactly the same dimensions and quality as the 

 bars employed in Experiments 1 and 2, excepting that it was 

 not annealed. 



Experiment 4. 



