OF ARTS AND SCIENCES. 



299 



Without going through the process of analysis, let me simply state 

 what seems to me to be the truth. 



Each magnet probably distributes upon the other as much magnet- 

 ism as it would were a steel bar, without magnetism, in the place of 

 the other magnet ; and this amount is about one-half or two-thirds the 

 amount that would be distributed on a bar of soft iron. The result- 

 ing distribution is simjjly the algebraic sum of its components. 



Table V. gives the magnetism actually observed ; and it is remark- 

 able, that, if these curves are plotted, the very same line that repre- 

 sents the theoretical represents also the observed magnetic curve for 

 this case. I would state that the curves were not chosen to suit the 

 occasion, but are identical with the curve of the preliminary expei'i- 

 ment, where the poor juncture or the shortness of the bar made up 

 for the superior capacity of the soft iron. 



Whether the theory be true or not, I leave it to be judged. It is at 

 least useful in eliminating the contra-distribution inevitable in experi- 

 menting with soft-iron armatures ; for, if the law holds so nearly in 

 case of such large values, the error in small values must be inappre- 

 ciable. 



The law is as follows : Find the curve of the armature when a 

 -perfectly non-magnetic bar of soft iron, of half the length of the mag- 

 net, is joined to it ; then subtract algebraically this magnetism from 

 the observed. 



TABLE V. 



DISTRIBUTION OF TWO MAGNliTS UNITED BT OPPOSITE POLES. 



