and Pke7i07nena of Magnetic Induction. 277 



Hence the comparative capacities for induced magnetism of 

 the three series, as estimated by the differences of deviation, are 

 as follows ; 



Itt Series. 2d Seriet. 3d Series. 



Direct influence, - 3.28 1.41 0.S& 



Transmitted influence, - 7.32 1.12 0.33 



Total inductive energy, 1 1.0 2.63 1.28 



The proportion of energy of the magnetism directly induced 

 on the different portions, and that transmitted from portion to 

 portion, it must be observed, affords no measure of the relation 

 between the two influences in an actual bar of iron, because 

 there the number of the particles, and the intimacy of their 

 connection, renders the transmitted energy by far more consi- 

 derable in soft iron than the direct influence. 



Sect. 2. —On the Inductive Effects of the Magnet on Iron. 



The experiments detailed in the preceding parts of this essay 

 are all illustrative of these effects ; but, being designed for the 

 examination of the laws and nature of induction, they have been 

 limited in their character to that particular class which seemed 

 the best calculated for the attainment of these objects. This 

 section of the essay, however, not being confined to any particu- 

 lar investigation, will admit of all such original experiments as 

 may serve to illustrate any of the various influences and pheno- 

 mena of this interesting property of the magnet. 



Series A. 



With a single bar-magnet, or with two or more equal bars 

 placed over each other in parallel juxtaposition, and with 

 similar poles coincident. 



As these experiments are the more striking, in proportion to 

 the power of the magnets, it is advisable, if the bars be well tem- 

 pered, so as not to injure each other by their proximity, to em- 

 ploy at least a pair of magnets, according to the arrangement of 

 fig. 1. before given. The original experiments were made with 

 a pair of three-feet magnets : but nearly the whole series can be 

 exhibited, though with less striking effects, with a pair of good 

 twelve-inch bars. 



