36 ON MAGNETISM. 



sary to begin by taking the ordinates c, e, in all their 

 generality; and, after differentiation, to substitute the 

 specific values of c, e, 6. The special investigations 

 will be found to be easier. 



20. Investigation of the cases of Articles 14, 15, 16, 

 17, 18, on the supposition that magnetism is not confined 

 to two poles of each magnet but is disseminated accord- 

 ing to some law through its whole length, being entirely 

 red magnetism on one side of the center and entirely blue 

 on the other side, with similar laws of distribution. 

 Definition of the " magnet-power " of a magnet. 



Let x be measured from the center of A towards 

 the right-hand pole or upper pole (in the preceding 

 diagrams), and let the amount of magnetic energy 

 there, for the length Sx, be ae. And let y be similarly 

 measured for B, and let the amount of magnetic energy 

 for the length By be (3y. To the action of these two 

 masses of magnetism, the investigations of Articles 14 

 to 19 will apply. But in the investigation for the 

 action of a single pole of A on a single pole of B, 

 certain terms appeared which disappeared in the 

 aggregate. We will therefore adopt the results of the 

 investigations as if those terms had never appeared at 

 all. 



(a) From Article 14, with the disturbing magnet 

 broadside-on and the disturbed needle end-on, the 

 angular momentum produced by these two masses is 



xxyx 



