the Laws of Magnetic Forces. 



307 



~with different magnets, marked 1, 2, 3, 4. D signifies the dis- 

 tance cd, Fig. 5. ; and f the corresponding force of induction, as 

 measured by the increments in the attraction in the case of the 

 opposite poles being opposed, and by the decrements when the 

 similar poles were opposed. 



TABLE XII. 



The limits within which the inductive action varied accord- 

 ing to a uniform law, would, from these experiments, appear to 

 depend on the magnetic intensities, and on the circumstances 

 before observed (24.) ; so that the precise distance at which it 

 becomes irregular in its action, is not the same for each magnet ; 

 and it may be further observed, that, when the inductive action 

 operates in a contrary sense to the poles of the magnets, the de- 

 crements vary at last more rapidly than the increments, sup- 

 posing in the latter case the induction to operate in the same 

 sense. These are points of great consequence in all experimen- 

 tal researches concerning the reciprocal attractive or repulsive 

 force, as exerted between two magnets. 



44. Similar variations from a regular law are observable, when 

 the force of a magnet is made to vary, the distance between the 

 two magnets remaining the same. Thus a magnet of a double 

 force, opposed to the inferior pole of another magnet, circum- 



VOL. XL PART II. Q 



