296 Mr HARRIS'S Experimental Inquiries concerning 



TABLE V 



29. From these experiments, therefore, we may conclude, that 

 the magnetic developement in masses of iron by induction is di- 

 rectly proportionate to the power of the inductive force, and in- 

 versely proportional to the distance, all other things remaining 

 the same ; and that the attractive forces which magnets can de- 

 velope in masses of iron at a given distance, may be considered, 

 within certain limits (24), as a fair measure of their respective 

 intensities. 



30. It will be here proper to examine the curious phenome- 

 non of the increased force which a magnet apparently gains at 

 one of its poles, by placing a mass of iron in contact with the 

 opposite one ; so that, in this case, it can sustain a much greater 

 weight, and hence its power is said to be increased. This 

 circumstance, recorded by almost every writer on magnetic at- 

 traction, may be readily explained on the generally received hy- 

 pothesis of magnetic developement, which supposes in every 

 magnet the existence of two opposite forces ; the magnetic cen- 

 tre being a point where these forces are in a state of neutraliza- 

 tion, whilst the intensity of the separate forces varies in some 

 direct ratio of the distance as they recede from each other. The 

 intensity of the magnetism thus set free, will, therefore, be the 

 greatest somewhere near the extremities of the bar ; so that, if 

 a portion of the magnetism at one extremity becomes neutra- 

 lized, the effect is more or less sensible at the other ; and thus a 



