MAGNETIC ATTRACTION . 



not confined to a ring, or even a series of rings, 

 but radiate in all directions. 



The object of the example is to show that it 

 is possible, without going far outside the or- 

 dinary conditions of mechanical action, to con- 

 ceive of arrangements by which bodies which 

 tend to move together are really pushed to- 

 wards each other by repulsions from behind. 



Is it equally possible to conceive of any 

 mechanical means by which bodies at a distance, 

 however small, can pull one another together ? 



The answer to this must be, no. 



The only means of pulling which we can 

 imagine is some kind of hooked rod or wire, 

 looped rope or chain. 



But, in the first place, such means of pulling 

 imply a windlass of some kind to wind up the 

 slack, an arrangement for which it is inconceiv- 

 able that there should be any equivalent among 

 the atoms and corpuscles which are the seat 

 of these actions. 



And, in the second place, if we imagine a 

 series of hooks or loops, as in a chain, we are 

 only deferring the difficulty, for we have to 

 explain how the former part of a hook can 

 draw the latter, which is not to be explained 

 by imagining still smaller hooks in the com- 

 ponent parts of the longer hooks. That would 

 be explaining a system by itself. 



The apparent pulling at a distance which 

 we see in magnetic attraction can, then, be 



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