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I lii>I(l in my hand an ordinary liorsc-slioe magnet. It attracts 

 from .a short (hstancc — say an t-ij^hth of an inch — a small piece 

 of steel or iron which we call its keeper. It also attracts iron 

 filings and various particles suljject to its influence, which are 

 termed magnetic suhstances. It also repiK. uikKt varying con- 

 ditions. The Xorth ])ole of our magnet repels the north-seeking 

 pole of a compass, and attracts the south-seeking pole. The 

 South pole of the magnet repels the south-seeking pole of the 

 compass, and attracts the north-seeking pole. Hence, we say 

 of magnetism tliat likes re])el and unlikes attract. The same 

 phenomena are found in static electricity, and are easily demon- 

 strahle with dxnamic electricity as well. This magneto-electric 

 force, called "action at a distance," was the unsolved puzzle 

 of the early jihilosophers. That inert matter, under certain con- 

 ditions, could reach out through no other medium apparently than 

 the atmosphere., la}- hold of another object and move it, 

 transcended all other human experience. Thales of ]\Jiletus, after 

 the manner of ancient Greek philosophy, sought to explain this 

 myster}- l)y attributing to it a greater mystery ; — he called it a 

 soul or spirit, it remained for Ampere and Faraday and other 

 patient investigators of the early part of the nineteenth century 

 to demonstrate the character of this force — to show- the con- 

 nection between magnetic and electric actions, — to establish 

 clearly the conditions of its operation and to formulate the laws 

 by which this action is governed. Magnetism was found naturally 

 established in the loadstone — magnetic iron ore — but in manufac- 

 tured iron or steel it was artificially produced. The modern 

 theory which accounts mechanically for this condition of poten- 

 tiality, is that it consists of a peculiar molecular arrangement 

 in the magnet itself, whereby the normal electric current which 

 pervades the mass is given a uniform systematic spiral swirl 

 extending from one pole to the other. In other words, the 

 molecules of the magnet are arranged according to their polarity, 

 so that the north pole of each is presented to the south pole of 

 the next in succession, and each line proceeds in a spiral ; all of 

 the series composing the mass being arranged in parallel spiral 

 lines. By this arrangement it is believed that the polar activities 

 of all the molecules of the mass are cumulated and given uniform 

 direction, so that the sum of their forces is rendered available. 

 The best demonstration of this theory is that a magnet may be 

 formed by establishing an electric current in just this manner. 

 With a conducting wire wound into a helix, and a current passed 

 through its spiral convolutions from end to end we have what is 

 called a solenoid, which performs all the offices of a magnet. 

 It has its north and south poles, when free to act, adjusts itself 



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