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Common Science 



FIG. 138. The magnetized bolt picks up the iron filings. 



phone receiver, and so on. The following experiments 

 will show you how electricity moves things : 



Experiment 75. Bare an inch of each end of a piece of 

 insulated wire about 10 feet long. Fasten one end to the 

 zinc of your battery or to one wire from the storage battery ; 

 wrap the wire around and around an iron machine bolt, 

 leaving the bolt a foot or so from the battery, until you 

 have only about a foot of wire left. Hold your bolt over 

 some iron filings. Is it a magnet? Now touch the free 

 end of your wire to the carbon of your battery or to the 

 other wire from the storage battery, and hold the bolt over 

 the iron filings. Is it a magnet now? 



You have completed the circuit by touching the free end 

 of the wire to the free pole of your battery ; so the electricity 

 flows through the wire, around the bolt, and back to the 

 battery. 



Disconnect one end of the wire from the battery. You 



