392 



GENERAL SCIENCE 



magnet B because the current is entering only the two coils F and 

 E. Coils D and A have no magnetism in them, since the brushes 

 do not touch the sectors 1 and 2, called commutators, to which 

 these magnets are attached. As soon as magnets A and D get to 

 the places of magnets E and F, they lose their magnetism, and 

 the magnets E and F, taking the places of A and D, become 



FIG. 273. What is used for the return wire? 



magnets and are likewise pulled in the same direction, causing the 

 inner magnets on the axis to travel very rapidly. 



Commercial Motors. The commercial motors used for the run- 

 ning of cars, automobiles, vacuum cleaners, fans, etc., are made up 

 of a series of magnets which are constantly attracting and repelling 

 each other. Not only do they have magnets at B and C, but these 

 magnets are also wound with wire to produce very strong electro- 

 magnets when the current is turned on. 



