USE OF ELECTRICITY IN THE HOME 389 



A good conductor of electricity is some material which will carry 

 the current. A poor conductor of electricity is something which 

 will keep the current from being carried away. .Wires are covered 

 with rubber, cloth, paper, etc., because they are poor conductors. 

 Glass is used on telephone wires to keep the electricity from running 

 off into the ground, and on lightning rods to keep the electricity 

 from running into the house. When a house is protected with light- 

 ning rods these glass insulators must be carefully replaced as soon 

 as broken. 



QUESTIONS 



1. How does gas differ from electricity? 



2. How does the use of electricity compare with the use of water? 



3. How does a water meter compare with a wattmeter? 



Find out how much current the lights of your home consume 

 each hour. 



4. What are some of the causes of an increase in your electric 

 bill? 



5. If you were given carbon lights, would you save any money 

 by using them in place of Tungsten lights? 



6. What kind of insulation would you prefer on wires about 

 your home? 



7. What kind of wires should be used to connect vacuum cleaners 

 and lamp lights with lamp sockets? 



MAGNETS AND MOTORS 



Magnets. There are two types of magnets; permanent magnets 

 and electro-magnets. The word magnet came from an ancient city 

 of Asia Minor near Magnesia where a black ore of iron was found. 

 This ore attracted pieces of iron or steel, and also nickel and cobalt. 

 The ore is now found in various parts of the earth, and is called 

 lodestone (leading stone), since it points to the North and South 

 magnetic poles if suspended on a string. A piece of steel may 

 become a permanent magnet by stroking it with this mineral. Steel 

 retains its magnetism much longer than soft iron; hence steel is used 

 for needles of compasses to-day in place of lodestone which was used 



