CONDUCTORS. 23 



Q. Why is COPPER wire letter than iron ? 



A. 1st Because copper is a better 

 conductor than iron : 2ndly It is not so 

 easily fused or melted : and 3rdly It is 

 not so much injured by weather. 



Q. What is the GOOD of a lightning-con- 

 ductor ? 



A. Metal wire is a most excellent 

 conductor; and as the lightning makes 

 choice of the best conductors, it would run 

 down the metal wire, rather than the 

 bricks of the building. 



Q. How far witt the beneficial influence of a 

 lightning-conductor extend ? 



A. It will protect a circumference all 

 round, the diameter of which is (at least) 

 4 times as long as that part of the rod, 

 which rises above the building. 



Q. Give me an example. 



A. If the rod rise 2 feet above the 

 house, it will protect the building for (at 

 least) 8 feet all round. 



Q. Why are not lightning-conductors more 

 generally used ? 



A. Because they are often productive 

 of more harm than good. 



