192 COAL. 



Questions. 



What mineral body is the most universally useful 1 



How is it that iron is necessary to make other minerals 

 available to us ? 



Name some of the uses to which iron is applied. 



What is steel, and how may it be hardened ? 



Mention how far it may be tempered. 



What is the magnet, and what properties does it possess ! 



What is its use in the mariner's compass ? 



What value of hardware and cutlery do the English export 

 every year ? 



Why is care required in the use of copper vessels ? 



In what part of England is tin found abundantly? 



Why is it an important article of commerce? 



What is block-tin ? 



For what purposes is lead chiefly used 1 



Can you tell how small shot is made ? 



LESSON XLIV. 



COAL, SULPHUR, AND NAPHTHA. 



COAL is another mineral body deserving particu 

 lar attention. One great reason why the mineral 

 kingdom is so valuable in Great Britain arises from 

 her coal, as this enables the people both to bring 

 them up cheaply from the greatest depths by means 

 of the steam-engine, and to refine them when they 

 are brought to the surface. Other countries have 

 coal-mines as well as Great Britain, but few so 

 plentifully. 



