104 



HOW WE USE HEAT 



Wright Pierce 



Is this girl scout going to make a fire correctly? Could you do better? If so, 

 how would you go to work ? 



scouts make it today, from friction by means of rubbing 

 things together, or it may have come from a chance strik- 

 ing of two hard stones so as to make a spark. But with 

 it came comfort. Think of what home would be without 

 any heating apparatus, or without fire to cook with. 

 Think of the fun you have popping corn or making candy, 

 or getting warm around a bonfire. Think of how heat 

 is used in melting substances such as solder, and how it 

 can be used for casting lead toys. These are only a few 

 of the cases in which we use heat. Our uses of heat 

 depend upon our ability to control it. To control it we 

 must learn how it acts. Heat can make things larger, 

 can make gases from liquids and solids, and can change 

 the flavor of foods. Heat can be transported by water 

 or steam from a furnace in the cellar to our rooms, where 



