51 TIIK STORY-BOOK OF SCIENCE 



the lamp on the stove," added Jules, "ok! it was soon 

 done for : a linker's breadth of tin had disappeared.' 1 



"Tin and lead melt very easily," explained Uncle 

 Paul. "The heat of our hearth is enough to make 

 them run. Zinc also melts without much trouble; 

 but silver, then copper, then gold, and finally iron, 

 need (ires of an intensity unknown in our houses. 

 Iron, above all, has excessive resistance, very valu- 

 able to us. 



"Shovels, tongs, grates, stoves, are iron. These 

 various objects, always in contact with the fire, do 

 not -melt, however ; do not even soften. To soften 

 iron, so as to shape it easily on the anvil by blows 

 from the hammer, the smith needs all the heat of his 

 forge. In vain would he blow and put on coal ; he 

 would never succeed in melting it. Iron, however, 

 can be melted, but you must use the most intense 

 heat that human skill can produce. " 



