UNIT XH 



THE HUMAN MACHINE AND 

 HOW TO CARE FOR IT 



PREVIEW 



Each of you has seen a modern locomotive pull a heavy 

 train up a grade and has wondered at the work it does. 

 Who has not marveled at the efficient running of an 

 auto or an airplane engine? But each boy or girl who 

 reads these lines controls a more wonderful machine than 

 those just mentioned. Think of it for a moment a 

 self -regulated, intelligent machine which does many kinds 

 of work, which repairs itself when it is injured, and which, 

 if taken proper care of, will long outlast the locomotive 

 or auto. And yet we think little about its care and often 

 abuse it. When a navy battleship or destroyer is to 

 make a test run, the fuel is selected with the greatest care. 

 Every one knows that an auto engine requires constant 

 lubrication and a good quality of gasoline if it is to do its 

 work effectively. But how many boys and girls think 

 very much about what is the best fuel food for their own 

 machine, or what to do to keep the machine in good 

 running order? 



We say that the human body is like an engine or an 

 automobile, but can we prove this statement ? What is a 

 machine anyhow ? You have all seen the fireman shovel- 

 ing coal into the fire box of a locomotive engine or have 

 watched the man at the gas station fill the fuel tank of 

 your automobile. But have you ever stopped to think 

 of what happened to that fuel after it burned ? That fuel 



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