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THE HUMAN MACHINE 



Wright Pierce 



Where does the energy come from which pulls this heavy train up the grade? 

 Is the engine getting full efficiency from the fuel ? How do you know ? 



contained power or energy which was released as it burned. 

 Then this energy pushed the piston of the locomotive 

 engine and turned its wheels. In the auto engine the 

 gasoline exploded in the cylinders of the engine and drove 

 pistons which turned a shaft and transmitted the power to 

 the wheels. In both cases the power or energy locked up 

 in the fuel was let out in the process of burning or oxida- 

 tion, and this energy was transformed into work done by 

 the driving wheels. 



The human machine works in much the same way. 

 Most foods, as we know, are fuels. When taken into the 

 body, they are actually burned or oxidized and give up 

 their energy. This energy is then transformed in the 

 human machine and causes work to be done. That this is 

 actually so can be proved by some simple demonstrations 



