HUMAN MACHINE AND THE AUTOMOBILE 355 



a complicated system of bony levers 1 worked by muscles 

 gives us our ability to move about. We might even com- 

 pare the system Of pipes which carries the fuel in the auto 

 to the system of blood 

 vessels which carries 

 food to the parts of 

 the body where it is 

 used or the electric 

 wires of the car to 

 the nerves which 

 carry messages to 

 various parts of the 

 body. Both engine 

 and body must get 

 rid of the waste ma- 

 terial, for no engine 

 can run with its fire 

 box clogged with 

 ashes, nor can any 

 human being live 

 long without getting 

 rid of wastes. Neither 

 engine nor body can 

 be overworked with- 

 out breaking down. 

 Rest has been found to be necessary for metals as well as 

 for man. It is necessary to allow the most smooth-running 

 machine to take a rest now and then if the machinery is 

 to be kept in good condition. 



How the Auto and the Human Machine Differ. But 

 let us ask ourselves, how do these two machines differ? 

 Several differences are easily seen. In the first place the 

 automobile, once made, can never grow, while we know 

 the human machine, if properly cared for, can grow larger, 



1 Lever. A bar capable of turning around one point. 



Wide World 



Compare these two kinds of machines. List the 

 likeness and differences for your workbook. 



