474 TRANSFERRING AND TRANSFORMING ENERGY 



SUMMARY 



Man has invented many simple and complex machines 

 for transferring and transforming energy, and has thus 

 simplified the doing of work. Among the machines which 

 are used simply or in complex combinations are the lever, 

 the wheel and axle, the pulley, the inclined plane, the wedge, 

 and the screw. He has invented complex machines for 

 transforming the energy of running water, of burning fuel, 

 and expanding steam, and of exploding gases into forms of 

 energy that may be utilized at will. The natural sources of 

 power should never be monopolized for the commercial 

 gain of a few people; they should remain the birthright of 

 mankind. 



QUESTIONS 



Which of the six basic machines have you used? What ma- 

 chines have you seen that combined several of these basic ma- 

 chines? Explain how they were combined. 



In what ways have you ever observed energy transformed by 

 machines so as to do useful work ? 



What forces of Nature have you ever seen used for man's ad- 

 vantage ? How ? 



