EXERCISE 68 

 WHAT IS THE PBINCIPLE OF THE STEAM ENGINE ? 



Materials. A model of a steam engine, a toy engine, or a visit to a steam engine. If a model 

 is not available, the diagram on page 184 of the " Elements of General Science " should be used ; 

 also, diagrams furnished by manufacturing firms will be helpful. 



Directions. Examine a model of a steam engine if one is at hand, and learn how it works. 

 Make a drawing of the principal parts of the engine, and label all parts to show how steam enters 

 and leaves the cylinder and how the piston is affected. Indicate by arrows the direction of the 

 steam. How is the energy transmitted to the wheels of the engine ? In labeling your drawing 

 and in writing any additional notes, consult the drawing in the textbook for proper names of parts. 



If no model is at hand, examine the cylinder of an engine and its valves and piston, to learn 

 how it works. If neither the model nor the engine is available, make a drawing similar to that in 

 the text and explain in your own words how such an engine works. 



Additional problems. When the steam leaves the engine, do you think all of its energy has been used ? 

 What is the importance of the use of steam engines in industries ? How many kinds of steam engines 

 do you know ? 



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