312 FIRST TEAR SCIENCE 



Wherever there are good harbors we find seafaring 

 people. To make ocean traffic safe, seas are charted, coasts 

 mapped, lighthouses built and life-saving stations main- 

 tained. Water transportation is the cheapest, so good 

 harbors are needed by all commercial nations. Nations 

 with seacoast and harbors are usually more progressive 

 and more civilized than inland nations. 



QUESTIONS 



Of what do the borders of different coasts consist? 

 What do the waves do to the coast ? 

 How are beaches and bars made ? 



What form do the waves and currents tend to give to the coast ? 

 How can it be shown that coasts are subject to changes in position 

 in respect to the surface of the sea ? 



What are the characteristics of an elevated coast? 



What are the characteristics of a depressed coast? 



How are harbors formed ? 



How are coasts safeguarded ? 



What kinds of coasts are found in the United States? 



How have coast conditions influenced their inhabitants? 



