OCEANS CAUSE CHANGES IN LAND 



373 



markets insures thrift and success. Because rivers are the sole 

 highways of travel and trade in new countries settlements grow 

 up around them and form the beginnings of future cities. As 

 the country grows and progresses, trolley lines and railroads 



FIG. 242. Dangerous sea cliffs in northwestern France. 



penetrate into the lands remote from rivers and allow the 

 spread of population. 



Oceans cause changes in land. Rivers modify inland 

 regions, oceans modify seashores and coast lines. Oceans 

 wear back the shore and change its outline; they hurl 

 sediment on shores and form beaches; they deposit sand on 



