354 



FIRST TEAR SCIENCE 



These are but a few examples taken from our own 

 history of the importance of rivers. They could be dupli- 

 cated in almost every country of the globe. 



164. Great Rivers of the United States. There are four 

 great river basins wholly or partly within the United 

 States : the St. Lawrence, the Mississippi, the Columbia 

 and the Colorado. The first two of these are navigable 

 for great distances and furnish unexcelled interior water- 



DBAINAGE BASINS OF THE UNITED STATES. 

 Notice the positions of the divides separating the different drainage areas. 



ways. Notwithstanding the great development of rail- 

 ways they still exert a vast influence upon the commerce 

 of the country. 



The St. Lawrence River with the Great Lakes, which 

 are geographically a part of it, is the greatest internal 

 waterway in the world. From the head of Lake Superior 

 to the mouth of the St. Lawrence, a distance "of about 

 2400 miles, by aid of the canals which have been built 

 around the rapids and falls, vessels of 14 feet draft can 



