THE WORK OF RUNNING WATER 



63 



wide, and but 220 feet above sea-level. At Vicksburg it has a 

 similar width, and a height of but 90 feet. In general the flats of 

 valleys increase in width down stream. 



Fig. 49. Talus at base of valley slope, ready to be carried off by the stream. 

 Little Canyon looking south into Snake River. 



In conclusion, it may be said (1) that rivers tend constantly to 

 get the material of the land into the sea; (2) that in working to this 



Fig. 50. Diagram showing streams in adjacent valleys, under-cutting the 

 divide between them. They may, in time, destroy the divide by lateral 

 planation. 



