CHARACTERISTICS OF RTVERS. 15 



t ; onal low water this level may change in the future, and these changes depend upon 

 conditions which cannot always be ascertained or guarded against. 



American rivers are subject to floods of much greater height than are those of 

 Europe, where floods on large streams rarely exceed 50 feet above ordinary low water. 

 The Ohio River has had a number of floods exceeding 50 feet at Cincinnati and that 

 of 1884 was over 70 feet. 



Where rivers are fed by lakes they are not subject to such great extremes of level. 

 This is particularly noticeable in the river St. Lawrence, which has an approximately 

 constant level. To a certain extent the same is true of the Rhone, the Rhine, and a 

 number of other streams. 



