336 



FIRST YEAR SCIENCE 



of the current is on the outside of the curve and the slowest 

 on the inside. A river that is carding about all the load 

 that it can, on passing around a curve, is able in its 

 outer part to carry more than before and cuts into the 

 bank, while on its inner part it flows less rapidly and is 

 able to carry less, thus being forced to drop some of its 

 load. As a river flows along its graded stretches, eroding 

 in some places and filling in others, it broadens its valley 



RIVER PLAIN. 



floor, leaving at the border of its channel a low plain 

 which in time of flood may be covered with water. Such 

 a river-made plain is called & flood plain. 



If a river once begins to swing on its valley floor, it 

 continues to do so, since whenever it strikes the bank, it 

 is reflected toward the other side, and is made to move 

 in the direction of the opposite bank as well as down- 

 stream. The windings that it thus assumes on a flat 



