BROOKS AND RIVERS 171 



of rock that are washed into it, wearing the rocks 

 smaller while it wears its own bed deeper and deeper. 



Sometimes when there is a very hard storm and 

 the brooks and streams are full of rushing water, 

 large rocks will be carried along for a great distance, 

 and when the force of the water has lessened, the 

 rocks will be left in the strangest places. We call it 

 a flood when the water of a stream escapes from its 

 banks and flows over the countr}^, taking with it 

 whatever lies in its path. You could hardly believe 

 water could be so fierce and strong as it is when in 

 flood. 



It is not usually so strong as that, but in the moun- 

 tain brooks, where the water runs very swiftly, it is 

 always strong. If it were not so it would never be 

 able to carry the rocks and pebbles down into the 

 valley and to the river. 



It takes many brooks to make a river. From the 

 higher land and from the mountains the brooks 

 come rushing and tumbling down into the valleys, 

 then out of the valleys flow the rivers. All alon^ on 

 their way to the sea the rivers are joined by brooks 

 and streams and by other rivers. That is why the 

 river grows larger and deeper as it flows ever on- 

 ward to its home in the ocean. 



Suppose you hold up your hand with the fingers 

 outspread, and make believe that each one of your 

 fingers and your thumb is a brook flowing down 

 off the mountain into a broad valley. That valley 

 you can imagine the palm of your hand to be. Then 

 out of the valley would flow a river which would 

 grow larger and broader as it went to join the sea, 



