THE HISTORY OF THE GROUND. 2$ 



carried along by the water, there is sand sweeping 

 onward over the bed of the stream. It the stream is 

 a mere rivulet that quickly dries up after the rain has 

 ceased, we can examine its bed when it is dry, and 

 plainly see that the water carried along sand, small 

 stones, and fine mud. At low stages of the water, our 

 Western rivers show this very plainly wherever shoals 

 and sand-bars appear. Make full and careful notes of 

 all that is seen in such a dry bed, for there are two 

 great facts to be learned from these observations. 

 For those who live by the sea, the same observations 

 can be made all along the shore, at the mouth of 

 every bay or inlet on the coast. 



We have here the great soil-mover, water. The 

 rain, falling on the wasting rocks, sweeps away the mi- 

 nute specks and grains chipped off by the weather, and 

 carries them down to the nearest streamlet and brook. 

 These fine bits of rock do not float, but are suspended 

 in the water or roll along the bed of the stream. 

 The ragged flakes and scales of stone crash and grind 

 against each other. Every rough corner is knocked 

 off, and all the pieces become rolled into smooth round 

 particles. The brook is a mill. It is making, from 

 the chips brought down by the rain, sand. A flood 

 comes with- more water, and larger pieces of broken 

 rock are pushed into the rapidly moving water ; and 

 these, knocking, tumbling, and grinding over each 

 other, are soon ground into smooth round pebbles 

 and gravel. Onward rolls the confused mass of gravel, 

 sand, and finer bits of rocks, grinding and polishing 



