BROOKS AND RIVERS 169 



in their journey to the sea the small particles, the 

 pebbles and the larger rocks that they had worn 

 away or broken off. 



It was not far to the sea at first, and the rain 

 water ran merrily off the shoulders of the rocks into 

 the surrounding ocean much the way water rolls 

 off your umbrella. It was working hard, however, 

 to take some little particles of rock with it, and 

 these, washed about by the flowing water, helped 

 it very much in wearing its channel. 



As the land rose, and there was more surface 

 for the rain to fall upon, the water gathered into 

 these partly worn channels, making them deeper and 

 deeper. Into them it would wash all the particles 

 of rock which had been worn away or broken off, 

 while along the bed of the channel it would push 

 these rocks as it hurried on its way to the sea. All 

 along the way the bits of rock would jostle and 

 bump against each other, wearing down the bed of 

 the brook and wearing off their own sharp corners. 

 When they reached the sea they were no longer 

 sharp and angular bits of rock, but smoothly rounded 

 pebbles like those you find on the beaches to-day. 



When you have played with those smooth, round 

 pebbles on the seashore, did you ever think where 

 they came from, and what made them so smooth and 

 round? Did you suppose that they were always so? 

 Oh, no. Once those pebbles were part of a great, 

 solid rock. Perhaps some of them belonged to the 

 cliffs farther off along the shore where the watei- 

 pounds and foams all day and all night. Perhaps 

 some of them came a long distance, brought by a 



