Here we see it rushing rapidly down a steep slope. Its waters foam and dash between the great rocks that lie in the stream. Such places in the river are called rapids. Can you tell why they are so called?
| SUCH PLACES ARE CALLED RAPIDS. |
The stream flows on. It has now reached a high ledge of rock. Over this it leaps, making a great foam and noise.
When the water of a river falls over high rocks, it is called a waterfall or cataract.
You may have seen the Falls of Niagara, the greatest waterfall in the world.
Why is the river swift in some places, and in others slow?
At length it flows through an almost level country. It is here widest and deepest. Its course is more winding.
Do you know why it is crooked and winding?