Rivers rise from mountains or big lakes. Flowing through the mountains, rocks, plateau, and plain lands they fall into the sea or some otehr river. Some rivers are fed by snow-water and some by rain-water and some by both.
In their onward journey the rivers proceed with much force and sweap away everything in front of them. As the rivers fall from great heights, the rocks are ground into dust and the rivers carry and deposit the dust in the plains. This is called ‘silt’. The silt makes land fertile. The river is very thin and narrow at the place of its origin. But gradually, as it proceeds futher, it widens. On the way it is joined by other rivers. Sometimes, a river branch off into two or three currents. These are called tributaries of the river. The moUth of the river where it falls into the sea is much wider.
Rivers are of great use to us. They provide water for drinking and other purposes. River-bath is very good for health. It refreshes our body and mind. Transport by water is cheap and, therefore, a good deal of inland trade is done by water. Towns on the banks of big rivers are prosperous because of this Boats carrying goods of merchandise sail up and down the rivers and carry goods to big towns for sale. Thus, the rivers help trade, industry and agriculture. They also help industry in another way. At some places there are big water¬falls in a river.
The falls can be used to generate electricity which is called hydro-electric power. This power is arrested and utilized for lighting towns. It is also used for running mills and factories and drawing water from wells for irrigating land. It is used for turning the wheels of mills. The water of the river is carried through big canals to distant places for watering land. In this way barren and unproductive areas are converted into fertile lands.