Plants need more than good soil to make them grow. They will wither and die unless they have plenty of rain to keep the earth soft and moist. There are many places in the world where no trees, nor grass, nor plants of any kind can grow. This is because there is no water to wet the earth.
We all know that clouds bring the rain; but how do the clouds get the water? Whenever there is water on the earth, as in the rivers, the air is continually drawing up the moisture in tiny invisible [p61] drops. This moisture rises in the air and forms clouds. When the clouds get very heavy, down comes the water which we call rain. In cold weather it is changed into snow.
ELEPHANT IN THE “ZOO.”
Where there is no moisture there can be no rain, for the air cannot draw up moisture to form clouds. Where there are many rivers there has been much rain, and the soil is kept fertile. Plants will grow in it. Do you see how our food, our clothing and our shelter are dependent upon rainfall? Do you see how we are kept alive by rivers?
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Think of the many, many uses of rivers. There are thousands of useful rivers in the world.
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What are the three great necessities of human life? How do rivers help us to get food and clothing and to build our homes and make them comfortable?
SOME USES OF RIVERS
1. Water supply; washing and drinking.