WHERE THE WATER COMES FROM.
Day and night the brook ripples over the pebbles. It never gets tired and never stops. Did you ever wonder where the water of the brook comes from, and where it is going? Let us follow up the brook and see where it starts. Back into the hills we must go. We leave the meadows and the pretty valley. Up we climb until the slopes become steep and the brook dashes from rock to rock. Still smaller brooks join here and there, but we follow up the main one until at last we find where the stream starts. Under a mossy bank there is a clear spring. The water comes bubbling up out of the ground and runs singing away down through the hills.
If you want to know where the water of the spring comes from you must ask the raindrops. If we can find the home of the raindrops we shall find where all the water comes from.
We are sure that the raindrops are the source of the spring, for in the desert, where it does not rain, there are' no springs.
It does not rain when the sky is clear. The drops of water come from the clouds which come up and hide the blue sky. Where do the clouds come from? We will follow them back to where they start. We pass over valleys and hills, and at last find ourselves far out over the ocean.
The ocean is the home of the clouds. The ocean stretches farther than we can see. It covers three fourths of the surface of our earth. From over it all the little water particles are rising day by day. When they get up where it is colder we can see them. Now we call them clouds.
How do we know that water particles are rising from the water into the air. We set a basin of water out doors and after a few days the water has disap peared. It could get away only by going off in the air.
We cannot see the water particles leave the basin, but if we watch a pond of water when the air becomes cool at night we shall learn something about it.
Sometimes you will see a thin cloud or mist rising from the water. You can see the mist only when the water is warm and the air is cool. You
remember that steam from the engine boiler becomes visible when it comes out into the air because the air is so much cooler.
The mist rising and hanging over the pond is made of water particles. On cold mornings you can see them in your breath. How often you have puffed your breath out and played that you were a steam engine. Your breath contains these water particles all of the time, but they can be seen only when the air is cool.
The most of the water particles in the clouds start upon their journey from the ocean; for the ocean, you know, contains the larger part of the water upon our earth. The winds blow across the ocean and over the land. They carry the water particles, or vapor, with them. When they reach a region of colder air they form great masses of clouds. At last the little particles of water unite to form drops. These are so heavy that they cannot remain in the air any longer and so fall to the ground.
Some of the water sinks into the ground. This makes the cool springs. The rest runs away on the top of the ground. It becomes dirty and forms the muddy rills which we see during a rain storm.
All over the world streams of water are hurrying to the ocean. If the water never came back the ocean would by and by become dry, just as our basin did.
If there were no clouds the water would soon all gather in the ocean. The dry land would become a desert and nothing could live upon it.
So the water is always traveling from the earth to the sky and back again. The same particles never go in the same place twice. They are always seeing new places and meeting new people.
The water in the ocean is useful to us. It bears the ships from one part of the earth to another. In the sky it forms the clouds which furnish the refresh ing rain. As cool springs, it satisfies our thirst. At last, as little brooks, it runs away to join the river, and the river bears it again to the ocean.