Part 4 (1/2)
The farmer does not know that he has me to thank for the richest of his lands, those lands where the soil is deep and dark, and filled with plant food. I and my brother rivulets have been thousands of years in collecting the soil which forms the fertile lowlands in the valleys through which we flow. We all unite to form the mighty river which finally ends in the sea.
[Ill.u.s.tration: _H. W. Fairbanks_ Because some farmer was careless, a rivulet has nearly destroyed this rich valley.]
Upon all the slopes which drain toward the river we rivulets are at work. Other servants of Nature are working here. Some of them are making the rocks soften and fall apart. Others are bringing seeds of the gra.s.ses and trees that they may take root in the crumbling rock. It is their business to make a carpet of plants over the earth and thus stop my work. But wherever the slopes are steep we rivulets have our way. We pick up and carry away the particles of sand and clay so that only the bare, hard rocks remain.
When the steep slopes become gentle, and we can no longer carry away all the particles of crumbled rock, then the carpet of plants spreads over the surface. Now our waters become clear. We seem like different beings. Once in a while, when the rains fall very heavily, some of us break through the protecting carpet and dig great hollows and gullies into the earth.
Would you like to know how we rivulets get rid of the load we carry from the mountain slopes? When we are muddy and swollen with the heavy rains, we turn the river into a flood. The river then breaks its banks and spreads out over all the lowlands along its course. Now the river flows more slowly and drops a part of the sand and mud which we rivulets brought to it. Finally, when the storm is over and the river goes back into its channel, there is left on the surface of the valleys a layer of earth rich in plant food. We brought the river the finest of the rock particles, together with the leaves and stems of plants that lay in our way.
[Ill.u.s.tration: _H. W. Fairbanks_ The rivulets have united to form the broad, shallow river loaded with the soil from the farms along its upper course.]
As year after year we made the river overflow, the soil of the lowlands grew deeper and deeper until it became as you see it today. Now the slopes about the head of the river are not so steep as they were once.
Our waters do not run away so rapidly and the river seldom overflows.
Thus the farmer can use the land for his crops, which grow so luxuriantly that he is envied by his less fortunate neighbors who live upon the hills.
[Ill.u.s.tration: _U. S. Office of Farm Management_ The soil of this valley has been washed to its present location by flood waters.]
Upon the slopes about the valleys we rivulets did not leave so much soil. The farther one goes up the slopes the thinner one finds the soil, until at the top the bare rock may appear.
But our work, says the muddy rivulet, was not finished with the making of the fertile valley lands. We carried a part of our load of sand and mud on to the mouth of the river. Here in the bay into which the river empties we began another great task. It seemed hopeless at first to try to turn the bay into dry land, but year after year we kept at work, through a time so long that I have forgotten when we began. At last we succeeded in bringing so much material to the bay that the waters became shallow. Then the soft mud began to show itself when the water was low. At last the water was replaced by dry land, which appeared much like the lowlands which we had made along the river.
Now you who think we muddy rivulets do only harm see what we have accomplished. We have built a great delta of the richest land that extends away on every hand as level as a floor and almost as far as you can see. The soil of the delta is hundreds of feet deep and the richest to be found on the whole earth. It is on such river deltas that the first civilized men made their homes, and became rich and powerful.
Now I have told you what Nature has appointed the muddy rivulets to do.
Is not the good that we do far greater than the harm? When we do harm it is because people have not learned how, or have not tried, to obey Nature's laws. If we make people poor, it is their own fault.
We still find much to do upon the earth. Nature is still making mountains which we have to tear down. We are still building deltas which will sometime be inhabited by rich and prosperous people. We do not willingly spoil the lands of the farmers on the hills and make them labor hard for a living.
In those happy lands where people understand Nature we rivulets have a different kind of work to do. We become pure and clear. We furnish a home for the fish, drink for the thirsty flocks, and a never-failing power to turn the mill wheels. Our waters are of service to every living thing.
CHAPTER SEVEN
HOW FAR WILL NATURE RESTORE HER WASTED GIFTS?
The natural wealth of our country is its soil, water, forests, minerals, animal and bird life, and, finally, its climate and scenery.
Of all these, _climate_ and _scenery_ are the only ones which we can use and enjoy as much as we like without any danger of their ever failing us. The sun will s.h.i.+ne through the blue sky, the winds will blow, and the storms will come just the same, no matter what we may do.
Did you ever think how long a time it has taken to make the wonderful world in which we live, and place upon it the mountains and valleys, lakes and oceans? Did you ever think how long a time it has taken to make the rocks and store away in them gold, silver, copper, and iron?
Did you ever think how long a time it has taken to cover the rocks with soil, and spread over the surface the flowers and trees and to stock it with uncounted numbers of animals and birds?
Nature usually works very slowly, but she never rests. The earth and all things on its surface, have always been changing, but changing so slowly that we do not ordinarily notice what is going on. When there is an earthquake, or a slide of rock on a mountain side, or an eruption of a volcano, we are astonished and often terrified.
Stories that have come down to us from the distant past tell us that the earth looked then much the same as it does now. If we could look away back to a time long before the first men lived, when even the animals and plants were different from those around us, we should discover that the surface of the earth was quite different from that of today. We should then see mountains and hills where now we find valleys, and dry land where now lies the blue ocean.
Nature has been such a long time making the beautiful world in which we live, that we ought to treat it with great consideration. It is also a wise thing for us to be heedful of her requests, for, if we will work with her, the earth with all its treasures will be at our command.