However, it may be about the valleys, we are very sure that the river made many, many other things that we know about. Did you ever hear of the orator in the New York Legislature, who wondered how it was that the rivers most always flowed by the big cities? He certainly got his "cart before the horse," for it is the big cities that always grow by the big rivers. History has always grown along the banks of rivers, because all civilization has grown along their banks. The boundaries of nations change. The political maps of Europe that I studied when I was a boy are now out of date, and you would find they are all wrong, because the boundaries of kingdoms, states, and empires have changed so often; but the life of the world continues to be found largely along the banks of the rivers. Why is this? And here is another question for you to talk with your teachers about. If you get the answer, you will have the key that will let you into much of the wonders and triumphs of art, architecture, and commerce. Of course, the very earliest man would keep close to the river's edge, because he would have no other sure way of getting water to drink, and the fish in the water, the birds on the water, and the birds' eggs in the nests along the edge of the river offered him a sure supply of food. And then along the river the grass grows greenest, and this afforded good grazing for his cows, and his horses, and, may be, his camels. What kind of food does the camel like best, anyhow? Primitive man must have learned to swim early, and it must have been fun for the little boys of barbarism, as it is for the little boys of civilization, to plunge into the cooling water on a hot day. Man must have found out very early how to make a raft which would carry him down stream, and soon after he learned how to make a canoe that he could paddle up stream. So the river became his first road. On it he traveled when he went hunting, and with its help he protected his property and that of the tribe. The enemies were driven across the river, and kept on the other side. A good way to study what a river does for man is to find out all you can about the life that gathered about some particular river, for that will tell you more or less of what happened along the banks of all the great rivers. The best of all rivers for such study is the Nile. It is one of the long rivers of the world, so long that its sources have only been recently discovered by those who make geographies. Read the stories of Livingstone and Stanley, and the early explorers, who went in search of the head waters of the Nile. [Illustration: A MOUNTAIN RIVER. CHICAGO COLORTYPE CO.]