From the first settlement to the present, the use of the for ests for lumber has speedily grown. To the settlers much of the forest was, however, a real hindrance to agriculture. While great quantities of wood were used, still greater quan tities were wasted, trees being girdled, the ground burned over, the timber destroyed in any way that would clear the soil—timber which to-day would be of far more value than is the cleared land on which it stood. Such methods met the immediate need, but considering present conditions, the labor was worse than thrown away.
Our forests once covered 45 per cent of the land area of the United States and even now they cover 25 per cent. The yearly growth of 12 cubic feet per acre equals less than one third of the annual consumption (40 cubic feet). "We take 260 cubic feet per capita, while Germany uses 37 cubic feet, and France 25 cubic feet." The supplies of lumber must be sought on the very margins of our territory : Florida, Maine, northern Michigan and Wis consin, Washington, and Oregon, some of which supplies are so distant from the densely populated states as to be almost unavailable on account of the cost of transportation. Pro fessor Marsh, as long ago as 1864, characterized the policy that had been thus far pursued: "We are breaking up the foundation timbers and the wainscoting of the house in which we live in order to boil our mess of pottage." The indirect effects of these changes are fully as great as the direct ones. Forests greatly affect climate, temperature, and soil ; they influence the humidity. They equalize the flow of streams, moderate the floods, and by preventing the washing down of the rich soil, keep the mountain sides from becoming bare and sterile rocks. So, near the end of the nineteenth century, the people in America began most tardily to think of forestry. Of our forests remaining, one fifth are still in public, and four fifths are in private ownership. The purpose of scientific forestry is to make forest lands per manent use-bearers, durative agents, to make them yield not a single crop of timber, but an unending series of crops.
§ 7. Rapid consumption of coal. With care, the use of agricultural and .of forest lands may be durative ; but the extraction of coal is a purely consumptive use of the mine. Every ton used to-day is subtracted from the supplies for future generations. The coal deposits in the earth have only recently been drawn upon. A modern town with a few thou sand inhabitants probably uses to-day a greater quantity of coal than was used in all Europe two centuries ago. The
large deposits of coal in England and their early development long gave to English industry a great advantage over other countries. In England, however, has first been felt the fear of the exhaustion of the coal supply. Professor Jevons, in 1865, sounded the note of alarm; he prophesied that because the coal deposits in America were many times as great as those of England, industrial supremacy must inevitably pass to America. Already the supremacy in coal and iron produc tion has passed to America, and that in many other industries where fuel is an important element in cost soon will come. In England the accessible supply of coal is limited, deeper shafts must be sunk, and tunnels extended far under the ocean bed, and the coal got with greater difficulty and at greater ex pense. Coal has risen in price in England within the last few years, and will continue to rise in the future. The coal deposits of America have been estimated to be thirty-seven times as great as those of England, but many of the best American mines show signs of diminution. The best anthra cite beds will be gone in less than three quarters of a century. And yet there is in America little thought of the future in this regard.
§ 8. Disappearance of mineral stores. There are many other natural materials which, now that the exploration of the earth's surface is pretty well completed, appear to form a limited and unincreasable stock. Their gradual consump tion is making and will make great changes in the economic world. Natural gas is a wonderful substitute for coal, and when first found in a locality it brings a brief prosperity, but it is soon exhausted. Petroleum, little used before 1865, will help light the world for but a few decades, for it is drawn from natural reservoirs slowly, if at all, replenishing. The recent increase in the use of gasoline for motor-vehicles has directed thought to the limits of possible supply. Iron ore, the most essential single mineral resource, has been taken from the earth in greater quantities within the last fifty years than altogether before in the history of the globe, and the limits of rich accessible supplies in the United States are already in sight. China may be the next great center of iron and steel production. Copper, tin, lead, gold, silver, and potter's clay are a limited stock, inadequate to increasing needs. When any deposit has been worked out, the aban doned quarry, mine, or claybank is most often useless for any other purpose.