Technical changes destroy the uses of agents
2. A change in inventions and processes may reduce the rent of agents, independently of their material condition. Rent is dependent on the indirect relation of things to wants; that relation may be changed if some other agent is found fitted to serve these wants more directly. Not only do the materials of houses change, but fashion and engineering skill change, making the old mansions cheerless and inconvenient, and affecting their rent-earning power. At every moment, in a progressive society, many rent-earning agents are being thrown out of use. The machinery in flour-mills has been almost completely changed, parts of it repeatedly, while the roller process has been substituted for the old millstones. Water-power, because of its uncertainty, has been replaced in many places by steam-power, and in many places steam-power in turn, has been rivaled by water-power since the improvements in the generation and transmission of electricity. A change in the process of making paper threw out of use much machinery that was only in part saved by its removal and adaptation to the making of coarser grades of paper. Many minor inventions in the iron industry, still more the invention of the Bessemer process, threw out of use great numbers of the old appliances.
Industrial circumstances affect the uses of agents
3. A change in the outer conditions that give occasion to the use of agents may cause depreciation. The exhaustion of materials on which machinery is employed may reduce its usefulness. A sawmill located in the midst of a forest has a high-earning power while the forest lasts, but when the forest is cut off the mill itself declines in value. Unless it can be removed to another forest and thus have its earning power renewed, it will have the value only of scrap-iron; it has become an indirect agent in the wrong place. Oil-boring machinery where a rich supply of oil is found has a high rental for a time, but when the oil-fields give out the machinery falls in value, being worth more or less than the cost of transporting it according as the next oil-field is near or far. Changes in fashions, calling for different kinds of products, cause a depreciation in the value of the old agents. Coarse salt, evaporated by the sun, was used by our fathers, but the finer product of the steam process is driving out the product of the old solar plants. As homespun went out of use, much machinery still in good physical condition was cast aside. Changes in transportation work revolutions in industrial methods. Many prosperous small forges on the country roads of Pennsylvania became valueless after the building of the railroads. New forges were built at favored points where materials and products could be shipped by rail.
Various grades of efficiency in rent-bearers
4. The agents employed in any industry range from the more efficient, high rent, down to the less efficient, low rent, grades in a more or less regular series. It follows that as these changes are going on, the place of agents on the scale of efficiency is constantly shifting. The various agents represent all grades of efficiency. One depreciates, possibly is restored later and takes a high place, and again depreciates until finally it is thrown out of use. One loom embodies the latest improvements and corresponds to the most fertile field; another can still be made to yield a little rent; the use of a third results in certain loss. A great mass of no-rent agents lie just below the margin of utilization in every industry. Some of these are permanently abandoned; some will be taken back into use when business conditions improve. When the iron industry is dull, many forges are out of blast; but when iron is again in demand, there is a gradual taking up of the abandoned forges, factories, and machines as they are brought within the margin of profitable utilization. Many agents not actually earning a rent, may become rent-earning through a change in business conditions.
§ III. DESTRUCTION OF NATURAL STORES OF MATERIALS
Destruction of the American forests
1. A large part of industry is now conducted without regard to the preservation of the source of income. A striking example of this is the use, or rather the destruction, of the American forests. In the last century the demand for lumber grew rapidly both on account of domestic needs and of the needs of the older countries. Great quantities of wood have been used and still greater quantities 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. Considering present needs and conditions, the labor seems to have been worse than wasted.
Effects on value of timber
The direct effect of this destruction of the supply has been the increase in the value of timber. To the settlers much of the timber was worse than useless; they paid and labored to get rid of it; now the supplies of lumber must be sought on the very margins of our territory: Florida, Maine, northern Michigan and Wisconsin, Washington, and Oregon. The supplies in Washington and Oregon are almost unavailable in the Eastern states on account of the cost of transportation. Professor Marsh, thirty years ago, strikingly characterized the policy that has been 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."
Physical effects
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 floods, and by preventing the washing down of the rich soil, keep the mountain sides from becoming bare and sterile rocks. So, within the last two decades, the people in America have begun to think of forestry. Its purpose is to restore the forests to the condition of permanent rent-earners, to make the mountains yield not a temporary supply, but a perpetual crop of timber.
Possible exhaustion of the coal-supply
2. The extraction of coal and other mineral deposits reduces for future generations a supply already limited. The coal deposits in the earth have only recently been drawn upon. A small city like Ithaca probably uses to-day a greater quantity of coal than was used in all Europe two centuries ago. The large deposits of coal and their early development in England long gave a great advantage to English industry over that of other countries. In England, however, has first been felt the fear of the exhaustion of the coal-supply. Professor Jevons, in 1861, sounded the note of alarm; he prophesied that because the coal deposits of America were many times as great as those of England, industrial supremacy must inevitably pass to America. Already the supremacy in coal and iron production has passed to America, and that in textiles soon will come. In England the accessible supply of coal is limited, deeper shafts must be sunk, and the coal gotten with greater difficulty and at greater expense. 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 are thirty-seven times as great as those of England, but even these will soon be exhausted. And yet on the part of all except the coal trust, there appears in America a thoughtless disregard for the future. Supplies of copper, iron, and lead in favored positions are likewise limited, and are being rapidly centered in the hands of great companies. The increasing demand for these products insures a steadily rising income from their annual use. The value of the mines, being based on the series of incomes they will yield, may increase while their unused treasures dwindle in quantity.
Many natural resources are being rapidly exhausted
3. The exhaustion of natural stores of material is due to civilization, but it threatens to put an end to industrial progress. The savage does not go deep enough to use up permanently the world in which he lives. He uses the fruits that he finds, and those fruits are, almost without exception, renewed the next year. The only mines that were worked out in