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. [Sidenote: 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." [Sidenote: 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. [Sidenote: Possible exhaustion of the coal-supply]