conditions which the coal industry with its competitive overdevelopment, its load of parasite railroads, sales companies, company-owned houses and stores, its inefficient operating methods, and particularly its antiquated energy-producing equipment on which it must pay heavy interest, is prepared to meet. Because the supply of coal cannot much longer meet the cumulatively wasteful demands upon it; because the railroad system is breaking down under the increased bulk of coal to be transported; because the miners are increasingly insisting that the reward of their hazardous labor must give them a fair chance of the good life according to American standards of living; and because the community which must be served cannot indefinitely pay the price of inefficiency and waste, the present order in the coal industry is drawing to a close. The technicians have seen this impending change for a long time. Through their help the industrial revolution might have reorganized the coal industry decades ago under the pressure of an increasing demand for power, if it had not been held off by new discoveries of petroleum and natural gas. Petroleum, which had been used in a small way in many countries for centuries, first became an international commodity when Roumania began to ship it in 1857. It took on great industrial importance when the first American well, the famous Drake well in Oil Creek, Pennsylvania, was sunk in 1859. But in 1860 the world's total recorded production was less than five hundred and ten thousand barrels, of which five hundred thousand barrels are credited to the United States. By 1917 the world output had risen to nearly four hundred and fifty million barrels, of which the United States furnished nearly four hundred million. The coal and petroleum industries are closely interrelated. Coal and petroleum are largely interchangeable as sources of energy. Both can be used for fuel under boilers in their crude state, although crude oil is the more efficient; both provide an illuminating oil for use in lamps, although kerosene is so much better than coal oil as to have driven it out of the market; both furnish a satisfactory fuel for the internal-combustion engine, although benzol, a coal derivative, has not yet been recovered in sufficient quantities to make it a competitor of gasoline; both provide a fuel gas, although that derived from petroleum has the greater heat value. Ton for ton, petroleum has every advantage over coal, and there is every reason why it should drive coal out of its preeminent position in industry, except one--the limitations of the supply. For petroleum is far cheaper to produce, not only in terms of money, but in terms of human effort and life. Compare with the labor and hazard of opening and working a coal mine Pogue and Gilbert's description of the opening of an oil well.