Experts estimate that in the beginning there were somewhere about 2,000,000,000,000 tons of available coal, so that we have now, with all our wastefulness, used less than two per cent. of our original inheritance. But we must remember that in the ten years closing with 1905, we used as much as during the entire history of our country up to that time, and the rate of consumption is still increasing. In 1907 the amount mined was about 450,000,000 tons. Counting on a continuance of the same rate of increase, in 1917 it will be 900,000,000 tons a year, and if the same conditions should continue for twenty years we should be using and wasting in one year as much as we have used in all our history up to the present time. By that time more than one-eighth of our original supply will be gone, and in less than two hundred years nearly all of it will have for ever disappeared. That is a long time to look forward, but a short time in looking backward. It carries us back only to the childhood of Benjamin Franklin and others prominent in our early history; and if this nation could look forward to only an equal period of prosperous development in the future the time would seem short indeed. But the danger of our coal supply becoming exhausted lies not so much in its present use as in the rapid increase in its consumption. Fifty years ago (about the time of the Civil War) we were using an amount equal to a little more than a quarter of a ton for every man, woman and child then in the country. Now the rate is five tons, or twenty times that amount, for each person of all our greatly increased population. The Pittsburg Coal Company owns about one-seventh of the great Pennsylvania anthracite fields. From the amount it is now mining each year and judging from the amount of coal it is able, with present methods, to reclaim from an acre of coal land, the estimate is made that this Pittsburg field will be exhausted in ninety-three years. A like comparison of all the eastern fields indicates that by the beginning of the next century there will be practically no cheap fuel left in the entire Appalachian basin. The Geological Survey reports that, taking into account the available coal which can be reached and mined by present methods, and supposing the present conditions of use, waste, and increase to continue, the coal supply will be exhausted by the year 2015 A. D., but taking into account the probable improvements in its use, the year 2027 A. D. is estimated as the time when the present coal fields will be exhausted, and the middle of that century as the time when all coal fields in the United States will be gone.