A brief history of the discovery and introduction into use of the bituminous coals of Pennsylvania has already been given; but only casual reference has been made to the methods of mining in the bituminous regions. It is true that of the one hundred and twenty thousand square miles of workable coal beds in the United States less than five hundred square miles are of anthracite coal. It is true, also, that more than two thirds of the coal produced in the United States during the year 1887 was of the bituminous variety, and that the income from bituminous coal during that year was nearly twice as much as the income from anthracite. Yet it is obvious that in any description of coal mining methods the anthracite mines should be used as the chief examples. This is not only because of the greater commercial importance of anthracite, and of its greater familiarity as a domestic fuel, but it is principally because of the far greater skill, judgment, and ingenuity required in mining it and preparing it for market. In the bituminous regions the coal is soft, lies flat and near the surface, and is mined by the simplest methods. The reader is already familiar with some of the complications, obstacles, and problems that meet and beset the operator in the anthracite regions, and with the great labor, vast expenditures, and high degree of skill necessary to reach, take out, and prepare the anthracite coal. In view of these facts no excuse is necessary for attaching the greater importance to the description of methods in the anthracite region. But a brief outline of the systems in vogue at the bituminous mines will not be uninteresting, so far at least as they differ from those in use at the anthracite mines. In the year 1887 a little more than one third of the bituminous coal output of the United States came from the Pennsylvania mines. Pittsburgh is the centre of the soft coal trade of that state, and the principal coal seam of the region is known as the “Pittsburgh bed.” It is included in an area about fifty miles square, and varies in thickness from two or three feet in the northwestern part, and six feet at Pittsburgh, to ten feet up the Monongahela River, and twelve feet up the Youghiogeny. The exhaustion of so vast a coal bed is a practical impossibility, and the questions that engage the attention of the mining engineer in these regions are not so much questions of the economy of coal as they are questions of the economy of labor. The coal lies near the surface, and the outcrops on the flanks of the hills and banks of the rivers are so numerous that most of the mining can be, and is, done by drift above water level. The outlay of capital required in opening a mine is therefore very small, marketable coal being obtained at almost the first blow of the pick.