great as to give the rocks associated with the coal measures a true metamorphic or crystalline structure, and to transform the coal itself into an extremely hard anthracite; in some places, indeed, it has been altered to graphite. The flexures of the coal formation are very abrupt and full of faults, and the coal itself is greatly broken and displaced. Its condition is such that it cannot be mined with great profit, and but little of it is now sent to market. The only areas of readily workable anthracite in the United States are therefore in Pennsylvania. These are all east of the Alleghany Mountains, and are located in four distinct regions. The first or Southern Coal Field extends from the Lehigh River at Mauch Chunk, southwest to within a few miles of the Susquehanna River, ending at this extremity in the form of a fish’s tail. It is seventy-five miles in length, averages somewhat less than two miles in breadth, and has an area of one hundred and forty square miles. It lies in Carbon, Schuylkill, and Dauphin counties. The second or Western Middle field, known also as the Mahanoy and Shamokin field, lies between the eastern headwaters of the Little Schuylkill River and the Susquehanna River. It has an area of about ninety square miles, and is situated in the counties of Schuylkill, Columbia, and Northumberland. It lies just north of the Southern field, and the two together are frequently spoken of as the Schuylkill Region. The Eastern Middle or Upper Lehigh field lies northeast of the first two fields, and is separated into nine distinct parallel canoe-shaped basins. These extend from the Lehigh River on the east to the Catawissa Creek on the west, and comprise an area of about forty miles. They are principally in Luzerne County, but extend also into Carbon, Schuylkill, and Columbia counties. The Northern or Wyoming field is a crescent-shaped basin about fifty miles long and from two to six miles broad, with an area of about two hundred square miles. Its westerly cusp is just north of the Eastern Middle field, and it extends from that point northeasterly through Luzerne and Lackawanna counties, just cutting into Wayne and Susquehanna counties with its northern cusp. It lies in the valleys of the Susquehanna and Lackawanna rivers, and in it are situated the mining towns of Plymouth, Wilkes Barre, Pittston, Scranton, and Carbondale. There is also a fifth district, known as the Loyalsock and Mehoopany coal field, lying in Sullivan and Wyoming counties. It is from twenty to twenty-five miles northwest of the Wyoming and Lackawanna field, its area is limited, and its coals are not true anthracite. It will thus be seen that aside from this last field the anthracite coal area of Pennsylvania contains about four hundred and seventy square miles. CHAPTER V. THE DISCOVERY OF COAL.