The coals of the lower beds are most hard and dense. The middle beds produce the purest coal, and the coal of the upper beds is most soft and friable under heat. The same description would apply to the general decrease of carbon and increase of volatile matter in these coal beds from east to west. There is a gradual decrease also in the dimensions of the beds in the same direction. The same gradual change from hard anthracite to semi-anthracite and bituminous is as marked a feature in the South Wales (English) coal fields as in the Pennsylvania coal fields. The general features and fractures of hard anthracite are peculiar and noticeable to the common observer. They are massive, hard, dense, amorphous or conchoidal in fracture, with fine, sharp edges when broken, and a rich satin or an iron-black sub-metallic lustre. With some local exceptions, the softer varieties, both red and white-ash, are less massive, hard, and dense, more regular and cubical in fracture, and, exclusive of the upper red-ash beds, less rich and lustrous. - The prominent anthracite fields of the world are those of Pennsylvania and South Wales, which produce nine tenths of the quantity used.
The developed coal fields of the world embrace an area of about 350,000 sq. m., of which over 300,000 are in the United States, exclusive of lignite. (See Coal.) About 2,000 sq. m. of this entire area contain anthracite, of which half is in the United States, including the somewhat doubtful New England coal fields. The entire coal production of the world in 1871 was between 225 and 250 million tons, of which England produced 110 millions and the United States 41 millions. About 20 millions of the entire amount was anthracite, of which 15 million tons were produced in Pennsylvania, and the remainder in South Wales, France, and other countries. - The South Whales coal field lies on the northwest of the Bristol channel, extending from St Bride's bay in the east to Pontypool in the west, a distance of 90 m., with a maximum breadth of 60 m. Its mean breadth is less than 20 m., presenting an area of about 1,500 sq. m., of which only 1,000 contain workable coal beds. It is divided by an axis parallel to its strike, and divided also into numerous intermediate basins, while the measures undulate both from E. to W. and from N. to S. The deepest part of the field is supposed to be 8,000 ft.
Most of the mining has been done by "drifts," and but few shafts had been sunk to any great depth up to 1864. Twenty-three workable seams exist in the principal basins, averaging altogether 92 ft. of coal. Of these, 12 are from 3 to 9 ft. thick, and 11 from 18 in. to 3 ft. Besides these there are numerous smaller seams from 6 to 18 in. thick. On the N. side of the field the coal is anthracite in character, and resembles the anthracites of Pennsylvania, though generally containing more hydrogen or volatile matter; on the E. or N. E. the coal is semi-bituminous, and is used extensively, both raw and coked, in the blast furnaces of the region. On the S. side the coal is of a bituminous character. The change from anthracite to semi-bituminous and bituminous is gradual, and much the same in its metamorphic phases as we find existing in the coal fields of Pennsylvania. There are 16 thin seams of ironstone interstratified with the coal; the general yield of this ore is not over 30 per cent, of metal in the furnace.
The coal production of South Wales in 1854 was 8,550,270 tons; of this amount only 1,000,000 tons was anthracite, the total being the products of 245 collieries. - The anthracites of Pennsylvania exist in four parallel coal fields, in the counties of Schuylkill, Carbon, Columbia, Northumberland, and Luzerne, embracing an area of 470 sq. m. Within these fields numerous parallel basins or synclinal troughs are formed by the peculiar undulations of the strata, which dip at every angle from horizontal to perpendicular. Fig. 2 represents the general grouping of the principal basins of the southern Pennsylvania anthracite field, and the eastern part of the middle field, without reference to local peculiarities and abrupt dips.
Fig. 1. - Anthracite Strata.
Fig. 2. - Group of Pennsylvania Anthracite Basins.
Wyoming or Northern Coal Field............
Middle or Second Coal Field.........
Lehigh Coal Field...................
Big and Little Black Creek........
Lower Black Creek..............
Green Mountain and other small basins.........................
Southern or Schuylkill Coal Field.....
Lehigh Region (E. extremity)...............
Pottsville Lykens Valley Region........
Middle Region (semi-anthracite).........
Dauphin Region (semi-bituminous)
Coal was discovered in the Wyoming valley soon after its settlement, but the first authentic account which we find of the use of anthracite in the United States was in 1768-'9, when it was used by two blacksmiths from Connecticut named Gore. One of these brothers, Jude Obadiah Gore, related the facts to Judge Jesse Fell of Wilkesbarre, who subsequently communicated them to Silliman's " Journal " and Hazard's "Register." In 1776 coal was quarried from the Baltimore bed near Wilkesbarre and the Smith mine near Plymouth, and taken down the Susquehanna in arks to the government arsenal at Carlisle. This trade was continued during the revolutionary war, and anthracite was used by the blacksmiths and gunsmiths of the lower Susquehanna from that time forth; but from the difficulty of making it burn it was not used for domestic purposes till 1808, when Judge Fell succeeded in burning "stone coal" in a grate of his own construction. Anthracite was sold in the vicinity of Wilkesbarre to the smiths at $3 a ton, and in Marietta, on the lower Susquehanna, at $8 to $9 a ton from 1810 to 1814. This was probably the first successful use of anthracite for general purposes in the world.
The earliest record of the production of anthracite in France, as given by Taylor, is in 1814; while Mr. Blakewell, an English geologist, says the Welsh coals were "inferior" and not used for domestic purposes in 1813, and but "little used" in 1828. - The northern or Wyoming coal field is naturally divided into two regions, the Lackawanna and the Wyoming, and these into several districts. The Lackawanna region includes the districts on the Lackawanna creek, which empties into the Susquehanna at Pittston. The districts are the old or original Lackawanna, at and around Carbondale, the Scranton, and the Pittston. Around these centres the early developments of the Lackawanna region were made, and collieries clustered. The Carbondale district was opened in 1829 by the Delaware and Hudson company's canal and railroad; the Scranton district by the Delaware, Lackawanna, and Western railroad, in 1854; and the Pittston ' district by the Susquehanna canal in 1843, and the Pennsylvania coal company's railroad in 1850. The production of the Wyoming or northern coal field in 1871 was 6,481,171 tons. Of this amount 2,867,598 tons was sent from the Wyoming region, and 3,613,573 from the Lackawanna. There are now (1873) nine railroads and two canals employed in transporting coal from these regions.