556 ANTHRACITE in this basin uncertain and precarious. The coal of Price's mountain basin is a true anthra- cite, but less dense, lustrous, and pure than that of Pennsylvania. The Brush mountain basin lies at the E. base of the North mountain, and resembles the opposite Price's mountain basin in lithological structure ; but the inverted strata of the W. side have been destroyed, ex- cept in a few localities, by erosion. In some few places where the inverted strata exist in this basin, they are folded back, so that the coal beds, which in their normal condition must have dipped to the west, are now lying on their opposite dip, and the strata of the entire basin in such localities dip east, abutting abruptly against the underlying sandstones or limestones. The coal of this basin is semi-anthracite. Coal has been mined in a small way from numerous localities in these basins, but to the present time (1873) it has all been drawn in wagons from the mines to the Virginia and Tennessee rail- road, a distance of from 2 to 8 m. The total amount mined cannot exceed 15,000 to 20,000 tons up to the year 1873. It has been used successfully in grates, stoves, cupola furnaces, puddling furnaces, and locomotives, but has not been tested in the blast furnace. Near the surface the coal is weak and friable, but at con- siderable depth it becomes more dense, solid, and pure. Much aluminous and carbonaceous shale exists in connection with this coal, and sometimes excludes it entirely, forming a "fault." The entire area of these two basins cannot exceed 10 sq. m. They are merely nar- row synclinal belts, with an occasional repeti- tion or fold forming two parallel basins, seldom more than 500 yards wide inclusively. The coal-bearing strata of this range or belt, how- ever, are much more extensive than those em- braced in the New river coal field, and extend over 200 m. N. E. and nearly 100 m. S. W. It is found in Sidelong hill, a continuation of Blue or North mountains in Pennsylvania, and ex- ists in a basin of considerable extent on North mountain, a short distance "W. of Martinsburg, "West Va. In this locality there are two basins, one on the E. side of the mountain and another on the W. side, or rather on the summit of the mountain. That on the east is narrow and folded in the form of a F, the left or E. side inverted in the usual form of this range ; but that on the summit is more regularly stratified, forming a comparatively shallow basin. Here we find all the indications of a true basin of the carboniferous era. The conglomerate and the red shale (Nos. XII. and XI. of the Pennsyl- vania geological survey) are in regular order and position, and the lower beds of coal are identi- cal with A, B, and C of the Pennsylvania fields, in the order of stratification, character of bed, and color of ash. The area of this small upper basin is perhaps 5 sq. m. It lies on the head waters of Back creek, which flows into the Potomac W. of Martinsburg. Yet notwithstanding the greater regularity and or- der of these anthracite beds, they are faulty and too small and impure to be mined for ordinary commercial purposes. The beds range from 3 to 5 ft. in thickness, of which two thirds may produce marketable coal. This range of coal- bearing strata may be traced with occasional gaps from this place to New river. The coal beds have been developed in a small way at the Dora mines on the North fork of the Shen- andoah, W. of Staunton, where anthracite of good character has been mined for local use. The next point at which the coal has been mined is W. of Fincastle on Catawba creek. From here it has been dug into in many places to the Brush mountain basin on New river, and from New river it has been opened at m ap- points to the Tennessee line ; but the only localities yet developed, where this range con- tains beds in workable condition and produc- tive of good coal for ordinary purposes, are those particularly described, including the Dora mines, which however are the most doubtful. This range of coal deposits has always been considered by geologists as belonging to the Sroto-carboniferous or false coal measures, ecent investigations have cast doubt on this classification, and those most familiar with the geology of the region are inclined to place it in the true coal measures as identical with the strata of the Pennsylvania coal fields. Besides the principal anthracite fields already described, there are other small, partially developed, and less known deposits of anthracite in Arkansas, New Mexico, Sonora, and Oregon. Of the re- maining anthracite deposits of the world, those of France are most largely developed. The first and most extensive is a continuation of the Belgian coal field, in the department of Le Nord. The coal is of a dry or semi-anthracite character in a portion of the French extension, and about one half the coal products of this field is denominated anthracite in the French reports, but it is not strictly anthracite. The other French fields producing anthracite are named from the departments of Pas-de-Calais, Calvados, Sarthe, Maine-et-Loire, Loire-Infe- rieure, Correze, Puy-de-D6me, Haute-Sa6ne, Tarn, Ilaute-Loire, Ardeche, Isere, and Hautes- Alpes. The total annual production of coal in France is now (1873) over 10,000,000 tons, of which about 2,000,000 tons is-anthracite and semi-anthracite, and of the latter more than one half is the product of the field of Le Nord. The European anthracite field next in impor- tance to these is that of Donetz in 8. Russia, between the Dnieper and Donetz rivers, which is perhaps the largest connected field contain- ing anthracite yet developed. It embraces over 8,000 sq. m. of coal area, but, like the South Wales and Pennsylvania anthracite fields, one end contains anthracite and the other bitumi- nous coal beds, according to Murchison ; while anthracite and bituminous beds are found in the same locality, and the undulations of the strata, which dip from 20 to 70, indicate a close resemblance to the peculiarities of th<> Pennsylvania anthracite fields. An analysis ol
