DESCRIPTION OF THE MAP.
The upper, or northern, end of the St. Clair, or Coosa, coal-field is near Gadsden, on the Coosa River. There appears to be no immediate connec tion between this isolated coal deposit and the larger area to the west, or the coal of Lookout Mountain to the north. But there is an evident de pression of the great Lookout range to the south, carrying the coal down with it. The seams on the northeast of this deposit are extremely thin, seldom over 18 inches thick, but very pure and clean. We should take the only seam we saw open, and the only one that appeared to exist at its northern extremity, to be A, or the lowest coal in the field. But about 30 miles farther to the south, nearly opposite Talladega, the next upper seam, B, is found ; and farther south a "split" of B, or the next seam, C, exists.
A never gets over 3 or 4 feet thick in the Alleghany coal-field, but B is sometimes 20 feet in thickness. Here it is about 5 feet when in its best condition; but farther south, on Broken Arrow Creek, and at Montevallo, it increases to 10 feet,—at the expense, however, of its purity. In St. Clair county, and particularly the mines on Trout Creek, the coal of B is ex cellent, containing about 30 per cent. of bitumen, and coking readily. It forms a hard, pure, and silvery coke, of the best description for the blast furnace or cupola.
The seam, where worked by Raglan & Co., on Trout Creek, nearly opposite Talladega, and 20 miles to the west of that place, was about five feet thick at the time of our last visit to this region. It was worked by a shallow shaft near the outcrops of the seam, and both water and coal were brought up by horse-power. The work was conducted on the most primitive order and in the most costly manner; while the coal was hauled 20 miles in wagons, over the worst of mud roads, to the railroad at Talladega, or hauled to the Coosa, and then floated in arks down that rapid and dangerous river to Montgomery, some 160 miles distant. Generally, about two out of every three of these arks got safely through. Yet on this pre carious supply did the foundries of Montgomery depend, since the coal of Montevallo, which went by rail to Selma, is not fit for smelting purposes. In fact, it is the worst coal to be used as a fuel that we ever saw, and con tained, besides much sulphur, about 20 per cent. of ash. It is singular that the coal in the middle and northern portion of this deposit should be so extremely pure, and that of the south so extremely impure.
That portion of the field on the Black Warrior River, which is by far the larger body, may contain the third or fourth seam, in the lower series, but we could not recognize any above B, which undulates much, and comes in constantly recurring waves to the surface ; though in the extreme southern edge of the field most of the coal is below water-level, and covered with the cretaceous formation of the Gulf shores. This part of
the field is, therefore, low, and the coal-seams appear to dip towards and under the cretaceous strata until lost to sight and gone with a final plunge under the Gulf. (?) The strata rise rapidly towards the head of the streams until they reach the elevation of the Lookout range, and the plateaus of the Great Sand Mountain, overlooking the waters of the Ten nessee.
Coal has been worked for a considerable period in Alabama at many localities, but chiefly on the Coosa, at Montevallo, on the Cahawba, on the Black Warrior, and on the Tennessee Rivers; but everywhere in the most primitive and costly manner.
We notice Professor Tuomey's remarks about the cheapness of diving for coal in the waters of Alabama, and we have no doubt any mode of mining coal would be cheaper than those generally practised. We have seen im mense areas of a coal-seam uncovered to the depth of ten and twenty feet to obtain 30 inches of coal, and that generally below water-level. Ten tons of earth were removed for every ton of coal obtained, at many points along the Coosa, when a simple water-level might have obtained the same coal at one-tenth the labor, Immense deposits of excellent iron ore exist almost entirely around the Alabama coal districts; but the best and most abundant appears to lie to the east of the coal. We have seen masses of the richest hematites, that may be called mountains without exaggeration, and beds of splendid fossi liferous iron-stone that could be traced for a hundred miles, parallel with the Coosa. These ores were used extensively in the charcoal furnaces; but we have yet to hear of a single coke-furnace in Alabama, or of a pound of iron having been made with mineral fuel in the blast-furnaces of that State.
The amount of coal mined in Alabama may be stated at 300,000 tons per annum.
Figure 126, from Taylor's Statistics, represents imperfectly the relative position of the coal-deposits of the Coosa and the Warrior. Both are represented at greater angles of dip than they naturally assume, and the number of seams on the Coosa is less than those represented. It is possible, however, that the seams are repeated by inversion on the east side of this field, as the strata in that direction are sharply folded, and the Great Valley limestone apparently overlaps the coal, much the same as it does at the New River coal-field in Virginia.
That portion of the field in Georgia is exceedingly limited, and similar to the coal of Tennessee. We shall not notice it separately, as Georgia receives all her coal from Tennessee, except such anthracite as may be received at her ports.