Volume cx.

The pressure of superincumbent strata, which renders the upholding of the roof, even at fourteen or fifteen hundred feet, a problem of ceaseless anxiety and expense, must also be taken into account. At depths much exceeding two thousand feet, it is very doubtful if the roofs could be securely upheld except at such an outlay as would considerably raise the cost of extraction, while the coal itself would be more and more dense, and therefore more and more difficult to dislodge. For these various reasons, all the strata of coal situated below the depth of two thousand five hundred feet, or at the very utmost three thousand feet, may be considered as practically unworkable; and thus sober-minded calculators, on comparing the available solid contents of our coal-fields with the rate of extraction, have come to the conclusion that a thousand years is the maximum of the probable future supply of England and Wales. Adding to this the Scotch and Irish coal, which are not included in the estimate, and swelling our account with lignite and peat, we have at any rate sufficient materials for keeping our fires burning for a good time to come, and may safely leave all desponding views on the subject to distant generations.

Next to England, no European country has so rapidly increased its coal production as the German empire, where, thanks to the railroads, the consumption of mineral fuel is yearly extending over a wider range, and gradually supplanting in many localities the use of wood. The official tables inform us that in 1866, 432,594,926 cwt. of black coal, and 130,661,182 cwt. of lignite—together, about 28 million tons—were produced, a mass considerably greater than the joint production of France and Belgium, and equal to about seven twenty-fifths of the production of England. The chief coal-fields are those of Upper Silesia, of the Ruhr, of the Saar, of Waldenburg (in Lower Silesia), of Dresden and Zwickau (in Saxony), of Aachen (Aix-la-Chapelle), Ibbenburen, and Minden, which not only supply the greater part of Germany, but also yield a considerable exportation to France, Switzerland, and Holland.

The German ports on the North Sea and the Baltic still largely consume British coal, which, however, has been entirely driven from the Rhine; and Berlin, which in 1860 burnt 202,970 tons of English coal, consumed little more than one-half that quantity (123,401 tons) in 1865, in spite of a considerable increase of population; while at the same time the consumption of coal from Upper Silesia increased from 61,700 to 323,712 tons.

The small but thriving kingdom of Belgium, where the collieries of Liège, Namur, and Hainaut give rise to a commercial activity unequalled on the Continent, occupies the third rank among the coal countries of Europe, its production in 1863 having amounted to 10,500,000 tons. The provinces of Namur and Liège consume almost all the coal they produce, while Mons and Charleroi, in Hainaut, export more than three millions of tons to France.

This country, which, in 1862, produced 9,400,000 tons of coal, requires at least 16,000,000 for its consumption, and imports the difference from Belgium, England, and Germany. The chief coal-basins are situated in the departments of the Loire, du Nord, Saône-et-Loire, and Gard, which furnish about seven-eighths of the whole production. Austria, whose principal coal mines are situated in Bohemia, produces about 3,500,000 tons. Spain possesses magnificent coal-fields in the Asturias and Santanders, but as yet they have been but little worked.

Besides the coal-basins of the mother country, Britain is richly provided with coals in many of her colonies. In New South Wales and Tasmania, in Labuan and Farther India, in Hindostan and New Zealand, in British Columbia and Honduras, valuable basins or seams of coal have been discovered; and a magnificent coal-field, far surpassing in magnitude those of the British Islands, extends from Newfoundland, by Cape Breton, Prince Edward Island, and Nova Scotia, across a large portion of New Brunswick. Thus far it has been but little worked, in countries but thinly peopled, and covered for the most part with boundless forests; but as from its general proximity to the sea it offers every advantage for mining operations, a brilliant future may safely be predicted for the lands it underlies.

The coal-fields of the United States are of still more ample proportions, as they surpass in extent all the known coal-basins of the world besides. Beyond the Alleghany Mountains we find the magnificent Appalachian Coal-field, traversing eight of the principal States in the American Union, from the northern frontiers of Pennsylvania to Alabama, and covering a space of about sixty-five thousand square miles.

Of scarcely inferior extent are the vast coal-fields of Indiana, Illinois, and Kentucky, which nearly equal in magnitude the whole of England; and another smaller but highly important coal region is situated between the lakes Erie, Huron, and Michigan, not to mention the minor coal-basins scattered here and there from Texas to Missouri, and from New York to Maine.

As yet, the Americans have not derived full benefit from their extraordinary coal deposits; but the possession of so vast an accumulation of _power_ allows us to predict a future of almost boundless enterprise and production for that wonderful country.

While in most of our coal-seams deep shafts have to be sunk to obtain the coal, and steam power has to be constantly employed to prevent its submersion, the Appalachian Coal-field is intersected by three great navigable rivers, the Monongahela, the Alleghany, and the Ohio, all of which lay open on their banks the level seams of coal. At Brownhill, on the first of these rivers, the main seam of bituminous coal, ten feet thick, breaks out in the steep cliff at the water’s edge. Horizontal galleries may be driven everywhere at very slight expense, and so worked as to drain themselves, while the cars laden with coal, and attached to each other, glide down on a railway so as to deliver their burden into barges moored to the river’s bank. The same seam may be followed the whole way to Pittsburg, fifty miles distant. Being nearly horizontal, it crops out, as the river descends, at a continually increasing, but never at an inconvenient, height above the Monongahela. Besides this main seam, another layer of workable coal, six feet thick, breaks out on the slope of the hills at a greater height. Here almost every proprietor can open a coal pit on his own land, and the stratification being very regular, he may calculate with precision the depth at which coal may be won.

One of the most remarkable collieries in the world is that of Maunch Chunk (or the Bear Mountain) in Pennsylvania, where an enormous bed of anthracitic coal, nearly sixty feet thick, and probably caused by the doubling back of a twenty-eight feet seam upon itself, is quarried in the open air; the overlying sandstone, forty feet thick, having been removed bodily from the top of the hill, which, to use the miners’ expression, has been ‘scalped.’