Cumberland coal, being remarkably free from sulphur, is admirably adapted for the smelting of iron and other ores. It makes a beautiful compact coke, and in this shape is unsurpassed for the manufacturing of all kinds of metal. For the forge or blacksmith-shop it is inestimable. It makes a cheerful, bright fire, gives out a steady heat, and resembles more nearly a wood-fire than that from any other variety of coal.
It has been urged by interested parties, and by others ignorant of its qualities, that Cumberland coal is dangerous by reason of its liability to spontaneous combustion. A more absurd or baseless hypothesis could not have been advanced. Careful analyses by the most skillful experts have effectually disposed of these invidious assertions, but as experience far outweighs the testimony of science, however positive may be its conclusions, careful inquiries instituted in the coal-fields along the Chesapeake and Ohio Canal, and at the depots where the coal is stored, have failed to disclose a single case of combustion without active extraneous interference. It has been exposed to the air in large heaps for several seasons, placed in damp cellars and piled on dry floors, stored away in barrels or in the holds of canal-boats, but it has invariably failed to gratify the anxieties of its enemies, whose inconsistency and eagerness have led them into the unpardonable error of asserting, at the same time that they urge its tendency to spontaneous combustion, that it is not sufficiently combustible.
The middle coal-field of Allegany is situated between Negro and Meadow Mountains. The coal approaches nearest in its composition to the Pittsburgh coal. It is a fine, compact mineral, and is only debarred from general use by lack of the means of transportation. There are three veins here, one of about forty inches in thickness, one of four feet, and another of about five feet. But comparatively a small portion of this coal-field lies in Maryland. The western coal-field lies in the valley of Youghiogheny River, and is destined to become an interest of great importance for the manufacture of the iron ores, which are associated with it in large quantities. It is very similar in quality to the coal in the middle field. As soon as a railroad shall penetrate this field, which is a matter of near accomplishment, a great industry will be developed. The coal veins in this region are a two-foot vein, a four-foot vein, a six-foot vein, and a five-foot vein. All these coal-fields, by reason of the peculiar formation of the country, — it being intersected by ravines, — can be very readily worked. Many of them drain themselves, and can be ventilated at a trifling expense. In the value of coal-lands this is a very important item, and materially lessens the cost of mining, while in the same measure it increases the profits.
On Town Hill, in the eastern section of the county, there is another coal formation, but the owners have as yet done but little in the direction of development.
The iron ore in this county may be divided into four kinds, — fossil, iron ore, red and brown hematite, and the clay iron-stone of the coal formation. At the head of Merley's Run, on the western slope of Warrior Mountain, there are found large quantities of red hematite ore. The vein is seen at intervals for a space of a mile and a half, and induces the belief that it exists there in very large quantities. This is strengthened by examinations made on the eastern slope of the same mountain, overlooking Town Creek. Here for several miles the red hematite shows itself, and at one opening made the bed disclosed a thickness of eighteen inches. It was opened far enough into the hillside to prove it to be a regular stratum lying between strata of brown shale. The ore, as far as penetrated, is a compact argillaceous oxide of iron, but has been changed by atmospheric agency. The quantity here is sufficient to justify the erection of furnaces on a large scale. The ore is of fine quality, and makes good malleable iron.
The abundance of large pieces strewn on the surface indicates the existence of other strata. There are good indications on a spur of Polish Mountain, near the Potomac.
Between Martin's and Evitt's Mountains, near the junction of the red shaly sandstone and the clay limestone soils, hematite ore also exists in considerable quantities.
The fossil ore and hematite are found in distinct veins on Dan's Mountain. As both of the ores in this locality have been worked for a long time, a particular description of them is deemed unnecessary. These veins have in a great measure supplied the furnaces in this. part of the country with ore, and are of very great extent. In the valley of Jennings' Run and its tributaries there are also hematite and clay ironstone ores, but not in large quantities. The evidences of its existence greatly increase as we approach the Pennsylvania line. Near Frostburg there are found two veins on the head-waters of George's Creek, which are from ten inches to three feet in thickness. The ore is of fine quality, and extends over a large space.
There are also found large bodies of red hematite ore on the benches of Meadow Mountain and the heads of several of the branches of Savage River. At the Little Crossings there is an immense deposit of bog-iron ore, and associated with the coal veins found there is also clay iron-stone (carbonate of iron). The ore here of each kind is rich in quality and of very great extent.
By far the largest quantity of iron ore is found in Garrett County, in the coal-fields of Youghiogheny River and its tributaries, which lie in the coal basin. On either flank of Will's Mountain there are outcroppings of important strata of iron in the formation. It is called the Clinton Group in the New York reports, and Sargent Shales in Pennsylvania. There are several strata of ore, some of which are too thin to be profitably mined. The lower strata, called hard ore, contain much sand, and vary in composition considerably, but usually contain less iron than those higher in the series, called fossil ores, because of the numerous impressions of fossil shells which they contain.
There is an outcrop of hard ore five feet in thickness a mile and a half above Cumberland (on the Baltimore and Ohio Railroad), containing twenty-four and three-quarters per cent, of metal. The fossil ore varies in the proportion of iron from thirty-five to fifty per cent., and has been extensively used in the furnaces at Mount Savage and Lonaconing. Much of it contains sufficient phosphoric acid to affect injuriously the quality of the metal.
There are several varieties of the carbonate of iron in the coal-fields, differing in appearance as well as in their proportion of iron. They exist either in flattened nodules, called " balls" by the miners, or in stratified masses called bands. The balls vary in weight from two or three to ten, and sometimes twenty, pounds, and are imbedded in courses in either shale or fire-clay. The bands are interposed between beds of shale, and are called clay bands and black bands.
These ores usually contain from thirty to thirty-six per cent, of iron, but there are some bands containing only twenty-five per cent., which will be available because of the low price for which they may be mined and delivered to furnaces.
Among the clay bands there is a thick stratum, which examination made at a point on Laurel Run, three miles from Lonaconing, in the George's Creek region, proved to be six feet thick, and it was found to contain twenty-five per cent, of iron. It rests upon a bed of shale six feet thick, which, although highly ferruginous, does not contain a sufficient proportion of the metal to constitute a workable ore. Numerous other bands of ore of lesser thickness, but richer in iron, exist in this coal-field which need not be particularly described.
There is, however, a variety of black band of sufficient importance to require special notice. This name was first applied by Mr. Mushett to an ore discovered by him in the year 1801, but which was not generally recognized until the year 1825, because it differed so materially in appearance from the ores formerly used in coal regions that iron-masters were slow to believe it to be an iron ore.
At its outcrops, the black band, owing to the action of atmospheric agents, crumbles down and becomes mixed up with the adjacent earthy matters, so as to give slight indications of its presence. The nodules and clay bands at their outcrops present themselves in larger pieces, which often resemble the earthy varieties of hematite, and indicate the proximity of the ores in their regular strata. The most important black band in the George's Creek coal-field lies about one hundred and seventy-seven feet below the main or fourteen. foot coal-bed, which was opened at several points during the progress of the explorations above referred to. It was ascertained that this valuable ore occupies an area of many square miles.
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