History of Western Maryland. J. Thomas Scharf
Horizontal drifts have been run through various distances to the belts of coal, but the thickest reached has not exceeded two inches. Fuel of such a nature being so very valuable in the vicinity of a large city might naturally attract the attention of capitalists, but a very thorough examination has shown that these beds do not belong to the carboniferous, or true coal formation, and that accordingly no large important deposits of this mineral need be expected in this region. The specimens examined from other parts of the new red sandstone belt have been fragments of calamites or other plants, having the black color and somewhat the appearance of coal, but possessing none of its most valuable properties.
Washington County, and the Great Valley. — This county is proportionally the longest and narrowest in the State. It extends from the summit line of the South Mountain chain to the western base of Sideling Hill; the creek of that name separating it from Allegany County. It stretches from east to west over a distance of forty-four miles, and its greatest length from north to south is about twenty-eight miles. Pennsylvania bounds it on the north, and the Potomac River separates it from Virginia on the south. Its general outline suggests the shape of a boot, the heel being at the bend of the South Mountain near its northern extremity, the toe at the Potomac River next to Elk Ridge, and the top of the leg at Sideling Hill. The entire area of the county is about four hundred and sixty-three square miles, of which more than three fourths are included in the Hagerstown Valley. At Hancock the county is contracted to a width of about one mile and a quarter by the great bend in the Potomac River.
The county may be properly divided into two natural sections, of which the smaller and most western belongs to the Appalachian Belt, while the eastern and larger, forming one of the grand divisions closely connected with the Blue Ridge Belt, is the Great Valley.
The Great Valley. — This great feature of the central mountain system forms the most important part of the territory of Washington County. It is a broad depression lying between the South Mountain range on the east and the North Mountain on the west. Its breadth between these two ridges is from twenty to twenty-three miles, while its length from north to south is about twenty-eight miles. That part of it within these limits is known as the Hagerstown, or Antietam Valley. No natural boundary separates this from its northern extension, called the Cumberland Valley, in Pennsylvania, but on the south it is detached from the Shenandoah Valley by the basin of the Potomac River. No depression of the surface of equal magnitude, beauty, and fertility exists on the eastern side of the United States. It forms also the principal valley within the State of Maryland, and yields to none in productiveness of the soil and in the grandeur and variety of its scenery. It is not a simple trough circumscribed by two great elevations of surface, but minor waves of uplift traverse it in various parts, running mainly from north to south. Nor is it a single hydrographic basin, for the Antietam River runs through its principal depression on the east, and the Conococheague River drains the section on the west. On the northern end the eastern division is set with high swells of surface, some of which rise into spurs running parallel to the main body of the South Mountain. The general level of the valley is probably somewhat more than five hundred feet above the level of the sea, and in the more northern parts rises to about seven hundred feet, while its southern extremity, near the Potomac River, slopes down to about two hundred and seventy-five feet.
On the west the Conococheague River winds in great loops through a somewhat less elevated basin, but where the country rises into an abrupt ridge along the belts of slate rocks. Almost the whole valley is spread with large farms of unsurpassed fertility. Being so generally underlaid by limestone, the soil is particularly well adapted to raising cereals and grasses, and accordingly it produces the largest crops of wheat and other grain to be met with in the State.
The limestone is chiefly of the strong, compact, dark-blue variety, invaded by seams and veins of white; but in certain sections,. as between Sharpsburg and Boonsborough, drab, yellowish-red, pale blue, and white occur in large beds. Many of the varieties from this section are very fine and massive, they take a fine polish, and can be taken out in monoliths of almost any required dimension. Between Keedysville and Boonsboro' a very hard, dense, bluish, wavy limestone forms a belt about five hundred feet wide, running from northwest towards the southeast, which may be removed in large slabs, and is highly esteemed for pavements and for buildings. It is called knuttle, is easily wrought, and proves to be an attractive and most enduring building-rock. In the neighborhood of Keedysville many varieties of stone suitable for industrial purposes are quarried. About one-half mile south of this place a species of fine-grained calcareous rock, white or yellowish in color, marked with wavy lines and zigzag streaks of brown or black, is extensively quarried, sawed into blocks, and dressed. It is a most novel variety, is easily worked, takes a good surface, and may be taken out in thick slabs of immense size. The ledges, angular hills, and masses of limestone rock, particularly in this part of the valley, are so striking as to arrest the attention, and give a highly picturesque effect to the landscape. A white, coarse-grained, distinctly crystalline limestone also occurs in this vicinity. It is really a hard marble, and is said to take a good polish. South of Boonsboro' a fine variety of this white marble abounds, which is remarkably free from impurities and foreign elements. It equals the Tuscan statuary marble in purity of color and evenness of texture, while it takes a fine polish, and readily admits the chisel of the sculptor. As these latter rocks have not yet been sufficiently developed, it will be necessary to penetrate deeper into their mass to reach the large blocks best adapted for fine monuments and sculpture. The auroral blue limestone, which forms the underlying bed of nearly the whole valley, the chief exceptions being the slates of the Conococheague belt and of the base of the Elk Ridge and South Mountain, belongs to the most extensive formation of this rock in North America.
Caves and Caverns. — A great variety of curious cavities occurs in this limestone, which lines the basin of the Great Valley. This is of the same kind of rock as that in which the Mammoth Cave, the Luray caverns, and all the celebrated caves of the Eastern United States occur. No correct idea can yet be formed of the number and extent of the cavernous spaces which lie concealed in the almost fathomless rock which underlies this valley. Sink-holes and openings in the surface of many farms, and particularly in the neighborhood of Williamsport and Hagerstown, attest the presence of a former deep underground drainage; and even now small streams of water are said to disappear beneath the surface and become lost to further observation. In the vicinity of Keedysville the yellowish calcareous rocks are cavernous, and cavities of a few feet in diameter are frequently discovered. These have usually been excavated by currents of spring and rain-water, carrying a certain amount of carbonic or other acids in solution, and softening and transporting the materials of the rock into which they find an entrance.
The most considerable and well-known caves at present accessible in this valley are those at Cavetown, on the Western Maryland Railroad, about seven miles east of Hagerstown. They are situated in a ridge, along the flank of which the railroad runs, the summit of which rises more than eighty feet above the track. The limestone composing the hill is of two kinds. The upper, or sandy strata, called " rocklime" by the quarrymen, mixed with siliceous and other impurities, is from five to fifteen feet in thickness; the lower and bed-rock of the country is the well-known blackish-blue compact limestone, so rich in lime, which is the most highly-prized fertilizer to be found in Washington County.
The entrance to the larger, or Bishop's, cave is a hole formed by the falling in of the wall of rock, leaving an aperture ninety-two feet wide and eight feet high. It is entered at a point about twenty-five feet above the level of the railroad, and is nearly one hundred feet west of Cavetown Station. A great deal of debris has fallen into the mouth of the cave, occupying an area of at least one hundred feet wide by thirty feet long and thirty deep. The first cavern entered forms a large hall, fairly well illuminated by daylight, sloping inward about twenty feet to a nearly level floor. It is almost circular, has a diameter from north to south of two hundred feet, a length of two hundred feet from east to west, and a height varying from thirty-five to forty-five feet. Formerly the walls, ceiling, and floor were studded with an endless variety of stalactites and stalagmites of almost every pattern and peculiarity. Unfortunately, the easy access to this cave made it ever open to the vandalism of curiosity-seekers, and accordingly it has been rifled of all the smaller-sized specimens which once belonged to it. Possibly by the planting of trees upon the hill, and by the consequent return of dripping moisture, it may be once more restored to