MAMMOTH CAVE, in Edmondson county, Kentucky, United States, 37° 14´ N. lat. and 86° 12´ W. long., by rail 85 miles south-south-west of Louisville, was discovered, in 1809, by a hunter named Hutchins, while in pursuit by a wounded bear. Its mouth is in a forest ravine, 194 feet above Green river, and 600 feet above the sea. This aperture is not the original mouth, the latter being a chasm a quarter of a mile north of it, and leading into what is known as Dixons Cave. The two portions are not now connected, though persons in one can make themselves heard by those in the other. Salpetre was formerly made from the nitrous earth in which the cave abounded ; but it is now mainly turned to account as a place of exhibition.
The cavernous limestone of Kentucky covers an area of 8000 square miles, is massive and homogeneous, and belongs to the Subcarboniferous period. It shows few traces of dynamic disturbance, but has been carved, since the Miocene epoch, into many caverns, of which the Mammoth Cave is the noblest specimen known. The region is undulating, but valleys are mostly funnel-shaped depressing emptying through fissures into subterranean streams, which feed rivers, often of navigable size, and whose waters, and never frozen over, even in severe winters. Such valleys are called sink-holes.
The natural arch that admits one to Mammoth Cave has a span of 70 feet, and from a ledge above it a cascade leaps 50 feet to the rocks below, where it disappears. A winding flight of the stone steps leads they way down to a narrow passage,. Through which the air rushes with violence, outward in summer, and inward in winter. The temperature of the cave is uniformly 54° Fahr. throughout the year, and the atmosphere is both chemically and optically of singular purity. While the lower levels are moist from the large pools that have secret connexion with Green river, the upper galleries are extremely dry. These conditions led, at one time, to the erection of thirteen cottages, at a point about 1 mile under ground, for the use of invalids, especially consumptive. The experiment ended in failure, and only two cottages now remain.
The Main Cave, from 40 to 300 feet wide, and from 35 to 125 feet high, has several vast rooms, e.g., the Rotunda, where are the ruins of the old saltpeter works ; the Star Chamber, where the protrusion of white crystals through a coating of the black oxide of manganese creates an optical illusion of great beauty ; the Chief City, where an area of 2 acres is covered by a vault 125 feet high, and the floor is strewn with rocky fragments, among which are found numerous half-burnt torches made of canes, and other signs of prehistoric occupancy. Two skeletons were exhumed near the Rotunda ; but no other bones of any description have been found. The so-called Mammoth Cave "mummies" (i. e.,. bodies kept by being inhumed in nitrous earth), with accompanying untensils, ornaments. Braided sandals, and other relics, were found in Short and Salt caves near by, and removed to Mammoth Cave of exhibition. The Main Cave, which abruptly ends 4 miles from the entrance, is joined by winding passages, with spacious galleries on different levels ; and, although the diameter of the are of the whole cavern is less than 10 miles, the combined length of all accessible avenues is supposed to be about 150 miles.2
The chief points of interest are arranged along two lines of exploration, besides which there are certain side excursions. The "short route" requires about four hours, and the "long route" nine. Audubons Avenue, the one nearest the entrance, is seldom visited, except by the bats that hang from the walls in clusters like swarms of bees. The Gothic Avenue contains numerous large stalactites and stalagmites, and an interesting place called the Chapel, and ends in a small double dome and cascade. Among the most surprising features of cave scenery are the vertical shafts that pierce through all levels, from the uppermost galleries, or even from the sink-holes, down to the lowest floor. These are styled pits or domes, according to the position occupied by the observer. A crevice behind a block of stone 40 feet long by 20 wide, called the Giants Coffin, admits the explorer to a place where six pits, varying in depth from 65 feet to 220 feet, exist in an area of 600 yards. This includes Gorins Dome, which is viewed from a point midway in its side, and is by many regarded as the finest room in the cavern. Others, admire more the Mammoth Dome, at the termination of Sparks Avenue, where a cataract falls from a height of 250 feet amid walls wonderfully draped with stalatitic tapestry. The Egyptian Temple, which is a continuation of the Mammoth Dome,
the crystal fibres curl outwards from the centre of the group. Thus spotless arches of 50 feet span are embellished by floral clusters and garlands, hiding nearly every foot of the grey limestone. The botryoidal formations hanging by thousands in Marys Vineyard resemble mimic clusters of grapes, as the oulopholites resemble roses. Again there are chambers with drifts of snowy crystals of the sulphate of magnesia, the ceiling so thickly covered with their efflorescence that a loud concussion of the air will cause them to fall like the flakes of storm.
Many small rooms and tortuous paths, where nothing of special interest can be found, are avoided as much as possible on the regular routes ; but certain disagreeable experiences are inevitable. There is peril also in the vicinity of the deep pits. The one known as the Bottomless Pit was for many years a barrier to all further exploration, but is now crossed by a wooden bridge. Long before the shaft had been cut as deep as now, the water flowed away by a channel gradually contracting to a serpentine way, so extremely narrow as to be called the Fat Mans Misery, the walls, only 18 inches apart, change direction eight times in 105 yards, while the distance from the sandy path to the ledge overhead is but 5 feet. The rocky sides are finely marked with waves and ripples contains six massive columns, two of them quite perfect, and 80 feet high and 25 feet in diameter. The combined length of these contiguous chambers is 400 feet. By a crevice above they are connected with an arm of Audubons Avenue. Lucys Dome, about 300 feet high, is supposed to be the loftiest of all these vertical shafts. A pit called "the Maelstrom," Croghans Hall, is the spot most remote from the mouth of the cave ; a son of Prentice, the poet, permitted himself to be lowered 190 feet by a rope to the bottom, in 1859. There are some fine stalactites near this pit, and others in the Fairy Grotto and in Pensio Avenue ; but, considering the magnitude of Mammoth Cave, its poverty of stalactitic ornamentation is remarkable. The wealth of crystals is, however, surprising. These are of endless variety and fantastic beauty. Besides the sparking vault of the Star Chamber (300 feet long and 80 high), there are halls canopied by fleecy clouds, or studded with mimic snowballs, and other displaying various grotesque resemblances on the walls and ceiling.
Clavelands Cabinet and Marions Avenue, each a mile long, are adorned by myriads of gypsum rosettes and curiously twisted crystals, called "oulopholites." These cave flowers are unfolded by pressure, as if a sheaf were forced through a tight binding, and as if running water had suddenly been petrified. This winding way conducts one to River Hall, beyond which lie the crystalline gardens that have been described. It used to be said that, if this narrow passage were blocked up, escape would be impossible ; but lately an intricate web of fissures, called the Corkscrew, has been discovered, by means of which a good climber, ascending only a few hundred feet, lands 1000 yards from the mouth of the cave, and cuts off one or two miles.
The waters, entering through numerous domes and pits, and falling, during the rainy season, in cascades of great volume, are finally collected in River Hall, where they form several extensive lakes, or rivers, whose connexion with Green river is known to be in two deep springs appearing under arches on its margin. Whenever there is a freshet in Green river the streams in the cave are joined in a continuous body of water, the rise sometimes being 60 feet above the low-water mark. The subsidence within is less rapid than the rise ; and the streams are impassable for about seven months in each year. They are navigable from May to October, and furnish interesting features of cave scenery. The first approached is called the Dead Sea, embraced by cliffs 60 feet high and 100 feet long, above which a path has been made, whence a stairway conducts us down to the banks of the River Styx, a body of water 40 feet wide and 400 feet long, crossed by a natural bridge. Lake Lethe comes nexta broad basin enclosed by walls 90 feet high, below which a narrow path leads to a pontoon at the neck of the lake. A beach of the finest yellow sand extends for 500 yards to Echo river, the largest of all, being from 20 to 200 feet wide, 10 to 40 feet deep, and about three-quarters of a mile long. It is crossed by boats. The arched passage-way is very symmetrical, varying in height from 10 to 35 feet, and famous for its musical reverberations, not a distinct echo, but an harmonious prolongation of sound for from 10 to 30 seconds after the original tone is produced. The long vault has a certain keynote of its own, which, when firmly struck, excites harmonics, including tones of incredible depth and sweetness.
The fauna of Mammoth Cave has been classified by Putman, Packard, and Cope, who catalogued twenty-eight species truly subterraneous, besides those that may be regarded as stranglers from the surface. They are distributed thus: Vertebrata, 4 species ; Insecta, 11 ; Arachnida, 6 ; Myriapoda, 2 ; Crustacea, 2 ; Vermes, 3. Ehrenberg adds a list of 8 Polygastric Infusoria, 1 fossil infusorian, 5 Phytolitharia, and several microscopic fungi. A bed of Agricus was found by the writer near the River fungi. A bed of Agaricus was found by the writer near the River Styx ; and upon this hint an attempt has been made to propagate edible fungi in this locality. The most interesting inhabitants of Mammoth Cave are the blind, wingless grasshoppers, with extremely long antennae ; blind, colourless crayfish (Cambarus pellucidus, Telk.) ; and the blind fish, Amblyopsis spelaeus, colourless and viviparous, from 1 inch to 6 inches long. The Cambarus and Amblyopsis have wide distribution, being found in many other caves, and also in deep wells, in Kentucky and Indiana. Fish not blind are occasionally caught, which are apparently identical with species existing in streams outside. The true subterranean fauna may be regarded as chiefly of Pleistocene origin ; yet certain forms are possibly remnants of Tertiary life. The strongly marked divergence of these animals from those found outside convinced the elder Agassiz that were specially created for the limits within which they dwell. But the opinion now held is that they are modified from allied species existing in the sunlight, and that their peculiarities may all be accounted for on principles of evolution,the process being accelerated (or retarded) by their migration from the outer world to a realm of absolute silence and perpetual darkness.
The literature of Mammoth Cave is extensive, though scattered though many periodicals, volumes of travels, and scientific reports. See especially Bullitt, Rambles by a Visitor, 1844 ; Collins, History of Kentucky, 1847 ; Forwood, The Mammoth Cave, 1870 ; Packard and Putnam, Inhabitants of Mammoth Cave, 1872 ; Shaler, Memoirs of Geological Survey of Kentucky, 1876 ; Hovey, "In Mammoth Cave," Scribners Magazine, 1880 ; Celebrated Caverns, 1882. (H. C. H.)
The above article was written by: Rev. Horace Carter Hovey; author of Celebrated American Caverns: Mammoth, Wyandot, and Luray.