Mammoth Cave is situated near the Green river in Kentucky, the entrance to which is by a pit forty feet deep, and one hundred and twenty in circumference. At the bottom of this pit is the mouth of the cave, which is open to the north, and is from forty to fifty feet in height, and thirty in width, for upwards of forty rods, when it becomes not more than ten feet wide and five feet high. ‘However,’ says Dr. Wood, ‘this continues but a short distance, when it expands to thirty or forty feet in width, and is about twenty feet in height, for about one mile, until you come to the first hopper, where salt-petre is manufactured. Thence it is about forty feet in width, and eighty in height, till you arrive at the second hopper two miles from the mouth. The loose limestone has been laid up into handsome walls on either side, almost the whole distance from the entrance to the second hopper. The road is hard, and as smooth as a flag pavement. The walls of the cavern are perpendicular in every passage that I traversed; the arches are regular in every part, and have bid defiance even to earthquakes. As you advance into the cave, the avenue leads from the second hopper west one mile, then south-west to the chief city, which is six miles distant from the entrance. This avenue is from sixty to one hundred feet high, and about the same broad, the whole distance from the second hopper, until you come to the cross-roads or chief city; and is nearly upon a level, the floor or bottom being covered with loose limestone and salt-petre earth. When I reached the immense area, (chief city,) containing upward of eight acres, without a single pillar to support the arch, which is entire over the whole, I was struck dumb with astonishment, and can give but a very faint idea of its splendor. Nothing under heaven can be more sublime and grand than this place, covered with one solid arch, at least one hundred feet in height, and to all appearance entire. After entering the chief city, I perceived five avenues leading out of it from sixty to one hundred feet in width, and from forty to eighty in height. The walls (all of stone) are arched, being from forty to eighty feet of perpendicular height, before the arch commences.
‘The next avenue which I traversed, after cutting arrows on the stones under our feet, pointing to the mouth of the cave, was one that led us in a southerly direction for more than two miles. We then left it, and took another that led us east, then north, more than two miles farther; and at last, in our windings, were brought out by another avenue into the chief city again, after having traversed more than five miles through different avenues. We rested ourselves for a few minutes on some limestone strata near the centre of this gloomy area, and having refreshed ourselves, and trimmed our lamps, again took our departure through an avenue almost due north, and parallel with the avenue leading from the chief city to the mouth of the cave, which we continued for more than two miles, when we entered the second city. This is covered with one arch nearly two hundred feet high in the centre, and very similar to the chief city, except in the number of avenues leading from it, this having but two. We passed through it over a very considerable rise in the centre, and descended through an avenue bearing to the east about three hundred rods, when we came upon a third area, about one hundred feet square and fifty in height, which had a pure and delightful stream of water, issuing from the side of the wall, about thirty feet high, and which fell upon some broken stones, and was afterwards entirely lost to our view. After passing this beautiful sheet of water a few yards, we came to the end of this passage.
‘We then returned about one hundred yards, and entered an avenue (over a considerable mass of stone) to our right, which led us south, through an uncommonly black avenue, something more than a mile, when we ascended a very steep eminence, about sixty yards, which carried us within the walls of a fourth city, which is not inferior to the second city, having an arch that covers at least six acres. In this last avenue, the farther end of which must be at least four miles from the chief city, and ten from the mouth of the cave, are twenty large piles of saltpetre earth on one side of the avenue, and broken limestone heaped up on the other, evidently the work of human hands. I had expected, from the course of my needle, that this avenue would have carried us round to the chief city; but was sadly disappointed, when I found the end a few hundred yards from the fourth city, which caused us to retrace our steps; and not having been so particular in marking the different entrances as I ought, we were very much bewildered, and once completely lost for fifteen or twenty minutes.
‘At length we found our way, and, weary and faint, entered the chief city at ten at night; however, much fatigued as I was, I determined to explore the cavern as long as my lights held out. We now entered the fifth and last avenue from the chief city, which carried us south-east about nine hundred yards, when we entered the fifth city, whose arch covers upwards of four acres of level ground, strewed with broken limestone. Fire beds of uncommon size, with brands of cane lying around them, are interspersed throughout this city. We crossed over to the opposite side, and entered an avenue that carried us east about two hundred and fifty rods; when, finding nothing remarkable in this passage, we turned back, and crossed a massy pile of limestone in the mouth of a large avenue, which I noticed but a few yards from this last-mentioned city as I came out of it. After some difficulty in passing over this mass of limestone, we entered a large avenue, whose walls were the most perfect of any that we had seen, running almost due south for five hundred rods, and very level and straight. When at the end of this avenue, and while I was sketching a plan of the cave, one of my guides, who had been some time groping among the broken stones, called out, requesting me to follow him. I gathered up my papers and compass, and also giving the guide who sat with me orders to remain where he was, until we returned, and moreover to keep his lamp in good order, I followed after the first, who had entered a vertical passage just large enough to admit his body. We continued to step from one stone to another, until at last, after much difficulty, from the smallness of the passage, which is about forty feet in height, we entered upon the side of a chamber eighteen hundred feet in circumference, and whose arch is one hundred and fifty feet high in the centre. After having marked arrows, pointing downwards, upon the slate-stones around the little passage through which we had winded, we walked nearly to the centre of this area. It was past midnight when I entered this chamber of eternal darkness, where “all things are hushed, and nature’s self lies dead.” I must acknowledge I felt a shivering horror at my situation, when, I looked back upon the different avenues through which I had passed, since I entered the cave at eight in the morning; and “at time of night, when church-yards groan,” to be buried several miles in the dark recesses of this awful cavern, the grave, perhaps, of thousands of human beings—gave me no very pleasant emotions. With the guide who was now with me, I took the only avenue leading from this chamber, and traversed it for the distance of a mile in a northerly direction, when my lamps forbade me going any farther, as they were nearly exhausted. The avenue, or passage, was as large as any that we had entered; and how far we might have entered, had our lights held out, is unknown.
‘It is supposed that Green river, a stream navigable several hundred miles, passes over three branches of this cave. It was nearly one o’clock in the morning, when we descended the passage of the chimney, as it is called, to the guide who sat on the rocks. He was quite alarmed at our long absence, and was heard by us a long time before we reached the passage to descend to him, hallooing with all his might, fearing we had lost our track in the ruins above. Very near the vertical passage, and not far from where I had left my guide sitting, I found some very beautiful specimens of soda, which I brought out with me. We returned over piles of saltpetre earth and fire beds, out of one avenue into another, until at last, with great fatigue and a dim light, we entered the walls of the chief city; where, for the last time, we trimmed our lamps, and entered the spacious avenue that lends to the second hopper. I found, when in the last-mentioned large avenue, or upper chamber, many curiosities; such as Glauber salts, Epsom salts, flint, yellow ochre, spar of different kinds, and some petrifactions, which I brought out together with the mummy, which was found at the second hopper. We happily arrived at the mouth of the cave at five in the morning, nearly exhausted and worn down with nineteen hours’ continued fatigue. I have described to you hardly one half of the cave, as the avenues between the mouth of the cave and the second hopper have not been named. There is a passage in the main avenue, about sixty rods from the entrance, like that of a trap-door. By sliding aside a large flat stone, you can descend sixteen or eighteen