Here my guide would willingly have played Charon to my Ulysses, but as no one had penetrated thus far into the cave for several months, the boat used to carry visitors over, and to voyage up and down the short river (only a hundred and fifty yards in length), had sunk, and we found it impossible to raise it.
The river is about twenty-five feet in width, its course crossing that of the cave at right angles, and its channel being simply another avenue or tunnel on a little lower level than the one by which the visitor approaches it.
In this stream, as well as in "Echo River," are found the famous eyeless fish. We dipped in vain, for a long time, in hopes of capturing some of these. At last I was fortunate enough to secure one tiny specimen, about two inches long, which was shaped like other minnows, but had no eyes, and was perfectly white, there being not the slightest shade of coloring on the back. The upper part of its head was as translucent as agate, through which could be seen opaque spots imbedded in the head where the base of the eye-sockets should have been. The specimen I obtained was one of the smallest, as the guide told me these fishes frequently attained the length of six or seven inches.
I secured also an eyeless crawfish about three inches in length. This forlorn little creature, like the fish, was entirely colorless. It had two slightly protuberant spots in its head where the eyes should be; but they were dull and opaque, and did not seem to differ in texture from the rest of its body, which had not the translucence of that of the fish, but looked as though carved out of white marble.
The fish are found also in "Lake Lethe," a quarter of a mile from the Styx, as well as in "Echo River," the largest and most interesting body of water in the cave. This last flows out of a tunnel which has such a low roof that the volume of water nearly fills it, and from here to where it enters the rocks again is three quarters of a mile. Here the blind white creatures that inhabit its dark, slow-flowing waters are more plentiful, but are as unlike those nimble, glistening fellows which inhabit the streams of the outer world, as the cavern's atmosphere of darkness and death is different from our atmosphere of light and life. They refuse to bite at any bait; they move sluggishly, and, when caught in a net, flop languidly, and die. The only food they are known to have is the smaller ones of their own kind; and, oddest of all, they, as well as the crawfish, give birth to their young alive, instead of spawning the eggs to be hatched by the sun. Last and remotest of these sunless streams is "Roaring River," the margin of whose solemn waters is nine miles from the entrance of the cave. This should be Acheron, which hated the light, and ran sighing down into a cave; for from this stream too comes a perpetual moan.
The region where the several rivers mentioned are grouped is lower than the rest of the cave, and much more gloomy in appearance than the high, dry chambers through which one passes in coming back toward the entrance.
I was somewhat disappointed in the display of stalactites and other similar formations of the protocarbonate of lime found in the cave. For a number of years I had been familiar with mines and mining operations in the lead-mining districts of Illinois, Wisconsin, and Missouri, and had there seen some of the most beautiful, though not the largest, specimens of calcareous spar known to exist. The lime in these localities being in most instances perfectly pure, the stalactites, to the length of three feet sometimes, are as free from coloring as icicles. Sometimes the miners' drift (which compared with the Mammoth Cave is as a rabbit's burrow to a railway tunnel) is opened into small, low-roofed caves; and in these, in addition to the translucent stalactites, there are little hollows in the floor covered with thin sheets of protocarbonate of lime, no thicker than a pane of window-glass, and as white as snow. From beneath these the water has sunk away, leaving a hollow space, and giving the whole precisely the appearance of those little pools which every one has noticed when a muddy road suddenly congeals: the pools of water freeze over, and the water disappears, leaving the ice only a shell over a cavity.
Nothing of this kind, however, is found in the Mammoth Cave. The lime of which the stalactites are formed being mixed with various oxides and other impurities, they are all of a dark brown, or gray, or muddy color. With the exception of some stalactite columns in the "Gothic Arcade," which form a fine alcove called the "Gothic Chapel," there are no stalactites of extraordinary size. There is a stalactite mass (or was some years ago) in "Uhrig's Cave," in the suburbs of the city of St. Louis, about twelve feet in height and four feet in diameter, which exceeds in size anything I saw in the Mammoth Cave.
The gypsum or alabaster flowers are the crowning beauty of the Mammoth Cave. These are an entirely different formation from the stalactites, being formed only in a perfectly dry atmosphere, while the stalactites are necessarily formed in a moist one.
The gypsum is formed by crystallization, and in that process exerts the same expansive force as ice. Wherever it forms in crevices it fractures the rocks that enclose it, and protrudes from the crevice; its own bulk divides, or splits, and curves open, and outward, with much more tenacity than ice. It seems to have a fibrous texture, in the direction of which the split always opens.