XIV
IN MAMMOTH CAVE
Some idea of the impression which Mammoth Cave makes upon the senses, irrespective even of sight, may be had from the fact that blind people go there to see it, and are greatly struck with it. I was assured that this is a fact. The blind seem as much impressed by it as those who have their sight. When the guide pauses at the more interesting point, or lights the scene up with a great torch or with Bengal lights, and points out the more striking features, the blind exclaim, "How wonderful! how beautiful!" They can feel it if they cannot see it. They get some idea of the spaciousness when words are uttered. The voice goes forth in these colossal chambers like a bird. When no word is spoken, the silence is of a kind never experienced on the surface of the earth, it is so profound and abysmal. This, and the absolute darkness, to a person with eyes makes him feel as if he were face to face with the primordial nothingness. The objective universe is gone; only the subjective remains; the sense of hearing is inverted, and reports only the murmurs from within. The blind miss much, but much remains to them. The great cave is not merely a spectacle to the eye; it is a wonder to the ear, a strangeness to the smell and to the touch. The body feels the presence of unusual conditions through every pore.
For my part, my thoughts took a decidedly sepulchral turn; I thought of my dead and of all the dead of the earth, and said to myself, the darkness and the silence of their last resting-place is like this; to this we must all come at last. No vicissitudes of earth, no changes of seasons, no sound of storm or thunder penetrate here; winter and summer, day and night, peace or war, it is all one; a world beyond the reach of change, because beyond the reach of life. What peace, what repose, what desolation! The marks and relics of the Indian, which disappear so quickly from the light of day above, are here beyond the reach of natural change. The imprint of his moccasin in the dust might remain undisturbed for a thousand years. At one point the guide reaches his arm beneath the rocks that strew the floor and pulls out the burnt ends of canes, which were used, probably, when filled with oil or grease, by the natives to light their way into the cave doubtless centuries ago.
Here in the loose soil are ruts worn by cart-wheels in 1812, when, during the war with Great Britain, the earth was searched to make saltpetre. The guide kicks corn-cobs out of the dust where the oxen were fed at noon, and they look nearly as fresh as ever they did. In those frail corn-cobs and in those wheel-tracks as if the carts had but just gone along, one seemed to come very near to the youth of the century, almost to overtake it.
At a point in one of the great avenues, if you stop and listen, you hear a slow, solemn ticking like a great clock in a deserted hall; you hear the slight echo as it fathoms and sets off the silence. It is called the clock, and is caused by a single large drop of water falling every second into a little pool. A ghostly kind of clock there in the darkness, that is never wound up and that never runs down. It seemed like a mockery where time is not, and change does not come – the clock of the dead. This sombre and mortuary cast of one's thoughts seems so natural in the great cave, that I could well understand the emotions of a lady who visited the cave with a party a few days before I was there. She went forward very reluctantly from the first; the silence and the darkness of the huge mausoleum evidently impressed her imagination, so that when she got to the spot where the guide points out the "Giant's Coffin," a huge, fallen rock, which in the dim light takes exactly the form of an enormous coffin, her fear quite overcame her, and she begged piteously to be taken back. Timid, highly imaginative people, especially women, are quite sure to have a sense of fear in this strange underground world. The guide told me of a lady in one of the parties he was conducting through, who wanted to linger behind a little all alone; he suffered her to do so, but presently heard a piercing scream. Rushing back, he found her lying prone upon the ground in a dead faint. She had accidentally put out her lamp, and was so appalled by the darkness that instantly closed around her that she swooned at once.
Sometimes it seemed to me as if I were threading the streets of some buried city of the fore-world. With your little lantern in your hand, you follow your guide through those endless and silent avenues, catching glimpses on either hand of what appears to be some strange antique architecture, the hoary and crumbling walls rising high up into the darkness. Now we turn a sharp corner, or turn down a street which crosses our course at right angles; now we come out into a great circle, or spacious court, which the guide lights up with a quick-paper torch, or a colored chemical light. There are streets above you and streets below you. As this was a city where day never entered, no provision for light needed to be made, and it is built one layer above another to the number of four or five, or on the plan of an enormous ant-hill, the lowest avenues being several hundred feet beneath the uppermost. The main avenue leading in from the entrance is called the Broadway, and if Broadway, New York, were arched over and reduced to utter darkness and silence, and its roadway blocked with mounds of earth and fragments of rock, it would, perhaps, only lack that gray, cosmic, elemental look, to make it resemble this. A mile or so from the entrance we pass a couple of rude stone houses, built forty or more years ago by some consumptives, who hoped to prolong their lives by a residence in this pure, antiseptic air. Five months they lived here, poor creatures, a half dozen of them, without ever going forth into the world of light. But the long entombment did not arrest the disease; the mountain did not draw the virus out, but seemed to draw the strength and vitality out, so that when the victims did go forth into the light and air, bleached as white as chalk, they succumbed at once, and nearly all died before they could reach the hotel, a few hundred yards away.
Probably the prettiest thing they have to show you in Mammoth Cave is the Star Chamber. This seems to have made an impression upon Emerson when he visited the cave, for he mentions it in one of his essays, "Illusions." The guide takes your lantern from you and leaves you seated upon a bench by the wayside, in the profound cosmic darkness. He retreats along a side alley that seems to go down to a lower level, and at a certain point shades his lamp with his hat, so that the light falls upon the ceiling over your head. You look up, and the first thought is that there is an opening just there that permits you to look forth upon the midnight skies. You see the darker horizon line where the sky ends and the mountains begin. The sky is blue-black and is thickly studded with stars, rather small stars, but apparently genuine. At one point a long, luminous streak simulates exactly the form and effect of a comet. As you gaze, the guide slowly moves his hat, and a black cloud gradually creeps over the sky, and all is blackness again. Then you hear footsteps retreating and dying away in the distance. Presently all is still, save the ringing in your own ears. Then after a few moments, during which you have sat in a silence like that of the interstellar spaces, you hear over your left shoulder a distant flapping of wings, followed by the crowing of a cock. You turn your head in that direction and behold a faint dawn breaking on the horizon. It slowly increases till you hear footsteps approaching, and your dusky companion, playing the part of Apollo, with lamp in hand ushers in the light of day. It is rather theatrical, but a very pleasant diversion nevertheless.
Another surprise was when we paused at a certain point, and the guide asked me to shout or call in a loud voice. I did so without any unusual effect following. Then he spoke in a very deep bass, and instantly the rocks all about and beneath us became like the strings of an Æolian harp. They seemed transformed as if by enchantment. Then I tried, but did not strike the right key; the rocks were dumb; I tried again, but got no response; flat and dead the sounds came back as if in mockery; then I struck a deeper bass, the chord was hit, and the solid walls seemed to become as thin and frail as a drum-head or as the frame of a violin. They fairly seemed to dance about us, and to recede away from us. Such wild, sweet music I had never before heard rocks discourse. Ah, the magic of the right key! "Why leap ye, ye high hills?" why, but that they had been spoken to in the right voice? Is not the whole secret of life to pitch our voices in the right key? Responses come from the very rocks when we do so. I thought of the lines of our poet of Democracy: —
"Surely, whoever speaks to me in the right voice, him or her I shall follow,
As the water follows the moon, silently, with fluid steps, anywhere around the globe."
Where we were standing was upon an arch over an avenue which crossed our course beneath us. The reverberations on Echo River, a point I did not reach, can hardly be more surprising, though they are described as wonderful.
There are four or five levels in the cave, and a series of avenues upon each. The lowest is some two hundred and fifty feet below the entrance. Here the stream which has done all this carving and tunneling has got to the end of its tether. It is here on a level with Green River in the valley below and flows directly into it. I say the end of its tether, though if Green River cuts its valley deeper, the stream will, of course, follow suit. The bed of the river has probably, at successive periods, been on a level with each series of avenues of the cave. The stream is now doubtless but a mere fraction of its former self. Indeed, every feature of the cave attests the greater volume and activity of the forces which carved it, in the earlier geologic ages. The waters have worn the rock as if it were but ice. The domes and pits are carved and fluted in precisely the way dripping water flutes snow or ice. The rainfall must have been enormous in those early days, and it must have had a much stronger and sharper tooth of carbonic acid gas than now. It has carved out enormous pits with perpendicular sides, two or three hundred feet deep. Goring Dome I remember particularly. You put your head through an irregularly shaped window in the wall at the side of one of the avenues, and there is this huge shaft or well, starting from some higher level and going down two hundred feet below you. There must have been such wells in the old glaciers, worn by a rill of water slowly eating its way down. It was probably ten feet across, still moist and dripping. The guide threw down a lighted torch, and it fell and fell, till I had to crane my neck far out to see it finally reach the bottom. Some of these pits are simply appalling, and where the way is narrow have been covered over to prevent accidents.
No part of Mammoth Cave was to me more impressive than its entrance, probably because here its gigantic proportions are first revealed to you, and can be clearly seen. That strange colossal underworld here looks out into the light of day, and comes in contrast with familiar scenes and objects. When you are fairly in the cave, you cannot see it; that is, with your aboveground eyes; you walk along by the dim light of your lamp as in a huge wood at night; when the guide lights up the more interesting portions with his torches and colored lights, the effect is weird and spectral; it seems like a dream; it is an unfamiliar world; you hardly know whether this is the emotion of grandeur which you experience, or of mere strangeness. If you could have the light of day in there, you would come to your senses, and could test the reality of your impressions. At the entrance you have the light of day, and you look fairly in the face of this underground monster, yea, into his open mouth, which has a span of fifty feet or more, and down into his contracting throat, where a man can barely stand upright, and where the light fades and darkness begins. As you come down the hill through the woods from the hotel, you see no sign of the cave till you emerge into a small opening where the grass grows and the sunshine falls, when you turn slightly to the right, and there at your feet yawns this terrible pit; and you feel indeed as if the mountain had opened its mouth and was lying in wait to swallow you down, as a whale might swallow a shrimp. I never grew tired of sitting or standing here by this entrance and gazing into it. It had for me something of the same fascination that the display of the huge elemental forces of nature have, as seen in thunder-storms, or in a roaring ocean surf. Two phœbe-birds had their nests in little niches of the rocks, and delicate ferns and wild flowers fringed the edges.
Another very interesting feature to me was the behavior of the cool air which welled up out of the mouth of the cave. It simulated exactly a fountain of water. It rose up to a certain level, or until it filled the depression immediately about the mouth of the cave, and then flowing over at the lowest point, ran down the hill towards Green River, along a little watercourse, exactly as if it had been a liquid. I amused myself by wading down into it as into a fountain. The air above was muggy and hot, the thermometer standing at about eighty-six degrees, and this cooler air of the cave, which was at a temperature of about fifty-two degrees, was separated in the little pool or lakelet which is formed from the hotter air above it by a perfectly horizontal line. As I stepped down into it I could feel it close over my feet, then it was at my knees, then I was immersed to my hips, then to my waist, then I stood neck deep in it, my body almost chilled, while my face and head were bathed by a sultry, oppressive air. Where the two bodies of air came into contact, a slight film of vapor was formed by condensation; I waded in till I could look under this as under a ceiling. It was as level and as well defined as a sheet of ice on a pond. A few moments' immersion into this aerial fountain made one turn to the warmer air again. At the depression in the rim of the basin one had but to put his hand down to feel the cold air flowing over like water. Fifty yards below you could still wade into it as into a creek, and at a hundred yards it was still quickly perceptible, but broader and higher; it had begun to lose some of its coldness, and to mingle with the general air; all the plants growing on the margin of the watercourse were in motion, as well as the leaves on the low branches of the trees near by. Gradually this cool current was dissipated and lost in the warmth of the day.
XV
HASTY OBSERVATION
When Boswell told Dr. Johnson that while in Italy he had several times seen the experiment tried of placing a scorpion within a circle of burning coals, and that in every instance the scorpion, after trying to break through the fiery circle, retired to the centre and committed suicide by darting its sting into its head, the doctor showed the true scientific spirit by demanding further proof of the fact. The mere testimony of the eye under such circumstances was not enough; appearances are often deceptive. "If the great anatomist Morgagni," said the doctor, "after dissecting a scorpion on which the experiment had been tried, should certify that its sting had penetrated its head, that would be convincing." For almost the only time in his life the superstitious doctor showed himself, I say, a true scientist, a man refusing to accept the truth of appearances.
But this frame of mind was not habitual to him, for the next moment he said that swallows sleep all winter in the bed of a river or pond, "conglobulated" into a ball. The scientific spirit would have required him to insist upon the proof of the alleged fact in this case the same as in the other. Has any competent observer verified this statement? Have swallows been taken out of the mud, or been seen to throw themselves into the water?
Albertus Magnus (1193-1280), in his book on animals, says that the eel leaves the water in the nighttime, and invades the fields and gardens to feed upon peas and lentils. A scientific man makes this statement, and probably upon no stronger proof than that some eels dropped by poachers in their hasty retreat had been found in a pea patch. If peas had been found, and found in many cases, in the stomachs of eels, that would have been pretty conclusive proof that eels eat peas.
The great thing in observation is not to be influenced by our preconceived notions, or by what we want to be true, or by our fears, hopes, or any personal element, and to see the thing just as it is. A person who believes in ghosts and apparitions cannot be depended upon to investigate an alleged phenomenon of this sort, because he will not press his inquiry far enough, and will take for granted the very fact we want proof of.
The eye does not always see what is in front of it. Indeed it might almost be said, it sees only what is back of it, in the mind. Whenever I have any particular subject in mind, every walk gives me new material. If I am thinking about tree-toads, I find tree-toads. If I am dwelling upon birds' nests, I find plenty of nests which otherwise I should have passed by. If bird-songs occupy me, I am bound to hear some new or peculiar note.
Every one has observed how, after he has made the acquaintance of a new word, that word is perpetually turning up in his reading, as if it had suddenly become the fashion. When you have a thing in mind, it is not long till you have it in hand. Torrey and Drummond, the botanists, were one day walking in the woods near West Point. "I have never yet found so and so," said Drummond, naming a rare kind of moss. "Find it anywhere," said Torrey, and stooped and picked it up at their feet. Thoreau could pick up arrow-heads with the same ease. Many people have the same quick eye for a four-leafed clover. I may say of myself without vanity, that I see birds with like ease. It is no effort, I cannot help it. Either my eye or my ear is on duty quite unbeknown to me. When I visit my friends, I leave a trail of birds behind me, as old Amphion left a plantation of trees wherever he sat down and played.
The scientific habit of mind leads a man to take into account all possible sources of error in such observations. The senses are all so easily deceived. People of undoubted veracity tell you of the strange things they have known to rain down, or of some strange bird or beast they have seen. But if you question them closely, you are pretty sure to find some flaw in the observation, or some link of evidence wanting. We are so apt to jump to conclusions; we take one or two steps in following up the evidence, and then leap to the result that seems to be indicated. If you find a trout in the milk, you may be justified in jumping to a conclusion not flattering to your milkman, but if you find angle-worms in the barrel of rain-water after a shower, you are not to conclude that therefore they rained down, as many people think they do.
Or if after a shower in summer you find the ground swarming with little toads, you are not to infer that the shower brought them down. I have frequently seen large numbers of little toads hopping about after a shower, but only in particular localities. Upon a small, gravelly hill in the highway along which I was in the habit of walking, I have seen them several seasons, but in no other place upon that road. Just why they come out on such occasions is a question; probably to get their jackets wet. There was a pond and marshy ground not far off where they doubtless hatched. Because the frogs are heard in the marshes in spring as soon as the ice and snow are gone, it is a popular belief that they hibernate in these places. But the two earliest frogs, I am convinced, pass the winter in the ground in the woods, and seek the marshes as soon as the frost and ice are gone. I have heard the hyla pipe in a feeble tentative manner in localities where the ground was free from frost, while the marshes near by were yet covered with solid ice; and in spring I have dug out another species from beneath the leaf mould in the woods. Both these species are properly land-frogs, and only take to the water to breed, returning again to the woods later in the season. The same is true of the tree-frog, which passes the winter in the ground or in hollow trees, and takes to the marshes in May to deposit its eggs. The common bullfrog and the pickerel frog doubtless pass the winter in the bed of ponds and streams. I think it is quite certain that hibernating animals in the ground do not freeze, though by no means beyond the reach of frost. The frogs, ants, and crickets are probably protected by some sort of acid which their bodies secrete, though this is only a guess of my own. The frog I dug out of the leaves one spring day, while the ground above and below him was frozen hard, was entirely free from frost, though his joints were apparently very stiff. A friend of mine in felling some trees in winter cut through a den of field crickets; the ground was frozen about their galleries, but the crickets themselves, though motionless, were free from frost. Cut the large, black tree ants out of a pine log in winter, and though apparently lifeless, they are not frozen.
There is something in most of us that welcomes a departure from the ordinary routine of natural causes; we like to believe that the impossible happens; we like to see the marvelous and mysterious crop out of ordinary occurrences. We like to believe, for instance, that snakes can charm their prey; can exert some mysterious influence over bird or beast at a distance of many feet, which deprives it of power to escape. But there is probably little truth in this popular notion. Fear often paralyzes, and doubtless this is the whole secret of the power of snakes and cats to charm their prey. It is what is called a subjective phenomenon; the victim is fascinated or spellbound by the sudden and near appearance of its enemy. A sportsman, in whose veracity I have full confidence, told me that his pointer dog had several times worked up to a woodcock or partridge and seized it in his mouth. Of course the dog brought no mysterious power to bear upon the bird. He could hardly have seen the bird till he came plump upon it; he was wholly intent upon unraveling its trail. The bird, in watching the eager motions and the gradual approach of the dog, must have been thrown into such a state of fear or consternation as to quite paralyze its powers, and suffered the dog to pick it up. In the case of snakes, they doubtless in most instances approach and seize their prey unawares. I have seen a little snake in the woods pursue and overtake a lizard that was trying to escape from it. There was no attempt at charming; superior speed alone gave the victory to the snake. I have known a red squirrel to be caught and swallowed by a black snake, but I have no belief that the squirrel was charmed; it was more probably seized from some ambush.
One can hardly understand how a mouse can be caught by a hawk except upon the theory that the mouse is suddenly paralyzed by fear. The meadow mouse when exposed to view is very wary and quick in its movements; it is nibbling grass in the meadow bottom, or clearing its runway, or shaping its nest, when the hawk poises on wing high in the air above it. When the hawk discovers its victim, it descends with extended talons to the earth and seizes it. It does not drop like a bolt from heaven; its descent, on the contrary, is quite deliberate, and must be attended by a sound of rushing wings that ought to reach the mouse's ear, if the form escapes its eye.
There is doubtless just as much "charming" in this case as in any other, or when a fish hawk falls through the air and seizes a fish near the surface in perfectly clear water – what hinders the fish from seeing and avoiding its enemy? Apparently nothing; apparently it allows itself to be seized. Every fisherman knows how alert most fish are, how quickly they discover him and dart away, even when he is immediately above them. All I contend for is that the snake, the cat, the hawk, does not exert some mysterious power over its prey, but that its prey in many cases loses its power to escape through fear. It is said that a stuffed snake's skin will charm a bird as well as the live snake.
I came near reaching a hasty conclusion the other day with regard to a chickadee's nest. The nest is in a small cavity in the limb of a pear-tree near my study, and the birds and I are on very friendly terms. As the nest of a pair of chickadees had been broken up here a few seasons ago by a mouse or squirrel, I was apprehensive lest this nest share the same fate. Hence when, one morning, the birds were missing, and I found on inspection what appeared to be the hair of some small animal adhering to the edges of the hole that leads to the nest, I concluded that the birds had been cleaned out again. Later in the day I examined the supposed hair with my pocket glass, and found it was not hair, but some vegetable fibre. My next conclusion was that the birds had not been molested, but that they were furnishing their apartment, and some of the material had stuck to the door jambs. This proved to be the correct inference. The chickadee makes a little felt-like mat or carpet with which it covers the bottom of the nest-cavity. A day or two later, in my vineyard near by, I found where a piece of heavy twine that held a young grapevine to a stake had been pulled down to the ground and picked and beaten, and parts of it reduced to its original tow. Here, doubtless, the birds had got some of their carpeting material.
I recently read in a work on ornithology that the rings of small holes which we see in the trunks and limbs of perfectly sound apple-trees are made by woodpeckers in search of grubs and insects. This is a hasty inference. These holes are made by woodpeckers, but the food they obtain at the bottom of them is not the flesh of worm or insect, but the flesh of the apple-tree – the soft, milky inner bark. The same writer says these holes are not hurtful to the tree, but conducive to its health. Yet I have seen the limbs of large apple-trees nearly killed by being encompassed by numerous rings of large, deep holes made by the yellow-bellied woodpecker. This bird drills holes in the sugar maple in the spring for the sap. I have known him to spend the greater part of a bright March day on the sunny side of a maple, indulging in a tipple of maple sap every four or five minutes. As fast as his well holes filled up he would sip them dry.
A lady told me that a woodpecker drilled holes in the boards that form the eaves of her house, for the grubs of the carpenter bumblebee. This also seemed to me a hasty conclusion, because the woodpeckers made holes so large that the next season the bluebirds nested there. The woodpeckers were probably drilling for a place to nest. A large ice-house stands on the river bank near me, and every season the man in charge has to shoot or drive away the high-holes that cut numerous openings through the outer sheathing of hemlock boards into the spaces filled with sawdust, where they find the digging easy and a nesting-place safe and snug.
My neighbor caught a small hawk in his shad-net, and therefore concluded the hawk ate fish. He put him in a cage, and offered him fragments of shad. The little hawk was probably in pursuit of a bird which took refuge under the net as it hung upon the drying-poles; or he may have swooped down upon the net in the spirit of pure bluster and bravado, and thus came to grief in a hurry. The fine, strong threads of the net defied his murderous beak and talons. He was engulfed as completely as is a fly in a spider's web, and the more he struggled the more hopeless his case became. It was a pigeon hawk, and these little marauders are very saucy.
My neighbor says that in the city of Brooklyn he has known kingbirds to nest in boxes like martins and bluebirds. I question this observation, though it may be true. The cousin of the kingbird, the great crested flycatcher, builds in cavities in trees, and its relative, the phœbe-bird, nests under bridges and hay-sheds. Hence there is this fact to start with in favor of my neighbor's observation.
But when a lady from Pennsylvania writes me that she has seen "swallows rolling and dabbling in the mud in early spring, their breasts so covered with it that it would take but little stretch of imagination to believe they had just emerged from the bottom of the pond beside which they were playing," I am more than skeptical. The lady has not seen straight. The swallows were not rolling in the mud; there was probably not a speck of mud upon their plumage, but a little upon their beaks and feet. The red of their breasts was their own proper color. They were building their nests, as my correspondent knew, but they did not carefully mix and knead the mud, as she thought they did; they had selected mortar already of the proper sort.
The careful observer is not long in learning that there is truth in the poet's remark, that "things are not what they seem." Everywhere on the surface of nature things seem one thing, and mean quite another. The hasty observer is misled by the seeming, and thus misses the real truth.
The little green snake that I saw among the "live-for-evers" the other day, how nearly it escaped detection by the close resemblance of its color to that of the plant! And when, a few days later, I saw one carelessly disposed across the top of the bending grass and daisies, but a few feet from where I sat, my eye again came near being baffled.