The pond had in the meanwhile skimmed over in the shadiest and shallowest coves, some days or even weeks before the general freezing. The first ice is especially interesting and perfect, being hard, dark, and transparent, and affords the best opportunity that ever offers for examining the bottom where it is shallow; for you can lie at your length on ice only an inch thick, like a skater insect on the surface of the water, and study the bottom at your leisure, only two or three inches distant, like a picture behind a glass, and the water is necessarily always smooth then. There are many furrows in the sand where some creature has travelled about and doubled on its tracks; and, for wrecks, it is strewn with the cases of caddis-worms made of minute grains of white quartz. Perhaps these have creased it, for you find some of their cases in the furrows, though they are deep and broad for them to make. But the ice itself is the object of most interest, though you must improve the earliest opportunity to study it. If you examine it closely the morning after it freezes, you find that the greater part of the bubbles, which at first appeared to be within it, are against its under surface, and that more are continually rising from the bottom; while the ice is as yet comparatively solid and dark, that is, you see the water through it. These bubbles are from an eightieth to an eighth of an inch in diameter, very clear and beautiful, and you see your face reflected in them through the ice. There may be thirty or forty of them to a square inch. There are also already within the ice narrow oblong perpendicular bubbles about half an inch long, sharp cones with the apex upward; or oftener, if the ice is quite fresh, minute spherical bubbles one directly above another, like a string of beads. But these within the ice are not so numerous nor obvious as those beneath. I sometimes used to cast on stones to try the strength of the ice, and those which broke through carried in air with them, which formed very large and conspicuous white bubbles beneath. One day when I came to the same place forty-eight hours afterward, I found that those large bubbles were still perfect, though an inch more of ice had formed, as I could see distinctly by the seam in the edge of a cake. But as the last two days had been very warm, like an Indian summer, the ice was not now transparent, showing the dark green color of the water, and the bottom, but opaque and whitish or gray, and though twice as thick was hardly stronger than before, for the air bubbles had greatly expanded under this heat and run together, and lost their regularity; they were no longer one directly over another, but often like silvery coins poured from a bag, one overlapping another, or in thin flakes, as if occupying slight cleavages. The beauty of the ice was gone, and it was too late to study the bottom. Being curious to know what position my great bubbles occupied with regard to the new ice, I broke out a cake containing a middling sized one, and turned it bottom upward. The new ice had formed around and under the bubble, so that it was included between the two ices. It was wholly in the lower ice, but close against the upper, and was flattish, or perhaps slightly lenticular, with a rounded edge, a quarter of an inch deep by four inches in diameter; and I was surprised to find that directly under the bubble the ice was melted with great regularity in the form of a saucer reversed, to the height of five eighths of an inch in the middle, leaving a thin partition there between the water and the bubble, hardly an eighth of an inch thick; and in many places the small bubbles in this partition had burst out downward, and probably there was no ice at all under the largest bubbles, which were a foot in diameter. I inferred that the infinite number of minute bubbles which I had first seen against the under surface of the ice were now frozen in likewise, and that each, in its degree, had operated like a burning-glass on the ice beneath to melt and rot it. These are the little air-guns which contribute to make the ice crack and whoop.
At length the winter set in good earnest, just as I had finished plastering, and the wind began to howl around the house as if it had not had permission to do so till then. Night after night the geese came lumbering in the dark with a clangor and a whistling of wings, even after the ground was covered with snow, some to alight in Walden, and some flying low over the woods toward Fair Haven, bound for Mexico. Several times, when returning from the village at ten or eleven o’clock at night, I heard the tread of a flock of geese, or else ducks, on the dry leaves in the woods by a pond-hole behind my dwelling, where they had come up to feed, and the faint honk or quack of their leader as they hurried off. In 1845 Walden froze entirely over for the first time on the night of the 22d of December, Flint’s and other shallower ponds and the river having been frozen ten days or more; in ‘46, the 16th; in ‘49, about the 31st; and in ‘50, about the 27th of December; in ‘52, the 5th of January; in ‘53, the 31st of December. The snow had already covered the ground since the 25th of November, and surrounded me suddenly with the scenery of winter. I withdrew yet farther into my shell, and endeavored to keep a bright fire both within my house and within my breast. My employment out of doors now was to collect the dead wood in the forest, bringing it in my hands or on my shoulders, or sometimes trailing a dead pine tree under each arm to my shed. An old forest fence which had seen its best days was a great haul for me. I sacrificed it to Vulcan, for it was past serving the god Terminus. How much more interesting an event is that man’s supper who has just been forth in the snow to hunt, nay, you might say, steal, the fuel to cook it with! His bread and meat are sweet. There are enough fagots and waste wood of all kinds in the forests of most of our towns to support many fires, but which at present warm none, and, some think, hinder the growth of the young wood. There was also the driftwood of the pond. In the course of the summer I had discovered a raft of pitch pine logs with the bark on, pinned together by the Irish when the railroad was built. This I hauled up partly on the shore. After soaking two years and then lying high six months it was perfectly sound, though waterlogged past drying. I amused myself one winter day with sliding this piecemeal across the pond, nearly half a mile, skating behind with one end of a log fifteen feet long on my shoulder, and the other on the ice; or I tied several logs together with a birch withe, and then, with a longer birch or alder which had a book at the end, dragged them across. Though completely waterlogged and almost as heavy as lead, they not only burned long, but made a very hot fire; nay, I thought that they burned better for the soaking, as if the pitch, being confined by the water, burned longer, as in a lamp.
Gilpin, in his account of the forest borderers of England, says that “the encroachments of trespassers, and the houses and fences thus raised on the borders of the forest,” were “considered as great nuisances by the old forest law, and were severely punished under the name of purprestures, as tending ad terrorem ferarum — ad nocumentum forestae, etc.,” to the frightening of the game and the detriment of the forest. But I was interested in the preservation of the venison and the vert more than the hunters or woodchoppers, and as much as though I had been the Lord Warden himself; and if any part was burned, though I burned it myself by accident, I grieved with a grief that lasted longer and was more inconsolable than that of the proprietors; nay, I grieved when it was cut down by the proprietors themselves. I would that our farmers when they cut down a forest felt some of that awe which the old Romans did when they came to thin, or let in the light to, a consecrated grove (lucum conlucare), that is, would believe that it is sacred to some god. The Roman made an expiatory offering, and prayed, Whatever god or goddess thou art to whom this grove is sacred, be propitious to me, my family, and children, etc.
It is remarkable what a value is still put upon wood even in this age and in this new country, a value more permanent and universal than that of gold. After all our discoveries and inventions no man will go by a pile of wood. It is as precious to us as it was to our Saxon and Norman ancestors. If they made their bows of it, we make our gun-stocks of it. Michaux, more than thirty years ago, says that the price of wood for fuel in New York and Philadelphia “nearly equals, and sometimes exceeds, that of the best wood in Paris, though this immense capital annually requires more than three hundred thousand cords, and is surrounded to the distance