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 vet comparatively solid and dark, that is,

you see the water through it. These bub bles are from an eightieth to an eighth of an inch in diameter, very clear and beauti ful, 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 1 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 be fore, 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. 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 parti

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tion 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 be' neath 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 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 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 nie 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 sup