HOUSE-WARMING. 
267 
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 lumber¬ 
ing 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, 
Flints’ and other shallower ponds and the river having 
been frozen ten days or more; in ’46, the 16th; in ’49, 
about the 81st; and in ’50, about the 27th of December; 
in ’52, the 5th of January; in ’58, the 81st 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 
