The phenomena of the year take place every day in a pond on a small
scale. Every morning, generally speaking, the shallow water is being
warmed more rapidly than the deep, though it may not be made so warm
after all, and every evening it is being cooled more rapidly until the
morning. The day is an epitome of the year. The night is the winter, the
morning and evening are the spring and fall, and the noon is the summer.
The cracking and booming of the ice indicate a change of temperature.
One pleasant morning after a cold night, February 24th, 1850, having
gone to Flint's Pond to spend the day, I noticed with surprise, that
when I struck the ice with the head of my axe, it resounded like a gong
for many rods around, or as if I had struck on a tight drum-head.
The pond began to boom about an hour after sunrise, when it felt the
influence of the sun's rays slanted upon it from over the hills;
it stretched itself and yawned like a waking man with a gradually
increasing tumult, which was kept up three or four hours. It took a
short siesta at noon, and boomed once more toward night, as the sun
was withdrawing his influence. In the right stage of the weather a pond
fires its evening gun with great regularity. But in the middle of the
day, being full of cracks, and the air also being less elastic, it had
completely lost its resonance, and probably fishes and muskrats could
not then have been stunned by a blow on it. The fishermen say that the
"thundering of the pond" scares the fishes and prevents their biting.
The pond does not thunder every evening, and I cannot tell surely when
to expect its thundering; but though I may perceive no difference in
the weather, it does. Who would have suspected so large and cold and
thick-skinned a thing to be so sensitive? Yet it has its law to which
it thunders obedience when it should as surely as the buds expand in the
spring. The earth is all alive and covered with papillae. The largest
pond is as sensitive to atmospheric changes as the globule of mercury in
its tube.

One attraction in coming to the woods to live was that I should have
leisure and opportunity to see the Spring come in. The ice in the pond
at length begins to be honeycombed, and I can set my heel in it as I
walk. Fogs and rains and warmer suns are gradually melting the snow; the
days have grown sensibly longer; and I see how I shall get through the
winter without adding to my wood-pile, for large fires are no longer
neces