The opening of large tracts by the ice-cutters commonly causes a
pond to break up earlier; for the water, agitated by the wind,
even in cold weather, wears away the surrounding ice. But such
was not the effect on Walden that year, for she had soon got a
thick new garment to take the place of the old. This pond never
breaks up so soon as the others in this neighborhood, on account
both of its greater depth and its having no stream passing
through it to melt or wear away the ice. I never knew it to open
in the course of a winter, not excepting that of '52-3, which
gave the ponds so severe a trial. It commonly opens about the
first of April, a week or ten days later than Flint's Pond and
Fair Haven, beginning to melt on the north side and in the
shallower parts where it began to freeze. It indicates better
than any water hereabouts the absolute progress of the season,
being least affected by transient changes of temperature. A
severe cold of a few days duration in March may very much retard
the opening of the fo