y 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