uch agitated, in clear
weather, so that the surface of the waves may reflect the sky at the
right angle, or because there is more light mixed with it, it appears
at a little distance of a darker blue than the sky itself; and at such
a time, being on its surface, and looking with divided vision, so as to
see the reflection, I have discerned a matchless and indescribable light
blue, such as watered or changeable silks and sword blades suggest, more
cerulean than the sky itself, alternating with the original dark green
on the opposite sides of the waves, which last appeared but muddy in
comparison. It is a vitreous greenish blue, as I remember it, like those
patches of the winter sky seen through cloud vistas in the west before
sundown. Yet a single glass of its water held up to the light is as
colorless as an equal quantity of air. It is well known that a large
plate of glass will have a green tint, owing, as the makers say, to its
"body," but a small piece of the same will be colorless. How large a
body of Walden water would be required to reflect a green tint I have
never proved. The water of our river is black or a very dark brown to
one looking directly down on it, and, like that of most ponds, imparts
to the body of one bathing in it a yellowish tinge; but this water is
of such crystalline purity that the body of the bather appears of an
alabaster whiteness, still more unnatural, which, as the limbs are
magnified and distorted withal, produces a monstrous effect, making fit
studies for a Michael Angelo.

The water is so transparent that the bottom can easily be discerned at
the depth of twenty-five or thirty feet. Paddling over it, you may see,
many feet beneath the surface, the schools of perch and shiners,
perhaps only an inch long, yet the former easily distinguished by their
transverse bars, and you think that they must be ascetic fish that find
a subsistence there. Once, in the winter, many years ago, when I had
been cutting holes through the ice in order to catch pickerel, as I
stepped ashore I tossed my axe back on to the ice, but, as if some evil
genius had directed it, it slid four or five rods directly into one of
the holes, where the water was twenty-five feet deep. Out of curiosity,
I lay down on the ice and looked through the hole, until I saw the axe
a little on one side, standing on its head, with its helve erect and
gently swaying to and fro with the pulse of the pond; and there it
might have stood er