ce.

To many it is a singular fact that Lake Tahoe never freezes over
in winter. This is owing to its great depth, possibly aided by the
ruffling and consequent disturbance of its surface by the strong
northeasterly winter winds. The vast body of water, with such
tremendous depth, maintains too high a temperature to be affected
by surface reductions in temperature. Experiments show that the
temperature in summer on the surface is 68 degrees Fahr. At 100 feet
55 degrees; at 300 feet 46 degrees; at 1506 feet 39 degrees.

Twenty years ago the thermometer at Lake Tahoe registered 18 degrees
F. _below zero_, and in 1910 it was 10 degrees F. below. Both
these years Emerald Bay froze over. Perhaps the reason for this is
found in the fact that the entrance to the bay is very shallow, and
that this meager depth is subject to change in surface temperature,
becoming warmer in summer and colder in winter. This narrow ridge once
solidly frozen, the warmth of the larger body of water would have no
effect upon the now-confined smaller body of Emerald Bay. Once a firm
hold taken by the ice, it would slowly spread its fingers and aid in
the reduction of the temperature beyond, first producing slush-ice,
and then the more solid crystal ice, until the whole surface would be
frozen solid.

An explanation of the non-freezing of the main Lake has been offered
by several local "authorities" as owing to the presence of a number of
hot springs either in the bed of the Lake or near enough to its shores
materially to affect its temperature. But I know of few or no "facts"
to justify such an explanation.

When I first visited Lake Tahoe over thirty years ago I was seriously
and solemnly informed by several (who evidently believed their own
assertions) that, owing to the great elevation of the Lake, the
density of the water, etc., etc., it was impossible for any one to
swim in Lake Tahoe. I was assured that several who had tried had
had narrow escapes from drowning. While the utter absurdity of the
statements was self-evident I decided I would give myself a practical
demonstration. To be perfectly safe I purchased a clothes-line, then,
hiring a row-boat, went as far away from shore as was desirable,
undressed, tied one end of the rope around the seat, the other around
my body, and--jumped in. I did not sink. Far from it. I was never more
stimulated to swim in my life. My ten or fifteen feet dive took me
into colder water than I had ever experi