Press and daily Dakotaian. (Yankton, Dakota Territory [S.D.]) 1880-1889, 1880-10-02
YANKToN
LONGER WINTERS.
Singular meteorological CInnge in the
Sierras.
Virginia City Enterprise.

Prof. Legate has just returned from
Trip INTO the Sierras OF eight days dura-
ton. He had with him two assistants
and his own vehicle for the transportation
OF his instruments, and camped out most
OF the time. The object of the professors
trip was the study Of recent interesting
meteorological changes in the elevated
regions OF the Sierras. He was led to be-
lieve that during the present season the
warm belt had shifted south. Beginning
ut point just north of Lake Tahoe, the
snow has not melted away as in former
years. There are now banks of snow
from fifty to one hundred feet IN depth
mt points where heretofore at this season
no snow has lain. Nearly the whole of
this snow will remain where it now lies
until the SHOWS of winter again set in.
UP toward the headquarters OF the north
FORK OF the Yuba river, where no snow is
usually seen at this season, it has but
little more than begun to disappear.
In that place are to be seen huge
banks OF snow, under which flow the
waters OF the stream, forming arches or
natural bridges one hundred feet in
helght and two or three hundred feet in
width. AS nearly the whole of this snow
VIII remain until snow again comes, the
accumulation next year will be still grea-
ter, and the whole region around the
head of that and other rivers high in the
mountains will probably lie under the
snow the year around.
IL was for the purpose of ascertaining
the cause of this remarkable change Of
climate to the northward that Prof.
Legate went on his expedition into the
mountains. Through the results obtained
by observations made at many points
with various delicate instruments, but
prlnipally by means of careful thermome-
trlcal tests, the professor has established
the fact that there has occurred in the
range of the Sierra Nevada mountains
this season, q grand isothermai change.
He finds that the warm current of air
which ever since the settlement of Cali
lorna by Americans-and probably ages
belore-has moved upward from the Pa
cific seaboard to the Sierra Nevada
mountains, and thence turned and flowed
to the northward along the west side of
the main ridge of the range, thus giving
to all regions in that direction a warm
longer moves in that direction.
1t now comes up from the side of the
ocean and pours eastward directly across
the crest of the Sierras near Lake Tahoe.
Prof. Legate has satisfied himself that |
this wonderful change, which is leaving
all the northern parts of the Sierras
buried in snow, summer and winter, is
caused by the denudation OF timber which |
the mountains have suffered through q
belt beginning at Lake Tahoe and
extending some twenty miles southwark |
Through the great gap thus left by the
sweeping away OF the forests now flows
the warm current Of air which formerly |
moved with something of the circling
motion of water in an eddy-far along
the mountains to the northward. Prof.
Legate says it must not be supposed that
the change has been caused merely on ac-
count of the gap or tongue left to the
clearing away of the forests. The denu-
dation Of. the ground is the principal
cause. The heat of the sun pouring
down upon the broad belt of the bare
ground now reaching across the noun
tains causes at that point an immense
ascending column of heated air which
formerly moved to the northward and
now all crossessthe Sierras, passing in an
and eastward direction.
Prof. Legate is Of the opinion that the
only thing capable of changing the iso-
thermal line which has peen recent
" accidentally and disastrously estab-
lished, is the creation. at some point well
north, of another broad belt Of denuda-
ton, the influence of which will be to
draw in that direction portion of the
warm current of air moving up to and
along the western slope of the Sierras,
and thus partly restore the equable tenn
perature that formerly prevailed. He
thinks the railroad which is to run in
the direction OF Oregon from Reno, and
which is to strike and tap the great
pine forests of the Sierras well to the
north, will after few years effect the
desired clanre