Millheim Journal. [volume] (Millheim, Pa.) 1876-1984, 1880-10-28
How the winters I'm the sierras Grow
Longer.

Professor 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 professor 8
trip was the study Of recent interesting
meteorological changes in the elevated
regions of the Sierras. lie was lea to be-
lieve that during the present season the
warm belt had shifted south. Beginning
at 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 100 feet in depth at 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 head waters
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 CT natural bridges
100 feet in height, and from 200 10 300
feet in width. AS nearly the whole of this
snow will remain until snow again comes,
the accumulation next year will be still
greater, and the whole region around the
head of that and other rivers high in the
mountains will probably lie under The snow
the year round.
1t was for the purpose Of ascertaining
the cause of this remarkle change of eli
mate to the northward that Professor Le-
gate went on his expedition into the noun
tains Through the results obtained by
observations made at many points with
various delicate instruments, but principal
ly by means of careful thermometrical tests,
the professor has established the fact that
there has occurred in the range of the Sierra
Nevada Mountains this season grand
isothermai change. He finds that the warm
current of air which ever since the settle
ment of California by Americans-and pro-
baby ages before-has moved upward
from the Pacific 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 q
warm climate, no longer moves in that di-
rection. Ii now comes up from the side of
across the crest of the Sierras near Lake
Tahoe
Professor Legate has satisfied himself
that this wonderful change, which Is leav
ing all the northern parts of the Sierra
buried in snow, summer and winter, is
caused by the denudation of timber which
the mountains have suffered through belt
beginning ut Lake Tahoe and extending
some twenty miles southwark. Through
the great gap thus lett 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 10 the
northward. Professor Legate says it must
not be supposed that the change has been
caused merely ON account Of the gap or
trough left 10y the clearing away OF the
forests. The denudation OF the ground is
the principal cause. The heat of the sun
pouring down upon the broad belt of bare
ground now reaching across the mountains
causes AT that point an immense ascending
column of heated air which draws in from
the west the current which formerly moved
to the nOrthward and now all crosses the
Sierras, passing in al upward and eastward
direction.
Professor Legate is of the opinion that
the only thing capable of changing the is
othermal line which has been recently ac-
cidentally and disastrously established is the
creation, at some point well north, of an
other broad belt of denudation, the intiu-
ence of which will be TO draw in that direc-
ton portion of the warm current of air
moving up to and along the western slope
of the Sierras, and thus partly restore the
equable temperature that formerely pre-
vailed. 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 a few years effect the desired
change.