The Universalist. [volume] (Chicago [Ill.]) 1884-1897, 1888-09-15
HOW GLACIERS ARE FORMED.

On this subject Prof. TyndslI writes
as follows in the Youths Companion:
"Some years ago, stood upon the roof
OF the great cathedral of Milan. The air
over the plains Of Lombardy was then as
pure and transparent as it in here to-day.
From the cathedral roof the snowy Alps
are to be seen; and, on the occasion to
which refer, light wind blew toward
them. When this air, SO pure and trans
parent, as long as the sunny plains Of
Lombardy we're underneath to warm it
reached the cold Alps and was tilted
their sides, the aqueous vspor it con
tanned was precipiteted in 70 clouds of
scowling blackness.
IF you pour cold water into tumbler
on fine summer day, a dimness will be
immediately produced by the conversion
into water, on the outside surface of the
glass, OF the aque ous vapor of the sur
rounding air. Pushing the experiment
still further, you may fill a suitable ves-
sci with q mixture of ice and salt, which
is colder than the coolest water. On the
hottest day in summer, thick fur of
boar frost is thus readily produced on
the chilled surface of the vessel. The
quantity OF vapor which the atmosphere
contains, varies from day to day. In
England, northessterly winds bring us
dry air, because the wind, before reach
ing us, has passed over vast distances of
dry ground. Southwesterly winds, on
the other hand, come charged with the
vapor contracted during their passage
over vast tracts of ocean. Such winds, in
England, produce the heaviest rains.
And now we approach question of
very great interest. The condensed va
por which reaches the lowlands as rain,
falls usually upon the submits as snow.
To resident among the Alps it is in
teresting to bserve, the morning after
nights heavy rain, limit sharply drawn
at the same level along the sides of the
mountains, above which they are covered
with snow while below no snow is to be
seen. This limit marks the passage from
snow to rain. To the mountain snow all
the glaciers OF the Alps owe their exist
ence. By ordinary mechanical pressure
snow can be converted into solid ice; and,
partly by its own pressure, partly by the
freezing CT infiltrated water, the snow of
the mountains is con verted into the ice of
the glaciers.
"The great glaciers, such as the one
now below me, have all large gathering
grounds, great basins or branches, where
the snow collects and becomes gradually
rcompacted to ice. Partly by the yielding
of its own mass, and partly by sliding over
its bad, this ice moves downward into
trunk valley, where it forms what Do
Saussure called "a glacier of the first or
der. Such glacier resembles a river
with it's tributaries. We may 60 further
and affirm, with Distinguished writer
on this subject. that between a glacier
and river the re is a resem blance so
complete that it would be impossible to
find in the latter popularity of motion
which does not exist in the former
SIT has been proved that, owing to the
friction of its sides, which holds the ice
back, the motion of glacier is swiftest
at its center; that, because of its friction
against its bed, the surface of glacier
moves more rapidly than its bottom;
that, when the valley through which the
glacier moves is not straight but curved;
the point of swiftest motion in shifted
from its center toward the concavs side
of the valley. All these facts hold equal
ly good for river. Wide glaciers, more.
over, are sometimes forced through mar
row gorges, after which they widen again.
At some distance below the spot where I
now write is the gorge of the Massa,
through which, in former agee, the great
Aletsch glacier was forced to pass, widen.
ing afterward, and ovsrspreading a large
tract Of country in it's descent to the val
ley of the Rhone.
ut is easy to understand that, with
substance like glacier ice, when some
parts of it are held back by friction
while other parts not so restrained tend
to move forward, tensions must occur
which will break up the ice, forming
clefts or assures, to relieve the strains
The crevasses of glaciers are tn Is pro-
duced."