The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1872-03-08

The Great March FrOst-Its Causes and
Conseauences-Early Iceberg Season.
Only day or two ago the HERALD chroni-
cled the great Southern cyclone and the open
ing battle of the equinox. We have just had
its severe and stunning counterpart in the
intense frosts and boreal blasts of the cold snap
just beginning to moderate. This tremendous
conflict of atmospheric forces is not meaning
less, and is worthy of attentive notice and
study. There can be no doubt that the northern
and eastern parts of the country have for two
or three days been in powerful stream Of
polar air descending with almost torrential
rush. The Signal Service and other reports
reveal the velocity and intensity of this cur
rent, which has spread itself out in fan-shape
all the way from Lake Superior to our Atlantic
seaboard, and formed majestic air-wave
covering the whole country from the lakes to
the Alleghanies and pouring over their sum-
mits.
At this season of the year Northern and
Eastern British America, with its numerous
ice-clad continent-an immense nser de gIace-
over whose dry and CLASSY surface our polar
winds have swept before they reached us.
Hudson Bay, the great Mediterranean of
North America, is also, at this time, doubtless
covered with solid surface, and would now
present to an explorer the sublime spectacle
of the Baltic Sea in the winter of 1868, when
Charles x. led his whole army across it from
Holstein to Denmark as over an immovable
bridge of ice. The great polar current which
moves down over Hudson Bay and the east
ern half of British America, in nearly meridi-
aside and diverted eastward by the vast equa-
torial current that sweeps from the Pacific
and streams through the passes of the Rocky
Mountains in Idaho and Montana; so that in
stead Of desc ending as it did In January, into
the Mississippi valley, the boreal current is
projected southeastward over Canada and the
Northern States. Only a few days ago the
evidence of this was afforded by the startling
intelligence of the breaking up of the ice in
the Upper Missouri at Fort Benton, and as late
as Monday (the 4th inst. }, while the mercury
was rapidly falling below zero on the lakes
and over Canada, the Signal Service reports
showed the high temperature of ifty-one de-
grees Fahrenheit at Fort Benton.
Such spells of cold as the present sometimes
mark important periods in history, as well as
in climatology; and it is Of the first impor-
lance to all classes of men to understand their
causes and to be forewarned of their conse-
suences. We have already suggested the
chief agent at work in the production of such
weather in the northern part of the United
States and Canada, in the southwesterly winds
from the Pacific. Formerly we have been
taught TO suppose that when we had cold
snap at this season in New York it was due to
a band of wind moving directly over the sum-
mits of the Rocky Mountains, and thus becom-
ing intensely chilled.
The published weather reports from the
region west of Lake Superior, extending to
the Upper Missouri, explode this theory and
fully establish the fact that the zero tempera-
ture comes from the far North. The weather
map daily exhibited in this city presents
also the additional and beautiful phenomenon
of an enormous wave of atmosphere heaped
up on the lakes southwark, around which, In
accordance with the celebrated law of Buys
the direction of the hands of a watch. 1t is to
this circumstance that meteorologists show
we are indebted for the violent northwest
winds of the last few days on the coasts of the
Eastern and Middle States. So potent are
these waves of high pressure in causing cold
winds that in the great December frost of 1860,
in Great Britain, the thermometer ranged
near zero for eight days, and in 1867 the same
conditions produced, even in January, a
fortnight of frosty weather in the sea-girt
island.
Interesting as it is to get the few rays of
light science has been able to throw over the
causes of these thermic phenomena, their re-
suits are what more deeply concern us.
These northwesters of March on the American
seaboard, attended by terrific snow storms,
both on and off the coast have been the terror
of AFOREMENTIONED mariners from time i'm
memorial Many ships annually founder in
these gales between the capes of the Delaware
and Chesapeake and Boston, and instances
abound in which vessels making this port
have encountered freezing snow storms
which have covered their masts and
rigging with dangerous masses of ice,
stiffened and frosted their crews, baf-
fed all their skill, and driven them back
time and again into the Gulf Stream, and kept
them out forty and fifty days. Our coasting
steamers and revenue cutters should now
maintain q sharp lookout for such craft in dis
tress and lend them every assistance The
extreme and concentrated violence of this
springs northwesterly gales, it is to be feared,
will put our transatlantic steamships also in
early and imminent peril of icebergs on the
Newfoundland Banks and southwark. The
Greenland and Labrador currents and the