The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1872-04-20
THE LAWS OF STORMS.

The meteorological report of Professor
j. P. Espy, of Washington, gives some in
teresting cancellations of the laws of
storms during the winter months, from
November to March, as they have been
deduced from the observations of the
Meteorological Bureau. When the Bureau
was established, it was understood that
storms were spiral movements of the at
mosphere, which had also general pro-
gressive motion from east to west, like a
dust whrlwind which whirls and travels
along the road. Further than this, no
definite hypothesis was advanced.
Professor Espy confirms the general
easterly motion of the storms. They are
accompanied with depression of the bar
ometer near the central line, and rise in
front and rear. The line of minimum pres
sure is generally of great length from north
to south, and is often curved, with its con-
vex side toward the east. 1t travels from
the Mississippi to the Connecticut in TWEEN
ty-four hours, and from the Connecticut to
st. Johns, N. F., in thirty six hours.
Wnen the barometer falls suddenly in
the western part of New England, it rises
at the same time in the valley of the Mis-
sissippi, and also at St. Johns n. F. In
great storms the wind for several hundred
miles on both sides of the line of minimum
pressure blows toward that line directly or
obllquely, with force proportioned to the
suddenness and greatness of the depression
of the barometer.
There is generally lull of wind at the
line of minimum pressure, and sometimes
calm. When this line passes toward the
east, the wind generally soon changes to
the west, and the barometer begins to RISE
There is generally but little wind near the
line of maximum pressure; what winds
there are, are irregular, and tend outward
from the line.
Great falls of the mercury are accompa-
MED by great rains or SHOWS. During the
high barometer on the day preceding the
storm it is generally clear and mild in tenn
perature, especially if very cold weather
preceded. The temperature generally falls
suddenly on the passage of the centre Of
great storms, so that sometimes, when a
storm is in the middle of the United States
the lowest temperature of the month will
be i'll the west on the same day that the
highest temperature is in the east.
~ hot o,Io hox,prI
the line of observation (which reaches from
the Gulf of Mexico to the northern lakes,
while the east and west diameter is COM
paratively small. Most storms commence
beyond the stations of the Western observ-
ers, but some commence within the United
States. In the latter case, the line of min
imum pressure is formed with the begin
ming of the storm, and does not come in
from abroad.
The fluctuations of the barometer are
greater in the northern and eastern parts
of the United States than in the southern
and western parts. In the northern parts,
the wind in storms generally sets in from
the north east and terminates from the
north of west. In the southern parts it
sets in from the south east, and terminates
from the south of west. The storm travels
more rapidly in the northern than in the
southern part.
In small storms, entirely within the
bounds of the observers, the minimum
pressure does not exhibit itself in a line of
great length, extending from north and
south, but it is confined to a region near the
centre of the storm, and travels with that
centre toward the east