Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1883-09-06
CYCLONES.
.-R-I-

Oergt. Finley, OF the Signal Service,
has reported on the character of 600
tornsdoes occurring in the United
States within the present century.
Three-fourths of those reported oc-
CURED within ten years. The report
gives the hour, date, direction, length
in miles, width in feet, velocity of pro-
gressive motion, form of cloud, dlrec-
ton of whirl-always from right to
left in the northern hemiSphere-tem-
perature before and after storm, char
acter of the central cloud giving birth
to the tornado, as well as the electrical
condition of the cloud, and whether it
bore rain or hail. The essential deduc-
tions of this very-interesting report as
regards time are: That no season OF
month is exempt; most occur in sum-
mer, and most CID in June and fewest
Cd in January. Tornadoes are most
frequent from noon to 6 o'clock, the
greatest number (52) between 5 and 6
p. m, and but two between and 2
a. m. As to distribution, that part of
the great basin west of the Mississippi
and including Iowa, Missouri, Kansas
and Nebraska, produces most. The
great number in this region has rela-
ton to its general physical features.
We have here a north and south Their
NAL belt of high contrasts, an immense
range of country without mountains or
bodies of water to oppose the free
sweep of air currents north and south.
These tornadoes almost invariably de
velop in the southwest quadrant OF
an area of low barometric pressure.
In most all cases previous to the in
ception of any given tornado the wind
has been found blowing from a south
erly quarter south of the central area OF
lowest aerial pressure, and also from a
northerly quarter north of the same
central area of low pressure, for a
period of two weeks. These conditions
may prevail in this vast territory until
the thermometric range on opposite
sides-north and south of the central
area-frequently reaches 80 degrees.
This great disturbance of atmospheric
equilibrium, due to the contact of the
southeastern return trade winds from
the equatorial regions with the north
western winds from the polar regions,
results in an enormous tornado center
in the States mentioned. In this CEN
ter arises the May and June cyclones
which have become a source of con-
slant terror to the people of this region.
There are two other "areas of frequen-
cy" in the United States-New York
and Georgia. The first is due to sim
liar contact of the warm winds of the
great lakes met and opposed by the
cold northerly winds of the Canadas.
To this center are due the New York
and New England tornadoes, as the
Wallingford, (Ct.,) tornado of Aug. 8,
1873, In which the contrasts of tempera
ture ranged from 80 to 60 degrees, The
Atlantic, or Georgian center is due, Of
course, to the formation of q similar
thermal belt of high contrasts, occa-
stoned by the warm, moist Gulf winds
sweeping over the heated plains OF
Georgia and Alabama, and then com
ing in contact with the cool winds of
the Appalachian mountain system.
Here are born the great wind-storms
and cyclones that sweep northwestward
along the Alleghenies and wreak de-
struction on the cities and shipping
of the Atlantic coast of the United
States.
In brief, we have in the United
States three well-defned cyclone cen
tiers; that is, three areas of low bar
ometric pressure, where, in the recovery
of atmospheric balance, the great OPP
posing air currents, northerly and south
erly, sweep against each other and pro-
duce the whirling eddies of air known
as cyclones, tornadoes or hurricanes.
They are all cyclic; all revolve opposite
to the hands Of watch. All move
eastward, and at a rate of twelve to
sixty miles an hour, the average being
twenty-eight The cyclic velocity within
the storm-cloud is variously estimated
at from 100 to 800 miles an hour. Tor
nadOes have four motions-progressiv
whirling, lateral, darting from one side
of their paths to the other, north and
south; lastly, rising and falling. 1t is
these bounding tornadoes" that some
times, as once in Iowa, suck up the
waters of pond or prairie slough"
and deluge a farm-yard, sweeping away
stock and fences. They also explain
the rain OF river-tish and frogs, known
to have occurred on dry lands. In
width they vary from forty to 10000
feet, with an average of 1000; in
length, from two to 200 miles, with an
average of nty-eight. -Four hundred
are reported as violent thunder-storms,
fifty without electrical phenomena; in
others the color is described as of red
hot iron, or as if filed with balls of fire.
They occupy from ten seconds to
fifteen minutesi in passing given point
with mean in fifty cases of six min
utes. AS to shape, 207 were described
as funnel-shape; others as "cone-
shape" "hour-glass shape" etc. In
general the appearance is that of a
black, threatening storm-cloud, from
the under side of which projection de-
sends to the earth's surface. An equal
variety of expressions were used to ex-
press the accompanying sounds, which
are sometimes audible several miles.
In regard to distribution by States,
Kansas takes the lead with 81; Illinois,
81; Missouri, A; Iowa, 81; Ohio, IS,
and Indiana, 27. Sergeant Finley gives
various suggestions for avoiding the
violence OF cyclones-as taking to
cellars, bank retreats and sodded sub
cellars; also by running out of the
storm-line and the like.