The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1907-06-20
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of these four States, or about a hun
dred miles east Of the geographical cen
ter of the United States is the tornado
area. According to the reports of the
United States weather bureau, lorna
does occur more frequently in May,
April. June and July, in the order
named, the most violent ones thus far
recorded having happened in April and
the greatest number in May. Already
tornadoes have occurred this season
In this territory, accompanied by much
damage to property and loss of life.
y tornado is the concentration OF
storm energy. 1t Is the most destruc-
tive and the most sudden in appear
ance of all forms of atmospheric dis
turbance, and Is least easily recog-
niZed in its early stages, even by the
expert. A tornado and an electric
storm arise from the same general
conditions, and in the beginning can
not be distinguished one from the
other. They often are identical up to
certain point and are DETECTED into
the one or the other by local condi-
tons with which the general cyclonic
storm comes in contact in its passage
from one point to another.
Edward II. Bowie, chief of the St
Louis weather bureau, has made a
special study of the subject of lorna
does and IS in a position to speak with
authority regarding them.
81 Think said he, at would be we'll
II bring out one point in the begin
ming of this subject, and that Is the
difference between tornadoes and cy-
clones. The sort of windStorm that Is
popularity called cyclone is not a cy-
clone at all. but is tornado. The
tornado Is the storm that makes its
appearance In the form of a funnel
shaped cloud, while the cyclone IS
general storm. or an area of low
barometrlc pressure. The word cy-
clone means a revolving wind. It is
true, and cyclone is a revolving wind,
only the revolution covers a much
greater area than that of the so-called
twisters, or tornadoes A cyclone may
be thousand miles in diameter. while
a tornado may not be more than a
hundred feet
THE CYCLONE
The cyclone is the parent of the tor
nado. 1t Is the general condition that
produces the tornado. There is al
ways cyclone somewhere In the Unit
ed States Without it this country
would dry up, for the cyclones bring
us our rains II you examine a wealth
err map you will see certain sections
marked low These are the areas of
low pressure, the storm centers or cv-
clones, and If you will look further
you VIII find that all the little arrows
which show the direction of the wind
In the different localities around This
low region point in direction gener-
ally slanting toward the center of the
area marked low circling from right
to left, or opposite to the hands Of .
clock. That means that the eGuiilib-
RUM OF the atmosphere is Disturbed
but not violently, and that the motion
Is in generally rotary direction. but
horizontal rather than vertical. These
storm centerS move across the country
from day to day, in a generally north
easterly direction, and the atmosnberic
conditions which they encounter on
route are the immediate causes of vio-
lent storms of one kind or another
Sometimes it is a severe Thunderstorm
and sometimes it is tornado. These
storm centers, or cyclones, extend over
large areas, varying from 800 or 400
miles to thousand or more miles in
diameter.
WHERE TCRNADOEs ORIGINATE.
''Tornadoes always originate in the
southeast quadrant Of these areas Of
low pressure, usually due southeast Of
the center at a distance of from 200
to DO miles, and they, like the parent
cyclone, travel in "A generally north
easterly direction.
The tornado travels ten or n hun-
'dred miles. and is dissipated in n few
hours. while a cyclone may travel for
days and cover thousands of miles of
territory in its progress. The Calves
ton hurricane is an instance Of this
That storm was first observed south
east of the island of Porto Rico on
September !. 1t moved westwardlv
with the general drift of the air. was
DETECTED from its normal course up
the Atlantic coast by a bank of cold
air over the eastern States, and on
September 10 was in northern Texas
It then recurved toward the northeast
passed over the great lakes and the St
Lawrence valley as a storm of marked
intensity and was diSsipated some
where off the coast of Canada 4 hur-
ricane Is an intensified cyclone
"A tornado is caused by n very un.
stable local condition of the atmos-
phere. The warm, moist air rises and
comes in contact with the descending
cold stream of air above. Breaking
through this cold stratum, it rushes
into the opening and the heavy cold
air PUSHES down to fill the space for
merly occupied by the heated air. pro-
ductng whirling motion similar TO
that in a stationary washbowl of
water when the stopper IS removed