Manchester Democrat. [volume] (Manchester, Iowa) 1875-1930, 1900-01-24

al clrCulat1On vast volumes OF warm,
moist air from the Gulf, giving in
intensity to the storm move
ment, and making this the best wat
cred and most productive midland val
ley upon the face OF the earth. And
thus we see that the Gulf is the great
thermal fountain for the irrigation of
this region. From this it may be IN
ferred that if we were deprived of the
Gulf winds this region
would dry up entirely. And if the
cyclones from the Pacific were defect
ed from their normal track across the
valley the moist winds from the south
would not be drawn hither to give us
our refreshing showers.
We are dependent, therefore, upon
the normal movement of cyclones
across our valley. 1t is watered and
made fruitful by cyclones, which OPP
crate like vast rotary pumps to bring
the life-giving streams to our fields
When they become for time sluggish
and cratic, as they were in 1894, we
suffer from drouth. When they are
more frequent, and greatly intensified
in action, we have occasionally vio-
lent wind storms, so-called cloud
bursts, and seasons of excessive moist
ure.
The fact should be noted that the
cyclones Of this region are not usually
destructive to life and property and
they should not be confounded with
the dangerous class of local storms
properly called tornadoes.
In some general characteristics cy-
clones and tornadoes are like. They
are both rotary in movement, and the
wind currents move from right to
left, in the northern hemisphere, or
opposite the hands of a watch. In
the southern hemisphere the movement
is reversed, or with the hands of a
watch. Thus far they have points of
resemblance.
But in respect to dimension, yeloci-
ty of wind, and duration of the dis
turbance there is an immense differ
ence between these two classes of
storms. The cyclone sweeps over
many thousands of square miles, and
freqently covers an area of half doz-
en- states; while the tornado is gener-
ally less than quarter of mile in
diameter. The cyclone progresses
slowly, taking two or three days to
cross the valley; but the tornado
moves with terrible swiftness, doing
its work of desolation within one loI
two minutes, and then passes onward.
The cyclone is general storm, sweep.
ing across the entire continent, and
sometimes we'll nigh around the earth
while the tornado makes a narrow
track generally but a few miles il
length.
But the tornado makes up in tre
i wi 4.
lack of size. While the velocity %,
the wind in a cyclone rarely exceeds
thirty miles an hour, the tornado re
wolves with terrible swiftness, thu
velocity estimated to be two to tire,
hundred miles IN hour around its cen
trail axis of rotation. From this i
will be seen that tornadoes, though
of great force within narrow limits
belong to the secondary or minor clas
of storms.
1t may be stated, that all storm
movements, whether of the first O
second class, are related to each other
Tornadoes, wind-squalls, water
spouts on the sea, hail and thunder
storms, are generally associated will
cyclones, and are undoubtedly pro
duced by the same general causes, viz
l-sharp contrasts of temperature an,
pressure, the action of expanding va
por, the formation of air currents o
eddies, and the rotation of the earth
Thunder and hail storms, with thei
attendant wind-squalls, may be con
sidered potential or possible lorna
does; that is, the tornado is the inten
sified product of the forces that gener
ate thunderstorm or hail storms
Unquestionably they must be regarde,
as analogous phenomena.
| In all severe hail storms there ar
evidences of strong ascending or up
lifting currents, such as are observes
in tornadoes. The rotary motion il
hail storms is apparent on horizontal
axis, and in tornadoes the axis of 70
tation is vertical.
| And here I may as we'll say there j
practically no danger of the develop
ment of tornadoes in any other tina
the southeast quadrant of low are
or cyclone. The reason is undoubt
eddy the higher temperature is in tina
portion of the advancing low area
The relation of heat to all violent at
mospheric disturbances is we'll under
stood by all who have studied natur
or the books.
i The conditions are favorable fo
the development of tornadoes nea
the close of the day, when the air
notably quiet, with excessive hea
and humidity, and when there is
wide-extended or general storm fror
two to four hundred miles to tn
northwestward In other words, whe
the cyclone center is somewhere i
South Dakota or northeastern Nebras
ka, after period of considerabl
heat, with southerly wind, there is.
possibility of tornado activity.
| In tornadoes we note evidences of
powerful uplift within the funnel, @
the center of the rotary column. Thi
creates relative vacuum, which pre-
duces explosive effects upon the al
that chances to be shut up in build
ings or rooms. All classes of struc
lures that are closed up, burst out
wardly from the effects of the vacuum
III the passing funnel.
But these tornadoes are the exceI
tional or occasional products of thi
region, of which we are not dispose
to boast, and for which we have NOR
than our due share of credit. Their
has been an immense amount Of exag
geratlon in the newspapers in relatio
to our wind storms, and people livin
at distance have been led to believ
that this. region is regularly plowe
by tornadoes every summer. and har
lowed by billiards. every winter.
1 l have resided in Iowa 2S years, an
have never been able to get nea
enough to tornado to interview TIL
critter," to make note of its peculi
arities. And the result of my obserya
tion is that there is hundred-fol
greater danger of being killed b.
lightning than by a tornado. An
there is a million-fold greater proba
bility that man will die in bed fror
natural disease, than that he will b
whirled out Of existence by tornado
So I guess we had better not worry
but it's wise provision to have
good cave or safe place Of retreat il
the cellar.
AS before suggested, we may hav
cyclonic storms with very little raj
or other form Of precipitation. So
fall in the barometer does not wit
any certain indicate rain or snow 70
this locality. 1t never rains over tn
entire extent of low area. I thin,
about two-fifths of the area covere
| nv low nressurn receivas moro or los