Evening star. [volume] (Washington, D.C.) 1854-1972, 1913-04-13

low pressure these air currents are SUBJ
jected to another influence. namely, the
rotation of the earth, which varies IN
speed as one proceeds from the pole to
the equator, from a state OF aDsoluto
rest at the pole to a. speed of about
thousand niles an hour at the equator.
Hence these air currents are twisted
askew on the way to the low-pressure
center. with the result that instead OF
going straight to the center of low pres
sure, they go flowing in a circular form
around this center. The fact, also, that
there are a number of currents from
various places of high pressure trying to
get to the single low-pressure center al!
at once, adds to this revolving motion OF
theirs.
Did you ever notice the water In a
bowl when you pull out the plug? AZ
first it will flow straight down through
the vent: but, as the f1owing-out process
continues. the whole mass of water COM
mences to rotate around that vent hole.
Well, that is just the way that the winds.
blowing in toward the low-pressure GEN.
ter set up this rotation.
1.-The extent of this movement depends
entirely upon the degree Of high and low
pressure. In this case of the late storm
in the west, the disturbed area extended
over vast territory. AS the lines show
here. there was a stately procession OF
winds, or air currents, revolving In a
rough circle whose western rim was over
in Wyoming. while its eastern edge
tOUcneQ the AlleSneIlleS-d Circle Oh uiOTe
than a thousand miles in diameter That
area. over which the winds blew in their
wide circular dance. was the storm area.
And that great mover .ent Of the air
currents in circle about the center IS
called a cyclone In this case. you OBJ
serve. it covered about third of the
United States. This is a very different
conception of a CYCLONE from that COM
monty in vogue in Kansas when they
speak of cyclone cellars The winds in
a cyclone may be of varying velocity; 1t
is not at all necessary that they should
blow at hurricane speed. They rarely do:
indeed, about the most expressive descrip-
ton of the cyclonic air current Is 'sttn
wind
1.-THE cyclone, then, is that great rotary
movement Of the air t,at takes place
around the true center of storm; that
is. the point of lowest barometric pres
sure. the movement being at a good, stiff
rate And the wind always blows in the
direction contrary to the movement of the
hands Of watch.
Now, the tornado, the specific local
Storm is the child of the cyclone. There
may be cyclones without attendant lorna
does-but there cannot be a tornado with
out an existing cyclone. In the recent
cyclone extending, as it did, over an
area more than thousand miles in
diameter, there were no doubt begotten
a good many dozen tornadoes, through
out its extent; many of them. in remote
and sparsely populated sections. were not
reported at all.
Just what specific atmospheric condi-
ton begets a tornado it is almost impos-
sible to state exactly. This much is GER
,lxr-oy S,y1p OH 70
in the southeasterly section Of the cy-
clonic area The theory of their origin,
commonly accepted, is this, that a warm.
damp wind, blowing in from a high pres
sure point in the south. gets in under a
cold, dry air. This causes a most alb
normal state of things. The air is stand
ing on it's head, so to speak. in a state of
most unstable equilibrium. Now. in try
ing to change places. the hot air finally
bursts up through the colder and drier
stratum-and in the resultant turmoil Of
adjustment the tornado is born and starts
on it's destructive course.
I'm support of this view, it has been
invariably observed that tornadoes most
frequently occur in those districts where
the conditions are most favorable for an
influx of warm. damp air from the lati-
tUdeS OF the SOuln NUS, Western MIS-
souri, and eastern Kansas, which have the
unhappy honor of being visited by the
tornado oftener than any other sections
of the country, are most fayorably sit
uated for the easy flood of these southern
air currents.
1T is the breaking through Of this
warm air that starts the trouble. At the
point of rupture, the cold, dry air, plung
ing downward. forms a cloud-the nucleus
of that baleful funnel-shaped mass Of
whirling vapor that is the distinctive
mark of the tornado. This cloud, which
Is first observed in the upper regions as a
mere point no bigger than mans
hand rapidly descends earthward, in
creasing in volume as it does SO, at the
same time starting into that mad gyra-
tory whirling that is the chief cause or
its destructiveneSs.
THE tornado has several movements;
principal is the rotary or gyratory mo-
ton of that funnel-shaped cloud which is
so characteristic of this type of storm