The Kimball graphic. (Kimball, Brule County, Dakota [S.D.]) 1883-1905, 1885-09-11
WIND AND

WIND AND WEATHER.
Cyclones. Thunder and Lightning and
Wind on the l~Ialf-Shell.
PtttsburE Dispatch.
''Cyclonespn said Sergeant 0. u.
Stewart, Of the Signal Service Station,
as he looked up from studying a map
OF the havoc made by one recently in
Southern Georgia. well, l am Just
now looking over the path OF one, and
it is a path of thorns, l assure YOU"
Always courteous and obliging, he
gave U? his study of the map, and in a
conversational tone. gave the follow
ing description of.these fearful. vista
tions:
10 understand the nature of a cy-
clone OF any other meteorological phe-
nomenon, a person should understand
the construction and use of barome-
ter. A barometer is a glass tube
closed at the upper end, and from
which the air has been extracted as
much as possible; it is then filled with
quicksilver, and the open end placed
in a cup filled with mercury, when it
will be found that the mercury in the
tube will remain some thirty inches
higher than the level of the mercury in
the cup at the base. This is because
the pressure of the atmosphere on the
mercury in the cup is great enough to
hold that in the tube at that height.
The general pressure of all atmospheres
range between 81 and 81 inches on a
stationary barometer, and hence they
are graduated to show the fluctuations
between these limits.
"Now as the atmosphere becomes
light or heavy the mercury is pushed
up or lowered, and thus we have indi-
cation of approaching changes. All
storms are laden with a light atmos-
pheric pressure. hence adec.ded fall in
the barometer is nearly always indica-
tive of a coming storm. The mean of
the atmospheric weight is twenty-nine
inches in the tube, and a fall below
that point invariably presages a storm
of great magnitude. When n cyclone
is approaching or passing the action
OF the barometer is very 1everish, ris-
ing and falling quickly, the ar is OBJ
served to be close and sultry and the
vino Is moderate or calm. Then it ri
ses and falls with a moaning sound,
Just as if it was human and knew the
damage and death with which it was
fraught, and after few hours it is sue
ceeded by a lull, which may last for
hours, then the wind comes out from
the west suddenly, with Il snort and
rush. and increases in velocity until it
often obtains a force of one hundred
miles per hour.
Cyclones almost invariably travel
toward the north and east, being di-
rected thereto by the rotary motion of
the earth. When a large mass of air
in the northern hemisphere is put in
rotation about q vertical axis, the par
ticles on the east side of the center,
crossing successfully parallels of lati-
tude whose easterly motion is less than
their own, are DETECTED toward the
east; that is, toward the right. So,
also. the particles on the west side of
the center crossing parallels of latitude
whose easterly motion is greater than
their own, are detected toward the
west, which is also toward the right.
Particles lying on the north or south
are detected IN Il similar manner; that
is, the particles of the revolving mass
OF air. in every portion of their circuit,
are detected toward the right. Hence
on the equatorial side of the revolving
a OF air there is a tendency toward
the poles. This detecting force be-
ZONES greater toward the pole, being
proportional to the line of latitude.
Hence the pressure on the polar side
toward the equator, and the revolving
mass accordingly moves in the direc.
ton of the greatest pressure; j. e.,
northeast.
There is a definite portion of an
area of low pressure within which the
conditions for the development of cy-
clones are more favorable, and this is
called the dangerous octant. This &C.
tant is the northern half of Mississippi.
Alabama, Georgia and the western
half of North and South Carolina.
Last year there were some forty cy-
clones in Georgia, and all of them in |
an area of 200 miles squar They
generally whirl from left to right or
against the sun. and are ACCOMPANIED
by rain. hail, thunder and lightning.
There is no means of knowing the an.
proach of a cyclone in sufficient tine
to get out of its way, and hence the
enormous destruction of life and prom.
erty in those states where they are
most frequent.
Storms in general a G caused by the
displacement of large masses of air
which ascend, being rariiied or made
lighter, and heavier or more humid at
mosphere rushing in to take its place.
The atmosphere receives heat from the
sun and loses it by radiation. When
a cloud begins to form in consequences
OF an ascending column of air, it
swells out at the top, and ON a warm
day continues to ascend until rain
falls. The expansion of the airin the
forming cloud, particularly after the
rain begins to fall. causes the air to
spread out in all directions above.
causing a barometer under the middle
OF the cloud to fall below its mean
height. Near the edge of the cloud
the air, in consequence of it's greater
weight. sinks downward, and a portion
OF 1t flows along the earth's surface
toward the center of the ascending
column, while beyond the limits of the
clouds there is a gentle wind outward
from the cloud. Since the air spreads
out more rapidly above the cloud than
1t runs in below, storms tend to in
increase in diameter, and they often
extend with great rapidly until they
v AN q more than !: thousand
miles in diameter.
Rain is condensed vapor of the air.
In order to produce an abundant rain
.ANAM- So