The Pulaski citizen. [volume] (Pulaski, Tenn.) 1866-current, 1886-08-26
Toruadoes and Cyclones.

Oy ClOuCS, plOPCl1J SO NoAAOO, ~ =
ur on the Atlantic and Indian c
oceans, or on the shores of these |
,reat seas. They have we'll defined
md regular movements, usually
over a great area; can be foretold
With some precision by the rising
md sinking of the barometer, and
hips at sea can avoid their great
,st fury by observing well-known
Jules. The tornado is very small
cyclone, having a breadth of feet
where the cyclone has miles. The
barometer gives little indication OF
its approach and its movements are
very cratic, as well as violent.
The two are similar in the impor-
tant fact that the wind has two mo-
onward movement like
ordinary wind, and a motion of ro-
tation about a vertical axis. The
movement in the northern
hemisphere is from left to right, or
opposite to the rotation of the
hands of a watch, while in the
southern hemisphere this motion is
reversed. This is equally true OF
cyclones, tornadoes and even the
little dust-whirls, which shows that
all these phenomena are governed |
by the same law. 1t has been an
alytically established by Prot. VIM.
Ferrel, that fluids on the earth's sur
tace moving toward a center must
necessarily take that form of gyra-
tory motion which all observation
shows them to take in cyclones and
tornadces, and this gyration also
accounts for the barometric huctua-
ton in the cyclone. We may there
fore conclude that the tornado orig
mates in the movement of air to-
ward a center, occasioned in most
cases by the sudden heating and
expansion of air, causing it to raise
the upper strata and so disturbing
the equilibrium, which the inflow
ing currents tend to restore. Were
this the only consideration, the
movements would be of short dura
ton and of no great violence. The
energy set free by precipitation
comes in here to intensity the at
mospheric movements until the tor
nado is equipped with all its power
for destruction. In accordance
with this, we find that all destruc-
tive tornadoes are accompanied by
great rainfall, and when the rain
ceases the storm soon dies out. The
funnel-shaped cloud which is the
sure predecessor of the tornado, is
the visible evidence of precipita-
ton, although it is not always that
such a cloud is evidence of a rain
fall. About six years ago a cloud
of this kind appeared three or four
miles southeast of Topeka, having
at its base on the earth cloud OF
dust and leaves, and this was con
nected to the tunnel shaped summit
by a long column of something
which looked at distance like a
column of water. 1t swayed to and
fro with a sinuous motion, till at
last the top separated from the base
and in a few minutes both had dis
appeared. No rain fell FROM this
cloud, though the wind was violent
enough to PROSTATE several stacks
of hay which came in it's path, and
its appearance was like what has
often been described as seen in wa
terspouts.
When the precipitation is more
abundant the heat set free gives the
upward air movements a greater
velocity and the rain is sometimes
carried so high as to be frozen and
falls to the earth as hail. 1t is very
probable that all great hail storms
partake of the tornado eharacteris
tics. The so-called waterspout is
tornado when it sweeps over bodies
of water. The downpour of water
from such clouds comes from the
air for the most part, and is simply
rain, and there is no good evidence
that tornado lifts great masses
of water into the air from a lake or
sea. Cases are not rare where
schools of small fish have been
caught and transported quite a dis
lance, but we believe that when a
tornado strikes the water it agitates
and scatters it without lifting much
of it high into the air. In this way
small pools and ponds have been
swept dry, the water and mud be-
ing scattered in every direction.
Reports that water has been lifted
from the bottom of wells by lorna
does may safely be regarded as de-
lusions. We find in the wind suffi-
cient energy to account for all the
destructive and transporting effects
seen In tornadoes. There is a We
locity which has been estimated
sometimes as high as 200 miles per
hour. The movement is upward as
we'll as onward, and few structures
can resist such force. It Is sufi-
cient TO carry men and animals into
the air, and everything thus lifted
and set in motion becomes a mis-
sile to crush objects in It's path.
The flying sand, pebbles and debris
is like shower of grape shot and
will soon pelt the bark from trees
or drive into the skin or flesh of an
imals. The popular delusion that
electricity plays an important part
in these tornadoes lacks scientific
evidence, and for the most part
thunder and lightning are not
prominent in them. The electric
phenomena are accompaniment of
violent atmospheric movements and
are effects rather than causes.
The question of practical interest
is how to foretell the approach of
tornadoes and avoid their conse-
quences. The prediction of a tor
nado cannot be made with certain
ty until we see it coming. All oh
servation teaches us to expect a
..o-sAI &c