The times. [volume] (Richmond, Va.) 1890-1903, 1891-08-09
lTo BIZ CONTINUED
Cyclones and Tornndoes.


The relentless violence of tornadoes is
direct result Of their whirling, and the whirl-
ing IS habit which they have inherited from
the rotation OF the cyc!onic storms in which
they are bred The cyclones have not Of
themselves originated the rotation that 50 uni
versally cbaracterzes them. but in turn have
received the habit from the great polar whirl
of the general atmospheric circulation in
which they are formed, and this has come by
immediate inheritance from the rotation of
that persistent and nyeterate spinner. old
Mother Earth. Tho whirling that cbarac-
terizes our tornadoes is, therefore, passed
down TO them in direct line OF IN
heritance from the rotation of their
Creat-srandparent, and you may ask
any astronomer if he thinks that will soon
cease. To be sure, there would be no polar
whirl If there were no equatorial overflow.
but there will be an overflow as long as the
sun shines on the equator, and the perma-
nence of this may also be referred T. the
astronomers They will indeed tell you that
the duration Of sunshine cannot be expected
TO reach as far into the future as the endu-
rance of the earths rotation, but both are ell
during enough for all practical purposes. 1t
may be well TO mention that most cyclones
have no tornado offspring. for which
we may be duly thankful, but others
have rather large family. Consider the
extraordinarily fruitful cyclonic storm
18th Of February. 1884 as ITS center moved
from Illinois into Canada, it gave birth to
some forty or fifty vicious tOrnadOes III the
Southern States. Most happily for us, these
little whirls are short lived; they seldom live
more than half an hour, sometimes an hour
advancing in this brief time from ten TO forty
miles although their parents may go on Tor
week or two and cross q continent and an
ocean: indeed, one cyclonic storm has been
traced in apparently continuous progress
all around the world. Again, lust IS 1t
is not every cyclone storm that gives
birth 10 tOrnadOes. 80 even the tornado
breeders do not generate these violent
offspring at all points on their course,
but have their breeding grounds; and
alas the fsvOrte ground is our fruitful Ms
sissippi Valley. AS they cross over that superb
stretch of country, particularly IN the spring
and early summer, the cyclonic indraught
brings together the unlike elements from
which the tornadoes arise; the warm, damp
lower winds from the Gulf and the cool. dry
upper winds from the western or northwest
efn interior where the temperature Is still
low. Nowhere else in the world IS there
a ike opportunity for the crossing OF winds
50 strongly contrasted. and nowhere else do
cyclonc storms SO often give birth TO lorna
does.
The same relation of short-lived offspring
and lonc-lved parent appears between the
ure in DAYS or in weeks. and the great polar
whrl, whose duration we may almost call I'M
mortal The polar whirl has times of greater
activity in winter when the contrast OF tenn
perature between equator and pole is at IT'S
maximum, and at this seasan the most and
the strongest cyclones are generated in 1t. In
summer time, when the difference of temper
allure between equator and pole is least, the
whirl runs slower, and its cyclones are fewer
and weaker: but il Is chiefly IN these latter
that the tornadoes are produced. The earth
must therefore already have been, and con-
tinue TO be for ages and ages 70 come. sub
iect to cyclones and tOrnadOes yet If we take
O very long view of the matter, 1t might be
allowable 10 say that the polar whirl is not i'm
mortal for it presumably was not at work
when the earth was glowing with It's own
heat; nor will it remain in operation when the
eat Of the sun. on which II now depends, IS
exhausted The polar whirl lives all through
that immensely Of time in which the sun de-
termnes our climate but the rotation of the
earth on which the whirling OF the atmOs-
phere depends, is more enduring still. In
the ardent youth IF the world long past. IS
well as in the cold old age, in the distant
future, its rotation prevails; we must
conceive of the turning being as
long lived a. the earth itself Whence
dbl it come by this persistent habit: The
earth turns on its axis from west to east. or.
as seen from the Rorth-star side, from right
to left. so do the moon and the sun, and
Mars. Jupiter. and Saturn, the only other
members of the solar system whose rotation
is certainly known. They all turn one way
Again the same strong family likeness. Not
only So the moon revolves around the earth
in the same direction as both turn on their
axis. and the planets all reyolve around the sun
in the same direction as they rotate day after
day. Saturn's rings turn in the same direc-
ton. Everywhere the same well-marked
habit of turning from west to east, from right
to left-William NJ. Davis. in the Atlantic
Monthly for July.