The Elk County advocate. [volume] (Ridgway, Pa.) 1868-1883, 1871-09-21
Tornado es and Water SpOutS.

Professor Whitfield gives in the 1mert-
can Journal Of Science the following state
ments relative to tornadoes and water
spouts:
One of the most remarkable accompa-
niments of the tornado is the black COL
umn or spout, extending from the cloud
down to the surface. 1t precisely re-
sembles a column of black smoke, such
as pours from the pipes OF steamer
burning pine wood; it is, in fact, con-
densed vapor or cloud, intensified in
blackness by the dust and Rubbish car
ried up from the ground.
The tornado is shell or hollow cylin-
der of air, and all its energy lies in its
rotating rim, which is powerfully COM
pressed by two antagonistic forces, CEN
trifugal and centripetal. The rapid
whirl draws the air from the centre to-
wards the circumference, where it is met
and opposed by the inrushing winds.
There is, consequently, rarefaction, a
great reduction of temperature by ex-
pansion, and condensation Of vapor with
in the shell.
The spout does not hug the earth con-
tinuously, but rebounds or ricochets
along the uneven surface, often skipping
the valleys, but generally desolating the
hills. 1t is disposed, however, at every
recurrence to strike at the same points.
1t is not an established fact, but it is
commonly believed, and with some rea-
son, that the tornado does, in the course
of years, return along its beaten path
and that it is unsafe to build where one
has ever passed. A house in Pickent
county stood on hill from which q log
cabin had been blown away some thirty
years before. L witnessed the last ot
three which have passed along the same
track. Near fernando, Miss, three
have followed an unvarying line. It il
probable that there are some localities
more favorable than others to the gen
Grafton OF these storms, and it this b'
true, then the law of direction, hereafte
explained, accounts for their progres
along the indicated path.
Such an opportunity as fell to my 10
of witnessing the formation and cours
of a tornado, is rarely enjoyed, and tn
, phenomena observed on that occasion ar
of great value in illustrating the origin
of these whirlwiuds. On the 20th O
April, 1867, at ten o'clock, A. NJ, l wa
approaching Tuscaloosa on the Elyto'
road, the general direction being eas
and west. The weather was hot am
oppressive, while perfect calm prevaile'
both at the surface and in the upper re
gions, for the leaves were not stirred up
on the trees, and the heavens were GOV
cred with fragmentary clouds, perfectl,
at rest Occasionally large drops OF rail
fell, and there was, now and then, light
ming. The atmosphere was evidentl
surcharged with vapor, and in a condi
ton of great electrical excitement. A
: the distance of three end half mile
from town, an elevated ridge, over whic
the road passed, afforded an extende
view, and saw a mass of black clou
detached and hanging over the wester
horizon. 1t appeared nearly circuls
in shape, with the exception of sligh
: angular projection, like an inverted con-
at It's lower edge. afterwards asce,
tanned that it was about five miles di'
tant from me at this time, and calcr
lation, based upon the estimated angle
fixed the elevation of its base above tt
surface at about fifteen hundred yard
q and its diameter, considering it spher
! at about six hundred. 1t was entirel
, at rest.