The Lebanon express. (Lebanon, Linn County, Or.) 1887-1898, 1889-08-23
ToRNADoEs.
The Result Of Eight Years investigators
BY Signal Service Ofiicer.


Lieutenant John P. Finley, Of the
Signal Corps, has been studying the
phenomena OF tornadoes for the past
eight years. Tornadoes are now SO
well understood that it 10 believed that
trustworthy warning can soon be sent
out to the localities threatened In fact,
experimental predictions have been
made for a year, with good result. Ac-
cording Lieutenant Finley. tornadoes
have distinctly marked characteristics
and are by no means to be confounded
with hurT1canas, ''blizz rds." cyclones
or northpasters. Their tracks are never
more than few hundred yards wide.
their otary motion, which is greatest
toward the center, ometimes reaches
the enor ous rate of 1000 miles an
hour, while thei forward movement,
alw W from southwest to northwest,
ordinarily doc not exceed forty or fifty
miles. They are usually unaccompa
led by electrical disturbances and are
believed to be uninfluenced by electrical
conditions, though violent thunder
storms sometimes follow them few
miles away
There is a distinct and cdrious rela-
tiohship between the tornado and the
general storm center, which is always
apparent in their uniform relative po-
sitlnns. the tornado always occurring
enthusiastically from the center CT low
barometric pressure, and at distance
of from one to six hundred mites. The
shape of the general storm centeI, the
direction in which its lowest barometer
lies and the appearance of the upper
and lower clouds enter as minor ele-
ments into the problem out OF which
the weather experts hope to work
complete system Of tornado warnings
The visits of the tornado are common
" between the hours Of two and six
o'clock in the afternoon. Its home is
an area which includes the whole of
Iowa, all of Missouri, except the south
eastern corner, the northwestern corner
of Arkansas, the northeastern part of
the Indian Territory, Eastern Kansas,
Eastern Nebraska, Southern Mime
sofa, Southern Wisconsin and Western
Illinois. Here its season extends from
April to August inclusive. 1t is also
frequent visitor to two other regions.
These are, first, strip along
the Gulf and South Atlantic coasts,
which takes in the central portions of
Alabama. Georgia and South Carolina,
with termini in Mississippi and North
Carolina, over which its deyastations
are confined TO the months of January,
February aud March. The second in
cludes a portion of Southern and Cen
tral Ohio. a large portion of Pennsylva-
MIA, small area in Maryland, strip
across New York and corner of each
of Massachusetts and Connecticut,
where it is in season only during Au-
gust and September.
The conditions which are favorable
to the creation Of tornadoes are present
when cool, dry current of air meets a
warm. moist current, bringing wide ex-
tremes both of temperature and hui
midity into close proximity. The cool.
dry currents come from the north, but
such as flow over the Great Lakes pick
up in their course both moisture and
heat and their destructive forces are
thus neutralized Those blowing from
the Northwest down over the dc
plains of Manitoba and Dakota, carry
something of their Arctic character
istics far South, and if in their course
they meet one of the heat
and vapor, laden breezes COM
ing mp from the Gulf the war
of the elements begins at the point OF
contact The storm always has it's
birth in the upper air its first visible
manifestation being the ominous fun
nel-shaped cloud, whose pendant trunk
is in form not unlike that of an ele-
phaut Within it the furies are confined,
and when and where its point touches
the earth the path of destruction be-
gins. When the isotherm of the morn
ing signal map shows the advancing
columns of air, with their wide con-
trasts of temperature, in proximity;
when the general storm center is in
that relative position which seems
necessary to the exercise of its mystic
rious influence; when the pressure is
low toward the east, disclosing a
vacuum into which the detected cur
rents may advance without obstruc-
tion-when all these conditions combine
it should become but simple problem
for the experts to determine with rea-
sonaple probability from the wind ve-
locities whether the threatening line Of
contact will have advanced to or beyond
the tornados accustomed baunts by the
time of day when the powers of ms
chief shall be loosed. - Washington Cor
Philadelphia Times
MONGOLIAN SCHOLARS.