The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1886-08-05
CAUSES OF CYCLONES.
CONTRASTS OF TEMPERATURE AND
BAROMETRlCAL PRESSURE.

The Chance Tornado Would Have at a
City Like Chicago-The Danger Too he
mote to Worry AbOut-A FavOrite Field
Necessary Conditions.
The recent destructive cyclone vista
tons have renewed interest in these
mysterious and terrible phenomena. Every
inha bitant of the section within range has
probably pondered over the possibilities Of
personal experience. The nearest point
TO Chicago recently reached by the wild
winds has been Racine, and the surmise is
not infrequenlly INDUCED as 10 what
would have been the effect if the cratic
visitor had taken more sOutherly point
on the lake shore for landing and
tackled Chicago. No instance is yet on
record of the whirling wind-wave meeting
with an obstacle sufficient TO break it up
and dissipate its deadly intensity into
harmless zephyrs; yet meteOroIogists
declare that it is only question of the
degree of resistance opposed to its appar-
emily all destroying course. The absence
of record evidence of this kind is ac-
counted for by the fact that negative re-
suits are not reported, while the destruc-
ton caused is always a matter of world
wide notoriety.
The atmospheric conditions preceding
cyclones or tornadoes are similar. They
consist, in the main, of strong contrasts of
temperature and barometrical pressure
Warm and cold currents meet on the con-
fines of "high" and "lown area of pres
sure and the result is a cyclone or tor
nadO, the character being largely deter
mined by the degree of contrast in the OPP
posing conditions The velocity with
which the storm travels is an important
element in distinguishing between the
two classes, cyclones sweeping their
tracks with swift destruction, while the
force of tornado is expended to a great
degree in its rotary movement.
A CYCLONE IN A CITY.
Sergt. Buell.. the observer in charge of
the signal office in this city, was asked
what chance a cyclone would have at
city like Chicago.
mo cyclone or tornado could get into
Chicago. except by the lake front, and
then it would soon be demoralized 10y its
contact with solid structures" he said.
The reason we never hear of a cyclone
devastating a big city is that it gets de-
moralized after doing little damage in
the suburbs. There is protecting infiu-
ence about all large communities; that is,
the volume of heated and rarefied air that
is ascending all the time, which acts as
cushion. The high winds that prevail Oc
casionally in this vicinity never get inside
the city without losing two-thirds of their
velocity
toledo was visited by a torp-d do few
years ago, but beyond tearin p some !
wooden sidewalks and carrying off
frame building in the suburbs it did no
damage. No substantial brick or stone !
buildings were damaged, except by having |
tin roofs or spires destroyed.
Anything that breaks the continuity of |
the revolutions will de1noralize either |
fov 10 CT
added Sergt. Buell. Hence, contact |
with a solid structure would be fatal to |
the continuance of a cyclone, or would at |
least break the force of the pendant portion |
which sweeps the ground and does all the ,
damage"
SCARCELY ANY DANGER.
Surprising a cyclone should strike this |
city from the lake front at point where |
a wide thoroughfare opens on the water?" |
well, if it did, and if it happened to be !
travelling upon the line followed by the |
street in question, it would damage the |
fronts of the buildings, carry away Signs |
and all movableS lying about until it |
should meet solid block of building, and |
then it would be broken up. It's violence
would be diminished also by the friction
of its outer edges against the sides of the |
building But the chances of such thing
happening are so remote that it is scarcely /
There is a record in Sergt Finley's RE
port on the Character of Six Hundred Tor
nadoes," of visitation to Cook and J effer-
son counties of a very violent tornado on
May %, 1855, when four persons were
killed. In this list Illinois takes second
place as a favorite field for tornadoes, hav-
ing a record of fifty-four, Kansas heading
the list with sixty-two There is reason to
believe that the large number of storms
reported from certain localities has some
relation to the general physical features of
the region. One of the necessary condi-
lions precedent to the formation of belt
of high contrasts is the existence of a wide
range of country offering no obstacle, like
ranges or large bodies of water,
to the free sweep Of air currents either
north or south. This condition is most |
cOnsummated in the vast e&-
tent of country, largely unbroken prairie,
from the gulf, east of the Missis-
sippi, nOrthward to the British posses
Mail.