Omaha daily bee., 1896-07-05
SCIENCE OF THE WEATHER
Extent Of the Work, Carried on by the
Signal Service Bureau,
ADVANTAGES OF WEATHER FORECASTS
How sunlight IL Measured, Tenn
p%crnturc Taken nnd the Winds
Velocity Rccorded-Protcction
Against Tornndoes

L lit lGIllult uNnllhNAluh Niu' NNNhNis 1919
waste st. Louis has caused the rest of the
world to look about itself and ask what likeli-
hood there is Of such a disaster Detailing
some of our other cities, perhaps several
others. This inquiry is especially pertinent
in view of the fact that storms, earthquakes
and other terrifying evidences of natures
power have been freely prophesied for the
end of this century, 1t being said that the
st. Louis tornado is but the forerunner OF
many calamities that are to come.
What is the danger of a tornado destroying
New York, Boston, Philadelphia, or any one
of a dozen cities of the west? And, first oil
all. what is a tornado? Let 1t be understood
that it is essentially different from a cyclone,
which acts over a much larger area ana In
hicts far less injury. A cyclone Is to a tor
rado what a barrel of g~unpowder is to a keg
of nitro glycerine, 1t takes up more space,
but its powers are far less deadly. Ana yet
a tornado is always accompanied by a cy-
clone, forming on its outskirts usually, the
direct cause being the rushing together OF
two air currents, the one very hot, the other
very cold. Should the hot current be on
top, no harm ensues, but when 1t Is under
meath and the conditions are just right, 1t
forces its way up through the cold WIND
forming a sort of chimney whose draft IN
creases with enormous whirling suction
until the tornado is born, and then let all
things beware that come within Its path.
Fortunately this path is narrow, varying
in width from fifty feet to two miles,
whereas, a cyclone will strike with varying
force over an area of from 500 to 1000 miles.
The cyclone. like the tornado, moves with
whirling motion, but there Is no sucn
strength in it's clutch, it's advance being only
from four to ten miles an hour, while the
greatest speed of it's whirling even at the
heart does not usually exceed seventy or
aiphty miles an hour. The speed OF q
cyclone is about that of a swift railway
train. the speed of a tornado has never been
calculated, it is more like that of a cannon
ball.
PROTECTION AGAINST TORNADOES.
Now as to protection from these tumults
of the air. Against cyclones people and
cities need no special safeguard, the danger
of loss of life or widespread destruction OF
buildings is small. Crops may suffer ana
shaky structures, and there may be fatalities
now and then, but that is all. Against the
tornado. however, stronger measures must
be taken and better precautions than have
so far been devised, If a series of horrors
is to be averted.
The only thing that will really break the
| force of a tornado being a mountain range.
| When the black, funnel-shaped monster
strikes a mountain, it cannot go through
it and it Is detected upward, the currents
that compose it becoming separated or lin
ishing their struggle far above the earth
where they can do no harm. Had st.
| Louis been protected by a mountain range,
| the tornado that has become historic, would
have been turned aside and it's destructive
force PARTED off. So far as it is known the
mountain range is the only safeguard a city
can possess against visitation by a tornado
And that makes 1t plain why New York
and Philadelphia and Boston may count
| themselves fortunate in this matter, since
they have the Orange mountains, the Blue
Ridge mountains and the Berkshire hills,
I-. -aAl. --l 49, II, tIAt, nfanen
But nearly all the cities in the region of
the great lakes, Chicago, Cleveland, Buff
falo, Detroit, which are not guarded by
ranges of hills or mountains are Just as
likely to be the victims of some murderous
! tornado as was St. Louis. 1t may be said
! that there is no defense for New York and
| other cities on the Atlantic seaboard from a
| visitation of tornadoes coming from the east,
but in reply to this there is the well es-
| tablished fact that the general movement
of great storms is from west to east, not
from east to west.
While the rise and advance OF a cyclone
may be noted hours ahead by the weather
bureaus all over the United States, 1t is
impossible for any weather expert to know
or predict when a cyclone will be accom-
panied by a tornado. That would be as
difficult as for a diver to tell in advance
whether any oyster in his catch will have
a pearl inside, although the comparison pays
a compliment to the tornado that is scarcely
deserved.
ORGANIZATION OF THE BUREAUS.
The organization of these weather bureaus
Is most interesting, just as the work they
do is most important. There are 200 OF
them scattered all over the country, and
twice a day, at 8 o'clock in the morning and
at 8 o'clock at night, they telegraph theii
reports to New York and other eastern cit
les. The stations on the Pacific coast dc
not make these daily reports, as 1t has beer
found that their observations are too dis
tant to be of much benefit in weather cal
culations in the middle and eastern states
Salt Lake City Is the most westerly point
and Corpus Christi, in Texas, the mos
southerly, from which these twelve-hour re
ports are received. Many people will b'
glad to know something of the appearance
and daily routine Of these meteorological
stations, for the maintenance OF which nearl!
a million dollars a year Is spent.
The New York weather bureau is located
in a tower built on the top Of the Manhattan
Life Insurance building, on lower Broad
way, one of the modern "sky-scrapers
eighteen stories in height. The tower itsel
is about twenty-five feet in diameter an
some thirty-five feet high. There are fou
floors, connected by a circular staircase
which goes up to the great red lantern Oh
the top of the tower, from which signals o
fair weather or foul are flashed far out t
sea. Here a force of eight men, under tn
direction of Local Forecast Oficial Il. i
Dunn, is constantly at work, receiving oh
seryatiOnS, making Tecorus, etc., etc. III
instruments themselves are all in a sep
arate observatory, about eighty-five fee
high, which is also built on the roof, nea
the main tower.
This observatory is a wrought iron struc
ture very strongly bolted together to resis
the pressure of storms, and the
ters. barometers, etc., are contained In
sort of box, the sides of which are of lattic
work to allow the air to circulate freely, tn
Stats being tilted so as to exclude rain o
snow. They are all self registering an
represent the very latest appliances {
science, from the weather yane on top t
the Instruments which measure sunshine.
THE INSTRUMENTS EMPLOYED.
This latter, by the way, Is very interest
ing. 1t consists of a glass tube, some eigh
inches long, which is mounted on an arr
at an oblique angle.c. The lower end of
is filed with mercury and across its uppe
end passes a wire which is connected wit
a recording instrument in the main Office
A raw of sunshine falling on the mercur
causes 1t to expand and crawl up toward tn
wire, and when 1t touches 1t, connection /
made closing an electric circuit and 6
causing a needle to make a dot on the recor
( paper. This dot is repeated automaticall
as long as the sunshine lasts, and as tn
! paper is ruled into spaces representing hour
and minutes, the exact time during whic
the sun has been shining is recorded faith
J fully upon the slip of paper.
The direction from which the wind
blowing, as we'll as Its velocity, are bot
recorded in the thermometer. AS the van
nj a fhlu n n