Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1889-08-30
NO. 1.
TO-mOrrOW'S Weather.
A Problem Whita the Signal Service
Tries 10 Solve.
Why 1t Does Not Always Tell.


msde the target for she wit of tine country.
and Notwithstanding the fact that Its pre-,
oletions often prove absurdly untrue, the
methods used by the sc vice in observing
snd prophesyiug meteorological changes
are both interesting and Instructive
Scattered all over the United States srs
about $50 weather stations, all of them
under control OF the chief office in Wash
lnston. From these stations, placed at
every altitude from Sea-level to the hiS hest
mountain peak, and embracing all grades
or temperature, observations are made
twice day, once at IN the mornlag and
again AT IN she evening. Various in
struments are used IN making these obser-
vstlons, but the barometer Is the principal
ons. Fortlns baromenter is used II every
station. 1t Is kept IN a room of as uni
form temperature as possible. and is
vertically suspended In II wooden box
A carefully adj listed thermometer is also
placed in an exposed position to record
the actual temperature of place une fected
by other than natural causes. Then at
each station are wet and dry bulb ther-
mometers to- measuring the humidity of
the air.
Maximum aud minimum Thermometers
also record respectively the highest and
lowest temperature reached during the DAY
A small tube about two inches in diameter,
with f1nnel at the top ten times as large
as the main tube, catches the drops or
flakes and indicates the amount of rain or
snow fall. The amount, quality, and
direction in which the clouds are moving
are also carefully studied. Some of these
different varieties,a as termed by meteorolo-
gists, are the "sclrrus," those that are light
i
streaks or layers; the ''cumulns," those
that are buachy and look like great masses
of snow, and the "nimbus," or rain and
snow clouds. The relative part of the
sky covered with clouds is also remarked,
and noted in tenths.
The velocity of the wind is measured by
the anemometer. This Is placed upon the
roof of the station, and consists of four
hemispherical cups revolving iu a hori-
zontal plane. The cups communicate
their motion to g vertical slate, which is
connected with speed recording instru-
ment IN the observatory. The velocity of
the wind is then ascertsined by multiply
ing this by three, it being known by tX-
pertinent that the motion OF the wind Is
three times as great as that of the cups.
These are the Instruments tor all the OBJ
servatIops used in calculating the condI-
tious and changes of the weather. The
most difficult, as well as the most impor-
tant work of the Signal Service Bureau, is
that of making prophecies on indications
as to the future. This is done by the officer
in charge of the principal bureau, his con
clus1on being based upon the data received
as to present weather conditions.
At night from 9 O'Clock until II the
headquarters of the Signal Service at the
corner of Twenty fourth and M streets
present an auimated appearance. In
one room half dozen teleg operat-
ors ere busy receiving reports from
stations throughout the country. Ia
another a half a dozen men are at work
making reports and computations. One
man interprets the cipher kilograms (all
teleg rams are sent in cipher for the sake
of economy as they are brought in from
the operators room. He then reads the
interpretations aloud. Half dozen men
record the reports upon as many differ
ent charts which lie on desks before
them. The temperature at each place Is
marked Hpon the chart in blue pencil.
the barometric pressure, direction and
velocity of the wind is also recorded.
Three short blue lines repres snt the pre-
valence of the clouds. Regions of high
and low barometer are shown with red
pencll, and lines are drawn between in
sobarometrical points.
After the maps have all been made ont
in full, the chief officer examines them
aud begins the work of making indica-
tlops for the next twenty -four hours. One
OF the greatest difficulties under which he
labors Is the uncertainty of the direction
in which the low barometer will move.
When science mas asoertained this, the
task of making weather predictions will
be much easier, and the Indications sent
out will then be almost absolutely cor
rect. At present, however, this is the un-
certain element, and it causes many re
ports to go wrong. BarOmetricGl press
ures furnish the prInoi pal data in de
termining the future condition of the
weather. Rain, it is known, usually comes
in advance of the movement of low
barometer, and dry an cooler weather in
q high one. Ia the vicinity of a low
barometer, it is usually warm and the air
IL full of moisture. When the barometer
is high, ON the other hand, il Is cool
end dry.
The direction of the wind, too, is
towards the region of the low barometer.
If the barometer is low i'll the northwest
and high in the southeast, soUtheasteily
winds prevail, and vice versa. As the
wind moves towards the low barometer il
becomes warm and rises, and passes back
to the region of the high barometer. In
this way current is kept up between the
two regions of the country. The relative
position of the two also enters largely
into computation.
AS soon a. these reports are made they
are telegrapheE at once TO all the princi
pal cities of the United States and also
to Canada, and farmers bulletins are dis
tributed at an early hour every morning
along the different railroads in this coun-
try. Storms are predicted by the relative
movement of the high and low barometer,
and the predictions have proved of great
benefit. Cool spells are indicated by the
movement OF the high barometer, and
farmers are enabled to protect tender
growing crops from damage.
Rurdettp's Revised SualIpr