The mirror. (Stillwater, Minn.) 1894-1925, 1901-08-29
Are Weather Predictions
A Science?

OuluuCy COIAOA, q lIoNOAOA OVOPPONe
at a farm house and asked the
farmer if the morrow would be
fine day. The farmer at once
took down the almanac and read
the predictions-''a about this time
look out for thunderstorms." AS
these words extended over ten
days of July, very likely they
would come true in the course of
the ten days. The traveller laughed
at the prediction; then the farmer
became vexed and said: 'They
calculate the eclipse, why shouldn't
they calculate the weather.
Today we read the weather in
dications in the morning papers
and govern our umbrellas accord
ingly. Yet with all the immense
advance from the blind guessing
of the Farmers Almanac to the
signal service indications, there is
lingering disbelief in the whole
business. There is very general
doubt as to whether the indica-
tons given out by the govern
ment are founded on any real
scientific basis. The severe storm
that did so much damage in Mexi-
co recently was not announced in
advance as so many other storms
have been announced. It is adj
mitted that about seventeen per
cent of all the indications fail, and
this comparatively large percent
age of failures is the direct cause
of this want of faith in the in
dications. How far is that want
of faith justified? How nearly is
weather prediction a science?
In the first place, the science of
the weather is, practically speak
ing, very new. We had no means
of studying the movements of
storms until the telegraph was
invented, and it was twenty years
after that before the idea of using
the telegraph as a scientific tool
occurred to men of science. Sec
ond, only a government could use
such a costly tool. The principle
on which the weather indications
are made up is we'll known. Re-
ports are made every few hours
from the signal stations to the
Office at Washington. From a
study of these reports the probable
changes Of the weather are es-
timated and telegraphed to all
points of the country. Theoretic-
ally, every one Of the predictions,
or as they are more properly
called, indications, should be cor
rect. About SO per cent are cor
rect on their face. Really about
80 per cent are correct, because
the districts for which indications
are not made are comparatively
small.
At first, the indications were
announced for large tracts, like
New England or the Middle states.
They are now given for single
states and parts of states, which
tends to increase the real value of
the percentage of successful re-
ports. When a storm was an
nounced for New England, and it
passed to the north, over Vermont,
New Hampshire, and Maine, people
in Connecticut and Rhode Island
were sure the indications failed,
and said: Il told you SO; the in
dications always fail;;'' and the
good people in Massachusetts,
said: ut was cloudy, but did not
rain, and the signal service people
do not know their business.
It must also be noticed that in
all this time the actual instru-
ments used in making the OBJ
servations at the stations have
not been materially changed.
Thermometers and barometers
are no better today than twenty
years ago. The number of sta
tions has not been very greatly
increased and the men employed