The Tiffin tribune. (Tiffin, Ohio) 1868-1887, 1878-06-27
How the weather Is ForeTOld.

In former times, the chief herald ol
/ the weather was the almanac, which
ambitiously prOphesied a whole year
Of cold and heat, wet and dry, diVid.
ing up the kinds of weather quite i'm
partially, 81 not always correctly.
But the almanac, good as it was, now
and then, and the westher-Wise farm
ers, correct as sometimes they might
have been, were not always able to
impart exact Information to the cOun.
try; and they have been thrown
quite into the shade of late, by one
who is popularity known under the
somewhat disrespectful title of "Old
| PrOb,n or "Old Probabilities. He
has become the Herald of the Wealth
er to the sailor, near the rocky, dan
gerOus coasts to the farmer, watch.
ing his crops, and waiting for good
days to store them to the traveller,
anxious to pursue his journey under
fair skies and to the girls and boys
to the woods for q picnic, what are
the probabilities" as to rain.
Every one who reads the daily pa
per is familiar with the weather
Record" Issued from the "War De-
partment, office Of the Chief Signal
| Officer" at Washington. These re-
ports give, first, a general statement
of what the weather has been, for the
past twenty-fOur hours, all over the
country, from Maine to California,
and from the Lakes to the South AT.
lantic States and then the "PrOba-
bilities," or 'IndicatiOns," for the
next twenty-four hours, over this
same broad territory. The annual re-
ports OF the Chief Signal Officer show
that in only comparatively few in
stances do these daily predictions fail
Of fulfillment.
The reason these prophecies are so
true is a simple and yet a wonderful
one. The weather itself tells the OBJ
server what it is going to do, some
time In advance, and the telegraph
sends the news all over the country,
from the central signal Office at WASH
ingtOn.
We shall see, presently, how the
weather interPrets itself to "Old Prob.
Abilities" Although it has proved
such q fruitful subj ect OF discourse
In all ages, yet [ am afraid many
people who pass remarks upon il do
not really think OF what the weather is
made. Let US examine its different
elements.
The atmosphere has weight, just as
water or any other fluid, although 1t
seems to be perfectly bOdIless. We
must comprehend that the trans
parent, invisible air is pressing inward
toward the center OF the earth. This
pressure varies according to the state
Of the weather, aud the changes are
indicated by an instrument called a
barometer. General speaking, the
falling OF the mercury in the tube Of
the barometer indicates rain, and its
rise herasds clear weather. Some
times the rise Is followed by cold
winds, frost aud ice. What these chan
ges really indicate, however, can he de-
termiIed only by comparing the barO-
metric changes, at certain hours, in
number Of places very far apart. This
is done by the Signal Service. OBJ
servations are made at about one
hundred and forty stations, in differ
ent portions Of the country, at given
hours, and the results are telegraphed
st once to Washington, where our
faithful weather clerk" receives
them, reasoning out from them the
probabilities" which he publishes
three times in every twenty-fOur
hours.
But the atmosphere varies not only
In weight, but also in temperature.
The thermometer tells Us of such
changes.
Besides this, the air contains q great
amount of moisture, and it shows as
much variation In this characteristic
as in the Others. For the purpose of
making known the changes in the
moisture OF the atmosphere, an in
strument has been invented called a
"Wet-bulb thermometer"
We are thus enabled to ascertain
the weight or pressure, the temPera-
ture, and the Wetness Of the air, and
now ii OHly remains for US to measure
the force, and point out the direction,
OF the wind. This is done by the IA
millar weather-vane and the anem-
Ometer. The Yane shows the direc-
ton, and the thermometer Is an in
strument which indicates the velOc-
ity ofthe wind.
Il is by q right understanding of
all these instruments that the signal
service officer is enabled to tell what
the weather says Of itself; for they
are the pens with which the weather
writes out the facts from which the
officer makes up his reports for the
benefit Of all concerned. Thus, how
ever wildly and blindly the storm
may seem to come, 1t sends messen.
gers telling just where it arose, what
course 1t will take, and how far it
will extend. But 1t tells its secrets to
those only who pay strict attention.
! James IL Flint; 81. Nicholas for Jaly.