The Republican. [volume] (Oakland, Md.) 1877-current, 1882-06-03
How to Foretell the weather.

carefully studied and recorded the
weather know best that beyond two or
three days no predictions can be made
possessing the slightest reliability, or
that should be taken into account in
making our plans There may be lucky
guesses, as there may be woeful failures
in guessing. if.a.s. .at F.e s."
Everybody has full, liberty to guess
what the weather will be at any time in
the future. But when anybody under
takes to label his guesses for weeks or
months ahead predictions, and to
issue them as guides for the farmer, or
the traveller, or the clothing dealer,
he, in the language of Shakespeare,
''writes himself down an ass" When
he undertakes to get money for doing
this he shows himself swindler on
level with other quacks. n-H
But for one or two, or even three days
ahead the weather may be foretold two
thirds of the time with great certainty,
the other third with more or less doubt.
And not only can this be done by the
trained observer at the signal station,
but it may be attempted with good sue
cess by any intelligent person who has
access to the daily weather maps or even
to the full daily report 1t would be a
great gain to the community if our daily
papers would give lis these reports in full
as they are sent out, instead of cutting
them down to mere indications for
their own vicinity, even if they had to
lessen the space given to horSe-races,
baseball matches, dog-tights and police
courts. .
The whole theory of foretelling
changes in the weather with the aid of
the telegraph is based upon the fact that
our weather changes come, as general
rule, from the west and not from the
east; that the great waves of barometric
pressure, which we name high and low,
and whose alterations produce our
storms, move across our country from
west to east, and almost never in the
opposite direction, so that for our wealth
er tomorrow we look to see what it is
to-day to the west of us, with very little
interest as to what is going ON to the
eastward. Thus in New England a
northeast snow-storm is often telegraph
ed as coming from the southwest, from
New York, or even from Virginia or the
Carolinas, or even from farther south.
The pressure of the atmosphere in the
temperate zone varies about one pound
per square inch, and is indicated by the
barometer, varying from twenty-nine
inches Qow) to thirty-one inches (high)
as the extremes the ordinary variations
being only about half as great. Now the
storm-center is at or near the place of
low barometer, where the pressure is
least, the air from all sides rushing to-
ward this with rotary motion, which
in very severe storms is named cyclone.
Sometimes, however, the areas of high
and low barometer extend in long lines
across the country from north to south,
but moving from west to east, as in many
OF our ''cold waves extending some
times from the lakes to the Gulf. The
greatest fall of rain or snow is usually
little in advance of the storm-center
While the barometer is falling. When
the center has passed the barometer be-
gins to rise, and clearing weather may
be expected, generally with northwest
winds.
These storm-centerS, or 'areas of low
barometer" or Glow pressure oftenest
make their appearance little east of the
Rocky Mountains, very often in Dakota.
and then move with greater or less
rapidity towards the Atlantic, generally
due east Occasionally storm-centre
develops in Texas and moves northeast.
More rarely cyclones make their appear
ance in the West Indies and follow along
the course of the Gulf Stream, the outer
edge sometimes reaching the Atlantic
onaSt worry aralu dive ;,,l,oI
Out of 100 storm-centers noted during
1879, one moved north, three southeast,
twenty-four northeast, and seventy-two
nearly due east. Their velocity varies
from twenty to forty miles per hour, so
that either storm-centers or cold waves
travel from the mountains to the sea in
from two to five days, then passing off
upon the ocean, frequently taking a
northeasterly direction after reaching
the coast. u, Sometimes storm may be
detected from its course, or spend its
force midway. or increase in severity as
it moves eastward. 1t is these possibili-
ties, together with the varying velocity
OF the wave, which render us dependent
on the telegraph for its record of daily
or even hourly progress, and which some
times contradict the best-founded predic-
tions. But with all these possibilities of
error, eighty to ninety per cent. of the
| predictions are verified, and upon per-
haps seventy-fve per cent. our reliance
may be almost perfect At'times, either
on land or sea, awarning may saveprop-
erty to an amount greater than the whole
annual expense of the bureau to say moth
ing of life and comfort. Our weather.
then, in general terms, comes from the
west, and when we read in the papers
that ian area of low pressure with heavy
rain and severe gales is developing in the
Upper Mississippi or Upper Lake region, -
the farmer had better not begin his hay
ing or his harvesting, and the traveller
had better not set out by way of the lakes
or the ocean until it has passed by. While
if in the fall or winter you read that ian
area of high pressure with violent winds
and rapidly falling temperature is pre-
vailing" in the same regions" the farmer
had better look to his young stock and
make all snugabout cellar and barn, and
the traveller will do well to take his
heaviest ovcrcoat.
Bearing in mind these few simple
facts, every farmer or farmers boy who
has access to the daily ''indications and
reports or, better still, to the daily
weather maps, may become to a Oreat