Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1879-08-13
NATURES WEATHER GUIDES.
Clouds as Indications of Approaching
Storms, and How to Study them.
Philadelphia Led ger.

Storms. and How to Study them.
Philadelphia Ledger.
Very few persons seem to closely
scan the minor and common incidents
of nature and trace their connection
with its grander operations. Especially
at this true as respects the clouds, which
is this season of the year so frequently
mount up before our eyes as unerring
signals Of approaching atmospheric
changes. Their variety and imposing
aspect would appear to mark them as
subscribing, among other offices, that of
natural weather guides, which, once I'M
derstood, whould not be likely TO mis-
lead the observant. Multiform as the
clouds of our latitude are, they may be
referred to two principal types, and
brought within the capacity of any
average mind to distinguish. These
are the cumulus and stratus, with Cir
rus and other notifications. The first
named, the cumulus sometimes called
the mount cloudy is the dense, rolling
cloud of the summer time, rising over
the heated and humid districts, and
forming first an obscure cloud like a
"cotton ball." as the Ducleus Of a
vaporous mass, which afterwards piles
up and spreads mass on mass in noun
tain-sized proportions. The stratus is
more peculiarly winter cloud, though
generated at all seasons, and forms Of
stretching in long lines and horizontal
strata, as its name implies. The cirrus,
which consists of fine, wavy fibers. is a
modification of one or the other of the
foregoing.
The investigation of these simple
cloudless forms and their variations has
proved one of the most interesting as
we'll as instructive Of modern re-
searches. Humboldt, many years ago,
noted the delicate, striated, cirrus
clouds in the tropics, ranging them
selves on the celestial hemisphere, as
the marks and stripes on the surface of
a melon, towards the magnetic poles of
the earth-from which circumstance
he called them "polar bands" These
fine cirrus clouds, though more conspic-
uous IN the tropics, are sometimes very
clearly seen by our signal service OBJ
servers. While the weather is still
tranquil and beautiful in the lower
regions of the atmospheric ocean, the
polar bands, sklrting the outermost
limits of the storm area, indicate the
currents of the air in the higher strata.
Storms thus occasionally announce the
approach Geographically to the careful
meteorologist by means of these
celestial signs. Especially does this
remark apply to the more destructive
h 1oh
tropical zones. Although we cannot
see the immense air-currents which
are rushing together to initiate the
storm. Or in which the aerial conflict,
already in action, is travelling, their
movements and velocities are betrayed
many hours in advance by their cloud
accompaniment. In like manner, the
approach Of northeastern on our
coast may be detected long before the
barometer gives warning, by the accu-
mutation of thin, hazy stripes Of
stratus.
But the cloud which most interests us
at this season is the cumulus, SO fire.
quent and abundant in summer, and
bearing in its vapor-laden bosom alike
the thunder-boit and the fertilizlng
shower. The cumulus is originated and
maintained by the upward current and
evaporation from humid and heated
surfaces, especially in valleys and near
water courses. If is said that DR.. Kane
observed no cumulus clouds in the
Arctic regions. where the suns force is
feebly felt. Upon the plateau of the
Valley of Mexico these clouds disappear
10
spring, forming about Ga. m. daily, and
attaining their highest elevation from
2 to o'clock in the afternoon, during
the greatest heat, but gradually vanish
ing by sunset.
Their behavior in our ATTITUDES,
though not quite so pronounced, is not
unlike what is seen in and near, the
tropics. While these summer clouds
do not invariably betoken rain, under
certain conditions single cumulus, in
the hottest part of the afternoon, may
prove the nucleus of storm. If it is
seen lowering while its cap is ascend
ing rapidly and high, with the feecy or
dense appearance, its upper portion is
already undergoing chilling and con-
densatlon; and the same may be said if
it encounters a cool, westerl y wind,
brushing portions Of it out into a stratus
shape. The vaporous mass is then
rapidly losing its heat, and, no longer
able to hold its liquid stores, answers
the description ofTennyson ofthe cloud
that
Onward Grags laboring breast
And topples round the dreary west,
looming bastion fringed with fire."
And it is then sure source of rain.
The signal Office has bestowed great
pains upon this part of aerial physics,
and one of its most beautiful, tri-daily
preparations is special cloud map,
showing the conditions Of the sky every
eight hours, and enabling its officers to
study the relations between the wind
and storm phenomena, and the clouds
which foreshadow and foretoken them.
No part ofits popular and valuable re-
searches demands more exact and ex-
tensive prosecution. For, as Professor
Poey, the late director of the Havana
Observatory, has well said, eve may