The Press., 1904-09-21
CLOUD BAROME1'ERS.
HOW TO FoRETELL THE WEATHER
BY LOOKING OVERHEAD.

HOW TO FoRETELL THE WEATHER
~ BY LOOKING OVERHEAD.
Cirrus In the Hfghest of All Clouds,
and CuMulus In Mach the biggest
Of Any FOrna of ClOud-The Wettest
CaOud Of Aha 10 Nimbus. .s.
lit is clouding up. 1t must be going
to rain" This is a remark you may
hear constantly, and few people seem
to realize that the one thing Is by no
means a consequence OF the other.
True, all clouds are composed of water
vapor, but 1t is absurd to imagine that
because clouds become visible In the
sky they are therefore going to dis
charge their contents upon our heads.
On the contrary. some clouds are
actually prophets of fine weather. Cir
rus, for instance, or curl cloud. as it Is
q fine weather harbinger. Cirrus Is
the highest Of oil clouds. You can tell
that by the fact that its thin. twisty.
fibrous streaks are Illuminated by the
last rays Of the setting sun long after
the earth below Is wrapped in shadow.
Threads and groups Of cirrus clouds,
the finer the better. appearing after a
gale, presage long continuance of
settled weather. On the other hand,
IL after several fine days cirrus appears
In long parallel bands stretching right
across the sky i'm the form popularity
known as kmares' tails" there will III
most certainly be change Of wind
and probably rain to follow.
Unlike other clouds, cirrus is COM
posed not Of water vapor, but of tiny
crystals of ice. You can tell by its
motion what the pace and direction
Of the highest current of wind. Quiet
~ as 1t appears to be moving, careful
observation has proved that cirrus
sometimes travels at the rate of mile
In eighteen seconds. .- s
Another form Of cloud which is
usually al accompaniment of fine,
warm weather are those cottOnlike,
whitish balls which are scientifically
termed camulus. &
Early In the morning of a fine sum-
mer day cumulus begins to form as a
few soft, scattered specks In the blue
above. These specks grow and enlarge
without, as rule. travelling very fast.
for they are formed by vapor ascend
ing from the earth In columns. By
early afternoon they often cover the
whole sky, but toward 4 or O'clock
they usually decrease and finally van
ish by sunset III they behave In this
way you may be almost certain that
the ensuing twenty-four hours will be
On the other hand. If the cumulus
clouds increase toward sunset. turn
black In their eenters and shine at the
edges with an angry light. rain will
follow. or. In very hot weather, thunder.
Thunder Ia specially fOretold by the
cumulus clouds showing rounded.
sharply marked tops with silyery white
edges. Cumulus. which turns very
dark with black. shaggy edges. means
cold rain accompanied by wind.
Cumulus is much the biggest of any
form OF cloud. A single cloud of this:
description will measure six or even
seven miles from its fiat. dark base to
it's rounded. giistening summit---that is
to say. its bulk and height far exceed
those; OF earth's greatest mountains.
The temperature In such cloud as
this has been measured to vary over
$50 degrees that Is. from so degrees
Fahrenheit at the base to Is degrees
below zero at Its summit.
Stratus Ia still another form Of cloud
which presents no special indication of
rain. lit Is more Common ut night than
In the day and consists of long. hori-
zOntal bands Of darkish cloud, which
lie very low. and near the earth's sur
face. 1t rises on calm. clear evenings
after warm days and may often be
seen In mountainous districts slowly
creeping up the hillsides. Ii the sun
rises through layers Of stratus 1t is
usually sign OF q fine. warm day to
come. After sunrise. stratus. as rule,
rises higher into the air and slowly dis
appears.
In early summer, when the weather Is
showery. you may perhaps notice
through breaks In the rain clouds. an
appearance OF dense white cloudlets
In small. irregular tufts brightly irradi-
ated by sunshine. The children call it
mackerel sky. Its real name Is GIRO
cumulus. and II is a sure sign Of heat
and probably fine weather. Seen. in
winter. mackerel sky portends thaw
and wet. mild weather. 1t IL the next
highest cloud to the cirrus and is some
times called sender cloud
A sure prophet of wind and rain is