The Daily state journal. [volume] (Alexandria, Va.) 1868-1874, 1873-01-02
CLOUDS, RAINS, AND RIVERS.
From Tyndalls Forms OF Water in Clouds and
Rivers


Every occurrence in Nature is preceded
by other occurrences which are its causes,
and succeeded by others which are its eli
fects. The human mind is not satisfied
with observing and studying any natural
occurrence alone, but takes pleasure In
connecting every natural fact with what
has gone before it, and with what Is to
come after it.
Thus, when we enter upon the study OF
rivers and glaciers, our interest will be
greatly augmented by taking into account
not only their actual appearances, but also
their causes and effects.
Whence do the earliest streams derive
water? A brief residence among the
mountains would prove to you that they
are fed by rains. In dry weather .you
would find the streams feeble, sometimes
indeed quite dried up. In wet weather
you would see them foaming torrents. In
general these streams lose themselves as
little threads of water upon the hill sides
but sometimes you may trace river TO
definite spring. The river Albula, in
Switzerland, for instance, rushes at its
origin in considerable volume from noun
tain side. But you very soon assure your
self that such springs are also fed by ram,
which has percolated through the rocks or
soil, and which, through some oriice that
it has found or formed, comes to the light
of day.
But we cannot end here. Whence comes
the rain which forms the mountain
streams? Observation enables you to an
swer the question. Rain does not come
from a clear sky. 1t comes from clouds.
But what are clouds? Is there nothing
you are acquainted with which they re-
semble? You discover at once q likeness
between them and the condensed steam OF
a locomotive. At every puff of the engine
cloud is projected in the air. Watch the
cloud sharply; you notice that 1t hrst
forms at o little distance from the top OF
the funnel. Give close attention and you
will sometimes see perfectly clear space
between the funnel and the cloud. Through
that clear space the thing which makes the
cloud must pass. What, then, is this
thing which at one moment is transparent
and invisible, and at the next moment visi-
BILE as dense Opaque cloud?
1t is the steam or Udp0r OF .odter from
the boiler. Within the boiler this steam is
transparent and invisible; but to keep it in
this invisible state o heat would be re-
quired as great as that within the boiler.
When the vapor mingles with the air above
the hot funnel it ceases to be vapor. Every
bit of steam shr;nks, when chilled, to a
much more minute particle of water. The
liquid particles thus produced form kind
of maier-dust of exceeding fineness, which
floats in the air, and is called a cloud.
Make the lid of kettle air-tight, and
permit the steam to issue from the pipe !; a
cloud is precipitated in all respects similar
to that issuing from the funnel of the loco
motive.
Permit the steam as it issues from the
pipe to pass through the flame OF spirit
lamp, the cloud is instantly dissolved by
the heat, and is not again preclpitated.
With special boiler and a special nozzle
the experiment may be made more striking,
but not more instructive. than with the
kettle.
Look to your bedroom windows when
the weather is very cold outside; they
sometimes stream with water derived from
the condensation of the aqueous vapor
from your own lungs. The windows Of
railway carriages in winter show this con-
densation in striking manner. Pour
cold water into dry drinking-glass on a
summers day /; the outside surface of the
glass becomes instantly dimmed by the
precipitation of moisture. On warm
day you notice no vapor in front of your
mouth, but on a cold day you form
there little cloud derived from the con-
densation of the aqueous vapor from the
lungs.
You may notice in ballroom that as long
as the doors and windows are kept closed
and the room remains hot, the air remains
clear but when the doors or windows
are opened dimness is visible, caused by
the precipitation to fog of the aqueous va
Dor of the ballroom. If the weather b.
intensely cold the entrance of fresh al
may even cause sno,o to fall. This ha
been observed in Russian bathrooms ant
also in the subterranean stables at Ere
room, when the doors are opened and thu
cold morning air is permitted to enter.
Even on the driest day this vapor in neve
absent from our atmosphere. The vapor dl!
fused through the air of this room may b
CONCEALED to boar frost in your presence
This is done by filling vessel with mix
ture of pounded lee and salt, which
colder than the ice itself, and which, there
fore, condenses and freezes the aqueous va
nor. The surface of the vessel is finall
coated with frozen fur 80 thick that TINA
be scraped away and formed into a snow
ball.
To produce the cloud, in the case Of tt
locomotive and kettle, heat is necessary
BY heating the water we first convert
into steam, and then by chilling the stea'
we convert it into clouds. Is there an
fire in nature which produces the clouds
our atmosphere? There is--the fire
the sun. :,
Thus, by tracing backward, witho'
break in the chain Of occurrences, our riv
from its end to its real beginnings, we con
at length to the sun.