The Elk Mountain pilot., 1882-02-02
FORMATION OF CLOUDS.

Interesting Facts In Physical Science.
Whence comes the ram which forms
the mountain streams? Observation
enables you to answer the question.
isain does not come from a clear sky.
Il comes from clouds. Bat what are
clouds? Is there nothing you ara ae-
quaiuted with which they resemble?
You discover at once . likeness betwaon
tlrem and tho condensed steam of loc,o-
motive. At every puff Of the engine a
c'oud is projected into tho air. Watch
the cloud sharply; you notice that it
first forms at little distance from tho
top of the fnnnel. Give close attention,
and you viii sometimes see perfectly
c car space between tho funnel aud the
Cloud Through that clear space tho
thing which makes tho cloud nust pass.
What, then, is this thing which As ono
moment is transparent aud invisible and
the next moment viaiblo rs dense,
opaque cloud?
It is tie steam or vapor Of water from
the boiler. Within the boiler this steam
is transparent and invisible but to
keep it in this invisible state . heat
would be required IS great IS that with
in the boiler. When the vapor ningies
with the cold air above the hot funnel is
ceases to be vspor. Every bit M rte~m
shriuks, when CHILLED, to . much more
minute particle Of water. The liquid
particles thus produced form = khll Of
water-dust of exceeding hnsness, which
floats in the air. This rs cloud. Waton
the ud-bAnner from the funnel Q \
locomotive; you soc it growing gradual
y less dense. It finally 1nelts away ~
together and, II you continue your OBJ
servaiens, you will not fail ~ no.ie.
shat the speed d its disappearance de-
peuds upon the character It tie day.
In humid weather the cloud hangs h,ng
and lsxtly ip the air (; in dry wea1,er ii
is rapidly licked up. What haa t'ecs,uaa
Of il? 1t has been reconvert=1 Ass
true invisible vapor.
The drier the air, and the hotter the
air, the greater is ths amount of cloud
which can be thus dissolved in i. When
the cloud FIRST forms, its quantity IL fAr
greater than the Air is able to maiusaaa
III en- invisible state. But ~ the cloud
mixes gradually with larger mass & air
it is more ard more dissolvsd, and finally
passes altogether from tho condition OF
tinely-divlded liquid into that Of trans
parsnt vapor gas.
Make the lid OF kettle air-hght, and
permit the steam to issue from tho pipe;
\ cloud is precipitated in ali respec:s
similar to that issuing from the funnel Of
lie locomotive.
Permit the steam as it issues from tho
pipe to pass through the flame of spir-
lt-lamp, the cloud is instantly dissolved
by the heat, and is not again precipi-
tated. With special boiler and special
nozzle, the experiment may be maze
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 win
dows Of railway carriages i'll winter show
this condensation in striking manner.
Pour cdd water into 8 dry drinking glass
on summers day; the outside surface
VI the glass becomes instantly din.m.I
by the precipitation OF moisture On \
warm day yn notice no vapor in front
Of your mouth, but on q cohl day YOU
fora there little cloud derived from
the condensation of the aqueous vapor
from the lungs.
You may notice in . ballroom that es
the door and windows are kept closed,
and the room remains hot, the air re-
mains clear but when the doors or win
dows are opened, dimness is visible,
caused by the precipitation TO fog Of The
aqueous vapor II the ballroom. Ii the
weather be intensely cold, the entrance
OF fresh air may evea cause snow to fall.
This mas been observed IL Russian ball
rooms, and 2lso III the sub.errauean
stables at Erzeroom, when the doors are
opened aud the cold morning air is per-
mitted to enter.
Even on the driest day this vapop i
never absent from the atmosphere. The
vapor ditfused through the air Of room
may be congealed to boar frost in your
presence. This is done by filing a ves-
sci with mixture of pounded ice and
salt, which is condensed and freezes the
aqueous vapor. The surface of the ves-
Sc. is finally coated with frozen fur,
50 thin that it may be scraped away and
formed into Snow ball.
To produce the cloud, in the case Of
the locomotive and the kettle, heat is
necessary. BY heating the water, We
first convert it into steam, and then, by
chilling the steam, We convert it into
cloni - +, rs.av fire in II ;,,ra which
pftN0ces tue lAouu- g, o,,r ..t.Av>,...r !:
There is, the fire of the sun.
Thus, by tracing backward without
any break in the chain of occurrences,
or river from its end to its real begin
l:ngs, we come at length to the sur.
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