Manchester Democrat. [volume] (Manchester, Iowa) 1875-1930, 1903-07-22
"wARs ARE A NECESSITY"
WHAT AcLoup euRsrMALLY IS
Result Is a. 1f-the Bottom Dropped
O4f of n Su.n nded Lake.

When we read in the newspapers
that "cloudburst' has occurred some
where and has resulted III great loss Of
life and destruction of property we are
prone to consider the term merely one
used for sudden and excessive rain.
storm. While, of course, 1t would be
wrong to consider a cloud as great
bag or envelope filled with water, and
which has only to burst iii order to de-
luge the earth beneath, there is really
such thing as q "cloudburst' MS dis
tinguished from n rainfall. however
heavy the latter may be. The New
York Herald gives clear and interest
ing explanation Of just what a cloud
burst" really is and study of the
phenomenon will prove of interest. par
tlcularly as it was n genuine "cloud-
burst which few days ago practical
ly wiped the town Of Heppner, Oregon.
from the face of the earth and de.
stroyed some 200 lives.
The "clondburst" is always preceded
and caused by a wlndstorm or small
cyclone, the air whirllng In a circle and
at the same time moving along hori-
zontally. AS the air whrls about in n
circle 1t forms Il sort of cone with the
apex at the top. This whlrling motion
causes an thrush of air from all sides
at the base and these masses OF mir
quickly form powerful and RAPIDLY
ascending current in the heart of the
nascent tornado.
| Now, IL the atmosphere through
| which this windstorm is passing is de
void of moisture, there will be no rain
fall, but If there Is quantity of moist
ure In the air the ascending current ii
the center of the tornado will natural
ly, in carrying great quantities of Il
skyward, pile ZIP this moisture i'll tb,
form of a cloud at the top. This cloud
being In colder stratum. of air, speed
| lily becomes densely saturated Will
moisture. Under ordinary circum
stances this moisture upon being con
densed into drops would be precipltat
ed to the earth, but in this instance tn
pressure OF the upward current pre-
vents it falling. On the outskirts O
the cloud, where the pressure is less
rain does fall, but at the apex of tn
whirlwind it continues to become NOR
and more dense.
i Finally the conditions become SC tina
the column of ascending mir is sur
porting above 1t veritable lake. Now
80 long as this air pressure is main
tanned the water cannot fall, but q
soon us the storm strikes n mountai
the raised land breaks and DESTROYS til
whirlwind and the water is permitte
to fall-always on the leeward side Q
the mountain. The water comes dow
in perfect deluge, much the same a
If lake had been suspended in tn
heavens and the bottom had suddenl
fallen out. If the "cloudburst," us thi
Is called, takes place over a mario,
valley down which the great mass @
the water must flow to find level on
can readily see what force it mus
bring to bear on everything whic
stands in the way. When it is borne i
mind that single inch of rainfall owe
one square mile weighs 10000 tons,
is not difficult to imagine what a rus
Of water follows the sudden downfa
Of several inches over space of eve
much less than square mile.
A glimpse of the illustration furnish
ed on this page will make very plat
the operation of this terribly destrut
tive phenomenon and convince til
reader that after ali the term ''clout
burst" is not altogether misnome
though perhaps CLOUD collapse" woul
come nearer expressing the fact.