Ottumwa semi-weekly courier. [volume] (Ottumwa, Iowa) 1899-1903, 1903-07-30
NO CLIO UD-BpRSTS.

NO AUTHORITY FOR USE OF "A
PHRASE DESCRIPTIVE OF
HEAVY RAINFALL.
A Misnomer in Common Use That Has
No tification-ProbabIe Causes
for Origin of the Term-Lightning
AcceIerates Rainfall.
Often when the dark clouds are seen
gathering in the west and later heavy
rain descends, someone is heard to OBJ
serve that it is evidently a CLOUD
burst" and this is common express
sion as applied to heavy rainfall.
The man who used the misnomer
might have had the idea
that the cloud was a package of wa
ter, variable in size, done up in wrap
PEI of vapors that would be torn and
spill the contents, provided it should
come in contact with HILL church
spire or tree top. The fact is that
clouds are dissolved or dissipated and
that there are no seams to give way
and no ripping sound as the fabric is
rent sasunder. This statement is ven
tured in the face of the old belief
that the cloud was something like a
sieve at times coarser or finer to reg
ulate the size of the drops, and that the
shaking occasioned by thunder caused
the water to be forced more rapidly
through the holes. This belief sprung
from the observed fact that lightning
did accelerate rainfall. but the acceler-
alton was due wholly to the cooling OF
the atmosphere caused by a loss of
electricity in the discharge.
The Western Deserts.
In the regions where the breezes
carrying moisture set from certain di-
rections for long periods and are forced
against mountains of any other barrier
that cannot be passed, the clouds in be-
ing driven TO a higher and cooler alti-
tude are deprived of their moisture.
This might be said to be the steady
cloudburst, for no cloud can engage
in the business of transporting water
W Tie lHtSllOl otlSh
1t is for this reason that desert tracts
occur just behind mountains along the
sea shores in the regions of the trades
winds But for such a barrier, the
Death Valley of California would nc
doubt be fertile place and the Great
American Desert would never have
found place OH the maps The laden
breezes coming from the sea are de-
priyed OF their burden of moisture and
continue on their way after passing
the mountains, as dry winds brought
to intense heat at times by passing ov.
er the burning surface of the earth.
The so-cailed "cIoud-Burst."
When a so-called cloud-burst oc-
ours it is due to the fact that the
cloud has come in contact with a
barrier, none the less real because it
is invisible. The happening is at a
point where the cloud lis n forced
against colder body of air, made
comparatively stationary by pressure
from another direction, thus forming
an upright wall of varying height. II
high enugh to correspond with a
mountain, and if the pressure behind
the storm is such as to compel it to
pass the barrier by going over the
top, the effect is the same as along
the coast in the case of mountains,
due to the sudden meeting Of moist
ure with lower temperature.
1t is all matter which the
weather bureaus, by the application of
the data at hand, should be able to pre-
dict with some certainty, for the direc-
lions, temperatures and moistures of
various air currents are known and
recorded.
Death Valley.
The mention of Death Valley, Cali
fornia, calls attention to another be
lief that may be wholly erroneous
This desolate bit of country is en-
closed by spurs of the mountains so
high that moisture passes from nc
direction and result the tract is en-
tirely without rain. 1t has been proved
by great toll that the land is fertile
for where small patches have been If
rigated by hauling water from a dis
tant creek, five crops of alfalfa are
harvested to the year. The alfalfa
season lasts there all the time, fol
there is no danger of frost at the
point where the mercury rare il evel
| drops below 80 and where 40 in thu
shade is nothing unusual.
| Plan of Irrigation.
The possible error is in connection
with the elevation of this space. 1
has been stated in Biographies anc
other books of authority that Dealt
| Valley is below the level of the
ocean. If this should be true, ant
if it should be possible to dig a cana
across the 200 intervening miles t.
the ocean, so as to fill the basin, thu
problem of irrigating that section o
might be solved. 1t may be supposed
that the rapid evaporation and the in
( ability of the vapors to pass tn,
mountain walls would result in spread
ing over the valley all the water tina
| the canal would carry.
| Barometer Unreliable.
But the agricultural department viii
not avow the belief that any part 0
Death Valley is below the level of th
/ ocean. Levels have never been run il
/ any direction to establish the correct
ness of the old belief, which is base
solely on barometic conditions, mar
ner of measuring elevation that ha
been proved to be grossly inaccurate
ana not worthy of credence in sue
/ A 80 e. 90 To,