Evening star., 1954-06-30
BY Fronk Corey
ASsoeiotsd Press Seienes Reporter


"A scientist breathed into a
home-type freezer eight years
ego and started . miniature
Gnowstorm that has grown into a
blizzard swirling around this
question:
"Can man control the wealth
err"
Tests Of rain and snow max
ing have been hailed as mile
stones of a new era in mans
relation to nature. The faithful
think it may be possible to break
droughts and hold back floods,
side-track hurricanes, prevent
tornadoes and hailstorrns and
diSsipate fog at airportS.
Some even envision man using
the weather as a weapon of war
begging down the enemy'S
troops in mud. parching his food
crops in burning sun, perhaps
manufacturing storms to be in
fected with germs or radio
active dust.
Skeptics See No Clear Proof.
Skeptics-including scientists
of the United States Weather
Bureau-maintain that evidence
is far from conclusive that
weather control has any chance
of being achieved on a practical
scale.
There is no clear proof, these
skeptics say, that when rain in
creased it was due to artificial
techniqueS-it might have rained
anyway.
Rain-making projects were in
spired by what happened one day
in 1916 in the laboratory OF DR.
Vincent Schaefer, then OF the
General Electric Co.. in Schen-
ectady, N. Y.
DR.. Schaefer had been trying
to duplicate in the laboratory
one of natures "super-cooled'
elouds-clouds which contain
water In liquid state even though
the temperature is below freez-
ing. The water doesn't freeze be-
cause it is perfectly pure. He
wanted to find out how this
"super-cooled" water is suddenly
changed, in nature, into a snow
storm.
Variety of Materials.
He produced clouds by blowing
his breath into a freezer. But he
couldn't produce snow ever
though he added to his clouds q
variety of materials-soap pow
der, sugar, talcum powder anc
volcanic dust.
Then one day he was having
trouble keeping the freezer al
low temperature. He dropped
some chunks of dry ice into the
box.
A miniature snowstorm devel-
oped before his eyes.
The find touched off a host oi
experiments involving the seed.
ing" of clouds with dry ice from
airplanes in an effort to make
them yield snow or rain.
DR.. Schaefer and other in
vestigators, both civilian anc
military. claim they produced
precipitation by this means-ol
at least that precipitation
quickly followed seeding
Later it was found that silver
iodide, dispersed from planes o.
generated as a kind of smoke
from devices on the ground
could serve the same purpose
Crystals of silver iodide closely
resemble those of dry ice.
Gist of a Theory.
The theory is that these sub
stances provide nuclei" for mil
lions of tiny ice crystals in th(
cloud. AS the natural crystals at
tach themselves to the nuclei
the formation grows and event
ually falls to the ground as snow
or rain. depending upon th'
temperature beneath the cloud
In general seeding works onl!
on "super-cooled clouds" For
tunately for the rain makers, {
lot of these are floating around
even in summer. But they art
found only above attitudes o.
about $4,000 feet.
Silver iodioe is supposed tt
have some advantages over dry
ice because it can be dispersed
in a sort of smoke" over rela
lively large areas. Also, it Cal
be dispensed from generators OF
the ground. Dry ice must Away