Evening star., 1952-06-18
Artificial Clouds Tested
In a Gigantic Bottle
Weather Bureau Scientist
Makes Rain in Old Mine
By Thomos R. Henry

in the sky are being made in q gigantic
bottle" by United States Weather
Bureau scientist.
The bottle" is an old mine shaft
nearly 700 feet deep sunk into an Ari.
zona mountain, now unworked although
1t once produced more than $500 million
OF copper, silver and gold. It's next
yield-proof or diSproof of the possi-
bility of artificial rain-making-may be
worth lot more over the centuries.
Here DR.. Ross Gum is creating actual
clouds by saturating the air inside the
shaft and then COMPRISING the sat-
urated air. His experiments already
have demonstrated, he says, that pro-
duction Of these clouds is entirely prac-
tical and that they can be controlled
precisely enough for scientific expert
ments.
Artificial rain-making, as practiced at
present. is difficult to prove and hitherto
there have been no means of bringing it
down to laboratory basis. DR.. Gum
already has been able to solve some
problems Of the growth Of water
dropletS.
Creates Two Different Kinds.
two quite different kinds Of clouds, both
OF which are quite close to natural
formations. One type Is produced in
about ten seconds. It is extremely
dense. An observer can see only about
four yards through it. It is composed
of particles less than a thousandth of
millimeter in diameter. Such a cloud
preSiStS for from five to seven minutes.
The second cloud type is formed much
more slowly. The water in the atmosphere
condenses on relatively fewer minuts
particles and there is sufficient time for
them to grow into droplets Of reason
ably large diameter.
This last type DR.. Gum says, closely
approximates droplet size In actual
clouds. He is making precise measure
ments on the rate Of growth Of droplets
Of various sizes falling through this kind
Of cloud whose counterpart in the sky
might be expected to produce rain.
Explorations Of the bizarre world Of
extreme cold have started to pay divi-
dends.
This is the region between about minus
800 F. to absolute zero, the ultimate cold
possible, at -459. Through this temper
ature range properties Of matter seem
radically changed. but hitherto this has
been of chief interest to laboratory
physicists.
Now, according TO q bulletin Just
issued by tho Arthur D. Little Co. of
Cambridge, Mass. there have been sew
eral notable practical developments,
with others which appear likely in the
near future.
One Of these developments Is an ex-
tremely hard stainless steel prepared by
immersion in liquid nitrogen at $40.
Apparently the low temperature slows
down the motion Of atoms, and rolling
them rearranges them in some pattern
which produces increased hardness.
Potentially Useful Product.
A potentially useful product is q re-
erigerated crystal TO pick up radio sig
mails too faint to be detected by heated
tube. This possibility - suggested, ac-
cording to the bulletin, BY the super
conductivity Of number Of metals and
crystals at extremely low temperatures.
When atoms are slowed down In an
extreme degree-aS u the case ut very
low temperatures - internal friction
among them IL largely eliminated and
current flows easily.
Through some metals ct very low
temperatures, known as super-con-
ductors, an electric current will flow
indefinitely, once it had been started.
The first practical development In the
low-temperaturs field was the utiliza-
ton Of liquid oxygen. produced at
temperature Of -297, for steel making
and rocket fuels. A few years ago 1t was
4 scientific curiosity.
There Is o distinct possibility. It Is
pointed out. that eventually liquid he
lium and liquid hydrogen can hnd
equally important uses. The possible
commercial importance is that there
now are about so cold-generating labo-
ratories in the United States. compared
with five In 1945.