Evening star., 1924-12-31
METHOD Of MAKING
CLOUDSISSHOWN
Many Amazing Demonstra-
tions Given by Scientists
at G. w. U. Exhibit.

Like the weirdest dreams of the
night before circus, or the tricks of
magician, except there is no catch
TO it, are the wonder tricks played
by lenses, crystals, electrons and
models which scientists are showing
to streams of visitors at their eN-
hiblts at the George Washington
University gymnasium, on H street
near Twentieth.
Did you know that a metal bulges
Just like rubber when you press
either end of it? In one of the ex-
hibits of the scientists-the American
Association for the Advancement of
Science-there is steel bar several
feet long and three inches thick, and
by a pressure measurement you can
see this bulging register, although
the movement is but five-millionths
of an inch-an infinitesmal fraction
of a human hair.
CIoud-Making Shown.
Would you see how clouds are
made? One exhibitor has an
"electron gum" and he shoots alpha
particles through space and leaves
tiny trails of fog.
The United States Weather
Bureau puts thermometer in Old
Soils mouth, figuratively speaking,
and the result is recorded automati-
l.
instrument is shown which registers
the temperature of the sun.
The radio, it would seem, not only
can transport you in effect to an
opera house in New York or a speak
er's platform in Chicago, but If you
use it rightly it can tell you exactly
where you are at any given moment.
For the Bureau of Standards is show
ing a device by which the radio sig
nails from the United States Naval
Observatory (the zero milestone of
American location) can be combined
with place observations, and thus you
can tell, with an error of only 20 or
80 feet, just how far from the OBJ
servatory you stand in any part OF
the United States
Light Moves Globe.
BY way of illustrating magnetism
one exhibitor has devised a globe
which revolves when the sun shines
on it-and, in the absence of sun, his
pasteboard globe turns merrily on by
the f1ickering light of a, candle.
Most amazing of all the demonstra-
tions, perhaps, is that of polarized
lght-polarized light being the kind
in which the waves come in a sort of
broadside. The light of the moon,
roughly speaking, is polarized light;
and you can manufacture" moonlight
Wy uledHS VI QUARTZ crystals. linen
you can take one quartz crystal which
is transparent and another quartz
crystal which is transparent and so
manipulate them that the broadsides
or waves hit at an angle, as If you
put your fingers together croSSWiSe,
and you get no light at all!
What is the use of 1t all? Well,
Tor one thing, polarized light insures
the purity of the sugar you eat. Also
the old-time farmer who planted his
grain in certain seasons of the moon
was right. For it has been shown
that plant life responds, at certain
stages, to polalized light better than
the suns direct rays
All the optical laws of refraction,
polarization and reflection can be
demonstrated with this one instru-
ment.
There are movie machines for the
home, there is camera which will
take pictures only an inch wide
which can be enlarged to full cab
met size, there is a microscope that
will pick up an object in a one
twelfth-inch field, juggle it through
lenses and project it on a screen,
one, two, ten or twenty feet in
diameter, at the operators will
Practically every exhibit repre-
sents centuries of research and study,
some of them typify accomplish
ments which medieval dreamers were
executed for dreaming about, and
they range in their apparatus from
the sun itself, which is brought
down and measured and submits to
having it's temperature taken before
your eyes, to tiny electrons whose ef-
fectS are visible in amazing ways,
yet no human eye nor even any man.
made microscope has seen one.