Laurel outlook., 1947-11-12
Engineers Solve
Crystal Problem
Synthetic Quartz Replaces
Natural Product for
Phone Channels.

NEW YORK. - Artificial crystals,
the Bell laboratories announce, now
r being produced in quantities al
most large enough to supplant ma
tural quartz, a product hitherto in
dispensable in long distance tele-
phone and radio work. The artificial
crystals resemble large clusters
of rock candy, or ice cubes, as they
grow in the laboratory in large glass
tanks.
Technicians explained that as a
result of this practical solution of
the crystal problem, urgently-need-
ed phone channels will go into opera
ton much sooner than otherwise
thought possible. Some circuits, it
was said, already are operating with
the synthetic product, notably chan
nels between New York and St.
Louis.
In the laboratory, artificial crys-
tails slowly increase in weight and
size from small seeds" implanted
in watts of easily obtained chemi-
Gals. Eventually they T expected
to replace as much as 80 per cent
of the natural quartz, and do as
good or better job"
The best natural quartz is labori-
ously mined in the mountains of
South America and is now scarce.
Try Many Formulas.
The new substance is known tech
nically as "ethylene diamine tar
~trate," or EDIT, and was evolved
by Bell chemists and physicists after
more than 100 other chemical for
mulas IRE investigated, it was
said. A special plant, built by West
ern Electric company at Allentown,
Pa, nov is geared to produce ''hun-
dreds of thousands" of units an
nually.
When the artificial crystals in their
growing tanks have in
creased about one pound, Oh six
inches long and two to three inches
in cross-section, they are removed,
sawed into thin waters, ground
carefully to precise thicknesses,
mounted in special holders and in
stalled in electrical circuits.
Company experts explained that
such waters are ''piezo-electric."
That is, when twisted or pressed
they generate an electrical voltage.
when a voltage is applied
to them they generate mechanical
forces by bending. Telephone en-
gineers use these properties to sub
divide a wide communication chan
mel into smaller ones, or hold ap-
.oaratus on an assigned frequency.
Television to Telephone. 4
A coaxial cable capable of carry
ing "a whole television program of
several million cycles from city to
,ity one instant can be quickly
;ubdivided, it was explained, into
an ideal telephone channel capable
If carrying several hundred tele-
,hone conversations without mixing
hem up.
The new product is the direct re-
iult of research that has been in
progress for more than 25 years.
the war, company experts
developed another type of crystal
Iseful in SONAR" underwater equiv
lent of radar. The chemical COM
,osition was different than EDIT, but
10Th were piezo-electric. More than
0 million of them, it was said, were
reduced. The knowledge thus
aimed has been turned largely to
ieaceful ways and large-scale EDIT
is expected.
Artificial crystal growing is a very
recise process. Temperatures, for
Example, are held in the chemical
olution to less than one-tenth of a
egree variation. One crop of crys-
ais is sawed off the parent body,
only a silver to immerse
gain in the tank to start another
rop. Harvest time is every three
lonths.