Douglas daily dispatch., 1927-12-11
INTERCONTINENTAL RUBBER FIRM
SHOWS INDICATIONS THAT IT
WILL ANSWER MOTOR PROBLEM

NEW YORK Q9.-The first automo-
bile tires ever made from American
grown rubber are now being tested by
the Intercortinental Rubber company.
The rubber for the tires was OBJ
tanned from guayule shrubs grown at
Salinas, Calf The plant, native Of
Mexico, was imported some time ago
into the western United States where
it is being successfully cultivated.
Many refinements in production meth
DDS were necessary, however, before
the rubber could be made into tires,
but years of patient experiment have
been rewarded.
'"There is every indication from the
J work already done and in progress"
/ says Dr. David Spence, vice president
of the company, that the product
from the gllayule shrub will be manu-
factured at a price that will compare
faVorably with that of plantation rub
ber grown in tropical climates.
1--WE have not only gone further in
improving the quality of rubber OBJ
tanned from the shrub, but we have
actually succeeded in manufacturing
tires made entirely from the improved
product of guayule shrubs grown in
Salinas, Calf. On the basis of labora-
tory tests, these tires promise to give
a good account Of themselves"
The company also has experiment
stations in Arizona and Texas, Eight
hundred acres Of shrubs are under cul-
tivation at Salinas and an additional
2O,OOO,00O plants will be set out there
next spring.
Success Of the tire experiment, Off
cials of the concern believe, will mean
that vast areas of land in the United
States may be used to produce rubber,
thereby reducing the inportations nee
essary each year to supply the demand.
America at present buys all her rub
ber abroad. &
The guayule shrub will thrive and
produce rubber under broad climatic
conditions, for rain, frost and drought
are necessary to its cultivation. 1t is
an erect woody shrub, usually not more
than two feet high, and under undis-
turbed natural conditions lives prob
ably 40 or so years. Its powers Of
vegetative reproduction are weak. q
fact that added greatly to the diff
culties of evolving practical cultural
methods
Production of guayule rubber on a
commercial basis is possible only be-
cause all the stages of cultivation can
be handled by machinery, thus elinni-
mating the factor Of labor in q country
where that commodity is expensive.
The guayule seeds are planted by me-
chanical drills, the little plants, are
watered, weeded and transplanted by
machines, and the seeds are removed
by vacuum cleaners. Thus large. scale
production is possible with minimum
of human effort. 4. -,.
Tests made by the United States bu-
reau of standards at Washington show
that guayule rubber, properly prepared,
compares favorably with Hevea, the
imported plantation product in elasti-
city, strength and durability. ..,s.
In the bureaus comparative tests,
the pure-gum, zinc oxide and gas-black
with guayule substituted for plantation
crepe. California guayule, processed to
preserve its inherent qualities prior to
milling and extracted with acetOne
while still in an elementary stage, was
found to have tensile strength Of 1920
pounds to the square inch and elonga-
ton of 7l5 per cent against 1885 pounds
and $50 per cent for standard Hevea
after As minutes of curing. It has also
been learned that guayule, rubber
mixes readily with compounding in
gradients. ,., go
Rubber from guayt1le has long been
exported from Mexico. The ancient
Aztecs, who called it yule, were fa-
miliar with its properties and adapted
it to their own uses.