The Washington herald., 1911-04-09

In the dark continent there are two dis
tinct varieties of crude rubber supply: the
vine called Landolphia and the tree
Kivkxia Africana, which fiourishes in
West Africa.
Central America contributes a large
quantity of rubber, called .Centrals- in
the trade, the supply being drawn from
| the tree castillo elastica
In the East Indies rubber is being cui-
tivated on large scale, the plants hav-
ing been transplanted from Brazil In
trade parlance the rubber coming from
| the cultivated fields of the East Indies is
called '-Ceylons'' and sells in the market
almost at the level set by the Para prod
uct.
Peru contributes considerable rubber to
the general supply, and Brazil. south OF
the Amazon, is gaining in Importance
Madagascar and other tropical islands
also produce some rubber.
Contrary to general belief. vast quanti-
ties of this raw rubber are imported di-
dectly from the Para fields into the United
States. The idea that practically all the
raw rubber in the world Is shipped to
England, Antwerp and Bordeaux is found
ed in error, for the customs statistics OF
the United States show that an increasing
amount is brought here direct each year.
Rubber is bought by the tire factories
largely by sample, but sometimes on a
definite guarantee as to what it viii ac-
complish. With the terrific demand that
is being exerted in the market the ten
dency is to emphasize the former practice
and as result the buyers of tire-makinS
houses are required to be the keenest sort
OF experts in their line
After the crude rubber has been clean
ed and partially vulcanized, IT goes to
the making room. where workmcn ara
ready to convert it into tires and other
merchantable articles. In the process of
tire-making there is another important
element. BY weight, automobile tires
are composed of from one-quarter to
one-third of the stoutest, heaviest kind
of cotton fabric.
This fabric is not woven IN the tire
factory. but is purchased from The cloth
weavers in large quantities. Each tire
contains from four to six piles of this
material. 1t is made Of the longest and
strongest fiber OF Sea Island cotton, and
in its condition prior to manufacture into
tires it seems strong enough to turn buck
shot
The tires are shaped on the moids by
the worknen and when the correct size
and shape have been given the tire IS
inspected by the superintendent and
taken to the vulcanizer. This is simply
a steam press where live heat can be
applied to the articles to be made. The
action OF the heat Is to change the
chemical status of the rubber.
The finished tires are subject to q
searching examination at the factory.
and the usual percentage of defective
tires so discovered is about two in 100
Tires are tested with pressure of
about 400 pounds to the square inch IN
several OF the well-ordered factories be-
fore being sent to the stock room It is
said that the new tires VIII Withstand a
pressure of Zoo pounds, but such q tese
is given them only on special occasions.
In the fiscal year of 1903 $500 tons OF
rubber, two-thirds of which was from
Para, was imported into the United
States. During the fiscal year ending
June 90, 1910. the imports into this coun-
try amounted to H.eoo tons, with the per-
centage from Para slightly less.