Evening capital news. (Boise, Idaho) 1901-1927, 1917-02-04
ARMERS in the grain belt are
4 carried millions of miles every
year on pneumatic tires. II
Shonld undertake. to give the

carried millions of miles every
year on pneumatic tires. II l
should undertake to give the
figures as to the number OF
tire miles made in the grain belt states
each year they would be so large as
to be unbelievable. One of the grain
belt states has about $4,000 automo-
biles owned by farmers. Each auto
mobile has four tires. 1t has been estl-
mated that the automobile mileage in
this state is close to 500 100000 miles
a year. Most of these miles are made
on country roads They are made In
comfort because of good rubber tires,
Without good tires speed and comfort
would be incomp atible. Imagine max
ing 40 to SO miles an hour over a
country road with a wide tired wagon
and you will get some conception OF
the convenience and luxury of pneu-
matte tires. The farmer is such ire
mendous consumer of tires that we
feel sure he must have great interest
in how they are made. II should I'M
dertake to acquaint the reader with
the bigness OF the tire industry, with
the immense capital invested, the large
force of men employed, the WONDERFUL
buildings used, he would be almost as
much astonished as at the figures on
tire mileage. Manufacturing tires is
one of the greatest industrial occdpa-
tons Of the age.
Rubber is the foundation stock for
tires and tubes. Tires are not all rub
Der. If they were we would not be able
to pay for them. Neither would they
give the splendid wearing value that
they do under the present system or
manufacture. Rubber is imported from
Brazil, and the highest quality comes
from the native trees and is usually
spoken of as Para rubber. Para is u
seaport of Brazil. The rubber coun-
try is many miles distant from Para,
UP the Amazon valley. Rubber is
sap, or juice. from a forest tree, and
is taken out in such the same manner
as sugar sap. There IS supply OF
natural rubber in parts OF Africa and
Mexico. but these do not come up to
the upper Amazon valley standard.
The lower Amazon valley rubber is al
so Il cheaper grade. The more diff
cult it is to get the rubber trees the
better the supply seems to be. Even
before the world began to take note
of the fact that tires would eventual
ly create a scarcity of rubber an ef-
fort to supply the market was start
cd and rubber tree plantations were
set out. This makes two classes of
rubber commonly spoken of as the ma
tive rubber and plantation rubber.
WHERE RUBBER COMES FROM.
There are large rubber plantations
in Ceylon and the Malay states. The
quality of plantation rubber depends
largely upon the source from which
the trees were imported. Rubber comes
to America in varied grades. 1t comes
usually in what is called a biscuit. This
biscuit is formed by rolling up the
rubber on a stick, SO that a native can
grab both ends Of the stick and carry
the rubber out of the forest. When
the stick is removed the chunk or
lump of raw rubber is left. The rub
Der coming from plantations is not in
the biscuit form. 1t usually comes in
square chunks. such as may be con-
venientlv packed in barrels or boxes.
Any large tire factory has thousands
upon thousands Of pounds Of this raw
rubber ON hand.
Until one visits a tire factory he
usually has a hazy sort of notion that
the crude rubber is dumped into a
large melting pot and boiled. But he
is entirely wrong. Crude rubber, as it
is received at our factory, contains
more or less dirt. usually in the shape
of sand, dried leaves and twigs. These
foreign substances are removed by
washing til" gum, which is soaked in
warm water and taken into n machine
called 1t cracker. In this machine the
crude rubber is maSticated and sub
jected to Il continual flow OF water
washing away most of the foreign SUD-
stances. The work Of completing the
removal of foreign matter is carried
on i'll a washer. The pure gum is fl
nally run through a rolling machine
and spread out in sheets on linen
These sheets must be dried three oil
four weeks. The next step is mixing
the crude rubber with compromising
ingredients. The chemist in the mix.
ing room weighs out the ingredients Il
the fractional part of an ounce. In tn,
work rooms the entire mass is worked
upon rollers until it becomes a plasti,
whole.
RUBBERiZiNG THE CLOTH.
RubberiZing the cloth which goe!
into tires is done by means of a fric
tioning machine, which grinds the plas