re is literally a "rubber belt" around the
world, for nearly all rubber comes from the countries lying between
the Tropic of Cancer and the Tropic of Capricorn. More than half of
all that is brought to market is produced in the valley of the Amazon
River; and some of this "Para rubber," as it is called, from the
seaport whence it is shipped, is the best in the world.

[Illustration: _Courtesy General Rubber Co._

TAPPING RUBBER TREES IN SUMATRA

The plantation on which this photograph was taken has 45,000 acres of
planted rubber trees, and employs 14,000 coolies.]

The juice or latex flows best about sunrise, and so the natives who
collect it have to be early risers. They make little cuts in the bark
of the tree, stick on with a bit of clay a tiny cup underneath each
cut, and move on through the forest to the next tree. Sometimes they
make narrow V-shaped cuts in the bark, one above another, but all
coming into a perpendicular channel leading to the foot of the tree.
Later in the day the collectors empty the cups into great jugs and
carry them to the camp.

When the rubber juice reaches the camp, it is poured into a great
bowl. The men build a fire of sticks, and always add a great many palm
nuts, which are oily and make a good deal of smoke. Over the fire they
place an earthen jar shaped like a cone, but without top or bottom.
Now work begins. It is fortunate that it can be done in the open air,
and that the man can sit on the windward side, for the smoke rises
through the smaller hole thick and black and suffocating. The man
takes a stick shaped like a paddle, dips it into the bowl, and holds
it in the smoke and heat, turning it rapidly over and over till the
water is nearly dried out of the rubber and it is no longer milky, but
dark-colored. Then he dips this paddle in again and again. It grows
heavier at each dipping, but he keeps on till he has five or six
pounds of rubber. With a wet knife he cuts this off, making what are
called "biscuits." After many years of this sort of work, some one
found that by resting one end of a pole in a crotched stick and
holding the other in his hand, a man could make a much larger biscuit.

For a long time people thought that rubber trees could not be
cultivated. One difficulty in taking them away from their original
home to plant is that the seeds are so rich in oil as to become rancid
unusually soon. At length, however, a consignment of them was packed
in openwork baskets b