there was found ready in the Far East, as a result of the
planting that had been done there, a supply that took care of the
sudden emergency.

A little more than ten years ago American business men began to
take an interest in the rubber plantations. They have shown
characteristic energy in the field, and the greatest single rubber
plantation in the world is owned by an American company, the
United States Rubber Company. This plantation is on the island of
Sumatra in the Dutch East Indies, one of the best governed
colonies in the East. On this island is an orchard of rubber
trees, as beautifully laid out and as well cared for as any
orchard of fruit trees in our own country. For seventy square
miles, an area as large as the District of Columbia, the orderly
ranks of trees fill the gently rolling landscape, every inch of
which is weeded as carefully as a garden. It takes twenty thousand
employees to care for the trees, which number more than 5,000,000.

On this plantation the science of growing rubber trees has been
brought to a perfection known nowhere else in the world. Groups of
botanists, chemists and arboriculturists study constantly tree
diseases, methods of increasing the yield, and the other problems
of growing fine trees that will produce high grade rubber. Here,
by experiment and inspection, the secrets of the rubber tree are
being brought to light, so much so that growers look to this
plantation for leadership in methods of rubber culture. This great
project so far from American soil and in a field so new gives a
thrill of pride to the Americans visiting Sumatra on their way
around the world.

CHAPTER 6

PLANTATION LIFE

The moist but very hot climate which rubber trees require is found
only in a zone around the world between the parallels of latitude
thirty degrees north to thirty degrees south of the equator.
Within this zone there have been found more than 350 rubber
bearing trees, shrubs and vines. For this reason this zone is
called the Rubber Belt. As most of the rubber used commercially is
gathered from trees growing within a zone extending from ten
degrees north to ten degrees south of the equator, this latter
zone is sometimes called the Inner Rubber Belt.

If you will trace this belt on a map of the world you will see
that it includes the Amazon region which produces more than
three-quarters of the wild rubber used in manufacturing. Most of South
America's wild rubber is obtained fr