ter America took the lead in this business. In 1913 the United
States exported $3,000,000 worth of tires and tubes. In 1917 the
American exports rose to $13,000,000, not counting what went to the
Allies. The number of pneumatic tires sold in 1917 is estimated at
18,000,000, which at an average cost of $25 would amount to
$450,000,000.

No matter how much synthetic rubber may be manufactured or how many
rubber trees are set out there is no danger of glutting the market, for
as the price falls the uses of rubber become more numerous. One can
think of a thousand ways in which rubber could be used if it were only
cheap enough. In the form of pads and springs and tires it would do much
to render traffic noiseless. Even the elevated railroad and the subway
might be opened to conversation, and the city made habitable for mild
voiced and gentle folk. It would make one's step sure, noiseless and
springy, whether it was used individualistically as rubber heels or
collectivistically as carpeting and paving. In roofing and siding and
paint it would make our buildings warmer and more durable. It would
reduce the cost and permit the extension of electrical appliances of
almost all kinds. In short, there is hardly any other material whose
abundance would contribute more to our comfort and convenience. Noise is
an automatic alarm indicating lost motion and wasted energy. Silence is
economy and resiliency is superior to resistance. A gumshoe outlasts a
hobnailed sole and a rubber tube full of air is better than a steel
tire.

IX

THE RIVAL SUGARS

The ancient Greeks, being an inquisitive and acquisitive people, were
fond of collecting tales of strange lands. They did not care much
whether the stories were true or not so long as they were interesting.
Among the marvels that the Greeks heard from the Far East two of the
strangest were that in India there were plants that bore wool without
sheep and reeds that bore honey without bees. These incredible tales
turned out to be true and in the course of time Europe began to get a
little calico from Calicut and a kind of edible gravel that the Arabs
who brought it called "sukkar." But of course only kings and queens
could afford to dress in calico and have sugar prescribed for them when
they were sick.

Fortunately, however, in the course of time the Arabs invaded Spain and
forced upon the unwilling inhabitants of Europe such instrumentalities
of higher civilization as arithmetic