But it was
left to a Yankee inventor, Charles Goodyear, of Connecticut, to work out
a practical solution of the problem. A friend of his, Hayward, told him
that it had been revealed to him in a dream that sulfur would harden
rubber, but unfortunately the angel or defunct chemist who inspired the
vision failed to reveal the details of the process. So Hayward sold out
his dream to Goodyear, who spent all his own money and all he could
borrow from his friends trying to convert it into a reality. He worked
for ten years on the problem before the "lucky accident" came to him.
One day in 1839 he happened to drop on the hot stove of the kitchen that
he used as a laboratory a mixture of caoutchouc and sulfur. To his
surprise he saw the two substances fuse together into something new.
Instead of the soft, tacky gum and the yellow, brittle brimstone he had
the tough, stable, elastic solid that has done so much since to make our
footing and wheeling safe, swift and noiseless. The gumshoes or galoshes
that he was then enabled to make still go by the name of "rubbers" in
this country, although we do not use them for pencil erasers.

Goodyear found that he could vary this "vulcanized rubber" at will. By
adding a little more sulfur he got a hard substance which, however,
could be softened by heat so as to be molded into any form wanted. Out
of this "hard rubber" "vulcanite" or "ebonite" were made combs,
hairpins, penholders and the like, and it has not yet been superseded
for some purposes by any of its recent rivals, the synthetic resins.

The new form of rubber made by the Germans, methyl rubber, is said to be
a superior substitute for the hard variety but not satisfactory for the
soft. The electrical resistance of the synthetic product is 20 per cent,
higher than the natural, so it is excellent for insulation, but it is
inferior in elasticity. In the latter part of the war the methyl rubber
was manufactured at the rate of 165 tons a month.

The first pneumatic tires, known then as "patent aerial wheels," were
invented by Robert William Thomson of London in 1846. On the following
year a carriage equipped with them was seen in the streets of New York
City. But the pneumatic tire did not come into use until after 1888,
when an Irish horse-doctor, John Boyd Dunlop, of Belfast, tied a rubber
tube around the wheels of his little son's velocipede. Within seven
years after that a $25,000,000 corporation was manufacturing Dunlop
tires. La