eads, softened rubber is forced through a
die. Rubber bands are made by cementing a sheet of rubber into a tube
and then cutting them off at whatever width may be desired. Toy
balloons are made of such rubber. Two pieces are stamped out and
joined by a particularly noisy machine, and then the balloon is blown
out by compressed air.

Early in the nineteenth century it was known that rubber would keep
out water, but it was sticky and unmanageable. After a while a Scotch
chemist named McIntosh succeeded in dissolving rubber in naphtha and
spreading it between two thicknesses of cloth. That is why his name
is given to raincoats made in this way. Overshoes, too, were made of
pure rubber poured over clay lasts which were broken after the rubber
had dried. These overshoes were waterproof,--there was no denying
that; but they were heavy and clumsy and shapeless. When they were
taken off, they did not stand up, but promptly fell over. In hot
weather they became so sticky that they had to be kept in the cellar;
and in winter they became stiff and inelastic, but they never wore
out. How to get rid of the undesirable qualities and not lose the
desirable ones was the question. It was found out that if sulphur was
mixed with rubber, the disagreeable stickiness would vanish; but the
rubbers continued to melt and to freeze by turns until an American
named Charles Goodyear discovered that if rubber mixed with sulphur
was exposed to about 300 deg. F. of heat for a number of hours, the
rubber would remain elastic, but would not be sticky and would no longer
be affected by heat or cold. This is why you often see the name Goodyear
on the bottom of rubbers.

Rubber overshoes were improved at once. As they now are made, the
rubber is mixed with sulphur, whiting, litharge, and several other
substances. An honest firm will add only those materials that will be
of service in making the rubber more easy to mould or will improve it
in some way. Unfortunately, substances are often added, not for this
purpose, but to increase the weight and apparent value of the
articles. That is why some rubber overshoes, for instance, wear out
so much faster than others.

To make an overshoe, the rubber is run through rollers and formed into
thick sheets for soles and thinner sheets for uppers. Another machine
coats with gum the cloth used for lining and stays. Rubber and
rubber-lined cloth go to the cutting-room, where all the different
parts of the shoes are