So Forester took Marco to the wheel, and showed him the parts of
which the rim was composed. While Marco was looking at the wheel, the
blacksmith began to push away the burning brands a little from the
tire, as it began to be hot enough. Presently he went into his shop
and brought out several pairs of tongs. With these the men lifted the
tire out of the fire, but the blacksmith said it was a little too hot,
and he must let it cool a minute or two.
"Why, if it's very hot," said Marco, "it will grip the wheel all the
harder."
"It will grip it _too_ hard," said Forester. "Sometimes a tire
shrinks so much as to spring the spokes out of shape. Didn't you ever
see a wheel with the spokes bent out of shape?"
"I don't know," said Marco. "I never noticed wheels much."
"They do get bent, sometimes," said Forester. "It requires great care
to put on a tire in such a manner, as to give it just the right degree
of force to bind the wheel strongly together, without straining it."
[Illustration: THE TIRE.]
As soon as the tire became of the right temperature, the men took it
up again with the pairs of tongs - taking hold with them at different
sides of it - and then they put it down carefully over the wheel.
