There was a large door in the front, and a very
low window, with a shutter hanging over it, by the side of the door.
In an open yard, by the side of the shop, was the fire. The fire was
in the form of a ring. There were several men standing about it; one
of them, whom Marco supposed was the blacksmith, by his leather apron,
was putting on small sticks of wood and chips, here and there, around
the ring. Marco saw that there was a large iron hoop, as he called it,
on the fire. It was not really a hoop, it was a _tire_. It was
made of a much larger and thicker bar of iron, than those which are
used for hoops. It was a tire belonging to a wheel. The wheel was
lying upon the ground near, ready to receive the tire. It was the hind
wheel of a wagon. The wagon itself was standing in front of the shop,
with one end of the hind axletree supported by a block.
"What do they heat the tire for?" asked Marco.
"To swell it," replied Forester. "It is necessary to have the tire go
on very tight, so as to hold the wheel together with all the force of
the iron. Now when iron is heated it swells, and then shrinks again
when it cools. So they heat the tire hot, and put it upon the wheel in
that state. Then when it cools it shrinks, and binds the whole wheel
together with a very strong grip.
Pages:
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61