e ejector. Watch him now," he
went on, following the action of the workman; "he takes a piece of steel
out of the furnace behind him, lays it on the die, touches a lever, and
the big drop-hammer comes down,--once, twice. He turns it over, brings
the drop-hammer down again, once, twice, and the piece is shaped. It has
rough edges all round, of course, and so he takes it, while it is still
glowing red, to a more exact die, and brings the drop-hammer down once,
and turns it over, then brings down the hammer again once. Now the shape
is almost perfect but for that fringe of metal all round. He picks it
up, puts it on that die on this next machine close by his hand, touches
a lever, and a knife, exactly the shape of the die comes down, crunch!
shaving off the iron clean all round, and there is your forging done,
and all with the one heating. Of course it isn't finished off, but you
can see for yourself that the rough work is done, and all in the space
of a few moments."

Hamilton found it hard to tear himself away, for while the principle was
the same, all the different forges were turning out different parts, and
it was a fascination to the boy to see those glowing lumps of steel come
out of the furnace and with the few strokes of the drop-hammer, fall a
few seconds later, the shaped part of a rifle. Some of the machines were
making receivers for the stock, the largest piece of metal, and other
small parts like the trigger or the hammer, while still others were
preparing the barrels of the gun for drilling.

"It is not likely to occur to you," said his guide, "that it would not
do to let all those various parts cool off by chance. For example, in
winter they would cool more rapidly than in summer, and those near the
door more quickly than those in the inner part of the forging house.
That would make them of varying hardness. So, in order to make sure that
they shall be the same, all those pieces you have seen being made are
annealed."

"How is the annealing done?" asked Hamilton.

"That is simple enough," was the reply. "All that has to be done is to
heat them again all to the same degree of heat, then let the oven cool
at a certain rate. Here are the annealing ovens."

"This is certainly a hot place," said the boy, as he stepped into the
next building. "Whew! I wonder any one stays in here."

"No one does," his conductor answered. "We have this arranged so that
all the furnaces are filled in the morning, when they ar