, Jim?" he queried, as the old man straightened up.

"Yes, Mr. Nebett," was the reply.

"All right," the other said, "we'll go into the room." He pointed out to
Hamilton, as they passed from one part of this little building to the
other, that each of these percussion caps was attached to a wire which
ran through the wall to the little room into which they were going.

"Look out, Mr. Nebett," said the old man, after he had closed and
fastened the heavy door, "and you, young sir, don't be frightened," and
he pulled the wire hanging overhead.

There was a terrific explosion and a roar, and though Hamilton had been
half expecting it, he jumped. Then he laughed.

"I guess I did jump, after all," he said. "What was that for?"

"To test the strength of the barrels," said his friend, as the old
workman slid back the heavy door. "There, you see," he added, "one of
them did burst." He pointed to one of the gun barrels rent at the side.
"Once in a while," he continued, "they just go up in pieces, and if you
look at the walls and the ceiling you'll see any number of bits of metal
driven in deeply."

"But he seemed to be putting in an awfully heavy charge," said the boy.

"We do that in order to be sure that we shall not expend a great deal of
labor on a barrel which in the end would fail to pass inspection, and
also to safeguard against accident," the other explained. "We do use a
very heavy charge because our guns sell all over the world, and in some
countries--England, for instance--the test is extremely severe. It's a
costly process, as it spoils a lot of barrels, but it is better to lose
material than to put out a piece of work which might not be
trustworthy."

Hamilton looked around the proof-room carefully. Certainly it seemed to
have gone through the wars. From the thick wood huge gashes had been
rent, and the entire interior was jagged and splintered.

"How much of a charge do you put to each barrel?" he asked; and when the
formula was given him for each of the different styles of rifle, the boy
whistled in amazement.

"I should think that any barrels that stood that test could stand
anything afterwards," he said admiringly.

"Well, they do," the other said. "It's very seldom that you hear of a
first-class gun exploding. I don't recall a case of one of ours for
years and years. And even if by some chance flaw they did, the good
ones, being nickel steel, would just make a hole in the barrel,--not fly
to pieces.