the ticket!"

The gun was found all right, in its great tarpaulin cover, and Tom had
the latter taken off that he might go over every bit of mechanism. He
made a few slight changes, and then got ready for the final trials.

On an improvised platform, not too near the giant cannon, had gathered
the ordnance board, the specially invited guests, a number of officers
and workers in the canal zone, and one or two representatives of
foreign governments. Von Brunderger was there, but his "familiar," as
Ned had come to call the stolid German servant, was not present.

Tom took some little time to explain, modestly enough, the working of
his gun. A number of questions were asked, and then it was announced
that the first shot, with only a practice charge of powder, would be
fired.

"Careful with that projectile now. That's it, slip it in carefully. A
little farther forward. That's better. Now the powder--Koku, are you
down there?" and Tom called down the tube into the ammunition chamber.

"Me here, Master," was the reply.

"All right, send up a practice load."

Slowly the powerful explosive came up on the electric hoist. It was
placed in the firing chamber and the breech dosed.

"Now, gentlemen," said Tom, "this is not a shot for distance. It is
merely to try the gun and get it warmed up, so to speak, for the real
tests that will follow. All ready?"

"All ready!" answered Ned, who was acting as chief assistant.

"Here she goes!" cried Tom, and he pressed the button.

Many were astonished by the great report, but Tom and the others, who
were used to the service charges, hardly noticed this one. Yet when the
wireless report came in, giving the range as over fourteen thousand
yards, there was a gasp of surprise.

"Over eight miles!" declared one grizzled officer; "and that with only
a practice charge. What will happen when he puts in a full one?'

"I don't know," answered a friend.

Tom soon showed them. Quickly he called for another projectile, and it
was inserted in the gun. Then the powder began to come up the hoist.
Meanwhile the young inventor had assured himself that the gun was all
right. Not a part had been strained.

This time, when Tom pressed the button there was such a tremendous
concussion that several, who were not prepared for it, were knocked
back against their neighbors or sent toppling off their chairs or
benches. And as for the report, it was so deafening that for a long
time after it many coul