Page:Tom Swift and His Giant Cannon.djvu/159

Rh jectile was used. Tom was perfectly satisfied, however. Several more trials were given the gun, and each one confirmed the young inventor in his belief that he had made a wonderful weapon.

"If that doesn't fortify the Panama Canal, nothing will," declared Ned.

"Well, I hope I can convince Uncle Sam of that," spoke Tom, simply.

The muzzle velocity and the pressure were equal to Tom's highest hopes. He knew, now, that he had hit on just the right mixture of powder, and that his gun was correctly proportioned. It showed not the slightest strain.

"Now we'll try another bursting shell," he said, after a rest, during which some records were made. "Then we'll call it a day's work. Koku, bring up some more powder. I'll use a little heavier charge this time."

It was while the gun was being loaded that a horseman was seen riding wildly down the valley. He was waving a red flag in his hand.

"Bless my watch chain!" cried Mr. Damon. "What's that?"

"It looks as though he was coming to give us a warning," suggested the steel foreman.

"Maybe someone has kicked about our shooting," remarked Ned.

"I hope not," murmured Tom.