"Thirty-one miles!" he announced.
"Hurray!" cried Mr. Damon. "Bless my telescope! The longest shot on record!"
"I believe it is," admitted the chief of the ordnance department. "I congratulate you, Mr. Swift."
"I think I can do better than that," declared Tom, after looking at the various recording gauges, and noting the elevation of the gun. "1 think I can get a little flatter trajectory, and that will give a greater distance. I'm going to try."
"Does that mean more powder, Tom?" asked Ned.
"Yes, and the heaviest shell we have—the one with the bursting charge. I'll fire that, and see what happens. Tell the zone-ship to be on the lookout," he said to the wireless operator, giving a brief statement of what he was about to attempt.
"Isn't it a risk, Tom?" his chum asked.
"Well, not so much. I'm sure my cannon will stand it. Come on now, help me depress the muzzle just a trifle," and by means of the electric current the big gun was raised at the breech a few inches.
As is well known, cannon shots do not go in straight lines. They leave the muzzle, curve upward and come down on another curve. It is this curve described by the projectile that is called the
