"Good for you, Hugh," he remarked. "Those sharp eyes of yours let nothing escape. Now we'll just circle around a bit and give those precious foreigners the scare of their lives. I happen to have a supply of small experimental bombs along, which are heavy enough to frighten them into believing one of the new explosives may follow, after we have the range. Watch out for some fun, my son!"
CHAPTER XI
GOOD-BY TO THE FOREIGN SPIES
When Hugh saw the air pilot reach back and take a small black object from a box attached to the body of the monoplane close to the gasoline tank, he knew that those skulkers below were in for a lively time of it.
Undoubtedly they had been creeping toward the rear of the camp with the hope either of picking up valuable information, or finding a chance to make way with precious plans connected with this latest war airship which Uncle Sam was trying out, and which possessed features far in advance of anything known abroad.
At a certain second, when he judged that he could drop the bomb very close to where the couple were secreted, the lieutenant hastened to do this. Almost immediately afterwards he caused the monoplane to make a curve, so that they would be in shape to circle around that particular spot and repeat the bombardment as long as the supply of missiles held out.
Twisting his head so that he could watch the result, Hugh's gaze followed the descending bomb until it struck the ground. Instantly there was a pretty loud racket and the dirt flew, although this missile undoubtedly contained but a small portion of the new and terrible explosive, being intended only for experimental purposes in the way of gauging distances correctly.
The two spies instantly sprang into view and started to dash madly away. They undoubtedly labored under the impression that once the range had been properly found, one of those fearful projectiles would be dropped down on them. No doubt they had before now examined the great hole in the earth showing where aviators had dropped one of the larger bombs, and knew what to expect in case such a missile fell anywhere near them.
"You've given them a bad scare already, sir!" remarked Hugh, greatly enjoying the experience, although it made him think of a fable in one of his earlier books concerning the sport of stoning that was "fun for the boy but death to the frogs."
"That is only a beginning," declared the lieutenant. "This monoplane is so well constructed that we can hover over them, no matter what they do, just as a hawk shadows a rabbit."