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.”

Indeed, the entire performance did remind Hugh of occasions when he had watched a red-tailed hawk chasing a frightened bunny, now slowing up on quivering pinions, then making numerous pretended lunges in order to frighten the quarry still more, and finally ending the pursuit by a well-directed swoop that gave the bird of prey its fine dinner.

The two men were bewildered as well as alarmed.  Another bomb exploded close behind them, and started them off on a new tack.  Run which way they might, it seemed as though that terrible enemy in the air kept hovering above them, sending a little black object shooting earthward every half dozen seconds, to be followed by a sudden crash, many times magnified in their excited imaginations.

Once the taller man started to fire his automatic revolver upwards, as though in sheer desperation he hoped to cause the air pilot to give over the chase.  The reports sounded like the detonation of toy fire-crackers to Hugh; and if the bullets came as far as the monoplane, he heard nothing that sounded like their passing.

Dodging this way and that as though almost panic-stricken, the spies finally betook themselves into the sheltering forest.  Before they could hide under the branches of the oaks, the tall man was seen to stumble at the top of a rather steep declivity and roll all the way to the bottom, as though he might be a barrel that some mischievous lad had started downhill for the fun of seeing it jump.

Some seven of the little bombs had been used by the time both men vanished into the shelter of the woods a mile or so away from camp.  The Lieutenant was laughing heartily as though he had enjoyed the diversion greatly.