“Keep your eyes ahead,” the officer advised, and Rob thereafter did so.

But his ride was not destined to become monotonous with such an aviator as the army officer at the levers. Suddenly the machine gave a downward, forward dip, and began rushing to the ground, or rather the ground appeared to be rushing up toward it.

It was all Rob could do to keep from crying out. He firmly believed that an accident had happened and that they would be dashed to bits when the aeroplane struck the ground. His mouth grew dry with terror, and he could have no longer checked a terrified shout, when all at once the motion ceased; or, rather, it altered. The descent was checked when within twenty feet of the ground, and up and round they swung, landing a few minutes after as lightly as a wafted feather upon the broad, smooth terrace of the De Regny mansion. How the old marshal would have gasped if he could have witnessed the antics of this new weapon of warfare cavorting above his ancient domain, from which he had watched so many weary days for his emperor.

“Well?” said the officer, with a twinkle in his eye as Rob, a bit shaky still from his terrible fright, clambered to the ground.

“Well,” rejoined Rob, taking off his goggles, “It was pretty strenuous work, but I enjoyed every minute of it.”

“Now for your friends,” said the officer, but Tubby had strangely vanished, and only Merritt and Paul could avail themselves of the invitation. They both enjoyed rides, and Paul proved so apt a young aviator that on a second trip aloft he was even allowed to handle the levers, at a safe distance above the ground, however.

“You boys certainly have plenty of pluck,” said the officer, after the sport of the afternoon was over. “Some day I may take you for a cross-country ride, or when we start real bomb-dropping work——”

He stopped abruptly and smiled.

“I forgot—that’s a service secret,” he said mystifyingly.

Not until the aeroplane was safely housed did Tubby emerge, and then he had to undergo a fine cross fire of joshing, you may be sure.