“It’s been a wonderful trip for us,” remarked Billy, as they again soared above the fleet, and kept up “without half trying,” as he himself would have said.

“The greatest thing about it, according to my mind!” Pudge declared, “is that not a single plane was brought down with all that firing. Why, even up where we were I heard a queer singing noise several times, that must have been made by parts of the bursting shrapnel shells. They’re filled chock full of bullets and all that sort of thing, I understand. How about that, Frank?”

“Yes,” the pilot told him, “as far as I know what is called shrapnel to-day is pretty much the same as grape and canister used to be in the time of our Civil War. It scatters in every direction, but is driven now by a much more powerful explosive than in the old days when gunpowder alone was used.”

“Now that you mention it, Pudge,” said Billy, “I heard some of those whining noises myself. It must have been our swift movements that kept us from being struck; and that’s what makes it so hard for ground guns to fetch an aëroplane down.”

“Yes,” Frank continued, “anyone who has tried to stop a duck speeding past at the rate of seventy miles an hour knows what small chances he has to wing the quacker. It takes nice judgment and a quick eye to do it.”

“So our excursion with the air raiders is all over, is it?” Billy asked, with a tinge of regret in his tone; for being engaged in the building of aëroplanes he naturally took the keenest interest in seeing such a fleet of the aircraft in action.

“I was thinking of making a proposition to M. Le Grande here,” ventured Frank, without, however, taking his attention from his levers.

The experienced French aviator had been observing everything that occurred with almost breathless interest. He had clapped his hands enthusiastically and cried “bravo! bravo!” when the bold British birdmen made that death dip, and succeeded in blowing up the magazine, taking terrible risks of perishing themselves when the air waves caused their machine to dance madly.

At hearing Frank say this he showed a keen interest in the possibility of something new developing that had not been on the program.

“I should be pleased to hear what it is, young m’sieu,” he now hastened to say.