So Frank began to turn on full speed, and the wonderful creation of Dr. Perkins’ inventive brain was soon swooping along in a manner calculated to make some of those who were staring through glasses far below gasp with astonishment bordering on awe.

After all, Frank Chester was a boy, and must have felt a natural pride in being able to thus surprise the whole of the Kaiser’s army with his amazing new aircraft. He knew that tens of thousands of eyes must be riveted upon them at that particular moment, from the officers at Headquarters to the mud-spattered and half frozen men concealed in the irregular trenches.

“See the Taubes giving us all the room they can, Frank!” cried Billy.

“Evidently they’re not hankering after an engagement with the Sea Eagle, Billy.”

“They make me think of a flock of wild ducks on a lake when an eagle poises on fluttering wings above them, picking out his dinner,” Billy went on to say. “They scatter and dive and act half crazy; but nearly every time the eagle gets what he’s after.

“Well, all we want is a clear road back over the way we came,” the pilot pursued. “Fact is, we’re not near so dangerous as we look. All we could do just now would be to ram a Zeppelin, and go down with it.”

“But they don’t know that, Frank, which is lucky for us!” declared his chum.

No doubt, Billy, in common with most other boys, must have learned at school the familiar saying that “pride always goes before a fall.” He had just been doing considerable boasting, and his heart was even then swelling with the conviction that he and his chum were virtually snapping their fingers at the whole of the Kaiser’s scattered army with every enlisted man craning his neck in wonder.

Then came the sudden shock, all the more terrifying because so utterly unexpected. It seemed to Billy that his very breath was taken away. The joyous buzz of the motors that had amounted to almost a shriek ceased as if by magic; and the Sea Eagle, shooting forward a bit under the impetus of her great speed, quickly began to volplane toward the earth, thousands of feet below!