For an instant the clatter of the motor drowned all other sounds. Throughout the roar of the exhaust the sharp ears of the two boys could discover a strange vibration that told of trouble.
Before they could again turn to examine the aeroplane that had been wheeled along the ground for some distance, there came a crash, followed by a rending, tearing sound. Then all was still again.
As Jimmie and Dave turned they saw the aeroplane lying a wreck, torn by its own propellers.
CHAPTER XVI
UNDER FALSE COLORS
"Well, let 'em come," declared Harry, hastening toward the Eagle with the last load of gasoline. "We are ready for a quick start now, and if they want to see a correct imitation of three boys beating it down the road they'd better hurry. We can't wait much longer."
"Sure!" put in Ned. "Shall we whistle a warning signal to hurry them up a little, or shall we let them miss the boat?"
"Let 'em miss the boat if they can't get here on time," laughed Jack, carrying out the joke, although the case of the lads was apt to become anything but a joke if their presence was discovered by the German soldiers who were approaching at some distance down the road.
"Hurry, boys," cautioned Ned, laying aside his jovial air as he began preparations for departure. "We mustn't get caught now."