And Andrews did. A perfect din again floated over the air; and then the sounder of war-calls sank back quite exhausted.
Before the last echoes had ceased, a series of tremendous yells came from the Thorntons. They rose in a crescendo and ended in a medley of long-drawn-out groans.
“The correct answer to signal number three,” remarked Stiles, with satisfaction. “But say, aren’t those fellows getting cheeky, though?”
The “Reindeer” was now rapidly approaching the house-boat, which had stopped its engine; and now the swift-flying “Dart” was so close to its rival that the faces of the boys could be clearly seen.
“Stop your engine!” commanded Stiles, fiercely.
“Stop nothing!” yelled Lon Bates, defiantly. “Keep off!”
“Didn’t you hear what I said?”
“Yes! And this is our answer,” and again the war-call of the Thorntons broke forth.
Stiles smiled grimly, but made no response.
Gradually the “Dart” drew abreast, and, as the two motor boats raced side by side, Colonel Ellison and his chauffeur looked on in astonishment.