That was the way matters looked. The | _Clarion_ was riding high, and was so close by this time that the windows in her cabin could be made out. Against those panels of glass our friends felt sure some of the rival crew were even at that moment pressing anxious faces as they watched the Sky-Bird steadily creeping up on them. It was such an auspicious moment that Paul went and aroused John and Tom, so that they could see the Sky-Bird overtake and pass her adversary. Those two worthies grumbled a whole lot for a few moments, being half asleep, but when they grasped the situation and saw the _Clarion_ just ahead, they were as much interested as anybody. Slowly, surely the Sky-Bird overtook the rival machine. When it seemed her nose was almost up to the tail of the _Clarion_, they saw a movement in the bottom of the fuselage of the craft above them, where her trapdoor of glass was situated in the floor of the cabin. Then something gray streaked down through the air. It went whizzing by just in front of the Sky-Bird, and a few moments later plunged into the sea with a great splash. "Huckleberry pie!" ejaculated Tom Meeks, "one of their rocks has burst through their floor trap. Say, that was a close call for us!" "Watch out! Here comes another!" cried Paul, as a second gray missile went by them on the other side. Barely had it struck the waters beneath, when a third rock came so close that they could feel the rush of air as it passed downward. It was as if they were being bombarded by an enemy above, who used great stones instead of explosives. Their faces paled when the truth struck them like a thunderbolt. With calm deliberation, deadly intent, and a skill born of dropping bombs on targets during the war, some of the fellows in the machine above were trying to wreck the Sky-Bird with the rocks they had gathered in the field back in Ceylon! "Quick, Bob!" cried John to their pilot. "Swerve out from under these devils as fast as you can! If another stone comes down here, it may--" The words he intended to say never were uttered. At that very moment another gray object streaked its way down through the heavens, whirling uglily. They thought sure it would strike the cabin roof and crash through, and intuitively they cowered back in the corners for protection. But their speed carried the stone farther to the rear. There was a tearing, rending sound. Their faces blanched. And then Bob called out: "Hi, fellows, something's gone wrong! The Sky-Bird's bound to put her nose into the sea. The tail elevators don't work!" CHAPTER XXIV RIDING AN AIRPLANE'S TAIL Filled with the gravest fears for the safety of the Sky-Bird and themselves, all except Bob rushed to the rear windows of the cabin and looked out to see what had caused the ripping noise, and what could be wrong with the tail.