"Hold fast, if it does that," cautioned Orissa. "If we become separated from the boat we will drown like rats. The engine may swamp the boat, in any event, but it has air compartments which will keep it afloat under any favorable conditions, and we must trust to luck, Sybil—and to our own coolness."

"All right, Ris. A watery grave doesn't appeal to me just now," was the reply. "I'm too hungry to drown comfortably, and that's a fact. On a full stomach I imagine one could face perpetual soaking with more complacency."

"Huh!" cried Orissa. "Listen!"

Sybil was already listening, fully as alert as her chum. The speed of the engine was diminishing. Gradually the huge propeller slackened its rapid revolutions, while its former roar subsided to a mere moan.

"Thank goodness," said Sybil, fervently, "the gasoline is gone at last!"

"Look out, then," warned Orissa.

With a final, reluctant "chug-chug!" the engine stopped short. Like a huge gull the frail craft remained poised in the air a moment and then a sudden light breeze swept it on. It was falling, however, impelled by its own weight, and singularly enough it reversed its position and proceeded before the wind with the stem foremost.

Splash! It wasn't so bad, after all. Not a volplane, to be sure, but a gentle drop, the weight of the heavy engine sustained by the "air-cushions" formed beneath the planes.

Orissa wiped the spray from her eyes.

"That would have been a regular bump, on land," Sybil was saying affably, "but the old ocean has received us with gracious tenderness. Are we sinking, Ris, or do we float?"