"Six hundred? Oh, yes," Alfred said indifferently. "Well, what of it?"
"Just this much of it," said Vincent thoughtfully. "I've been going over and over it in my mind the last little while. What if we send out our S. O. S. now and some selfish landlubber such as we were is talking about matters of little importance and muddles our message? We might be left to drown."
"Aw, can that sob stuff," grumbled Alfred angrily. "Are you going to send that S. O. S. or am I?"
"I will," said Vincent, preparing to climb to a position on the plane above him where the radiophone was located. "But"—he suddenly began to sway dizzily—"but where are we?"
He sank back into his seat. For a full moment, with the waves tossing the plane about and the black clouds mounting higher and higher, the two boys stared at one another in silence. Yes, where were they? Who could tell? They were not trained mariners. They could not have taken a reckoning even had they been in possession of the needed instruments.
"Why," said Alfred hesitatingly, "we must be somewhere near that spot where the island was supposed to be located. That's as near as we can come to it. Send out that latitude and longitude; then we'll climb back into the air. We'll be safer there than on the water and we can keep the searchlight shooting out flashes in all directions. A ship coming to our aid will see the light."
"If they come," Vincent whispered.
"Hurry!" exclaimed Alfred, as a giant wave, rising above its mates, threatened to tear their plane into shreds.
With benumbed and trembling fingers the boy unwrapped his instruments, adjusted a coil, twisted a knob and threw in his switch. Then his heart stood still. The motor did not start. Had it been dampened and short-circuited? Would it refuse to go? Were they already lost?
Just as he was giving up in despair, there came a humming sound and a moment later the well-known signal of distress had been flashed out across the waves. Three times he repeated it. Three times in a few sharp words he told their general location and their plight. Then with wildly beating heart, he pressed the receivers to his ears and awaited a reply.