For perhaps an hour he endeavored in vain to pick up a ship or a station in any of the South American countries. The signature he put to each message was "J. T."—his own initials, but he could think of none better.
As he was about to give up his tests as a failure, he suddenly caught a faint clicking.
"J. T," came faintly to his ears.
He answered promptly.
"Who are you?" was the message he sent.
"U. S. cruiser Virginia," was the reply. "Who are you?"
"Survivors of merchant ship Albatross," Jack flashed back. "Castaways on uncharted island."
"What's your location?"
"Don't know. But there is a German submarine base on this island."
The wireless seemed nervous as the next message came in.