nd cry, but would cruise about or hide in
some little frequented part of the coast. But he hoped that if the
wireless "caught" some vessel that had spoken to her, he could at least
obtain a line on which direction she had taken.

The first "session" at the wireless was taken by Hiram, then came the
others in rotation; but when at ten o'clock that night Donald, who had
learned wireless on his father's yacht, came on duty, there had come no
word from the air of a green motor boat. Several ships had been spoken
to, but not one reported anything to give the boys hope.

"Well, good-night, old man," said Merritt, as Donald, who relieved him,
came on duty, "and good luck."

"I'll keep a good watch out, all right," was the earnest response.
"It's our only way to get poor old Rob back."

"I'm afraid so," sighed Merritt, leaving the place with a despondent
air. As Donald had said, it was a chance--but what a long, seemingly
hopeless one!

Donald, left alone, began sending out calls, and every little while he
paused for an answer out of space to his appeals. As he pressed the
sending key the blue, lithe spark leaped and crackled between its points
like a fiery snake. Then all would become silent again as he listened
for an answer to his call.

Once he caught a steamer bound north and carried on quite a conversation
with its operator. He felt quite lonesome when he closed down his
sending apparatus with a parting "good-bye."

It was very still about the encampment. So still, in fact, that the boy
began to feel more and more lonesome. He longed for someone to talk to;
but he knew that chance would not come till Tubby, his relief,
appeared.

The stout youth was almost due when Donald suddenly got into
communication with a steamer called the _Cambria_, bound north from New
Orleans to New York. He put his customary query about the green motor
boat.

"A green motor boat?" came back the reply.

"Yes," flashed Donald.

"With one signal mast and a high cabin?"

"Yes! yes," shot out Donald, pounding the key excitedly. "Have you seen
such a craft?"

"We sighted her this evening."

The boy's fingers shook as he wrote down the reply with flying pencil on
the scratch pad at his elbow.

"Down off some islands about Lat. 80 deg., Long. 33 deg.," came the
answer. "She was coming straight toward us and then all of a sudden she
headed away. Seemed like she didn't want to get near us. Is that all?"

"Yes; good-bye, and thank you