s were as yet unrelieved, for he could not doubt that the
gunboat was the same that had been dispatched from Brisbane to their
assistance. Before many minutes had elapsed he had overtaken the
vessel. Slowing down and wheeling overhead, he saw that the aeroplane
was the object of wondering interest on the crowded deck.

"Ahoy, there! Who are you?" he shouted through his megaphone.

"Gunboat _Frobisher_, Captain Warren," came the reply. "Who are you?"

"Aeroplane without a name, Lieutenant Smith of H.M.S. _Imperturbable_,
bound for Ysabel Island to relieve Lieutenant Underhill."

"The dickens! That's my job! Where do you hail from?"

"From London, sir. I'm afraid I've beaten you by a neck."

"Great Scott! Is this the Admiralty's latest?"

"Not official, sir; I'm here in a private capacity. My father's among
the wrecked party. I'm on leave."

"So it seems. When are you due back?"

"On Friday morning."

"I'm sorry for you, then. But, goodness alive! when did you start? The
wreck was only reported four days ago."

"Started Friday morning, sir."

"Gammon!"

"Rasher to you, sir."

"You haven't lost much time, at any rate. What's your speed?"

"About a hundred and ninety. Whereabouts was the wreck, sir?"

"A hundred miles or so up the coast, according to the men of
Underhill's party with me."

"Then I'll bid you good-bye for the present. I'll tell him you're
coming."

"Hope you'll find him alive."

Waving a good-bye, Smith flew on at full speed. For twenty minutes he
did not attempt to follow the indentations of the coast, but set a
course parallel with its general trend. Then, however, he steered so
that, without actually tracing every curve of the shore, he was able
to survey it pretty closely. By dead reckoning and the assistance of
his chart he was able to check from minute to minute his approximate
position.

He had passed Mount Gaillard, and saw, some miles to the north, the
remarkable saddle shape of Mount Mahaga. Then he made a bee-line for
Fulakora Point. Rounding this, his course was to the north-west. The
coast was steep and precipitous; here and there were reefs, over which
the sea broke in white upward cascades, and he was at no loss to
understand how even the most skilfully navigated vessel might easily
come to grief. About forty miles from the extremity of the island he
flew over an immense lagoon, extending for several miles between
Ysabel Island and a series of islets and reefs lying o