tell you about this
plant," said the shepherd. "The scientific fellows call it Algae. When
the world was first made this algae covered the whole surface of the
ocean."

"How did you learn this?" asked Juarez.

"You know that the Captain is quite a collector, and in his travels has
gotten together among many other things some interesting books. He gives
them to me when convenient." The face of the lanky shepherd was
perfectly grave when he spoke of Captain Broom as a collector.

"What makes the water so clear around here?" asked Juarez. "I never saw
anything like it."

"Well, you see," replied their mentor, "this island is placed
peculiarly, I mean this side of it. You see how quiet the water is?"

"It is certainly smooth and blue," said Juarez. "More like a lake than
the ocean."

"That's only true of this side," resumed the shepherd, "the other is
rough enough, but you see the prevailing winds are from the Northwest
and this shore is never disturbed. So on the beaches you will find not
sand, but smooth round pebbles, because there is no action of the water,
no breakers or waves to grind them into sand."

About four o'clock the Sea Eagle came into a perfectly beautiful little
harbor, at the South-eastern end of the island. There was a small level
plot back from the beach and on all sides rose steep hills and back of
them the mountains. It was the most picturesque scene the boys had ever
beheld in all their travels.

What would they not have given to have been free to roam that island,
hunting inland, or fishing or bathing along those quiet, enchanted
shores. But this was no pleasure excursion. Far from it. Captain Broom
had his own ideas, and he did not intend to make a landing at all.

"Get the whale boat ready, lads!" he ordered. "And put her over, we've
got no time to lose."

They lost no time either, under Captain Broom's commanding eye.

What was necessary for the cruise was already in the boat. Two casks of
water, several guns, and a lot of provisions. Then the boat was hove
overboard into the quiet bay. The captain was ready with a much battered
satchel in his hand. Not for one second did he entrust it to any one
else.

"Now over with you, you two lads," he commanded and Juarez and Tom,
with a sinking of the heart, got into the boat. This was the last leg of
their mysterious journey, and it boded them no good they felt sure of
that. The mate they noticed stayed aboard in charge of the ship.

They