bled.

"What is there down there?" asked Charley regarding his chum curiously.

"The demon work of the fiends who built this wall," said Walter
fiercely, "It's their old stone quarry. They didn't bring rock from
the coast, they just dug down till they found the kind they wanted.
And Charley, all around the sides, chained to the solid rock, are the
skeletons of the workers."

"I am right about the Spaniards building this place then," Charley
observed. "That's the way that most Christian nation always used to
treat its captives."

"Let's go," his chum urged, "I guess my nerve is shaken from being down
there with those skeletons so long. The sun is getting low, anyway.
We will not have time to more than get back home before dark."

"You're right, we must go, but I wish we had time to go through the
balance of those buildings," said Charley, regretfully.

The two boys soon regained the canoe and paddled safely past the
floating crocodiles.

"We haven't solved the mystery, after all," remarked Walter, as he
urged the canoe forward.

"No, but we have done far better," declared Charley, enthusiastically,
"we have found a place where we will have ample protection in case we
are attacked by the outlaws. I am in favor of moving our camp there
to-morrow morning."

"Of course that is the wisest plan," Walter agreed, "but since my
experience in that pit I have a dread of the place."

"That will wear off in time. Hallo, there's our island and there's the
captain and Chris on the bank waiting for us."

"I expect we will get a good lecture," grinned Walter, "I guess we
deserve it, too."

But the captain was so delighted over their safe return, that he let
both off with a light scolding.

Over the supper, the boys related the story of their discoveries amid
exclamations from the captain and Chris.

The captain readily agreed to their proposal to move camp to the larger
island. "The young chief showed me how to fix signs that would tell
him which way we had gone in case we left the island before he
returned," the captain observed.

This removed the only possible objection to the plan, and early next
morning the hunters prepared to shift camp.

The little patch of yams was dug up, yielding several bushels of the
sugary tubers, the remaining ears of Indian corn were plucked from the
stalks, and a large quantity of dry gourds gathered, these, together
with the little that remained of their stock of provisions, wer