"I've heard old sailors tell of such things off of this yer coast. These islands—as they are called—are nothing more or less than huge sections of forest torn from the banks of the Amazon when it is in flood and floated out ter sea on its current."
"But how can they keep afloat?" asked Harry.
"Why the tangled roots and tree limbs keep 'em up for a long time," rejoined Ben, "and then they sink."
"I hope our island isn't sinking," exclaimed Frank, anxiously looking about him.
"Not much fear of that; but it's moving, all right," replied the old sailor, "just fix your eyes on that cloud for a minute."
The boys did as directed, and, sure enough, the island, as they now knew it, was moving slowly along, doubtless urged by some current of the ocean.
"Suppose the ship never finds us," gasped Billy.
"Now, just put thoughts like that out of your head, youngster," exclaimed Ben sharply. "I've been in worse fixes than this and got out of them. What we had best do now is to gather up some of those big cocoanuts that's scattered about there and make waterholders out of them."
"But there's plenty of water flowing from the springs. We passed several of them," objected Harry.
"That's just the water that has soaked into the ground after the rain," said Ben. "It will soon dry up as the day goes on."