The serpent on being measured with Frank's pocket rule proved to be a trifle over twenty feet long and of great girth.
"It's an anaconda," said Ben, "there are lots of 'em up along the Amazon and they are as deadly a snake as there is. I've heard tell they can crush a horse in their folds."
"I hope there are no more of them on the island," exclaimed Billy.
"We shall have to be careful," rejoined Ben, "there may be other dangerous creatures here, too. This island, as I should judge, must be all of six miles around and there's room for a lot of ugly critters in that space."
Leaving the dead body of the snake the adventurers made their way back to camp. The first thing that all wanted was a drink of water. They made for the place in which the drinking fluid had been left.
As soon as his eyes fell on the row of improvised water pots Frank gave an exclamation of dismay.
"Look here," he shouted, "there's some one on this island besides ourselves."
"What!" was the amazed chorus.
"There must be," went on the lad, "see here, there were twenty cocoanut shells of water when we went away, and now there are only fifteen."
"Five gone!" exclaimed Ben in an alarmed voice, "and the spring has already dried up."