All these things interested the boys, and they took delight in every part of it, and it gave them satisfaction to see the results of their work on every hand. But that which attracted them more intensely were the series of exploits which brought to light the hidden mysteries of the island, and which caused them to name it "Wonder Island."
Four exploring trips had been made by land, and one by sea in a boat which had been specially built for the purpose, and this vessel was wrecked shortly after they had discovered the location of the savages. In the previous expeditions they saw mysterious lights, and had evidences of human beings by the camp fires used by them.
The first crude boat turned out was left at the foot of a high falls in a river to the south of their home, and after the return the boys set out to get the boat. It was missing, and recovered several months afterwards, but to their surprise, when found, it had two oars and rope that were placed there by some one.
On returning from one of the trips their flagpole and staff, which was put up on a high point, called Observation Hill, was missing. Later on a gruesome skeleton was found on the seashore not far from Observation Hill, and the wrecked portions of a boat, and to this may be added the discovery of a lifeboat, similar to their own, among debris on South river, fully ten miles inland, which must have come from the interior.
Fig. 1. The First Boat.
In this boat was found, accidentally, a note written by a captive in distress, showing that some of the party had been taken by the inhabitants of the island, and this occurrence determined them the more to put themselves in condition to aid the captives.
The last important development grew out of the finding of a cave, or a series of caverns, not far from their home, which contained numerous skeletons and a vast amount of treasure, showing that it was a pirates' cave, but up to this time it had not been fully investigated in view of the more serious need of haste to relieve those who were in the hands of the savages.
Shortly before leaving on the present expedition, and after returning from the expedition by sea, which had wrecked the boat, they were surprised to find a man at their home, who had entirely lost his memory. This happened six weeks before the occurrence in the opening page, and during that time he had not uttered a single word, and seemed to be entirely unconscious of his surroundings.
He was evidently a cultured man, but how he came to the island, or in what manner his faculties were lost, they could get no clue. He had proven himself to be harmless, and in many ways he was of great service to them, and was now with the party, this being the fifth day of the journey, and the distance from their home was from sixty to seventy miles.