A further search through the cave was fruitless of results, so far as looked for treasure was concerned, and their original plan of investigating the smoke signal was taken up.
A walk of another mile brought them to the spot they sought. They had thus far encountered no one, or any indication of the presence of inhabitants on the island. They gained finally the summit of the hill from which the column of smoke was ascending. They found that this had been made by building a fire in a small chimney of stones and covering it with wet leaves. There was an opening below which gave just sufficient draft to keep the fire smouldering.
But little could be seen of the land from the top of the hill on account of the thick woods, but by climbing one of the taller trees, which they did in turn while the others kept guard, they were enabled to make out that they were on an island of many miles extent, and that another island lay some five or six miles to the southwest. Most unexpected of all their discoveries, they saw in the distance far out upon the ocean a steamer which was apparently approaching the island. The distance was too great to determine with any definiteness anything about her character or probable intentions, and further information on that point would have to be sought at a later time.
“I can’t understand that smoke business,” said Tom, once more examining the chimney-like arrangement curiously. “It was certainly made by someone, yet there doesn’t seem to be anyone about.”
“They may be on the other side of the island,” suggested Jim, “or they may have come from the other island and gone back again.”
“But why should they have come over here and made the fire?” persisted Tom.
“You will have to ask them,” laughed Jim. “I am sure I don’t know, or why they should have lighted it at all. But some of us had better return to the ship or I am afraid that the professor will be getting anxious.”
Arriving at the landing place, Tom elected to go on board. He felt that he had had enough of excitement and adventure for one day. Jim accompanied him, while Jo and Juarez, the spirit of investigation awakened, promptly set out on an exploring expedition returning however without incident at nightfall.
“Well,” began the professor that evening when they had gathered on the deck awaiting the supper call, “what did you find out about the island to-day?”
“Not much of importance,” replied Jim, “except that it is of very considerable extent, very rugged and mountainous.”