the telephone that nothing in the shops had been disturbed, and the inventor received the news with evident satisfaction. He requested Tom to come back to the hotel in the morning, in order that the three of them might go for a ride about the lake in the afternoon, and Tom decided to make an early start.
The night passed without incident, though Tom, who kept the gun Mr. Duncan had given him in readiness for use, got up several times, thinking he heard suspicious noises. After an early breakfast, and having once more cautioned the engineer and housekeeper to be on their guard, Tom started back in the Arrow.
As it would not be much out of his way, the young inventor decided to cut across the lake and stop at the sanitarium, that he might inquire about Mr. Duncan. He thought he could speed the Arrow up sufficiently to make up for any time he might lose, and, with this in mind, he headed out toward the middle of Lake Carlopa. The engine was working splendidly with the new spark plugs, and Tom was wondering if there was any possible method of getting more revolutions out of the motor. He had about come to the conclusion that a new propeller might answer his purpose when he heard the noise of an approaching boat. He looked up quickly and exclaimed:
