their father and their Uncle Randolph and Aunt Martha at a pleasant place known as Valley Brook farm, in New York state.
While their father was in Africa on a mission of importance, the three boys had been sent by their uncle to boarding school, as related in the first volume of this series, entitled, "The Rover Boys at School." The place was Putnam Hall Military Academy, and there the lads had made many friends and also a few enemies.
From school the boys had made a short trip on the ocean, and then another trip into the jungle after their father. Then had followed a trip out West, and another on the Great Laks. Later the youths had camped out in the mountains during the winter, shooting quite some game. Then they had returned to school, to go into camp during the summer with the other cadets.
The boys by this time thought their adventures at an end, but more were soon to follow. There came a long trip on land and sea, and then a voyage down the Ohio River, and soon after this the Rovers found themselves on the plains, where they had some adventures far out of the ordinary. From the plains they went further south, and in southern waters—the same being the Gulf of Mexico—they solved the mystery of the deserted steam yacht.
