INTRODUCTION
My Dear Boys: This is a complete story in itself, but forms the fifteenth volume of the "Rover Boys Series for Young Americans."
Twelve years ago the line was started with the publication of the first three stories, "The Rover Boys at School," "On the Ocean," and "In the Jungle." I earnestly hoped that the young people would like the tales, but never did I anticipate the tremendously enthusiastic welcome which was given to the volumes from the start, nor the steady sale, ever increasing, which has been accorded the series up to the present time. The publication of the first three books immediately called for a fourth, "The Rover Boys Out West," and then followed yearly "On the Great Lakes," "In Camp," "On Land and Sea," "On the River," "On the Plains," "In Southern Waters," "On the Farm," "On Treasure Isle," and then "At College," where we last left our heroes.
Dick, Tom and Sam are older than when we
