"Boy Scouts of the North Sea; or, The Mystery of the Submarine" is an exciting adventure novel by the famous author H. Harvey Ralphson. In this book, embark on an exciting journey with the characters who find themselves at the heart of the mystery of a mysterious submarine. During their adventures, the boy scouts will face danger, test their courage and friendship. The book, which fascinates with its atmosphere, exciting plot and bright images, will not leave indifferent readers of any age.