CHARACTERS THAT APPEAR IN THIS STORY.
Reading edition
Motor Matt, a lad who is at home with every variety of motor, and whose never-failing nerve serves to carry him through difficulties that would daunt any ordinary young fellow. Because of his daring as a racer with bicycle, motor-cycle and automobile he is known as "Mile-a-minute Matt." Motor-boats, air ships and submarines come naturally in his line, and consequently he lives in an atmosphere of adventure in following up his "hobby."
Carl Pretzel, a cheerful and rollicking German boy, stout of frame as well as of heart, who is led by a fortunate accident to link his fortunes with those of Motor Matt.
Dick Ferral, a young sea dog from Canada, with all a sailor's superstitions, but in spite of all that a royal chum, ready to stand by the friend of his choice through thick and thin.
Archibald Townsend, a wealthy though eccentric gentleman, who owns a remarkable submarine boat on which our friends have seen various adventures in the past.
Cassidy, mate of the submarine Grampus.
Whistler, Jurgens, Bangs, } a trio of rogues bent upon gaining possession of a prize.
Joe Dashington, Motor Matt's double, who proves how small a matter will sometimes turn a fellow from the wrong road into the right one.
Shirley, of Scotland Yard, who springs a surprise at the end of the story.
Fetterman, assistant chief of police, who helps the Scotland Yard man.