Larry Dexter’s Great Search or, The Hunt for the Missing Millionaire by Howard R. Garis (1909). A young journalist gets a scoop!
Howard Garis was a prolific author of children’s and juvenile literature. Uncle Wiggily, the Bobbsey Twins, Tom Swift, The Curlytops, Dick Hamilton and Larry Dexter were some of his productions.
Project Gutenberg has several other works by Garis under his own name, though this is the first Larry Dexter work represented.