A strange discovery

In this early work of science fiction narrated by an Englishman in America on business, Doctors Bainbridge and Castleton discover that their patient is one Dirk Peters, a character from Edgar Allan Poe's novel The Narrative of A. Gordon Pym. Bainbridge recounts the story Peters tells, of his journey with Pym to a strange land at the South Pole, where they find an island utopia inhabited by descendants of fourth-century Romans.