An odd maritime adventure tale with science fiction trappings, this anonymously published novel recounts the voyage of one Captain Adam Seaborn, who ostensibly set out on a whaling expedition, with the secret agenda to explore the South Pole, and to there find an entrance into a Hollow Earth. Seaborn deflects a threat of mutiny as he discovers a passage through "the icy hoop" which is the visible Antarctic ice, and finds that the seas closer to the South Pole is actually basked in extremely hot weather. At the outskirts of the Pole, the crew encounter a tribe of dark-skinned savages, but further south they come upon the land of Symzonia, which is inhabited by a delicate, light-skinned people living in a highly evolved, chaste and pacifist society. Finally Seaborn sets out to explore the actual Pole, hoping to find the entrance to the Hollow Earth. He abandons his expedition before he reaches his destination, making for a rather disappointing ending of the book.
The idea of the Hollow Earth presented in this novel was based on that of John Cleves Symmes, who in 1818 declared his theory that the Earth was constructed out of five concentric spheres, all accessible through giant holes at the Poles. In the novel Seaborn gives a thorough explanation of Symmes' theory and hails him as a genius, which has led to speculation that Symmes himself wrote the novel. However, it does makes some satirical jabs at Symmes' theory, which would rule him out. Several scholars have suggested maritime author Nathaniel Ames as the writer of the book, as his familiarity with Jonathan Swift and the similar subtle satirical style of his books and "Symzonia" would make this likely. The book was highly influential on Edgar Allan Poe's 1838 novel "The Narrative of Arthur Gordon Pym".