Summary:

This is among the first and rarest of the Hollow Earth books. In the early 19th century, John Cleves Symmes proposed that the earth was actually a set of five nested spheres, each with polar openings. He unsuccessfully lobbied congress to fund an expedition to the poles to investigate this theory. This novel, based on Symmes' theories, was published in 1820. Some believe that Symmes was the author, but this has not been established beyond a shadow of doubt.