John Cleves Symmes Jr (1779 - 1829) nephew of John Cleves Symmes. Soldier in the War of 1812. Famous for his theory of a Hollow Earth, with openings at both poles. He named the supposed subterranean lands Symzonia.
Believed to be the true author of [Symzonia]]; Voyage of Discovery, a book based on his theory. ISBN 0405063121.
This theory and book provided the inspiration for a work of Edgar Allen Poe's: The Narrative of Arthur Gordon Pym (serialised 1837-1838)]].