This strange book expounds quite convincingly the theory that the earth is hollow. Interestingly, this book was published well after scientific experiments had proven quite conclusively that the idea was not valid. The discovery of the North pole four years earlier also challenged the author. This accomplishment dented the assertion made by author Marshall Gardner that the pole was the site of an entrance into the earth's depths.
Englisch
Symmes's Theory of Concentric Spheres : Enriched edition. Demonstrating that the Earth is hollow, habitable within, and widely open about the poles
The Cellular Cosmogony
The Enlightenment of the World
The Smoky God
Paradise Found
Symzonia; Voyage of Discovery
Flat Out Fascinating : The World According To Flat Earthers
Man's Place in the Universe
The Martians: Evidence of Life on the Red Planet
The Poison Belt
Ultima Thule : Further Mysteries of the Arctic
Savage Pellucidar
