"Flying Ships, Humanoids, and Creatures of the Subterranean World" is a wealth of source material on the Hollow Earth theory, which proposes that the earth does not consist of molten metal at its core, but is instead quite hollow. This book was originally printed in small quantities, and thus became extremely rare and expensive. Finally, it has once again been made available to the general public.In this Saucerian roundtable discussion, hosted by...