When we read and think about Barsoom, Amtor, and the there worlds created by Edgar Rice Burroughs it’s easy to look at the creations from the perspective of 2012 …. but a lot more interesting to look at them from the perspective of the time in which they were written. Take Pellucidar — the world within the Earth discovered by David Innes and Abner Perry. Burroughs began writing “At the Earth’s Core” in January 1913 at a time when there was a substantial body of belief that a world existed within our world — a “hollow earth” theory in which there were entrances to the inner world at one or the other (or both) of the poles.
Erbzine summarizes the Pellucidar series:
David Innes and Abner Perry build a giant mechanical prospector with which they hope to uncover vast mineral David Innes and Abner Perry build a giant mechanical prospector with which they hope to uncover vast mineral deposits far beneath the surface. On the “Iron Mole’s” first trip, however, they discover that their vehicle can’t be steered. Death seems certain, for doesn’t everyone know that the center of the Earth is a molten mass of white-hot magma?
Instead what Innes and Perry discover is that the earth’s crust in only 500 miles thick and that the inner surface is inhabited. This is the land of PELLUCIDAR, a place where dinosaurs roam through the jungles, and where saber-toothed tigers hunt the mastodon and mammoth. A tiny sun, the molten core of the Earth, hangs in the center of the heavens, shedding perpetual daylight upon Pellucidar. Because the sun never sets, because it is always now, there is no such thing as time in Pellucidar! Stranger still, because Pellucidar rests on the inner side of the Earth’s crust, there is no horizon. The land curves* upwards*, as if you were standing on the inside of a gigantic bowl.
Humans dwell in Pellucidar as well, stone-age men and women who must fight to survive in this savage world. Even worse, these people have been made slaves of the Mahars, a race of intelligent but sinister reptiles who look upon humans as nothing more than beast of burden or as tasty snacks in one of their ghoulish ceremonies.
The struggle of David Innes and Abner Perry to free humanity from the Mahar tyranny is only the beginning of their adventures in Pellucidar. There are a total of seven books in this exciting series, in which Edgar Rice Burroughs takes you on journeys across savage seas infested with plesiosaurs and other hungry creatures, to mountains where pterodactyls roost, and to lands where every waking moment is a struggle to survive. Even Tarzan visits Pellucidar, taking a ride on a dirigible through “Symmes Hole” at the North Pole. So take a journey, via Iron Mole or dirigible, and discover for yourself the wonders, the terrors, and the excitement of Pellucidar…
The roots of “Hollow Earth” theory go back at least as far as the 17th Century, when British astronomer Edmund Halley put forward the theory that Earth consists of four concentric spheres. Under Halley’s concept, the interior or the earth was populated with life and lit by a luminous atmosphere. Under his theory the aurora borealis, or northern lights, was a phenomenon that was caused by the escape of this gas through a thin crust at the poles.
In the 1800’s John Symmes vigorously promoted the idea of an inner world and eventually received recognition in the form of “Symmes Hole” … the opening to the inner world. Symmes lobbied publicly for an expedition to the North Pole to find the entrance to the world below.
Another promoter of the hollow earth theory, Cyrus Reed Teed, promoted the idea of a hollow earth for nearly forty years, printing pamphlets and giving speeches and founding a cult called the Koreshans.
In 1906, William Reed published The Phantom of the Poles, in which he put forward the theory that the poles are entrances to the hollow Earth.
In 1913, the same year that ERB started writing At the Earth’s Core, Marshall B. Gardner published, privately, Journey to the Earth’s Interior, which postulated a hollow earth with an interior sun 600 miles in diameter.
It’s unlikely that Burroughs read all of these — it is equally unlikely that he read none of them. Burroughs’ own library contained the fictional Through the Earth, published in 1898 and written by Clement Fezandie.
Erbzine is a good source for further reading: