At the Earth’s Core

At the Earth’s Core, published in 1914, is the first of a series of science fiction novels written by Edgar Rice Burroughs set inside a hollow earth with a central “sun,” a land called Pellucidar. However unlikely this scenario, it allowed Burroughs free play to create heroic adventures in yet another alien environment in addition to his fantastic version of Mars in his Martian series. The story’s hero, David Innes, is recruited by an old man, Perry, to help fund his invention, a “mechanical subterranean prospector,” and then to test it out.