The Hollow Earth Series by Rudy Rucker

In 1836, Mason Algiers Reynolds leaves his family's Virginia farm with his father's slave, a dog, and a mule. Branded a murderer, he finds sanctuary with his hero, Edgar Allan Poe, and together they embark on an expedition to the South Pole. It is there where strange people, and stranger creatures abound, that their bizarre adventures truly begin.

Two mind-stretching steampunk SF novels in one volume.(1) "The Hollow Earth," now in its third edition. Our young narrator Mason Reynolds leaves his farm, befriends the dissolute Edgar Allan Poe, and falls through a thousand-mile hole in the ice of Antarctica. Astounding adventures in the Hollow Earth ensue. Mason finds Seela, the love of his life.  Mason, Seela and Poe make their way back to surface. And then they encounter Poe's double.. moreTwo mind-stretching steampunk SF novels in one volume.(1) "The Hollow Earth," now in its third edition. Our young narrator Mason Reynolds leaves his farm, befriends the dissolute Edgar Allan Poe, and falls through a thousand-mile hole in the ice of Antarctica. Astounding adventures in the Hollow Earth ensue. Mason finds Seela, the love of his life.  Mason, Seela and Poe make their way back to surface. And then they encounter Poe's double...(2) "Return to the Hollow Earth" is Rucker's 2018 sequel to "The Hollow Earth" Our young hero Mason and his wife Seela embark on a return voyage to the Hollow Earth with Edgar Allan Poe, traversing a great maelstrom at the North Pole. The god-like sea cucumbers at the Earth's core have a startling plan. When Mason and Seela return to the Earth's surface, they're in Santa Cruz, California--in the year 2018... less