The Smoky God, or, a voyage to the inner world

Willis George Emerson wrote the Smoky God in 1908. It is subtitled A Voyage to the Inner Earth. Olaf Jansen was a Norwegian sailor who sailed his sloop though an entrance near the North Pole to the earth's interior. This novel is an early example of an underground civilization. Jansen spent two years living with the inhabitants in a network of subterranean colonies. A smoky central sun lighted the world. Their capital city was believed to be the original Garden of Eden.