Richard Sharpe Shaver
Richard Sharpe Shaver published science fiction stories in pulp magazines from the late 1940’s to late 1950’s, mostly in Amazing Stories. Shaver’s stories dealt with a civilization living inside the earth. He used fiction to promote a theory he believed was true.
The following is from a segment on Shaver’s wikipedia page (link) under the title The Shaver Mystery:
“During 1943, Shaver wrote a letter to Amazing Stories magazine. He claimed to have discovered an ancient language he called "Mantong", a sort of Proto-Human language that was the source of all Earthly languages. In Mantong, each sound had a hidden meaning, and by applying this formula to any word in any language, one could decode a secret meaning to any word, name or phrase. Editor Ray Palmer applied the Mantong formula to several words, and said he realized Shaver was on to something.
According to Palmer (in his autobiography The Secret World), Palmer wrote back to Shaver, asking how he had learned of Mantong. Shaver responded with an approximately 10,000-word document entitled "A Warning to Future Man". Shaver claimed to have worked in a factory where, in 1932, odd things began to occur. As Bruce Lanier Wright notes, Shaver "began to notice that one of the welding guns on his job site, 'by some freak of its coil's field atunements', was allowing him to hear the thoughts of the men working around him. More frighteningly, he then received the telepathic record of a torture session conducted by malign entities in caverns deep within the earth". According to Michael Barkun, Shaver offered inconsistent accounts of how he first learned of the hidden cavern world, but that the assembly line story was the "most common version".[1]
Shaver wrote of extremely advanced prehistoric races who had built cavern cities inside the Earth before abandoning Earth for another planet due to damaging radiation from the Sun. Those ancients also abandoned some of their own offspring here, a minority of whom remained noble and human "Teros", while most degenerated over time into a population of mentally impaired sadists known as "Deros"—short for "detrimental robots". Shaver's "robots" were not mechanical constructs, but were robot-like due to their savage behavior.
These Deros still lived in the cave cities, according to Shaver, kidnapping surface-dwelling people by the thousands for meat or torture. With the sophisticated "ray" machinery that the great ancient races had left behind, they spied on people and projected tormenting thoughts and voices into our minds (reminiscent of schizophrenia's "influencing machines" such as the air loom). Deros could be blamed for nearly all misfortunes, from minor "accidental" injuries or illnesses to airplane crashes and catastrophic natural disasters. Women especially were singled out for brutal treatment, including rape, and Mike Dash notes that "[s]ado-masochism was one of the prominent themes of Shaver's writings".[2] Though generally confined to their caves, Shaver claimed that the Deros sometimes traveled with spaceships or rockets, and had dealings with equally evil extraterrestrial beings. Shaver claimed to possess first-hand knowledge of the Deros and their caves, insisting he had been their prisoner for several years.”
Rock Books
Later in life Mr. Shaver took up photography. He photographed rock segments, then outlined and colored over the prints to reveal thier hidden stories. He believed these stories told the history of a lost civilization.
He explains his process here:
Shaverton.com is a cool relic of the old internet with a lot if information on Richard Shaver, his art, and his theories. (link)