At the Earth's Core is a 1914 fantasy novel by Edgar Rice Burroughs, the first in his series about the fictional "hollow earth" land of Pellucidar. It first appeared as a four-part serial in All-Story Weekly from April 4–25, 1914. It was first published in book form in hardcover by A. C. McClurg in July, 1922.
Short summary:
The author relates how, traveling in the Sahara desert, he has encountered a remarkable vehicle and its pilot, David Innes, a man with a remarkable story to tell.

A Princess of Mars (1917) is a science fantasy novel by Edgar Rice Burroughs, the first of his Barsoom series. Full of swordplay and daring feats, the novel is considered a classic example of 20th century pulp fiction. It is also a seminal instance of the planetary romance, a sub-genre of science fantasy that became highly popular in the decades following its publication. Its early chapters also contain elements of the Western. The story is set on Mars, imagined as a dying planet with a harsh desert environment. This vision of Mars was based on the work of the astronomer Percival Lowell, whose ideas were widely popularized in the late 19th and early 20th centuries.

The World Set Free is a novel written in 1913 and published in 1914 by H. G. Wells. The book is based on a prediction of nuclear weapons of a more destructive and uncontrollable sort than the world has yet seen. It had appeared first in serialised form with a different ending as A Prophetic Trilogy, consisting of three books: A Trap to Catch the Sun, The Last War in the World and The World Set Free.
A frequent theme of Wells's work, as in his 1901 nonfiction book Anticipations, was the history of humans' mastery of power and energy through technological advance, seen as a determinant of human progress. The novel begins: "The history of mankind is the history of the attainment of external power. Man is the tool-using, fire-making animal. . . . Always down a lengthening record, save for a set-back ever and again, he is doing more." (Many of the ideas Wells develops here found a fuller development when he wrote The Outline of History in 1918-1919.) The novel is dedicated "To Frederick Soddy's Interpretation of Radium," a volume published in 1909.

In his final years he aspired to publish his fringe beliefs. Here is the cover of his loon-tastic 84-page “handbook of the Millennium” The White Spark (1920)…

Pellucidar is a fictional Hollow Earth milieu invented by Tarzan creator Edgar Rice Burroughs for a series of action adventure stories. In a notable crossover event between Burroughs' series, there is a Tarzan story in which the Ape Man travels into Pellucidar.
The stories initially involve the adventures of mining heir David Innes and his inventor friend Abner Perry after they use an "iron mole" to burrow 500 miles into the Earth's crust. Later protagonists include indigenous cave man Tanar and additional visitors from the surface world, notably Tarzan, Jason Gridley, and Frederich Wilhelm Eric von Mendeldorf und von Horst.

Peter Cotterell’s Treasure (1922) This book, re-edited and illustrated by e-kitap projesi and published again in ebook format. In this book, telling that Cooterell’s adventures, and so was a treasure adventure, Naturally then Ben felt that this puzzle of Peter Cotterell’s treasure was right in his line, and the finding of the half-sheet of parchment whetted his appetite to discover more. He walked about the room, whittling shavings right and left, he sat down and kept on whittling, he stood up again, and since by now the willow-stick had been whittled down to almost nothing, he threw what was left in the fireplace. That done, he went to a bookcase and took down from the shelf on top the old notebook that Tuckerman had found in his uncle’s bedroom. He shook his head in deep thought. “I don’t understand why that piece of parchment wasn’t discovered before. Probably it didn’t tell them any more than it’s told us so far.”

So I had a headache. The grandfather of all headaches. You try working on the roof line sometime, with the presses grinding and the overhead cranes wailing and the mechanical arms clacking and grabbing at your inner skull while you snap a shiny sheet of steel like an armored pillowcase and shove it into the maw of a hungry greasy ogre. Noise. Hammering, pounding, shrieking, gobbling, yammering, incessant noise. And I had a headache.

This fourth novel of Boothby's Dr. Nikola series reveals that Nikola has discovered all of the facts necessary to extend a human being's life. He has studied science and magic secrets of Tibetan monks. He explains:
"It has been a long and tedious search, but such labour only makes success the sweeter. The machinery is now prepared; all that remains is to fit the various parts together. In six months' time, if all goes well, I will have a man walking upon this earth who, under certain conditions, shall live a thousand years."

Alan Thurston was an immunologist at Midwestern University Medical School. Like most men in the teaching trade, he also had a research project. If it worked out, he'd be one of the great names in medicine; like Jenner, Pasteur, and Salk.

But it didn't work. Quite the opposite . . . he created a disease the ravaged the human race.

When does life begin?... A well-known book says "forty". A well-known radio program says "eighty". Some folks say it's mental, others say it's physical. But take the strange case of Mel Carlson who gave a lot of thought to the matter.