Already in 1871,
Edward Bulwer-Lytton speculated about The Coming Race in one of the very first sci-fi novels. An ante-deluvian civilisation lives underground, but once they’ll run out of space there, they will return to the surface and wipe out mankind…
Sadly, it’s much more likely that we’ll do that by ourselves – with the invention of androids.
Auguste Villier de l’Isle-Adam writes about L’Eve Future, a female android made by Edison, that (who?) ends up with an English lord.
Don Sindulfo, the inventor of the Anacronópete, is not giving it up. Instead, he takes it to Granada in 1492, to Pompeii before the eruption, and many other places of historic importance. This delightful novel by