Though it it seemed to be just acorroded lump of some sort when it was found in a shipwreck off the coast of Greece near Antikythera in 1900, in 1902 archaeologist Valerios Stais, looking at the gear embedded in it, guessed that what we now call the “Antikythera mechanism” was some kind of astronomy-based clock. He was in the minority—most agreed that something so sophisticated must have entered the wreck long after its other 2,000-year-old artifacts. Nothing like it was believed to have existed until 1,500 years later.
In 1951, British historian Derek J. de Solla Price began studying the find, and by 1974 he had worked out that it was, in fact, a device from 150 to 100 BC Greece. He realized it used meshing bronze gears connected to a crank to move hands on the device’s face in accordance with the Metonic cycle, the 235-month pattern thatancient astronomers used to predict eclipses.