The Antikythera device -- a triumph of ancient Greek technology

"Anti-kythera" isn't the negation of some obscure cosmic force. It's a Greek island where the first ancient shipwreck was discovered and recovered at the beginning of the 20th century.

The device is one of the ancient wonders, even though it's in pretty rough shape.

As USA Today's article says, referring to a newly published study in the prestigious journal Nature:

With one dial in front and two in back, the hand-cranked device replicated cycles of the sun and moon's appearances in the sky over a repeating 76-year pattern, the study suggests, as well as the planets' motion. The reconstruction supersedes an older, simpler model of the mechanism and shows the ancient Greeks invented differential gears and miniaturized mechanisms in ways unseen until the Renaissance.

Here's what it may have looked like (leaving out the wooden case):

The new study results from some more sophisticated x-ray tomography and digital imaging, and shows the corroded device originally had 30 hand-cut differential gears.

This reminds me of Watt, who was an instrument maker for a university lab in Scotland before he devised his radically improved steam engine.

The articles noted above have a number of interesting links.