[Socratic]

Although not nearly as noteworthy for it's scientific ground breaking, for sheer beauty one should check out Giovanni deDondi's astronomical clock. I have a book which relates the historical development of clocks and it devotes a large section to someone who built a replica of this, based upon the original drawings and specifications. I don't remember if this is the one which is in the Smithsonian Institution or not, but I sure would like to see it in person.

[SunkenCiv]

Casselman also sez, "Several kinds of evidence point incontrovertibly to around 80 B.C. for the date of the shipwreck." One of those bits of evidence is the accuracy of the mechanism. It's possible that the reason more of these haven't been found is that they ceased to be useful, and wound up getting used for other things. And of course, the ships could have gone down.