Editing Antikythera mechanism (section)

==Similar devices in ancient literature==

The level of refinement of the mechanism indicates that the device was not unique, and possibly required expertise built over several generations.<ref name=marchant-06/> However, such artefacts were commonly melted down for the value of the bronze and rarely survive to the present day.<ref name=marchant-06/>

=== Roman world ===

[[Cicero]]'s ''[[De re publica]] (54-51 BC)'', a first century BC philosophical dialogue, mentions two machines that some modern authors consider as some kind of [[planetarium]] or [[orrery]], predicting the movements of the [[Sun]], the [[Moon]], and the five planets known at that time. They were both built by [[Archimedes]] and brought to Rome by the Roman general [[Marcus Claudius Marcellus]] after the death of Archimedes at the [[Siege of Syracuse (214–212 BC)|siege of Syracuse]] in 212 BC. Marcellus had great respect for Archimedes and one of these machines was the only item he kept from the siege (the second was placed in the [[Temple of Honor and Virtue|Temple of Virtue]]). The device was kept as a family heirloom, and Cicero has Philus (one of the participants in a conversation that Cicero imagined had taken place in a villa belonging to [[Scipio Aemilianus]] in the year 129 BC) saying that [[Gaius Sulpicius Gallus]] (consul with [[Marcus Claudius Marcellus (consul 166 BC)|Marcellus's nephew]] in 166 BC, and credited by [[Pliny the Elder]] as the first Roman to have written a book explaining solar and lunar eclipses) gave both a "learned explanation" and a working demonstration of the device.

{{cquote|I had often heard this celestial globe or sphere mentioned on account of the great fame of Archimedes. Its appearance, however, did not seem to me particularly striking. There is another, more elegant in form, and more generally known, moulded by the same Archimedes, and deposited by the same Marcellus, in the Temple of Virtue at Rome. But as soon as Gallus had begun to explain, by his sublime science, the composition of this machine, I felt that the Sicilian geometrician must have possessed a genius superior to any thing we usually conceive to belong to our nature. Gallus assured us, that the solid and compact globe, was a very ancient invention, and that the first model of it had been presented by [[Thales of Miletus]]. That afterwards [[Eudoxus of Cnidus]], a disciple of [[Plato]], had traced on its surface the stars that appear in the sky, and that many years subsequent, borrowing from Eudoxus this beautiful design and representation, Aratus had illustrated them in his verses, not by any science of astronomy, but the ornament of poetic description. He added, that the figure of the sphere, which displayed the motions of the Sun and Moon, and the five planets, or wandering stars, could not be represented by the primitive solid globe. And that in this, the invention of Archimedes was admirable, because he had calculated how a single revolution should maintain unequal and diversified progressions in dissimilar motions.

When Gallus moved this globe, it showed the relationship of the Moon with the Sun, and there were exactly the same number of turns on the bronze device as the number of days in the real globe of the sky. Thus it showed the same eclipse of the Sun as in the globe [of the sky], as well as showing the Moon entering the area of the Earth's shadow when the Sun is in line&nbsp;... [missing text] [i.e. It showed both solar and lunar eclipses.]<ref name=cicero/>}}

[[Pappus of Alexandria]] (290 – {{circa|350 AD}}) stated that Archimedes had written a now lost manuscript on the construction of these devices titled ''On Sphere-Making''.<ref name=rorres-11/><ref name=fildes-10/> The surviving texts from ancient times describe many of his creations, some even containing simple drawings. One such device is his [[odometer]], the exact model later used by the Romans to place their [[mile marker]]s (described by [[Vitruvius]], [[Heron of Alexandria]] and in the time of Emperor [[Commodus]]).<ref name=needham/> The drawings in the text appeared functional, but attempts to build them as pictured had failed. When the gears pictured, which had square teeth, were replaced with gears of the type in the Antikythera mechanism, which were angled, the device was perfectly functional.<ref name=sleeswyk-81/>

If Cicero's account is correct, then this technology existed as early as the third century BC. Archimedes' device is also mentioned by later Roman era writers such as [[Lactantius]] (''Divinarum Institutionum Libri VII''), [[Claudian]] (''In sphaeram Archimedes''), and [[Proclus]] (''Commentary on the first book of Euclid's Elements of Geometry'') in the fourth and fifth centuries.

Cicero also said that another such device was built "recently" by his friend [[Posidonius]], "... each one of the revolutions of which brings about the same movement in the Sun and Moon and five wandering stars [planets] as is brought about each day and night in the heavens&nbsp;..."<ref name=cicero-1/>

It is unlikely that any one of these machines was the Antikythera mechanism found in the shipwreck since both the devices fabricated by Archimedes and mentioned by Cicero were located in Rome at least 30 years later than the estimated date of the shipwreck, and the third device was almost certainly in the hands of Posidonius by that date. The scientists who have reconstructed the Antikythera mechanism also agree that it was too sophisticated to have been a unique device.

=== Eastern Mediterranean and others ===
[[File:Clock Tower from Su Song's Book desmear.JPG|thumb|Su Song's Clock Tower]]

This evidence that the Antikythera mechanism was not unique adds support to the idea that there was an ancient Greek tradition of complex mechanical technology that was later, at least in part, transmitted to the Byzantine and [[Islamic Golden Age|Islamic worlds]], where mechanical devices which were complex, albeit simpler than the Antikythera mechanism, were built during the [[Middle Ages]].<ref name="charette-06" /> Fragments of a geared calendar attached to a sundial, from the fifth or sixth century [[Byzantine Empire]], have been found; the calendar may have been used to assist in telling time.<ref name="madison-85" /> In the Islamic world, [[Banū Mūsā]]'s ''[[Book of Ingenious Devices|Kitab al-Hiyal]]'', or ''Book of Ingenious Devices'', was commissioned by the [[Caliph of Baghdad]] in the early 9th century AD. This text described over a hundred mechanical devices, some of which may date back to ancient Greek texts preserved in [[Monastery|monasteries]]. A geared calendar similar to the Byzantine device was described by the scientist [[al-Biruni]] around 1000, and a surviving 13th-century [[astrolabe]] also contains a similar clockwork device.<ref name="madison-85" /> It is possible that this medieval technology may have been transmitted to Europe and contributed to the development of mechanical clocks there.<ref name="marchant-06" />

In the 11th century, Chinese polymath [[Su Song]] constructed a mechanical clock tower that told (among other measurements) the position of some stars and planets, which were shown on a mechanically rotated [[armillary sphere]].<ref name="Auto82-47"/>