On Jun 22, 1:26 am, Bob Cain arcanemethods.com> wrote:

It is fairly obvious to any of the experts examining the Antikythera
Machine that it is not a "one off" but the latest (by definition) in a
long series of such devices. One point to be made is that the shape of
the teeth is the same as Arab gears used and the differential gearing
of the AM is used to transform synodic months into sidereal months,
the same use such gears found in 16th century astronomical clocks.

"Cicero's De re publica, a 1st century BC philosophical dialogue,
mentions two machines that function as a planetarium or orrery,
predicting the movements of the Sun, the Moon, and the five planets.
The first device was built by Archimedes and brought to Rome by the
Roman general Marcus Claudius Marcellus after the death of Archimedes
at the siege of Syracuse in 212 BC. Marcellus had a high respect for
Archimedes and this was the only item he kept from the siege. The
device was kept as a family heirloom, and Cicero was shown it by
Gallus about 150 years later. Gallus gave a 'learned explanation' of
it and demonstrated it for Cicero.

hanc sphaeram Gallus cum moveret, fiebat ut soli luna totidem
conversionibus in aere illo quot diebus in ipso caelo succederet, ex
quo et in [caelo] sphaera solis fieret eadem illa defectio, et
incideret luna tum in eam metam quae esset umbra terrae, cum sol e
regione
When Gallus moved the globe, it happened that the Moon followed
the Sun by as many turns on that bronze [contrivance] as in the Earth
itself, from which also in the sky the Sun's globe became [to have]
that same eclipse, and the Moon came then to that position which was
[its] shadow [on] the Earth, when the Sun was in line.[9]

Pappus of Alexandria stated that Archimedes had written a now lost
manuscript on the construction of these devices entitled On Sphere-
Making.[10][11] The surviving texts from the Library of Alexandria
describe many of his creations, some even containing simple
blueprints. One such device is his odometer, the exact model later
used by the Romans to place their mile markers (described by Heron of
Alexandria and in the time of Emperor Commodus).[12] The blueprints 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. Whether this is an
example of a device created by Archimedes and described by texts lost
in the burning of the Library of Alexandria, or if it is a device
based on his discoveries, or if it has anything to do with him at all,
is debatable.

If Cicero's account is correct (and there is reason to doubt it) then
this technology existed as early as the 3rd 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 4th and 5th centuries.

Cicero also says 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..."[13]

It is unlikely that either of these machines were the Antikythera
mechanism found in the shipwreck, because both the devices mentioned
by Cicero were located in Rome at least 50 years later than the
estimated date of the shipwreck. So we know of three such devices. The
modern scientists who have reconstructed the Antikythera mechanism
also agree that it was too sophisticated to have been a one-off
device.

It is probable that the Antikythera mechanism was not unique, as shown
by Cicero's references to such mechanisms. This adds support to the
idea that there was an ancient Greek tradition of complex mechanical
technology that was later transmitted to the Islamic world, where
similarly complex mechanical devices were built by Muslim engineers
and astronomers during the Middle Ages. In the early 9th century, the
Banū Mūsā's Kitab al-Hiyal (Book of Ingenious Devices), commissioned
by the Caliph of Baghdad, describes over a hundred mechanical devices,
some of which may date back to ancient Greek texts preserved in
monasteries. Similarly complex astronomical instruments were
constructed by al-Biruni and other Muslim astronomers from the 11th
century.[14] Such knowledge could have yielded to or been integrated
with European clockmaking and medieval cranes.

#9 ^ M. TVLLI CICERONIS DE RE PVBLICA LIBER PRIMVS. Retrieved on
2007-03-23.
#10 ^ Spheres and Planetaria (Introduction)
# 11^ BBC NEWS | Science/Nature | Ancient Moon 'computer' revisited
# 12^ Needham, Volume 4, Part 2, 285.
# 13^ Cicero, De Natura Deorum II.88 (or 33-34). Retrieved on
2007-03-23.
# 14^ "In search of lost time" and "Archaeology: High tech from
Ancient Greece", Nature 444 (7119).