Editing Antikythera mechanism (section)

== Design ==

The original mechanism apparently came out of the Mediterranean as a single encrusted piece. Soon afterwards it fractured into three major pieces. Other small pieces have broken off in the interim from cleaning and handling,<ref name="marchant-06-01"/> and others were found on the sea floor by the Cousteau expedition. Other fragments may still be in storage, undiscovered since their initial recovery; Fragment F was discovered in that way in 2005. Of the 82 known fragments, seven are mechanically significant and contain the majority of the mechanism and inscriptions. Another 16 smaller parts contain fractional and incomplete inscriptions.<ref name=freeth-06/><ref name=freeth-08/><ref name=wright-07/>

{| class=wikitable
|+ Major fragments
!Fragment
!Size [mm]
!Weight [g]
!Gears
!Inscriptions
!Notes
|- align=center
| A ||180&nbsp;×&nbsp;150 ||369.1 ||27 ||Yes
| style="text-align:left" | The main fragment contains the majority of the known mechanism. Clearly visible on the front is the large b1 gear, and under closer inspection further gears behind it (parts of the l, m, c, and d trains are visible as gears to the naked eye). The crank mechanism socket and the side-mounted gear that meshes with b1 is on ''Fragment A''. The back of the fragment contains the rearmost e and k gears for synthesis of the moon anomaly, noticeable also is the pin and slot mechanism of the k train. It is noticed from detailed scans of the fragment that all gears are very closely packed and have sustained damage and displacement due to their years in the sea. The fragment is approximately 30&nbsp;mm thick at its thickest point.

Fragment A also contains divisions of the upper left quarter of the Saros spiral and 14 inscriptions from said spiral. The fragment also contains inscriptions for the exeligmos dial and visible on the back surface the remnants of the dial face. Finally, this fragment contains some back door inscriptions.
|- align=center
| B ||125&nbsp;×&nbsp;60 ||99.4 ||1 ||Yes
| style="text-align:left" | Contains approximately the bottom right third of the Metonic spiral and inscriptions of both the spiral and back door of the mechanism. The Metonic scale would have consisted of 235 cells of which 49 have been deciphered from fragment B either in whole or partially. The rest so far are assumed from knowledge of the [[Metonic cycle]]. This fragment also contains a single gear (o1) used in the Olympic train.
|- align=center
| C ||120&nbsp;×&nbsp;110 ||63.8 ||1 ||Yes
| style="text-align:left" | Contains parts of the upper right of the front dial face showing calendar and zodiac inscriptions. This fragment also contains the Moon indicator dial assembly including the Moon phase sphere in its housing and a single bevel gear (ma1) used in the Moon phase indication system.
|- align=center
| D ||45&nbsp;×&nbsp;35 ||15.0 ||1 ||
| style="text-align:left" | Contains at least one unknown gear; according to [[Michael T. Wright (curator)|Michael T. Wright]] it contains possibly two, and according to Xenophon Moussas<ref name="Auto82-30"/><ref name="auto"/> it contains one gear (numbered 45 "ME") inside a hollow gear giving the position of Jupiter reproducing it with epicyclic motion. Their purpose and position has not been ascertained to any accuracy or consensus, but lends to the debate for the possible planet displays on the face of the mechanism.
|- align=center
| E ||60&nbsp;×&nbsp;35 ||22.1 || ||Yes
| style="text-align:left" | Found in 1976 and contains six inscriptions from the upper right of the Saros spiral.
|- align=center
| F ||90&nbsp;×&nbsp;80 ||86.2 || ||Yes
| style="text-align:left" | Found in 2005 and contains 16 inscriptions from the lower right of the Saros spiral. It also contains remnants of the mechanism's wooden housing.
|- align=center
| G ||125&nbsp;×&nbsp;110 ||31.7 || ||Yes
| style="text-align:left" | A combination of fragments taken from fragment C while cleaning.
|}

Many of the smaller fragments that have been found contain nothing of apparent value, but a few have inscriptions on them. Fragment 19 contains significant back door inscriptions including one reading "...&nbsp;76 years&nbsp;..." which refers to the [[Callippic cycle]]. Other inscriptions seem to describe the function of the back dials. In addition to this important minor fragment, 15 further minor fragments have remnants of inscriptions on them.<ref name=freeth-06-1 />{{rp|7}}