# Antikythera Mechanism > Unidentified Hellenistic astronomer-engineer (workshop tradition disputed) - Disputed. Proposed dates for construction range from c. 205 BC to the early first century BC. The Hellenic Ministry of Culture and Sports gives a working range of c. 150-100 BC. This is a separate question from the date of the shipwreck that carried it, which independent archaeological evidence places at c. 70-60 BC. > Canonical HTML: https://iconotheca.com/artworks/antikythera-mechanism-maker/antikythera-mechanism-nama/ > Published by Servola Systems GmbH. Last verified: 2026-08-18 ## Tombstone - **Artist:** Unidentified Hellenistic astronomer-engineer (workshop tradition disputed) - **Date:** Disputed. Proposed dates for construction range from c. 205 BC to the early first century BC. The Hellenic Ministry of Culture and Sports gives a working range of c. 150-100 BC. This is a separate question from the date of the shipwreck that carried it, which independent archaeological evidence places at c. 70-60 BC. - **Medium:** Cast and hand-cut bronze (gear wheels, plates, dial faces, pointers and axles), originally mounted in a wooden case with bronze cover plaques front and back - **Dimensions:** 82 surviving fragments. The largest, Fragment A, has a maximum dimension of 17.7 cm and carries 27 of the mechanism's 30 surviving gears; Fragment B measures 11.8 cm and Fragment C 10.5 cm. The wooden case is estimated, from corrosion traces and fittings, at approximately 33 x 18 x 10 cm. No original weight is recorded, and the case does not survive intact. - **Object type:** Clocks and instruments - **Period:** Hellenistic Greek - **Current location:** National Archaeological Museum, Athens (NAMA), Collection of Bronzes, permanent Antikythera Shipwreck exhibition - **Attribution:** disputed ## Summary What survives is 82 corroded bronze fragments, salvaged by Symi sponge divers and the Hellenic Navy from a Roman-era shipwreck off the island of Antikythera in 1900-1901 and sitting largely unexamined in the National Archaeological Museum of Athens for half a century afterward. Inside the corrosion, radiography by Derek de Solla Price in the 1970s and computed tomography by the Antikythera Mechanism Research Project in 2005-2006 found a geared calculating machine: 30 surviving bronze gears driving dials that tracked the sun, the moon's true irregular motion, the 19-year lunisolar calendar cycle, eclipse prediction across the 223-month Saros cycle, and the four-year rhythm of the Panhellenic games. Nothing else of comparable mechanical sophistication survives from anywhere in the ancient world.Who built it, and exactly where, remains argued rather than settled: the astronomical design has been traced to a Rhodian tradition associated with the astronomer Geminus and, through Cicero's testimony, the Stoic philosopher Posidonius, while the calendar inscribed on its dials has been read first as Corinthian-Syracusan and more recently, more persuasively, as Epirote. The two need not conflict, and this record states both positions and names who holds each rather than picking one. A 2021 reconstruction proposing a full planetary display on the mechanism's ruined front face is presented here as a contested hypothesis, not an established design.What is not in dispute is custody. Unlike almost everything else catalogued in this publication, the mechanism has never been sold, exported or privately owned: it has been Greek state property, without interruption, since the day it came up from the sea. ## Provenance Every link carries a grade. `documented` means a cited source supports it, `disputed` means the identification is argued but not established, `unknown` means we have no owner for that span and have not bridged it. - **c. 205-100 BC (disputed)-c. 70-60 BC** Unknown maker and unknown subsequent owner(s) `[disputed]` (manufacture and use) Manufacture date, place and maker are all disputed; see attribution and open_questions. Nothing is known about who owned or used the instrument between its construction and its loss with the ship, a gap of unknown length that the shipwreck date does not close. - **c. 70-60 BC-1900** None (lost with the wreck) `[documented]` (loss) The ship carrying the mechanism, along with statuary, glassware, jewellery and a coin hoard, sank off the island of Antikythera. The wreck date rests on Rhodian and Koan amphorae and silver Pergamene tetradrachms minted 76-67 BC. - **1900-1901** Kingdom of Greece, via the Hellenic Royal Navy salvage operation `[documented]` (discovery and salvage) Discovered by Symi sponge divers under Captain Dimitrios Kontos sheltering from a storm; diver Elias Stadiatis first reported the wreck. The Greek state organized a formal, Navy-supported salvage running through 1900-1901 at c. 45 metres depth. The mechanism fragment was recovered probably in July 1901. - **1901-present** National Archaeological Museum, Athens (Greek state) `[documented]` (continuous custody) Transferred to NAMA immediately after salvage and never sold, exported, or privately owned. Recognized as a geared mechanism in 1902 (Valerios and Spyridon Stais); studied by Rehm and Svoronos in the following years; radiographed by Price and Karakalos, 1971-1973; CT- and PTM-imaged by the Antikythera Mechanism Research Project, 2005-2006; displayed with all 82 fragments together in a dedicated permanent gallery since 2013. ## Open questions - Where, and within which workshop or school, was the mechanism actually built? The astronomical design has been argued to Rhodes and the calendar to Epirus by way of a Corinthian colony; the two need not conflict, but neither is proven, and no third-party physical evidence (metallurgical sourcing of the bronze, for instance) has settled the question. - What was the front dial's full display, and did it show the five planets? The 2021 UCL reconstruction proposes a planetary 'Cosmos' gear train consistent with the surviving fragmentary evidence, but the gears that would prove it, if they ever existed, have not survived, and earlier, simpler reconstructions remain in the literature. - What was Fragment D for? Its 63-tooth gear has been proposed as part of a planetary train and, more recently, as part of a previously unidentified lunar-node ('draconic') gear train; the fragment's original position in the assembled mechanism is not established. - What is the mechanism's precise construction date? Published proposals range across more than a century, from c. 205 BC to the early first century BC, and the shipwreck date does not resolve this because the object could have been decades old when it sank. - Was the mechanism cargo, being shipped for sale or as a diplomatic gift alongside the statuary and luxury goods recovered from the same wreck, or was it a personal possession of someone travelling on the ship? Nothing in the published record distinguishes these possibilities. - Do more fragments of this mechanism, or a second comparable instrument, remain at the wreck site? The Return to Antikythera project has recovered further artifacts in most seasons since 2012 and has suggested the debris field may include a second wreck, but no further mechanism components have been confirmed as of the most recently published results. ## Sources - [1] Wikipedia, 'Antikythera mechanism'. Tertiary source consolidating the research history; flagged for replacement with the primary AMRP publications and Jones 2017 where those are cited directly elsewhere in this record. - [2] Wikipedia, 'Antikythera wreck'. Tertiary source for the shipwreck discovery and dating; flagged for replacement with the excavation reports of the Hellenic Ephorate of Underwater Antiquities. - [3] Hellenic Ministry of Culture and Sports, official page on the Antikythera Mechanism, giving inventory number X 15087, working construction date c. 150-100 BC, and case dimensions. - [4] Woods Hole Oceanographic Institution, 'Return to Antikythera' project, History page, on the modern (2012-present) return expeditions to the wreck site led with the Hellenic Ministry of Culture and Sports and Brendan Foley. - [5] Freeth, T., Bitsakis, Y., Moussas, X. et al., 'Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism', Nature 444, 587-591 (2006). - [6] Freeth, T., Jones, A., Steele, J.M. and Bitsakis, Y., 'Calendars with Olympiad display and eclipse prediction on the Antikythera Mechanism', Nature 454, 614-617 (2008). - [7] Freeth, T., Higgon, D., Dacanalis, A. et al., 'A Model of the Cosmos in the ancient Greek Antikythera Mechanism', Scientific Reports 11, 5821 (2021). - [8] Iversen, P.A., 'The Calendar on the Antikythera Mechanism and the Corinthian Family of Calendars', Hesperia 86.1 (2017), pp. 129-203. - [9] Review of Alexander Jones, 'A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World' (Oxford University Press, 2017), Bryn Mawr Classical Review 2018.05.16. - [10] Price, D.J. de Solla, 'An Ancient Greek Computer', Scientific American 200.6 (June 1959), pp. 60-67. Consulted via full-text archive. - [11] Voulgaris, A., Mouratidis, C. and Vossinakis, A., 'The Draconic gearing of the Antikythera Mechanism: Assembling the Fragment D, its role and operation', arXiv:2104.06181 (2021). - [12] Wikipedia, 'Antikythera Ephebe'. Tertiary source used only for confirming that this statue was recovered from the same wreck as the mechanism; flagged for replacement with the NAMA catalogue entry. - [13] Field, J.V. and Wright, M.T., 'Gears from the Byzantines: A portable sundial with calendrical gearing', Annals of Science 42.2 (1985), pp. 87-138. --- Images on this record are public domain or CC0 and are hosted by us. No image on this site is generated or simulated. If you quote this record, quote the provenance grades with it.