From: J. V. Field [mailto:[log in to unmask]]
Sent: 13 October 2005 22:40
A new reconstruction of the Antikythera mechanism
The Antikythera mechanism makes an appearance in histories of science and technology as providing a glimpse of an Ancient hi tech tradition. However, because the gearing is so complicated, detailed accounts tend to appear in journals addressed to specialists in horology. So readers of this list may like to be alerted to the fact that a new, complete reconstruction of the Antikythera mechanism has now been proposed, and will be presented at a conference on Ancient Greek technology in Athens on 20 October (details of the conference are given at www.emaet.tee.gr). The reconstruction is by Michael Wright (Imperial College, University of London). The official summary of his paper is appended.
The new reconstruction is based on a set of tomographic radiographs made between 1991 and 1994, in collaboration with Allan Bromley (Sydney), who died in 2002. The resolution of the radiographs is about the same as the size of the particles of corrosion products that make up the fragments of the object.
Derek Price's main thesis, in 'Gears from the Greeks' (_Transactions of the American Philosophical Society_, New Series, 64 (7),1974), was that a tradition of making mathematical gearing existed in the Ancient World and historians had been condescending in their interpretations of texts. This thesis is not in dispute. However, the details of Price's reconstruction are open to question, particularly in view of extra detail revealed by the use of tomography.
Wright has been making a brass working model as his research progressed, and has published a number of papers. The most recent describes the epicyclic gearing that Price (working from ordinary radiographs) had interpreted as a differential gear. Wright argues that the lower back dial, whose use Price did not explain, was used to predict eclipses (M. T Wright, 'Epicyclic Gearing and the Antikythera Mechanism', _Antiquarian Horology_, 29 (1) (September 2005), 51 - 63).
Further details of the reconstruction and of publications may be obtained from Wright (Michael Wright <[log in to unmask]>).
J. V. Field
Birkbeck College, University of London
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Summary of invited lecture for conference "Ancient Greek Technology, Athens, October 2005. Understanding the Antikythera Mechanism
M. T. Wright, Centre for the History of Science, Technology and Medicine, Imperial College, London.
A project to examine the detailed mechanical arrangement of the original fragments of the Antikythera Mechanism, with a view to establishing the instrument's true character and function, is nearing its successful conclusion.
With the help of staff at the National Museum, data was collected during several campaigns of direct visual examination, photography and radiography. The amount of fine detail visible to the trained eye, the high resolution of the many radiographs prepared, and the success with which the technique of linear tomography was applied in determining the arrangement of internal details in depth, led to the accumulation of a great mass of useful material. Its analysis has been greatly assisted by the application of computer-aided techniques to digitized images. It is now possible to describe all the surviving mechanical detail, and its arrangement, with considerable confidence, and to explain most of it.
The work of analysis has gone hand-in-hand with the construction of a model of the instrument, sufficiently close to the original in dimensions, material and workmanship to act as a practical test of the understanding that was being developed. Initially the model served mainly to demonstrate that the perceived arrangement was workable, but it has also proved to be a powerful tool in conveying an appreciation of the instrument to others.
The publication in any direct traditional form of a detailed description of this complex artefact, involving a high density of technical detail and relying heavily on radiographic evidence, is peculiarly difficult. Developments in information engineering, offering new possibilities for visual presentation, are being explored. However, a growing understanding of the coherence of the evidence prompted the decision to present a new reconstruction of the instrument as an early priority. Most features identified within the fragments can now be named and described according to their demonstrable functions; and others that are found to have no clear function provide evidence of adaptation and modification of the instrument during its useful life. Papers on several aspects of the instrument have now been published and further papers are forthcoming. Preparation of a written account of the detailed evidence is also well advanced. It is however perceived that, for historians of technology in general, the conclusions of this study are of far greater interest than the evidence on which they are based.
Further investigation of the fragments will doubtless reveal more information, and new imaging techniques should make it easier to present an attractive image of what remains. There is however little further understanding of the instrument as a whole to be got through looking more closely at the fragments themselves. Such an appreciation can be gained only through the exercise of an informed imagination, in seeing what is lost.
It is time for the historian of technology to move away from the state of denial, in which the imagined difficulty of conceiving and making such an instrument without modern aids, and the uniqueness of its survival, are all too often seen as stumbling-blocks, and to make intelligent use of what the artefact has to tell us: that there was indeed a Hellenistic tradition of elaborate instruments of this type, illustrating astronomical theory and perhaps dedicated to other purposes, just as the literary references should have led us to expect.