A Portable Cosmos: revealing the Antikythera Mechanism, scientific wonder of the ancient world

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A Portable Cosmos

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A Portable Cosmos

Revealing the Antikythera Mechanism,

Scientific Wonder of the Ancient World

ALEXANDER JONES

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Oxford University Press is a department of the University of Oxford. It furthers

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© Oxford University Press 2017

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Library of Congress Cataloging-in-Publication Data

Names: Jones, Alexander, author.

Title: A portable cosmos: revealing the Antikythera Mechanism, scientific

wonder of the ancient world / Alexander Jones.

Description: New York, NY: Oxford University Press, 2017.

Identifiers: LCCN 2016045108 | ISBN 9780199739349 (hardback)

Subjects: LCSH: Antikythera mechanism (Ancient calculator) |

Astronomy, Ancient—Greece. | Calendar, Greek. | Science—Greece—History—To 1500. |

Technology—Greece—History—To 1500. | Greece—Intellectual life—To 146 B.C. |

Greece—Antiquities. | Antikythera Island (Greece)—Antiquities. | BISAC: HISTORY /

Ancient / Greece.

Classification: LCC QB107 .J65 2017 | DDC 681.1/11—dc23

LC record available at https://lccn.loc.gov/2016045108https://lccn.loc.gov/2016045108

9 8 7 6 5 4 3 2 1

Printed by Sheridan Books, Inc., United States of America

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For Elizabeth and Martin Jones

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Contents

Preface  ix

Acknowledgments xiii

1. The Wreck and the Discovery  1

2. The Investigations  16

3. Looking at the Mechanism  47

4. Calendars and Games  63

5. Stars, Sun, and Moon  95

6. Eclipses  128

7. The Wanderers  161

8. Hidden Workings  200

9. Afterword: The Meaning of the Mechanism  233

Glossary  247

Notes  253

Bibliography  269

Index  281

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Preface

In the name of his master Theoderic, king of the Ostrogoths,

Cassiodorus wrote a letter to the philosopher Boethius about AD

506, commissioning him to arrange to have two time-telling devices

made, a sundial and a water clock; they were to be a present to dazzle

Gundobad, the king of the Burgundians.1

A rhetorical manner was

expected in such official correspondence, and Cassiodorus expands

floridly on the astonishing works of which the mechanical art is capa￾ble:  it can raise water, move fire, cause the organ to make music,

defend cities, drain flooded buildings, and fashion sounding effigies

of singing birds and hissing snakes. Nay, it even creates a means of

imitating the heavens with no risk of impiety, through something

called the “sphere of Archimedes,” in which the mechanical art

has made a second Sun take its course; it has fashioned

another zodiacal circle by human cogitation; it has shown

the Moon restored from its eclipse by the light of the art—

it has set in revolution a little machine, pregnant with the

cosmos, a portable sky, a compendium of all that is, a mir￾ror of nature, in the image of the ether in its unimaginable

mobility.…What a thing it is for a human being to make

this thing, which can be a marvel even to understand!

Perhaps a still greater marvel is that a specimen of such a portable

cosmos, which Cassiodorus had probably read about only in books,

was found a little over a century ago off the small Greek island of

Antikythera, where it had been lost 2000 years ago in a shipwreck. It

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may now be seen on public display in the National Archaeological Museum in

Athens, bearing the inventory number X 15087.

During the first half century following its discovery, hardly anyone even

in the scholarly world had heard of the Antikythera Mechanism. News reports,

magazine articles, and television documentaries have now rendered these

tiny fragments of bronze plate, bristling with gears and inscribed texts, one of

the most familiar artifacts from the ancient Greek world. Much of this recent

attention has focused on the technologies applied to studying the Mechanism’s

fragmentary remains, and on the personalities of the researchers. By now the

enigmas of what it did and how it worked are largely solved. Yet the impres￾sion is still widely held that the Mechanism is a thing mysteriously foreign to

Greco-Roman civilization as we know it, echoing Derek de Solla Price’s 1959

statement that “from all we know of science and technology in the Hellenistic

age [late fourth to late first centuries BC] we should have felt that such a device

could not exist.”2

I hope that this book will convince the reader that this impression is false.

The Mechanism does indeed represent a level of technology exceeding any￾thing else of the kind for which we have either physical remains or detailed

descriptions from antiquity, but the devices it employed were a plausible exten￾sion of simpler inventions that we do know about. This technology was applied

to displaying a profusion of astronomical and time-related functions, all of

which were grounded in ancient Greek science. They would, with a little guid￾ance from the Mechanism’s operator, have been meaningful to an educated

layman of the day, because they connected in diverse ways with Hellenistic

society and with the prevailing understanding of cosmology and the physical

environment. Changing one word in the title of Price’s classic monograph on

the Mechanism, Gears from the Greeks, we could fairly describe the Mechanism

as “Gears for the Greeks.”

The story of how the Mechanism was found and how we have come

to know as much as we do about it is told in the first two chapters of this

book. We would not have had this singular object to study had it not been

for repeated instances of foresight, persistence, and luck, starting with a

team of sponge divers’ chance discovery of an ancient shipwreck in a part of

the sea where they would not normally have been working, and the vision

of a financially straitened government to fund an unprecedented undersea

salvage operation, and to continue it well after the pace of “big” finds had

slowed down. The investigation of the shattered and corroded fragments was

a gradual, interdisciplinary process, involving the efforts of archeologists,

historians, scientists, and technicians, and culminating by late 2006 in a

reconstruction of much of its appearance and workings. This reconstruction

was supported by extensive evidence and internal consistency, and, with very

slight modifications, it has earned the acceptance of the entire community of

researchers on the Mechanism.

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The rest of this book takes this reconstruction as its starting point and

seeks to make sense of the Mechanism as a product of its world, going from

outside in. Chapter 3 provides a general picture of what the Mechanism looked

like and how it operated, from the point of view of a nonexpert observer, when

it was intact. Chapters 4 through 7 explore contexts of ancient astronomy and

its cultural role and applications that relate to the displays and functions that

were on the Mechanism’s outside, while the Mechanism’s inner workings and

their background in the Greco-Roman technology of practical instruments and

wonder-working devices are the subject of chapter 8. The book closes with a

tentative exploration of the broader tradition of astronomical mechanisms in

antiquity and the impact they may have had on ancient thought.

A prominent theme of my book is the public face of Greek astronomy in

the Hellenistic period: the numerous ways in which specialists and populariz￾ers sought to make the science visible, intelligible, and relevant to the layman.

Following their example, I have tried to explain the astronomy and technol￾ogy behind the Mechanism by using a minimum of specialized jargon and

assuming no more than grade-school science. The central chapters on the

Mechanism’s displays and gearwork are more thematic than cumulative, and it

should not be necessary for the reader to absorb the more technical discussions

in full detail in order to follow my main lines of argument. A glossary at the end

provides brief explanations of key terms.

Fruitful work continues to be done on many aspects of the Mechanism, but

with respect to the largest questions we probably now have learned what we can

learn from the known fragments. There remains the prospect that more frag￾ments may be found. The sponge divers who salvaged the Antikythera ship￾wreck in 1900–1901 brought up only part of the Mechanism, comprising what

may have been little more than half the internal gearwork and a much smaller

fraction of the exterior with its dials and inscriptions. All they would have seen

was a piece or pieces of corroded metal, which was all that they had to notice to

make this an item worth picking up, and they had neither the training nor the

time to record where they found it. Jacques Cousteau and Frédéric Dumas dove

briefly at the shipwreck site in 1953, and Cousteau returned in 1976 in a col￾laboration with the Greek Institute of Marine Archeology, but new fragments

of the Mechanism were not among the objects that they recovered. In 2012,

a team of divers of the Hellenic Ephorate of Underwater Antiquities and the

Woods Hole Oceanographic Institution began surveying the wreck site, using

up-to-date methods and technology, and in 2014 they began a new, multiyear

scientific excavation of the wreck. Finding more pieces of the Mechanism is not

their primary goal, and it may seem a long shot, but if there still are significant

pieces of bronze gears, dial plates, or pointers on the sea bottom, their under￾water metal detectors stand a good chance of locating them. The excavations

will in any event tell us much more than we now know about the voyage on

which the Mechanism was lost to its ancient owner and saved for us.

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Acknowledgments

Like all students and admirers of the Antikythera Mechanism, I am

indebted in the first instance to the National Archaeological Museum

for its stewardship of the delicate fragments since their discovery, and

for encouraging and facilitating the work of a succession of research￾ers. I am also deeply grateful to the Antikythera Mechanism Research

Project (AMRP) for inviting me to join in their ongoing research fol￾lowing the publication of their first results in late 2006. Among the

original members of the AMRP team, I have especially profited from

exchanges with Mike Edmunds, John Seiradakis, Xenophon Moussas,

Tony Freeth, Yanis Bitsakis, Agamemnon Tselikas, Tom Malzbender,

Andrew Ramsey, and Mary Zafeiropoulou, and among those who

(like me) joined later, John Steele and Magdalini Anastasiou. I have

also gained enormously from conversations and correspondence

with other scholars working on the Mechanism: first and foremost

Michael Wright, and also James Evans, Christián Carman, Paul

Iversen, and John D. Morgan. Brendan Foley has generously shared

news of the ongoing archeological surveying and excavation at the

Antikythera shipwreck site.

For access to archival materials, I  thank the National Archaeo￾logical Museum; the Historical Archive of Antiquities and Monu￾ments (Hellenic Ministry of Culture and Sports, National Archive

of Monuments); the National Hellenic Research Foundation; the

Bayerische Staatsbibliothek, Munich; the archives of the Athens

Department and Berlin Office of the Deutsches Archäologisches Institut;

the Antikensammlung, Staatliche Museen zu Berlin Preussischer

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Kulturbesitz; the Archivzentrum of the Goethe Universität, Frankfurt am Main;

the Adler Planetarium, Chicago; and the heirs of Derek de Solla Price.

Stefan Vranka, my editor with the Oxford University Press (OUP), suggested

in 2009 that I should write a book presenting the Antikythera Mechanism as

a gateway to exploring broader aspects of ancient science and society, and he

showed astonishing patience with a project that I repeatedly put off until I felt

that the groundwork of current research was firm enough to build on. Mike

Edmunds and OUP’s anonymous reader gave me long and very helpful lists of

suggestions for improving the first draft.

My profoundest gratitude remains to my wife, Catherine Haines, my

book’s first and most supportive reader.