Tuesday, July 7, 2009

2009.07.14

Version at BMCR home site
Nicholas Nicastro, Circumference: Eratosthenes and the Ancient Quest to Measure the Globe. New York: St. Martin's Press, 2008. Pp. xi, 223. ISBN 9780312372477. $23.95.
Reviewed by T.E. Rihll, Swansea University, Wales, UK

[Table of contents at the end of the review.]

This book is not written for academics. It is more ambitious than its title: besides Eratosthenes, we meet all the famous scientists of the period, and beside ancient attempts to measure the globe, we are told about many of the famous achievements of ancient science. Having lamented (in the Preface) classicists' relative neglect of ancient scientists, Nicastro seems to want to rectify the situation by introducing as many of them as possible between the covers of this book. The intended readership is general, and the author's experience in writing novels is apparent throughout. Nicastro provides an easy introduction to ancient science in the Hellenistic era. Production quality is good. Most of the text is supported with notes at the back, and the notes identify the sources of quotes.

The book is divided into five chapters. The first describes Athens and Alexandria and sets the tone for the whole, conjuring up a picture of people going about their daily lives in two busy Greek ports. A huge amount of imagery is piled on. Between pages 1 and 3, for example, we meet reputable shipping companies, good profits, bulk exports, intellectuals as the most important exports from Athens, passengers pitching tents on the deck of merchant ships on which they bought passage, and smelly cities with buildings high enough to cut off the sunshine and street crime such as to deter residents going out at night. The ancient world thus brought to life is not a familiar one. The chapter ends with Eratosthenes' computation.

The second chapter is one of overviews: an overview of Greek astronomy in order to contextualise the astronomical assumptions necessary to Eratosthenes' method for calculating the circumference of the earth. Next is an overview of Alexander's successors, their names and territories, and the founding and growth of the city of Alexandria, to provide the temporal and spatial context. A sketch of the kingdom's resources follows, illustrating the extraordinary wealth at the Ptolemies' disposal in a few well-drawn brushstrokes.

In the third chapter Eratosthenes' hometown is the first focus, then attention switches to the place of books in Classical and Hellenistic Greece. This leads to the story of the founding of the library in Alexandria, and a discussion of its physical features and location, its librarians and its internal politics. Here a great deal of interpretation is superimposed on the flimsy evidence, sometimes 'illuminating' ancient Alexandria and its institutions by anachronistically modern lights. Eratosthenes himself takes centre stage next, and Nicastro makes clear the extraordinary range and scope of his work. Eratosthenes' 3D slide rule for finding cube roots creates the link for a discussion of the astonishing Antikythera mechanism and its discovery, where Nicastro's dramatic style is given full reign.

Chapter four opens with Greek stereotypes of themselves and of others. The stereotypes drawn are as much modern as ancient. Medea's murder of her children is cited as an example of an act arising from her uncontrollable passion (qua barbarian or woman is not clear; when such an act occurs in the modern world it is usually performed by the father and it has never, to my knowledge, been attributed to his uncontrollable passion; it is, on the contrary, considered heartless). Nicastro then focuses on the practicalities of gathering the data needed for the calculation of the circumference of the earth: verification that the sun was overhead at Syene at noon on the summer solstice, measurement of the angle of the sun at the same time in Alexandria, and the straight-line distance between Syene and Alexandria. It includes discussion of other ancient methods and results on the size of the world. In the last section Nicastro summarises the contents of Eratosthenes' lost Geography and his efforts at calculating the size and distance of the sun and moon from earth. This chapter concludes with an overview of political and military events about the time of his death, and an amusing account of Nicastro's trials and tribulations trying to perform the same sort observations and measurements that Eratosthenes did; his result was accurate to within 7%.

The last chapter covers ancient developments in the field after Eratosthenes. Claudius Ptolemy features centrally here, especially his Geography. Attention then turns to the role of the early Christian church in the decline of 'ancient rationalism' (157). Strikingly, he compares the Christian zealots of the early fifth century AD with the Taliban of modern Pakistan and Afghanistan: 'Like the Taliban, the monks' ignorance of what they opposed was equalled only by their zeal to destroy it' (161). He points out the irony in the idea that science is a modern subversive force undermining established religion, when ancient rationalism preceded and was displaced by that religion (when it was the newcomer, 166). Nicastro then sketches the contributions made by various Indians, Arabs, and residents of medieval Western Europe, to science, especially as it related to working out the size and landmasses of the earth we stand on. The book ends with a lament for Eratosthenes.

Many sound points about science are made en route. For example, that it is not a solitary activity (107), that luck plays a role (120), that much ancient science was done by people at their own expense (165), that mistakes (a) happen, and (b) can be productive (181). There is an excellent graphic of use to anyone wishing to teach this topic, a satellite photo showing Alexandria, Syene, and the tropic (119), and there is a very good discussion of the old chestnut: which stade Eratosthenes used (123-9).

Nicastro often asks the right questions, but there is some carelessness in the act of researching the answers or writing that is bound to trouble the scholar and undermine the whole. For example, on p. 11 Nicastro claims to be quoting Canfora, The Vanished Library, Berkeley and Los Angeles 1990, p. 83. Canfora, quoting his source, has

'I have conquered the great city of the west ... Let me say only that it contains four thousand palaces, four thousand public baths, four hundred theatres or places of amusement and twelve thousand fruit shops; and that forty thousand Jews pay tribute there'.

Nicastro, supposedly quoting Canfora, has:

[the general wrote a letter saying he had taken] 'a city of which I can only say that it contains 4,000 palaces, 4,000 baths, 1,200 greengrocers and 40,000 Jews'.

In this short circumlocution posing as a quote, the theatres or places of amusement have disappeared, 12,000 fruit shops have been reduced by a factor of ten (and have turned into greengrocers), and 40,000 Jews have become the subject instead of the tribute that they pay.

Another example concerns background material: the super-freighter Isis is noted but leviathan ships are said to have appeared only late in antiquity; what about the Syrakosia, which was of Eratosthenes' time, and sailed to Alexandria? It would also have provided another peg for Nicastro to insert Archimedes into the book. A simpler but more basic example concerns the number of stars in Ptolemy's star catalogue: 1,022 in Ptolemy (p. 399 of the Toomer translation, for example) becomes 1,028 in Nicastro (151). This may be a typographic error but the other examples suggest not.

Some confusions are more serious or more misleading, e.g. most of what is said about the Egyptian calendar (14), a supposed 'tag-and-release research project' that is conjured out of Pliny 8.119 (65), and the description of the Olympic victor list and the Spartan king list as 'secure' sources (82). Familiar stories are repeated, e.g. the existence, and the Library's cunning acquisition of, 'definitive editions' of the Athenian tragedians' plays (13 and 73; the original source is the section on Lykourgos in the Lives of the ten orators attributed to Plutarch, Mor. 841F), which story was shown to be unlikely by Rutherford in 1905 (A Chapter in the History of Annotation, London, 1905 1.1.Note b). Only Euripides' works were frequently revived after the C4 BC; comments upon nine of his plays by ancient scholars make clear that there were significant variants in the text when they were writing, and they do not mention an 'authorized' or 'master' version, so if an 'authorized' version ever existed, it was not known to these commentators. A similar situation exists for Shakespeare's plays.

Nicastro repeatedly castigates classicists for (variously) neglecting, underestimating, and misleading 'us' on the topic of ancient technology. Some of the criticism is justified, and he may be right that Finley's 'arguments were so effective that technophobia came to characterize the ancient world in the popular mind as thoroughly as swords and sandals' (100). But some of us never agreed with Finley, and quite a lot of people have been busy rewriting the history of ancient technology for decades now, so this complaint is rather passé.

Given the paucity of material in English on Eratosthenes, anything is a welcome addition, but this book is much better than nothing. In its pages, historians of science will learn much about the ancient world, and historians of the ancient world will learn much about science.

Table of Contents

1. The Philosopher's Run
2. A Zoo of Universes
3. Mr Beta and the Ancient Plan B
4. Greeks and Barbarians
5. Eclipse

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