The Purse of Eratosthenes

For about 10 years in the 1990s, I worked on assembling a collection of ancient coins worth about a day's wages from the towns and times of Greek philosophers. I was inspired by an episode of Carl Sagan's Cosmos, "Backbone of the Night." Although I discovered that I lack the passions of a true collector for rarity, condition, and completeness, I was rewarded with explorations in ancient history and the opportunity to learn enough classical Greek to do my own translations.

Drachmon from Kyrene c. 550 BCE Zeus Ammon and Silphium
(About the size of US 5-cent nickel)

I discovered the town of Cyrene (Kyrene), near what is today Benghazi. Eratosthenes of Cyrene was the third Librarian of Alexandria (from 245 BCE) after Zenodochus and Callimachus. Circumference by Nicholas Nicastro (St. Martins 2008) reviewed on this blog (here) is a modern biography of Eratosthenes and his works. He was also a grammarian and historian. His other mathematical work includes a "sieve" to find prime numbers.  His biography is on Wikipedia, of course: https://en.wikipedia.org/wiki/Eratosthenes  It is also repeated more succinctly here: 
http://www.math.wichita.edu/history/men/eratosthenes.html  
and more fully here:
http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Eratosthenes.html

The Hellenistic world was very much like our own time: held in tension by science and superstition, commerce and war, ecumenism and parochialism.

Kyrene was founded by Dorians from the island of Thera in 631 BCE. Its primary claim to fame was the presence of silphium. Silphium was discovered to prevent pregnancy. It was highly valued and eventually harvested to extinction, despite valiant attempts to cultivate it there and elsewhere. Not surprisingly, the history of Kyrene reflected many of the cultural trends of the times. Twice, it suffered from constitutional crises as factions in the assembly became gangs in the streets. Both times, the solution was to send to Athens for philosophers skilled at politics who created compromises. 

Obol or hemi-drachm. Demeter with Eagle killing snake.
(About half the size of a US dime.)

The town also was home to two women who married a Ptolemy: Berenike I and Berenike II. The constellation Coma Berenices was supposedly the hair  of Berenike II, offered to the gods for the safe return of Ptolemy III Euergetes from a war in Syria. "Veronica" is the latinized form of Berenike. 

Among the ancient philosophers, the Cyrenaics followed the teachings of Aristippos. The school was maintained and extended by his daughter, Arete, and her son, Aristippos. Though originally a student of Socrates, Aristippos asserted his own line of thought. He advocated seeking pleasure by adapting to circumstances. He gave up the safety of a city and traveled widely. To understand the consequences of that, remember that Diogenes the Cynic was captured by pirates and sold as a slave. It was not unusual for the times. There was no safety outside the city walls. Yet, the Alexandrians coined the word "cosmopolitan" for the universal citizen or citizen of the world, not tied to any one city, but comfortable anywhere.

Ptolemy II and Berenike I. Alexandria Mint.
(Bronze coin about the size of a US quarter)

Eratosthenes, the town of Kyrene, and the Library at Alexandria became a focus for my interests and one of the first articles I wrote about the numsimatics of the ancient world was “The Purse of Eratosthenes: the Coinage and Commerce of Cyrene,” The Celator, Vol. 8, no 1, (January 1994).  (Founded by Wayne G. Sayles, The Celator passed to a couple of other editors and publishers and then closed just a few years ago.)  

We quip and quote about the long run of history, which may or may not repeat itself to our doom. The fact is that the Library of Alexandria attracted savants from all across the Greek koinon ("union").  They developed their own distinct and universal dialect, in which, ultimately, the New Testament was written. When the house of Ptolemy fell on hard times, the library released many of its scholars to find their own ways. Rather than marking a nadir, it caused a secondary flourishing in the Hellenistic world as accumulated learning was cast to the winds to flourish wherever open minds were found.

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