Long before people could look upon Earth from afar,the Greeks and the Romans of antiquity had to struggle to understand the worlds size and shape. Their approaches differed: The philosophical Greeks,it has been said,measured the world by the stars; the practical,road-building Romans by milestones.
As the Greek geographer Strabo wrote at the time: Whenever we have not been able to learn by the evidence of sense,there reason points the way.
Strabos words greets visitors to a new exhibition,Measuring and Mapping Space: Geographic Knowledge in Greco-Roman Antiquity,which opened Friday at the Institute for the Study of the Ancient World.
The rarely exhibited material is on loan from the Morgan Library and Museum,the Metropolitan Museum of Art,the New York Public Library,the American Numismatic Society and the libraries at Columbia and Harvard.
Roger S Bagnall,director of the institute,an affiliate of New York University,said the exhibition crosses not only ancient borders and cultures but also modern disciplines. Our exhibitions and digital teams, he said,present a 21st-century approach to the ancient mentality concerning geographic space and how it is represented.
The show brings together more than 40 objects that provide an overview of Greco-Roman geographical thinking.
Geography is not just maps, said the guest curator,Roberta Casagrande-Kim,a scholar of classical concepts of the underworld that go back well before Dante took his journey through the nine circles of hell. There is also the cognitive side underlying mapping, she said.
Plato wrote of Socrates saying the world is very large and those who dwell between Gibraltar and the Caucasusin his memorable imagerylive in a small part of it about the sea,like frogs about a pond,and that many other people live in many other such regions.
An early advance was Aristotles discovery,in the latter half of the fourth century BC,that the world must be spherical. He based this on observations of lunar eclipses,and ships disappearing hull first on the horizon.
Then Eratosthenes,a librarian at Alexandria in the third century BC,employed the new geometry to measure the worlds size with simultaneous angles of the suns shadow taken at widely distant sites in Egypt. That yielded a remarkably accurate measure of Earths circumference.
Across the wall of the first gallery is projected a digital replica of the Peutinger Map,more than 22 feet long and 2 feet high,illustrating how Roman mapping was at once practical and magnificent. It charts the empires roads,cities,ports and forts from Britain to India. Sketches of trees mark forests in Germany.
The most influential of the ancient Greeks was Claudium Ptolemy,the foremost scholar at the Alexandria library in the second century AD.
Notes accompanying the exhibition point out that Ptolemys Geographia provided ample information on locations of ancient lands and cities,enabling Renaissance cartographers to prepare the first fairly modern world maps,in the Mappa mundi style. The maps were decorated with the eight classical headwinds; symbols taken from Aristotles conception of the primary elements of fire,earth,water and air.
Even Ptolemys errors were influential. Instead of sticking to Eratosthenes more accurate estimate of Earths size,Ptolemy handed down a serious underestimate that later apparently emboldened Columbus to think he could reach China or Japan. Instead,he reached what became known as the West Indies.
After 1492,there were new worlds to measure and map. Eventually,new discoveries made Greco-Roman geography obsolete. But its influence helped shape the way we still look at the world.
John Noble Wilford