There's no denying that Google Maps makes it easy to navigate a city, but people who use it do lose some spatial awareness. When researchers set people loose with either paper or digital maps as a guide, the digital folks can find their destination all right but fail to capture the rest of the environment. They know where they're going, but not what's going on around them.
That's kind of the way things were back in the Greco-Roman era, says ancient mapping scholar Roberta Casagrande-Kim. Travelers in that period, which bracketed the death of Christ by a few centuries on either side, used maps that merely listed a succession of destinations. If they strayed off the established path they struggled to orient themselves and find their way.
"I think the itinerary of the Greek and Roman times functioned the same way as Google Maps directions function today," says Casagrande-Kim. "It's not an awareness of all landscape in all its topographical and geographical elements, but rather a wayfinding approach to space."
The history of humanity's spatial awareness — and occasional lack thereof — is on display in a new exhibition called "Measuring and Mapping Space: Geographic Knowledge in Greco-Roman Antiquity" at the Institute for the Study of the Ancient World in New York (with many elements also featured online). The show celebrates the fundamental principles of geography established during that age and how these ancient maps helped early civilizations perceive both city and world.
"What I'm trying to convey to the visitor is the idea that geography permeates ancient life on so many different levels," says Casagrande-Kim, the program's curator. "It's not just about maps but how geography affected the political, the cultural, the religious life of the individual."
The Peutinger Map, a replica of which is on display at the exhibition, gives a sense of both the promise and limitations of early spatial visualizations. The map identifies all the roads, cities, waterways, and mountains that fell under the auspices of the Roman empire. Aside from showing which places connect to one another, however, the map holds little practical value.
Early geographers can be divided into two types: those who focused on the whole Earth and those who documented localities.
The former crowd consisted largely of philosophers and mathematicians. Long before satellites scanned pictures of the globe on command, these geographers waited for the solstice to get some sense of the world's scale, says Casagrande-Kim. By scattering to different cities, measuring the angle of the sun's shadow on a stick, and popping these figures into an equation, they calculated the distance from place to place and the circumference of the Earth.
Local geographers, meanwhile, dealt with everyday problems "linked to the construction and management of the cityscape," says Casagrande-Kim. These were practical matters — how to divide a land properly for the purposes of taxation, or how to find the best access route into a city for the design of a new road. The Corpus Agrimensorum Romanorum, a 5th-century handbook on display at the show, outlines many of these common scenarios for young surveyors to study.
None of the original Greco-Roman documents remain, but what does exist are dutiful recreations made during later times. Renaissance cartographers used the Geographia, written by Ptolemy in the 2nd century and also on display at the show, to gain a sense of ancient territories. The maps that emerged may even have influenced Columbus — one possible reason his voyages missed their mark was that Ptolemy's calculations were slightly off.
"I think his mistake on the circumference of the Earth was 20 percent," says Casagrande-Kim. "For that age, it's not that bad."
All images courtesy of the Institute for the Study of the Ancient World,