Digital mapping at Stanford reveals social networks of 18th-century travelers

Through a digital analysis of correspondence from travelers on the famed European "Grand Tour," classicist Giovanna Ceserani is discovering how international travel fostered cultural and academic trends in the 18th century.

network map

In the network view of travelers with recorded trips to Rome from the 'Dictionary of British and Irish Travelers to Italy, 1701-1800,' connections between individuals are based on whether there exists a record of correspondence (orange) or other relationship (blue). In this close-up view, architect Robert Adam is highlighted.

We live in a world of networks, of nonstop messaging and degrees of separation. So did intellectuals of the early modern age, according to new research at Stanford.

During the 18th century, thousands of letters, often on academic subjects like mathematics, were exchanged between scholars across Europe. Wealthy aristocrats and their tutors penned many of those letters when they were on the famed "Grand Tour" of ancient sites in Europe.

A pioneering digital visualization project has allowed Giovanna Ceserani, an associate professor of classics, to map the routes of thousands of British and Irish elite travelers who went to Italy in the heyday of the Grand Tour.

Ceserani's digital humanities project, the Grand Tour Travelers, has uncovered unexpectedly close connections between intellectuals, illuminated the rise and fall of cities, and occasionally offered warnings about how visualization can sometimes prove misleading.

Analysis of digital interpretations of the records of over 6,000 travelers from the British Isles illustrate just how small the elite world of tourists in this period was, as well as how, "irrespective of profession and social status, travel abroad seems to have lowered social boundaries and enabled otherwise unlikely connections," Ceserani said.

The project began with the encoding of a digitized version of the Dictionary of British and Irish Travelers to Italy, 1701-1800, generously supplied by the Paul Mellon Centre in London. For each traveler, Ceserani and her team recorded the sites they visited, the dates of their visits and their birthplace and year, as well as their area of expertise, educational background and social status, among other variables.

A scholar with an interest in how classical sites in Italy influenced broader European culture, Ceserani wanted to trace "the actual movements of scholars, of travelers," as they undertook journeys across Europe, often coming into contact with other travelers as they did so.

Digital humanities experts within the Mapping the Republic of Letters project, of which Ceserani is a core member, helped Ceserani build the platforms "to place these objects and events onto maps and graphs, visualizing in revealing ways our material."

Tracing cultural trends and travel hot spots

Visual timelines that showed which travelers were in various cities at what times allowed Ceserani to confirm some scholarly hunches. For example, she was not surprised to see that Vicenza was the Italian city most visited by architects in the early part of the 18th century, because the celebrated architect Andrea Palladio had endowed the city with splendid new buildings a few decades earlier.

But the visualizations also revealed a dramatic variation in fortune among cities. "There are some clear shifts in where people traveled," Ceserani said. By the end of the century, Vicenza had ceded its place as an architectural mecca to Naples, by then the center of the Greek Revival.

Beyond this, the visualizations also made clear which Grand Tourists were in the same city at the same time, raising the possibility that they met.

When the records showed that two people had actually met, Ceserani and her team drew lines between them on a network. The larger picture revealed ties over several degrees of separation that otherwise would have gone unremarked.

For example, architect Robert Adam and poet James Thompson seem to have inhabited separate worlds, and most likely never met in person – but in Ceserani's visualization they are connected by a few links to travelers and art collectors.

Importantly, Ceserani noted that the digital analysis "allows us as scholars to probe the sources further; in this case, for example, we are pushed to trace the actual, specific human network track which connected Adam and Thompson, a track that might well have remained unnoticed to specialists of either the poet's or the architect's work."

Visualizations also reveal 'what we don't know'

With visualization, "we can see a tremendous amount of data at once," Ceserani said. But at the same time digital interpretations create the ability to zoom in more closely at specific points – the individuals that cultural historians are usually most interested in.

"But visualization does more than this," Ceserani added. "It also allows us to appreciate the gaps in our data." Digitization, then, doesn't only present what we do know in a more accessible way – it also reveals what we don't know.

"The visualization process," Ceserani said, "also gave us methodological insights." What looks at first like cultural change may turn out to have a more pedestrian explanation in the way the data was collected.

The best example is the sudden fall-off in travelers to Padua, Italy, in the 1720s. Rather than an actual change in tourist traffic, the drop turned out to be a change in bookkeeping. The city university, which had been keeping track of the number of visiting foreign students, had simply stopped doing so.

In many ways, as Ceserani acknowledges, her project represents "a big departure from much that characterizes traditional humanistic research," starting with its collaborative methodology.

The project had help from academic technology specialist Nicole Coleman, and Sarah Murray and Molly Taylor-Poleskey, who lent their assistance as graduate students.

The project's most noticeable feature is its combination of humanistic questions and technological tools. It's a partnership that has led to ongoing innovation at Stanford (such as the new Humanities + Design Research Lab) and that Ceserani believes holds great promise for future researchers.

She insists though, that the ongoing exchange between humanists and scientists can't be one-way. "There is," she said, "a pressing need for a humanistic approach to technology."

James Kierstead is a doctoral candidate in classics at Stanford and a Geballe Fellow at the Stanford Humanities Center.

Corrie Goldman, director of humanities communication: (650) 724-8156,