Unlocking Scrolls Preserved in Eruption of Vesuvius, Using X-Ray Beams

By NICHOLAS WADEJAN. 20, 2015
Researchers have found a key that may unlock the only library of classical antiquity to survive along with its documents, raising at least a possibility of recovering vanished works of ancient Greek and Roman authors such as the lost books of Livy’s history of Rome.

The library is that of a villa in Herculaneum, a town that was destroyed in A.D. 79 by the eruption of Mount Vesuvius that obliterated nearby Pompeii. Though Pompeii was engulfed by lava, a mix of superhot gases and ash swept over Herculaneum, preserving the documents in a grand villa that probably belonged to the family of Lucius Calpurnius Piso Caesoninus, the father-in-law of Julius Caesar.

Though the hot gases did not burn the many papyrus rolls in the villa’s library, they turned them into cylinders of carbonized plant material. Many attempts have been made to unroll the carbonized scrolls since they were excavated in 1752.

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But all were highly destructive, and scholars eventually decided to leave the scrolls alone in the hope that better methods would be invented. More than 300 scrolls survive more or less intact, with many more fragments.

The archaeological excavations of Herculaneum in the villa dei Papiri, Italy. Credit Splash News, via Corbis Researchers led by Vito Mocella, of the Institute for Microelectronics and Microsystems in Naples, Italy, now say that for the first time, they can read letters inside the scrolls without unrolling them. Using a laserlike beam of X-rays from the European Synchrotron in Grenoble, France, they were able to pick up the very slight contrast between the carbonized papyrus fibers and the ancient ink, soot-based and also made of carbon.

The contrast has allowed them to recognize individual Greek letters from the interior of the roll, Dr. Mocella’s team reported on Tuesday in the journal Nature Communications. “At least we know there are techniques able to read inside the papyri, finally,” Dr. Mocella said in an interview. His team is considering several ways to refine the power of their technique.

“If the technology is perfected, it will be a real leap forward,” said Richard Janko, a classical scholar at the University of Michigan who has translated some of the few scrolls that can be read.

The research team look upon the Herculaneum Scrolls during a sample installation. Credit J. Delattre

The Mocella team’s work is the second recent advance in reading the Herculaneum scrolls. In 2009, Brent Seales, a computer scientist at the University of Kentucky, succeeded in delineating the physical structure of a Herculaneum scroll by X-ray-computed tomography, a process similar to a CT scan. The layers of papyrus wound up inside the scroll are highly ruffled and irregular because the hot gases liberated all the water from the fibers as well as carbonizing them.

The Mocella team’s method visualizes letters free floating inside the scroll, but each letter will need to be assigned to its correct place on Dr. Seales’s surface before the letters can form words. Dr. Seales and Dr. Mocella worked with Herculaneum scrolls acquired by Napoleon in 1802 and belonging to the Institut de France in Paris.

“This is absolutely a major step forward,” Dr. Seales said of the Mocella report. “These guys are focused on showing the imagery with best contrast. But to really read the papyrus, you need to untangle its surface, which is the active area of my work.”

The Herculaneum Papyrus scroll. Credit D. Delattre/Bibliothèque de l'Institut de France

Classical scholars are particularly interested in the physicists’ progress because of the chance of uncovering lost works of Latin and Greek literature. Piso’s grand villa — which is the model for the Getty Villa, part of the J. Paul Getty Museum in Los Angeles — is thought to have probably contained a large and wide-ranging library, much of which may still exist in unexcavated portions of the building.

“It would have been odd for a villa of this sort not to have had a major library,” Dr. Janko said. “So this technology, when perfected, does open the way to rediscovering a lot more ancient literature.”

The scrolls that have been opened pertain mostly to Greek philosophy and contain several works by Epicurus and his adherent Philodemus. But the library may also have had a Latin section. This could contain some of the many lost works of Roman history and literature. Even the texts of known works would be of great interest.

“For a scholar, it would be wonderful to have a manuscript of Virgil written in his lifetime, because what we have are medieval manuscripts which have suffered many changes at the hands of copyists,” said David Sider, a professor of classics at New York University.