Only one library from the classical world is known to have survived along with its texts: the Villa of the Papyri at Herculaneum, which was ravaged by the eruption of Vesuvius in 79 CE. Ever since its discovery in 1754, archaeologists have attempted to crack open the villa’s carbonized texts with knives, chemicals, and unrolling machines, all with little success and often irreversibly destructive results. Last week, researchers finally revealed a technique for reading the interiors without destroying the fragile scrolls.
Published in the journal Nature Communications, the article “Revealing letters in rolled Herculaneum papyri by X-ray phase-contrast imaging” outlines a method tested at the European Synchrotron in Grenoble by Vito Mocella of the Italian National Research Council and his team. The researchers state:
Here for the first time, we show that X-ray phase-contrast tomography can reveal various letters hidden inside the precious papyri without unrolling them. This attempt opens up new opportunities to read many Herculaneum papyri, which are still rolled up, thus enhancing our knowledge of ancient Greek literature and philosophy.
Aside from the extreme fragility of the papyri, the major issue with the scrolls has been that the words they contain were scrawled in a carbon-based ink (likely made of soot). The entirety of the scrolls was also carbonized by the volcanic eruption, and this similarity means that X-ray computed tomography (what you experience in a CT scan) wouldn’t work. So Mocella and his team experimented with phrase contrast X-ray phase tomography instead, turning a scroll sample 360 degrees; with a refraction of X-rays sensitive to the different densities of the surface and ink, the words on top of the papyrus showed up in contrast.
This is a technical way of saying that, through the use of high-energy beams, enough of the writing can be imaged in a discernible way. As X-ray microtomography specialist Graham Davis of the Queen Mary University of London told Chemistry World, the main question “was whether there was a method of retrieving text that was written with carbon ink and here’s the answer.” Two hundred and sixty years after these blackened coils of ancient writing were discovered at Herculaneum, there may finally be a way to read them.
While this represents a coup for papyrologists, any major step in non-invasive archaeology is promising beyond its subject, potentially offering new ways of examining other volcanic sites or charred texts that are too warped and battered to open. It wasn’t long ago that researchers were rapidly unwrapping mummies and exposing inks on papyrus scrolls to the air for transcription instead of preservation. According to the New York Times, this new research joins a 2009 study by computer scientist Brent Seales at the University of Kentucky on using X-ray computed tomography to unravel the shape of a scroll without physically doing so. Coupled with the Grenoble research, the two studies might offer an entirely new way of reading the ancient world.