College undergrads find hidden text on medieval manuscript via UV imaging

A page from a 15th-century medieval manuscript turns out to contain hidden text that is only visible under UV light. The discovery is due to the efforts of a team of undergraduate students at Rochester Institute of Technology, who built their own multispectral imaging system as part of a class project and managed to complete it despite the ongoing pandemic.

It's not unprecedented to uncover previously hidden texts on ancient manuscripts. In 2016, an international team of scientists developed a method for "virtually unrolling" a badly damaged ancient scroll found on the western shore of the Dead Sea, revealing the first few verses from the Book of Leviticus. Similarly, in 2019, we reported that German scientists used a combination of cutting-edge physics techniques to virtually "unfold" an ancient Egyptian papyrus, part of an extensive collection housed in the Berlin Egyptian Museum. Their analysis revealed that a seemingly blank patch on the papyrus actually contained characters written in what had become "invisible ink" after centuries of exposure to light.

And earlier this year, we reported on a new analysis using multispectral imaging showing that four Dead Sea Scroll fragments housed at the University of Manchester in the UK—previously presumed to be blank—had readable text written in carbon-based ink, along with parts of characters and ruled lines. One fragment in particular showed the remnants of four lines of text, consisting of about 15 letters. Only one word, Shabbat (Sabbath), was readable, but based on the analysis, Joan Taylor of King's College London thought the text related to the passages in Ezekiel 46:1-3.

So the RIT undergrads are in good company. Their project began earlier this year. The 19 students enrolled in a course known as the Innovative Freshman Experience, offered by RIT's Chester F. Carlson Center for Imaging Science. The goal was to bring students from various disciplines together and have them combine their expertise to solve a particular problem—in this case, building a multispectral imaging system to analyze historical documents.

Traditionally, the students would have presented their completed project at the annual Imagine RIT: Creativity and Innovation Festival in the spring. But just as the device was nearing completion, the COVID-19 pandemic hit in March, and the university closed its campus, just like every other educational institution in the US. To compensate, the students in the class divided into four smaller groups, each with a different task. One group created a technical manual for the imaging system, another produced an end-user guide, a third group wrote a research paper, and a fourth produced a video documentary about their project. Coronavirus willing, they'll be able to present at next year's Imagine RIT.

“Something really valuable that we’ve done in the absence of being able to work on the system in person is integrate more useful workplace skills into our learning,” Liz Stublen, a photographic sciences student, said in May. “When we were building the system, a few of us were focused on programming and 3D modeling, and now we’ve been able to shift the focus for the whole class to be able to develop their skills in that area. So even though this is not a great situation, we’ve been able to turn things to maximize the benefit from this time.”

Three students in particular—Zoe LaLena, Lisa Enochs, and Malcom Zale—spent their summer completing the system. When classes resumed in the fall they started examining the 15th-century medieval manuscript leaves housed in RIT's Cary Graphic Arts Collection. The parchment leaves had been acquired about ten years ago from historian and collector Otto Ege, who regularly compiled such leaves from damaged or incomplete manuscripts. The collection has, of course, been studied by many scholars. But this was the first time anyone had looked at the leaves under UV light.

When the students imaged one such leaf, they found that the page was actually a palimpsest, with multiple layers of writing—specifically, the imaging revealed a "dark French cursive," according to LaLena. During the 15th century, parchment was pricey, so it was often scraped clean and re-used. But even centuries later, a telltale chemical signature remains if one looks at the page in the right spectrum of light. The next step is to use their imaging system to analyze the other 29 known pages from Ege's collection, which could also turn out to be palimpsests.

“The students have supplied incredibly important information about at least two of our manuscript leaves here in the collection and in a sense have discovered two texts that we didn’t know were in the collection,” said Steven Galbraith, curator of the Cary Graphic Arts Collection. “Now we have to figure out what those texts are, and that’s the power of spectral imaging in cultural institutions. To fully understand our own collections, we need to know the depth of our collections, and imaging science helps reveal all of that to us.”

Listing image by RIT