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Science Is Uncovering The Exquisite Detail In This Faded Painting
Sam Lemonick
A young Roman woman peers out across the centuries from a crumbling fresco in an ancient town. Thanks to new technology, we may soon see her portrait as it looked when it was first painted.
The portrait as it looks in Herculaneum (left) and Del Federico's map of iron atoms (right).
Roberto Alberti
Herculaneum was famously buried in ash and lava during the eruption of Mt. Vesuvius in 79 AD, which destroyed Pompeii as well. The thick covering preserved parts of the city almost perfectly, including organic material like wood. But paintings and other fragile things started to decay as soon as archaeological digs exposed them to the air.
That includes a portrait of a young woman (pictured above), found in a house where she is thought to have lived. It was uncovered about 70 years ago, and has since degraded significantly.
With the help of brand new technology, chemist Eleonora Del Federico is helping artists and archaeologists see what this and other paintings once looked like. She presented her research at the American Chemical Society's national meeting this week.
"The chemistry is letting us see them in a different way. The portrait is mostly overlooked. But then you see the iron map and she's just so beautiful," says Del Federico, a professor at the Pratt Institute in New York City.
The iron map she's talking about comes from a macro x-ray fluorescence spectrometer (Macro-XRF), a device that can plot the location of iron and other elements in two-dimensions. Del Federico took this new technology to Herculaneum to test it out.
X-ray fluorescence spectrometers shine a beam of x-rays that can excite electrons in the atoms in a sample up to higher energy levels. When the electrons relax they emit their own bursts of electromagnetic radiation. Different wavelengths of radiation correspond to different elements, allowing the spectrometer to ID the atoms. The technology has often been used to analyze paintings and sculptures to understand how they were made.
Until recently, these devices were bulky and lived in laboratories, meaning the art had to come to them. Handheld Macro-XRF technology emerged in the last five years. In Herculaneum, Del Federico simply held the device a centimeter or so away from the fresco—which is flaking off in places—and it produced a map of the iron, copper, lead and other atoms in the painting.
Those elements can tell chemists and art conservationists what color paints the artist used, based on what we know about Roman art. Yellow ochre pigment contains iron, Egyptian blue has copper, and some red paints contain lead.
"The iron map has the sketch of the face, but the lead map shows the eyeliner," Del Federico says.
Her team worked in collaboration with the Herculaneum Conservation Project, a local public-private partnership that manages the historic site.
Del Federico hopes her analysis will help conservationists make virtual restorations of the painting of this young woman and others. Painting on top of what's already there is frowned upon these days—remember that fresco of Jesus that a well-meaning amateur turned into some kind of misshapen monkey? Instead, conservationists could use her element maps to recreate the painting digitally.
The research has special meaning for Del Federico. She grew up in Argentina with an Italian grandfather and says she feels at home in Herculaneum. Being there, she says, almost feels like time traveling.
Her work will help make sure Herculaneum's art is appreciated. "The whole place is falling apart," she says. "It's so sad. So many frescoes are considered gone. Now this technique has the potential to see other frescoes that you can't see with the naked eye."
Disclosure: I am a former employee of the American Chemical Society and a writer for the ACS's video series, Reactions.