A brief hiatus: Onwards to Uzbekistan

My apologies for a few weeks hiatus over here at Artful Science. Last summer I got married and we are finally off on our honeymoon to Uzbekistan (aka the honeystan) where we will explore some awesome Silk Road architecture. Given that we’ll be looking at a lot of mosaics, I thought I’d point you to this post on the conservation of tile art and the 2011 Nobel Prize in chemistry. See you at the end of...

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Gold gilding, ancient amber and a mysterious hidden sculpture: A new cultural heritage journal launches!

There’s beautiful gold gilding at Reales Alcazares royal palace in Seville, Spain. Yet it turns out that the pretty gold gilding you see in the image on the left is not precisely original. The World Heritage Site was originally built in 914 AD, and then expanded from the 14th to the 16th century. Recently, Spanish researchers found a layer of paint lying below the gold gilding that contains lead chromate, a pigment that wasn’t used until the 19th century. So the gold lying above must have been added afterwards. Yellow lead chromate pigment is responsible for the bright color of many old school buses, and it was even used as a colorant for yellow candy before falling out of favor because both lead and chromate are extremely toxic. Spanish researchers report that the lead chromate layer was added sometime after 1818 above a deteriorated layer gold gilding, probably as part of a 19th century restoration project. The lead chromate may have been painted on as false gold to keep up appearances before new gold gilding could be applied. Or it’s possible that the lead chromate was painted on just before the new gold gilding: The paint may have acted as a foundation layer to help the new gold gilding adhere. This conundrum is reported in the inaugural issue of Heritage Science, the first peer-reviewed journal to focus entirely on cultural heritage science. (Welcome!!) There’s a variety of interesting topics reported in the journal’s first edition, including a way to determine the geographical origin of amber which provides clues about early trading roots of the fossilized tree resin. There’s also an analysis of medieval Hungarian silver coins, and several papers on the effects of pollution and humidity on cultural heritage objects, from ancient architecture to antique books. The issue also contains a cool paper about a sculpture accidentally discovered behind a wall of St Petersburg’s Winter Palace in 2010. The sculpture, called Fugitive Slave and made by the Russian artist Vladimir Beklemishev, was inspired by the anti-slavery novel Uncle Tom’s Cabin. It was initially exhibited at the World’s Fair in Chicago in 1893, and then sent to Russia before being hidden in the palace wall after the sculpture suffered heavy damage during World War Two. The sculpture was made to look like bronze, even though it is definitely not bronze. That’s why the scientists are keen to study its make-up: The pseudo bronze involves creative use of gypsum, iron, copper and arsenic. But perhaps the most interesting read in the inaugural issue of Heritage Science is the very pointed essay by journal editor Richard Brereton. Brereton does not mince words...

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Daisies, frankincense, mint, and mercury help preserve Richard the Lionheart’s heart

This is a guest blog post from Stu Borman, a C&EN senior correspondent for science, technology & education. A French-based research team recently had a rare opportunity to get to the heart—quite literally—of some 12th century European history. Using a battery of scientific equipment, they took a closer look at how the heart of English king Richard I was preserved for posterity. Also known as Richard the Lionheart because of his military prowess, Richard I was king of England from 1189 to 1199. He led a Crusade to the Holy Land in 1190, but the mission failed to take Jerusalem, its main objective. On the way back home he was imprisoned by an Austrian duke and the German emperor and then only released after payment of what was literally a king’s ransom. He died in 1199 when he was shot with a crossbow while besieging a castle in Chalûs, France. According to a then-common practice, his body was divided up for burial in multiple graves. His internal organs were buried in Chalûs, his heart was embalmed and placed in a tomb at Notre Dame de Rouen cathedral, and the rest of his body was buried at an abbey in southern France. In 1838, a lead box containing the remains of Richard’s heart was found at the cathedral. The box is engraved “HIC IACET COR RICARDI REGIS ANGLORUM”—“Here is the heart of Richard, King of England.” To learn more about how the seat of the king’s soul was preserved for posterity in medieval times, forensic medical investigator and pathologist Philippe Charlier of University Hospital Raymond Poincaré, in Garches, France, and coworkers analyzed Richard I’s mummified heart. The wide variety of techniques they used to get to the heart of the matter included everything from scanning electron microscopy to mass spectrometry. In their paper on the study, the team writes that the heart “was deposed in linen [and] associated with myrtle, daisy, mint, frankincense, creosote, mercury, and, possibly lime.” They conclude that the goal of using these materials was both to preserve the heart and keep it smelling good, insofar as possible. “This embalming method is of great importance, as we do not have any procedure or surgical treatise known for this period (end of the 12th century A.D.) describing the methodology and/or composition of the embalming material,” the researchers...

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Photo fraud: eBay to the rescue!

In the 1990s the market for photos exploded. As snapshots started selling for millions of dollars, sham photos also slipped into the fray before the art world had any way to authenticate originals. And so cultural heritage researchers had to play some serious catch-up, and quickly. That’s the gist of my recent cover story on photo conservation. It explores how two fraud cases helped turn the field from a niche research area to a mature science. And as always happens when reporting, many cool tidbits didn’t fit in to the final piece… In this case, the pivotal role eBay played to help researchers develop ways to catch fakes. But first, a bit of background on photo fraud: In the photo market, people will pay more money for an image when it was actually printed on paper by the photographer himself or herself. The price can also increase when the print is older. So, for example, the Getty Conservation Institute’s Art Kaplan told me that an Ansel Adams photograph printed in the 1920s can sell for hundreds of thousands of dollars, while the exact same photograph printed a few decades later (say, the 1970s) can sell for just tens of thousands of dollars. It turns out that researchers wanting to authenticate a photo spend a lot of time scrutinizing the paper on which it has been printed, because photo paper generally provides the best dating and provenance clues. For example, researchers look for chemicals called optical brighteners which were added to all photo paper to brighten images starting in the 1950s. If a photo is purported to have been made earlier than the 1950s, then it can’t have any optical brighteners in the photo paper. Likewise, in the 1880s, companies started adding a so-called baryta layer to the top of photo paper as a physical barrier between image and paper, so trace impurities in the paper wouldn’t leach into the image layer and wreck the picture. Each company used a different ratio of barium and strontium in the baryta layer, and companies also changed these ratios over time. Since most photographers were loyal to a particular photo paper brand, authenticators check to see whether a suspect photo has barium and strontium ratios that correspond to the photographer’s preferred company during the era when the photograph was supposedly printed. Of course to make these comparisons, you need an enormous database of reference photo paper, says Paul Messier, a photograph conservator who helped develop ways to authenticate Lewis Hine prints in one of the world’s first million-dollar photo fraud cases. “A switch flipped on when I was working on the Hine project,” Messier says. “I...

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Two million-year-old whale fossils printed with 3D technology

These may look like real fossils, but they are actually perfect plastic replicas of 2 million-year-old whale skeletons made using a 3D printer. This printing technology, which can create 3D versions of objects as diverse as a guns or the brain of a man with no memory, was hyped last week by President Obama when he said that 3D printing “has the potential to revolutionize the way we make almost everything.” The technology certainly saved the day for Smithsonian paleobiologist Nick Pyenson. Pyenson had been finishing up a research trip in Chile in 2011 when he decided to check out a local highway construction site in the Atacama Desert where workers had supposedly uncovered dozens and dozens of whale skeletons. “I didn’t really believe the rumors at first,” Pyenson says. But when he arrived, “It was unlike anything I’d ever seen.” Pyenson described the experience at the American Association for the Advancement of Science meeting in Boston. Local museum officials were racing to dig out the skeletons before highway workers paved over the area, Pyenson says. Although the skeletons clearly needed to be removed, a problem with removal is that spatial information about different constellations of fossilized bones is then lost. This information is essential for answering all sorts of interesting research questions, such as why so many whales died and were buried together two million years ago. For example, the whales could have swum into a bloom of toxic algae and died or they might have fallen victim to a landslide. Pyenson went home to DC and immediately recruited the Smithsonian’s in-house 3D imaging and printing team (aka the Laser Cowboys), who came back with him to Chile and spent a week imaging the whale fossils with a high resolution laser scanner. The team then went home and began analyzing the fossil images. They also also began printing out awesome replicas like the one you see above, which is many times smaller that the original. (The whale fossils span between 20-30 feet in real life.) Pyenson says the Smithsonian has industrial partners who will soon print out a full sized version pro bono, which would have otherwise cost the museum $1 million. It seems Pyenson’s team has already figured out why all these whales died but he’s staying mum about it, while the scientific paper winds its way through the peer-review process—so stay tuned. Once the discovery is published, Pyenson says they’ll put the data online so others around the globe can access and analyze it. Although this laser scanning and 3D printing could give researchers around the world the ability to study skeletons without physically handling them, old-school...

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