Category → historical buildings
Authenticating Pieces Of The Berlin Wall
Fifty one years ago today, communist officials in East Germany erected the Berlin Wall to stop the exodus of their citizens to capitalist West Berlin.
The 155-km barricade came down 28 years later in 1989, and since then, every self-respecting tourist shop in town sells chunks of spray-painted concrete to anyone seeking a piece of 20th century history.
Today’s price for a chunk of the Wall, as determined during my lunch-time walk to the local tourist shop from my office at the East-West border in Berlin: €4.95 or about $6.10.
You can get a better deal if you buy these cellophane-wrapped mementos from street vendors.
A few years ago, the rather ample supply of German history for sale got Ralf Milke, a geochemist at Berlin’s Free University, wondering whether he could find a way to authenticate pieces of the Wall. Continue reading →
Bringing A Controversial Mural in LA Back To Life
In 1932, David Alfaro Siqueiros got kicked out of Mexico for his political leanings so the artist spent six months in Los Angeles, California, where he produced a controversial mural called América Tropical.
Siqueiros may not be as well-known as his teacher and contemporary Diego Rivera, but these two, along with José Orozco, formed “Los Tres Grandes,” the big three Mexican muralists of the early 20th century.
During his stint in LA, Siqueiros was asked to paint a mural on a second story wall that overlooked Olvera Street, which was–and still is–a romanticized, somewhat kitschy Mexican market set up for tourists.
The idea was for Siqueiros to produce something that celebrated tropical America. The expectation was probably that it might be a romanticized vision of Mexico—just like the street below.
Instead Siqueiros, who was a die-hard Communist, produced a profoundly political piece of art: A crucified indigenous Mexican is at the forefront of the mural, with an American Eagle flying ominously above. A sharp shooter approaches from the right with his gun aimed at the Eagle.
To say the piece made a splash is a pretty major understatement. Continue reading →
Christians Artists Embellished Spain’s Muslim Paintings

The interior paintings of Granada's Madrasah Yusufiyya in Spain date from 1349. Credit: Carolina Cardell.
For nearly 800 years, the Islamic Moors occupied Spain, building extraordinary buildings that still draw hordes of tourists today. Case in point: the Alhambra.
Less well known is the Madrasah Yusufiyya of Granada, the only Islamic university from the Moorish era left standing in Spain. It was built in 1349 and operated for about 150 years, until the Christians conquered the region in the late 1400s.
The lovely Madrasah Yusufiyya was then used extensively by the Christians, most likely as administration buildings, says Carolina Cardell a conservation scientist at the University of Granada.
In fact the Christians liked the building so much, Cardell says, that in the last 500 years they have done a lot of touching up, repainting, restoring and embellishing of paintings covering the stucco and wooden interior walls of the Madrasah Yusufiyya.
Yet art historians haven’t really known the extent of these interventions. So over the past few years, while the Madrasah Yusufiyya has been under restoration, Cardell and her team of scientists took a closer look at the paintings with a suite of analytical technology. She’s just published a paper in Analytical Chemistry
about the interventions to the Madrasah Yusufiyya over the past 500 years. Continue reading →Conserving Mosaics: A Nod To The Chemistry Nobel Prize

When blogger David Bradley posted this lovely image of a Moorish mosaic, I knew I had to learn more about how tile art is conserved.
In honor of today’s Nobel Prize in chemistry to Dan Shechtman for the discovery of quasicrystals, I thought I’d write a little post on the world of mosaic art conservation.
Bear with me–there is a connection.
(This is precisely what I said when Paula Artal-Isbrand, a mosaics conservator at the Worcester Art Museum, answered the phone. Luckily, she didn’t deem me a random freak and then hang up.)
OK. So back to the Nobel Prize. Quasicrystals are regular patterns of atoms that never repeat themselves, much “like the fascinating mosaics of the Arabic world,” noted the prize’s press release.
This got me thinking–and blogger David Bradley too—because moments later he tweeted the perfect Moorish mosaic example you see here. And I knew I had to learn a bit more about mosaic art conservation and restoration.
Continue reading →
Dredging Up A Dredge In The Yukon
When we embarked on what was possibly a harebrained, 406 km-long vacation canoe trip along the Yukon River in Northern Canada, I wasn’t particularly expecting to encounter a conservation site.
I was wrong: Our final destination on the Yukon River was Dawson City, the site of the Klondike gold rush in 1896. By 1898 the city had swelled to 40,000 people. Now there are now about 1000 inhabitants left and many abandoned turn-of-the-century buildings still left to restore.
But actually the most impressive conservation site was that of Dredge No. 4, a lackluster name for a colossal machine built in 1912 to sift gold out of the gravel, using the same principle as the folks who panned for the precious metal in streams–albeit at a rather larger scale.
The monster Dredge No. 4 is 8 stories high and 2/3 the area of a football field.
Since gold is 19 times heavier than water, the easiest way to separate gold from gravel is to dig up some ground, put it in a bowl of any size, shake everything back and forth in water and wait for the gold to sink to the very bottom of the wet mixture by means of gravity. Then you pour off the water and swipe off the top layer of gravel and presto there’s your gold nugget at the bottom of the bowl (or in my case, a single, barely visible flake of gold that garnered a rather sympathetic look from the teacher when I took a brief gold panning course).
Continue reading →