A unique library of medieval manuscripts, devastated by fire during World War II and considered lost by scholars, could be restored using technology developed to study the surface of planets.
The medieval library at Chartres, France, was destroyed in an allied bombing raid on the evening of 26 May, 1944.
The collection, then housed in an annexe of Chartres town hall, comprised around 2,000 medieval books and parchments, many of which dated to the 12th Century.
The library was considered a national treasure and a good proportion of the works were unpublished.
After the fire was quelled, volunteers moved in to save what they could from the smouldering ruins. Although thousands of texts were recovered, the fierce inferno carbonised the majority, rendering them unreadable.
But digital technology called multispectral imaging may now be able to reveal text on even the most badly burned manuscripts, allowing scholars to study them again.
Non-invasive technique
A key member of the team using multispectral imaging to decipher burned scrolls from the Roman town of Herculaneum, which was buried by the eruption of the volcano Vesuvius in AD 79, says the technique could be ideal for reading the damaged Chartres manuscripts.
"The beauty of [multispectral imaging] is that it is not invasive," Professor Richard Janko of the University of Michigan, US, told BBC News Online.
"It's worth a trial [on the Chartres texts]. It could do a lot for the study of medieval literature," he added.
"The library at Chartres was possibly the greatest medieval library," said associate professor Constant Mews, an expert in medieval literature at Monash University in Victoria, Australia.
Multispectral imaging is widely used on satellites that produce detailed images of the Earth. But it is now gaining ground as a technique in archaeological restoration.
Researchers take several images of a manuscript with a special multispectral camera.
The photos are then passed through different filters to produce a set of images viewed at different wavelengths of light.
These wavelengths range from colours in the visible spectrum to infrared and ultraviolet light - which are invisible to the naked eye.
This image set is then processed to show up subtle features on the page, revealing text previously concealed from human vision.
Like the manuscripts from Chartres, the Herculaneum scrolls were carbonised by intense heat.
But manuscripts from Chartres were also dowsed in water from fire hoses, which has had a particularly damaging effect on the rolled-up parchments.
"The action of water after the fire vitrified the parchments, making them like glass. They are also very breakable," said Dominique Poirel, a research engineer at the Institut de Recherche et d'Histoire des Textes in Paris, France.
It is not known whether this will pose any obstacle to reading the parchments with multispectral imaging.
Fateful raid
There are two alternative accounts of the events that led to the destruction of the library.
Some contemporary newspaper reports say a British plane, hit by German fire, dropped its bombs on the library as it fell from the sky.
But another version of the story maintains that a German pilot released his bombs over Chartres by accident, prompting other pilots in his formation to do the same. One of these bombs hit the library, causing the fire.
At the beginning of hostilities in 1939, the precious manuscripts were moved to Chateau de Villebon, a country house about 20 kilometres outside Chartres and deemed a safe location.
But in 1940, an official in the town's new German administration ordered the texts be returned to the library premises.
Ironically, this was a propaganda move designed to reassure the town's inhabitants that they had nothing to fear from Nazi occupation.
The centrepiece of the collection was the Heptateuchon, a treatise on the arts by the 12th Century philosopher Thierry de Chartres.
Mr Poirel said that while some pages of the Heptateuchon were still intact, much of it had been damaged by fire.
Mr Poirel said he had not yet looked into the possibility of using multispectral imaging to decipher texts from the medieval library but added: "If there were some reason to [request funding] we would."
