Scientists have detected the face of an ancient Roman man hidden below the surface of a precious 19th-century wall painting in the Louvre Museum in Paris.
In the latest achievement in efforts to see what may lie underneath the surface of great works of art,scientists described the first use of an imaging technology like that used in airport whole-body security scanners to detect the face of an ancient Roman man.
They described unveiling the image,which scientists and art historians say may be thousands of years old,during a meeting of the American Chemical Society in New Orleans. J Bianca Jackson,who reported on the project,explained that it involved a fresco,which is a mural or painting done on a wall after application of fresh plaster.
In a fresco,the artist’s paint seeps into the wet plaster and sets as the plaster dries. The painting becomes part of the wall. The earliest known frescoes date to about 1500 BC and were found on the island of Crete in Greece.
“No previous imaging technique,including almost half a dozen commonly used to detect hidden images below paintings,forged signatures of artists and other information not visible on the surface has revealed a lost image in this fresco,” Jackson said.
The technology is a new addition to the palette that art conservators and scientists use to see below the surface and detect changes,including fake signatures and other alterations in a painting.
Termed terahertz spectroscopy,it uses beams of electromagnetic radiation that lie between microwaves,like those used in kitchen ovens,and the infrared rays used in TV remote controls. This radiation is relatively weak,does not damage paintings and does not involve exposure to harmful radiation.
“Terahertz technology has been in use for some time,especially in quality control in the pharmaceutical industry to assure the integrity of pills and capsules,in biomedical imaging and even in homeland security with those whole-body scanners that see beneath clothing at airport security check points,” said Jackson,who is now with the University of Rochester.
Artists,including some of the great masters,sometimes re-used canvases,wiping out the initial image or covered old paintings with new works. They often did this in order to avoid the expense of buying a new canvas or to enhance colours and shapes in a prior composition.
The scientists turned to terahertz technology when suspicions surfaced that a hidden image might lie beneath the brushstrokes of a precious 19th century fresco,Trois homes armes de lances,in the Louvre’s Campana collection.