Leonardo da Vinci, Portrait of Young Girl in Profile
The London Time describes how sophisticated forensic techniques were able to authenticate a portrait profile drawing in inks and chalks as the work of Leonardo da Vinci.
The 33 x 23cm (13 x 9in) picture, in chalk, pen and ink, appeared at auction at Christieâ€™s, New York, in 1998, catalogued as â€œGerman school, early 19th centuryâ€. It sold for $19,000 (Â£11,400). Now a growing number of leading art experts agree that it is almost certainly by Leonardo da Vinci and worth about Â£100 million.
Carbon dating and infra-red analysis of the artistâ€™s technique are consistent with such a conclusion, but the most compelling evidence is that fragment of a fingerprint.
Peter Paul Biro, a Montreal-based forensic art expert, found it while examining images captured by the revolutionary multispectral camera from the LumiÃ¨re Technology company. …
The fingerprint corresponds to the tip of the index or middle finger, and is â€œhighly comparableâ€ to one on Leonardoâ€™s St Jerome in the Vatican. Importantly, St Jerome is an early work from a time when Leonardo was not known to have employed assistants, making it likely that it is his fingerprint.
Martin Kemp, Emeritus Professor of History of Art at the University of Oxford, is convinced and recently completed a book about the find (as yet unpublished). He said that his first reaction was that â€œit sounded too good to be true â€” after 40 years in the business, I thought Iâ€™d seen it allâ€. But gradually, â€œall the bits fell into place.â€
Professor Kemp has rechristened the picture, sold as Young Girl in Profile in Renaissance Dress, as La Bella Principessa after identifying her, â€œby a process of eliminationâ€, as Bianca Sforza, daughter of Ludovico Sforza, Duke of Milan (1452-1508), and his mistress Bernardina de Corradis. He described the profile as â€œsubtle to an inexpressible degreeâ€, as befits the artist best known for the Mona Lisa.
If it is by Leonardo, it would be the only known work by the artist on vellum although Professor Kemp points out that Leonardo asked the French court painter Jean PerrÃ©al about the technique of using coloured chalks on vellum in 1494.
The picture was bought in 1998 by Kate Ganz, a New York dealer, who sold it for about the same sum to the Canadian-born Europe-based connoisseur Peter Silverman in 2007. Ms Ganz had suggested that the portrait â€œmay have been made by a German artist studying in Italy … based on paintings by Leonardo da Vinciâ€. …
Carbon-14 analysis of the vellum gave a date range of 1440-1650. Infra-red analysis revealed stylistic parallels to Leonardoâ€™s other works, including a palm print in the chalk on the sitterâ€™s neck â€œconsistent … to Leonardoâ€™s use of his hands in creating texture and shadingâ€, according to Mr Biro.