In Toby Lester’s Da Vinci’s Ghost: Genius, Obsession, and How Leonardo Created the World in His Own Image (to be published February 7 of next year), the author explains that Leonardo da Vinci carried a notebook on his belt in which he constantly sketched or left memoranda to himself.

Robert Krulwich, at an NPR blog, offers a translation of Leonardo’s personal To-Do list from some point early in the 1490s.

It’s an interesting list, testifying to its author’s remarkably broad range of practical and abstract interests, and as Maggie Koerth-Baker notes admiringly, to his recognition of superior expertise in the possession of others.

I think it’s pretty interesting that of the nine tasks shown, six involve consulting and learning from other people. Leonardo da Vinci needs to find a book. Leonardo da Vinci needs to get in touch with local merchants, monks, and accountants who he hopes can help him better understand concepts within their areas of expertise.

Leonardo da Vinci knows he doesn’t know everything.

I think that’s a big deal.

The fact that questions Leonardo intends to address so commonly include notes of just how he intends to obtain the necessary information is, I think, likely to make many of us with experience in research smile in recognition of a kindred spirit.

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 Christie’s, New York, in 1998, catalogued as “German school, early 19th century”. It sold for $19,000 (£11,400). Now a growing number of leading art experts agree that it is almost certainly by Leonardo da Vinci and worth about £100 million.

Carbon dating and infra-red analysis of the artist’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 Lumière Technology company. …

The fingerprint corresponds to the tip of the index or middle finger, and is “highly comparable” to one on Leonardo’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 “it sounded too good to be true — after 40 years in the business, I thought I’d seen it all”. But gradually, “all the bits fell into place.”

Professor Kemp has rechristened the picture, sold as Young Girl in Profile in Renaissance Dress, as La Bella Principessa after identifying her, “by a process of elimination”, as Bianca Sforza, daughter of Ludovico Sforza, Duke of Milan (1452-1508), and his mistress Bernardina de Corradis. He described the profile as “subtle to an inexpressible degree”, 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 Perréal 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 “may have been made by a German artist studying in Italy … based on paintings by Leonardo da Vinci”. …

Carbon-14 analysis of the vellum gave a date range of 1440-1650. Infra-red analysis revealed stylistic parallels to Leonardo’s other works, including a palm print in the chalk on the sitter’s neck “consistent … to Leonardo’s use of his hands in creating texture and shading”, according to Mr Biro.

“Cerca Trova” (Seek and Find) appears on a banner on Vasari’s mural of the Battle of Marciano

Only 15 surviving paintings are generally attributed in whole or in part to Leonardo. His responsibility for another six is disputed.

Dr. Maurizio Seracini, an engineering professor from UC San Diego, had been pursuing a quest to recover Leonardo Da Vinci’s largest painting, a 1505 fresco depiction of the 65 year earlier Battle of Angiarhi between Florence and Milan which once ornamented the Hall of Five Hundred in Florence, which disappeared in the course of a mid-16th century remodeling by Giogio Vasari, for a number of years.

The New York Times reports that scientific instruments are now ready to test Seracini’s hypothesis that Vasari simply walled-up the Da Vinci fresco.

“The Battle of Anghiari,” (was) the largest painting Leonardo ever undertook (three times the width of “The Last Supper”). Although it was never completed — Leonardo abandoned it in 1506 — he left a central scene of clashing soldiers and horses that was hailed as an unprecedented study of anatomy and motion. For decades, artists like Raphael went to the Hall of 500 to see it and make their own copies.

Then it vanished. During the remodeling of the hall in 1563, the architect and painter Giorgio Vasari covered the walls with frescoes of military victories by the Medicis, who had returned to power. Leonardo’s painting was largely forgotten.

But in 1975, when Dr. Seracini studied one of Vasari’s battle scenes, he noticed a tiny flag with two words, “Cerca Trova”: essentially, seek and ye shall find. Was this Vasari’s signal that something was hidden underneath? …

(N)ew analysis showed that the spot painted by Leonardo was right at the “Cerca Trova” clue. The even better news, obtained from radar scanning, was that Vasari had not plastered his work directly on top of Leonardo’s. He had erected new brick walls to hold his murals, and had gone to special trouble to leave a small air gap behind one section of the bricks — the section in back of “Cerca Trova.” …

Dr. Seracini was stymied until 2005, when he appealed for help at a scientific conference and got a suggestion to send beams of neutrons harmlessly through the fresco. With help from physicists in the United States, Italy’s nuclear-energy agency and universities in the Netherlands and Russia, Dr. Seracini developed devices for identifying the telltale chemicals used by Leonardo.

One device can detect the neutrons that bounce back after colliding with hydrogen atoms, which abound in the organic materials (like linseed oil and resin) employed by Leonardo. Instead of using water-based paint for a traditional fresco in wet plaster like Vasari’s, Leonardo covered the wall with a waterproof ground layer and used oil-based paints.

The other device can detect the distinctive gamma rays produced by collisions of neutrons with the atoms of different chemical elements. The goal is to locate the sulfur in Leonardo’s ground layer, the tin in the white prime layer and the chemicals in the color pigments, like the mercury in vermilion and the copper in blue pigments of azurite. …

Once he gets permission, Dr. Seracini said, he hopes to complete the analysis within about a year. If “The Battle of Anghiari” is proved to be there, he said, it would be feasible for Florentine authorities to bring in experts to remove the exterior fresco by Vasari, extract the Leonardo painting and then replace the Vasari fresco. Of course, no one knows what kind of shape the painting might be in today. But Dr. Seracini, who has extensively analyzed the damages suffered by many Renaissance paintings, said that he was optimistic about “The Battle of Anghiari.”

“The advantage is that it has been covered up for five centuries,” he said. “It’s been protected against the environment and vandalism and bad restorations. I don’t expect there to be much decay.”

If he is right, then perhaps Vasari did Leonardo a favor by covering up the painting — and taking care to leave that cryptic little flag above the trove.

Rubens chalk, ink, and water-color copy of Da Vinci study for “The Battle of Anghiari,” Musée du Louvre

Leonardo da Vince, The Virgin and Child with St. Anne, oil on wood, circa 1508, Louvre, Paris

Reuters:

A curator at the Louvre Museum in Paris has stumbled upon some unknown drawings on the back of a painting by Leonardo da Vinci that look like they might be by the Italian master himself, the Louvre said on Thursday.

The extraordinary find was made by chance, when Louvre staff unhooked Leonardo’s “The Virgin and Child with Saint Anne” from the museum wall as part of a broad programme of study and restoration of paintings by Leonardo, including the “Mona Lisa.”

“When the work, which is painted on wood, was unhooked, a curator noticed two barely visible drawings on the back of the painting, showing a horse’s head and half a skull,” the museum said.

It was such an astonishing discovery that other Louvre staff present at the time could not believe it and initially said the marks on the wood must be stains.

“The Virgin and Child with Saint Anne” was painted in the early 1500s and no one had previously noticed the drawings — at least not to the knowledge of the Louvre.

After the initial find, the museum conducted detailed tests on the back of the painting. Photographs taken with an infrared camera revealed that there were not two but three drawings. The third one is of a Child Jesus playing with a lamb.

“This is an exceptional discovery because drawings on the back of paintings are very rare and no example by Leonardo was previously known,” the Louvre said.

It said the drawings recalled some of Leonardo’s known works and suggested that the child and lamb could have been sketches for the painting on the other side of the piece of wood.

Sketches visible on reverse of painting

1:58 London Times video

Sketch of horse’s head