Читать книгу The Last Leonardo - Ben Smith Lewis - Страница 12

Leonardo was the most prolific draftsman of his age, with approximately four thousand surviving drawings attributed to him, four times the number left by his most active contemporaries.1 He drew diagrams, emblems, allegories, architecture, anatomy, maps, landscapes, biblical figure groups, nude studies and portraits from life. He was an expert in silverpoint, using a hard-edged metal stylus to draw lines into paper covered with a mixture of pulverised bone and mineral colours. He liked ink and quill pens plucked from the wings of domestic geese. After the turn of the sixteenth century he preferred chalks: red, black and white. He often touched up his drawings with white highlights in yet another medium, gouache. Some of Leonardo’s early paintings, St Jerome and Adoration of the Magi among them, progressed little beyond the full-size drawing stage.

As a draftsman, Leonardo was a revolutionary. To him we owe the world’s first dated landscape sketch, the world’s first ‘exploded’ diagram of machine parts, and the world’s first freeform compositional sketches, in which he plans – or perhaps rather finds – a composition out of a rapid-fire maelstrom of spontaneous, half-automatic lines, scribbled in ink and chalk. One of his most famous and most reproduced works is a diagrammatic drawing, Vitruvian Man, in which a man’s body with extended limbs forms a square and a circle. According to the sixteenth-century Italian writer Giambattista Giraldi Cinzio, citing the reminiscences of his father, who had observed Leonardo first-hand, the artist rarely left his studio without a sketchbook hanging from his belt. In his notes for his treatise, Leonardo issued the first known exhortation about drawing from real life:

As you go about town, be always alert when out walking, to observe and consider the actions of men while they are talking, thinking, laughing or fighting together, what actions are within them, and what actions the onlookers are doing … and make brief notes of these forms in your small notebook, which you must always carry with you, and it should be of tinted paper, so that it cannot be erased, and must be kept diligently, because the positions and actions are many, and the memory is unable to remember them all.

The surviving studies for the Salvator Mundi, however, which are drawn in red chalk on red tinted paper, were executed in the studio, because they were sketches of clothing – or drapery, to use the art historian’s terminology – and they were almost certainly based on draped mannequins, not live models. Today these drawings can be found in the Royal Collection at Windsor Castle.

‘Leonardo sometimes made clay models,’ wrote Giorgio Vasari, the great sixteenth-century Florentine art historian of the Renaissance, ‘draping the figures with rags dipped in plaster, and then drawing them painstakingly on fine Rheims cloth or prepared linen.’ Drapery was one of the essential components of Renaissance painting, and acted as a form of messaging in itself. The classical robes in which the saintly starring cast of Renaissance paintings were dressed elevated biblical stories to the level of the Antique, fusing the two great sources of wisdom of the age, the Bible and classical civilisation. Their sheen, dips and pleats were bravura exercises in realism, which advertised the illusionistic skill of the artist. There is a series of sixteen drapery studies drawn on linen, usually dated to the early 1470s, some attributed to Leonardo at the tender age of nineteen. The young artist shows the texture and characteristics of the fabric depicted as well as indicating the body underneath, the cloth flowing with curving arabesques and hard-edged angles, receding in pockets of shadow, and gleaming where it catches the light.

Leonardo usually planned his paintings with three stages of drawings. First, there were the studies of body parts, gestures, faces, drapery, anatomy and landscapes, drawn from life or sometimes from models or classical statues. In a second stage, he made sketches of combinations of figures or laid out the entire composition. Last came full-scale cartoons, which were traced onto the panel on which the final painting would be executed. There must have once been many preparatory drawings for the Salvator Mundi – for Christ’s face, the blessing hand and the orb, and perhaps for the entire composition – but only two pages of sketches survive. On one sheet there are two drawings – one of a man’s torso clothed with an episcopal garment known as a stole, and the other a smaller depiction of a forearm emerging from a rich crumple of sleeve, drawn in red chalk and then overdrawn in white. On the second sheet is a forearm with a sleeve finishing in a cuff, with drapery around it.

These sketches provide a host of intriguing clues about the Salvator Mundi. The fabric covering the chest is drawn in obsessive detail, one of the characteristics of Leonardo’s style, with thin rivulets of cloth, each one differentiated, running down from the band of embroidery around the neck, which has bunched up the fabric in tiny pleats. Looking at the painting, on the left side of the chest, just above a diagonal band, the garment’s fabric has become curiously scrunched. The artist seems to take particular care in showing how untidy this part of the clothing is. The shape and position of this crumple is momentous. At exactly the spot where the Holy Spear pierced Christ’s body on the cross, the wound of the Passion, it forms the Greek letter omega, a symbol of the divine. Novelists and historians of varying academic qualifications have written numerous outlandish interpretations of hidden symbols they have discerned by carefully squinting at Leonardo’s paintings, such as the Virgin of the Rocks and the Mona Lisa, but here in the Salvator Mundi there is a real one.

Other aspects of these sketches muddy the artistic waters of attribution. The forearm on this same page seems to have been drawn not by Leonardo but by another artist entirely, surely one of Leonardo’s assistants. In the 1930s, the great Leonardist Kenneth Clark catalogued the collection of Leonardo’s drawings owned by the British royal family, which included both of these sketches. He observed that the draftsmanship of the forearm is heavy-handed compared to the chest, and that, furthermore, the hatching runs left to right, while Leonardo’s always runs right to left, as one would expect of a left-handed artist.

The second drawing holds a puzzle too. The sleeved limb emerges from two loose loops of fabric, which closely resemble the drapery around Christ’s arm held up in blessing in the painting. But in the drawing the forearm is sleeved with a cuff at the end; in the painting it is bare. As a preparatory study it bears a surprisingly loose relationship to the finished painting.

We can vaguely date both drawings to the first decade of the sixteenth century, because of the evolution of Leonardo’s style and technique. He spent most of his early career sketching in pen and ink or silverpoint. In the mid-1490s he began using red chalk for studies for the apostles in The Last Supper. In the first decade of the sixteenth century, chalk became Leonardo’s primary drawing medium. The material was better suited to the style he was developing. Chalk’s softness allowed him to intensify his sfumato, the most gradual light-to-dark transitions which became the hallmark of his painting.2 It is in this later drawing style that the preparatory sketches are executed.

Drawing is the common denominator between all of Leonardo’s diverse activities as engineer, scientist and artist. And yet Leonardo had criticisms of drawing. One of the fundamental aspects of his thinking, which set him apart from his contemporaries, was his radical attitude to line. ‘Lines are not part of any quantity of an object’s surface, nor are they part of the air which surrounds this surface,’ he wrote. ‘The line has in itself neither matter nor substance and may rather be called an imaginary idea than a real object … Your shadows and lights should be blended without lines or borders in the manner of smoke losing itself in the air … O painter, do not surround your bodies with lines!’ There were no lines in the real world, he said, so don’t paint them.

In the cool and pungent backstreets of Milan, in the dark shops of the apothecaries, majolica vases lined the shelves, full of herbs, medicines, chemicals and pigments – the raw material for colouring the world. These were roughly chopped preparations of minerals, insects, animal remains and plants, waiting to be finely ground into powder, mixed with egg yolk or oils to make paint, and with water for dyes. The customers came and went – dyers, glassmakers, tailors, the manufacturers of ceramics and furniture, manuscript illuminators and painters.

Behind every Leonardo painting lay a global network of anonymous collaborators, with professions far removed from the creative arts. The minerals for pigments came in ships from distant Central Asian cities that few Europeans had seen, often via Syrian merchants. Some were manufactured in Venetian or Florentine laboratories run by religious orders. There was ultramarine powder ground from blue-veined chunks of lapis lazuli by the Jesuits of the Florentine Convent of Santo Giusto alle Mure; the semi-precious rock was imported from what is now Afghanistan and Uzbekistan, via Damascus. A more sensibly priced version of the same colour, from the same convent, was made of azurite acquired from Austrian and Balkan mines and manufactured with copper oxide. The chromatic reputation of these priests was so high that the Florentine contract commissioning the Adoration specified that Leonardo had to buy his colours from them. A red pigment came from the dried bodies of kermes lice from the eastern Mediterranean, mixed with water, alum and soda. Another came from boiled brazilwood, which Spanish and Portuguese merchants imported from the Latin American colonies. A third red, ‘dragon’s blood’, was a resin derived from various plants, and was used both as a medicine and a varnish. Cochineal was a scarlet named after the insects from which it came, and was imported to Italy via Antwerp. Rubies, which could be ground down into an expensive colour, were available too. White, ochre, and yet another red came from different treatments of lead. A dark ‘bone black’ came from a distillation of carcasses. Verdigris, a green familiar to us as the patina on old copper, was obtained by exposing copper plates to vinegar. Gold leaf was made from old coins, the thin sheets carefully placed between sheaves of paper in books. Saffron was used to make an intense yellow colour when mixed with alum and egg yolk. Thus, science and trade formed a basis for art.

Leonardo would probably have sent one of his teenage apprentices to buy the pigments, a shopping list in his hand. The artist’s notebooks contain to-do lists, often compiled before a long journey, which give an indication of the errands his ‘boys’ had to run. One, from 1490, reminds the apprentice to get hold of ‘a book that treats of Milan and its churches, which is to be had at the stationers on the way to Cordusio [a piazza in the centre of the city]’. Another, from the years 1508 to 1510, quite possibly the time when Leonardo began to work on the Salvator Mundi, lists ‘boots, stockings, comb, towel, shoelaces, penknife, pens, gloves, wrapping paper, charcoal, spectacles with case, firestick, fork, boards, sheets of paper, chalk, wax, forceps …’ This list may refer to items he had already bought from Milan’s shopkeepers and kept in his studio, but Leonardo does add a note about one thing that he clearly didn’t have: ‘Get hold of a skull.’

For the Salvator Mundi, the apprentice would have had only a small number of pigments on his list, because this painting was made with remarkably few colours: lead white, lapis lazuli, lead tin yellow, vermilion, red iron oxide, carbon and charcoal black, bone black and umber. Back in the studio, the assistants would then have to grind the colours to create a fine powder. However, on this occasion, as later restoration showed, they didn’t do a very thorough job: the brilliant blue grains of the lapis lazuli were rather coarse compared to those in Leonardo’s other paintings.

There was probably a cartoon by Leonardo for the entire composition of the Salvator. This would have been pricked with tiny holes, or spolveri. The cartoon was laid on top of the panel, dusted with fine powder and then removed. An outline of the composition, traced by the dark dust seeping through the pinpricks, remained. Microscopic photographs of the Salvator Mundi have revealed a handful of tiny black dots, but only enough to raise the possibility, not the certainty, of a cartoon. The artist definitely used a pair of compasses to make the circle of the orb, because there is a hole where the compass point went in. Then another layer of underpainting was added in thin, semi-transparent washes of browns and blacks, some derived from charred wood, others from charred bones.

Leonardo was a member of the Arte dei Medici, Speziali e Mercai – the Guild of Doctors, Apothecaries and Mercers. He had his own recipes for making colours, and he listed many of them in his notebooks. That was unusual for a Renaissance painter, but it fits our knowledge of Leonardo the artist-scientist. The master of light and shade was particularly interested in the variety of ways he could mix colour for shadows: ‘Take green [i.e. malachite] and mix it with bitumen, and this will make the shadows darker. And for lighter shades mix green with yellow ochre, and for even lighter green with yellow, and for the highlights pure yellow. Then take green and turmeric together and glaze everything with it … to make a beautiful red take cinnabar or red chalk or burnt ochre for the dark shadows, and for the lighter ones red chalk and vermilion, and for the highlights pure vermilion, and then glaze with fine lake.’

We don’t know how the artist of the Salvator Mundi prepared his palette, but there is a description by Vasari of the way another artist, who was taught in the same studio as Leonardo, did. Lorenzo di Credi and Leonardo were both trained by the Florentine master Andrea Verrocchio, and sometimes worked on the same pictures together. Di Credi, says Vasari, ‘made on his palettes a great number of colour mixtures, so that they went gradually from the lightest tint to the darkest, with exaggerated and truly excessive regularity, so that sometimes he had twenty-five or thirty on his palette, and for each of them, he kept a separate brush’. Such preparation would also have been necessary for the delicate, painstaking and time-consuming manner in which the Salvator Mundi was painted.

Now Leonardo could pick up his brush and begin to paint – should he have had the inclination, of which we cannot be certain. Unlike every other picture Leonardo is widely recognised to have executed after his fame was established, there is no documentary evidence that his hand ever painted the Salvator. That is not in itself an unusual problem for a Renaissance painting. Thousands of artworks before 1700 were unsigned and undated, leaving art historians with thousands of picture-puzzles to solve. The tool of connoisseurship was developed two centuries ago specifically to tackle this problem. But it is a process which art dealers such as Robert Simon and Alex Parish cannot undertake on their own, since however gifted they might be as connoisseurs, they are potentially compromised by commercial motivations. Thus, it was time to call in the experts.