Leonardo da Vinci

by Martin Kemp

There was a strong tradition in Tuscany of artist–engineers. Verrocchio was involved in at least one engineering project, and the great Florentine architect Filippo Brunelleschi (1377–1446) was renowned as an engineer. However, it is unlikely that Leonardo could demonstrate hands-on experience of most of the techniques he claimed to have at his command. There are a limited number of engineering drawings that can be attributed to his first period in Florence.

  Leonardo is here illustrating a way to dislodge the ladders used by an enemy to scale a castellated wall. Each section of a pole running near the top of the outside of the wall is thrust outward by three horizontal poles attached to a lever that is operated either by two men pulling on a rope or by one man turning a windlass. Whether this is his own invention or illustrates a known device is unclear.

  Leonardo’s methods of illustrating the mechanism already exhibit some novel features, compared with standard engineering drawings of the time. He has shown a schematic section of the wall in succinct perspective. He has added cutaway details of how the pole that extends to the fulcrum of the levers is anchored into the wall by joints that expand when the pole is driven in. The lowest study appears to show a system of lamination, perhaps for the wooden beam that runs along the edge of the platform.

  17. Studies of Archimedean Screws, Wells, and Pumps and an Underwater Breathing Device

  c. 1475–80, Milan, Biblioteca Ambrosiana, Codice atlantico, 1069r

  The management of water was a major economic and social concern in all Renaissance societies. Engineers who could facilitate safe and reliable water supplies in urban settings were well rewarded for their services.

  One of the prime needs was to be able store water in high tanks or reservoirs to produce a head of water to generate the pressure needed to transmit water from one place to another. One device for lifting water, credited to the Greek inventor Archimedes, was a pipe arranged as a helix and placed at an angle so that when the axle of the screw is rotated, the water in one part of the pipe will run into the next part of the pipe. In effect, the water is being wound uphill.

  The system involving two towers (on the top left of the right sheet, opposite) shows two screws feeding reservoirs at the top of short and tall towers. The lower screw is turned by a waterwheel, drawing water from an onrushing stream. The top of this screw is geared to turn a second screw that draws water from the reservoir at the top of the shorter tower, which is fed by the first screw. There is no indication of how the screws are to be supported.

  The other main devices on the sheet involve the raising of water from wells or deep reservoirs, either with conventional systems of buckets or with the use of pumps. The precise operation of the devices is difficult to determine. Again the method of demonstration, involving the perspectival rendering of the components and transparent views of sections underground, surpasses the methods of conventional drawings in engineers’ treatises.

  Characteristically, while thinking about devices for water, Leonardo squeezed a sketch into the left-hand margin of the sheet that shows how to breathe underwater. A flexible breathing tube is kept aloft by a circular float so that air can be drawn into the diver’s mouth. Similar devices were found in earlier notebooks by fifteenth-century engineers.

  “Characteristically, while thinking about devices for water, Leonardo squeezed a sketch into the left-hand margin of the sheet that shows how to breathe underwater.”

  18. Studies of a Scythed Chariot, an Armored Wagon, and the Point of a Halberd

  c. 1483–85, London, British Museum

  This sheet presents entertaining examples of the war machines designed to demonstrate Leonardo’s prowess as an inventor for his patron in Milan, Ludovico Sforza. They can be regarded as exercises in “visual boasting,” typical of the kinds of extravagant inventions paraded in presentation treatises by engineers. Practicality does not seem to have been uppermost in the inventor’s or patron’s mind.

  The upper study of the chariot emulates ideas in the treatise De re militare (On Military Matters, 1472) by Italian engineer Roberto Valturio (1405–75), who delighted in a range of inventions of modern and ancient kinds. Leonardo’s study, beautifully drawn in fine pen and ink, with a spirited pair of rearing horses and a horseman with a fluttering cloak, goes far beyond the functional. The spiked wheels of the chariot engage a lantern gear that turns a central axle. This axle drives the paired blades and spike at the rear and provides the motive power for the four whirling scythes. The apparatus appears to be high in visual intimidation and low in applicability to actual war.

  The same is true of the “tank” on the lower portion of the sheet. The study on the left, showing the wagon without its conical roof, reveals four spoked wheels driven by two camshafts with four lantern gears. Leonardo tells us that it is to be operated by eight men and is to be used to penetrate the ranks of the enemy. Were the gears to be located as he shows, the front and rear wheels would be driven in opposite directions! The drawing on the right shows the scuttling wagon dispersing a spray of missiles from the small cannons around its periphery. Leonardo did not take account of how the cannons might be loaded and what effect they would have on the occupants.

  In the right margin, drawn in different ink, is a spear or halberd with a collar of secondary spikes, one of many elaborate and seemingly inexhaustible variations by Leonardo on the basic form.

  “Leonardo’s study, beautifully drawn in fine pen and ink, with a spirited pair of rearing horses and a horseman with a fluttering cloak, goes far beyond the functional. . . . The apparatus appears to be high in visual intimidation and low in applicability to actual war.”

  19. Study of a Woman’s Head in Profile

  c. 1481–82, Paris, Louvre

  In the list of works he apparently compiled after his move to Milan (see page 31), Leonardo included “an Our Lady finished / another almost which is in profile.” The only known candidate for the “Madonna in profile” is the Madonna Litta painting in the Hermitage (below), named after the Milanese family who owned it in the nineteenth century.

  The wonderfully refined if somewhat damaged metalpoint drawing on greenish paper shown here is preparatory for the Madonna Litta. It is surely done from life, using a model who has bound her hair in a plain scarf. Leonardo has handled the refined medium with incredible delicacy, above all in the parallel hatching that renders the shadows on the woman’s face, neck, and hair. The hint of the top of her ear under her hair is notably subtle. The lines are rather softer in texture and more blended than would normally be the case with silverpoint, suggesting that the artist may have used a softer metal. The outlines appear to have been inscribed more emphatically with a metalpoint (or even with a pen) that is less pointed at its tip. There is also a little unrelated figure in the lower left corner.

  Is the madonna litta actually by leonardo? Once assumed to be by Leonardo himself, it is now generally recognized as being painted by Giovanni Antonio Boltraffio (c. 1467–1516), who was Leonardo’s most technically accomplished assistant in Milan. Although a little abraded, the painting of the flesh tones is very slick, giving the forms a smooth, rather generalized quality, particularly noticeable in the Virgin’s hands. Most decisively, a study for the Madonna’s drapery in the Staatliche Museen in Berlin is skillfully drawn with silverpoint in Boltraffio’s pedantically polished and precise manner. It is tempting to attribute the awkwardly twisting pose and disconcerting stare of the suckling child to Boltraffio, but the bold torsions and direct communication are characteristic of Leonardo’s early ambitions. It seems that Leonardo willingly handed over his unfinished panel to be completed by his amanuensis.

  Madonna Litta, c. 1495, attributed to Giovanni Antonio Boltraffio,St. Petersburg, Hermitage.

  20. Virgin of the Rocks

  c. 1483–93, Paris, Louvre

  21. Head of a Young Woman Looking Outward

  c. 1483–84, Turin, Biblioteca Reale

  22. Cartoon for the Head of the Infant St. John the Baptist

  c. 1
483–96, Paris, Louvre

  The story of the commission for the Virgin of the Rocks is one of the most convoluted in the history of art, involving a complex contract awarded to Leonardo and two brothers in 1483, a dispute about payment, the apparent sequestration of the picture by Ludovico Sforza, the commencement of a substitute and its abandonment, prolonged legal action by the commissioners, and the painting’s eventual completion twenty-five years later. Into this story we need to fit two prime versions of the picture, one in the Louvre and the other in London’s National Gallery (see page 152).

  On April 23, 1483, Leonardo and the brothers Evangelista and Giovanni Ambrogio da (or de) Predis were commissioned to provide the painted components for a very large and complicated architectural and carved altarpiece for the Confraternity of the Immaculate Conception in the Milanese church of San Francesco Grande. The tasks included the costly gilding and painting of statues, including important wooden sculptures of the Virgin and God the Father; and a series of reliefs and architectural components, most of which were to be colored in the “Greek [i.e. Byzantine] style.” There were also “flat surfaces” to receive paintings, including four angels. The middle panel, as specified in the contract, was “to be painted on the flat surface [with] Our Lady and her Son with the angels all done in oil to perfection . . . in colors of fine quality as specified above.” The painters were given about twenty months to complete the substantial assignment.

  Things did not go according to plan. The extensive tangle of documentation leaves plenty of room for alternative explanations. Leonardo and Ambrogio claimed in a letter, apparently to Duke Ludovico Sforza, that they had been underpaid, and asserted that they should have received 100 ducats for the painted panel at the center of the complex. They announced caustically that the “blind cannot judge colors.” It is probable that the Duke took advantage of the dispute to commandeer the Madonna in 1494 as a wedding gift for the Holy Roman Emperor Maximilian I and Bianca Maria Sforza (the duke’s niece). This left the painters to fulfill their obligation, which they did not do before Leonardo left Milan in 1499. We will pick up the story after 1500 when we look at the second version on page 152.

  Leonardo interpreted the brief for the central panel quite freely. Rather than a Madonna and Child with angels, he has shown Mary and her Son in exile in the wilderness meeting the infant St. John, who is chaperoned by the angel Uriel. This story is one of the legendary accretions surrounding the early years of Jesus. Leonardo tells of the meeting of the infants through a network of spatial gestures and glances under the shelter of Mary’s cloak and outstretched hand. There is no doubt about the identity of the children. John prays in supplication, receiving Christ’s blessing. Uriel’s pointing hand, added to the picture quite late, points emphatically to her charge. Clearly, a lovely metalpoint drawing in Turin of a young woman (opposite, left) turning to look at us served as the basis for the angel’s tender and knowing glance.

  The setting is pregnant with science, meaning, and mystery. Leonardo’s study of nature is vividly apparent throughout: the foreground strata at the edge of what may be a pool; the formations of angular and rounded rocks in the grotto; the variety of precisely characterized plants; and the atmospheric distance. The flowers are likely to carry symbolic meanings. The iris at the lower left stands alongside the lily as a symbol of the Virgin, and its pointed leaves signal the swords of sorrow that will pierce her heart. The flower of the columbine in the center above the pool can be seen as referring to the dove of the Holy Spirit, perhaps also alluding to the description in the Song of Songs of the Virgin as a “dove in the cleft of rocks.” The rocky setting combines science and spiritual presence in equal measure. Leonardo’s pioneering naturalism and traditional symbolism are melded into an imaginative compound that speaks of the supreme mystery of the sacred encounter in the wilderness.

  Leonardo’s individualistic handling of light, shade, and color gives us some idea of how the Adoration of the Kings (page 26) and St. Jerome (page 30) might have looked if completed. Although the Paris Virgin of the Rocks was damaged when it was transferred from panel to canvas in 1806, we can still see how remarkable Leonardo’s method is. He is practicing what was later called tonal painting; that is to say the colors operate within an overarching system of light and shade, in which they are all subject to the same process of darkening in the shadows, finally losing almost all their independent color.

  In the unfinished Adoration, the shaded areas were underpainted as a dark substratum from which the illuminated forms would have emerged. Leonardo was above all aiming to create what he called rilievo (three-dimensional relief) by setting spotlit forms against dark backgrounds. The result can be readily seen in the Virgin of the Rocks, in which the individual colors rise into the light, progressively declaring their inherent nature. The dark blue of the Virgin’s dress remains quite deep in tone, while the yellow fabric leaps into radiance. The red of the angel’s garment catches the light in a way that is between these extremes.

  Set in its heavily gilded altar, Leonardo’s penumbral cavern must have looked very cavernous.

  Finally, it is good to report the exceptional survival of a pricked cartoon, not for the whole painting but for the charming head of St. John (opposite, right), drawn with skilled economy. Perhaps Leonardo used a series of separate cartoons for key parts of the painting. We know the head was replicated by at least one senior assistant in the workshop to make a small painting of the Madonna and Child.

  Head of a Young Woman Looking Outward, c. 1483–84.

  Cartoon for the Head of the Infant St. John the Baptist, c. 1483–96.

  “A lovely metalpoint drawing in Turin of a young woman turning to look at us served as the basis for the angel’s tender and knowing glance. The setting is pregnant with science, meaning, and mystery. Leonardo’s study of nature is vividly apparent throughout.”

  23. Study of a Rocky Cliff and Ravine

  c. 1481, Windsor, Royal Library, 12255

  Artists before Leonardo must have made landscape drawings. Netherlandish art is full of landscapes that must have been directly observed and recorded. Leonardo’s master, Verrocchio, followed the Northern artists in this respect, as did Domenico Ghirlandaio (1449–94) and Pietro Perugino (c. 1450–1523), fellow pupils of Leonardo. But none approached landscape with Leonardo’s analytical and narrative eye.

  Although the locale has not been identified, the drawing here is based on hard observation and systematic thinking about form and process in nature. A jagged cliff stands on the left, composed from the reddish limestone that is plentiful in Tuscany. The vertical splitting and horizontal fracturing of the rocks has been faithfully recorded. At the top, two trees have desperately insinuated their roots between horizontal strata. At the base of the cliff, smaller fragments and boulders have been cast down by the waters. A vertical ravine has been cut by a watercourse that has reshaped boulders and broken rocks into stones. At the mouth of the ravine, the waters have uncovered a small stack of strata, partly dammed by collapsed blocks of stone. At the foot of the cliff, rocks have been progressively broken down into gravel, and in the left-hand corner plants begin to grow from the first layer of fertile soil.

  Later, in the Codex Leicester (c. 1506–13), Leonardo was to write about this graded geological process: the splitting of rocks, the shattering and erosion of boulders into pebbles, the formation of sand, and the deposit of soil. There is no indication that Leonardo was developing a framework of geological theory at this time, but he was clearly aware of the embedding of time in rocky topographies. There is already a powerful sense of the “body of the earth” as a living and changing entity, in which inert materials become infused with life.

  It might be tempting to identify the out-of-scale waterfowl in the foreground as additions made by a cheery pupil. However, the dynamism of the flapping swan (?) is typical of Leonardo himself.

  “He is clearly aware of the embedding of time in rocky topographies. There is already a powerful sense of
the ‘body of the earth’ as a living and changing entity, in which inert materials become infused with life.”

  24. Portrait of a Man with a Sheet of Music

  c. 1483–86, Milan, Pinacoteca Ambrosiana

  The fixed pose and stare of this sitter have been cited as reasons why the portrait seen here is not by Leonardo. The modeling of the head aligns reasonably well with that of the angel in the Louvre Virgin of the Rocks (see page 40). The scintillating vitality of the sitter’s vortical hair and the incisive use of light and shade on his lean face speak of Leonardo’s analytical naturalism. But the most decisive factor is the sense of intense intelligence and sensitivity in the young man’s eyes and mouth.

  The head and hair have been brought to a full level of finish, but the other parts of the picture are incomplete to various degrees. The man’s stole is no more than a rough underpainting. The hand and sheet of music are both unfinished and badly damaged. The way the man’s fingers grasp the folded paper is strange spatially, and we must assume that it has been folded very stiffly. The music on the paper has been heavily abraded and the remaining is difficult to decipher. It appears to show the sesquialtera proportion (three notes sung in the space of two) as described by Franchino Gaffurio, the leading composer and theorist in Sforza Milan. The damaged writing is best interpreted as designating the voice part, contratenor acutus (“high countertenor”).

  Gaffurio has been suggested as the sitter. The great French composer Josquin des Prez, who was in Milan at more than one point in the 1490s, has also been identified as the musician. The intimate feel of the portrait makes it most likely that it portrays Atalante Migliorotti, the Florentine singer, master of the lira da braccio (an early form of violin) and maker of stringed instruments. It seems likely that Atalante and Leonardo traveled together from Florence. In Leonardo’s list of drawings from c. 1482, he mentions “a head portrayed from Atalante who raises his face.”