Leonardo and the Last Supper

by Ross King

  Leonardo may have been worried about prying eyes because he planned a death-defying flight as a surprise during one of Lodovico’s numerous festivals. A few years later, in 1498, as entertainment for a marriage feast, a mathematician from Perugia, Giovanni Battista Danti, would, according to legend, fashion a pair of wings and launch himself from the city’s tallest tower. To the amazement of the spectators, he sailed across the piazza before his steering mechanism malfunctioned and he crashed onto the roof of a church, breaking a leg but escaping with his life.45

  No contemporary documents record that Leonardo’s uccello ever took flight. A half century later Gerolamo Cardano, whose father knew Leonardo in Milan, claimed the painter “tried to fly but in vain.” 46 Cardano failed to tell where and when the test flight occurred, or why the test was unsuccessful, but a launch from the top of the Corte dell’Arengo seems unlikely. Leonardo’s researches into human aviation were far more sophisticated and advanced than any of the previous ones. He was also more mindful of safety, projecting the use of not only the wineskin lifejacket but also the equivalent of airbags: he hoped to lessen the impact of a crash by means of a series of bags “strung together like a rosary” and fixed to the pilot’s back.47 Even so, it is difficult to imagine his test flight having a happier outcome than those of earlier bird-men, especially if the launch pad was the parapet of a castle in the middle of a crowded city.

  Leonardo at this point, in the mid-1490s, was full of optimism about the possibilities of flight. The reverse of the page detailing his plans for a flight from the Corte dell’Arengo shows a sketch of Europe (copied from Ptolemy’s Cosmographia) to which he added the words: “In the dream of the conquest of air the immense field open to the miraculous pilot.” All of Europe, in other words, lay at the feet of the miraculous pilot. But the year 1496 marks a temporary end to Leonardo’s studies of flight. After devoting himself to the subject for more than a dozen years, he abruptly ceased his investigations, possibly because of some catastrophic design failure, or else simply due to an awareness that his prototypes were simply not airworthy.

  Leonardo would resume his studies some eight years later, back in Florence, when he began his Codex on the Flight of Birds. A note on the inside cover testifies to his continued hopes for human aviation: “The great bird will take its first flight on the back of his great swan, filling the universe with wonders; filling all writings with his fame and bringing eternal glory to his birthplace.”48 The “great swan” refers to Montececeri, a mountain outside Florence named for large birds, ceceri, that in turn took their name from a protuberance on their beaks shaped like a chickpea (cece). Here, above the rock quarries of Fiesole, Leonardo evidently hoped to launch one of his flying machines. Yet if his flight ever did occur, it failed to fill all the writings with his fame: no documentary evidence exists to support it.

  CHAPTER 10

  A Sense of Perspective

  One of the first things Leonardo did after laying his base coat of lead white on the wall of Santa Maria delle Grazie was to hammer a nail into the plaster. This nail marked the very center of the mural, the point on which all lines and all attention would converge: the face of Christ.

  A small hole is still visible in the right temple of Christ, like an eerie prevision of the crown of thorns. For Leonardo the nail marked what he called the “diminishing point”: the location on which all lines of sight “tend and converge.”1 Rediscovery of the laws of linear perspective revolutionized art during the fifteenth century. Artists learned to create spatially realistic scenes by making lines perpendicular to the picture plane (known as orthogonals) converge on a vanishing point, and by calculating the graduated scale at which horizontal lines (or transversals) recede into the distance. Leonardo wrote extensively on perspective, which he called “the daughter of painting.” He described it as the phenomenon by which “all objects transmit their image to the eye by a pyramid of lines.”2 The eye was the vertex of this visual pyramid, and the artist’s job was to capture in a painting precisely the diminution of scale and spatial relationship between objects seen by the eye in nature.

  Leonardo created the most famous perspective drawing in history in the early 1480s when he made a pen-and-ink study for his Adoration of the Magi. It shows a geometrically rigorous mesh of lines through which swarm, in chaotic contrast to this rigid net, a host of ghostly human and equine figures. He must have done a similar drawing for The Last Supper, establishing how the orthogonals (such as the beams on the ceiling and the edges of the table) converge on the right temple of Christ. This drawing would then have been scaled up to create cartoons. But any perspective drawing of The Last Supper, like the cartoons and so many other sketches done for the mural, have long since vanished.

  The only trace of Leonardo’s efforts to generate his perspective scheme are the nail hole and, radiating outward from it, the lines in the wall marking the orthogonals. The use of a nail and incised lines reveal how he was using a classic fifteenth-century fresco technique pioneered by the Florentine painter Masaccio in works such as The Holy Trinity (in Santa Maria Novella) and The Tribute Money (in the Brancacci Chapel). In both frescoes Masaccio fixed a nail into the point in the wall at which the orthogonals were to converge; he then attached a long string to the nail, stretched it tight, and “snapped” it into the wet plaster, leaving behind a radiating pattern of orthogonals that are still visible today.

  The architectural space that Leonardo created for Christ and the apostles—a narrow, tapestry-hung room with a coffered ceiling and three windows—reveals something intriguing about his approach to design. He longed for (but was so far denied) architectural commissions. However, he had firm ideas about how to organize architectural space, and in The Last Supper he painted architectural features that were arranged according to musical harmonies worked out two thousand years earlier by Pythagoras.

  As a musician who played and designed stringed instruments, Leonardo was sensitive to the potency of musical harmonies. Like a number of his contemporaries (Verrocchio among them) he believed these harmonies could be translated into optical space. A correspondence existed, as he saw it, between how we hear sounds and how we see objects: “I give the degrees of the objects seen by the eye,” he wrote, “as the musician does the notes heard by the ear.”3 He was paraphrasing Leon Battista Alberti, who wrote that the same musical harmonies that please the ears “can also fill the eyes and mind with wondrous delight,” and that artists and architects therefore ought to apply the ratios of musical harmonics to their own creations. Leonardo was familiar with one such application: Verrocchio’s tomb slab for Cosimo de’ Medici, whose symmetrical geometrical forms have been found to express musical proportions.4

  Leonardo’s perspective scheme for The Last Supper

  An indication that Leonardo intended to use harmonic ratios to structure pictorial space comes from a sketch for The Last Supper—the one showing Christ offering the sop of bread to Judas—on which he jotted a series of numbers in a column. His notation reads 3.4.6. -6.3-6-4 = 32. He would have known from various sources that the musical scales could be expressed numerically, since pitch depended on variables such as length and weight of a musical instrument or its constituent parts. For example, if you cut a string in half, its pitch will be an octave higher than the note produced by the whole string, with the octave therefore expressed by the ratio 1:2. Meanwhile two thirds of the whole length produces the tonal interval of a fifth (expressed by the ratio 2:3) and three quarters of the string a fourth (3:4).

  Leonardo used these ratios in the module by which he designed the room in which Christ and the apostles sit, turning musical notes into a kind of visual music. The architectural features of his painting seem to be organized, at any rate, according to a series of units related to the tonal intervals. As one scholar has pointed out, the sequence of twos, threes, fours, and sixes on Leonardo’s drawing are intended to represent the ratios of, respectively, the fourth and fifth within the octave (3:4:6), the octave (3:6), and
the fifth (4:6).5

  The Last Supper does appear to reveal an arithmetical progression. For example, if the total width of the refectory wall is divided into twelve units, that of the coffered ceiling at the front of the picture plane is six units, giving a ratio of 1:2 (an octave). The width of the rear wall in the painting is four units, while that of the windows is three (that is, if the measured width is that between the centers of the two flanking windows rather than from their outside edges). Thus we have (with only a little bit of fudging) the ratios 12:6:4:3. Similar ratios can be found in the relationships between the tapestries on the wall in the painting. They are of unequal breadth, with those toward the rear of the room increasing according to the ratios 1:½:⅓:¼—offering (this time without any fudging) the mathematical intervals 12:6:4:3.6

  The influence of Verrocchio and Alberti lay behind this musical calibration of optical space. Leonardo probably did not believe, like some of his contemporaries, that these ratios were inherently divine. But, like Alberti, he no doubt believed that their application could bring “wondrous delight” to the eyes as well as to the ears.

  Leonardo’s method of working makes it impossible to determine where exactly on the wall he first began painting. Frescoists normally worked their way systematically across a wall or vault, painting adjacent patches of plaster on consecutive days, working (as Pontormo’s diary revealed) on the right arm on Thursday, the left arm on Friday, and a thigh on Saturday. Leonardo had no desire to work in these discrete units. He approached the wall in the same way that he tackled his panel paintings, on which his style was to work slowly and deliberately, layer by layer, touching and retouching, carefully contemplating the effects as he progressed.

  The outlines of the entire scene would first of all have been sketched roughly on the base coat in charcoal, either transferred from cartoons or else drawn freehand with reference to sketches. The outlines of the apostles’ heads, like the ceiling beams, were emphasized with a stylus. When the time came to paint, he proceeded at a pace that was sometimes leisurely, sometimes frantic, and he no doubt worked on several areas of the mural at once, ranging from one end of his scaffold to another in the course of a single day.

  An eyewitness account of Leonardo’s work in Santa Maria delle Grazie confirms this unorthodox approach. The eyewitness was Matteo Bandello, the young nephew (he was born in 1485) of the prior of Santa Maria delle Grazie. Matteo later became a popular writer of humorous novellas in the tradition of Boccaccio; one of his stories, Giulietta e Romeo, first published in the 1550s and then translated into English in 1567, was the source for Shakespeare’s play. Another of his novellas would be taken up by Lord Byron.

  One of Matteo’s stories features Leonardo as the narrator: he puts into Leonardo’s mouth the various misadventures of the talented but libidinously wayward painter Filippo Lippi. The story is prefaced with Matteo’s remarks about his personal experience of watching Leonardo at work in Santa Maria delle Grazie. His stories are full of comical exaggerations and improbably fanciful conceits, and the circumstances of his account—a novella published many years later—must make us cautious about its veracity. However, the description of Leonardo’s unpredictable and apparently dilatory working habits has an undeniable ring of truth.

  “Many a time,” Matteo began, “I have seen Leonardo go to work early in the morning and climb on to the scaffolding.” On these occasions, he claimed, Leonardo was the picture of industry, working “from sunrise until the dusk of evening, never laying down the brush, but continuing to paint without remembering to eat or drink.” On other days, Leonardo arrived early for work, though much less painting got done. Instead, he studied the mural for hours on end without touching his brushes, “considering and examining it, criticizing the figures to himself.” On still other days he would break off work at the Corte dell’Arengo, where he was still (Matteo claims) working on “the stupendous horse of clay,” and arrive in the refectory at noon. He would clamber onto the scaffold, swiftly apply only a touch or two of paint, “and then go elsewhere.”7

  Matteo himself made no judgment on Leonardo, but this capricious regime evidently left his uncle, the prior, Vincenzo Bandello, frustrated and aggrieved. Vasari tells the story that Bandello, who wished to see Leonardo toiling “like one of the labourers hoeing in the garden,” complained to Lodovico about the painter’s slow and unpredictable progress. For Bandello as for many other people at the time, an artist was a mere craftsman, someone paid to cover a certain number of square feet of wall per day. (Borso d’Este, the grandfather of Lodovico’s wife Beatrice, literally paid his frescoists by the square foot.) Leonardo took another view of his task: he believed that originality and creativity were more important than economics or square feet. He explained to Lodovico that “men of genius sometimes accomplish most when they work the least,” adding that they are “thinking out inventions and forming in their minds the perfect ideas which they subsequently express and reproduce with their hands.”8

  Vasari’s story is probably apocryphal, but Leonardo certainly did not regard himself as someone who worked to order like a laborer hoeing the garden. Perhaps, too, Bandello and his friars were baffled and angered by Leonardo’s unusual approach, which meant the unsightly scaffold—along with the smell of oil and paint—would be a fixture in their refectory for an indefinite period. The difference between Leonardo’s eccentric style and the more usual method was underscored by the performance of Giovanni da Montorfano at the other end of the refectory. Montorfano had succeeded in quickly covering his wall with a Crucifixion scene. Teeming with color, his fresco featured more than fifty figures, not only Christ and the two crucified thieves but also Roman soldiers on horseback, grieving women, and various Dominican worthies such as St. Dominic and St. Catherine of Siena. In the background was a multitowered castle, fluttering banners, and a rocky landscape. On a tablet at the foot of the cross he proudly painted his name: GIO. DONATVS MONTORFANVS. Above, he added the year: 1495. After as little as a year on the job, Montorfano had completed his work. By the beginning of 1496 there were no obvious signs that Leonardo would soon make an end of his own wall.

  Although Leonardo had painted the infant Christ numerous times, The Last Supper marked the first time he painted the adult Christ. The notes about Alessandro Carissimi da Parma and the man in Cardinal Sforza’s entourage allow us to disregard Vasari’s story that Leonardo was “unwilling to look to any human model” for Christ because he believed no one had the requisite grace and beauty.9 Painting the head of Christ would nonetheless have been a daunting task, not least because of its prominent location at the very center of the mural. Years later, Lomazzo would claim that Leonardo’s hand trembled whenever he tried to paint Christ’s face. The story is not entirely incredible. Painters of religious scenes were often deeply moved by their task. Fra Angelico, a Dominican friar, was said to have wept as he painted his frescoes. “Whenever he painted a Crucifixion,” claimed Vasari, “the tears would stream down his face.”10 But the tremor in Leonardo’s hand—if the story has any truth—probably had more to do with the momentous nature of his assignment and the conspicuous location of the Savior’s head than with any iconoclastic reservations about depicting the face of Christ.

  Lomazzo is also the source for the story that Leonardo despaired of creating perfect features for Christ. He therefore turned for advice, Lomazzo says, to a friend, the painter Bernardo Zenale, who told him it would be impossible to create features more perfect than those he had already given to both James the Greater and James the Lesser. Zenale advised Leonardo to “leave the Christ imperfect” since he would “never be able to accomplish the Christ after such apostles.”11

  These anecdotes about Leonardo’s trepidations, along with paint loss in the mural, ultimately gave rise to the mistaken belief, first expressed by Vasari, that Leonardo deliberately left the head of Christ unfinished, “convinced he would fail to give it the divine spirituality it demands.” Recent cleaning has shown that the face of Chris
t in Leonardo’s Last Supper was, in fact, highly detailed.12 Leonardo did not need to leave the head unfinished because he was a master at capturing divine spirituality. In The Virgin of the Rocks, the faces of the Virgin and the angel are animated by an inscrutable otherworldly allure, and Leonardo applied to the face of Christ—with its downcast eyes and mournful features—this same numinous resplendence.

  Leonardo in concentrating the focus of viewers on the face of Christ was following a fifteenth-century artistic tradition that has been called the “Catholic vanishing point”: the practice of situating the vanishing point at a particularly sacred site such as the eucharistic wafer or even the womb of the Virgin Mary (a technique one art historian has dubbed “uterine perspective”).13 He also made Christ conspicuous in a number of other ways. For one thing, Christ is significantly larger than many of the other apostles: he is as tall as Bartholomew (the last figure on the left) even though Bartholomew is standing. So subtle in Leonardo’s hands that we barely notice it, this technique is a throwback to earlier centuries, when painters arranged their figures in what art historians call “hieratic perspective”—the practice by which figures are enlarged according to their theological importance (which explains why so many medieval paintings show enormous Madonnas surrounded by pint-sized saints and angels).