by Ross King
‘Your Holiness must disregard his offence,’ he told Julius, ‘because he offended through ignorance. Painters, outside of their art, are all like that.’4
The Pope may have been exasperated by the ‘humours of such men of genius’ as Michelangelo, but as a patron of artists he did not take kindly to the implication that all of them were uncouth and ignorant. ‘You are the ignoramus and the wretch,’ he roared at the bishop, ‘not he. Get out of my sight and go to the devil.’ When the astonished bishop failed to vacate the room, he was driven away ‘with jabs by the Pope’s attendants’.5
And so artist and patron were reconciled. There was, however, one minor problem. Michelangelo refused to work on the giant statue. Casting in bronze, he informed the Pope, was not his profession. Julius, however, would hear no excuses. ‘Set to work,’ he ordered the sculptor, ‘and cast it over and over again until it succeeds.’6
*
Bronze casting was a difficult business. Like fresco painting, it required much experience, and casting a life-size statue, let alone one fourteen feet tall, could take many years, as Antonio del Pollaiuolo discovered when he spent nine years on the sepulchre for Sixtus IV. The process required a model made from seasoned clay — what would form the statue’s core – to be covered with a layer of wax. The artist added his sculptural details to the wax, which was then coated with several layers of a paste made from, among other ingredients, cow-dung and burnt ox-horn. Bound with iron hoops, this bulky mass was baked in a furnace until the clay hardened and the melted wax drained through holes, or ‘risers’, drilled in the bottom of the statue. Molten bronze would then be poured through another set of tubes, the ‘runners’, to replace the coat of wax. After the bronze solidified over the clay base, the husk of cow-dung and ox-horn was cracked open and the statue emerged, ready to be chiselled and polished.
Such, at least, was the theory, though the practice was prone to all sorts of mishaps and delays. The right kind of clay needed to be found and properly seasoned to prevent it from cracking, while the bronze had to be heated to exactly the right temperature or else it would curdle. For a variety of reasons, one of which was the sheer size of the work, Leonardo da Vinci had failed in his attempts to cast a bronze equestrian for Lodovico Sforza, the Duke of Milan. But at least Leonardo was trained in the art of casting bronze, having worked for many years in the studio of Andrea del Verrocchio, a leading Florentine goldsmith. Michelangelo, on the other hand, did not exaggerate when he claimed that bronze casting was not his profession. He may have received some instruction in casting metals in the Garden of San Marco, but by 1506 he had executed only a single bronze figure: a four-foot-high David commissioned in 1502 by the French Maréchal Pierre de Rohan.fn1 In other words, he had little more experience at casting bronze than he did at painting frescoes.
As with the Sistine Chapel decorations, Julius did not trouble himself with minor details such as Michelangelo’s lack of experience. He was determined to have his statue, and so Michelangelo, who dared not flee the Pope a second time, was given a studio behind San Petronio and set to work. The statue was clearly a test for him, not merely of his sculptural skills, but also of his loyalty to the Pope.
The following year was a miserable one for Michelangelo. He was unhappy with his cramped lodgings, having discovered how he was obliged to share his bed with three other men. He found the wine available in Bologna not only expensive but also of an inferior kind. Nor was the weather to his liking. ‘Since I have been here,’ he complained as summer arrived, ‘it has only rained once and has been hotter than I ever believed it could be anywhere on earth.’7 And he was still convinced that his life was in danger, for not long after arriving in Bologna he wrote to his brother, Buonarroto, that ‘anything might happen to shatter my world’.8 His supposed enemy, Bramante, was still in Bologna, and he noted uneasily that, with the papal court in town, the dagger-makers had been inundated with business. Bologna was also full of bands of ruffians and disgruntled supporters of the exiled Bentivoglio clan, making it a violent and dangerous place.
After two months, Julius visited the workshop to inspect the clay model. Michelangelo then wrote to Buonarroto: ‘Pray God it may go well for me, because if it goes well I hope to have the good fortune to be in favour with this pope.’9 Regaining favour with the Pope meant, of course, that he might be allowed to resume work on the papal tomb.
Work on the statue, however, did not begin at all well. Michelangelo hoped to have it ready for casting by Easter, but progress was slowed when, around the time of the Pope’s visit, he fired a pair of his assistants: Lapo d’Antonio, a stone carver, and a goldsmith named Lodovico del Buono, known as Lotti. Michelangelo found especially irksome the younger of the two, Lapo, a 42-year-old Florentine sculptor. ‘He is a deceitful good-for-nothing fellow who did not do what I wanted,’ he wrote home to Florence.10 In particular, he resented how his assistant was noising it about Bologna that he, Lapo d’Antonio, was working in full partnership with Michelangelo. The pair did have some justification in seeing themselves as Michelangelo’s equals rather than mere underlings. Each was at least ten years his senior, and Lotti had apprenticed under the great Antonio del Pollaiuolo. Michelangelo held Lotti in higher esteem, and his experience and expertise must have been crucial. But he had been corrupted, Michelangelo felt, by the poisonous Lapo, and so both men were sent packing. Given that Lapo and Lotti had been his bedmates, the dispute must have made for disagreeable evenings in the small workshop behind San Petronio.
Michelangelo’s situation in Bologna was soon to deteriorate even further. No sooner had Lapo and Lotti been dismissed than the Pope departed, claiming Bologna was bad for his health. As if to reinforce his point, the plague broke out soon afterwards, and on its heels came rebellion. With the Pope on the road back to Rome, the Bentivoglio family and their supporters, emboldened, tried to recapture the city. Ordinarily, Michelangelo took to his heels at the faintest whiff of gunpowder; now he was forced to remain in his studio as violent skirmishes were fought outside the city walls. It must have crossed his mind that the Bentivoglio, if they returned, would hardly look generously on the fact that he was sculpting their arch-enemy. But within a few weeks the exiles were beaten back, at which point they turned their efforts to a plot – equally unsuccessful – to have Julius poisoned.
In early July, little more than six months after beginning work, Michelangelo attempted to cast his giant statue. The end product failed because the bronze had not been melted properly, resulting in a statue that had feet and legs but no trunk, arms or head. A delay of more than a week ensued as the furnace was cooled down and then dismantled so that the solidified bronze could be removed, reheated and poured into the mould for a second attempt. Michelangelo blamed one of his new assistants, Bernardino d’Antonio, for the disaster, claiming that ‘either through ignorance or by accident’ he had failed to raise the furnace’s temperature sufficiently.11 He broadcast Bernardino’s disgrace so widely that the shamed assistant went about Bologna with his head lowered.
The second casting reached a happier conclusion, and Michelangelo spent the ensuing six months chiselling, polishing and retouching the statue, then preparing the porch of San Petronio for its installation. The statue should have been a personal triumph for him. Fourteen feet tall and weighing 10,000 pounds, it was one of the largest statues cast since antiquity. It was almost exactly the same height, in fact, as the equestrian statue of the emperor Marcus Aurelius that stood in front of the basilica of San Giovanni in Laterano – the bronze statue against which all others were measured.12 Furthermore, he had defied the sceptics who, a year earlier, had doubted his ability to accomplish the mammoth task. ‘The whole of Bologna was of the opinion that I should never finish it,’ he boasted to Buonarroto.13 And, having completed the task, he was once more, presumably, in the good graces of the Pope. Even before finishing the statue he began exchanging letters with Giuliano da Sangallo and Cardinal Alidosi, his two strongest allies and supporters in Rome,
expressing the hope that he would be allowed to continue with the tomb.
Nevertheless, modelling and casting the statue had exhausted Michelangelo. ‘I am living here in the greatest discomfort and in a state of extreme fatigue,’ he wrote to Buonarroto as he finished the work. ‘I do nothing but work day and night, and have endured, and am enduring, such fatigue that if I had to do the work over again I do not believe I should survive.’14 He longed to return to Florence, a tantalisingly close fifty-mile journey across the Apennines. But his patience was tried still further by the Pope’s orders that he remain in Bologna until the statue was actually in place above the church’s door. The papal astrologers eventually decreed 21 February 1508 to be the most auspicious date for its installation. Only then was Michelangelo permitted to return to Florence, though not before his assistants in Bologna had arranged a small party in his honour. Michelangelo’s delight in returning home was not even dented when he fell from his horse while riding back through the Apennines.15 However, no sooner had he arrived in Florence than a summons arrived from the Pope, ordering him back to Rome – but not, as it transpired, to resume work on the tomb.
fn1 This work, completed about the same time as the much larger and more famous marble David, was sent to France and eventually disappeared. It probably suffered the fate of numerous bronze statues over the centuries, and was melted down, during wartime, to make cannon.
5
Painting in the Wet
‘ON THIS DAY, May 10, 1508, I Michelangelo, sculptor, have received on account from our Holy Lord Pope Julius II five-hundred papal ducats toward the painting of the ceiling of the papal Sistine Chapel, on which I am beginning work today.’1
By the time Michelangelo wrote this note to himself, roughly a month had passed since his return to Rome. During that time a contract for the painting of the vault had been drawn up by the Pope’s friend and confidant, Cardinal Alidosi, who was continuing to serve as an intermediary between the temperamental Julius and his equally temperamental sculptor. He had been in close contact with Michelangelo regarding the bronze statue, exchanging a number of letters with him and then overseeing the installation of the finished project on the porch of San Petronio.2 Satisfied with the results achieved in Bologna, the Pope therefore left to his trusted cardinal the task of arranging many of the details for this new and much larger commission.
The contract written by Cardinal Alidosi, now lost, stated that the sculptor (as Michelangelo usually took pains to describe himself) would be paid a total of three thousand ducats for his work on the ceiling, triple the amount he was paid for casting the bronze statue in Bologna. Three thousand ducats was a generous amount – double the sum that Domenico Ghirlandaio had been paid to fresco the Tornabuoni Chapel in Santa Maria Novella. It was also thirty times as much as a qualified artisan, such as a goldsmith, could expect to earn in a single year.3 However, it was a good deal less than Michelangelo had been offered to sculpt the tomb. Also, he would need to use these funds to pay for his brushes, pigments and other materials, including the rope and wood to build a scaffold. He would, in addition, be required to fund a team of assistants and outfit his house in the Piazza Rusticucci to accommodate them. All of these overheads would, of course, eat swiftly into his payments. For instance, of the thousand ducats allotted for the bronze statue of Julius, he was left at the end, after paying out for his materials, assistants and lodgings, with a paltry profit of exactly four and a half ducats.4 And while the bronze statue consumed fourteen months of work, it was clear that frescoing the vault of the Sistine Chapel would take much longer.
Michelangelo did not actually start painting by the middle of May. The execution of a fresco, especially one comprising 12,000 square feet, took a great deal of planning and forethought before the first stroke of paint could be applied. The art of fresco enjoyed such esteem precisely because it was so famously difficult to master. Its myriad obstacles are reflected in the Italian expression stare fresco, meaning to be in a fix or a mess. Many artists besides Leonardo da Vinci (who failed so spectacularly with The Battle of Anghiari) had found themselves in a fix when confronted with a wall or vault to paint. Giorgio Vasari, himself an experienced frescoist, claimed that most painters could succeed in tempera and oil, but only a few triumphed at fresco. It was, he contended, ‘the most manly, most certain, most resolute and durable of all the other methods’.5 One of his contemporaries, Giovanni Paolo Lomazzo, likewise saw fresco as a distinctly masculine pursuit, insisting that tempera painting, in comparison to fresco, was the domain of ‘effeminate young men’.6
The technique of painting on wet plaster was already known in Crete in the second millennium BC, and centuries later the Etruscans, and then the Romans, used it to decorate walls and tombs. But the art of fresco assumed a particular currency in central Italy from the last half of the thirteenth century, when towns and cities like Florence were gripped by a building boom the likes of which had not been seen since the days of the Roman emperors. In Florence alone, at least nine major churches were built or begun in the second half of the thirteenth century. If in northern Europe (which had just undergone its own building spree) the new Gothic cathedrals were brilliantly decorated with tapestries and stained-glass windows, frescoes became the order of the day in Italy. The hills around Florence and Siena possessed in abundance the necessary ingredients: limestone, marble and sand, as well as the clays and minerals needed to make pigments. And like the Sangiovese grape, used in making Chianti, frescoes were well suited to the dry, scorching Tuscan summers.
The particular technique of fresco employed throughout the Renaissance was similar to that used by both the Etruscans and the Romans, having evolved around 1270, not in Florence but in the Roman workshop of a painter named Pietro dei Cerroni, nicknamed Cavallini (‘Little Horses’). Cavallini enjoyed a lengthy and celebrated career in both fresco and mosaic, living to the grand age of one hundred even though, it was said, he never covered his head in winter. His style and technique influenced the first great exponent of fresco during the Renaissance, a Florentine named Giovanni Cenni di Pepi, who was known unflatteringly as Cimabue (‘Ox-Head’) because of his ugliness. Hailed by Giorgio Vasari as ‘the first cause of the renovation of the art of painting’,7 Cimabue won fame in Florence with frescoes and other paintings that decorated several of the new churches, including Santa Trìnita and Santa Maria Novella. Then, in about 1280, he travelled to Assisi to execute his masterpieces, fresco cycles in both the Upper and Lower Churches of San Francesco.8
Cimabue was assisted, and eventually eclipsed, by a young painter, the son of a peasant, whom legend states he first met on the road between Florence and the nearby village of Vespignano: Giotto di Bondone. After Cimabue’s death, Giotto painted further frescoes in San Francesco and even moved into his master’s house and workshop in the Borgo Allegri, the ‘Joyful Road’ (so named because the people in the neighbourhood had reacted with a near hysterical exuberance when one of Cimabue’s paintings was borne in procession from his studio to be shown to the visiting King Charles of Anjou). Giotto schooled numerous pupils in the techniques learned from Cimabue, one of the most talented of whom, Puccio Capanna, learned the hard way that fresco was an occupation fit only for those made of the sternest stuff. Vasari reported that his life was cut short after he fell ill ‘by reason of labouring too much in fresco’.9
The technique of fresco was as simple in conception as it was difficult in execution. The term fresco, meaning ‘fresh’, comes from the fact that the painter always worked on fresh – that is, wet – plaster. This called for both good preparation and precise timing. A layer of plaster, known as the intonaco, was trowelled to a thickness of about a half-inch over another coat of dried plaster. Intonaco, a smooth paste made from lime and sand, provided a permeable surface for the pigments, first absorbing them and then sealing them in the masonry as it dried.
The design of the painting was transferred to this patch of wet plaster from the cartoon. Fixed to the wall or vault wi
th small nails, the cartoon served as a template for a particular figure or scene. Its design would be transferred by one of two methods. The first, called spolvero, involved perforating the lines of drawing on the cartoon with thousands of little holes through which a charcoal powder would be sprinkled, or ‘pounced’, by striking the cartoon with the pounce bag and thereby leaving on the plaster an outline that was then reinforced in paint. The second, much quicker, method required the artist to trace over the chalk lines on the cartoon with the point of a stylus, leaving marks on the fresh plaster beneath. Only then would he set to work with his paints and brushes.
The science behind fresco painting involved a series of simple chemical combinations. The intonaco was, chemically speaking, calcium hydroxide. The first step in making calcium hydroxide was to heat limestone or marble in a kiln – the practice responsible for the loss of so many of Rome’s ancient monuments. The fire drove off the stone’s carbonic acid and turned it into a white powder known as quicklime (calcium oxide), which then turned into calcium hydroxide when soaked, or ‘slaked’, in water. For the Renaissance painter, calcium hydroxide was the magical ingredient behind the art of fresco. Once it had been mixed with sand and applied to the wall, the series of chemical transformations gradually reversed themselves. First, the water evaporated from the mixture, then the calcium oxide reacted with carbon dioxide in the atmosphere to form calcium carbonate, the main component of limestone and marble. Thus, in a short space of time the smooth paste spread across the wall by the plasterer’s float had turned back into stone, locking the colours in crystals of calcium carbonate. A frescoist therefore did not need to dilute his pigments with anything other than water. The various binding agents used in tempera painting – egg yolk, glue, gum tragacanth, and even sometimes earwax – were unnecessary for the simple reason that the pigments were set in the intonaco.
