Leonardo Da Vinci

by Charles Nicholl

  A larger-scale map, oriented the same way as the Val di Chiana map (with north to the left), shows the whole river-system of central Italy. It includes the Mediterranean coast from Civitavecchia to La Spezia, a stretch of about 170 miles, and extends across to the Adriatic coast at Rimini. It has been shown that Leonardo’s model was a manuscript map of c. 1470 then in the library at Urbino, but he has transformed it by using contour shading, abandoning the ‘molehill’ convention of Quattrocento mapping and giving a sense of objectively recorded terrain.53 Leonardo would have been able to study the map in Urbino in late July 1502. This reinforces the idea that these maps were created in the context of his Borgia work, and some of them may have been actually done at Imola.

  Machiavelli sickened. On 22 November he wrote from Imola, ‘My body is in a bad way after a heavy fever two days ago.’ On 6 December he asked once more to be recalled, ‘to relieve the government of this expense, and me of this inconvenience, since for the last twelve days I have been feeling very ill and if I go on like this I fear they’ll be bringing me back in a basket’.54

  Borgia negotiated with the rebels: an illusory reconciliation. Then, on 26 December, Machiavelli reported grimly from Cesena, ‘This morning Messer Rimino was found lying in the piazza cut into two pieces; he still lies there, so that everyone has had an opportunity to see him.’ Beside him lay a bloodied knife and a wooden wedge, as used by butchers to split open the carcasses of animals. Rimino or Ramiro de Lorqua was not a rebel, but a loyal thug whose reign of terror in the Romagna had made him unpopular and hence expendable. ‘The reason for his death is not yet clear,’ Machiavelli added, ‘except that such was the pleasure of the Prince, who shows us that he can make and unmake men according to their deserts.’

  On the morning of 31 December Borgia entered Senigallia. There, under pretence of reconciliation, he met with the ringleaders of the rebellion: Vitellozzo Vitelli, Oliverotto da Fermo, the Orsini brothers. But the meeting was a trap. The rebels were seized and bound; their foot-soldiers camped outside the town-walls were disarmed. That evening Machiavelli scribbled a dramatic dispatch: ‘The sack of the town continues although it is now the 23rd hour. I am much troubled in my mind. I do not know if I can send this letter having no one to carry it.’ As for the rebels, ‘It is my opinion they will not be alive tomorrow morning.’ He was partly right: Vitellozzo and Oliverotto were strangled that night; the Orsini brothers lived a couple of weeks longer and were strangled at Castel del Pieve.55 Was Leonardo also present at Cesena and Senigallia as his patron dispensed justice with the butcher’s knife and the garrotte? It is not unlikely.

  In the first weeks of 1503 Il Valentino took Perugia and Siena. Brief comments in Leonardo’s notebook suggest he was with him in Siena. He admires an enormous church-bell, 10 braccia in diameter, and bids himself remember ‘the way it moved and how its clapper was fastened’.56 Again his notes are tangential, serene, escapist: he is looking the other way. On 20 January, during the siege of Siena, Machiavelli gratefully welcomed a new Florentine envoy, Jacopo Salviati, said his goodbyes to Valentino and Leonardo, and set off back to Florence, convinced that he had seen a new model of political leadership – decisive, lucid, ruthless, and quite divested of morality and religion. Ten years later, in The Prince, he wrote of Borgia:

  If I summed up all the actions of the Duke I would not know how to reproach him. On the contrary it seems to me he should be put forward, as I have done, as a model for all those who have risen to empire by fortune and the arms of others. For with his great spirit and high intention he could not have conducted himself otherwise.57

  Borgia proceeded to Rome in February 1503, to confer with his ailing father, Pope Alexander VI. Leonardo may have gone with him, but if so the visit was short, as he was back in Florence by the beginning of March.58 The decision to quit Borgia’s service – if it was his – was a wise one. Borgia’s fortunes had reached their zenith, for with the death of his father on 18 August 1503 his true power-base of papal influence was shattered. The new pope, Julius II, refused to recognize his title of Duke of Romagna and demanded the restitution of his dominions. There followed a saga of arrest and escape, an anti-papal venture in Naples, and in 1507 an early death in Spain, in action as a mercenary, at the age of about thirty.

  A LETTER TO THE SULTAN

  In 1952 a remarkable document was discovered in the State Archives at the Topkapi Museum in Istanbul.59 At the head of it, in elegant Turkish script, it is summarized as ‘the copy of a letter that the infidel named Lionardo sent from Genoa’. If it is genuine, it is a contemporary Turkish translation of a letter in which Leonardo offered his engineering services to Sultan Bejazet (or Beyazid) II. At the bottom of the text the copyist notes, ‘This letter was written on 3 July,’ but he neglects to say which year. It was almost certainly 1503, in which case it was written in Florence, when Leonardo’s mind was full of big technological projects after the Borgia adventure. (That the letter is described as ‘sent from Genoa’ need only mean that it arrived on a ship from Genoa.)

  It begins, somewhat like the famous prospectus addressed to the Moor twenty years earlier, with offers of technological expertise: ‘I your servant… will build a mill which does not require water, but is powered by wind alone’ and ‘God, may He be praised, has granted me a way of extracting water from ships without ropes or cables, but using a self-propelling hydraulic machine.’ But these are only a warm-up before the main offer, which is to design and build a bridge over the Golden Horn:

  I, your servant, have heard about your intention to build a bridge from Stamboul to Galata, and that you have not done it because no man can be found capable of it. I, your servant, know how. I would raise it to the height of a building, so that no one can pass over it because it is so high… I will make it so that a ship can pass under it even with its sails hoisted… I would have a drawbridge so that when one wants one can pass on to the Anatolian coast… May God make you believe these words, and consider this servant of yours always at your service.

  The notebook Paris MS L, intensively in use during the Borgia adventure of 1502–3, contains what seem to be some working drawings connected with this project, though the design departs in some respects from the description in the letter. The drawing shows a beautifully streamlined structure with ‘bird-tail’ abutments. Leonardo captions it as follows: ‘Bridge from Pera to Constantinople [‘gostantinopoli’, 40 braccia wide, 70 braccia high above the water, 600 braccia long, that is 400 over the sea and 200 on the land, thus making its own abutments.’60 The computation is well-informed: the width of the Golden Horn is about 800 feet so ‘400 braccia over the sea’ is exactly right. The proposed length of the entire bridge (600 braccia = 1,200 feet) would have made it the longest bridge in the world at that time.

  The probable source of this project is Leonardo’s brief sojourn in Rome in February 1503. The previous year ambassadors from Sultan Bejazet had been in Rome conferring with Pope Alexander. It is likely that they mentioned the Sultan’s desire for an Italian engineer to build a bridge over the Golden Horn – at the time there was only a temporary pontoon floating on barrels. Among those interested, according to Vasari, was the young Michelangelo: ‘According to what I have been told, Michelangelo had a desire to go to Constantinople to serve the Turk, who had requested him, by means of certain Franciscan friars, to come and build a bridge from

  Sketch for the bridge at Constantinople (left), and Vebjø Sand’s realization at Aas (below).

  Constantinople to Pera.’ Vasari places this during the period of Michelangelo’s dispute with Pope Julius II in c. 1504. Much the same story is told in Ascanio Condivi’s contemporary Life of Michelangelo (1553).61

  Leonardo’s visit to Rome in February 1503, in the suite of Cesare Borgia, thus provides the context: he learns of the Sultan’s interest, he sketches a prototype in his notebook, and he pens his bombastic letter with suitable flourishes. It has been argued that the bridge’s design was based on the Alidosi Bridge at Castel de
l Rio, on the road from Imola to Florence.62 This was begun in 1499, and was probably still under construction when Leonardo could have seen it during his topographical researches around Imola in the autumn of 1502.

  Like Leonardo’s parachute, preserved in a small note of c. 1485 and tested in the air more than five centuries later, the bridge has recently been built according to Leonardo’s specifications – albeit some 1,500 miles further north than its intended location on the Bosporus. On 31 October 2001 a scaled-down version of it (100 yards long) was unveiled at Aas, about 20 miles south of Oslo. Designed and built by Norwegian artist Vebjorn Sand, it was made out of pine, teak and stainless steel, and cost about £1 million. It serves as a pedestrian bridge over a motorway.

  Leonardo never rests: he works on through the generations, through all the latter-day Leonardeschi – the artists and sculptors and robot-builders and sky-divers whose imaginations are touched by his brusquely captioned little drawings and the concentrated thinking-power that resides in them. ‘It just had to be built,’ Sand was reported as saying. ‘It can be built in wood or stone, in any scale, because the principles work.’ And so the spores of an idea dreamed up in 1503 eventually flower on Highway E18 south of Oslo.63

  MOVING THE RIVER

  Leonardo was back in Florence by the beginning of March 1503, hard-bitten from his months at the court of the brigand Duke. On 4 March he drew out 50 gold ducats from his account at Santa Maria Nuova. He records the transaction on a page which also has an enigmatic note: ‘Get the Gonfalonier to cancel the book and the Ser [i.e. notary] to provide me with a written record of moneys received.’64 The sense of ‘cancel’ is legalistic (Latin can-cellare, to cancel a deed with criss-cross lines, from cancellus, a grating). The note is probably connected with the undelivered altarpiece for the Santissima Annunziata, a closing of the accounts, in which case the ‘Ser’ may be Ser Piero da Vinci, who was notary to the Servites of the Annunziata. Is this how Leonardo thinks of his father – ‘il Ser’, the sir or sire? The Gonfalonier is Piero Soderini, who in late 1502 had been elected Gonfalonier of the Florentine republic, in effect its prime minister: an upstanding but unimaginative man, whose dealings with Leonardo would not always be amicable.

  On 8 April Leonardo lent 4 gold ducats to ‘Vante miniatore’ – the miniature painter Attavante di Gabriello, a man much the same age as Leonardo, and probably an acquaintance from younger days. ‘Salai carried them to him and delivered them into his own hand: he said he will pay me back within the space of 40 days.’ On the same day Leonardo gave Salai some money for ‘rose-coloured stockings’ – the same colour as his own ‘tunic’ (pitocco), as recorded by the Anonimo Gaddiano: ‘He wore a short, rose-pink tunic, knee-length at a time when most people wore long gowns.’65 One gets a hint of the dandified air of the Leonardo circle, somewhat at odds with the mood of republican Florence. This glimpse of Leonardo’s garb was probably a memory of the Florentine painter whom the Anonimo calls Il Gavina or P. da Gavine.

  On 14 June Leonardo withdrew another 50 gold florins from his account. He was perhaps in something of a parlous state: his future uncertain, his savings leaking away. We don’t know where he was living at this time: the doors of the Annunziata were no longer open to him. It is perhaps around now that someone, probably a pupil, writes on a page in the Codex Atlanticus, ‘Tra noi non ha a correre denari’ – ‘Round here the money’s pretty tight…’66

  But a new and exciting project beckoned, its purpose nothing less than changing the course of the Arno river. There were in fact two separate projects: the diversion of the lower Arno, which was a purely military tactic intended to cut Pisa off from the sea, and the more grandiose scheme of canalizing the entire river west of Florence to make it navigable. Machiavelli, now Soderini’s right-hand man on military and political affairs, was closely involved in both of them. He had seen something of Leonardo’s work as Borgia’s engineer, and it may be that the Pisa diversion was first hatched up in conversations between them at Imola.

  Pisa had been temporarily ceded to the French by Piero de’ Medici in 1494, and had declared independence when the French withdrew from Italy the following year. Florentine efforts to retake the city had been embarrassingly ineffectual: the Pisans could hold out indefinitely while they had food and supplies coming in via their port at the mouth of the Arno. Hence this new stratagem – logical but technically ambitious – of rerouting the river and thereby, in the phrase of one of Machiavelli’s assistants, ‘depriving the Pisans of their source of life’.67

  On 19 June 1503 Florentine troops took possession of the fortress of La Verruca, or Verrucola, a knoll which can still be seen on the southern slopes of the Pisan hills, overlooking the flatlands of the lower Arno. Two days later Leonardo was there. The officer in charge, Pierfrancesco Tosinghi, reported back to Florence: ‘Leonardo da Vinci came in person, with some companions, and we showed him everything, and it seems to us that he found La Verrucola satisfactory, and that he liked what he saw, and afterwards he said he had thought of ways to make it impregnable.’68 This brisk dispatch catches Leonardo in action on a summer day in the Pisan hills: his thoroughness (‘we showed him everything’), his enthusiasm (‘he liked what he saw’).

  A month later he was in the area again, as part of an official delegation led by Alessandro degli Albizzi. He was there by 22 July, when he dated a sketch of the lower Arno, and on the 23rd he took part in discussions at the Florentine battle-camp, probably at Riglione, as reported by a certain Captain Guiducci the following day:

  Yesterday we received Alessandro degli Albizzi, bearing a letter from Your Lordship [Gonfalonier Soderini], together with Leonardo da Vinci and certain others. We studied the plan, and after many discussions and doubts it was concluded that the project was very much to the purpose, and if the Arno can really be turned or channelled at this point, this would at least prevent the hills from being attacked by the enemy.69

  Also in the party was one Giovanni Piffero, whom the Signoria later reimbursed to the tune of 56 lire ‘for a carriage with six horses, and the cost of meals, going with Leonardo da Vinci to level the Arno around Pisa’. He is elsewhere named as Giovanni di Andrea Piffero, and was in all probability Giovanni di Andrea Cellini, father of the famous sculptor Benvenuto Cellini, who was indeed a member of the pifferi, or pipers, of the Signoria.70

  Captain Guiducci’s dispatch of 24 July 1503 is the earliest specific mention of the Arno diversion, though the ‘plan’ which they studied and the authorizing letter from the Gonfalonier suggest that the project was well advanced on paper. The idea was to channel the river southward to an area of marshland near Livorno called the Stagno. The water would be diverted by weirs down a huge ditch, a mile long and 16 braccia (32 feet) deep, which would then fork into two smaller ditches. The distance between the river and the outflow at the Stagno diversion was about 12 miles, and Leonardo estimated that about a million tons of earth would have to be dug out for the ditches. In an early example of the time-and-motion study, he calculated how much earth a single worker could shift. Because the ditches would be so deep, he reckoned that a single bucket of earth from the bottom would be handled by fourteen workers before it reached the top. After some complex calculations he concluded that the entire project would require 54,000 man-days.71 Alternatively, he says, ‘various machines’ could be used to speed things up. One such is the mechanical digger found in the Codex Atlanticus: measurements beside the drawing correspond exactly with those proposed for the Arno ditches, so it seems this machine was specifically designed for the job. Another computation reads, ‘One shovel-load is twenty-five pounds; six shovel-loads made up one barrow-load; twenty barrow-loads made up a cart-load.’72 These are the nuts and bolts of Leonardo’s work as a civil and military engineer.

  Digging on the Arno–Stagno canal did not begin for over a year. Leonardo was not actively involved at this later stage: another engineer or maestro d’aqua, one Colombino, was in charge, and some of what was done differed from Leonardo�
��s plans. Work began on 20 August 1504 ‘at the tower of the Fagiano’, which was demolished to provide building materials for the weir. The project was a total failure, and was abandoned after two months, amid growing unrest about unpaid wages. A report by Machiavelli’s assistant Biagio Buonaccorsi sums up succinctly:

  When the decision was finally made, a camp was established at Riglione, and maestri d’aqua were summoned. They said they required two thousand workers, and a quantity of wood to construct a weir to hold the river in, and divert it along two ditches to the Stagno, and they promised to complete the project within thirty or forty thousand man-days [significantly less than Leonardo’s estimate] and in this hope the project was begun on 20 August [1504] with two thousand workmen hired at one carlino a day. In fact the project took much more time and money, and to no profit, for, in spite of these estimates, eighty thousand man-days were not enough to bring it even halfway… The waters never went through the ditches except when the river was in flood, and as soon as it subsided the water flowed back. The whole undertaking cost seven thousand ducats or more because as well as paying the workers it was necessary to maintain a thousand soldiers to protect the workers from attack by the Pisans.73

  In early October 1504 disaster struck. There was a violent storm; several boats guarding the mouth of the ditches were wrecked, and eighty lives were lost. The walls of the ditches collapsed, and the whole plain was flooded, destroying many farms. By mid-October, less than two months after the work had begun, the project was abandoned. The Florentine army withdrew, the Pisans filled in the ditches, and the episode was quickly forgotten – another waste of time, money and lives in the long war with Pisa, which continued until 1509.