Leonardo’s Most Daring Project
In 1503, Leonardo returned to Florence after his short and rather unhappy engagement as the military engineer for Cesare Borgia. But the Borgia episode had one fortunate result with tremendous consequences for Leonardo’s career. While in Borgia’s camp, he had met the young envoy from Florence, named Niccolò Machiavelli — yes, that’s the Machiavelli, later known for his work “The Prince.” Thin, brainy and cunning, Machiavelli had been dispatched to Borgia’s camp to find out what on earth Cesare was up to. But while there, he soon found himself drawn to Leonardo’s charisma and intellect, as shown in this still from the upcoming film The Search for the Mona Lisa. During the three months that Machiavelli spent among Borgia’s entourage — much to the despair of his young bride in Florence, who ached for his return — the two men, Niccolò and Leonardo, had begun to talk about a daring plan. For seven years now, Florence had been enmeshed in a costly war with Pisa that had entered a stalemate. But Leonardo and Machiavelli were hatching a plan that was guaranteed to bring Pisa to its knees.
Their idea was to divert Pisa’s lifeline, the Arno river. This would deny Pisa access to the sea, deprive it of its principal source of supplies, and block the main outlet for its trade. It was the type of project that summoned all of Leonardo’s scientific skills: his study of soil, of geological formations, of the movement of water, of weirs and sluices, of floodgates and bulwarks, as shown in this map (see picture). Unfortunately, it would also be very expensive; in one of his studies, Leonardo calculated that it would require some 54,000 man days just to create a 12-mile diversion of the Arno. Would the Florence government go for it?
Unfortunately, by the time Leonardo returned to Florence in March of 1503, the Arno project had not yet been approved, and wouldn’t be approved for quite some time. In the meantime, Leonardo and his companions needed to eat and have a place to sleep. Naturally, a return to the Servite monks of the Annunziata, who were still waiting for their painting, was out of the question. Leonardo had no choice but to fall back on his savings; a withdrawal of fifty gold ducats on March 4 was followed by another drawdown of fifty ducats on June 14. On one of Leonardo’s notebook pages, now a part of the Codex Atlanticus, someone wrote, ‘Tra noi non ha a correre denari’ — “there’s not a lot of money around here.”[i]
And yet, Leonardo insisted on staying in Florence. Why did he do so? Because word had reached him — most likely through Machiavelli — that the city was planning another important project, a bit of military propaganda to buck up the patriotic spirit of its citizens. And this project would change the trajectory of Leonardo’s career.
[i] Beltrami, Luca, Documenti e memorie riguardanti la vita e le opere di Leonardo da Vinci. Milan, 1919; document 125.
