Leonardo represents this watercourse on f. 23r in the Codex Madrid II. The Bure Torrent originates in Candeglia, forming where two streams meet – the Bure di Baggio (which flows down the eastern slope from the Passo della Porretta) and the Bure di Pratale (a river originating on Mount Poggio all’Orsa) and then runs through the river basin of the Ombrone. Before hydraulic regulation was introduced in the 12th and 13th centuries, all of the streams flowing from the surrounding mountains down to the plains of Pistoia came together in a relatively narrow band of confluences extending from Ponte alla Pergola to Badia a Pacciana, and emptied into the Ombrone River. This often caused the river to flood, creating serious problems for the inhabitants of the surrounding lowlands.
Calenzano appears on the map RL 12279 (Royal Collection, Windsor Castle) along the curving line traced by the artist to indicate the road connecting Florence and Prato, and on f. 23r in Codex Madrid II, along the course of the Marina River which the Florence canal crossed at one point. The same river appears on a hydrographic map on RL 12277 (Windsor), where it empties into the Bisenzio River.
Leonardo represents Campi Bisenzio on map RL 12685 (Windsor Castle), and mentions it in Madrid Ms. II (f. 23r) and on map RL 12279. He planned for the water of the Bisenzio to traverse the navigable Arno Canal, in the plain between Florence and Pistoia, where Campi Bisenzio constituted a reference point, close to the "Vincian locks" on the Royal Canal. In one of the folios of anatomical studies (19106v, dating from 1508-1510), Leonardo also notes experiments on the analogy between hydraulics and acoustics. In particular, he writes of an experiment to be made at home, based on observations of a cask at Campi Bisenzio: "You will have heard that, in the portion of a wave of air that passes through a narrow opening, a human voice is closed in, as I saw at Campi one that was closed into a cask open at the bung-hole (an opening made in the barrel at the point of its maximum diameter, where the bung is inserted).
A reference to Montale appears just once, in the map on f.23v of the Codex Madrid II, in a notation on the hill close to the blue line indicating the Bure torrent. On the hill overlooking the hamlet of Montale was Montale Alto with its Castello, a castle of which little remains today.
Leonardo cites the town of Montemurlo on f. 23r in the Codex Madrid II, and indicates that it lies just 4 miles from the city of Pistoia.
Pistoia, a city of art, whose diocese also included Vinci, undoubtedly influenced Leonardo, who could see here famous works such as the sculptures of Nicola and Giovanni Pisano and cycles of frescoes such as those in the Tau chapel. His aunt Violante and her husband Simone di Antonio lived in Pistoia, as well as several of Leonardo's friends (mentioned in the Codex Atlanticus). These were the years when Verrocchio was working in the Cathedral and, probably, in San Domenico (where the fresco of "San Girolamo" recalls the "Baptism", fruit of the collaboration between Verrocchio and Leonardo, now in the Uffizi). Leonardo mentions Pistoia several times in his studies for deviating the Arno through Prato and Serravalle Pistoiese, in the Codex Atlanticus, in Madrid Ms. II (with topographic calculations and cost estimates) and in RL 12685 and RL 12279 (Windsor Castle), as well as on the hydrographical map RL 12277. To the Diocese Museum have been brought works of religious art from the territory of Vinci (in particular from the church of Santa Maria a Faltognano), which Leonardo almost certainly saw in his youth and during the periods spent in his native land.
A centre of art and commerce, Prato was one of the focal points of Leonardo's project for deviating the Arno; the city thus appears on numerous maps (RL 12277, 12685, Codex Atlanticus and Madrid Ms. II). Several of Leonardo's friends, such as Filippino Lippi, came from Prato. The works of Donatello and Sangallo found in the city, as well as the fortifications and the textile machines used in the Prato manufactories, were undoubtedly of interest to Leonardo the sculptor, architect and technician.
Leonardo mentions this torrent on f. 23r of the Codex Madrid II. On f. 6v of the Codex Leicester is the reference to a river in an abbreviated notation “…fiume (Vin)” which from the context could refer to a watercourse in the area around Pistoia or one close to Leonardo’s birthplace, Vinci: “… flows down the mountains, depositing a great quantity of large stones in its ghiareto (river bed), which stones still retain some of their angles and flat sides; and in the process of its course it brings smaller stones with edges that are more worn, that is, the large stones make smaller ones; and in addition leave coarse gravel, and then finer …”. The Vincio di Brandeglio, which is “closer to Pistoia” (Repetti), and the Vincio di Montagnana together with the Stella, are the three principle streams lying to the right of the Ombrone River.