The municipal mill of Vinci is mentioned for the first time in the Statutes of 1418. At the time of drafting the lease, the da Vinci family is described with these words: “molendino dicti comunis cum foveo et goraio et aliis suis pertinentiis et situm ipsius molendini et pro edificando et ad conficiendum aliud molendinum sive factorium positum apud dictum castrum vincii in populo sancte crucis”. The concession included the use of the mill, the millrace that fed it, and the drainage ditch. However, as was customary, the concession provided for an intervention to improve the asset acquired by the concessionaire: in this specific case it was desired that there would be a construction of a second works, whether mill or oil mill, also in the proximity of the castle. It is possible that the desired improvement with the stipulation of the contract of declaration in favor of the da Vinci family actually was achieved. At least since 1505, the municipality of Vinci had, on the castle moat, a mill with a single millstone insulla ghora de fossi di Vinci (on the millrace of the ditches of Vinci) and the fattoio da olio a acqua Apichato chol sopradetto mulino (water-powered oil press attached to the aforesaid mill). Whether the construction of the mill really did represent respect of the rule ad meliorandum in the contract of concession of the public mill to the da Vinci family, we do not know. Nonetheless, we can point out that one of Leonardo's half-brothers, Giovanni, had a concession since at least the 1530s for the premises adapted for use as tavern and butcher shop, which bordered right on the municipal mill. The sketch of the castle of Vinci drawn by the Capitani di Parte Guelfa shows the details of the system of canals that powered the hydraulic works of Vinci at the end of the 16th century. To the north of the castle a long canal, the goraio, captured the waters of the rio castellano, to power in succession first the mill of La Doccia, just above the castle, and then the municipal mill, in the village. The drawing shows the abundant flow from the goraio coming down from the west side of the castle, to arrive to the piazza del mercatale, the village square, turning left from this point toward the valley, alongside the last building of the village, marked as an osteria, or tavern. The millrace appears to feed two hydraulic works in succession, which could correspond to the municipal mill and the other works indicated in the 1478 lease (aliud molendinum sive factorium).