The leicester codex, also known as the "Hammer" codex from the name of the american millionaire who owned it before Bill Gates, was compiled between 1506 and 1513, during the period when Leonardo was dividing his time between short stays in Florence and returning to Milan, this time under the protection of the French king, Louis Xii. Unlike the other manuscripts where the subject changes on each page according to Leonardo's mood or his innumerable interests, this codex is almost totally dedicated to an in-depth study of a sole theme: the study of water. Currents, whirlpools, waves, heads, canals, banks, locks, dams, tunnels, projects for docks, for land reclamation, [...]