Coclea

Coclea drawings recur in various sketches ( Forster codex, pag.52v. 53r., 54v., Codex Atlanticus 1069r.): the are almost always arranged for lifting water or cereals to great heights with the use of low powers. Such tool is also to be found drawings by the Senese engineers Francesco di Giorgio Francesco and Taccola. Leonardo seems to guess that the cochlea is a machine able not only to raise water but to produce movement itself, like a hydraulic engine. Such reflection comes from the observation of a cochlea full of water that, just put standing and reached a particular inclination, starts rotating when the water flows from the lower part. In a few passages Leonardo clearly shows that he knows the working method of the cochlea: he points out for instance the importance of the inclination according to the number of coils wrapped.