The excellent Leonardo da Vinci National Museum of
Science and Technology in Milan is housed in an
early 16th century Olivetan monastery. It has an
enormous range of exhibits covering all aspects of
science and technology, only a small proportion of
which are directly connected to Leonardo. However,
amongst them is this model of a multiple cylinder
watermill, as shown in the photograph above.
(Apologies for the poor quality as it was of
necessity taken through glass.)
The model was constructed in 1952-3 by Alexander
Siriati, based on a drawing by Leonardo (Codex
Atlanticus, folio 830 (1493), Biblioteca Ambrosiana,
Milan). The description on its label (fortunately
all the labels in the museum are in Italian and
English!) reads:
“This mill, conceived to be positioned straddling
a watercourse, is equipped with a large number of
millstones actuated by a single motor force. The
drawing probably dates from 1493 when Leonardo
sojourned at Vigevano, Ludovico il Moro’s favourite
ducal city, during which he performed studies and
observations relating to land reclamation,
hydraulics, and irrigation. Four series of
hydraulic wheels are positioned along the canal at
different levels, each connected to a different
transmission shaft, which engage 32 millstones, 16
on each side. The paddle wheels, moved by the
falling water, actuate the system of shafts and
gears so as to move the millstones simultaneously.”
There is a clearer picture on the museum’s website:
see
http://www.museoscienza.org/english/leonardo/modello_dettaglio.asp?id_macchina=53
.
This shows that beneath the floors supporting the
millstones are horizontal shafts connected to the
waterwheel. They have crown gears meshing with what
look to be lantern pinions on vertical shafts that
act as stone spindles; unfortunately they are not
very visible in my photograph. On the platforms
above the watercourse are what look to be sluice
controls.