DaVinci

Leonardo da Vinci is the most famous example of an artist/engineer in Western Civilization.  He is proof positive that not only did these two disciplines coexist in one person, they drew equally upon his creativity.  His genius as both engineer and artist makes it appropriate that, in this book, he serves to link the canal's history to canal-inspired art.

Leonardo was working for the Duke of Milan, Ludovico Sforza, in 1497 as the City Engineer when he was asked to design a canal to connect two existing canals that were at different elevations, requiring the use of a lock at San Marco.  Locks were used or written about by Leon Battista Alberti and Bertola da Novate earlier in the 15th century.  These locks employed vertical lift gates.  Leonardo considered all previous gate structures and came up with an entirely different approach.

He developed what we now call mitered gates, pairs of gates at the upstream and downstream ends of the lock rotating horizontally around a vertical axis and opening into recesses in the masonry walls to permit passage of boats.

When closed, the gates would point upstream in a "V" or miter shape; water pressure would hold them tightly together on the vertical contact surface and against a sill along the bottom of the gates to minimize leakage.  To permit gradual discharge of water from the lock a smaller gate, called a wicket, would be opened on the lower gate when the boat was being dropped.  Similarly an opened wicket would allow an inflow of water through the closed upper gates into the lock when the boat was being raised.

Leonardo showed a complete lock section with mitered gates and wickets in his notebook Codex Arundel, 341v-b and hist study of other gates in Codex Arundel, 7v-b.  This design was used on all early European can lock gates and those in the United States, including the Erie Canal.