How Close a Ship Can Sail to the Wind
Mast placement, points of sail, and beating to windward against a NE wind
On this verso Leonardo works out points of sail against the named compass winds. He observes that the mast stands at three-fifths of the length toward the stern for a lateen sail but amidships for a square sail, and that a vessel cannot lie closer to the wind than about "one wind and a half": with a northeast (greco) wind she can only head between southeast and east, while a square-rigged ship does worse, barely one and three-quarter winds. To gain ground to windward against a NE wind he must beat by the orza, running from a to b to e. Several pen and pencil diagrams set sails against crossed wind-lines, with the winds named greco, scirocco, levante and libeccio.
On this page
How close to the wind a ship can lie
A ship cannot sail nearer the wind's line than about one wind and a half: with a NE (greco) wind she turns her bow only between the SE (scirocco) and the E (levante). A square-rigged vessel manages no better than one and three-quarter winds, and only barely.
Mast placement for lateen and square sails
The mast is set at three-fifths of the hull toward the stern for a lateen sail, but amidships for a square sail. Point a is the bow and b the stern.
Beating to windward by the orza (a–b–e)
If the wind blows from the NE (greco) and he wishes to gain ground to windward, he must go by the orza, that is, from a to b and from b to e, and so on. The note breaks off before completing the course.
Wind-rose sketches naming the winds
Captions on the diagrams name the winds and sail parts: scirocco and levante, the pull of the greco, and libeccio, alongside the penna and carro of the yard. The sketches show sails crossing ruled wind-lines.