Waves, wind on water, and the circles of birds' flight
Water leaping over a hill of stones; hollows and deposits along a bank
Worked with the sheet turned upside down, this page joins studies of moving water to an observation on the flight of birds. Leonardo notes that after a hollow there always follows a hill of stones, labelling one figure hill of stones and hollow, and that when the wind prevails at a the wave hurls itself with a great roar at b. A lettered water figure traces a stream falling from a b into n e, leaping over a hill and striking at c d before descending into o p. In the left half a bird figure carries the remark that the circles made by a bird's flight never lie within the diameter of the circle whose centre it marks with the tips of its wings.
On this page
Wind driving a wave against a bank
When the wind prevails at a, the wave hurls itself with great roar at b. The lettered figure sets the force of the wind against the throw of the water at the marked points.
Water leaping over a hill of stones
The water falls from a b into n e and leaps over the hill e f, but first strikes at c d, and from c f, the hill, descends into o p and jumps into n b. The passage tracks the bouncing path of a fall of water across an obstructed bed.
The circles of a bird's flight
The circles made by the flight of birds will never lie within the diameter of that circle whose centre the bird marks with the tips of its wings. The note reads the turning of a bird against the geometry of a circle.
After the hollow, the hill of stones
Always after the hollow comes the hill of stones. A neighbouring figure labels the two features, hill of stones and hollow, recording how scour and deposit shape a bank.