Wing proportions and an articulated wing linkage
Calculating wing width and length; the greatest wing-beat is half the wing's length
Leonardo works out the proportions of a wing from those of a bird, scaling fractions of a braccio up to a large flying body 30 braccia across and arriving at a wing about 4 and a half wide and 12 long. A marginal rule adds that the greatest movement of the wing should be half its length. The sheet is dominated by a large articulated wing-linkage mechanism of jointed rods, with smaller mechanical details and a few slight figure sketches, including a small nude, in the lower corners.
On this page
Scaling a wing from a bird's proportions
Starting from a small bird whose wings are 3/4 of a braccio wide, Leonardo reduces the widths to twentieths of a braccio and scales them to a body 30 braccia across, obtaining a wing about 4 and 1/2 wide and 12 long, with the bird 6 thick: 4 of chest breadth and 2 of remiges, that is, a space without motion.
The greatest wing-beat is half the wing's length
A marginal note on the left instructs that the greatest movement of the wing should be made equal to half of its length.
Articulated wing linkage
A large mechanism of jointed rods and pivots fills the centre and left of the sheet, an articulated linkage evidently designed to drive a wing, accompanied by smaller studies of its joints. This apparatus is drawn but not covered by the transcription.
Small figure sketch
In the lower right corner is a small, lightly drawn nude human figure, with further faint figure sketches in the lower area, none of which are included in the transcription.