Leonardo's aerial screw

The Italian polymath Leonardo da Vinci drew his design for an "aerial screw" in the late 1480s, while he was employed as a military engineer by Ludovico Sforza, Duke of Milan from 1494 to 1499.

Leonardo biographer Walter Isaacson has expressed the belief that it was “devised for a theatrical spectacle”.

The upper half of the pole is the supportive axis for a large spiralling sail of linen with a radius of about 5 m (16 ft), stiffened with starch.

The design envisions a crew of several people on the wooden platform running around the central pole while holding handles that rotate the sail.

In 2022 a drone based on Leonardo's design was made by a team of engineers from University of Maryland and was presented at a conference in San Jose.

Detail of Leonardo's "aerial screw"
The page of Paris Manuscript B, folio 83v, that depicts Leonardo's aerial screw, held by the Institut de France