Mechanical drum

This drum on wheels is designed to be attached to a cart and work automatically taking advantage of its movement. It can reproduce various cyclically-repeated rhythms: the axle of the cart wheel turns a cog-wheel. The latter moves other wheels which operate five strikers on each side of the drum. The drawing is executed in sanguine, outlined in pen and it is not captioned.
Codex Atlanticus, sheet 837 About 1490