Folio 12

This page contains a mechanical study, likely for a clock mechanism or a lifting device. It is drawn in pen and ink with red chalk underdrawing. No handwritten text by Leonardo appears on this page, except for the folio number 12 added by a later hand in the upper right corner. Faint marks on the left side are ink from the reverse side of the paper showing through.

A technical study of a mechanical assembly, possibly part of a clock or a winch. The drawing features a central toothed gear connected to a vertical drum, mounted on a horizontal frame. Red chalk shading provides depth and form to the components. This sketch is a characteristic engineering study showing how Leonardo integrated gears, shafts, and winding drums.

A simplified diagram shows a cylindrical weight suspended by a vertical cord. This likely represents the power source or a pendulum component for the mechanism depicted above.

A small thumbnail sketch depicts a wheel with a connected linkage or lever. This explores the mechanical transmission of motion.

toothed gear (ruota dentata), drum (tamburo), mechanism (meccanismo), gear (ingranaggio)