The Viola Organista and Its Details
Red-chalk study of the viola organista, a bowed keyboard instrument, and its mechanism
The caption identifies this red-chalk sheet as the viola organista, a bowed keyboard instrument, together with studies of its parts. The largest drawing shows a rotating friction wheel mounted inside a tapering trapezoidal case with an upright rod and foot. Around it Leonardo sketched separate details: a cranked linkage of jointed arms, a toothed cog wheel, and rough smaller studies of the mechanism at the lower centre.
On this page
Friction-wheel mechanism in its case
A large disc wheel is set within a tall, downward-tapering box, driven from an upright shaft that rises from a footed stand. This is the sounding mechanism of the viola organista, in which a turning wheel bows the strings.
Detail of cranked linkage and cogwheel
At upper right a bent, jointed linkage of straight arms connects to a hub, and a toothed cog wheel is drawn beside it. These are separate detail studies of parts belonging to the instrument's drive.