This instrument, described by Jean-Antoine Nollet in Leçons de physique expérimentale (Paris, 1743-1748) and built in the woodworking shop of the Museo di Fisica e Storia Naturale, was used for many important experiments in classical mechanics. In particular, it allows the study of equilibrium conditions and the attrition of bodies placed on surfaces inclined at different angles.

The base holds a veneered wooden arc at one end. At the other end is hinged a moving wooden board whose inclination on the arc can be adjusted by means of a sliding brass strip. The top of the board holds a pair of pulleys. Two cords connect two lead weights through the pulleys to a stirrup holding an ivory cylinder that rolls down the inclined plane.

By changing the angle of the board and applying different weights to the cylinder, one can examine the changes in the equilibrium conditions and the attrition of the cylinder on the wooden plane. Provenance: Lorraine collections.