This first-order lever, of nearly the same design as item inv. 1007, was probably used to show the action of an oblique effort. There is a beam with two notches and twelve small equidistant nails indicating the points where the effort could be applied. The weight that served as effort was applied to the lever by means of an oblique cord passing over a pulley fixed to a table. The instrument reproduces a lever illustrated by Willem Jacob 's Gravesande in Physices elementa mathematica, experimentis confirmata (3rd ed., Leiden, 1742). Provenance: Lorraine collections.