This rare and unusual mechanical apparatus illustrates the analogy between the human arm and a third-order lever: the fulcrum is the elbow, the effort is provided by the muscle attached to the forearm, and the load consists of a weight held in the hand. The wooden skeleton of the arm, forearm, and hand is attached to a marbled wooden table. The shifts in the weights suspended from the arm show the arm's movement. When the weights descend, the hand rises. Provenance: Lorraine collections.