One variation on the steelyard is the balance in which the weight is fixed and set at one end of a graduated beam, and the fulcrum slides along the beam. In the one shown here, perhaps for weighing liquids, the handle of the patera acts as a graduated beam and the hanging hook is free to slide along the slot marked at the side with weight values. The weight is configured as a youthful head of Mercury with winged petasos and was added following arbitrary 19th-century restoration.