(Latin statera, campana; καμπανός/kampanós, καμπανόν/kampanón). Steelyard refers to the form of straight-beam balance with arms of varying length, which has been demonstrated in Italy beginning in the late 1st cent. BC, and was later widespread in the Roman Empire. The early form of the typical Roman steelyard and its mechanical principle was described by Vitruvius, who provides the then common term statera ('scale'; Vitr. De arch. 10,3,4), while much later, around AD 600, Isidorus calls it campana (Isid. Orig. 16,25,6). Correspondingly, in the late ant…