The balance (σταθμός, libra, bilanx) of two pans at equal distance from the point of suspension is an invention of the earliest times; in Mycenaean tablets (see mycenaean language) it is the symbol for the largest unit of weight, and Homer is familiar with its use, which persisted through antiquity. The steelyard, in which the rod is unequally divided, the object to be weighed being suspended from the short arm against a sliding counterweight on the longer, does not appear before Roman times (statera: originally statera campana, from an alleged Campanian origin; see campania); but from its greater convenience it became the most popular form of balance. There may be alternative positions for the fulcrum, and two different scales can be marked on the bar. Inscriptions can guarantee the standard. Trutina is a pan-balance for large masses; momentana and moneta are for small objects, or coins. Weighing instruments were only as accurate as the weights used, and it seems that some error was created by using worn items. See weights.