Similar to those still adopted in markets, the steelyard is based on the principle of the lever. Goods are placed in a pan (sometimes replaced with hooks or bowls) and counterbalanced by a weight that slides along a graduated beam (scapus). The weight portrays a little boy although it was also customary to fashion them as protective deities of trade and transactions. The beam features two different graduated scales - from 1 to 14 and from 10 to 50 - which correspond to two different fulcrum positions. An inscription punched on the beam shows a consular date of 47 AD, confirming that the balance and weights complied with a decree issued by the Roman aediles Marcus Articuleianus and Gnaeus Turranius.