Similar to those still in circulation in local markets, the steelyard was the most common Roman weighing instrument. Featuring an asymmetric beam, a single pan on which goods are placed and a small, sliding weight, the steelyard is a perfect representation of the principle of the lever and it is not surprising that the principles behind its functioning were the focus of in-depth analysis by scholars such as Euclid and Archimedes in the 3rd century BC.