Egyptian balance with scale pans, from Tel El-Amarna, Upper Egypt, c. bc 1370-1350
This Ancient Egyptian equal-arm balance, dated 1370-1350 BC, was found at Tel El-Amarna, Upper Egypt. Equal-arm balances of this type are the simplest and earliest method of weighing. They consist of a beam that has a pan suspended at either end. In use objects to be weighed are placed in one pan while weights of known mass are placed in the other pan until the two are balanced with the bar level. The product of these weights gives the mass of the commodity being measured.