As a unit of weight, the ounce derives from the Roman uncia (meaning “twelfth part”), which was 1/12 of a Roman foot or ounce. The standard or physical embodiment of the Roman foot, a copper bar, constituted the Roman pound standard and was divided along its length into 12 equal parts, called unciae.
When was the ounce invented?
King Henry II of England adopted the troy weight system, which was widely used in Britain's coinage system in the 1400s. In the early 1500s, the troy ounce was accepted as the official standard of measure for gold and silver in Britain, with the US adopting this measurement method as well in 1828.
Where did pounds and ounces come from?
Roman libra
The libra (Latin for "scales / balance") is an ancient Roman unit of mass that was equivalent to approximately 328.9 grams. It was divided into 12 unciae (singular: uncia), or ounces. The libra is the origin of the abbreviation for pound, "lb".
