Pound (mass) for the weight of certain precious metals, especially in the trade; these are normally quoted just in ounces (e.g. "500 ounces") and, when the type of ounce is not explicitly stated, the troy system is assumed. Historically, the pound sterling was a Tower pound of silver. In 1528, the standard was changed to the Troy pound. The avoirdupois pound, also known as the wool pound, first came into general use c. 1300. It was initially equal to 6992 troy grains. The pound avoirdupois was divided into 16 ounces. During the reign of Queen Elizabeth, the avoirdupois pound was redefined as
Anglo-Saxon pound Thomas Snelling writes that the division of the pound into 12 ounces was in use with the Romans, and the division of ounces into 20 pennyweights was introduced into France by Charlemagne, and then brought to England by William the Conqueror. The Latin word for "pound" is libra. The £ or ₤ is a stylised writing of the letter L, a short way of writing libra. This is similar to how a pound of mass is abbreviated "lb". Up until 1972, especially on typewriters or keyboards without a "£" symbol, it was common to write "L" or "l" instead of