Troy Weight

a system of measures used in weighing precious metals. In the Middle Ages each commercial city had its official measures, as the foot, gallon, pound, etc. Troyes, a city of some importance, situated southeast of Paris, was one of these. Among the local measures that have survived and have acquired national and even international acceptance are the Winchester bushel and, it is believed, the pound of Troyes, or the pound troy, as it came to be known. It had been for some time the standard of weight for silver spoons, etc., but in 1527 it was made the basis of English coinage. It was for a time the standard of weight in England for bread, silk, and jewelry as well. The pound troy contains 12 ounces, or 240 pennyweights, or 5,760 grains. The pound avoirdupois contains 7,000 grains troy. See Avoirdupois