Comparison of the imperial and US customary measurement systems metre, as 1852 metres. Traditionally, both Britain and the US used three different weight systems: troy weight for precious metals, avoirdupois weight for most other purposes and apothecaries' weight for medicines. However, apothecaries' weight has now been superseded by the metric system. One important difference is the widespread use in Britain of the stone of 14 pounds () for body weight. This unit is not used in the United States, although its influence was seen in the practice, until World War II, of selling flour by a barrel of 196 pounds (14 stone). Another difference arose when Britain abolished the
Trade during the Viking Age so there was no danger of them being rearranged or switched during the course of an exchange. Estimated exchange rates at the beginning of the 11th century in Iceland were: If the weight of a piece of jewelry was more than needed to complete a purchase, it was cut up into smaller bits until the correct weight needed for the transaction was reached. The term hack silver is used to describe these silver objects. Silver ingots were primarily used for large/high-value transactions. The largest found weights weigh more than 1 kilogram each. Precious metals were also used to display personal