Pound (mass) No standards of the Tower pound are known to have survived. The Tower pound was equivalent to about 350 grams. The merchants' pound ("mercantile pound", "libra mercantoria", or "commercial pound") was considered to be composed of 25 rather than 20 Tower shillings of 12 pence. It was equal to 9,600 wheat grains (15 tower ounces or 6,750 grains) and was used in England until the 14th century for goods other than money and medicine ("electuaries"). The London pound is that of the Hansa, as used in their various trading places. The London pound is based on 16 ounces, each ounce
Pound (mass) as a mass equal to to match the definition of the international pound agreed in 1959. A troy pound is equal to 12 troy ounces and to 5,760 grains, that is exactly grams. Troy weights were used in England by jewellers. Apothecaries also used the troy pound and ounce, but added the drachms and scruples unit in the Apothecaries' system of weights. Troy weight may take its name from the French market town of Troyes in France where English merchants traded at least as early as the early 9th century. The troy pound is no longer in general use or