From 10 dirhems of 48 grains, more or less, came the ounces of the Troy pounds.
The weight of the dirhem is now: Turkey 49·6 grains, Greece 49·4 grains, Morocco 49 grains, Egypt 47·6 grains, Tripoli 47·07 grains. In Tripoli there is a small weight = 12·55 grains called a dirhem, which seems to be 1/4 of an original weight dirhem = 50·1 grains.
The fall of the dirhem weight, and consequently of the weights which are multiples of it, accounts for the Egyptian Cantar having fallen from its original weight to somewhat over 98 lb.
The quarter-Cantar gave its Arabic name to other quarter-hundredweights, the Arroba of Spain, the Rubbio of Italy, the Rub of Southern France (from Ar. rouba, four; cf. Rubaiyát, quatrain).
Measures of Capacity derived from Arabic Linear
Measures
Al-Mamūn’s cubit cubed became the medieval standard of grain measure on the Mediterranean coasts—
21·28 in. cubed = 9639 c.i. = 347·314 lb. water,
which is equal to 34·73 gallons or 4·34 bushels.
This measure subsists in Egypt as the Rebekeh = 4·32 bushels. It passed to Marseilles as the Cargo, and to Paris as the Setier.
These developments of the Arabic cubit and foot will be more fully explained in the chapters on foreign systems. They are sketched in order to show how the Eastern caliphate took up the system begun by the great monarchies of many centuries before, and elaborated by Greece and Rome. Thus, from Moslem Egypt as from Pharaonic Egypt have come virtually all the weights and measures of the Western world.