1. As the Romans had divided the Alexandrian talent into 125 pounds of 12 ounces, so the new talent was divided into 125 parts each = 5763 grains. This was the Arabic lesser Rotl, its ounce = 480·25 grains. The rotl was also divided in the Greek way into 100 drachms or dirhems = 57·63 grains.
2. Another mode of division was into 100 greater Rotl, thus becoming a Cental of 100 lb. each = 7204·4 grains.
This greater rotl was divided, commercially into 16 ounces (Ar. _ukyé_, Gr. _oggia_, L. _uncia_) of 450,275 grains, and uncially for coin-weight into 12 × 12 dirhems of 50·03 grains.
Both these dirhems became, like the drachma coin-weights of Greece, the bases of other systems of weight, either at their original weight or at the lower weights to which coins might fall.
1. With its ounce of 480-1/4 grains would seem to have given rise to the Troy pounds, but it is much more probable that their variable ounces were 10 dirhems of about 48 grains.
2. From 8 of its drachms came the Venetian pound and the German apothecaries’ pound with an ounce of 8 × 57·63 = 461 grains.
1. Eight of its ounces of 450-1/4 grains = the Marc of Cologne, its double being the German Imperial pound = 7218 grains; our royal Tower-pound of Plantagenet times being 12 ounces = 5400 grains.
The 100 lb. centner of North Germany = 103·1 lb. was almost exactly the same weight as Al-Mamūn’s Cantar.
2. WEIGHTS OF EASTERN EUROPE (see Chap. XV)
The Polish pound 16 × 8 dirhems of 48·9 grains „ Russian „ „ „ 49·37 „ „ Austrian „ „ „ 50·6 „
From 8 dirhems of 50 to 47 grains came the ounces of the pounds of Southern France.
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).