7. The Arabic Talent

To the talents and measures of capacity evolved from the feet of the three principal cubits of antiquity, must be added the talent and other measures evolved from the Black foot of Al-Mamūn’s cubit. They have had great influence on the weights and measures of Europe.

Al-Mamūn’s cubit was = 21·28 inches, the foot = 14·186 inches.

The foot cubed gave a measure of water, the weight of which was the Egyptian Cantar or Cental—

14·1868³ = 2855 c.i. = 102·92 lb. water = 720,441 grs.

This talent was divided in two ways:

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.

The Lesser Rotl—

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.

From the Greater Rotl came—

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).

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.

[5]. The Imperial pound = 27·727 cubic inches of water, 7000 grains: the gallon 10 lb. or 277·274 c.i.

[6]. Essai sur les Systèmes Métriques (1859).

[7]. The Metretes was one-tenth more than our firkin. In the story of the Marriage at Cana (John ii.) the Greek has ‘two or three metretes.’ This term is kept in Wycliff’s version (1388) and in the modern Dutch version.

[8]. 5050 grs.—Smith’s Dict. of Antiquities. 5047 grs.—Daremberg and Scaglio’s Dict. of Antiquities.

[9]. There was a custom of rhōpi, turn of the scale, or long weight, which increased the legal commercial weight to a customary weight tending towards that of the Alexandrian talent series.

CHAPTER IV
THE INVOLUTION OF LINEAR MEASURES FROM
WEIGHTS

The Sources of the English and of the Rhineland
Foot

Commerce is the great conservator of standards. These may become altered by the ill-advised action of rulers, by municipal or parochial carelessness, even by the desire of profit on short measure, or occasionally, as seen to a slight extent in our old Bushel, by the faulty dimensions of a standard; but wholesale trade, supported, in weights at least, by the goldsmith and the apothecary, preserved the integrity of many standards during the Middle Ages and up to modern times. Commerce conveyed to the West the standards that had developed in the great Oriental Kingdoms, sometimes with the modifications due to Roman influence. Masons and architects also preserved the standards of length and, allowing for variations inevitable under the feudal system, the principal linear measures can generally be traced to their sources as surely as weights. But there are two, yea three, striking exceptions among the linear standards of the West: the English foot, and the Rhineland foot, and also the Pán of Marseilles. These are quite unconnected with any ancient measures, and there is no record of their origin. The only clue to it is found in the simple relation of each to the corresponding weights and measures of capacity, the origin of which can be satisfactorily traced. This leads to the hypothesis that these linear measures were ‘involved,’ that is produced by a method of involution the inverse of that which had evolved the measures of weight and capacity.