The capacity of the Persian cubic foot was 2000 c.i. = 72·13 lb. = 7·213 gallons.
This cubic foot, increased in water-wheat ratio, gives 7·213 × 1·22 = 8·8 gallons or 70·4 pints, as the capacity of the Amphoreus metretes.[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.
Some archæologists have given it as = 8·68 gallons, a very slight difference.
The Metretes was divided into 36 Choinix or 72 Xestes, which contained O·977 pint as against the O·955 pint of the Xestes, which was 1/96 Medimnos. A mean figure, 0·96 pint, is usually taken as the common capacity of the two Xestes.
The Greeks had thus two standards of capacity, the Metretes and the Medimnos, both cubic feet increased in water-wheat ratio to make them corn-measures. It is very likely that, having these two measures from different sources, the one of 72 Xestes, the other of 96, they would use the smaller as a fluid measure. In modern measures there are several instances of corn-measures having become wine-measures. Our Imperial gallon used for fluids is a slightly altered corn-gallon; at present the multiples above the gallon are used for corn, the gallon and its divisions for fluids.
4. ROMAN WEIGHTS AND MEASURES OF CAPACITY
Used by the Greek colonies in Asia, the Greek-Asiatic talent passed to the Greek or Trojan colonies in South Italy, and became the source of the old Roman pound, the _As libralis_ = 5049 grains, 1/100 of the talent; (72·13 × 7000)/100 = 5049 grains.[8]
5050 grs.—Smith’s _Dict. of Antiquities_. 5047 grs.—Daremberg and Scaglio’s _Dict. of Antiquities_.
The Aes or As, the bronze or copper pound of the Roman republic in its earlier times, was divided into 12 ounces, each = 420·75 grains.
It remained the mint-pound of both Republic and Empire.
The Aurei of Julius Caesar, 1/40 As, weigh 127 grains, those of Augustus 125 grains. The mean weight appears to be about 126 grains, which gives 5040 grains for the As.
The Aurei of the later Empire were struck at 1/72 As, and weigh 70 grains, giving the same weight, 5040 grains, for the As. At 70·1 grains they would give 5049 grains, the calculated weight of the As.