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.
The evolution of the As from the Greek-Asiatic talent leads to consideration of the measures connected with it, and with the Alexandrian talent.
It has been seen that the Roman foot, 1/5000 of the Roman mile, 8 Olympic stadia, was 11·67 inches. This foot being cubed, the weight of the cubic foot of water was made the basis of the Roman measures of capacity—
11·673 inches = 1589 c.i. = 57·32 lb. water
= 401,240 grains.
This calculated measure, 57·32 lb. = 5·732 gallons = 45·8 pints, was the Amphora Quadrantal, supposed to weigh, of wine, 80 As or primitive pounds. Quadrantal vinei octoginta pondo sit. The correspondence was only approximate. The Quadrantal should have been = 57·7 lb. for its 1/80 part (= 5049 grains) to correspond with the As. Its capacity was probably adjusted so as to make it half a Medimnos and = 3 Modii.
There are specimens extant of the Quadrantal, of cubical shape, showing that it was named from its being a cubic foot in measure.
The Quadrantal, being equal to 45·8 pints, was almost exactly half the Greek Medimnos, equal to 91·5 pints; so that, divided into 8 congii, each of 6 sextarii, the Sextarius, 1/48 Quadrantal, was practically the same as the Xestes, 1/96 of the Medimnos.
And the Quadrantal being also very nearly two-thirds of the Greek Metretes, equal to 70·4 pints, the Sextarius was also nearly the same as the other Xestes, 1/72 of the Metretes.
So the Sextarius was 1/48 Quadrantal, 1/72 Metretes, and 1/96 Medimnos.