ounce prior to 268 B.C., for it is an ascertained fact that the old Roman uncia did not exceed 420 grs.65 It must be remembered that the weight of the ounce would depend on the standard foot by which the bar was measured. Now, whilst the Roman foot measures 296 millim., there was likewise in use in Campania, and probably in many parts of Southern Italy, a foot of 276 millim. The relation of bars of these lengths and of a given thickness to the Roman libra is not without interest. If we take an ordinary engineer’s table of materials we shall find that a copper rod a Roman foot long, and half a Roman inch in diameter, weighs 5040 grs. Now, as the Roman pound weighs 5184 grs. this approximation seems almost too close to be a mere coincidence. If on the other hand we take a rod of a foot of 276 millim. and with a diameter of the corresponding half-inch, we shall get a pound of 4680 grs. and an ounce of 390 grs, which is certainly not far from the weight of the small gold talent. It follows from this that we may expect pounds of different weights in Italy, according as the foot-unit varies in different districts.
In later times, besides the pound of 12 unciae, there were several commercial pounds on Italian soil, the pound of 16 ounces (from which our own avoirdupois is probably descended), that of 18 unciae, and that of 24. The last two are easy of explanation, since one is simply the double, the other one and a half times the Roman pound. But perhaps a different explanation must be sought for the 16 ounce pound. The foot was divided by Greeks and also by Italians into 16 fingers as well as into 12 thumbs. Was therefore the pound of 16 ounces simply derived from the division of the foot bar into 16 fingers, the weight of the finger being however equated to that of the Roman thumb or inch of copper?
The as, having been once subjected to weight, its hundredfold, the centumpondium or “hundred weight,” became the highest Roman weight-unit. Thus the as and the centumpondium of the Italians correspond to the mina and talent of the Greeks. But it will be observed that