of weight, so in Cambridge the yard of butter is identical with the pound of butter[428]. Our next step will be to trace the process by which the _as_ or rod became the general weight-unit, the pound (_libra_). The term _libra_ is not the oldest Latin name for _weight_, for _pondus_ or its cognate verb _pendeo_, which literally means to _hang_, is the true claimant for that position. _Libra_ seems properly to mean the _balance_, as is seen from the legal formula (employed in Mancipatio) _per aes et libram_, by means of copper and the balance. From the fact that its chief use was to weigh _asses_ of copper, the mass of an _as_ came to be termed the _weight par excellence_, just as the most usual amount weighed in the Greek _talanta_ (scales) became the _talanton par excellence_. This process can be illustrated by modern examples. Thus in the south of Ireland potatoes are sold by the unit of 21 lbs., which consequently is termed a _weight_, and instead of speaking of so many stones or hundredweights, everyone speaks of a weight of potatoes. But, as already remarked, it was only at a comparatively late epoch that the bars of copper were weighed. It would be only with the growth of greater exactitude in commercial dealings that the art of weighing, which was employed for all dealings in gold and silver, would be applied to copper. Just as the Malays and Tibetans have been gradually taught by the careful Chinese to employ weights commercially, so the Italian tribes may have been led to do so under the influence of the astute Greek traders from Magna Graecia and Sicily. The system in vogue for gold was that of our old friend the ox-unit. This is proved from the fact that not only is the oldest gold coinage of the Etruscans, the close neighbours of Latium, based upon this standard, but that also in Sicily and Southern Italy there was the small gold talent, the three-fold of the ox-unit. This three-fold of the stater was also used at Neapolis. Although the earliest Greek colonies in Sicily employed at first the Aeginetic standard for silver, we soon find them reverting to the gold or Euboic standard for that metal, whilst the early silver coinage of the Etruscans (before 350 B.C.) is also of the Euboic standard. We may with high probability assume that when the Sicilians and Italians first essayed to weigh their copper rods, they naturally employed the standard already in use for gold and silver. The highest unit of this was the small talent of 3 staters which weighed about 405 grs. The bar was divided into 12 inches, and it was found that an inch of copper rod closely approximated in weight to the small gold talent. The weight of the bar, which was the ancient unit for copper before weight had been employed, now became the standard weight-unit for that metal. It is to be observed that this ounce of 405 grs., though some 27 grs. less than the full Roman _uncia_ of later times, is only 15 grs. lighter than