Beyond doubt dealings of barter and traffic were carried on at these fairs long before the first Greek or Phoenician vessel entered the western sea. When bad harvests had occurred, different districts supplied each other at these fairs with grain; there, too, they exchanged cattle, slaves, metals, and whatever other articles were deemed needful or desirable in those primitive times. Oxen and sheep formed the oldest medium of exchange, ten sheep being reckoned equivalent to one ox. The recognition of these objects as universal legal representatives of value or in other words as money, as well as the scale of proportion between the large and smaller cattle, may be traced back--as the recurrence of both especially among the Germans shows--not merely to the Graeco-Italian period, but beyond this even to the epoch of a purely pastoral economy.(16) In Italy, where metal in considerable quantity was everywhere required especially for agricultural purposes and for armour, but few of its provinces themselves produced the requisite metals, copper (-aes-) very early made its appearance alongside of cattle as a second medium of exchange; and so the Latins, who were poor in copper, designated valuation itself as "coppering" (-aestimatio-). This establishment of copper as a general equivalent recognized throughout the whole peninsula, as well as the simplest numeral signs of Italian invention to be mentioned more particularly below(17) and the Italian duodecimal system, may be regarded as traces of this earliest international intercourse of the Italian peoples while they still had the peninsula to themselves. Transmarine Traffic of the Italians