number predominates in the Roman system of weights where the pound (libra), and in the measures of length where the foot (pes), were by use and wont subdivided into twelve parts; the unit of the Roman measures of surface was the "driving" (actus) of 120 feet square, a combination of the decimal and duodecimal systems.[1] Similar arrangements as to the measures of capacity probably have passed into oblivion. If we inquire into the basis of the duodecimal system, and consider how it can have happened that, in addition to ten, twelve should have been so early and universally singled out from the equal ranks of number, we shall be able to find no other source to which it can be referred than a comparison of the solar and lunar periods. The double hand of ten fingers and the solar cycle of nearly twelve lunar periods first suggested to man the profound conception of an unit composed of equal units, and thereby originated the idea of a system of numbers, the first step towards mathematical thought. The consistent duodecimal development of this thought appears to have been of national Italian origin, and to have preceded the first contact with the Greeks.
Hellenic measures in Italy. But when at length the Hellenic trader had opened up the route to the west coast of Italy, the measures of surface remained unaffected, but the measures of length, of weight, and above all of capacity—in other words those definite standards without which barter and traffic are impossible—experienced the effects of the new international intercourse. The Roman foot, which in later times was a little smaller than the Greek,[2] but at that time was either equal in reality or was at any rate still reckoned equal to it, was, in addition to its Roman subdivision into twelve twelfths, divided after the Greek fashion into four handbreadths (palmus) and sixteen finger-breadths (digitus). Further, the Roman weights were brought into a fixed proportional relation to the Attic system, which prevailed throughout Sicily but not in Cumæ—another significant proof that the Latin traffic was chiefly directed to the island; four Roman pounds were assumed as equal to three- ↑ Originally both the actus, "driving," and its still more frequently occur. ring duplicate, the jugerum, "yoking," were, like the German "morgen," not measures of surface, but measures of labour; the latter denoting the day's work, the former the half-day's work, with reference to the peculiarly marked division of the day in Italy by the ploughman's rest at noon.
- ↑ 2425 of the Greek foot = one Roman foot.
