Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
The art of measuring brings the world into subjection to man;
the art of writing prevents his knowledge from perishing along
with himself; together they make man--what nature has not made
him--all-powerful and eternal. It is the privilege and duty of
history to trace the course of national progress along these paths
also.
Italian Measures
Measurement necessarily presupposes the development of the several
ideas of units of time, of space, and of weight, and of a whole
consisting of equal parts, or in other words of number and of
a numeral system. The most obvious bases presented by nature for
this purpose are, in reference to time, the periodic returns of
the sun and moon, or the day and the month; in reference to space,
the length of the human foot, which is more easily applied in
measuring than the arm; in reference to gravity, the burden which
a man is able to poise (-librare-) on his hand while he holds
his arm stretched out, or the "weight" (-libra-).
