History of Roman Coinage
Like the Spartans the early Romans were a military race with little
need for commerce, which they left to their Greek neighbors. Until
the Romans starting getting tribute from Carthage, much of the Roman economy
was based on bronze coins. Bronze was exchanged in Roman pounds, "Libra"
or lbs which cointained 360 grams and was divided into 12 bronze coin units
called uncia (ounce) so there were 12 ounces to a Roman lbs of 360 grams.
Today's pound (lbs) is 25% more or 16 ounces (uncia) to a pound of 480