<< My dictionary defines the word "as" as an ancient Roman unit of weight
equal to about one Troy pound. It also defines "libra" as an ancient unit of
weight correspoinding to one pound. I know that the as was also a coin at
some point in the Roman history. My question is, can anyone tell me if one
preceeded the other or were they in use at the same time. >>
My Oxford English Dict. informs me that the "as" was a coin of 12 (Roman)
ounces or one (Roman) pound of copper until the 1st Punic War, when inflation
reduced it to 2 ounces. It went to 1 ounce during the Second Punic War, and
to 1/2 ounce by the Lex Papiria in 191 BC, which is a few years after
Carthage lost that second war. The same source gives fewer facts about
"libra": only the same weight, 12 ounces, the vague date, "medieval Latin,"
and a first English citation from 1398. On the other hand, that might well
be sufficient to answer half the question by demonstrating that the libra
must have been introduced at 12 ounces at a time after the as had been
devalued to 1/24 of a pound (though who could measure it in the Middle Ages
so far had standards deteriorated in weights and measures). Whether the
coins or the denominations were ever used together, most likely in medieval
Europe, needs more than such half-baked desktop research to decide.
-Bill Everdell, Brooklyn