Ounces and pounds
In the English, or customary, system of measurement, bread, butter,
people, and many other things are weighed in ounces and pounds. But why
are there sixteen ounces in a pound? And why do ounce and pound have the
strange abbreviations oz. and lb.?
Well, it all goes back to the Romans. The Romans had a small unit of
weight called an uncia. Twelve of these made what they called a
libra. The English followed the Roman system of twelve small units in
one large unit. They called their small unit an ounce, from the Latin
word uncia, which means “a twelfth.” They called their larger unit a
pound, from the Latin word pondus, which means “a weight.”
Uncia, of course, is the same word from which we get inch. But if inch
and ounce come from the same word, why are they pronounced and spelled
differently? It’s really quite simple. Inch came directly from Latin.
But ounce came through French. The Old French word was unce. So, we
say and spell ounce much the way the French did.
All weights were once based on the weight of grains of wheat. There were
so many grains to
an ounce and so many ounces to a pound. But, for a long, long, time,
there were “ounces” of different weights and “pounds” of different
weights. Even so, things worked fairly well for hundreds of years. Then,
about seven hundred years ago, England began to sell a lot of wool in
Europe. As this trade became more important, it led to changes in the
system of weights.
Finally, in the year 1340, King Edward III of England set new standards
for the ounce and the pound. At that time, most of England’s wool trade
was with Italy. So, to make trade easier, the new ounce was to weigh the
same number of grains as the Italian ounce. At the same time, it was
decided that the new pound was to have sixteen ounces. And that’s how an
ounce became a sixteenth of a pound, even though ounce really means “a
twelfth.”
But why the abbreviations oz. and lb. ? They don’t seem to have anything
to do with the words ounce and pound. Well, the Italian merchants of
King Edward’s time called an ounce an onza, and used the abbreviation
oz. The English merchants just picked up oz. from the Italians. As for
lb., it goes back to the Romans. It comes from the Latin word libra,
their name for a weight of about one pound.
