Re: More on number bases

Raymond Brown scripsit:

> (1/12 of a pound troy* - still used by
> gold- and silversmiths when I was young, but now legally obsolete in the
> UK).
Since 1879, so I doubt you remember its abolition!  Nonetheless, it could
doubtless still be used internally to the trade, if not in the currency,
just as guineas as a money of account were still in use long after the
coin ceased to be coined.

> *named from Troyes in France, not the place inhabited by Trojans of old!
> Why the pound avoirdupois assumed 16 ounces, I know not - but 'twas nothing
> to do with the Romans  :)
Probably due to 16 being a power of 2, allowing splitting in half neatly,
but nobody knows for sure.  It was imported to England from Italy
about 1300.  Note that the Italian "libra", though, is still
a metricated troy pound of 300g, rather than the French/German
metricated avoirdupois pound of 500g.

Note that the troy ounce is slightly larger than the avoirdupois ounce,
probably because of standards drift: 1 troy oz = 480 grains =~ 31.1g,
but 1 av. oz = 437.5 grains =~ 28.3g.

So we now all know why a pound of feathers is heavier than a pound of gold,
and can contemplate this:

# Because of their many eccentricities, English customary units clearly
# are more cumbersome to use than metric units in trade and in science. As
# metrication proceeds, they are less and less in use. On the other hand,
# these traditional units are rich in cultural significance. We can trace
# their long histories in their names and relationships. We should not
# forget them, and it is unlikely that we will, even when Britain and
# America complete their slow conversion to the metric system. The American
# economy of the 22nd Century may be completely metric, but probably
# Americans will still call 30 centimeters a "foot" and 1600 meters a
# "mile."

--
John Cowan <jcowan@...>     http://www.reutershealth.com
I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith.  --Galadriel, _LOTR:FOTR_

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