> wrote in message
...
> In rec.food.cooking, "Bob (this one)" > wrote:
>
> > Dry ounces are
> > still volume measure, like fluid ounces.
>
> Does anyone know how it happened that "ounces" refers to either weight or
> volume, depending on usage? Is there some nexis between the two? All I
> can imagine is that one fluid ounce of water at STP weighs one ounce. Is
> that it?

as i understand -

the old labs of the amateur scientists 400-500 years or so back needed a way
to calibrate their instruments (tolerance was somewhat slack back then than
now) . Later, after merchants picked up those measures, they also needed an
easy way to be checked.

Water was commonly available, so weight and temperature scales were
established and agreed upon using water-related parameters.
If you had the container of the correct dimensions, call it one "pint",
and you filled it with water, you had a lb weight. Calibration can be done.

So the volume of a pint measure hanging on the wall of the lab defined
the weight of one pound, and the volume of a pint.

Volume meets weight.

The old easily-remembered-by-ordinary-uneducated-humans 3 by 4 system in
use at the time was not good enough for them, so someone wanted to change it
to a more logical 8 based system.

Divide the measure into 2x8 parts and call it an ounce, and if you are not
too careful defining which measure it was, and either by design so we could
remember it or by accident, we get 16 ounces and 16 ounces, weight and
volume.

-------------------
Similar for the metric system, except someone in France decided that
one millionth of the distance from the equator to the pole was better than
using the weight of water in a measured container that those evil English
were using.

They then set the nexis at 1ml liquid = 1gram mass = 1 cubic centimeter
volume when using water, so instruments could also be calibrated easily in
the metric system.
-------------
humans remember 3s and 4s groups more readily than any other values

sets of 8 is the most natural when using octal or counting when your thumbs
are used as the next digit
(why octal for the uneducated? count to eight twice using your fingers as
the ones and use the thumbs as the next-place-holder eights, and you get two
thumbs worth, i.e., 16 - you can count to sixteen on your hands without
remembering in octal, while the evil enemy the french with their new-fangled
metrics can only count to ten before they have to scratch a mark in the dirt
to go higher)

the original metric had (and some still do have) 100 degrees in a circle,
100 degrees between water boiling and freezing, 100 parts to a time and
geometry minute, 10 increments in everything.
works ok in theory, and quite well in many applications, but in geometry,
in time, in most water-based applications such as steam calculations which
were devised to be simple by using "specific" parameters, forces ( several
measures), pressures (there are probably six or seven metric measures that
can drive the engineer nuts), and rapid mental calculation of small digital
amounts, the British 3-4 and octal length-force-second system and the 60
multiple time, temperature, and geometry units beats the original metric
length-meter-mass hands down.

All those odd measure - chains, barrels, tons, are standards for
specific purpose that were used by both countries in international commerce
are blamed on the british system. As I understand, one of the french kings
had all of France surveyed in great part to scrap the old and get the new
measure in place

or so the story goes


>
> --
> In the councils of government, we must guard against the
> acquisition of unwarranted influence, whether sought or unsought,
> by the military-industrial complex. The potential for the
> disastrous rise of misplaced power exists and will persist.
> -- Dwight David Eisenhower