The ounces as we know them today are slightly different, though, as the Troy ounce is 31.1035 grams and the avoirdupois ounce is 28.3495 grams. This means the Troy pound is now 373 grams, while the avoirdupois pound is 454 grams, but what these ounces and pounds were in the past, we have little chance of finding out now.
One the other hand, we have some ways of assessing what an inch was in times gone by, from occasional specifications, like the decree of Edward I, in 1305, which stated that
"Three grains of barley, dry and round, make an inch . . .".Since we can still obtain barley, this offers us a chance to work out how long an inch was then, assuming that the modern breeds are the same. That's a big assumption!
Of course, the inch was also defined in terms of a reference length, the "iron ulna of our lord the King" in Edward's time, later replaced by bronze rods under Henry VII and again under Good Queen Bess, before a gunmetal rod became the Imperial yard in 1835.
Using a standard bar or any other standard not linked to the sovereign was probably a good move so far as the merchants were concerned, at least in Edward's time, given his nickname of Edward Longshanks.
Incidentally, the barley corn lives on as a measure today: the difference between a size 7 boot and a size 8 boot is just the length of one barley corn. I didn't think there is any link there to the corns we get on our feet, so I checked the OED. I was right: it comes from the Latin cornu, which is a horn (as in the unicorn).
Back to the uncia, though: the first meaning of 'uncial' is anything to do with either an inch or an ounce, or anything divided into twelfths, but somewhere along the way, 'uncial' came to be a form of writing where the letters have large rounded forms, and instead of being cursive, joined together, the letters of an uncial script are separate.
Biologists refer to the things which are hook-shaped as uncinate or unciform, but these come from a different Latin word, uncus, the most common use in Roman times being to jab it into criminals so they could be dragged to the Tiber.
|Gold scales like these ones, seen in a museum in Hobart,|
were delicate balances, used to weigh gold that was often
just a fraction of an ounce (a pennyweight) or even very
Not that modern Italians need to know this — like just about all of the rest of the world, they weigh in metric units. The uncial script, though, is something of a problem to explain. Presumably, the letters, side by side, looked something like a row of coins. I am still digging on this one.
That leaves only the question of why people would use a measure that was based on 12, when all our counting systems seem to be based on 10, or occasionally on 20.
Most probably, a 12-part measure was convenient because you can divide it into halves, thirds, quarters or sixths. In the case of inches and a foot, it is comparatively easy to halve, halve again, and then manually divide the quarter foot into three inches, which as we now know, were really twelfths.
Then think of an ordinary pan balance, and consider how easily the same division process could give twelfths — and then think how much easier it is to get sixteenths. In fact, when you look at the history of the gallon (which I will come to later), you will see that doubling was the normal method of progression for measurements in the Middle Ages and since. It seems the binary system is older than anybody thought.
Now just harking back to the as for a minute, this unit of mass went into French as the 'one' of cards or dice, which in some games scores also as a 10. In World War I, it supposedly came to mean a pilot who had shot down ten enemy aeroplanes and so came into English as an 'ace'.
The French word as also means a first-rater, which may explain why others are happy to say an ace pilot was somebody who had shot down three enemy aircraft, rather than ten.
Figures may not lie, but it's amazing what tangled webs we can weave with them!