Well... I think the whole Metric thing is WAY overblown, and in particular, at its core downright sappy.
Understand - first and foremost - I am a practicing scientist. Every last thing that is touched in research is covered by the metric system. I use it effortlessly - and enjoy the brilliance of its SI 'powers of 10'. This is not to say that there aren't subtle -ahem- irreconcilable differences between those of use who like CGS (centimeter, gram, second) and those who do everything in the MKS (meter, kilogram, second) systems. But really, they're minor differences.
The more important point is that Metric, for all intensive purposes essentially fails from a practical-man's and woman's perspective. A 2 by 4 is ... well... 2 inches by 4 inches (before bright planing - its true!). Oh, I suppose you could remember that it is a 5 by 10 (cm), and that'd work out OK. But what's the equivalent of a 3/4 (three quarters) or a 5/4 (five quarters) or 3/2 (three halves) piece of timber? The first time I heard five quarters, I thought ... how elegant! I intuitively know exactly what is being discussed ... a quarter more than 1 inch. Brilliant!
But architecture can, and does (elsewhere in the world) get on in Metric well enough. Not the best example.
A better one is Kitchen Science.
My wife is an excellent and accomplished cook. We have several dozen European cookbooks all nicely metricized. The result is utter stupidity, on a scale so thick headed that it defies belief. ALL the recipes would appear to be translations of "standard english" or pre-metric European measurements into metric. So, you have 225 milliliters of water. No, not a cup. 225 milliliters. You gonna remember whether its 225 or 315 or 900 divided by 4? Are you? Day after next year? It gets even more amusing when the rest of the ingredients are put in. 1.5 grams of pepper, 2.5 grams of salt. 375 grams flour. 4 eggs. 15 milliters of oil.
Are you confused yet? This is a recipe for PASTA. Try it in English:
2 cups of flour, 4 eggs, 1 tablespoon oil, 1/2 tsp salt and 1/2 tsp pepper.
You know, I know, and EVERYONE knows that you're not going to be measuring grams of salt. You'll remember (maybe) what 'a gram' looks like, and you'll estimate. I, at least, can reach into the larder drawer and get out the teaspoon measures, and the measuring cup. Dip into the flour jar, crack a few eggs, measure out the oil and voila. Pasta. Meanwhile, my French (they're the worst), German (almost as bad) and Italian friends are busily cleaning up their weights and scales and finicky milliliter cylinders. Bah.
It gets better, actually. What about the idiotic Centigrade scale? Freeze your butt off is like -5C. Fear of death through heat stroke is 40C. They don't sound a whole lot different to me. Somehow, I get the idea that 'damn cold' is 0F, and 'hotter than hell' is above 100F. Very practical range, for us doughty humans. I know that mid-scale (50) is pretty cool. I might expect it to be a bit warmer, but it isn't. We learn. This is though the same in the metric system. Nothing "centigrade" (celsius) is as you would expect. Temperatures never are. But it IS based on something just about as arbitrary as the length of the King's Foot. The freezing and boiling points of pure water. OK. Nice compound, pretty important and all ... but hardly a UNIVERSAL metric for temperature!
So there, in a long diatribe is the thesis: that the majority of the world benefitted from "going metric" due to their hopelessly out-of-kilter independent systems of measurement. It worked and works for many things. I wouldn't be much of a scientist if I still did things by stones, drams, minims, gills and BTUs.
But for some areas of our world-existance ... ya think that the prehistoric invention of POWERS OF 2 might have met some really practical need? Ya think? I sure do. Powers of 10 is great, but powers of 2 (and 3) are emminently practical for guessing and estimating things. And yes... they do result in odd conversions between infrequently converted things. Like why is a mile 5280 feet, and why are there 640 acres per square mile. But apart from that ... its pretty straight forward. Miles for long measures, yards for middlin', then feet and inches for construction. Bushels for agriculture, gallons and barrels for large measure, ounces for small. Cups and quarts, teaspoons and tablespoons for the kitchen. Quarters and halves, inches and feet for timber. Pounds are fine for weights, G's for accelleration, foot-pounds for torque, etc.
There's something intuitive about measuring force as being analogous to mass (not so with Newtons and Kg), something intuitive about being able to pace yards. And bloody hell: I do NOT need a gram scale to weigh out flour to make bread, thank you very much. Or weigh oatmeal to get that to happen, or carefully measure water to the milliliter.
End/o/Rant
"There's something intuitive about measuring force as being analogous to mass (not so with Newtons and Kg)"
Intuitive maybe, but wrong. Force and mass are two entirely different things, as I'm sure you're aware. A unit like a lb(mass) or Kg(force) is an ambomination as far as I'm concerned.
Exactly. Halving and doubling are really possible and practical tasks. If I gave you a pile of flour or a container of water and asked you to divide it into 8, this would be a lot easier than dividing it into 10.
SD