Heee… I remember a couple of those pushes to go metric.
For the non US folks, a little digression: here in the US we have what’s called Madison Avenue, the advertising business, and when they get behind something ( as they were paid to do with those ‘lets go metric’ campaigns) then it’s generally hokey, generally something that the people who do work with numbers will immediately distrust. For good reason; most of the time, what they are pushing is junk, lies and nonsense of no value except to sell worthless goods.
Is the metric system a helluva sight easier to use? Oh yeah. Calculating the buoyancy of something like a boat ( or a board) in the foot/inch/pounds system, you need to get an answer for volume in cubic feet ( cubic inches divided by 12 x 12 x 12 ) , multiply by 60-something ( depends on specific gravity of the water, salt or fresh ) and eventually you get there. Maybe.
And if you come up with an answer that’s waaaay wrong, got the maths wrong someplace, it’s not immediately apparent, due to all the oddball numbers involved. In the metric system, that’s relatively hard to do. If you get an answer that’s maybe wrong, call it a buoyancy of 2160 kg rather than 21.6, it jumps right out at you.
How many fluid ounces in a cubic inch? Dunno, have to look it up. How many milliliters in a cubic centimeter? That’s pretty easy.
There’s a lot of weird survivals of older or different systems. Booze was sold in 4/5 of a quart bottles ( now, thankfully, 750 ml ) - why that is I don’t know, as they are 4/5 of a US quart, not an Imperial quart, which would make more sense as 4/5 of an Imperial quart is a US quart… Troy ounces, grains ( still found in the firearms world - calculating what a bullet will do gets kinda complex) , karats, ells, rods. Those of us who owned British sports cars way back when may remember Whitworth wrenches.
There’s a few adaptations like the British Thermal Unit or BTU - it’s the very metric-like formulation for heat energy, a BTU is by definition the heat needed to raise one pound of water one degree Fahrenheit. Heating systems are rated in BTUs in the US. On the other hand, refrigeration systems are rated in pounds. Don’t ask me why, or what the pounds refer to.
For what it’s worth, Thomas Jefferson ( circa 1802 ) tried to switch the US over to metric measurements. It’s a shame he didn’t succeed at that.
Funny thing, Cat diesels are rated in metric measurements ( kW) these days, weighed in kg and displacement measured in liters with an alternative pounds-feet-inches-horsepower rating in parentheses. They are trying to sell outside the US, so they have to. I own some tools with bolts in 'em that have metric threads and fractional inch cap sizes - try replacing those at the corner hardware store.
Me, I keep one of the little pocket references by my calculator, lots of nice conversion tables. It’ll do for the moment.
doc…