Back in the 1970s this country made a conscious effort to modernise its systems of measurement. Money was decimalised, Centigrade replaced Fahrenheit (although it's still wheeled out at times of extreme temperatures just to make sure we understand) and in the transport industry at least, time was expressed in English ("hours") rather than Latin (ante / post meridian).
A start was made on weights and measures: drams, chains, furlongs, rods, poles and perches all disappeared and children began to be taught metres and kilos. But then, it all ground to a halt. So now, although petrol is sold in litres rather than gallons (it makes it sound cheaper), beer is sold in pints, not litres (unless its in a bottle, when it's sold in half-litres!) Milk can be either in litres in plastic containers or in pints in glass bottles (or plastic containers!). Pedestrian signs give distances in metres, but vehicular signing is in miles. Meat in butchers' shops is priced in kilos, but everyone asks for "a pound of sausages". What a mess.
Normally I find this only mildly irritating (on a bad day) or amusing (on a good one), but occasionally I find it exasperating. Take, for example, the simple procedure of washing a boat.
I've recently discovered Miracle Leisure Products' Wash "n" Wax" (sic) An excellent cleaner/polisher - but why is using it so difficult? Well, read the instructions:
Did you spot it? "Add 2 fluid ounces to 10 litres of warm water! The water part is easy. I have two 5-litre water containers aboard Starcross. I think there were 20 fluid ounces in a pint and. . . er, is it 2.2 litres to the pint? Or the other way round? So how many pints is 10 litres - or to put it another way how many litres is 2 fluid ounces?! See what I mean?
Personally I'm quite happy with metric measurements although I can also understand those who prefer the old ways, but can we please just have one or the other?!