@j_bertolotti @mansr @johncarlosbaez
The French also use a crazy system. The base unit of distance is metres (Earth's circumference/40,000 to make it roughly equivalent to a yard) but don't lead directly to volume in litres, you have to remember to do your measurements in decimetres. The unit of weight isn't the gramme but the thousand-gramme (kilogramme). Instead of a cube of sides 1 metre containing one litre and that volume of water weighing 1 gramme, it weighs 1 thousand thousand-grammes. ;)

@clacke

The decimeter is almost exactly the same measurement as a "hand" (equal to 4 inches) which is the unit most often used to measure the height of a horse.

@mansr @johncarlosbaez @j_bertolotti @Arcaik