John Cowan recently said: > Marco Cimarosti scripsit: > > > You could generalize it a bit: Alignment Of Metric And Imperial Units Whose > > Difference Is So Small As To Be Pointless. > > > > E.g., I never understood why on earth metres and yards should be kept > > different. In a public park somewhere in UK or Ireland I have seen the > > following sign: > > Because the yard isn't just an isolated unit, like the pound in various > European countries. It's part of a coherent (if profoundly messy) system. > If we reduce the yard by 9%, the inch has to shrink too, and the last > thing we want is to try to fit a 1/4 inch bolt (6.35 mm) into a nut > whose inside diameter is only 5.81 mm. It's bad enough to have to have > two kinds of hardware already: having incompatible things both labeled > "1/4 inch" would be the facilis descensus Averno indeed.
In the UK the inch is now defined as 25.4mm rather than a subdivision of a standard yard kept under lock and key. If you peruse electronics catalogues you will discover that many components have leads spaced at a pitch of 2.54mm which seems a remarkable degree of accuracy. When I was younger they were a nice round 0.1". Tim -- Tim Partridge. Any opinions expressed are mine only and not those of my employer
