[BITList] Metric

[HUGH]

John,

In my experience of "metric", which goes back to 1949 when I started my 
apprenticeship (all Kincaid engine stuff was metric, so I had to learn 
imperial when I started evening classes), nuts and bolts were all imperial, 
though called the nearest metric equivalent, eg, 1/2" was 12mm.  Some 
threads, eg, pipe, were imperial, the UK system having become the standard 
for them, and piping was dimensionally imperial, though defined in metric. 
However, when I was in Denmark, 1965-67, the Danes called a 50mm pipe a 2 
inch (to tomme) pipe, and so on, the inch in question being the Danish inch, 
which was probably defined as the width of a Viking's thumb.  Housewives 
asked the butcher for a pund of hakkeboeuf (mince) as often as as they asked 
for a halv kilo.  As you illustrate, the trouble started when people 
ventured to convert from one to the other with little skill.

Hugh.