bograt said:
I remember a factor of 1760, does anyone else?
Of course - it's yds / mile, with 5280 being ft / mile.
There again, in flying, altitudes are still given in feet, or multiples thereof, so if a pilot talks of FL50, that's flight-level 50 x 100 =5000', and not just in the UK.
Speeds are given in knots, which of course are nautical miles per hour, where a nautical mile is equivalent to 1 minute of latitude so that the distance from equator to pole is 60 x 90 =4500 NM, whereas the metre is defined as 1 ten-millionth of the same distance. So in theory 4500 NM = 10,000 km, but actually it turns out to be 8334 km.
Considering all this nonsense, it's a miracle anything works.....