It always tickles me that the metre was originally defined as the distance from the north pole to the equator via Paris (=10,000,000 metres). The gram was defined as 1cc of water. Unfortunately they got the measurement wrong, so the whole metric system is based on a cock-up.
Going back years and a foggy memory I think at school when we were covering latitude and longitude and working out travel on the globe surface using pi and circle geometry we had to assume radius of the earth was 3960 miles, it made things easier as divisible by 360 - that maybe a false memory :-)
//whole metric system is based on a cock-up.//
and the kilogramme was a kilogramme of splock
(er Pt actually but this is AB and I dont want to be too er brainy) - splock den - and it took up gas ( adsorbed but you know ... AB and all that.) and so got heavier
Jesus I remember having to do Maff Ao level ( addl maff) in foot-pound-second, aaaargh torture .... ( 1965 )
The diameter of the Earth at the equator is 43 kilometres (27 mi) larger than the pole-to-pole diameter. Thus the point on the surface farthest from Earth's center of mass is the summit of the equatorial Chimborazo volcano in Ecuador. The average diameter of the reference spheroid is 12,742 kilometres (7,918 mi).
// Peter - the Imperial system is easier to understand than some of your posts.//
chrissakes: the diameter of the earth is four thousand miles ( nearly ) shouldnt tax the brains of even the most average usual suspect. Measure up man!