Thanks again Pieter
I have looked a bit more closely at your deductions and even if it is a theory, it is a good one and I cannot personally say anything against it, not with my own limited sources. So I confess I have copied it to keep it!
Hope you don't mind...
Also thanks to Chris, who started the thread, to Gerhard who took the bait and everyone else who took up the challenge.
This proved to be a very interesting subject, indeed minute, but very rewarding never-the-less.
Thank You Guys
Cheers
Stig