I must apologise to the several listers who asked for a copy of my book in
case they found a few mis-spellings etc. I want to point out that the book
was written in 1993, before I had a computer, so I have had to scan it on to
my computer. If anyone has done this themselves they will know that these
little errors can creep in. I have tried to edit it but I hope it hasn't
spoilt the reading for anyone.