ABSTRACT
One of my recurring nightmares, though I am glad to say it has not come true yet, is that I shall arrive for a lecture with the wrong set of apparatus. The nearest I came to this was only a year or two ago when I was booked to give a lecture on 'Colour3 about three weeks after a lecture visit to the USA. Through some mischance over documentation my apparatus had returned by air freight to London Airport but
could not be released from the customs authorities until the mistake had been rectified. Fortunately I was able to give my hosts two or three days5 notice that the lecture would have to be on a different topic!
