The episode of the Black Cloud has always had a great fascination for me. The thesis that won me my Fellowship at Queens’ College, Cambridge, was concerned with some aspects of this epic event. This work was later published, after suitable modifications, as a chapter in Sir Henry Clayton’s History of the Black Cloud, much to my gratification.
It was not altogether surprising therefore that Sir John McNeil, our late Senior Fellow and well-known physician, should have willed to me on his death a voluminous collection of papers dealing with his own personal experiences of the Cloud. More surprising, however, was the letter that accompanied the papers. It read:
Queens’ College,
19 August 2020
My dear Blythe,
I trust you will forgive an old man for chuckling occasionally to himself over some of your speculations concerning the Black Cloud. As it happened, I was so placed during the crisis that I learned of the real nature of the Cloud. This information for various cogent reasons has never been made public and seems unknown to the writers of official histories (sic!). It has caused me much anxiety of mind to decide whether my knowledge should pass away with me or not. In the event I have decided to hand on my difficulties and uncertainties to you. These will I believe become clearer to you when you have read my MS., which, incidentally, I have written in the third person so that I myself do not obtrude too much on the story!
In addition to the MS., I am leaving you an envelope containing a roll of punched paper tape. I beg you to guard this tape with the greatest care until you come to understand its significance.
Sincerely,