Turing Solitaire LetterComing up for auction at Bonhams in London is a letter written by Alan Turing, in which he explains to 8 year-old Maria Greenbaum how to solve a game of Peg Solitaire. Maria was the daughter of Turing’s analyst and the letter is dated July 10, 1953, less than a year before the famous code-breaker’s suicide.

I find it helps, if I am trying to do the puzzle to use four kinds of pieces like this or better still to use a board with the squares in four colours. Each piece always stays on the same colour until it is taken. You start with only four x’s and you must still have on [sic] at the end so you must be very careful of them, But there are 12 o’s to be got rid of. One needs to remember this all the time.

The auction is scheduled for June 24th. Bonhams’ estimate for the letter is £40,000-60,000.