Keith Devlin at the website of the Mathematical Association of America:
What’s your reaction when you see the term “double-entry book-keeping”? Do you associate it with cool, societal-changing innovations like the Internet, Google, social media, laptops, and smartphones? Probably not. Neither did I—until I was asked to write a brief article about the fifteenth century Italian mathematician Luca Pacioli, to go into the sale catalog for the upcoming (June) Christie’s auction of an original first edition of his famous book Summa de arithmetica, geometria, proportioni et proportionalita (“Summary of arithmetic, geometry, proportions and proportionality”), published in 1494, which I referred to in last month’s column. (I also gave a talk at a public showing Christie’s organized in San Francisco on April 24, which gave me an opportunity to examine the book myself.)
More here.