Jack London’s hero is in solitary confinement on death row, trying to pass the time. London devotes a paragraph to one of his techniques. “I squared and cubed long series of numbers, and by concentration and will carried on most astonishing geometric progressions.” This was long before calculators and apps destroyed the ability of students to do arithmetic and make change. Trachtenberg had an interesting book on how to do mental arithmetic, which I read and managed to do briefly before moving on. “I even dallied with the squaring of the circle … until I found myself beginning to believe that that possibility could be accomplished. Whereupon, realizing that there, too, lay madness, I forwent squaring the circle, although I assure you it required a considerable sacrifice on my part, for the mental exercise involved was a splendid time-killer.” That made me smile at the memory of trying to construct an angle trisection back in elementary geometry. I should say that I see this book as early science fiction with a metaphysical theme, which is why I read it. Those reasons appear in the next post.