This morning I found only one electronic-mail message waiting for me in my inbox. It was from my No. 1 son. “Japanese fart scrolls,” ran the subject line. The message contained a link to a page on the World Wide Web (www.dangerousminds.net/comments/japanese_fart_scrolls), and my son’s good wishes in a single but precise word: “Enjoy!” The link leads to a number of scrolls from the Edo period (1603-1868) depicting what is called ha-gassen or “farting competition.” They show people happily farting at cats, horses, trees, and each other. Farts are represented by long, gray triangles coming out of naked buts. The gray becomes lighter as the triangle lengthens. Precision farting is showed by narrow triangles whereas indiscriminate farting is shown by wide triangles. But I was delighted by a wavy triangle going toward the sky, which can be seen in only one scroll. A useless fart, in short. That wavy triangle made me smile for hours. Enjoy it I surely did.