For nearly an hour on Aug. 7, 1974, Philippe Petit walked a wire he had illegally rigged between the New York World Trade Center’s twin towers. Petit’s latest feat is writing and illustrating the perfect little book of knots. It’s an instruction manual, a meditation on the history and science of knots, and a mini-memoir of his high-“Why Knot? How to Tie More Than Sixty Ingenious, Useful, Beautiful, Lifesaving, and Secure Knots!”wire life. (Abrams) even includes a practice rope. Petit, who knows how to tie 200 knots and has a knot library of 200 volumes, is a poetic and passionate instructor.