On the eve of a 1917 performance at New York City’s Hippodrome, Harry Houdini was cinched into a straitjacket and hoisted upside down from his ankles by a subway derrick. Thirty feet above Forty-Sixth Street and Broadway he convulsed, wriggled, and swayed. Seconds later he maneuvered free, escaping the brutal bond to a roar of applause from the throng of onlookers. Typically from his high perch, Houdini would brandish that straitjacket in the air as a sign of his conquest and his freedom. For the hundreds or often thousands of spectators who craned their necks to witness Houdini’s outdoor performance, the trick may have seemed more important as a symbol than a stunt.