When the performer stands on the tip of the hidden foot, the two shoes are raised together, and the audience assumes that these are both of the performer's feet. This illusion is also known as the King Rising levitation. Chair suspension The chair suspension is an illusion where a person appears to float in midair, supported only by the back of a fold-up chair. "The Levitation of Princess Karnac" American magician Harry Kellar performed a trick where his assistant, introduced as a Hindu princess, was brought onto the stage apparently sleeping on a couch. He would then levitate her, passing a hoop back and forth along her body to show that she was not being suspended. Kellar supposedly developed this trick by abruptly walking onto the stage during a levitation show by John Nevil Maskelyne, seeing what he needed to know, and leaving. The Buffalo writer John Northern Hilliard wrote that the levitation was a marvel of the twentieth century and "the crowning achievement of Mr. Kellar's long and brilliant career." The trick was done by having the assistant rest on a flat board concealed inside her dress, connected to a metal bar going out the side into the backstage which was hidden by the assistant's dress and the stage curtain. The other end of the bar was connected to a machine which could raise and lower the woman. To allow Kellar to "prove" with the hoop that she was floating, the bar was formed as a rough "S" shape, which would allow him move the hoop through the length of her body in either direction. David Copperfield's flying illusion Magician David Copperfield has performed an illusion in several magic shows since 1992 in which he appears to fly on stage for several minutes, while surrounded by audience members. During the trick, Copperfield flies acrobatically on the stage, performs a backflip in midair, and then has spinning hoops passed around him, supposedly to prove that he is not suspended by wires. Copperfield then descends into a glass box, which is covered with a lid, and continues to float inside it. The method was created by John Gaughan, who described how the trick works in US Patent #5,354,238. The illusion utilises a series of wires controlled by a complex computer-controlled rig above the stage. In the glass box demonstration, the top of the box is threaded between the two sets of