Method
The bird cage is designed to collapse if it is not supported from both ends. Two of the opposite corners of the cage pull away from each other so that the box becomes somewhat of a tube, about 18 inches long and only one or two inches thick, that resembles a bundle of wire that is thicker in the middle than at the ends. An elastic cord attached to one end of the cage runs up the sleeve of the magician's jacket so that when the cage collapses, it is drawn up his sleeve and hidden from view. As a living bird is likely to be injured or killed when the cage collapses, fake birds are most commonly used in modern presentations of the vanishing bird cage. ==References==