The success of this trick to a great extent depends on the abilities of the magician’s assistant, whose main task is to be able to maintain her feet and hands in a position similar to that of an ordinary upright human posture inside a very small and oddly-shaped box.
A glass of water is placed on the table which is covered with a handkerchief. Then, the magician lifts it up and throws it into the air. The result: the handkerchief falls on the floor, and the glass disappears. The trick here is two-fold: firstly, there’s a wire ring sewn into the handkerchief, which creates the illusion that the glass is underneath the handkerchief. Secondly, the glass is then lowered into a secret pouch through a hole in the table.
The secret of this trick, which is highly popular among street magicians, is in the cleverly hidden support. That is why the magicians who perform it often stand in a way which perfectly conceals the end of their staff or rod: the latter simply has an extended support passing through their clothes.
Some time ago, people wondered how David Copperfield managed to seemingly tear a folded dollar in half right in front of people, then unfold it to reveal that it had been completely undamaged. The secret here is making cunning use of a pencil: the latter has been cut in half diagonally and connected with strong magnets! This allows the banknote to be easily passed between the two magnetised halves and remain undamaged.