Dip the pencil into the bottle of dark glass. Turn it upside down - the pencil out of the bottle does not fall out.
Why? The bottle is easy cork ball. If the bottle turn slowly, the first ball will close the hole and the pencil will remain inside. To the pencil fell out, the bottle need to turn sharply. This difference, the audience will not notice.
Valery Postolati. "Merry magic" (M, "Panorama", 1992)
