Metamorphses is a trick of switching from one place to another place,, David Copperfield performed it in a different and effevtive way without using old method and technique
David's performing stage is prearranged,, in this trick he used twin girls to make it effective..
1= when he went in side of the round cloth and his assistent is locking him in it,, from behind the cloth David and his 2nd assistent switched places,, the hand you see is assistent's hand,,
2= now on the wooden stage when his 1st assistent lift the curtain David sneaks in,,
3= when the curtain is tossed up 1st assistent jump behind the wooden stage, and David catches it and throws,,
4= it seems that the places have been switched,, but as you know places were switched in the beggening,,
5= There you have his Metamorphses Trick,,, Pretty cool han? :-)