Sentence:  He borrowed another hat and displayed its perfect emptiness; he held up his empty hands: "This is one of the most marvellous bits of <WSD>prestidigitation</WSD> known," he said. "You have all seen this hat holds nothing in the world: I will now see if I can extract anything from its emptiness. You can all observe my hands go nowhere but into the hat, and they are both open and turned to you. Yet what is this?" 
Meaning of the word marked with <WSD> tags:  A performance of or skill in performing magic or conjuring tricks with the hands.