The Complete Walton Vol 1. by Roy Walton 1981 Page 6 et seq.
Personal Comment: Actually this is a good trick for magicians. This surprise ending, which also works for laypeople is actually a lot better for magicians. How do I know, for the last few days I tried it. And it got a "soso"-reaction by normal people. Magicians seem to get something out of this. Oh well!