I originated this presentation of an old but not any too well known principle in the spring of this year while working in the Green Room of the Madison Hotel in New York. The first magician or devotee of magic who saw it was Sidney Dreyfuss and he put up a great argument for my putting it on the market. However, I was getting a lot out of it at that spot and I know only too well how the stunt could and would be pirated and bootlegged. Right at this moment I don't know of more than four magicians…