Place the pack face down on the table and cover it with a serviette.
Then request a member of the company to put his hand under the serviette
and take a card at random; to be careful not to let you see it but show
it to the company and then return it to the pack and to square the pack
through the serviette after the card has been replaced. You then lift up
the side of the serviette nearest to you and at once produce the card.
EXPLANATION.--When the company are looking at the card slip your hand
under the serviette and turn the pack over, and, of course, you can at
once detect the "faced" card when it is replaced. On withdrawing it with
your right hand turn the pack over with your left and lift off the
serviette.