TO SHOW A CARD CHOSEN BY THE AUDIENCE IN A DARK ROOM.
Arrange the cards of a pack so as to name them all according to their positions after several changes. This is done in various ways, as explained in The Secret Out and the last few pages.
After the pack has been cut by different persons spread it out on the table and ask one of the company to select a card quite at random. Take up the pack, and in doing so divide it into two parcels, and place the one which preceded the drawn card below the other.
While pretending that you wish to convince the audience that the cards are of different suits, hold the pack in such a position that your accomplice in the next room can see which is the last card. Knowing, then, that the following one is the drawn card, he writes the name or draws the figure of it in black on a transparent screen in the adjoining room.
This screen is to be placed within an aperture in the wall, on withdrawing a curtain to which, the person who selected the card has but to look in to see the writing or picture of it “staring him in the face.”
The inner room should be quite dark, so that nothing but the writing is perceived.