That statement above was true in 1921 when Adamathica was first released in a very limited run of 100 copies. Bertram Adams expanded the 27-card trick to a pack of 52 cards. The mathematics are based on Gergonne's Pile Problem.
EFFECT: The spectator is asked to make a free mental selection of any card in a deck of 52. This selection is made purely mentally without reference to any deck, hence it is not forced in any way. The same spectator or another, if there be more than one, is now asked to name any number from one to 48. The spectator is then told that the card which he has mentally selected will be made to assume a position in the pack at the number mentioned. Throughout the entire experiment, the performer does not see the face of the cards as they are handled face down.
