William Eastman Chenery, Home Entertaining: Amusements for Every One
“ The secret lies in the fact that the performer is in possession of a piece of paper exactly the same in every detail as that handed to the audience, on which, previous to the entertainment, he has had four rows of figures written in different handwritings. In the course of the entertainment, all is fair and aboveboard until it comes to adding up the sum, when the performer, in the act of giving the paper to the fifth person, changes it for that of his own, with the total of which he is already acquainted. He has now only to run to the stage and write down the answer on the blackboard. ”
