Modern Magic: A Practical Treatise on the Art of Conjuring

This feat, which appears perfectly miraculous to the uninitiated, is performed by the simplest possible means. All that you have to do is to count secretly the row of dominoes as far as the thirteenth from the left-hand end, or (which is the same thing) the eighth from the right hand end, the points of which will invariably be the same as the number moved from the right to the left of the row. You do not know, until the domino is turned up, what that number actually was, but you must by no means let the audience suspect this. You must boldly assume to know the number, and from that knowledge, aided by some clairvoyant faculty, to have selected a domino whose points shall represent that number. Thus, having selected the proper domino, you call upon the audience to state the number moved, after which the turning up of the selected domino is regarded by the audience merely as a proof that you were correct in the previous knowledge for which they, without the smallest foundation, give you credit. After this domino has been turned up, it is easy, knowing the original order of the thirteen of which it forms one, to name two or three on either side of it. In most instances you will only know the total figure of a given domino, as two or three different combination of points will give the same total. (Thus a total of seven may be represented by either six and one, five and two, or four and three.) But there are two or three dominoes of which, if you know the total, you know the points also. Thus a total “twelve” must be always “double-six,” a “blank” always “double-blank,” a “one” always “blank one.” By naming one or two of these, as if hap-hazard, you will prevent the audience suspecting, as they otherwise might, that your knowledge is limited to the total of each domino.