Modern Magic: A Practical Treatise on the Art of Conjuring

III. THE “Q” TRICK.--This is a very simple and a very telling trick for the parlor. You take a number of coins or counters, and form them into a circle with a tail to represent a Q, as shown in the sketch annexed. You then ask a person to think of a number, and to count that number, commencing from the tail of the Q at B, and counting round the circle. When he has finished he is to count the number back again, but instead of counting the tail of the Q to go round the circle, and you promise to tell him every time at which counter or coin he left off counting. In order that you shall not see him count, you leave the room while he does so. Supposing he selects the number 6; he commences to count from B, and leaves off at C; he then counts again and leaves off at A. Now, while there are three counters in the tail of the Q, whatever number he thinks off, he will always stop at A; so all you have to do is to count the number of counters or coins there are in the tail, and the same number in the circle will always be the coin last counted. You must be careful, when repeating the trick, to add one or two, or take one away from the tail, as always fixing upon the same counter would perhaps expose the trick.