CHAPTER XII.
Tricks with Dominoes and Dice.
To Arrange a Row of Dominoes face downwards on the Table, and on returning to the Room to turn up a Domino whose points shall indicate how many have been moved in your absence.—This is a capital drawing-room feat. You place a row of twenty dominoes face downwards upon the table, avoiding as far as possible the appearance of any special arrangement, but nevertheless taking care that the points of the first domino (commencing from the left) shall amount to twelve, the points of the second to eleven, and so on, each decreasing by one point till you reach the thirteenth, which will be the double-blank. The points of the remaining seven are a matter of indifference. You now propose to give the company a specimen of your powers of clairvoyance, and for that purpose leave the room, first requesting the company to remove during your absence any number of dominoes (not exceeding twelve) from the right to the left hand of the row, in other respects retaining their order. On your return you advance to the table, and address the company to the following effect: “Ladies and gentlemen, as I have already told you, I have the privilege of possessing the clairvoyant faculty, and I am about to give you a specimen of my powers. Now it would seem at first sight sufficiently surprising that I should be able merely to tell you the number of dominoes which have been moved in my absence, but that might be easily effected by confederacy, or many other very simple expedients. I propose to do much more than this, and to show you not only that I know the number that you have just displaced, but that I can read the dominoes before you as readily in their present position as though they were lying face upwards. For instance, this domino” (touching one of the row with your finger or wand) “represents the number which have been moved in my absence. Will some one please to say what that number was?” The answer is, we will suppose, “Seven.” “Seven,” you repeat, turning over the domino you have touched. “You see that I was right. Would you like me to name some more? They are all equally easy. This, let me see—yes, this is a two; this is a nine; this is a double-six; this is a double-blank;” turning over each domino to show that you have named it right.
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.
It is obvious that this is a trick which cannot be repeated, as the necessary rearrangement of the dominoes would at once attract attention. You may, however, volunteer to repeat it in a still more surprising form, really performing in its place the trick next following, one of the best, though also one of the simplest, in the whole range of the magic art.
To allow any Person in your absence to arrange the Dominoes in a Row, face downwards, and on your return to name blindfold, or without entering the Room, the end numbers of the Row.—You invite the audience to select any one of their number to arrange the whole of the dominoes face downwards upon the table. This he may do in any manner he pleases, the only restriction being that he is to arrange them after the fashion of the game of dominoes—viz., so that a six shall be coupled with a six, and a four with a four, and so on. While he does this, you leave the room, and, on being recalled, you at once pronounce, either blindfold, or (if the audience prefer it) without even entering the room, that the extreme end numbers of the row are six and five, five and two, etc., as the case may be.
This seeming marvel depends upon a very simple principle. It will be found by experiment that a complete set of dominoes, arranged in a row according to domino rules (i.e., like numbers together), will invariably have the same number at each end. Thus if the final number at one end of the row be five, that at the opposite end will be five also, and so on; so that the twenty-eight dominoes, arranged as above, form numerically an endless chain, or circle. If this circle be broken by the removal of any domino, the numbers on either side of the gap thus made will be the same as those of the missing domino. Thus, if you take away a “five-three,” the chain thus broken will terminate at one end with a five, and at the other with a three. This is the whole secret of the trick: the performer secretly abstracts one domino, say the “five-three;” this renders it a matter of certainty that the row to be formed with the remaining dominoes will terminate with a five at the one end and a three at the other, and so on with any other domino of two unequal numbers.
The domino abstracted must not be a “double,” or the trick will fail. A little consideration will show why this is the case. The removal of a double from the endless chain we have mentioned produces no break in the chain, as the numbers on each side of the gap, being alike, will coalesce; and a row formed with the remaining dominoes under such conditions may be made to terminate in any number, such number being, however, alike at either end. A domino of two different numbers, on the other hand, being removed, “forces,” so to speak, the series made with the remainder to terminate with those particular numbers.
