148 THE POPULAR SCIENCE MONTHLY. 



dollar is hollow and the other fits into it; that the box has a 

 double bottom ; that the nail has been substituted for one that 

 fits around the finger, and that one half of the card is printed 

 on flap which by falling down shows another aspect. All these 

 are technical devices which amuse us by the ingenuity of their 

 construction and provoke about the same kind of mental inter- 

 est as does a puzzle or an automaton. Ignorance of this tech- 

 nical knowledge or lack of confidence in its existence may con- 

 vert these devices into real deceptions by changing the mental 

 attitude of the spectator. However, the plausibility of such per- 

 formances depends so much upon their general presentation that 

 they seldom depend for their effectiveness solely upon the ob- 

 jective appearances they present. Asking the reader, then, to 

 remember the very great number and ingenuity of such devices, 

 and insisting once more that the only complete safeguard against 

 being deceived by them is the acquisition of the purely techni- 

 cal knowledge that underlies their success, I will cite in detail 

 a trick combining illustrations of several of the principles to be 

 discussed. A number of rings are collected from the audience 

 upon the performer's wand. He takes the rings back to the stage 

 and throws them upon a platter. A pistol is needed, and is handed 

 to the performer from behind the scenes. "With conspicuous in- 

 difference he hammers the precious trinkets until they fit into the 

 pistol. A chest is hanging on a nail at the side of the stage. 

 The pistol is fired at this chest, which is thereupon taken down 

 and placed upon a table toward the rear of the stage. The chest 

 is unlocked and found to contain a second chest. This is unlocked 

 and contains a third ; this a fourth. As the chests emerge they 

 are placed upon the table ; and now from the fourth chest there 

 comes a fifth, which the performer carries to the front of the 

 stage and shows to contain bonbons, around each of which is tied 

 one of the rings taken from the audience. The effect is indescrib- 

 ably startling. Now for the real modus operandi. In the hand 

 holding the wand are as many brass rings as are to be collected. 

 In walking back to the stage the genuine rings are allowed to slip 

 off the wand and the false rings to take their places. This excites 

 no suspicion, as the walking back to the stage is evidently neces- 

 sary, and never impresses one as part of the performance. The 

 pistol is not ready upon the stage, but must be gone for, and as 

 the assistant hands the performer the pistol, the latter hands the 

 assistant the true rings. The hammering of the rings is now de- 

 liberately undertaken, thus giving the assistant ample time to tie 

 the rings to the bonbons, and, while all attention is concentrated 

 upon the firing of the i)istol, the assistant unobtrusively pushes a 

 small table on to the rear of the stage. This table has a small 

 fringe hanging about it, certainly an insignificant detail, but none 



