Among the conjuring tricks depending upon the principle of electro-magnetic attraction, the simplest is that of
The Light and Heavy Chest.—This is a small brass-bound box, with the ordinary handle at top. The performer shows that it is empty, and without mechanism or preparation. Having been duly inspected, it is placed upon a small pedestal fixed to the stage, when the performer requests that some gentleman of considerable personal strength will step forward. A volunteer having been found, the magician asks him whether he thinks he can lift the little box before him. He naturally answers that he can, and proves his assertion by lifting it accordingly, which, as the box only weighs a few pounds, it is not very difficult to do. “Wait a bit,” says the professor, “you were able to lift it then, because it was my will and pleasure that you should do so. It now weighs” (say) “six pounds. I have only to breathe on it thus, and it will instantly weigh two tons. Try if you can lift it now.” Again he tries, but the chest is as if glued to the pedestal, and the most violent efforts cannot dislodge it. Once more the performer breathes upon it, and it may be lifted with one finger.
The explanation may be given in half-a-dozen lines. The bottom of the box is an iron plate. The top of the pedestal is also an iron plate, and within it is contained a powerful electro-magnet, the poles being in contact with the plate, and the wires to convey the current passing beneath the stage to the hiding-place of the assistant. The latter, on receiving his cue from the expressions of the performer, presses the connecting stud and completes the circuit, thereby bringing the magnetic force into operation. Upon again receiving an agreed signal from the performer, he ceases to press the stud, the circuit is broken, and the iron ceases to possess any magnetic force. This may be repeated as often as desired.
The above trick is cited by Robert-Houdin in illustration of the great difference which there may be, in point of effect, between two modes of presenting the same illusion. The reader may possibly be aware that Robert-Houdin was employed by the French Government, at one period of his career, in a mission to Algeria, with the object of destroying, if possible, the popular belief in the pretended miracles of the Marabouts, whereby these latter had obtained an extraordinary ascendency over the minds of the ignorant Arabs. The plan adopted was to show, first, that a European could perform still greater marvels, and then to explain that these seeming mysteries were mere matters of science and dexterity, and wholly independent of supernatural assistance. The “Light and Heavy Chest” was one of the prominent features of the programme, but if presented under that name it would have produced but very little effect. The fact that the chest became immoveable at command would only have been attributed by the Arabs to some ingenious mechanical arrangement, beyond their comprehension, but exciting only a momentary wonder. With great tact, Robert-Houdin contrived to turn the attention of his audience from the object to the subject of the trick, professing, not to make the chest light or heavy, but to make the person who volunteered weak or strong at his pleasure. Thus presented, the trick had the appearance no longer of a mere achievement of mechanical or scientific skill, but of a manifestation of supernatural power. We will tell the rest of the story as nearly as possible in Robert-Houdin’s own words, as related in the story of his life:—
“An Arab of middle stature, but well-knit, wiry, and muscular; the very type of an Arab Hercules, came forward, with plenty of self-confidence, and stood by my side.
“‘Are you very strong?’ I inquired, eyeing him from head to foot.
“‘Yes,’ he replied, carelessly.
“‘Are you sure that you will always remain so?’
“‘Perfectly.’
“‘You are mistaken; for in one moment I shall take away all your strength, and leave you as weak as a little child.’