By varying the disposition of mirrors, prisms, lenses, and light, an infinite number of the most surprising effects may be shown, with a comparatively small amount of trouble and expense. We shall, therefore, devote this chapter to the explanation of a large number of allusions, which have been devised by Robertson and other adepts in the art of honest deception.
One of Robertson’s most famous delusions was the “Dance of Demons,” an effect he discovered quite accidentally. One evening, while experimenting with the phantasmagoria, he suddenly found himself in the dark, when two persons, each bearing a light, crossed the room on the other side of the screen. A little window which happened to be between the lights and the screen, immediately threw its double image on the cloth, and the method of multiplying shadows was discovered.
Fig. 55.—Wizard Dance.
The figures used in this experiment are cut out of fine cardboard, and may be made a foot high or there-abouts. They are placed on a second screen in front of the principal one, and by multiplying the lights, as shown in [fig. 55], you may have as many shadows as you please. The effect is much heightened if the figures are cut out so as to show as lights when thrown on the screen. A little ingenuity shown in the arrangement of the distance and movements of the lights, will produce an endless amount of amusing effects. Thus, a small image of the principal figure may be produced by carrying the second light to a great distance, and the lesser figure may be easily made to jump over the former, by moving the candle in a semicircle over the light that is stationary. It is only necessary to recollect that whatever movements are made by the lights, the shadows of the figures follow their example. With a little ingenuity the heads and limbs of the figures may be made moveable; and if one assistant attends entirely to the working of the figures, and the rest to the lights, an infinite number of changes may be carried out. If mounted in a frame, they may be made to throw somersaults, fall down, or jump up in the air at will.
A knowledge of optics will often serve to explain with great ease the tricks played by conjurers and impostors on princes and other great people, for their own vile ends. It is well known that Nostradamus, on being consulted by Marie de Médicis on the future destiny of France, was shown by him in a mirror events that left no doubt on her mind that she would one day share the throne of the Bourbons. These illusions were possibly effected in the following manner, and may be readily understood by reference to [fig. 56].
The throne in the first chamber is reflected in a mirror concealed in the canopy overshadowing a second mirror, placed carelessly on a table in the room in which the Princess and astrologer are standing. The arrangement of the mirrors is such that, on looking into the smaller glass, the Princess sees all that is going on in the adjoining chamber. The very fact of her consulting Nostradamus on her future fate, shows that under certain circumstances, at least, this clever woman was as silly as a child. It is not, therefore, to be supposed that she would notice that the mirror she was looking into was inclined at such an angle that it could not reflect her beautiful face. Nothing could be more natural, either, than that this magic looking-glass should be placed on a daïs, and shaded by a canopy. Nostradamus, who was a shrewd man, could no doubt pretty well see the course that events would take, and must consequently have felt quite safe in showing the Princess the throne of France occupied by Henry of Navarre. This was not the first time that the rulers of the earth were duped by so-called magicians, who possessed the knowledge that the angle of reflection was always equal to the angle of refraction.
We may also mention, while speaking on this subject, the adventure of the Emperor Alexander of Russia, à propos of a singular optical experiment at which he was present, which had for its end the changing of a man into a wild animal, or vice versâ. Certain cynics will possibly say that this is by no means difficult, and that it is an event that happens every day; but the clever trick at which Alexander was so astonished was not moral but purely physical. After having gained much money and fame in France, Robertson directed his steps towards Hamburg, where the Emperor was at that time stopping. He performed before the Czar an experiment that puzzled his Majesty beyond endurance. He showed him a man upon whose shoulders he saw successively the head of a calf, a lion, a tiger, a bear, and a whole menagerie of other animals. At last, the Czar could stand it no longer, and he suddenly rose, put his shoulder against the partition, and brought the whole to the ground with a loud crash, just at the moment that the confederate was assuming the form of a goat. If our readers would like to join the Czar in his discovery of the manner in which the trick was performed, they can easily do so.
Fig. 56.—Nostradamus and Marie de Médicis.