| FIG. 1. APPARATUS. | FIG. 2. ARMOR SCENE. |
DIAGRAM OF BLUE ROOM.
“When the two objects or sets of objects thus successively presented to the view are properly placed and sufficiently alike, the audience will be unaware that any change has been made. In some cases, in place of a single sheet of glass, two or more sheets may be employed.”
By consulting Fig. 1, the reader will understand the construction of the illusion, one of the best in the repertoire of the {102} conjurer. The shaded drawing in the left upper part, represents a portion of the mirror, designed to show its graduated opacity.
“a is a stage. It may be in a lecture-room or theatre. bb, the seats for the audience in front of the stage. cc is a small room—eight or ten feet square and eight high will often be sufficiently large; but it may be of any size. It may advantageously be raised and approached by two or three steps from the stage a.
“d is a vertical mirror, passing diagonally across the chamber c and dividing it into two parts, which are exact counterparts the one of the other. The mirror d is so mounted that it can be rapidly and noiselessly moved diagonally across the chamber in the path represented by the dotted line d 1, and be withdrawn whenever desired. This can conveniently be done by running it in guides and upon rollers to and from a position where it is hidden by a screen, e, which limits the view of the audience in this direction.
“In consequence of the exact correspondence of the two parts of the chamber c, that in front and that behind the mirror, the audience will observe no change in appearance when the mirror is passed across.
“The front of the chamber is partially closed at cx by a shield or short partition-wall, either permanently or whenever required. This is done in order to hide from direct view any object which may be at or about the position c 1.
“The illusions may be performed in various ways—as, for example, an object may, in the sight of the audience, be passed from the stage to the position c 2, near the rear short wall or counterpart shield f, diagonally opposite to and corresponding with the front corner shield cx, and there be changed for some other. This is done by providing beforehand a dummy at c 1, closely resembling the object at c 2. Then when the object is in its place, the mirror is passed across without causing any apparent change. The object, when hidden, is changed for another object externally resembling the first, the mirror is withdrawn, and the audience may then be shown in any convenient way that the object now before them differs from that which their eyesight would lead them to suppose it to be. {103}