The following is somewhat in the same line, and is called the “Educated Fly.” When the curtain rises a large mirror, in a gilt frame, is seen resting against an easel. (Fig. 21.) The magician takes the mirror in its frame from the easel and rests it on the floor, showing both sides to the audience. He also removes the glass from the frame, and rests the glass against the easel while he exhibits the frame to the audience. The frame has a solid wooden back. The mirror is about four and a half feet wide and three feet high, and after it has been inspected, the magician replaces it in the frame. He now takes a piece of soap and marks the glass off into twenty-eight even squares, which he numbers from one to twenty-six, and letters from A to Z; one of the remaining squares is zero, and the other is left, as the prestidigitateur says, for a starting point. He now takes a large fly from the table and places it on a little shelf which projects from the empty square. He then asks that a letter or number be called. As soon as this is done, the fly is seen to travel across the mirror and stop at the desired square. This is repeated time and time again, the fly every time returning to the starting point. [Illustration: Fig. 22.--The Mystery Explained.] The reason for having the mirror separate from its frame, and exhibiting it separately, is this: It will be remembered that the mirror is rested against the easel as the frame is shown, and that this frame has a wooden back. In addition to the wooden back, it has a cloth back, which is firmly fastened to the frame, and then comes the wooden back. This back is hinged to the frame at the bottom. Now, when the frame is placed on the easel and the mirror rested on the floor, the space behind the easel from the floor up is concealed by the mirror, and this gives an opportunity for a boy to get through a trap in the floor and pull down the back of the frame, to make a shelf on which he sits. (Fig. 22.) Of course, the cloth back is still in the frame; so the boy cannot be seen. The mirror is taken up and replaced in the frame; then it is marked off into squares, as already mentioned. The black cloth is previously marked off into squares which exactly duplicate those which have been made on the face of the mirror. The fly is made of cork, with an iron core which is set flat against the glass. The boy behind the mirror is provided with a strong electro-magnet attached to a wire running down the leg of the easel and under the stage, where it is connected to a powerful battery. He brings up the magnet and several feet of wire with him while the mirror is resting on the stage. When the boy hears the numbers called, he applies his magnet to the corner where the fly is resting on the little shelf, and the magnetic attraction, working through the glass, draws it successively over the squares until it comes to the desired spot, which the boy can see on his chart; and, of course, the proper