WRITING ON THE WALL.
A hand appears on the wall, and writes, and then rubs out what it has written. Light the gas in a dark room. Next procure a mirror, stand at the door of the room, and hold the mirror so that it will throw the light of the gas on the wall or a white sheet outside of the room. Now observe that, by holding your hand over the face of the mirror, the same hand appears on the white wall or sheet. Next procure a small paint-brush, about the size of a pen, and dip it in black paint, and then make any figure or character the reverse way on the mirror, and of course the same will appear on the wall on which the mirror reflects. Now lay the brush aside, and rub out the figures or characters off the mirror, and of course they will disappear off the wall also.
THE THEATRE WITH THE CURTAIN DOWN AND UP.
The sides of the proscenium and stage before the curtain unfold, and the curtain is a slip of paper which is pulled up to discover the tableau as above. The two figures are cut out and mounted on small spiral springs, which make them stand out upon the stage when released from pressure.
THE MAGIC INVERSION.
Join two square parallel ends by a third piece, half an inch broad and an inch and a half long, using a piece of cardboard doubled up, with that interval between, as the simplest material. In the middle of one end make a round hole, a little more than one-twelfth of an inch wide, and in the centre of it fix the head of a pin or point of a needle. Directly opposite, in the other side, make a large pinhole. If the latter is held to a strong light, and the eye is applied to the other hole, the head of the pin will be seen, not only greatly magnified, but turned upside down.
THE PRETENDED ENDLESS ARCADE.
In public gardens an apparently endless walk, under arches of gas-jets, is often seen. But, on walking down it, it is seen to be of restricted length, the illusion being obtained by an artful lessening of the sweep and height of the arch, after, during a certain distance, the arches have been regularly spaced out. This being done according to the rules of perspective, the keenest are deceived.
