CHANGEABLE PICTURES.
Paint any subject on thin paper slightly with light colours, so arranged that by painting the paper stronger on the other side, it may be disguised. Then cover the last side with a piece of white paper to conceal the second subject, and frame the whole. It may even be put between two pieces of clear glass.
On holding up this picture to the light, a different scene is presented to what is usually beheld.
MAGIC DRAWING.
Take a box about 18 inches long by six deep, and remove the lid and one side. In the centre set a square of glass at right angles to the bottom, and parallel with the plane of the ends.
Place a picture which you wish to copy on the left of this upright glass, and a sheet of paper on the right.
On holding the head on the left of the glass, and looking into it downwards, the reflection or spectre of the picture will be seen on the paper, where the lines may be traced.
TRANSPARENCIES.
Put a chafing-dish or gas-stove under a wooden frame on which you strain, that is, stretch, a piece of strong linen or silk, while you do it over with a solution of wax in oil of turpentine. It will then be equally diffused.
Paint with oil colours mixed with spirits of turpentine.