Lantern slides are made from prints, photographs, etc., in the following way. Make a negative of the subject by cops'ing in the camera in the usual way. Focus the picture sharply within a square 3 1/4in. by 3 1/2 in., leaving iin. each way for binding and masking. Copying is merely photographing at close quarters. If the camera will not extend far enough to obtain a picture of the required size, the lens and front can be removed from the camera proper, and the camera lengthened by attaching to it a box at one end of which the lens and front can be fitted, the join between the box and the camera being covered with a dark cloth. From the negative thus obtained a lantern slide may be made either by contact or through the camera. Making slides by contact is the simpler plan if the lantern plate is large enough to contain the whole of the picture. Place the lantern plate in contact with the negative (film to film) in the dark room and expose to the light of a gas flame; a. thin image is developed. Bromide plates are the least troublesome to use, and a simple developer is metol and soda. After development, the plate is fixed and washed as usual.

When the negative is dry a mask is laid on the film side, and over the mask is placed a carefully cleaned cover glass; the two glasses are then bound together with strips of black gummed paper. The glasses should be gripped iirmly in the centre with the thumb and forefinger of the left hand, and the moistened paper laid along the top edge in position and smoothed gently towards the two ends. When dry, do the opposite side, then the remaining sides. Lastly, clean off any gum and finger marks. For copying through the camera, the negative should be fixed in the bottom of the box, glass side out (so that the sides of the box shade the him), and either placed on a slanting board pointing to the clear sky, or set up on a table in front of a lamp shaded with a sheet of ground glass. The picture is then focussed to the desired size, and the exposure is made by daylight, if possible, or by artificial light, such as a lamp or a piece of magnesium ribbon burnt behind ground glass. Masks can be bought; they are used to define the extent of the picture to be shown on the screen. The cover glass protects the film of the negative. The binding strips can also be bought; their use is obvious.

A white spot (a small circular piece of white paper) is placed in each of the top corners of the negative as a guide to the lantern operator. When photographs or book prints are to be copied on to slides the grain of the paper may be got rid of by wetting the print or photograph and squeegeeing it on to clean glass, carefully stroking out the air bubbles between the print and the glass. If it is not desirable to wet the photograph it may be put in a printing frame with glass before it and then exposed before the camera. A line drawing may be copied the same size by coating a piece of glass 3 1/4 in. by 3 1/4 in. with a weak solution of gelatine. The glass should be placed over the design and a tracing made on the gelatine film with pen and ink (Stephens' ebony stain answers well). When very fine lines are required the film may be rubbed with medium and a retouching pencil used. This tracing can be used as a lantern plate. The masking, binding, and fixing of the cover glass are described above.