It is a good plan to try the chimney on the top before the top is fixed on, and then if the top is left a little larger all round than will be required it can be shifted about until the proper position of the lamp with regard to the lens and slides can be found by experiment, and all risk of failure avoided. When the correct distance is found the top should be screwed down and trimmed to shape. Inside the box, below the chimney, a ring or stop should be screwed to prevent the lamp slipping about in the event of the lantern receiving a sudden knock.
In another form of this lantern the back is in one piece, and the slides are introduced through a slit at the side, a plan, however, having a few disadvantages. The principle of the opaque-slide lantern is apparent at a glance, and once that is understood no difficulty should arise in devising many patterns of the instrument and utilising old materials for the purpose. Any pictures can be shown, coloured or uncoloured; even our own designs in this book can be thrown on the screen with good effect.
CHAPTER XXI.—HOW TO MAKE AN APHENGESCOPE, OR APPARATUS FOR EXHIBITING PHOTOGRAPHS, OPAQUE PICTURES, AND LIVING INSECTS IN THE MAGIC-LANTERN.
By Frank Chasemore.
In the last chapter there is an illustrated [description] of a magic-lantern for opaque slides, and as I have for some time used a contrivance on the same principle for use with an ordinary lantern, the few words I have here to say may not prove uninteresting. Like the opaque lantern, this modification of it is very inexpensive.
The interest of a magic-lantern is greatly increased by its being made to show photographs of friends or public men, and also pictures or engravings, Christmas cards, etc. This can be done by the following simple contrivance, which will cost but a few pence. Indeed, the one I use cost me only threepence, and is made out of a cigar-box; but a better and stronger one can be made for less than a shilling. It consists of a five-sided box, with top and bottom, as seen in [Figs. 2], [3], and [6]. In two of the sides are circular holes, and one side is left open about two-thirds of its length, which opening is closed by a door or shutter revolving on a pivot at the top and bottom, to carry the photograph. This shutter is fitted with four small clips on each side for the purpose of securing the card in its place.
Fig. 1.
