The Optical Magic Lantern Journal (June 1889)

2 The Optical Magio Lantern Journal and Photographio Einlarger. The Magic Lantern: Its Construction, Illumination, Optics & Uses. CHAPTER 1L.—THE LANTERN Bopr. HILE it makes no difference whether a lantern is formed of tinware, iron, or wood, it certainly does make a very great difference in the estimate formed of it by spectators in the school-room or lecture-hall. It ought not to be so, but it certainly is the case, that in the lantern, equally as certain as in human beings, a showy exterior frequently elicits an admission greatly in excess of opposing feelings germinated by possible shortcomings in performances, and, like charity, cloaks a multitude of errors. For this reason it is well that the body of the lantern be made as much as possible a thing of beauty, Understand, it adds nothing to the real working of the instrument, which depends upon the illumination and optical portion, hereafter to be treated. Your wife or daughter will be quite as amiable, domesticated, and intellectual in a calico gown as in the silks and satins they don for the drawingroom, and the diamond will be of the same intrinsic value when forming the eye of the Eastern idol as when it is transferred to its gorgeous setting of the Western jeweller ; and so with the lantern. Given a good inside, and the exterior, except for the purpose referred to, is of minor consequence. After all, what is the body of the lantern, and what are its functions? Merely a means of preventing the light from passing out and being distributed over the room, which has to be kept in darkness. Tin, or more accurately, tinware, forms the simplest material of which the body may be constructed. It must, of course, be japanned, and the junctions at sides and top must be made by overlaying and rivetting, and not by solder, which, especially near the top, is apt to be melted by the heat from the lamp. It is especially necessary that the chimney be rivetted together, the greatest heat being here; and both in chimney and everywhere else the light must be trapped, so as to prevent its escape. Russian. iron, or any other iron possessing similar characteristics, is an admirable material out of which to construct the body of the lantern. It has a smooth, unpretending elegance about it with which japanned tin cannot compete for a moment ; added to which: it is very rigid and |durable. Ifit gets dirty owing to its being stored away in a damp place, it may easily be restored to its pristine beauty by being rubbed with a rag charged with paraffin oil, to which has been added a little Florence oil or sweet oil. In a wooden lantern: it is necessary that there be an inner lining of tin or thin sheet iron. This should not, as used to be the case, be placed in close contact with the wood, but should be at least a quarter-of-an-inch from it, allowing an air space tointervene. Itshould be made of seasoned mahogany, and by preference there should be a door on each side to permit of easy access to the interior. It should also have a small, circular, deeply-coloured blue pane of glass in each door, to enable the state of the light to be ascertained without having the trouble to throw open the door. This should also be the case with the metal lanterns as well as the wooden ones. Brass fittings and fronts by all means for the wooden bodies, unless where strict economy prevents it. It adds so much to the apppearance of a lantern, that when one is going in for a wooden one, at any rate, it is wise to incur just a little more expense, and have the entire front fittings of brass. Nevertheless, as already stated, fittings formed of tin will work equally well. Our present remarks-have reference only to appearances. Concerning the general shape of the body little need be said. While some are formed of a cylindrical tube, and others still more of anarched form, the great majority of lanterns, at least in this country, have square bodies. It is, however, the lighting and optical parts that determine the real quality of the lantern, and these fall to betreated in our next and subsequent numbers. Various Names by which the Lantern is Known, T is scarcely saying too much when we assert that not only has each country its own variety of designation for the lantern, but that each maker has adopted special titles by