The Optical Magic Lantern Journal (January 1892)

The Optical Magic Lantern Journal and Photographio Enlarger. 3 Our friend informed us that the lamp leaked a little, but he “could easily mend that.” We need not repeat the advice we gave upon the subject, but the whole affair suggested the desirability for giving some simple instructions. which in this series we intend doing. Apart from the look of the lantern body, it matters little of what it is constructed. Its chief use is to confine the rays of light ; but although a soap box would perhaps answer the purpose, it is probable that something more ornate will be desired. In the cheaper form of lanterns the body is made of tin japanned ; this, although good of its kind, soon presents a shabby appearance, as the enamel begins to flake off the upper part by the action of the heat. A good serviceable material fora single lantern is what is known as Russian iron. This is used without being japanned, and retains its good appearance; but perhaps the best material for the body is well-seasoned mahogany witha metal lining, there being a good air space between. We will take it that in this case the illuminant is to be oil. The lamp commonly adopted for this purpose, is made with either three or four wicks standing lengthways in the lantern. Those lamps containing four wicks are in the form of a W, are a little more expensive than those only having three, and are perhaps a little more difficult to manipulate, but they givea better light. The wicks are raise} or lowered by milled heads at the back of the lantern, the relative heights of each flame being seen through a small hole at the back, which usually contains a piece of coloured glass. At the front of the lamp will be found a cap, which when unscrewed, reveals the place where the lamp is charged with paraffin oil. Great care should be taken that no oil is spilled, for with an oil lamp, freedom from smell depends upon cleanliness. But once oil is spilled, it is not sufficient to merely wipe it up, it isrequisite to remove all traces of greasiness, and too great stress cannot be made about this point. Some little difficulty may be experienced in getting the wicks level, and the flame free from forks; but once the wicks are right, the scissors should be used as seldom as possible. It will be found best to trim the wicks with a slight arch, and it may or here be mentioned that we gave an illustration of a cutter on page 9< of our last volume, by which the wick can be evenly cut at one operation. Before purchasing an oil lantern, it is well to see it tried, for we have known cases in which the stop for the lamp had been put in at random, which prevented the light from being placed sufficiently close to the condenser to give a clear disc. Another fact we have found (in wooden body lanterns), is that, in some cases, the front is screwed to the body either too high or too low, so that part of the disc is not illuminated, Of course these defects can be located and readily remedied by one who is conversant with the subject, whilst others who may be ignorant of the cause will be apt to condemn the lantern as bad. (To be continued.) Dissolving Views with Single Lantern. THE word “dissolving” is a somewhat elastic term, but when applied to lanterns it has usually been considered as the gradual melting of one picture into another, and for a brief time during this change both pictures are visible, the light which causes the first picture to be projected being diminished, whilst that of the second picture is increased. Dissolving also means fading or melting away, and if a view projected by the lantern fades into a luminous mist, from which another picture is evolved, this can, of course, be included under the heading of dissolving views. The effect first spoken of usually requires two lanterns, but by means of a dissolving carrier, which has been introduced by Messrs. Archer and Sons, of Lord-street, Liverpool, we have been able to obtain a pleasing dissolving effect with an ordinary single lantern, provided with an open stage. The apparatus is termed the “Ideal dissolver for single lanterns,” and consists of a double carrier, which is actuated by means of a lever placed on top, the upper part of which is provided with two curved arms of the same radius, but from different centres. Working in connection with this is a second lever, the fulcrum of which is placed about an inch below that of the other. + This is provided with a pin, which causcs it to engage with the first lever. The. second lever terminates in a handle, and it is this from which the movements are actuated. Attached to the fulcrum is an adjustable arm, which is secured to it by athumb-screw. At the extremity of the arm is a hinged fan, which passes in front of the lens, and cuts off the detail of the picture at the time of the change without cutting off the light itself. We havetried various forms of a cut off, including celluloid,and ground-glass, but that which we considered the best was one in which the glass was sufficiently large to remain in front of the objec