The Optical Magic Lantern Journal (July 1895)

116 The Optical Magic Lantern Journal and Photographic Enlarger. get the help you need at first hand. I constantly use one of the advertised forms myself, and I think that the strongest point in its favour is the fact that, once the working of it is thoroughly understood, it is capable of giving a good light on all occasions with a minimum of trouble and care. I hope the above hints may help you over your difficulty. From them you will see that to obtain the best possible results all you have to do is to make sure that the optical system of your lantern is perfect, that your jets are serviceable, your limes of best quality, your geses pure, your screen opaque, and your head clear. Given these, together with a little experience, care, forethought and intelligence, I am sure you will succeed in the future ; -you can see for yourself that the matter is quite a simple one. Iam, My dear Sir, Faithfully yours, Bompastes TRIPLE. A. B. Ginner, Eea. —'0: The Lanterns of Fhotographic Societies. A MATTER which does not seem to have attracted attenticn, is the vast amount more instruction and amusement which photographic societies might obtain from their lanterns—by incurring a little more expense in their purchase —in obtaining those which have a vertical attachment anda prism. Chemical reactions, and crystallisation by the heat of the radiant on a level surface, instead of with all the liquid running down to the bottom of the plate, could then be shown upon the screen, and some of these phenomena are extraordinarily beautiful. Professor Tyndall “ brought down the house” by the exhibition of the crystallisation of red prussiate of potash, as projected on the screen at the British Association at Dundee, a quarter of a century ago ; to see the molecules building themselves into these wonderful structures is as interesting, he said, as if we saw the bricks of the town of Dundee running about and building themselves up into fairy palaces, and Kinnaird Halls. Some slides of crystals of hippuric acid, prepared by Dr. Charters White, were shown recently at the Camera Club, and it was suggested that if photographed on wood cr paper, what wild designs, rich in organic form, they would make for wall decoration. How much more effective would they have been had they been shown in actual course of formation ? By the vertical attachment, an ordinary meeting room with a level floor is in many respects placed on an equality with the theatres at the Universities with raised seats, so that the spectators can look down into the dishes on the lecture table and see what is going on in them. Photographs of paintings on the roofs of cathedrals, with their architectural immediate surroundings, look unnatural when projected on a whitened wall, but let a prism be brought into play and project them on a white ceiling, and their full beauty comes out. Then again, the prism does for erecting purposes, and shows many an interesting physical and chemical experiment on an enlarged scale, which otherwise would be seen bottom upwards. Many of the better educated members of photographic societies are prevented showing interesting experiments to their fellow members because the ordinary lanterns of those societies are not adapted to the purpose. The black-board can be abolished by the vertical attachment, and the lecturer draw his own diagrams on a small horizontal surface, showing the designs projected on the screen as they are drawn. ——:0: Why are Lantern Exhibitions Less Popular ? By R. Moss. ALMOosT every number of the Optica, Maaic LanTERN JoURNAL contains articles or correspondence dealing with this important question. A recent letter by Mr. Taunt, being perhaps the best explanation that has yet been given, while an article in the April issue entitled, ‘‘ Lecture Notes” is also very suggestive of some causes of failure, many other contributors also make valuable suggestions. In almost every case however, the writers argue, not so much for the well-being of lantern work as a whole, as against something which touches them personally ; thus, the professional lanternist blames the amateur for incompetency, the lecturer ridicules the bungling reader, while these in return have a grievance against the prefessionals for the sneers, etc., cast upon amateurism. Now, I am quite prepared to admit there is a good deal of reason in all that has been said, yet as lanternists—be we amateur or pro