The Optical Magic Lantern Journal (June 1896)

104 The Optical Magic Lantern Jou rnal and Photographic Enlarger. electric energy. In fact, what we want, and many others outside the lantern world as well, is what I may term compressed electricity as an addition to or substitution for compressed gas. THAT some such accumulator will one day be discovered is certain. We shall then be able to send our battery to the nearest electrical station to be charged in the morning, and obtain a sufficient supply of electricity for our evening's work or lecture. TuE lantern is not only a source of amusement, pleasure, and instruction, but is often employed in the cause of charity and goodwill. A few years ago a few enthusiastic lanternists resolved to see what they could do to cheer up the lives of the inmates of the London hospitals and workhouses, and for some two or three years their good work was carried on and ‘much appreciated by their audiences. Bur the cost of carrying on the work and the lack of assistance from those who could well assist in the work, led to the gradual discontinuance of the entertainments. Is the society to ba revived? ANOTHER instance of the use of the lantern in the good cause of charity came under my notice a few weeks ago, when a lantern lecture was given in one of the London suburbs to aid the funds of the local hospital. The admission prices were not cheap, but a very good audience was brought together. Of course, radiography or shadowgraphy figured largely in the bill. No doubt our manufacturers are racking their brains for novelties for the next season. Cannot | some of our opticians turn their attention to the question of a compact set of lenses of | varying foci for the optical lantern? The present system, besides being expensive, also greatly increases the weight of the lantern apparatus when, say, three different sets of lenses are carried. Wuat is required is a sort of casket of lenses —say a front combination with three interchangeable back combinations—so as to give foci of say 5, 8, and 12 inches; or possibly a | single lens combination might be devised with adjustable negative lenses, somewhat after the method introduced by the late J. Traill Taylor many years-ago. Such a combination would considerably lighten the outfit, and lessen the cost of the optical portion of the lantern. The Oxyhydrogen Incandescent Gas Light. By Wiuiiam Penman, C.E. WE have received the following lecture, with illustrations, from Mr. Penman, which he lately gave before the Edinburgh Photographic Society :— I have much pleasure in communicating the result of a few experiments I have made in order to adapt the use of the Welsbach lamp for optical lamp enlargement work in place of the oil pattern, and I hope to demonstrate some decided advantages possessed by this lamp, Ido not wish to claim for this light when burning ordinary house gas, or even when aided by other means explained in this paper, that for intensity it can approach the limelight, but it is rather in the direction of showing slides to a small audience, and making photo enlargements, that I have hitherto worked. To my mind there are three pretty sharplydefined classes of photographers in these days. Firstly, the ‘‘button-presser’’; secondly, the ‘‘half-plate carrier’; and, thirdly, the ‘“ studio man.’ Claiming myself to be one of the second class, [ have to confess that this communication, while intended to interest all, will, I hope, commend itself to this great and growing class, amateur as well as semi-professional. Let me define it more sharply. It contains those who, having produced a good negative and a good print, have sufficient knowledge of their photograph to cause them either to attempt a lantern | transparency or make a bromide enlargement of the picture. But, unfortunately, it also contains those who can produce the perfect negative with its charming print, who have to stop short for want of an easily worked and comfortable projection light. You ask me what J mean by an easy and comfortable light? At this stage you will pardon me replying in the negative form—(1) A light requiring no preliminary trouble before lighting ; (2) no trouble or adjusting after lighting ; (3) no smoke or smell ; (4) a minimum of heat ; and (5) a sufficient intensity with great actinism and pleasing colour. Now, in these specifications you will doubtless think I strike for a very high standard, but when we remember some of the great objections which pertain to the oil lamp on the one hand, and the limelight on the other, I venture to say that the elaborate drying, trimming of wicks, and cleaning with oily rags which precede the