The Optical Magic Lantern Journal (June 1898)

100 The Optical Magic Lantern Journal and Photographic Enlarger. find that the glass protector would break more easily than the condensers, as it would b3 much nearer the heat; of course the flame from the jet should ba so looked after that it is not allowed to pit the lim3 to such an extent as to make it branch towards the condenssr. I have known cases where this has been so neglezted that not only has tha condenser cracked but the whole front _ of a bi-unial burnt out. Asan oparator I am perfectly aware that with many lecturers not much time is allowed for proper attention to the lima and flame, all tha attention being directed to slide effects, etc., and I think that where this is the casa it is preferable to guard the condensers, esp3ciallywhen powerful mixed jets or electric light is used, but do not use glass, as it is apt to break and fall towards the lime, and break that such would make matters worse thin if the condenser cracked. The smash of glass would be heard, the light go out, and perhaps half of the scared audience would go out too, in search for the daily paper reporter. What I would suggest, is that a pieca of clear mica be obtained by ordering a mica chimney for au incandescant burner. These can be got made in one piece, are very clear, and when cut open measure about 8 inches by 4 inches; this will stand any amount of heat, and if one falt so disp2sed he could make a kind of chimney to fit over the lime and jet nipple, and so direct the heat to the top of the lantern. : Yours truly, “CRACKS.” East Greenwich, May, 1898. ——! 0.5 AUB owe. —_) ; Détes and Queries. A. M. C.—We cannot publish your statement, as in several matters we know it to be incorrect. Regisiration.—Having as you say got the lantern stages to coincide, the next thing is to plane off or add to the frames of the slides, so that they will rezister correctly. Your letter is rather too indefinite for us to grasp your exact meaning, but if you will put your questions in definite language we will endeavour to assist you. You appear to know a good deal about registration by your remarks, so we do not exactly know on which point you wish information. Arthur Johnston.—With very little trouble you can make a trimmer for the wicks of your 4-wick lamp. Proceed as follows :—Take a strip of tin, say an inch deep and about twice as long as the wick is wide, fold it in two lengthwise, placing a piece of m3¢al or woodat the bend so as to keep the two leaves apart, slightly round the upper side by means of a file. All that is necessary is to place this round the wick when it is well turned up, pinch together with the fingers, and run a pair of sharp scissors along the top of the.wick; thus allowing the tin shape to act as a sort of template. A little practice will make perfect. First Attcmpt.—To say the lantern slide was in any way good or even approaching it would not-be correct, for it is as bad as any we have seen. Try a-very much shorter expusure, and then note the difference. Saturator.—Mr. A. W. Scott, of Cardiff, died a few years ago. His ether saturator is not now made, but | several good ether saturators are upon the market. Consult our advertising pages. . X. Y. Z. writes:—I am making a new screen stand, | and want to splice a loop on the end of some ropes. How is it done? Ans.—We regret that we cannot at the moment say more than that the strands of the rope are separated and threaded inand out through the rope. . If you can get some nautical friend to show you, one lesson would be worth a Jot of reading. Jas. G. Styles.—For a 7 feet disc'ata distance of 14 feet from the screen you will require a lens of 6 inch focus, but for the sama size of disc at a distance of 35 feet you must use a lens with a focus of 15 inches. The method by which this is calculated is to multiply the distance between where you decide to place the lantern and the screen by 3, which represents the diameter of slide, and divide this by the diameter of the disc you wish— thus 14 by 3 equals 42. This divided by 7 gives 6 in focus of lens required. In the second instance, 35 is multiplied by 3 and divided by 7, which gives 15 as the focus required. Showman.—The series of articles on ‘‘ Modern Optical Illusions" by Mr. Edmund H. Wilkie, of the late Royal Polytechnic Institution, was commenced in this joumal for Ssptember, 1894. The journals containing the whole series, with illustrations, may be obtained from our publishers. T. H.—Thanks for the newspaper cutting. We are following the case, and are sorry to see the man in this plight, and do not intend, at leasiat present, making any note in our columns. It is questionable as to whether he is in his right mind. B. Turney.— Kerosene lamps, specially constructed as to the admission of air to wick holder, will give a flame similar to that from a Bunsen’s gas burner, and if a mantle be used with this, it should give as much light as the gas buraer with mantle. We caanot learn that such lamp; have yet been placed on the market, although there has been talk of it for some months. A lamp can be obtained with a mantle burning methylated spirits. Those we have seen do no’ give much liglit, and are expensive to use. A. R.—Had the letter referred to been in English instead of French it would have recaived immediate ” attention. TO OUR READERS. Dear Srrs,—I have commenced the Macic Lanrean ALMANAC AND ANNUAL for 1898-9, which is to be published about the beginning of October next. Each year’s issue is highly appreciated in every part of the ~ world, principally by reason of the practical articles which appeared therein from the pans of my esteemed friends. Should you wish to assist lantern users in general with a short practical article of such subjects as are embraced in connection with the lantern, photographic enlarging or kindred subjects, I would like to receive your manuscript at as early a date as possible. Many articles, the batter to explain details, require an illustration, and in this case a few rough lines or a photograph will suffice from which I can prepare a finished sketch. I feel assured that many readers of this journal will have some suggestion or other to offer, either by way of an original idea or improvement of some appliance already in existence, or at least some experience in connection with lanterndom. Yours fraternally, J. HAY TAYLOR, Editor.