The Optical Magic Lantern Journal (June 1891)

124 Tho Optical Magic Lantern Journal and Photographic Enlargar. relying on 2 who will be using them first, to return them at stipulated time; but Lb does not do go, or possibly the ; f ‘lator wearing out or bursting (which I should think railway company may not be prompt, and thus calculations are upset. The dealer has to bear the blame for all this, although the fault is not his. Since I adopted the plan of sending all country orders well in advance, I have had very few mishaps ; still, as I said, it is possible for them to occur. Your correspondently evidently has not thought of the invested cupital, experienced assistants required, and the breakage of slides (which in most cases the customcrs repudiate). When tine quality slides can be had on such moderate terms, few, I imagine, will care torun the risk of inferior amateur made slides. The proposed club would only be of use to those who already have large quantities of ; good slides and were able to give something in return for what they require. I fail to see the utility of this circulating club.—Yours, &c., WALTER TYLER. Wuterloo-road, $.E. CARDIFF EXHIBITION, {Lo the Editor.) DEAR SirR,—We should like to explain the raison d'étre of Class 15 at the forthcoming Cardiff Exhibition. Our object in offering an optical Jantern for the best fifty slides of a town or district is merely an incentive to societies to form such collections, and although we stipulate that the winning slides shall become our property, they arc in: tended to form a loan collection, to circulate amongst the British and American societies. Of course, with the present high standard of lantern slides, the whole of the work sent in should form most interesting collections, and, by arrangement with the competing socicties, a valuable slide interchange should result, and here, we think, the utility of the scheme comes in. We trust, therefore, it will receive the cordial support of societies generally. — Yours truly, Gt. H. BEDFORD, Hon. § tH, Pauuxs, j URE RECS: Cardiff, May 21, 1S01 10: Notes and Queries. W. Viearey.—I read an article by Mr. Andw. Pringle, in which he speaks of using lime-light with mixed jets, and goes on to say: ‘I use oxygen from acylinder, with Leard's regulator, and hydrogen from the house-main. ‘This arrangement of itself necessitates a specially small nipple, and I see no element of danger in it, nor have I had any hitch in its management. This is so directly opposed to all that I have ever heard, that I should esteem it a favour if you would kindly give your opinion. I have a mixed jet thus. question of the ether light. I for one should like to use it, but am deterred by fear of explosion, as it would be a very | serious thing to bring an element of danger into a crowded ' schoolroom. I hope the question will be thoroughly . thrashed out.” Mep/y.—Mr. Pringle is a most experi| enced lanternist, and could ascertain by glancing at the light whether everything was working under safe conditions. We would not, however, like to recommend it, as lanternists of less experience might be led to employ it and obtain results of a totally different nature. If you do try it, be sure you use a regulator on the bottle. R. (/. writes: ‘Could some of your readers oblige occasionally by a few hints on painting photographic slides, either in water colours or oils? The lessons should , be both short and simple. Jéey/y.—We hope shortly to have a series of articles on the subject, by Mr, A. W, Scott. Amateur states that he intends using mixed gases from bottles, and asks ‘‘(1) Shall I require a larger bottle for hydrogen than for oxygen? (2) In event of one regu always liable to occur) while jets are alight, pressure would be taken off; what would result? (3) Shall I require two gauges, or can one be used for hoth the oxygen and hydrogen bottles?” Jécply.—(1) About 10ft. of oxygen to lift. of hydrogen. (2) If the oxygen pressure were thus released the hydrogen would continue to burn at the jet; if the other, the light would go out. You will find a descriptive article on regulators in this issue. (3) Yes, a separate gauge for each. We lately heard of a serious explosion, caused by employing the same gauge for both gases. ; HW. N.—We may beable to give a sketch as requested ; the communication will, we hope, appear in next issue. Jus. J. Luss. —Glad it is so much appreciated. Number was sent. Robt. Simpson asks: Ifa gauge is attached to a gas bottle of 12ft. capacity, and it registers 1,500, showing it is fully charged, should the gauge show 1,»C0 or ‘00, when half empty ?—Answer. 900. M, 2. writes: “ Will you kindly say in “Notes and Queries,” whether Meszrs. Perken, Son and Rayment's dissolving tap is better than that of Messrs. Noakes and Son. If you let me know the cost of reply to this query I will send the amount, J’eply.—We cannot institute comparisons between the goods of different manufacturers. Both are inakers of repute, and would not produce articles which would reficct discredit. We make no charge for answers in this column, Ncreen says: “J am having a screen made, and intended making a frame according to the instructions given in January issue, by Mr, Hilton Grundy, but instead of the broom-handles I wish to use bamboo cane. Can you oblige by telling me where I can get this latter, and the price for a 12ft.screen?” A’eply.—There is a shop in the same street as your address ((Jueen Victoria-street), near St. Paul's Station, where bamboo can be obtained in a variety of thicknesses and lengths. We have no idea of the price. Cc. B.—Perhaps you can manage to reduce the drawing with a pentagraph. Cumera,.—Your informant is quite right. The picture would have been greatly improved had you placed the camera just off the side of the road instead of in the middle of it; try onc from the side and observe the improvement. a Jerfeet.— Lantern size cover glasses with clouds can be obtained from almost any photographic dealer. C. G. Nortun.—Your jet is at our office: you forgot to : send for it. Cook, Shaw, § Co.—The piece of Papier Vermeil you ‘gent was too small to ascertain its merits. always understood that itis 2 very dangerous thing to use | Iam very vlad you are taking up the-' Ch. E. Gladstone.—Particulars of lantern slide exchange with America crowded out for this issue; will make a note of it in next. . JT, S.—In next issue ; came too late for this. A. B. aska : —‘ Would there be any likelihood of an explosion ifa lighted match were held at an oxygen cylinder, the tap being turned on part way, or is there any danger in this?” Axsner.—It would make the match burn brighter ; no danger. if, V. 1:—If you tilt the topof the screen so as to bring it ata right angle with the lantern, you will not be under the necessity of placing the lantern on a series of empty boxesas you suggest. Jip the lantern backward, until the disc is in tne placc required, and then adjust the screen. A. W. S.—Thanks, but it came :ather too late for this issue. {An interesting reply re “ Ether Saturators,” by Mr. Norton, came just as we were going to press, and will | appear in next issue.—ED. ]