The Optical Magic Lantern Journal (December 1891)

188 Tho Optica’ Magic Lantern Journal and Photographio Enlarger. my idea.” As it may interest him and your readers, | now append some particulars of shutters I have constructed. I first adapted a supplemental slide to the curtain shutter of a triple lantern I built for Mr. Edward J. Smith, of Halifax, in 1887. This, I believe, was the jirs¢ that permitted the curtain shutter to remain always in the lantern of either bi-unial or triple form, and allowed either two or three stages, as the case may be, to be used, and also provided for the perfect adjustment of the dividing line between the rolling up picture (of curtain, : view, &c.) and the one being revealed. This was effected by a milled head screw from the top shoulder of the supplemental slide of shutter, which also obviates the removal of the shutter from the lantern, and facilitates an exact amount of adjustment. I see by a letter sent me on 12th May, 1888, Mr. Smith says, “ The special double curtain shutter you fitted to my new lantern last aatumn has been much admired by both professionals and amateurs as a great improvement on the usual arrangement.” : When I constructed Sir David Solomon's latest: pattern large triple lantern, “The Premier,” in Augast, 1890, I fitted a special curtain shatter, by means of which any two of the three stages could be used at will for rolling up effects, or the whole three exposed without removing any portion of the shutter from the lantern. The adjustment for dark line was also arranged for. In those described by Mr. Thompson, no provision seems to be made for adjusting the distance between opening and bottom of cartain shutter, hence the separating line of curtain and view on the screen may be much too broad and black, or white, according to the angle of the fronts and the focus of the objective.—Yours, &c., J. H. STEWARD. 406, Strand, London. 10: Notes and Queries, Ch, Itice asks how he can render his lantern screen, which is made of calico, fireproof? <Ansver,—Soak it either ina satarated solution of alum, or tungstate of soda. B. BR. writes: “I hear that glass-lined tubing is nowan article of commerce. Would this not be better for lantern connections than indiarubber, which causes gas, ether, &c., to deteriorate?” No; the fact of it being unbendable is against it. J. C.Oliphant writes: “I saw it stated lately, by a speaker at a photographic society meeting, that there was a great advantage in using special colourless French glass for lantern slides, and that this is very largely done in America. Are such lantern plates to be obtained in this country?" Ansover.—We have communicated with several makers respecting this query. The Britannia Works Company say that they do not coat this glass, as its cost would not find customers, and that the specially thin glass they use is sufficiently colourless for all practical purposes. Messrs. R. Manson and Swan say'they avoid French and Belgian glass, because of the inferior quality, but if there is any likelihood of a demand for a quantity, they would be prepared to coat it at the risk of the purchaser, that is, he must be prepared to pay for and accept allimperfections. Messrs. B. J.jEdwards and Co, say that their lantern plates are coated on thin glass, so’ nearly colourless that even in micro-photography no colour is discernible. The Pry Manufacturing Company state that they keep lantern plates on French colourless glass for special iustomers, price 18s. a gross. Up to the time of going to press we had had no reply from Messrs. R. W. Thomas and Co. (Limited). F. Weeks writes: “ In‘ Hints and Helps,’ No.3, C. E. R, i mentions pivot holes getting too large, and suggests a remedy, but a much quicker and simpler way to obviate this, is to get a small piece (to size required) of thin sheet, , brass, bend into shell of a ferrule, and insert into pivot hole of wheel.” R. G. W.—We replied per post. W. Vicarey.—Thanks for particulars sent, also for your good wishes, £. Andrews.—You will have received our reply ere this. Archer and Son.—Package post arrived as we were going to press ; consequently no time to try, and report in this issue, John W, Spencer.—We do not know where the plates mentioned can be obtained, and would think that developing up would be preferable. W. £. 7. writes: “(1) Can you tell me if the hole in nipple of a mixed gas jet should be larger when using two cylinders than for bags, if so would it stop the roaring and give a better light? (2) Would the light be improved by passing the gases through a brass wire gauze placed in the chamber of jet.” Reply.—(1) No. (2) Opinions are divided on this point, some holding the opinion that fine gauze is beneficial, whilst others dispense with it and find that the gasses mix readily without, Bristol writes : “ Is any ill effect, accident or explosion, likely to happen if I connecta steel cylinder. just charged with 40ft. of oxygen up to a cylinder which has been used down to 5ft., and allow as much as will pass from the full one into the nearly empty one? How many times may I do this with safety, without sending the one to be re-filled ?” Ansover,—There is no danger in connecting cylinders in the way you mention, but the number of times the one cylinder may be charged from the others depends, of course, upon its size. Practically, if a large and small cylinder are thus connected, and the valves opened for a few moments, upon testing each with a gauge, the large one will show greater pressure than the small. J. Bennett.—If you consult the index in this issue, you will find a number of articles, both for and against ether saturators. The one you name is said to be quite safe, but as you speak of yourself as ‘“ arather nervous person,” who wishes to try lime-light instead of oil, we would recommend the blow-through jet. S. John Sutton (Darabe).—We will send you an illustration of a lantern which has a moveable fitting for condenser, so that you can insert a large size for the purpose you name, ora smaller for ordinary lantern purposes, H, M. Houghton—-It is more than probable that the bags when partly empty were re-filled with the wrong gasses. Mrs, H. M. Scattergood.—You have our sympathy in your trouble. Shall be pleased to hear from your husband when he is again able to write. Hampton, Judd and Co.—Received just as we were going to press. Bull’'s-Eye.—“ Flashes " came too late for this issue. G. Y. L. E.—Yes, it is good. B. J. Malden,—Thanks; but received too late for this issue. 10° WE have been reluctantly compelled to omit several interesting Society Reports from this issue for want of space.