The Optical Magic Lantern Journal (January 1896)

The Optical Magic Lantern Journal and Photographic Enlarger. 15 this lantern. The body and front are made of stouter and firmer material. Instead of the 4 inch condenser, he has added one of 44 inch diameter, and the lens itself has also undergone a change; whereas a lens of 12 inch diameter was used, it has now given place to one of 23 inch diameter of the Petzval form, which is also suitable for portraiture. One of the most curious things is that with all these improvements the price still remains as of old. It is to be hoped that Mr. Tyler has not a large stock of the old form on hand, for it is evident that one seeing the new form will not purchase the old style unless at a considerable reduction in price. STEREOSCOPIC PICTURES ON THE SCREEN. A few days ago we had the opportunity of | inspecting, with stereoscopic. effect upon the | screen, a number of slides that are being introduced by Messrs. Newton & Co., of Fleet Street. Unaware that others were and had been experimenting in the same direction, Mr. Freshwater has without that knowledge brought his system to perfection. The effect produced is grand, and stereoscopic pictures projected in this manner lend a special enchantment to a lantern exhibition, especially as without any alteration an ordinary bi-unial lantern can at once be used. The effect is given by the manner in which the slides are mounted, together with the use of a special pair of spectacles by the members of the audience. Mr. Freshwater intends giving a public demonstration on the 2nd inst. at the London and Provincial khoto Association. 70: Patent Intelligence. _ Lhe following list, relating to current Patent Applications, is compiled expressly for ‘The Optical Magic Lantern Journal” by a registered Patent Agent. For further information apply to The Patent Department, ‘‘ Optical Magic Lantern Journal,” 56, Chancery Lane, London, WAC. No. 22186. ReEcENT PaTENT APPLICATIONS. Qlst November, 1895. E. Underwood. Certain improvements in portable apparatus for making photographic lantern telides. 22nd November, 1895. W. Butcher, W. F. Butcher, and W. J. Spurrier. Improvements in optical lantern slides. 23rd November, 1895. H.C. Newton. An improved electric arc lamp for magic lanterns. 25th November, 1895. G. W. Gwyer, jun. Improved means for thoroughly mixing the gases for limelight prcduction, and in apparatus therefor. 27th November, 1695. F. J. Ricarde-Seaver and L. Pernot. Improvements in and connected with photographic enlarging apparatus. 22282. 22369. 22515. ££682. 22732. 28th November, 1895. C. A. Burghardt and G. Rigg. Improvements in the production of oxygen gas 23079. 3rd December, 1695. H. C. Newton and T. BE. Freshwater. A method of producing. a stereoscopic effect on the screen. 23938. 15th December, 1895. J. Davenport and F. O. Scott. A mechanical contrivance for determining the angle at which optical lantern screens should be hung. ReceNntTLy-PRINTED SPECIFICATIONS. Copies of the following specifications may be obtained by remitting I/for each specification to I'he Patent Depurtment, ‘* Optical Magic Lantern Journal," 56, Chancery Lane, London, W.C. 17306 of 1895. Herp (Hanlaos) Stereoscopes.* 1287 of 1895. Barton and Stuart. Optical lanterns, etc. :O; Editorial Table. WALTER TyLER’s CATALOGUE.—Again Mr. Tyler, of Waterloo-road, has brought out a ponderous volume which is a catalogue of the various goods in which: he deals. This year it contains nearly 500 pages. Much lantern apparatus of a new kind is introduced, including the new form of helioscopic lantern (particulars of which will be found on another page). The names of ths slides would fill this journal for several numbers, so we will not touch upon them. At the commencement of the book a very useful form of index pertaining to the slides has been arranged, and at a glance one is enabled to see the full title, the number of slides in a set, the price of the reading, and the number of the page of the catalogue, on which full particulars will be found. 70: Correspondence. ACETYLENE. Yo the Editor. Drar Siz,—I read in the September number of your interesting journal the mention of a new gas, acetylene. I was very much interested. I have sent to the address mentioned for a supply. You mention in your article that the gas in its pure state gives off smoke, but it can be obviated by introducing common air. How can you do this? There is no provision made in the apparatus shown. Kindly say how it can be done. Please mention if the gas is liable to explode. Yours respectfully, W. H. MATHIESON. Invercargill, N.Z. [The explosive foint is reached when 1 volume of acetylene is mixed with 1} vols. of air. It is then only slightly explosive. As the proportion of air is increased, the explosive also increases. When 12 vols. of air and 1 of acetylene are combined, it reaches its greatest explosive point, and as the proportion of air increases beyond this, so the explosive nature diminishes, so that with 20 vols. of air to 1 of acetylene. it is no longer explosive.— Ep.]