The Optical Magic Lantern Journal (February 1894)

40 The Optical Magic Lantern Journal and Photographic Enlarger. Patent Intelligence. The following list, relating to current Patent Applications, ts compiled expressly for ‘The Optical Magic Lantern Journal" by a registered. Patent Ayent. For further information apply to S. Dicker, “The Optical Magic Lantern Journal,” 56, Chancery Lane, London, W.C. RECENT PaTENT APPLICATIONS. 158. 3January, 1894. William Greenwood and Roughsedge Wallwork. Imrovements in lantern microscopes. 17 January, 1894. Henjamin John Malden. Improvements in chamber jets for oxyhydrogen lime-light effects. * 17 January, 1894.°, Frederick Woodward Branson. Improvements in the construction of safety boxes for the transport of compressed gas cylinders or other articles liable to suffer from concussion. } January, 1894. Franz Heinrich Klodt. Improvements in optical operations for producing magnified pictures or images in both horizontal and vertical directions. + 19 January, 1894. Robert William Perry. Improvement connected with magic lanterns and other apparatus for optical illusions. ; Application filed with complete specification. 1024. 1035. 10S1. 18 1216. CoMPLETK SPRCIFICATION PRINTED. 4257 of 1893. Chadwick. Optical lanterns. 23756 of 1893. Allen. Optical lanterns. — 0: Editorial Table. “ Protocrapay, INDOORS AND Out.'' —In this book Mr. A. Black, the author, after tracing photogruphy from its carly days gives minute particulars in everyday language as to the requirements in the way of camera and lens suitable to make good work in proper hands. The principles of lenses are given: methods of lighting in studios are dwelt onat length, as is also the problem of obtuining suitable lighting in private rooms. Flash light photography comes in for a share, whilst outdoor photography, both with stand and hand camera is well treated. Chapters are devoted to the dark room, developing, printing, etc. Some dozen pages are devoted to the making of lantern slides and enlargements. Various other subjects go to make up a book that will be found at once instructing, interesting, aud devoid of all language that requires a person schooled in the subject to understand. In the preface the reader is assured that the author will not write AIK(SO,),12H,O when he means alum. The book contains 240 pages, and is published by Houghton, Miffin and Co., of Boston and New York. We have no advice as to the price at which the book is published, but would surmise that it was about a dollar. “(Les ProsgecTions SCrenTiriQces,'' by H. Fourtier and A. Molteni (published by A. Molteni, 44, Rue du Chateau d'TMau, Paris), is a most useful book, dealing with scientific projections. The optical system of lanterns is given as a foundation for many of the interesting experiments which are explained throughout the book. Many subjects such as astigmatism and achromatism are dwelt on, the use of the polariscope is explained, and many illustrations given in connection therewith: Various experiments relative to persistence of vision are described, Altogether the reader will find about 280 pages of matter which cannot fail to intereat unless he be totally ignorant of the French language, and evon then he will find a great number of illustrations which—if we may use the term—speak for themselves. : “ PRACTICAL PHOTOGRAPBER.’”’—Our thanks are due to Messrs. Percy Lund & Co., of Bradford, for a bound volume of the past year of the ‘Practical Photographer," & monthly paper which contains much valuable information. Hitt & Sows’ “rst.—A preliminary list of effect slides has been sent to us by the well-known artists, Messrs. Hill & Son, 13, Beversbrook-road, Tufnell Park, N. To one unaccustomed to the exceedingly high-class work, the prices may perhaps at first seem high, but after an examination of the fineness of the a , Work, this impression will be changed. SI! Messrs. Hill have adopted this profes2 fo sional mark which will in future appear me on all their work. Hree List.—Mr. R. Clark, 31, Mosley-street, Newcastleou-Tyne, has sent us his new hire list, which contains a large number of interesting sets of various classes of subjects. Profi. Mark. —-—:0: Correspondence. PRICE OF HYDROGEN WHEN COMPRESSED. To the Editor. S1e,—I agree with ‘‘Bombastes Triple” and ‘‘ Fred" as to the high price charged for compressed hydrogen gas, but am afraid there is no remedy so long as Janternists are compelled to get their cylinders charged by other people, unless, indced, those other people commence competing one against the other for this business. To my mind, there seems here to be a good opening for a manufacturer to put upon the market a small, portable hand compressing pump for gas. Unless very expensive, such an article would soon pay for itself, and it would have the further advantage that lanternists need not have more than one cylinder for coal gas, and that of quitc medium size, certainly not larger than of twenty feet capacity, which, moreover, would usually not require being more than half-charged; just enough for the evening. A piece of india-rubber tubing would be suffcient to attach to the inlet of pump from the nearest gas bracket. A pressure gauge would of course be necessary. Such a pump would enable many lanternists to avoid all need of using ether saturators, which, though they may be serviceable in practised hands, are deemed by many to be too risky to use at public entertainments. Like ‘‘ Fred,"' I also shall be glad to hear the views of others in this matter. THE I am, Sir, yours faithfully, Jan. Ist, 1894. HENRY. SATURATORS IN AUSTRALIA. Yo the Editor. Sir.—The lautern is getting very popular here (Victoris) ; gas bags are not used at all, but tanks made of galvanised iron. The oxy-ether light being the only kind used, we uce a thrce and four barrel saturator and make our gas as we waut it during the exhibition. This gives no trouble and no wastc of gas, and can be used in any of the country towns. I remain, yours truly, Hamilton, E. CLINCH. Victoria, Australia. METAL-FACED SCREENS, To the Editor. Sir,—Mr. Harrison (p. 12) speaks of the matt silver screen as ‘‘one portion” of Mr. Anderton's invention,