The photographic news

• Bandzählung: 29.1885
• Erscheinungsdatum: 1885
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-188500006
• PURL: http://digital.slub-dresden.de/id1780948042-18850000
• OAI: oai:de:slub-dresden:db:id-1780948042-18850000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Seite I-II fehlen in der Vorlage. Paginierfehler: Seite 160 als Seite 144 gezählt.
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

234 THE PHOTOGRAPHIC NEWS. [ArRI 10, 1885. Specification Published during the Week. 6885. Thomas FURNIVAL and George Daniels, both of Welling ton Terrace, Reddish, near Stockport, in the County of Chester, Machinist and Draughtsman, for “ Improvements in coating paper with thin layer of varnish, size, colour, gum or like liquid material, and apparatus therefor.”—Dated 23rd January, 1885. The patentees appear to claim the “ roller ” method, in which a band of paper is led over a quickly running roller which revolves in a trough of the preparation. We have already recommended this as a means of coating paper with emulsion. Patents Granted in America. 314,317. Walter Clark, New York, N.Y., “Photographic camera.”—Filed August 15, 1884. (No model.) Claim.— 1. In a camera provided with a separate focussing chamber, a lens-holder of cylindrical form fitted to rotate so as to bring its aperture in line with either the object-glass or the exposure-apertures, substantially as described. 2. In a ph otographic camera having a partition forming a separate focu ssing-chamber, a lens-holder fitted closely in an aperture in the partition, so as to exclude light, and arranged to rotate in its seat, substantially as described. 3. The rotating holder and pinion, combined with box and partition, substantially as described. 4. The lens-holder, shaft, spring, combined with camera-box, substantially as described. 5. The combination of cylindrical lens-holder and box, having partitions formed to lap upon the ends and side of the holder, substantially as described. 6. In combination with a photographic camera, the mirror, hung by pivots entering grooves in flanges on box, substantially as described. 7. The sliding weight, combined with the lens-tube holder and pinion, as and for the purpose specified. 8. The rotary shutter, combined with rotary lens-holder and box, having apertured partition, substantially as described, for operation as specified. 314,346. Thomas C. Roche, Brooklyn, assignor to E. and H. T. Anthony and Co., New York, N.Y, “ Photographic paper, and sensitive emulsion therefor.”—Filed March 18, 1884. (No specimens.) Claim.-— 1. As a hew and useful or improved article of manu facture, a photographic printing paper made with a toothed facing of gelatine and bromide of silver, as herein set forth. 2. The within-described compound for facing photographic paper, consisting of gelatine, bromide of silver, and a suitable toothing substance, such as the sulphate of baryta, prepared in the manner and proportions substantially as described. 3. The combination, with a photographic emulsion of gela tine and bromide of silver, of a toothing substance, sueh as the sulphate of baryta, substantially as herein described. GELATINO-BROMIDE PAPER FOR NEGATIVES. BY R. L. KIDD.* Our argentic gelatino-bromide paper for negatives. This is a fine paper prepared with an argentic gelatino-bromide coating, and is designed to act in place of glass-supported films. We all know that many efforts have been made to find a perfect substitute in the way of pellicle films made of insoluble gelatine—also in some cases of gummy substance and collodion ; but of all these substitutes that have come under our notice, we have found considerable drawbacks—either the pellicles have been liable to show fracture markings in handling, or else they have been affected by atmospheric influences, and there is a difficulty in making the films of large dimensions. Many photographers think that a sensitive film capable of being trans ferred from a paper support would solve the difficulty of weight, &c. This is true ; but we find that a film which has to be transferred shows more grain when printed from, than one which is allowed to remain on the paper support, however care ful one may be to prepare a paper with a good textureless surface. This is caused by the difficulty of avoiding some of the fibre of the paper adhering to the transferred film. We believe that the risk which always attends the transferring of a delicate film from one support to another would be a serious bar to its adoption to any extent, putting on one sile the time, * A communication to the South London Photographic Society. trouble, and the delay which it must necessarily cause. The paper which we bring before your notice to-night is entirely freed from these drawbacks, and the only thing wanting to make it a perfect success is some simpler method of fixing it in existing dark slides. The method we use ourselves is to place it between two pieces of glass, or to stretch it by means of a folding piece of cardboard double the size of the negative cut half way through. The manipulations, &c., of the paper are precisely the same as for ordinary dry plates ; pyro or ferrous oxalate can be used for developing. There is, however, one slight variation we may note : it is found difficult to varnish paper n egatives in the ordinary way, as they cannot be got as flat as w ould be neces sary, but may be protected by squeezeeing down o n a collodion- ized plate while wet, and stripped. With regard to rendering the paper translucent, this can be done with a solution of castor oil and ether, equal parts ; but the only advantage we find is that it prints quicker. On looking through a paper negative treated in this manner, it appears to be very much more transparent, and the treatment appears to have wholly got rid of the grain. But this is not borne out in the print; the negative prints quicker, but the waxing certainly does not decrease the grain. This wholly depends on the quality of the paper used, and we have subdued the fault by using only the very best quality of paper obtainable. The wonderfully little grain observable in the prints we have here is partly due to the fine quality of the paper, and partly from the fact that the sensitive coating, unlike that of the old “ wax-paper process,” is wholly on the surface, and not sunk in the fibre of the paper. A special feature in nega tives taken on paper is an entire absence of halation ; even when the conditions are favourable to this defect they also lend them selves especially to “dodging,” by retouching with pencil or stump. Those parts which print too dark may be lightened, and cloud effects, &c., stumped on the back. As regards economy, the production of paper negatives will be found cheaper than glass ; it also adapts itself to enlarging from transparencies, and may be printed from either side—a great advantage for many of the mechanical printing processes ; also for single transfer carbon. • Hictionary of dqotograpky. BATH.—A general term applied to any solution in which photographic plates are immersed, but more especially to the nitrate of silver solution used in sensitizing wet collodion plates. BATHS, DISHES, AND TRAYS Vessels used by the photo grapher for containing the various solutions when in actual use. When size and circumstances allow, nothing is better than glass; but porcelain, ebonite, gutta-percha, tin-plate, and other materials are often used. The nearly vertical dipping bath—so long a characteristic feature of the collodion process—is one of the most convenient forms when a plate has to be left in a solution for some minutes without being watched, especially if the same solu tion is to be used for a number of plates. For dipping, the plate is supported on a slip of glass or other material turned up into a hook at the lower end. The swing or wave bath of Mr. H. J. Burton is especially convenient when large plates are to be manipulated, and its general design is sufficiently indicated by the following sketch. The bath is set at an inclination of about 20° with the vertical, and the plate is laid on the flat surface A, the lower edge of the plate being allowed to rest on the ledge near B. The liquid in • Continued from page 164.