The photographic news

• Bandzählung: 12.1868
• Erscheinungsdatum: 1868
• 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-id1780948042-186800009
• PURL: http://digital.slub-dresden.de/id1780948042-18680000
• OAI: oai:de:slub-dresden:db:id-1780948042-18680000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

248 THE PHOTOGRAPHIC NEWS. [May 22, 1868. over the plate a 20-grain solution of nitrate of silver con taining a few drops of acetic acid to one ounce of solution. Let this stay on a few seconds ; pour off into another bottle : this must not be used over again. This is the backbone of the process, as every plate gets the benefit of a new bath, and is thereby equally good. After this the plate only wants thoroughly washing, and you have a plate which, when dry, is capable of producing the best results (equal to wet plates), and should it fail, the development or exposure is to blame. To develop, pour on a 3-grain solution of pyro gallic acid, and, when the picture is faintly but thoroughly out, intensify in the usual manner with pyro and silver; fix with hypo of soda, I never use distilled water for any of the washings, but use it for silver baths and pyro for developing solutions. I think nothing more need be said in favour of this pro cess than that Mr. England uses it in preference to the wet. X o Berent thtenfs. PRODUCING TRANSPARENT DESIGNS ON PAPER. BY WAITER B. WOODBURY AND R. i ASHTON. The object of this invention, which is simply one of the variously ramified applications of the photo-relief printing process, is to produce by pressure on paper, with a relief photographically obtained, designs resembling the ordinary water-mark, with the object of preventing forgery in bank notes, cheques, &c. The method is also applicable for pro ducing images on lithographic stones, by placing thin paper charged with a greasy substance between the relief and a lithographic stone. The operations are described in the specification as follows :— In carrying out our invention a relief is first obtained in gelatine by the process described in the specification of letters patent granted to Walter Bentley'Woodbury, and dated 23rd September, 1861, No. 2338, or by any other analogous means. This relief is mounted or laid on a plate of hard metal, and the paper to be impressed is rolled or passed through a press in contact therewith, by which means the paper will bo rendered transparent at those parts where it has been pressed in contact with the relief parts of the design. On looking at the paper by reflected light a positive picture will be seen (the transparent parts appearing darker than the surface), but upon viewing the same by transmitted light it will appear as a negative ; if the reverse effect be desired it will be necessary to replace the ordinary negative by a transparent positive in the production of the gelatine relief; or a metal relief or intaglio may be obtained from the gelatine (by pressure or by the electrotype process) and used with the ordinary paper machinery for pro ducing the water-mark. Either line subjects or those bearing half-tints may be thus impressed on the paper; in the latter case the different amounts of pressure given to the paper by the varying heights of the relief will produce the effect of the middle tints as well as the extremes of light and shade. In place of using the relief direct as obtained to produce the water-mark in the paper, a reverse of this relief may be obtained by means already known, and a number of casts of it may be made in gelatine on the surface of a steel or zinc plate, and when dry these plates may be used for pressing the paper, or a sheet of highly pressed paper may take the place of the steel or zinc plates. Where the reliefs obtained by light are used, having for their support collodion, these may bo cut to any shape, and mounted on the zinc or copper plate by means of india-rubber or other varnish or cement. It will be evident that if (while the paper is undergoing pressure in contact with the gelatine relief) a piece of fine paper charged with a coloured greasy material similar to the carbonized paper used for copying letters is interposed between the relief and the sheet of unsized paper, a design bearing half-tones, according to the variations of tho relief, will be impressed upon the latter, which may be transferred to stone, and used to print litho graphic impressions in the ordinary manner; or the image may by the same means be impressed at once on to the stono with out transferring. Having now described the nature and object of our said invention for “ Improved Means of Producing Designs upon Paper,” together with tho manner in which the same is to be or may be performed or carried into practical effect, we would remark in conclusion that we claim as our invention the pecu liar method hereinbefore described of producing transparent designs or water-marks upon paper from reliefs or intaglios obtained by the aid of photography, and also of producing by the same means (with tho interposition of paper charged with a greasy substance) of designs either directly upon stone, or which may be transferred on to stone for printing by tho ordin ary lithographic process. PRODUCING PRINTING SURFACES. BY A. A. DISDERI. This process, for which M. Disderi received provisional pro tection, is not very fully stated, as the patent was not com pleted. The provisional specification is as follows:— This invention comprises two distinct features: first, the transformation of a photographic image into a matrix obtained by galvanoplasty ; and, secondly, the production with this matrix either of impressions with inks or of any colour upon paper, textile fabric, glass, ceramic ware, wood, stone, and metal, or of countertypes in relief or in intaglio on any metal, or of engraved blocks for printing. The invention consists—1st. In obtaining by means of a vehicle (say albumen, gelatine, or other analogous body) a coating or layer containing salts which modify under the action of luminous rays, such as nitrates, chlorides, bichromates, prus siates, and the like, double salts of different metals, gold, silver, copper, and the like. The said coating or layer gives a proof in relief by causing to dissolve, according to its nature, the parts not impressioned by light, by means of water at different tempe' ratures, alcohol, ether, or acids, and thus leaving bare the parts gradually metallized. This coating, or layer, obtained in relief after the mode of an ordinary photographic negative, will give a positive proof by transparency with the blackest lines in relief and the whitest in intaglio. 2nd. In varnishing the contour of the glass bearing this posi tive proof with gutta percha, in order to avoid damage; in then employing the moans ordinarily adopted in galvanoplasty in order to cause a deposit upon this image of a layer of gold, silver, copper, or other metal, and to obtain thus a matrix, tho hollows of which will be formed by the black or dark parts and the relief by the white or light parts. The production of this matrix constitutes the first part of this invention. Now with the matrix I can obtain various artistic and industrial results, which constitute the second part of the invention. Firstly. I can coverthis matrix with an ink at the ordinary temperature, and apply it to printing upon glass, wood, stuffs, porcelain, paper, and other bodies. Dessication takes place; then, to detach the image easily from the matrix, and to leave it adherent to the body applied to receive the impression, I heat the matrix gently with a spirit lamp. I compound the ink by mixing therewith ingredients which melt under heat, such as gelatine and the like, and colouring ingredients to vary the effects ; 1 also add vitrifiable matters if I wish to print on por celain and to obtain enamels and the like. Finally, I can, by the process above-described, produce impressions on wood, metals, paper, glass, stuff', stone, plastic substances, and other surfaces. Secondly. I can submit the matrix to a second galvanic opera tion to obtain proofs in relief in gold, silver, copper, or other metals, which, besides appearance, will give results the most favourable to great preservation. These proofs can also, by the known typographic processes, servo for printing, as with engravings in wood or metal. PORTABLE APPARATUS FOR THE FIELD. by henry cook. This portable laboratory or apparatus for working wet plates in the field was only provisionally protected. The specification is as follows :— The photographic apparatus which forms tho subject of the present invention has for its object tho construction of a con- voniant form of portable apparatus lor taking views without the necessity of carrying about a cumbrous and unwieldy quan tity of apparatus.