The photographic news

• Bandzählung: 27.1883
• Erscheinungsdatum: 1883
• 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-id1780948042-188300004
• PURL: http://digital.slub-dresden.de/id1780948042-18830000
• OAI: oai:de:slub-dresden:db:id-1780948042-18830000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. Vol. XXVII. No. 1318.—Decenxber 7, 1883. CONTENTS, PAGR Photographi: Engravings 769 The Cyanotype or " Blue" Printing Process in Practice 770 An Automatic Printing Apparatus 771 Review 772 Collodio-Chloride Printing. ByDr.E.Liesegang 772 Frame for Printing Lantern Slides. By Alexander Cowan ...773 Photo-Lithography and Photo-Zincography. By Major J. ■Waterhouse, B.S.C 773 On Print Waahing—A Hint for Beginners. By C. W. Bentley 775 Notes 776 PAGR Patent Intelligence. 777 Cutting up the Albumenized Paper. By W. Coles 778 TypographicPrinting Blocks from ITalf-Tone Negatives. ByC. .. T. 778 Thirty Years of Photographic Progress. By Jabez Hughes ... 779 Stereoscopic Portraits by a Single Camera "80 Correspondence 781 Proceedings of Societies 781 Talk in the Studio 783 To Correspondents 784 The Photographic News Registry 784 PHOTOGRAPHIC ENGRAVING. In fulfilment of our promise we will now proceed to pass in review some important steps in the progress of photo graphic engraving that have been made since the time when Niepce pursued his rudimentary experiments with bitu men and metal plates. In 1813, writes Isidore Niepce, “ My father made some attempts at engraving and reproducing drawings by litho graphy,” which had then only been introduced into France. The grain of stone was considered to be too coarse, and polished metal plates were tried coated with different sorts of varnish. Upon these varnished-coated plates, Niepce placed drawings and printed them by the action of light. At last, in 1826, he obtained imprints in bitumen, on metal plates, and attempted to etch the image so obtained, but his experiments came to no practical issue. Subsequently experiments were instituted by W. R. Grove, Donn, Fizeau, and other experimenters, with a view of transforming the Daguerreotype plate into an engraving fitted for the printing press. To Fox Talbot, however, we must accord the credit of discovering the first practi cal engraving process. Two patents were obtained by this inventor, one in 1852, the other in 1858. By Talbot’s pro cess photographs from natural objects were transferred to copper or steel plates, and etched so as to render them available for printing in a copper-plate press. The second patent was a process by which the photograph was first etched on copper, and afterwards faced with steel. The ingenuity of this discovery is only surpassed by its extreme simplicity. Before the process could be adapted to the reproduction of photographs from nature, many methods were tried for breaking up the shadows and half tones into stipple or line, or aquatint ground. The plan described in the patent of 1858 was the following :— After removing the metal plate from the printing-frame, a very finely-powdered gum, copal, or common resin was dusted over its surface. It was then heated so as to secure the adhesion of the grains of gum. After the plate was cool, the etching fluid was applied, consisting of hydrochloric acid, saturated by the aid of heat with per oxide of iron. This solution was filtered and diluted with water in proportions to suit the print to be engraved. By this method the process of etching was so successful in Talbot's hands as toenab’e him to supply engraved plates of remarkable excellence, some of which were published in the PHOTOGRAPHIC News, notibly a view of the Tuiler ies, which appeared with the issue of 301 h September, 1859. Although it is unnecessary to set down the whole woik- ing detiils of tins fascinating process, it accords with our plan to give at least a suggestive outline cf its preliminary stages, as it embraces discoveries which are the parents of many modern photographic processes. The copper plate had first to be thoroughly cleansed. It was then coated with a mixture of gelatine and bichro mate of potash. It must be noted that this mixture was the first of its kind employed in photography. The plate was dried, and an impression printed upon it from a posi tive transparency. The result was an image having the parts affected by light fitted to resist the action of the ferric chloride etching solution, while the parts unaffected by light were readily penetrated, allowing the fluid to act upon the metal plate. The etching process was carried on in a partially- darkened room, skill being required to determine the strength of the etching solution suited to obtain the de sired result. Talbot appears to have originated the idea of using a network or gauze as an alternative for the aquatint ground produced by powdered gum or resin, and he clearly describes the method of using the network in his patent of 1852 (No. 565). He speaks of the grain or stipple pro duced by the network as photographic veils, and says that the image of the gauze should be impressed upon the gela tine prior to the exposure under the positive. M. Buchtold made an analogous claim in 1859. He forms or impresses the photographic image on a plate coated by Niepce’s method, and before it is etched, he exposes it under a glass coated with black varnish, and covered by a multitude of closely-drawn parallel lines traced by a sharp point. This glass so prepared was then used as a negative, by which the lines were printed over the image on the metal plate. In his own words, “ When the metal plate coated with its bitumen varnish has been exposed to light under the negative, before it is washed, the ruled glass plate is substituted for the negative, and the light allowed to act.” “ Wherever the bitumen has been acted upon while it was under the negative, no new action is effected by the light passing through the ruled plate, because the bitumen has become insoluble, but only on those parts which have been partially or not at all influenced by light. After sufficient exposure, the ruled glass is lifted and turned in an opposite direction—that is, placed at right angles to the first lines—and again exposed to light, but for a shorter time than before. The ruled glass is next placed diagon ally to the squares obtained, and re-exposed in the opposite direction, the time of exposure decreasing with each change of position. In this manner a multitude of flue points are obtaine 1 over the plate, but only in those parts where they are required. This description appeared in June, 1859. In January of the same year Mr. C. J. Burnett describes a similar mode of obtaining lines or dots. He advises the operator " to follow out a plan or plans sug gested to me by the shade of fine lines mentioned by Mr. Fox Talbot, as adopted by him in one of his old pro cesses. “ I (he continues) would recommend a set of fine