The photographic news

• Bandzählung: 11.1867
• Erscheinungsdatum: 1867
• 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-id1780948042-186700008
• PURL: http://digital.slub-dresden.de/id1780948042-18670000
• OAI: oai:de:slub-dresden:db:id-1780948042-18670000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. Vol. XI. No. 459.—June 21,1867. CONTENTS. Zinc for Washing-Trays 289 Photography at the French Exhibition 290 Foreign Miscellanea 291 Report of the Commission Appointed to Award the Prize of 8,000 Francs Presented by the Hue de Luynesfor the Best Photo Mechanical Printing Process 292 About Leptographic Paper. By Jabez Hughes 292 On the Cause of the Central Spot, or “Flare,” in Photographic Lenses ; and on a New Form of Wide-angle Rectilinear Lens entirely Free from this Defect. By Mr. 294 PAGE Anthony’s New Developer 296 Mr. Davies’ Memoranda on the History of Carbon Printing, Photo-Lithography, and Photo-Engraving 296 Scrum Process for Enlarging. By A. J. Drummond 297 Proceedings of Societies—The American Photographical Society —South London Photographic Society 297 Correspondence—Mr. Firling’s Enamel Process—Reproducing Photographic Portraits.... 298 Talk in the Studio 299 To Correspondents 300 ZINC FOR WASHING-TRAYS. A brief but instructive communication was made to the members of the South London Photographic Society, at the last meeting, by Mr. Arthur Bedford, in whose charge the printing department of Mr. Francis Bedford is placed. At a previous meeting Mr. Bedford had exhibited to members some prints which were disfigured with dull surface-spots, which could be removed by brisk rubbing without leaving any stain, but which were, nevertheless, sufficiently annoy- ing. Various conjectures were hazarded as to the cause of the spots, which looked very like spots from soapy water; but as strict instructions had been given that no soap or soapy water should be permitted near the prints, it was scarcely thought possible that this could be the cause. The common idea that zinc was quite innocuous prevailed, and it was scarcely thought probable that the spots could arise from this cause. It was true that the perforated zinc of which the false bottom of the trough was made was, when new, coated with a greasy substance which would mark the prints; but this had been carefully washed with an alkaline solution, and had, moreover, been in use for some time. To make assurance of cleanliness doubly sure, one member sug gested another thorough cleansing and the use of dilute nitric acid, to remove any oxide formed on the zinc, and make it clean and bright. This last suggestion was acted on, and although it did not effect a cure, it revealed the cause of the spots. After the cleaning and thorough rinsing, the trough was used again for washing prints, and the result anxiously watched. The spots which had before appeared in tens now appeared in hundreds. The zinc was the cause of the spots, and the cleaner its surface the more complete and energetic its operation. Whether this was due to galvanic action or not is not here important to enquire: a decomposition was set up by the traces of hyposulphite and silver, which caused a deposit of some kind wherever it touched the print, and the surface stain which we have described was the result. Many other photographers have noticed a similar result from new zinc, but have attributed it to the greasy dressing upon it; and the spots generally disappear when the zinc has been in use a little time : this view has been confirmed. The real cause of the cessation appears to be the formation of a coating of oxide on the zinc, which causes the injurious action to cease. We found this experience confirmed a few days ago in the photographic printing establishment connected with the Royal Arsenal at Woolwich, where the manager stated, as his experience, that new zinc always caused stains ; but ceased as soon as it was covered with oxide. . The simplest and safest plan is, however, to varnish the zinc. Mr. Bedford gave the whole a coating of Bate’s black varnish, which at once effected a cure. Any protective var nish of good body would doubtless answer the purpose. Shel lac in wood naphtha, about a drachm of the lac to the ounce of spirit, forms a capital varnish for such a purpose, and gives a very hard and tough surface. It should be applied in a warm place, to prevent chilling. Plain collodion, with about one-fourth of jts bulk of boiled linseed oil added, gives an exceedingly excellent waterproof varnish for such a purpose. For wooden washing-trays, perhaps the last-mentioned var nish is the most valuable which can be employed. For all vessels for washing purposes varnishing presents a cheap and easy escape from the chance of stains and injurious action. MEDALS AT THE FRENCH EXHIBITION. So many statements and counter-statements have been made regarding the medals at the French Exhibition and the period of their distribution, that it is difficult for the out side public to obtain any definite idea of the probable facts: Some of the rumours regarding the photographic medals have been amusingly wide from or short of the truth. No official announcements have yet been made of any of the awards, and it would have been obviously indiscreet on our part to avail ourselves of unusual facilities for obtaining information, whilst in Paris, to anticipate the announcement of the jurors themselves, which will shortly be made, as the distribution takes place on the first of July. We may, however, without impropriety mention that no gold medals have been awarded to "English photography. Rumour states that three gold medals in Class 1X. have been given to Frenchmen: M. Lafon Camarsac, as the inventor of a secret process of photo-enamelling ; M. Garnier, as the inventor of a process of photo-engraving; and M. Tessie du Motay, for his process of phototypie. It is doubtful, how ever, whether more than one gold medal has been awarded, which will be received by M. Garnier. We are glad to be able to state that the award of these gold medals (if the rumour be true) was not the work of the class jury, but of some superior (!) jury, who undertook to revise, alter, or add to the work of the class jury. We shall probably have more to say on this subject when it comes before us in an official form. The number of silver medals awarded to English photo graphers is seven; the names mentioned in connection with them being those of Francis Bedford, H. P. Robinson, Wm. England, Thurston Thompson, James Mudd, J. W.Swan, and W. B. Woodbury. Twelve bronze medals have been awarded, in almost every instance, we think, with the greatest pro priety and justice. About four-and-twenty honourable men tions have also been made. It is a singular corroboration of our expressed opinion as to the inferiority of the show of English portraiture at the Exhibition, that not a single medal has been awarded to it, although some of the medals