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

230 THE PHOTOGRAPHIC NEWS. [May 15, 1868. with the developer is impossible until after the lapse of the months necessary to prepare a bath, no inconvenience can have arisen from the error. COLLODION NEGATIVES WITHOUT GLASS. In a recent notice of M. Marion’s transparent tissue we re ferred to Mr. Woodbury’s experiments in a similar direction, with a view to provide a light support for dry collodion negatives. We have recently received from him some interesting results illustrating the extent to which ho has already worked his project out. These consist of negatives on a support of tough, transparent, flexible collodion, and sensitive plates ready for exposure on a similar support. The support is not too thin to permit easy and safe mani pulation with the negatives, or to risk cockling or forming creases; but is, nevertheless, sufficiently thin to permit either side of the negative to be placed in contact with a 8 nsitive surface without loss of sharpness. The mode of preparing the dry-plate films is very simple. It consists in applying to a plate of glass a coating of castor oil collodion; when this is dry, applying a very dilute solu tion of india-rubber to protect the first collodion film from being dissolved, when a second is applied. The second coating of collodion is a sample suitable for the dry plate required. This is applied on the india-rubber coating, and excited, washed, treated with a preservative, &c., in the man ner usual with the dry process which may be selected. When the prepared film is dry it is cut round the edges, lifted from the plate, and stored in the dark for subsequent use. It will be seen that it will be easy to prepare such sensitive films in large sheets, which may be cut up subse quently to any size which may be required. We believe that Mr. Woodbury contemplates the commercial preparation of such sensitive films ; but he has promised, in any case, to supply more precise details of his operations for the benefit of our readers. IRON DEVELOPMENT FOR GUM PLATES* BY RUSSELL MANNERS GORDON. As some of your readers may perhaps be working gum plates, I recommend them, in preference to an alkaline developer, the following iron one :— Gelatine ... ... 1 grain Acetic acid ... ... ... 15 minims Iron ... ... ... 20 to 30 grains Water ... ... ... ... 1 ounce. It is perhaps a good plan to dissolve the gelatine in the acid and a part of the water, and the iron in remaining por tion, adding them together after complete solution. A gentle heat may be necessary to get the gelatine to dissolve. After wetting the plate previous to the development (with distilled water), take as much of the above iron solution as may be found necessary to cover it; and add to each drachm one drop of a 30-grain solution of nitrate of silver. Add the silver to the iron before pouring it over the film. The development is nearly as rapid as that of a wet plate. After the details are out, a few more drops of silver may be added to the iron, and this, again and again, poured over the plate to complete the primary development. When all is out, the necessary intensity may easily and quickly be obtained by the usual solution of— Pyro... ... ... 2 grains Citric ... 2 „ Water .. 1 ounce And a few drops of the silver solution. I do not approve of iron development for dry plates in general; but with these gum plates it seems to answer better than anything else. * We have recently seen some of Mr, Gordon’s negatives, which leave nothing to be desired in technical beauty. In point of sensitiveness, the plates equal, or exceed, any dry plates we know. We shall have more to say on the process in our next. —Ed. The advantages in this way of working are :— 1st. Better adhesion of the film. 2nd. Much less blurring. 3rd. The appearance of the finished negative is very much like that of a good wet one; there is therefore no difficulty in judging of the correct amount of intensity. 4th. The exposure is, if anything, shorter than with alka line pyro, &c. It is curious that when using a gelatino-iron developer, the deposit of silver on the film is not removable by friction, while with an ordinary iron solution containing no gelatine it may be entirely rubbed off. And, again, although gela tine certainly necessitates a longer exposure in the wet pro cess when used in the above quantity, it does not seem to do so in the least with these plates. In preparing gum plates the gum and gallic acid might, of course, be mixed together before applying them to the film ; but I found that a solution containing 20 grains of gum and 3 of gallic acid to the ounce of water darkened to the colour of brown sherry in about an hour, and I fancy that a white preservative is less likely to affect the expo sure than one of so non-actinic a colour. PICTORIAL EFFECT IN PHOTOGRAPHY; Being Lessons in Composition and Ciiiaroscura for Photographers. BY II. P. ROBINSON. Chapter XVI. " Another important means of expressing unity is to mark some kind of sympathy among the different objects, and perhaps the pleasantest, because most surprising, kind of sympathy, is when one group imitates or repeats another; not in the way of balance or symmetry, but subordinately, like a far-away and broken echo of it.’’—Ruskin. " As men are not to mistake the causes of these operations, so much less are they to mistake the fact or effect, and rashly to take that for done which is not done.”—Bacon's Natural History. •’Unhappy man ! to break the pious laws Of nature Howe’er the doubtful fact is understood.”—Dryden. “ In things the fitness whereof is not of itself apparent, nor easy to be made sufficiently manifest unto all, the judgment of antiquity, concerning with that which is received, may induce them to think it not unfit.”- Hooker. Variety and Repetition {continued).—Fitness. This law of repetition will be found to pervade all great pictures, perhaps more notably in colour, but also, to a great extent, in the disposition of lines and light and shade. The repetition of incident is almost invaluable in telling a story, of which both Wilkie and Hogarth were great masters. In Wilkie’s picture of the First Ear-ring, now in the gallery at South Kensington, in which a woman is performing an act more worthy a savage community than a civilized nation— that is, boring a hole in a child’s ear, that jewellery may be hung in the flesh, under a mistaken notion of ornamentation —the action is repeated, or at least alluded to, by the spaniel on the ground scratching his ear with his paw; and in the first of the series of Hogarth’s great pictorial epic now in the National Gallery, the Marriage a la Mode, the indifference of the intended bride and bridegroom, who turn their heads away from each other, is repeated in the two dogs at their feet, linked together, but of different minds. The way in which Hogarth made insignificant objects perform a double purpose, and help to tell the story, is simply wonderful. Instances must occur to all admirers of his works, and may be imitated by photographers. In Leslie’s “ Handbook ” many instances are cited ; the following, referring to two of the best known works, I quote:—“ In the marriage scene in his ‘ Rake’s Progress,’ in which the hero, having dissipated his patrimony, appears at the altar with an ancient heiress, we are shown the interior of Old Marylebone Church, at that time standing in an out-of-the-way part of the suburbs, and, therefore, resorted to for stolen marriages, or marriages of which either of the parties had any reason to be ashamed. The church, a very small one, is in a neglected condition, and cracks in the walls, mildew, and cobwebs, would occur to an ordinary painter; but Hogarth has shown a fracture running through the table of the Commandments; the Creed