The photographic news

• Bandzählung: 35.1891
• Erscheinungsdatum: 1891
• 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-id1780948042-189100009
• PURL: http://digital.slub-dresden.de/id1780948042-18910000
• OAI: oai:de:slub-dresden:db:id-1780948042-18910000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

the same size are made from the subject, one of them being reversed as if it be destined for collotype. If a trans printing ink, and the paper was well imitated. Although the facts were brought to light and reported to my friends before the end of the year 1861, I am not aware that the source of the forgery was ever traced and brought home to the guilty parties ; so that it may well happen that the conviction of 1863, mentioned by Mr. Mew in connection with the Austrian Bank, was actually the first prosecution undertaken against a photographic forger, although it would still be untrue to say, as asserted, that it was “ the first attempt to forge bank-notes by photographic aid,” the Spanish case, proved up to the hilt, and known to certain parties in this country, being evidence to the contrary. However, it is doubtful whether the facts ever came to be widely known either in England or Spain, a policy of silence being usually observed under such circumstances. notes were ornamented with an elaborate green device and red border, which behaved differently when treated with acids, the spurious paper giving up its colours immediately, and the other only after the lapse of a longer time. The numbering of the notes was done alike with Since the invention of the collotype and photo-engrav ing processes, the nature of the ink might be practically identical with that employed by the authorised bank-note printers, and so new difficulties would be introduced. Now comes in the further advantage of perfecting the system of non-actinic overlays, whereby it would become impossible to secure a photographic counterfeit of the original engraved plate ; but to do this, one requires to find a substance of the requisite photo-opacity, which in itself is unattacked by all the ordinary chemical solvents, and yet be possessed of the transparent qualities fitting it for application on the face of a bank-note. Few solid pigments satisfy this requirement, and colours which are opaque give but an indifferent artistic effect. There is room for further experiment in this direction, account being taken of the extraordinary facilities offered to the piratical copyist by the use of isochromatic plates, and reward awaits the successful operator. EARLY BANK-NOTE FORGERIES-A PAGE OF ; HISTORY. j BY JOHN SPILLER, F.C.S. The interesting article on “Photographic Fraud,” by Mr. James Mew, which appeared in the News of 29th May i (page 401), recalls to my mind some experiments made nearly thirty years ago conjointly with a firm of paper makers and bank-note engravers, which resulted in the detection of a photographic fraud that was being practised at that time upon the Bank of Spain. In December, 1861, a couple of Doscientos notes of the Banco de Espana were brought to me at the Royal Arsenal, one of which was stated to be genuine, and the other was believed to be a forgery possibly effected by photographic means. I was requested to try and find out the way in which the latter had beenproduced; and my opinion was further asked respecting the correctness of a certain certificate given by an expert, which document, after setting forth critically the chief points of physical difference between the true and spurious notes, concluded with the following remark :— “We are not aware of anything more to add except that the imitation has not been effected by photography.” Mere inspection did not at once disclose any very per ceptible difference. There was, perhaps, a little want of definition in the geometrical design printed on the body of the forged note, but only such as might readily escape notice in a specimen which had either been a long time in circulation, or become dingy by wear. On comparing parent film—for instance, an Eastman gelatino-bromide film, which can be printed from both sides is used for the reproduction, the process is much simplified, a single negative being then sufficient. For printing, gelatino- ‘chloride paper is used which has been made transparent previously by treating it with paraffin or with benzole. To prevent the evaporation of these volatile oils during printing, the paper is covered with a transparent gelatine paper—as it is used for counter-drawing—which has been treated with a chrome alum solution in order to render it more flexible and resistant. As the oil evaporates entirely after printing, it does not at all affect the subsequent toning, fixing, and washing processes. A mode of double printing, which forms the base of the entire process, is now effected by exposing the gelatino-chloride paper at first from the back beneath the negative, then from the front or film side. During the second printing it is, of course, absolutely necessary that the print produced by the first ' exposure and the negative are exactly in register. It will be evident that by this method prints are obtained of PHOTOGRAPHY IN GERMANY. BY HERMANN E. GUNTHER. Intensifying Process by Double Printing—Paramido- PIIENOL Developer—Chloro-Cyanin as a Sensitiser for Red. The Process of Intensifying which has been employed in thework, Who is Rembrandt? " by the Author of it.— Herr Max Lautner, the author of that remarkable book, “Who is Rembrandt?”—in which, as I mentioned on a previous occasion, it is demonstrated by photographic reproductions that on many of the magnificent paintings attributed hitherto to Rembrandt the name of this latter has been falsified, and that they are in reality the works of Ferdinand Bol—has just published in Liesegang’s Photogr. Archiv the method of intensifying which he has employed in reproducing the falsified monograms. The author states that, in order to increase the contrasts of the tones in the photographic reproductions as much as possible, it was necessary to make use of a special intensifying method—one giving a much more powerful intensification than the various processes generally in use for similar purposes. This new method—if it is altogether a new one—consists in the following -.—Two negatives of exactly the notes superposed, and examining them by transmitted light, there appeared, however, to be a slight difference in dimensions, so that it was inferred that they had not been printed from the same engraved plate, although the measurements of the paper absolutely coincided. Such, then, was the problem submitted to me, and I set to work to apply chemical tests. First, by burning small portions of the notes, it was found that the true ink was entirely consumed, whereas the ash left by the spurious note was still legible, and contained both gold and silver. Now, by reversing the mode of attack, and soaking the notes—or pieces of them—in cyanide of potassium, the true note resisted well for a long time, whilst the piracy soon cleared up to a fragment of plain paper, as would happen in the event of its being a gold-toned photograph. Here, again, silver and gold were detected in solution. The