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

Formula 1. Solution of sandarac (1 to 10) ... ... 100 cm. 3 Benzole ... ... ... ... ... 65 „ Alcohol (absolute) ... ... ... 2 to 4 „ The addition of 4 cm. 3 of alcohol makes the matt coat ing more transparent than does 2 cm. 3 of alcohol. If one increase the amount of alcohol to 6 cm. 3, one gets unequal matt coatings ; with 8 cm. 3 of alcohol no matt coating can be obtained. The formation of grain is prevented.* A dilution of the above varnish with 20 cm. 3 of ether pro duces a matt varnish which flows very easily, and makes more transparent and tender matt coating, but which, as already mentioned, is very easily damaged. Even a dilu tion with 40 cm. 3 of ether still permits the formation of a very tender matt coating, which, in certain cases, can do retouching very good service. An addition alternately of alcohol and benzole acts on the benzole matt varnish as follows. Adding a small quantity of alcohol makes the grain finer ; if one then adds benzole, the coating becomes coarse-grained, and at the same time more transparent. This is to be understood so ; the grain separates in more compact little lumps, by which means its interstices become larger. A renewed addition of alcohol again pro duced close grain ; thus the coating appeared less trans parent. By adding benzole, alcohol, ether, and solution of sandarac alternately, any matt varnish may be modified at pleasure, so that it is never necessary to throw away unsuitable matt varnish, presupposing that one has employed pure, colourless, cool benzole, and not petroleum benzene. 4. On the Addition of Dammar and Mastic.—10 g. of the dammar-resin of commerce were treated with 100 cm. 3 of ether ; the solution was not complete. Further, 10 g. mastic were dissolved in 80 cm. 3 ether. Neither of the solutions produces matt varnish if treated with benzole or toluol; but the influence on formation of grain in ordinary matt varnish—mastic in particular—acts astonishingly. The matt coatings become softer with a considerable addition of mastic or dammar—nay, even sticky—and, before beginning the retouching, must be allowed to dry for some minutes. With the following mixture I obtained a good sandarac-dammar matt varnish :— Formula 2. Sandarac solution (1 to 10) ... ... 50 cm. 3 Dammar solution (1 to 10) 50 ,, Benzole ... ... ... ... ... 50 ,, Alcohol ... ... ... ... ... 2'5 ,, The alcohol is added gradually as required, and, after each addition of alcohol, one prepares a specimen plate. In the above formula the quantity of dammar may be diminished; increasing it to 80 cm. 3 produces cloudy coatings not sufficiently matt; a grade between, even without alcohol, produces useful, delicate matt coatings. I obtained a very fine grain with the following mastic matt varnish:— Formula 3. Sandarac solution (10 to 100) ... ... 90 cm. 3 Mastic solution (10 to 80) ... ... ... 10 „ Benzole ... ... ... ... ... 50 , Ether 20 „ An increase of the mastic solution leads to milky-looking matt coatings, but which do not become regular, and look cloudy. 5. General Demarks.—Mostly one may at once retouch on the matt coating with a soft pencil No. 1; if harder * In toluol matt varnish, the effect of an addition of alcohol is not so good as in benzole matt varnish. pencils are used, the coating must first dry well. The bottles of matt varnish must be kept well corked, as the ether evaporates very quickly, resulting in coarse-grained coating. Matt varnish coatings will bear washing with cold water, and may therefore be treated with water colours. Warming does not hurt the matt coating, and the use of hard pencils is thereby made easier. Chloro form and coal benzole spoil the matt coating; bisulphide of carbon does so less ; petroleum benzene not at all. Thus, the matt coatings must not be covered with ordi nary solutions of india-rubber to protect the retouching, but, according to Dr. Albert’s proposal, a solution of gutta-percha in benzene would probably be suitable. Automatic PHOTOGRAPH Company. — A special meeting of this company was held on the 28th ult. at Win chester House, to receive the report of a committee of investigation as to the position of its affairs. The committee reported that, if the full capital of the company had been sub scribed, or even had its crippled capital been more carefully and watchfully administered, under contracts less onerous to the company, the company might, perhaps, have been able to tide over the interval necessary for perfecting the machines and reducing the expenditure for plaques, so as to make their operations profitable. But the machines had been worked at a steady loss, until the entire resources of the company had been exhausted. To continue the company, therefore, in its pre sent insolvent condition would be to deteriorate the value of the patents. The committee, therefore, saw no course but to recommend a voluntary winding up of the existing company, but were of opinion that the patents were proved to be of very considerable value, and that a reconstructed company, with moderate capital, to enable it to modify and improve the machines and reform the system of plaque supply, might be able to return a substantial dividend to its shareholders. Admiral Sir R. Macdonald presided, and stated that the best was done to work the machines, but for five months they never registered a day when a “photo ” could be taken. When he was told they should wind up the company, he replied that they were bound in justice to the shareholders to show what the machines were capable of doing. As the summer was about to come—but it never did come—he thought the capa- bilities of the machines should be proved, if for no other reason, to save the continental and colonial companies from ruin. Every way was tried ; but the company was so unfor tunate as to have officials who did not come up to expecta tion. When they got their machines into good positions, with honest treatment and moderately fine weather, £1 or £2 a week was made, yet they were losing by it. He thought, however, that anyone taking up the machine, with respectable people willing to hire it, might, under good circumstances, get a glorious return. The chemicals of the plaques formed part of the secret of the patent ; and when the plaques failed to pro duce the result expected, and were returned by the thousand, they should be examined by an expert, but he was told that that would be suicidal, as it would reveal the company’s patent to a rival photographer. In his opinion, it was not a hopeless affair if worked under more auspicious circumstances. Sir James Carmichael said the management of the company had been deplorable, and it had been proved that it was impos sible to work the present machines at a profit. They had been worked hitherto at an enormous loss. He believed in the invention and patents ; but the company had not the money to carry out the suggested improvements that might make it a success. These machines only produced £1 a week, and it would take £4 a week to clear them. The idea of letting the machines at £1 a week was out of the question. Mr. Dalton Miller contended that it would be the worst thing in the world to wind up the company, for then their patents would be sold for an old song. In the end, a motion by Mr. Dalton Miller against winding up the company was put to the vote, and declared carried, but a poll was demanded.