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

3G0 THE PHOTOGRAPHIC NEWS. [May 8, 1891. the objects. He thought it would be of great value, because a person could, by its means, carry in his eye (having the key below) the colour the bird or fly might possess. The Chairman enquired if Mr. Sachse knew whether the sample tissue colours shown were aniline colours or not. Some of these colours were very fugitive. Mr. Sachse said he could not answer that question. He had used these tissue colours, on the spur of the moment, as the best set of colours he could get. Of course he would try to match the colours exactly—probably by the use of water colours—but the examples he had used were merely ordinary commercial samples of tissue paper, the best he could get. Mr. Cheyney asked whether it would not be possible to flow orthochromatic plates with a stained soluble gelatine, which would act as a colour screen, and thus avoid the necessity of carrying screens to be placed in front of the lens. Mr. Carbutt said he could only answer that in a theoretical way. He had never tried the experiment, yet did not see why it should not answer. The disadvantages would be, however, that one would be compelled to use the fixed plate as it was, while under present conditions he could use the plate with or without screen, or vary it from the light yellow to the orange, as he desired. This, he thought, was the better plan. Photo-Mechanical Prints with an Ordinary Copying Press.—-A Russian photographic paper publishes the following : “Ona thick sheet of glass I obtain a clich by means of bichro mated gelatine, which, after developing, I leave to dry at the ordinary temperature for twenty-four hours, after which I flood it with the following ‘ bain mouilleur’ : Water, 100 c.c. ; glycerine, 200 c.c. ; hyposulphite, 2 grammes. This is allowed to act from one to two hours, according to the desired relief. Then I remove the liquid from the glass by means of a very soft pad and blotting paper, and then I ink up the clich by means of a gelatine roller. The first pull or two are generally poor, and are somewhat spoilt by the dampness of the clich, but the subsequent impressions are excellent. In order to print in the copying press, I lay the inked clichs on a piece of india-rubber cloth, a mask of paraffin paper, and then the paper on which I wish to have the impression, and over this a thin bag of fine cloth filled with wadding. It is the use of this blanket which makes it possible to press the paper into contact, and to obtain all the fineness and details of the cliche. Of all the formula! I have tried for the ‘ bain mouilleur,’ I have found the above the best, as well for the relief as for the number of impressions. If after about twenty pulls the details of the high lights begin to show grey, one only need damp the cliche with a pad dipped in the same liquid, in order to make it as good as ever.” Royal Society.—At the meeting held at Burlington House, London, on Thursday, a paper, entitled “ Cloud Photography conducted under the Meteorological Council at the Kew Observatory,” by Lieut.-General R. Strachey, R.E., F.R.S., and G. M. Whipple, B.Sc., F.R.A.S., superintendent of the Observatory, was read. The authors described the work which had been in progress under their charge since 1878, illustrating it copiously with lantern slides and photographs, many of which were admitted by those who saw them to be unique and of great beauty, while the methods they employed for deter mining the heights of the clouds above the earth’s surface, and the system adopted for finding the rate of motion of the currents of air in which they floated, were commented upon by the president, Sir William Thompson, Lord Rayleigh, the secretary, and other speakers, as extremely ingenious, and being capable of rendering far more accurate results than any others, hitherto employed, either at home or abroad. The range of observations in the list of results given by the authors extended from clouds floating less than one and a half miles high in air, moving at seven miles per hour to nine miles above the ground, in gales blowing sixty-five miles an hour, whilst the surface wind was only a gentle breeze of five miles per hour. The advantages of a knowledge of such aerial investiga tions in the preparation of weather forecasts was ably pointed out by Mr. Symons, the secretary of the Royal Meteorological Society. 6 Rnshers to Corresponents. All Communications, except advertisements, intended for publication, should be addressed to the Editor of the PaotoGraPnIO News, 5, Furniva Street, London, E.C. All Advertisements and communications relating to money matters, or to the sale of the paper, should be addressed to the Publishers of the PaorogRaparc News, Messrs. Piper & Carter, 5, Furnival Street, London. Questions requiring a reply in this column should be addressed to Mr. John Spiller, F.C.S., 2, St. Mary’s Road, Canonbury, N. V. B. R.—Cabinet Mounts. The cardboard contains very little chloride, but so large an amount of sulphate of lime (plaster of Paris) as to be positively objectionable. The reduction of this sulphate to sulphide, by organic matter under the influ ence of moisture and sunshine, may very possibly account for the yellow staining of the silver film which is now so very marked. Where screened from light, this sulphuration does not appear to have taken place, neither is there any fading. J. M. Briggs.-—Estimation of Silver. The hydrometer test would probably meet your case, being sufficiently near for all practical purposes. But if you wish to be exact, precipitate, say, two drams of the silver bath with an excess of hydro chloric acid, wash the heavy chloride once or twice with warm water by decantation, drain closely, and dry nearly to the point of fusion in a tared porcelain crucible ; 143’5 parts by weight of dry chloride correspond to 170 of nitrate of silver ; then multiply by four to give the number of grains of real nitrate per fluid ounce. Referee.—Operator’s Duties. All depends upon your original agreement, but it cannot be to your advantage to engage a skilled operator to do the work of an ordinary printer. He might be asked to assist in retouching, enlarging, and work ing-up residues, if you have any occasion for these services. It is possible to overweight the establishment by carrying the division of labour too far in quiet seasons. A. C. (Macclesfield). — Cracked Negative. Try the method of rubbing in lamp-black, which often succeeds, or at least gives you a print that requires very little working-up by hand. G. G. M. and F. D. T. (Edinburgh).—Historical Photographs. An excellent portrait of Daguerre (6 in. by 5 in.), together with a photo-lithographed reproduction of the partnership deed drawn up between Nicephore Niepce and Daguerre, appears in the new monthly, Paris Photographc, edited by M. Paul Nadar (Paris: 53, Rue des Mathurins ; price 2 fr. 50 c.). You would do well to get this copy. V. McC.—Gold Line round Photo on Glass. If you mean a narrow gold edging, this is done with gold leaf upon the glass itself, properly prepared with oil gold size, or varnish. No pen is required, for it is not done with the so-called gold ink, w’hich, being only a bronze powder, would cause the speedy destruction of a silver photograph laid in contact. F. R. I. B. A.—The Renaissance in England. We called upon the publisher this week, who showed us Part I. of the new work, containing eighteen reproductions from photo graphs, size 14 by 10 inches, executed by Sinsel, Dorn, and Co., of Leipsig. They are for the most part entirely satis factory, but two or three of the plates, probably from the nature of the subjects, appear to be grey and flat. Urban.—The Crystal Palace Exhibition closed on Saturday last, so it is now too late to think about coming up to see it. M. C. (Paisley).—Aristotype. Slow toning is a common diffi culty ; you should try a borax-gold bath made rather strong, and give plenty of time. The prints are not only red, but injured in the mounting, probably from being rolled before they were quite dry. The process is not so easy as with albumenised paper, and your pretty cabinet print only proves the fact. C. N. and Co.—Reducing Furnace for Residues. Make friends with the nearest brass founder, or his bricklayer, and get him to come and put up such a furnace as he would use. It is simply a square chamber, lined with fire-bricks set in Stourbridge clay, with sunken ash pit, cast-iron fire bars, and flattened square flue leading from the back of the furnace into an ordinary upright chimney. A flat, movable slab— iron-bound, Stourbridge square—to cover the top. The fuel is coke.