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544 IHE PHOTOGRAPHIC NEWS. [August 24, 1883. Proceedings Of Societies. London and PROVINCTAL Photographic Association. At the meeting held 16th August, Mr. J. B. B. Wellington in the chair, Mr. J. S. Smith, of Edinburgh, exhibited a quarter-plate pocket camera, devised by a friend in Dundee. It was con structed on a principle similar to an opera hat, and fitted in a box. When folded, it was about five inches square and two deep. A flap shutter was fitted to it to work behind the lens on the crank principle. The weight of the camera, flange, shutter, and focussing glass, was three quarters of a pound, and with the dark slide, about 17 ounces. Mr. Cowan showed a finishing frame for taking transparencies with chloride plates ; it was so arranged that the positive could be taken from any part of the negative without coming in actual contact with it. Mr. Haddon said that he had been troubled with transparent spots in the high lights of his negatives, which he found was due to the gelatine, as, although he had changed all his chemicals, they did not disappear till he had changed the gelatine. Mr. Henderson suggested they might be due to a partial decomposition of the gelatine. Mr. Haddon said he had soaked a plate a quarter of an hour, then exposed, and developed ; but the spots were still there, and quite as transparent. Mr. Henderson suggested that a quarter-plate should be washed, then put on a warm brick so as to melt the gelatine, then, when re-set, exposed and developed. He thought then they would have disappeared. A discussion was then commenced in reference to an assertion made at the last meeting by Mr. Henderson, that the density of a gelatine negative was increased after it had been flooded by alcohol. Mr. Haddon showed a plate which, not being quite dry in one part, was flooded with alcohol, and in that part which was wet there was a decided increase in density. He suggested that if the negative was wetted, and allowed to dry, the density would again be uniform. Mr. Debenham suggested that the density, insteadfof being in creased in the wet portions, was decreased in the dry parts. Mr. Henderson had prepared an emulsion as follows :— Gelatine ... ... ... ... ... 30 grains Bromide potassium 30 grains Water ... ... . . ... ... 10 ounces Ammonia about 2 drops He dissolved the gelatine and silver in ten ounces of water, then added two ounces of gelatine, and on removing the stirring-rod after a little time, found it was slightly opalescent. He then added 2 drachms ammonia, and 14 ounces ammonia, and allowed it to set in ice ; he then broke it up with 1} ounces gelatine, washed, melted, and measured up to 8 ounces. With this he coated plates rather thickly, and exposed with a 2B lens, No. 2 stop, five seconds ; under same conditions with collodion, he would have allowed twenty seconds. blk in Studio. J Pure Filter Paper.—Some weeks ago we called attention to a very pure filter paper which Messrs. Morgan and Co., of Cannon Street, bad submitted to us, specially prepared for chemical and photographic use. Since then, the same firm has forwarded us other samples of the same material, but of varying thicknesses, destined either for blotting or filtering. We have lately used the material for soft padding in the packing of plates for travelling, its freedom from acid and hyposulphite of soda being a strong recommendation to its employment for the purpose. Photographic Society of Great Britain.—The next monthly technical meeting of this Society will be held on Tuesday next, August 28th, at eight o’clock,at 5a, Pall Mall East. Electrical Exhibition in Vienna.—To-morrow Sir William Siemens will deliver a lecture, and has addresssei a letter to the Electrical Society in London, informing it that the importance of the Vienna Exhibition has been underrated in England, and that exhibits should be sent even now, as they might be of great use. On Tuesday night the great light on the lantern of the Rotunda was visible for many miles around. The light penetrates through the glass roof, producing a magic effect outside, which attracts crowds in front of the entrance gate. Cholera and Heliography.—The Dally News correspondent at Cairo reports that heliographic communication has been established between head-quartersand the hospital at Mokattam. New Paper-making Substance.—The great and growing increase in the consumption of paper naturally calls attention to substances suitable to the paper manufacturer. Already the alfa and the ramie have been pressed into his service ; and the same country which produces these—viz., Algeria—also affords another plant, the dwarf palm, the fibrous properties of which have long been known to the Arabs, while they have been unable to turn them to account. A Frenchman, M. Reynaud, has found means for utilising the whole plant, except the roots, which serve for firing. Every part, from the stalk to the topmost leaves, is transformed into fibre of excellent quality, and it makes no difference if the plants have been pulled up several years previously. The plants are placed in a kind of cage, which is immersed in a boiler filled with a special lye, and heated. The substance being thus retted, becomes soft, so that the fibre may be readily separated. It is withdrawn from the bath, and drained, the lye being saved for use over again. It is then passed between rollers, while at the same time being made cold by quantities of water. The number of rollings, rinsings, and combings depend upon the degree of fineness required. The product is allowed to fall into a receptacle containing pure water, whence it is withdrawn to be tied up in bundles for transport. Photographic Club.—At the next meeting, on August 29th, the subject for discussion will be, “ Defects in Gelatine Plates, especially of Surface Markings.” O. Eoxxesgundents. L. W. R.—1. We suppose that it is due to the lowness of the tem perature ; but the information you give is not sufficient to enable us to speak confidently, 2. A small proportion of carbolic acid should be added, say one drop to each ounce. 3. It is a very good plan, but in ordinary cases it is not worth while to expend so much time and material upon it. 4. A, 90 grains; B, 180 grains. 5. Ten ounces is very near the mark, but no experi mental data exist for calculating it out with exactness. The pro portions to which you refer are those which we should recommend for ordinary use. J. Harvey.—Use the gum rather stiff, and add a little ox-gall. A. D.—We imagine that the official list is correct, but you had better write to the secretary. J. Parish.—We have seen such an objective with an extra positive lens for shortening the focus, and a negative lens for lengthening it. If yours is of the same character, that marked “ Larger” should be the negative lens, and that marked “Shorter” the positive lens. It is not likely that there is any provision for using the objective with both the extra glasses at the same time, as it is difficult to see any reason for so doing. Photo Artist.—The best method of obtaining them will be to take them yourselves, as those having good work of this kind do not usually allow others to obtain the credit of having done it. G. W. K.—We do not at present know of a suitable person, but think that you might hear of someone if you were to advertise. Charles Auty.—Le Moniteur de la Photographie, published at 15, Quai -Voltaire, Paris. M. G. M.—1. A mixture of whiting and raw sienna will be found to answer very well. II. G. Pike.—Thank you for the photograph. D. Macearlane.—Probably from accidental contact with hypo after washing. J. W.—1. They can be obtained through any dealer in optical goods. 2. From Barnaid, artists’ colourman, Oxford Street. 3. It will answer very well, as regards illumination and definition, but distorts marginal lines to an appreciable extent. Herbert and Dubbin.—We will endeavour to put it in the proper channel. W. H. Mason.—The last day for sending contributions to the forthcoming exhibition of the London Society is the 28th of next month. W. G. H. SPRAY.—We have no means of obtaining the photo graph, and have returned your stamps. J. D. V.—If it was registered (which you can ascertain at Stationers’ Hall on payment of a fee of one shilling), and you took the picture on your own account, you are probab'y well protected. *,* Several answers must stand over.