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THE PHOTOGRAPHIC HEWS. [JANUARY 30, 1885. Aroceedings of Sorteties. PIOTOGRAPHIC Society of GREAT Britain. A technical meeting was held in the small room attached to the Gallery, 5a, Pall Mall East, Mr. John Spiller, Vice-president, in the chair. Mr. Sands exhibited a camera with duplex focussing arrange ment, also a metal case for holding sensitized paper, this case being constructed like a single drawer; but to ensure absolute protection against the ingress of light, a cap is provided which fits over the open end of the sheath enclosing the drawer. A camera clip, constructed by Mr. Shew, was next handed round. Instead of being provided with two studs like that of Mr. Beard (see page 17), it has a fixed hinge-piece, B, connected with a split socket, 0, the arrangement being such that one tightening screw serves not only to fix the hinge-piece, B, but also to tighten the sliding rod in the socket, C, so that a universal motion is se cured without unshipping any parts. In other respects, the clip shown resembles that already described. Mr. William Cobb exhibited a camera by McKellen, of Man chester; after which, prints developed on gelatino-bromide paper were handed round by Mr. Kidd and Mr. Ince. Mr. Wollaston showed a negative which had been developed with a commercial developer, sold already made up in one solu tion, and supposed to contain pyrogallic acid. Opinions differed as to whether the negative, or one developed at the same time with an ordinary pyrogallic and ammonia developer, was the better. Mr. Arnold Spiller said that concentrated pyrogallic deve lopers which will keep have been made, but not come into gene ral use. He instanced the developer recommended by Cramer, which is made up as follows :— Sulphite of soda 3 ounces Bromide of ammonium ... } ounce Bromide of potassium 1} ounces Pyrogallic acid 2 „ Distilled water 32 „ Dissolve and add :— Sulphuric acid 120 minims Strong ammonia 3 fluid ounces Water to make up to 40 „ For use, mix one part with eleven of water. The advantages of using Russian leather for making the bellows of the camera were then discussed, and it appeared to be the gene ral opinion that when the genuine article is secured, there is very little fear of attacks by insects, even in tropical climates. As an illustration of the kind of daylight—or rather, day-dark ness—we have been having in London of late, Mr. J.D. England showed two transparencies which had been made on gelatino- bromide, one having had an exposure of half a second at a dis tance of one foot from gas burning at a No. 4 burner, and the other twenty seconds to daylight at about 11 a.m. on the previous Tuesday. No difference was noticeable. London and Provincial Photographic Associaton. A meeting of this Society was held on Thursday, the 22nd inst., Mr. W. E. DEBENHAM in the chair. Mr. C. J. Collins was introduced to the meeting by the Chair man, who alluded to the interest taken by that gentleman’s father in the affairs of the Association. Mr. Collins then showed an improved portable tripod, capable of expanding from 2 ft. to 4 ft. 10 in., having both sliding and folding joints in each leg for rapid adjustment to any desired height, the joints becoming locked when adjusted. The legs were secured to the top by hooking on to rivetted bolts which passed through the head, and were tightened with a fly nut, the head being recessed to receive the bosses of each leg. The Chairman thanked Mr. Collins, and said the tripod was very firm, and an improvement on many he had seen. Mr. A. Cowan handed round a modified camera—half-plate size—sent by Mr. G. Hare. The novelty consists in enlarging the frame to form a recess for the front board, thus reducing the thickness three-quarters of an inch, and doing away with the hinged tailboard ; the slides are made to slip in at the top, and are clipped at the base. The camera, with its various swing movements, permits focussing from seventeen inches to that of the shortest lens in use. The Chairman said it was a very neat and compact camera ; he thought a necessary disadvantage of all cameras like the Kinnear was the circumstance that the lens could not be raised to the top of the plate. Mr. D. Hubert suggested the Society purchasing collodio- chloride paper from Dr. Liesegang with a view to further experiments, and bringing the collodio-chloride process into general use, as he thought such beautiful results as he had seen in Germany could not be obtained on the best albumenized paper, which cost about the same price. The Chairman said the process was well known, having been introduced in England twenty years ago ; many firms had tried it, and obtained good results. Mr. A. L. Henderson used to make opaltypes by the process ; some specimens sealed up years ago had altered in tone a little, so he did not consider prints by that process absolutely perma nent. Further discussion on Mr. Hubert’s suggestion was postponed until the following meeting. Mr. A. Haddon said the opaque marks shown on plates by Mr. Henderson at the previous meeting were made up of a series of lines denser than the background, and between the lines the film was less dense. He suggested coating the strips of card board with gelatine to prove whether the marks were due to light or chemical action, as the ink being covered would then have no influence. The discussion which followed failed to elicit anything beyond what has been already published. Mr. J. H. TRrKS said he had recently put some over-exposed negatives in boiling water to clean off, and found, after the layer of gelatine had gone, a positive image remained. Why did this occur ? Following the subject up, he said he could make certain of a perfect image with freshly developed negatives, but had never yet succeeded with old plates. He was seeking a fine grain for a photo-mechanical process. Mr. A. Cowan made plates some time ago without alum in the emulsion, which were exposed through the glass; in every case the image, after removing the gelatine, was sufficient for trans fer on crayon paper. Mr. Warnerke patented a similar pro cess. Mr. W. K. Burton said over-exposed plates developed to get density might be considered to possess two images, a positive and a negative image. Where the image was reduced, bromine was liberated, and increased the restraining power of the deve loper. At other places, the developer was not so restrained. Very little bromine acted as a restrainer. Mr. J. Barker referred to the images developable on collo dion plates where mercurial intensification had been previously employed. Mr. Haddon remarked that the image was positive on the front, and as the developer passed through it became spent, which resulted in a clear positive image at the back. Mr. Henderson suggested that Mr. Trinks should expose through the glass as mentioned by Mr. Cowan, and after fixing, lay the negative in a vessel of water, face uppermost, and heat the water to dissolve a large portion of the gelatine. Mr. Trinks replied that he could easily get a grain all over the picture by passing the plate through boiling water. Mr. Haddon showed a plate in which grain was only seen in the image, the rest being clear. He would try Mr. Henderson's suggestion. Dr. T. Charters White and Mr. J. Hubert were elected members of the Society.