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Proceedings Of Societies. Edinburgh Photographic Society. The sixth ordinary meeting of the Society for the current session was held in 5, St. Andrew Square, on the evening of Wednesday, 4th April, Mr. A. CRAIG-CHRISTIE, F.L.S., vice- president, in the chair. The minutes of the previous meeting having been approved, Messrs. Alfred C. Hooker and Thomas Swanston were unanimously elected ordinary members of the Society. Mr. Wm. Forgan then described very fully, with illustrative experiments, the best way of securing a dead black surface on optical brass work (see page 247). Mr. Thomas H. W. KNOLLES exhibited and described two appliances he had invented for securing moving objects in the camera, without the necessity of resorting to an inspection of the focussing screen, and for finding the position in which to place the camera without resorting to the usual experimental inspection of the image on the ground glass (see page 252). Mr. A. Mathison considered the “ director ” quite as valuable as a “ detector-camera.” He had had an opportunity of using the arrangement exhibited by Mr. Knolles, and found it possessed all the merits claimed for it, and being not more than one ounce in weight, and easily carried in the waistcoat pocket, possessed advantages over the detector-camera, which with him the simple apparatus had entirely supplanted Mr. TAMKIN thought the director might be of use in the studio. Mr. TURNBULL believed that a lens-finder would be of greater value in the studio, where weight and bulk were immaterial; but for out-door work the invention of Mr. Knolles was unquestion ably superior. To indicate the usefulness of the “view-finder,” he mentioned that a gentleman bad called to know if a certain lens was capable of taking a certain building within a limited space. Mr Turnbull simply gave him a view-finder adjusted to the lens in question, and asked the gentleman to go to a building of similar dimensions at the limit of distance necessaiy, and inspect how much of the building was visible. By this simple means the gentleman had arrived at a demonstration to his inquiry. The following question was found in the box—“ Do gelatine dry plates deteriorate in sensitiveness by age ?" Mr. W. T. Bashford said that in his experience some makes of plates certainly became less sensitive by keeping. Some which originally were so sensitive that it was impossible to develop them into bright crisp negatives, were, after being kept some time, all that could be desired ; while others, that were fine when first received, became exceedingly slow, and liable to produce hard images; yet the plates were kept under the most favourable conditions for stability. Mr. Crooke had noticed an iridescent colouring round the edges of some plates after having been on hand some time, and wherever this occurred the image was very unsatisfactory. Mr. Tamkin had found plates positively improved when kept a long time. Mr. Turnbull was quite familiar with the defect alluded to by Mr. Crooke, and stated it was due to impure air having access to the plates—probably sulphuretted hydrogen was the chief cause. The defect was chiefly noticed in those plates packed with folded cardboard at the edges to keep them apart, the space thus formed allowing a film of air to intervene, which, if impure, was sure to affect the plates disadvantageously. He had noticed this peculiarity develop throughout the entire surface of plates within twenty-four hours. He did not think that plates did deteriorate to the extent mentioned by Mr. Bashford, though he was aware that some plates did not keep so well as others; he had noticed that some certainly improved, especially in regard to frilling. Mr. Alex. Mathison considered that the deterioration in plates was certainly established in regard to some makes. He thought the defect arose chiefly through improper packing, or from being packed before thorough desiccation. The Chairman fancied the discussion had not thrown all the possible light on what was evidently a dark subject, but con sidered that much must depend on the store-rooms, the presence of gases from combustion, or sewage, and it was very important that these deleterious influences should be absolutely prevented from affecting the plates, by excluding them from apartments in which plates are stored, Another question was concerning the simplest means for producing photo-micrographs. This elicited a discussion, which eventually terminated in Messrs. Forgan and Mathison under taking to bring the matter forward at the next ordinary meeting, by which time they hoped to prepare specimens, and demonstrate their mode of work. Mr. Crooke exhibited some interesting lantern transparencies, which were much admired. The first out-door meeting for the season was held on Friday, 6th April, at Falkland, a small town twenty-five miles north of Edinburgh. The weather was exceptionally fine. Luncheon was hastily partaken of at the hotel, where a fine view of the old palace could be obtained, and the light being just about right, no time was lost in bringing a battery of cameras, such as the old place had never seen before, to bear on this the principal subject for the day ; and a very fine subject it is, both as a picture, and likewise for its many associations with events recorded in Scottish history. The old structure is a mixture of Gothic, Baronial, and Palladian architecture, which makes it of much interest to the antiquarian as well as the photographer, and it is remarked by architects how admirably the various styles are made to harmonize. A goodly number of plates having been exposed from different positions, the party resolved to visit Falkland House, it being a fine modern structure. Only a few plates were exposed, but a number of beautiful peacocks tempted one of the youngest members to try a couple of plates on them. A fine dell and waterfall were next visited, but the light being dead against the subject, the members, with two exceptions, reserved their plates for some of the quaint old thatched houses which still survive in this district. About four o’clock the members met at the hotel, where tea was quickly despatched, to allow of a plate to be exposed on the interior of the palace before the conveyance started to catch the 5.30 train for Edinburgh. It is needless to say every one was greatly pleased with the day’s outing. Newcastle-on-Tyne and Northern Counties’ PHOTOGRAPHIC Association. The ordinary monthly meeting of this Association was held in the Patents Room of the Literary and Philosophical Society’s Institute, on Tuesday, the 10th instant, Colonel SMEPPEE, President, in the chair. The minutes of the last ordinary meeting having been con firmed, Mr. James Edwards was nominated for membership, and Mr. Gibson was elected a member of the Association. The Secretary stated, in reply to a question by Mr. Galloway, that the presentation prints were expected daily. Some excellent photographs were presented to the Association by Mr. Galloway, and the Chairman proposed a vote of thanks to that gentleman, which was carried. The meeting then adjourned to the adjoining lecture theatre of the Institute, when the Rev. T. F. Hardwich, M.A. (briefly introduced by the Chairman), read a communication « On the Lime Light ” (see page 245), before a numerous audience. The paper was received with many marks of interest and approval. At its conclusion,— The Chairman moved a hearty vote of thanks to the lecturer, which was accorded with acclamation. He (the Chairman) invited discussion, and no remarks being made by the audience,— The Rev. F. F. Hardwich said he had received two or three notes from friends at a distance, from which the following are extracts :— From E. G. IFood:—It would ill become me to take exception to your observations about the precise angle of incidence that will give the best results. I am quite sure that, so far as present knowledge goes, there is room for a fairly-large difference in the details of such arrangements; and until we have found out the precise values of the shape and size of the chambers holding the gas to be employed, and the amount of velocity of the gas when in use, as well as the absolute effects of the shape and dimension of the aperture of the jet, I hardly prefer anything that approaches to an axiom. There is an aspect of the case that perhaps has not had sufficient attention—that is, the part that the velocity of the gas at the point of ignition plays in the production of the light. Then there is the question as to tho bear ing of a larger or smaller area of ignition on the definition of tho picture, all other things being equal. It was the late Professor Daniell who first proposed to use concentric tubes for the jet. He was led to this, I believe, from the absolute perilousness of Dr. Clarke’s copper box containing the two gases compressed into it, and the unhandy and imperfect attempt to improve upon it by the water chamber and the asbestos and wire gauze. Edward Marmaduke
