Edited by J. Traill Taylor
In a science like photography it is not easy to indicate with anything like definiteness the various stepping-stones by the aid of which progress from one year to another is achieved; for our art-science is insidious in its advances, and things which are at the time considered small frequently lead to results the importance of which cannot be adequately realised. There are, however, some steps which stand out in sufficient prominence to be worthy of notice, and among these the following may well be linked with the progressive results of the past year:-
In mechanics, a useful portable stand has been devised by Mr. Kennett. In this stand he has taken that of Sir Thomas Parkyns as a basis, and has to some extent simplified the latter by substituting sliding ferrules or runners for certain screws previously in use.
In cameras, one for dry plates, based upon one previously introduced by Mr. Aird, has been manufactured by M. Jonte, of Paris, and introduced into this country. In this apparatus the plate-box is situated below the camera, and by means of an ingenious appliance any plate can be brought up form the plate-box into the camera. Another camera, for working wet plates in the field, has been devised and patented by Mr. W. A. Brice. Some account of this will be found in our epitome of progress. A revolving dark slide was exhibited at a meeting of one of the photographic societies. It consisted of a disc of wood having apertures for plated so arranged that each of the latter could, in rotation, be brought opposite the lens of the camera. Its necessarily great bulk prevented it from finding favour with photographers.
The appliances in use in connection with the lime light have made a considerable advance during the year. With a view to the manufacture of oxygen just as it is wanted two separate pieces of apparatus have been invented, both of them being protected by patent. Mr. Birrell is the inventor of one of these, Mr. Young being that of the other. The former I have not seen, but it seems from the patent specification as if it would do all that was claimed for it. The apparatus of Mr. Young I have seen in action and have tested thoroughly, and hence can speak as to its efficiency from personal knowledge. It would seem as if the days of oxygen gas bags were drawing to a close.
A very ingenious and perfectly satisfactory method of making panoramas by the junction of several negatives has been devised and published by Mr. Leon Warnerke. Making use of a roller dark slide upon which is rolled a long web of sensitive tissue, Mr. Warnerke exposes the first part of the picture, then rotates the camera upon its stand and exposes to the second part of the picture a fresh portion of the tissue, the first having been wound out of the way; and son on with a third and even a fourth picture, if necessary. After exposure the pictures are all developed without separation, but after this they are divided and placed upon a plate of glass, the subject on the end of one negative exactly overlapping that on the other. By a sharp knife both are cut through and the loose ends of each pricked away. The ends are secured by a coating of collodion, and the continuity of the subjects is thus preserved.
To aid in the retouching of photographs with facility Messrs. Burrows and Colton have introduced a retouching-desk, which is replete with every appliance experience can dictate. It has a revolving stage, so constructed as to hold any size of plate, and, in addition has various fittings by which comfort is enhancedsuch as a powerful magnifier supported upon an arm, a reflector, a rotating plate of ground-glass discs for softening the light, a pencil-sharpener, a drawer, &c. This desk leaves the retoucher nothing more to desire.
The enameling or glazing of paper prints has received a slight impulse during the year by the publication of articles and manuals devoted to this branch. Retouching, too, owing to the same reason, has received more attention than usual.
In emulsion work Mr. Johnston has come to the front with an emulsion that contains a double salt of silver and ammonia. The value of this will be fully appreciated in the course of a few weeks, when the gloom of winter shall have given away to the pleasant smile of spring.
The suggestion concerning the preparation and use of an organic pyroxyline, published in our ALMANAC of last year by Mr. J. W. Gough, seems to have been fully appreciated. Organified pyroxyline is now one of the commercial productions of the present time.
Mr. M. Carey Lea has again bestowed a boon upon photographers by giving them a new collo-developer. This consists in the preparation of a solution of gelatine in dilute sulphuric acid, which yields a product (now popularly designated “collocine”) having restraining powers so great when added to the iron developer that one drop is more than sufficient to be added to three ounces of the developer. This restainer is now being extensively used all over the country.
Under the designation, “A New Method of Photography,” a mode of producing photographs in antimony was brought before the notice of the Photographic Society of Great Britain. The troublesome nature of the process of printing, the noxious character of the gas employed, and the very indifferent results obtained, all conduced to prevent this process for securing any adherents.
An important discovery has been made by Captain Abney, F.R.S., which is that if, when an image has become impressed upon a bromide emulsion film upon which only a feeble image would have been developed, a second coating of a dense-image emulsion be applied previous to the application of the developer, the resulting image will partake of the qualities of both films-the rapidity of the one and the intensity of the other. This discovery, which is as yet in its infancy, is likely to prove of great importance.