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504 THE PHOTOGRAPHIC NEWS, [October 16, 1868 p. 57 in the sixth edition. It is our practice in writing for non chemical readers to deal with a subject as popularly as possible, avoiding technical terminology and the use of symbolical formul. Ignorance is pardonable where it is modest and confessed. It only becomes very contemptible when it is paraded and exulted in. OxONIENSIS.- In double printing there is constant necessity for the exercise of personal judgment and ingenuity', and these will grow with practice. There are often several modes of doing the same thing, but there are also certain recognized methods which are most simple and effective. In a landscape with a soft, tender dis tance forming the sky-line, it is a good plan to practically vignette the mask which covers the sky into the landscape by means of a little cotton wool. Where a spire, or a series of pinnacles, or simi lar objects cut sharp against the sky, if it be necessary to mask the sky, there is no better plan than painting on the varnished surface of the negative with lampblack or other suitable water colour, or black varnish, carefully following the outline of the ob ject. An ordinary roughly cut mask is then used, which does not come quite close to the spire, &c., but overlaps the painted portion. 2. Sunning down a sky, so as to produce a graduated tint, may be . done in several ways after the print has left the pressure-frame. A piece of board may be used to shade it, gradually uncovering in the degree required; or, the landscape portion being quite covered, a cylindrical roll of paper may be placed upon the sky in such a position that it partially protects the paper, and just allows sufficient light to produce a graduated tint to fall on the white sky. Where a spire or similar object projects into the sky, it may be disregarded in the process of sunning down; in this way the slightly increased depth of the top portion will not be apparent in the finished pic ture. 3. It is probable that large prints will be injured in a small syphon tub. The principle of such machines is very good, but it should be applied in vessels of suitable size for the prints. The plan of Mr. England’s machine is a good one for large prints. We described it a few months ago. There are several good washing machines to be bought; but there is nothing superior to constant change and draining by hand for those who only require a few prints, and take a personal interest in their excellence. 4. Baths often rapidly discolour again after the use of kaolin, because they arc often made slightly alkaline by some impurity in the kaolin. There is no serious harm in using a discoloured bath, so long as the tint acquired by the paper is removed by the hypo bath, which it commonly is. We prefer decolourizing the bath by the addition, with agitation, of a few drops of a strong solution of common salt, which, in forming a precipitate of chloride of silver, carries down colour and other contaminations. The use of one-eighth of alcohol in place of water in the nitrate bath often checks dis colouration. J. Carter Browne, M.A.—We are glad that you got rid of your troubles by returning to your old process. We fear that there is no developer which will give tones similar to those of Ferrier’s trans parencies on tannin or tannin and sugar plates. Gallic acid would not help you. The ordinary pyro and citric acid developer gene rally gives very good tones; but you may possibly get a colour more approaching to black by the use of tartaric acid in place of nitric acid. 2. The soft, somewhat hazily-defined effect of the print to which you refer is not in any way due to the printing pro cess, but entirely to the negative, which was probably purposely taken a little out of focus. 3. As almost any pigment you may choose may be employed in the tissue in Swan’s process, there can be no great difficulty in obtaining a suitable green to give the tint of foliage, if you wish it. Such a colour could only be used, of course, in close bits, in which no. sky is seen, as nothing would be more hideous than a tint of green in the sky. You might produce the tint by the additicn of some of the green pigments sold by artists’ colourmen, such as sap green, emerald green, malachite green, &c., or by the mixture of a blue and yellow pigment. 4. We should be glad to have a fuller description, for publication, of your printing-frame for transparencies. W. J. A. G.—Mr. Gordon prefers the iron development for his gum plates, as giving the best results and securing immunity from some troubles. The details of iron development were given by Mr. Gordon in our number for May 15th, p. 230 of the present volume. W. S.—Mr. Solomon, of Red Lion Square, is the agent for the sale of Hamecker’s dry collodion in this country. Quandary.—The term plain paper is used simply as a distinction from glazed or albuminized paper, and, for transferring collodion prints to any good smooth plain paper, whether photographic paper or not, will serve. The only advantage of using photographic paper is derived from the fact that it is of a more even, perfect texture generally than ordinary writing papers. 2. The glazed or enamelled papers for the purpose are prepared in France, but are, we believe, sold by most London dealers. We do not know the price. If we remember aright, we have seen it for sale at Mr. Hughes’s, in Oxford Street. 3. If albuminized paper be employed, it would not be necessary to gelatinize it, probably, but it would be necessary to have it without salt, which commercial samples are not; so you had better abandon the notion of using albuminized paper. 4. In referring to the dry method of transferring, we said the manipulations were similar to those used in enamelling, because we had often described the process. You will find details in our Year-Book for 1865, page 82. We may briefly state the plan thus: when the transparent print is toned and dried, coat it with a warm solution of gelatine, 1 ounce in 12 ounces of water. When this is set, moisten the paper for transfer, and bring it into contact with the gelatinized paper. When dry, a knife point is run round the edge, and the whole leaves the glass. We prefer the wet transfer as simpler and requiring less delay, and as also giving a little less gloss, which we prefer. 5. Yes; the gelatinized paper should be moistened with cold water. A Constant Reader of the News.—Both the lenses you name are very excellent, but we prefer that you distinguish as A. B. L.—A transparent trick, very common in the quarter you mime, which we understood before we received your letter. Thanks. Young Amateur.—In Mr. Bartholomew’s acetate of morphine process the plate is not washed after treating with the 1-grain morphine solution, but is simply drained and dried. 2. In Mr. Gordon’s gum process, the gum and sugar-candy solution is not washed off; the plate is simply drained after its application, and dried. 3. The choice must depend much on circumstances. The first is simplest, but it should only bo used for plates to be used within a few days. Plates by the latter will keep for months. 4. All good bromo-iodized collodions answer well. That you mention (Rouch's) will, we believe, bo found suitable. 5. A good developer for collodion positives on glass stands as follows : proto- sulphate of iron 15 grains, nitric acid 2 drops, glacial acetic acid 15 drops, water 1 ounce, alcohol quantum suf. 6. Dry plates are not well suited for the production of positives, but it is possible to produce tolerable results upon them. James Kerr.—You will find an article describing several methods of employing two prints to form one picture on page 544 of the Eighth Volume of the Photographic News, the number being that for November 11th, 1864. The process, with slight, modifica tions, has been repeatedly patented, but we do not think that any of the patents are in force. Actinic (Jersey).—The design and general proportions of your proposed studio are excellent. The only modification wo would suggest is the extension, if convenient, of the side light on the north side to ten feet. E. Sawyer.—We hope you will receive sufficient information to enable us to rectify the matter satisfactorily in our next. W will bear your request in mind. Gum Gallic Amateur.—Your communication arrived just as we were going to press, but shall have attention in our next. Although the handwriting and crest make our correspondent known to us, he should have enclosed his card in a letter making such an offer. Received : A series of Micro-photographs from the Surgeon-General of the United States army ; the Quarterly Journal of the Quekett Microscopical Club ; and a Portrait from Netterville Briggs. Com- munications from E. L. Wilson (Philadelphia), Diogenes, Major M. (Rajanporc), and several other Correspondents. *,* An Article on the Late Eclipse, “ Visits to Noteworthy Studios,” an Article fn >m Mr. Bovey, some Reviews, and several other Articles in type, are compelled to stand over from the pressure on our pages. Several Correspondents in our next. •hotograp)s Registere. Mr. C Mum by, London. Six Photographs of Robert E. Gay, Esq., M.R.C.S., Ac. Mr. J. Stuart, Glasgow, Photograph of David Macrae, Esq. Messrs. BEAUFoRO & Bruce, Nuns Island, Galway, Photograph of the late Father P. Daly. Mr. J. Collings, Cardiff, Ten Photographs of Ball-room and Cardiff Castle. Messrs. W. & D. Downey, Newcastle, One Photograph of Iler Majesty the Queen. Three Photographs of H.R II. the Duke of Edinburgh. One Photograph of Prince and Princess of Wa cs and Famiy Three Photographs of Right Hon. B. Disraeli. One Photograph of Dr. Norman McLeod. Mr. II. BIRLON, Bradford, Photograph of Mr. Chippendale. *,* All photographs forwarded to the Publisher for registration receive attention at once ; but the pressure on our space sometimes compels to defer the acknowledgment in this column. It should be born mind, therefore, that non-acknowledgment at once does not necess" ’ imply non-receipt or non-registration.
