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of linear perspective to a degree that is almost beyond the power of the pencil, not to speak of the difficulties with which a photographer has to contend in any departure from exact portraiture of nature. There are very strong objections, on the ground of truth, to any alteration of permanent natural features; besides which, such attempts generally result, at the best, in showing the distance as a set of perpendicular plains. The real remedy is to be sought in the use of atmospheric effects. Photographing objects under any degree of mist is accompanied with great difficulties; but, when the mist is slight enough, the effect is sometimes very pleasing. The processes by which painters procure their aerial perspective are often more mechanical than many of those used by accomplished photographers. One of the commonest ways of painting a distance in oils is, to work-in all the features of it as strongly as they would appear on the clearest day, or even more so, and then scumble or cover it with a thin, semi-transparent coat of the colour of the desired mist. The washing of skies and distances common amongst landscape painters is a similar mechanical process. Could not something of this kind be effected in photo graphy, either in retouching or printing? It would, no doubt, be hard for a photographer to sacrifice that per fection of detail wnich is the glory of his art; but the minuti, though veiled, need not be lost. FRENCH CORRESPONDENCE. Eosine Plates—M. LuGARDON’s Instantaneous Pictures— Drop-Shutter in Simple and Double Lenses—M. Carlo Relvas’ Developer—Photo-typographic Prints —M. Lisbonne’s Emulsion. Eosine Plales.—Having received from MM. Clayton and Tailfer some of their plates prepared with eosine, I have made some conclusive experiments with them, by exposing to the action of coloured rays, both in the camera and by contact. A Newton’s disc was reproduced by an ordinary gelatine plate, and one specially prepared simultaneously, and the results were totally different. In the first plate only three rings appear luminous, while the four others were of sombre tone. The luminous bands were violet, indigo, and blue. But the reproduction by the eosine plate showed not only these three luminous rings, but also the green and yellow, and the orange slightly. In short, the isochro matism was almost perfect, with the exception of the red. There seem to be a series of interesting studies to be worked out on these lines, and by the help of certain combinations of coloured screens, and preparations analogous to eosione, perhaps perfect isochromatism may result; that is to say, an exact reproduction of different colours according to their relative value and tone. Such experiments might, perhaps, command the attention of Mr. Sawyer, whose work on “ Photography in Relation to Colour ” I have read with interest. It may be argued that this is not a new discovery, but it must be confessed that MM. Clayton and Tailfer render good service to photographic art by experimenting on the various properties of eosine—properties not dis covered by them, but of which they were the first to recognise the nse. M. Lugardon's Instantaneous Pictures.—M. Lugardon, of Geneva, whose pictures of animals in motion we have spoken of in terms of high praise, has told us that he is very satis fied with the developing process of MM. Wild and Goerlitz, which permits the development to be prolonged to half-an- hour or longer, and gives greater detail than the other. This process consists in the introduction of the tincture of iodine, instead of bromide of potassium, into the oxalic liquid. One part of iodine is dissolved in 200 of alcohol to which 200 parts of water are afterwards added. From five to ten diops of this tincture are required for fifty c.c. of oxalic developer. The shutter employed by M. Lugardon is by Thury and Arney. It is composed of two slides, each having a circular opening, and working in opposite directions. The opening and closing, therefore, both take place at the centre of the lens. This shutter is fitted exactly in the place of the diaphragm, between the two lenses; it is set to work by pneumatic action. Its average rapidity is so of a second. Position oj Vie Drop-Shutter.—Apropos of shutters opening at the centre, it is interesting to note that the best position for them is: where the diaphragms are placed, in either single or double objectives. In the case of the simple drop-shutter, it never prevents all the reflected rays from penetrating the sensitive plate ; it only obscures them more or less as the opening is smaller or larger. In a word, the image may be seen entire on the ground glass while work ing the apparatus slowly. This action is not seen if the shutter occupies a place immediately behind or in front of the lens. M. C. Relva's Developer.—M. Carlo Relvas, the eminent Portuguese amateur, indicates his method of development as follows :—Ho begins with an old ferrous-oxalate bath, then puts the plates in a new bath, and finally returns to the old. By this means he says that he obtains much more vigour, and the development is better graduated. Photo-Typographic Prints.—M. Rousselon continues his researches in photo-typography by his special process. I have seen some very fine results, only one wonders how such typographic blocks will print, unless satin paper, or paper printed on one side only, be used, although in this matter we are able to state that considerable progress has been made. Herr Meisenbach, of Munich, has produced some excellent prints by a process similar to that of Mr. Ives, of New York, but the results are better and clearer. The use of tinted paper is very ingenious. These blocks are easier to print than M. Rousselon’s, but the latter have the advantage of showing no streaks. Photo-typography is in a very good state for further improvement. Leon Vidal. APPARATUS FOR PRINTING BY THE BLUE PROCESS. BY CHANNING WHITAKER.* An Inexpensive Drying Case for Use in Coating the Paper.— When the apparatus is in continuous use, time may be saved by having a convenient arrangement for drying the sheets that have been coated with the sensitizing liquid. I have made an inex pensive drying case, which serves the purpose very well. It con sists simply of a light-tight rectangular case of drawers. There are twenty-five drawers in all. They are constructed in an in expensive manner, and are the only parts of the case that are worth describing. They are very shallow, being but 12 inches deep, and as it appeared that the principal expense would be for the materials of which the bottoms of the drawers should becom- posed, it was decided to make the bottoms of cotton cloth. This cloth is stretched upon a frame, the dimensions of which are greater than that of the paper to be dried. The stock of which the frame is made of is pine, J 4 inches wide, and three- eighths of an inch thick. The corners are simply mitred together and attached to each other by means of the wire staples that are commonly used for fastening together pages of manu script, and which are called “ novelty staples.” Eight staples are used at each mitre, four above and four below the joint. Two of the staples, at the top and near the ends of the joint, are set square across it, and two others, at the top and near the middle of the joint, are placed diagonally across it. The staples at the bottom are similarly placed. The joint is quite firm and strong, and is likely to hold for an indefinite period with fair usage. The cloth, stretched upon the frame, is fastened to it by means of similar staples. A dark-coloured cloth not transparent to light is to be preferred. A strip of pine, 144 inches wide, and three-eighths of an inch thick, forms the vertical front of the drawer, and prevents the admission of much light from the front while the sheet is drying. Two triangular knee-pieces, three- quarters of an inch thick, serve to connect the front board with the frame, and four small screws with a few brads are used in attaching them. The lower edge of the front board drops one- ’ Continued from page 349.