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246 the PHOTOGRAPHIC Hews. [APRIL 17, 1885. would rather impress upon those who prefer this formula, to confine each successive washing to the length of time mentioned. It is necessary, as in all washed emulsions, to extract some of the superfluous water, otherwise it would be found to lack body in coating ; and half an hour’s draining on a filter is sufficient to effect the purpose. The usual methods adopted for melting, filtering, coating, and drying, follow ; the details of which are too familiar to require repetition. A suitable oxalate emulsion to mix with the chloride spoken of at the commencement of this article may be formed as follows :— Gelatine 2 grammes in 30 c.c. of distilled water Potassium oxalate I „ 6 „ ,, Silver nitrate 2 „ 10 ,, „ Dissolve separately, and mix, then add to the chloride emulsion in the same proportion, and in a similar manner to that recommended in the case of the citrate. The method of washing differs in no way from that already mentioned ; but previous to melting, half a gramme of citric acid dissolved in ten c.c. of water should be added. The compound emulsion with potassium oxalate is both white and slow, and is especially useful in making trans parencies for the lantern, enlarging, &c. Almost any colour may be obtained, from warm brown to black, pro vided sufficient toning be given. This operation, as previ ously stated, is not a rapid one ; still, it can be somewhat accelerated by the use of two baths, the first an ordinary borax, such as given in the Photographic News Pormu- lary, and the second either before or after fixing the thio cyanate toning bath given in page 43 of the current Year- Book. An especial feature in a compound emulsion is the facility afforded for printing negatives of a black-and- white character, for, as a rule, very much more harmonious results will be obtained by this means than in any other way. And it is remarkable to how far this effect may be carried in practice by a slight modification of the formula. Thus, by increasing the amount of haloid, and decreasing the proportion of acid, we obtain harmony; and by decreas ing the haloid and increasing the acid or organic compound, we obtain brilliancy—nay, hardness; in a word, a reliable formula is a necessity ; but having such, judicious modifi cations are allowable. THAT DREADFUL FOCUSSING CLOTH ! (A Moan of One who has Suffered). I cannot understand why the ingenuity of photographic apparatus makers has not yet devised an efficient substi tute for the focussing cloth. There is nothing more har- rassing in the whole range of a photographic outfit. Take it in its out-of-door aspect. If there is the least wind blowing, is it not the most tiresome thing to manage possible ? Hasn’t it got the habit of falling over the focus sing screen, after you have put the latter on the ground, and of hiding it, and you only find out what you’ve done when you’ve put your foot down and you hear a smash ? Have a camera with a folding screen, you say. Y es, that’s all very well, but suppose you haven’t got one? Besides, allow that you have a camera with a screen of this kind: hasn’t the focussing cloth been known to catch in some part of the camera, and when you drag it off you throw the whole arrangement out of balance, and you have to begin again? Nay, is it altogether out of knowledge that an attachment of this kind has more than once upset the camera and legs altogether? Take the appearance of the photographer out of doors, when his head is under the cloth. Doesn’t it give a horrible uncanny look, which makes him at once the object of ridicule to the unthinking and unscientific masses ? When his head is thus concealed, has not the ubiquitous boy a desire to meddle with his dark slide ? Hasn’t he been represented in comic journals times out of number, assaulted in the rear by innumerable bulls ? Not that 1 ever heard of a photographer in real life so troubled ; but it shows the weakness of the focussing cloth when it is thus pitched upon as the mark for the caricaturist. Out of doors bad, indoors the focussing cloth is worse. It ruffles the photographer’s hair, and towzles his beard. It forces him to wear skull, smoking, and other unhealthy head-coverings which bring on premature baldness, and impart a flashy aspect to his bearing which does not pro perly belong to him. If the weather is hot, putting one’s head under the focussing cloth is an abomination and a terror. If the focus sing cloth be too small, words cannot picture the irritation caused by straining one’s eyes, and the slipping of the tor menting piece of stuff at the very moment when you think you have focussed correctly, but are not quite sure. If it be too large, the perspiration pours down the face, and you emerge hot, flushed, and fatigued from the trial of sup porting its weight. Let the focussing cloth be mislaid, and you are crushed. In despair, you seize the first thing that comes to hand. You have a rush of sitters, and they must not be kept waiting while you hunt for the missing article. You rush wildly at the camera with some black calico which you dis cover thrust behind the fixed background. It is as thin as gauze, and on putting your head underneath, you find the daylight streaming through the interstices. Another dart at the store behind the background. Ah ! this is much thicker. You use it, focus, and re-appear with your eyes, mouth, and nose, filled with dust. The sitter smiles, and you don’t know why. You accidentally catch sight of your reflection in the mirror, and then you discover. The black calico has been used in some remote period to stop out light in the studio roof, and your perspiring face is well peppered with smuts. Eventually you find that the friend of the sitter has been sitting on the missing focus sing cloth all the time. It is very easy to say that one ought to have a studio dark at one end, and move about one’s screens to shut off the light, but what is a man to do if his studio refuses to be managed that way ? Besides, why shouldn’t we do away with the focussing cloth ? Has anybody any vested interest in a focussing-cloth ? Has a focussing-cloth any interest in itself ? Why then should it be held sacred? I read some time ago in an American paper, this:—“ Our Chicago amateurs are trying to do away with focussing cloths.” Now, what I want to know is, have they done away with them ? If not, why should not our English amateurs try their hands and abolish the hateful thing ? In this hope I live. FRENCH CORRESPONDENCE. Gelatino-Chloride of Silver PAPER—PHOTO-TRACING Process — Phototypes — Gelatine Plate-Makino Machine. Morgan’s Gelatino-Chloride of Silver Paper.—The process of obtaining positive prints by developing takes a long time in becoming popular. Photographers are slow in adopting new methods requiring learning on their part. The firm of Morgan and Co. have, however, facilitated matters by offering an excellent gelatino-chloride of silver paper. I have been trying it, and with complete success, not without hesitating the first three or four times as to either the length of exposure, or the right time at which to stop developing. But the thing is so speedily ac complished ; and what great advantages Buch a process offers by allowing of printing at any time, day or night under absolutely regular conditions I It is easy to obtain a light of practically equal luminosity after making a trial beforehand to find out the requisite length of exposure, and placing the paper always at the same distance away- It is better to under-expose rather than over, as in tn