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JUIY 31, 1885.J THE PHOTOGRAPHIC NEWS. 493 upon the very strong—equal parts of hypo and water—neither was there any slowing of action, or at all events not any of con sequence, seeing that the plates were fixed in twenty seconds, whilst in the weaker baths considerably longer time was required. The most remarkable effect, however, was shown with the plates containing iodide. These fixed in the strong baths as rapidly as in the pure bromide—i.e., ia twenty seconds —but in the 1 to 5 bath required three minutes instead of the forty seconds which the bromide plate took, and in the 1 to 10 bath occupied eight minutes in fixation against the ninety seconds taken by the bromide plate. With plates containing, as has often been re commended, more iodide than those used, the time of fixation in the weaker bath would doubtless be proportionately pro longed. When it is considered that the strength of the hypo bath is continually being reduced—that is, where many negatives are taken—by the water carried into it with each developed plate, and that photographers are but little likely to use baths of really saturated solution of hypo, it seems to be regretted that they should be advised to use weak baths which will constantly be getting weaker. It is generally admitted, too, that plates for perfect fixition should be left for some time longer in the hypo than is necessary for visible fixation, and therefore, unless the fixing agent works with fair rapidity, plates are liable to deteriorate in time, or at once if intensification be attempted, from imperfect fixation. One pound of hypo to a pint of water makes a solution that fixes rapidly, and will bear some use before becoming too dilute. If it is only intended to fix a few plates, a quart of water may be used instead of a pint. I have since repeated these experiments with eight other makes of plates, including some of the best known commercial ones, and although the time of fixing differed in nearly all the samples, and with some was notably slower in the absolutely saturated solution than in a merely strong one, yet in every instance the strong solutions—equal parts of hypo and water, or one of hypo to two of water—fixed more rapidly than those of less strength. RECTILINEAR PHOTOGRAPHS BY DISTORTING LENSES. Tins would seem at first sight to be an anomaly. Notwithstand ing this, it is not only capable of being done, but done without entailing much trouble. When a single landscape lens is employed in producing a view exceeding a very moderate angle, no defect whatever is appreci able, provided the subject be one in which there arc no square marks or straight lines near the margin, as such would be re presented with a greater or less amount of curvature. For land scapes or groups such single lenses, therefore, answer quite well. While we would hesitate to say that for the former purpose they are superior to any of the best compound lenses introduced for this purpose, we do not doubt they are at least equal to them. Except in the sole matter of curvature of marginal lines when overworked (by which we mean the including of too great an angle of view), the single lenses leave nothing to be desired. They work clean and with brilliancy, define well with a moderately large diaphragm, and give images sharp to the corners. When an architectural view, a map, or a chart, has been made or copied by a lens of this class, and the curvature or distortion is such as to be observable, the way to eliminate all error is to make a transparency from the negative by means of a camera with a single lens, by which an amount of distortion equalling that in the previous case is produced, the resulting photograph being absolutely rectilinear. With a transparency quite perfect as regards drawing, there is no difficulty in producing, by superposition, a negative from which all error shall bo eliminated. It stands to reason that if distortion of a certain nature be pro duced by the use of a single lens having a diaphragm in front, distortion of an opposite nature will result from the employment of a disphragm behind the lens, ft follows, therefore, that if a view which has been distorted be returned through the lens by which it was so treated, it will, when arrested by the focussing screen, be found to be practically free from all d stortion. This principle is a simple one, but it is not quite so well recog nized as it ought to be. What is of importance to the photographer to know is this, that no matter how imperfect his photographic negative may be as regards curvilinear distortion, it can be cured, and that in a perfect manner,—Photographic Times, SHAM AMATEUR PHOTOGRAPHERS IN THE UNITED STATES Decide that it is Not RIGIT to Proeit upon Professional Courtesies. On account of two or three of the members of the Amateur Photographers’ Association having gone into the business of making pictures for sale, the question came up last evening, at a meeting of the Association, as to whether this is honorable, in view of the courtesies extended to members by professional photographers of this city. After some plain talk, the Association decided that its members cannot, under the circumstances, honourably engage in making and selling photographs. But, as a compromise, it was finally agreed that members of the Association shall not make and sell pictures at prices below the schedule adopted by professionals. A majority of the members are of the opinion that when members enter into the manufacture and sale of pictures, they become professionals, and are no longer entitled to the courtesies usually extended to purely amateurs by professionals. In other words, the ‘‘ gall ” that is necessary to pretend to be an amateur for the purpose of deadheading points from professionals is more than the Association can stand without violent contortions in the abdominal region. The Association does not pretend to say that one or more of its members shall not retire and sell photographs on their own account; but that while favours are being extended to the Association, as such, by professionals, it is not honourable for individual members to take advantage of this for pecuniary profit. One of the members, who holds a high position in the public schools, Mr. W. 8. Goodnough, is reported as having pictures on sale, with a business card attached, giving the name and number of his residence, or place of picture-making business. —Columbus {Ohio} Dispatch, quoted in the St. Donis Photo grapher. —o- Uorrespondnce. PAPER NEGATIVES. Sir,—Seeing that my friend, Mr. Holroyd, has again taken up this subject, I venture to suggest to him and my fellow amateur photographers a more simple plan of pro ceeding than his, of gluing the argentic gelatine paper to a metal or veneer suppoit for exposing in the slide. In using paper, I have always had a glass in front, and, pro vided the inner surface of it agrees with the focussing screen, it answers every purpose, and does not interfere with the sharpness of the picture. Until the dry plates were introduced, I never used any. thing but paper, either the calotype, or various modifica tions of the wax paper process. Three prints from nega tives after Le Gray’s process are now in the historic section of the Inventions Exhibition, taken in 1861 or 1862. As I took up photography in ’45, I have bad rather longer experience in this particular than even such an enthusiast in "the art as Mr. Holroyd is. What is so material to success in the use of paper for negatives is to obtain that with the least possible grain ; but the principal drawback I have found to the commercial gelatino-bromide paper, is the unevenness of the coating, some samples being full of pinholes and comets; some are liable to blister after development, both of English and French make ; it is not quite so rapid as plates, but sufficiently so for ordinary work. My plan of proceeding is to get the paper in rolls, and cut it to the siz s wanted, and to use as a holder what most photographers have by them—a single slide, easily converted for a few pieces of paper by putting a glass in it for the front. 1 had one made specially four or live years ago, and have used it ever since. It holds, besides the glass front, eighteen or twenty pieces of paper, and two pieces of card, one thicker than the other ; the thinner I plice at the back of the first piece of paper against the glass, which separates it from the store behind, and prevents any light striking through ; at the back of