BLEACHING ENGRAVINGS FOR PHOTOGRAPHIC

REPRODUCTION.

Engravings are often received for copying and reproduction. They may be steel, copper, wood, and even lithographs. If they are old and usually they are, the pictures are likely to be soiled and the ground (paper) which originally was white, yellow. This makes it difficult to make a satisfactory negative unless we can, more or less, restore the picture to something like its original condition. Some of the methods which have been suggested for cleaning often do more harm than good, for instance strongly acidified water and light petroleums. These have the tendency to attack both the paper and the ink. A safer way is to bleach the picture with chlorine water. This can easily be prepared by taking a large wide mouth bottle and filling it about three-quarters with soft or distilled water, then adding a quantity of good chloride of lime and shaking well for some time. After allowing the bottle to rest for a while the lime will settle to the bottom. The supernatant liquid, the chlorine water, is then carefully poured out into a large tray, which preferably should not be of metal. The print is now immersed and must be kept under the surface of the liquid. The treatment may take several hours, or until the paper has become clean and white. The print while wet with the chlorine water should be kept from contact with the air as much as possible. The print is then transferred to a second tray and washed in a number of changes of water, then removed and the superfluous moisture removed with clean white blotting paper. It is now treated with common vinegar which causes the print to become brilliant by acting upon the ink. After treating with vinegar the print is placed in water 100 parts, ammonium hydroxide 30

parts. This prevents the mold fungi from recurring. The print is again placed between clean white blotting paper and placed under some pressure until nearly dry. It is now removed and placed between two sheets of smooth paper and run through a burnisher to remove roughness caused by the solutions. Engravings so treated yield good black and white negatives. Should the prints have rust spots, these must be removed before treating with chlorine water as this will not remove them. A solution of citric acid is applied to the back of the picture by means of a small brush, and this continued until the spots have disappeared. The spots are then touched with cotton wet with ammonium hydroxide, which prevents their return. -Deutsche Photographen Zeitung, Vol. 32, No. 14.

BORIC ACID IN DIAMIDOPHENOL DEVELOPER.
BY DR. R. NAMIAS.

For some years I have recommended the addition of boric acid to alkaline developers to correct over-exposure. A 10% postassium bromide solution containing boric acid to saturation is of particular value to have on hand in the darkroom when dealing with over-exposure. Many have adopted this mixture which I call bromo-boric acid and Dr. Dilay found it very useful in the development of bromide prints. In my exhaustive tests on the application of boric acid to various developers I proved that in such solutions which act only in the presence of alkalies that the boric acid had a different action from those which develop without this addition. In the alkaline solutions the boric acid possesses a considerable retarding action on the development. On the other hand a diamidophenol developer made according to the usual formula without potassium bromide can be

saturated with boric acid without influenc

ing it noticeably. The appearance of the image is retarded very little and in the case of over-exposure there is practically no action. One advantage is that a diamidophenol developer containing 50.0 gms. (13 ozs.) of boric acid per liter (33 ozs.) possesses much better keeping qualities than one without this addition so that it is not nccessary to prepare the solution every time it is to be used. A solution so prepared is also less sensitive to a difference of temperature even at 25°C. (77°F.) it caused no difficulty. I noticed that potassium bromide possessed only a limited retarding action in a diamidophenol developer and even the addition of large quantities of potassium bromide is not capable of correcting to any degree errors in exposure (see also PHOTOGRAPHIC TIMES, page 428, 1909). One might be led to add an alkaline bisulphite in order to make possible corrections, but bisulphite posse ses the disadvantage of weakening the reducing power of amidol and if a certain limit is exceeded only a little the development will be suppressed. Amidol which in itself possesses the power of producing weak images in the presence of bisulphite gives even less density and as Lumière and Seyewetz recently proved that the time of development is only lengthened without increasing the contrasts to any degree. In regard to the preservation of the developing solution the small amount of bisulphite permissible has but little influence. The exclusive addition of boric acid to diamidophenol solution does not have the drawbacks of bisulphite, it does not lessen its reducing power and preserves the solution almost as well as bisulphite and a smaller quantity may be added. Boric acid as I have mentioned before retards the development very little and besides the increased keeping qualities of the solution, the solution possesses also the important property of being more sensitive to potassium bromide so that considerable over

Metric. 1000 C.C. 40.0 gms. 50.0 gms.

13 ozs. Sodium sulphite, cryst 123 ozs. Boric acid, powdered 75 grains Diamidophenol chloride 5.0 gms. For an example I will give the time of development of four negatives having the same exposure with:

First, developed in ordinary diamidophenol of the above composition but without boric acid, five to six minutes; second, the same developer, but with the addition of 3.0 gms. (45 grains) of potassium bromide per liter (33 ozs.) of developer, eight to nine minutes; third, developed with the boric acid developer given above, six to seven minutes; fourth, the same boric acid developer containing 3.0 gms. (45 grains) of potassium bromide per liter (33 ozs) of developer, seventeen to twenty minutes.

The density was the same in all cases but the contrast with No. 4 solution was greater than with the others. Another advantage of a developer containing considerable amounts of boric acid is its hygienic properties. The skin of some persons is easily irritated by certain developers, producing ulcers, but a solution of this kind will prevent such disagreeable action. -Das Atelier des Photographen, Vol. 16, No. 10.

The usual method for making a reversed negative requires a glass positive and from this the negative is made. A much simpler and quicker way is to expose a plate in the printing frame in contact with the negative in bright sunlight for several seconds. This of course greatly over-exposes the plate but the result is a negative and not an over-exposed positive as one might be led to think. It is said that a good negative is obtained in this way.

-Photographische Welt, Vol. 22, No. 9.

METHOD OF FIXING A METAL TOP TRIPOD.-My method of fixing a metal top tripod so that it will not mar the camera bottom or allow it to become brassy from a brass tripod top. First procure a piece of felt and also a sheet of rubber packing such as used by engineers for packing cylinder heads. Take a compass and draw a circle on the rubber and one on the felt the size of the tripod top. Cut out with a sharp knife or shears and placing the rubber on first and the felt on top of the rubber, fasten by running a needle and thread through the felt and a hole in the tripod top and bring the two ends together and tie. The felt and rubber should be fastened in three places. Also make a hole in the felt and rubber for the tripod screw. Also if the felt is not thick enough use several thicknesses.

B.-Wishing to take a picture one day and not having any film on hand I took my No. 3 Folding Brownie (34 x 44) in the darkroom and loaded it with a 32 X 31⁄2 in. dry plate. The emulsion side towards the lens. This method will help you out more than once. Also you can use this method when, you have only one picture to take as in film you have to take six pictures before you can develop. The two springs in the camera back hold the plate in place.

WALTER J. ORBISON.

Chemicals dissolve quicker and better in hot water, especially during the cold weather. I find that it is much quicker and more convenient when making a large quantity of developer to mix a concentrated solution in a thirty-two ounce graduate of hot water and pour the proper proportion into the sixteen or thirty-two ounce bottles which have previously been partially filled with

pure water. After the concentrated solution has been measured into the bottles they are filled to the stopper with pure water, making the solution normal strength. Metol-hydrochinon and straight hydrochinon solutions will keep a long time in bottles which are filled to the stopper.

I used to pour the hot solution into the empty bottles and then filled them with cold water but after breaking two or three of my nice large bottles I learned to partially fill the bottles with water before pouring the hot solution into them, obviating such a sudden change of temperature in the glass as a large proportion of the heat is taken up by the cold water.

A. A. COULT.

TRANSLUCOGRAPHS.-The scientific and ra- . tional proceeding to develop any pigment print, on a basis of gelatine, gum, starch, or any such vehicle, is to dissolve away the light-hidden portions of the pigment from the opposite side to that which came in contact with the negative. From the earliest attempts in pigment printing up to this very day inventors have essayed to evade this necessary. The “evasion” processes are most numerous; sawdust, brush, and other means of abrasion being used to wear down the insoluble thickness covering the image. In the earliest attempts the difficulty was overcome by using a translucent substance to support the pigment and then printing from the back of the film; in this way the picture "washed-up" directly it was placed in warm water. The present writer has been using a modification of this process to produce, rapidly and cheaply, prints in which fuzziness is not an objection. This consists of brushing bichromated gum over a sheet of tracing paper and simultaneously working into it any hue of dry pigment just as procured at the painters' ware

houses. To hasten the drying methylated spirit is added to the mix-up. Dried in obscurity and printed, plain-paper side against the negative or tracing plan or print to be copied, the image will wash-up directly it is placed in cold or tepid water. For line drawing copies it is a cheap process, and for very large negatives it serves to make a permanent print having a certain grain but to which those who print their negatives through bolting cloth will certainly find no objection. The image is greatly improved if gelatine is used instead of gum. The image is always reversed. If gum is used and the print immersed in alum the image will disappear. The utility of the process is its cheapness for large surfaces.

For small prints those rolls of wasted films, or cut films, familiar to all workers, are cleaned and coated with pigmented, bichromated gelatine, or gum; dried, printed on the uncolored side and then most easily developed. Note well that even the thinnest celluloid or gelatine film that was ever produced, being printed through to the pigmented coating, always causes a loss of sharpness in the resulting print or transparency. Even with a good thick gelatine coating the image is never equal to transferred carbon prints; but this "soft" effect is often deliberately sought by a complicated process of diffusion in lenses, in focusing, in "dodged" printing, etc., whereas in this translucent printing process it is arrived at automatically.

The process is also useful for multichrome printing, by outlining on the transparent support the principal objects on the negative and then painting on the support in various gum or gelatine colors the corresponding pools within the sketched outlines. This is reapplied in correct register on the negative and printed. The process has one notable inconvenience-that is, some of the colors containing blue will print nearly twice as fast as those containing yellow and red. To avoid this, colors of near about the same actinic value should be chosen. In some cases the great opacity of the parts representing blue-as the sky-on negatives, corrects this over

printing of the blue. With a dense "sky" the blue portion would otherwise be unaffected and then appear as white. But if the same blue color is applied to water scenes, sea or lake, we get a cake of opaque blue, i.e., overprinted.

In the windows of Braun & Co., Avenue de l'Opéra, Paris-celebrated for their museum and art-gallery copies, there was shown, for many years, a very beautiful seascape in blue, brown, and white, the brown for the deepest shadows and the blue for the half tones. With translucographs a double coat of colors would realize this effect.

CHARLES R. KING.

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In mounting with dry mounting tissue it is usually difficult to keep small prints (34 x 4 and under), from shifting after the iron is placed thereon. To prevent this, have the paper used above the print, a couple of inches longer than the mount and tack one edge to the ironing board. The other edge can be held lightly by the left hand while the iron is being used by the right and can be raised to take out the picture and place another.

M. M. KNOWLES.

PEN AND INK DRAWINGS WITH A BLUE PRINT.-Make your blue print of any desired shade and then follow the lines with waterproof ink and allow it to thoroughly dry.

When it is dry immerse it in a strong solution of either potassium or sodium carbonate (I use 10 to 15 ounces of water), and then wash and dry and you have a pen and ink drawing. If you desire to make your own blue print paper, here is a good formula:

A. Green ammonio-citrate of iron 4 oz. Water

B. Potassium ferricyanide

Water

Mix equal quantities and brush on.

I OZ.

1/4 oz.

I OZ.

RALPH NEW MAN.

TORONTO CAMERA CLUB, TORONTO, CAN. The Nineteenth Annual Exhibition of the club will be held April 4th to 9th inclusive. Gold, silver, and bronze medals will be awarded to the three best prints. Prints must be received not later than March 22d. For further particulars address Hugh Neilson, Secretary-Treasurer.

CAMERA CLUB, NEW YORK.

The stated meeting of the club was held March 3rd. Mr. Harold M. Bennett gave a lecture entitled "A Little Journey through Japan," illustrated by colored lantern slides in the club room, March 11th. The ninth dinner of the club was held at the Hotel Brevoort, March 12th.

The exhibition of Miss Tracy and Mr. Wolf and twenty other members will remain on the wall until about April 1st.

The Print Committee announce a spring exhibition to begin April 9th. Prints for this exhibition must be delivered to Print Committee not later than March 31st.

GREATER MONTREAL CAMERA CLUB, MONTREAL. This club, organized only last month, starts out with enough members to assure its success. The club is open to those of either sex over eighteen years who wish to promote the interests of amateur photography and for social intercourse. Suitable rooms will be engaged and periodical lectures will be given. The officers are: President, R. Roeder; Vice-President, F. A. Dakin; Secretary, H. E. Allen; Treasurer, P. Longmire.

TOLEDO CAMERA CLUB, TOLEDO, OHIO. The annual report of the secretary of the Toledo Camera Club shows that the

activities of the club have been most marked and beneficial during the past year, with tangible results to show for their labors.

The plan of studying afield has been carried out more successfully than could have been hoped and much of our success and enthusiasm is due to this particular feature of the club.

During the year, we have had two lectures on timely subjects, have had the benefit of Mr. Stevens' knowledge in the way of criticism on prints submitted, as well as talks by him on art subjects.

We have had lantern slides from the St. Louis and Milwaukee clubs and have had our set of slides in these two cities.

We have had examples of our work shown in most of the big exhibitions of this country, namely: Jamestown, N. Y.; Wilkes-Barre, Pa.; Buffalo, N. Y.; have eight prints in the Sixth Salon, Montreal; eight prints revewed in the "Photograms of the year 1909," London; and work hung in the Dresden exhibition. The American Federation of Photographic Societies officers for 1909 were selected from our club and the Sixth Salon was assembled in the Toledo Museum of Art.

We have a healthy membership and our finances are in fine condition.

The following officers were selected for the ensuing year: President, J. F. Jones; Vice-President, W. A. Ward; Secretary, C. C. Taylor; Treasurer, M. W. Chapin ; on Membership, Frank Miller; print and exhibition, E. C. Brownson; general, G. W. Stevens.

The club's set of lantern slides will be loaned to any club wishing them, either with or without exchange, although we prefer to exchange. The usual rule of the club receiving slides to pay expressage both ways, we to do same. Address the secretary.