It sometimes happens that one is so unfortunate as to break a valuable negative. If the glass is broken, but the film uninjured, the film may be removed, and transferred to another glass with very little trouble. (Directions for this process were given in No. 856 of the Round Table.) If the film as well as the glass is broken, there is no way of restoring the negative, but a new negative may be made from an unmounted print.
The printing-frame must be fitted with a plain glass, free from defects. Lay the print on the glass face up, and place over it a slow plate—a plate about the sensitomer of the Carbutt "B" gives the best results. If the print is of average density, expose to an ordinary gas-flame or lamp-light for five seconds. A little longer time must be given to a strong print, and a little less to a weak print. Develop the same as any negative properly timed, starting with a slow developer.
In case one has only mounted prints, remove the print from the card by soaking in warm water till it can be easily stripped off from the mount. Lay the print face down on a sheet of glass, and sponge carefully to remove all particles of paste. Sometimes the print requires soaking after it has been removed from the mount if the paste used was very adhesive. After the print is cleaned, dry on a ferrotype plate free from scratches. Old albumen prints make fine negatives, as the paper gives deeper prints. It is always a good plan to make a paper negative from fine plates, so that if a negative is accidentally destroyed one has still a good substitute.
Sir Knight Russell Senior, who is much interested in the formulas for tinted papers and transparencies, sends the following process for changing blue prints to brown:
"After washing and drying as usual, immerse the print in a solution made of strong ammonia water, 1 oz., water, 8 oz. Leave the print in this solution till it has lost its blue color, which will take from three to five minutes; then rinse and place in a solution of water, 6 oz., tannic acid, 1 dram. (This must be filtered before using.) The print must remain in this solution till the required sharpness and tone are obtained, which will take from ten to fifteen minutes. If the color is not dark enough at the end of fifteen minutes, add a few drops of ammonia; leave in two minutes longer, and wash."
Our members will probably like to try this formula, and very soft tones of brown may be obtained if the directions are carefully followed.
Sir Knight Frank F. Smith, P.O. Box 236, Cumberland, Md., one of the prize-winners in our recent contest, says that any of the other prize-winners who wish a copy of his prize picture may have it by sending a copy of his or her own picture that also took a prize, and that any members of the Camera Club who would like a photo-etching of the picture may have it by sending two-cent stamp for postage. Sir Knight Frank would like to exchange photographs with each of the prize winners.
Sir Knight J. M. Corey asks how to transfer the film on a photograph to glass, and how a drop-shutter is made. The best way of transferring film to glass is to use the transferrotype paper for prints, and then transfer according to directions given in No. 840 of the Round Table. Directions for a drop-shutter could not be given without illustrating with diagrams, and our space does not allow of illustrations.
"New Patron," Nova Scotia, asks for a formula for a flash-light powder. Why not use the pure magnesia? It makes a strong actinic light, and if burned on metal is comparatively harmless, but when combined with other compounds is sometimes dangerously explosive, and requires great care in handling. In regard to mixing the solutions without hydrometer, the simplest way would be to use the rule for ten-per-cent. solutions—one ounce of the chemical and nine ounces of water. A twenty-per-cent. solution would be two ounces, Troy measure, and eight ounces of water. A thirty-per-cent. solution would be three ounces, Troy measure, and seven ounces of water.
Sir Knight F. T. Watson asks how to make solio and aristo paper; what is litmus paper, filtering paper, and distilled water; how many sheets 4 by 5 blue prints can be made with formula given in No. 797; if the formula given for glycin developer is good for pocket Kodak; wishes a formula for combined toning and fixing bath; and what is a ferrotype plate, and for what it is used. Do not attempt to make either solio or aristo paper; it is much more expensive than to buy the ready-prepared paper. Formulas for toning both in one and two solutions are enclosed in each package. Litmus paper is unsized white paper steeped in a solution of litmus and dried in the air. It is used to test solutions, the red litmus paper for alkalies, and blue litmus paper for acids. Filtering paper is unsized porous paper, and is used to filter or strain solutions to remove any impurities which they may hold. Distilled water is water evaporated by boiling, and again collected and condensed by means of a still. In making up solutions where one cannot get distilled water, water which has been filtered will often serve as well as distilled water. A ferrotype plate is a thin iron plate highly varnished. It is used by amateurs to dry aristo prints. The prints are squeegeed to the plate, and when dry have a high polish. The glycin developer works well for films, but is rather slow. Metol-quinol is better, and more easily managed. Three or four dozen sheets of paper may be sensitized with the blue-print formula.