268. Several years since I published a simple and effectual method of cleaning the prints of hyposulphite of soda by employing the acetate or nitrate of lead; whether this process would leave the prints in a condition that would secure greater permanency was a question which time only could determine. I think the verdict, without a single exception, from those who have given it a trial, has been in its favor.
I have kept prints treated with the lead about six years, and some of them have been exposed for eight or ten months at a time to the direct action of sunlight, and yet show no perceptible change, while prints made at the same time and treated the same in all respects, except the washing, which was of the ordinary kind, have become yellow and faded. The process is as follows: Make a stock solution of the salts of lead, before mentioned, by dissolving two ounces in sixteen ounces of water. If nitrate of lead is used, the water had better be hot, as it dissolves very slowly in cold water. When the prints are fixed, wash them off in two or three changes of water, and place them in water containing two ounces of stock solution to every four quarts of water; they need remain in this lead - water only from five to ten minutes, and then they should again be washed in a few changes of water wringer frequently between the operations. The last application of the water should remove all spots and specks from the surface of the pictures previous to their being mounted upon the cards intended for them. Allowing the prints to remain in "lead-water" a few moments is highly recommended.
264. After the final and thorough washing of the prints, they must be taken from the water, and unless, as some prefer, they are mounted upon the cards wet, they are then dried. One way is to hang them back to back upon a rack provided with cords, as shown in Fig. 64. If this method is practised, the cords should be frequently changed, lest, becoming stained, they injure the prints. The best method is to place the wet prints between chemically pure white blotting-pads, and there allow them to remain until dry. These blotting-pads, too, must be occasionally renewed. The " Treasury " blotter is the purest and best.
and the work is completed, and, by applying the most delicate tests, no trace of hypo will be found. When the lead solution is put into the water to receive the prints, there will be produced a trace of carbonate of lead, which will give the water a milky appearance. If the prints are put into it in this condition, the albumen surface will be injured by the carbonate adhering to it. The carbonate should therefore be dissolved before the prints are put into it, which is done by adding a little acetic acid, just sufficient to make the water clear. - H. J. Newton.
The principal use of this room is to sensitize the paper after it is albumenized, or, in the case of the plain paper, after it is salted, and then later in the day, when the sensitizing is through with, to tone and fix as well as to wash the prints in, all of which things can be done without at all interfering with each other. A is a dark curtain, which in the figure is partly raised, but during the silvering and toning process it is brought down to a , and the white bleached cloth screen, b (which is shaded in the figure so as to show it more distinctly), covers the rest of the glass, and thus in the toning a soft and diffused light is given to that part of the room (the shelf, c,) where the toning is done; v is the silvering-dish, and D is the place where this silvering-dish is kept when not in use; E is where the kettle of potash is kept for the purpose of cleaning old plates; v is where the nitric acid tray is kept; G G are two sinks; H is a shelf on which the toning - bottles may be kept; K is a rack with three overlapping pieces of wood, to which there are a number of spring clips attached, which hold the pictures while draining as they are removed from the water; L is a washing - tank which has a perforated false bottom, through which the water panes into the lower part, and thence Into the waste - pipe . The stop - cock, M, is adjusted after the tank becomes three - quarters filled, so that it will permit the water to flow out as fast as it enters through the pipe, n; p p is an overflow pipe which conducts the water, when it reaches that place, into the waste-pipe, L; R is the place where the hypo - dish is kept; S is the place where the two - gallon hypo - bottle is placed. This bottle is always kept full of a saturated solution of hyposulphite of soda. V is the door that leads into the drying-room. - C. W. Hearn, in the Practical Printer.
265. The same general rules daptod to printing are also applicable to landscape printing,except that in the latter ease clouds are sometimes "printed in "or worked upon the negatives. Upon the subject of stereoscopic printing, however, a few notes will not be out of place, both as to the preparation of the negative for printing and for printing the same. Some " Centennial" experience will now come in well, hut another shall tell of it.
In answer to the question in the Philadelphia Photographer, What is the best way to wash prints when the water supply is small ? My plan is to use Newton's acetate of lead bath, and having used it over a year, I can say it is a great saving of time and of water, besides the prints have a greater gloss than with the old method of long washing; and as V their keeping qualities, so far I think they have done well. The prints will last in direct sunlight longer than those washed by the old method. - W. H. Kibbe..
265. No eyes, however good their capacities for seeing, can at a glance gauge the separate sides of a stereo. It was obviously necessary to place guide marks upon the negatives. These had to be most carefully adjusted, otherwise the effect of relief would be marred, and the complaint would come from the office that prints from negative number were not stereoscopic when looked at through an instrument The method of placing those register lines was for awhile a serious difficulty. A number of different plans were adopted from time to time. Ours was to make use of an ordinary retouching-stand. Upon the ground - glass inclosed by it draw a few lines as shown by the diagram Place one side of the stereo, negative on the ground-glass, over the indicated shape, and adjust it to suit the requirements of the subject You will see that there is a perpendicular line. Note with the utmost exactness where that mark intersects the first half of your negative. Then slide your plate across the frame, and make the same perpendicular pass through exactly the same points on the other side. The establishment of a base line is the first item to be attended to. Make use of any sharp instrument, and with it scratch a line across the bottom of your negative, being careful to make the line pass through the same points that an indicated on each side. After having arranged your negative over the shape, paste a piece or rather a strip of yellow paper along the edge that is marked 2. After moving the negative across the retouching-14