EX CATHEDRA: Organic Intensifiers; The Donalty of Negative; Glass for the Studio; Defects in Sketch.

Organic Intensifiers.

         Many as are the processes which have been evolved by the ingenuity of the chemical experimenter, it cannot be said that we yet have a perfect process of intensification, speedy in use, performed in one operation, and thus capable of being stopped at the required stage and permanent in the results Hitherto, with one exception, all intensifies have been based upon the use of mineral or inorganic compounds, such as the metallic salts which exert an oxidizing action upon the silver deposit, and thus, in one way or another, allow of an increase of density. The exception to which we refer the single example of an organic intensifier is that invented some eight or nine years ago by MM. Lumiere, in which the oxidizing agent is a quinone compound. The departure thus made into the infinitely wide field of organic chemistry is one which has not been followed, although there is every probability that among the many compounds and series of compounds of carbon which exist there are some in which the two properties of oxidizing the silver image and of adding density when so doing are united. Now that the demands of photography, in the matter of developers, are becoming familiar to makers of organic products and intermediates in this country it may happen that the sister process of intensification may come in for a share of attention, even though the commercial rewards may be small in comparison with those yielded by a developer.

The Donalty of Negative Fog.

         The old idea that a negative must have a certain amount of clear glass is held by few printers now, but it is an undoubted fact that with a negative that is at all inclined to be on the thin side a very slight amount of fog reduces the printing value in a marked degree. It also gives a false impression of the real contrast present and prevents proper judgment of exposure when bromide or other development papers are used. It is an instructive experiment to reduce with ferricyanide and hypo one half of a foggy negative until the shadows are fairly clear, when it will usually be found that although the image, plus fog, appears fairly vigorous, yet, minus fog, it is really quite weak. It is therefore evident, when a negative cloud over in development more than it should do, that the development should be prolonged until considerable density is obtained; then when the fog is removed what is practically a normal negative will be left. If any one suffers from this class of negative, it is advisable that all precautions should be taken to avoid all possible causes of veiling. A very common one is diffused light in the camera; this may be through insufficient shading of the lens, to a dusty or cloudy condition of the glasses, or even to reflection from imperfect blacking of the bellows or woodwork. It is curious fact that in the wet collodion era, when there was much lees liability to fogging, photographers was very careful as to shading the lens with long hoods, cones, or canopies, while now we may find people using rapid anastigmats with half-inch hoods or none at all, and this with ultra-rapid plates. The point should receive especial attention at the hands of those who go in for «fancy’ lighting, with the lens pointing more or less directly to the light. With dirty lenses the remedy is obvious: a little alcohol and a soft rag are all that is needed, although a coating of dead black or even black velvet inside the lens tube, is a valuable addition, while treatment with a really dead blacking such as nitrogen on the bellows and framework should complete the cure. If the fogging occurs in the camera the edges of the plate where protected by the rebate should be clear, otherwise the cause must be sought in the dark-room. Coloured fabrics fade and some red glasses permit a considerable proportion of blue light to pass through. It is worth taking a little trouble in tracing the cause of fog in order to secure clean, easily printed negatives.

Glass for the Studio.

         A correspondent recently asked whether the use of rolled or ground glass for glazing the studio would obviate the necessity for white blinds or curtains in addition to dark ones. In our opinion, in an at all well-lighted position it would not do so, as although either kind would prevent the direct glare which sometimes comes through clear glass, there would, be no effective control of the light. There is, however, much to be said in favour of what is generally called "rolled plate" for both roof and sidelights. For one thing, it effectually excludes all view from the outside, even when using artificial light, while another advantage is that the light is more evenly distributed about the studio, with the result that the shadows are less intense, and the exposures shortened in spite of a certain proportion of the light being absorbed. If the glass is neglected dust and dirt will accumulate in the ribs and cause considerable waste of light, but an occasional wash with soap and water, applied with a soft brush, will remedy this. Of ground glass we cannot speak so well. It certainly diffuses the light and is, therefore, useful where there are outside obstructions, for it is well known that a side light of ground glass will give better illumination if there is a wall near than clear glass On the other hand, it rapidly gets yellow in a smoky atmosphere, and it is then more difficult to clean than the rolled plate. Moreover, as it diffuses the light more than rolled or clear glass, it is more difficult to get decided effects in lighting with it.

Defects in Sketch Portraits.

         Few photographers pay sufficient attention to the lighting of the sitter when producing negatives for sketch portraiture and many examples that we have seen in professional show-cases point to negligence in this respect The charm of a good sketch portrait, in our opinion, lies in its fine tonal quality and delicacy, while if an over-harsh or too unequal lighting is arranged a very inferior effect is obtained. One of the best sketch portraits that we have seen was made with a decidedly flat lighting, but one that, at the same time, by the aid of first-class photography, was a delightful result of tonal quality and colour suggestiveness. While on the subject a word may be added with reference to the sitter’s costume. In the case of feminine sitters the sketch portrait should always be in a high key and if possible the receptionist should advise light clothing free from any trace of dark. We recently saw a bust sketch portrait of a feminine sitter in a high key that was absolutely ruined from the artistic point of view by the inclusion of a dark tie. The removal of this should have been: tactfully suggested by the photographer. Many child -portrait sketch effects in a high key are considerably reduced in artistic value through a dark-coloured hair ribbon, and: we have before us a delightful full-length sketch portrait of a youthful sitter in a light dress completely spoilt by reason of the fact that the sitter is wearing dark socks, or, perhaps, those of a colour that photographed too dark, if a non-earthy plate was employed. The above are some points that have a real bearing upon success and' should be noted by all sketch portrait workers.

Practicus In The Studio: Home Portraiture.

Work which conies frequently to some photographers and only at long intervals to others are that of taking portraits at the sitter's own homo. Some firms specialize in it to the extent of sending operators long distances, poaching upon the territory of the local man. There is no more remunerative class of work than this if properly managed, and if the prints are of good quality, yet many photographers fight shy of it, and these, it is to be feared, are generally those who bungle the job. With regard to terms, these are largely governed by local conditions and the prices obtained at any particular studio, so that I will do no more than suggest that no additional fee be charged for "going out." One does not make a charge for going out. to take a house, a horse, or a dog, and there its therefore no justification for making a charge if the model happens to 'be a human being. I recommend, however, that an order for a decent amount be secured, say, at least for a dozen of the highest class of cabinets, as a condition of the special visit. The fact that no additional charge is made will often induce a delicate or infirm person to be taken at once, instead of postponing the matter on account of the weather or other cause, with the possible result of the order being lost through death or the action of a more enterprising artist. It is an excellent thing, from point of view, to secure the entree to as many good possible, for, with a little tact, it is easy to obtain views of the home interior and exterior, and often horses, dogs, and other domestic pets.
To make home portraiture easy and successful the outfit should be carefully chosen. The old way was to pat the studio remora and stand in a cab and to trust to finding a dark-room in which to fill in the plates. This is not a fancy picture Years ago I did it many times for a first-class firm, and I believe many do it still The latest idea is to use a reflex camera which has its advantages but, on the whole, I prefer a stand camera, which is not only more- adaptable as regards rise, swings, and the use of different lenses, but impresses the sitters with the idea that the work is being done properly and that they are not being "mapped" with a port able camera, tike Cousin Jim uses. Personally, I prefer a parallel -bellows camera for whole-plates, fitted with a 12-inch / 5 6 lens. I also carry a Dallmeyer 2B portrait lens, which is useful for children or in very badly lighted rooms. The shutters Packard Ideal or a Gaerry doable flap is fined inside the camera. Usually six slides are carried, filled with such sued plates at the order calls for. It is, how- a good plan to have a couple of whole-plates in one of the slides, in case there is not sufficient room to get in the desired amount of too figure, although the order may be for cabinets only. The 2B, however, will give a three-quarter figure in a small room. The stand is an ordinary three-fold tripod, but rather heavy and provided with the folding wooden base so often described. This latter is a very useful addition, as not only are the feelings of the housewife relieved when she was that it is not proposed to stick spikes into her rugs and pets but it permits of the camera being moved by sliding, instead of lifting, that saving much time and labour.
Sometimes it is desirable to carry a small background, beet a double-sided one of light and very dark grey, about 5 ft by 4 ft upon two light rollers; it does not weigh much and is easily carried. A piece of calico to serve as a reflector is also useful, but if more impediments are not objected to, one of the Kodak portable reflectors may be substituted with advantage.
Now we come to the moat important part of the business the placing and lighting of the sitter. In rooms which are lighted by only one window the choice of position is limited, unless the window is unusually large and high. With small windows it is necessary to place the titter close to the windows to ensure the light falling at the proper angle, which should be as nearly as possible the orthodox forty-five degrees. It is surprising now nearly studio lighting may be approximated to it this be done. One important preliminary is to cover the lower part of the light with opaque material, and if the out side light to vary strong, the upper part should be covered with a translucent fabric, nainsook for choice. Bolter muslin is sometimes used, bat it to too open in texture for direct sun-light. In practice I find it convenient to sew the two pieces a stuff together, the upper half being a piece of nainsook about 4 ft wide and 5 ft. to 6 ft. long, and the lower black or dark green sateen, the same width, and about 4 ft long ; this allows for windows which go down to the floor. This curtain is sassily fixed in position with three or four push pins, any surplus length at the top being closely folded or rolled and pinned through. In a dull light the white half may be folded down behind the dark part and the clear glass used.
As the conditions do not vary greatly in this class of work, the inexperienced photographer will do well to make a few exposures in an ordinary room at home and note upon the prints the positions in which the camera and sitter were placed the different effete; some will probably be good and more probably some will be bad, and. by selecting the more successful ones, he will find oat the best way of working. For ordinary three-quarter lighting the sitter most be placed about 2 ft. back from the edge of the window and about 3 ft. into the room. This distance will vary with the height of the window; if the room be very lofty; the sitter may come further in and still be well lighted. Only in very lofty rooms should fall lengths be attempted, otherwise the angle at which the light strikes the head is too small and the shadows of the features are flattened and the eyes filled with light. In some large houses, where the windows are 12 to 14 ft. in height, studio effects are easily got. For plain lighting the camera should be kept as near to the window side of the room as possible, but for other effects it may be placed in many other positions. The so-called Rembrandt lighting is easily got in an ordinary room, more easily than in most studios. In this style the wall at one-aide of the (window carries the background. Here the dark grey pound will be very useful; the sitter looks straight across the light, which should give a broad line of light down the profile. By turning the head, a little light may be allowed to fall on the cheek-bone, but this is a matter of taste. The shadow aide of the face which is turned to the lens should be lighted up by the reflector, which must be near the camera; in fact, it is sometimes an advantage to cut a hole in the reflector for the lens to look through.
There are great possibilities in the use of an ordinary looking-glass, especially in small rooms, and when photographing invalids in bad, as by its aid the sitter may turn his face towards the window and still present the- lighted side of it to the camera. In the very difficult case of a sitter in bed in a small room, the mirror may be so placed as to enable the photographer to work through the doorway. It should be remembered, as far as the working distance is concerned, that this is made up of the distance from sitter to mirror, plus the distance from lens to mirror, so that in a room where it to only possible to get 3 ft. between lens and sitter by the use of the mirror, the working distance may be doable or more. It must not be forgotten that negatives so taken are laterally inverted that is to say, that if printed in the ordinary way the hair will be parted on the wrong aide; in fart, the image will be as seen in the mirror. To overcome this the prints may be made in single transfer carbon in Kodak transfer type bromide paper, or they may be printed in the enlarger with the glass side to the lens, or if portrait films be used, simply by printing from the back Some objections to the use of the mirror may be raised upon the ground that there is the possibility of getting doable outline of the image, and this, of course would occur if the mirror and lens axis were at an angle of say, 45 deg. with each other; but when the lens and mirror are at right angles to each other there to no danger of this defect appearing.
The scope of home portraiture may be greatly extended by the use of artificial light, and I look forward to the time when the nitrogen filled or half-watt lamps will hare entirely displaced the ordinary vacuum ( f) type. We shall then be able to work where we like in the room and get fireside and card table groups as easily as in the studio. Meanwhile we must rely upon magnesium, either in the form of the flash, or, as 1 prefer to use it for this class of work, in ribbon. Two feet of ribbon cut into four lengths and twisted into a torch give a light equal to an arc-lamp, and, if burned behind a diffuser leave nothing to be desired in the way of lighting. There is no explosion, as with the mixed powders; no snowstorm, as when the pure metal powder is used; the flame is small, and there is no risk to draperies, the only precaution necessary being the provision of an old tea, tray or mat to catch any burning ash which may drop from the torch. I always carry a roll of magnesium ribbon in my camera case with a bit of sandpaper to brighten it with and a wooden clip to hold it while burning. Do not try to light oxidised ribbon; it is a slow job; brighten it with the sandpaper and then it light- quickly and burns evenly.

PRACTICUS.

Training The Retoucher

The incompetence of a large proportion of retouches is a, fact which many photographers know too well. Thin deplorable state of things is chiefly doe, I consider, to the sloppy methods of instructing that are in vogue in the profession. Much valuable tins U waited in having to inspect the work of such assistants before it goes to the next department, whereas it ought to be expected of them to be competent enough to pass it along through all departments until final inspection. I advocate the giving of an abort allotted time and direct personal attention for a few days as a bogs tune-saver in the long run, and as an aid to high quality.
The majority of assistants do not know what retouching exactly should be. Generally speaking their knowledge does not go beyond the idea that they must aim at a decent stipple. What should be done, or -what to do for the greatest improved effect with the least possible amount of labour, and how it affects the next department ('i.e., the enlarging and "finishing" artist) they lack knowledge of. In some cases masters lack knowledge of art principles and their application. Retouching taught without these, in my opinion, is absolutely valueless. Supposing the method usually adopted in training pupil for retouching was applied in the darkroom or printing-room, disaster would sooner or later happen to a batch of work or soon tell its tale by the work not proving permanent. Naturally the first thing one does in these rooms is to explain the reasons for doing certain things.
Some sort of guidance in theory ought to be in vogue among all photographers who have the profession at heart beyond that of the mere making of money. The pupil wants a thorough knowledge of what is required in the branch he is being instructed in. One would not look at the end of a pencil to draw a straight line; otherwise there would be no means to the end in getting that line straight. The mind judges where that line should be to be straight and the brain directs the hand accordingly. It cannot be said that the hand directs the pencil to make the line straight; if the pencil is held correctly the mind draws the straight line. I take this principle as illustrative of my method of instruction for retouching. A negative cannot be retouched unless the whole affect required is in one's mind. How to hold the pencil is half the battle. I have noticed that retouches who hold their pencils at right angles to the negatives and the forefinger tightly in the shape of triangle are usually bad workers and their stipple is wormlike and has no symmetry. This is caused by their being unable in this manner to work the fingers freely, the guidance having to be done by the arm and wrist, making the arm an eccentric.
The correct style, and one which saves hours of labour for the finishing artist, is to hold the pencil very loosely between the thumb and first two fingers, and almost perpendicular, thug using; the side of the pencil point and obtaining any desired angle of movement above the wrist by the fingers (the little finger resting on the negative). Never mind how you get a stipple so long as you work to follow the lines of the muscles of face and texture of the skin of the sitter, not to smother the negative. Many so-called expert retouches (stipples) place a beautiful sheen of lead all over the face, whether it is old man, lady, or child; in reality, a lead wash, such as a painter employs as a ground-tint. It is an absolute waste of time, and the effect mechanical, causing many a master to employ two retouches where one would suffice, and giving an effect which is artistically and commercially valueless. Aim at altering defects only and improving the artistic value by the following course: Select your pupil and give half an hour's persona' instruction each day for a week, first getting the pupil to master the taking away of complexion blotches and spots. Aim at nothing else until the pupil can do these to match the surrounding ground without overlapping.
The next step is to instruct where the muscles are exaggerated by the necessary side-lighting of the studio. With a satisfactory stroke there should be no so-called stipple. Then get your pupil to look at the whole of the face and imagine the negative as a line drawing in the positive sense, considering exactly what lines would be drawn to represent the character of the person (dismiss the half-tones for the moment). Get the pupil into the habit of bearing in mind the curve of the main lines that represent the character, such as the shape of the nose, main lines of lips and eyes. Any small complementary shadows there are to these do not need retouching. The next to consider is the relation of the strong highlights to the imaginary line drawing, and in doing this treat all the half-tone lights as that of a thin wash of paint an artist would put over his drawing. They need no altering; only blending into the main lines (i.e., massed shadows). The direct alteration of any half-tone or massed shadow representing the line of the facial muscle is fatal in retouching. These are the chief points to consider for artistic retouching. Any other work such as squaring noses and altering nose shadows are not necessary, if the face is properly lighted. All that is needed is the minimum work and the maximum result, which is only obtained by keeping the whole face in mind all the time. Try this method on your next pupil as against the old style of practice-practice without aim and you will be surprised at the result and time saved.

GEO. F. BURRELL.

The Longevity Of Photographic Prints In Relation To Record And Survey Work.

A recent dictum of the Camera Club indirectly revives the question of the permanence of different printing processes to be used as records by photographic survey and record societies. Perhaps the most widely understood meaning of the word "permanent," applied to everyday things, appertains to inalterability, but in photographic circles when questions arise as to tine relative permanence of different printing processes their respective "durability" is generally meant and as so understood. Degrees of (.inalterability is rather a contradiction in terms, whilst durability may widely vary. To put the matter bluntly, if any printing process will afford lasting results for, say, a dozen, or so years and upwards, it is generally considered to be permanent in the restricted sense alluded to. But the matter is on another footing when, photographs are to serve as records for posterity, for here it is not enough that they should last for fifty or even a hundred years, but a life is reasonably demanded limited only by the holding together of the picture supports. By general consensus of opinion, two commercial printing processes only, or variants of them, fulfill this condition. The life of silver prints at the best is one of conjecture, which the lapse of time only can settle, and many are known to be more or less evanescent. In the case of photographs utilized purely as records their useful existence is longer than for most other purposes: if discolored or partially faded, so long as all details are preserved, they serve their purpose. On the other hand, when once deterioration has begun it often proceeds apace.
Though all are agreed that complete fixation and thorough washing are essential elements in the stability of silver prints, yet it cannot be said that deterioration can only be ascribed to these operations being ecamped, and there may be operative causes which are quite unsuspected. Printers of the old albumenized paper have narrated how prints known to be hurriedly fixed and washed have sometimes long outlasted those which had received orthodox treatment. In past days albumenized prints appear to have been over-washed, as in addition to prolonged changes by hand they were frequently left to soak all night. Impure air, damp, impurities in the mount or mountant, or a mountant tending to turn acid or are all known factors tending to alteration and fading Even with one brand of paper puzzling differences he durability of prints arise, one worker recording rapid fading, or other troubles, whilst another experiences he opposite. Inquiries often fail to reveal any variation in procedure to account for such difference, which in some irrational way seems to be connected with the ''personal equation" which looms largely in other directions.
In daylight silver-printing processes the image may be to consist of something in the nature of a stain, whilst with bromide prints we have reduced silver in a fine state of division in gelatine, and the general opinion is that them are the most stable of all silver prints. The life of a dry-plate bears on the permanency of bromide prints, though we should expect the former to outlast the latter owing to the silver and gelatine being present in greater degree, and also to the fact that there is no paper to retain residual traces of hypo. Comparatively few old dry-plate negatives show unimpaired condition, but at Greenwich Royal Observatory there is no indication of fading in any dry-plate negatives of stars, although many date back more than twenty years. Doubtless scrupulous care was exercised in fixing and washing and none have been indemnified or even reduced.
Whilst nobody can place a limit on the life of a carefully made bromide print, which may last many a long year, yet the official pronouncement of the Camera Club that "a well-made, thoroughly fixed and washed bromide print is probably as permanent as a print in any other process" cannot be justified. The probabilities are against this conclusion, and at variance with the opinion of recognized authorities, and with the views of the great majority of photographers. In essence, the assertion is equivalent to saying that finely divided silver, vulnerable to many adverse influences, is as stable a substance as, say, lamp- black, or platinum black, both regarded as unalterable trader every atmospheric condition, and respectively employed in the carbon and platinum processes. Having regard to the support and to the fact that the platinum image is in actual contact with the fibred of the paper, mercenarily of the highest grade, a platinum print may present an advantage over % carbon when a long-distant future is concerned, but both can fairly be bracketed together as truly permanent photographic printing images. Neither, of course, exists commercially on the strength of feature, but on the distinctive qualities associated with them. The extraordinary resisting properties of platino- type prints were illustrated some yean ago, when a number remained at the bottom of the sea for some months in a sunken warship and were eventually salved none the worse for the adventure. Subsequently shown at the Brussels
Exhibition, they perished by fire. Although the image of a carbon print is not in contact with the fibred of the paper, the pigment it locked in insoluble gelatine, known to be most durable in Ha normal state, and presumably more so when tanned by the action of light. As to the danger of peeling, sometimes alleged to exist, all that can be is that this is of the rarest occurrence, and when it does take place may usually be traced to the under-soaking of the transfer paper, or over-hardening of the prints by chrome alum or similar chemical, or to undue baste in drying Preference, naturally, will be given to those tissues which contain carbon pigment, however durable other pigments utilized may be.
If the opinion of those responsible for the recent utterance of the Camera Club is based on the undoubted fact that many bromide prints made years ago show not the slightest signs of alteration, this proves that the prints are long-lived, but affords no information as to their ultimate life. We have in our possession a framed salver print (apparently albumen) of French origin purchased over sixty years ago, made long prior to the introduction of bromide papers, and only during the last few years has it shown signs of deterioration, though continuously exposed to daylight, and occasionally hung on walls none too dry. Possibly in another twenty years or less the picture may have disappeared.
Granted that carbons and platinotypes are the processes for record work, which nearly all secretaries of photographic record societies fully recognize, yet the unfortunate fact remains that if these were insisted upon few prints would be received, as the majority of amateurs print in neither process. So such societies are practically forced to accept silver prints, and with no guarantee even that they have been thoroughly fixed and washed. Possibly a dry silver print hermetically sealed and kept in the dark might last almost indefinitely, but this is outside the region of practicability. However stored for access, it is impossible to prevent a limited circulation of air and of any impurities in it over the prints owing to barometrical changes. Dry-mounting on pure paper, and a coat of good varnish applied to the surface, should materially help towards longevity. In the case of subjects obviously valuable as records, the loan of the negatives might be sought to enable permanent prints to be obtained, but unfortunately funds are often not available for the purpose. We feel sure carbon or platino type printing concerns would charge on the lowest possible basis, and on inquiry have received from two well-known firms an unofficial intimation to this effect.
There appears to be no specific authority conferred on any local authority to enable a small grant to be made for such a worthy object. But when the record society becomes part of the public free libraries (as in most cases should be the case for convenient reference) the general powers of expenditure are available. These are by no means great under the existing rate, which leaves but little margin for the purchase of necessary books, to say nothing of other desirable acquisitions. Many towns, however, have proposed an advance in the rate to 3d, and if than materializes prospects will be brighter for the societies associated with the libraries, if not for the ratepayer.
We wish all good-luck to the scheme of the Camera Club, and commend our observations to its attention, and in doing so a gentle reminder may be given to readers every where not to forget their local survey and record in the approaching season. Upon the executive, as a rule, falls the major part of the work, cheerfully undertaken and with no hope of being personally thanked by posterity, but we would urge a large measure of contribution by the general body of photographers.

A Bichromate-Mercury Iintersifier

It was while working under active service conditions that the experiments leading to the discovery of a new method of intensifying negatives .was made. Some very brilliant results were required in the way of transparencies, and the only plates in tock of the size wanted were very stale, and though labelled "Process," would not give even ordinary printing density. So the only thing to do was to make the best possible, and then clear and intensify as much as possible. Lead was tried, but owing to the lack of proper washing accommodation, bad water, and also to the strong colour it gives to the very slightest trace of veil in the whites, it did not answer in this case. After trying every method that I could to persuade the "quarter-bloke" in charge of the stores to let me have the material without the usual circumlocution, and still not getting enough density, I began to experiment, and eventually found a method of greatly increasing the density without risk of stain provided that the negative was thoroughly fixed.
The procedure finally adopted was to bleach the negative in an acidified solution of potass bichromate (as for chromium intensification), and then, after washing for a short while, immersing in a mercury-iodide solution, and after a further wash to darken the bleached image in a sulphide bath; or else in a hydroquinone developer if there were any likelihood of subsequent reducing being called for.
I found that a lot of washing, after fixing the plate, between the various baths, was not essential to clean working, and the increase in density was far greater than I have been able to get with any other intensifier except lead. If the bichromate is not all out before the negative goes into the mercury bath, it comes out into that solution, but does not seem to affect its working.
Like the mercury-ammonia intensifier (which it easily beats for density-giving power) this new method can be worked with out accurately weighed and measured solutions, but in that case it requires rather a lot of bottles. Being minus reference books or any accurate measures at the time referred to, I got on quite well without, and did not find any appreciable difference resulting from varying strengths and proportions of ingredients of solutions. The way I arranged matters was, first of all, to keep a saturated solution of potass bichromate, of which a little was diluted for use as required, and a few drops of hydrochloric acid added. If this did not bleach it was poured into a jar, and a few more drops of acid poured in. This bleaching bath does not keep, so it was thrown away after use. The mercury-iodide bath, on the other hand, keeps well in the dark-room, and can be used over and over again. As I had no formula by me, I made a fairly strong solution of each of mercury bichloride and potass iodide. Then a little of the latter was put aside, and into the remainder I poured the mercury solution a little at a time, well stirring and shaking to dissolve the red precipitate that forms when these two chemicals are mixed. A point is reached when a little of the red powder fails to re-dissolve, and it was to get this into solution that the email quantity of the potass iodide liquor was kept aside. On adding this to the bulk the precipitate disappeared. This strong solution was kept for stock, and was used diluted, but both the stock and working solutions appeared to keep well. The sulphide solution was made as required from the crystal, but there is no reason why a stock solution should not also be employed for this. The used liquor should not be kept after the same day, as in the case of bromide toning. It seemed difficult to get the image thoroughly sulphide right through, so that if the density was too great some reduction was obtained by simply immersing the negative in a hypo bath. Another use al point with this intensifier, as in some others, is that if the plate before sulphiding is seen to be too dense or the lines are veiled, a dip in hypo solution will clear it. Of course, this means another good wash before sulphiding, and it should be pointed out that these extreme methods of working are seldom suitable for anything but line work, as the uneven nesses of the emulsion are usually very much accentuated by employing strong measures.

D. CHARLES.

EX CATHEDRA: Liver Toning; Rapid Plates and Donalty; Carbon Printing and Fumes; Simper Paratus; For Print-Out Papers.

Liver Toning.

There seems to be in some quarters a difficulty in getting satisfactory tones on bromide prints with the ordinary sulphide toning process. Instead of obtaining good rich sepia tones a rusty colour is got, due sometimes to a want of density in the negatives, or to over-exposure followed by insufficient development, while in other cases no modification in working will give the desired colour. To those who find themselves troubled in this way we recommend a trial of liver of sulphur (potassa sulphurata) as a toning agent. This has the advantage of giving a variety of colour, ranging from a warm black to sepia, including some very fine purple browns. One of its good points is an absence of the slight reducing tendency of the ferri cyanide bleacher, and another is that even if the prints are inclined to be weak there is no liability to give a "ginger" colour. The process is a simple one; the toning bath consists only of sixty grains of "liver" to a pint of warm water, a few drops of ammonia being added when solution is complete. This should be raised to a temperature of about 100 deg. Fahr, and the print immersed until the desired colour is reached. A little allowance must be made for the further toning action, which goes on in the subsequent washing. Borne papers will stand the heat of the solution without requiring hardening, but if there is any tendency to melt the prints should receive a preliminary bath of formalin, a convenient strength being two ounces to the pint. As with the hypo-alum bath, all papers will not tone to sepia in the liver of sulphur solution, some is refusing to go beyond a purple black similar to P.O. P. A few trials with various papers will show the most suitable makes.

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Rapid Plates and Donalty.

It is commonly believed that it is difficult to obtain full density when using very
rapid plates and some operators prefer to use a slower grade in order to secure plucky negatives. The idea is fostered by the fact that the films of nearly all fast plates appear much more transparent before development than do those of slower ones, and this gives rise to the belief that such plates are thinly coated and lacking in silver. Such is certainly not the case; the fast plates having in some cases twice as much silver bromide spread over the square inch u the "ordinary" ones. We have used plates which were so transparent that ordinary printing could easily be read through the emulsion, but which gave almost perfect opacity when developed. The fact is that much longer development is necessary for a fast emulsion than for a slow one. If we take two plates of the san e make, one an ordinary and the other a "supersensitive" expose both correctly and develop in the same developer for the same length of lime, the difference will be most marked, but if the rapid plate be developed twice or even three times a long the densities will then be pretty even. Instead of prolonging the development the Mine effect may be produced by increasing the amount of alkali, or by raising the temperature of the developer. With regard to the former expedient, a little mishap which recently occurred to us will be instructive. By mistake carbonate of soda was used instead of sulphite in making a stock pyro solution, and by so doing the amount of alkali in the mixed developer was more than doubled. Upon developing for the usual time plates which normally gave thin delicate images became so dense that considerable reduction was necessary before the negatives were printable, a conclusive proof that a full quantity of silver was present.

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Carbon Printing and Fumes

In some unaccountable way the notion, has been created that carbon tissue is extremely sensitive to various fumes, and many have been deterred "from using this charming process because they thought that special precautions had to be taken to avoid "tinting," or what would be called "fog" in other processes. We have recently seen excellent carbon prints, which were produced day after day under conditions which are popularly believed to be impossible. They were made in a work-room in which an evil-smelling dry mounting press was used almost constantly; by the side of the sink a geyser was used to supply the hot water needed, and three feet away the sulphide of bromide prints was constantly done. The reason for the immunity from the ill effects of this combination was a simple one; only ready-sensitized tissue was used. In a dry state the fumes had practically no effect upon it, and the short time it was exposed while wet during the mounting did not allow any action either. The great stumbling-block in carbon work is the drying when home-sensitized tissue is used, and practically all risk of "tint" may be avoided by drying the tissue in an air-tight box or cupboard over chloride of calcium. By so doing, not only is the atmosphere excluded, but the drying is done in the same time whatever the hygroscopic conditions may be outside. Another advantage gained by this method of drying is that the tissue is of uniform sensitiveness, which is not the case when it is dried in the open.

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Simper Paratus

There is an old joke which is sometimes trotted out when anything uncommon presents itself "that you always see these things when you have not got your gun." If for gun we substitute camera we are recording the experience of nearly every photographer. Most of us can recall many occasions when we have seen effects of light and shade, or occurrences, which are not likely to be repeated, and have been compelled to leave them unrecorded because our camera was out of reach. We have known some photographers, mostly enthusiastic amateurs, who never went out without a camera, and at least one professional who did the same, told us that, on the whole, the practice had been a profitable one, besides being the means of securing many pictures of personal interest. This was in the days when the smallest camera was of the dimensions of a cigar box, and it required much more enthusiasm than in these times of pocket Kodak’s and "baby" plate cameras. Apart from the constant carrying of a camera, it is an excellent to keep a small instrument, say, half-plate or less, ready filled with plates or films which can be picked up and used without a moment's delay. In this respect the amateur with his film outfit is usually much better prepared than his professional brother, who often has to assemble his outfit before it is ready for use. Perhaps the most convenient apparatus is of the folding local plane or "press" type, in which plates can be kept for weeks without danger of deterioration. Such a camera is of great value for sports, pictures, street scenes, and the like, while used with discretion it is very handy for home portraiture. The great point is that it should be semper paratus, always prepared.

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For Print-Out Papers.

The consistent reader of the photographic papers is constantly coming upon hints so ancient that, like the anecdotes of Miss Volumnia Deadlock, they have become in the cycles of time new again. At least forty years ago photographers who had need to make a very dense part of a negative impress its detail fully on the print would use for the purpose the concentrated light of a burning-glass. This old expedient must have been disinterred scores of times or, quite possibly, has been invented by those who have heralded it as a new device. Its latest appearance as something original is in a recent issue of a New York photographic paper. None the less, it is a plan which may often be employed with advantage in the case of negatives of interior subjects in which most probably windows or other brightly lighted parts have become too dense in the developer. In place- of risking the negative by reducing or rubbing down the more opaque parts, an ordinary reading-glass of about three inches diameter may be held in front of the negative during printing and, while kept gently in motion, caused to concentrate its light upon the part which needs help. The American writer prefers to fit a disc of black card with a hole in it in the rim of the glass and so to obtain the utmost concentration of light.

Assistants' Notes: Dark-Room Clock

How to Construct a Dark-Room Clock.

A clock to measure the seconds, the face and fingers of which be plainly seen in the dark room, is a most desirable and useful ring. But one specially made for the purpose at the present time is rather an expensive item. The following instruction will enable any photographer to adapt an ordinary clock at vary little cost. Any make or sue will do providing it has a good, bold, white dial and a minute finger, and is one without a which will go in any position like a watch. Unless it has a finger it will be of no use for our purpose. It does not how old the movement is or bow defective it’s time-keeping qualities; these are of no consequence. If we have not one in our one can be picked up very cheaply, often for a few at a clock repairer's or secondhand stores.
Having secured this, we can proceed with the work of converting into a dark-room clock.

Carefully take the movement out of the case, noticing particularly bow it m fixed in, and remove the fingers. Sometimes this latter has to be done before the movement will come out of the case. All screws, washers, fingers, ate, should be put into a purser or small tray so that they will not get lost, as they will be required later. We should now carefully look at the works and notice just those wheels and spindles which are required to keep the clock going and the minute finger moving. All the rest of the movements are not required by us, and are better taken out. The beet way to take these out without disturbing any other works is to cot through the spindles which carry the wheels with a three-cornered file anywhere where it is convenient. They can then easily be taken out. When all the unnecessary parts have been removed we shall have a clock which, when going, only takes round the minute band. The dial should now be pot back on the clock in such a manner that the centre of the dial where the hour hand was should be fixed over the minute finger movement. This may necessitate a little cutting of the dial, etc., or other parts, to allow it to fit in its right position, but can easily be accomplished. When this is fitted in position the long; finger is carefully soldered on to the minute finger and blacked, the minute finger placed in position, and the whole movement put back into the case. We have now a clock which takes just one minute for the finger to go completely round the dial, and each of the hours five seconds. The dial being of a large size and white, and the finger black, it is very easy to see and count the time in the dark room. Of course, the clock will go with once winding as long as ever it did.