,,the ,,barnet ,,book ,,of ,,photography4 ,,the ,,barnet ,,book ,,of ,,photography4 ,a ,,collection ,,of ,,practical ,,articles ,,by ,,capt4 ,w4 ,,de ,w4 ,,abney1 ,c4,b41 ,f4,r4,s41 ,,etc4 ,,charles ,h4 ,,bothamley1 ,f4,c4,s41 ,f4,i4,c4 ,,chapman ,,jones1 ,f4,c4,s41 ,f4,i4,c4 ,,harold ,,baker ,a4 ,,horsley ,,hinton ,,john ,h4 ,,avery ,w4 ,,thomas ,,andrew ,,pringle ,,john ,a4 ,,hodges1 ,f4,r4,p4,s4 ,,rev4 ,f4 ,c4 ,,lambert1 ,m4,a4 ,w4 ,,ethelbert ,,henry1 ,c4,e4 ,,james ,,packham1 ,f4,r4,p4,s4 ,,tho',s4 ,s4 ,,skelton ,illustration ,,third ,,edition4 ,published by ,,elliott ,,son1 ,,barnet1 ,,herts4 ,,percy ,,lund1 ,,humphries ,,co41 ,,ltd41 #c1 ,,amen ,,corner1 ,,london1 ,e4,c4 #ahih4 ,illustration ,,contents ,,of ,,the ,,book4 ,,page4 ,,alpine ,,photography4 ,w4 de ,w4 ,abney1 ,c4,b41 ,f4,r4,s4 #i ,,negative ,,making4 ,c4 ,h4 ,bothamley1 ,f4,c4,s41 ,f4,i4,c4 #bc ,,lenses4 ,chapman ,jones1 ,f4,c4,s41 ,f4,i4,c4 #eg ,,portraiture4 ,harold ,baker #gg ,,pictorial ,,photography4 ,a4 ,horsley ,hinton #hg ,,architectural ,,photography4 ,john ,h4 ,avery #aag ,,the ,,hand ,,camera ,,and ,,its ,,use4 ,w4 ,thomas #aca ,,lantern ,,slides4 ,andrew ,pringle #ada ,,how ,,to ,,make ,,enlargements4 ,john ,a4 ,hodges1 ,f4,r4,p4,s4 #aee ,p4,o4,p4 ,rev4 ,f4 ,c4 ,lambert1 ,m4,a4 #agg ,,platinotype ,,printing4 ,a4 ,horsley ,hinton #aig ,,contact ,,printing ,,on ,,bromide ,,paper4 ,w4 ,ethelbert ,henry1 ,c4,e4 #bbe ,,the ,,gum-,,bichromate ,,process4 ,jas4 ,packham1 ,f4,r4,p4,s4 #bda ,,an ,,introduction ,,to ,,carbon ,,printing ,,for ,,beginners #bec ,,the ,,carbon ,,process4 ,thomas ,s4 ,skelton #bfa ,,illustrations4 ,,homewards4 ,,karl ,,greger #af ,,among ,,the ,,alps4 ,w4 ,,de ,w4 ,,abney #bd ,,winter ,,time ,,on ,,the ,,alps4 ,w4 ,,de ,w4 ,,abney #dj ,,melton ,,meadows4 ,a4 ,,horsley ,,hinton #gb ,,miss ,,lily ,,hanbury--,a ,,portrait4 ,,harold ,,baker #hh ,,gather ,,the ,,roses ,,while ,,ye ,,may4 ,,alex4 ,,keighley #abj ,,birch ,,and ,,bracken4 ,w4 ,,thomas #acf ,,drifting ,,storm ,,clouds4 ,w4 ,,thomas #afh ,,streonsalch4 ,w4 ,j4 ,,warren #bjj ,,cupboard ,,love4 ,t4 ,,lee ,,syms #bcb ,,at ,,the ,,fountain4 ,j4 ,w4 ,,wade #bfd ,,preface4 ,illustration3 ,,the ,,barnet ,,book ,,of ,,photography4 ,the purpose of this book is to place in the hands of every ,photographer instructive articles on essential processes and manipulations1 by eminent writers who have given such subjects their especial study1 and who have borne in mind that whilst the experienced ,amateur and the ,professional may each find much to learn from a comparatively elementary description of methods and means1 it is the ,beginner who stands in greatest need of help4 ,in the mind of every photographer the name of ,barnet is inseparable from a great ,photographic ,industry1 and now it is intended that the name shall be associated with a good and useful book1 which is called the ,,barnet ,,book ,,of ,,photography1 and it is left to the reader to say if the fulfilment of its purpose and the manner of its doing are such as to justify its existence4 ,to all who are interested in photography1 who love it for itself and for its productions1 and who desire to improve their own practice of its many processes and applications1 this ,book is respectfully dedicated4 ,barnet1 ,herts4 ,april1 #ahih4 ,,elliott ,,son4 ,illustration3 ,,copyright4 ,,negative ,,by ,w4 ,l4 ,f4 ,,wastell4 ,a ,,famous ,,pike ,,stream4 ,contact ,print on ,,barnet ,,platino-,,matt ,,bromide ,,paper4 ,alpine ,photography4 ,illustration ,writing in ,london on a day in winter with a murky sky and sloshy streets1 the title of ,alpine ,photography is verily refreshing4 ,it brings back days of sunlight and joyous experiment1 and as we write the soul stirring scenery is before us called up by photographs taken under varying conditions of comfort and discomfort4 ,that there is something different in ,alpine photography to photography in our own country1 we are bound to believe1 since a special article is demanded for it4 ,the first question invariably asked is as to the nature of the outfit required4 ,we should here like to divide our reply into two divisions4 ,the one concerning the mountaineer1 and the other the ordinary tourist4 ,for the former we have no doubt in our minds that a hand camera to take #a_/d plate or #e #d pictures is the most convenient form of camera to take4 ,it is not our business to advertise any person's wares and we shall content ourselves by saying that personally we prefer a camera which has separate slides and does not possess a magazine1 more particularly when glass plates are to be used1 though a form of ,kodak is not to be despised4 ,but perhaps we are prejudiced in favour of glass plates1 for they are simple to manipulate and have no cockles nor other drawbacks which the careless photographer may have to encounter4 ,probably the most useful lens to employ is a doublet of which the focal length is about a quarter more than the width of the plate1 since it includes a fair angle and the margins of the photographs are not likely to be markedly different in general density to the centre1 as is the case when wide-angle lenses are employed4 ,in ,england a lens which will cover with a large stop1 say f_/#h1 is a desideratum1 but in the ,alps it is very rarely that such a large ratio of aperture to focal length is required4 ,as a rule for ordinary plates a lens has to be stopped down to f_/#af to give a negative in say #a_/ejth of a second4 ,nevertheless where orthochromatic plates are to be employed it is very necessary to have a lens which will cover a plate satisfactorily with f_/#h in order to use a colour screen for producing orthochromatic effects1 since the loss of photographic light caused by the screen can only be compensated for by such an aperture even when the shutter is slowed down4 ,the reader is therefore recommended on the whole to furnish himself with one of the modern lenses which work at f_/#h1 though he must remember that the larger the aperture employed the more the margins and centre of the picture will suffer from unequal exposure4 ,with some hand cameras there is a means of attachment to a stand1 but a stand on a mountain is difficult to use and moreover has on more than one occasion been proved dangerous to carry4 ,the mountaineer if he desires to give a time--and not an instantaneous--exposure on his excursion1 would do well to have a small clip ready to attach to the head of his ice axe4 ,the axe will form a sufficiently stable stand for the more prolonged1 but still short1 exposure that he may be required to give on some particular subjects such as a photograph at sunrise or near sunset4 ,photographers in ,england are rarely afflicted with breathlessness through exertion1 but it is different in mountaineering4 ,a mountaineer may keep his wind1 but it would be rare to find that his heart was beating equably after some spurt of exertion1 such as rock climbing4 ,it is often after some such exertion that he comes upon some view which he may wish to record on his photographic plate4 ,the usual method of holding the hand camera would under such circumstances prove a failure so far as sharpness of image is concerned4 ,pressed against his middle or upper chest1 the beatings of the heart will record themselves on the photograph4 ,under such circumstances resort must be had to some form of support on which to rest his camera4 ,after many years' experience1 the writer has come to the conclusion that there is no support superior to the ice axe4 ,it is not necessary to cause it to stand upright in the ground1 ice1 or snow1 though this should be done if possible4 ,it will suffice to rest the point on the rock1 and place the camera on the axe head1 with the pick parallel to the body4 ,we then have a firm support in one direction1 and the hands1 which are not affected by the automatic motion of the heart1 can be trusted to keep it steady in the other direction4 ,photographs taken with a good lens1 and with such a stand1 will bear enlarging up to #bb inches1 at least4 ,it is because these photographs will bear enlarging that a small plate is recommended to the mountaineer4 ,there is not a large proportion of ,alpine views taken on the mountain side of which one would care to have anything but a memorandum1 and it is such a size as that recommended which gives such a memento1 and which1 if desired1 allows a more formidable size to be acquired at home1 where we may suppose there are all the conveniences that a photographic laboratory affords4 ,the writer has had experience on mountains with cameras varying from #ab #aj to the #a_/d plate size4 ,when younger and more inclined to waste a few valuable minutes of daylight in putting up a camera stand1 the #ab #aj gave pictures which we often lamented having taken1 whilst in his more mature years1 a snap-shot has never been regretted4 ,the cameras which require stands1 require one porter at least to carry them1 for although the late ,mr4 ,donkin carried his own #g-a_/b #e camera up the highest peaks1 it is few men1 who1 even if they had the energy or the physique that he had1 would imitate his example4 ,a porter means an extra expense in fees1 and an extra mouth to feed1 and very likely entails slowness in a climb through having an additional man upon the rope4 ,a quarter plate or a #e #d camera the owner1 however1 can himself carry2 but the best form of attaching it to his body has been a difficult task to evolve4 ,many and many different attachments have been tried4 ,one thing is quite certain1 and that is1 the camera should be in a stout case1 but it cannot be carried over the shoulders by a strap as we can do in comparatively level countries4 ,let anyone try to come down a rock with the camera slung over his shoulders1 and he will soon find it dangling in front of his stomach1 or swinging like a pendulum1 and threatening to displace him from what at best may be a treacherous handhold4 ,the method of attachment we adopt now1 will be readily seen from the diagram4 ,illustration ,the shoulder strap is utilized1 but a ring is attached to the back of the case as shown1 and a strap or piece of whipcord comes over the strap as shown4 ,the two shoulders are in ,,aa and the case is carried as a knapsack4 ,the length of the cord or strap ,,bb is so adjusted1 as is also the length of the shoulder strap1 that the camera lies against the small of the back1 and that it will not swing away from the body4 ,at one time the ring was placed in front of the case1 but the result was merely to cause the top of the case to rest against the back4 ,the plan shown above has answered under almost every variety of circumstances1 and the weight is inconsiderable4 7,a friend has his camera attached to the bottom of a small rcksac and this answers1 but as the writer does not carry his own provisions or change of garments he has not adopted this plan74 ,a long day's march may be undertaken if this contrivance be employed1 and the weight is scarcely felt4 ,for those who have not had extensive practice with hand cameras1 a view finder is1 if not a necessity1 at all events1 a great help4 ,on the whole1 perhaps the best form is that in which a miniature view falls on a ground glass4 ,it must be recollected1 however1 that each view finder is adapted for some particular focal length of lens4 ,the view in the finder and on the plate should be compared1 and if the former is more extensive1 the surplus ground glass should be covered up with a black mask4 ,if it be determined to take a camera with its stand1 very few directions are required beyond those which apply to ordinary view work on the plains4 ,it may perhaps be as well to mention that a camera stand placed on ice or snow1 is not immovable until the iron shoes of the legs attain the temperature of the surrounding snow or ice4 ,an exposure of a few seconds will often show an image which has moved on the plate4 ,the next point that we may call attention to is the plate to be employed4 ,with a hand camera there is no absolute necessity to have the most rapid plate1 as far as exposure is concerned1 but in mountain work it must be recollected that there are very great contrasts to represent on the print4 ,the slower the plate the steeper the gradation is almost axiomatic1 and it must be recollected that only a certain amount of opacity will print if the deepest shadows only are to be kept of the greatest black obtainable in a print4 ,it is evident that the greater the range of light and shade that is obtained of a printable density1 the more true to nature the picture will be4 ,for this reason a quick plate with a moderate gradation is to be preferred--as being most generally useful--but it should be a plate which is absolutely free from fog1 and it should also be of as fine a grain as possible1 the size of which has something to do with development4 ,this is still more true when a camera stand and hand exposures are made4 ,with a slow plate with feebler intensities of light1 which must be the case when the lens is stopped down to admit of hand exposures1 the gradation becomes more steep than if a fairly bright light be employed4 ,a quick plate does not suffer in the same way1 however small the stop may be4 ,it has already been stated that isochromatic plates may be employed with a hand camera4 ,for ice and snow views there is not much to commend their employment1 unless to give a deeper shade to the sky and to the vast crevasses which so often form part of the foreground4 ,the darker sky allows faint clouds to be visible in a print when they otherwise would be absent4 ,pictorially thus the isochromatic plate has something to recommend it4 ,celluloid films have often been substituted for plates by the writer1 and excellent photographs have been obtained on them when they were fairly rapid4 ,there is not much to be said in their favour as regards weight1 for in most cameras the support for them weighs nearly as much as the glass plate4 ,there is also a disadvantage in developing them1 for they are not so easily manipulated as a rigid body4 ,for convenience in travelling1 however1 they are to be highly commended4 ,a gross of cut films do not weigh so much as a dozen plates and occupy much less space in the baggage4 ,the question of the use of a ,kodak camera with its roller slide1 has not been brought forward1 not because excellent results cannot be obtained with it1 but simply because the writer prefers to use plates and films which can be got at any time for the purpose of development4 ,for travelling on the continent1 and to one's mountain destination1 experience has shown that a small hamper is the safest receptacle of all the necessary kit4 ,a hamper which will contain two camera cases side by side is really sufficient2 but it should be a little greater in depth4 ,it may be thought that two cameras are to be taken1 but such is not the intention4 ,if a zinc trough be made of the size of one camera case it will contain all the developing apparatus necessary1 the lantern1 and the plates or films1 and all the few etceteras which go to make one happy4 7,a screwdriver1 a file1 and some extra screws1 and gummed paper and white blotting paper cut to the size of the plates should be enough for the etceteras74 ,the hamper may be arranged so that the camera and view finder may be taken out without any derangement of the rest of the articles in it4 ,the developing bottles and cups1 with the dishes1 may be similarly extracted4 ,this prevents undue trouble in unpacking and packing4 ,one grand thing to remember is1 pack well but not distressingly tightly1 in other words don't employ an expert packer if you wish for comfort4 ,have the hamper a size too large rather than a size too small4 ,also be it remembered that it is useless to stopper the bottles with all sorts of devices at home1 and have to pack in an ordinary manner when once the contents of the hamper have been brought into use4 ,have your bottles covered with an indiarubber cap which can easily be removed and replaced2 of course we are assuming that development is to take place during one's travels1 and not to be left over for home4 ,personally we think that a speedy development after a view is taken will give the best picture4 ,it may often happen that an undeveloped sensitive plate or film will suffer by its travels4 ,there will or may be scratches and what not1 which would be absent if the negative is finished at the time4 ,the outfit for development which need only be taken is as follows3 four developing dishes1 bottles or cartridges of the dry developer1 ammonia diluted to half its strength in a glass stoppered bottle 7if in a wooden case1 as for medicine bottles1 it will be a further protection71 a couple of tins of hyposulphite pounded up before the journey1 carried in small tins 7such tins as the half-plate platinum paper comes in are very convenient71 two or three empty six ounce medicine bottles with good corks1 a two or four ounce measure1 a washing rack with a trough 7there is a folding rack in the market which answers admirably2 it has v shaped grooves which never damage the edges of the film1 and one rack will take twenty-two glasses back to back74 ,a zinc trough can be made to cover the plates with water when in the rack1 a lantern 7by preference a paper folding one71 a dusting brush1 a couple of dusters1 and blotting paper cut into squares the size of the plates1 with which to pack them--it is useful also to have spare pieces of blotting paper to place beneath the plates when drying1 also a piece of mackintosh to place on the wash stand during developing operations--an empty pint wine bottle will be got at any hotel and in this the hyposulphite can be dissolved4 ,the list looks formidable but the whole can be readily packed in the hamper of the size given4 ,it will be seen that no intensifying solutions are enumerated amongst the requisites4 ,a negative is better strengthened in the quiet of one's dark-room at home4 ,illustration3 ,,homewards4 ,,karl ,,greger4 ,now we must give a hint or two as to the exposures required4 ,we will suppose that on the plates to be used a satisfactory negative of an open ,english landscape1 on a bright ,june day with fleecy clouds in the sky1 can be secured with an aperture of f_/#aa in #a_/beth of a second4 ,if that be so1 then on an equally fine day in ,july or ,august1 at an altitude of about #fjjj feet1 the same kind of view should theoretically be secured in #a_/ejth second1 and a stop of f_/#af--that is1 the photographic light is about four times as strong4 ,it must1 however1 be recollected that at this altitude1 and particularly near mid-day1 the shadows are not illuminated to the same degree from the sky4 ,the darker blue sky shows that the light which at a low altitude goes to make a pale blue sky is to be found in the direct rays of the sun1 and not scattered to give a luminous sky4 ,as the shadows are principally illuminated by the light from the sky1 it follows that the shadows will be darker at a high than at a low altitude1 for this reason amongst others1 the exposure should not be curtailed to the amount given above4 ,if the aperture be reduced to f_/#af it is probable that the exposure of #a_/beth second will be not more than sufficient to give4 ,for our own part we prefer to give longer and to expose well for the deep shadows1 trusting to development to give us properly gradated pictures4 ,as the sun goes down toward the horizon1 the shadows get more illumined from local reflection1 and it is scarcely necessary to alter the exposure until considerably nearer sunset than at home1 when the exposure must be considerably prolonged4 ,for views in which there is little but ice and snow1 the exposure should be very much curtailed4 ,there is so little contrast that if the exposure be at all prolonged the picture will be inevitably flat4 ,the shadows are illumined by an immense quantity of light reflected from the white surface1 and the difficulty is to get sufficient contrast4 ,the writer well remembers one set of beautiful views1 taken from the top of a mountain some #aj1jjj feet high1 where the eye could see nothing but snow-fields and ice and swirling masses of clouds4 ,the day was not bright1 but to get a satisfactory picture a stop of f_/#cb was necessary with only an exposure of #a_/gjth of a second4 ,plates given an exposure of #a_/beth second with a stop f_/#af showed little besides a plain white mass4 ,it would be difficult to give hints for every kind of view4 ,the judgment of the operator must be brought into play and no actinometer will be of much use under the varied conditions which are the rule1 not the exception4 ,now as to development4 ,the one-solution given by the metol and amidol cartridges are the most readily prepared1 and in five times out of six will scarcely be bettered1 but for the sixth time may fail1 because of their rigidity4 ,for these exceptional negatives1 solutions of an oxidizing agent such as pyrogallol1 of a restrainer 7bromide71 and of an accelerator are to be recommended4 ,for the latter1 the carbonate 7not the bicarbonate7 of potash is much to be recommended1 though some prefer ammonia4 ,two formul are given1 either of which will be found extremely useful4 ,when the exposure has been prolonged enough for details in deep shadows to be brought out1 it will generally happen that over-exposure has been given to the high-lights1 and it is to keep these in the printing state that care is required4 ,in the old collodion dry plate days1 it was very usual to bring out a complete phantom image of a subject before any density was given to it4 ,when this was properly out1 the intensifier of silver nitrate and pyrogallol was applied1 and the picture gradually brought up to printing density4 ,it was usually full of detail in the high-lights and shadows1 all of which would be found in the finished print4 ,such is the same procedure which we recommend1 strive to get out an image of feeble density but full of detail1 and then give the density4 ,the plate should first of all be thoroughly soaked in a solution of the alkali which can be used1 and then a few drops of the pyrogallol solution be dropped into the developing cup with an equal number of drops of the restrainer4 ,the alkaline solution is then returned to the cup and again poured into the dish and over the plate4 ,by degrees the required phantom image will make its appearance1 and now bromide and pyrogallol are added until it is evidently complete4 ,the plate is then washed in water1 a final wash being given in a very weak solution of acetic acid or citric and water4 ,after a final rinse with water the plate is treated with the pyrogallol solution and restrainer in the proportion recommended for the ordinary development of the plate1 omitting the alkali4 ,the density will begin to appear1 and when it flags1 a little alkali is added 7a few drops at a time7 to the solution4 ,keep the image fairly feeble at above half the proper printing density1 and fix4 ,the plate should then be kept for intensification1 preferably by ,mr4 ,chapman ,jones's1 when a mercury solution is applied1 and then a ferrous oxalate to reduce the latter to the metallic state4 ,it will be found if this procedure is adopted1 that the negative is built up with a greater range of light gradation than by bringing it out by a one-solution method of development4 ,if one wishes to exercise artistic treatment1 then in the preliminary stage more importance can be given to any desired part by applying a camel's hair brush soaked in normal pyrogallol solution with its restrainer4 ,the prominence thus gained will be kept in the subsequent operations4 ,when applying the brush care must be taken that the image blends as it were with the rest of the picture4 ,no abrupt increase of density must be permitted1 as if it be1 the result will be anything but satisfactory4 ,the following is an ammonia-pyro developer1 with which the writer usually works4 ,a ,ammonia #a part4 ,water #i parts4 7,of course1 should the ammonia be taken half strength allowance must be made for the dilution47 ,b ,potassium bromide #bj grains4 ,water #a ounce4 7,when travelling it is very convenient to have the bromide weighed out into #bj grain packets47 ,p ,pyrogallol dry4 ,s ,saturated solution of sulphite of soda4 ,when the view has strong contrasts and the plate has been exposed for the shadows take of ,a #cj minims and #b ounces of water and soak the plate in it as given above4 ,then add to the cup1 of ,b #b drams1 of ,s #a dram1 and about quarter grain of ,p4 ,pour back the solution of ammonia from the dish1 and then apply the mixture till all detail appears1 and proceed as indicated above4 ,a saturated solution of potassium carbonate may be substituted for the ammonia solution4 ,before closing this chapter it may be of use to the reader to tabulate the number of thicknesses of atmospheres through which light has to travel at different altitudes of the sun at sea level4 ,altitude4 ,atmosphere4 #ij #a4jjj #hj #a4jae #gj #a4jfd #fj #a4aee #ej #a4cje #dj #a4eee #cj #a4iie #bj #b4ijd #ae #c4hji #aj #e4ega #e #aj4baf #d #ab4aea #b #ah4hhb #j #ce4ejc ,if sunlight outside the atmosphere be represented by #a and say #a_/ajth be cut off by #a atmosphere1 then after transmission through #b atmospheres only 4#ha will reach the spectator1 and if through #c only 4#gbi4 ,for any atmosphere the diminution will be #a_/ajth1 that is1 it will be 4#ix where x is the number of atmospheres4 ,if we ascend the factor varies1 there are less thicknesses of atmosphere to go through and we get the following table4 ,photographically ,visual ,transmission ,actinic ,light ,barometer 7,sunlight outside ,transmitted in ,inches4 the ,atmospheric 7,sunlight outside being #a74 the ,atmospheric being #a74 #cj 4#hec 4#fci #bi 4#hff 4#fed #bh 4#hge 4#fgb #bg 4#hhd 4#fhi #bf 4#hia 4#gjh #be 4#hii 4#gcj #bd 4#ijh 4#gdf #bc 4#iae 4#gfc #bb 4#ibb 4#ghg #ba 4#ibh 4#hjj #bj 4#icd 4#hai #ai 4#idj 4#hcc ,this table and the preceding one will enable a calculation to be made as to the exposure to be given4 ,thus at sea level with a photographic brightness of sun of #fci1jjj candles when nearly overhead1 it will at #e above the horizon only have a photographic brightness of about #ajjj4 ,at about #ijjj feet high the photographic brightness would when the sun is overhead be about #hjj1jjj candles1 and at #e it would have a value of #cej1jjj1 showing the greater penetration through the thinner atmosphere4 ,w4 de ,w4 ,abney1 ,c4,b41 ,f4,r4,s41 etc41 etc4 ,negative ,making4 ,,development1 ,,intensification1 ,,reducing1 ,etc4 ,illustration ,when a sensitive plate has been properly exposed under ordinary conditions1 there is no visible change4 ,the action of light produces what is known as a latent image or developable image1 and in order to convert this into a visible image with sufficient opacity to be useful for printing purposes1 it must be developed4 ,in the operation of development1 the plate is treated with some solution that will act on the exposed parts of the sensitive film and reduce the silver salts contained therein to metallic silver1 in quantity proportional to the amount of light-action1 whilst at the same time it produces no appreciable change in those parts of the film on which light has acted the least or not at all1 and which correspond to the darkest shadows of the object that has been photographed4 ,the solution used for this purpose is called the developer4 ,,developers--,,general4 ,the substances that can be employed as photographic developers are now somewhat numerous1 but the most useful for negative making are pyrogallic acid 7also known as pyrogallol1 or for brevity as pyro471 ortol1 metol1 and hydroquinone 7also known as quinol74 ,ferrous oxalate is likewise used in special circumstances1 but not for general work4 ,an ordinary developer as mixed for use contains3-- #a4--,one of the above-mentioned substances 7pyrogallic acid1 ortol1 metol1 quinol7 which is the actual developing constituent1 and is known as the reducer1 but requires the addition of the next constituent before it can work4 #b4--;,an alkali1 which may be sodium carbonate1 potassium carbonate1 caustic soda1 caustic potash1 or1 if pyrogallic acid is used1 ammonia4 ,the alkali sets the reducer in action and is called the accelerator4 #c4--;,a soluble bromide1 which must be potassium bromide except when ammonia is used as the alkali1 and then it may be ammonium bromide4 ,the chief use of the bromide is to retard the action of the developer1 and in particular to prevent its affecting those parts of the film that have not been acted on by light4 ,for this reason the bromide is called the restrainer or1 sometimes1 the retarder4 #d4--;,a sulphite1 the function of which is to prevent the solution from becoming strongly discoloured and consequently staining the film4 ,it also affects the colour of the reduced silver that forms the developed image1 this colour being browner1 and consequently of higher printing opacity1 the lower the proportion of sulphite present4 ,sodium sulphite and potassium metabisulphite are the most commonly used4 ,the composition of a developer has to be so arranged that1 whilst reasonably rapid in its action1 it is not so rapid as to be beyond control1 and does not produce general fog by acting on those parts of the film that have not been acted on by light4 ,illustration3 ,,among ,,the ,,alps4 ,,capt4 ,w4 ,,de ,w4 ,,abney1 ,c4,b41 ,f4,r4,s4 ,,etc4 ,,development--,,general ,,operations ,,and ,,phenomena4 ,a developer is usually compounded immediately before use by mixing two or more solutions1 and in order to ensure uniform action it is essential that the constituents should be thoroughly mixed before the liquid is applied to the plate4 ,if the measuring or mixing vessel is large enough1 this can be done by agitating the liquid2 if not1 the liquid may be poured once or twice from one vessel to another4 ,the quantity of developer necessary for a plate of a given size depends in some degree upon the size and character of the dish that is used1 and is smallest when the bottom of the dish is quite flat and has no ridges or grooves4 ,it is false economy to use too small a quantity1 and it may be taken that for a quarter plate #a-a_/b oz41 for a half plate #b-a_/b or #c oz41 and for a whole plate #d oz4 of developer should be used4 ,ebonite1 xylonite1 or papier mach dishes are the best for all operations connected with negative making1 since they are not so liable as porcelain or earthenware to break a plate if it is allowed to drop into them4 ,when applying the developer to the plate it is important to cover the whole surface of the plate rapidly and in such a manner as to avoid the formation of air bubbles1 and the best way is to begin to pour on the developer at one corner of the developing dish and whilst pouring somewhat quickly move the vessel rapidly but steadily along the edge of the dish to the other corner4 ,if there should be any froth or air bubbles on the surface of the developer1 the last portions should not be poured out of the vessel into the dish1 and then the risk of air bubbles forming on the surface of the plate will be lessened4 ,sometimes after the developer has been poured on and the plate seems to be uniformly wetted1 the liquid will recede from one corner or one edge of the plate and the part thus left uncovered will appear as a patch of lower opacity when the negative is finished4 ,this happens either because the dish is not standing level on the table or because the bottom of the dish is not flat2 sometimes it happens because too small a quantity of developer has been used4 ,after the plate has been covered by the developer the dish should be carefully rocked from time to time1 and1 for reasons that will be explained presently1 the time required for the first appearance of the image and the manner in which the different parts of the image follow one another1 should be carefully observed4 ,if the plate has been correctly exposed1 the brightest parts of the image will appear 7as black1 of course17 in about a minute1 more or less1 according to the temperature1 composition of the developer1 and character of the plate1 and the other parts will follow steadily in the order of their brightness1 after which the image as a whole will continue to gain vigour or opacity up to a certain limit4 ,the essential point is that the principal details in the deepest shadows of the subject shall appear and acquire a distinct printable opacity1 before the highest lights become so opaque that the details in them are no longer distinguishable4 ,whether this condition is realisable or not depends very largely on the exposure that the plate has received4 ,if the image appears in considerably less than a minute and the different parts follow one another very quickly1 the plate has been over-exposed1 and the degree of over-exposure is indicated by the rapidity with which the image appears4 ,in this connection it ought1 however1 to be stated that with metol and certain other developers1 even when the plate has been correctly exposed1 the different parts of the image appear almost simultaneously1 though the first appearance may not begin until about a minute after the developer has been applied to the plate4 ,it follows that with these developers it is difficult to recognise over-exposure1 but it so happens that they are not suitable developers to use when there is any probability that the plates have been over-exposed4 ,on the other hand1 if the image is slow in appearing and the brightest parts of the subject are not followed in due course by the middle tones1 the plate has been under-exposed1 and there is considerable danger that the high-lights may become quite opaque before any details have appeared in the shadows1 or even1 in extreme cases1 in the lower middle tones1 that is to say1 in those parts that are next in darkness to the shadows4 ,when it is desired1 as it frequently is1 to alter the composition of the developer during development1 the substance or substances to be added should be put into the measuring or mixing glass1 the developer poured out of the dish into the glass1 and the well-mixed liquid poured over the plate as before4 ,any attempt to add substances to the developer whilst it is in contact with the plate will probably result in uneven action4 ,it should be borne in mind that temperature has an important influence on development1 the time required for the first appearance of the image and for the completion of development being1 as a rule1 less the higher the temperature4 ,further1 if the developing solutions are very cold1 it is often almost impossible to obtain sufficient opacity4 ,perhaps the most difficult thing in connection with development is to know when to stop the process1 that is to say1 when the image has acquired sufficient opacity1 or density1 as it is often called4 ,after all the required detail has become visible1 the plate from time to time is lifted carefully out of the developer1 allowed to drain for a moment or two1 and then held between the developing lamp and the eye2 the opacity of the image1 especially in the highest lights and deepest shadows1 being carefully scrutinised4 ,the appearance of the image as seen when looking at the back of the plate1 is also carefully observed4 ,for this purpose it is very much better that the light of the developing lamp should pass through transparent glass 7ruby or deep orange7 so that the flame itself is distinctly visible1 instead of through ground glass or a coloured translucent fabric4 ,further1 the flame of the lamp1 whether gas or oil1 should always be turned up to the same height1 for it is clear that if the brightness of the flame used for making the examination is not fairly constant1 all sorts of variable results will be obtained4 ,for this reason it is much better to judge the opacity of negatives by artificial light than by daylight1 the intensity of the latter being so variable4 ,a paraffin lamp with a circular wick and a deep ruby chimney with a metal cap at the top1 answers admirably4 ,no general rules can be laid down2 the appearance of the properly developed image depends on the thickness of the film1 the granularity of the silver salt1 the presence or absence of silver iodide1 and the composition of the emulsion used4 ,experience only is of value1 and the best way to secure uniformly satisfactory results1 is to keep as far as possible to one brand of plates4 ,with some plates1 for example1 very little of the image should appear at the back of the plate1 with others the greater part of the image must be distinctly visible there4 ,sometimes1 especially when using small sizes of plates1 it is not easy to tell whether all the necessary detail in the shadows has been brought out1 and this is an important matter1 for if the small negatives are to be used for making enlarged negatives or prints1 or lantern slides1 there should be very little clear glass indeed even in the deepest shadows of the subject4 ,as a rule it may be said that when every part of the image is at least gray the maximum possible amount of detail has been brought out4 ,if the greyness begins to spread to the margins of the plate where it has been protected by the rebate of the dark slide1 general fog is being produced1 and1 as a rule1 little will be gained1 but much may be lost1 by continuing the development for any considerable time after this is observed4 ,when development is completed the developer is poured off1 the plate is well rinsed under the tap or in two or three changes of water1 and is then ready for fixing4 ,,development ,,with ,,pyro-,,ammonia4 ,this method of development has the advantage that the constituents can be kept in concentrated solutions1 considerable modifications in the composition of the developer can be made very readily and the negatives obtained are of excellent printing quality4 ,on the other hand it cannot be satisfactorily employed with certain brands of rapid plates1 because with them it has a tendency to produce general fog1 and with some other plates1 especially when they are old1 it has a tendency to produce what is known as green fog4 ,three solutions are prepared3-- ,,reducer4 ,pyrogallic acid #a oz4 or #aj parts ,potassium metabisulphite#a #a oz4 or #aj parts ,water1 to make up to #aj oz4 or #ajj parts ,,accelerator4 ,ammonia #a oz4 or #aj parts ,water1 to make up to #aj oz4 or #ajj parts ,,restrainer4 ,ammonium bromide #a oz4 or #aj parts ,water1 to make up to #aj oz4 or #ajj parts #a ,the metabisulphite is dissolved in about #h oz4 7#hj parts7 of water with the aid of heat1 and the pyrogallic acid is then added4 ,when the liquid has cooled it is made up to #aj oz4 7#ajj parts7 by addition of water1 the whole being well mixed by shaking4 ,for each ounce of developer1 take #bj minims of reducer1 #bj minims of restrainer and #dj minims of accelerator1 and make up to #a oz4 with water4 ,with some plates #fj minims of accelerator and #cj minims of restrainer may be used1 but any greater proportion of accelerator has considerable tendency to produce general fog4 ,on the other hand the proportion of restrainer can often be increased with advantage since1 unless the amount added is very large1 its chief effect is to prevent general fog2 #cj minims of restrainer to #dj minims of accelerator1 or #dj minims of accelerator to #fj minims of restrainer are proportions that can be recommended4 ,too low a proportion of bromide should be carefully avoided4 ,it is very important to ascertain1 by careful trial with each brand of plates that is to be used1 what is the maximum proportion of ammonia that can safely be added1 and what proportion of bromide to ammonia is necessary in order to prevent general fog4 ,as a rule1 the more rapid the plates the smaller is the quantity of ammonia that can be used with safety4 ,by far the best plan is to keep development well under control by adding only part of the accelerator at the beginning of development and adding the rest as circumstances require4 ,for each ounce of developer take #bj minims of pyro solution and make up to the required bulk with water4 ,in another measure mix for each ounce of developer #dj minims of bromide solution and #fj minims of ammonia solution1 and regard this as the maximum quantity that can be added with that bulk of developer4 ,now to the diluted pyro solution add about a quarter or one-third of the ammonia and bromide solution1 pour this mixture on the plate and observe what happens4 ,if the mode of appearance of the image indicates that the plate has been correctly exposed1 about half the remaining ammonia and bromide mixture may be added to the developer at once1 and the action allowed to continue1 with occasional rocking of the dish4 ,if development proceeds satisfactorily and1 in particular1 if the chief details in the shadows begin to appear before the highest lights have become too opaque1 it is not necessary nor advisable to add the last portion of the ammonia and bromide mixture1 since the tendency to general fog and green fog is reduced when the proportion of ammonia is kept as low as possible4 ,on the other hand1 if the development flags and the appearance of shadow detail is a little tardy1 the rest of the ammonia and bromide mixture must be added4 ,if the plate seems to be over-exposed1 no more of the ammonia and bromide mixture should be added for some time1 until it is seen whether the quantity already in the developer will suffice to complete development4 ,if it seems that the over-exposure has been considerable1 a further quantity of pyro solution 7#aj to #bj minims per oz47 and also of bromide solution 7#aj1 #bj1 or #cj minims per oz47 may be added with advantage4 ,development is then allowed to continue and the negative is examined from time to time2 if it is seen that the opacity does not increase1 or if sufficient detail in the deep shadows does not appear1 further small quantities of the ammonia and bromide mixture may be added cautiously until the required result is obtained1 waiting a little while to see the result of each small addition before adding more4 ,when the plate behaves as if under-exposed1 dilute the developer at once with half the quantity or an equal quantity of water1 according to the degree of under-exposure indicated1 and add the whole of the ammonia and bromide mixture4 ,these modifications should check the rate at which the high-lights of the subject gain opacity1 whilst accelerating the appearance of the middle tones and shadows4 ,should this effect not be produced1 further quantities of ammonia and bromide mixture may be added or1 in extreme cases1 ammonia alone1 and the developer may be still more diluted with water4 ,if any considerable parts of the image still show no detail1 local development with a brush may be tried as a last resource4 ,a soft camel's hair brush1 preferably mounted in quill1 is used4 ,some of the ammonia and bromide mixture is placed in a vessel and diluted with two or three times its volume of water4 ,one corner or edge of the plate is raised so that the part to be treated is lifted out of the developer1 the diluted ammonia and bromide mixture is applied rapidly with the brush1 and the plate is allowed to drop gently back into the developer4 ,the treatment may be repeated if necessary4 ,should all these devices fail1 the plate is hopelessly under-exposed4 ,sometimes1 when working with a diluted developer as just described1 it happens that although all the necessary detail has been brought out1 the image gains in opacity very slowly4 ,provided that all the required detail is visible1 small quantities of pyro solution may be added in order to gain opacity more quickly4 ,illustration3 ,,teasels ,by ,carine ,cadby4 ,,pyro-,,soda ,,development4 ,when sodium carbonate is used as the alkali in place of ammonia the developer acts somewhat more slowly and is less liable to produce fog1 especially with very rapid plates1 and there is very little tendency to produce green fog4 ,on the other hand1 variations are not so easily made in the composition of the developer4 ,some people find the absence of the smell of ammonia a decided advantage4 ,,stock ,,pyro ,,solution4 ,the same as for ,pyro-,ammonia4 ,,dilute ,,pyro ,,solution4#b ,stock pyro-solution #a oz4 or #aj parts ,water #aj oz4 or #ajj parts ,,soda ,,solution4 ,sodium carbonate1 crystallised4 #a oz4 or #aj parts ,sodium ,sulphite #a oz4 or #aj parts ,potassium bromide #aj grains or #j4bc part ,water to make up to#c #aj oz4 or #ajj parts #b ,no more of the dilute pyro solution should be made up than is likely to be used during the same day1 but it will keep well enough for a day or two4 #c ,the sodium sulphite and carbonate are dissolved1 with the aid of heat1 in about #h oz4 7#hj parts7 of water1 the bromide added1 and the liquid when cold made up to #aj oz4 by adding water4 ,for use mix equal parts of dilute pyro solution and soda solution and pour over the plate4 ,if the exposure has been correct the image will begin to appear in about a minute1 and development is then allowed to go on with occasional rocking of the dish1 until the negative is sufficiently opaque4 ,if the plate behaves as if it were under-exposed1 at once dilute the developer with an equal bulk of water and pour it back over the plate4 ,if the high-lights continue to increase in opacity1 but the rest of the image does not appear1 add some more of the soda solution with or without some more water4 ,should parts of the plate still remain blank1 apply some of the soda solution to them with the aid of a brush as described under pyro-ammonia 7page #cb74 ,if the rapid appearance of the image indicates that the plate is over-exposed1 at once pour off the developer into a measure or mixing glass and rinse the plate well with water4 ,add to the developer a small quantity of potassium bromide solution 7#a in #aj of water7 which should be kept at hand for this purpose4 ,a small quantity of pyro stock solution may also be added4 ,the developer is then poured over the plate again4 ,when the over-exposure seems to have been considerable1 the amount of potassium bromide added may amount to #d grains 7or #dj minims of the #a in #aj solution7 per ounce of the developer1 but this proportion should not be exceeded2 even small quantities of bromide in the pyro-soda developer have a marked influence in retarding development4 ,when there is reason to suspect over-exposure1 not more than half the soda solution should be added at the beginning of development1 and the rest may be added or not1 as the case may require4 ,,development ,,with ,,ortol4 ,,ortol ,,solution4 ,ortol #acj grains or #a4e parts ,potassium metabisulphite#d #fe grains or #j4ge part ,water to make up to #bj ounces or #ajj parts ,,soda ,,solution4 ,the same as for pyro-soda4 #d ,see foot-note to page #cj4 ,mix equal parts of ortol solution and soda solution4 ,this developer behaves in much the same way as pyro-soda and gives very similar results4 ,it has the advantage1 however1 that it does not stain the fingers1 and has practically no tendency to produce either fog or stain on the plates4 ,moreover the same quantity of solution can be used for several plates2 when the action becomes perceptibly slower or weaker1 part of the old solution is poured away and an equal quantity of freshly mixed ortol and soda solutions is added4 ,the chief differences to be observed are 7#a7 that the different parts of the image follow one another more rapidly than with pyro-soda1 even though the plate may have been correctly exposed1 and 7#b7 the colour of the reduced silver is somewhat bluer than with pyro-soda1 and therefore in order to obtain the same degree of printing opacity1 as distinct from visual opacity1 development must be carried a little further4 ,apart from these differences1 what has been said of pyro-soda holds good for ortol soda and need not be repeated4 ,,development ,,with ,,hydroquinone 7,,quinol74 ,,quinol ,,solution4 ,hydroquinone #ij grains or #b parts ,sodium sulphite #a oz4 or #aj parts ,water to make up to #aj oz4 or #ajj parts ,,alkali ,,solution4 ,potassium carbonate 7dry7 #a oz4 or #aj parts ,potassium bromide #bj grains or #j4df parts ,water to make up to #aj oz4 or #ajj parts ,mix two parts of hydroquinone solution with one part of alkali solution and one part of water1 or1 if a more energetic developer is wanted1 mix equal volumes of the hydroquinone and alkali solutions4 ,hydroquinone is not an advantageous developer for general purposes1 but it is useful when negatives are required showing strong contrast between the highest lights and the deepest shadows1 and especially when it is important that there should be no deposit at all in the deepest shadows4 ,this is the case1 for example1 when copying line engravings1 pen and ink drawings and similar subjects4 ,,development ,,with ,,ferrous ,,oxalate4 ,this method of development also is not well adapted for general work1 but it is invaluable for certain purposes4 ,the reduced silver has a pure grey-black colour and there is exceedingly little tendency to produce fog of any kind4 ,on the other hand1 the developer admits of little modification in its composition and therefore the exposure must be fairly correct4 ,it is also important to avoid contamination with even minute quantities of hypo1 since this substance very readily causes stains4 ,,ferrous ,,sulphate ,,solution4 ,ferrous sulphate #b-a_/b oz4 or #be parts ,sulphuric acid ,small quantity ,water to make up to #aj oz4 or #ajj parts ,about three-quarters of the total quantity of water is mixed with a small quantity 7not more than #ej minims per #aj ozs41 or one part per #ajj7 of sulphuric acid1 and the ferrous sulphate 7proto-sulphate of iron7 which must be in clear pale green crystals without any yellowish incrustation1 is dissolved in it with the aid of a gentle heat4 ,after the solution has cooled1 it is made up to the specified volume with water4 ,this solution alters when exposed to air1 and should1 therefore1 be kept in small 7#b oz47 bottles1 filled up to the neck and tightly corked4 ,,oxalate ,,solution4 ,potassium oxalate #aj oz4 or #be parts ,potassium bromide #dj grains or #j4bc part ,water to make up to #dj oz4 or #ajj parts ,for use take four parts of oxalate solution and one part of ferrous sulphate solution1 pouring the latter into the former and not vice versa4 ,in order to obtain slower action with a rather softer image and a slightly browner deposit1 the developer may be diluted with an equal volume of water4 ,slower action1 with slightly increased printing contrasts1 and clearer shadows1 results from an increase in the proportion of bromide4 ,,fixing4 ,after development is finished1 the dark-coloured reduced silver that forms the image remains mixed with a considerable quantity of semi-opaque1 yellowish unaltered silver bromide1 which would not only interfere with the printing1 but would also gradually darken when exposed to light4 ,the negative must therefore be fixed by dissolving out the unaltered silver bromide1 and this is accomplished by immersing the plate in a fairly strong solution of sodium thiosulphate 7formerly called sodium hyposulphite7 commonly known as hypo4 ,the usual strength of the fixing is as follows3 ,,fixing ,,bath4 ,hypo 7sodium thiosulphate7 #aj oz4 or #be parts ,water to make up to #dj oz4 or #ajj parts ,a solution of double this strength is1 however1 not unfrequently used1 and acts more rapidly1 especially in cold weather4 ,the developed plate1 after being well rinsed with water1 is placed in the fixing bath and allowed to remain in it with frequent rocking until the silver bromide has all been dissolved out of the film4 ,this is ascertained by lifting the plate out of the dish and looking at the back by reflected light1 the plate being held in front of something dark4 ,it is not difficult to see whether the silver bromide has all disappeared or not1 but in order to ensure complete fixing the plate must not be taken out of the bath as soon as this has happened1 but should be left in for a few minutes longer1 the dish being rocked so that the dissolved silver salt may diffuse out of the film into the fixing bath4 ,when removed from the fixing bath the plate should be allowed to drain into the bath for a few moments and should then be washed for five or ten minutes in running water under the tap4 ,it is best to put the plate in a dish standing on the sink and have a piece of flexible indiarubber tubing reaching from the tap to within a couple of inches or so of the top of the dish1 so that the water may not splash too much4 ,after washing in this way1 the plate is placed in a grooved zinc rack1 which is immersed in a tank 7preferably of zinc71 containing sufficient water to completely cover the plates1 and here it remains until the whole batch of plates in hand has been developed and they can all receive their final washing together4 ,the plates stand upright in the rack1 and the entrance and exit of the water must be so arranged that the water enters at the bottom and overflows at the top1 or1 what is perhaps better1 enters at the top and is drawn off from the bottom1 the waste pipe opening at the bottom of the tank and being bent and carried upwards until its mouth is at the level at which the water is to stand in the tank4 ,when running water is not available the plates may be washed in dishes4 ,after being well rinsed to remove the adhering hypo solution1 the plate is covered with water 7about #c-a_/b oz4 for a half plate or #e oz4 for a whole plate7 and allowed to remain with frequent rocking for five or six minutes4 ,the water is then well drained off1 a second quantity added and allowed to remain for the same time as before1 with frequent rocking1 when it is poured off in its turn4 ,treatment in this way with six successive quantities of water will remove all the hypo1 provided that the film has not been treated with alum4 ,another plan1 rather less troublesome1 but also less expeditious1 is to place the rack containing the plates in a tank not much more than big enough to hold it1 taking care that there is not less than two inches between the lower edges of the plates and the bottom of the tank4 ,after standing for some time the rack and the plates are slowly and carefully lifted out and allowed to drain1 the tank emptied and filled with fresh water1 and the rack and plates then replaced4 ,eight or ten successive quantities of water applied in this way should remove all the hypo1 but if there is any doubt on this point the plates1 after they are supposed to be washed and have been removed from the tank1 should be allowed to drain into a measuring glass or into a dish1 the contents of which are afterwards transferred to a measuring glass and mixed with a small quantity of a solution of silver nitrate4 ,if the plates are really completely washed nothing will happen1 or at most a white precipitate will be produced which will remain white if not exposed to daylight4 ,if1 on the other hand1 the plates still retain hypo1 the silver nitrate will produce a precipitate which will gradually become orange and eventually dark brown4 ,should this happen1 the washing must be continued4 ,illustration ,,drying4--,if the negatives are allowed to dry in the rack in which they were washed1 the process is slow1 and sometimes if the washing has not been complete1 the middle portions of the negatives1 which dry last1 are less opaque than the rest4 ,an excellent method of drying negatives rapidly and in such a way that no dust can fall on the film1 is to drive nails 7preferably of copper7 into a wall or a board fixed against the wall1 at distances apart depending on the size of the plates4 ,each plate then rests1 with the film downwards1 between a pair of nails1 the lower corner of the plate resting against the wall1 as shown on previous page4 ,illustration3 ,,winter ,,time ,,on ,,the ,,alps4 ,,capt4 ,w4 ,,de ,w4 ,,abney1 ,c4,b41 ,f4,r4,s41 ,,etc4 ,,alum ,,bath4--,it is frequently recommended that all plates should be immersed in a strong solution of alum1 for the purpose of preventing frilling by hardening the film4 ,its use is1 however1 attended with the great disadvantage that liquids diffuse into and out of a film so treated with much greater difficulty than in the case of an ordinary film1 and consequently if the film is alumed between development and fixing1 the fixing is not only much slower1 but the washing after fixing requires a very much longer time4 ,if1 therefore1 the alum bath is used at all1 it should not be applied until after the film has been well washed after fixing4 ,the following solution may be used3-- ,,alum ,,bath4 ,alum #a oz4 or #e parts ,water #bj oz4 or #ajj parts ,if a strong solution of alum is applied to the plate for a long time1 the film may become so thoroughly hardened that it partially loses its adhesiveness1 and there is a possibility that it will begin to peel from the glass after the negatives have been stored for some time in a dry place4 ,the solution given above is quite strong enough and plates need not be immersed in it for more than five minutes1 after which they must1 of course1 be again well washed4 ,the hardening of the film1 if not carried too far1 no doubt makes it less liable to be injured by abrasion and the like4 ,,frilling4--,it sometimes happens that during the various operations of development1 fixing and washing1 the film begins to leave the plate and rise in puckers along the edges4 ,this is known as frilling1 and in bad cases it may spread until a large part of the film has detached itself from the glass4 ,it is due to excessive or irregular absorption of water by the gelatine1 and at one time was commonly met with1 but it rarely occurs with the dry plates of the present day4 ,it is most likely to arise if there is any considerable difference of temperature between the various liquids and the wash-water1 or during very hot weather when all the liquids are much warmer than usual4 ,when frilling does occur1 the plate must be treated carefully1 so as to avoid tearing the film1 but unless it is very bad and shows a tendency to spread1 all the operations1 including washing after fixing1 should be completed before any special measures are taken to remedy the defect4 ,on the other hand1 if the frilling spreads rapidly1 the plate should be carefully rinsed two or three times with water and placed for five minutes in the alum bath1 with occasional gentle rocking1 after which it is again well washed to remove the alum1 and the various operations are completed4 ,there is one exception to the procedure just indicated2 if the frilling becomes bad while the plate is being fixed or during washing after fixing1 the alum must not be applied until the fixing and the washing after fixing are completed4 ,if something must be done in these circumstances1 the plate1 after draining1 but without any previous washing1 may be placed for about ten minutes in a saturated solution of common salt4 ,it can afterwards be put back into the fixing bath1 also without any intermediate washing1 and the remainder of the process carried through4 ,although the methods just described will check the frilling1 they will not remove its effects4 ,for this purpose the plate after its final washing is allowed to drain thoroughly and is then immersed in methylated alcohol1 preferably of the old kind1 though the new kind can be made to do4 ,the alcohol abstracts water from the film1 which consequently shrinks to its original size and can be pressed back with the fingers into its proper position on the plate4 ,should the film be opalescent it should be removed from the first quantity of alcohol and placed in a second quantity1 after which it should be set up to dry4 ,the plates should not remain too long in the alcohol or the gelatine will contract too much4 ,,defects ,,in ,,negatives4 ,a perfect negative presupposes a perfect plate1 correct exposure1 and correct development stopped at exactly the right time4 ,it is almost unnecessary to say that all these conditions are rarely satisfied1 and consequently most negatives fall more or less short of perfection4 ,the defects may be broadly grouped under two heads1 namely1 those due to imperfections existing in the film before exposure1 and those due to defects or errors in the way in which the plate has been treated4 ,it will be more convenient to deal with the latter1 and larger1 group first1 but there is really no hard and fast division between them4 ,,the ,,negative ,,is ,,thin1 or in other words1 whilst showing good gradation1 and sufficient relative contrast between the different parts1 is as a whole lacking in opacity or printing strength1 and gives prints that are deficient in vigour and contrasts4 ,the plate has been removed from the developer too soon1 and the remedy is to intensify the image 7see p4 #ea74 ,sometimes the want of opacity is due to the fact that the developer was too cold4 ,,the ,,negative ,,is ,,too ,,dense ,,or ,,opaque and consequently although showing good contrasts and gradations1 takes a long time to print1 especially on dull days4 ,the developer has been too energetic1 or development has been continued too long2 the remedy is to reduce the image 7see p4 #ej74 ,,the ,,image ,,is ,,flat1 or shows comparatively little contrast between the highest lights and the deepest shadows4 ,this may1 of course1 be due to the absence of contrasts in the subject photographed2 it is commonly due to over-exposure2 it may be caused by using a developer containing too little reducer1 or restrainer1 or both1 and too much alkali2 sometimes it arises from a defect in the quality of the emulsion1 or from the fact that the plate has been coated with an abnormally thin film of emulsion4 ,,the ,,image ,,is ,,hard1 or shows excessive contrasts between lights and shadows1 and is defective in the range of its half-tones4 ,this is probably due to under-exposure1 but may have been aggravated by the use of a developer containing too much bromide or too little alkali4 ,local reduction 7see p4 #ej7 may partially remedy the defect4 ,,fog4--,a more or less marked grey deposit of reduced silver extends over the whole surface of the image4 ,it may be due to over-exposure1 in which case the edges of the plate that have been protected by the rebate of the dark slide usually remain clear4 ,it may also be caused by using a developer containing too much alkali1 or too little restrainer1 or both1 or by the plate having been exposed to actinic light outside the camera1 including the light from the dark-room lamp if the glass or coloured fabric used as the screening material is not efficient4 ,in any of these cases the defect would be observable up to the extreme edges of the film4 ,the character of the dark-room light should be tested by exposing one half of a plate to it at a distance of say nine or twelve inches for five or ten minutes1 the other half of the plate being protected by some opaque substance4 ,the best plan is to put the plate into a dark slide and draw out the shutter half-way4 ,after exposure the plate is treated with a developer in the usual manner1 and it can then be seen whether or no the light has exerted any action on the plate4 ,slight general fog may as a rule be neglected1 but if the amount of fog is at all considerable the plate should be treated with a reducer1 and afterwards the image can1 if necessary1 be intensified4 ,,green ,,fog4--,the surface of the film shows a peculiar brilliant green or yellowish-green lustrous appearance1 generally in patches1 when examined by reflected light1 but is more or less distinctly pink when the plate is looked through4 ,this effect is rarely observed except when pyro-ammonia has been used as the developer1 and it most frequently occurs with old plates1 especially if development has been long continued or has been forced by the addition of comparatively large quantities of ammonia4 ,if the green fog is only slight it does not affect the prints made from the negative1 but in bad cases the prints have a patchy appearance and are less deeply printed at those points where the green fog is worst4 ,two methods are available for the removal of green fog4 ,in one of these the plate1 after being fixed and washed1 is placed in a hypo solution of half the strength of the ordinary fixing bath1 and to this hypo solution is added a very small quantity of a solution of potassium ferricyanide1 and the mixture is allowed to act on the plate for some time1 the dish being rocked occasionally4 ,the green fog will gradually disappear and some more of the ferricyanide may be added1 if necessary1 to secure this end1 but it is important to keep the proportion of ferricyanide as low as possible1 otherwise the image itself will be reduced4 ,for this reason1 if it is seen or suspected that the green fog is likely to be bad1 development should be carried a little farther than usual in order to allow for the slight reduction that accompanies the removal of the green fog4 ,the other plan is to immerse the plate in a dilute solution of ferric chloride 7perchloride of iron7 until the green fog has been completely bleached1 then wash1 first in a dilute solution of oxalic acid and afterwards in water1 and finally treat with a developer1 preferably ferrous oxalate4 ,the green fog is converted into a very fine grey deposit which is almost invisible and has no appreciable effect on the printing qualities of the negative4 ,,black ,,spots may be due to particles of dirt that have been allowed to lodge on the film during one or other of the operations1 or during drying4 ,they may also be due to particles in the emulsion1 and in the latter case are generally round and sharply defined4 ,,black ,,marks of the nature of irregular streaks1 looking1 so to speak1 like black scratches1 are generally due to mechanical abrasion of the film4 ,pressure produces a developable image similar to that produced by the action of light4 ,,black ,,bands1 indistinct or nebulous at the edges1 are sometimes caused during the coating of the plate with the emulsion1 in which case they1 as a rule1 extend all the way along or across the plate4 ,more commonly they are due to defects in the hinges of the dark slides1 which may produce the bands either by allowing light to pass through1 or by giving off exhalations that affect the plates if they are allowed to remain in the dark slide for a long time4 ,if the bands are due to the hinges1 they will1 of course1 correspond with them in position1 and if the hinge is double1 in the distance between them4 ,,transparent ,,bands1 or bands showing less opacity than the rest of the image1 are sometimes caused by exhalations from the material forming the hinges of the dark slides4 ,,transparent ,,spots if small 7pinholes71 are generally due to the presence of particles of dust on the surface of the plate when it was exposed4 ,prevention lies1 of course1 in carefully dusting the plate and the dark slide with a soft1 clean1 dry camel's hair brush1 before putting the former into the latter4 ,if the spots are larger and circular1 they are due either to the formation of air bubbles on the surface of the plate during development1 or to the presence in the film of insensitive particles4 ,,uneven ,,opacity ,,or ,,density1 varying gradually from one end or side of the plate to the opposite end or side1 is due to uneven coating of the plate4 ,if there is a distinctly defined patch1 less opaque than the rest1 the plate was not properly covered by the developing solution4 ,,stains4--,a uniform stain1 of a yellowish or brown colour1 is produced when the pyro developer contains too small a proportion of sulphite or is allowed to act for a very long time4 ,such a stain is rarely observed with the other developers mentioned above4 ,the pyro stain can be more or less completely removed by immersing the plate for some time1 with repeated rocking1 in the alum solution given above1 #a drachm of sulphuric acid being added to every #aj ounces4 ,the plate must afterwards be well washed in soft water4 ,similar stains in patches may be caused by using dirty dishes or a developer that has become turbid by being frequently used4 ,,deep ,,yellow-,,orange ,,or ,,brown ,,stains1 appearing gradually in patches or all over the negative1 some time after it has been fixed1 and washed1 and dried1 are due either to imperfect fixing or to incomplete washing after fixing4 ,there is no practicable remedy4 ,illustration3 ,,dock ,by ,carine ,cadby4 ,,halation4--,when the subject photographed includes some part much more brightly lighted than the rest1 such as a window in an interior subject1 the details of the bright part are not only lost1 but the image of it seems to spread in all directions1 obliterating the details of the surrounding portions4 ,the effect is especially noticeable when the subject includes dark parts which necessitate a somewhat long exposure4 ,a window at the end of a long dimly lighted interior1 or dark trees against a bright sky are cases in point4 ,the effect is really due to the fact that the sensitive film is not perfectly opaque1 and some of the incident light passes through the film and is reflected from the back surface of the glass on to the under side of the film1 producing a blurred image superposed1 as it were1 on the normal image formed at the surface of the film by the action of the direct light4 ,the effect is known as halation4 ,it is prevented by having a perfectly opaque film1 which is a condition difficult to realize in practice1 and which1 moreover1 introduces certain other disadvantages4 ,it is also prevented by coating the back of the plate with some substance that will absorb the rays that have passed through the film1 and so prevent their being reflected back against the under side of the film4 ,the substance used must either be opaque or must have a deep orange1 brown1 or red colour1 and it must have the same refractive index as the glass1 otherwise the reflection will not be prevented4 ,for practical convenience it must also be easily applied and easily removed4 ,many substances have been recommended but nothing is so good as caramel1 prepared by the action of heat on sugar4 ,in order to get the mixture to dry completely after it has been applied1 a somewhat troublesome process of purification is necessary1 but caramel specially prepared for the purpose can now be obtained from dealers in photographic materials4 ,the caramel 7which is a solid substance7 is dissolved in just enough water to make a thick syrup1 which is carefully applied to the back of the plates in a thin layer by means of a flat brush4 ,if the caramel does not dry properly the solution may be thoroughly mixed with about one quarter 7or more7 of its weight of very finely powdered burnt sienna or burnt umber1 ground in water4 ,after being coated1 the plates require some time to dry1 and must1 of course1 be carefully protected from light4 ,if the dark-room is thoroughly dark1 the plates may be put up to dry in the same manner as negatives 7see page #dj71 but if the dark-room is not suitable1 some sort of drying box must be used4 ,after exposure and before development the backing is removed with a damp sponge2 if caramel only is used in a form completely soluble in water1 it need not be removed unless a developer is being used that is to be applied to several plates in succession4 ,,reduction4 ,when a negative is too opaque or dense it must be reduced by dissolving away part of the silver that forms the image4 ,the same process is also applied for the removal of general fog1 sometimes with a view to subsequent intensification4 ,the simplest solution to use for this purpose is known as the ,howard ,farmer reducer and is a solution of hypo mixed with a small quantity of potassium ferricyanide 7red prussiate of potash74 ,,ferricyanide ,,solution4 ,potassium ferricyanide #a oz4 or #aj parts ,water to make up #aj oz4 or #ajj parts ,this solution must be protected from light if it is to be kept for any length of time4 ,the negative which1 if it has been previously dried1 must be soaked in water for some time until it is thoroughly and uniformly wetted1 is placed in some fresh hypo solution 7the ordinary fixing-bath solution diluted with an equal volume of water7 to which a small quantity of the ferricyanide solution has been added1 and the dish is rocked repeatedly to ensure uniform action4 ,the rapidity of the reducing action depends on the proportion of ferricyanide solution added1 and it is very important not to add too much1 otherwise the process gets out of control and reduction goes too far4 ,the image should be carefully watched and the plate removed from the solution and rapidly washed before the apparent reduction is quite as great as it is intended to be4 ,it is much better to stop too soon than too late1 because if it is found that a little further reduction is necessary1 the plate can be again immersed in the hypo and ferricyanide4 ,the ferricyanide reducer can be applied locally for reducing high-lights1 halated windows1 etc41 and this is often very valuable1 especially in the case of under-exposed negatives4 ,a small quantity of hypo and ferricyanide solution is mixed in a measuring glass or some other suitable vessel4 ,the plate is immersed in plain hypo solution in a white dish for a short time and is then raised by one corner or one edge until the part to be reduced is above the solution4 ,the mixture of hypo and ferricyanide is carefully applied with a camel's hair brush to the parts that are too opaque1 and after a few moments the plate is allowed to slip back into the hypo solution and the dish is rocked4 ,if the reduction is not sufficient1 the same proceeding is gone through as often as necessary4 ,the reducer should not be allowed to act too long before putting the plate back into the hypo1 otherwise the reduction may spread further than is desired4 ,further1 the reducer must not be too strong 7i4e41 contain too much ferricyanide71 otherwise it will produce brownish stains and the action may be too energetic4 ,the other reducer is known as ,belitzski's reducer1 and is made up as follows3-- ,ferric potassium oxalate #a oz4 or #e parts#e ,sodium sulphite #a oz4 or #d parts ,oxalic acid #a_/d oz4 or #a part ,hypo solution 7#be in #ajj7 #e oz4 or #be parts ,water #bj oz4 or #ajj parts #e ,the formula in parts does not strictly correspond with that in ounces1 but the difference is immaterial4 ,the constituents must be dissolved in water in the order given4 ,the solution can be used at once and it keeps fairly well if protected from light1 in well corked bottles filled up to the neck4 ,,intensification4 ,intensification is a process in which the opacity of the image is increased by adding some fresh matter1 metallic or otherwise1 to the reduced silver that constitutes the developed image4 ,the usual plan is to bleach the image by means of a solution of mercuric chloride 7mercury perchloride or corrosive sublimate71 which converts the dark-coloured silver into a white mixture of silver chloride and mercurous chloride1 and this is subsequently treated with some re-agent which will reconvert the image into a dark product of greater opacity than the original4 ,it is absolutely essential to successful intensification that the negative be completely fixed and completely washed after fixing1 for any trace of hypo left in the film will give rise to brown stains4 ,it is also important1 in order to prevent stains of another sort and to secure uniform action1 that the mercuric chloride solution be mixed with a small quantity of hydrochloric acid4 ,too much acid will cause frilling4 ,if the negative has been dried it must be immersed in water for1 as a rule1 not less than half-an-hour1 in order that it may be thoroughly and uniformly wetted4 ,,mercuric ,,chloride ,,solution4 ,mercuric chloride #a oz4 or #e parts ,hydrochloric acid #a-a_/b drachms or #a part ,water to make up to #bj oz4 or #ajj parts ,when uniform intensification is required the negative is allowed to remain in this solution until it is completely bleached4 ,if1 however1 it is desired to intensify the shadows more than the high-lights1 the plate should be removed from the solution as soon as the shadows have bleached1 and should be rapidly washed in order to stop the action on the more opaque parts of the image4 ,in either case the negative must be thoroughly washed after bleaching1 and the water used must be soft water4 ,hard water tends to produce a precipitate of the mercury salt in the film1 which may subsequently lead to stain or fog4 ,perhaps the best plan of all1 when constant results are desired1 is to treat the bleached negative with the ferrous oxalate developer1 which will gradually convert the white image into a black one1 after which the plate is thoroughly washed and dried4 ,it is recommended that the first water used for washing should be slightly acidified with oxalic acid4 ,instead of using ferrous oxalate the bleached plate may be treated with a weak solution of ortol or metol to which some sodium carbonate 7soda crystals7 solution has been added1 but no sulphite4 ,after the image has blackened completely the plate is washed4 ,with any of these methods if the first intensification is not sufficient1 the plate may be again bleached with the mercury solution and the process repeated4 ,an old method1 frequently used1 is to treat the bleached plate with dilute ammonia1 which converts the white image into a dark brown one of very considerable printing opacity4 ,the results are often very good1 but are somewhat uncertain1 since the precise effect obtained depends on the strength of the ammonia solution and the time during which it is allowed to act4 ,with somewhat strong ammonia1 allowed to act for a fairly long time1 part of the intensification first produced is removed4 ,this affects the shadows more strongly than the lights and the result is to increase the contrast of the negative1 which is very useful for certain purposes4 ,the negatives intensified with mercury solution followed by ammonia are more liable to spontaneous change and deterioration than those intensified with mercury solution followed by one of the developers4 ,the latter1 in fact1 if properly washed1 may safely be regarded as permanent4 ,,uranium ,,intensifier4--,a very considerable degree of intensification can be obtained by the use of the uranium intensifier1 which is very different in its mode of action1 and is a little uncertain in its results4 ,a solution containing potassium ferricyanide and a uranium salt1 generally the nitrate1 is applied to the negative1 and a deposit of a deep orange-red colour is formed upon the silver image and very greatly increases its printing opacity4 ,the great difficulty is to prevent this deposit forming on the whole of the film1 and it is absolutely necessary that every trace of hypo should be washed out of the film4 ,the addition of acetic acid to the solution not only promotes uniformity of action1 but also helps to keep the shadows of the image clear4 ,,ferricyanide ,,solution4 ,the same as for the ferricyanide reducer4 ,,uranium ,,solution4 ,uranium nitrate #a oz4 or #aj parts ,water to make up to #aj oz4 or #ajj parts ,,the ,,intensifier4 ,uranium solution 7#a3aj7 #a drachm or #e parts ,ferricyanide solution 7#a3aj7 #a drachm or #e parts ,acetic acid 7glacial7 #b drachms or #aj parts ,water to make up to #b- oz4 or #ajj parts ,the negative is placed in this solution and allowed to remain with occasional rocking until the degree of intensification is sufficient1 which can only be learnt by experience4 ,if it is seen that the deposit is beginning to form on the clear parts of the negative1 the plate should be at once removed4 ,after intensification the plates are well washed4 ,if the water is hard the intensification will be slightly reduced during washing1 and this is often useful in removing a slight stain over the whole of the plate4 ,treatment with water containing a small quantity of ammonia or sodium carbonate removes the whole of the deposit1 but leaves the original image slightly reduced and also partially altered in composition4 ,,varnishing4 ,a negative after been thoroughly dried may be used for printing without any further treatment1 especially if only a few prints are required and the ordinary ready sensitized papers or emulsion papers are used4 ,it is1 however1 better to protect the negative from mechanical as well as chemical injury by means of a film of hard varnish or collodion4 ,many excellent negative varnishes can now be purchased1 and the general mode of application is the same4 ,the negative must be thoroughly dry1 and in order to secure this and to make the varnish flow more easily1 the negative is very carefully heated in front of a fire or over a small stove until it is just warm1 but not hot4 ,the negative is best supported by means of a pneumatic holder held in the left hand1 and a fairly large pool of varnish 7the exact amount can only be learnt by experience7 is poured on the plate somewhat towards the right-hand top corner1 and by carefully tilting the plate it is made to run first to the nearest corner1 then along the edge to the further left-hand corner down to the nearer left-hand corner1 and back to the right-hand bottom corner1 from which it is poured into a bottle4 ,the plate is gently rocked whilst it drains into the bottle1 and as soon as the varnish ceases to drop the plate is again carefully warmed until the back of it is just too hot for the back of the hand to bear1 after which it is placed in a rack to cool4 ,it is necessary that the varnish should be quite clear and free from any solid particles1 and if necessary it must be filtered through a plug of cotton wool moistened with alcohol and placed in the apex of a glass funnel which is resting in the neck of a clean and dry bottle4 ,since dust may fall into the varnish whilst it is on the negative1 it is the best plan to pour the excess of varnish off the negative into a second bottle instead of back into the first1 out of which it was poured4 ,to put it in another way1 one bottle should be kept for the clear varnish1 and a second bottle for the varnish poured off the plate4 ,when the second bottle is full1 its contents are filtered into the first bottle for use again4 ,instead of varnish1 a film of collodion1 toughened by the addition of a few drops of castor oil1 and known as leather collodion1 may be used4 ,the collodion is applied to the plate in the same way as varnish except that the plate is not warmed4 ,c4 ,h4 ,bothamley4 ,illustration ,lenses4 ,illustration ,photographs of flat objects such as leaves1 lace1 drawings1 etc41 can be made by simply putting the object on the sensitive surface and exposing the arrangement to light4 ,but this method will not serve if the photograph is wanted of any other size than the original1 nor with solid objects of any size1 except perhaps in the production of full-size profiles of faces4 ,it is therefore quite the exception in photography to print directly from the object itself1 and the only alternative is to produce an image on the sensitive surface4 ,all illuminated objects reflect light and so become for practical purposes sources of light1 just as the moon shines1 as we say1 although it only shines because it is shone upon by the sun4 ,the simplest source of light to consider is a point of light1 and if we can get a dot of light on a white surface from a point of light we have at once an image of that point of light4 ,the smaller the dot the sharper or more perfect is the image1 the larger the dot the more diffused or fuzzy is the image4 ,it is impossible by any known means to get the dot so small that it is an actual point1 that would be absolute perfection1 and on the other hand there is no size of the dot at which it can be definitely said that it ceases to be an image4 ,every point of an illuminated object is a point of light1 and fine definition consists in keeping these points separate in the image4 ,so far as the dots overlap they are confused4 ,confusion1 or diffusion1 or fuzziness is sometimes desirable1 as for example in a portrait1 which may be excellent although it is impossible to distinguish in the picture the individual hairs on the person's head4 ,illustration3 ,fig4 #a4 ,the simplest means for getting an image is a small hole in an opaque screen4 ,in fig4 #a1 two points of light1 ,a and ,b1 shine through the hole in the screen ,s and produce two dots of light1 a and b1 on the surface ,t4 ,the two pencils of light do not practically interfere with each other although they pass through the same small hole1 nor would any greater number2 so that an illuminated object1 which may be regarded as consisting of an infinite number of points of light1 would give an image on the surface ,t4 ,the disadvantages of a small hole1 or pinhole1 for the production of images are 7#a7 it must be so small that it lets very little light through and therefore gives a very feeble image1 7#b7 that it can never give a sharp image4 ,the first disadvantage is obvious4 ,with regard to the second1 a little consideration will show that the image of a point must be larger than the hole itself1 it is always larger though it may have a central brighter part that is smaller4 ,if the hole is reduced in size beyond a certain limit1 it gives an increased spreading of light on the surface1 so that a sharp image can never be produced4 ,illustration3 ,fig4 #b4 ,now the function of a lens is to obviate these drawbacks as far as possible2 namely1 to let more light through and form a brighter image1 and to give sharper definition4 ,in figure #b1 the lens ,l collects all the light that falls upon it from the point ,b1 and condenses it to the point b on the surface ,t4 ,the light from the point ,a that falls on the lens is also condensed and would be brought to a point or focus at a beyond the surface ,t1 but on the surface the light forms a patch of considerable size4 ,suppose that the lens is thirty times the diameter of the pinhole its area is #ijj times as large1 and the light that falls upon it is #ijj times as much as the light that passes through the hole4 ,such an enormous gain of light is worth so much that photographers willingly put up with the very many imperfections of lenses for the sake of it1 and if to this gain there is added the superior definition that is possible1 it will be seen that lenses are indispensable to the photographer4 ,to take a ,daguerreotype portrait with a pinhole might have required several days if not weeks exposure of the plate and therefore would have been impossible1 so that the gain in brightness of image is a great deal more than a mere convenience4 ,it will be observed in figure #a that both points of light1 ,a and ,b produce images on the surface ,t1 although they are at different distances from it1 but in fig4 #b1 although the effect of the lens is to concentrate the light from both points to two other points1 one of these is beyond the surface ,t4 ,this is a disadvantage inherent in lenses4 ,they have so many other imperfections or aberrations that it is desirable to consider these separately4 ,the reader should bear in mind that the one aim of opticians in perfecting lenses is to concentrate as much light as possible from each point in the object to a corresponding point1 or as small as possible a dot1 in the image1 and the image should be flat because the plates used in photography are flat4 ,illustration3 ,fig4 #c4 ,spherical ,aberration4--,the surfaces of lenses are always ground to spherical curves1 and this fact makes it impossible for a single lens1 such as that shown in figure #b1 to bring to a point all the light that falls upon it from a point4 ,if a pencil of light passes through a piece of glass with sloping sides it is bent or refracted towards the thicker part of the glass1 and the greater the angle of inclination of the two sides the more is it refracted from its original path4 ,in figure #c it is clear that the two sides of the lens shown in section are inclined to each other at a continually increasing angle as they approach each other at the edges of the lens4 ,the refracting effect of the lens increases from the centre outwards1 and it increases to a greater extent than is necessary to bring the incident light to a point4 ,the focus of the pencils of light that pass through the edges of the lens is nearer to the lens than the focus of the pencils that pass through its central part4 ,in the figure two foci are shown1 a and b1 but of course1 in fact1 intermediate parts of the lens produce intermediate foci1 and what should be a point in the image1 is spread out into a line on the axis of the lens1 and all along this line is surrounded with the light that either is coming to a focus or that has come to a focus and has spread out again4 ,on a screen placed at b there would be a point of light surrounded by a halo1 while at a1 nearer the lens1 the central focus or point is surrounded by a brighter or more condensed light1 and the appearance is of a circular patch of light with a brighter boundary4 ,this is positive spherical aberration4 ,negative spherical aberration is due to over correction1 the focus of the light passing through the margins being furthest from the lens1 and the appearances on a screen are of course reversed4 ,chromatic ,aberration4--,when light is refracted1 that is bent out of its original path by a single piece of glass1 it is not refracted as a whole1 but each constituent behaves as if none other were present4 ,ordinary white light or daylight is a mixture of many coloured lights as seen in the rainbow1 and when refracted1 the blue is bent more than the green1 the green more than the yellow1 and the yellow more than the red4 ,so that using a single lens the focus of the blue light is nearer the lens than the focus of the red light and the others come in between4 ,in figure #d this is represented in an exaggerated degree to make it more distinct4 ,it will be observed that a screen placed at the focus of the blue light will show a reddish margin and if removed further from the lens the margin or halo will be bluish4 ,illustration3 ,fig4 #d4 ,these two aberrations1 spherical and chromatic were the principal faults that opticians had to deal with1 because they affect the whole of the image1 even the very central parts4 ,but in photography it is necessary to get an image of a very large size as compared with the focal length of the lens1 and there are some faults that only begin to show themselves at a little distance from the centre of the image and increase as the distance from the centre is greater4 ,these aberrations were1 practically speaking1 incurable until a few years ago1 but as recent optical advances have provided kinds of glass by the use of which they may be eliminated1 or nearly so1 they have become of practical importance4 ,they are astigmatism and curvature of field4 ,astigmatism and ,curvature of ,field4--,if a diagram of suitable size is made with a series of concentric circles and radial lines upon it1 and the centre of it is arranged exactly opposite the centre of the lens1 and in a line with the centre of the focussing screen1 the screen and diagram being parallel1 then if the lens suffers from astigmatism it will be found impossible to get the outer circles and the radial lines where they cross them simultaneously focussed4 ,where this difficulty begins the astigmatism begins1 and the greater the difference there is between the focal planes of the radial lines and the circles1 the greater is the astigmatism4 ,it will probably be found with any of the older types of lenses that neither is in focus at the same time that the centre of the diagram is1 but that the screen must be racked in2 this is due to curvature of field1 and the difference between the curvature of field for the circles and the radial lines is due to astigmatism4 ,in the older lenses a flatter field could only be obtained by the introduction of astigmatism1 but now by the employment of the new glasses made at ,jena1 it is possible to practically eliminate astigmatism1 and still keep the field flat4 ,illustration3 ,fig4 #e4 ,the ,development of ,photographic ,lenses4--,when photography was first practised the best lenses available were those made for use as telescope objectives1 and they had to be used with a small diaphragm to get good definition over a sufficient field4 ,with the slow processes then in vogue a more rapid lens was much desired1 and ,voigtlander introduced a portrait lens constructed according to the results of the calculations of ,professor ,petzval4 ,this portrait lens is still very largely used1 and figure #e will serve to show its general character and will be a guide to the putting of one together correctly if it has been taken to pieces for cleaning4 ,a rapid lens such as this could not cover a sufficiently large field for landscape work1 so that single lenses were still used for work in which rapidity was not of very great importance4 ,single lenses were improved1 and other kinds of lenses were introduced from time to time1 but it was not till #ahff that the rapid rectilinears or rapid aplanats1 called later rapid symmetricals1 and by innumerable other names according to the fancies of the makers1 were introduced4 ,probably no lens has been made in such large numbers as this4 ,at about the same time1 ,dallmeyer introduced his portrait lens in which the position of the convex and concave elements of the back combination is reversed1 the concave lens being outside1 and this gives the photographer the opportunity of screwing it back a little1 and so introducing a measurable amount of spherical aberration which has the effect of modifying the otherwise exceedingly fine definition at the centre of the field1 and giving a greater depth of definition4 ,in #ahha1 ,messrs4 ,abbe ,schott began a series of experiments in the manufacture of optical glasses1 and they were so successful in making new and useful varieties1 that an optical glass factory was eventually established at ,jena1 by ,schott ,co4 ,by the use of these newer glasses the limitations that had previously restricted opticians were removed1 and it became possible to correct astigmatism and secure a flat field at the same time4 ,zeiss of ,jena1 towards the end of #ahij1 introduced his first series of anastigmats4 ,the concentric lens of ,ross was introduced in #ahib1 a lens which probably remains unsurpassed for flatness of field and freedom from astigmatism2 but as spherical aberration is present to a notable degree1 an aperture of about f_/#bb is the largest that gives sharp definition4 ,the double anastigmat of ,goerz of ,berlin was put on the market in #ahic4 ,it is a symmetrical lens1 and in this different from the ,zeiss anastigmats that preceded it4 ,it consists of two similar combinations1 each of three lenses cemented together4 ,the unsurpassed qualities of this lens stimulated other opticians to seek to rival it1 and there appeared similar lenses with four and even five lenses in each combination1 besides other lenses that are more or less a copy of the double anastigmat4 ,one of the most notable of these is the satz-anastigmat of ,zeiss1 each combination consisting of four lenses cemented together and forming an excellent single lens4 ,these combinations are interchangeable in the same mount so that with1 for example1 one mount and three lenses1 six different focal lengths can be obtained1 as the lenses may be used singly or any two together as a doublet4 ,the ,cooke lens is remarkable for the simple means by which the various corrections are made1 consisting as it does of only three single lenses separated from each other4 ,obviously it must be used entire4 ,these lenses do not cover so large a plate in proportion to their focal lengths as most of the other anastigmats1 but perform excellently over the plates for which they are constructed4 ,the stigmatic of ,dallmeyer is the latest lens of general utility4 ,it gives good definition to the margin of the circle of light that it transmits1 reduction of aperture being necessary1 when its full field is employed1 to get equality of illumination rather than to improve the marginal definition4 ,its two combinations are different1 and either may be used alone as a single lens1 giving focal lengths of approximately one-and-a-half and twice the focal length of the whole lens4 ,the planar of ,zeiss introduced just as we write1 is a symmetrical doublet characterized by a very large aperture1 from f_/#c4f to f_/#d up to #aj inches in focal length1 and a little smaller above that4 ,it is therefore comparable with portrait lenses4 ,although it is symmetrical1 a single combination cannot with advantage be used alone as a single lens4 ,telephotographic lenses are subsequently referred to4 ,the one aim of opticians in improving photographic lenses has been to get good definition all over a comparatively large flat surface without having to use small apertures4 ,a defining power on the axis of the lens1 that is1 at the centre of the field1 far exceeding what can be taken practical advantage of in ordinary photography1 has long been possible4 ,but until recently1 the defining power always rapidly deteriorated as the distance from the centre was increased4 ,but to judge of the quality of a lens1 or to compare one lens with another1 there are other matters that must be understood1 and these we shall proceed to consider4 ,focal length1 aperture and image angle are the chief details concerning lenses1 granting that the aberrations referred to above are satisfactorily corrected4 ,focal length4--,the focal length or focal distance of a thin lens is the distance between it and the point to which it converges parallel rays4 ,the rays of light are parallel when they issue from an object at an infinite distance4 ,for ordinary practical purposes1 any object1 that is not nearer than a thousand focal lengths of the lens may be regarded as at an infinite distance1 that is the image of an object so far off1 and the image of the sun or stars 7which are situated at the nearest approach to an infinitely great distance that we know of7 would if separately focussed give an inappreciably small difference of position of the focussing screen4 ,but no photographic lens is very thin4 ,the measurement from the back surface of the lens to the screen1 when focussed on a distant object1 is called the back focus1 but this is of no use whatever except as to the determining of the camera length necessary4 ,the equivalent focal length is the focal length 7or focal distance7 of a thin lens that would give the same effect1 so far as focal length is concerned1 as the lens in question4 ,when the simple expression focal length is used1 it always refers to the equivalent focal length4 ,the single word focus is sometimes used erroneously instead of focal length4 ,the focal length of all lenses 7except to a very small extent1 with single or so-called landscape lenses7 is proportional to the linear dimension of the image that it gives under similar conditions4 ,for example1 a lens of #f inches focal length will give just the same amount of subject on a quarter plate that a lens of #ab inches focal length will give on a whole plate1 because the linear measurement of the whole plate is exactly double that of the quarter plate4 ,the easiest way to compare the focal lengths of two lenses1 is to focus both on a fairly distant object or view1 and to measure in the image the distance between two fixed points in both cases4 ,the proportion between these measurements is the proportion between the focal lengths of the lenses4 ,by this method the focal length of any lens can easily be determined if one has a lens of known focal length4 ,if a lens is first focussed on a distant object1 and the focussing screen is then moved back until the image of any object is of the same size as the object1 the distance travelled by the focussing screen is exactly the focal length of the lens4 ,it is however exceedingly difficult to get at the same time an image of an exactly predetermined size1 and to secure the very best definition1 so that it is more convenient to get the image as near as it happens to come to the size of the object and then to allow for the difference1 as then nothing interferes with the operation of focussing4 ,the best near object to use is an accurately divided scale1 and the details wanted in addition to those mentioned above are the comparative lengths of the image and the object4 ,to get these1 two fine marks are made on the focussing screen1 and the distance between these is the length of the image4 ,the scale is focussed with critical exactness and so that it falls over these marks1 then the amount of the scale represented between the marks can be measured1 and the divisions counted for the length of the object4 ,the distance over which the focussing screen was moved between the two focussings is to be multiplied by the length of the object and divided by the length of the image1 and the result is the focal length of the lens4 ,aperture4--,the aperture of a lens is the diameter of the cylinder of light that it can receive and transmit4 ,if the diaphragm is in front of the lens1 the hole in the diaphragm is the aperture1 but if the diaphragm is behind a part of the lens1 so that the incident light passes through a lens first1 the hole in the diaphragm is not the aperture1 the aperture is larger because the lens condenses the light before it gets to the diaphragm4 ,the aperture of any lens can be measured by focussing a distant object1 then replacing the focussing screen by a sheet of cardboard with a pinhole in the middle of it4 ,in a dark-room a light must be placed behind the pinhole1 and a bit of ground glass held in front of the lens4 ,a disc of light will be seen on the ground glass and the diameter of this is the diameter of the aperture1 or simply1 the aperture1 with the diaphragm employed4 ,rapidity4--,the rapidity of a lens depends almost wholly on its focal length and aperture4 ,the thickness of the glass makes a little difference1 and at every surface in contact with air there is loss by reflection1 but these and analogous matters are of comparatively little importance1 and as they are uncertain and cannot be determined it is customary to refer rapidity to the focal length and aperture only4 ,the aperture found1 that is1 the diameter of the effective incident cylinder of parallel rays1 should be divided into the focal length1 and the diaphragm corresponding to the aperture should then be marked with a fractional expression indicating the proportion of aperture to focal length4 ,thus if the aperture is one eighth the focal length1 it is marked f_/#h1 if a sixteenth f_/#af1 and so on4 ,all lenses with the same aperture as so marked may be regarded as of equal rapidity whatever their focal lengths may be4 ,now the more rapid a lens is the shorter the exposure that it is necessary to give for any subject1 and the exposure required is proportional to the square of the figure in the expressions as given above4 ,namely #h and #af squared give #fd and #bef which are as one to four1 the proportional exposures required4 ,or we may say that #h to #af are as #a to #b and square these and get #a to #d the proportional exposures4 ,illustration3 ,fig4 #f4 ,the best way to mark stops is1 for example1 f_/#h and f_/#af1 as these expressions are universally understood1 but some persons think that the relative rapidities or intensities are better1 others prefer to express the relative exposure necessary1 and every system of numbering on these plans has a unit which is merely empirical1 not one of them adopting the only true or scientific unit of f_/#a4 ,zeiss has recently changed his unit from f_/#ajj to f_/#ej4 ,dallmeyer marks some of his lenses now with the practical expression4 ,the following table may be of service to those who happen to have lenses with their diaphragms marked on any of these empirical systems4 ---------------------------------------- --------------------------- ,royal ,photographic ,paris ,zeiss ,zeiss f_/ ,society4 ,dallmeyer4 ,congress4 7old74 7new74 ---------------------------------------- --------------------------- #c4af #a #a_/aj #c4b #ajbd #bef #d #a #e #b4e #a_/d #d4e #eab #abh #e4ff #b #f4c #d #d_/aj #bef #fd #g4jg #e #a_/b #h #d #h4ff #g4e #c_/d #i #abh #cb #aj #aj #a #aa4c #h #ab4be #ae #a4e #ab4e #fd #af #ad4ad #bj #b #ae4ha #be #b4e #af #af #ag4cb #cj #c #ah #cb #h #bj #dj #d #bb4cf #ej #e #bb4f #cb #be #af #d #bg4cf #ge #g4e #ca4fb #ajj #aj #cb #fd #cf #h #b #ch4g #aej #ae #dd4gb #bjj #bj #de4b #abh #ej #bej #be #d #a #ed4gg #cjj #cj #fc4be #djj #dj #fd #bef #gj4ga #ejj #ej #ga #b #ajj #a ---------------------------------------- --------------------------- ,image ,angle4--,the image angle represents what is called covering power4 ,it may be expressed in terms of the focal length1 and doubtless this is the best method1 but it is not customary4 ,it may be expressed as an angle1 the angle formed when a line is drawn from each extremity of a line equal to the diameter of the circle covered1 and caused to meet at a point distant from the base line equal to the focal length of the lens4 ,the angle where the two lines meet is the image angle4 ,but generally the covering power is expressed more roughly1 as the ordinary size of the plate that sufficiently good definition can be obtained on4 ,tele-,photographic ,lenses4--,if a negative 7or dispersing or concave7 lens is introduced between the ordinary lens and the plate1 the equivalent focal length of the arrangement is greater than that of the ordinary lens alone1 but the length of camera necessary is not proportionately great4 ,it is possible therefore to obtain an image of a size that would otherwise require a lens of long focal length and a corresponding and perhaps impossible length of camera4 ,but this is not the only advantage1 for if the ordinary lens and the negative lens are separable to a variable extent1 the amount of magnification of the image1 or increase in the equivalent focal length of the optical system1 is adjustable at will4 ,for further details concerning tele-photographic lenses and their use1 reference should be made to ,mr4 ,dallmeyer's pamphlet on the subject4 ,there are two other subjects connected with the production of images by photographic lenses that must be referred to1 though neither of them is of great importance if we exclude the use of hand cameras 7which are separately treated of7 and bear in mind the ordinary practice of to-day4 ,these are depth of definition and the distortion due to the use of single lenses4 ,depth of ,definition4--,it has already been shown that the action of the lens is to bring to a point in the image all the light that falls upon it from the corresponding point of the object4 ,now it is clear from fig4 #b that1 if different parts of the object are at different distances from the lens1 and this must be the case with solid objects1 these different parts cannot be in focus at the same time4 ,still it is possible to get them so nearly in focus that the result is serviceable1 and the ordinary method of doing this is to examine the image on the ground glass1 and if the whole subject is not sharp enough1 to reduce the size of the aperture4 ,depth of definition is increased by using a lens of shorter focal length or by reducing the aperture4 ,if a large aperture has to be used1 the focal length must be short if much depth of definition is wanted1 or conversely1 if the focal length must be long the aperture must be small4 ,it follows that very rapid lenses that have a very long focus are of no use1 for in portraiture1 for example1 this combination of properties would lead to the ear in the image being fuzzy if the eye was sharp4 ,if a lens were perfect and had a flat field1 the depth of definition would depend only on the aperture and focal length4 ,but if the lens gives inferior definition towards the edges of the field1 it is quite obvious that there must be less depth of definition there1 if a minimum of defining power is accepted4 ,the definition at its best may be inferior to the minimum accepted and then obviously there is no depth4 ,depth of definition therefore at the centre of the plate depends entirely on the focal length and aperture1 but away from the centre it depends also on the quality of the lens1 and is much greater in a flat field anastigmat than in a lens of an older type4 ,but depth of definition is not a quality apart1 it depends entirely upon other factors1 and it is better in examining a lens to determine these factors separately rather than to lump them together as depth4 ,distortion produced by single lenses is due to the fact that the diaphragm is either in front of or behind them4 ,if the diaphragm is in front1 the image is drawn towards the centre of the plate to an extent that increases as the margin of the field is approached4 ,a line along one side of the plate has its ends drawn in to a greater amount than its centre1 because they are further from the middle of the plate1 and therefore it becomes curved like the side of a barrel1 and this effect is called barrel-shaped distortion4 ,if the diaphragm is behind the lens1 the displacement is outwards1 also increasing towards the edges of the field1 and a straight line at the edge of the plate becomes curved so that it is convex towards the centre of the plate4 ,this is known as hour-glass distortion4 ,both these effects are illustrated 7and exaggerated for clearness' sake7 in fig4 #f1 the central square representing the true figure4 ,this curvilinear distortion is absent in all cases in the middle of the plate and generally for a considerable area1 and if single lenses of only long focal length are used1 say of a focal length equal to at least one and a half times the length of the largest side of the plate1 it may be neglected4 ,wide-angle single lenses should never be used except on a suitably small plate1 so that the above conditions hold4 ,the nearer the diaphragm is to the lens the less is the distortion1 and some of the most modern single lenses have the diaphragm so near that the photographer is even more safe in the use of them4 ,illustration3 ,,melton ,,meadows4 ,a4 ,,horsley ,,hinton4 ,the ,comparison and ,use of ,lenses4--,the optician when he tests lenses looks for each fault individually1 but this the ordinary photographer is hardly able to do1 nor is it particularly desirable for him1 because if a lens is inferior it matters little to him why it is so4 ,on the other hand occasion may arise when he wants to identify a fault1 then the information already given will probably be sufficient to enable him to do so1 if to it is added that a small pinhole with a flame behind it is a convenient point of light1 and that if the image of this luminous point is examined with a good eyepiece1 without the focussing screen1 at various parts of the field1 the character of the defect may be discovered4 ,the main things that the photographer needs to look to in judging of a lens or comparing it with another1 are 7#a7 that it works to focus1 7#b7 the quality of its defining power especially towards the edges of the plate4 ,there must also be taken into account the focal length and aperture1 and if both these are not the same in the lenses to be compared they should be nearly the same1 and the proportion that the aperture bears to the focal length should be exactly the same4 ,a special diaphragm may have to be cut out of card for one of them4 ,the best test object that is always at hand is a newspaper pinned flat against a flat wall4 ,the camera must not be moved during the work4 ,each lens is very carefully focussed and a negative made1 using the same aperture1 time of development1 and in all ways similar treatment for both4 ,if the focal lengths are different1 the images will be of correspondingly different sizes1 and then the same detail must be compared1 not the definition at the same distance from the centre4 ,all good lenses work to focus1 but some of the cheaper ones do not4 ,to test this1 any series of small objects arranged side by side1 but at distances varying by intervals of say two inches from the camera1 is photographed after carefully focussing on the middle one4 ,if any other than the middle one is the best defined1 the lens is at fault4 ,but in this1 as in all similar tests1 it must be remembered that ordinary dry plates are not quite flat1 and the error of the plate may make an appreciable difference4 ,the use of lenses comprises the whole art of working with the camera1 it is therefore not our province to say much about it4 ,but so far as lenses themselves are concerned it may be remarked that1 if a lens has a round field1 it may be advantageous to tip up the lens with regard to the plate when only a part of the plate is being used1 as for example sometimes in taking a landscape4 ,but in using the modern flat field lenses special care should be taken to keep the lens and plate exactly true to each other1 the plate exactly at right angles to the lens axis4 ,the image and plate must coincide or definition will suffer4 ,if the image is rounded and the plate flat1 then in any case the result is only a compromise1 but to take full advantage of the larger apertures when the field is flat1 much more care than has been usual must be devoted to this matter4 ,simple uncorrected lenses such as spectacle lenses or monocles1 suffer from the defects that have already been described1 and are valued on this account by some workers because they give blurred or soft images4 ,with a small enough diaphragm they will give good definition1 and generally it may be stated that reducing the aperture lessens the effect of any fault that a lens may possess4 ,to get the best definition that a simple lens will give1 the plate must be brought nearer the lens after focussing by about one-fiftieth of the focal length of the lens1 so that it may be brought from the best focus of visual light into the best focus of the photographically active light4 ,if the object photographed is nearer to the lens than about one hundred times its focal length1 the amount of movement after focussing must be increased4 ,if four focal lengths distant1 the correction is nearly one-thirtieth of the focal length1 at three focal lengths distant1 nearly one-twentieth1 and at two focal lengths1 about a thirteenth4 ,pinholes give an image that for all practical purposes may be said to be equally blurred or soft over the whole plate4 ,much has been written about pinholes and their use1 but it is not definitely known yet whether the exposure should be longer or shorter than the exposure required when a lens is used1 allowing1 of course1 for the smallness of the aperture4 ,the following short table and exposure rules from the writer's ,science and ,practice of ,photography1 will probably prove useful3-- ---------------------------------------- ------------------ ,pinholes--diameters #a_/af #a_/bb #a_/cb #a_/de #a_/fd ---------------------------------------- ------------------ ,distance from plate for sharpest image 444 #fd #cb #af #h #d ---------------------------------------- ------------------ ,all the above figures are in inches4 ,whatever pinhole and at whatever distance1 estimate the exposure for a lens at f_/#af1 f_/#bb1 f_/#cb1 f_/#de1 or f_/#fd1 as the case may be1 and multiply it by the square of the number of inches that the plate is distant from the pinhole4 ,but if the distance is as given above for any hole1 it is sufficient to expose for as many minutes as the plate is inches distant from the hole1 for a subject that would require one second with an aperture of f_/#af4 ,chapman ,jones4 ,portraiture4 ,illustration ,the photographer who may be expert at landscape or architectural work1 will find himself at a loss when he essays portraiture4 ,for apart from the art of managing the sitter 7a most important element in producing a successful result71 he will soon find that the kind of plate that is suitable for outdoor work does not answer well for portraits1 unless the developer is greatly modified1 for quite a different kind of negative is required4 ,as a general rule it is advisable to use very rapid plates for portrait work2 and in this respect1 at the present day we are much better supplied than even five or six years ago1 and with an extra-rapid plate it is possible to secure a fully exposed negative in half a second1 in weather and under lighting that was quite impossible ten years ago4 ,the best expression and pose are generally secured when the sitter is unaware of the actual moment of exposure2 and for this purpose a silent shutter working inside the camera is best4 ,the sitter should never be asked to keep still unless1 in groups1 and when circumstances necessitate a long exposure2 and nowadays an exposure of five or six seconds is a long one4 ,every effort should be made to put the sitter quite at ease4 ,a head-rest should not be used unless absolutely necessary1 and few photographers are aware how easily it can be dispensed with1 and fail to realize how strong an objection nearly every sitter has to it4 ,it is far better to have an occasional plate spoilt by working without the rest than to make every sitter uncomfortable by its use4 ,in fact some portrait negatives are actually improved by a slight movement4 ,in a special kind of lighting when the face is in shadow relieved against a light background1 a slight movement which produces the effect of diffusion of focus greatly improves the result4 ,great care must be exercised in choosing the background even when it is only plain or graduated1 and it is well worth exposing three or four plates on the same sitter1 in the same position and lighting1 and with the same exposure1 but with different backgrounds1 and then carefully comparing the resulting prints4 ,even if only one background is at hand its depth can be varied by placing it nearer or farther from the source of light4 ,the background must also be selected to suit the lighting of the sitter1 as a background of medium tint suitable for what is called ordinary lighting would be quite unsuitable for ,rembrandt effects1 or where strong contrasts of light and shade are used1 when part of the face is in dark shadow4 ,for such effects a dark background is usually best1 as it gives luminosity to the shadow side of the face4 ,but such dark grounds are not suitable for ordinary lighting where the face should be full of delicate half-tone1 all of which would be killed by the strength of the dark background4 ,for the ,rembrandt effects a much longer exposure is necessary as less light is reflected from the face on to the sensitive plate2 they will often need twice or three times as much as for ordinary portraits4 ,when pictorial backgrounds or accessories are used it must be remembered that the object of the photograph is to secure a portrait of the sitter1 not to show what a large stock of accessories the photographer possesses4 ,it is best to use as few accessories as possible2 ,i have heard a lady complain bitterly of a well-known photographer1 who having posed her in a very difficult position1 kept her waiting for five minutes while he arranged a screen1 a palm1 a footstool1 a tiger-skin1 etc41 so that she felt positively ill before the exposure was made4 ,the sitter should not be kept waiting in the pose to be photographed any longer than is absolutely necessary4 ,if accessories must be used they should be simple and suitable4 ,when portraits have to be taken in ordinary rooms it is advisable to get a friend or assistant to experiment upon1 if possible beforehand4 ,even a few minutes spent in studying the possibilities of light and arrangement of furniture will save a great deal of worry when making the actual exposures1 and nothing upsets nervous sitters more than having all kinds of experiments and arrangements made with them4 ,but it is sometimes well worth wasting a few plates on exposures which the photographer thinks will be useless1 in order to give the sitter time to get accustomed to the room2 it must not be done in a fussy1 irritating way1 but rather to show that it is not such a very dreadful operation and really doesn't hurt4 ,this plan often works well with nervous children1 who soon become accustomed to the room and the photographer4 ,there is a great deal to be said in favour of the maxim leave your sitters alone4 ,the photographer must cultivate quick observation so that he sees at once a good pose1 and secures it2 and here again quick plates are essential1 as many of the most charming poses are caught unexpectedly4 ,it has been well said that the best poses the photographer secures are those he observes1 not those he creates4 ,but a spontaneous pose may not be quite perfect and a slight alteration may be easily made without disturbing the rest of the figure4 ,it will generally be found that a pose that takes a great deal of arranging is not a success4 ,when taking portraits in an ordinary room it is usual to place the sitter near the window1 so that one side of the face is strongly lighted and the other in deep shadow1 and then use a white reflector to light up the shadow side4 ,it is often better1 when the window is a large one1 to place the sitter farther back in the room almost facing the window1 and put the camera near the middle of the window looking into the room2 a softer lighting will then be secured4 ,for outdoor portraits a shady corner is best1 and if possible1 one where the side light is much subdued on one side2 a light head-shade may be used with advantage4 ,a large grey rug out of focus makes a good background2 a blanket is too light4 ,a portrait lens is best for the work2 but if the photographer does not possess one1 he need not despair of producing good work4 ,a rapid rectilinear lens used at a large aperture will answer the purpose well2 it should always be used at full aperture1 partly for the sake of quickness in exposure1 and partly to prevent accessories and parts of the dress appearing too sharp and competing in importance with the face4 ,subordination of parts is one of the essentials of a picture2 and if we examine a good portrait we shall find that probably no part of the photograph is quite sharp except the eyes and face4 ,otherwise the less important details are apt to obtrude themselves on our notice4 ,a stop will generally be necessary1 however1 with a portrait lens if a full or three-quarter length is to be taken1 and it will be found that heads only 7as a rule7 can be taken at full aperture4 ,just as good work1 however1 can be done with a rapid rectilinear as with a lens specially made for portraits1 except where rapid exposures are to be made2 but it is necessary to use one of fairly long focus4 ,a rapid rectilinear lens used for landscape work on a half plate would be much too short in focus for giving good portraits on the same sized plate1 for in order to get the figure large enough it is necessary to place the camera so near the sitter as to produce distortion4 ,for portraits on a half plate a lens of at least nine inches focus should be used and for a whole plate not less than sixteen or eighteen inches1 and longer if possible4 ,the swing back of the camera will be found useful in portrait work for getting parts of the figures into focus that are either too far behind or too far in front of the plane of the face4 ,for instance1 a full-length figure leaning back in a chair will have the feet out of focus when the face is sharp if the back of the camera is vertical1 and this applies with even greater force to groups4 ,a side swing too is useful1 but is not absolutely necessary4 ,even in bust portraits the swing back is useful in getting the shoulders in focus when using a large aperture1 for although it is well not to have the whole of the figure in perfect focus all over1 it is not advisable to have the face sharp and the rest so out of focus as to be blurred4 ,the development of a portrait plate should be different from that of a landscape1 because a different kind of negative is required4 ,a rapid plate developed so as to give a soft delicate image is best2 and a developer containing more alkali and less density giver is good1 and it may be considerably diluted with advantage4 ,the image should appear within ten seconds of pouring on the developer1 and the negative will generally be developed to sufficient density in from two to three minutes4 ,with a good average rapid plate the image should show fairly well on the back of the plate1 but this and the time of development will vary so much with different developers1 and with the taste of each photographer that no hard and fast rule can be laid down4 ,developers that give a brown deposit1 or that stain the film will require shorter development than those of the newer developing agents that give a cold black colour to the negative2 another fact to be borne in mind is that the image formed by these latter appears to lose more density in fixing than when pyrogallic acid is used4 ,a perfect portrait negative should have no clear glass shadows1 and no part should be so dense as to give white in the finished print1 and some negatives which give the best results may have a decided veiled appearance in the shadows4 ,the temperature of the developer is another important point2 in very cold weather the developer should be kept warm1 or if in concentrated solutions may be diluted with warm water4 ,in cases of known under-exposure the developer may be used quite hot with advantage4 ,a convincing experiment can be made by cutting an exposed plate in two and developing one half with icy cold developer and the other half with warm4 ,the difference is really remarkable4 ,if the developer has been used hot enough to make the gelatine of the plate feel slimy an alum bath is necessary1 unless the fixing bath contains chrome alum4 ,,metol4 #a4 ,water #ajj parts or #aj ozs4 ,metol #a part or #ej grains ,sodium sulphite #aj parts or #a oz4 #b4 ,water #ajj parts or #aj ozs4 ,potassium carbonate #aj parts or #a oz4 #c4 ,potassium bromide #a part or #a oz4 ,water #aj parts or #aj ozs4 ,for normal exposures take #c parts ,no4 #a and #a part ,no4 #b2 to each ounce of mixed developer add #dj minims of ,no4 #c4 ,,pyro ,,and ,,soda4 #a4 ,pyro #a oz4 ,water #gj ozs4 ,nitric acid #ab drops #b4 ,sodium sulphite #aj ozs4 ,sodium carbonate 7pure7 #h ozs4 ,water #gj ozs4 ,equal parts of each1 for soft negatives dilute with water4 ,to restrain for over-exposure use potassium1 not ammonium bromide4 ,unless an acid fixing bath is used the negatives are rather green in colour4 ,,rodinal ,,and ,,hydrokinone4 ,a4 ,sodium sulphite #a oz4 ,water #bj ozs4 ,citric acid #a crystal ,potassium bromide #a dram ,hydrokinone #b drams ,b4 ,potassium carbonate #b ozs4 ,water #bj ozs4 ,rodinal #a fluid oz4 ,use #a part ,a1 #a part ,b1 and #a part of water4 ,the question of retouching is a difficult one4 ,there is no doubt that a certain amount of it is necessary on nearly all portrait negatives and even on those of children4 ,but it is equally certain that the great majority of portrait negatives are over-retouched1 so much so that their value both as portraits and pictures is nearly destroyed4 ,yet a certain amount is necessary even for pictorial effect1 and perhaps still more when the question of likeness is considered4 ,for as a rule the untouched negative is no more a true likeness than the over-retouched one4 ,the truth lies somewhere between the two4 ,even if isochromatic plates are used the little differences of colour in the face1 and the incipient wrinkles are exaggerated in an unpleasant way4 ,under-exposed negatives will show these defects in a very marked manner1 full exposure will greatly reduce them4 ,large heavy patches of shadow may be lightened by coating the back of the negative with matt varnish1 and when it is quite hard hatching upon it with a soft lead4 ,harsh lights may be reduced by scraping away the matt varnish with the point of a knife4 ,in some cases the matt varnish may be stained with a little aurine or uranine4 ,exaggerated lines and small shadows must be worked upon from the front and a retouching desk is necessary4 ,the film of the negative will not take the pencil without some preparation4 ,the best surface is obtained by spreading a little retouching medium with the tip of the finger on the part to be touched4 ,a thin film of soft resin is left upon the plate which takes pencil marks readily4 ,a hard lead1 ,no4 #d ,faber or ,hardtmuth1 should be used4 ,the loose leads used in what are called the ever-pointed holders are most convenient4 ,the point must be very long and fine1 like a large darning needle1 and is best made by rubbing the lead on a piece of fine glass-paper4 ,the pencil must be held very lightly and the lines touched away with short light strokes1 a heavy stroke only rubs the medium up4 ,the little shadow at the end of the mouth often has to be reduced1 often at the risk of spoiling the shape of the lips1 but sitters will insist upon it being done1 and say ,you have made my mouth much too large4 ,freckled faces are perhaps the most difficult to retouch1 as it is well nigh impossible to remove the black patches caused by the freckles without at the same time destroying the modelling of the face4 ,yet it must be done1 for probably the most severe stickler for truth would not insist on the black blotches that freckles produce in a photograph4 ,a great deal can be done to improve a hard negative as soon as it leaves the fixing bath1 by applying a mixture of hypo solution and a solution of ferricyanide 7not ferro7 of potash with a piece of cotton wool to the dense parts4 ,the proportions for this reducing bath are as follows3--,to each ounce of the ordinary hyposulphite of soda fixing bath add a few drops of a #aj solution of ferricyanide of potassium or red prussiate of potash1 making the whole about the colour of pale brandy4 ,by adding more of the ferricyanide solution the reducing action is quicker1 but there is a greater liability to stain the film4 ,the work should be done over a sink with a tap of running water at hand4 ,the solution should be of a deep lemon colour 7it is almost impossible to give exact quantities71 and after a short application must be washed off under the tap1 and the negative may then be examined1 and the reducer applied again and again till the desired reduction is obtained4 ,it is advisable to make a few trials on spoilt plates4 ,for if any really good work is to be done there will be plenty of rejected negatives4 ,probably1 of all the plates exposed on portraits by first-rate professional photographers1 not more than one-fourth ever get as far as the printing-frame4 ,moral3 ,do not be chary of exposing plates1 they are cheap enough now4 ,don't feel1 ,oh6 this will be good enough4 ,i won't do another4 ,on the other hand don't expose carelessly and recklessly and say1 ,it will all come right in developing4 ,good work is not done that way4 ,use every opportunity of seeing good work4 ,study the work of great portrait painters1 but don't neglect the photographers4 ,go to all the exhibitions of pictures and photographs within reach4 ,don't be satisfied with what you have done1 but make a resolve to do something better next time4 ,remember1 what is worth doing at all is worth doing well4 ,harold ,baker4 ,illustration3 ,off ,boulogne4 ,by ,a4 ,horsley ,hinton4 ,pictorial ,photography4 ,illustration ,unlike the subjects of the other articles in this book1 in pictorial photography we are not brought to consider one of the many processes which go to make up the photographic craft1 but merely a special and exceptional application of any and all means known to the photographer4 ,the particular end to which this application is made will be explained as far as the limits of space will permit1 and some of the methods of such application will be described4 ,beyond this ,i have no intention of going4 ,i do not present pictorial photography as a branch of photography especially worthy of study--,i am not concerned in making converts4 ,it is for the photographer who has already formed a desire to give his attention to the pictorial side of photography and who is seeking help1 that this chapter is designed4 ,first let us come to a mutual understanding as to the term ,pictorial ,photography4 ,picture-making by photography would perhaps be a simpler phrase1 but that to my mind the word picture-making is too similar in idea to boot-making1 lace-making1 etc41 all of which imply a mechanical manufacturing1 whereas a picture--a real picture--like a musical composition1 a poem or a beautiful thought1 grows or is evolved rather than made to order4 ,art photography would be a better term1 but that in photography the word art has been so often coupled with things the very antithesis of artistic and might hence be misleading1 moreover the photographer will show discretion rather than weakness if he be not too hasty to claim for photography a position among the arts1 and whilst its claims to that dignity remain as yet in dispute1 we may be content with ,pictorial ,photography as a less assuming title1 yet one which will sufficiently differentiate between what we may call the ordinary photographic production and---- ,well1 what8 ,that is the first thing ,i have to try and explain4 ,look at the illustrations in this book on pages #gb1 #acf1 and #abj1 and1 making due allowance for some loss of quality due to reproduction by a half-tone block1 try to imagine what the originals were like4 ,then say if they please you4 ,if you say no1 you do not care for them1 they do not appeal to you1 you do not mind if you never saw anything of the kind again from this day henceforth2 very well1 doubtless there are other things in the world in which you can find pleasure1 but so far as my present subject is concerned1 here you and ,i part company4 ,these illustrations are more or less successful reproductions of pictorial work1 and if you do not like them1 making as ,i have said due allowance for their being reproduced and reduced1 then it is certain you do not want to hear anything about them1 and it is not my intention to persuade you1 so please pass on and make room for those who do care for these things and wish to learn all they can concerning them1 or at most stand aside and peradventure some stray word dropped unintentionally may quicken your interest and discover in you a sympathy of which you were previously unconscious4 ,illustration3 ,,miss ,,lily ,,hanbury--,a ,,portrait4 ,,harold ,,baker4 ,referring now again to the illustrations which in the absence of anything else we take as fairly typical of pictorial photographs and assuming that one or the other1 if not all1 do please some of my readers1 ,i will ask them to endeavour to analyse their feelings when confronting such productions4 ,take now an ordinary commercial photographic view such as one may purchase from any sea-side stationer1 and compare the sensations awakened by each4 ,in the case of the topographical view we feel some satisfaction at being able to recognise a familiar spot1 or the view reminds us of some other place1 or it may be quaint buildings1 or rugged mountains1 or miles of foliage1 or what not inspire curiosity or interest because we know the photograph to be a true record of facts1 that is to say we accept the photograph in lieu of the actual presence of the objects represented1 and experience nearly the same feelings as we should were we to visit the spot represented4 ,we know that the wonderful1 curious1 or unusual things portrayed have an existence1 otherwise we could not have a photograph of them4 ,in all such cases our interest and value of the photograph would vastly diminish1 were it possible for a photograph of this kind to be made simply by the photographer's hand and imagination without any original at all4 ,you look at a photograph of this or that sea-side place and remark1 ,ah1 yes1 that's dear old ,yarmouth1 many a time1 etc41 etc41 or else1 ,dear me1 ,i wonder what place that is1 it's so like---- such and such a town1 or it may be you enquire ,where's that8 and you express or think to yourself you would like to go and visit the spot4 ,these and kindred sensations are those kindled by the average photograph1 but there is yet another1 for you may be impelled to exclaim1 ,how wonderfully clear and bright that photograph is1 ,what a good photograph4 ,in this case you are interested purely in the execution as an example of clever manipulation and skilful craftsmanship4 ,now1 compare such feelings as these with those stirred by an example of good pictorial work4 ,in the first place your esteem for it1 if you value it at all1 is quite as great whether you know the place where it was made or not4 ,if it pleases you1 that pleasure is not dependent upon the fact that it does represent some place4 ,in the case of paintings and drawings as often as not they do not pretend to represent any place at all1 but are pure fiction1 yet we do not value them the less4 ,to what then is the pleasure we feel when looking at a good picture due8 ,is it not that a picture stirs up1 that is1 creates pleasant or beautiful thoughts and ideas--by pleasant ,i do not mean necessarily merry or joyous ones1 for some hearts feel profounder pleasure in the grandeur of storm or the majesty of the mountain than in the sweet wilderness of flowery wastes1 but notice that such beautiful ideas are created by the picture4 ,you were thinking of something totally different before you came upon the landscape picture which instantly made you feel the glowing light1 the stirring breeze1 and hear the rustling corn and noisy brook1 and yet it cannot be said it is because we recognise these things in the picture that we receive these impressions1 at least it is not the kind of recognition which takes place when we see a photograph of ,brighton ,pier or ,haddon ,hall4 ,notice1 it is not the exact and faithful portrayal of objects that creates the emotions instanced1 for if you closely observe the manner in which a good painting is done you will find that rude splashes of paint1 broad brush strokes1 and the like stand for foliage or water1 or corn stalks as the case may be1 when we know that had the painter desired he could have produced his likeness of nature with a good deal more of the precise detail and fidelity to outlines which photography excels in1 had he wished4 ,but if the painter or other pictorial artist needs not to trouble about accuracy to details to secure the effect aimed at he must be faithful to general facts4 ,there is a great difference between not recognising things or having no particular wish to do so1 and feeling conscious that a portrayal is so utterly unlike anything in our past experience of nature that we should not recognise the objects even if we were acquainted with them4 ,to take an extreme case--our enjoyment of the effect and sentiment of a beautiful landscape picture is not enhanced by our being able to recognise whether the trees are oaks or elms1 but it would be distinctly disturbed if the palm trees were represented as growing on the slopes of a ,welsh mountain4 ,innumerable examples and instances might be given to show that the artist1 whatsoever his medium1 be it colour or monochrome1 may depart from truth1 or may be indifferent to precise details1 only so far as he avoids palpable untruth4 ,why is this8 ,when we look at a powerful and impressive picture we feel at once the sentiment1 our emotions are at once stirred1 subsequently we recognise objects and facts portrayed1 but only when we begin to look for them or think about them2 but a gross exaggeration or a very obvious error strikes us at once before we begin to receive sentiments and ideas1 and that error or exaggeration once seen is never lost sight of1 and whole enjoyment of the picture is hopelessly marred4 ,now1 from the foregoing 7for want of space ,i am aware that the argument is incomplete1 and must therefore ask the student to think the matter out and grasp the side issues by reading between the lines7 we may formulate the broad definition that a picture does not depend for its excellence on the faithful representation of objects1 and is not chiefly valuable on account of our immediate recognition of things portrayed1 yet on the other hand it must not let us feel that there is obvious inaccuracy4 ,here then we have two opposite positions in both of which the mere objects employed to build up the picture are subordinated to the effect or impression of the picture4 ,in one case the spectator must not be allowed to feel that the representation is wrong1 in the other success will not directly depend on the representation being very right1 neither startling rightness or truth nor the obvious wrongness or untruth should thrust the objects composing the picture upon the beholder's attention1 he should be left free to receive the expression or sentiment of it4 ,i hope the reader is following me in this line of thought closely4 ,i am aware that it may seem dry and uninteresting1 but ,i see no other way of placing the student in a proper position at the outset than by explaining the essential elements of pictorial work1 and ,i will make this introductory part as brief as possible4 ,reverting now to our argument1 ,i have in other words suggested that obvious violation of truth will prevent the sentiment or effect of the picture from being paramount1 and now ,i will submit that an excess of accuracy to detail is equally detrimental to the success of a picture as a picture4 ,if by now the reader is prepared to admit that the chief purpose of a picture is the feelings1 emotions1 ideas which it suggests or creates1 and not the facts it portrays1 he will be able to go further and perceive that in a landscape1 for instance1 cottages1 trees1 or what not are introduced1 not for their own intrinsic interest but as vehicles of light and shade1 which go to express the picture's sentiments4 ,if we stand before a good picture with closed eyes and suddenly open them1 our first impression 7precluding any question of colour7 is that of masses of light and shade pleasingly and harmoniously arranged2 if we retreat to such a distance that the objects constituting those lights and shades are unrecognisable the balance and pleasing arrangement should still be felt1 and our sthetic sense is satisfied1 although we do not see fully of what the picture is composed4 ,this is the quality which is termed breadth and which is admittedly of very great value4 ,if on the other hand the shadow masses are filled with innumerable details1 and are thus broken up into tiny lights and shadows they no longer exist as broad masses of dark1 but if before retreating as proposed from the picture1 the lights or shadows appear so blank as to prompt particular investigation1 and upon examination we find detail absent which we know must have been present1 then we encounter an instance of untruth and exaggeration which is obvious and which disturbs our appreciation of other fine qualities4 ,thus we require sufficient detail to avoid giving the idea that detail is left out4 ,the delineation of sharp outlines and redundance of detail is not wrong in itself1 but it is usually inexpedient when considered with respect to the effect to be produced1 similarly the suppression of sharp focus both as regards outlines and details has no artistic merit of itself except as it assists the picture to impress the beholder first with the general effect4 ,the painter and photographer start from two opposite standpoints4 ,the painter1 or draughtsman1 starts with nothing but blank paper1 and having built up his picture and produced his desired effect he elaborates no further2 the photographer with his more or less mechanically produced facsimile starts from the opposite extreme with a transcendentally elaborate image1 from which he will require to eliminate all such excess of truth as is likely to force the mere facts of the view upon the beholder's attention4 ,photography1 so faultlessly complete in its delineation1 gives us more than the pictorial worker needs for the expression of an idea1 and this is why ,i would remind the student that pictorial photography is not photography in the full sense of the word1 but the application of some of its powers1 just as much as we need and no more1 to a definite end4 ,as just hinted the purpose of a picture is to express ideas1 hence ,i will fall back on a kind of definition which ,i have used on a previous occasion that a picture is the portrayal of visible concrete things for the expression of abstract ideas4 ,to give an example by way of exposition we may look upon a picture and be made to feel by it the calm and luminous atmosphere of evening2 we feel at once the restfulness1 and almost feel the warmth of the humid air1 giving place to the chill gathering mists of night2 but the same objects1 the same tangible materials1 paper1 pigment1 metallic salts1 etc41 in another picture give us the sense of angry turbulent storm or perhaps bright joyous sunshine frolicking with the fresh breezes on the hill-tops4 ,these are abstract ideas expressed or created by the manner in which concrete things1 commonplace facts1 are portrayed and rendered4 ,finally1 let me enunciate that a very excellent photograph may not necessarily be a good picture1 because it may contain more than is required for the expression of its idea1 and the surplus will overwhelm it2 again1 a good pictorial photograph may be but a poor photograph1 because if we claim the right to apply photographic means to pictorial ends1 we may find it convenient to leave out the very qualities which the scientific or technical expert considers most precious4 ,and now ,i think we may proceed to more practical matters4 ,,composition ,,and ,,selection4 ,in all matters from which the eye expects to derive pleasure1 symmetry of design seems essential4 ,in the formation of the letters that we write1 in personal attire1 in the decoration of our homes1 in buildings1 and practically in everything which is not of a purely utilitarian character1 a sense of proportion and a symmetrical disposition of parts is observed4 ,hence it is no source of surprise that in a picture which as much as anything should aim at pleasing the eye1 design1 otherwise ,composition1 is with ,expression a co-essential4 ,in a purely decorative production this natural desire of design is the only thing to be observed1 but in a picture which may be decorative1 but must be something more1 we have expression as well to consider4 ,if decoration alone were to be regarded1 something like fixed rules might perhaps be tyrannically laid down1 but in a picture the implicit observance of rules of composition would be certain to make itself seen in the result1 and the undue obtrusiveness of a code of rules would be as inimical to the supremacy of ideas and feelings1 as the excessive prominence of fact would be1 which has already been described4 ,hence the difficulty in prescribing any definite course for the beginner1 because whilst to most instinctive artistic temperaments a certain knowledge of or feeling for composition is natural1 so soon as this is reduced to definite rule and given to another1 the1 as it were1 secondhand use1 is nearly certain to betray itself by its misapplication4 ,i would ask therefore that any suggestions given here on the subject of composition should be taken as one takes lessons in the rudiments of a language1 which rudiments we violate and forget so soon as we have become proficient enough to speak it4 ,such rules in composition should be observed only so far as to avoid the appearance of having infringed or ignored them4 ,the rules of composition which may be found to apply in one of the pictorial arts must necessarily apply equally in the others1 and so therefore to pictorial photography which at least aspires to be considered an art4 ,if on a sheet of paper a rectangular space is given us wherein to draw the likeness of anything1 the most natural course to pursue would be to draw that figure in the centre or thereabouts1 and if then we are asked to add the likeness of two or three more objects we should naturally place these near the first object4 ,thus should we compose a group of objects which draw the attention to the middle of the picture or space4 ,suppose we are asked to draw the picture of a church tower we should probably comply with the request somewhat as shown in fig4 #a4 ,next we will suppose we are asked to add a cottage1 some trees1 and a path to the church1 we should1 if possessed of some sense of symmetry and order1 coupled with average intelligence1 make the additions somewhat as in fig4 #b4 ,it would surely be an unusual thing to follow instead the course suggested by figs4 #c and #d4 ,in figs4 #a and #b we have instinctively placed the primary object in or near the centre1 and the others near and around it1 and the result strikes one at once as being better composed1 that is1 more symmetrical1 than in fig4 #d1 in which amongst other things one is not sure which object to regard as the principal one1 and one also feels that but for the boundaries of the picture left and right we might have seen a good deal more beyond1 which would have added to the interest of the picture4 ,illustration3 ,fig4 #a4 ,illustration3 ,fig4 #b4 ,illustration3 ,fig4 #c4 ,illustration3 ,fig4 #d4 ,in this we have one of the first rules in composition1 namely1 that the principal object should be near the centre1 and the next important near to1 and as it were supporting it1 and no object likely to attract the eye should be so near the edge of the picture as to make us instantly conscious of the boundaries and wish to see more beyond4 ,but now if in compliance with the supposed request we had made our drawing as in fig4 #e1 might it not at once be felt by the observer that we had put the objects in a central position intentionally1 which is equivalent to saying that we had allowed our endeavour to observe the rule just laid down to betray itself4 ,fig4 #b is preferable as being only just sufficiently symmetrical to avoid being unsymmetrical1 which is an example of what has already been said about the necessity of observing rules of composition just so far as to escape the appearance of having broken them4 ,illustration3 ,fig4 #e4 ,illustration3 ,fig4 #f4 ,if this rule is right as regards voluntarily drawing a picture1 it is equally so in the case of a photograph1 but instead of deliberately placing things in such and such positions1 we attain the same end by moving the camera and selecting our point of view so that the objects come into the positions desired4 ,now suppose then1 we have done this1 but in doing it we are quite unable to prevent other objects coming into the field of view and occupying undesirable places near the margins of the picture1 as for instance in fig4 #f4 ,here we are brought to consider another rule or principle in composition1 namely1 that there must be one and only one chief object in the picture1 whereas in fig4 #f1 apart from the gate and tree on the one side and the windmill on the other attracting attention to the margins of the picture1 these same objects arrest the attention quite as much as the church1 and we feel the eye wandering about from one to the other and missing the sensation of centralization and rest which fig4 #b gives4 ,if we were drawing or painting we should put in what we want and then stop1 we should omit or ignore what we did not require1 but in photography our powers in this direction are limited1 and hence we must as far as possible select those views1 and only accept such1 as comply with what we feel to be right4 ,the angle of view included by different lenses is an auxiliary not to be neglected1 for by substituting a narrower angle lens1 that is1 one of longer focus1 we may cut off or leave out undesirable objects which the shorter focus lens might include4 ,then again1 when the print is finished we can after careful consideration cut off what would have been better left out1 for it will be better to have a picture half the size well composed1 than double the number of inches with a distracting and unsatisfactory arrangement of objects1 hence with many most successful workers it is no uncommon thing to take quite a small portion of a negative1 and either print it as it is or else enlarge it up to the desired size1 but mere size will reckon as nothing as compared with pleasing composition4 ,if it is inexpedient to let the principal object or group of objects occupy the exact centre of the picture1 measured from left to right1 it is equally so if the centre be measured from top to bottom1 and hence we may formulate the rule 7to be broken perhaps later when we are strong enough to be independent of guiding7 that the horizon should not be allowed to come midway between the top and the base of the picture4 ,illustration3 ,fig4 #g4 ,illustration3 ,fig4 #h4 ,remembering now that1 as set forth in the earlier part of this article1 a picture should appeal to our feelings and stir our emotions1 it may be pointed out that in most ordinary things1 and certainly in the arts1 the most powerful things are those which possess one dominant idea or feature1 as in a piece of music the refrain keeps recurring1 a preacher takes a text1 in a story there is one hero1 and so forth1 and in point of composition fig4 #g is better than fig4 #h1 although the view is less comprehensive4 ,illustration3 ,fig4 #i4 ,it may not1 however1 always be easy for the beginner to determine what is the chief object which should occupy the central position1 or which object or group to choose in a landscape4 ,illustration3 ,fig4 #aj4 ,this brings us to speak of another important matter1 and that is the right disposition of lines which form the view or the selection of view so that the lines formed by the component parts shall fall in a desirable manner4 ,the various objects in any view tend to form or suggest lines1 thus in fig4 #i the outline of the trees1 the bank along the shore1 the clouds1 and the boats suggest the lines shown in the diagram1 fig4 #aj1 which lines all run the same way1 but in fig4 #aa we have a similar view in which the lines suggested counterbalance each other1 and not only so1 but by their convergence they carry the eye to a spot near the centre1 and so make the boat1 although not very large nor conspicuous1 the one and principal object 7see diagram fig4 #ab74 ,illustration3 ,fig4 #aa4 ,illustration3 ,fig4 #ab4 ,for the sake of training one's perceptions look at any good pictures1 and in your mind resolve them into line diagrams and see how these lines fall1 and in considering any landscape or other subject to be photographed make up your mind as to what lines are suggested1 and then select your point of view so that these lines balance or are symmetrical in arrangement1 and also that they converge towards some point well within the picture1 and near the centre of it4 ,illustration3 ,fig4 #ac4 ,but in fig4 #ac we have a subject in part well composed1 but the composition is spoilt because of the line formed by the road and fence1 which seem to cut the picture in two1 whereas could we have chosen the same subject from a point of view giving such an arrangement as fig4 #ad1 a difference is at once felt and a more pleasing effect gained4 ,illustration3 ,fig4 #ad4 ,illustration3 ,fig4 #ae4 ,illustration3 ,fig4 #af4 ,lines which seem to separate us from the picture and cut off one part from another must be carefully avoided1 and an endeavour to find something which will1 as it were1 lead the eye into the picture1 should be diligently sought for1 and indeed a subject1 however it may interest us1 must often be abandoned if it lacks those things which go to make pleasing composition1 remembering as we should always do that in pictorial work the fact that objects are curious1 or interesting1 or pretty1 has nothing to do with the case1 but that they are only to be valued according as they act as media for expressing pleasing ideas1 beautiful thoughts and sentiments1 which they will not do if some part creates a feeling of unpleasing arrangement or design4 ,if a scene does not compose well1 we should as pictorial workers feel no desire to reproduce it4 ,but you may say ,cannot we often by changing our point of view get an otherwise ill-composed subject to compose well8 ,most decidedly1 that is precisely what we should do1 but it is no longer the same subject or view4 ,and now let me say that it is often surprising how much alteration may be made by changing our position4 ,figs4 #ae and #af are together an instance of this1 the outline here given being made from a pencil sketch made on the spot1 whilst figs4 #ag and #ah are examples of the desirable change brought about by watching and waiting for a change in the position of light and the condition of the river's tide4 ,illustration3 ,fig4 #ag4 ,illustration3 ,fig4 #ah4 ,where the beginner most often fails is in taking things as they are without pausing to consider whether they might not be improved1 and if so in what way1 and then patiently searching to see if such better way can be found4 ,pictorial success will as often as not depend on the exercise of fastidious taste1 which is satisfied with nothing but the very best1 and not quite content even then4 ,a great deal more might usefully be said with reference to the composition of lines if space would permit1 but this general reference may be given as a sort of summing up4 ,if the disposition of the lines constitutes such a perfectly symmetrical design that it is at once recognised as symmetrical1 then it is wrong1 because the artifice by which pleasing composition is attained is betrayed1 and we feel the thing to be artificial4 ,if1 on the other hand1 the lines fall so as to make the beholder conscious of their presence1 as1 for instance1 cutting off a portion of the subject or presenting a one-sided appearance1 again it is wrong4 ,in neither case should the lines or the objects suggesting them be felt at all until sought for1 neither as being very right or very wrong4 ,in art it is a maxim that the means by which the thing is done should not proclaim itself1 and hence it must apply to pictorial photography1 which is an effort after the artistic4 ,a composition should please without our quite knowing why1 and without our being able to see the machinery1 as it were1 by which our pleasurable sensations are set in motion4 ,but whilst it is convenient to speak of lines in the landscape1 it is only a manner of speaking1 for1 as we know very well1 photography1 unlike pen drawing1 has to do with tones1 that is1 masses of light and shade4 ,now the general rules suggested as regards the arrangement of lines1 apply in much the same way if we regard a picture 7as we should do7 as consisting of masses of light and shade4 ,if when standing before a picture we close the eyes and then suddenly open them1 our attention is certain to be drawn to the highest light or the deepest shadow1 and hence1 as a general rule1 whichever of these is the strongest to attract attention1 that should be in or near the principal object 7indeed it will make of itself the principal object71 and should therefore be well removed from the margins of the picture4 ,refer back to fig4 #h1 in which the light patch of sky1 the light in the water and the two clusters of light rushes1 all form competing points of attraction1 and if these are too near the margins1 they remind us of those margins1 hence the improvement in effect when these are cut away or left out4 ,but disposing of the highest light and deepest dark does not finish the matter4 ,there is a certain relative degree of lightness and darkness between everything in nature4 ,moreover1 colours have to be interpreted by certain degrees of light and shade according to the distance objects are away from us1 and according to the amount of light falling on them4 ,such relative lightness and darkness is called tone4 ,the word used in this sense has nothing to do with tone as applied to the colour of a print1 which colour we change by a process we call toning1 and upon the correct rendering of relative tones so much of the effect of a picture depends1 and so much of its emotional qualities4 ,generally speaking1 although there are often exceptions1 the further an object is from us the grayer it seems4 ,white becomes less white1 and dark objects grow less dark1 until in the distance both1 under ordinary circumstances1 come almost to the same tone1 and we see the distance only as a gray hazy mass4 ,if for a subject we have a figure of a woman by a stream of water and we make an under-exposed negative of it1 or develop the negative to too great a density1 we shall very likely have a print in which the water and the woman's apron and cap come very much whiter with regard to the rest of the subject than ever they appear in nature1 whilst the distance will very likely come too dark4 ,here we show a disregard for the correct rendering of relative tones and the effect is hard and harsh1 unlike nature4 ,we must therefore endeavour1 both in exposure and development and printing1 to preserve relative tones exactly as they are in nature1 and constant study and observation of nature should be carried on in order that the eye may be trained to know how things come relatively in nature1 and so be able to decide at a glance if the photograph is good4 ,ultimate success1 by the way1 often depends less on knowing what to take and how to take it than on a well-trained judgment which knows what is good or bad when we have taken it4 ,whilst the mere lines or forms of objects may impart some amount of feeling and sentiment to a scene1 inasmuch as there is restfulness and repose in the long horizontal lines of the river-side pastures1 something rhythmical in the sinuous curves of the winding stream1 or vigour and variety in the irregular forms of the rugged cliffs and so on1 yet the ideas and feelings which the picture will promote depend more on the lights and shades1 and the masses contrasting or merging each with each4 ,but ,nature does not always present herself in pleasingly arranged masses1 and is consequently at such times commonplace and unpicturesque in the literal sense of the word4 ,at such times she will not attract the pictorial worker any more than she will when perchance the lines and groupings are unsuitable4 ,the landscape which basks under the full blaze of sun1 glittering throughout every inch with a myriad twinkling lights and sharp details1 awakens no feeling akin to those which probably everyone feels when in the twilight of evening plane after plane recedes as one broad flat tint behind the other4 ,under the bright light of day we may wonder at the richness and plenty upon the earth1 we may rejoice in that there are so many curious and pretty things to look at1 but these are like the feelings inspired by reading a book on natural history1 rather than the emotions created by the perusal of a poem1 or listening to sweet music4 ,illustration3 ,fig4 #ai4 ,compare for a moment the two photographs1 fig4 #ai and fig4 #bj4 ,the first is by no means an extreme case of the ordinary photograph1 and notice that although the composition is fairly good as far as grouping goes1 there is an absence of any quality which might make one feel anything outside the bare recognition of the facts depicted1 but the second1 if it be good at all1 must depend for admiration on a certain amount of sentiment which it suggests or creates4 ,you will notice that in the first there is no sense of distance1 and although a church tower1 behind the masts of the boats1 is half a mile or so away it does not possess the tone and veiling of atmosphere which would make it appear distant4 ,every part of the view seems equally near1 or nearly so2 the eye wanders over the whole1 alighting on details here and there which interest and amuse1 yet there is an absence of just that breadth which is noticeably present in the second example4 ,illustration3 ,fig4 #bj4 ,now let it be distinctly understood that detail1 its omission or suppression1 and its introduction or sharp delineation1 is not a question of lens focus only1 or even chiefly1 but it is largely a question of light4 ,imagine the photograph1 fig4 #ai1 with the greater part of the detail taken out so that the quay1 the houses1 the shore1 etc4 were just broad masses of lighter or darker tone1 should we not then get a composition which would be less disturbing1 more compact1 more concentrated in interest8 ,is not this the case in fig4 #bj1 in which detail is almost entirely absent8 ,and yet detail could not have been truthfully introduced in this photograph1 because with the light in the position it is1 and in the misty evening air1 no detail was there to reproduce2 it was the fact that objects ranged themselves in masses one against the other1 leaving room for imagination and creating ideas that determined its selection and its consequent portrayal4 ,in many cases a clear and sharp delineation of details will perhaps be desirable1 not1 however1 for the sake of showing detail1 but just so far as the production of the effect may require2 on the other hand1 just the full amount of detail that a lens will give is by no means always wanted4 ,lenses were not invented for pictorial purposes1 and therefore there is no reason for concluding that what the lens gives is necessarily right1 for remember that we started with the distinct understanding that we were merely applying to a certain purpose just so much of the photographic process as we considered we needed2 because ,i have the means of travelling at sixty miles an hour there is no reason why ,i should not apply the same means of locomotion to coaching a pedestrian at a tenth of that speed if ,i choose4 ,it may be said that in the two photographs referred to the comparison is not a fair one1 because so much depends on the sky4 ,granted that much in the second example does depend on the sky1 which is an essential part of the picture1 and indeed one cause of its very existence1 but in the other 7fig4 #ai7 the presence of clouds would not improve the pictorial faults to which reference has been made4 ,as a mere record or portrayal of ,old ,woodbridge ,quay1 the absence of clouds is as much a characteristic of its particular species1 as the clouds in the second one are inseparable from its existence4 ,so1 but little more than half hinting at the principles involved in the due suppression of unnecessary details1 and the elimination of undesirable objects in order to obtain breadth1 and having said but little as to the preservation of correct relative values or tones1 ,i must pass on4 ,every corner of nature's broad expanse is1 as it were1 enveloped in atmosphere1 and invisible as we are commonly in the habit of considering it to be1 it affects to a greater or less degree everything we see1 and the visible atmosphere is often responsible for some of nature's most beautiful and most appealing aspects4 ,obviously then we cannot afford to leave out so important a contributory to picturesque effect1 and it is on this account rather than on account of sharp or un-sharp detail that the question of stops and lens apertures comes in4 ,look at the image of a landscape on a moderately hazy day1 as it appears on the ground-glass focussing screen of your camera1 using the lens at full aperture--then quickly insert f_/#cb1 and notice the difference4 ,not alone have objects near at hand and more remote become more sharply or more equally defined1 but you may also notice that objects are more brilliant1 and that a sense of atmosphere has been cut out4 ,compare if you will two photographs1 the one made respectively with full aperture of f_/#f or f_/#h and the other made with f_/#cb or f_/#de1 and provided that in the first case we have not actual blurring to the extent of destroying form and structure1 does not the first remind you more of nature8 ,i do not say it is so instructive1 so surprising1 so dainty1 or of such exquisite finish1 but is it not more reminiscent of the effects we remember to have seen and felt in nature4 ,it is not the function of this article to say to what optical laws this difference is due1 and yet the student may expect to receive something by way of practical working instructions4 ,my recommendation is then to use a single landscape lens or the single combination of a doublet1 and in starting to use the full aperture4 ,with this it may be that when the foreground is moderately sharp1 trees more remote are so ill defined as to appear as a collection of little blots and irregular patches4 ,whilst sharp detail in all places may not be productive of pictorial effect1 yet the extreme opposite will be displeasing in another way1 and it will be best to secure just so much definition and no more as shall save the representation from appearing to have been wilfully put out of focus--once let the destruction of detail be obvious and we betray the artifice by which we are working1 which is just what we should avoid4 ,in the case just supposed then1 we may now introduce the first stop1 simultaneously racking the lens in a little until we get middle distance without unpleasantly obvious blurring4 ,the foreground may be a little out of focus1 and in practice ,i find it is rather helpful to general effect if detail is sacrificed more in the foreground than in the middle distance4 ,this ,i believe is contrary to the teaching of many1 but my feeling is that with a sharply defined foreground the eye is attracted and the interest so far arrested1 that it is difficult to travel further and enter into the poetry and sentiment of the scene beyond4 ,wide-angle lenses have a double disadvantage1 shared in part by so-called rapid rectilinear doublet lenses4 ,in the first place they flatten the view1 bringing distant planes to appear as near as the nearer ones1 and by including a comparatively wide angle they bring into the plane of the foreground1 objects so near that they appear out of proportion1 and hence proportions are false when judged as the observer must judge by the standard of visual perspective4 ,a long-focus1 narrow-angle lens necessitates a camera which racks out to a considerable length1 and probably a greater extension than any camera in the ordinary way can give1 would be an advantage on some occasions4 ,passing reference has been made to the interpretation of colours in nature in their true relative value of black and white4 ,if we have a subject in which brilliant orange-coloured rushes in autumn are seen as glowing bright against a background of dark blue water1 and the rushes made still more golden of hue by the ruddy rays of a sinking sun1 a difficult case is before us4 ,such a case ,i remember very well in the south of ,devonshire1 close to what is known as ,slapton ,ley4 ,it was late afternoon in ,november1 and from over the rounded hills behind me to the westward1 the declining sun sent warm red rays on to the belt of faded reeds which stretched out into the expanse of the still land-locked water of the ,ley--a great sheet of fresh water which placidly lay under the shelter of the bank of shingle which alone separated it from the ever-restless sea--placidly listening to the ceaseless voices of sea music1 and at this particular hour reflecting the sky deep blue and of almost leaden hue--just above the bank rose the full moon1 orange in tint1 on a background of blue-green sky--the yellow reeds1 kindled into glowing amber tints by the sun's rays1 flamed out from the deep blue water--yellow the shingle bank against the blue water and green-blue sky1 deeper yellow the moon as it rose from out the sea4 ,so grand a scheme of colour that by its side the essays of the most daring painter might well seem feeble1 so exquisite a poem that the intrusion of the photographer1 analysing the values and tones and calculating his powers of reproduction seemed like sacrilege4 ,in the main it was yellow1 orange-yellow1 and red standing out as luminous against the deep blue of water and only a little less blue sky4 ,it was gorgeous non-actinic colour appearing as light against a highly actinic but darker colour4 ,the consequence of an indiscreet exposure with an ordinary plate might be anticipated to produce dark rushes against a pale grey background of water1 and so probably the very effect we were minded to secure1 reversed and dissipated4 ,this is an extreme case1 perhaps1 but throughout the whole range of nature the contrasting and blending of adjacent colours is so subtle a thing that ,i should feel one were throwing away at least a possible advantage by not using colour-corrected or isochromatic plates on nearly every occasion1 and in order to get the full advantage of isochromatic plates1 ,i should consider the addition of a yellow screen an essential4 ,the rapidity of one's plates1 isochromatic or otherwise1 must be governed entirely by the nature of the subject1 as also to some degree must be development and subsequent printing4 ,in every case ,i would endeavour to get a comparatively thin negative1 with even the portions representing deepest shadows slightly veiled4 ,clear glass shadows is an enormity and an outrage both of science and art2 equally are solid high-lights to be shunned4 ,with modern printing methods it needs much less than actual opacity in the negative to produce white paper1 and if the picture requires any part of it at all to appear as quite white1 no subject will need more than the very smallest region to be so4 ,a general softness and very subtle gradation1 with a total absence of sparkle and brilliancy in the negative1 will yield by at least most processes the most suggestive print1 bearing in mind that delicate gradations suggest atmosphere1 and atmosphere is one of nature's most precious qualities4 ,whilst plain salted papers sensitized with silver present possibilities not yet sufficiently exploited1 yet until such time that something more entirely satisfactory in all respects is given us in silver papers1 platinotype and carbon1 and perhaps also gum bichromate will be the processes most suitable for our purpose4 ,personally1 platinotype has been the favoured medium1 being1 as ,i believe1 more ductile and more amenable to various methods of control than is generally recognised4 ,and leaving much more of importance unsaid than space limits admit of my saying1 ,i must leave it4 ,a4 ,horsley ,hinton4 ,architectural ,photography4 ,illustration ,to the majority amateurs1 the photographing of architectural subjects presents considerable1 and in many cases apparently insurmountable difficulties4 ,undoubtedly there are difficulties to be grappled with1 but they are neither so formidable nor so numerous1 but that any ordinary photographer with the average amount of common sense can master them be he so minded4 ,unfortunately there are a great many who take up photography as an amusement to whom the slightest departure from the ordinary routine presents a difficulty4 ,it is however to the amateur photographer who desires to be able to portray architecture1 be it either of our cathedrals1 churches1 historic mansions1 or places of personal interest1 and at the same time wishes to be able to do the subjects fair justice1 that it is hoped the following particulars may be of some service4 ,to the beginner taking up this or indeed any branch of photography1 size is of course a great consideration either from the weight carrying or pecuniary point of view4 ,another reason is the fact that young photographic workers have an idea that the smaller the plate1 the easier the working4 ,sound though this reasoning may appear1 nevertheless it is not entirely correct4 ,as a matter of fact all things being taken into consideration the larger the plate up to #ab #aj or #ae #ab employed the more rapidly will the worker progress4 ,large plates1 especially in architectural work1 tend to make the operator more careful and conscientious when out with the camera2 and even more so when in the developing room4 ,so much more can be done with a large plate than with a small one2 the use of a large plate moreover checks the common failing so prevalent among amateurs of rushing work and recklessly using plates4 ,taking all things into consideration1 ,i would strongly recommend the whole plate or #aj #h camera to the student taking up this branch of our art4 ,in selecting a camera purchase a front extending one with bellows only slightly tapering4 ,see that it has both rising and cross movement to the front1 and also that the amount of movement in each case is a not too restricted one4 ,makers1 unfortunately1 do not give sufficient attention to this matter1 the usual rise allowed being very slight whereas it should be at least equal to one-third of the longest way of the plate2 even more than this is advantageous if it can be obtained4 ,by the rise ,i mean the amount of upward movement that can be obtained1 the lens being in the centre before starting4 ,the cross-front should have a movement of about one-quarter of the length of the plate each way4 ,it may be useful to know that a little more rise can be obtained by the placing of the lens above the centre of the cross-front2 reference to the photograph of camera will explain this matter more fully4 ,the swing-back should be a practical one1 working from the centre1 and capable of being swung either to or from the lens4 ,in many of the cheaper front extension cameras it is not possible to use the swing-back when tilting the camera down1 only when tilting upwards4 ,the swing-front1 although not an absolute necessity1 is undoubtedly a movement possessing great advantages1 especially when the front is raised rather high1 and one is using a lens of limited covering power4 ,this movement should be acquired if possible4 ,the camera should possess double extension1 focussing by rackwork1 and having a reversing back so made that it will fit on all ways2 it is then possible to draw the slide shutter out in any position4 ,in selecting a tripod stand purchase one of the kind known as the sliding leg variety1 two-fold is better than three1 giving greater sliding power4 ,the top of stand should be as large as possible2 this is preferable to a turntable1 as this piece of workmanship is seldom rigid after a little use1 and some difficulty is experienced when trying to spread the legs out rather wide4 ,a two-fold ,ashford stand is as good as any on the market4 ,the blocks herewith illustrate the kind of camera used by myself1 and with the exception of the turntable1 which is not a great success1 it answers all requirements4 ,in the selecting of suitable lenses a great deal will depend upon the inclination of the purchaser and the depth of his pocket4 ,there is such a great variety upon the market at the present time1 that to the young photographer the buying of the right lenses is somewhat a difficult problem4 ,illustration ,illustration ,the ,zeiss series are undoubtedly the finest obtainable and for architectural work are unrivalled1 possessing great covering power1 good marginal definition1 and in fact very fine definition all over the plate4 ,the lenses of this series1 although quite new1 have met with great favour amongst architectural workers4 ,they work at an aperture of f_/#ah1 but ,i understand that they can be opened to f_/#af and numbered on the f system4 ,as regards their relative working capabilities they give about the same picture at f_/#cb that the majority of wide-angle lenses give at f_/#fd4 ,the ,goerz anastigmats are also another very fine series but do not give anything like the covering power of the last mentioned1 and moreover are nearly double the price4 ,their special merit is that one can work at f_/#h or f_/#aa1 and get a picture sharp up to the edges4 ,taylor1 ,taylor ,hobson also make a good wide-angle lens1 possessing great covering power and at a moderately low price4 ,with one of their nine inch lenses ,i have covered a plate #ab #aj inches4 ,illustration3 ,,gather ,,the ,,roses ,,while ,,ye ,,may1 ,,old ,,time ,,is ,,still ,a-,,flying4 ,,alex4 ,,keighley4 ,for a whole-plate camera1 a useful battery would be a #e inches1 #g-a_/b inches1 #i inches and #ab inches2 for #aj #h1 #g inches1 #i inches1 #aj-a_/b inches and #ad inches4 ,the three last in each case are the most useful4 ,having selected the lenses1 another very important point and one not to be decided hastily is the question of levels4 ,four are required1 two circular and two ordinary4 ,they are placed as follows3 ,fix the circular levels1 one on the baseboard near the front of the camera1 the other on the top of the back part of camera4 ,the other two should be placed one on the side of the back part and the other on the back of camera just under the reversing back4 ,care must be taken to purchase slow moving levels as some work so quickly that it is next to impossible to level the camera with them1 and as this is one of the most important points in the whole business1 too much care cannot be taken in selecting and fixing the right kind of level4 ,illustration ,the focussing screen should be ruled as accompanying diagram4 ,this will divide the screen into inch squares1 working from the centre1 and will considerably assist the photographer in sizing his subject up4 ,one other thing required is a set of clamps for binding the tripod legs together4 ,these are1 ,i believe1 made by ,george ,mason1 of ,glasgow1 but any dealer will procure them for you4 ,the use of the right kind of plate constitutes a very important factor in the production of a satisfactory negative1 particularly in this branch4 ,owing to the greater difficulty experienced in developing extra rapid plates1 one generally sees the slower variety recommended4 ,no hard and fast rule can however be laid down4 ,to gain the best result1 the plate must be suited to the subject4 ,for instance1 in a very dark interior in which heavy black shadows predominate1 many of them appearing much darker than they really are owing to their close proximity to a strong light1 the quicker the plate used the better4 ,this tends to break down the harsh contrasts1 and at the same time the shadow detail is considerably better rendered4 ,on the other hand1 working in a light interior or one which is flat owing possibly to the large amount of light present1 a slower plate can be used with advantage1 and1 providing the exposure is sufficient the result will be all that is wished for4 ,exteriors1 particularly those in sunshine1 should be photographed on a fairly quick plate4 ,slow plates1 although good1 do not yield nearly such good negatives1 and unless very fully exposed give excessive hardness4 ,taking this class of work all round1 the quick plate is the more useful of the two and is undoubtedly the best for interior work1 particularly such interiors as one meets in our ,english cathedrals4 ,for all subjects possessing strong high-lights1 such as windows1 stained or otherwise1 rapid plates combined with a suitable backing composition yield the best results1 and ,i would impress upon the reader the fact that no plate should ever be placed in a dark slide without being covered at the back with a suitable composition for the prevention of halation4 ,illustration ,the value of this agent is distinctly demonstrated by the accompanying illustrations1 and ,i would point out the fact that the negatives were both developed with the utmost care4 ,the unbacked plate was so developed as to prevent the appearance of halation as much as possible1 and it will be noticed that all portions of the photograph1 other than that where halation has occurred1 are nearly as good in the unbacked as in the backed one4 ,having obtained all the apparatus and materials1 a very good subject to begin on and one giving good opportunities for the exercise of the various movements connected with the camera1 etc41 is a general view of the choir in some cathedral or church near at hand4 ,having erected the camera1 the next thing is to decide upon the most pleasing point of view4 ,speaking from my own experience ,i would advise the shifting of the camera either to the right or left1 so that the centre aisle is thrown slightly in perspective4 ,this tends to give a much better and decidedly more pleasing effect to the resulting photograph4 ,of the two sides1 moving to the right seems to be the best4 ,the next item is the fixing of your ground line1 this must be so arranged that it is quite clear1 not obstructed by the backs of chairs1 etc41 which look very badly if left standing4 ,personally1 ,i have generally found it necessary to move one or two rows of chairs so as to make the ground line myself4 ,in adjusting the height of the camera from the ground it is well never to exceed six feet4 ,five feet to five feet six inches is the most useful height4 ,this will give a photograph in which the point of sight is the same as that of the person actually viewing the subject4 ,the placing of the camera on step ladders1 chairs1 or other supports1 so as to overlook objects in the immediate foreground is a practice to be condemned1 giving results very rarely pleasing and always bad from the sightseer's point of view4 ,having settled upon the point of view and the lens to be used1 the student should then roughly focus the image4 ,notice the amount of subject on the plate and how much rise is required4 ,if having a camera such as described1 the rise is easily accomplished and the camera can then be truly levelled up4 ,care should be taken over this as unless you have the camera exactly level you cannot expect a true picture4 ,the bubbles of the levels should be exactly in the centre1 a little bit out will not do4 ,illustration ,if it is found that the rising front fails to give the amount of subject required1 recourse must be made to the swings1 and it is here that the swing front triumphs over the swing back4 ,to swing the back necessitates the shifting of the camera and tripod stand1 and at once throws all the levels out of gear4 ,then comes re-focussing1 etc4 ,sometimes this will have to be gone through five or six times before the desired amount of swing has been achieved4 ,owing to the re-focussing required every time the camera is moved it is very difficult1 especially for the beginner1 to rightly estimate the amount of rise required4 ,with the swing front the desired amount of rise is attained easily and quickly1 and it can be worked with the head still under the focussing cloth1 which is a great convenience4 ,at the same time the baseboard and back of camera always remain level4 ,after gaining the correct amount of rise the sides of the subject should be considered4 ,a golden rule to remember in this class of work is when you show a column1 show the base of it1 and always start the sides of plate with either half or three-quarters of a column4 ,it looks very queer to see the bend of an arch wandering away out of the side of the picture without any apparent support4 ,in arranging the sides it is usual to have a preponderance of subject on the opposite side to which the camera is1 and to start that side with a column4 ,sometimes the subject fails to fit the plate nicely1 in that case it is better to trim the print than to have uninteresting features present4 ,of course a great deal depends upon the personal taste of the worker1 what one man considers right another will rebel against2 so although ,i advocate the use of columns to fill the sides of the plate it does not follow that that is the one and only method of photographing these subjects4 ,the student having carefully gone into these matters and arranged the subjects to suit his own satisfaction the question of what point to focus for arises1 and indeed in very dark interiors the question of focussing anything at all comes in4 ,a method ,i use myself is to roughly divide the distance from the camera to the farthest object in half1 and then to focus midway between the camera and the middle of the subject4 ,then stop down the lens until the most distant object is sharp4 ,in practice ,i have found this rule so good that ,i can recommend its adoption for all subjects1 and if carried out correctly will always result in the production of crisp negatives4 ,exposure is not a very difficult thing to overcome4 ,arrange the focussing cloth well over the head1 open the lens out to its largest aperture and remain under the cloth until you can see the image distinctly all over the plate4 ,then without uncovering the head proceed to slowly stop down until you can only just see the image all over the plate4 ,now using a plate of the rapidity of ,barnet extra rapid1 an exposure of ten minutes will yield a satisfactory fully exposed negative4 ,the varying exposures for other plates and stops are easily obtained4 ,for instance you find the image can just be seen all over at f_/#cb and you wish to use f_/#fd ,the exposure will be forty minutes4 ,after having used this method for over seven years1 and having invariably found it correct1 ,i can unhesitatingly recommend its adoption1 and if used with a little common sense the worker will seldom suffer from his plates being either badly under or over-exposed4 ,in photographing side aisles1 transepts1 or long rows of pillars1 the worker is often troubled by the unnatural way in which the floor runs up4 ,this is more especially noticeable when there are no prominent objects in the immediate foreground4 ,a considerable amount of this can however be overcome by the lowering of the camera to about three feet from the ground4 ,it is here where the sliding legs of the tripod stand become of service4 ,i would ask the student always to use the longest focus lens possible1 consistent with the effect desired4 ,the use of extreme wide-angle lenses has had a disastrous effect upon the public taste in respect to architectural photography due principally to the abortions one sees exposed for sale in the shop windows of our cathedral cities4 ,it should be seldom necessary for the amateur to use very wide-angle lenses4 ,of course1 when it is a question of getting a detailed photograph in a confined situation a wide-angle lens is of great service4 ,but it is when you see the whole length of a cathedral photographed on a whole plate with a five inch lens that the fault is so noticeable4 ,in photographing exteriors great care should be taken in the placing of the camera in a suitable spot4 ,try and so arrange it that the short side of the building does not run off too violently1 indeed1 it is often much better to leave out a portion of the subject rather than to cram the whole subject upon the plate4 ,general views are much better if photographed when there is a little sunlight4 ,this gives to the subject a sharp1 clean-cut appearance4 ,details on the other hand are better if photographed in a subdued light and slightly over-exposed4 ,in focussing very high subjects some difficulty will be found in getting bottom and top in focus at the same time1 especially if the lens be strained by either altering the back or front of the camera4 ,the best place to focus is a little way above the centre of the screen1 so that when stopped down the bottom of the building is quite sharp4 ,a slight softness towards the top of the subject is scarcely noticeable in the final print4 ,the exposure of exteriors varies between three seconds at f_/#fd to ten minutes1 and no correct guide can possibly be given4 ,to the beginner a ,watkins' exposure meter will here be of some service4 ,if people are continually passing and repassing stop the lens down to f_/#fd and give as long an exposure as is possible2 this will as a rule completely obliterate them4 ,i have found that an exposure of from ten to twenty seconds entirely destroys all trace of moving objects4 ,another method of making an exposure where there is much traffic past the building1 and perhaps people standing about whom you cannot very well ask to move1 is1 to break the exposure as many times as possible4 ,expose for two seconds1 then wait until the traffic has somewhat altered2 then give another two seconds and so on until finished4 ,by this means ,i have been able to photograph buildings in the centre of a crowded street or thoroughfare without a trace of anybody showing4 ,it is often interesting for the student to be able to successfully tackle the photographing of drawing-room1 ball-room1 or other apartments either of his own or friends' houses4 ,this work is considerably more difficult than it seems2 and it is in such subjects that the taste of the operator becomes manifest4 ,a great deal depends upon the point of view chosen and also upon the arrangement of the furniture4 ,if a long room1 the camera should be placed at one end at about a quarter of the width of room away from one side and from the end wall4 ,keep the camera parallel with the sides of the room and use the sliding front so as to obtain more of the opposite side of the room4 ,this will give the ceiling a true square appearance and the side of the ceiling will not run off with an unpleasing effect4 ,in some subjects it is perhaps necessary to include one or more windows4 ,this can of course be accomplished by the aid of backed plates1 but it is always better to block those particular windows out4 ,this is usually done by covering the outside with black cloth or brown paper or pulling the sun blinds down4 ,to get the effect of the windows you must remove the paper or cloth at the end of the exposure for a few minutes1 three minutes being generally sufficient4 ,by this means it is possible to show the landscape as seen from the window4 ,do not place your camera too high4 ,four feet to four feet six inches is quite sufficient4 ,if the camera is higher you look over the immediate foreground objects1 touching the ground past them1 which is undesirable4 ,in arranging the furniture be careful that round or oval objects are not placed so that they appear on the edges of the plate which gives them an exaggerated appearance4 ,in exposing on all such interiors ,i would strongly recommend a very full exposure1 the object being to flatten the subject4 ,a great thing to study in this branch of work is the careful lighting of your subject4 ,this can be largely varied by the use of the inside blinds1 also by the sun blinds found outside many windows4 ,it is not advisable to draw the blinds up to their fullest extent4 ,by so doing you accentuate your cast shadows thrown by tables1 chairs1 etc4 ,in fact1 the softer the light in the room coupled with a corresponding exposure1 the better the result4 ,another point to notice is that a comparatively dull day is often the best for interior work1 the light being much softer and subdued4 ,as a slight guide to exposure ,i would suggest that an additional twenty-five per cent4 be added to that recommended for church work4 ,john ,h4 ,avery4 ,the ,hand ,camera and its use4 ,illustration ,what is the best form of hand camera8 ,how often this question is asked1 and yet how impossible to give any definite reply1 the conditions of use1 and requirements of each worker being so widely different4 ,one1 desires a form of apparatus1 capable of being closed up into the smallest space1 weighing but the least possible number of ounces1 the necessary movements1 confined to touching a spring1 or pressing a button1 and the total cost not to exceed two or three pounds1 while others do not care so much as to its possessing these qualities1 if by a little increase in bulk1 weight1 and cost1 it is capable of use in a less restricted manner1 on subjects of wide variety1 and under such conditions of light1 and atmospheric effects1 as1 when shutter exposures are being given1 call for the maximum light passage to the plate4 ,assuming the camera to be intended exclusively for use without a tripod1 then it becomes not a difficult matter to point out its essential features4 ,first and foremost1 it should be characterized by simplicity in construction1 and every part be easily accessible1 complicated movements being rarely found necessary1 except perhaps1 to raise the price of the instrument4 ,when being employed in the field1 the camera and its working parts ought not to need the slightest consideration1 each movement1 whether they be few1 or many1 being made1 without requiring troublesome attention at the moment when every thought should be devoted to the subject4 ,the component parts of an instrument1 complete and effective for this class of work1 may be taken to be a good lens capable of covering at f_/#h1 a shutter1 some simple means of focussing1 adequate finders1 and the means of carrying plates either in some form of magazine1 or ordinary dark slides4 ,each system of holder for plates possesses its own distinctive advantages1 which are preferable1 depending entirely on individual needs1 or tastes4 ,some admire one method1 and some the other4 ,when plates are carried in one of the many forms of magazine which cameras are nowadays fitted with1 it is important when re-charging it1 that care be taken to see each sheath and plate is laid true in its place1 as the slightest irregularity at this point1 means certain trouble when changing a plate after exposure1 indeed1 perhaps fifty per cent4 of the misfortunes which occur when out at work1 from failure to act of the changing arrangements1 are directly caused by carelessness when laying the plates in the magazine4 ,given reasonable care in this matter1 almost any of the modern automatic changing methods1 may be relied on to answer satisfactorily4 ,when however the slight additional bulk1 weight1 and it may be increase of cost is not objected to1 then there can be no denying separate dark slides possess many and important advantages4 ,no need to fear a wasted day1 caused by some plate sticking1 and rendering further work impossible1 without having recourse to a dark-room1 which probably is miles away2 and again1 one must not overlook the opportunity they give of carrying plates of different degrees of sensitiveness1 a matter of service1 when subjects to be dealt with are varied1 such as1 say1 clouds and water1 landscapes and figures4 ,in the first case1 when light is fairly good1 the ordinary speed plate will be found amply quick enough during the daytime1 and fifty per cent cheaper in price4 ,when open landscapes are being taken1 during summer time1 medium rapid plates generally will be quick enough1 but many opportunities1 for pictorial work1 arise under conditions of atmosphere and light1 in which to obtain fully exposed negatives with a shutter1 demands a plate of extreme sensitiveness1 and if for no other reason than that they offer this opportunity of carrying a varied assortment of plates1 many workers prefer dark slides1 to any form of magazine4 ,there are advantages1 and disadvantages1 with both systems1 and it becomes simply a question for each worker to consider which fulfills his requirements best4 ,the ,lens4--,good work can be1 and is done1 with cheap single lenses1 but the opportunities offered are considerably restricted1 what is needed1 being such a lens as may be used at full aperture of f_/#h or f_/#f1 and will then cover the plate from corner to corner1 sharply4 ,this is necessary not only because the actinic quality of light is not always over good1 but that moving subjects demand the shutter should be working with rapidity1 sometimes indeed with considerable speed3 under which conditions two factors are absolutely essential1 a large working lens aperture1 and a rapid plate4 ,it is well1 therefore1 to buy the best lens you can afford1 it more than pays in every way4 ,for #a_/d-plate work1 a rectilinear of #e1 or #e-a_/b in4 focus1 working say at f_/#e4f1 and with iris diaphragm1 by one of the best makers1 will allow work being done under any condition of weather1 or other circumstances1 when shutter work is possible4 ,finders4--,years ago1 the question of whether finders were necessary1 or not1 in a camera of this kind1 was a matter on which some at least expressed very different opinions1 from those now held by most workers4 ,further experience has shown that when certainty in working is desired1 some kind of finder is an absolute necessity as part of the working mechanism4 ,it usually takes the form of a small camera obscura1 what is required being1 that it should not be too small1 should give a perfectly discernible image1 and be so adjusted1 that only so much of it is shown1 as will be projected on to the sensitive plate1 when the exposure is made4 ,the reason of its importance is that it enables the subject being arranged tastefully1 as well as ensuring that the whole of it is on the plate4 ,where no attempt at pictorial work is intended1 and the important matter is simply that the object being photographed should be in the centre of the plate1 then it is only necessary that the finder should show as wide an angle of vision1 or a little wider than the lens being employed inside the camera4 ,but when something more is aimed at1 viz43 ,tasteful composition over the whole plate1 then it is necessary to block out on the finder all excess of view1 beyond what will be received on the sensitive plate4 ,the ,shutter4--,what particular form may be best is a matter of doubt1 but whatever it be1 exposure must be possible without vibration1 it should give greater exposure to the foreground than the sky1 and ought to allow of being regulated for exposures ranging from #a_/dth of a second up to perhaps #a_/ajjth for ordinary work4 ,where shutter work has to be done1 which demands anything less than #a_/ajjth of a second1 then special shutters for the purpose are needed1 but after having used hand cameras of one form or another for the last nine or ten years on such classes of subjects as are ordinarily dealt with1 the occasions on which any greater speed than #a_/cjth of a second has been called for have been extremely rare4 ,it may be said this would not allow of taking subjects such as a close finish of a cycle race and such like1 which is quite true2 did occasion arise for so doing1 then a shutter such as the focal plane would be employed as a matter of course4 ,but by far the greater amount of work done with hand cameras would be the better for receiving a longer exposure1 better because light action on the sensitive plate would be more thorough1 and far better because when slowly moving objects1 such as waves rolling shoreward1 are given #a_/ajth instead of #a_/ajjth of a second1 we get less of petrified naturo1 and a more natural appearance in the resulting photographs4 ,as a general rule it is well to give the slowest exposure possible4 ,the ,focussing ,arrangements4--,these need be only very simple1 and generally are done by scale to distances4 ,as a rule with the lens working at f_/#aa1 and the scale set at #ae feet1 it will be found that the depth of focus is sufficient for most ordinary work1 and any alteration in the focussing seldom necessary1 when dealing with subjects where figures are included1 that are not required to be approached much closer than the distance mentioned4 ,so far as may be necessary for hand-camera work simply1 the instrument should be without complications1 is better for having a good rectilinear lens1 needs a shutter easily adjusted for exposures ranging if possible1 from a #a_/dth of a second1 up to say #a_/ajjth1 properly adjusted finders1 some means of quickly altering the focus of lens1 one or other method of carrying the plates or films1 and for purely hand-camera work1 there is no need for any other addition to it4 ,passing away from the camera to its use1 one is faced immediately with the fact1 that in spite of the multitude of such instruments now in use1 the general average of results produced by its means are1 in quality1 unmistakably below those done with a camera and tripod1 nor is the reason for this far to seek4 ,in the latter case1 a plate of medium rapidity is generally employed1 such an exposure given1 as makes no serious strain on the developer used to bring the latent image fully out2 the action of light having been ample1 and the plate not so easily spoiled1 as one of higher sensitiveness1 there is not that call for such skilful treatment1 as where light action on a highly delicate emulsion1 has been but brief1 and needs to receive careful handling1 before good1 well-graded negatives may be produced4 ,to use a hand camera is the simplest matter imaginable1 to properly employ it the most difficult--simple1 because of the facility with which plates may be exposed1 difficult1 because to succeed1 demands careful practice1 and a thorough understanding of photographic manipulation4 ,we must have learnt to see1 and that quickly1 must have gained coolness and self-restraint1 and perhaps not the least qualification necessary is that of being a good photographer4 ,whether content to produce good straightforward representations of such scenes as come before you1 or more ambitious attempts at pictorial work be made1 they can both be done with the hand camera quite as well1 nay indeed1 given sufficient technical skill1 and trained perception to see the beauty presented in line and mass1 it is by no means clear this form of implement does not offer greater facilities for successful working1 than the more complicated form used with a tripod4 ,illustration3 ,,birch ,,and ,,bracken4 ,w4 ,,thomas4 ,the choice of subject is only bounded by the limits of exposure1 speed of plate and actinic action of light available4 ,the first has already been touched upon1 when the lens1 and shutter1 were dealt with4 ,plates have recently been so increased in speed1 that it becomes necessary to somewhat modify advice1 which a year or two ago1 might have been perfectly correct1 viz41 to work with the fastest plate procurable4 ,but there is this advantage now1 as then1 that if some convenient form of actinometer be used to test the light1 we are able to judge at once1 what speed of plate will be necessary to deal with each subject as it arises4 ,there are several forms available1 amongst which1 the one introduced by ,watkins1 made so that it becomes a permanent part of the camera1 answers remarkably well1 especially as it cannot be left at home1 without being noticed4 ,in developing shutter-exposed plates1 if full exposure has been obtained1 then the ordinary modes of procedure suffice1 so also when over-exposure occurs1 but by far the greater proportion of failures one sees in this class of work1 arise simply from under-exposure4 ,there seems so much charm in driving a shutter at its highest speed1 and at the same time using the lens stopped down1 to secure sharp definition1 the wonder is1 not that failures flourish1 but that any good work is done at all4 ,with regard to particular developers there is only this to be said4 ,whatever agent be employed1 so arrange that before density is obtained1 all the detail you require is first brought out2 this simply means1 if pyro is being used1 it is kept low1 until the plate is ready to be treated for density1 then a further addition of pyro and bromide will generally suffice to rapidly finish off the work4 ,when a batch of exposed plates is being dealt with1 a most certain method of negative making1 will be found in employing in one dish1 either one or other of the following one-solution developers3-- ,,no4 #a ,,formula4 ,amidol #bj grains ,sodium sulphite #a_/b oz4 ,water #g ,,no4 #b ,,formula4 ,dissolve in water #bj oz4 ,metol #ge grains then add ,sodium sulphite #a-c_/d oz4 ,carbonate of soda 7crystals7 #a-c_/d ,bromide of potassium #f grains ,,no4 #c ,,formula4 ,sodium sulphite #a-a_/d oz4 ,carbonate of potassium #a_/b ,eikonogen #a_/d ,boiling water #ab ,any of the above developers will be found to rapidly bring out all there is in the plate1 and if over-exposure is feared1 they may all with advantage be diluted1 with an equal quantity of water1 in order to slow down their action4 ,in another dish1 it is advisable to have the following re-developer1 to impart density to the plates1 as they become ready for that operation1 or to successfully deal with any1 which are found to have been considerably over-exposed1 and upon which1 the first developer is acting too vigorously4 ,,re-,,developer4 ,,no4 #a4 ,hydroquinone #a_/d ounce ,sodium sulphite #b ,potassium bromide #a_/d ,boiling water #ab ,,no4 #b4 ,washing soda #b ounces ,sodium sulphite #b ,water to make #ab ,for use mix equal quantities4 ,by employing two different developers in the manner suggested1 it becomes a simple matter to produce good negatives1 from plates having had all kinds of exposures1 some under1 some over1 and it may be some which have had about the right exposure2 in this way one of the most fruitful causes of failure in the production of hand-camera pictures1 error in exposure and development1 is minimized1 if not altogether done away with4 ,there are sometimes occasions when out with a hand camera1 when subjects present themselves1 offering exceedingly good opportunities for securing pleasing little pictures1 but which require one1 or two seconds' exposure1 to render them successfully4 ,at such times it may generally be arranged to rest the camera on a stone1 wall1 or gate1 or to hold it pressed against a tree1 or some other rigid support4 ,as an example1 the illustration of a woodside with birch trees1 facing page #acf1 may be pointed to4 ,in this instance1 when out cycling1 the place and lighting on the tree trunks1 struck us as pleasing1 and worth trying to secure a record of1 even though but a hand camera was being carried at the time4 ,having dismounted1 and found a point from where it might be attempted1 and where conveniently grew a single tree1 the lens was opened to 7if recollection does not deceive7 f_/#aa4 ,then the camera jammed close to the tree trunk1 and two seconds' exposure given1 taking especial care that no movement took place4 ,the plate being in due time carefully developed1 and as far as possible contrasts kept down1 the result proved satisfactory enough4 ,it could more conveniently have been photographed1 of course1 if a camera and tripod had been available1 but it is one of many such instances1 where1 when shutter exposures only had been prepared for1 occasions arose1 demanding longer exposures than were possible1 unless1 some such temporary support be pressed into use1 as in this instance4 ,for successful work1 see that the camera is simple1 its parts1 of the best your pocket can afford4 ,give the slowest exposures your subject will allow4 ,develop for softly modelled negatives first1 getting what density is required afterwards4 ,see that the camera is held perfectly steady1 during exposure1 and don't forget it is simply a camera1 and lens1 and will require you behind it1 just the same as any other employed with a tripod1 and in conclusion bear always in mind1 it is the simplest form of camera work and the most difficult1 making the utmost demands on your skill1 if high-class results are to be the outcome of its use4 ,w4 ,thomas4 ,lantern ,slides4 ,illustration ,a lantern ,slide is a transparent positive on glass or other transparent support1 usually #c-a_/d inches square1 and is placed in the lantern in such a way that by suitable illumination and optical arrangements the image on the slide is made to intercept some of the light given off by the illuminant from a screen1 which without the screen would be wholly and evenly illuminated by the light4 ,in viewing a paper print we are really observing the paper by reflected light1 part of our view being intercepted by the image formed of pigment or reduced metal2 the amount of light not being very great a very thin layer of pigment is required to produce the appearance of a sufficiently robust image4 ,if the image alone or with its vehicle be stripped from a good print on paper this image viewed by transmitted light will be found to be extremely faint1 far too faint to be of any use as a transparency1 and also too thin to be of any use as a lantern slide4 ,on the other hand1 what we know as a transparency1 such as is often used for window decoration1 backed1 perhaps1 with ground glass1 would be found much too dense or robust for use as a lantern slide4 ,in density1 then1 a slide1 as it shall hereafter be called1 comes between the image on a paper print and that on a transparency4 ,in gradation1 or gamut of tones1 the slide ought to be superior to either the paper print with its almost absolute clearness over large areas1 or the transparency with its dense shadows and its comparatively heavy lights4 ,in fact1 in a good slide we have every grade of deposit from perfect transparency to nearly complete opacity4 ,but the extremes must be very sparingly present1 and the transition from one tone to another must be gradual1 all intermediate notes between highest and lowest should be represented4 ,other qualities go to make the perfect slide2 the metallic or other deposit forming the image must be in the utmost degree fine1 no approach to grain must be perceptible even under the highest magnification4 ,the colour1 or tone1 must be not only pleasant but appropriate4 ,the loss of light in its journey from the illuminant to our eyes is enormous2 the disc on the screen is simply a greatly magnified image of the light1 and here is great loss2 add to this the interception of some light by the opacity of the slide1 and the fact that much more is lost in reflection from the screen1 and absorption by the screen1 and it is easy to realize that the image from the screen reaching our eyes is vastly less bright than that reaching the eye when1 for instance1 we examine a slide in the hand by transmitted light4 ,and loss of light means increase of contrast1 so that a slide which would seem about right in gradation in the hand would be altogether soot-and-chalk as a screen-image4 ,so too if we have in the slide already shut out much light1 by making the slide foggy1 or over dense1 it is easy to see that when the image reaches our eyes from the screen this vicious opacity will be immensely increased in its mischievous properties4 ,the first style of slide gives screen-images sometimes called midsummer snow-scenes2 the other slide is simply called foggy4 ,both must be assiduously avoided4 ,it need hardly be said that the plates prepared by some processes are more likely to yield good slides1 such as are described above1 than plates prepared by other processes2 no one process can claim to possess in itself superiority in all respects4 ,collodion1 for instance1 is less apt to give foggy slides1 and it is easier to intensify than gelatine1 but it is also more prone to give hard images4 ,collodion is at its finest in the form of collodio-bromide emulsion1 which gives slides remarkable for fineness of grain1 for clearness1 and for richness of tones2 but when we have to copy in the camera1 the operation with collodion emulsion is protracted1 unless we have bright daylight or a condensing arrangement1 which with large negatives is often out of the question4 ,on the whole it may be taken that gelatine-bromide emulsion is the process to be recommended1 not only on account of its convenience and celerity1 but in view of the many inherent points of excellence that it possesses4 ,in any case1 want of space will cause us to confine attention here to that process1 and any one mastering the use of gelatine-bromide slide-plates will have nothing to fear from competition with other processes in all-round work4 ,the writer has a leaning towards slide-plates as slow as he can procure them1 because slowness almost always goes hand in hand with fineness of grain and freedom from fog4 ,there is one point of importance that should be noted in working with gelatine for this purpose4 ,distilled water should be used if possible for all solutions4 ,tap water--especially hard water--is apt to produce with the gelatine a certain amount of scum which1 if present in any appreciable degree1 cannot fail to affect the quality of the slides2 but treatment with an acid alum bath as described later has a very salutary effect in removing any scum that may have formed during the liquid operations4 ,in the mechanics of making a slide from a negative we have only two methods to consider4 ,if the slide-image is to be the same size as the negative1 or a part of the negative1 we print by contact1 that is1 we put the negative and the slide-plate face to face in contact1 and we expose to light1 the negative being next to the light2 this corresponds with making a print on paper4 ,but when we desire to make a slide including all the subject of a negative larger than a slide-plate1 or1 in fact1 when we desire to alter the size of the image at all1 we copy the negative in the camera4 ,the simplest method of doing this is to fix up the negative so that it is evenly lighted and make a photograph of it in a camera2 but the adjustments necessary for such an operation would be found awkward1 and so a reducing camera of some kind is generally used4 ,many such cameras are on the market1 and consist of devices for holding the negative in a suitable position with regard to a small camera furnished with a lens and a dark slide holding a lantern plate4 ,either the negative-holder or the camera should have possible movement in all directions vertical to the optical axis of the whole1 and in addition it is often desirable to have a certain amount of movement in other planes1 in order to correct certain optical defects that are sometimes found in negatives4 ,the writer has for many years used a small camera with its front stuck into the front of a large camera1 one or other of these cameras has every necessary movement4 ,the device is figured here4 ,illustration ,whatever arrangement is used the end of the apparatus bearing the negative is directed towards a good and even light2 and it is well to place about two inches in front of the negative towards the light a piece of finely ground glass for ordinary negatives2 this glass is with advantage omitted with extra dense negatives4 ,it goes without saying that the exposure1 whether we are working by contact or in the camera is of the utmost importance2 but it is not possible in an article such as this to give even an approximate idea of the exposure suitable under any concatenation of conditions4 ,the best clue to exposure is to be found in development1 and in results4 ,it is necessary to know what happens after normal exposure with a given developer1 and then if any variation is noticed to alter the exposure4 ,if a plate develops more rapidly than the normal1 it may fairly be deduced that the exposure has been too long2 but if we are dealing with a specially contrasted negative it is better so4 ,on the other hand1 when we are dealing with a thin negative1 especially if the scale of gradation is short1 we require an exposure less than what would under normal conditions lead to complete development in the normal time4 ,and again some plates require to be developed to a greater point of apparent density than others2 this is a matter of experience4 ,briefly put1 there is no royal road to good slide-making1 experience is necessary4 ,in actually making the exposures certain points must be kept in mind4 ,if we are copying in the camera with daylight as illuminant it is very important to use the light from the north2 if we use other light we shall be much put out on most occasions by awkward variations of the brightness4 ,a very large number of operations are rendered nugatory by carelessness in this matter4 ,even the most experienced worker will find it impossible to expose plates with anything like accuracy when he has to deal with direct sunshine at one time1 thin white clouds at another1 and dark clouds at a third4 ,and in making exposures by contact the beginner must be fairly accurate in judging the time of exposure and the distance from the radiant4 ,a good plan is to tie to the gas jet a piece of cord having knots at convenient intervals1 such as at #i1 #ab1 #ah and #bd inches1 and in making an exposure to use these knots as guides to the distance2 moreover1 the law of squares of distance must be remembered2 the intensity of light varies inversely as the square of distance from radiant to receiver1 provided1 of course1 no optical arrangement is introduced to modify the path of the rays4 ,consequently1 for example1 if ten seconds is found to be a proper exposure at nine inches from the light1 the corresponding exposure at eighteen inches will not be twenty1 but forty seconds 7#ibha4 #ahbcbd74 ,and as it is sometimes awkward to hold the frame and attend to a watch at the same time1 a metronome1 ticking seconds1 will be found convenient1 or a clock with a second hand may be placed where it can be seen during the exposure4 ,a landscape slide without clouds1 if the horizon is in the picture1 is usually considered a failure1 and has been dubbed bald-headed4 ,really good workers often put clouds into slides by combination printing1 which in some cases is comparatively easy1 in others very difficult4 ,if we are working by reduction from a good-sized negative1 with a fairly even horizon1 the difficulty is not great4 ,the landscape part of the negative is first exposed1 the sky being masked if necessary1 and a cloud negative is then substituted for the landscape negative1 a part of the former being masked to correspond with the landscape on the latter1 and a second exposure is made on the same slide-plate4 ,admittedly in all cases this requires some doing1 in many cases it is extremely difficult4 ,an easier1 if less sportsmanlike1 method is to make the cloud slide on a separate slide-plate1 and to use the latter as a cover-glass for the slide4 ,the cloud may cover the whole of the second slide1 and that part of it not required may be wiped out by means of a reducing solution1 used with a brush1 such as the ferricyanide and hypo one described later4 ,this method will be found useful even in contact slide making1 but it also requires not only good taste in the selection of the cloud1 but some deftness in manipulation2 but the neat-handed beginner need not fear to make the attempt4 ,,development4 ,it has already been stated that judgment of exposure is a matter of experience1 and that results are the best criterion2 here follow some more explicit statements on the same matter4 ,whatever plate or developer is used1 and whatever the time occupied in complete development3 #ast4--,if by the time the high-lights are sufficiently strong the shadows are too dense or blocked1 the plate has been under-exposed4 #bnd4--,if by the time the high-lights are sufficiently strong the shadows have not attained sufficient density1 or are veiled1 the plate has been over-exposed4 #crd4--,if at the same moment the high-lights show sufficiently and the shadows are transparent but sufficiently plucky1 the plate has been properly exposed4 #dth4--,with a normal negative the normal exposure is the proper exposure2 but 7a7 a negative abnormally strong in contrasts will require an abnormally long exposure2 and 7b7 a thin negative1 or one with a very short scale of gradation from densest to clearest1 will require an abnormally short exposure1 with probably some after-treatment in the direction of intensification4 ,ambitious slide-makers generally aim at warm-toned slides for pictorial effect1 and rightly4 ,but slides intended for scientific purposes are generally better when cold in tone1 the definition is usually better4 ,but whatever the aim1 a good tone of one kind is preferable to a poor one of another kind1 and the beginner should first make sure of getting a really good cold tone1 which is comparatively easy1 and then try his 'prentice hand on warm tones4 ,warm tones are obtained by using greatly super-normal exposures and greatly restrained developers2 and the danger probably lies in the fact that the long exposures are apt to lead to fog1 and the great restraint to over-density in the shadows1 the latter especially when the exposure has not been quite long enough for the developer used2 herein probably lies the whole secret of warm slide-making4 ,if we aim at really warm tones and use developers suited to such design1 we must on no account stint the exposure4 ,,cold ,,tone ,,developing ,,solutions4 ,illustration ,the classical solution for cold tone slides is a solution of ferrous oxalate in potassic oxalate4 ,of all developers it is most free from fogging propensities4 ,it is made from so-called saturated solutions of proto-sulphate of iron and potassium oxalate4 ,thus1 into a bottle put a quantity of iron proto-sulphate1 and pour on about three times its weight of water containing a dram of sulphuric acid to each pint4 ,shake well1 and keep always at about #fj ,fahr42 some of the iron must always be visible in the bottle1 if not1 more is to be added4 ,the crystals of iron salt must be green and not rusty in colour4 ,this is the iron solution4 ,the oxalate solution is made by dissolving potassium oxalate in about three times its weight of water4 ,this also must be kept at #fj ,fahr41 shaken occasionally1 and oxalate added if none is visible in the bottle4 ,to make the ferrous oxalate solution we pour one part of the iron solution into six parts of the oxalate1 and it is advisable to add to each ounce of developer at least half a grain of potassium bromide2 #e minims of a #aj solution1 made by dissolving one ounce of the bromide in about #i ounces of water1 and then making up to #aj ounces--all chemical4 ,in about four minutes or less this ought to fully develop a properly exposed plate4 ,if the development is much shorter the slide is apt to have an unpleasant greenish tone1 a result that may also follow the use of an inordinate amount of bromide in the developer4 ,the developing solution may be made in quantity greater than is required for one plate1 and may be used several times if a little of the surplus and fresh solution is added when the quantity in use becomes slow in action4 ,for really fine cold black tones the following formula by ,,messrs4 ,,elliott ,,son will be found admirable3-- ,a ,metol #dj grains4 ,soda sulphite #a ounce4 ,water #h ounces4 ,b ,potassium carbonate #abj grains4 ,ammonium bromide #bd ,potassium bromide #dh ,water #h ounces4 ,the developing solution consists of equal parts of ,a and ,b4 ,if either of the above developers is to be used1 the exposure is to be kept down as compared with the exposure to be followed by developers intended for very warm tones4 ,the two developers which follow next1 require about the same exposure as the two already formulated4 ,ortol is a reducing agent quite lately introduced by ,mr4 ,hauff1 of ,feuerbach in ,germany1 and ,mr4 ,hauff's agents in this country are ,messrs4 ,fuerst ,bros41 of ,london4 ,ortol gives the finest tones of the warm black type that we have as yet come across1 it is singularly free from fogging propensity1 and the tones do not easily degenerate into the greens so apt to occur after severe over-exposure with other black developers4 ,we suggest a simple formula3-- ,a ,water #bj ounces4 ,metabisulphite of potassium #ge grains4 ,ortol #aej grains4 ,b ,water #bj ounces4 ,soda carbonate #c-a_/b ounces4 ,soda sulphite #b-a_/b ounces4 ,to make the developer1 take one part of ,a1 one of ,b1 and one of water1 and to each ounce of the mixture add one and a half or two grains of potassium bromide4 ,the development of a properly exposed slide will take two or three minutes1 and the result will probably be highly appreciated4 ,the above is worthy to stand alone as representing developers for warm black tones1 but the following works well4 7,messrs4 ,elliott ,son47 ,a ,hydroquinone #hj grains4 ,soda sulphite #a ounce4 ,potassium bromide #ae grains4 ,water #aj ounces4 ,b ,caustic soda #hj grains4 ,water #aj ozs4 ,the developing solution consists of equal parts of ,a and ,b1 and the plate may be fully developed in about two to three minutes4 ,it has already been stated that in order to obtain really warm red or reddish tones by development1 it is necessary to give very long exposure1 and to use a developer very much restrained4 ,it is further found that carbonate of ammonia has a considerable effect in reddening the developed image1 and so we now come to procedure based on these lines4 ,carbonate of ammonia is found in commerce in the shape of chunks more or less square4 ,if one of these is pared with a knife--unless the sample is quite fresh--the outside will be found to be a soft amorphous powder1 the inside a clear1 very hard crystal2 the clear crystal is in development an accelerator1 though a very weak one1 the outside substance is a restrainer4 ,probably both the inside--sesquicarbonate--and the outside--bicarbonate--are useful1 and the best plan is to make a ten per cent4 solution of the substance as obtained from a good chemist--not druggist4 ,of this solution one grain of the salt is represented by ten minims4 ,if now we take an ounce of ,a1 and one of ,b of the last formula1 and if we add to the ounce of ,a #c grains of ammonium bromide1 and to the ounce of ,b #c grains of ammonium carbonate1 and if we have given a proper exposure and develop with equal parts of the ,a and ,b modified as above1 we shall get a slide of rich chocolate colour2 and if we double the proportions of carbonate and bromide1 and expose still longer1 we shall get a slide still ruddier in tone1 even to red4 ,but there is always danger of fog1 and of clogged shadows1 and this must be reckoned with4 ,there is a more certain and less dangerous way of getting handsome tones1 which shall be described presently4 ,gelatine slides are always fixed in hyposulphite of soda1 about one part by weight to six parts of water2 after this they must be well washed1 say five minutes under a good rose tap1 or in many changes of water in a dish for an hour1 and every slide should be treated with a saturated solution of potash alum1 of which each pint should contain a dram of hydrochloric acid4 ,very many1 if not most1 slides are all the better for just a touch of a reducer such as follows3--,the ordinary hypo4 solution is weakened with about four times its measure of water1 and the plate is soaked for a minute in this4 ,a few drops of a ten per cent4 solution of potassium ferricyanide are put into the measure1 and the hypo4 mixed with it1 and the whole allowed to work on the plate for a short time1 carefully watched4 ,of course a weak slide must not be thus treated1 but it is often a good plan to develop slides to such a point that they will permit of this treatment4 ,on the other hand it is often advisable to keep a slide thin in development1 for instance1 when the negative wants pluck1 and intensification is indicated2 or when we wish a good warm tone after a black developer such as our metol formula3 a good average treatment is as follows3-- ,take half an ounce each of ammonium chloride and mercury bichloride and dissolve in #af ounces of water1 soak the slide in this till it is bleached4 ,wash well and treat with weak liquid ammonia1 or a solution of soda sulphite1 or of metabisulphite of potash1 or fresh lime water4 ,this will strengthen the slide and give it in most cases a fine rich colour4 ,it is important to let these solutions act thoroughly1 and not to stop the action half-way4 ,the writer considers this the best and safest way to obtain warm tones1 the reader may find out for himself which of these solutions produces the tones he chiefly affects4 ,crystal varnish is not wasted even on a gelatine slide4 ,in conclusion1 it must be realized that the screen-image is a greatly enlarged edition of the slide-image2 any small defect on the slide is a huge one on the screen4 ,consequently the slide-maker must sedulously cultivate cleanliness and manipulative care4 ,andrew ,pringle4 ,illustration3 ,fishing ,smacks4 ,w4 ,thomas4 ,how to make ,enlargements4 ,illustration ,enlargements may be made by daylight1 or by artificial light1 and there are two methods of producing them1 namely1 by enlarging direct from the negative on to a sheet of bromide paper2 or by first making a small transparency1 and from that producing an enlarged negative upon a slow dry plate4 ,the first is the method usually adopted by amateurs1 probably because the necessary operations are fewer1 and perhaps more simple4 ,the second plan1 however1 possesses the advantage that the prints may be made by any process1 be it carbon1 platinum1 or silver1 and thus a great variety of effect obtained4 ,the first point however that the reader must decide is whether he will work by artificial light or by daylight4 ,each may be said to possess certain advantages1 and with many the question resolves itself into one of personal convenience4 ,artificial light is1 or should be1 fairly constant in intensity1 and if adopted there will probably be less waste of material through miscalculation of exposure4 ,but if the source of light employed be other than a mixed jet1 or the arc-light1 if in fact it be of low intensity1 negatives of a somewhat delicate type will be required in order to produce enlargements of the highest excellence4 ,if the negatives are dense and strong1 illuminants of low intensity1 like oil or gas1 do not possess sufficient penetration to duly register the denser portions of the negative1 and the enlargements so made are apt to be deficient in half-tone1 and hard4 ,with well-graded negatives of suitable quality1 however1 most excellent enlargements may be produced by artificial light4 ,when artificial light is used work may be carried on at any time of day or night1 in winter or summer4 ,those who adopt the daylight plan will1 of course1 be subjected to greater restrictions1 at any rate1 during the winter months1 but amateurs who take a real interest in the work will do well to adopt the writer's plan1 and provide themselves with apparatus for each method of working4 ,,enlarging ,,by ,,daylight4 ,there are two ways of enlarging by daylight4 ,the first involves the exclusion of all actinic light from a room except that which passes through the negative4 ,the alternative method of working is to employ an ordinary enlarging camera1 such as are made by ,middlemiss1 or ,lancaster4 ,it is desirable1 but not necessary1 if the first plan be adopted1 to secure the exclusive use of a room4 ,one with a northerly aspect should be chosen1 for if sunlight falls upon the window shadows will at some period of the day fall upon the negative1 and produce unevenly lighted enlargements4 ,an upper room will be most suitable1 and1 if the light be a northern one1 and there are no trees or buildings to obstruct the view1 a reflector may be dispensed with4 ,if external objects intervene1 however1 one must be employed4 ,it should be fixed outside the window-sill1 at an angle of #de1 and should be capable of adjustment4 ,let it be the full width of the window1 and securely fixed for obvious reasons4 ,a plate-glass mirror is effective1 but expensive4 ,a large drawing board painted dead white also answers well1 but should not be left outside exposed to the weather4 ,illustration3 ,fig4 #a4 ,illustration3 side view ditto ,provision for excluding the light from the room is best secured by making a wooden frame large enough to fit closely against the window frame4 ,upon this a piece of stout calico should be tightly strained and secured with tacks4 ,it should then be sized1 and when dry will be as tight as a drum2 it must then be covered with two thicknesses of stout brown paper pasted on4 ,the frame is shown complete in ,fig4 #a4 ,now at ,,aa4 ,,bb4 screw two strips of wood1 the distance apart must be regulated by the size of the negatives to be enlarged4 ,the ordinary camera is intended to be used as the enlarging camera1 and the distance from ,c4 to ,c4 should be just equal to the size of the back portion of the camera4 ,on the lower rail ,,bb screw a piece of #i in4 board to form a shelf or support ,d4 for the enlarging camera4 ,make a frame ,e4 of #a_/b in4 wood #a in4 deep1 the same size as the back of the camera1 and screw to the shelf and top rail ,,aa4 ,now carefully cut away the brown paper and calico from the inside of this frame1 at the part marked ,h4 and paste strips of brown paper round it so as to prevent any light passing except through the opening ,h4 ,a strip of felt should be tacked all round the large frame to prevent any light from creeping in between it and the window frame4 ,a couple of turn buttons will keep it in position4 ,a firm table should be placed against the window close up to the wall to form a support for the enlarging easel4 ,now a little care must be taken in fitting up this portion of the apparatus1 and it is better to have something more exact than the propped-up drawing board or printing frame1 which is sometimes recommended4 ,get a carpenter to run out two ,v shaped rails as shown in ,fig4 #b at ,,cc4 ,they should be about the length of the table1 and screwed down upon it4 ,procure a cheap drawing board about #ae x #ab1 and to the under side affix two pieces of wood with ,v shaped grooves corresponding in angle to the rails4 ,this forms the base of the easel ,,aa4 ,make a frame #bb x #bj1 or rather larger than the biggest enlargement that it is desired to produce4 ,it should be constructed of #a_/b in4 wood1 and be #b in4 deep4 ,it is shown in ,fig4 #b at #a ,,dddd4 ,now make1 or get made1 a set of carriers ,,ee1 the largest of which should just fit into the frame4 ,narrow fillets of wood screwed each side will afford a rise and fall adjustment1 and a thumb screw at ,g will fix the carrier in any desired position4 ,to obtain the cross-movement screw the frame ,,dddd to a piece of inch board #e in4 wide ,,hh4 ,place this exactly in the centre of the base board1 and screw fillets ,,ii of #a in4 wood to each side4 ,this will afford a cross motion1 and a thumb screw at ,j will fix the carrier frame when the necessary adjustment has been made4 ,illustration3 ,fig4 #b4 ,in setting up an enlarging apparatus1 whether it be for day or artificial light1 it is absolutely essential to preserve the parallelism of its various parts1 otherwise it will be impossible to produce sharp or evenly defined enlargements1 and for this reason ,i have described somewhat fully the construction of a suitable easel4 ,i may add that it will serve equally well for either daylight or artificial illumination1 and ,i strongly advise the reader to construct1 or have constructed1 an easel on the lines ,i have laid down4 ,with it either direct enlargements on paper can be produced1 or plates may be used and enlarged negatives made4 ,the easiest way of holding the paper during exposure is to procure two sheets of clear glass1 patent plate is most suitable1 sandwich the bromide paper between them1 and secure with two strong bands of elastic4 ,the complete apparatus in position for working is shown at ,fig4 #c4 ,illustration3 ,fig4 #c4 ,illustration3 ,fig4 #d4 ,the second method of enlarging by daylight is by employing an ordinary enlarging camera4 ,the same conditions as to lighting1 etc41 should be sought for1 and the most convenient way of working will be to tilt the camera at such an angle as that the negative receives unobstructed illumination from the sky4 ,a reflector in this case will not be necessary1 but a piece of very finely ground glass should be placed about an inch in front of the negative in order to soften and diffuse the light4 ,this method of working is shown in ,fig4 #d4 ,,enlarging ,,by ,,artificial ,,light4 ,before describing the actual process of making an enlargement it will be well to deal with the alternative method of working1 namely1 by artificial light1 as the manipulations of the sensitive material used are the same in either case4 ,practically the most satisfactory way of working by the latter method is to use an enlarging lantern properly fitted with a condenser4 ,the general principles of such an apparatus are identical with those which obtain in an ordinary optical lantern4 ,methods which dispense with the use of a condenser are more or less unsatisfactory1 and should be avoided4 ,in the space at the disposal of the writer it is not possible to give directions for the construction of an enlarging lantern1 but those who may desire to make their own1 will find full instructions and working drawings in #f,practical ,enlarging4 #f ,a ,iliffe ,son4 ,illustration3 ,fig4 #e4 ,enlarging lanterns of excellent quality are obtainable commercially1 but for the guidance of the uninitiated it may be useful to refer a little in detail to one or two important points with regard to their construction4 ,the condenser will first claim attention4 ,the ordinary pattern consists of two plano-convex lenses mounted as shown in section at ,fig4 #e4 ,this answers fairly well with the smaller sizes1 but when the diameter of the condenser is large1 a good deal of light may be lost4 ,the interposition of a small meniscus or plano-convex lens1 in the manner first suggested by the late ,j4 ,traill ,taylor1 and shown in ,fig4 #f1 will be found a great improvement4 ,its proper position will be at the point where the divergent cone of rays proceeding from it just covers the large condenser4 ,in our own practice we always place a diffusing screen of very finely-ground glass in front of the condenser at ,,ee ,the diameter of the condenser is governed by the size of the negatives to be enlarged1 it must be of sufficient size to include the longer sides of the plate within its circumference without cutting the corners4 ,if it is much larger than this1 an unnecessary loss of light will occur1 because only that which passes through the negative can be utilized4 ,illustration3 ,fig4 #f4 ,,the ,,illuminant4 ,the smaller and more intense the light1 the nearer we approach to the ideal projection illuminant1 and the better will be the definition of our enlargements4 ,the arc light most nearly fulfils the desired conditions1 and if it be available it should certainly be employed4 ,next in point of utility comes the limelight1 preferably in the form of the mixed jet1 and those who understand its manipulation are recommended to adopt it1 but the majority of amateurs will probably find it more convenient to use either incandescent gaslight or an oil-lamp4 ,parallel wick-lamps should be avoided on account of the unequal illumination they produce1 and if oil must be used a good circular wick burner will be found more suitable4 ,where house-gas is available the incandescent gaslight is however much to be preferred4 ,the light is perhaps not so powerful as that given by a really good parallel wick-lamp1 but it is far more actinic and penetrating4 ,the writer has used this light with great satisfaction1 and therefore has no hesitation in recommending it4 ,some workers have been troubled by the appearance of an image of the mantle on the screen1 but this can usually be got rid of by a suitable adjustment of the lenses and the light1 and in any case by the interposition of a piece of ground glass between condenser and negative4 ,,the ,,choice ,,of ,,the ,,lens4 ,it is commonly stated that the lens with which the original negative was taken will serve equally well to enlarge it1 and in the abstract the statement is perhaps not inaccurate4 ,but assuming that a lens of a focus equal to about #a-a_/d times the base of the plate has been used1 it will be found that better results1 both in regard to definition and equality of illumination1 will be obtained by substituting a lens of rather longer focus1 for example a half-plate lens for enlarging from quarter-plate negatives4 ,this1 although applying to both methods of working is particularly desirable when enlarging by artificial light1 for an objective of small diameter and short focus cannot possibly pick up or receive the whole of the cone of rays proceeding from the condenser4 ,a reference to ,figs4 #g and #h will explain why this is so4 ,in ,fig4 #g we see what happens when a lens of too short a focus is used1 but when one of longer focus is substituted1 the whole of the cone of rays passes through and is utilized 7,fig4 #h74 ,in selecting a lens one should be chosen which has a sufficiently large diameter to permit the apex of the cone of rays from the condenser to pass through4 ,this point will1 of course1 vary with the degree of amplification1 and in order to obtain the best results optically1 the distance of the light from the condenser must be carefully adjusted in every case1 and a clear1 evenly lighted disc obtained before inserting the negative to be enlarged4 ,illustration3 ,fig4 #g4 ,illustration3 ,fig4 #h4 ,with regard to the type of lens1 one of the rapid rectilinear form will answer well4 ,a portrait lens is often used on account of the brilliancy of image1 but although it answers well for enlarging portraits1 the roundness of its field makes it less suitable for landscapes unless it is considerably stopped down4 ,if the very finest results as regards definition are required1 then one of the now numerous flat-field lenses should be used4 ,the writer can from practical experience speak well of the ,ross-,goerz and the ,cooke lens4 ,the latter is perhaps preferable for working with artificial light on account of the larger diameter of the back lens4 ,wide-angle lenses1 on account of their small aperture and short focus1 are not suitable for use with a condenser1 both for the reasons given1 and on account of the difficulty in focussing owing to the small amount of light transmitted4 ,when daylight is used1 however1 there is less objection to their employment4 ,illustration3 ,fig4 #i4 ,before leaving this part of the subject it should be noted that in regard to preserving the parallelism of its parts the same care in erecting and fitting up the enlarging lantern must be observed1 as was insisted upon in the description of the apparatus for daylight4 ,it will be found convenient1 therefore1 to mount the lantern on a base similar to that upon which the easel rests1 so that both may move on the same rails4 ,the easel described for daylight enlarging will serve equally well for working by artificial light4 ,the complete apparatus is shown at ,fig4 #i1 which is a reproduction from a photograph of the apparatus constructed and used by the writer4 ,,the ,,negative4 ,in general practice one may find it necessary at times to enlarge from negatives of very dissimilar types1 but there is no reason1 when the negatives are to be produced with the special object of subsequently making enlargements from them1 why care should not be taken to make them of a suitable character4 ,thin delicate negatives should be enlarged by artificial light2 dense1 strong ones by daylight4 ,if the negatives are very strong it will be difficult to produce soft and well-graded enlargements with a weak illuminant1 the light not being sufficiently intense to properly penetrate the high-lights4 ,a soft and clear negative1 with good gradation1 fully exposed1 and neither exhibiting patches of clear glass shadow devoid of detail1 nor of hard impenetrable high-light1 will be found most suitable4 ,fog should be avoided1 as also should the yellow stain produced by pyro when improperly used4 ,not that the pyro developer is unsuitable1 for if sufficient sulphite is used1 and the quantity of pyro kept down1 negatives of very beautiful quality for enlarging purposes may be produced4 ,great care should be taken to avoid bubbles1 stains1 scratches1 or any kind of mechanical defects1 as such when enlarged become painfully obtrusive1 and spoil the effect of the best work4 ,it will be found a good plan to bind the edge of the negative before enlarging it with a strip of lantern slide binding1 so as to cover the clear glass rebate mark4 ,if this be omitted the margins of the enlargement may become fogged by the lateral spreading action of the light4 ,no hand-work should be attempted on the original negative1 for any such treatment will become painfully apparent in the enlargement4 ,if retouching be deemed necessary1 it should in the case of a direct enlargement be executed upon the print itself1 or upon the enlarged negative or preferably upon the enlarged transparency1 when that method of reproduction has been adopted4 ,,direct ,,enlargements4 ,the following concise instructions for enlarging upon bromide paper will apply equally to the daylight or artificial light methods of working4 ,in the first case the negative is placed in the dark slide of the camera1 both shutters being drawn fully out4 ,the camera is then put upon the shelf close up against the opening in the shutter1 as shown in ,fig4 #c1 any light creeping in between shutter and camera being blocked out with the focussing cloth4 ,if the enlarging lantern is used the negative will be placed in the carrier1 just in the same way as a lantern slide1 with the film side towards the enlarging lens4 ,now the first difficulty that will be experienced will be to get the enlarged image of the required size4 ,it will be well to content ourselves at the outset with a moderate degree of enlargement1 say from #a_/d plate to #ab #aj1 and when proficiency is acquired1 larger sizes can be attempted4 ,at first we shall probably not succeed in getting any image at all4 ,in adjusting the various parts of the apparatus we shall find the work easier if we remember that the nearer we place the lens to the negative the further will it be necessary to move the easel from the lens1 and the greater will be the enlargement4 ,a useful table of enlargements will be found in the ,british ,journal ,almanac1 showing the distance of lens from negative1 and negative from paper1 for almost any required degree of amplification4 ,now it will be found much easier to focus the enlarged image by looking at it through a piece of finely ground glass1 than by receiving it on a piece of card or paper1 and the adoption of the easel plan of focussing previously described will enable this to be done4 ,the ground surface of the glass 7which must be of the same thickness as the piece behind which the paper is to be exposed7 should be away from the lens and towards the person focussing1 when it is placed in the carrier of the easel1 it being retained in position with the spring ,s41 ,fig4 #b4 ,focussing must be carefully performed1 and is effected by sliding the easel to and fro upon the runners1 and which should have been previously rubbed with blacklead4 ,bromide paper is made in several varieties1 such as smooth1 rough1 snow-enamel1 cream crayon1 etc41 and is put up either in tubes1 or packed flat4 ,the latter is decidedly the more convenient1 it being somewhat difficult to take the curl out of paper that has been rolled4 ,the choice of paper is a matter of taste2 for landscape work the rough paper or the cream crayon will perhaps be found most suitable4 ,for finer work1 and some classes of portraiture the enamel will prove effective4 ,rough paper is better for strong broad effects1 smooth for more delicate work and the rendering of fine detail4 ,the coated side may be distinguished by its tendency to curl inwards4 ,the easiest way of exposing it is to procure two pieces of patent plate glass of the same thickness as the focussing glass1 sandwich the sheet of paper between the two1 and secure with strong elastic bands4 ,this will hold it quite flat during exposure1 and will not disturb the actinism of the lens or impair the definition of the enlargement4 ,,development4 ,this part of the work of producing an enlargement will only be lightly dealt with1 as the subject is fully treated elsewhere in this volume4 ,the writer prefers the ferrous-oxalate developer for bromide enlargements to any of the more recently introduced developers1 but as it requires more skill and judgment to employ it with complete success1 beginners may find it better to use amidol or metol1 either of which when properly used gives excellent results4 ,hydrokinone we do not recommend for this purpose owing to its tendency to give rusty blacks in the event of over-exposure1 or undue hardness if it has been too short4 ,with amidol a pure delicate black is easily obtainable1 and it is moreover a very simple developer to use4 ,our own plan is to employ a weak solution and give a full exposure1 and by these means we find no difficulty in obtaining good gradation and pure blacks4 ,the dish used for development must not be used for other developers or stains will probably occur4 ,although a quick appearance of the image is usually a characteristic of amidol1 no trouble will be experienced when the developer is used in the way we advise1 for the picture will be found to develop slowly and regularly1 and gradually grow in strength4 ,quick development by this method would be an indication of over-exposure4 ,a correctly exposed enlargement should take about ten minutes to develop4 ,one stock solution only is necessary4 ,it will keep indefinitely4 ,sulphite of soda #a ounce4 ,citric acid #bj grains4 ,distilled water #dj ounces4 ,potassium bromide #ae grains4 ,to each ounce of the above add1 just before using1 three grains of dry amidol4 ,the exposure must be accurately timed4 ,it is1 however1 impossible to give useful information on this head1 unless such varying factors as the rapidity of the paper1 the intensity of the light1 the aperture of the lens1 and the degree of enlargement are known4 ,the best plan is to cut one of the sheets of bromide paper into twelve strips1 and on these make several test exposures1 carefully noting the duration of each4 ,it is better 7at any rate for a beginner7 not to vary the constituents or strength of the developer1 but to increase or diminish the exposure until a good result in colour and tonality is obtained4 ,by entering full details relating to the production of a successful enlargement in a notebook1 great exactitude in working will be obtained1 and there need be little or no waste of material when additional enlargements have to be made from the same negatives at a future time4 ,illustration3 ,,drifting ,,storm ,,clouds4 ,w4 ,,thomas4 ,a glass dish1 though expensive1 is very suitable for developing1 for being flat-bottomed a minimum of solution can be used1 and moreover if the dish should be dirty1 the fact is at once apparent4 ,the exposed paper should be soaked in water for a few minutes until uniformly wetted1 and any air-bells removed with a camel-hair brush4 ,the water is then poured off1 and the developer applied in an even wave1 so that the whole of the paper is covered uniformly and quickly4 ,the image will appear slowly1 and gradually gain in detail4 ,when all the detail has appeared it may still appear lacking in vigour and contrast1 but this will come if sufficient time be allowed4 ,development should not be stopped until the print is of the full strength required1 but it is not advisable to allow it to become much darker than it is desired to appear when finished1 because there is very little loss of strength in the fixing bath4 ,if the image flashes out immediately upon the application of the developer1 the paper has been over-exposed4 ,a strong dose 7one or two drams7 of ten per cent4 bromide added to the developer may help to save it1 but the enlargement will probably look poor and flat and of bad colour when finished4 ,if the picture appears very slowly1 and refuses to gain in strength1 under-exposure is the cause1 and two or three drams of a ten per cent4 solution of sulphite of soda may improve matters1 but as a rule the most satisfactory plan will be to make another exposure4 ,with regard to the strength of the developer1 that given is very suitable for negatives of normal density1 but some papers may require a little more amidol1 the appearance of the finished enlargements will guide the reader in regulating the quantity to suit the particular paper with which he may be working4 ,the enlargement should be washed in plenty of running water from the tap to arrest development1 and then fixed in3-- ,hyposulphite of soda #d ounces4 ,water #bj ,a quarter of an hour should be allowed for fixation1 but it is better to use two baths1 giving ten minutes in each4 ,after washing in running water for a couple of hours they may be hung up by one corner to dry1 or pinned down to a blotting board4 ,enlargements produced in the manner described should be of a pure engraving black colour1 and if they are mounted upon pure boards with freshly made ,glenfield starch1 they should prove permanent4 ,enlargements are frequently toned to various shades of brown and red1 generally by the employment of the uranium-toning bath4 ,although the colours so obtained are often very artistic and pleasing1 no reliance can be placed upon the permanence of an enlargement so treated1 and the writer strongly recommends that when warm coloured prints are desired1 an enlarged negative should be made and prints made therefrom in carbon1 silver1 or sepia platinotype4 ,,enlarged ,,negatives4 ,the production of an enlarged negative presents no difficulty that need deter any careful worker from attempting the work4 ,no additional apparatus to that already described will be required1 and either day or artificial light may be employed4 ,in the first place a transparency must be made from the small original negative4 ,it may be made either by contact or in the camera1 preferably the latter as then the acme of sharpness will be obtained4 ,if1 however1 the reader is acquainted with the carbon process he cannot do better than make a carbon transparency1 for such are specially adapted for the production of enlarged negatives4 ,many1 however1 will prefer to make the transparency on a bromide plate1 and as this is the part of the process which requires the greatest amount of care1 and as in fact the quality of the enlarged negative will entirely depend upon the character of the small transparency1 it is necessary to deal with the matter somewhat in detail4 ,preconceived ideas of quality based upon the appearance of a good lantern slide must be put aside1 for that is not at all what is required4 ,what is wanted is a transparency in which every possible detail existing in the negative has been reproduced1 and which in comparison with a lantern slide would look rather flat and over-exposed4 ,every possible precaution should be taken to avoid granularity or coarseness of image1 therefore a slow plate is almost essential2 plates coated with lantern-slide emulsion are now obtainable1 and will be found very suitable4 ,a full exposure should be given1 and a weak and well-restrained developer employed4 ,these conditions tend to the production of the qualities desired4 ,warm coloured transparencies so produced generally have a finer grain than those developed to a black or colder colour1 but unless the colours produced are fairly uniform1 considerable variation in exposure when making the enlarged negatives will be necessary1 and for this reason it would perhaps be better for the beginner to aim at the production of good black transparencies possessing the qualities indicated4 ,the small transparency1 having been fixed1 washed and dried1 should be edged with black paper to prevent any subsequent fogging of the plate1 by the lateral spreading action of the light4 ,it is then placed in the enlarging apparatus1 just as in the case of a negative1 and carefully focussed4 ,this operation must be very carefully performed4 ,the writer uses a thin and very sharp negative of an architectural subject to focus with1 afterwards substituting the transparency which is to be enlarged4 ,landscape subjects1 consisting chiefly of foliage1 are seldom critically sharp1 and it is then difficult to secure a sharply-focussed enlargement4 ,the remainder of the operation is extremely simple4 ,in the place of the ground-glass screen 7which in this case should have its rough or ground side nearest to the enlarging lens7 a slow dry plate is placed1 backed with a piece of cardboard covered with black velvet to avoid reflections and possible fog4 ,the exposure should be full1 and a weak developer employed4 ,trial exposures may be made on quarter-plates1 coated from the same batch of emulsion1 which the manufacturers will willingly supply1 if the purpose for which they are required is made known4 ,pyro will be found the most suitable developer1 but it should contain a full proportion of sulphite1 and not be too strong4 ,exposure and development should be so adjusted that by the time every possible detail has been developed up1 the plate will not have become unduly dense4 ,if expense has to be considered1 a piece of slow smooth bromide paper may be substituted for the large dry plate in which case the result will be an enlarged paper negative4 ,for large sizes1 #ae #ab and beyond1 the latter is a very economical method of working1 and the negatives will be found to yield most artistic prints1 and if the operations have been carried out as described1 and the prescribed conditions carefully observed1 the grain of the paper will not show obtrusively or unpleasantly in the prints4 ,an alternative method of working1 and one which admits of a large amount of control over the ultimate result1 is to make in the first place a large transparency of the full size that the enlarged negative is desired to be4 ,all the precautions upon which stress has been laid should be observed in regard to the choice of plate1 developer1 etc42 but in this case the enlarged transparency may be given a little more vigour and sparkle than would be desirable if the other method of reproduction were adopted1 though in this the reader must be guided by the particular effect which he may be seeking to produce in his prints4 ,for this purpose pyro will be found to be the most suitable developer1 in that it permits of a large amount of control4 ,from the large transparency a negative is produced by contact printing either upon a plate1 or upon a piece of bromide paper4 ,the great advantages of the latter mode of working are the facilities which are afforded for retouching or working upon the large transparency4 ,negative retouching is always a difficult operation to an amateur1 for he cannot see the effect of his work until he has made a print2 whereas1 in retouching a transparency the effect produced by each stroke of the pencil or brush is at once apparent4 ,in the space at disposal it is not possible to describe the various ways in which improvements can be effected4 ,first there are the chemical aids of local intensification or reduction4 ,then much may be done by the judicious use of a pencil1 but the part to be retouched must first be lightly rubbed with a little retouching medium in order to make the pencil bite4 ,in extreme cases the back of the negative may be covered with tissue paper upon which a stump and chalk may be used at discretion4 ,the novice must not be disappointed with the appearance of his enlarged negative when it is finished1 nor should he form an adverse opinion of its printing qualities until he has made a print from it4 ,confessedly an enlarged negative generally presents a different appearance to one that has been taken direct1 and may even seem to lack some of those qualities that are commonly regarded as essential to perfection1 but if the final result1 the picture1 comes up to our expectations1 we may surely dismiss any lingering doubts as to whether the enlarged negative conforms to certain preconceived notions of technique1 and it should be enough for us to know 7and the fact is incontrovertible7 that some of the finest and most artistic photographs ever shown owe their existence to this method of production4 ,john ,a4 ,hodges4 ,illustration3 ,walberswick4 ,by ,rev4 ,a4 ,h4 ,blake4 ,p4,o4,p4 ,illustration ,the three letters ,p4,o4,p4 are now so widely understood as referring to the ,gelatino-,chloride ,printing-,out class of ,papers that it may be said that ,p4,o4,p4 is known to many who are not acquainted with the fully-written name of this class of productions4 ,also it should be mentioned that when these papers are spoken of as gelatino-chloride papers it is not to be concluded therefrom that chloride of silver is the only silver salt present4 ,what they do actually contain is probably only known to their respective producers4 ,but generally speaking1 it is enough to say that so far as the ordinary consumer is concerned1 the family resemblance is so strong and chief characteristics so general that the following directions for using them may be held as generally applicable to the various well-known brands now on the market4 ,at the outset1 however1 it will be convenient to note that for the purposes of manipulation we may roughly group them into two chief classes--viz41 the matt 7probably from the ,german word matt1 i4e41 dull7 and the glazed1 glossy or enamelled4 ,the latter comes to us with a highly glazed1 i4e41 shiny smooth surface1 the former being slightly rough1 of a surface and texture somewhat like that of very finely ground glass4 ,care of the ,paper4--,the paper is sent out either in the full-sized sheet1 measuring about #bd #ag inches1 or in smaller cut sizes1 suitable for the usual #a_/d1 #a_/b1 #a_/a plate and other popular dimensions of plates4 ,compared with albumenized print-out paper1 ,p4,o4,p4 is more sensitive to light2 therefore1 some care must be taken to avoid needlessly exposing it to the influence of daylight or strong artificial light4 ,for example1 the printing frames should be filled as far away from any window as possible1 and the prints examined from time to time either by gaslight or as feeble daylight as possible4 ,in handling the paper--cutting it up1 etc4--care must be taken to avoid touching the sensitive surface with the fingers in any case4 ,the touch of a moist or hot finger is very likely to produce a mark or stain which is usually irremovable4 ,the paper should be protected from damp1 excessive heat and impure air4 ,if kept rolled in a tin tube or flat under pressure in the original packages1 it will keep a considerable time--i4e41 longer than ordinary albumenized paper4 ,printing is done in the usual way4 ,strong diffused light reflected from the sky or clouds usually gives a better print than direct sunshine4 ,in case1 however1 of a thin flat negative--i4e41 one with insufficient contrast--good results may sometimes be obtained by covering the printing frame with a sheet of green glass and printing in moderately strong sunshine4 ,in hot summer sunshine it is as well to cover the green glass with a sheet of tissue paper or fine-ground glass4 ,care must be always taken when printing in sunshine or very hot weather to see that the negative itself does not get too warm1 or the paper may stick to it4 ,in this case the print is of course lost1 and the negative1 unless varnished1 is also probably seriously damaged by silver stains1 which are very difficult to remove4 ,printing should not be carried quite so far as in the case of ordinary albumenized paper because in the subsequent operations of toning1 etc41 not so much strength is lost4 ,the same care as regards shielding from light1 etc41 should be given to the prints after they leave the printing frame4 ,they may be proceeded with at once or kept for some days before being toned1 etc41 but if this is done the prints should be kept under pressure4 ,some workers have thought that the light action goes on1 continues in the print after it is removed from the printing frame4 ,this1 however1 is not the generally received opinion4 ,washing4--,it is important that the first washing should be done with some care1 or the prints may become stained4 ,the points calling for attention are 7#a7 running water and plenty of it1 7#b7 care to see that the prints do not stick together4 ,what is needed is that the soluble salts should be washed out of the paper as quickly as possible1 and that the prints be not allowed to remain in the water containing these soluble salts longer than is necessary4 ,hence the advantage of running water and plenty of it4 ,the washing water must not be too cold or the salts will not pass out of the paper quickly enough2 and again1 it must not be too warm or the gelatine will melt4 ,the best temperature is about #fe ,f41 and the limits should not go beyond #fj and #gj ,f41 and preferably are kept within #fj and #fe ,f4 ,as the paper is usually rather stout1 it will need washing in running or constantly changed water for about ten to fifteen minutes1 and in any case must be continued until all milky appearance of the water ceases4 ,the print at this stage has a red-brown colour4 ,if it is now passed direct into the fixing bath without toning it becomes somewhat more yellow1 and when dry is usually a colour somewhat between yellow ochre and sienna4 ,toning is usually our next operation1 and for this purpose we have a variety of toning baths recommended by different workers4 ,the sulphocyanide and gold is perhaps the chief favourite4 #a4 ,ammonium sulphocyanide #aj to #ae grains4 ,gold chloride #a grain4 ,water #h to #aj ounces4 ,the proper way to mix this bath is to add the gold to the solution of sulphocyanide a little at a time4 ,the following method will be found convenient4 ,as ammonium sulphocyanide is somewhat deliquescent1 it is convenient to keep it in solution4 ,therefore1 one ounce of the salt dissolved in twenty ounces of 7distilled or filtered rain7 water gives us roughly a strength of twenty-two grains per ounce4 ,dissolve the contents of a fifteen-grain chloride of gold in fifteen drams of distilled water4 ,to mix a bath1 take of the sulphocyanide solution half-an ounce2 to this add eight ounces of water4 ,now take one dram of the gold solution and dilute with one ounce of water4 ,then add this dilute gold solution a little at a time to the eight ounces of sulphocyanide solution1 and stir well with a glass rod4 ,it will be noticed that as the gold solution drops into the sulphocyanide solution an orange-red precipitate is formed1 which is redissolved on stirring4 ,hence the gold must be added to the sulphocyanide1 and not vice versa4 #b4 ,another favourite bath is as follows3-- ,ammonium sulphocyanide #bb grains4 ,soda sulphite #b ,gold chloride #b ,water #bj to #be ounces4 ,instead of weighing out two grains of sulphite it is more convenient to weigh twenty grains and dissolve in two-and-a-half ounces of water--i4e41 at the rate of one grain per dram of solution4 ,thus1 to mix this bath1 take an ounce of the above-mentioned sulphocyanide solution dilute with twenty ounces water4 ,to this add two drams 7#a_/d oz47 of the sulphite solution4 ,then take two drams of the gold chloride solution and dilute with an ounce of water1 and add slowly with stirring as before4 #c4 ,another favourite bath is3-- ,sodium chloride 7table salt7 #fj grains4 ,ammonium sulphocyanide #ae ,gold chloride #b ,water #aj to #ab ounces4 ,some of the adherents of this bath recommend that the prints be only washed in running water for a few minutes and then put into the toning bath4 ,others advise the prints to be immersed in the toning bath without any previous washing--i4e41 straight from the printing frame4 #d4 ,here1 again1 is another bath which usually yields excellent results3-- ,soda phosphate #e grains4 ,sodium chloride 7table salt7 #bj ,gold chloride #a grain4 ,water #aj ounces4 #e4 ,other workers omit the sodium chloride and increase the phosphate and get good tones4 ,soda phosphate #bj grains4 ,gold chloride #a grain4 ,water #aj ounces4 #f4 ,others1 again1 combine the phosphate and sulphocyanide baths thus3-- ,sodium phosphate #aj grains4 ,ammonium sulphocyanide #ae ,gold #a ,water #aj ounces4 ,the various toning baths mentioned above have one drawback common to them all in varying degrees--viz41 that when once mixed and used they do not keep in good working order longer than a few hours4 #g4 ,the following bath claims to have the advantage that it will keep in working order for a short time at any rate1 but the disadvantage that it cannot be used until it has been mixed twelve to twenty-four hours4 ,soda acetate #fj grains4 ,ammonium sulphocyanide #bj ,gold chloride #a grain4 ,water #ab ounces4 ,toning should be conducted in very weak daylight1 or what is much better1 gas or lamplight4 ,the latter1 being practically constant1 enables the operator to judge the relative colour of the prints from time to time4 ,care must be taken so that the prints do not stick together in the toning bath1 and preferably only a few1 say half-a-dozen or so1 dealt with at a time1 so that each print can be frequently turned over and examined4 ,the change of colours proceeds somewhat slowly at first1 but when once it begins it seems to gain in rapidity of rate of change1 so that a careful watch must be kept4 ,let it be remembered that the print1 after fixing and drying1 will appear a little darker and more blue 7less red7 than when wet in the toning bath4 ,the temperature of the bath must not be too cold or toning is very slow1 nor too warm or the gelatine may melt and toning be uneven4 ,from #fj to #fe ,f4 will be found a convenient range4 ,the prints should not be touched on their printed surface more than can be helped4 ,the fingers must be quite clean1 the solutions uncontaminated with other chemicals1 and a dish set apart for toning operations only4 ,this dish should always be washed out well with tepid or cold water before and after use1 and when put away should rest flat1 opening downwards1 on a shelf covered with a sheet of clean blotting paper4 ,many failures in toning are entirely due to lack of care in details and sufficient attention to cleanliness4 ,when toning is judged to be carried far enough1 the prints should be placed in a roomy dish containing a solution of common salt1 strength one ounce to twenty or thirty ounces of water1 to stop further toning4 ,fixing is done with a one in ten solution of sodium thiosulphite--i4e41 hypo4 ,this should be prepared with tepid water1 or some time before use1 as the dissolving of hypo in water is accompanied by a fall of temperature4 ,a convenient method is to place a couple of ounces of hypo in a clean pint jug1 and add about half a pint of fairly warm water and stir with a glass rod until the salt is dissolved1 then fill up the jug from the tap with cold water4 ,it is highly desirable to have plenty of fixing solution1 and never attempt to use the same lot twice4 ,place each print face down in the bath and submerge by pressing on its back4 ,again see that the prints do not stick to each other1 and turn each print two or three times4 ,they should be in the fixing bath not less than twelve or fifteen minutes1 and a few minutes longer will do no harm4 ,at the end of1 say1 fifteen minutes1 pour away about one half of the fixing bath and slowly fill up with water4 ,turn the prints again1 and then transfer them one by one to another roomy dish and wash in running water for a couple of hours1 or in a dozen changes of water every five or ten minutes4 ,then hang up to dry1 using either clips or pin a corner to the edge of a wooden shelf or long lath suspended in a cool1 airy place4 ,alum ,bath4--,hot weather considerably increases the danger of the gelatine melting4 ,to meet this trouble the following plan has to be resorted to3-- #h4 ,dissolve common 7potash7 alum1 one ounce in a pint of tepid water4 ,let it stand until cold and pour off gently the clear part should any sediment appear4 ,after washing and before toning1 place the prints in this alum bath for about ten minutes and again wash before toning for ten or fifteen minutes in running water4 ,the ,combined 7,toning and ,fixing7 ,bath4--,the general weight of opinion is not in favour of combining these two operations at one time when reliable results are desired4 ,nevertheless1 there are times when this method may be found a convenience and yield results which are all that may be desired4 ,the following bath is a favourite with some workers3-- #i4 ,ammonium sulphocyanide #ae grains ,table salt #cj grains ,hypo #b ounces ,water #aj ounces ,to this is slowly added one grain of gold chloride in half an ounce of water4 ,the prints first washed for five or ten minutes in running water1 and placed in the combined bath and kept moving by being constantly turned over and over for about ten or fifteen minutes4 ,the longer they remain in the bath the more blue and less red will they be when dried4 ,here is another bath which finds some stout supporters3-- #aj4 ,ammonium sulphocyanide #bj grains ,hypo #a ounce ,alum #cj grains ,water #aj ounces ,shake well1 until thoroughly dissolved1 then add ,lead nitrate #bj grains ,again shake well and set aside to settle1 pour off the clear part1 and add ,gold chloride #a grain dissolved in half an ounce of water4 ,others recommend a still more simple bath as follows3-- #aa4 ,hypo #a ounce ,water #h ounces ,gold chloride #a grain ,it is said that this bath gives better results if it is prepared a few hours before use1 e4g41 prepared in the morning and used in the evening4 ,meanwhile1 it should be kept away from daylight1 and not in a very cold place4 ,drying and ,glazing4--,some workers are of opinion that it is better to first rough dry the prints1 e4g41 by suspending by clips1 or pinning one corner to a strip of wood1 etc41 and then to wet again and dry on a rough or smooth surface according as a matt or glazed final effect is desired4 ,if however1 the print has been through the alum bath 7,no4 #h47 this preliminary rough drying may not be necessary4 ,matt ,surface4--,the matt paper when rough dried has a matt or slightly rough surface1 but it may be desired to accentuate the effect4 ,this may be done as follows3--,thoroughly clean with soap water and a nail brush a sheet of fine-ground glass similar to that used for a focussing screen4 ,when quite dry1 lightly dust it with fine talc powder 7,french chalk7 and polish off again with a bit of clean rag4 ,now slip this plate rough side up into a dish of cold water1 which also contains the print face downwards4 ,bring the print and glass into contact under water1 carefully avoiding any air bubbles between them1 as the two together are now raised from the water2 firmly1 evenly1 but lightly pass a squeegee over the back of the print now in contact with the glass4 ,then lightly press a sheet of blotting paper over the print to take up all adhering water1 and set up in a cool airy place to dry1 e4g41 in a passage or between the door and half-open window4 ,when quite dry1 the print will very probably of itself come away from the glass1 but if not1 the finger nail inserted under one corner and a gently backward pull will separate it from the glass4 ,in place of the fine ground glass1 rougher glass of course may be employed4 ,some workers also use for the same purpose a sheet of roughened celluloid4 ,this is more costly than glass1 but being not so fragile may prove cheaper in the end4 ,glazing ,prints is done exactly in the same way1 with the single difference1 of course1 that we use a smooth piece of glass1 vulcanite1 celluloid1 paper mach slab1 sheet of ferrotype metal1 etc41 etc41 in place of a ground-matt1 or rough surface4 ,all the above-named substances have their partizans2 perhaps the greatest favourite being good plate glass free from scratches4 ,in all cases it is important to attend to two points1 viz41 thoroughly cleaning the support and waxing it4 ,various substances and mixtures have been recommended for giving a glaze1 polish to the glass1 etc4 ,many workers adhere to the powdered talc or ,french chalk already mentioned4 ,others prefer some of the mixtures given below3-- #ab4 ,bees wax #bj grains ,turpentine #a ounce #ac4 ,spermaceti #bj grains ,benzole #a ounce ,a few drops only of the lubricant are applied to the glass plate with a bit of clean flannel1 and well rubbed all over4 ,then a final polish is given with a clean old silk handkerchief1 or clean dry wash leather4 ,on no account attempt to strip the print from the glass until the print is quite dry or failure is more than likely to arise4 ,mounting4--,care should be taken that the mountant does not give an acid reaction4 ,test with litmus paper4 ,clearly it is no use being at the trouble of producing a high gloss on the print if we are going to damp the print and so destroy the gloss in the operation of mounting4 ,to avoid this1 various plans have been adopted4 7#a47 ,if a cut-out mount is used it will suffice if the print be attached to the mount by glue at the edges only of the cut-out4 7#b47 ,another method is to paste down on to the back of the print before it is quite dry1 and while still on the glazing support1 a backing of thin waterproof paper specially prepared for this purpose4 ,this prevents the moisture of the mountant penetrating to the print4 7#c47 ,another plan is to use a mountant which does not contain water4 ,the following mixtures are recommended3-- #ad4 ,masticated rubber #aj grains ,benzole #a ounce ,a thin layer of this is applied by means of a short1 stiff1 flat hog's hair brush to the back of the print4 ,it is then allowed to evaporate for a minute or so1 and when tacky is applied to the mount1 covered with a sheet of glazed paper1 and a roller squeegee passed over the surface4 #ae4 ,saturated solution of bleached shellac in alcohol4 ,this must be applied as thinly as possible4 #af4 ,le ,page's fish glue applied to the edges only of the back of the print4 ,a fourth method is to first carefully clean the edges of the glass surrounding the print still adhering to it4 ,then to paste down the mount to the print and let all dry4 ,then strip the print from the glass now already mounted4 ,this is1 however1 a process not to be recommended1 because requiring a long time for the print to dry1 as the evaporation has to take place through the substance of the mount4 ,,additional ,,procedures ,,with ,p4,o4,p4 ,development of ,partially ,printed ,proofs4--,this method of procedure is sometimes a matter of convenience in dull weather1 etc4 ,the printing is to be carried on until one can just see a very slight indication of detail in the high-lights4 ,it is then washed in running water for about ten minutes1 and then put into a ten per cent4 bath of potassium bromide1 and there it remains for another ten minutes or so4 ,in this bath some of the image seems to fade away1 and generally the print takes on a yellow tinge4 ,the print is next washed in running water for about ten minutes1 and then developed with ortol1 metol1 or preferably1 hydroquinone4 ,a considerable variation in the proportions of the constituents of the developer are possible4 ,in general terms1 one may say that a developer which gives a good black and white lantern slide when diluted with about an equal quantity of water will give a satisfactory print4 #ag4 ,as an example of a thoroughly practical developer for this purpose we may give just one example3-- ,a ,hydroquinone #gj grains ,potassium metabisulphite #e ,potassium bromide #cj ,water #bj ounces ,b ,soda sulphite #a ounce ,caustic soda #fj grains ,water #bj ounces ,take equal parts and mix just before use1 wash for at least ten minutes in running water at once after development4 ,developed prints may be toned in the combined bath #i1 #aj or #aa1 or may first be fixed1 then thoroughly washed1 and then toned and again washed4 ,if good results are wanted by the development process it is important to be careful that the paper is not exposed even to weak daylight more than can be helped1 and not even to strong artificial light more than is necessary4 ,at the same time it is quite practicable to do the operation of the bromide bath and developing in fairly strong gaslight1 i4e41 one need by no means be limited to the ordinary dark-room light as when developing plates4 ,another point worth noting is that it is quite practicable to use magnesium ribbon for printing4 ,for a rather thin negative it will be perhaps found sufficient to burn about a foot of the metal ribbon about three or four inches from the glass4 ,the printing frame should be set up on edge in the vertical plane4 ,the strip of metal ribbon is held by a pair of pliers1 and ignited at the flame of a candle or spirit lamp4 ,the lid of a biscuit box just in front of the frame does very well to catch the white magnesium oxide formed by burning4 ,it is as well to move the flame of the burning metal opposite various parts of the negative during the exposure4 ,it will be found a comfort to wear a pair of rather dark blue glasses during this operation1 as the bright light of combustion prevents one seeing anything with ease for a little while4 ,after development the print may be fixed only1 and under certain conditions it is possible to obtain a fairly satisfactory black or brown colour without toning1 but there is usually a slight tendency towards rather too much yellow4 ,platinum ,toning4--,this method of toning is a favourite with many workers4 ,by it a considerable variety of colour tones may be obtained1 from a rich red chocolate brown through sepia brown to a warm black4 ,the following toning baths have each their several advocates1 and each worker must discover by experiment the one that gives him the particular brown colour he prefers3-- #ah4 ,potassium chloroplatinite #a grain4 ,water #a_/b ounce4 ,add dilute nitric acid 7one part strong acid1 twenty parts water7 drop by drop until the mixture just turns a bit of blue litmus paper a red tinge4 ,now take a glass rod and make of it a mop by tying a small bunch of clean cotton wool over one end1 using for the purpose a bit of white cotton4 ,having thoroughly washed the print for at least ten minutes in running water1 lay it face up on a sheet of glass1 and apply the above toning solution with the cotton wool mop4 ,having got a tint or colour nearly what you want1 but allowing for a loss of red in fixing1 wash off the toning solution and immerse the print in3-- #ai4 ,washing soda #a ounce4 ,water #aj for three or four minutes1 and then fix in the usual way in a ten per cent4 hypo bath4 ,here are some platinum toning baths well recommended3-- #bj4 ,lactic acid #b drams4 ,water #ab ounces4 ,pot4 chloroplatinite #b grains4 #ba4 ,citric acid #bj grains4 ,water #aj ounces4 ,table salt #bj grains4 ,pot4 chloroplatinite #b grains4 #bb4 ,phosphoric acid #c drams4 ,water #aj ounces4 ,pot4 chloroplatinite #b grains4 ,the chief points to bear in mind in platinum toning are3 7#a7 that the print must have practically all the free silver washed away before toning4 ,to this end it is a very good plan to dip each print for a couple of minutes or so in a bath of table salt one ounce1 water ten ounces1 and again rinse under the tap for a minute or two4 7#b7 ,that the toning bath is acid1 therefore one must either neutralize this acidity by passing through an alkaline bath1 such as ,no4 #ai1 or what perhaps is rather more convenient1 though not quite so desirable--i4e41 using a fixing bath made distinctly alkaline4 ,the following proportions are recommended3-- #bc4 ,hypo #a ounce4 ,water #aj ounces4 ,soda sulphite #a_/b ounce4 ,washing soda #a_/b ,toning with ,gold and ,platinum4--,a large number of experimenters have tried to find out how to produce platinotype-like effects with ,p4,o4,p4 papers4 ,perhaps none of them have been completely successful4 ,the following procedure1 however1 seems to give the nearest approach to that ideal4 ,the best results are obtained with a slightly matt-surfaced paper4 ,this should be printed a shade or two deeper than the print is intended to appear finally4 ,the print is well washed and then partly toned in a gold bath3-- #bd4 ,soda acetate #cj grains4 ,borax #be ,water #aj ounces4 ,gold chloride #a grain4 ,it is then washed for a minute or so1 and the toning continued in the following bath4 #be4 ,phosphoric acid #a dram4 ,water #e ounces4 ,pot4 chloroplatinite #b grains4 ,wash for five minutes and fix in bath #bc4 ,intensifying and ,reducing ,p4,o4,p4--,when the negative is obtainable and printable it is very much better1 and altogether more satisfactory to make a fresh print than to attempt to intensify or reduce an unsatisfactory one4 ,nevertheless1 it sometimes happens that this course is not possible1 and the best has to be made from an unsatisfactory print4 ,if the print is only very lightly printed1 and comes straight from the printing frame1 it is best to strengthen it by development 7see formula #ag et seq474 ,if the print has been toned and fixed1 etc41 the following may be tried3-- #bf4 ,make a saturated solution of mercury bichloride in cold water1 let it settle1 and use only the quite clear supernatent liquid4 ,immerse the print in this for #ae minutes1 turning it from time to time1 and see that no air bells are clinging to either side4 ,wash the print in running water for #ae minutes at least1 and longer if convenient4 ,then immerse it in a bath consisting of strong ammonia one part1 water ten or twelve parts4 ,again wash for five minutes under the tap4 ,reducing ,p4,o4,p4-- #bg4 ,hypo #abj grains 7#abj7 ,uranium nitrate #d ,water #b ounces4 ,the advocates of this solution claim for it that it can be used either before or after toning with equal facility and advantage4 ,prints must be well washed both before and after its use in any case4 ,another method1 which is somewhat risky except in expert hands1 is as follows3-- #bh4 ,dissolve metal iodine in alcohol to a rich dark port wine colour4 ,dilute a small quantity with cold water until the whole is a pale sherry colour4 ,now prepare a one in ten solution of potassium cyanide 7,n4,b43 a powerful poison7 and add this a little at a time until the pale yellow colour of the iodine solution is just discharged4 ,the print may be immersed in this until sufficiently reduced1 or it may be applied locally with cotton wool mop 7as described above under platinum toning formula #ah74 ,the print must of course be quickly washed just before the desired degree of reduction has been produced4 ,this solution acts somewhat quickly when once the action begins1 and therefore it is well to deal with prints one at a time4 ,,defects1 ,,etc4 ,red-orange patches are usually due to touching the gelatine surface with dirty fingers1 etc4 ,these places1 being somewhat greasy1 repel the various fluids and cause uneven action of the developing1 toning1 etc4 ,brown ,stains are also often produced in the same way4 ,they may sometimes be removed by the application of a saturated solution of alum4 ,if this fails one may try chloride of lime 7bleaching powder7 one part in twenty parts of hot water4 ,allow to stand until cold and apply with cotton wool mop4 ,yellow ,stains may sometimes be removed by a dilute solution of potassium cyanide 7poison7 of strength one part cyanide in fifty parts water4 7,yellow stains usually indicate hypo splashes47 ,general ,fog from ,age4--,this sometimes may be considerably reduced by giving the prints the bath of3 ,soda sulphite 7one in fifteen7 before toning1 but well washing after this bath and before toning4 ,very ,slow ,toning generally points to the fact that the toning bath is too cold1 or that it has been spoilt by a small quantity of hypo or developer1 or that it does not contain sufficient gold4 ,uneven ,toning1 i4e41 blue edges1 generally points to a bath too strong in gold1 or that there are too many prints in the bath at once1 so that the edges are getting more of the metal than the central parts1 or it may arise from prints sticking together or to the bottom of the dish4 ,blue-,grey ,tones indicate too long a time in the toning bath1 or a bath too strong in gold4 ,red-,yellow ,tones arise from just the opposite state of affairs4 ,pinking of the high-lights points to the bath being too weak or becoming worked out4 ,double ,toning1 i4e41 the print shewing different colours1 points to insufficient washing or uneven action of the toning bath1 i4e41 not keeping the prints moving1 or too slow toning1 or that the toning bath does not suit the brand of paper4 ,blisters are usually due either to using a hypo fixing bath too strong1 or passing the print from one solution to another of a markedly different temperature4 ,hence the importance of dissolving the hypo either in tepid water or some time before use4 ,the best all-round temperature for working this process is between the limits of #fj and #fe ,f4 ,tinting ,p4,o4,p4--,the colours to be used may be the usual moist water colours by some good maker1 or solutions of aniline colours4 ,these latter may usually be dissolved in water and applied in thin washes4 ,the surface of the print should be rubbed as little as possible4 ,if water colours are to be used it will be found helpful to prepare the surface of the print with one or other of the following preparations4 #bi4 ,white 7bleached7 lac4 #a part ,alcohol #ab--ae parts ,apply evenly and quickly with a spray diffuser or with a broad soft brush1 and let the print become nearly dry before applying the colours4 #cj4 ,the white of an egg in twenty ounces of water4 ,shake well1 then add ammonia drop by drop until the mixture just very faintly smells of it4 ,filter and brush over the surface of the print4 ,in mixing the water colours also use this albumen solution in place of water4 ,advantages of ,p4,o4,p4--,as compared with ordinary albumenized silver paper the ,p4,o4,p4 class has the advantage of giving more detail with marked transparency in the shadows4 ,the operations are more flexible and the results are as permanent1 if not more so1 than those on albumen paper4 ,the paper keeps in good condition for a longer time4 ,the negative giving the best results with ,p4,o4,p4 is one having delicacy rather than vigour1 i4e41 a long scale of gradation of delicate steps is well rendered4 ,printing takes place quicker with ,p4,o4,p4 than with albumen papers4 ,the cost of paper and materials is much about the same in both instances4 ,notes4--,in the glazed variety of paper the smooth shiny surface is the sensitive one1 and1 of course1 goes next the negative in the printing frame4 ,in the matt paper the sensitive side may generally be known by its tendency to curl inward1 i4e41 the concave or hollow side is the printing side4 ,formalin may be used in place of alum for hardening the gelatine4 ,of the usual #dj per cent4 solution of formalin take one ounce and dilute with ten or twelve ounces of water4 ,dark spots or specks are frequently due to metallic dust either from the fingers or in the water4 ,mounts having sham gold edges or bronze powders should be banished from the dark-room4 ,dry pyro floating in the air may also account for spots4 ,rev4 ,f4 ,c4 ,lambert1 ,m4,a4 ,illustration3 ,,unloading4 ,a4 ,m4 ,,morrison4 ,platinotype ,printing4 ,illustration ,amongst the various printing processes in common use amongst photographers1 platinotype is unique in several respects4 ,printing is conducted by daylight in precisely the same manner as silver printing1 but the action of light only suffices to make the image partially visible4 ,in this respect1 platinotype stands1 as it were1 midway between what are familiarly termed print-out processes--that is1 those in which the image is made completely visible by daylight1 and those in which the action of light is latent or invisible1 such as bromide paper and in the carbon process4 ,the distinctive character of the platinotype print1 with which1 probably1 everyone is so familiar that a platinotype effect almost amounts to a generic term1 is not so much essential to the process1 but has been largely determined by the different kind of papers and the preparation of those adopted by the manufacturers of platinotype printing papers4 ,in the first place1 the platinotype print is before anything a matt surface print1 and possesses a certain kind of texture or surface which gives the finished print an appearance similar to a pencil drawing or an engraving2 an appearance largely assisted by the characteristic colour of the platinum image1 which is black4 ,the invention and production of platinotype paper is due to ,mr4 ,willis and the ,platinotype ,company1 and although subsequently there have been both ,english and foreign imitators1 we may safely confine our attention to those papers made and supplied by the ,platinotype ,company4 ,as1 however1 the purpose of this article is to furnish the beginner with simple working instructions1 rather than to describe the principles of the process1 we will at once proceed to say how a platinotype print is made4 ,to begin with1 platinotype printing is divided into cold-bath process and hot-bath process4 ,of the latter we shall speak later on1 but for the present1 as being most suitable for the amateur and beginner1 we will consider the cold-bath method4 ,the reason for this division and the meaning of the name will be abundantly evident presently4 ,we first of all procure a tin of paper of the quality marked ,,aa4 ,the paper is put up in tin cylinders containing twenty-four pieces of either #a_/d-plate or #a_/b-plate sizes1 or less for larger sizes4 ,it may1 if preferred1 be obtained in full-size sheets #bj #bf inches4 ,we have now to bear in mind that the paper is sensitive to daylight to a slightly greater degree than are the silver print-out papers1 and hence1 whilst handling the paper1 placing it in the printing frames1 or what not1 we need to be a little more careful as to how near the window we bring the paper4 ,at the side of the room furthest from the window1 or with an intervening screen between the paper and the window1 or yet again1 with the blind drawn down1 we shall be quite safe in opening our tin of paper and inspecting it4 ,on removing the lid of the tin we find a false top or cover hermetically sealing it1 which has to be cut through in the manner becoming customary with various tinned foods and comestibles4 ,we then find that the paper within is yellow on one side which is the sensitive side4 ,within the roll of papers at the bottom of the tin we shall find a hard irregular lump of some substance wrapped round with cotton wool4 ,keep this in the tin and now note its use from the following3--,platinotype paper is highly susceptible to moisture and deteriorates under its influence4 ,the air we breathe1 and therefore the air enclosed within the tin case or any other vessel contains a large amount of moisture1 and this moisture would be taken up by the platinotype paper to its own detriment4 ,the presence of water or moisture in the atmosphere or in things we handle1 although quite unperceived by us1 would be discoverable by the platinum salts on the paper1 which would thus become unfit for use1 hence the only way of preserving it is by placing in the tin containing the paper some chemical which is even more susceptible to moisture than platinotype paper4 ,such a body is calcium chloride1 and this it is which we find wrapped in cotton wool in each tin tube of paper1 or to speak more accurately it is asbestos prepared in a solution of calcium chloride4 ,so long as that little lump remains dry and hard we may be quite sure that it has left no moisture in the air around it for the platinotype paper1 and it will go on drinking it up until it becomes softened by saturation1 when it must be removed and a fresh piece substituted1 or it may be restored to its former condition by drying it on a red-hot shovel1 the asbestos remaining unconsumed4 ,whilst perhaps in after practice we may find it possible to relax our precautions against damp1 yet at the outset the necessity of the utmost caution being observed cannot be too strongly insisted upon4 ,out of a very large number of prints representing the beginner's first attempts at platinotype1 by far the greatest number of failures are due to damp1 and this1 probably1 for want of conception of the danger to which the paper is exposed4 ,remember then that where there is ordinary air there is also abundant moisture1 and as no tin box with a movable lid is air-tight1 neither is it moisture-proof1 but in the case of our tin of platinotype paper when once opened will go on admitting moisture which the calcium chloride will take up until it can take no more4 ,after having cut through the inner sealed top of the tin1 close up the little hole in the outer lid where the cutting point is with sealing wax1 next cover the mouth of the tube with a piece of waxed paper or tinfoil1 shut the lid down on to this1 and then cover the junction of the lid with a broad indiarubber band4 ,in this way damp may be prevented from gaining access to the inside of the tube to a great extent4 ,specially constructed tubes are made which close with an air-tight stopper and have a false bottom with a perforated partition in which the calcium chloride may be kept4 ,such a calcium-tube1 as it is called1 if not an absolute necessity1 is a very desirable acquisition4 ,if you now take the negative to be printed from and hold it near the fire or a spirit lamp1 it will on becoming warm give off perceptible moisture1 thus showing that it was distinctly damp before4 ,the negative1 therefore1 should be dried before being brought into contact with the platinotype paper4 ,illustration3 ,,streonsalch4 ,w4,j4 ,,warren4 ,the wood printing frame itself1 if it has been used for printing in the open air1 should be placed in an oven or held near the fire to thoroughly dry it4 ,having placed the negative and the platinotype paper in the frame in the ordinary manner1 there should next be placed at the back of the paper a thin sheet of waterproof cloth1 vulcanized rubber of the proper size and thickness being sold for the purpose2 this will prevent damp from penetrating to the paper from the back of the frame4 ,the frame may now be closed and placed in the light for printing1 and even having taken all these elaborate precautions against damp it would not be advisable to print out of doors except in dry weather1 nor should the paper be left in the frame longer than need be1 but if it is not proposed to finish the print off at once1 it should be returned as soon as convenient to the security of the calcium tube4 ,,general ,,outline ,,of ,,the ,,process4 ,platinotype paper is ordinarily only available for daylight printing1 though the ,platinotype ,company have introduced a lamp of special construction and great power1 by the use of which daylight may be dispensed with1 and electric light1 should it be available1 may be used4 ,as has been already said1 platinotype paper is rather more sensitive to light than silver paper1 and hence takes proportionately less time to print4 ,the duration of the exposure to light constitutes the only real difficulty in platinotype printing1 and whilst just at first it may result in the beginner's meeting with much disappointment1 yet probably1 with a little care and watchfulness the trouble will be surmounted1 and sufficient experience gained to secure fairly uniform success thereafter1 before even the first tube of paper has been used4 ,the printed image shows on the yellow ground of the sensitized side as a faint grey1 the darkest portions assuming an orange-grey tint1 whilst the lighter parts remain all but invisible4 ,a little practice will enable one to judge the right depth1 that is to say1 how visible the image should be before printing is to be stopped1 but as a rough guide to commence with it may be said that printing is complete when the image is about half as deep as we should expect it to be if it were a print-out process4 ,as we shall have occasion to return to the question of printing presently1 we may now pass to the next step in the process4 ,in twenty-five ounces of hot water dissolve half a pound of best neutral oxalate of potash1 and keep this in a stoppered bottle as stock solution4 ,what is known as neutral oxalate should be used1 and in order to ensure having a suitable salt it had better be obtained from a recognised photographic chemist or dealer4 ,as the above solution becomes cool1 a good deal of the oxalate will probably settle at the bottom in the form of solid crystals2 of these no notice need be taken1 for as long as there are undissolved crystals at the bottom of the bottle we know we have a saturated solution4 ,we shall now require a dish of porcelain or enamelled iron1 and if we choose the latter great care must be taken to see that the enamel is not cracked or blistered1 as it will have an injurious effect if the oxalate of potash solution obtain access to the iron under the enamel4 ,as it will be convenient to be able to alter the temperature of the solution when in this dish at will1 a spirit lamp or stove or a small gas-stove will be a useful1 if not an essential addition4 ,over such heating apparatus the dish should be supported on an iron tripod1 or by any extemporized substitute4 ,if a porcelain dish be used1 a thin sheet of iron should be placed first on the tripod stand1 and then three or four scraps of iron1 large common iron nails will serve very well1 and on these the porcelain dish is allowed to rest so that it does not come into direct contact with the iron plate4 ,the purpose of this is to save the dish from cracking1 moreover the iron plate becomes hot1 and retaining a good deal of heat serves as a kind of accumulator which goes far to maintain the dish and the contained solution at a uniform temperature for at least a short time4 ,even better than this arrangement will be an iron dish filled with clean dry sand1 the porcelain dish to rest on the sand which retains much heat4 ,if an enamelled iron dish be employed1 these precautions are not so necessary1 though they may still be used with advantage4 ,next we shall require another dish or similar vessel into which we pour a weak solution of hydrochloric acid1 the usual proportions being3-- ,water #gj parts ,pure hydrochloric acid #a part ,this constitutes the whole of the very simple apparatus needed1 and we may now proceed to develop our print1 which as already described is exposed to light in a printing frame in the usual manner until the image appears rather less than half-printed4 ,,development ,,of ,,the ,,print4 ,if convenient it would be an advantage to have the above-mentioned apparatus set up close to the window or other situation where the printing is actually carried on in order that each print may be developed and finished off forthwith12 the reason for this will1 ,i think1 appear as we proceed4 ,development--that is1 the changing of the print from the partially visible condition to its full degree of intensity--is practically instantaneous4 ,the image does not gradually attain its maximum strength as in a negative or bromide print1 but does so within a few seconds of its coming into contact with the oxalate of potash solution4 ,illustration3 ,fig4 #a4 ,having put into the dish on the tripod stand sufficient of the saturated solution of oxalate of potash to cover the bottom of the dish to the depth of half an inch or an inch1 we light the lamp or stove and bring the solution up to a temperature of about #gj ,fahrenheit4 ,this may be tested with a thermometer or may very well be guessed by touch2 we merely require the solution quite warm1 but not so hot as to cause the slightest inconvenience if the fingers are placed therein4 ,this will be a sufficiently accurate guide as to temperature4 ,in case any dust or scum should have accumulated on the surface of the bath1 wipe the surface of the solution with a piece of clean paper1 and now take the first print to be developed in both hands1 giving it a decided curl1 or roll it round into a cylinder sensitive side out1 so that it naturally takes a curled-up form 7,fig4 #a74 ,we now take the print to the dish containing the oxalate solution without previous washing and without exposing the paper to the influence of light or moisture1 and lowering the edge of the paper held in the left hand1 sensitive side downwards1 until it touches the fluid quickly and smoothly bring the rest of the print down until the right-hand end finally reaches the solution1 then give it a sliding sort of shake in order to set free any bubbles of air which may be imprisoned under the paper1 and then on raising the paper again after five to ten seconds1 the image will be found to have come out to the full degree of visibility1 which the amount of exposure had paved the way for4 ,the paper may be returned to the oxalate bath for a minute or two longer if it be thought desirable1 though only in the case of a very cold bath is any effect produced on the print by the oxalate after the first few seconds4 ,the print is then passed direct to the hydrochloric acid bath1 which should be ready in a dish close at hand1 and the print is now practically finished4 ,before placing the print in the acid bath it may be noticed that the portions of the print not affected by light still remain yellow1 and this yellowness the acid bath removes almost at once4 ,in order to effectually remove the yellow surface 7which is the unacted-upon sensitive salts and hence upon their removal the permanence of the print depends7 three successive applications of the acid bath should be resorted to1 the prints remaining for #e to #aj minutes in each1 and then finally washed in running water for a quarter-of-an-hour1 dried between blotting paper or in any other manner preferred1 and the platinotype print is finished and ready for mounting4 ,it should be seen from the foregoing general outline of the process that for directness1 simplicity1 and for the short time in which a finished print may be produced that platinotype stands alone amongst printing methods4 ,there are1 however1 some points needing careful consideration at each stage of the print's production1 and to these we may now pay attention4 ,,practical ,,considerations ,,as ,,regards ,,exposure4 ,as has already been stated right exposure constitutes the crux of the whole process2 this once mastered the rest of the performance--development1 clearing in acid and washing--is so simple that the chance of failure is remote4 ,hence the greater need of paying especial attention to the question of exposure or printing4 ,obviously1 the duration of time of exposure cannot be fixed1 not even to the extent it can be in bromide printing or any other method of printing with artificial light which may be a definite and permanent quantity4 ,the variable quality of the daylight and the density of the negative are both fluctuating factors in the calculation and hence some means may advisedly be resorted to for acquiring a sort of exposure index suitable for each individual negative and every variety of light4 ,first let it be noted that even with very great over-exposure the image will not become wholly visible1 whilst to the inexperienced eye but little change takes place in the appearance of the printed image after the correct exposure has been reached4 ,if then the print has been over-exposed1 the fact is not made evident until the print is subjected to the influence of the oxalate developing bath4 ,to start platinotype work trusting to chance or good fortune to secure for us good results1 means that our whole course will be one of uncertainty and filled with exasperating disappointments to say nothing of the amount of paper and material which is certain to be wasted in unsuccessful efforts4 ,the reader will probably have learned something of this from his past experiences of negative exposure1 the difficulties of which he has by now1 we may hope1 overcome by careful and patient study1 or else if he is not even now undergoing this stage of learning he is the victim of endless mistakes1 every plate exposed is a shot in the dark with no certainty attending any one of them4 ,exposure1 however1 in platinotype is not so difficult a matter as that of a dry plate1 and the correct exposure with any particular negative once ascertained1 every subsequent print from the same negative can1 by simple mechanical means1 be made with the certainty of its being an exact facsimile of the others4 ,,printing ,,with ,,an ,,actinometer4 ,several kinds of ,actinometers are made for sale1 the purpose of which is either to indicate the right exposure of a plate in the camera or to tell the duration of exposure for papers such as platinotype or carbon1 the image on which is invisible1 or nearly so4 ,a simple1 yet thoroughly efficient meter may be made as follows3--,cut some fine tissue paper or papier minral into strips about a quarter of an inch wide and attach one to a piece of clean glass #d-a_/d #c-a_/d with fresh starch or other colourless mountant4 ,upon this first strip and exactly over it place a second1 but bring it to within a quarter of an inch of the end of the first1 next place a third strip in like manner a quarter of an inch short of the second strip1 and so on until some seven or eight strips have been fixed4 ,the combination will now be somewhat as the following drawing 7,fig4 #b71 thus forming a tissue band which at each quarter-inch is one thickness more opaque4 ,illustration3 ,fig4 #b4 ,in the centre of each strip or increased thickness1 paint with opaque colour1 black or red1 a letter or figure as in 7,fig4 #c74 ,on the back or other side of the glass to which these strips are attached1 paint over or cover with opaque paper all except the space covered by the strips4 ,now place the whole in an ordinary #a_/d-plate printing frame1 with the paper strips inside1 next adjust a piece of silver paper1 albumenized1 or gelatine chloride precisely as though printing from a negative4 ,close the back and we then have a thoroughly efficient actinometer4 ,illustration3 ,fig4 #c4 ,we now put out our first piece of platinotype paper to print1 and alongside it so as to receive the exact same amount of light1 we place our actinometer4 ,the first print must admittedly be guess-work4 ,after an interval of time1 which may vary from say fifteen minutes to an hour according to the amount of light1 we will withdraw the frame containing the platinotype print1 and simultaneously turn the actinometer over with its face down1 thus stopping its printing whilst examining the platinotype4 ,retiring from the light we examine the progress of printing precisely as in silver printing1 and we shall probably find that the image on the negative is now faintly visible on the platinotype paper1 impressed in a sort of warm grey colour4 ,if the darkest portions are of about the tint which we might produce by shading with an ,h pencil on a piece of primrose yellow or pale buff paper1 we may reckon that the print has been sufficiently exposed4 ,now refer to the actinometer and see what has taken place on the silver paper which we put into it4 ,probably while the platinotype paper has been reaching the required depth of printing1 the silver paper has also registered the image of the strips of paper1 and has become printed through up to the fourth or fifth step of the tissue strips1 showing on each strip its letter in white4 ,make a note of the highest letter visible and proceed to develop the platinotype print4 ,if upon development the print is weak and grey1 lacking depth or intensity in the deepest shadows1 and having blank and detailless whites for the higher tones1 we may reckon that our print is under-exposed4 ,the letter visible then1 with that particular negative is not sufficient4 ,we then shift the paper in the actinometer so as to get a fresh portion under the tissue strips1 or we substitute a new piece4 ,we refill the printing frame and print again until the actinometer registers one1 two1 or three more steps and letters1 and then try again4 ,if1 however1 in the first case the platinotype print upon development gives a heavy dark print1 with the details in shadows blocked up1 and the high-lights grey1 the whole possessing an overdone appearance1 then in our second attempt we shall stop printing when the actinometer records some one or two letters less4 ,but we may be more fortunate in our first attempt1 and the print may be about right4 ,in that case we mark on that negative in some way the tint or step or letter in the actinometer at which we arrested action1 and henceforth1 no matter the time of year1 hour of the day1 or latitude1 that negative will give a similar print if stopped in accordance with that memorandum which it bears4 ,if1 however1 we do not hit the right exposure the first time1 we are pretty certain to do so the second1 or at the most the third time1 and having done so1 we have not only an infallible guide for all subsequent prints from that same negative1 but we have also some sort of index to base our calculations on for other negatives4 ,thus if we at once proceed to print from another negative1 that is1 before any considerable alteration takes place in the light1 we may by comparing the negatives at least estimate what will probably be the second negative's printing letter or step on the actinometer4 ,sooner or later every negative 7especially those from which we anticipate wanting subsequent prints7 should bear either on the negative itself1 or else in a carefully kept register or note book its correct printing letter4 ,although this may seem a rather laborious practice1 it is not so in reality1 and so great is its educational power that ,i anticipate that after the first dozen or so negatives we shall almost dispense with the actinometer altogether1 having by then trained the eye to tell when a print is finished merely by the appearance of the half-visible image4 ,do not let this prospect1 however1 tempt the beginner to dispense with this valuable help at first1 for to the inexperienced eye the appearance of the platinotype image is very deceptive1 and having under-exposed the first print1 it will not be safe to judge the extra printing of the next print only by the eye2 the beginner is nearly certain to err1 and the eye must not be trusted until it has had considerable training4 ,after having had some considerable and varied experience in platinotype printing1 one feels no little regret that an operation which has become so simple cannot be laid before a beginner in a more precise and definite manner1 and ,i can only assure my reader that in a very little while what may now look like a very serious business1 only surmountable by long and serious practice1 will become a sort of intuitive faculty1 and just as one feels after a little practice the precise amount of pressure which one should use when the fingers are placed on the notes of the piano1 so just the right visible depth of print required to give a developed print of such and such intensity comes to be a matter of instinct4 ,it may here be stated that paper which has been affected by damp gives a slightly less visible image than dry paper4 ,but moisture alone without oxalate will effect partial development1 and if the time of exposure to light be so greatly prolonged1 that despite all precautions moisture obtains access to the print during exposure1 this may1 as it were1 start a kind of local development whilst the paper is still in the frame and printing1 so that on looking at the print to watch its progress some of the deeper shadows may have sprung quite suddenly into a deep blackish-grey colour4 ,in many cases this will quite spoil the finished result1 whilst in others no harm seems to be done when the print is ultimately developed4 ,remembering that the high-lights and indeed some of the lighter tints of the print are quite invisible until after development1 care should be taken to look at the paper only in decidedly subdued light1 or better still1 artificial light1 because the injury which is being done by even a short exposure to actinic light is not made manifest until after development1 and as most of us know how soon a piece of silver paper will discolour in even moderately faint daylight1 we should be additionally cautious with platinotype paper which is from twice to three times as sensitive to light4 ,illustration3 ,fig4 #d4 ,,some ,,points ,,to ,,be ,,considered ,,with ,,regard ,,to ,,development4 ,to avoid confusion it will be well to repeat here that at present we are only considering the practice of what is known as the cold-bath paper4 ,this term is applied only in a comparative sense4 ,the older hot-bath process requires the developing bath to be raised to a temperature of about #agj ,f41 whereas the best temperature for the cold process is about #gj ,f4 or even less2 nevertheless1 the cold-bath paper may be developed in an oxalate bath of #agj or even hotter1 so also it may be developed on a solution which is quite cold4 ,the result of altering the temperature is two-fold and may be stated thus3--,the colder the bath1 the colder the colour1 that is1 the bluer the greys and blacks1 also development is slower and takes longer1 and the contrasts harder4 ,the hotter the bath the warmer or browner the colour of the print2 the more sudden the development and the greater the amount of half-tone and consequent softer contrasts4 ,with these maxims in mind some amount of control may be exercised over the prints produced1 especially as regards arresting development at any point desired if a cold developer be used1 but in such case the print must be instantly removed to and plunged into the acid bath1 until which immersion development continues1 even after the print has been removed from the bath4 ,development1 as a general rule1 should be conducted in feeble daylight or artificial light4 ,development need not take place immediately1 but at some subsequent time1 provided the prints be meanwhile stored in a calcium tube and in every way rigorously protected from damp4 ,the proportions which ,i have given for the oxalate of potash bath represent the standard developer as given by the makers of the paper for the hot-bath papers1 and they recommend that this be diluted to about half strength for cold-bath papers4 ,personally1 ,i use it at full strength for the cold process1 and see no reason for diluting it4 ,it may be said that such a course is calculated to give strong1 vigorous prints1 for generally speaking1 the stronger the bath1 the stronger the contrasts of the print4 ,the difference1 however1 produced by altering the strength of the bath is not very great4 ,there are two alternatives to the oxalate of potash developer1 both possessing certain1 if not very strongly marked characteristics4 ,the first of these is known as the ,d salts4 ,these are sold in tins by the ,platinotype ,company1 and consist of a loose admixture of certain salts1 and hence it is essential that the entire contents of a half-pound tin be dissolved at once and kept thus as a stock solution4 ,the proportions to be used are as follows3 ,dissolve #a_/b lb4 of ,d salts in #ej ozs4 water1 and then take equal portions of this solution and water1 in other words1 dilute it to half-strength4 ,the ,d salts are said to give colder colours and more half-tone1 but the colour derived from development on the first-named oxalate bath may be made colder by adding to #bj parts of developer #a part of a saturated solution of oxalic acid1 in like manner slightly warmer colour may be obtained if the oxalate bath be made alkaline by the addition of carbonate of potash1 but only just enough should be added to turn a red litmus test paper blue4 ,if prints developed on ,d salts should appear mealy or granulated1 the bath should be strengthened or used at the full strength of the stock solution 7salts #a_/b lb4 to water #ej oz474 ,another developer1 the effect of which is to minimize half-tone and increase the vigour of the contrasts1 and so give very brilliant and even hard blacks and whites1 is as follows3 ,oxalate of potash #af ozs4 ,phosphate of potash #d ozs4 ,sulphate of potash #a_/b oz4 ,water #abj ozs4 ,this should be made with hot water1 and to get the full advantage of its contrast-giving powers1 used quite cold4 ,development will then probably take one or two minutes1 but can be arrested sooner when the desired effect is attained4 ,it may now be as well to enumerate and describe the various kinds of platinotype paper obtainable1 and whilst the general treatment of them all is the same as described in the foregoing1 some special recommendations may be made in each case4 ,the papers for the ,cold-,bath process are two called respectively ,,aa and ,,cc4 ,,aa is a smooth surface paper and is the kind usually employed for portraiture and general small work4 ,,cc is a heavier1 stronger paper with a surface similar to stout cartridge or drawing paper4 ,for pictorial work and for landscapes1 also for large portraits or heads this paper is eminently suitable4 ,next we have the papers for ,hot-,bath process1 to be presently described4 ,these are firstly ,a and ,c1 both precisely the same in character as the ,,aa and ,,cc just referred to1 but intended to be developed in a bath at high temperature4 ,these four kinds of paper all yield a picture of the normal platinotype black colour1 the black tending to cooler or warmer tints according to slight modifications of treatment1 but it is also possible to produce a platinotype print of a rich sepia brown by using the papers ,s and ,,rs--these both in substance and character corresponding with ,,aa or ,a and ,,cc or ,c respectively4 ,thus we have a thin smooth and a thick rough paper for each ,cold bath1 ,hot bath1 and for ,sepia printing4 ,,development ,,of ,,hot-,,bath ,,and ,,sepia ,,papers4 ,with the ,hot-,bath papers perhaps the precautions against damp should be rather more stringent than for ,cold-,bath papers1 certainly they may not be relaxed1 and in the sepia papers1 ,s and ,,rs1 there seems to be even greater susceptibility still1 but for this1 printing and development are performed precisely as already described1 but the temperature of the oxalate bath should not be less than #aej to #agj1 whilst in some cases it may be convenient to raise it still higher4 ,the oxalate solution should1 moreover1 always be at full strength1 namely1 #a_/b lb4 in #be ozs4 of water or thereabouts1 a much more diluted bath will result in granular prints4 ,as a general rule the colour of ,a and ,c prints is a rather browner black than their cold-bath equivalents--,,aa and ,,cc--with also rather softer contrasts4 ,development takes place in shorter time than with cold-bath papers1 and is indeed so instantaneous that any control is next to impossible4 ,on this account1 rather more dexterity will be required in development1 that is to say1 between the time that one end of the print touches the developer and the rest of the print is brought into contact with it1 the shortest possible time should elapse4 ,there must be no hesitation1 the whole surface must be brought down gradually but swiftly1 and accompanied by a sliding movement in order to squeeze out or wipe out any air bubbles which might cling to the surface of the paper4 ,if this be not done evenly and continuously1 it is more than likely that there will be marks of unequal development on the surface4 ,illustration3 ,fig4 #e4 ,it is no uncommon thing for the tyro to let the print hover over the bath before giving it its plunge in the hot solution1 but in so doing it should be remembered that he is submitting it to the direct action of the steam which the bath is giving off1 and so exposing it to damp4 ,whilst with prints of #a_/b-plate size and under it may be sufficient to hold the print by one corner and wipe it across the surface of the solution1 pressing it down with the fingers of the other hand1 with larger sizes it will be well to cultivate a little trick in manipulation1 and the accompanying figure may perhaps be suggestive 7,fig4 #e71 in which it will be seen the left hand is bringing one end of the print into contact with the bath1 whilst the right hand holds the opposite end above and well back1 and the left hand will next be moved in the direction of the arrow1 drawing the print with it along the surface of the bath1 the right hand following but simultaneously lowering the whole of the print--thus the solution attacks the print smoothly and continuously1 whilst the air is pressed out in the opposite direction4 ,instantly the entire print is floating on the bath it should be moved about a little1 as a further means of disengaging any air bubbles4 ,as far as possible1 prevent the developer from flowing over the back of the print1 but this will be a far less evil than not bringing the whole printed surface immediately and at one stroke on to the developer4 ,the print is next passed direct and without intermediate washing into the hydrochloric acid bath1 as already described4 ,the sepia papers1 ,s and ,,rs1 are both hot-bath papers1 and no special instructions need to be given as regards development1 except that to get the full benefit of the sepia tint and secure a fine rich bright colour1 the ,special ,sepia ,solution prepared and supplied by the ,platinotype ,company should be employed in the developer4 ,of this1 one or two drams should be added to each ounce of oxalate bath1 either before heating it in the dish or afterwards and just before floating the prints4 ,in the latter case stir the whole so as to get it equally mixed1 and wipe the surface to remove any scum4 ,a good substitute for the bath as above prepared for sepia prints may be made by adding one part of saturated solution of oxalic acid to each ten parts of oxalate of potash solution4 ,the ,sepia papers are rather more sensitive to light than the ,black papers1 and hence all operations should be conducted in very subdued daylight1 a precaution even extending to the first acid bath4 ,the bath containing the special solution should be used for sepia prints only1 and when done with kept in a separate bottle for future use1 but the bottle must be kept from the light1 and the sediment which will fall should be left undisturbed at the bottom of the bottle or filtered out1 and the dish used for sepia development should be well washed before using it for black prints4 ,opinions seem to differ as to the wisdom of keeping old developing baths1 but as far as my own experience goes ,i use the oxalate solution for black prints again and again1 taking no heed of its discoloured condition4 ,after developing1 the bath is poured into the stock bottle1 and so long as undissolved crystals remain at the bottom of the bottle hot water may be added from time to time to make up the loss occasioned by spilling and waste1 thus the stock solution is always a combination of old and freshly-dissolved oxalate1 and ,i have had one large jar of solution thus in very frequent use for over twelve months1 a greenish-black encrustation gradually accumulating at the bottom without detriment4 ,,concerning ,,the ,,hydrochloric ,,clearing ,,or ,,fixing ,,bath4 ,little needs to be said as to the ,hydrochloric ,acid bath into which the prints are passed immediately after development4 ,the purpose of the acid bath is to dissolve out the sensitive salts which have been unaffected by light and which are still light-sensitive1 the removal of these making the paper white and clean4 ,thus the acid bath is both fixing and clearing in its action4 ,into the first acid bath the prints will carry a good deal of the oxalate solution in which they have been developed1 and it therefore soon becomes very much discoloured1 wherefore after a lapse of about five minutes the print should be removed to a second acid bath of the same strength as the first 7pure hydrochloric acid #a part1 water #gj parts7 and after five or ten minutes into a third4 ,after the prints 7many may be done at the same time7 have been in the third acid for five minutes1 the bath should be examined1 and if it is quite colourless1 that is if the prints have not discoloured it at all1 we may rest satisfied that clearing and fixation are complete1 but if not1 yet another acid bath should be given4 ,whilst five or ten minutes in each acid bath is long enough1 probably no harm to the print itself1 yet no good1 will follow a longer immersion4 ,there may1 however1 be a danger of softening or rotting the paper1 a danger which is increased should the bath be made stronger in acid4 ,if a number of prints are being made1 or if numerous dishes for acid constitute a difficulty or inconvenience1 we may modify procedure as follows3-- ,make up the first acid bath to about half the prescribed strength1 say hydrochloric acid one part to water #abj to #adj parts4 ,into this each print may be flung as soon as developed1 until the entire batch is thus far finished4 ,in this weak acid bath the prints will take no harm if left for several hours1 when an acid bath 7one to seventy7 of full strength having been prepared1 the first weak solution may be poured off and the fresh poured on4 ,in this the prints should be separately turned over1 so that each receives thorough treatment1 when the second bath may be thrown away and a third substituted4 ,one dish thus serves for the whole series of acid baths4 ,if adopting this course1 it will be safer not to mix sepia and ordinary black prints in the same first acid bath1 after which1 however1 they may be treated altogether4 ,sufficient washing to rid the paper of acid is all that is required to complete operations2 but acid does not cling to the print as does hypo1 moreover1 we have not an absorbent gelatine surface to deal with1 so that if prints were dealt with individually and washed by hand1 probably a few minutes sluicing under a tap would suffice1 but in a properly constructed print-washer1 or even a large dish1 twenty minutes to half-an-hour should be ample4 ,if any doubt is felt1 the last washing water may be tested with blue litmus paper4 ,,modifications ,,in ,,development4 ,to impart a warmer and richer tone to prints on ,,cc 7cold-bath7 paper1 the following slight modification may be resorted to1 but it must be regarded merely as an exception for definite purposes1 being in violation of the instructions and rules already laid down4 ,it consists of developing ,,cc paper as though it were hot-bath paper1 using a bath of about #agj ,f and submitting it to the influence of damp to a slight degree4 ,this latter very heterodox course may be effected by leaving the paper laid out all night in a room where there has been no fire to dry the air1 or by using paper which has been kept for a week or so in its tube without calcium chloride and without sealing the lid1 or yet again1 the print may be held over the steam of the developer for a few minutes before developing it4 ,it must be remembered that in doing this we are taking liberties with the process1 and if poor1 muddy prints result1 we can only blame ourselves1 but as a rule this will not be the case1 the effect being rather to impart a slight creamy tone to the whites without otherwise degrading their brilliance1 whilst the use of a hot bath gives the whole a distinctly brown-black image1 which combined with the cream tint of the high-lights has a very luminous and warm effect4 ,another method of development which must also be taken as an exceptional one1 only to be used in special cases to attain special ends1 is local development with a brush1 using glycerine as a medium4 ,as may have been seen from the foregoing descriptions1 the development of a platinotype print1 even with a cold bath1 is so rapid that there is not a possibility of developing one portion more than another1 or if such could be done1 still it would be done with the certainty of leaving a mark where development had been stopped4 ,these difficulties1 however1 may be overcome by the use of glycerine1 the effect of which is to retard development to almost any degree1 and by its soft1 viscid character to soften and blend the line of demarcation where greater or less development ceased4 ,the method of applying it is as follows3 ,on removing the print from the frame it should be fastened to a board with pins1 print side upwards4 ,next pour on to the surface a small pool of pure glycerine1 and with the finger tip1 a brush or soft pad1 spread it evenly and thinly over the print4 ,it must not be allowed to remain on the surface in irregular patches of unequal depth1 but after spreading it had better be wiped with a fresh pad of cotton wool1 so as to remove any superfluous glycerine4 ,now have four small vessels at hand1 and into ,no4 #a place an ounce or two of the ordinary oxalate developing solution1 in ,no4 #b put equal parts of oxalate solution and glycerine1 in ,no4 #c one part oxalate solution and two parts glycerine1 and in ,no4 #d pure glycerine4 ,with a broad1 soft hair brush apply the contents of ,no4 #c to the less printed portions of the image and wait results4 ,these portions will presently begin to gain in depth and to slowly develop up1 now spread the ,no4 #c mixture to the rest of the print and apply the contents of ,no4 #b to the portions first treated with ,no4 #c4 ,the most obstinate parts may be touched with ,no4 #a1 plain oxalate solution1 whilst any spots which have come up too quickly may be promptly arrested from further progress by the application of pure glycerine4 ,here we have a method of developing up any one part1 and restraining or entirely stopping any other4 ,i do not think any good will be done by a more detailed description of its working1 even if there be anything more to tell4 ,it is essentially a method of development in which the individual worker will invent modifications and dodges for himself1 and when all is said for it1 it must be admitted only as a means of improving a subject when ordinary procedure fails4 ,,the ,,character ,,of ,,the ,,negative ,,for ,,platinotype4 ,in the earlier days of platinotype printing it was generally insisted upon that the most suitable negatives were such as we should describe as somewhat vigorous or plucky4 ,whether it is that some alteration has been made in the manufacture of the paper or that taste as regards what constitutes a good print has changed1 ,i cannot say4 ,certain it is that in the experience of a good many1 a plucky negative is by no means essential to the production of a good platinotype print4 ,the soft1 delicate negatives1 of which the best professional portrait negatives are a good sample1 yield the best possible results1 whilst with the ,,cc paper1 negatives so thin and delicate as to be suitable for hardly any other printing process1 give all that can be wished for4 ,much1 of course1 will depend on the kind of print desired and the paper used1 and here it may be remarked that from a given negative the different kinds of platinotype paper give different results4 ,from a given negative the hot-bath papers yield the greatest amount of half-tone1 the hot development tending to yield flatter results4 ,next comes the smooth1 cold-bath paper1 and finally as yielding the maximum amount of vigour is the ,,cc paper4 ,hence if we make our negatives specially for our chosen printing process1 a stronger negative will be needed for ,s1 ,,rs1 ,a and ,c than for the ,,aa and ,,cc1 whilst for the latter a negative distinctly erring on the side of extreme thinness will be best4 ,if a negative gives prints which are too weak and flat for our purpose1 a great improvement may be effected by printing through blue glass4 ,if on the other hand the prints are too hard and harsh in contrast1 it is advisable to print through signal green glass4 ,,toning ,,platinotype ,,prints4 ,several formula and methods have been published from time to time1 the object of which is to change the colour of the platinotype print by subsequent staining or toning1 and whilst by such methods pleasing colours may sometimes be obtained1 they possess an element of uncertainty1 and must not be too much relied upon4 ,an exception in this respect must1 however1 be made in the case of what is known as ,packham's method1 the effect of which is to change the black platinotype to a sepia brown1 or a brown slightly tinged with green4 ,the necessary tinctorial powder must be obtained from ,mr4 ,packham or through a dealer4 ,to prepare the bath a packet of this powder is dissolved by boiling for three or four minutes in five fluid ounces of water1 to which when cold add one ounce methylated spirit4 ,this forms the stock solution and will keep for a long time if well corked4 ,for use add thirty or forty minims of the stock solution to one pint of water1 and in this steep the prints1 turning them over frequently4 ,toning may occupy several hours4 ,to expedite matters1 the dilute solution should be made with water of #aej ,f41 and the bath maintained at this temperature as in the case of hot-bath development4 ,as soon as the desired tint is secured1 remove the prints and wash well in three changes of cold water4 ,prints may be so treated at any time after they have been made4 ,glycerine developed prints are not suitable4 ,prints must have been very thoroughly washed1 so as to free them from every trace of acid1 also thoroughly fixed in acid if they are to be toned by ,packham's method4 ,if after toning and washing the whites of the print appear to have suffered1 the prints should be placed for five or ten minutes in the following bath1 which should be kept at a temperature of #ahj ,f4 ,castille soap #dj grains ,bicarbonate of soda #hj grains ,water1 hot 7#ahj ,f47 #a pint ,this will clear the whites and intensify the colour generally4 ,platinotypes may be toned to a red-brown by uranium nitrate1 or to a bluer colour with chloride of gold4 ,they may also be intensified by pyrogallic acid or hydroquinone1 but as the purpose of this article was merely to give simple working instructions for platinotype printing for the beginner1 he may defer the consideration of such side issues until he has become au fait in the production of a good platinotype print4 ,a4 ,horsley ,hinton4 ,contact ,printing on ,bromide ,paper4 ,illustration ,it is well to bear in mind at the outset that bromide paper is extremely sensitive to light1 almost as much so as is a rapid dry plate4 ,for this reason1 it is obvious that it must not be carelessly exposed to actinic light4 ,all manipulations except the actual printing must be conducted by red or yellow light1 such as is allowed to pass through glass of these colours4 ,for evenness of result1 it is better to use a lantern than daylight1 because the fluctuation in intensity of the latter is very misleading and liable to lead to failures through over or under development4 ,the actual colour of the light1 also1 is of far more importance than one would suppose3 ruby light tends to give one the impression that development is complete long before that is the actual case2 it is also somewhat more difficult to handle the paper satisfactorily by this light than by a good yellow4 ,for these and other reasons ,i strongly recommend the use of yellow light1 a thoroughly safe one being given by gas or lamplight passing through one sheet of yellow glass and one thickness of canary medium4 ,this light1 while being absolutely safe1 gives such perfect illumination that it is as easy to control and estimate results as it would be by ordinary unfiltered gaslight4 ,if a ruby glazed lantern is already in use for negative work1 it can readily be prepared for bromide printing by merely removing the ruby glass and substituting the yellow and canary medium4 ,with these brief hints as to illumination1 let us consider the entire process in its various stages4 ,unpacking the ,paper4--,the sensitive paper is generally packed in envelopes sufficiently opaque to protect it from the admission of light4 ,the packet must be opened in the dark-room from which all light 7even stray streaks beneath the door7 is excluded1 excepting only that given by the yellow glazed lantern4 ,the outer envelope being carefully undone1 an inner cover will be found and these wrappers should be placed on a dry table while a sheet of the paper is removed4 ,it is a good plan to have a light-tight box 7obtainable from any dealer7 in which to put the paper after unpacking it2 this prevents loss of time and awkwardness of handling in having to replace the paper in its wrappers each time a piece is withdrawn for use4 ,when several prints from one or more negatives are required1 it is an excellent thing to have two of these boxes1 one for the unexposed paper and one in which to put the prints as made until all are ready for development4 ,the ,class of ,negative4--,bromide paper gives us a great command over results2 in fact1 so vast is the control we may exercise that it is possible to secure good results from almost all classes of negatives1 from mere ghosts to those with density almost equal to that of a brick wall4 ,but there is1 of course1 a class of negative that gives a good result with the least expenditure of skill1 such a one is generally known as of average density1 having a full scale of gradation with high-lights dense1 yet not so opaque as to prevent you seeing a window clearly defined when looking towards it through the densest parts of the film1 such as the sky1 for instance4 ,another way to test the density is to put the negative1 film side down1 on some large print on white paper1 the large letters should be just visible through the sky1 but the smaller print should not be readable4 ,that is the class of negative usually considered in ,instructions for ,use1 as an average negative4 ,the ,sensitive ,side of the ,paper4--,a difficulty sometimes occurs in telling which is the sensitive side of the paper3 this may be easily ascertained by the appearance of the edge1 which turns slightly inwards towards the sensitive side4 ,this is quite apparent to the sense of touch as well as sight4 ,some people moisten their finger and thumb and squeeze the paper and see which sticks 7the sensitive side71 but that is a dirty method and quite unnecessary4 ,printing from the ,negative4--,having unpacked the paper1 after making sure that all but the yellow 7or ruby7 light has been excluded from the room1 we are ready to print4 ,for this purpose1 different workers favour different classes of light3 one prefers gaslight1 another swears by magnesium ribbon1 and some even prefer the light of day4 ,personally1 ,i favour ordinary gaslight passed through a ,no4 #e ,bray's burner1 because it is quite rapid enough for all practical purposes and is perfectly under control and free from serious variation4 ,illustration3 ,fig4 #a4 ,the burner should be within easy reach of the worktable and should be fitted with a byepass to obviate the necessity of continually striking matches4 ,several years ago ,i had my bromide printing rooms fitted with an excellent lantern of this class in which the byepass was connected to two jets 7one inside and the other outside the lantern7 in such a way as to turn down the white light with the same movement that raised the coloured light1 and vice versa4 ,by this means no gas was wasted and the simple action of pulling or pushing a lever operated either light at will4 ,by placing the same lever amidships1 both jets were lowered to the point of invisibility and could so remain for days at a time1 yet always ready at a moment's notice4 ,the accompanying sketch 7fig4 #a7 will give some idea of its construction4 ,if the dark-room is small1 and space is an object1 the sink may be fitted with a wooden cover and this may be used as a table for printing the paper1 but care must be observed to avoid the slightest moisture upon it or satisfactory work is impossible and the negatives may be ruined4 ,in a large room1 it is much better to have an ordinary kitchen table removed some distance from the sink2 with this and a comfortable chair bromide printing is a very pleasant occupation4 ,the following sketch 7fig4 #b7 will explain the arrangement of the table1 and it applies equally well to the movable top of the sink4 ,illustration3 ,fig4 #b4 ,supposing that some arrangement of this sort is devised1 we must unpack some bromide paper and put it in its box and then put a negative of average density in an ordinary printing frame4 ,on the film side of the negative we must now place a sheet of bromide paper with its sensitive side in contact1 replace the back of the frame and it is ready for exposure4 ,before exposing it1 make sure that both boxes are shut or their contents will be ruined the moment the white light is turned up4 ,upon reference to the instructions that accompany each packet of bromide paper1 you will observe a certain number of seconds' exposure is advised at a certain distance from the light2 in the case of the ,barnet extra rapid paper the time is given as about four seconds at a distance of eighteen inches4 ,when all is ready for exposure1 place the printing frame upright opposite the lantern at the mark indicating eighteen inches 7see fig4 #b71 note the time on the seconds hand of the clock and throw the lever over for white light for four seconds and then reverse it4 ,remove the paper and if many are likely to be required from that negative1 it would be well to develop the first print in order to judge as to the accuracy of the exposure4 ,if over or under-exposed1 the time must be reduced or lengthened as required4 ,when the best time and distance has been ascertained for a certain negative1 mark it with a narrow strip of paper bearing full particulars for future guidance1 such as3 #d sec41 #ah in41 ,no4 #e ,bray2 in this way absolute correctness of future exposures is assured4 ,of course1 if gas is not obtainable1 magnesium ribbon may be used instead4 ,in this case the negative would be marked #a inch 7or more7 ribbon1 #c ft4 distant1 as the case may be4 ,using ,masks and ,discs4--,prints are sometimes required with an oval 7or square7 centre and white margins3 this is effected by interposing a black mask of the desired size and shape 7obtainable from all dealers7 between the negative and the sensitive paper4 ,the black paper prevents the passage of light and leaves white margins to the print4 ,if grey margins are required1 a disc 7to fit the mask7 is attached to a sheet of glass the same size as the negative and arranged so that registration is easily effected2 the print is first made with a mask and is then placed in contact with the disc and plain glass 7the negative being removed from the frame71 and again exposed for a second to the light4 ,if a black border is required the exposure of the margin must be extended three or four seconds4 ,vignetting4--,to vignette bromide prints1 the printing frame must be covered with a piece of cardboard in which a small hole 7about #a-a_/b inches by #a inch for a cabinet head and bust7 is pierced4 ,the hole must be covered with a sheet of white tissue paper which will diffuse the light and cause it to travel without harsh lines beneath the opening1 and make the print with perfectly gradated edges4 ,it is sometimes an advantage to move the negative while printing vignettes2 but it is not absolutely essential if the hole in the cardboard is not too large and if the card is removed some little distance from the negative4 ,if the card is too close to the negative1 the gradation will be abrupt and the vignette will not look well4 ,cloud ,printing4--,this requires some care in order to avoid harshness and sharply defined lines4 ,if the sky of the negative prints white1 the addition of clouds from another negative is not difficult2 but if it is at all thin1 the entire sky must be carefully painted out with a deeply opaque pigment in order to make it quite dense and unprintable4 ,as a bromide print cannot be examined while in progress3 that is1 cannot be seen at all before development1 careful registration is desirable in order to prevent printing the clouds across the landscape instead of above it4 ,to do this an opaque mask should be made thus3 ,make a print from the negative on ,p4,o4,p4 and1 without fixing or toning it1 cut it carefully in two parts following the horizon line as nearly as possible1 then expose to light1 until quite black1 that part representing the landscape4 ,attach this to the glass side of the cloud negative 7with the paper side of the ,p4,o4,p4 in contact7 and see that the bottom edge and the right corner of the paper and glass 7viewed from the glass side of the negative7 exactly coincide4 ,to make use of this arrangement1 you first make a print from the landscape negative1 making sure that the negative and paper are firmly pressed against the bottom and left-hand side of the printing frame when looking towards the film side of the negative2 mark the registered corner with lead pencil thus ,l in order to prevent mistakes in the second printing4 ,to print the clouds1 you put the negative in the frame and press it well home to the left-hand corner and the base of frame 7looking at the film side1 of course71 and then put the print in contact with the same precaution and replace the back4 ,now take a piece of brown paper with one edge roughly torn in shape of the horizon line of the mask and cover the entire negative on the glass side4 ,hold the covered frame in your hands at a distance of 7say7 four feet from the gas and turn on the white light4 ,directly the light is up1 draw the paper slowly downwards until the horizon line is just passed1 and then immediately begin to slowly push it upwards towards the top of the sky4 ,do this steadily and slowly for 7say7 four to six seconds1 according to the density of the cloud negative4 ,with a good thin cloud1 four seconds should be quite enough1 but you can easily settle this point on developing the first print4 ,printing from ,dense ,negatives4--,dense negatives require much longer exposures than those of average 7or ideal7 density4 ,this may often be prolonged to twice or three times the normal exposure at the same distance4 ,a yellow coloured negative increases the exposure greatly1 as much as ten to thirty times the normal frequently being requisite to get a decent print4 ,an over dense negative that gives very harsh prints by other printing processes can be made to yield prints of exquisite softness on bromide paper by giving a full exposure at a short distance from the gas4 ,illustration3 ,,cupboard ,,love4 ,t4 ,,lee ,,syms4 ,printing from ,thin ,negatives4--,thin negatives on the other hand1 require quite different treatment4 ,in order to get plucky prints from very thin negatives1 useless in other processes1 we must give a very brief exposure at some distance from the gas2 and here it may be well to note that removing the negative to a greater distance from the light is equal to decreasing the actual time of exposure and has other advantages in connection with thin negatives with which theory does not seem to agree4 ,to print from a very thin negative1 then1 instead of four seconds at eighteen inches1 let us cover it with a sheet of tissue paper and give it four seconds at a distance of three or four feet and note the result on development4 ,if it appears to be over-exposed1 we may reduce the time of exposure to three seconds at the same distance and modify the developer1 as will be explained later on4 ,development of ,prints4--,all my remarks in this article apply equally to most commercial brands of bromide paper2 but it is only fair to state that they are particularly intended for that made by the firm of manufacturers publishing this book4 ,development1 and so on1 is very similar with all makes of paper1 but most of my recent experiments have been made on the ,barnet matt surface bromide4 ,i shall presently describe the use of several well-known developers1 but it must be well understood that1 whatever formula is adopted1 a preliminary soaking of the print before development must be done4 ,when we are about to develop a number of prints we must first soak them in plain cold water until quite flaccid1 otherwise the application of the developer would cause the dry print to cockle and curl1 and the development would not be regular4 ,this rule applies equally in the case of one print only as when a hundred are ready for development2 a prolonged soaking in plain water having no ill effect4 ,the ,iron ,developer4--,this is one of the developers most frequently recommended for bromide work1 but personally ,i never advise its use 7especially by a novice7 because the use of the acid clearing bath1 which is an essential part of the process1 is so frequent a cause of disaster and yellow prints4 ,the ,barnet formula is as follows3-- ,a4 ,potassium oxalate #a lb4 ,potassium bromide #e grains ,hot water #dh ozs4 ,b4 ,iron sulphate #a lb4 ,citric acid #d drams4 ,hot water #cb ozs4 ,to six ounces of ,a1 add one ounce of ,b2 this order of mixing must be observed or a dense precipitate of ferrous oxalate will be formed4 ,place one of the soaked prints face 7which may be distinguished by its slippery surface7 upwards in a clean porcelain dish and pour the developer over it as evenly as possible4 ,with this developer1 the image comes up very rapidly1 so that it is not advisable to try and develop more than one at a time4 ,if the first print of a batch appears to be over-exposed1 that is1 if it flashes out instantly and the high-lights become rapidly clouded1 add to each ounce of mixed developer from #aj to #cj drops of a ten per cent4 solution of potassium bromide which will act as a restrainer1 retard development1 and keep the high-lights clear while the shadows acquire density4 ,under-exposed prints can rarely be made to give passable results with ferrous oxalate4 ,the addition of a trace of hypo to the developer has been recommended for bringing up their detail1 but the result is far from good4 ,as soon as development is complete the prints must not be put in clean water1 but must be transferred direct from the developer to the following acid bath3-- ,acetic acid #a dram ,water #cb ounces ,after an immersion of one minute1 the operation must be twice repeated in similar baths that have not been previously used2 this is to remove the iron from the print4 ,a thorough washing must next be given to remove the acid and the print may then be fixed for at least fifteen minutes in ,hypo #b ounces ,water #bj ounces ,after fixing 7no matter what developer has been used7 the prints must be thoroughly washed in several changes of water for at least two hours4 ,the chief reasons against the use of ferrous oxalate are lack of control over development and the necessary use of an acid bath4 ,unless the acid bath is used1 the prints will be yellow because of the iron in them1 and if the acid is not entirely removed before fixing the prints will be yellow owing to the decomposition of the hypo by the acid in the print which causes deposition of sulphur4 ,metol ,developer4--,with this1 and the other developers ,i shall mention1 an acid bath is not necessary and so one cause of failure 7and extra work7 is obviated4 ,i have somewhat amended the ,barnet formula to meet the needs of workers on a small scale and have also arranged ,a and ,b to balance each other without disturbing the relative proportions of the ingredients4 ,a4 ,metol #abj grains ,water 7cold7 #bd ounces ,dissolve completely and then add ,sodium sulphite #b-a_/b ounces ,potassium bromide #ae grains ,shake until completely dissolved but do not apply heat4 ,b4 ,potassium carbonate #cej grains ,water #h ounces ,for use1 mix three parts by measure of ,a and one part of ,b4 ,with this developer and a normal exposure1 the image should appear in a few seconds and development should be complete in about two minutes4 ,as fast as the prints are developed they should be immersed in ,salt #b ounces ,water #bj ounces to stop development4 ,when all are developed1 they must be rinsed for a minute or two in clean water and then fixed4 ,over-exposure is remedied by the addition of potassium bromide solution 7as in the case of ferrous oxalate72 under-exposed prints should be developed in a weak solution such as ,a #c parts ,b #a part ,water #d parts ,development will take longer1 but the weaker solution will help to bring up the detail without the harshness of the shadows that would be the case if the normal developer was used4 ,hydroquinone and ,eikonogen4--,the advantage of combining eikonogen with quinol lies in the fact that one provides what the other lacks1 the eikonogen tending to give detail without density and the quinol 7in inexperienced hands7 giving density without detail4 ,the following formula will be found very satisfactory3-- ,a4 ,quinol #dj grains ,eikonogen #abj ,sodium sulphite #dhj ,citric acid #bj ,water to #bj ounces ,dissolve the sodium sulphite and citric acid in #ae ounces of water1 then add the other ingredients and enough water to make a total bulk of #bj ounces4 ,b4 ,sodium carbonate #fj grains ,sodium hydrate #cj ,potassium bromide #e ,water to #bj ounces ,for use1 mix one part of ,a1 one part of ,b and two parts of water4 ,the same remarks as to over and under-exposure apply as in the case of metol4 ,toning ,bromide ,prints4--,the tone or colour of the deposit depends largely upon the accuracy of exposure and the developer employed4 ,ferrous oxalate gives a rich black deposit1 but to my mind metol and the combined eiko-quinol give tones at least as beautiful with pretty gray half-tones4 ,but some people prefer warmer colours1 brown and red for instance1 and some get brownish blacks 7through over-exposure and the use of bromide7 which they would like to change4 ,the colour of the deposit may be changed in various ways by treating the print in baths of different metals4 ,i will give a brief outline of the methods employed1 leaving readers to modify them to suit each particular case4 ,black and ,blue-black ,tone4--,brownish black prints can be much improved after fixing by immersion in a strong bath of gold chloride2 the following is the strength used by me3-- ,a4 ,ammonium sulphocyanide #bj grains ,water #a ounce ,b4 ,gold chloride #b grains ,water #a ounce ,when quite dissolved add ,b very gradually to ,a1 shaking almost continuously4 ,the fixed print should be washed for at least fifteen minutes before toning and should then be placed in a clean tray while the toning bath is poured over it4 ,the solution must be kept moving and the print must be removed and washed directly the desired tone is reached4 ,prolonged immersion will cause the print to acquire a deep blue tone4 ,brown and ,red ,tones with ,uranium4--,prints immersed in the uranium toning bath gradually become warmer in tone1 changing from black to brown and brownish red until they assume a deep red nearly approaching the well-known ,bartollozzi chalk4 ,prints to be toned by this process must be thoroughly free from hypo or stains will be the inevitable result4 ,the toning bath should be made up as follows1 and it must be used at once as it will not keep after mixing ,a and ,b3-- ,a4 ,potassium ferricyanide #bj grains ,water #bj ounces ,glacial acetic acid #a ounce ,when quite dissolved add ,b4 ,uranium nitrate #bj grains ,water #a ounce ,immerse the print and keep the solution in motion until the desired colour is produced1 then wash the print for half an hour in several changes of water acidulated 7#a dram in #cj ounces7 with acetic acid4 ,weak1 under-developed prints are much improved by this method of toning4 ,at the end of half an hour1 if the whites are at all yellow they may be cleared by immersing the print for a minute or two in the following bath3-- ,ammonium sulphocyanide #bj grains ,water #aj ounces ,after immersion1 rinse the print for five minutes and dry4 ,intensification4--,it sometimes happens 7especially when too little light has been used to properly judge development7 that one acquires a collection of prints that1 owing to under or over-development1 are useless2 let us see how they may be rendered serviceable4 ,an under-developed print1 though weakly looking and washed out1 simply needs intensification to give it the requisite pluck4 ,the foregoing uranium bath acts as an intensifier while conferring a ruddy tone on the deposit4 ,a black deposit can be obtained by intensifying the well-washed print with mercury4 ,the print must first be immersed in a saturated solution of mercuric chloride until the image disappears2 it must then be again thoroughly washed to remove all traces of free mercury and may then be redeveloped by flowing over it an old ferrous-oxalate developer4 ,if ferrous oxalate is not at hand1 an old metol developer may be substituted1 but the former is the more reliable4 ,when the image is sufficiently intense1 the print must once more be thoroughly washed4 ,all the toning and intensifying operations may be conducted by daylight4 ,reduction of ,density4--,over dense prints can be made fit for many purposes by means of a reducer capable of dissolving part of the deposit4 ,the best for the purpose and the one least liable to cause stains is know as the ,belitzski's2 it is prepared thus3-- ,water #fj ounces ,potassium ferric oxalate #c ,sodium sulphite #c ,dissolve and add to the red solution so obtained4 ,oxalic acid #a ounce ,shake until the solution turns green and then immediately pour off the solution from any crystals remaining undissolved4 ,to this solution add ,hyposulphite of soda #ae ounces and shake until dissolved1 when it is ready for use4 ,the print to be reduced need not be free from hypo1 but should be rinsed for a few minutes after fixing 7or soaked until limp1 if previously dried7 and may then be placed in a tray and flooded with the reducer4 ,the tray must be well rocked and the print1 when sufficiently reduced1 must be removed without delay and rapidly washed in running water4 ,some ,cheap and ,useful ,trays4--,if large-sized prints are made1 the cost of suitable trays becomes a very serious item4 ,the expense of these may be reduced to a mere nothing1 without loss of effectiveness1 by the substitution of home-made ones4 ,all that is required to make a tray of any size is a thin wooden confectionery box 7or the bottom part of a larger case7 lined with the shiny white marbled oilcloth known as ,american moleskin4 ,this is fitted inside the box 7the corners being turned under7 and secured by a row of tacks around the top edge4 ,no further lining or preparation is required and the tray will stand all sorts of ill-treatment4 ,as for durability3 ,i had three such trays made out of old herring-boxes picked up at ,calgary and lined with moleskin that had already seen service as cover to a wash-handstand and chest of drawers in a ,canadian boardinghouse4 ,for upwards of a year those trays were used daily and travelled many hundreds of miles by mule and dog train1 and were not worn out when ,i returned home4 ,my porcelain trays were smashed by a fall from a refractory mule1 but the rough and ready makeshifts were a priceless boon4 ,it seems to me that by practising economy of this kind and in various similar ways 7i4e41 where economy is necessary as1 unfortunately1 it sometimes is7 the cost of practising our pet recreation is very materially reduced4 ,w4 ,ethelbert ,henry1 ,c4,e4 ,the ,gum-,bichromate ,process4 ,illustration ,pictorial photography is answerable for the revival of this1 one of the almost forgotten methods of printing4 ,results unacceptable to bygone requirements have been reintroduced with advantage1 where suggestive individuality and artistic effect have been desired4 ,the gum process has an unlimited range of possibilities1 it would be impossible to describe them all4 ,the minutest details1 or the broadest diffusion together with the power of working from the highest to the lowest keys of chiaroscuro are values that can only be realized when the infatuation consequent on successfully working the process is experienced4 ,this method of printing1 as with the so-called carbon process1 is dependent upon the characteristic behaviour of the chromic salts when in combination with organic substances1 such as gelatine1 gums of various kinds1 starch1 etc4 ,when any of these mixtures are submitted to the action of actinic light1 they become more or less insoluble4 ,this property was partially discovered as far back as #agih1 by ,vauquelin4 ,professor ,sucrow1 ,mungo ,ponton1 ,beauregard and others advanced its application to photography up to about #ahdj1 but it was not until some ten years later that its great value as a photographic agent was definitely established4 ,hunt1 ,fox ,talbot and ,poitevin1 each worked indefatigably to bring the application of the chromic process to a successful issue2 but to ,poitevin must be accredited the honour of being the original inventor of the chromated pigment or carbon process4 ,this brings us up to about #ahee4 ,none of these investigators appear to have been remarkably successful1 beyond having established definite1 but valuable facts of the changes produced4 ,this want of success may possibly be accounted for by the general employment of gelatine and direct printing4 ,it was not until ,pouncey and others1 about #ahei1 employed gum as the colloid medium1 that any great advance was made4 ,about this time an important commission of inquiry decided that to ,pouncey1 ,gamier and ,salmon1 and ,beauregard the honour of producing permanent prints must be equally credited1 and accordingly divided the ,duc de ,luyue's prize between them1 giving to ,poitevin the credit of the priority of invention4 ,pouncey appears to have followed up the process with some considerable success1 as some of his existing examples are excellent2 it is much to be regretted that we have not more detailed particulars of his methods of working2 but he evidently was before his time and met with but little encouragement4 ,to ,alfred ,maskell and ,m4 ,demachy must be accredited the revival of this long neglected process1 and during the last three years much advancement has been made towards perfecting it4 ,serious workers1 both at home and abroad1 are industriously exhausting the possibilities of the process1 and crude as some of the earlier examples of this revival have been1 improvements and simplicity of working are giving us productions of every description1 of such excellent quality that it may soon be expected to satisfy even the caustic criticism that has so persistently opposed its re-introduction4 ,dexterity in the various stages of practical manipulation is necessary before skilful efficiency can be secured1 and in order to arrive at this1 due consideration must be given to the selection of the paper the colour most suitable to the subject and the effect desired4 ,almost any kind of paper will be found workable1 if it be of fairly good quality4 ,those that are thickly coated with soluble sizing media are unsuitable1 for although they may give clear whites they sometimes produce harsh prints1 the half-tones are also liable to be lost in development unless very deeply printed4 ,several of the continental kinds are well adapted to the process and work in an excellent manner1 giving soft and even results2 of course1 it will be understood that for definition and fine detail the finer grained descriptions are the best1 but where diffusion is desired those of a coarser texture may be advantageously used1 they give a granulation that tends materially to secure the peculiarities of gradation characteristic of this process4 ,a few of the continental papers that will be found to work with ease to the beginner1 are as follows3-- ,michallet paper is rather coarse1 but takes the gum coating easily1 it has a series of lines running in both directions1 which are rather objectionable for some subjects2 but it is an excellent paper for first experiments4 ,ingrs1 is also a paper of similar character1 and can be worked with equal facility4 ,lallane is another paper of the same class1 but much finer4 ,allong paper is entirely free from the markings peculiar to those previously mentioned4 ,this paper is best worked on the reverse side1 which can be distinguished by examining the name marked in one corner4 ,among the ,english papers the ordinary cartridge1 ,whatman's drawing papers and many others are adaptable1 but it must be borne in mind that those with a toothed or grained surface are preferable4 ,there are two methods of working1 and results of equal excellence have been produced by either4 ,some of the most proficient workers of the process adopt the easier one of coating the paper1 without previous preparation1 with a mixture of gum1 bichromate of potass and pigment4 ,others adopt the precaution of first saturating the paper with a strong solution of bichromate1 and when dry coating it with a mixture containing only gum and pigment4 ,experience is in favour of the previous saturation of the paper1 this is recommended especially for beginners1 as there are several kinds of paper that will not work efficiently by the first method2 but when skill and practical knowledge of the special behaviour of the materials employed is acquired1 either method can be adopted4 ,we may presume that the advantage of the previous saturation of the paper with the chromic salt is1 that should there be any inequality in its structural character1 or should it be unequally sized1 the bichromate appears to act as a kind of resist to the penetration of the pigment1 thereby securing an increased range of tone and a corresponding purity of the whites4 ,the process may be divided into the following operations3-- ,saturation or sensitizing of the paper4 ,preparation of the gum mucilage4 ,mixing and preparing the pigments4 ,coating the paper4 ,printing and exposure4 ,development4 ,for working by the previously chromated paper method1 the sensitizing solution is made up of one part of bichromate of potassium dissolved in ten parts of water4 ,this strength will not keep at all temperatures4 ,should the salt crystallize out1 it is necessary to warm a portion of the solution and re-dissolve the crystals4 ,the solution may be used repeatedly1 but it will be necessary to filter it occasionally4 ,before saturation it is convenient to cut the paper into the most useful sizes--quarter sheets are handy4 ,having decided which is to be the working side1 mark the back distinctly4 ,into a dish of sufficient depth pour in the one in ten bichromate solution to a depth of about one inch1 and immerse your paper sheet by sheet1 until you have in it all you intend to sensitize4 ,as each sheet is placed in the solution1 remove air bells and turn it over and repeat this precaution4 ,the time necessary for immersion is of no importance so that the saturation is absolute1 about five minutes being generally sufficient for the thickest of papers4 ,by removing the bottom sheet to the top and passing through the whole in this manner1 turning over each sheet and removing all air bells1 even saturation is secured4 ,each sheet is carefully and slowly removed from the solution and dried in the dark4 ,the paper is now very sensitive to actinic light1 which must during all future operations be carefully guarded against4 ,after the paper is dry1 it will--if kept so--be in good condition for a long time4 ,to prepare the gum mucilage1 take two ounces of ,soudan or ,turkey gum and dissolve it in five fluid ounces of cold water1 strain out the floating impurities through fine muslin1 and allow others1 and finer to subside4 ,this mucilage will keep in good condition in a well-corked bottle1 for a considerable time4 ,m4 ,demachy employs gum mucilage of twice this density4 ,pigments in powder are more suitable than in any other form1 if in cakes or paste4 ,the medium in which they are prepared1 does not work kindly with the gum1 and it is also difficult to accurately measure quantities4 ,no advantage is gained by using expensive colours1 they can all be purchased at a good colourman's1 and at a small cost4 ,lamp or any carbon1 black1 red ochre1 yellow ochre1 burnt sienna1 and raw sienna1 all work well2 there is some uncertainty with the umbers and sepias4 ,it will be found that much time will be saved if a combination of these dry colours is made up in bulk1 as for instance--one hundred and seventy-five grains of vegetable black and one hundred of burnt sienna1 give a rich soft brown colour4 ,these must be finely and intimately mixed with each other1 which is conveniently accomplished by grinding with a small pestle and mortar2 after which the mixture may be kept in a wide-mouthed bottle4 ,another advantage in thus keeping combinations of dry colours in bulk1 is the absolute certainty of repeating the actual tint when required4 ,various combinations of similar mixtures can be made4 ,of course it will be understood that any or all of the above-named colours may be used singly4 ,the grinding of the pigment with the mucilage is easily done on a stone slab with a palette knife4 ,take half a fluid ounce of the two in five gum mucilage1 to which add the same quantity of water and thoroughly mix4 ,weigh out fifteen grains of the mixed pigment and place in a heap on the slab1 add a few drops of the diluted mucilage1 grind and regrind the mixture until it is completely smooth1 then remove it to a cup1 and clean the stone with another portion of the reduced mucilage1 finally adding the whole of the ounce1 intimately mix1 and it is then ready for coating the paper4 ,for extra fine work on smooth paper1 and in fact for all classes of work1 the fine grinding of the colours adds materially to extend the range of gradation1 and although the trituration may be carried out fairly well with a palette knife1 when the finest possible grades are desired1 recourse must be had to the muller and stone4 ,mullers are obtainable of any artist's colourman1 they are made in glass1 and a convenient size is about one inch in diameter4 ,the most convenient brush for applying the mixture of combined gum and pigment to the paper1 is of the description known as bear's hair1 these are usually set in tin2 a flat one about two inches wide is a useful size4 ,in order to coat the paper evenly1 pin it down to a drawing board by each corner with a double layer of blotting paper an inch or two larger than the paper to be coated4 ,the blotting paper will absorb the excess of colour at the margins and enable you to secure an even coating up to the extreme edge4 ,take a fairly full brush of the mixture after thoroughly incorporating the colour and spread it evenly over the paper1 crossing and recrossing it with the brush4 ,allow the mixture to lie upon the paper for a second or two so that the paper may expand2 now release each of the corners and pin the paper down again4 ,upon the next operation depends the evenness of the coating4 ,take a four inch wide artist's badger's hair softener1 hold it vertically and lightly by two fingers and the thumb about an inch and a half from the top of the handle1 and pass it rapidly over the whole surface of the paper as quickly and evenly as possible4 ,the motion producing the best effect is not the usual sweeping action1 but a series of sudden short jerks1 difficult to describe but easily acquired4 ,continue this softening down until the paper has an even semi-transparent surface without uneven cloudy spots4 ,allow it to dry spontaneously1 but before it is stored for future use dry it carefully by the fire1 but avoid overheating4 ,uncertainty of result is a defect often brought into argument against this process2 but absolute uniformity is not difficult if strictly accurate quantities only are employed4 ,with constant strength of bichromate and gum1 uniform weights and combination of pigment1 similarity of repeats are obtained3 but these can only be secured when each sheet of paper is coated identically with its fellow4 ,to get this evenness the badger hair softener must be washed out and dried after coating each sheet4 ,this is very quickly accomplished by an energetic shaking and drying upon a smooth towel4 ,if the paper has been coated properly1 it has an even semi-transparent surface slightly glassy4 ,failures often occur from using an excess of pigment and allowing the gum to become too thick in consequence of evaporation4 ,excess of pigment gives dense heavy shadows and increases the difficulty of printing2 excess of gum gives clear high-lights1 tending to hardness and easy solubility endangering the half-tones4 ,the paper1 if it has been correctly coated will work satisfactorily1 if on steeping a small piece of it downwards upon cold water1 the pigmented gum dissolves and drops from the surface leaving the paper nearly clean4 ,from ten to fifteen minutes should complete this test4 ,the method of working without previously chromatizing the paper is as follows3--,take half a fluid ounce of four-in-ten gum mucilage and add to it an equal quantity of saturated solution of bichromate of potass2 to this1 with all care as to grinding and mixing1 add the pigment2 coat the paper as before directed4 ,this method will be considerably slower in printing than that in which the paper had been previously saturated with the bichromate2 neither are the whites as a rule quite so clear2 but it will possess a peculiar grain and softness not otherwise obtainable1 which is much approved by some workers of the process4 ,exposure is so much dependent on circumstances that it is difficult to give precise directions1 being governed by the density of the negative1 the thickness of the coating and the intensity of the light4 ,even and not too dense negatives are the more suitable1 for if the intermediate and high-lights are over dense the shadows are considerably over printed before the lighter parts can be brought out4 ,skill in development can do much to overcome these defects1 but they may be considerably modified by the judicious employment of matt varnish1 and by other methods of locally retarding printing4 ,the greatest assistance in obtaining uniformity in printing is the employment of a reliable actinometer1 ,wynne's print meter is probably the most useful for this purpose1 with ordinary gelatino-chloride paper as a register2 from twelve to sixteen numbers will be mostly sufficient for an ordinary negative1 on not too thickly coated paper4 ,another method of judging exposure is by the appearance of the shadows2 they may frequently be seen by transmitted light1 and when well out printing may be judged to be correct1 but this is a slovenly method and only approximately correct at the best4 ,if the bichromate is used only in the pigmented gum1 without previous saturation of the paper1 exposure must be much more prolonged4 ,by no other process is it possible to obtain such diversity of effect as by this2 much will1 however1 depend on the skill which is exercised in development4 ,should the printing exposure have been fairly correct it is a simple procedure4 ,the print is floated face downward upon cold water contained in a deep dish2 see that all parts are equally acted upon by the water1 and that no air bells exist2 if any1 they may be easily removed by gently raising the print and immersing it again once or twice4 ,after it has been soaking some five or ten minutes it may be examined2 if all is going well1 and the exposure has been approximately correct1 the pigmented gum on the unexposed margins will have left the paper1 and possibly some of the high-lights and half-tones may be making an appearance1 if so1 the treatment must be of a gentle character1 and the print may be safely left for some time longer in the same position face downward2 never allow it to lie either in or out of the water face upwards for any long time1 or unremovable stains will be developed4 ,many prints will develop almost entirely without assistance1 or with only an occasional laving of water if allowed to lie in this position for a long time4 ,on the other hand some may1 even when only slightly over-printed1 give no indication of development4 ,when this is the case remove the print from the water and place it face upwards upon a thin1 smooth board1 fix it in position with one drawing pin on the extreme margin1 then gently lave cold water over it2 should some of the darker parts still resist this action1 longer soaking will be found advantageous4 ,if there are still parts on which the colour will not move1 recourse must be had to the brush1 and for this purpose nothing is better than a large camel's hair mop4 ,keeping the brush always full of water1 touch where necessary very softly2 do not sweep it up or down1 but just dab here and there as may be required1 constantly flowing over the surface a copious supply of water4 ,if there are still parts in the shadows1 or even in the high-lights that will not move1 a jet of water from an enema syringe or from the household service pipe is very useful4 ,as a last resource a prolonged steeping in water of varying degrees of temperature1 even up to the boiling point1 may be resorted to1 but the application of increased temperature requires judicious management4 ,when the print is sufficiently developed1 if the creamy yellowness of the chromate stain is not desired1 the print must be cleared or bleached1 either in a solution of alum1 sulphite of soda1 or hyposulphite of soda1 strength being immaterial with a careful after-washing4 ,if the print is only just sufficient or only slightly over-printed1 care must be taken that the clearing bath is not acid1 neither must the washing be too prolonged1 but if the print is first dried and submitted to light1 this precaution is unnecessary4 ,always allow the prints to dry spontaneously4 ,it will not do to use any kind of pressure or blotting paper1 for the surface of the colour is very tender and delicate4 ,jas4 ,packham1 ,f4,r4,p4,s4 ,an ,introduction to ,carbon ,printing for ,beginners4 ,illustration ,in the article that follows next will be found a complete exposition of the carbon process1 with its various adaptations from the preparation of the paper and material forwards4 ,whilst at the present time carbon printing is more largely used by professional photographers1 yet its simplicity1 the absence of chemical formul and complications combined with the beauty of the results1 makes it eminently suitable for amateur workers1 and hence it has been thought desirable that as an introduction to the subsequent article1 a brief and simple outline of the process should be given for the benefit of those who have not hitherto made its acquaintance4 ,in the first place then let it be understood that in carbon printing instead of depending on light to make a visible alteration of the sensitive salts as in silver printing1 we expose the prepared paper or tissue1 as it is called1 under a negative and secure a positive in insoluble gelatine1 the gelatine having combined with it a pigment1 and hence we get an image in pigment1 not in platinum1 or silver1 or gold1 but in a simple pigment which may be of any colour4 ,if bichromate of potash is mixed with an organic substance such as gelatine1 that gelatine becomes insoluble after exposure to light1 and if that gelatine carries with it a pigment1 then on becoming insoluble it holds the pigment with it4 ,if now1 paper or other material be coated with bichromate1 gelatine1 and pigment1 and exposed to light under a negative in the usual way1 the thin portions of the negative will admit of the light acting on this coating and making it insoluble1 whilst the parts which are protected from light1 as for instance the sky or white objects1 will remain unchanged and soluble1 and on being washed in water will dissolve away1 leaving white paper1 whilst the light-affected portions which have become insoluble remain in proportion as the light has penetrated the various densities of the negative4 ,this then is how we obtain our print4 ,for fuller explanation of the paper or tissue and its manufacture the reader is referred to the next article4 ,the beginner will certainly first obtain his tissue ready made1 and he can purchase it ready sensitized or otherwise4 ,the former will be best at the outset1 but it must be borne in mind that it should not be kept longer than can be helped before use1 and never more than ten to fourteen days at the utmost4 ,various shades of blacks1 browns1 and reds are the usual colours1 also grey1 green1 and blue4 ,the tissue is rather more sensitive to light than silver paper1 and should therefore be opened and handled in subdued light4 ,it must be kept as dry as possible4 ,a rather vigorous negative is best for carbon printing1 one not too strong in contrasts4 ,before placing the negative in the frame1 we must give it what is termed a safe edge4 ,this is done by making a narrow border1 say of about a quarter of an inch or less1 round the negative1 either on the glass or film side1 with opaque black varnish1 or it may be done by gumming on narrow strips of paper1 such as lantern-slide binders4 ,if binders and not black varnish are used1 they must be applied to the glass side4 ,the ,carbon printing paper which will hereinafter be called the tissue will be found to present an unpromising appearance1 and as the coating is the full colour of the pigment in which the print is eventually to appear1 it follows that the progress of printing will not be visible1 and a mechanical means of gauging the exposure must be resorted to4 ,an actinometer1 similar to that described in the article on ,platinotype1 will do1 and another and simpler form is described in the next article4 ,printing will occupy about one-third of the time occupied by gelatino-chloride of silver paper4 ,development is conducted in daylight1 but not too close to a window4 ,the absence of chemical solutions has been suggested as an advantage1 in this process the developer being merely hot water4 ,it is not necessary to have this laid on1 a can of hot water close at hand and a kettle on the fire or gas stove not far off are all that are required4 ,we shall require four or five dishes1 one at least of which should be a good deal larger than the size of the prints we are to develop and several inches deep--a good-sized pie-dish or a basin will do4 ,development merely consists of washing away the unaffected and therefore soluble coating1 but it must be remembered that the less affected portions representing the half-tones have received their modicum of light on the surface1 and therefore the soluble part of the film is underneath the part that has like a surface skin become insoluble4 ,this necessitates the printed film or tissue being transferred to another paper or support1 so that we may develop or wash away from the back4 ,in procuring your carbon tissue order at the same time a packet of ,single ,transfer ,paper1 which is paper with a thin coating of hard gelatine4 ,now to proceed4 ,place a piece of single transfer paper into a dish of cold water1 and in three or four minutes the coated side will feel slimy1 then place in the same dish a piece of the printed tissue face upwards4 ,this will probably curl up at first and afterwards flatten out again4 ,when this has happened or in a few minutes after immersion bring the piece of single transfer paper and the print together1 film to film1 so that they may be in contact1 and square one with the other4 ,now holding them by one edge1 withdraw them together by sliding them out of the dish on to a sheet of thick glass1 a large cutting glass serves well1 or stout sheet of zinc4 ,this should be supported in readiness at the rim of the dish4 ,having the transfer paper and print now on the glass or zinc1 hold them firmly and with a rubber squeegee press them closely into contact1 squeezing as much water out as possible4 ,a better way perhaps is1 if the dish is large enough1 to place the glass or zinc under the two papers whilst in the water and so raise them out4 ,the squeegeeing must be done thoroughly1 firmly1 and all over--several strokes being given in each direction4 ,next lift the papers1 now in firm contact and sticking together1 and place them between blotting paper on which is a heavy weight4 ,the next print may now be proceeded with and so on4 ,the print should be between blotting paper and under pressure for about twenty minutes1 after which it is removed to a dish of hot water--almost as hot as the hands can comfortably bear1 say #ajj to #abj ,f4 ,after lying in this for a few moments the dark pigment will be seen to be oozing out from between the two papers4 ,when this has begun to come pretty freely take one corner of the print and pull it away from the transfer paper4 ,it should come quite easily1 and on being peeled off entirely it is thrown away4 ,we have now the transfer paper bearing the printed film reversed1 that is1 the side which was previously at the bottom and next the original paper support1 is now uppermost and can therefore be got at4 ,if we splash it or lave it with the hand1 using the hot water1 we shall soon see what happens4 ,the smudgy mass of pigment begins to wash away and the picture gradually appears4 ,this constitutes development and we continue working it with hot water until the whole is clear and bright1 being careful not to touch the film with fingers or anything but water1 for being in a very delicate and soft condition it would be certain to sustain injury4 ,the hotter the water the greater its washing-off action1 and hence in cases of over-exposure very hot water may go far to recover the print4 ,when the desired result is secured1 transfer the print to a dish of cold water1 this instantly tends to slightly harden the film by cooling it1 and after two or three minutes it is passed into a dish of alum and water1 which further hardens it and also clears the print of any bichromate salts which may still remain4 ,in the alum bath the print should remain until any sign of yellow stain has disappeared1 when after a final rinse of a few minutes in cold water to remove the alum1 the print may be hung up to dry4 ,it will be seen that there is no prolonged washing as with those processes in which hypo is employed1 and the print is absolutely permanent4 ,it must be remembered1 however1 that in the finished picture we are looking at the back of the printed film as it received the light impressions from the negative1 and hence the image is reversed1 that is1 the left is on the right and the right on the left4 ,for landscape and views this reversed position will probably be of no importance1 but if it is desired to have things right way round--in portraits it will be essential--we must either work from reversed negatives1 or we must again transfer the film which will then constitute a double transfer4 ,we shall now understand why previously we called the paper to which the film was transferred single transfer4 ,inasmuch as it will be seen that the print is not on paper1 but consists of a transferable film of pigmented gelatine1 it will be understood that the paper employed is merely a support to that film1 hence it is customary to speak of the paper as the support1 whilst moreover it maybe1 and as often as not is ivory1 glass1 textile fabrics1 wood1 or other substances4 ,if now we wish to again transfer the film so as to correct the lateral reversal1 we substitute for the single transfer paper a temporary support4 ,the temporary support which is to receive the film merely whilst it is being developed1 and with the intention of its being subsequently transferred again to a final support1 may be paper or many other things4 ,moreover1 remembering that the film is mainly gelatine1 it should be clear that whatever the nature of the surface of the temporary support1 the soft glutinous film will take that surface just as we may make the impression of a seal in sealing-wax4 ,the normal carbon print is shiny1 due to the gelatine1 and so1 if as a temporary support we were to use ground glass or matt opal1 the carbon print film would receive the fine granulated surface and give a matted print as a result4 ,this merely by the way as suggesting an additional advantage offered by the double transfer process as a set-off against the slight extra trouble4 ,if double transfer is determined upon1 and it is not intended to experiment with ground glass1 etc41 then when purchasing the carbon tissue1 some temporary support 7sheets of paper coated with gelatine and shellac7 should be procured1 also some pieces of final support4 ,whatever the temporary support1 it must receive an application of waxing solution4 ,this also may be bought1 or can be made of3-- ,yellow resin #cf grains4 ,yellow wax #ab ,ether #b ounces4 ,melt the wax1 add the resin1 stir together and then add the ether4 ,pour a little of this mixture on to the temporary support and spread with a tuft of cotton wool1 and rub over to make it even4 ,the final support for double transfer may be purchased1 and is made ready for use by soaking for ten minutes in alum4 ,the temporary support1 after being waxed and the waxing solution having become dry1 is to take the place of the single transfer paper in every respect1 and the film developed as already described4 ,when it has reached the final washing1 after the alum clearing bath1 it is brought into contact with the final support 7which has been for ten minutes in alum bath as just described7 and is removed to the glass or zinc plate and squeegeed4 ,it is now hung up to dry1 and when quite dry the blade of a knife should be inserted at one corner and the temporary support gently pulled off4 ,such is the carbon process1 neither difficult nor lengthy1 and with this brief outline to form an introduction1 the reader who is a tyro will the better appreciate the fuller description which follows4 99 99 99 99 99 ,whilst the article that follows is more comprehensive than the beginner may require at first1 he is nevertheless advised to read it carefully through1 and some points which may not seem clear at first will explain themselves after a very little experience4 ,the ,carbon ,process4 ,illustration ,before proceeding to practical details of working1 it may be as well to realize what a piece of carbon tissue is1 and what takes place in the process of exposing such tissue to light4 ,mr4 ,j4 ,w4 ,swan1 who is to be regarded as the inventor of carbon process as we now know it1 was justified in giving the name tissue to the film of pigmented bichromatized gelatine1 as at first it was a tissue unsupported by paper backing and containing pigment practically1 if not entirely1 carbon4 ,the terms carbon and tissue have been generally accepted as describing a pigmented paper containing permanent colour1 therefore little if any misunderstanding is caused by such general description4 ,the carbon process1 like other kindred methods1 is based upon the well-known hardening action of light upon a bichromate salt in combination with organic matter4 ,when paper is coated with a mixture of gelatine pigment and a bichromate salt1 dried under favourable conditions and exposed to light under a negative it naturally follows that a positive image is produced4 ,the negative acting as a screen1 prevents any undue hardening of such portions of the picture as are intended to form the high-lights1 only slightly interfering with what are to be the middle tints1 and practically permitting full play in the shadows4 ,the latent image is imprinted on and into the film of tissue compound with the most delicate portions on the surface1 and means must therefore be adopted to protect the surface during the washing away of all parts of the film not intended or desired to form any part of the finished picture4#g ,in ,swan's process this object was secured by cementing the surface of the printed tissue to its temporary support with rubber solution1 but after ,j4 ,r4 ,johnson discovered that the printed tissue would adhere without any cement to any surface impervious to air and water simply by atmospheric pressure1 the same end was gained by soaking the undeveloped print in water until about half saturated1 then bringing it into contact under water with either its temporary or permanent support1 slightly squeegeeing or sponging to remove as much water as possible without injury to the print2 as to air1 there ought not to be any present if care is taken to exclude it before lifting from the water bath4 ,the half-soaked tissue after mounting absorbs every particle of water from between the surfaces1 and thus secures optical contact4 #g ,it is generally asserted by non-practical carbon printers that all portions of the film behind that which finally forms the print1 are unacted upon by light4 ,that is to say1 unchanged and quite as soluble as if not printed at all4 ,the upholders of such a theory should try the following experiment3--,take a piece of tissue1 cut it through the centre1 expose one piece1 then mount both under precisely similar conditions and wash in the same warm water bath4 ,paying special attention to the backing papers1 they will find the one unacted upon by light will have parted with its load of coloured material in much less time than the piece that formed the backing of the print4 ,the squeegee1 handy tool as it is1 ought to be used with great care1 in no case with any degree of force1 or serious injury will result1 particularly to the finer kinds of work1 such as double transfer prints of all kinds1 either on paper1 ivory or opal4 ,the rubber edge of the squeegee should be free from notches1 often caused by contact with the sharp edges of glass plates4 ,the notches can be removed by rubbing on a sheet of glass paper placed on a plane surface4 ,,tissue ,,making4 ,the tissue compound consists of a mixture of the following ingredients3--,gelatine1 sugar1 pigment and water4 ,the proportions are of infinite variety according to season1 the nature of the pigment used1 and the purpose for which the tissue is intended4 ,for convenience it is the rule for tissue makers to prepare what is termed stock jelly by dissolving1 by the aid of a water bath1 gelatine and sugar in water1 in varying proportions--roughly speaking3-- ,gelatine #b parts4 ,water #d to #g ,sugar#h #c_/d to #a-a_/d #h ,for some purposes 7instead of sugar71 glycerine1 sugar of milk1 or treacle may be substituted4 ,the pigments are made up into what are termed jelly colours1 which are ground either by hand on a slab of glass1 marble or granite1 using a suitable muller for the purpose1 or when large quantities are required a paint mill driven by steam or other power is employed4 ,in hand grinding the colour is kept moist by syrup on greatly reduced stock jelly4 ,after grinding by hand the pigment is lifted from the slab with a palette knife and stirred into melted stock jelly4 ,when the mill is used1 the pigment is mixed with the jelly before grinding4 ,the proportion of pigment to jelly varies enormously according to the nature of the pigment1 and may be anything between #b-a_/b per cent4 and #be per cent4 ,having prepared stock jelly and jelly colours1 and allowed both to set1 they are weighed out in proper proportions1 the jelly being dissolved in a tin vessel placed in a water bath4 ,the colour1 generally speaking1 is dissolved in a small proportion of the stock jelly placed in the mill and again ground into the bulk of the jelly4 ,in some cases the pigment is dissolved in warm water and filtered through cotton wool1 fine felt or flannel4 ,after adding powdered recrystallized bichromate1 the jelly compound is ready for coating or spreading on the paper4 ,the coating may be done by hand or machine4 ,several forms of machine are in use1 including the first form invented by ,mr4 ,swan4 ,when only a small quantity is required1 it is the general practice to coat by hand4 ,in hand coating1 the tissue compound may be strained through fine muslin into a flat tin dish placed on a water bath2 the surface cleared of air bubbles by dragging over it a strip of stiff paper4 ,the sheet of paper to be coated is held in an upright position at the further end of the dish with its bottom edge just touching the surface of the solution1 gently lowered until the whole surface of the sheet is in contact with the solution4 ,if the lowering is properly done there will not be any default in contact1 but if allowed to rest on the solution a few moments1 the presence of air bubbles1 if any1 will be detected by the presence of little lumps on the back of the paper1 these may be removed by raising a corner and touching the spots with a finger tip4 ,the sheet is then raised with a rather slow and steady motion1 allowed to drip1 then clipped to a line by its top corners and left to dry in a warm dry room from which white light has been excluded4 ,when this method of coating is adopted it is best to have the sheets of paper an inch longer than the dish2 the blank edge prevents contamination of the fingers and distortion of the sheet caused by contraction in drying4 ,another method of hand-coating is to roll the sheet into a tube shape1 placing the roll on the surface of the jelly compound one and a half inches from the top of the free end1 raising with rather slow and steady motion as before4 ,when the second method is chosen an oblong and somewhat deep dish will be found better than the flat shape2 the flat dish may be used if tilted to give greater depth of solution in a corner4 ,illustration3 ,,at ,,the ,,fountain4 ,j4 ,w4 ,,wade4 ,in the manufacture of tissues the greatest care must be taken to avoid over or long-continued heating of the gelatine solution4 ,either a too high temperature or a lower temperature1 long continued1 destroys the solution by rendering a considerable portion of it soluble in cold water and to a great degree reducing its gelatinous character4 ,the samples of gelatine used in tissue making are of two kinds1 although both of good quality they differ in solubility1 in hot weather a larger proportion of the hard sample is used1 in cold weather vice versa4 ,,insensitive ,,tissues4 ,all insensitive tissues are made with a single sample of hard gelatine4 ,they are stocked by dealers and must of necessity be fit for use at any season of the year1 to say nothing of those exported to hot climates4 ,,transfer ,,papers4 ,papers of many kinds are necessary for single transfer prints1 the tint of the paper must blend and harmonize with the tone of the tissue or by contrasting help to produce a pleasing effect4 ,for prints of warm tones such as red chalk1 terra cotta and the various tints of sepia1 a yellowish or cream-toned paper forms the most harmonious basis2 the various tints of black1 blue1 and purple look best on a slightly bluish-tinted paper4 ,for instance1 a copy of an old engraving in tissue1 of the brown tone of the original would be utterly spoilt by a blue-tinted basis4 ,the above remarks apply only in a limited degree to double transfer papers which in general use are confined almost exclusively to portraiture4 ,such papers are sometimes modified by tinting mauve1 rose1 opal1 etc41 etc4 ,such tints are only in small demand and are in all cases confined to papers coated with enamel preparations4 ,the best and most durable form of double transfer paper is that prepared on fine chemically pure paper with colourless gelatine and made insoluble by the smallest possible quantity of chrome alum1 entirely without white or tinted pigment of any kind4 ,the best variety of double transfer paper only differs from the finest form of single transfer paper in having on its surface a rather thicker and softer coating of colourless gelatine4 ,all transfer papers1 either for single or double transfer1 may be coated in the same way as tissue1 with the exception of those having a very rough surface4 ,all drawing papers and in fact all papers of very rough surface are prepared by brushing over their surfaces several coatings of a very thin solution of gelatine containing a larger proportion of chrome alum or formalin than is used in making ordinary single transfers4 ,a flat camel-hair brush is best for this form of coating1 care must be taken to avoid air bubbles4 ,,flexible ,,temporary ,,support4 ,is paper coated with a gelatine solution in the first instance1 and after drying1 again coated with an aqueous solution of shellac4 ,,sensitizing ,,the ,,tissue4 ,pour the bichromate solution into a deep flat dish 7porcelain1 ebonite1 zinc1 wood or tin7 to the depth of half an inch to an inch2 place a sheet of tissue in it face upwards1 remove air-bubbles with a camel-hair brush or soft sponge1 using as little pressure as may be2 turn the sheet and remove bubbles formed on the paper1 turn the sheet again face upwards1 and passing brush or sponge gently over the surface1 keep it evenly wet until it is fairly limp2 remove from the solution1 place face downwards on a perfectly clean glass or zinc plate1 squeegee to remove excess of solution1 blot or wipe with a soft cloth1 remove any solution from the fingers1 lift from the plate1 handle by edges only1 clip to a line1 small sizes by one corner only1 larger sheets by two corners1 leaving a little slackness between the two clips to allow for contraction in drying1 otherwise the sheet will be distorted and difficult to press into contact with the negative4 ,the sensitizing may be done in ordinary daylight4 ,the drying must take place in a room from which actinic light is excluded1 and in a current of warm dry air1 free from impurities1 such as the products of combustion from burning gas1 or an escape of sewer gas1 etc41 and at a temperature not higher than #abj ,f4 ,the drying should be done as quickly as possible1 otherwise the tissue's keeping property will be greatly reduced1 and in all probability a thin film formed on the surface1 of insoluble gelatine1 known to printers as decomposed tint1 degrading the high-lights1 and1 except in the case of very hard negatives1 spoiling the work4 ,it will be evident to anyone that the fancy forms of sensitizing have been carefully avoided--floating on the back1 floating on the face1 etc41 etc4 ,all the results desired can be obtained by immersion4 ,if a hard negative has to be dealt with1 a stronger solution1 or longer soaking in the bichromate solution1 is all that is needed2 for weak negatives vice versa4 ,note4--,in the dry frosty air of winter1 sensitized tissue will dry without heat1 and continue soluble for a considerable length of time1 often as long as a month1 or even longer4 ,in hot weather it is recommended that the solution of recrystallized bichromate be made immediately before using1 as in dissolving the crystals a considerable reduction of temperature is produced4 ,should the temperature then be over #fj ,f41 ice must be used1 not in the solution1 but roughly broken up and mixed with salt in an outer vessel4 ,if ice is placed in the bichromate bath allowance must be made by keeping out part of the water4 ,the ice should be encased in several thicknesses of fine muslin to prevent the solid impurities it generally contains getting into the solution4 ,when recrystallized bichromate is not procurable1 a few drops of liquid ammonia added to solution of crude bichromate is recommended4 ,as bichromate is cheap1 a fresh solution should be made for each large batch of tissue4 ,,printing ,,the ,,negative4 ,any negative that will yield a thoroughly good albumen print is suitable for carbon work4 ,the thinner negatives now made for ,p4,o4,p4 and similar processes are less satisfactory for direct prints in carbon1 for enlargements and reproductions such negatives can be made to yield most satisfactory results by modifying the transparency and the enlarged or reproduced negative4 ,the latitude in this direction is great4 ,no matter how flat the original negative may be1 if all the grades are present it can be manipulated in such a way that the most brilliant result will be produced4 ,,preparation ,,of ,,the ,,negative ,,for ,,printing4 ,the negative is prepared for printing as in all other processes by removing all defects such as pinholes1 streaks1 etc4 ,for the carbon process the negative requires to be further provided with what is termed a safe edge2 this is a line of black varnish1 from one-eighth to half an inch in width according to the sizes of the negatives1 painted on its margin1 either on the film or glass side4 ,in the case of original negatives masks of opaque paper are used instead of the painted edge1 the masks having openings cut in them slightly less than the size of the negative4 ,the purpose of the safe edge is to secure a margin on which light has not acted1 as such a margin gives greater freedom to the operator in the process of development by preventing the more deeply printed portions of the picture leaving the support when the backing paper is removed4 ,,double ,,transfer ,,printing4 ,it may be explained in a few words why an ordinary 7non-reversed7 negative must be printed by double transfer4 ,in all other solar processes when the print is removed from or taken off the face of the negative1 it is turned over to view1 it therefore follows that the details on the left side of the negative are found on the right side of the positive print2 with the carbon print no such turning occurs1 it is mounted upon its support in the same position as it lay on the negative1 developed in that position from the back and leaving the position of objects the same as in the negative4 ,in some cases this reversal of the position of details is unimportant4 ,we will first consider the double transfer4 ,in all double transfer processes a temporary support must be provided4 ,such supports are of two kinds1 flexible and rigid4 ,when a matt-surface print on paper is required1 finely grained opal glass is used4 ,for the enamelled surface patent plate1 for intermediate or only slightly glazed surface1 a flexible support is used4 ,flexible support yields a surface similar to an albumen print without special preparation4 ,when the higher glaze of the double-albumenized print is desired1 the printed tissue is coated with thin collodion before mounting on the flexible support4 ,rigid supports1 zinc or ground-glass plates1 have been used1 but owing to the difficulty of seeing the details during development their use is practically discontinued4 ,flexible temporary support is always used in transferring to canvas1 wood panel1 opal1 ivory1 etc41 etc4 ,in the case of canvas1 the double transfer process has two great advantages4 ,first1 staining is avoided1 the bichromate has been thoroughly got rid of in the process of development4 ,secondly1 the canvas is prepared to receive the print by a substratum that allows the carbon image to expand and contract with the expansion or contraction of the canvas and not in opposition to it4 ,there are also two advantages in adopting the double transfer process for the production of pictures on ivory4 ,the first1 is freedom from bichromate stains4 ,secondly1 the ivory is not distorted by washing in hot water1 such distortion generally takes place when the single transfer process is adopted4 ,wood panels are prepared in a similar way to canvas4 ,stains are avoided1 and as there is not the expansion and contraction of canvas to provide against1 the substratum is modified in composition and greatly reduced4 ,the stains above alluded to are caused by the chemical combination of bichromate with the lead of the paint1 forming chromate of lead or chrome yellow4 ,in the case of opal1 opaque celluloid1 and similar substances1 no staining takes place1 the double transfer is only required to restore the image to its proper position4 ,,single ,,transfer4 ,the single transfer process is practically the only method in use when large sizes or large numbers of prints are required4 ,for large sizes the negatives are reversed in the process of enlargement4 ,for small sizes one or more reproduced reversed negatives are made1 either in the camera from a carbon transparency1 or by contact printing from a carbon transparency on a dry plate4 ,with reasonable care1 little if any loss of quality occurs in reproduction4 ,as the single transfer process is the most simple form of carbon printing1 it is generally recommended to beginners4 ,probably the most simple form of all is single transfer on opal4 ,the opal plate does not require any preparation beyond cleaning4 ,neither soap nor grease of any kind must be permitted to contaminate the surface1 otherwise the print will fail to adhere4 ,opal plates are cleaned by scrubbing with fine graining sand and water1 and a muller or a small plate1 either of ordinary or opal glass1 placed upon the wetted sand and moved over the surface with a circular motion until soiled or discoloured markings are ground off4 ,,the ,,actinometer4 ,an actinometer must be used to gauge the amount of exposure1 as only a faint image1 and in some tissues none at all1 is visible during or after exposure4 ,the simplest form of instrument is the best4 ,that in general use is known as ,johnson's ,actinometer1 a square tin box containing a long strip of sensitive albumen paper1 and provided with a glass lid painted to the colour of printed albumen paper1 an opening in the paint in the form of a slit three-sixteenths of an inch in width1 from which the paint has been removed4 ,the strip of sensitive paper is made to pass between the top of an inner lid and the painted side of the glass lid underneath the clear slit with the end of the strip protruding at one side of the box4 ,on exposure to light the sensitive silver paper gradually discolours until it closely resembles the colour of the paint1 that is called one tint2 the tint is changed by pulling the slip forward just the width of the slit1 and so on until the requisite number of tints have been printed for the strongest or densest negative in the batch exposed1 those negatives requiring less exposure are turned down or removed when the requisite number of tints are registered in each case4 ,,exposure4 ,for double transfer from opal the materials required are opal plates1 sensitive tissue1 ,french chalk1 collodion1 double transfer paper1 pressure frame1 flat camel-hair brush1 chamois leather4 ,before placing the negative in pressure frame1 carefully clean from both sides all finger marks1 etc41 with the leather1 place negative in frame on a paper mask1 or provided with a safe edge4 ,after exposure to light1 remove from frame and develop on plate prepared as follows3--,rub the whole surface with ,french chalk on a pad of muslin1 afterwards removing loose particles by gentle brushing4 ,coat with collodion made as follows3--,enamel collodion1 #a part2 ether1 #a part2 alcohol1 #a part4 ,filter and coat by pouring a pool on centre of the plate1 and1 by tilting it1 force the collodion to flow into the top right corner1 then to the left1 then to bottom left1 and finally drain off at bottom right corner1 rocking the plate the while4 ,the collodion must be allowed to set until it will bear the gentle pressure of a finger in its thickest part1 but must not be permitted to dry in any part before plunging into clean cold water to remove the solvents by washing4 ,the time required in washing is variable according to time of year4 ,when the collodion ceases to repel water it is ready to receive the printed tissue4 ,soak the tissue for the requisite time1 but not so long as to become quite saturated1 bring it into contact with collodionized side of plate1 remove to squeegeeing board1 place over it a piece of wet rubber cloth1 or a piece of wet thick single transfer paper1 coated side up1 to prevent injury to exposed margin of collodion and to facilitate the smooth passage of squeegee over the surface in removing excess of water4 ,if1 on removing the covering from the plate1 the back of tissue is found to be unevenly wet1 blot or place plate in a rack to drain2 in a few minutes develop in warm water1 temperature #ij to #ajj ,f4 ,be careful to remove the backing paper under water1 and as soon as possible after immersion in the warm bath4 ,finish development by laving or pouring warm water over the print from jug or other vessel1 until all details are brought out4 ,when washing is finished the print should look rather light1 as in drying a decided increase in strength is obtained2 rinse slightly in alum solution to stop bleeding only1 place in clean cold water to wash out any remains of bichromate1 thoroughly rinse by dashing water upon the print to remove any particles of solid matter that may have stuck to its surface2 place in a rack to dry1 and transfer as soon after drying as possible4 ,the transfer paper is cut a trifle larger than the net size of the print1 but less than the opal support2 it is soaked in warm water until the surface is slimy to the touch1 but not soft enough to break under pressure between finger and thumb4 ,the softened transfer paper is placed in clean cold water into which the dry print is plunged1 water dashed upon its surface to remove air2 the two surfaces are brought into contact under water1 and squeegeed into contact as in first mounting before development4 ,when thoroughly dry1 the print may be removed from the opal plate by inserting the point of a knife at the edge4 ,double transfer prints with enamelled surface are produced precisely as above1 only substituting patent plate for ground opal1 and by adding a second thickness of paper to the back of the finished print before removal from its temporary support4 ,,double ,,transfer ,,from ,,flexible ,,support4 ,the flexible temporary support is prepared by waxing4 ,the waxing solutions are3-- ,no4 #a4 ,benzol #a oz4 ,pure beeswax 7natural not bleached7 #c grs4 ,no4 #b4 ,turpentine #a oz4 ,yellow resin #aj grs4 ,after dissolving1 mix the two solutions1 pour a little of the mixture on fine flannel1 rub it over so as to evenly moisten the surface of the flexible support1 wipe off with a second flannel using only slight pressure but rubbing briskly and with circular motion4 ,when finished1 the waxed surface should be perfectly even and quite free from streaks or other markings4 ,the waxing should be done some considerable time before the support is required for use1 and exposed to the free action of air to remove all trace of the solvents4 ,,paper ,,prints ,,with ,,ordinary ,,or ,,slightly ,,glazed ,,surface4 ,after removal from the pressure frame1 the tissue is plunged into cold water with a piece of support slightly larger4 ,after soaking the necessary time1 the prepared surfaces are brought into contact under water1 removed from the bath and placed upon any even plane surface1 such as zinc1 glass1 etc41 squeegeed into contact1 blotted or otherwise treated to remove uneven dampness1 and developed in warm water as in double transfer from rigid support1 then slightly rinsed in alum solution and washed in clean cold water until all traces of bichromate are removed4 ,after the transferring is done as before described1 only the print on flexible support must be soaked in water until quite flat before bringing into contact with its final support4 ,,paper ,,prints ,,with ,,highly ,,glazed ,,surface4 ,the printed tissue after removal from the pressure frame is coated with collodion1 for this coating allowance must be made in printing4 ,a considerable reduction in temperature takes place and any moisture present in the air is condensed on the tissue1 bringing into action the well-known effect of continued moisture1 i4e41 considerably increasing the depth of the print4 ,great care must be taken to coat evenly and to prevent the collodion running in streaks on the back of the print4 ,when such streaks or unevenness of any kind are present1 a corresponding dark line or lines will be found on the face of the finished print4 ,transfer same as for prints with ordinary surface4 ,all prints from flexible support on paper with a highly glazed surface as well as those intended for transfer to ivory or opal are coated with thin collodion3-- ,enamel collodion #b parts ,ether #d ,alcohol #d ,,double ,,transfer ,,to ,,opal ,,and ,,ivory4 ,after development the print is allowed to dry1 and as soon after drying as possible it is transferred to its final support1 whether opal or ivory1 by a solution of gelatine composed of the following ingredients3-- ,gelatine 7fairly hard7 #a-a_/b ozs4 ,water #bj ,chrome alum solution 7#cj grs47 #b ,soak the gelatine in the water until quite limp1 dissolve by heat1 then add the #cj grain chrome alum solution2 roughly filter through two or more thicknesses of fine muslin into a flat dish on a water bath4 ,after cutting the print to a size a trifle less than opal or ivory1 place both print and final support in gelatine solution1 allow print to stretch until quite flat1 then bring them into contact under solution1 squeegee and place on edge to dry4 ,when quite dry1 remove temporary support by inserting the point of a knife between the surfaces at the edge1 wash with benzol or ether to remove all traces of the waxing solution4 ,the print is now ready for the artist4 ,,double ,,transfer ,,prints ,,on ,,canvas4 ,for double transfer prints on canvas1 as a basis for oil painting1 there is not at the present moment a large demand4 ,a strong prejudice exists1 and deservedly so1 against such prints1 for the following reasons4 ,some thirty years ago1 in the principal establishment in which carbon work was done1 a process of printing on canvas was in vogue4 ,it was roughly this3--,a stretched artist's canvas without other preparation was coated with dammar varnish2 after drying1 the canvas was used in pretty much the same way as single transfer paper is now--that is to say1 a piece of printed tissue was squeegeed into contact with its surface1 developed by floating on hot water1 and practically in that crude condition placed in the hands of artists for oil-colour painting or finishing as it is sometimes prudently called4 ,the natural result followed--viz41 in a dry warm room the canvas stretched1 the film of unmodified gelatine contracted2 hence cracks1 peeling1 etc41 until the work1 valuable or otherwise1 was utterly ruined4 ,the method of preparing the canvas for the reception of the carbon image introduced by the writer is based upon opposite principles1 as mentioned in the preceding general remarks1 and may be described as follows3--,a yielding and elastic substratum of gelatine forms a crust1 so to speak1 that expands and contracts according to the corresponding behaviour of the canvas support4 ,ordinary painted canvas1 such as is used by artists1 or strong linen may be used with special treatment4 ,,preparation ,,of ,,painted ,,canvas4 ,the canvas is first stretched tightly on a drawing board1 same size as picture required1 the greater part of paint removed by scrubbing with soda solution 7either nail brush1 sponge or a piece of flannel will answer the purpose7 until the surface of the fabric is exposed and little of the paint remains beyond the priming4 ,after drying1 the canvas is coated with the following solution1 applied with a flat camel-hair brush4 ,several coats 7three in cold1 four in warm weather7 are given1 drying between each and rubbing with fine sand paper if at all uneven4 ,coating ,solution4 ,cooking gelatine 7,cox's soup answers perfectly7 #d oz4 ,sugar #b ,glycerine #b ,water #cj #cj grain chrome alum solution #a ,the print is exposed in the ordinary manner1 developed on temporary support1 allowed to dry and transferred to the canvas as follows3--,the canvas is placed face upwards1 on a level surface by preference1 on a broad board over a large tank4 ,the dry print is placed face upwards in a flat dish1 the warm coating solution poured over it1 air bells removed with the brush1 the surface of the canvas brushed over with the solution4 ,the bulk of the solution is then poured on the canvas and before it has had time to run off the print is lowered carefully and quickly upon it and squeegeed to remove excess of solution4 ,after thorough drying1 the temporary support is removed1 the surface of the print cleaned with benzol or ether or a mixture of both to remove every trace of the waxing compound1 and mounted on a stretcher in the usual manner4 ,a print on canvas prepared as above1 is perfectly reliable1 it will neither crack nor peel1 and can be used with perfect confidence as a basis for the most costly form of artistic finishing1 as the carbon image rests upon an elastic substratum in actual contact with the fibrous substance of the canvas4 ,,to ,,prepare ,,ordinary ,,strong ,,linen ,,or ,,calico4 ,proceed precisely as for painted canvas 7of course without scrubbing71 using the same coating solution with half-a-pound white pigment added1 sulphate of baryta answers perfectly4 ,sand or glass paper must be used pretty freely as the surface of the unpainted fabric washes up roughly when the gelatine coatings are applied4 ,,wood ,,panels4 ,wood panels are prepared by removing the surface of the paint only with soda solution4 ,after drying1 a tooth is given by rubbing with fine sand paper and coating with solution as under3-- ,gelatine 7,cox's soup7 #c oz4 ,sugar #a ,glycerine #a_/b ,water #cj #cj grain chrome alum solution #c_/d ,note4--,before transferring to either kinds of canvas or wood panel in cold weather1 it is absolutely necessary to thoroughly warm the final support1 otherwise the gelatine solution will gelatinize before the excess can be removed from between the surfaces4 ,,the ,,single ,,transfer ,,process4 ,the single transfer process may be briefly described as follows3--,the sensitive tissue is exposed under a negative and the exposure gauged by actinometer as for double transfer printing4 ,after removal from the pressure frame the printed tissue is plunged into clean cold water along with a piece of transfer paper of any desired surface or quality1 cut a little larger than the tissue 7to provide a margin by which the picture may be handled without injury during development74 ,after soaking the requisite time1 the two prepared surfaces are brought into contact under the water1 removed to a squeegeeing board1 plate of glass or zinc1 and squeegeed into contact2 care must be taken to use only as much pressure as is needed to remove the superfluous water from between the surfaces4 ,a sponge may be used instead of a squeegee1 or both may be dispensed with1 if care is taken to remove every trace of air from surfaces before lifting from the cold water bath4 ,when neither squeegee or substitute for it is used1 the print must be handled with greater care1 as undue bending before atmospheric pressure comes into operation would destroy contact4 ,the print is hung up to drain1 and more time allowed between mounting and development4 ,development is the same as in double transfer1 with one or two rather important exceptions4 #ast4 ,the single transfer print is developed upon the material on which it is to remain4 #bnd4 ,there is no preparation of the supports1 neither in the case of paper or opal4 #crd4 ,the developed print can be soaked for a considerable time in a saturated solution of alum without injury1 the alum solution greatly assisting in removing bichromate4 ,,carbon ,,transparencies4 ,carbon transparencies1 either for projection1 enlargement1 or reproduction1 are printed in a special tissue known as transparency tissue1 and developed on glass plates prepared with a thin coating of fine hard gelatine4 ,the coating solution is composed as follows3-- ,gelatine #c_/d oz4 ,water #dj ,bichromate potash #a dram4 ,the glass plates are carefully selected1 free from bells1 scratches1 and other defects2 thoroughly cleaned1 either by acid or rubbing with plate powder to remove every trace of grease1 and then coated with the gelatine solution1 and placed in a rack to dry2 when dry1 exposed to light to render the film somewhat insoluble4 ,it is not desirable to print until the film is absolutely hardened throughout4 ,the print adheres firmly to the plate when the substratum is not over-printed4 ,a positive intended for projection should show clear glass in the highest lights without undue density in the shadows1 all details plainly seen--in a word1 quite transparent4 ,positives intended for enlargement must be fully exposed--that is to say1 every detail on the highest lights brought out1 but no more2 beyond that point there is nothing to be gained4 ,over-printing in the transparency tends to bury detail in the shadows of the enlarged negative1 and to blend the highest grades in the high-lights1 reducing the roundness or modelling of the picture4 ,in the case of very hard negatives intended for enlargement1 the usual treatment is to sun the whole surface of the transparency in order to secure detail in the high-lights4 ,a moment's consideration will convince any practical printer that nothing but injury to the final print can result from such treatment of the transparency4 ,the high-lights are degraded1 the details in the shadows further buried4 ,the better method is to make an extra special transparency tissue1 for the printing of such hard negatives1 containing a greatly reduced proportion of pigment to gelatine4 ,such a tissue permits greater depth of printing1 retains all details in the shadows and high-lights1 and1 in fact1 enables the enlarger to produce a negative that will yield a thoroughly satisfactory print4 ,,reproduced ,,negatives4 ,in making reproduced negatives from hard originals1 ordinary transparency tissue will serve every purpose4 ,the transparency is printed in the usual way1 and developed on a prepared glass plate2 when dry a negative is printed from the transparency without special treatment and also developed on glass1 when a decided reduction of density will be found to have taken place4 ,the reproduced negative will possess all the good qualities of the original1 plus improved printing quality4 ,it is only in the case of extremely hard negatives that the extra special tissue is required4 ,if a perfect reproduction of an original negative is required1 the transparency must be printed either in very weak light or in direct sunlight4 ,either method gives a brighter image than that produced in ordinary diffused daylight4 ,the same method must be adopted in printing the negative4 ,note4--,care must be taken when direct sunlight is used to see that the pressure frame and everything in and about it is thoroughly dry1 otherwise the tissue may stick to the negative1 spoiling the print and probably the negative also4 ,it must also be noted that two tints1 printed in direct sunlight1 although of apparently the same depth1 mean quite as much as three such tints printed in diffused light4 ,,failures ,,and ,,defects3 ,,their ,,causes ,,and ,,cure4 ,as a rule1 failures in working the carbon process are caused1 as in most other cases of failure1 by imperfect knowledge of the substances and nature of the ingredients used in the process4 ,before going into further detail1 it may be as well to point out that a great deal of misunderstanding has been caused1 by writers on this subject--that may be fairly termed blind leaders of the blind4 ,with only slight knowledge of the subject they have misled beginners by assuring them that the process is simplicity itself1 in fact the most simple photographic printing process extant4 ,up to a certain point1 and to that certain point only1 is such description true4 ,there are no subtle chemical combinations1 no mixing and maturing of toning or other solutions4 ,but--and in this case there is great virtue in the but--the greatest care is not only required1 it is absolutely demanded1 in manipulation4 ,a carbon print from start to finish is probably subject to more chances of injury than any other form of print in existence4 ,when this fact has been fully grasped by the novice1 and he has been thoroughly prepared for the difficulties before him1 the rest is plain sailing4 ,care1 and care only2 nothing beyond4 ,he who wishes to succeed in carbon work must pay infinite attention to every small matter of detail as far as such detail relates to manipulation1 otherwise he will only succeed in achieving failure4 ,,frilling ,,and ,,reticulations4 ,frilly reticulations are generally caused by over-soaking the tissue before development1 or failing to provide protection of the clear portions of the margin of the negative by a safe edge4 ,,spots ,,on ,,the ,,finished ,,print4 ,spots are generally caused by solid particles of grit or other impurities being allowed to find their way into the water in the process of development1 or1 as in the case of certain peculiar circular spots that often deface the carbon print1 such spots are caused by small fragments of tissue broken from the edges in cutting1 which1 being of the same colour as the prepared surface of the tissue and exceedingly small1 often escape notice4 ,they adhere most tenaciously to the surface of the tissue1 and if not removed before the print is mounted upon its temporary or final support1 cause the mischief referred to2 being confined between two surfaces they cannot escape1 but are dissolved by the water used in developing the print1 swell and make a circular patch1 often greatly injuring the picture4 ,spots of a different character are produced in quite an opposite direction4 ,instead of being black they are light1 in groups each spot having a dark rim on the outside4 ,they generally occur in under-exposed prints1 and are formed by fine particles of air imprisoned between the coating of gelatine and the paper support4 ,when the tissue is mounted for development and placed in warm water1 the fine particles of air swell1 and not being able to escape from between the surfaces1 impress themselves into the yielding portions of the printed tissue and make the marks above referred to1 unless the printing has been deep enough to allow of their removal before development is completed4 ,,cause ,,of ,,failures ,,in ,,the ,,second ,,transfer4 ,other causes of failure refer particularly to prints by double transfer1 either to paper1 opal1 ivory1 canvas or wood panel or any similar surfaces4 ,such failures are generally produced by soap1 fat1 or any kind of greasy substances being permitted to find their way into the water in which such prints have been manipulated previous to their final transfer4 ,another point should be mentioned3 the sooner a print intended for second transfer is finished the better the result will be4 ,,pressure ,,marks4 ,pressure marks are caused by using damp tissue or damp pads in the pressure frame4 ,it is recommended that a piece of waterproof material1 such as mackintosh cloth1 be placed between the tissue and the padding1 and that the pads be as smooth and free from grain as possible4 ,it will be found on close examination that the mottled1 spotty appearance1 known as pressure marks1 closely resemble the texture of the pads behind the tissue4 ,thos4 ,s4 ,skelton4 ,,index4 ,a4 ,alpine ,photography1 #i ,outfit for1 #i ,lens for1 #aj ,carrying camera in1 #ab ,plates for1 #ad ,carrying ,baggage for1 #ae ,outfit for ,developing1 #af ,exposures1 #ag ,development1 #ah ,formul1 #bj ,light 7tables71 #ba1 #bb ,accelerator1 #bd ,alum ,bath1 ,formula1 #da ,aberration1 ,spherical1 #fj ,chromatic1 #fa ,astigmatism1 #fb ,aplanat ,lens1 #fd ,astigmat ,lens1 #fd ,aperture of ,lens1 #fh ,angle of ,image1 #gj ,accessories in ,portraiture1 #gi ,architectural ,photography1 #aag ,camera for1 #aah ,lenses for1 #aai ,plates for1 #abb ,actinometer for ,platinotype1 #bjh for ,carbon ,process1 #bga ,b4 ,backing ,mixtures1 #di ,background in ,portraiture1 #gh ,breadth in ,pictorial ,work1 #ic ,blisters on ,p4,o4,p1 #aid ,bromide ,printing1 #bbe ,safe light for1 #bbf ,negative for1 #bbg ,bromide ,paper1 sensitive side of1 #bbg ,printing1 #bcb1 #bcc1 #bbg ,lamp for1 #bbh ,bromide ,printing1 masks and discs1 #bcj ,vignetting1 #bca ,cloud ,printing1 #bca ,bromide ,paper1 development of41 #bcc ,iron developer for1 #bcd ,metol1 #bce ,hydrokinone for1 #bcf ,eikonogen 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,varnishing ,negatives1 #ed ,vignetting ,bromide ,prints1 #bca ,w4 ,washing ,plates after ,development1 #ch ,wood1 ,carbon ,prints on1 #bgi ,z4 ,zeiss-,planar ,lens1 #fe ,lens for ,architecture1 #abj 99 99 99 99 99 99 99 99 99 ,,end ,,of ,,work 99 99 99 99 99 99 99 99 99 ,,advertisement 99 99 99 99 99 99 99 99 99 ,,twelve 444 ,,perfect ,,productions4 ,,barnet ---------- ,ordinary ,plates ---------- ,studio ---------- ,extra ,rapid ---------- ,rocket ---------- ,lantern ---------- ,photo-,mechanical ---------- ,astronomical ---------- ,platino-,matt ,bromide ,paper ---------- ,ordinary ,bromide ,paper ---------- ,snow ,enamel ,paper ---------- ,p4,o4,p4 ---------- ,carbon ,tissue ,price ,list on application4 ,manufactured by ,,elliott ,,son1 444 ,,barnet4 99 99 99 99 99 99 99 99 99 ,transcription ,notes3 ,the original spelling and grammar have been retained4 ,footnotes have been moved to the end of the paragraphs in which they are referenced4 ,minor adjustments to hyphenation and other punctuation have been made without annotation4 ,the caret symbol is used to represent a number or expression raised to some power 7#ebbe74 ,typographical changes to the original work are as follows3 pg #aj kodak_/,kodak3 a form of 444 pg #ae removed repeated word at3 can be got at 444 pg #fb simultaneouly_/simultaneously3 where they cross 444 pg #ha two_/too3 too far behind or 444 pg #ie frolicing_/frolicking3 joyous sunshine 444 pg #ajh rythmical_/rhythmical3 something 444 pg #add salutory_/salutary3 has a very 444 pg #ade concatention_/concatenation3 under any 444 pg #aec potass_/potash3 metabisulphite of 444 pg #aic power_/powder3 7bleaching 444