be er aN - Em! PS : ae rest Rae — é aft ees! cers eee ny SN Es Be stunie sche ag Re Ng HORE SARS : : meek ear << oe emits Per EN * adhe ae ier fa eee Se 3 key are aie FEO A ye Sette ole Sot a oe eT ofa = ia es crest cet Re Seaewe Seats aa ee ee EseTes ieee ep 1s ae es eae, Rae a bo-Ve-uer ae) Sarah SSE SR et Set ; : h ee eh Ve aed fae oer cs AB eee Fi! if " 4 itt ‘ i pbies tay Bh has % f ' eh Vea a f a ‘ HOUSE NEAR ROUEN, FLRANGE. From a Negative by F. W. Mills. OT OGRAPHY | FOR atk MeesiTeECTS BY bere eee ill TS, Member of the Camera Club, and the Huddersfield Photographic Society ; Author of ‘‘The Art and Practice of Interior Photography.” PeeUSTERATED, >) * ENTERED AT STATIONERS’ HALL poner. ILIFFE & SON, 3, ST. BRIDE STREET, E.C. 1890. Pane AC E. FEW weeks ago the Author, in the course of spending a pleasant evening with a friend—an architect—the subject of the great advantages which might be obtained by architects from an elementary knowledge of photography was discussed. | This conversation convinced the Author that a book containing short instruction would be of benefit to architects. He has therefore endeavoured to prepare such a one as shall prove useful to them. THORNLEIGH, HUDDERSFIELD, September, 1899. PRINTED By ILIFFE & Son, 3, ST. BRIDE Works CovENTRY. — * + = = - ¥ ~ 5 + bode? lk , hee a Wes ‘é e ij ey pe 1 ‘ y 4 rs bal ‘ f re \ A = F 4 * 2. ”~ a he coal tt GON FEN ES: PREFACE TABLE OF CONTENTS PAR Peel. INTRODUCTION. DESCRIPTION OF PHOTOGRAPHIC APPARATUS CHAPTER ZA PLATES AND THE DARK-ROOM Cie Lik 11, EXPOSURE OF THE PLATE... CHAP FLERE, NECESSARY SOLUTIONS CHAP PIR LV. DEVELOPMENT OF THE IMAGE CHAPTER V. DEFECTS IN NEGATIVES AND THEIR REMEDIES CHAPTER VI. DocTORING AND FINISHING NEGATIVES... {%. CHARTS VL: A SIMPLE PRINTING PROCESS DL 14 19 OR | 24 29 32 CONTENTS—continued. PART II.—CHAPTER VIII. PHOTOGRAPHING INTERIORS CHAP Twix SECOND LESSON IN DEVELOPMENT CHAPTER X; Positive BromipEe PRINTING CHAPTER a2 PLATINOTYPE. «. CHaie Ee iveect is ENLARGING ON BROMIDE PAPER ... CHAREE heecia. SPECIAL APPLIANCES CHAPTER « ts ae ot ae aa 2 ounces Water .. ¥e Bie oe ee ee ae 3050 44 PHOTOGRAPHY FOR ARCHITECTS. The new eikonogen developer has received so much praise by experts that is it quite possible that some who peruse these pages may desire to see for themselves its developing power. A. Sulphite of soda* ... dle Sr 0 Spoace Eikonogen ... 14 drachms Water Bee ie niet es ... 30 Ounces B. Carbonate of soda (crystals)... .++ ) of Ounce Water os aa fee ye Pa mey t To develop take of— Solution A a ee ae 5 Be ... 3 Ounces © Bap et dB) or Hee oe oe sag tk eee No acid batk will be required after this developer *Dissolve the soda thoroughly before adding the eikonogen. Laden d oad Eid aig 5 wes al PLATINOTYPE. HOT, BATH. NS it is presumed that the sensitive paper is pur- chased ready for exposure, the following direc- tions only need be followed; but a few words may with advantage first be said as to the theory of the process. The paper is sensitised with ferric oxalate and chloride of platinum, and after drying it must be kept quite dry. For this reason a sheet of india- rubber should always be placed behind it, in the printing frame, so as to prevent moisture from the atmosphere being absorbed. Light acting on the platinotype paper has the effect of decomposing the ferric oxalate into ferrous oxalate and carbonic an- hydrate. The paper is exposed to diffused daylight (not in the sun) in the usual manner, in an ordinary printing frame, the sensitive side of the paper (the yellow) being placed against the film of the negative, anda piece of india-rubber placed at the back of the paper in order to prevent the dampness of the atmosphere causing the paper to print in uneven blotches. The lemon-yellow tint of the paper becomes ereyish when affected by light, and sometimes, when, the negative contains great contrasts, pure yellow in the shadows. 46 PHOTOGRAPHY ~FOR ARCHITECTS. Only experience can teach when the exposure is complete, but, fortunately, there is a wide latitude permissible. It may, however, be taken as a general rule that the detail in the shadows shall be visible before the paper be removed from the printing frame. It is a good plan, if the negative be a ‘‘ flat” one, that is to say, wanting in contrasts, to varnish the rebates with opaque varnish. The edges of the paper will, therefore, during exposure, remain un- changed, as no light will reach them. The printed portion may then be estimated as to its density with considerable accuracy. Direct sunlight should only be employed when the negative be very dense, 7z.e., black and white. | Possibly the best devoloping solutions for the paper are as follows (although various modifications have been recommended) :— To develop the exposed paper float it upon a saturated solution of potassium oxalate made faintly alkaline with sodium carbonate. ‘This is heated to from 100° to 150° Fahrenheit, according to the exposure. An under-exposure may even be treated with'a solution‘as 0t 487100 «2 * A weak solution of carbonate of soda, or of other alkaline salts, such as sodium phosphate, may be used to develop the prints, instead of potassium oxalate, especially when the prints have been over-exposed, or the paper has a tendency to fog by reason of its having been kept over long. The action of the sodium carbonate appears to be rather to retard the solution of the iron salts, and so to give them time to reduce the platinum, than to develop the image in the sense that potassuim develops it. It is advisable not to commit those errors that give the advantage to such salts as those men- tioned.—Science and Practice of Photography, Chapter XVIII., by Chapman Jones, F.1.C,, F.C.S. London: Iliffe & Son. 7 PHODOGKAPHY “FOR ARCHITECTS. 47 The prints, after developing, should be placed ina solution made as follows :— Hydrochloric acid es Zhe ae: 4 ounce Water ZAGER, without being peevionnts asked If by any chance this fixing solution presents a slightly milky appear- ance, it is not strong enough in acid, and more should be added without delay. The prints may be changed from this solution to a similar one three or four times, remaining in each three or four minutes. This must be continued until the last solution, after having received them for some minutes, does not turn yellow. The prints should be then thoroughly washed, and will be quite permanent. The Platinotype Company sell paper and solution for producing sepia tones, the mode of preparation of both of which is unknown to the author, but the following developing solution (Borlinetto’ ‘) eives the same result :— Saturated solution of potassium oxalate TO ounces Saturated solution of cupric chloride Pep OU RCE Oxalic acid fu M < a ... I drachm The prints should remain in ane solution from ten to twenty minutes if necessary. Cold Bath.—lThe paper tor this process is pur- chased ready prepared with ferric oxalate, to which some mereutic chloride has been added. It may, however; be easily prepared by being previously sized with the following solution :— Arrowroot ... ree oo es fee i tachi. Hot water ... Mas Ounces. (The solution tiuct be cold when employed.) WA it 45 PHOTOGRAPHY FOR ARCHITECTS. Lay the paper flat upon the solution, taking care that no air-bubbles are present, for three minutes, then hang up to dry. The paper may then be sensitised by floating for two minutes upon the following solution :-— Ferric oxalate a. a ne See Pete ata. Mereusic chloride ... 2, de a+ 5 2a es Water ey ier nas aa ... — 5 OURGES: The paper is then dried, and again floated a second time for a few seconds upon the last solution, and dried again. The mode of developing prints with a cold solution was fully explained by its introducer, Mr. W. Willis, at the Conference of the Camera Club, two years ago.* The cold is far superior to the hot bath process, as shorter exposure is required, and a wider latitude in exposure is permissible. It has also the advantage of allowing the printer to vary considerably the character of his prints. Prints may be kept several days (in a dry atmo- sphere) before being developed without any appreci- able deterioration taking place. However, they should be slightly damped before printing or before developing, as paper exposed na perfectly dry state, and developed without being previously damped, will give but a comparatively feeble grey print, whilst if they are damped they will assume a rich, velvety appearance. * See the Fournal of the Camera Club, Vol. II., Pp: 47s Per opOoGrRAPHY DOR ARCHITECTS. 49 To damp the paper, spread it out upon clean sheets of blotting paper (in the dark room) for about ten minutes in winter or twenty in summer. A simple rule to be guided by is that the paper is moist enough immediately it loses its crispness. In developing the prints many variations may be made, both in the constitution of the developer and in the method of applying it. Different proportions and quantities of oxalate and of platinum salt may be used. The following bath, which is employed by the author, will prove, however, of good average strength :— Potassium oxalate, ... Se ee 635 tO.65 grains Bere chioro-platinite (3K, PtCl,).... 9 ,, Water oh z oc te 2 eet SOUnce It must, however, be borne in mind that the stronger the oxalate the harder and colder will be the tones. The Platinotype Company, in their instructions supplied with this paper, give the following formula :— A. Developing salts * ce i Hie 4+ pound Water .:: ty =) in x15 SOLOUNCES feetoatinum salts (3K, Pt Cl,) ... we OO frains BVater —:.. Ge: ee jae So ee OULOeS * Potassium oxalat (neutral). The developer is made by mixing three parts of A to one of B, and adding two parts of water. Do not mix more developer than will be sufficient to develop your exposed prints, as the solutions when mixed will only keep a few hours. 50 PHOTOGRAPHY “FOR VARCHIIE Clas: Small prints are best developed by floating, but large ones by being brushed with a large squeegee (the breadth of the print) covered with flannel soaked in the developing solution. The acid bath above described on page 47 must be applied immediately the development has pro- ceeded far enough. Unexposed platinotype paper should always be preserved in a chemically-dry state. To accomplish this it is convenient to place it in long, circular tin cases (similar to those of card-board used for silver paper), with a perforated false bottom, below which is anhydrous calcium chloride, and having strong indiarubber bands round the joinings between the lids and the bodies of the cases. Such cases may be purchased ready made at almost any photographic. apparatus dealer’s. When opening or closing the case care must be taken that no metallic dust finds its way on to the paper. The calcium tubes should always be lined with felt or cloth. It is a fact, worthy of note, that negatives or fingers which have been in contact with platino- type paper prepared for the hot bath process must be thoroughly cleaned before touching cold-bath paper. GHA LER 58) 53) 5 Io | 15 20° 25 30 30) 40 45 10 4 62 64 6 6 52 5 sy | MM | 16h) 22 | 278) 33° | 0 30ee eee Pees +) 82 | 62] 964) 6S Geseecee 6 12 18 24 30 36 42 48 54 12 9 8 7% 5] ae OF | OF 7 | 14 | 20) 28) 35) |) 4a tS Ly Ioy | 94 4 83 tae 3 g 16 24 Boe Ved 48 56 64 ie: 16 | 12 | 108 | 10 | 93} Ohs)ss se 9 18 7 | 36 | 45 | 54 | | G3atiissa ue 18 ee Se eal 114 | 104 | 10% |} 102) ios *From the British Fournal of Photograthy Almanack. GTPAP LEK XIII, SEECIAL APPLIANCES. Nee is often desirable, when travelling, to photograph for oneself certain architectural features of a building which are not shown in any photographs that can be bought. The weight of glass plates would prove a great nuisance, besides the great inconvenience of not having a dark room always at hand to empty and refill the dark slides. To obviate this difficulty, compact and light boxes are made to take the place of dark slides, called ‘roll-holders.” These roll- holders contain two rollers, one having a long spool of flexible celiuloid coated upon one side with the same emulsion as are plates. As each exposure is made, the exposed portion of the spool is wound on to the other roller. Fig. 6 represents one of these roll-holders. 56 PHOTOGRAPHY FOR ARCHIDEGIS. When the roll-holder is placed in position, a portion of a continuous roll of sensitive film is brought into | the plane occupied by the ground glass whilst the image was being focussed. Between this film and the lens there intervenes nothing but a_ shutter similar to that used with an ordinary dark slide. In fact, the film on its basis simply replaces the film on elass, but with this great difference, that when it is necessary to replace one film with another, instead of having to reverse the slide, or take up another one, we have only to turn a key till a certain indica- tion is given, when, by the winding of the exposed film on to one roller, and the unwinding of an un- exposed one from the second roller, we have a fresh film in position.* ON EASTMAN From fig. 7 may be easily seen the construction of the roll-holder. To remove the lid press the springs at each end of the holder inwards. * Burton’s Modern Photography, page 113. London: Piper and Carter. or PHOTOGRAPHY FOR ARCHITECTS. 57 An exposed portion may be cut off with a knife by drawing it along the rollers, as illustrated in 'Fia. 8. fig. 8. The remainder of the spool must then be pulled, so as to unroll it, and passed through the slit into the box, and attached as in the illustration (fig. 9). One other piece of apparatus which calls tor notice on account of its usefulness to architects is an ingenious camera particularly adapted for photo- graphing panoramic views. The ‘ Cylindrograph,” as the inventor, M. Moessard, has named it, was patented by him in 1884. Fig. g illustrates this camera ready for use 58 PHOTOGRAPHY * FOR” ARGHIVPEC (Ss, ‘When it 1s desired to focus, the crank (m) 1s moved from side to side. If the image on the ground glass remains stationary when the lens () is moved by means of the crank, the focus is accu- rately adjusted. Should, however, the image move in the same direction as the crank, the lens must be moved further forward; if in the opposite direction, the lens must be brought a little nearer to the focussing screen. A few turns of the screws will effect the necessary alteration. : Pre. 26 ‘The sizes of the films used with this camera are as tollows -—— SIZE OF FILM. FOCUS OF LENS. . 174°x -5 inches 5 |) OTGhies ZS de Sen ae ‘ a 20 RO aes, ee nih 344 x Io} ,, eh Abe, ene <7) ee PHOTOGRAPHY FOR ARCHITECTS. 59 The whole apparatus closes into the small space shown in fig. 11. CHAP PER eis PROCESSES FOR) COPYING TRACING] ee processes may be divided under two headings, viz.: (1.) White lnes on a blue eround, and (2), black lines on a white ground. The former is now well known, being employed largely by engineers and by a few architects; the latter, however, is by no means so well known. The print opposite is an illustration of it. The author advises his readers to purchase their ferro-prussiate paper, but for the benefit of the few who may,desire to prepare their own, and thus save - expense, the following particularly simple method is described. Ordinary Ferro-prussiate Process.—Dissolve Potassium ferricyanide ... wie ... 2% ounces. In watery =-. rs ae "2 ee sake ? and Ammonia citrate of iron ... or ... 24 ounces. Iniwater ... Se fare rs Rey Fs " Spread a sheet of stout, smooth drawing paper on a drawing board, and with a soft sponge dipped in a mixture of the two above-described solutions, stroke the paper first lengthways, then across, taking care that no portion be missed. So long as the. paper has been coated all over, it matters but little whether it be evenly done or not. ee eee Sag (cd ciSeeE TRICO ‘NVild GNNOY9D vet eed ee ONINIG AYVYG/7 ¥ sh - PHOTOGRAPHY FOR ARCHITECTS. 61 This should be done in a weak light, and the paper must be dried in a very dark place, and prefer- ably warm. Paper so prepared and kept dry will keep for weeks. To print upon it (or similar paper which has been purchased already prepared), the following simple instructions only need be followed :—Place a piece of clean glass in a large printing frame, and behind it the tracing to be copied, the ink side towards the glass, then a piece of ferro-prussiate paper with the coloured side to the back of the tracing, place the back on the frame, and clamp down the springs. Asin all other photographic printing processes, light is the agent employed to cause the chemical change which produces the print. Place the printing frame ina good light (not in the sun), and leave it there until the groundwork turns slightly bronze colour. This will take about ten minutes on a bright summer day, and ona dull day, in winter, possibly half-an- hour. ‘Take the paper, when printed enough, out of the ’ frame, and lay it upon a slab of glass or zinc, allow- ing a tap of cold water to run over it until the water which runs off ceases to be of a yellow tinge.* Positive Blue Process.—The following process has great advantage over the one previously described, but on account of it being less simple is little used. It is known by some as “‘ Pizzighelli’s Blue Process.” *If the background is not intense enough in colour, dip the print in a weak solution of hydrochloric acid in water. 62 PHOTOGRAPHY FOR: ARCHITECTS. A, iGum arabicwaye. ies ce og OUMCES WV erees te +3 i + eee B. Citrate of iron and ammonia... mere cy WaAteia ss es set ee <0 eee C.. ‘Ferric chloride: Bi: = ig) Ee Waters 2. Are a i ee D. Potassium ferrocyanide (yellow prussiate of potash) se WO ee Water _... Hie Re Ae Bee ae ee ke: E. Hydrochloric acid +e ae cee WV ECE etsy a AS: ie gee A, B and C.are mixed, and paper isieoatedewite it as soon as possible, just as described in the last process. The exposure is very short, being only about half or one-third that necessary with sensitised albuminised paper. After exposure (in the printing frame), D is applied with a brush till the image appears blue on a white ground. If the ground be darker than very light blue, this shows that the exposure has been too short. The print is now dipped in F, which removes the slight tint from the ground and darkens the lines. It is washed and dried.* This process is known as “UCyanotype: | Black Lines on White Ground.—Thisis a process more suited to architects than either of the above, as it presents the appearance of a lithographic print. It 1s an improvement upon Herschell’s positive pro- * Practical Guide to Photography and Photo-mechanical Printing, by W. K. Burton, p. 354. London: Marion & Co., Soho Square. PHOTOGRAPHY FOR ARCHITECTS. 63 cess (the one lastly above described) by Pizzighelli and Pellet and Co. Pellet’s formula is— Oxalic acid ng ae re a¥io> SS grains Ferric chloride... ae 4 east g tee ay Water | ees bet es Hee: er TOO..Ces A well-sized paper is coated with this solution, and after it has dried, and been printed upon in the usual manner, it is developed by soaking in a 15 per cent. solution of ferrocyanide of potassuim, then thoroughly washed in water, after which it requires fixing in a 10 per cent. solution of hydrochloric acid. A final washing and drying between blotting paper com- pletes the operations. ; Portwin’s Process.—As this chapter would not be complete without a description of this process, it is here described. The paper is first floated on a warm solution of gelatine (1 to 15), to which some suitable pigment has been added. When dry it is sensitised by immersion in the following simple solution :— Perrte Chloride ... eF: ae ... 480 grains Peateanic acid | -... bes 255 Ae ee ema! paeter .. bal ia 2) (LO.OUNCES The paper is dried in the ae “aie effect of the action of light is to convert the ferric chloride to ferrous chloride in those parts on which the light has acted, thus rendering the gelatine coating’ soluble in hot water, where it is in contact with the ferrous salt, 64 PHOTOGRAPHY FOR ARCHITECTS. It will be seen, therefore, that a reversed positive is necessary to yield a positive print. When sufficiently printed, the image is developed by simple immersion in hot water. The insoluble parts remain in the paper and form the image. The great drawback to the process is the necessity of printing from reversed positives,* but it is probable that this defect might be remedied.t — — ———— *Or negatives. + Photographic Printing Methods, by W. H. Burbank, page 23. New York: Scoville Manufacturing Company. APPIN DIX. ooapearghN tor eee Or CubMIiCALS KREOUIRED.: Hydrokinone, 31. me Bromide of Potassium, 3 Sulphite of Soda, 3vi. Hydrate of Potassium, iv. Carbonate of Potassium, Ziv. ~ For developing solution recom- | mended in Chapter III. For finishing negatives—Alum, 1lb. Thiosulphite of Soda, 7lbs. metGHiils AND MEASURES. TROY WEIGHT. Pounds. Ounces. Pennyweights. Grains Grams fee I2 = 240 = 5,760 = 373.25 Ty y+ 202 ASO. ry 31210 Tae rae 24. = 1°55 Pee ee eCAKTES WEIGHT. (The pound, ounce, and grain are the same as in Troy weight). lb. z 5 iS) gr. Pound. Ounces, Drams. Scruples. Grains. Grams, Meee 12 = 96 = 288 = 5,760 = 373°25 ee ap OR Ga) PEt 480° ah 93 T10 I = 3 = 60 = 3°89 I = 20 = 1°30 fey ‘06 (154 = 1°00 AVOIRDUPOIS WEIGHT. Pound. Ounces, Drams. Grains, _ Grams. (Troy.) tees 0s 256) =. 7,000, =e. 453°60 Ua eed tO ee A575. ee 25°35 Fete RA. eae 4°77 APPENDIX.— Continued. LIOUTIDS MEASUK i: 60 Minis ae er eon, 8 drachnisme ... 1 Ounce” = 1°73 Cube 20 ounces i .. pint =. 6460eue 8 pints = 2) I pallon = ia79ere N.B.—The imp. gallon is exactly 10 lbs. avoirdupois of pure water. The pint is 14 lbs. The above weights are those usually adopted in formule. All chemicals are usually sold by avoirdupois weight, in which there are 4374 grains to the ounce. The precious metals, such as silver and gold, are sold by troy weight, containing 480 grains to the ounce. FRENCH: WEIGHTS. AND MEAG AND THEIR EQUIVALENTS IN ENGLISH. I cubic centimétre = 17 minims nearly. ad) Se = la dtachny ODAC ss * = 1° Cunce: Soe, i = 1 ounce, 6 drachms; 5 minimis, TOoLeys - — 3 ounces, 4 drachms, 9 minimis. TPOOOm,, 25 ) or r litre, -= 35 ounces, 1 drachm, 36 minims. = to 61 cubic inches] The cubic centimétre, usually represented by ‘c. c. ’, is the unit of the French measurement for liquids. It contains 16.896 minims. The weight of this quantity of water is one eramme. Hence it will be seen that the cubic centimétre and the gramme bear to each other the same relation as our drachm for solids and the drachm for fluids, or as the minim and the grain. An easy way to convert grammes into English 1s to divide the sum by 4, which gives the equivalent in drachms very nearly thus :— Grammes. Diachms, Ozs. Drachny. ‘Grains, 100) A= iA a ~ INDEX. | PAGE cid. Bath .,. vb ahs ini a ON Be eer aay Alum Solution oes as een aS Ammonia 10 °/, pave pii: Saincga is" a 37 Apparatus ... Sve Fr ae ay ce ae 7. Aperture of Lens ... e ite ise a 9 Backing Plates, Methods of a 5 Ke ey Oy Blisters and Frilling bas ae oo et ee 27 Bromide Printing Process We aos ae ar 39° Camera a ee Ne a oe a Ss 8 Camera Stand a a set a aa Cs IO Colour, Chemical Action we a es cs ape ie Dark Room... a aes eos ee Re Be 9 ~ Dark Room Lamp... sy es oa = = 13 Density of Negative ee a8 a ie oes 29 Detail.. sm inp fe ae oe is 16 Boe bese for Plates eee Pe eh TQ,83 [39 Developers for Bromide Paper ... co an Aig! 42 Developers for Platinotype Prints de Aes Tee O) Eikonogen as a Developer ae spe Se Le 44. Exposure of Bromide Paper... res oe ia 4I Exposure of Platinotype Paper... aoe as bee 45 Hmposure Lable ... a Hee st < Deen 7 Ferro-prussiate Process ... ai #e ie ri 60 Fixing Solution ... a ns a ae re 20 POG Carecn ... ba ag ae ae ae