T R 
 
 IRLF 
 
 IE 
 
 PHOTOGRAPHY 
 
 H. W. THOMAS, F. 0. S. 
 
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 No. ... 
 
 Division ..... 
 
 Range 
 
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 Received C^^ ..187^ 
 
THE 
 
 MODERN PRACTICE 
 
 OF 
 
 PHOTOGRAPHY 
 
 BY 
 
 R W. THOMAS, F.C.S. 
 
 INTRODUCTORY SKETCH. 
 HOW TO MAKE THE NEGATIVE. 
 HOW TO CLEAN THE GLASS PLATE. 
 HOW TO VARNISH THE NEGATIVE. 
 HOW TO PRINT FROM THE NEGATIVE. 
 HOW TO PREVENT FOG, STAINS, AND STREAKS 
 IN THE NEGATIVE. 
 
 PHILADELPHIA: 
 HENRY CAREY BAIRD, 
 
 INDUSTRIAL PUBLISHER, 
 
 406 Walnut Street. 
 
 1868. 
 
"I have said, and I abide by it," cries Voltaire, 
 " that the fault of most books is their being too long." 
 
 " A writer who has reason on his side will always 
 be concise." 
 
 BISHOP HORNE. 
 
 H, 0, BAIED, Philadelphia, 
 
 PUBLISHES 
 
 THE PRACTICE OF PHOTOGRAPHY. By ROBERT HUNT. 
 With numerous Illustrations. 12mo. 75 cents. 
 
 THE DAGUERREOTYPIST AND PHOTOGRAPHER'S COMPAN- 
 ION. Illustrated. 12mo. . . . $1 25 
 
 PHILADELPHIA : 
 COLLINS, PRINTER, 705 JAYNE STREET. 
 
INTRODUCTORY SKETCH. 
 
 PROBABLY no modern science or art can boast of 
 so many roads to success, as that which owns itself 
 the 'servant of the sun. It is easy to understand 
 why this should be so, for all things, animate and 
 inanimate, are affected by the sun, which at the same 
 moment gives us both light and life, and is a fertile 
 source of chemical decomposition. It becomes, there- 
 fore, evident that the slightest investigation, the mere 
 cursory examination of the many valuable store- 
 houses of knowledge, is sufficient for developing that 
 which at first sight appears new, but which, in re- 
 ality, is only proof of the statement above made, that 
 all bodies are more or less acted upon, and changed 
 by the agency of light. 
 
 Hence the innumerable processes in photography, 
 which spring up daily, giving constant occupation 
 and food to the experimentalist, engaging earnestly 
 his attention, and so absorbing his interest by a suc- 
 cess more or less certain, as to make the pursuit of 
 this art, probably the most fascinating, the most 
 exciting, and the most productive of results of any 
 followed by the intelligent and intellectual classes of 
 the present day. 
 
 If * he above paragraph has been carefully read, it 
 
will be easily seen that as there are many roads 
 pointing to the same end, so, in proportion to their 
 number, will be found the difficulty in selecting that 
 path which the novice will gladly seek, as leading 
 direct to a successful practice of the art in question. 
 It will be my endeavor to point out that road, and 
 in doing so, I would not for a moment disparage the 
 opinions of others, but merely show, without turning 
 either to the right or to the left hand, how perfect 
 results may be obtained ; but, in doing this, I feel 
 that brevity must take the place of a system more 
 prolix, and to some minds, more agreeable. Let, if 
 you will, these pages be a primer a first lesson on 
 one of many processes ; yet, the object I have in view 
 is to put before those who require instruction on the 
 subject of photography, a pamphlet which shall en- 
 able them at once, not only to succeed, but, with a 
 little practice, to rival those who stand foremost as 
 the most successful votaries of this engaging art. 
 
 Now it would hardly do, from this preamble, to 
 descend suddenly to a process, without feeling sure 
 that the reader, who, perchance, may be altogether a 
 novice, has some knowledge of the principles on 
 which the art of photography is based ; a writer must 
 have no slight acquaintance with his subject who can 
 make a complex matter clear and intelligible to the 
 understanding of his reader by the use of a few 
 paragraphs only. I despair of doing this to my own 
 satisfaction, but, nevertheless, such an attempt has to 
 be made, and in making it my aim shall be rather to 
 excite the interest and attention of a student, so as 
 to compel him to turn for fuller information on the 
 various heads of the subject under notice, which may 
 
be found by making reference to works on optics and 
 chemistry. 
 
 The first question, what is light 1 ? naturally sug- 
 gests itself. In answer, this much is known: light 
 comes to us through the medium of our atmosphere, 
 pure and white, yet it is easily decomposed; its rays, 
 analyzed and divided by means of the prism, show 
 seven principal colors, each color has its own pro- 
 perty, and specifically its own chemical action ; it is 
 with this latter fact that we have to do, our whole 
 practice of photography depending on the actinism of 
 the violet color and the invisible rays beyond, as 
 shown by chemical experiment to exist in the spec- 
 trum ; the red and yellow rays at the opposite end, 
 although most luminous, affect only in a slight de- 
 gree, chemical bodies. It becomes, therefore, evident, 
 bearing this fact in mind, that photographic lenses 
 must be constructed, not possessing the power of 
 giving the most luminous and, consequently, the 
 jnost brilliant image only, on a ground-glass, placed 
 at a point termed the focus of a lens, but the visual 
 and chemical foci must be blended, so to speak; this, 
 the skilful optician effects by combining lenses of 
 various curves and densities, with a view of obtaining 
 at the same focus two distinct powers, light and 
 actinism, each, under ordinary conditions, being re- 
 fracted at different distances. I need only remark 
 that the problem has been well and satisfactorily 
 worked out by our great opticians, who have also 
 given to photographers a variety of useful combina- 
 tions of lenses, not dreamt of in the earlier days of 
 their art. 
 
 I have shown already that light produces chemi- 
 
cal change in bodies, but before proceeding with my 
 explanation in this direction, as the picture to be 
 formed is a monochrome made up of light and shade 
 only, it will be as well to feel sure that the novice 
 clearly understands what would be the effect of 
 throwing a shadow by any means whatever on to a 
 piece of white paper, prepared in such a manner as 
 to be visibly affected by exposure to diffused light, or 
 to the sun's rays ; the effect of course will be to pro- 
 duce a modification of the action of light on the 
 parts so shaded, and in proportion to the intensity of 
 the shadow, so will be the want of intensity in the 
 action of light on the prepared paper. Now, in 
 order fully to realize this in a manner evident to the 
 senses, we must make use of paper, prepared with 
 chloride of silver in the dark; the albumenized paper 
 of commerce, when floated on a solution of nitrate of 
 silver, becomes such a paper ; it must be then care- 
 fully dried either in the dark or in yellow light; a 
 slip of this paper exposed to white light, eithe^ 
 natural or artificial, immediately changes color, the 
 silver being reduced, and according to the time of 
 exposure so will be the intensity of the color, chang- 
 ing from light brown to bronze. 
 
 I have before stated that the shadow of any object 
 thrown upon this paper during its exposure to light, 
 will, according to its intensity, protect the prepared 
 surface, and should the hand, with its fingers extended 
 and held between the paper and the source of light, 
 be the object chosen, a representation of the form of 
 the fingers on the sensitive paper will be the result. 
 In this we find the key to the formation of a photo- 
 graphic picture ; bearing it in mind, it is easy to 
 understand that which follows. Now the lens and 
 
camera are the instruments used by the photographer 
 for the production of the image of any object capable 
 of being represented by light and shade. It is, I 
 think, fair to presume that a person wishing to follow 
 the art of photography will have acquainted himself 
 with at least this fact, that a lens fitted to the outside 
 of a dark box, so arranged that one part shall slide 
 within the other, does, at a certain point called a 
 focus, which varies with the distance of the lens from 
 the object, produce a representation on a ground-glass 
 of any object at which the lens may be pointed. If 
 the ground-glass be made movable, and a slide with 
 a shutter properly arranged, containing a plate sen- 
 sitive to light, be made to occupy exactly the same 
 position as that occupied by the ground-glass, it 
 follows that a representation of the object will fall 
 upon the sensitive plate placed as described. This is 
 the first step in the process by which photographic 
 views, portraits, &c., are produced. I will now pro- 
 ceed to speak of the chemicals used for preparing the 
 plate that has been, as above shown, placed in the 
 slide occupying the position of the ground-glass. I 
 must, however, pause for a moment to explain some 
 distinct properties possessed by different chemical 
 preparations sensitive to light. I have already shown 
 how chloride of silver is affected, the change which 
 takes place being visible, and, so to speak, accumu- 
 lative : this change is, however, slow, and cannot be 
 accelerated or developed to any further extent when 
 the light has been withdrawn. It is, therefore, evi- 
 dent that such a process, although excellent for the 
 production of the positive photograph on paper, is 
 not suited for the preparation of a highly sensitive 
 
8 
 
 plate to be placed in the camera for the purpose of 
 portraiture. We find in the iodide and bromide of 
 silver a peculiar property, viz., that of receiving an 
 impression rapidly, which, although at first invisible, 
 is capable of being further developed and intensified. 
 It is with these chemicals that the sensitive plate is 
 prepared. The most convenient vehicle for holding 
 the salts in solution, capable of being easily trans- 
 formed into the iodide and bromide of silver, is collo- 
 dion, to which I must now allude briefly. 
 
 Collodion is a solution of pyroxyline (gun-cotton) 
 in ether and alcohol, which, when poured upon glass, 
 sets readily, leaving a film, structureless, trans- 
 parent, and porous; it, moreover, adheres perfectly 
 to the glass. If a solution containing a salt of iodine 
 and bromine be added to a solution of nitrate of silver, 
 a precipitate of iodide and bromide of silver imme- 
 diately takes place ; it can, therefore, be easily under- 
 stood, that if the same salts be dissolved in collodion, 
 and the film, when properly set on the glass, placed 
 in a bath of nitrate of silver, the insoluble salts, iodide 
 and bromide of silver, are formed and retained in the 
 body of the film, rendering that which was trans- 
 parent, opaque and yellow. Such a film is more 
 sensitive to light than any with which we are ac- 
 quainted; a glass prepared with this sensitive film 
 may therefore be, in the wet state, at once transferred 
 to the dark slide and placed in the camera, where it 
 occupies the position of the ground-glass; the lens 
 being uncovered, a few seconds' exposure is sufficient 
 to impress this highly sensitive plate with an invisi- 
 ble image. 
 
 At this stage it will be instructive to explain what 
 
takes place when certain solutions are made use of for 
 the purpose of developing the latent image with which 
 the film has been impressed; and bearing in mind 
 what has been said in the first part of this essay con- 
 cerning the non-actinic quality of yellow light, it will^ 
 be hardly necessary to remark, that the preparation of 
 the sensitive plate and its subsequent development, 
 must be performed by light passed through a yellow 
 medium, such as glass stained of a proper color. 
 
 Proto-sulphate of iron is the deoxidizer now gene- 
 rally used for continuing that change which has been 
 effected on the plate in the camera by light. On 
 applying a solution of this salt, the image is seen to 
 develop, and precisely in proportion to the light re- 
 flected from the various parts of the object copied, so 
 will be the intensity or blackness of the parts of the 
 plate thus acted upon. This first picture is termed a 
 negative, the lights and shades, as seen in nature, 
 being in it reversed; for instance, the sky of a land- 
 scape, as reflecting most light, would be black, and 
 the dark-shaded parts of trees would be represented 
 on the plate as parts much less opaque, shading off to 
 a point at which the glass has been entirely protected 
 by the deep shade of foliage; or a portrait may be 
 taken as another illustration; in this case, the face 
 would be more or less dark, the white shirt black, 
 and dark clothes more or less light in the negative. 
 
 Now the development of this image, as I have 
 shown, must take place in yellow light; it is evident, 
 therefore, that all sensitive salts should be removed 
 before viewing it by daylight, and thus the further 
 action of white light is arrested. For this purpose 
 it is only necessary to wash off the developing solu- 
 
10 
 
 tions with water, and act upon the iodides and bro- 
 mides by means of any solvent capable of removing 
 these salts from the film ; the cyanide of potassium 
 performs this operation effectually; and, lastly, when 
 ( the excess of cyanide has in its turn been removed by 
 washing with water, the negative picture is completed, 
 and may now be dried and varnished. When viewed 
 by transmitted light, a perfect representation of the 
 subject is seen, the lights and shades being reversed. 
 Such a picture, although highly interesting, and beau- 
 tiful in the extreme, would be considered useless as a 
 work of art; moreover it is upon glass, consequently 
 liable to injury. It is at this stage, therefore, that we 
 avail ourselves of the paper process before alluded to, 
 and the advantage of such a process for the produc- 
 tion of the prints, or positive pictures, as they are 
 called, is at once apparent. 
 
 The negative picture thus produced may be looked 
 upon as a matrix for the production of any number 
 of positives, the process is most simple, and if the 
 reader comprehends that which has been already 
 written, it becomes evident that light passing through 
 the negative on to a sensitive paper, prepared as be- 
 fore described, will be admitted or intercepted in pro- 
 portion to the resistance offered to its passage by the 
 opaque or shaded parts of the negative, and the re- 
 sulting positive on paper will be consequently the 
 reverse of that on glass, the lights and shades being 
 found now to occupy their correct positions. This 
 end is brought about by merely placing the face of 
 the negative in close contact with the surface of the 
 sensitive paper, subjecting both to very slight pres- 
 sure in a suitable frame, sufficient to prevent shifting 
 
11 
 
 and to insure perfect and equal contact; they are now 
 exposed, so placed, to the action of light for the proper 
 time, this being ascertained by an occasional exami- 
 nation of the print during exposure. 
 
 As in the completion of a negative picture, the 
 superfluous sensitive salts must be washed out; an 
 agreeable tone is then imparted to the proof by 
 immersion in a solution of chloride of gold, and the 
 excess of chloride of silver removed by means of a 
 proper solvent (hyposulphite of soda); the print is 
 then freely washed in water, dried, and mounted. 
 
 The finished photograph is a marvel of science ; it 
 calls forth the admiration even of him who is little 
 skilled in the technicalities of art, appealing as it does 
 to a new sensation, that vibrates with a strange plea- 
 sure on viewing for the first time, a picture having 
 reality in the perfection of its light and shade, the 
 gradations produced being so delicate and subtle, as 
 to set at defiance both the painter's brush and the 
 graver's tool. In this consist the charm, the perfec- 
 tion, and the individuality of photographic art. 
 
HOW TO MAKE THE NEGATIVE, 
 
 USING 
 
 COLLODION BROMO-IODIZED 
 
 FOR 
 
 IRON DEVELOPMENT. 
 
 1. THE edges of the glass should be ground all 
 round, also slightly on the surface of the edges; this 
 prevents contraction of the film, enabling it to resist 
 the action of a heavy stream of water; mark one side 
 in the corner with a diamond, and upon this side be- 
 stow the greatest care. 
 
 2. To CLEAN THE GLASS IF NEW. Make a mix- 
 ture of Spirits of wine and Solution of Ammonia, 
 equal parts : render it as thick as cream with Tripoli ; 
 with a piece of cotton-wool kept for this purpose rub 
 a small quantity over that side marked as described, 
 wash well under a tap of water, and wipe dry with a 
 piece of old linen, washed without soap, and kept 
 scrupulously clean for this purpose. Plates should 
 not, however, be cleaned in the operating room with 
 the above mixture; the vapor of ammonia might 
 prove injurious to the chemicals. Vide also my paper 
 on cleaning the plate. 
 
13 
 
 3. Now polish with an old white silk handker- 
 chief; if this latter precaution be not taken, small 
 particles of linen will be left upon the plate ; these 
 are perhaps only seen when draining off the collodion, 
 they form nuclei and eddies, checking the collodion 
 in its course; some of these minute fibres are washed 
 off and contaminate the next picture. To all lovers 
 of clean pictures my advice, therefore, is, having well 
 dried the plate with old linen, lay it, clean side up- 
 wards, upon a few sheets of common glazed demy 
 paper (not blotting), and rub it hard with the silk 
 until sensibly warm ; this has the double advantage 
 of dispersing fibres and moisture, for all glass plates 
 are slightly in a hygrometric condition. Double the 
 silk rubber up to form a pad, and with this the glass 
 must be firmly dusted down just before pouring on the 
 collodion, which will then run most evenly ; if the 
 coated plate is now viewed by transmitted light not a 
 speck or blemish will be seen upon it. When a plate, 
 cleaned as above described, is breathed upon, the 
 moisture does not evaporate slowly, but flies off. Do 
 not be afraid of putting the glass into an electrical 
 condition with the silk rubber; on this account objec- 
 tions have been raised to the use of silk ; practically, 
 however, I find it a most valuable auxiliary in this 
 starting point of the process, the perfect manipulation 
 of which makes an important difference in the value 
 of the finished picture. What can be more unartistic 
 and annoying to an educated eye than spots, patches, 
 stars, and sky rockets, the forms and shapes of which 
 rival, in numberless variety, a display of fireworks ] 
 Let us not, therefore, be contented with pictures, how- 
 ever good in other respects, presenting these deformi- 
 ties so many blots on the photographic escutcheon. 
 
14 
 
 N. B. To CLEAN A GLASS AFTER HAYING USED IT, 
 WHEN NOT VARNISHED. Wash off the collodion film 
 with water, then clean the marked side with plain 
 Tripoli and water, and dry as above. 
 
 To COAT THE PLATE. First remove all lU^particles 
 of dried collodion from the mouth of the b(^Je. Now 
 pour upon the centre of the cleaned glass as much 
 collodion as it will hold ; do not perform this opera- 
 tion hurriedly, take time, and systematically incline 
 the plate in such a manner that the collodion may run 
 into each corner in succession; when perfectly cov- 
 ered, pour off gently the excess into the bottle at one 
 of the corners nearest to you; with observation and 
 practice, dexterity is easily acquired. There are 
 many ways of coating the plate ; each person will 
 adopt that which practice teaches him is best. The 
 pneumatic plate holder is a convenient little instru- 
 ment to use for holding the plate whilst pouring on 
 the collodion ; it may be used for both small and large 
 plates. 
 
 N.B. Keep the corner of the glass plate in contact 
 with the neck of the bottle whilst pouring off the 
 collodion, otherwise the film will be wavy in places. 
 
 4. As soon as the collodion ceases to run, plunge 
 the prepared glass gently without stopping into the 
 Nitrate of Silver Bath. Vide instructions for making 
 the Nitrate of Silver Bath. 
 
 5. Allow the prepared glass to remain in this bath 
 from five to ten minutes, according to the tempera- 
 ture. Move it up and down three or four times, 
 whilst in the bath, in order to get rid of the greasy 
 appearance on the surface; drain it, but not too 
 closely; when in the frame, place upon the back a 
 
15 
 
 piece of common blotting-paper to absorb moisture ; 
 the two lower silver wires should be covered with 
 slips of blotting paper; the sooner it is placed in the 
 camera the better. 
 
 6. The time of exposure can only be ascertained 
 by practice no rules can be laid down and I am 
 unacquainted with any royal road, but that of ex- 
 perience, leading to constant success in this most im- 
 portant point. 
 
 7. The plate having been taken from the camera, 
 and placed upon a levelled stand, or held in the hand, 
 develop immediately the latent image with the fol- 
 lowing solution: 
 
 IRON DEVELOPING SOLUTION. 
 
 Protosulphate of Iron . i oz. 
 
 Glacial Acetic Acid . . i " 
 
 Spirits of Wine . . . \ " 
 
 Distilled Water . . . 8 " Mix. 
 
 Pour on of this solution only enough to cover the 
 plate easily, commencing at that edge of the negative 
 which stood uppermost in the camera, move the solu- 
 tion to and fro until it has become intimately mixed 
 with the silver on the plate, then pour off into the 
 developing glass, and at once return it on to the plate ; 
 when as much intensity has been obtained as possible 
 with the iron developer, it should be thoroughly re- 
 moved by washing with water; any intensity may be 
 obtained afterwards by using either of the following 
 solutions: 
 
16 
 
 INTENSIFYING SOLUTION. 
 
 Pyrogallic Acid ... 6 grs. 
 Glacial Acetic Acid . . i oz. 
 Distilled Water ... 6 ozs. Mix. 
 
 A few drops of a 30-gr. solution of Nitrate of Silver, 
 the quantity to be regulated according to the in- 
 tensity required, to be added, afc the moment of using, 
 to as much of the Pyrogallic Solution as may be 
 necessary. 
 
 INTENSIFYING SOLUTION. (Another Form.) 
 
 No. 1. 
 Pyrogallic Acid ... 8 grs. 
 
 Citric Acid 20 " 
 
 Distilled Water ... 2 ozs. 
 
 No. 2. 
 
 Nitrate of Silver ... 8 grs. 
 Distilled Water ... 2 ozs. 
 
 Mix small quantities of the solutions Nos. 1 and 2 in 
 equal portions, the moment before using. 
 
 The pyrogallic solution, made with good acetic 
 acid, may be kept for a month or more in a cool 
 place. Nevertheless, if the conditions of light and 
 situation are unfavorable, I should prefer this solu- 
 tion just made. The iron solutions act best when 
 freshly prepared. 
 
 It is supposed by some that a prolonged action of 
 the iron developer produces fogginess ; this may be 
 the case when impure or improperly prepared collo- 
 dion is used, but certainly not when this preparation 
 is pure and of the proper quality. 
 
17 
 
 Some operators are in the habit of flushing the 
 plate with the iron solution, causing it to run off and 
 carry with it all the silver on the plate. This prac- 
 tice cannot be too strongly condemned. A protest 
 against it by a writer in the "American Journal of 
 Photography," is made in such forcible language, that 
 I give it in his own words, at the same time adding, 
 as the result of my own observations, that no amount 
 of silver used afterwards, compensates for the loss of 
 that, which has been carelessly washed off by dashing 
 on the developer. The silver retained on the plate, 
 and present during the action of light upon it in the 
 camera, imparts a peculiar quality to the developed 
 picture. The writer referred to above, says: 
 
 "The reckless style of manipulation seems to me 
 to be the origin of a vicious style of developing, which 
 with many has become a habit, and a practice which 
 is sometimes defended. I allude, to the dashing on 
 the developer, and deluging the plate with it. Did 
 it ever occur to those who develop in this way, that 
 the developer was needed on the plate and not in the 
 sink'? that the silver which might have assisted to 
 strengthen an image is swept away beyond reach 1 
 In my opinion, about half the re-developments and 
 strengthenings might be omitted, except for this 
 washing away of the life of pictures. 
 
 "The rule ought to be in treating a plate, not to 
 spill a drop of collodion, developer, or fixing.' Some 
 may fear fogging, or over development, by following 
 such a system. But let such try the plan thought- 
 fully, and they will find their fears are groundless. 
 Let them recall their ordinary rules, and the seeming 
 difficulties vanish. If the developer is too active, add 
 acid, or dilute. 
 2 
 
18 
 
 /- 
 
 "The chief item in my receipt for intense negatives 
 is, Do not spill the developer." 
 
 I have heard it remarked by excellent operators, 
 that unless the plate be flooded in the way described, 
 the negative would be stained all over; such an evil 
 can only be due to the imperfect quality v of the collo- 
 dion used, and my advice is, under such circum- 
 stances, to let it go the way of all worthless rubbish. 
 
 8. When the image is sufficiently intense, wash 
 freely with common filtered water; then pour on a 
 saturated solution of Hyposulphite of Soda, which 
 should immediately remove the iodide of silver: wash 
 again well with water; allow as much as the plate 
 will hold to soak in for at least a quarter of an hour, 
 changing the water occasionally, to remove all traces 
 of hyposulphite ; lastly, wash the plate with a little 
 distilled water, stand up to dry, and if required, var- 
 nish either with spirit or amber varnish. 
 
 The following solution is also very commonly used 
 for fixing the negative: 
 
 Cyanide of Potassium . . i oz. 
 Water 12 ozs. 
 
REMARKS ON THE USE 
 
 OF 
 
 COLLODION IODIZED 
 
 FOR 
 
 PYROGALLIC DEVELOPMENT 
 
 THE collodion for use with pyrogallic acid only, as 
 the developer, is iodized, either with iodide of cad- 
 mium or iodide of potassium, but whatever iodide be 
 used, no salt of bromine should be added to the col- 
 lodion. 
 
 Formerly this was the only preparation used by 
 photographers for the production of negatives, but 
 now it has been superseded by the bromo-iodized 
 collodion for iron development. Considerable inten- 
 sity is easily obtained with this preparation ; there 
 is, however, always a danger of producing negatives 
 too black and white, the contrasts being too violent ; 
 it is, however, still employed by some most skilful 
 photographers, both professional and amateur. The 
 question is often asked, Which collodion do you 
 recommend for general use I It will be best answered 
 by giving a description of the properties of both a 
 plain iodized collodion and one containing a bromide: 
 the operator can then select for himself. 
 
20 
 
 PLAIN IODIZED COLLODION. 
 
 Properties briefly stated : 
 
 1. Its special fitness for use with a pyrogallic 
 acid developer, with which the maximum of intensity 
 is obtainable. 
 
 2. Its suitability also for use with an iron de- 
 veloper, with which a little more detail is obtained, 
 and a modification of the intensity of the image. 
 
 BROMO-IODIZED COLLODION. 
 
 The characters of a Bromo-Iodized Collodion are 
 marked and well-defined ; they may be briefly 
 stated : 
 
 1. Its special fitness for use with an iron de- 
 veloper, giving the maximum amount of half-tone 
 obtainable. 
 
 2. A decided decrease in the intensity of the 
 image. 
 
 3. A peculiar property of resisting solarization 
 of those parts of the image strongly lighted, which 
 enables the operator to expose his plate long enough 
 to bring out details in deep shadow, without impair- 
 ing the definition of those portions of the picture, 
 first impressed on the plate. 
 
 It will be at once gathered from these remarks 
 that a Bromo-Iodized Collodion gives the utmost 
 amount of half-tone obtainable, when used with an 
 iron developer. There is still a difference of opinion 
 
2L 
 
 among photographers as to the value of the two pre- 
 parations ; some prefer a plain Iodized Collodion, 
 with an iron or pyrogallic developer, whilst the 
 majority always use a Bromo-Iodized Collodion. I 
 myself think that the latter preparation is decidedly 
 best adapted for the production of that class of 
 pictures, now generally considered to be the most 
 pleasing and artistic. Bearing, however, in mind 
 the character of each preparation, it is better to be 
 provided with plain Iodized Collodion, which can be 
 mixed in suitable proportions with that Bromo- 
 Iodized, for the purpose of modifying the results. 
 
 It is only necessary to give the formula for Pyro- 
 gallic Acid developer, for the method of working and 
 rules to be observed are precisely the same as those 
 described in the preceding chapter. 
 
 PYROGALLIC SOLUTION. 
 
 Pyrogallic Acid ... 6 grains. 
 
 Glacial Acetic Acid . . ^ oz. 
 
 Distilled Water ... 6 ozs. Mix. 
 
 In cases where it is desirable to add to the in- 
 tensity of the negative, a few drops of a 30-grain 
 solution of Nitrate of Silver may be mixed with the 
 developing liquid towards the end of the develop- 
 ment. 
 
 The Collodion Iodized with Cadmium retains its 
 sensitiveness without change for years. The Collo- 
 dion Iodized with Potassium undergoes a slow change 
 when kept for some time Iodized ; this property is 
 much esteemed by professional photographers who 
 require Collodion in various conditions of sensitive- 
 ness and intensity. 
 
22 
 
 ATTENTION TO THE FOLLOWING RULES 
 AND CAUTIONS WILL ASSIST THE 
 OPERATOR IN THE PRODUCTION OF 
 PERFECT PICTURES. 
 
 1. Do not disturb the deposit which will occa- 
 sionally be found at the bottom of the bottle con- 
 taining the Collodion. 
 
 2. Remove all particles of dried film from the 
 neck of the bottle before pouring Ihe Collodion on 
 the plate. 
 
 3. Never use damp clothes, leathers, or buffs, for 
 giving the final polish to the plate ; negatives with 
 an indistinct and muddy surface are frequently pro- 
 duced from this cause. 
 
 4. Let the film set properly before immersion in 
 the Nitrate of Silver Bath; its condition can be 
 ascertained by gently touching the lower part of the 
 coated plate with the end of the finger. 
 
 5. Never omit to pass a broad camel-hair brush 
 over the plate just before pouring on the Collodion. 
 
 6. Bear in mind that, as light is the producing 
 agent, so will it prove a destructive one ; not less 
 than four folds of yellow calico should be used to 
 obstruct white light ; and in that case the aperture 
 covered should be no larger than is necessary to 
 admit sufficient light for working by. Examine oc- 
 casionally the yellow calico; when this material is 
 used to exclude white light, it becomes bleached by 
 constant exposure. Do not trust alone to any colored 
 
glass ; no glass yet made is adi-actinic under all as- 
 pects of light and conditions of exposure. 
 
 7. When the negative requires intensifying, care- 
 fully wash off all traces of the first developing solu- 
 tion before proceeding to intensify. This operation 
 may be performed either before or after the Iodide is 
 removed by fixing. 
 
 8. Glass Baths are preferable to Porcelain, Ebon- 
 ite, or Gutta-Percha Baths for solution of Nitrate of 
 Silver. 
 
 9. In using either Spirit or Amber Varnish, be- 
 fore pouring it off, keep the plate horizontal a few 
 seconds this gives time for soaking in, and prevents 
 the formation of a dull surface arising from too thin 
 a coating. 
 
 10. Rub the lenses occasionally with a soft and 
 clean wash leather ; the rapidity of action is much 
 influenced by the brightness of the lenses: their 
 surfaces are constantly affected by moisture in the 
 atmosphere, which, condensing, destroys the bril- 
 liancy of the image. 
 
 11. The white blotting-paper used for some pho- 
 tographic purposes is not suitable for filtering solu- 
 tions ; that only should be employed which is made 
 for this purpose, and is sold under the name of filter- 
 ing-paper. 
 
 12. HYPOSULPHITE OF SODA. A great deal of rub- 
 bish is sold under the name of this salt ; as a test of 
 its quality, li drachms should entirely dissolve in 
 one drachm of water, and this solution should dissolve 
 rather more than 4i grains of Iodide of Silver. 
 
 13. CHEMICALS. The purity of photographic 
 chemicals cannot be too strongly urged the cheapest 
 are not always the most economical. The commercial 
 
24 
 
 preparations are generally not to be depended upon, 
 as these, though perhaps unadulterated, are, strictly 
 speaking, not chemically pure. It is best to procure 
 them from well-known chemists, who understand the 
 purpose for which they are intended, and make the 
 preparation of these substances peculiarly a branch of 
 their business. 
 
 14. Never leave chemical solutions exposed in 
 dishes ; when done with, pour them back into glass- 
 stoppered bottles and decant for use from any deposit, 
 or filter if necessary. 
 
 15. In all photographic processes it is absolutely 
 necessary to be chemically clean ; and this sometimes 
 is not easy : as a rule, never be satisfied with cleanly 
 appearances only, but take such measures as shall 
 insure the absence of all the extraneous matter in pre- 
 paring the solutions, cleaning the glasses, dishes, c. 
 
 16. All stains on the hands, linen, &c., may be 
 removed by means of Cyanogen Soap or Cyanide of 
 Potassium, which should be applied without water at 
 first, then thoroughly washed off. To assist the 
 operation, the hands may be now gently rubbed with 
 a fine piece of purnice-stone, when the stains quickly 
 disappear. 
 
'-'5 
 
 NOTES. 
 
 1'. WHEN working with a double lens in the open 
 air, or in situations where there is much light, the 
 full aperture of the lens being used, it is necessary to 
 provide against the action of diffused general light 
 which, under these circumstances, enters the lens, 
 destroying the brilliancy and intensity of the image 
 in fact, acts chemically over the plate ; thus giving 
 a muddy, flat, or otherwise imperfect picture an 
 appearance corresponding to the fog produced by 
 some collodions. This general action of diffused 
 light, during the exposure of the plate in the camera, 
 interferes subsequently with a prolonged or even 
 necessary development. My attention was drawn 
 more particularly to this fact, from the circumstance 
 of having to make alterations in my glass room for 
 the purpose of obtaining twice the amount of light ; 
 when completed, I was quite unable to take a picture, 
 simply because the extra light introduced, although 
 a north light, interfered with the darkness necessary 
 for the production of clean and vigorous pictures in 
 the camera. The remedy for this is simple : I screw 
 on to the front of my camera a sliding dark box, 
 open at the end. I can, by this means, regulate the 
 amount of protection according to circumstances, viz.? 
 from twelve to twenty-four inches ; brilliant and 
 intense negatives are thus obtained. Now remove 
 the protector, and the reverse is evident ; the picture 
 is flat, faint, shows a want of detail and a general 
 tendency to blacken over under the influence of the 
 
26 
 
 developer. It is obvious that this arrangement is 
 more particularly useful when double lenses with 
 large aperture are used. 
 
 2. Under all circumstances, throw a large black 
 cloth over the slide when placed in position, and if 
 the camera has a sliding front, let the black cloth 
 hang a few inches over the front of the camera, 
 before drawing up the shutter; now put the left 
 hand underneath the cloth, place this on the top of 
 the slide to keep it in place, and with the right hand 
 outside feel for the leather tongue ; pull up the cloth 
 and shutter together ; the cloth should not be re- 
 moved until the slide has again been closed ; this 
 sufficiently indicates the necessity for preventing 
 ever so slight a ray of light attacking the plate 
 during the exposure. First-rate pictures cannot be 
 obtained in the open air, unless this precaution be 
 taken. 
 
 3. Use as little light as possible in the dark 
 room ; the quantity must be regulated by the aspect 
 of the window through which the yellow light is 
 admitted. A candle would entirely spoil a collodion 
 plate, unless protected by means of a yellow calico 
 shade. 
 
 4. Condition of collodion best suited for different 
 purposes : For portraiture with a double lens, mix 
 the collodion twelve or twenty-four hours before it is 
 required for use ; the picture thus obtained is more 
 intense than when collodion recently mixed is used. 
 For works of art and still objects, &c., collodion a 
 week old is best; and for landscapes, a greater 
 general intensity and sufficient rapidity of action are 
 obtained, when the collodion has been mixed a 
 fortnight. For black and white objects, i. e., engrav- 
 ings, &c., use collodion a month old. 
 
21 
 
 5. Collodion in hot weather may become too 
 thick to use conveniently ; it should then be slightly 
 diluted with a mixture made of two parts of ether 
 and one part of absolute alcohol of known purity, 
 and well shaken. 
 
 6. THE CAMERA DESCRIBED. A good and well- 
 made camera is more or less useful in proportion to 
 the skill bestowed on its construction. The best 
 seasoned wood and most accurate measurements are 
 necessary ; moreover, every part must be easily under 
 command. A camera should be made on the most 
 simple principles ; all unnecessary complication of 
 screws and joints avoided. Let strength, simplicity ', 
 and correct workmanship be the primary considera- 
 tion. For the collodion process, I prefer a plain 
 sliding trunk camera, half the bottom board hinged 
 to turn up thus forming a box in which to pack and 
 carry some of the necessary apparatus, and a stout 
 handle screwed to the top. The camera should also 
 have a sliding front, by means of which the lens is 
 made to move vertically, for the purpose of cutting 
 off foreground an arrangement at times desirable 
 when other portions of the picture are of more im- 
 portance. The piece of ground-glass upon which 
 the image falls must be finely ground plate ; and if 
 an upset or smash occurs, take care, in replacing, that 
 the ground side faces the inside of the camera. 
 Double slides are most convenient for the dry plate 
 processes ; these slides are hinged and open in the 
 centre ; the sensitive plates are then placed face 
 downwards, and shut up back to back, with two 
 pieces of blotting-paper or a diaphragm between 
 them. The slide for wet collodion is, of course, con- 
 structed on a different principle ; it contains a frame 
 to hold the collodionized glass, which rests upon 
 
28 
 
 * 
 
 silver wires inserted diagonally at each corner ; the 
 loose frame is hollowed out to prevent the wood com- 
 ing in contact with the wet silvered plate. A very 
 slight imperfection in the collodion slide, sufficient to 
 admit* an infinitesimal ray of light, would have a 
 damaging effect upon the beauty and perfection of 
 the negative picture. 
 
 Expanding or bellows cameras are now excellently 
 constructed ; they are very light and rigid ; the focus 
 can be obtained with great precision and ease by 
 means of a screw movement. 
 
 THE LENS. GENERAL REMARKS. It is a mistaken 
 economy to purchase cheap and inferior lenses : if 
 photography be worth doing at all, it is certainly 
 worth while to do it well. A good lens is the photo- 
 grapher's sine qua non. The double combination is 
 used for portraits, and in all cases where great rapidity 
 of action is desirable. These lenses do not cover a 
 large surface, but the size of the picture may be in- 
 creased, if the time of exposure is immaterial, by 
 making use of smaller stops, even to the size of half 
 an inch in diameter. At times, such an arrangement 
 with the double lens is useful. A lens which covers 
 six by five inches can thus be made to give a picture 
 sharp to the edges eight by six inches, or even more. 
 Reduced copies of oil paintings are advantageously 
 made with a double lens and small stop. 
 
 The triplet lens is now used for landscapes, and 
 copying still objects and works of art generally. It 
 is furnished with different stops ; when the object to 
 be taken is well lighted, the smallest may be em- 
 ployed ; but for masses of dark foliage, &c., the 
 larger stop should be made use of. A little observa- 
 tion and exercise of judgment will soon determine 
 
29 
 
 the operator in the use of his stops. The rack and 
 pinion movement to the portrait lens is desirable, as 
 it can be readily reached with the hand, for the pur- 
 pose of getting the sharpest focus. I consider that 
 this addition to the landscape lens is unnecessary, 
 owing to its greater focal length, which makes the 
 rack and pinion movement inconvenient to use. A 
 perfect focus can always be obtained with a well-made 
 sliding camera. Portraits and groups can also be 
 taken in the open air with the triplet, in a good light. 
 
 It may not be out of place to conclude with a few 
 general remarks worthy of consideration when abso- 
 lutely perfect negatives are desired: The sliding 
 body of the camera should undoubtedly be lined with 
 black cotton or silk velvet. I prefer the latter, the 
 black dye of silk being more permanent. Landscape 
 lenses, under very many circumstances, should be 
 protected as much as possible from reflected light, 
 entering the tube of brasswork, by means of a shade 
 over the upper portion of the tube ; this helps to 
 prevent solarization of the sky. The shade need not 
 project beyond four inches ; a piece of brown paper 
 and string answer the purpose. 
 
 To prove the necessity for this precaution, focus a 
 landscape, withdraw the ground-glass, throw r the vel- 
 vet over your head, and look into the camera. A 
 considerable quantity of light will be perceived on 
 the lower surface of the lens tube ; place a shade 
 over the upper portion of the tube, and the extraneous 
 light will vanish. All rays of light that do not actu- 
 ally emanate from the object to be copied ought to be 
 dispensed with, when brilliancy of image is aimed at. 
 It cannot be too frequently urged that the velvet cloth 
 must be thrown over the slide when in position, be- 
 fore pulling up the shutter ; and also that this should 
 
30 
 
 be large enough to extend somewhat over the rigid 
 portion of the camera, in order to prevent light en- 
 tering the sliding body. 
 
 I would remark, in conclusion, that experiments 
 with ordinary double lenses of short focal length are, 
 comparatively speaking, worthless for testing the 
 actual value of photographic preparations or pro- 
 cesses; the results obtained on small plates are also 
 not sufficiently conclusive. In order to arrive at a 
 full and satisfactory conclusion, when working either 
 for the purpose of chemical investigation in photog- 
 raphy, or with a view of establishing the value of any 
 process, plates not less than 10 by 8 inches should be 
 used, and a single lens of ordinary focal length, with 
 not more than half an inch aperture. I have for 
 some time past adopted this course, and have found 
 in every respect the indications more valuable and 
 instructive. 
 
 I would say to all who appreciate this art for its 
 great usefulness and numberless appliances, don't 
 be contented with any but the best results ; the 
 practised eye soon gets accustomed to detect flaws 
 and imperfections, arising in some instances from the 
 use of bad tools. The connoisseur in photographic 
 matters has now become fastidious, and ceases to ad- 
 mire a photograph for the interest attached to its 
 wonderful production; apart from this, in the ad- 
 vanced and perfected state of the art, correct drawing 
 and pleasing realizations of natural objects are looked 
 for; and surely we may expect, that after twenty 
 years and more of up-hill labor, this young giant of 
 science will stride rapidly onwards, destined, even 
 yet, to take a much higher position as ah important 
 and advancing art. 
 
31 
 
 ON THE PREPARATION 
 
 OP A . 
 
 NORMAL NITRATE OF SILVER BATH 
 
 THE quantity of nitric acid wrapped up in the 
 interstices of crystals of nitrate of silver varies very 
 much, and of course according to the degree of 
 acidity of the solution from which the crystals are 
 formed. My attention has been given to this sub- 
 ject ; during my investigations I have found a me- 
 thod of preparing a nitrate of silver bath in the 
 normal state. The process is as follows: It is as- 
 sumed that all crystals of nitrate of silver contain 
 more or less a small portion of nitric acid ; fusing, to 
 get rid of its presence, is a clumsy and objectionable 
 method, for it is difficult to fuse nitrate of silver, 
 even in very small quantities, with a view to per- 
 fectly driving off the free nitric acid (for which the 
 crystals have a great attraction), without producing a 
 new decomposition or contamination; the object, 
 therefore, is to render inert this free nitric acid. 
 The alkaline carbonates have been suggested: this 
 method, to my mind, is very objectionable; in the 
 first place, a new compound is introduced, carbonate 
 of silver; secondly, if too much of the alkali be added, 
 the strength of the silver bath is impaired; it is also 
 not unlikely that triple salts are formed. The most 
 simple, and therefore the best plan, and one which I 
 
32 
 
 find answers invariably, whether the bath be old or 
 new, is to add to the prepared silver bath a small 
 quantity of freshly precipitated oxide of silver; the 
 free nitric acid seizes upon this with avidity, and 
 forms at once nitrate of silver (nitrate of silver being 
 a nitrate of oxide of silver); it matters not whether 
 just sufficient of this oxide be added or a large ex- 
 cess; if the latter, the strength of the bath is not 
 impaired, the undissolved excess being simply left 
 upon the filter. Having treated the bath in this 
 way, it is in an alkaline state, and no picture can be 
 taken with it; fortunately, however, its condition is 
 perfectly normal, for the water which dissolves the 
 crystals of nitrate of silver, dissolves also a specific 
 and homoeopathic dose of the oxide used hence the 
 alkaline reaction. It now becomes a nice point to 
 act upon this atom of oxide with nitric acid: in the 
 first place, the excess of undissolved oxide of silver 
 must be separated by filtration, and to the bright 
 filtered solution add Iths of a minim of nitric acid, 
 sp. gr. 1.50 to 200 ozs. of the bath; this quantity is 
 sufficient to correct the alkalinity produced by the 
 presence of oxide of silver dissolved in the water of 
 the bath, and at once, as if by magic, a most perfect 
 picture can now be produced ; the sensitiveness of the 
 bath is insured by the known quantity (being minute) 
 of the acid added. 
 
 I consider that the presence of this acid, when it 
 can be so nicely calculated as now described, is far 
 less objectionable than the excess of acetic acid 
 sometimes used, this latter "being more volatile, and 
 the attraction for nitrate of silver not so strong. The 
 bath, when acetic acid is added to correct the oxide, 
 is liable to change from a possible liberation of this 
 
33 
 
 acid, due to a want of a powerful affinity for silver, 
 which it fails to possess ; whereas the nitric acid now 
 recommended, however small the quantity present, is 
 with difficulty got rid of. The object of this paper 
 is, therefore, to establish these facts: 1st. It is best 
 to employ fine and pure crystals of nitrate of silver 
 for preparing the bath; 2d. To get rid of the excess 
 of acid wrapped up in their interstices by adding to 
 the solution sufficient, or an excess of oxide of silver; 
 3d. That the bath so prepared is in a normal condi- 
 tion; 4th. To render it efficient and in working 
 order, Iths of a minim of nitric acid, sp. gr. 1.50, must 
 be added to every 200 ozs. of the filtered nitrate of 
 silver bath to neutralize the oxide dissolved by the 
 water; 5th. It is very evident that, having corrected 
 the nitrate of silver bath with the oxide, the undis- 
 solved excess must be filtered away before adding 
 the specified quantity of nitric acid ; 6th. I consider 
 that test-papers are not serviceable for indicating a 
 delicately balanced state of the nitrate of silver bath, 
 in which case a developed plate gives the best indi- 
 cation of its condition. I would not for a moment 
 be supposed to ignore the value of test-papers for 
 showing the presence of either acid or alkali when 
 present in a greater quantity than that now referred 
 to. 
 
 In this paper I make reference to nitric acid for 
 correcting, sp. gr. 1.50. Acid of this strength is fre- 
 quently met with in commerce ; my object, therefore, 
 in taking this acid as a standard of strength, is suffi- 
 ciently obvious; first, to show the exceedingly mi- 
 nute quantity necessary to produce the desired effect; 
 and secondly, for the convenience to be derived from 
 making reference to nitric acid of usual strength. It 
 3 
 
might, however, appear to many not desirous of 
 taking the trouble to calculate fractions of a drop, 
 that the correction required for 10 or 20 ozs. of the 
 bath must be attended with some trouble. In order 
 to meet this difficulty, I subjoin the following alkali 
 and acid formula: 
 
 THE ALKALI. 
 
 Oxide of silver in a moist state. 
 
 THE DILUTE ACID. 
 
 Nitric Acid 1.50 ... 6 minims. 
 Distilled Water . . V . 1 oz. 
 
 Treat the bath, as described, with the oxide of 
 silver ; filter from the excess, and add to each 20 ozs. 
 of this filtered bath, five minims of the dilute nitric 
 acid. 
 
35 
 
 F 1 O R M TJ L, 
 
 FOR THE PREPARATION OF THE 
 
 NITRATE OF SILVER BATH. 
 
 INTO a 20 oz. stoppered bottle put 
 Nitrate of Silver, 1 ounces, 
 Distilled Water, 4 ounces dissolve, 
 To this solution add 
 
 Iodide of Potassium, 4 grains, 
 Dissolved in 1 drachm of distilled water. 
 Mix these two solutions ; the precipitate (iodide of 
 silver) thus formed is, by shaking, entirely dissolved. 
 Add 16 ounces of distilled water, when the excess of 
 iodide of silver is again thrown down, but in such a 
 finely divided state as to render the saturation of 
 the bath with iodide of silver perfect. Now drop >in 
 sufficient of the oxide of silver to turn the turbid 
 yellow solution a dirty brown color ; so long as this 
 effect is produced the quantity of oxide of silver, how- 
 ever much in excess, is of no consequence; shake the 
 . bottle well for 10 minutes or so at intervals, then add 
 alcohol, 30 minims, and filter ; to the filtered solution 
 add dilute nitric acid of the strength stated, 5 minims. 
 The bath is now ready for use, and should be quite 
 neutral. 
 
 NOTE. The above formula has been given for the 
 convenience and instruction of those who may have 
 
36 
 
 to obtain nitrate of silver that has not been specially 
 dried and freed from the excess of nitric acid for 
 photographic purposes ; but if the nitrate of silver be 
 pulverized and dried at 212, the free nitric acid 
 being thereby driven off, the oxide of silver and acid 
 may be omitted. 
 
 Formerly, when plain iodized collodion, potassium 
 or cadmium, was used only, in the bath, the oxide of 
 silver and acid could be employed with advantage, 
 at times, as a corrective ; but since the introduction 
 of salts of ammonium into collodion, giving rise to 
 the production, in the bath, of nitrate of ammonia, 
 which dissolves oxide of silver, forming with it a 
 triple compound, it has not been found desirable to 
 use this preparation as a doctor for a disordered 
 bath, the remedy in such a case being worse than 
 the disease. 
 
 Photographers now generally agree that it is better 
 to set aside a faulty bath rather than waste time in 
 vain attempts at doctoring; but I cannot refrain from 
 stating how, as I was informed, a perfect cure had 
 been effected by a genius, whose perseverance was 
 deserving of all praise, he having tried every known 
 and unknown process with which he was acquainted, 
 or found himself inspired with at the moment, at 
 last, dashed into the refractory solution a lump of 
 cyanide of potassium, an unknown quantity, and as a 
 last resource, added two drachms of the strongest 
 nitric acid to every pint of the solution!! This is 
 merely inserted as a caution, and should be remem- 
 bered as something to avoid : the perfect cure may 
 be a matter of opinion. 
 
37 
 
 OBSERVA.TIONS 
 
 IN REFERENCE TO THE STATE OF THE 
 
 NITRATE OF SILVER BATH, 
 
 AND ITS ACTION UPON 
 
 COLLODIONIZED PLATES. 
 
 THE ALKALINE NORMAL BATH, WHEN FILTERED 
 FROM EXCESS OF OXIDE. The plate when developed 
 has a grayish color, it is streaky, dirty, and greasy 
 in appearance ; the image shows through the film in 
 parts very faintly: i.e., it is only just discernible; the 
 developer flows over the plate very easily. 
 
 THE BATH, WITH AN INSUFFICIENT QUANTITY OF 
 NITRIC ACID AS A CORRECTIVE. The plate when de- 
 veloped gives at first, indications of a perfect pic- 
 ture, but with a suspicion of full exposure; the proper 
 and gradual growth of intensity does not, however, 
 take place ; the half-tints in deepest shadow are ren- 
 dered, and show simultaneously with the high lights; 
 a flat, poor, and feeble image is the result ; if the 
 subject be landscape, the sky is faint, transparent, and 
 streaky ; the exposure in the camera may have been 
 very short, and under this condition of the bath, per- 
 haps half the legitimate exposure gives the result 
 described. 
 
38 
 
 THE BATH, WITH A PROPER QUANTITY OF NITRIC 
 ACID AS A CORRECTIVE. The image springs out 
 shortly after the developer is poured on : first, of a 
 well defined metallic gray color, the highest lights 
 being from the first well defined ; the growth of 
 middle tints next becomes discernible ; the parts in 
 deepest shadow show next in rotation, the whole pic- 
 ture being evident before increase of intensity takes 
 place ; this now goes on gradually until an unmistak- 
 able harmony pervades the whole ; the brilliancy of 
 the picture is well preserved, and no sign of fogging 
 exists. If the exposure has been well timed, there is 
 not much fear of over-development. The intensity of 
 sky is good, and uniformly opaque : when viewed by 
 reflected light, the negative whilst wet presents a 
 soft and partly positive appearance ; when dry, this 
 image is more difficult to see, but it should not be 
 too clouded. 
 
 THE BATH, WITH AN EXCESS OF NITRIC ACID. 
 The image appears in parts of the plate only, and 
 that with great difficulty ; the black deposit is very 
 transparent ; it is altogether most evident that the 
 deoxidizer acts inefficiently, the decomposition of the 
 nitrate of silver being checked by the presence of 
 nitric acid in excess ; under these circumstances no 
 amount of exposure in the camera compensates for 
 acidity of the bath; the developer flows with difficulty 
 over the plate. 
 
 THE BATH UNDER SOME CIRCUMSTANCES REQUIRES 
 THE ADDITION OF AN ACID. The indications are, of 
 course, those stated in the second paragraph. In hot 
 weather it is very desirable to add a few drops of the 
 dilute acid to every half-gallon of the bath. I find, 
 also, that when testing and experimenting with collo- 
 
39 
 
 dion just iodized, after immersing a dozen plates, a 
 slight alkalinity is evident to an extent not abso- 
 lutely injurious but nevertheless discernible by a 
 falling off in brilliancy of the negative ; add a drop 
 of the dilute nitric acid, and all again goes well. No 
 alkalinity is discernible when collodion a day old is 
 employed. 
 
 NOTE. I find it convenient to use a dilute nitric 
 acid, the strength of which has been already given. 
 
40 
 
 DIRECTIONS 
 
 FOR 
 
 CLEANING THE GLASS PLATE. 
 
 IT is not at all an uncommon thing to hear that 
 collodion gives spots, stains, streaks, and sundry other 
 cutaneous affections to which "the children of the 
 sun" are said to be peculiarly liable ; very much, 
 however, is erroneously, attributed to the collodion, 
 which more properly and with greater justice, should 
 be ascribed to want of cleanliness and method in 
 cleaning the plate. Nothing is so easy ; and although 
 there are many ways of arriving at this very desirable 
 end, I unhesitatingly recommend the following as 
 most efficient, safe, and simple. Cleaning the plate 
 is of much greater consequence than some are pre- 
 pared to admit. Every photographer should make 
 himself thoroughly acquainted with this process ; 
 much time, expense, and subsequent labor will be 
 saved by a systematic attention to what may at first 
 be thought sheer drudgery, and which is too often 
 delegated to inexperienced and careless hands. I am 
 not saying too much when I state that, in point of 
 manipulation, cleaning the plate is the key to the 
 whole position. I now proceed to describe, for the 
 benefit of those who can fit up their operating-room 
 with conveniences, the plan I adopt. 
 
 I have a shallow sink, three inches deep, lined 
 
41 
 
 with lead, and a pipe to convey away the waste water 
 (the size of this sink must, of course, be regulated by 
 the size of the plates to be cleaned); it is firmly 
 mounted on a stand of convenient height, and securely 
 fixed to the wall of the room; in this sink I place 
 two blocks of deal (1| inch stuff) a little larger than 
 the plate, covered with thick felt strained over one 
 side of the block and nailed to the edges all round ; 
 over this, in the same manner, I strain white calico ; 
 the blocks are now prepared, and present a firm but 
 sufficiently soft surface, on which to cleanse the plates ; 
 place them in the sink and wedge up tight with loose 
 wedges. I use one of these blocks for the first ope- 
 ration. Place the plate to be cleaned in the centre 
 of the block, and pour on to it a small quantity of 
 the following mixture : 
 
 Prepared Tripoli .... 2 ozs. 
 
 Water 3i " 
 
 Spirits of Wine .... 4 " 
 Solution of Ammonia ... J " 
 
 Take a tuft of cotton-wool and rub the plate well 
 and firmly over with the above mixture for a minute 
 or so ; then remove the plate to block No. 2 (over 
 this I have fixed a tap of water, a few inches above 
 the plate) ; turn on a gentle stream and rub off the 
 tripoli mixture with a second tuft of cotton-wool. 
 Keep these tufts upon their respective blocks; they 
 are then always ready for use. Be very careful to rub 
 the edges of the glass with the tuft, to remove parti- 
 cles of tripoli which become attached to the rough- 
 ened edge, and which, if not removed, will give a 
 prolific crop of spots on the picture. Having washed 
 off the tripoli, plunge the plate into a deep dish of 
 
42 
 
 water, and there let it remain until six plates or more 
 have been in like manner cleaned ; then take each 
 out singly, again wiping the edges with a tuft of 
 cotton, and pass each plate through a dish of distilled 
 water. Do not set up more than six at a time to 
 drain; when six have been thus treated, commence 
 drying off the first set up. The plates must not be al- 
 lowed to become dry before rubbing with the cloths. 
 In order to dry them quickly and effectively, place 
 upon the table a piece of felt or ironing-blanket, over 
 which spread one of the cloths (washed in clean water 
 without soap); place the plate upon this, and rub 
 it well on both sides with another cloth doubled up so 
 as to form a pad. One side of this plate should be 
 marked with a diamond, and upon this marked side 
 the greatest care should be bestowed. The plates, so 
 far cleaned, may be stowed away in a box ; before use, 
 however, the final rub must be given, to remove all 
 superfluous moisture ; this is best effected by two 
 wash-leathers, previously purified by washing and 
 rinsing them freely in water, for two days or so ; they 
 must be allowed to dry spontaneously. Lay the plate 
 upon one of these leathers, and rub it well on both 
 sides with the other leather doubled up so as to form 
 a pad. Breathe occasionally upon the plate whilst 
 rubbing ; this tends to equalize the moisture. Rub, 
 lastly, with a well-washed silk handkerchief. Even 
 now, some small particles of fibre may be left from 
 the cloths, and these attach themselves very tena- 
 ciously to the glass; in order, therefore, to remove 
 these enemies to an absolutely pure plate free from 
 " comets/' I take a flat and broad camel-hair brush 
 two inches wide, and pass it firmly over the plate just 
 
43 
 
 before pouring on the collodion. This brush must be 
 most carefully prepared for the purpose, by soaking 
 it in water for two or three days, and rubbing out all 
 dust and extraneous matter with the fingers ; it must 
 then be suffered to dry spontaneously, and kept free 
 from dust in a card-board box ; if this cleansing be 
 neglected, more impurities will be added to the plate 
 than removed from it. 
 
 I have been at some pains to describe clearly a 
 systematic method of plate-cleaning, feeling certain 
 that the necessity for carefulness in this process is 
 not sufficiently attended to. I am sure that nearly 
 all " comets" and other abominations arise from the 
 imperfect removal of fluff and fibre from the plate. 
 These minute particles are not seen until draining off 
 the collodion : they then show themselves in the 
 form of nuclei, checking the collodion in its course, 
 and, what is very much to be avoided, they contami- 
 nate the collodion, which becomes full of floating par- 
 ticles, and thus prevents the possibility of getting 
 clean plates, until the collodion has again been 
 allowed to settle ; if, therefore, it is required to 
 make experiments only, without regard to the 
 purity of the result, keep a bottle of collodion for 
 this purpose. 
 
 When working at home with all the conveniences 
 described at hand, plates used (if the picture is not 
 approved of) may be at once placed in a dish of 
 water ; the film then floats off and carries with it all 
 impurities; rubbing with plain tripoli and water and 
 drying as described, will then be found sufficient. 
 New plates must always be put through the whole 
 process, and also those which have become dry with 
 films on. 
 
44 
 
 A perfectly clean glass shows little or no irregu- 
 larity on the surface when breathed upon, having 
 then, very much the appearance of ground glass, and 
 if properly dried, the moisture flies off rapidly. 
 Collodion flows easily and freely over a well-cleaned 
 ancl dry plate, presenting a surface free from irregu- 
 larities, either before or after the action of the nitrate 
 of silver bath. 
 
 The practice of cleaning glass plates with deter- 
 gents, said not to require subsequent washing, is one 
 fraught with great risk and full of objection ; it is 
 impossible to get rid of fixed alkalies or salts by mere 
 friction with a cloth without washing. I allude to 
 this method of cleaning (?) because I know that it 
 has been a cause of much trouble to many who have 
 for a time adopted the plan ; moreover, it is by such 
 a process impossible to remove the tripoli from the 
 ground edges of the glass. 
 
 
45 
 
 HOW TO 
 
 VARNISH THE NEGATIVE. 
 
 THIS subject is deserving of careful attention; at 
 the same time, all that can or need be said concerning 
 it, may be stated very plainly and in a few words. 
 
 I will endeavor to explain and comment upon 
 the two methods now in use, and will distinguish 
 them by the terms "hot" and "cold." I apply the 
 first term, hot, to the process making the warming of 
 the plate necessary previous to pouring on the varnish, 
 which is applied whilst the plate is still warm. This 
 method is very generally followed, notwithstanding 
 the inconvenience of heating the plate for the 
 reason that the coating left upon the surface, is 
 perhaps harder, than when cold varnish is applied, 
 and consequently stands a greater amount of rough 
 treatment: no doubt a desideratum. Ordinary spirit 
 varnish, whether French or English, contains a certain 
 amount of water ; that is to say, the spirit generally 
 used is not absolute. A more fluid, and consequently 
 a better varnish, can, I think, be made with absolute 
 alcohol at least, such is the result of my experiments ; 
 but whatever strength of spirit is used, the effect of 
 all spirit varnishes, more or less, is to interpose between 
 the image on the surface of the negative, and the pre- 
 pared surface of the paper, a layer of gum more or less 
 thick. I need hardly say that any intermediate film 
 
46 
 
 must prevent absolute contact of these surfaces, and 
 consequently detract somewhat from the sharpness of 
 the picture. 
 
 There can be no very great mystery as to the 
 composition of spirit varnishes, when it is considered 
 that the gums we have to select from are not nume- 
 rous, viz., copal, animi, sandarac, thus, mastic, lac, and 
 dammar; these gum resins have, however, various 
 properties, some being harder and more vitreous than 
 the others, whilst some are sticky and resinous. It 
 is, therefore, very desirable to make use of both these 
 qualities, by selecting and combining judiciously such 
 of the gums, just enumerated, as shall give a varnish 
 possessing hardness and durability, with sufficient 
 elasticity. The hardest gum cannot be used alone, 
 but must be mixed with others more resinous. I 
 find that a mixture of the three first on my list 
 answers the conditions just laid down, if absolute 
 alcohol with a small percentage of chloroform is used 
 for the solvent. This varnish has proved, in my 
 hands, the best of the spirit varnishes. I have heard 
 it remarked that this, and no doubt other strong 
 spirit varnishes, occasionally have a very unhappy 
 property of removing the image from the negative ; 
 I must say that I have never been able to produce 
 this undesirable result myself, and think that perhaps 
 such an action may have been due either to moisture 
 in the film, unequal application of heat to the plate, 
 imperfect washing-out of the Hyposulphite of Soda 
 or ' Cyanide, or to some rottenness or peculiar condi- 
 tion of the film of Collodion. The advantage and 
 disadvantages in the use of spirit varnish may be 
 briefly stated : in its favor, a greater hardness of 
 coating ; against it, the inconvenience of having to 
 
47 
 
 heat the plate, and loss of sharpness in the positive 
 from the interposed film of gums left upon the sur- 
 face of the negative. Having disposed of what I 
 have termed the hot process, it only remains to draw 
 attention to that designated "cold." It is not my 
 intention to enumerate the various solvents and gums 
 which are or might be used for the manufacture of 
 cold varnishes. I have tried many of them, and find 
 that all are, more or less, tacky when dry. 
 
 I shall confine myself to a few words descriptive of 
 the best cold varnish, which, unquestionably, is that 
 made by dissolving amber in chloroform. Many will 
 be surprised to hear that such a thing as a package 
 of fine amber seldom, if ever, finds its way to this 
 country; but plenty of a very inferior and rough de- 
 scription is to be met with. The finest kind is used 
 for making the mouth-pieces of pipes, which are, I 
 am given to understand, of foreign manufacture. 
 Having learnt this much, I set to work to obtain, 
 through my drug merchants, some further information 
 on the subject, and was fortunate enough to find out 
 the holder of a large quantity of the chippings, from 
 the fine pieces of amber, which he had been provident 
 enough to store away. This is not a coarse powder of 
 amber, but unmistakable chippings cut as with a 
 sharp instrument, bright and clear in quality, in every 
 respect equal, for making varnish, to the fine and 
 most costly pieces, of which, indeed, these chippings 
 are a portion. With such a sample as this there is 
 no difficulty in producing a varnish in every respect 
 desirable for photographic use, and sufficiently tyard 
 to withstand any friction that the surface of a nega- 
 tive is likely to meet with. The coating left upon 
 the negative is perfect, and can hardly be distin- 
 
48 
 
 guished from the patent plate: this varnish penetrates 
 the film, and adds very much to the beauty and clear- 
 ness of the negative, at the same time leaving upon the 
 film the thinnest possible coating, thus admitting of 
 the most perfect contact' with the excited paper. 
 
 I have had opportunities of examining some hun- 
 dreds of negatives, produced by various operators, 
 both amateur and professional, many of which were 
 more or less disfigured, if not damaged, by the var- 
 nishing operation. My method of using the amber 
 varnish is as follows: I invariably make use of a little 
 distilled water, with which I wash finally the finished 
 negative ; this removes the salts of lime that exist, 
 more or less with other impurities, in all waters, in 
 quantities quite sufficient to prevent the formation of 
 a brilliant surface. I consider this simple but cleanly 
 operation one of the important photographic "insect 
 cares." Now set the negative up to drain and dry 
 spontaneously, its face to the wall, and its lower part 
 resting upon a slip of clean bibulous paper; it is as 
 well to change this slip of paper once or twice: when 
 surface-dry, the negatives may be put into a grooved 
 box to keep them from dust, and if more convenient, 
 they may be varnished next day. All varnishes should 
 be applied in a dry room.* Attach the back of the 
 negative to a pneumatic holder kept for the purpose, 
 and having poured into a glass measure more of the 
 varnish than is required to cover the plate, proceed 
 to pour on as much as the plate will hold; keep the 
 plate as horizontal as possible, and let the varnish 
 soak well in for twenty or thirty seconds; then gently 
 
 * Just before varnishing, pass the back of the plate over the flame of a 
 lamp, to drive off any moisture ; when amber varnish is used, allow the 
 plate to cool before pouring on the varnish. 
 
49 
 
 raise the plate and pour back into the measure the 
 excess, from the nearest right-hand corner. The var- 
 nish must not be dashed off, but the plate very gently 
 elevated, at first only just out of the horizontal, and 
 very gradually raised until it stands vertically on the 
 edge of the measure; in this position let it remain a 
 few seconds; on no account rock or give it any eccen- 
 tric motion, and during the whole operation hold the 
 breath, or turn the head away from the plate to 
 breathe. 
 
 Always have two bottles for varnishing the one 
 to contain the stock of bright filtered varnish, the 
 other to receive the portion poured back into the 
 measure from the plate; when sufficient has been 
 collected in this bottle, filter it through paper into 
 the bright stock bottle. Both amber and spirit var- 
 nishes filter rapidly and with a very slight loss. The 
 measure used should not be washed out, but kept 
 turned down and free from dust; it is then always 
 ready for the purpose required. 
 
 I possess a negative portrait of Sir John Herschel, 
 taken about ten years ago, which I value very much. 
 This plate was varnished with some varnish made of 
 very fine amber; it does not show the slightest sign 
 of decay, is, indeed, harder than when first varnished. 
 I have also negatives kept under various circum- 
 stances of damp and heat for twelve years, and still 
 perfect. 
 
 NOTE. I have occasionally been asked to account 
 for cracks in negatives; fortunately this complaint is 
 not of common occurrence, and therefore indicates an 
 exceptional condition of the film. I have been at 
 some pains to collect all the reliable information on 
 this subject from those who have a large stock of 
 4 
 
50 
 
 negatives, some of which were varnished five years or 
 more ago. From the facts collected, I have no hesi- 
 tation in saying that all cracks in negatives arise from 
 want of attention to the following points, viz., drying 
 the negative, washing out the hyposulphite or cyanide, 
 and lastly, the mode of drying the plate before var- 
 nishing.* I have before said that negatives should 
 be' allowed to dry spontaneously. It is of the utmost 
 consequence, as regards the permanency of the nega- 
 tive, that the fixing agent should be thoroughly re- 
 moved; also, that the heat required to warm the plate 
 before varnishing should be applied in a regular man- 
 ner, and only just sufficient to accomplish the object 
 in view. When these three points are attended to, 
 negatives will remain intact and free from cracks (as 
 far as my own experience goes) for an indefinite time. 
 Now, with reference to the first point, I say, let the 
 film dry spontaneously, because there may be some 
 conditions of a collodion film, presenting a proneness 
 to split up on the sudden and irregular application of 
 heat to it, whilst still in a wet state: recollect that 
 the edges of the glass plate are usually ground ; this 
 restrains a natural tendency of the film to contract 
 after removal of the iodide of silver by the fixing 
 agent; the film is therefore more or less in a state of 
 tension, being extended, so to speak, by the ground 
 edges of the glass. This simple operation of passing 
 a cloth (the thumb-nail being inserted) round the 
 edges of the negative, to the distance of one-eighth 
 
 ' * Negatives should not be kept in damp and cold rooms ; no matter how 
 carefully they may have been washed and dried, or how good the varnish 
 may be, if exposed to frost and moisture, symptoms of cracks will be soon 
 evident. I have known instances of negatives becoming cracked in the 
 film, from exposure in the printing-frame for some hours on wet and cold 
 days in winter. 
 
51 
 
 of an inch, sets the film free, removes the thick dirty 
 edge of the negative, and is a safeguard against in- 
 jury arising from continued tension of the film; 
 moreover, it adds to the neat appearance of the nega- 
 tive, and admits of the film being overlapped with 
 the varnish an additional advantage. The reason 
 for scrupulous attention to my second point is suffi- 
 ciently obvious: a slight trace of cyanide or hypo- 
 sulphite might not show itself at first sooner or later 
 this wrapped-up element of decay will begin to make 
 itself known, and brings about a disintegration of the 
 film. An impression has got abroad that cyanide of 
 potassium requires for its removal less washing than 
 the hyposulphite of soda. I think this is erroneous: 
 my opinion is, that the former salt should be as well 
 washed out as the latter, and to effect this I believe 
 that quite as much water is necessary. The collo- 
 dion film has a very retentive action on most chemi- 
 cal solutions presented to it. I do not see why 
 it should be less an absorbent of the cyanide than the 
 cuticle of the body. I take this as a familiar illus- 
 tration, because most people must have observed, 
 that when the fingers have been cleaned with cyanide 
 of potassium, the peculiarly disagreeable odor remains 
 for a time, even after the most perfect ablution. 
 Lastly, the instructions already given sufficiently ex- 
 plain the manner of warming a negative previous to 
 varnishing. Varnishes will be selected by the photo- 
 graphic artist for qualities especially adapted to pho- 
 tographic use, viz., facility of application, hardness of 
 film, and absence of tackiness. These conditions are 
 well fulfilled in the preparations spoken of in my 
 paper " How to varnish the negative." 
 
HOW TO 
 
 PRINT FROM THE NEGATIVE. 
 
 TN order to print from the negative, very little 
 skill in manipulation is necessary; but very much 
 judgment and taste must be exercised in order to 
 produce the best results, if really good proofs are 
 cared for. Many look upon the operation of printing 
 as mere drudgery beneath notice ; this work is fre- 
 quently handed over to the care of boys and girls, 
 who have as much feeling for art as the pressure- 
 frame used to produce the picture. Having a first- 
 rate negative, it is quite possible to obtain from it 
 proofs of various qualities ; so that, it may be, there 
 are not two alike in a dozen prints, and perhaps one 
 of them will be found superior to the other eleven. 
 I admit that a difficulty exists, and one not easily 
 removed ; it lies solely in the variability of sunlight 
 in this climate. At first sight it would appear easy 
 enough to obviate this by a watchful examination of 
 the picture whilst printing; such a course gives a 
 proximate notion only of the real state of the print ; 
 for, presuming the day be dull, and occasional glimpses 
 of sunshine flit over the printing-frame, it will be found 
 impossible to calculate to a degree, the amount of re- 
 duction that will take place in fixing the picture. If 
 exposed for some time on a dull day without sun, 
 the positive may appear to be very much overdone, 
 and yet be too much acted upon whilst undergoing 
 
53 
 
 the necessary immersion in the bath of hyposulphite 
 of soda, in consequence of the greater reducing power 
 of this salt on proofs printed in feeble light. 
 
 I am, of course, taking for granted that there is a 
 shade of intensity to be sought for in the positive 
 picture, which the negative is capable of giving, and 
 which shade shall be acknowledged to be that best 
 suited to the particular subject represented. For the 
 reasons just stated, it will be found difficult to obtain 
 this quality at will with a variable sunlight. The 
 natural deduction to be drawn from these remarks, 
 therefore is, that in order to produce from a negative 
 several copies uniform in quality, it is necessary to 
 print in direct sunlight ; one or two experiments will 
 then show the character of the negative ; the time 
 required to print from it, in order to obtain a special 
 intensity of tone, can be easily noted. I do not 
 now refer to color ; but, by intensity of tone, I mean 
 that amount of force giving artistically the best result 
 from a particular negative; and this leads me to 
 another remark, viz., the quality of the negative ; for, 
 supposing the same collodion to have been used for 
 the production of a series of negatives of different 
 subjects, the printing peculiarities of each negative 
 will vary, according to the subject represented, the 
 color of which, and quality of the light used to pro- 
 duce the negative, affect its resisting power to stop 
 out rays of transmitted light. It is therefore neces- 
 sary to be acquainted with the peculiarities of each 
 negative. There is this advantage in printing in 
 direct sunlight the subsequent reduction can be 
 calculated to a nicety, whether the negative be faint 
 or vigorous; for, as I have before stated, the positive 
 produced under these circumstances does not suffer 
 
54 
 
 such an excessive and variable reduction in the 
 hyposulphite of soda, as when a bad or variable light 
 is used. I am, of course, aware that some sort of 
 compromise may be effected by very much over-print- 
 ing, and then reducing the excess of intensity by a 
 prolonged immersion in the hyposulphite of soda 
 bath. I am by no means satisfied with this plan ; 
 the picture then is not of first-rate quality, but hard 
 and inferior in tone, and seldom brilliant. Of course, 
 in allowing for the over-printing, it is necessary to 
 lay down a given time for fixing in hyposulphite of 
 soda; I put this at half an hour, and never fix more 
 than a few proofs in a dish at a time. Now it can 
 be very readily demonstrated that positives printed 
 in a bad light are much more rapidly acted upon by 
 the hyposulphite of soda, as I k have before said; no- 
 thing, therefore, seems so easy of confirmation as this 
 proposition, that in proportion to the acting power 
 of the hyposulphite of soda upon the reduced silver, 
 so will be the action of other external influences of a 
 chemical nature on the picture when finished. To 
 my mind this appears only a plain, common-sense 
 view of the case, and the inference to be drawn there- 
 fore is, that a greater general permanency is obtained 
 by printing in direct sunlight. These observations 
 may open up a new field of inquiry, and may, per- 
 haps, account for the variableness in the permanency 
 of photographic pictures. All good negatives should 
 stand sunlight printing: I am certain that a finer 
 definition of detail is obtained, and both a greater 
 richness and brilliancy of color, when prints are made 
 under these circumstances. 
 
 I may as well remark here, that a very faint 
 
00 
 
 negative will, under no conditions of light, give a 
 fine, rich, and dark-colored positive; the picture may 
 certainly be cooked in baths of gold and much variety 
 of smudginess produced a dead, cold, and leaden 
 hue shades of black fit only to represent scenes in 
 pandemonium. This is the character of color forced 
 upon faint positives by over-dosing with gold. A 
 well- printed positive of good vigorous color will 
 stand a longer immersion in the gold bath, and yet 
 be free from the objectionable color just described. 
 There is considerable room for display of taste in the 
 selection of shades and tones of color in photographs, 
 according to the subject represented ; the most in- 
 felicitous choice is sometimes made. I think that a 
 great deal of the evil is to be attributed to the whole- 
 sale and reckless use of gold, which, if skilfully used, 
 is capable of producing every variety of good photo- 
 graphic color. 
 
 I once heard of an amateur who apologized to his 
 friend for the bad color of a photograph he was 
 anxious to present him with, at the same time saying, 
 somewhat mournfully, " he had expended on it the 
 contents of a 15-grain bottle of gold;" but even then 
 it fell short of some ideal standard of perfection. 
 The doctrine of sunlight-printing which I have 
 endeavored to lay down would, of course, be fatal to 
 general photographic business in this country; it 
 would never do to be waiting upon and otherwise 
 dodging our great luminary ; the principle involved, 
 however, may nevertheless be true, although its 
 practice may be difficult or perhaps impossible. I 
 am now addressing the few who, like myself, are 
 anxious to produce at will, a first-rate impression 
 from a negative of good quality. 
 
56 
 
 There are several good toning processes ; I prefer 
 the simple Alkaline Chloride of Gold process, to 
 which a preference is also given by some of our most 
 successful photographers. Albumenized Paper, either 
 Saxe or Rive, may be used; with the latter a darker 
 color is obtainable. Float each piece of paper for 
 three minutes upon a solution of nitrate of silver, 
 60 grains to 1 ounce of distilled water; and use it as 
 soon as it is quite dry. I have observed that a 
 brighter color is obtained, when the paper is used 
 very soon after excitation; let the paper, however, 
 be quite dry before using it; expose in the frame in 
 the usual way. I prefer, for my own use, the bars of 
 pressure-frames fitted with screws the contact may 
 then be made so perfect all over; but spring-back 
 pressure-frames are generally used by photographers, 
 and they can now be obtained of excellent quality. 
 In sunlight the time of exposure will vary from ten 
 minutes (the minimum time) to half an hour for 
 ordinary subjects; but a much longer exposure will 
 be necessary for the representation of black and 
 white subjects, such as engravings. Be very careful 
 to examine the print in yellow light, whilst printing: 
 if the frame be opened, even for a few seconds in 
 sunlight, a slight general action of light will take 
 place over the whole surface of the picture. Conduct 
 the operations of toning and fixing in yellow light. 
 When the print has reached the proper intensity 
 (allowing for the reduction), remove it from the 
 printing-frame, and wash away in several changes of 
 common water, all the nitrate of silver; when this 
 has been properly effected, prepare the following 
 bath, which will be ready for use an hour after 
 mixing: 
 
57 
 
 Solution of Bicarbonate of Soda, 40 minims. 
 
 (Strength, 8 grains to 1 oz. of distilled water.) 
 
 Solution of Chloride of Gold, 20 minims. 
 
 (Strength, 15 grains to 5 drachms of distilled water.) 
 
 Distilled Water, 4 ozs. Mix. 
 
 The solutions both of gold and soda may be kept 
 ready for use in separate bottles. I throw away the 
 coloring bath after use, or it may be set aside for the 
 purpose of recovering the Gold, when a sufficient 
 quantity has been accumulated. The above quantity 
 will tone half a dozen pictures 10 x 8, if warm tones 
 only are required ; the time of immersion varies from 
 thirty seconds to two minutes. Over-color the posi- 
 tives slightly, to allow for subsequent reduction in 
 the hyposulphate of soda bath. Now wash away the 
 excess of gold solution rapidly in two or three changes 
 of water, and fix the proofs in a bath of hyposulphite 
 of soda, 1 oz. to 6 ozs. of water. In order to make 
 sure of the pictures being perfectly fixed, let the 
 proofs remain in this bath half an hour not less, 
 moving them about occasionally; then wash in run- 
 ning water for twelve hours, and let them dry spon- 
 taneously. I have a strong feeling in favor of a 
 particular color for photographs; no word-painting 
 will describe this or any other tone of color; I shall 
 be happy, however, to show to any one, specimens of 
 coloring by the above formula. It is very evident 
 that paper treated and washed as just described, in- 
 volving an immersion of twelve hours in liquids, 
 must have undergone some alteration in the arrange- 
 ment of its atoms; these are now, of course, more 
 open, spongy, and porous, consequently the particles 
 of silver forming the image must of necessity be 
 somewhat divided and less compact than is desirable; 
 
58 
 
 I think, therefore, more in a condition to absorb 
 deleterious gases, and more susceptible .of damage 
 from moisture in the atmosphere or other injurious 
 influences. It is most desirable to restore the paper 
 to its original condition; this is easily done at a very 
 small charge by the hot presser. The pictures must 
 not be over-rolled such an action would be injurious 
 to the surface. I order mine to be rolled flat only; 
 this last operation is, I consider, most beneficial, both 
 as regards the beauty and permanency of the finished 
 photograph. 
 
 I cannot conclude this paper, without stating that 
 it was written previous to the use of iron as a deve- 
 loper, and consequently, had special reference to 
 printing from a class of negatives, not so frequently 
 seen now a days. I have also to remark that, as a 
 rule, printing is now generally performed in the 
 shade by -all professional photographers, this plan 
 being found practically to give the most uniform re- 
 sults, and admitting of a greater latitude in the time 
 of exposure in the printing-frame; but notwithstand- 
 ing this, the principle I have endeavored to enun- 
 ciate applies with equal force and truth, to the pro- 
 duction of prints from any kind of negative whatever; 
 although, as I have before stated, printing by sun- 
 light could not be carried out with any chance of 
 commercial success. I republish the paper, feeling 
 sure that it will be read with interest by those who 
 print only for amusement, and are anxious about the 
 permanency of their pictures. 
 
59 
 
 THE CAUSE OF 
 
 FOG, STAINS AND STREAKS 
 
 IN THE 
 
 COLLODION NEGATIVE. 
 
 FOGGING of the plate or a general haziness of the 
 image, may be due to several causes ; it may be pro- 
 duced by the action of light in the camera. All 
 things considered, is it not wonderful that we have a 
 clear image in a latent state upon the highly sensitive 
 surface of the collodion plate I Light passes equally 
 into the darkened box through the full aperture of 
 the lens ; but at the focus of the lens it is also depo- 
 sited, so to speak, in a ratio equal to the reflecting 
 power of the surfaces of the objects to be copied, im- 
 pressing the first atoms of the sensitive film, in a de- 
 gree equal to the amount of light, projected from the 
 bodies to be represented. It will be readily granted 
 and very easily conceived, how soon a disturbing in- 
 fluence may be brought about, by the introduction of 
 any false light in the camera wherein this image is 
 produced ; but, notwithstanding this incontrovertible 
 fact, there are those who remain careless as to the 
 manner of rendering the camera absolutely dark, in- 
 attention to which, prevents brilliancy of the image, 
 producing what is termed fog. The indistinctness 
 referred to, may also be produced by sensitizing and 
 developing the plate in a room lighted either by 
 
60 
 
 means of light, improper in quality, or by using too 
 much of this light. What, therefore, is the charac- 
 ter and amount of light that can be safely used in the 
 operating room'? In reply to this inquiry there is 
 fortunately a very clear answer ; let me state it. And 
 first I wish to lay down as a rule, that with properly 
 prepared collodion, no matter what the light out-of- 
 doors be, the negative image, whether under-exposed, 
 or just enough exposed, should more or less, on some 
 portions, and generally of course on those parts in 
 deepest shadow, show a bright positive surface, when 
 developed and fixed. Too much light in the operating 
 room will destroy this brilliancy. Another guide is 
 the behavior of the developer. The developer should 
 remain bright for some time ; too much light in the 
 room will cause it to blacken, and in some cases throw 
 down a loose black deposit at a very early stage of the 
 development ; I recommend every one to adopt the 
 course I am now going to suggest. Darken the room 
 entirely, so that no object be discernible ; slits, cre- 
 vices, and holes will then be seen. Now let light into 
 the room, passed through a piece of amber-colored 
 glass, covered closely on each side with a single thick- 
 ness of yellow tammy. For the purpose of experi- 
 ment only, let this aperture of yellow light be as 
 small as possible ; under these inconvenient condi- 
 tions of light, .develop a picture, and note well its 
 character ; then find out by degrees how much larger 
 the aperture of yellow light may be made, so that the 
 beauty and purity of the picture be not less on com- 
 parison with the first result, obtained almost in dark- 
 ness, and which may be called, the test plate. It will 
 then be very soon ascertained how large the aperture 
 of yellow light may be made with safety. Let it be, 
 
61 
 
 however, remembered that this experiment must be 
 performed on a bright day, when the light is strong- 
 est upon the covered yellow glass. I do not believe 
 that either yellow glass or dyed stuffs alone can be 
 depended on ; the perfection of a yellow light for 
 photographic purposes will be found in a combina- 
 tion of these two substances. The number of super- 
 ficial square inches of light, passing through this me- 
 dium, must be regulated according to the position of 
 the window through which the light passes ; hence 
 the necessity for these experiments, and the difficulty 
 in laying down any fixed rules. This is my formula 
 for lighting a room with yellow light ; but bear in 
 mind that the want of a perfectly light-tight cover to 
 the bath for use, whilst the plate is iodizing, would 
 be equally a source of stains and fogging ; therefore, 
 in making the test experiment, cover the bath and its 
 case entirely over with black velvet or some other 
 dark material, should there be occasion to open the 
 door during the preparation of the plate. The win- 
 dow of the room should also be fitted with a move- 
 able shade of yellow material, in case the sun's rays 
 should at some hour of the day fall too strongly upon 
 it. An extensive correspondence confirms me in the 
 opinion, that many suffer from a want of knowledge 
 of the deleterious action of light, under the circum- 
 stances stated. 
 
 Again, the Collodion may be the cause of fog. The 
 absorption of Iodine that takes place, more or less, in 
 Collodion containing a Bromide, renders it too neu- 
 tral, frequently giving rise to a haziness of the image, 
 and consequently, an impression that the Nitrate of 
 Silver Bath is out of order is frequently conveyed, 
 when such is really not the case. 
 
62 
 
 When Collodion becomes colorless or lighter in 
 color, after having been kept a few days iodized, a so- 
 lution of Iodine in Spirit should be added, in quantity 
 just sufficient, to restore the pale amber color which 
 it possessed when freshly iodized. 
 
 A bright picture is always obtainable with properly 
 prepared Collodion, when used of the proper color, ac- 
 cording to these instructions ; it therefore follows, 
 that when fogging occurs, it must be due either to 
 the deteriorated state of the bath, or to causes stated 
 in this paper, viz., improper lighting of the subject, 
 or to extraneous light either impinging on the lens, 
 or entering the operating room in improper quality 
 and quantity. 
 
 An under-exposed picture is the best test for the 
 condition of the chemicals (i. e., as to freedom from 
 fog. The image in parts, when under-exposed, should 
 be, when viewed by transmitted light, as clear and 
 bright as the glass, and more or less positive by re- 
 flected light. No more Iodine should be added to 
 Collodion than is necessary to produce this result. 
 The addition of acid to the bath should be avoided, 
 as this tends to impair the quality of the negative, 
 lessening sensitiveness and density. 
 
 The atom of Iodine recommended, develops Nitric 
 Acid, and insures its presence in proper quantity, 
 and, moreover, in the proper place, being first libe- 
 rated in the body of the film of Collodion, thus giv- 
 ing the greatest amount of brilliancy combined with 
 the maximum of sensitiveness. 
 
 Formula for Solution of Iodine : 
 
 Iodine 2 grains. 
 
 Spirits of Wine .... 1 drachm. 
 
63 
 
 One drop added to each ounce of Iodized Collo- 
 dion will be found to produce the desired effect. 
 
 It may sometimes be necessary, after a few days, 
 to repeat the dose. 
 
 N.B. The above remarks apply also to Collodion 
 sold Iodized, which, if colorless, should be rendered 
 pale yellow by the addition of Solution of Iodine as 
 above directed. 
 
 Glass may be viewed as a chemical compound, the 
 silica, of which it is composed, combines with the 
 alkaline bases, soda and potash, in definite propor- 
 tions. Like other chemical bodies it is affected by 
 atmospheric influences the harder the glass the less 
 it is altered by moisture and chemical agents, a soda 
 glass being preferable to that made with potash. 
 Although silica unites definitely and in equivalent 
 proportions with the alkaline base, a variable quantity 
 of the basic oxide is found to exist in most glass, 
 hence the difference in hardness and hygrometric 
 properties. Bearing these facts in mind, it is easy to 
 understand the necessity for attention to the condition, 
 not only of the surfaces, but also of the body of the 
 glass at the time it receives the collodion solution ; 
 to insure a dry condition it must be well rubbed in 
 winter, on both sides with dry or warm cloths. I 
 find nothing better than the mixture recommended 
 in this pamphlet for obtaining a clean and uniform 
 surface. I can always produce a faultless negative 
 when the plate has gone through the process re- 
 ferred to. 
 
 Now it will be very easily seen how moisture 
 operates in producing streaky or stainy pictures ; 
 if the operator adds a drop or so of his collodion to 
 a small quantity of water in a measure, the incom- 
 
64 
 
 patibility of the two fluids is very evident, and no 
 amount of agitation will produce solution or mixture. 
 
 It is, however, quite true that a drop or two of 
 water added to collodion, becomes taken up by 
 shaking ; in the case of the moist plate we have an 
 illustration of the first example, viz., the collodion to 
 the moisture ; or if it be thought, that the excess of 
 collodion in this case favors the absorption of mois- 
 ture presented to it, as in the second example, recollect 
 that the operations are not analogous, for the neces- 
 sary agitation is wanting, and hence a cause of the 
 streaky and smeary appearance resulting from the 
 contact of bodies having no affinity for each other. 
 The effect of moisture or water when brought into 
 contact with collodion is to precipitate the pyroxyline 
 held in solution ; a streaky condition of the plate is 
 thus produced, and in consequence, these parts absorb 
 the nitrate of silver unequally. 
 
 Secondly, a too rapid immersion of the plate will 
 produce a similar result. In winter or in damp 
 weather the film does not set rapidly, a few seconds 
 should then be allowed to elapse before immersing 
 the plate ; when the thermometer is at about 60 the 
 plate may be placed in the bath soon after the collo- 
 dion ceases to run, without any fear of producing 
 streaks; perform this operation leisurely and watch 
 the appearance of the film at that corner nearest the 
 bottle. 
 
 Thirdly, an excessive accumulation of ether and 
 alcohol in the bath. The bath in time becomes con- 
 taminated with ether and alcohol (ether being only 
 miscible with water in a certain proportion) especially, 
 so in winter, the ether and alcohol in damp and cold 
 weather not leaving the film so freely. The excess of 
 
65 
 
 ether floats on the surface of the bath in a greasy 
 condition, combined with some organic matter from 
 the film: this impurity is not readily separated by 
 filtering the bath through paper, the greater portion 
 passing through the filter ; it may, to a certain ex- 
 tent, be got rid of, by lightly passing a slip of filtering 
 paper over the surface of the bath, by which the 
 greasy matter is absorbed. This plan is, however, 
 troublesome and requires repetition ; exposure of the 
 bath for some days, in a wide-mouth bottle, to light, 
 and heat, shaking up with it at the same time a little 
 carbonate of soda, will frequently again render the 
 bath workable. 
 
 A better plan is, to make use of a stoppered glass 
 bottle with a glass tap inserted about an inch or so 
 from the bottom, by means of which, the intermediate 
 bright solution is drawn off for use, and all floating 
 matter avoided; this arrangement has the further 
 advantage of leaving all particles of detached pieces 
 of film and iodide, at the bottom of the vessel, and 
 does away with the inconvenience of having to filter 
 the bath so frequently. The bottles here described 
 can be procured to hold from four to sixteen pints, 
 and are most useful for all chemical solutions. 
 
 Fourthly, from floating particles of film and iodide 
 in the bath which having been acted upon by light 
 are in a catalytic condition, and, becoming attached 
 to the film, assist in intensifying the action along the 
 stream of liquid flowing from this nucleus. In these 
 suggestions I think will be found means for overcom- 
 ing and providing against streaks : there is, however, 
 another enemy to absolutely clean and perfect plates 
 I allude to the innumerable varieties of spots, met 
 with more or less at times by even the most accom- 
 5 
 
66 
 
 plished photographers. I do not think that these 
 arise frequently from, dust ; I have worked occasion- 
 ally in a most dusty room, and still dustier camera, 
 without a speck on the negative. Presuming that 
 the collodion be of good quality, my own experience 
 in this matter points to one special cause, and one 
 only, providing the remarks on this subject in my 
 paper, " How to Clean the Glass Plate," be borne in 
 mind ; they arise chiefly from the breaking or rather 
 grinding-up of the film of iodide, by means of the 
 stopper inserted into the neck of the bottle, after the 
 preparation of the plate ; the film is not easily re- 
 moved by wiping, for this act often fails to remove 
 the dried film, a portion of which becomes only 
 displaced and falls undissolved into the collodion. 
 The remedy at once suggests itself work without a 
 stopper ; this may be easily done at home, but not 
 so out of doors; for home use, a bottle with a cap 
 only, can be used, but the bottle should be provided 
 also with a stopper to insert after work, the neck to 
 be wiped clean before replacing it. When working 
 out of doors, perfectly clean pictures can always be 
 insured, by first pouring away a few drops of the 
 collodion, and then proceeding at once to coat the 
 plate ; this latter plan can also be adopted with 
 advantage, even when the capped and stopperless 
 bottle is employed. 
 
APPENDIX. 
 
 FORMULA FOR GOLD TONING BATH WITH 
 ACETATE OF SODA. 
 
 Chloride of Gold 3 grains 
 
 Acetate of Soda 1 drachm 
 
 Water 20 ounces. 
 
 This bath should be prepared twenty-four hours before it 
 is required for use ; it keeps well, and only needs strength- 
 ening from time to time with more of a freshly made solution. 
 
 FORMULA FOR GOLD TONING BATH WITH 
 CHLORIDE OF LIME. 
 
 Chloride of Gold 3 grains 
 
 " Lime 2 grains 
 
 Water 20 ounces. 
 
 Very dark tones are easily obtained with this bath ; it 
 must, however, be prepared some days before it is required 
 for use ; if made with boiling water it may be used the follow- 
 ing day. 
 
 FORMULA FOR AMMONIO-SULPHATE OF 
 IRON DEVELOPER. 
 
 Ammonio- Sulphate of Iron . . 25 grains 
 
 Glacial Acetic Acid . . . . 15 minims 
 
 Alcohol ........ J drachm 
 
 Water . . . . . . 1 ounce. 
 
 A preference is given by some to the above formula. 
 
MR. CAREY LEA'S DEVELOPER. 
 
 I give the formula for this new developer with Mr. Lea's 
 remarks thereon, in his own words : 
 
 " It has seemed to me probable that if an organic matter 
 could be chemically combined with an iron developer we 
 might expect to obtain a development uniting the advantages 
 of an iron and a pyrogallic development the delicacy and 
 detail of the one, and the force of the other. 
 
 " An attempt has already been made in this direction, and 
 not without a share of success. A so-called saccharo-sulphate 
 of iron has been tried, and by some operators liked. But it 
 appears extremely improbable that this developer, as made 
 according to the usual directions given, can contain the sugar 
 in the form of a chemical combination. It has, indeed, been 
 formally asserted that sugar will crystallize with sulphate of 
 iron in any proportion, depending altogether upon the quan- 
 tity of each that chances to be present. Besides, we know 
 that sulphuric acid is capable of forming a large number of 
 conjugated acids with organic substances, but in every case 
 the organic body must be presented to the free sulphuric 
 acid. In no case does the union of the organic body with 
 the acid take place when the latter has been first combined 
 with a strong base. It is, therefore, I think, pretty clear 
 that the term " saccharo-sulphate," us used in photography, 
 is a complete misnomer. To obtain a true saccharo-sulphate 
 of iron it is essential that the saccharo-sulphuric acid be first 
 formed, and, subsequently, be combined with the iron. 
 
 "It seemed to me, therefore, probable that a true sulpho- 
 conjugated salt of protoxide of iron would have great advan- 
 tages as a developer ; and I therefore concluded to make the 
 experiment, using gelatine as the organic substance. Follow- 
 
69 
 
 ing out these experiments, I obtained an excellent developer, 
 very manageable, giving all the detail of sulphate of iron, and 
 a strong dark image like that of pyrogallic acid, rarely re- 
 quiring re- development, and giving light, clean negatives, 
 with singularly little tendency to fog by prolonged use of 
 the developer. 
 
 "I shall now proceed to give the mode of preparation of 
 this developer. 
 
 " Add an ounce of sulphuric acid to three ounces of water, 
 and set aside to cool. Then add to this liquid an ounce of 
 good gelatine ; let it swell and dissolve, placing it for that 
 purpose in a slightly warm place, not exceeding blood heat, 
 for twenty-four hours. Then add iron filings in excess, 
 avoiding all application of heat ; let it stand for several days. 
 Finally add a little acetate of soda as before ; filter, and 
 dilute to fifteen ounces. 
 
 " It is very curious to observe the power which the gela- 
 tine exerts as a restraining influence. This developer eon- 
 tains a very large quantity of sulphate of iron, much more 
 so than is usually employed in a developer, and yet it stands 
 in need of no free acid to check it; and the restraining is so 
 effectual that it may be kept on the plate twice as long as a 
 common iron developer without fogging. In this respect, as 
 well as in the color which it gives to the image, it resembles 
 pyrogallic acid. 
 
 " I would especially warn those who may prepare this de- 
 veloper for themselves to apply heat only as directed in the 
 formula, and not to any greater extent or degree. If, for 
 example, heat be applied to expedite the solution of the iron, 
 a decomposition appears to set in, and the liquid obtained, 
 though it may still develop, will not possess the good quali- 
 ties of that prepared strictly in the manner which I have 
 described." 
 
INDEX. 
 
 Acetate of soda, gold toning bath with, 
 
 67 
 
 Acid, dilute, 34 
 Albumenized paper, 6 
 Alkali, the, 34 
 Alkaline chloride of gold, 56 
 
 normal bath, 37 
 Amber varnish, 23 
 Ammonio-sulphate of iron developer, 
 
 67 
 
 Bath, alkaline normal, 37 
 faulty, 36 
 preparation of a nitrate of silver, 
 
 31, 35, 37 
 requiring an addition of an acid, 
 
 38 
 Bath with an excess of nitric acid, 
 
 38 
 with a proper quantity of nitric 
 
 acid as a corrective, 38 
 with insufficient quantity of nitric 
 
 acid as a corrective, 37 
 Baths, 23 
 
 Bellows cameras, 28 
 Black cloth, use of, 26 
 Bromide of silver, 8 
 Bromo-iodized collodion, 12, 20 
 
 Cadmium, collodion iodized with, 21 
 Camera, 7 
 
 the, described, 27 
 Cameras, expanding or bellows, 28 
 Cautions to be observed, 22 
 Chemicals, purity of, 23 
 Chloride of gold, alkaline, 56 
 
 of lime, gold toning bath with, 67 
 
 of silver, 7 
 
 Clean a glass, after having used it, to, 
 14 
 
 glass, 13 
 
 the glass for negatives, 12 
 Cleaning glass plate, 40 
 Cleanliness in photographic processes, 
 
 24 
 
 Coat the plate, to, 14 
 Collodion, 8, 27 
 
 bromo-iodized, 12, 20 
 
 Collodion, condiiion of, best suited for 
 
 different purposes, 26 
 iodized, 19 
 
 iodized with cadmium, 21 
 iodized with potassium, 21 
 negative, fog, stains and streaks 
 
 in, 59 
 
 plain iodized, 20 
 Collodionized plates, action of nitrate 
 
 of silver bath on, 37 
 Construction of photographic lens, 5 
 Corrective, nitric acid as, 37, 38 
 Cracks in negatives, 49 
 
 Dark room, light in, 26 
 Deoxidizer, 9 
 Developer, 67 
 
 Lea's, 68 
 Developing, 17 
 
 solution, iron, 15 
 Dilute acid, 34 
 
 Double lens, working with, 25 
 Drying of negatives, 50 
 
 Ebonite baths, 23 
 
 Edges of the glass for negatives, 12 
 
 Expanding or bellows cameras, 28 
 
 Fascination of the art of photography, 3 
 
 Faulty bath, 36 
 
 Finished photograph, 11 
 
 Fixing the negative, 18 
 
 Flushing the plate with iron solution, 
 
 17 
 Fog, stains and streaks in the collodion 
 
 negative, 59 
 Formula for ammonio-sulphate of iron 
 
 developer, 67 
 for gold toning bath with acetate 
 
 of soda, 67 
 for gold toning bath with chloride 
 
 of lime, 67 
 
 for nitrate of silver bath, 35 
 for solution of iodine, 62 
 
 Glass, 63 
 
 clean, 13 
 
 baths preferable, 23 
 
72 
 
 Glass for negatives, 12 
 
 for negatives, to clean, 12 
 
 plate, cleaning, 40 
 
 polish, 13 
 Gold toning bath with acetate of soda, 67 
 
 toning bath with chloride of lime, 
 
 67 
 Gutta-percha baths, 23 
 
 How to make the negative, 12 
 Hyposulphite of soda, 11, 18, 23 
 
 Innumerable processes in photography* 
 
 3 
 
 Intensifying solutions, 16 
 Iodide of silver, 8 
 Iodine, formula for solution, 62 
 Iodized collodion, 20 
 Iron developing solution, 15 
 
 solution, flushing the plate with, 17 
 
 Lea's developer, 68 
 Lens, the, 6, 28 
 
 triplet, 28 
 Lenses, combinations of, 5 
 
 construction of photographic, 5 
 Light in dark room, 26 
 
 what is it ? 5 
 
 Monochrome, 6 
 
 Negative, 9 
 
 collodion, 59 
 
 formation of, 9 
 
 how to make, 12 
 
 how to print, 52 
 
 how to varnish, 45 
 
 solution for fixing, 18 
 
 use of, 10 
 Negatives, cracks in, 49 
 
 drying, 50 
 
 edges of the glass for, 12 
 
 precautions necessary on perfect, 
 
 29 
 
 Nitrate of silver bath, action upon col- 
 lodionized plates, 37 
 
 of silver bath, preparation of, 31, 
 35, 37 
 
 of silver bath, state of, 37 
 
 of silver bath, to use, 14 
 Nitric acid, 38 
 Notes, 25 
 
 Objects of the author, 4 
 Open air pictures, precautions, 28 
 portraits and groups, 29 
 Oxide, excess filtered off of bath, 37 
 
 Paper, albumenized, 6 
 prepared, 6 
 
 Perfect pictures, rules and cautions for 
 
 production of, 22 
 Photograph, finished, 11 
 Photographic lenses, construction, 5 
 
 pictures, key to the formation of, 6 
 Photography, difficulty in the success- 
 ful practice, 4 
 fascination of, 3 
 innumerable processes, 3 
 many roads to success in, 3 
 l^tures, rules and cautions for pro- 
 duction of perfect, 22 
 Plain iodized collodion, 20 
 Plate, to coat. 14 
 Polish glass for negatives, 13 
 Porcelain baths, 23 
 Portraits and groups in the open air, 
 
 29 
 
 Potassium, collodion iodized with, 21 
 Prepared paper, 6 
 Preparation of a nitrate of silver bath, 
 
 31, 35, 37 
 
 Print the negative, how to, 52 
 Properties of bromo-iodized collodion, 
 
 20 
 
 Properties of certain chemical prepara- 
 tions sensitive to light, 7 
 of plain iodized collodion, 20 
 Proto-sulphate of iron, 9 
 Pyrogallic development, 19 
 solution, 16, 21 
 
 Rules and cautions for the production 
 of perfect pictures, 22 
 
 Sensitive plate, preparation of, 8 
 Shadow, effect of upon prepared plate, 
 
 6. 
 Solution for fixing the negative, 18 
 
 of iodine, formula for, 62 
 
 of proto-sulphate of iron, 9 
 
 pyrogallic, 16, 21 
 Solutions, intensifying, 16 
 Solvent, 11 
 Spirit varnish, 23 
 
 Stains and streaks in the collodion ne- 
 gative, 59 
 
 removal of, 24 
 
 Toning processes, 56 
 Triplet lens, 28 
 
 Use of collodion iodized for pyrogallic 
 development, 19 
 
 Varnish, selecting, 51 
 
 the negative how to, 45 
 
 What is light? 5 
 
AND 
 
 SCIENTIFIC BOOKS, 
 
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 . 406 
 
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 Among the contents sire -.Linear Drawing, Definitions and Problems, 
 Plate I. Applications, Designs for inlaid Pavements, Ceilings, and Balco- 
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PBACTICAL AND SCIENTIFIC BOOKS, 
 
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 Friction of surfaces in contact. 
 
 THE INTERSECTION AND DEVELOPMENT OF SURFACES WITH APPLICA- 
 TIONS. The Intersection of Cylinders and Cones, Plate XIV. The Delineation 
 and Development of Helices, Screws, and Serpentines, Plate XV. Application 
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 of boilers, Dimensions of fire grates, Chimneys, Safety valves. 
 
 THE STUDY AND CONSTRUCTION OF TOOTHKD GEAR. Involute, cycloid, 
 and epicycloid, Plates XVIII. and XIX. Involute, Fig. 1, Plate XVIII. 
 Cycloid, Fig. 2, Plate XVIII. External epicycloid, described by a circle 
 rolling about a fixed circle inside it, Fig. 3, Plate XIX. Internal epicycloid, 
 Fig. 2, Plate XIX. Delineation of a rack and pinion in gear, Fig. 4, Plate 
 XVIII. Gearing of a worm with a worm-wheel, Figs. 5 and 6, Plate XVIII. 
 Cylindrical or Spur Gearing, Plate XIX. Practical delineation of a couple of 
 Spur-wheels, Plate XX. The Delineation and Construction of Wooden Patterns 
 for Toothed Wheels, Plate XXI. Rules and Practical Data Toothed gearing, 
 Angular and circumferential velocity of wheels, Dimensions of gearing, 
 Thickness of the teeth. Pitch of the teeth, Dimensions of the web, Number 
 and dimensions of the arms, wooden patterns. 
 
 CONTINUATION OF THE STUDY OF TOOTHED GEAR. Design for a pair 
 of bevel-wheels in gear, Plate XXII. Construction of wooden patterns for 
 a pair of bevel-wheels, Plate XXIII. Involute and Helical Teeth, Plate XXIV. 
 Contrivances for obtaining Differential Movements The delineation of eccen- 
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 effect, The simple machines, Centre of gravity, On estimating the power of 
 prime movers, Calculation for the brake, The fall of bodies, Momentum, 
 Central forces. 
 
 ELEMENTARY PRINCIPLES OF SHADOWS. Shadows of Prisms, Pyramids 
 and Cylinders, Plate XXVI. Principles of Shading, Plate XXVII. Continua- 
 tion of the Study of Shadows, Plate XXVIII. Tuscan Order, Plate XXIX. 
 Rules and Practical Data Pumps, Hydrostatic principles, Forcing pumps, 
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 water-course of uniform section and fall, Velocity of the bottom of water- 
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 of narrow edges, Calculation of the discharge of water through overshot 
 outlets, To determine the width of an overshot outlet, To determine the 
 depth of the outlet, Outlet with a spout or duct. 
 
 APPLICATION OF SHADOWS TO TOOTHED GEAR, Plate XXX. Application 
 of Shadows to Screws, Plate XXXI. Application of Shadows to a Boiler and its 
 furnace, Plate XXXII. Shading in Black Shading in Colors, Plate XXXIII. 
 
 THE CUTTING AND SHAPING OF MASONRY, Plate XXXIV. Rules and Prac- 
 tical Data Hydraulic motors, Undershot water-wheels, with plane floats 
 and a circular channel, Width, Diameter, Velocity, Number, and capacity of 
 the buckets. Useful effect of the water-wheel, Overshot water-wheels, Water- 
 wheels with radical floats, Water-wheel with curved buckets, Turbines. 
 Re marks on Machine Tools. 
 
 THE STUDY OF MACHINERY AND SKETCHING. Various applications and 
 combinations : The Sketching of Machinery, Plates XXXV. and XXXVI. 
 Drilling Machines; Motive Machines; Water-wheels, Construction and set- 
 ting up of water-wheels, Delineation of water-wheels, Design of a water- 
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 XXXVII. Steam Motors ; High-pressure expansive steam-engine, Plates 
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PUBLISHED BY HEWRY CAREY BAIRD. 
 
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 OBLIQUE PROJECTIONS. Application of rules to the delineation of an 
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 PARALLEL PERSPECTIVE. Principles and applications, Plate XLII. 
 
 TRUE PERSPECTIVE. Elementary principles, Plate XLIII. Applications 
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 of Iron, Copper, and Lead, Tables of the Circumferences and Areas of Cir- 
 cles, Sizes and capacity of Tinware in form of Frustrum of a Cone, such as 
 Pans, Dish Kettles, Pails, Coffee-pots, Wash Bowls, Dippers, Measures, 
 Druggists' and Liquor Dealers' Measures, American Lap Welded Iron 
 Boiler Flues, Table of Effects upon Bodies by Heat, Weight of Water, 
 Effects produced by Water in an Aeriform State, Practical Properties of 
 Water, Effects produced by Water in its Natural State, Effects of Heat at 
 certain Temperatures, Tempering, Effects produced by Air in its Natural 
 and in a Rarefied State, Table of the Expansion of Atmospheric Air by 
 Heat, Size, Length, Breadth, and Weight of Tin Plates, Crystalli/ed Tin 
 Plate, List of Calibre and Weights of Lead Pipe, Calibre and Weights of 
 Fountain or Aqueduct Pipes, To ascertain the Weights of Pipes of various 
 Metals, and any Diameter required, Weight of a Square Foot of Sheet Iron, 
 Copper, and Brass, as per Birmingham Wire Gauge, Recapitulation of 
 
 4 
 
PUBLISHED BY HENRY CAREY BAIRD. 1 
 
 Weights of Various Substances. Practical Receipts. Japanning and Vat 
 nishing, Varnishes Miscellaneous, Lackers, Cements, Miscellaneous Re 
 ceipts, Britannia, Solders, etc., Strength, of Materials. 
 
 Booth and Morfit. The Encyclopedia of 
 Chemistry, Practical and Theoretical: 
 
 Embracing its application to the Arts, Metallurgy, Mineral- 
 ogy, Geology, Medicine, and Pharmacy. By James C. Booth, 
 Melter and Refiner in the United States Mint, Professor of 
 Applied Chemistry in the Franklin Institute, etc., assisted 
 by Campbell Morfit, author of "Chemical Manipulations, "etc. 
 7th edition. Complete in one volume, royal 8vo. 978 pages, 
 with numerous wood-cuts and other illustrations $5.00 
 
 Brewer; (The Complete Practical.) 
 
 Or Plain, Concise, and Accurate Instructions in the Art of 
 Brewing Beer, Ale, Porter, etc., etc., and the Process of 
 making all the Small Beers^ By M. Lafayette Byrn, M. D. 
 With Illustrations. 12mo $1.25 
 
 Buckmaster. The Elements of Mechanical 
 Physics. 
 
 By J. C. Buckmaster, late Student in the Goverment School 
 of Mines ; Certified Teacher of Science by the Department 
 of Science and Art ; Examiner in Chemistry and Physics 
 in the Royal College of Preceptors; arid late Lecturer in 
 Chemistry and Physics of the Royal Polytechnic Institute. 
 Illustrated with numerous engravings. In one volume, 
 
 12ino $2.00 
 
 CONTENTS. The Elements of Mechanical Physics CHAP. I. Statics and Dy- 
 namics ; Force ; Gravitation and Weight ; On Matter its Mass, Density, 
 and Volume. II. Centre of Gravity ; Stable and Unstable Equilibrium ; 
 To find the Centre of Gravity of a Material Straight Line of Uniform Den- 
 sity ; To find the Centre of Gravity of two heavy Points joined by a rigid 
 bar without Weight ; To find the Centre of Gravity of a number of heavy 
 points ; To find the Centre of Gravity of a Material Plain Triangle. III. 
 Levers ; Levers are of three kinds ; Virtual Velocity ; Balances ; The Safety 
 Valve ; Mechanical Combinations and their Advantages. IV. The Wheel 
 and Axle : The Compound Wheel and Axle. V. The Pulley ; Wheels and 
 Pinions ; Crank? and Fly- Wheel. VI. The Inclined Plane ; The Wedge ; 
 The Screw. VII. Composition and Resolution of Forces. VIIL Falling 
 Bodies ; Ascent of Bodies ; Projection of Bodies Horizontally. IX. Mo- 
 mentum. X. Sound ; The Pendulum. 
 
 Elements of Hydrostatics. CHAP. I. Hydrostatics ; Bramah Hydrostatic 
 Press. II. Specific Gravity ; Table of Specific Gravities. III. Elastic Fluids ; 
 The Air Pump and its Operation ; The Construction of the Condenser and its 
 Operation ; The Barometer ; The Action of the Siphon ; How to Graduate 
 a common Thermometer ; To Reduce the Degrees of a Thermometer in Fah- 
 renheit's scale to a centigrade and the converse ; The Construction of a 
 Siphon gauge ; The Construction of a common Pump and its Operation ; 
 The Construction and Operation of a Force Pump ; The Operation of a Fire 
 Engine ; The Operation of a Lifting Pump ; The Hydraulic Ram ; The 
 Archimedian Screw ; The Chain Pump ; Mercurial Steam Gauge ; Examina- 
 tion Papers. 
 APPENDIX. Examples ; Answers to Examples. 
 
^PRACTICAL AND SCIENTIFIC BOOKS, 
 
 Bullock. The Rudiments of Architecture 
 and Building : 
 
 For the use of Architects, Builders, Draughtsmen, Ma- 
 chinists, Engineers and Mechanics. Edited by John Bul- 
 lock, author of "The American Cottage Builder." Illus- 
 trated by Two Hundred and Fifty Engravings. In one vol- 
 ume, 8vo $3.50 
 
 Burgh. The Slide Valve Practically Consid- 
 ered. 
 
 By N. P. Burgh, Engineer. Completely Illus. 12mo.. 42.00 
 
 Burgh. Practical Rules for the Proportion of 
 Modern Engines and Boilers for Land and 
 Marine Purposes. 
 
 By N. P. Burgh, Engineer. 12mo $2.00 
 
 CONTENTS. High Pressure Engines; Beam Engines (condensing); 
 Marine Screw Engines ; Oscillating Engines ; Valves, etc. ; Land and 
 Marine Boilers. Miscellaneous. Coal Bunkers. Marine ; Decimals, etc. ; 
 Eccentric, Position of, for Land Engines ; Eccentric, Position of. for Marine 
 Screw Engines ; Fire Bars ; Keys and Cotters ; Link for Land Engine, Ra- 
 dius of; Levers ; Link for Oscillating Engine, Radius of; Link for Marine 
 Screw Engine, Radius of; Proportion of Connecting Rods having Strap 
 Ends; Paddle Wheels, Centres of Radius Rods; Plummer Blocks; Propor 
 tions of Steam Cocks with Plugs secured by Nuts and Screws ; Proportion 
 of Marine Cocks ; Proportions of Bolts, Nuts, etc. ; Proportions ot Pins, 
 Studs, Flanges, etc. ; Proportions of Copper Pipes ; Proportions of Engines ; 
 Sliding Quadrant ; Toothed Wheels (Gearing). Proportions of Engines Pro- 
 duced by the Rules: Proportions of an Engine 20 HP nominal ; Proportions of 
 a Condensing Beam Engine 150 HP nominal ; Proportions of a Pair of Marine 
 Engines of 200 HP Collectively ; Proportions of a Pair of Oscillating Engines 
 of 400 HP Collectively ; Proportions of Boilers. 
 
 Byrne. Pocket Book for Railroad and Civil 
 Engineers. 
 
 Containing New, Exact, and Concise Methods for Laying 
 out Kailroad Curves, Switches, Frog Angles and Crossings ; 
 the Staking out of Work; Leveling ; the Calculation of Cut- 
 tings, Embankments, Earth-work, etc. By Oliver Byrne. 
 Illustrated, 18mo $1.25 
 
 Byrne. The Practical Metal- Worker's As- 
 sistant. k 
 
 Comprising Metallurgic Chemistry ; the Arts of Working all 
 Metals and Alloys ; Forging of Iron and Steel; Hardening 
 and Tempering ; Melting and Mixing ; Casting and Found- 
 ing ; Works in Sheet Metal ; the Process dependent on the 
 Ductility of the Metals ; Soldering ; and the most Improved 
 Processes and Tools employed by Metal-Workers. With 
 the Application of the Art of Electro-Metallurgy to Manu- 
 facturing Processes : Collected from Original Sources, and 
 6 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 from the Works of Holtzapffel, Bergeron, Leupold, Pluraier, 
 Napier, and others. By Oliver Byrne. A New, Revised, 
 and Improved Edition, with additions by John Scoffern, 
 M. B., William Clay, William Fairbairn, F. K. S., and James 
 Napier. With Five Hundred and Ninety-two Engravings, 
 illustrating every Branch of the Subject. In one volume, 
 8vo. 652 pages $7.00 
 
 CONTENTS. Oil Metallurgic Chemistry ; Special Metallurgic Operations ; 
 Recently Patented Refining Processes ; Refining and Working of Iron ; 
 Manufacture of Steel; Forging Iron and Steel; On Wrought-Iron in Large 
 Masses ; General Examples of Welding, Hardening and Tempering; Hard- 
 ening Cast and Wrought-Iron ; On the Application of Iron to Ship-Build- 
 ing ; The Metals and Alloys most commonly used ; Remarks on the Char- 
 acter of the Metals and Alloys ; Melting and Mixing the Metals ; Cas 
 and Founding; Works in Sheet Metal made by Joining; Works in S 
 Metal made by raising and flattening of thin Plates of Metal ; Processes de- 
 pendent on Ductility ; Soldering ; Shears ; Punches ; Drills ; Screwrcutting 
 Tools; Electro-Metallurgy. 
 
 Byrne. The Handbook for the Artisan, Me- 
 chanic, and Engineer. 
 
 By Oliver Byrne. Illustrated by 11 large plates and 185 
 wood engravings. 8vo $5.00 
 
 CONTENTS. Grinding Cutting Tools on the Ordinary Grindstone ; Sharp- 
 ening Cutting Tools on the Oilstone ; Setting Razors ; Sharpening Cutting 
 Tools with Artificial Grinders ; Production of Plane Surfaces by Abrasion : 
 Production of Cylindrical Surfaces by Abrasion ; Production of Conical 
 Surfaces by Abrasion ; Production of Spherical Surfaces by Abrasion ; Glass 
 Cutting ; Lapidary Work ; Setting, Cutting, and Polishing Flat and Rounded 
 Works ; Cutting Faucets ; Lapidary Apparatus for Amateurs ; Gem and 
 Glass Engraving ; Seal and Gem Engraving ; Cameo Cutting ; Glass Engrav- 
 ing, Varnishing, and Lackering; General Remarks upon Abrasive Pro- 
 cesses ; Dictionary of Apparatus ; Materials and Processes for Grinding 
 and Polishing, commonly employed in the Mechanical and Useful Artu. 
 
 Byrne. The Practical Model Calcufc-tor: 
 
 For the Engineer, Mechanic, Manufacturer of Engine Work, 
 Naval Architect, Miner, and Millwright. By Oliver Byrne. 
 1 vol. 8 vo., nearly 600 pages $4.50 
 
 The principal objects of this work are : to establish model calculations to 
 guide practical men and students ; to illustrate every practical rule and 
 principle by numerical calculations, systematically arranged ; to give infor- 
 mation and data indispensable to those for whom it is intended, thus sur- 
 passing in value any other book of its character ; to economize the labo of 
 the practical man, and to render his every-day calculations easy and com- 
 prehensive. It will be found to be one of the most complete and valuable 
 practical books ever published. 
 
 Cabinet-maker's and Upholsterer's Compan- 
 ion. 
 
 Comprising the Eudiments and Principles of Cabinet-making 
 and Upholstery, with Familiar Instructions, illustrated by 
 Examples for attaining a proficiency in the Art of Drawing, 
 as applicable to Cabinet-work; the processes of Veneering, 
 Inlaying, and Buhl-work ; the Art of Dyeing and Staining 
 Wood, Bone, Tortoise Shell, etc. Directions for Lackering, 
 
PEACTICAL AND SCIENTIFIC BOOKS, 
 
 Japanning, and Varnishing ; to make French Polish ; to pre- 
 pare the best Glues, Cements and Compositions, and a num- 
 ber of Receipts particularly useful for workmen generally. 
 By J. Stokes. In one vol., 12mo. With Illustrations. ..$1.25 
 
 Calvert. On Improvements and Progress in 
 Dyeing and Calico Printing since 1851. 
 
 Illustrated with Numerous Specimens of Printed and Dyed 
 Fabrics. By Dr. F. Grace Calvert, F. R. S., F. C. S. A 
 Lecture delivered before the Society of Arts. Revised and 
 enlarged by the author. (Nearly Ready.) 
 
 The Works of Henry C. Carey: 
 
 CONTRACTION OR EXPANSION? REPUDIATION 
 OR RESUMPTION? Letters to Hon. Hugh McCulloch. 
 8vo 35 
 
 FINANCIAL CRISES, their Causes and Effects. 8vo. 
 paper 25 
 
 FRENCH AND AMERICAN TARIFFS : Compared in a 
 Series of Letters addressed to Mons. M. Chevalier. 8vo. 
 paper 50 
 
 HARMONY OF INTERESTS : Agricultural, Manufacturing, 
 
 and Commercial. 8vo., paper $1.00 
 
 Do. do. cloth 1.50 
 
 LETTERS TO THE PRESIDENT OF THE UNITED 
 STATES. Paper 75 
 
 MANUAL^)F SOCIAL SCIENCE. Condensed from Ca 
 rey's " J^hciples of Social Science." By Kate McKean. 
 1 vol., 12mo $2.25 
 
 The Text-Book of the Universities of Berlin (Prussia), Pennsylvania, 
 and Michigan, and of the College of New Jersey, Princeton. 
 
 MISCELLANEOUS WORKS : comprising " Harmony of In 
 terests," " Money," " Letters to the President," " French 
 and American Tariffs," " Financial Crises," " The Way to 
 Outdo England without Fighting Her," " Resources of the 
 Union," "The Public Debt," "Contraction or Expansion?" 
 etc., etc. 1 vol. 8vo., cloth $3.50 
 
 MONEY : A LECTURE before the N. Y. Geographical and 
 Statistical Society. 8vo., paper 25 
 
 PAST, PRESENT, AND FUTURE 8vo $2.50 
 
 PRINCIPLES OF SOCIAL SCIENCE. 3 volumes. 8vo., 
 cloth $10.00 
 
 CONTENTS. Volume I : Of Science and its Methods $ Of Man, the Subject 
 of Social Science ; Of Increase in thfl Numbers of Mankind ; Of the Occu- 
 pation of the Earth; Of Value ; Of Wealth ; Of the Formation of Society ; 
 8 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 Of Appropriation ; Of Changes of Matter in Place ; Of Mechanical and 
 Chemical Changes in the Forms of Matter. Volume II: Of Vital Changes 
 in the Form of Matter ; Of the Instrument of Association. Volume III : Of 
 Production and Consumption ; Of Accumulation ; Of Circulation ; Of Dis- 
 tribution ; Of Concentration and Centralization ; Of Competition ; Of Popu- 
 "ation ; Of Food and Population ; Of Colonization ; Of the Malthusian 
 Theory ; Of Commerce ; Of the Societary Organization ; Of Social Science. 
 
 THE PUBLIC DEBT, LOCAL AND NATIONAL. How 
 to provide for its discharge while lessening the burden of 
 Taxation. Letter to David A. Wells, Esq., U. S. Kevenue 
 Commission. 8vo., paper 25 
 
 "HE EESOUECES OF THE UNION. A Lecture read, 
 Dec. 1865, before the American Geographical and Statistical 
 Society, N. Y., and before the American Association for the 
 Advancement of Social Science, Boston 25 
 
 "tTE SLAVE-TRADE, DOMESTIC AND FOREIGN: 
 Why it Exis-ts, and How it may be Extinguished. 12mo. 
 
 cloth $1.50 
 
 VHE WAY TO OUTDO ENGLAND WITHOUT FIGHT- 
 iNG HER. LETTERS TO THE HON. SCHUYLER 
 COLFAX, Speaker of the House of Representatives United 
 States, on "The Paper Question," "The Farmer's Ques- 
 tion," " The Iron Question," " The Railroad Question," and 
 the " Currency Question." 8vo., paper 75 
 
 Campin. A Practical Treatise on Mechan- 
 ical Engineering: 
 
 Comprising Metallurgy, Moulding, Casting, Forging, Tools, 
 Workshop Machinery, Mechanical Manipulation, Manufac- 
 ture of Steaxn-engines, etc., etc. With an Appendix on the 
 Analysis of Iron and Iron Ores. By Francis Campin, C. E. 
 To which are added, Observations on the Construction of 
 Steam Boilers and remarks upon Furnaces used for Smoke 
 Prevention; with a Chapter on Explosions. By R. Arm- 
 strong, C. E., and John Bourne. Rules for Calculating the 
 Change Wheels for Screws on a Turning Lathe, and for 
 Wheel-cutting Machine. By J. La Nicca. Management of 
 Steel, including Forging, Hardening, Tempering, Annealing, 
 Shrinking, and Expansion. And the Case-hardening of Iron. 
 By G. Ede. 8vo. Illustrated with 29 plates and 100 wood 
 
 engravings $6.00 
 
 CONTENTS. Introduction On Metallurgy; On Forging Iron: On Moulding 
 and Casting; On Cutting Tools; On Workshop Machinery; On Manipulation ; 
 On the Pnysical Basis of the Steam-engine ; On the Principles of Mechanical 
 Construction ; On the General Arrangement of the Steam-engine ; On the 
 General Principles of Steam Boilers ; Preliminary considerations on the 
 Applicability of various kinds of Steam-engines to various purposes ; On 
 the details of Steam-engines ; On Pumps and Valves ; On Steam Boilers ; 
 On Propellers ; On various applications of Steam-power and Apparatus 
 connected therewith ; On Pumping Engines ; On Rotative Engines ; On 
 Marine Engines ; On Locomotive Engines ; On Road Locomotives ; On 
 Steam Fire Engines ; On Boilers generally, and a Radical Reform in those 
 
PBACTICAL AND SCIENTIFIC BOOKS, 
 
 for Marine purposes suggested ; Smoke Prevention and its fallacies ; Re- 
 marks on Smoke-burning, by John Bourne; Explosions: an investigation 
 into some of the causes producing them, and into the deterioration of Boil- 
 ers generally ; Rules for Calculating the Change Wheels for Screws on a 
 Turning Lathe, and for a Wheel-cutting Machine ; Explanation of the 
 Methods of Calculating Screw Threads ; The Management of Steel. 
 
 APPENDIX. The Analysis of Iron and Iron Ores. 
 
 GLOSSARY. INDEX. 
 
 Capron de Dole. Dussauce. Blues and Car- 
 mines of Indigo. 
 
 A Practical Treatise on the Fabrication of every Commer- 
 cial Product derived from Indigo. By Felicien Capron de 
 Dole. Translated, with important additions, by Professor H, 
 Dussauce. 12mo .*. $2.50 
 
 Clough. The Contractor's Manual and Build- 
 er's Price-Book : 
 
 Designed to elucidate the method of ascertaining, correctly, 
 the Value and Quantity of every description }f Work and 
 Materials, used in the Art of Building, fron their Prime Cost 
 in any part of the United States, collected from extensive 
 experience and observation in Budding and Designing ; to 
 which are added a large variety of Tables, Memoranda, etc., 
 indispensable to all engaged or concerned in erecting buildings 
 of any kind. By A. B. Clough, Architect, 24mo., cloth. . .75 
 
 Colburn. The Locomotive Engine: 
 
 Including a Description of its Structure, Rules for Estima- 
 ting its Capabilities, and Practical Observations on its Con- 
 struction and Management. By Zerah Colburn. Illus- 
 trated. A new edition. 12mo $1.25 
 
 Daguerreotypist and Photographer's Com- 
 panion. 
 
 12mo., cloth $1.25 
 
 Distiller. (The Complete Practical). 
 
 By M. Lafayette Byrn, M. D. With Illust'ns. 12mo.. . .$1.50 
 
 Duncan. Practical Surveyor's Guide. 
 
 By Andrew Duncan. Illustrated. 12mo., cloth $1.25 
 
 Dussauce. Practical Treatise on the Fabri- 
 cation of Matches, Gun Cotton, and Fulmi- 
 nating Powders. 
 
 By Professor H. Dussauce. 12mo $3.00 
 
 CONTENTS. Phosphorus History of Phosphorus ;' Physical Properties; 
 Chemical Properties ; Natural State; Preparation of White Phosphorus j 
 Amorphous Phosphorus, and Bonoxide of Lead. Matches Preparation oJ 
 
 10 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 t 
 
 Wooden Matches ; Matches inflammahle by rubbing, without noise ; Com- 
 mon Lucifer Matches ; Matches without Phosphorus ; Candle Matches : 
 Matches with Amorphous Phosphorus ; Matches and Rubbers without 
 Phosphorus. Gun Cotton Properties ; Preparation ; Paper Powder ; use of 
 Cotton and Paper Powders for Fulminating Primers, etc. ; Preparation of 
 Fulminating Primers, etc., etc. 
 
 Dussauce. A New and Complete Treatise on 
 the Arts of Tanning, Currying, and Leather 
 Dressing: 
 
 Comprising all the Discoveries and Improvements made in 
 France, Great Britain, and the United States. Edited from 
 Notes and Documents of Messrs. Sallerou, Grouvelle, Duval, 
 Dessables, Labarraque, Payen, Rene, De Fontenelle, Mala- 
 peyre, etc., etc. By Prof. H. Dussauce, Chemist. Illus- 
 trated by 212 wood engravings. 8vo $10.00 
 
 Dussauce. Treatise on the Coloring Matters 
 Derived from Coal Tar : 
 
 Their Practical Application in Dyeing Cotton, Wool, and 
 Silk ; the Principles of the Art of Dyeing and of the Dis- 
 tillation of Coal Tar, with a Description of the most Import- 
 ant New Dyes now in use. By Professor H. Dussauce, 
 Chemist. 12mo $2.50 
 
 Dyer and Color-maker's Companion: 
 
 Containing upwards of two hundred Receipts for making 
 Colors, on the most approved principles, for all the various 
 styles and fabrics now in existence ; with the Scouring Pro- 
 cess, and plain Directions for Preparing, Washing-off, and 
 Finishing the Goods. In one vol., 12mo $1.25 
 
 Easton. A Practical Treatise on Street or 
 Horse-power Railways : 
 
 Their Location, Construction, and Management ; with gen- 
 eral Plans and Rules for their Organization and Operation ; 
 together with Examinations as to their Comparative Advan- 
 tages over the Omnibus System, and Inquiries as to their 
 Value for Investment ; including Copies of Municipal Ordi- 
 nances relating thereto. By Alexander Easton, C. E. Il- 
 lustrated by 23 plates. 8 vo. cloth $2.00 
 
 Engineer's Handy-Book: 
 
 Containing a Series of Useful Calculations for Engineers, 
 Tool-makers, Millwrights, Draughtsmen, Foremen, and Me- 
 chanics generally. (In Press.) 
 
 Erni. Coal Oil and Petroleum : 
 
 Their Origin, History, Geology, and Chemistry ; with a view 
 of their importance in their bearing on National Industry. 
 
 11 
 
. PBACTICAL AND SCIENTIFIC BOOKS, 
 
 By Dr. Henri Erni, Chief Chemist, Department of Agricul- 
 ture. 12mo $2.50 
 
 Erni. The Theoretical and Practical Chem- 
 istry of Fermentation: 
 
 Comprising the Chemistry of Wine, Beer, Distilling of Li- 
 quors ; with the practical methods of their Chemical exam- 
 ination, preservation, and improvement such as Gallizing of 
 Wines. With an Appendix, containing well-tested Practical 
 Kules and Keceipts for the manufacture, etc., of all kinds of 
 Alcoholic Liquors. By Henri Erni, Chief Chemist, Depart- 
 ment of Agriculture. (In Press.) 
 
 Pairbairn. On Machinery of Transmission. 
 
 By William Fairbairn, C. E., LL.D., etc. Illustrated by 
 numerous engravings. (In Press.) 
 
 CONTENTS. On Wheels and Pullies ; Wrapping Connectors ; Toothed 
 Wheels ; Spur Gearing ; Pitch of Wheels ; Teeth of Wheels ; Bevel Wheels ; 
 Skew Bevels ; The Worm and Wheel ; Strength of the Teeth of Wheels ; ON 
 THE STRENGTH AND PROPORTIONS OF SHAFTS ; Material of which Shafting 
 is Constructed ; Transverse Strain ; Torsion ; Velocity of Shafts ; On Jour- 
 nals ; Friction ; Lubrication ; ON COUPLINGS FOR SHAFTS AND ENGAGING 
 AND DISENGAGING GEAR ; Couplings ; Disengaging and Re-engaging Gear ; 
 Hangers ; Plummer Blocks, etc., for carrying Shafting ; Main Shafts. 
 
 Pairbairn. Useful Information for Engi- 
 neers. 
 
 By William Fairbairn. (In Press.) 
 
 Kobell. Erni. Mineralogy Simplified : 
 
 A short method of Determining and Classifying Minerals, by 
 means of simple Chemical Experiments in the Wet Way. 
 Translated from the last German edition of F. Yon Kobell, 
 with additions, by Henri Erni, M. D., Chief Chemist, Depart- 
 partment of Agriculture, author of " Coal Oil and Petro- 
 leum." In one volume, 12mo $2.50 
 
 Fisher's Photogenic Manipulation. 
 
 16mo., cloth 62 
 
 French Dyer, (The) : 
 
 Comprising the Art of Dyeing in Woollen, Silk, Cotton, etc., 
 etc. By M. M. Kiffault, Yernaud, De Fontenelle, Thillaye, 
 and Mallepeyre. (In Press.) 
 
 Gilbart. A Practical Treatise on Banking. 
 
 By James William Gilbart, F. R. S. A new enlarged and 
 improved edition. Edited by J. Smith Homans, editor of 
 "Banker's Magazine." To which is added "Money," by 
 
 H. C. Carey. Svo $3.50 
 
 12 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 Gregory's Mathematics for Practical Men ; 
 
 Adapted to the Pursuits of Surveyors, Architects, Mechan- 
 ics, and Civil Engineers. 8vo., plates, cloth $2.50 
 
 Gas and Ventilation. 
 
 A Practical Treatise on Gas and Yentilation. By E. E. Per- 
 kins. 12mo., cloth $1.25 
 
 Griswold. Railroad Engineer's Pocket Com- 
 panion for the Field. 
 
 By W. Griswold. 12mo., tucks $1.25 
 
 Hartmann. The Practical Iron Manufactu- 
 rer's Vade-mecum. 
 
 From the German of Dr. Carl Hartmann. Illustrated. (In 
 Press.) 
 
 Hay. The Interior Decorator: 
 
 The Laws of Harmonious Coloring adapted to Interior De- 
 corations : with a Practical Treatise on House-Painting. By 
 D. R. Hay, House-Painter and Decorater. Illustrated by a 
 Diagram of the Primary, Secondary, and Tertiary Colors. 
 12mo. (In Press.) 
 
 Inventor's Guide: 
 
 Patent Office and Patent Laws ; or, a Guide to Inventors, 
 and a Book of Reference for Judges, Lawyers, Magistrates, 
 and others. By J. G. Moore. 12rno., cloth $1.25 
 
 Jervis. Railway Property. 
 
 A Treatise on the Construction and Management of Rail- 
 ways ; designed to afford useful knowledge, in the popular 
 style, to the holders of this class of property; as well as 
 Railway Managers, Officers, and Agents. By John B. Jervis, 
 late Chief Engineer of the Hudson River Railroad, Croton 
 Aqueduct, etc. One volume, 12mo., cloth $2.00 
 
 CONTENTS. Preface Introduction. Construction. Introductory : Land 
 and Land Damages ; Location of Line ; Method of Business ; Grading ^ 
 Bridges and Culverts ; Road Crossings; Ballasting Track ; Cross Sleepers ; 
 Chairs and Spikes ; Rails ; Station Buildings ; Locomotives, Coaches and 
 Cars. Operating. Introductory : Freight ; Passengers ; Engine Drivers 
 Repairs to Track ; Repairs of Machinery ; Civil Engineer ; Superintendent ; 
 Supplies of Material ; Receipts ; Disbursements ; Statistics ; Running 
 Trains ; Competition ; Financial Management ; General Remarks. 
 
 Johnson. A Report to the Navy Department 
 of the United States on American Coals, 
 
 Applicable to Steam Navigation, and to other purposes. 
 By Walter R. Johnson. With numerous illustrations. 
 
 607 pp. 8vo., half morocco $6.00 
 
 13 
 
f 
 PBACTICAI AND SCIENTIFIC BOOKS, 
 
 Johnson. The Coal Trade of British America : 
 
 With Researches on the Characters and Practical Values of 
 American and Foreign Coals. By Walter R. Johnson, Civil 
 and Mining Engineer and Chemist. 8vo $2.00 
 
 23= These important volumes of Prof. Johnson, now becoming scarce, 
 contain the results of the experiments made for the Navy Department, upon 
 which their Coal contracts are at present based. 
 
 Johnston. Instructions for the Analysis of 
 Soils, Limestones, and Manures. 
 
 By J. F. W. Johnston. 12mo 38 
 
 Keene. A Hand-book of Practical Gauging, 
 
 For the Use of Beginners : tc which is added a Chapter on 
 Distillation, describing the process in operation at the Cus- 
 torn-House for ascertaining the strength of Wines. By 
 James B. Keene, of H. M. Customs. (In Press.) 
 
 Kentish. A Treatise on a Box of Instru- 
 ments, 
 
 And the Slide Rule ; with the Theory of Trigonometry and 
 Logarithms, including Practical Geometry, Surveying. Meas- 
 uring of Timber, Cask and Malt Gauging, Heights and Dis- 
 tances* By Thomas Kentish. In one volume, 12mo.. .$1.25 
 
 Larkin. The Practical Brass and Iron Found- 
 er's Guide: 
 
 A Concise Treatise on Brass Founding, Moulding, the Metals 
 arid their Alloys, etc. : to which are added Recent Improve- 
 ments in the Manufacture of Iron, Steel by the Bessemer 
 Process, etc., etc. By James Larkin, late Conductor of the 
 Brass Foundry Department in Reaney, Neafie & Co.'s Penn 
 Works, Philadelphia. Fifth edition, revised, with Extensive 
 Additions. In one volume, 12mo $2.25 
 
 Lieber. Assayer's Guide; 
 
 Or, Practical Directions to Assayers, Miners, and Smelters. 
 By Oscar M. Lieber. 12mo., cloth $1.25 
 
 Love. The Art of Dyeing, Cleaning, Scour- 
 ing, and Finishing, 
 
 On the Most Approved English and French Methods : being 
 Practical Instructions in Dyeing Silks, Woollens, and Cottons, 
 Feathers, Chips, Straw, etc. ; Scouring and Cleaning Bed 
 and Window Curtains, Carpets, Rugs, etc. ; French and Eng- 
 lish Cleaning, any Color or Fabric of Silk, Satin, or Damask. 
 By Thomas Love, a working Dyer and Scourer. In 1 vol.. 
 
 12ino $3.00 
 
 14 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 Lowig. Principles of Organic and Physion>- 
 gical Chemistry. 
 
 By Dr. Carl Lowig. Translated by Daniel Breed, M. D. 
 8vo., sheep *. $3.50 
 
 Main and Brown. The Marine Steam-engine. 
 
 By Thomas J. Main, Professor of Mathematics, Royal Naval 
 College, and Thomas Brown, Chief Engineer, R. N. Illus- 
 trated by engravings and wood-cuts. 8vo., cloth $5.00 
 
 mg" THE TEXT BOOK OF THE UNITED STATES NAVAL ACADEMY. 
 
 CONTENTS. Introductory Chapter The Boiler ; The Engine ; Getting up 
 the Steam ; Duties to Machinery when under Steam ; Duties to Machinery 
 during an Action or after an Accident ; Duties to Engine, etc., on arriving 
 in Harbor. Miscellaneous. Appendix. 
 
 Main and Brown. Questions on Subjects Con- 
 nected with the Marine Steam-engine, 
 
 And Examination Papers ; with hints for their Solution. 
 By Thomas J. Main, Professor of Mathematics, Royal 
 Naval College, and Thomas Brown, Chief Engineer. R. N. 
 12mo., cloth ..$1.50 
 
 Main and Brown. The Indicator and Dyna- 
 mometer, 
 
 With their Practical Applications to the Steam-engine 
 By Thomas J. Main and Thomas Brown. With Illus- 
 trations $1.50 
 
 Makins. A Manual of Metallurgy, 
 
 More particularly of the Precious Metals, including the 
 Methods of Assaying them. Illustrated by upwards of 50 
 engravings. By George Hogarth Makins, M. R. C. S., F. C. S., 
 one of the Assayers to the Bank of England ; Assayer to 
 the Anglo-Mexican Mints ; and Lecturer upon Metallurgy 
 at the Dental Hospital, London. In one vol., 12mo.. .$3.50 
 
 CONTENTS. General Properties of the Metals ; General View of the Com- 
 bining Properties of the Metals ; Combination of Metals with the Non- 
 Metallic Elements ; Of Metallic Salts ; Of Heating Apparatus, Furnaces, 
 etc. ; Of Fuels Applicable to Metallurgic Operations ; Metals of the First 
 Class ; Metals ol the Second Class ; The Principles of Electro-Metal- 
 lurgy. 
 
 Marble Worker's Manual: 
 
 Containing Practical Information respecting Marbles in 
 general, their Cutting, Working, and Polishing ; Veneering, 
 
 etc., etc. 12mo., cloth , $1.50 
 
 15 
 
PRACTICAL AND SCIENTIFIC BOOKS, 
 
 Molesworth. Pocket-book of Useful For- 
 mulae and Memoranda for Civil and Me- 
 chanical Engineers. 
 
 By Guilford L. Molesworth, Member of the Institution of 
 'Civil Engineers, Chief Resident Engineer of the Ceylon 
 Railway. From the Tenth London edition $2.00 
 
 CONTENTS. Civil Engineering Surveying, Levelling, Setting Out, etc. ; 
 Earthwork, Brickwork, Masonry, Arches, etc. ; Beams, Girders, Bridges, 
 etc ; Roofs, Floors, Columns, Walls, etc. ; Railways, Roads, Canals, Riv- 
 ers, Docks, etc. ; Water-works, Sewers, Gas-works, Drainage, etc. ; Warm- 
 ing. Ventilation, Light, Sound, Heat, etc. 
 
 Mechanical Engineering. Gravity, Mechanical Centres and Powers: Mill- 
 work, Teeth of Wheels, Shafting, Belting, etc. ; Alloys, Solders, and Work- 
 Bhop Recipes ; Steam Boilers, and Steam-engines ; Water-wheels, Turbines, 
 etc., and Windmills ; Paddle and Screw Steamers ; Miscellaneous Machinery. 
 
 Weights and Measures, English and Foreign ; Logarithms of Numbers ; 
 Triangles, Trigonometry, and Tables of Sines, etc. ; Properties of Ellipse, Pa- 
 rabola, Circle, etc. ; Mensuration of Surfaces and Solids ; Tables of Arena, 
 and Circumferences of Circles ; Weights and Properties of Materials ; 
 Squares, Cubes, Powers, Roots, and Reciprocals of Numbers; Engineer- 
 ing Memoranda and Tables ; Supplement by J. T. Hurst, C. E., contain- 
 ing Additional Engineering Memoranda and Tables : Tables by Lewis 
 Olrick, C. E. 
 
 Miles. A Plain Treatise on Horse-shoeing. 
 
 With illustrations. By William Miles, author of the " Horse's 
 Foot" $1.00 
 
 Morfit. A Treatise on Chemistry, 
 
 Applied to the Manufacture of Soap and Candles : being a 
 Thorough Exposition in all their Minutiae of the Principles 
 and Practice of the Trade, based upon the most recent Dis- 
 coveries in Science and Art. By Campbell Morfit, Professor 
 of Analytical and Applied Chemistry in the University 
 of Maryland. A new and improved edition. Illustrated 
 with 260 engravings on wood. Complete in 1 volume, large 
 8vo $20.00 
 
 Mortimer. The Pyrotechnist's Companion : 
 
 By G. W. Mortimer. Illustrated. 12mo., cloth $1.25 
 
 Napier. Manual of Electro-Metallurgy: 
 
 Including the Application of the Art to Manufacturing 
 Processes. By James Napier. From the second London 
 edition, revised and enlarged. Illustrated by engravings. 
 In one volume, 12mo $1.50 
 
 Napier. Chemistry Applied to Dyeing. 
 
 By James Napier, F. C. S. Illustrated. 12mo $3.00 
 
 16 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 Nicholson. Bopkbinding : A Manual of the 
 Art of Bookbinding : 
 
 Containing full Instructions in the different Branches of 
 Forwarding-, Gilding, and Finishing. Also,' the Art of Mar- 
 bling Book-edges and Paper. By James B. Nicholson. Il- 
 lustrated. 12mo.. cloth $2.25 
 
 CONTENTS. Sketch of the Progress of Bookbinding, Sheet-work, Forward- 
 ing the Edges, Marbling, Gilding the Edges, Covering, Half Binding, Blank 
 Binding, Boarding, Cloth-work, Ornamental Art, Finishing, Taste and De- 
 sign, Styles, Gilding, Illuminated Binding, Blind Tooling, Antique, Color- 
 ing, Marbling, Uniform Colors, Gold Marbling, Landscapes, etc. ; Inlaid Or- 
 naments, Harmony of Colors, Pasting Down, etc. ; Stamp or Press-work, 
 Restoring the Bindings of Old ooks, Supplying imperfections in Old Books, 
 Hints to Book Collectors, Technical Lessons. 
 
 Norris. A Hand-book for Locomotive En- 
 gineers and Machinists. 
 
 By Septimus Norris, C. E. New edition, illustrated, 12mo., 
 cloth $2.00 
 
 Nystrom. On Technological Education and 
 the Construction of Ships and Screw Pro- 
 pellers for Naval and Marine Engineers. 
 
 By John W. Nystrom, late Acting Chief Engineer U. S. N. 
 Second edition, revised with additional matter. Illustrated 
 by 7 engravings. 12mo $2.50 
 
 CONTENTS. On Technological Education ; The knowledge of Steam En- 
 gineering behind the knowledge of Science ; Failure of Steamers for a want 
 of Applied Science ; Fresh water Condensers, and combustion of Fuel ; 
 Knowledge of Steamship Performance; Expansion experiments made by 
 the Navy Department ; Natural effect of Steam or maximum work per unit 
 of Heat ; Natural effect of Steam-engines ; Nystrom's Pocket-book ; Reform 
 wanted in Scientific Books ; America has taken the lead in Popular Edu- 
 cation ; Technological Institutions wanted ; The National Academy of 
 Sciences ; Object of Technological Institutions ; Steam-engineering and 
 Ship-building ; Necessity of complete Drawings before the building of 
 Steamers is commenced ; America has taken the lead in the new Naval 
 Tactics ; The Naval Academy, at Annapolis, not proper for a School of 
 Steam-engineering ; Want of applied Science in our Workshops ; Locomo- 
 tive Engineering; Communication to the Secretary of the Navy on the 
 Science of Ship-building ; Ship-builders consider their Art a Craft ; Ship- 
 builders' jealousy ; Ship-building developed to the condition of a Science ; 
 Memorandum ; Chief Engineer Isherwood does not approve the Parabolic 
 Construction of Ships ; On the Parabolic Construction of Ships ; Applica- 
 tion of the Parabolic Construction of Ships ; Recording Formulas ; Record- 
 ing Tables ; The labor of calculating the Ship-building Tables ; Mr. W. L. 
 Hanscom, Naval Constructor, on the Parabolic Method ; Mr. J. Vaughan 
 Merrick on the Parabolic Construction ; Resignation, by the Author, as 
 Acting Chief Engineer in the Navy ; Memorandum ; The Science of Dyna- 
 mics in a confused condition ; Illustrations required in Dynamics ; Mr. 
 Isherwood declines having the subject of Dynamics cleared up ; The sub 
 ject of Dynamics submitted to the National Academy of Sciences ; On the 
 elements of Dynamics ; force, power, and work, defined ; Work, a trinity of 
 Physical Elements ; Discussion with Naval Engineers on the subject of 
 Dynamics ; Questions in Dynamics submitted to the Academy of Sciences ; 
 Vis-viva ; Unit for Power ; Unit for Work ; Navy Departmen attciru>tif 
 
 r 
 
PRACTICAL AND SCIENTIFIC BOOKS, 
 
 to reorganize the Corps of Engineers ; Washington Navy Yard ; Engineer* 
 In the Navy Department ; Captain Fox on Engineering and the Construc- 
 tion of Ships ; Secrecy respecting Ships' Drawings ; Steam Boiler Explo- 
 sions; Review of Screw Propellers; To Construct a Plain Screw; Pro- 
 peller with a Compound Expanding Pitch; Propeller as Constructed by 
 Chief Engineer Isherwood ; Propeller as Constructed from Mr. Isherwood's 
 Drawings; Centripetal Propeller; Centripetal Propeller with Compound 
 Expanding Pitch ; The Office of the Coast Survey an example of what 
 the Bureau of Steam-engineering should be; The Engineer-in-Chief of the 
 Navy a Grand Admiral ; Constructions ought not to be made in the Navy 
 Department: The office of the Coast Survey and the Light-house Board na- 
 turally belong to the Navy. 
 
 O'Neill. Chemistry of Calico Printing, Dye- 
 ing, and Bleaching: 
 
 Including Silken, Woollen, and Mixed Goods ; Practical and 
 Theoretical. By Charles O'Neill. (In Press.) 
 
 O'Neill. A Dictionary of Calico Printing and 
 Dyeing. 
 
 By Charles O'Neill. (In Press.) 
 
 Painter, Gilder, and Varnisher's Compan- 
 ion. 
 
 Containing Rules and Regulations in every thing relating to 
 the Arts of Painting, Gilding, Varnishing, and Glass Stain- 
 ing : with numerous useful and valuable Receipts ; Tests for 
 the detection of Adulterations in Oils and Colors ; and a 
 statement of the Diseases and Accidents to which Painters, 
 Gilders, and Varnishers are particularly liable, with the sim- 
 plest methods of Prevention and Remedy. Eighth edition. 
 To which are added complete Instructions in Graining, Mar- 
 bling, Sign Writing, in Gilding on Glass. 12mo., cloth. $1.50 
 
 Pallett. The Miller's, Millwright's, and En- 
 gineer's Guide. 
 
 By Henry Pallett. Illustrated. In 1 vol., 12mo $3.00 
 
 CONTENTS. Explanation of Characters used : Definitions of Words used 
 In this Work; United States Weights and Measures; Decimal Fractions; 
 On the Selection of Mill-stones; On the Dressing of New Mill-stonesmak- 
 ing their Faces Straight, and ready for putting in the Furrows ; Furrows : 
 the manner of Laying them out : their Draft, and cutting them in : Direc- 
 tions for laying off and cutting the Holes for the Balance Ryne and Driver ; 
 Directions for putting in the Balance Ryne and the Boxes for the Driver, 
 and making them fast; Of Setting the Bed Stone, and fastening the Bush 
 therein; Directions how to Bridge or Tram the Spindle; Instructions for 
 Grinding off" the Lumps of New Stones, Turning the Back of the Running 
 Stone, Rounding the Eye and Balancing the Stone ; Directions for Dressing 
 and Sharpening Mill-stones when they become dull ; Respecting the Irons 
 of the Mill; Description of Plate 4. ShoAving the Principle upon which the 
 Mill-stones work; How to Fit a New Back on a Stone that has been Run- 
 ning; Of the Elevator, Conveyor, and Hopper Boy: Of Bolting Reels and 
 Cloths, with Directions for Bolting and Inspecting Flour; Directions for 
 Cleaning Wheat; Instructions for Grinding Wheat: Directions for Grind- 
 jog Wheat with Garlic amongst it, and for Dressing the Stones suitable 
 
 18 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 thereto ; Directions how to put the Stones in Order for Grinding Wheat 
 that has Garlic amon^it it. Directions for Grinding Middlings, and how to 
 Prevent the Stones from Choking, so as to make the most of them; Reels 
 for Bolting the Middlings ; Instructions for a small Mill, Grinding different 
 kinds of Grain ; Of the Manner of Packing Flour ; Table Showing the num- 
 ber of Pounds which constitute a Bushel, as established by Law in the 
 States therein named; The Duty of the Miller; Pearl Barley or Pot Barley; 
 The Art of Distillation : Of the Importance of Draughting and Planning 
 Mills : Cogs : the best time for Seasoning and Cutting them; The Framing 
 of Mill- work: Windmills; A Table of the Velocity of Wind; Instiuctiona 
 for Baking: Receipt for making Babbitt Metal, etc.; Cement; Solders; 
 Table Showing the Product of a Bushel of Wheat of different Weights and 
 Dualities, as ascertained from Experiments in Grinding Parcels ; Of Saw- 
 mills and their Management; The Circular Saw ; Rules for Calculating the 
 Speed the Stones and other pieces or parts of the Machinery run at ; To find 
 the Quantity, in Bushels, a Hopper will Contain; Table of Dry Measure; 
 Spouts; the Necessity of making them Large; To lay off any required 
 Angle: Of Masonry; of Artificer's Work; Bricklayer's Work; Bricks and 
 Lathes Dimensions ; Timber Measure ; Table Diameters in inches of Saw 
 Logs reduced to inch board measure; Of the Wedge; Of Pumps; The 
 Screw; Table showing the power of Man or Horse as applied to Machinery ; 
 Measure of Solidity ; Rules for calculating Liquids ; A Table showing the 
 Capacity of Cisterns, Wells, etc., in Ale Gallons and Hogsheads, in propor- 
 tion to their Diameters and Depths ; Steel Of the various degrees of Heat 
 required in the Manufacture of Steel ; Composition for Welding Cast Steel ; 
 Directions for Making aud Sharpening Mill Picks; A Composition for Tem- 
 pering Cast Steel Mill Picks; Governors for Flouring Mills;. The Governor 
 or Regulator; The Pulley; Of the Velocity of Wheels, Pulleys, Drums, etc. ; 
 On Friction : Belting Friction ; Of the Strength of different Bodies ; Falling 
 Bodies ; Of the different Gearings for propelling Machinery ; The Crown or 
 Face Gearing; On matching Wheels to make the Cogs wear even ; On Steam 
 and the Steam-engine; Of Engines their Management, etc. ; Prevention of 
 Incrustation in Steam Boilers; Double Engines ; The Fly-wheel; Table of 
 Circumferences and Areas of Circles, in Feet, suitable for Fly-wheels, etc. ; 
 To calculate the effects of a Lever and Weight upon the Safety-valve of a 
 Steam Boiler, etc. ; Of the Slide Valve ; Boilers ; Chimneys ; Explosion of 
 Boilers; On the Construction of Mill-dams : Rock Dam; Frame Dams; Brush 
 or Log Dam : Gates ; Description of Water-wheels ; Of Npn-elasticity and 
 Fluidity in Impinging Bodies ; Motion of Overshot Wheels ; The Breast 
 Wheel ; Overshot or Breast Wheels ; Table of the number of inches of water 
 necessary to drive one run of Stones, with all the requisite Machinery for 
 Grist and Saw-mills, under heads of water from four to thirty feet ; Table 
 containing the weight of columns of water, each one foot in length, and 
 of various diameters ; The Undershot Wheel ; Tub Wheels ; The Flutter 
 "Wheel ; The Laws of Motion and Rest ; Power of Gravity, Percussion, or 
 Impulse, with the Reaction Attachment; Table of the velocities of the 
 Combination Reaction Water-wheel per minute, from heads of from four 
 to thirty feet; Tables to reckon the Price of Wheat from Thirty Cents to 
 Two Dollars per Bushel. 
 
 Pradal, Malepeyre and Dussauce. A Com- 
 plete Treatise on Perfumery: 
 
 Containing Notices of the Eaw Material used in the Art, 
 and the best Formulae. According to the most approved 
 methods followed in France, England, and the United States. 
 By M.'P. Pradal, Perfumer Chemist, and M. F. Malepeyre. 
 Translated from the French, with extensive additions, by 
 Professor H. Dussauce. 8vo $7.50 
 
 CONTENTS. Nature of the Trade of the Perfumer ; Raw Material ; Po- 
 mades ; Almond Oils ; Perfumed Oils, called Huile Antique ; Powders ; 
 Cosmetic Preparation for the Lips and Skin ; Almond Pastes ; Cosmetic 
 Glovea Paints ; Dentifrices ; Volatile Oils ; Aromatic Waters ; Spirituous 
 
 19 
 
PBACTICAL AND SCIENTIFIC BOOKS, 
 
 Odors ; Colors ; Infusions ; Tinctures ; Spirits ; Aromatic Alcohols ; Fuming 
 Pastils ; Cloves ; Sachets ; Cosmetics ; Cassolettes ; Toilet Vinegars ; Phar- 
 maceutical Preparations made by the Perfumer ; Toilet Soaps ; Various 
 Substances and Processes belonging to the Perfumer's Trade. 
 
 Proteaux. Practical Guide for the Manufac- 
 ture of Paper and Boards. 
 
 By A. Proteaux, Civil Engineer, Graduate of the School of 
 Arts and Manufactures, and Director of Thiers' Paper-mill, 
 Puy-de-D6me. With additions, by L. S. Le Normand. 
 Translated from the French with Notes, by Horatio Paine, 
 A. B., M. D. To which is added a Chapter on the Manufac- 
 ture of Paper from Wood in the United States, by Henry 
 T. Brown, of the " American Artisan." Illustrated by six 
 plates, containing Drawings of Raw Materials, Machinery, 
 Plans of Paper-mills, etc., etc. 8vo $5.00 
 
 CONTENTS. Chapt. I. A Glance at the History of Paper-making. Chapt. II. 
 Raw Materials Rags. Chapt. III. Manufacture Sorting and Cutting ; Dust- 
 ing ; Washing and Boiling; Reduction to Half-stuff; Drainage; Bleaching; 
 Composition of the Pulp ; Refining or Beating ; Sizing ; Coloring Matters; 
 The Work of the Paper-machine ; Finishing. Chapt. IV. Manufacture of Paper 
 from the Vat. or by Hand Manufacture of Paper by hand ; Sizing ; Finishing ; 
 Manufacture of Bank-note Paper, and Water-mark Paper in General ; Com- 
 parison between Machine and Hand-made Papers ; Classification of Papei 
 Chapt. V. Further Remarks on Sizing Of the Sizing-room ; Method of Ex- 
 tracting Galatine ; Operation of Si/.ing ; Drying after Sizing : the Dutcu 
 method preferable to the French ; Some important Observations upon Sizing ; 
 Appendix upon Sizing ; Theories of Sizing ; Sizing in the Pulp ; M. Canson's 
 method of Sizing in the Pulp ; Comparison of the Two methods. Chapt. VI. 
 Different Substances Suitable for Making Paper Straw Paper ; Wood Paper. 
 Chapt. VII. Chemical Analysis of Materials employed in Paper-making 
 The Waters ; Alkalimetrical Test ; Examination of Limes ; Chlorometric 
 Tests ; Examination of Manganese ; Chlorometric Degrees of Samples of 
 Manganese ; Antichlorine ; Alums; Kaolin: Starch ; Coloring Materials ; 
 Fuel; Examination of Papers ; Materials of a Laboratory. Chapt. VIII. 
 Working Stock of a Paper-mill Motive Power; Rag Cutters; Dusters; 
 Washing Apparatus ; Boiling Apparatus ; Washing and Beating-engines ; 
 Apparatus for Bleaching and Draining the Pulp ; Paper-machines ; Finish- 
 ing-machines ; General Working Stock of a Paper-mill ; General Remarks 
 upon the Establishment of a Paper-mill ; General Remarks in reference to 
 Building ; General Considerations. Chapt. IX. The Manufacture of Paper 
 from Wood in the United States. Chapt. X. Manufacture of Boards. Chapt. 
 XI. Manufacture of Paper in China and Japan. 
 
 DESCRIPTION OF THE PLATES. 
 
 Regnault. Elements of Chemistry. 
 
 By M. Y. Kegnault. Translated from the French, by T. 
 Forrest Betton, M.D., and edited, with notes, by James C. 
 Booth, Melter and Eefiner U. S. Mint, and Wm. L. Faber, 
 Metallurgist and Mining Engineer. Illustrated by nearly 
 700 wood engravings. Comprising nearly 1,500 pages. In 
 two volumes, 8vo., cloth $10 00 
 
 AMONG THE CONTENTS ARE Volume I. : French and English Weights, etc. 
 Introduction Crystallography ; Chemical Nomenclature ; Metalloids ; Oxy- 
 
 fen ; Hydrogen ; Selenium ; Tellurium ; Chlorine ; Bromine ; Iodine ; Fluorine : 
 'hosphorus ; Arsenic ; Boren ; Silicum ; Carbon ; On the Equivalents oi 
 Metalloids. Metals Geology ; Physical Properties of the Metals ; Chemical 
 
 20 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 Properties of the Metals. On Salts. I. Alkaline Metals Potassium ; So- 
 dium ; Lithium ; Ammonia. II. A! kalino- Earthy Metals Barium ; Stron- 
 tium ; Calcium ; Magnesium. III. Earthy Metals Aluminum ; Glucinum ; 
 Zirconium; Thorinum ; Yttrium; Erbium; Terbium; Cerium; Lantha- 
 num ; Didymium. Chemical Arts Dependent on the Preceding Bodies Gun- 
 powder ; Lime and Mortar ; Glass ; Kinds of Glass ; Imperfections and 
 Alterations of Glass ; Pottery, the Paste of which becomes Compact by 
 Burning ; Pottery, the Paste of which remains Porous after Burning ; Or- 
 naments and Painting ; Chemical Analysis of Earthenware. 
 
 Volume II. : Preparation of Ores, Manganese, Iron ; Reduction in the 
 Blast Furnace ; Chromium ; Cobalt ; Nickel ; Zinc ; Cadmium ; Tin ; Tita- 
 nium ; Columbium; Niobium; Pelopium ; Ilmenium ; Lead, Metallurgy of ; 
 Bismuth, Metallurgy of ; Antimony, Metallurgy of ; Uranium; Tungsten; 
 Molybdenum ; Vanadium ; Copper, Metallurgy of; Mercury, Metallurgy of 
 Silver, Metallurgy of ; Gold, Metallurgy of ; Platinum; Osmium; Iridium ; 
 Palladium; Rhodium; Ruthenium. IV. Organic Chemistry Introduction 
 Ultimate Analysis of Organic Substances ; Construction of a Formula ; 
 Analysis of Gases ; Essential Proximate Principles of Plants ; Acids Exist- 
 ing in Plants ; Organic Alkaloids ; Neutral Substances in Plants ; Nitrils ; 
 Essential Oils ; Products of Dry Distillation ; Fats ; Organic Coloring Mat- 
 ters ; Action of Plants on the Atmosphere ; Animal Chemistry ; Secre- 
 tions ; Excretions ; Technical Organic Chemistry ; Manufacture of Bread ; 
 Brewing ; Cider and Perry ; Wine-making ; Beet Sugar ; Cane Sugar ; Sugar- 
 refining ; Manufacture of Bone Black ; Soap-boiling ; Principles of Dyeing ; 
 Mordants ; Calico-printing ; Tanning ; Charring Wood and Coal ; Manufac- 
 ture of Illuminating Gas. 
 
 Sellers. The Color Mixer: 
 
 Containing nearly Four Hundred Eeceipts for Colors, Pastes, 
 Acids, Pulps, Blue Vats, Liquors, etc., etc., for Cotton and 
 Woollen Goods : including the celebrated Barrow Delaine 
 Colors. By John Sellers, an experienced practical work- 
 man. In one volume, 1 2mo $2.50 
 
 Shunk. A Practical Treatise on Railway 
 Curves and Location, for Young Engi- 
 neers. 
 
 By Wm. F. Shunk, Civil Engineer. 12mo $1.50 
 
 Smith. The Dyer's Instructor: 
 
 Comprising 1 Practical Instructions in the Art of Dyeing Silk, 
 Cotton, Wool and Worsted, and Woollen Goods : containing 
 nearly 800 Receipts. To which is added a Treatise on tne 
 Art of Padding ; and the Printing of Silk Warps, Skeins, 
 and Handkerchiefs, and the various Mordants and Colors for 
 the different styles of such work. By David Smith, Pattern 
 Dyer. 12mo., cloth $3.00 
 
 53=* This is by far the most valuable book of PRACTICAL RECEIPTS FOR 
 DYERS ever published in this country has been eminently popular, and the 
 third edition is just now ready for delivery. 
 
 Strength and other Properties of Metals. 
 
 Eeports of Experiments on the Strength and other Pro- 
 pfcrties of Metals for Cannon. With a Description of the 
 Machines for testing Metals, a.iid of the Classification o f 
 
 21 
 
PKACTICAL AND SCIENTIFIC BOOKS, 
 
 Cannon in service. By Officers of the Ordnance Department 
 U. S. Army. By authority of the Secretary of War. Illus- 
 trated by 25 large steel plates. In 1 vol., quarto $10.00 
 
 g^= The best treatise on cast-iron extant. 
 
 Tables Showing the Weight of Round, 
 Square, and Flat Bar Iron, Steel, etc., 
 
 By Measurement. Cloth 63 
 
 Taylor. Statistics of Coal : 
 
 Including Mineral Bituminous Substances employed in Arts 
 and Manufactures ; with their Geographical, Geological, and 
 Commercial Distribution and amount of Production and 
 Consumption on the American Continent. With Incidental 
 Statistics of the Iron Manufacture. By K. C. Taylor. Second 
 edition, revised by S. S. Haldeman. Illustrated by five Maps 
 and many Wood engravings. 8vo. cloth $6.00 
 
 Templeton. The Practical Examinator on 
 Steam and the Steam-engine : 
 
 With Instructive References relative thereto, arranged for 
 the use of Engineers, Students, and others. By Wm. Tem- 
 pleton, Engineer. 12mo $1.25 
 
 This work was originally written for the author's private use. He was 
 
 Erevailed upon by various Engineers, who had seen the notes, to consent to 
 ts publication, from their eager expression of belief that it would be 
 equally useful to them as it had been to himself. 
 
 Turnbull. The Electro-Magnetic Telegraph : 
 
 With an Historical Account of its Eise, Progress, and Pre- 
 sent Condition. Also, Practical Suggestions in regard to 
 Insulation and Protection from the Effects of Lightning. 
 Together with an Appendix, containing several important 
 Telegraphic Devices and Laws. By Lawrence Turnbull, 
 M. D., Lecturer on Technical Chemistry at the Franklin In- 
 stitute. Second edition. Revised and improved. Illustrated 
 by numerous engravings. 8vo $2.50 
 
 Turner's (The) Companion: 
 
 Containing Instruction in Concentric, Elliptic, and Eccentric 
 Turning ; also, various Steel Plates of Chucks, Tools, and 
 Instruments ; and Directions for Using the Eccentric Cutter, 
 Drill, Vertical Cutter and Rest ; with Patterns and Instruc- 
 tions for working them. 12mo., cloth $1.50 
 
 Ulrich. Dussauce. A Complete Treatise on 
 the Art of Dyeing Cotton and Wool, 
 
 As practiced in Paris, Rouen, Mulhausen, and Germ%ny. 
 From the French of M. Louis Ulrich, a Practical Dyer in 
 22 
 
PUBLISHED BY HENRY CAREY BAIRD. 
 
 the principal Manufactories of Paris, Rouen, Mulhausen. 
 etc., etc. ; to which are added the most important Receipts 
 for Dyeing Wool, as practiced in the Manufacture ImpSriale 
 des Gobelins, Paris. By Prof. H. Dussauce. 12mo. . . $3.00 
 
 Watson. Modern Practice of American Ma- 
 chinists and Engineers : 
 
 Including the Construction, Application and Use of Drills, 
 Lathe Tools, Cutters for Boring Cylinders and Hollow 
 Ware generally, with the most economical speed for the 
 same ; the results verified by Actual Practice at the Lathe, 
 the Vice, and on the Floor. Together with Workshop 
 Management, Economy of Manufactures, the Steam-engine, 
 Boilers, Gears, Belting, etc., etc. By Egbert P. Watson, 
 late editor of the " Scientific American." Illustrated with 
 Eighty-six Engravings. In 1 volume, 12mo $2.50 
 
 CONTENTS. 
 
 PART 1. The Drill and its Office. 
 PART 2. Lathe Work. 
 
 PART 3. Miscellaneous Tools and Processes. 
 PART 4. Steam and Steam-engine. 
 
 PART 5. Gears, Belting, and Miscellaneous Practical 
 Information. 
 
 Watson. The Theory and Practice of the 
 Art of Weaving by Hand and Power : 
 
 With Calculations and Tables for the use of those connected 
 with the Trade. By John Watson, Manufacturer and Prac- 
 tical Machine Maker. Illustrated by large drawings of the 
 best Power-Looms. 8vo $5.00 
 
 Weatherly. Treatise on the Art of Boiling 
 Sugar, Crystallizing, Lozenge-making, Com- 
 fits, Gum Goods, 
 
 And other processes for Confectionery, etc., in which are 
 explained, in an easy and familiar manner, the various 
 methods of manufacturing every description of raw and 
 refined Sugar goods, as sold by Confectioners and others. 
 12mo $2.00 
 
 Williams. On Heat and Steam : 
 
 Embracing New Views of Vaporization, Condensation, and 
 Expansion. By Charles Wye Williams, author of a Treatise 
 on the Cumbustion of Coal Chemically and Practically 
 Considered. With Illustrations. 8vo $3.50 
 
 23 
 
PRACTICAL AND SCIENTIFIC BOOKS, 
 
 Bullock. The American Cottage Builder : 
 
 A Series of Designs, Plans, and Specifications, from $200 to 
 $20,000, for Homes for the People ; together with Warming, 
 Ventilation, Drainage, Painting, and Landscape Gardening. 
 By John Bullock, Architect, Civil Engineer, Mechanician, 
 and Editor of " The Rudiments of Architecture and Build- 
 ing," etc., etc. Illustrated by 75 engravings. In one vol., 
 
 8vo $3.50 
 
 CONTENTS. Chap. I. Generally Where to Build a Cottage ; Bird Cot- 
 tage : Objects Desired. II. The Various Parts Walls ; Cob Walls ; Mud 
 Walls ; Silverlocks' Hollow Walls ; Dearnes' Hollow Brick Wall ; Lou- 
 don's Hollow Brick Walls ; Flint Built Walls ; Walls of Framed Timber, 
 Rubble, and Plaster ; Walls of Hollow Bricks ; Covering for External Walls ; 
 Inside Work ; Floors ; Lime-ash Floors ; Concrete Floors ; Plaster Floor ; 
 Asphalte ; Floor of Hollow Pots ; Tile Floor ; Floors of Arched Brickwork 
 in Mortar ; Fire-proof Floor ; Tile-trimmer ; Girder Floor; Stairs formed 
 of Tile ; Roofs ; Thatch ; Tile for Roofing ; Slate Roof ; Cast-iron Roofing : 
 Eaves-gutter ; Chimney-shaft ; Ventilation and Warming. III. Terra del 
 Fuego Cottage. IV. Prairie Cottage Cottage of Unburnt Brick Plan ; Cross 
 Section ; Side View ; Manner of Laying the Brick and the Foundation ; 
 Chimney-cap, Perspective, and Top Views. V.The Farm Cottage Ground 
 Floor ; Attic Floor. VI. The Village Cottage. VII. Italian Cottage. VIII. 
 Thatched Cottage. IX. Cottage of the Society for Improving the Condition of the 
 Poor. X. Warming and Ventilation Ventilation. XL Model Cottage- 
 Hollow Brick Work. XII. Rural Cottage Basement Plan ; Plan of the First 
 Floor ; Plan of the Second Floor. XIII. Octagon Cottage Plan of Base- 
 ment ; Plan of Principal Story. XIV. Drainage. XV. Rural Homes Cir- 
 cumstances to be taken into consideration in the Choice of a Situation ; 
 Elevation ; The character of the Surface on which to Build ; Aspect ; Soi 1 
 and Subsoil ; Water ; Villa ; Rural Home, No. 1 ; Views of a Suburban Resi- 
 dence in the English style ; Rural Home, No. 2 ; Rural Home, No. 3 ; Rural 
 Home, No, 4. XVI. Paint and Color. XVII. Suburban Residences Gothic 
 Suburban Cottage of C. Prescott, Esq., Troy, N. Y. ; Basement ; First Floor ; 
 Attic; Second Floor; Suburban Octagonal Cottage. XV 'III. - Landscape 
 Gardening First steps in Forming a Landscape Garden ; The Roads and 
 Paths ; Trees, Shrubs, and Planting; Hills and Mounds ; Valleys and Low 
 Grounds ; Rock-work ; Of Water, and its Appropriation or Adoption ; Foun- 
 tains ; General Observations ; Formal Gardening ; Pleasure Grounds and 
 Flower Gardens ; The Flower Garden ; The Greenhouse ; The Conserva- 
 tory. XIX. Cost The Terra del Fuegan Cottage ; The Prairie Cottage ; 
 The Village Cottage ; The Italian Cottage ; The Thatched Cottage ; The 
 Cottage of the Society for Improving the Condition of the Poor ; Prince 
 Albert's Model Cottage ; The Rural Cottage ; Mr. Fowler's Octagonal Cot- 
 tage ; Rural Home, No. I ; Rural Home, No. 2 ; Rural Home, No. 3; The 
 Suburban Residence ; The Octagonal Suburban Residence designed by 
 Wilcox ; The Byzantine Cottage ; The Gothic Suburban Residence designed 
 by Mr. Davis. XX. Two Residences The Byzantine Cottage; Ground 
 Plan ; Plan of Second Story ; The Gothic Suburban Residence of W. H. C. 
 Waddell, Esq., N. Y. ; First Floor; Second Floor. XXI. Artist's and Arti- 
 san- 8 Calling. 
 
 Smeaton. Builder's Pocket Companion: 
 
 Containing the Elements of Building, Surveying, and Archi- 
 tecture; with Practical Kules and Instructions connected 
 with the subject. By A. C. Smeaton, Civil Engineer, etc. 
 
 In one volume, 12mo $1.25 
 
 CONTENTS. The Builder. Carpenter, Joiner, Mason, Plasterer, Plumber, 
 
 Painter. Smith, Practical Geometry. Surveyor, Cohesive Strength of Bodies, 
 
 Architect. 
 
 24 
 
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