DEPARTMENT OF THE INTERIOR ' John Barton Payne, Secretary United States Geological Survey George Otis Smith, Director THE PREPARATION OF ILLUSTRATIONS FOR REPORTS OF THE Vmm^ STATES GEOLOGICAL SURVEY WITH BRIEF DESCRIPTIONS OF PROCESSES OF REPRODUCTION BY JOHN L. RIDGWAY WASHINGTON GOVERNMENT PRINTING OFFICE 1920 DEPARTMENT OF THE INTERIOR John Barton Payne, Secretary United States Geological Survey George Otis Smith, Director THE PREPARATION OF ILLUSTRATIONS FOE, REPORTS OF THE DMTED STATES GEOLOGICAL SURTEY WITH BRIEF DESCRIPTIONS OF PROCESSES OF REPRODUCTION BY JOHN L. RIDGWAY WASHINGTON GOVERNMENT PRINTING OFFICE 1920 For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 65 cents THE PREPARATION OF ILLUSTRATIONS FOR REPORTS OF THE UNITED STATES GEOLOGICAL SURVEY BY JOHN L. RIDGWAY .jHgee^'-EN'^^'^ CONTENTS. Past I. Preparation by Authors. [Pag«. Introduction 7 Pui*pose and value of illustrations 8- Selection and approval of illustrations 8 Submittal of illustrations 10 Kinds of illustrations 10 Sizes of illustrations 11 Subdivisions of plates and figures 12 Preparation of copy by authors 12 Character of original material 12 Preliminary preparation of maps 13 Material available for base maps 14 Basic features of maps 17 Standard scales 18 Orientation of maps 18 Projection 18 Explanation , 19 Titles of maps and other illustrations 19 Symbols used on maps 20 General features 20 Letter symbols 20 Oil and gas symbols 21 Symbols for use on maps showing features of ground water 21 Black-line conventions 23 Materials used in preparing maps 23 Paper 23 Bristol board 24 Tracing linen 24 Inks 25 Drawing pens 2.5 Pencils 25 Rubber erasers and cleaners 25 Colored pencils and crayons 26 Water colors 26- Japanese transparent water colors 26- Coloring geologic maps 27 Diagrams 28; Essential features 28 Plans of mine workings 29 Sections 29 Lithologic symbols 32 Use of photographs as illustrations 32 Essential features 32 Copyrighted photographs 33 3 4 CONTENTS. Preparation of copy by authors — Continued. Use of photographs as illustrations — Continued. Page. Sources of photographs 34 Lending original photographs and dramngs 34 Unpublished photographs 34 Specimens 34 General requirements 34 Borrowed and fragile specimens 35 Transmittal of paleontologic specimens 35 Making up plates ^__ 36 Reuse of illustrations 37 Approval of finished illustrations 38 Revision of illustrations 38 Submittal of proofs 38 Proof-reading illustrations 39 General considerations 39' Pabt II. Prepakation by Draftsmen. General directions 41 Instruments 42 Classification of material 42 Preparation of maps 43 Projection 43 Details of base maps 45 Transferring or copying 46 Tracing 46 Celluloid transferring 47 Sketching by reticulation 47 The "shadowless drafting table" 47 Topographic features 48 Relief 48 Hydrography 51 Cultural features 52 Lettering 53 General directions 53 Lettering by type 54 Abbreviations 55 Names of railroads 57 IMake-up of maps 57 Forms for certain features 57 Border 57 Title 58 Explanation 58 Graphic scales for maps 59 Symbols 61 Areal patterns for black and white maps CI Standard colors for geologic maps 63 Reduction or enlargement of maps 63 Diagrams 64 Sections . 64 Plans and cross sections of mines G5 COXTENTS. O Page. Drawings of specimens of rocljs and fossils 66 Methods, used 66 Brush and pencil drawings 66 Pen drawings 67 Ketouching photographs of specimens 68 Landscape drawings from poor photographs 68 Pen drawings made over photographs ^ 68 Brush drawings from poor photographs 69 Outdoor sketches 69 Drawings of crystals 70 Retouching photographs 70 Part III. Peocesses of Repboducing Illustkatioxs. Methods employed 72 Photoengraving 72 General features 72 Zinc etching 73 Copper etching in relief 75 Half-tone engraving 75 Three-color half-tone process 78 Wax engraving (the cerotype process) 80 Wood engraving 81 Photogelatin processes 82 Lithography ^ 83 Original process 83 Photolithography 86 Offset printing 87 Chromolithography 87 Engraving on stone and on copper 89 Appendix. Length of degrees of latitude and longitude 91 Metric system and equivalents 92 Geologic eras, periods, systems, epochs, and series 92 Chemical elements and symbols 93 Greek alphabet 93 Roman numerals 93 Mathematical signs- 94 Names of rocks = 94 ILLUSTRATIONS. Page. Plate I. Methods of inserting plates and figures 10 II. Symbols used on geologic maps, economic maps, and mine plans 20 III. Lithologlc symbols used in structure and columnar sections to represent different Ifinds of rock 32 IV. Symbols used on base maps 52 V. Reduction sheet used in lettering illustrations 54 VI. Half-tone prints showing effects produced by the use of six standard screens 56 VII. Details of the make-up of a geologic map 58 VIII. Patterns used to show distinctions between areas on black and white maps 60 IX. Diagrams and curves 64 Figure 1. Diagrams showing principal, guide, and auxiliary meridians, standard and special parallels and correction lines, and sys- tem of numbering townships, ranges, and sections 16 2. Conventional lines used in preparing plans and diagrams of mine workings to distinguish different levels 39 3. Section and perspective view showing relations of surface features to the different kinds of rocks and the structure of the beds 30 4. Sections of coal beds 31 5. Diagram illustrating method of projecting a map 44 6. Methods of expressing relief by contour lines, by hachures, by shading on stipple board, and by a brush drawing 491 7. Designs for bar scales 60| 8. Method of making a bar scale for a map of unknown scale 60j 0. Map bearing six areal line patterns 62/ 10. Diagram showing method of marking maps for reduction or en- largement (for record) 6^ 11. Structure section showing method of determining the succession of folds 6{| 6 THE PEEPARATION OF ILLUSTKATI0N8 FOR REPORTS OF THE UNITED STATES GEOLOGICAL SURVEY. By John L. Ridgway. PART I. PREPARATION BY AUTHORS. INTRODUCTION. There has been an obvious need in the Geological Survey of a paper devoted wholly to illustrations. No complete paper on the character, use, and mode of preparation of illustrations has been published by the Survey, though brief suggestions concerning certain features of their use have been printed in connection with other suggestions per- taining to publications. The present paper includes matter which it is hoped will be of service to authors in their work of making up original drafts of illustrations and to draftsmen who are using these originals in preparing more finished drawings, but it is not a technical treatise on drafting. The effectiveness of illustrations does not depend entirely on good drawings nor on good reproduction ; it may be due in large part to the inherent character of the rough material submitted. If this material is effective or striking the finished illustrations, if well made, will be equally effective and striking. Each step in the making of an illustration — first the preparation of the author's original or rough draft, next the final drawing, and last the reproduction — is closely related to the others, and each is dependent on the others for good results. If the material has been well handled at all three steps the resulting illustration should be above criticism ; if it has been poorly handled at any one of the three the effectiveness of the illustration is either impaired or ruined. A consideration of processes of reproduction is essential in the preparation of all illustrations, and the influence or effect of the process to be selected on the methods of preparing a drawing has seemed to warrant the presentation of brief descriptions of the proc- esses usually employed by the Geological Survey. These descrip- tions include statements as to the kind of copy that is suitable for each process, the result produced by each, and the relative cost of the processes. 7 8 PREPARATION OF ILLUSTRATIONS. PURPOSE AND VALUE OF ILLUSTRATIONS. An illustration in a report of the Geological Surve}^ is not merely a picture having a remote bearing on the subject matter of the re- port; it must represent or explain something discussed or mentioned in order to become an illustration in the true sense of the term. The illustrations used in the Survej^'s reports are not employed for em- bellishment ; the more pictorial kinds may be in some measure decora- tive, but decoration is distinctly not their primary purpose. The illustrations used in popular literature are designed to meet a public demand for ornament or attractiveness. Those used in scientific publications should be made plain and direct, without attempt to ornament or beautify. In the literature of science illustrations made by the reproduction of photographs or of explanatory diagrams or maps are intended simply to furnish greater illumination, and if the illustrations display photographic reality most statements or con- clusions thus illuminated seem less open to dispute. A photograph may thus serve the double purpose of explanation and corrobora- tion. The graphic expression of data and of details in a Survey report is intended to aid the reader in comprehending the report, and this is the prime advantage of its use, but it also enables the writer to omit from his text numerous descriptive details. It would gen- erally be difficult without illustrations to present a clear picture of the geology of a region in its exact relations, and especially to de- scribe adequately the form and the details of the structure of many fossils. The tasks of both the writer and the reader of reports on geology and kindred subjects are thus greatly facilitated by geologic maps, sections, paleontologic drawings, and illustrations of other kinds. The responsibility for good and effective illustrations rests largely upon the author, who should select and plan his illustrations with a view to their utility in aiding the reader to understand his report. SELECTION AND APPROVAL OF ILLUSTRATIONS. There is no rule limiting the number of illustrations that may be used in a publication of the Geological Survey, but in selecting illus- trations for a report an author may easily fall into the error of over- illustration. The number of diagi-ammatic drawings or of drawings that express the author's deductions is rarely in excess of the needs of a paper, but the number of photographs submitted is often exces- sive. The number of images in a manuscript may be a factor in determining the proper number of illustrations, but as the need of illustrations varies greatly from paper to paper this factor alone is PREPAKATIOl^ OF ILLUSTRATIOH^S. 9 not decisive. The tendency to overillustrate led the Director to issue the following order ' governing the approval of illustrations : The primary responsibility for the selection of illustrative material shall rest upon the author and the chief of the branch transmitting the report. No one knows the subject matter ' of the report better than its author, though a sympathetic critic is usually needed to correct the personal equation that may express itself in an excessive number of illustrations or the use of photographs into which no one but the field man himself can read what he wishes to illus-; trate. The approval by the chief of branch of the illustrations selected by the author will be taken as vouching for those illustrations as essential and ade-i quate, and the scientific value of the illustrations will not be subject to review in the section of illustrations. The chief of the section of illustrations shall decide the technical questions relating to the preparation of these illustrations for reproduction and may recommend the rejection of any that do not promise effective or economical reproduction. In the consideration of such questions, especially any relating to maps, the cooperation of the editor of geologic maps and chief engraver will be expected. The judgment of an author as to the illustrative A'alue of a photo- graph is likely to be biased by his knowledge of the features that are actually included in the view represented, not all of which may be shown clearly in the photograph ; his knowledge of all the features enables him to see more in his picture than his readers will be able to recognize without detailed description. Photographs in which special or significant features are obscured by foliage or lost in hazy distance do not make acceptable illustrations, and the use of a picture that requires much description to make it illustrate reverses, in a measure, the relations of text and illustrations. A photograph is not necessarily good for reproduction simply be- cause it shows some particular feature to be illustrated; the quality of the print it will afford when reproduced from an engraved plate should also be considered. Some loss of detail by reproduction must be expected, and therefore only the clearest and most effective prints obtainable should be submitted. If an author has difficulty in making his preliminary or " original " drawings he may request that a draftsman be detailed to aid him. The request should be made to the Director through the chief of branch and properly approved. The work will then be done in the section of illustrations as advance preparation, but finished drawings should not be thus prepared unless the conditions are unusual. The administrative geologist reviews all illustrations submitted and rep^ resents the Director in matters relating to illustrations. ^From Survey Order 63, Oct. 20, 1915. 10 PREPARATION OF ILLUSTRATIONS. SUBMITTAL OF ILLUSTRATIONS. All material intended for illustrations, except paleontologic speci- mens, should be submitted with the manuscript of the paper to be illustrated but in a separate package marked " Illustrations to ac- company a paper on by ." The package should contain a carbon copj' of the list of illustrations that accompanies the manu- script or, if the titles to be printed on or with the illustrations in- clude fuller descriptions than are given in that list, a carbon copy of the list giving complete titles and descriptions, the original of which should also accompany the manuscript. In the list each plate and figure should be separately numbered consecutively in the order in which it should appear in the report, and a figure opposite each title should show the number of the manuscript page on which the illustration is first mentioned or most fully discussed. Roman nu- merals should be used for the plates and arabic numerals for the fig- ures. Each drawing or photograph should bear, in addition to the number and title, any suggestions concerning preparation, reduction, and method of reproduction which the author may consider especially desirable. The list should be headed " Illustrations." Specimens other than fossils that are to be illustrated must be sub- mitted directly to the section of illustrations, but the author may first obtain photographic prints of them in order to make up his plates. The specimens should be carefully packed and any that are fragile should be so marked. KINDS OF ILLUSTRATIONS. The illustrations in reports of the Geological Survey may be classi- fied into five more or less distinct groups — (1) maps, (2) diagrams (including graphs, sections, plans, figures of apparatus, and stereo- grams), (3) outdoor photographs, (4) photographs and drawings of specimens, and (5) sketches. These may be further divided into two large groups, which may be called permanent and ephemeral. The permanent group includes illustrations that do not lose value through lapse of time or by natural alteration, such as detailed geologic maps, well-prepared structure sections, views of specimens, and good photo- graphs or draw^ings of natural phenomena ; the ephemeral group in- cludes maps showing progress, key maps, diagrams showing yearly production, and many others that should be prepared in such a way as to minimize cost of preparation and reproduction. The illustrations will be finally divided into plates and figures when they are fully prepared, but if an author desires to determine the classification in advance of ti-ansmittal he should submit his material to the section of illustrations, where methods, processes, and reductions will be decided for each. In determining which shall be U. S. GEOLOGICAL SURVEY PREPARATION OF ILLUSTRATIONS PLATE I METHODS OF INSERTING PLATES AND FIGURES. 1, 2, 3, 5, 6, 7, plates; 4, 8, 9, 10, figures; 11, pocket. PREPARATION OF ILLUSTRATIONS. 11 plates and which shall be figures, size and method of reproduction are the only factors to be considered ; there are no other real differences. Illustrations that require separate or special printing, such as those reproduced by lithography and by the photogi-avure, photogelatin, and three-color processes, must be printed separately from the text as plates and inserted in the report at the proper places ; those that are reproduced by relief processes, such as zinc and copper etching and wax engraving, if not too large, can be printed with the text as figures. If an illustration to be reproduced by a relief process is marked for reduction to a size not exceeding that of the page of the text, it can be called a figure and be printed with the text. Half tones, though etched in relief, are rarely made text figures in Survey reports, because to give satisfactory impressions they must be printed on the best quality of coated paper, which is not used for the text. By using the coarser screens shown in Plate VI (p. 56), however, a half-tone cut may be made that can be used in the text if it is smaller than the page. SIZES OF ILLUSTRATIONS. The regular book publications of the Geological Survey are issued in three sizes — (1) octavo (annual reports of the Director, statistical reports on mineral resources, bulletins, and water-supply papers) ; (2) quarto (professional papers and monographs) ; (3) folio (geo- logic folios). The following table gives the measure of the text of each size and the measure of the trimmed page, in inches : Size of text. Size of page. Octavo.- _ 41 by 7^ H by 9i Quarto 7^ by 9H 9J by llf Folio ISM by 175 18i by 2U Most professional papers are printed in two columns of type, each 3 inches wide, and folios are printed in three columns, each 4f inches wide. A text figure in one of these publications can be made to fit one or more columns, and it may run the full length of the text page. The limits of the dimensions of plates and figures, in inches, are given in the following table. If for any reason a plate can not be reduced to the dimensions of a page it can be folded once or more; and if it is large and unwieldy it may be placed in a pocket on the inside of the back cover. (See PI. I.) Single- Plate with page plate. one side fold. Text figure. Octavo 4| by 7^ 7^ by 8^ 4| by 7^ Quarto-. 7 by 9^ 9^ by 14f 3^ or 7 by 9^ Folio 15 by 17i 41 or 13i| by 17i For an octavo report a single-page plate with side title should be 4 inches or less in width, and a plate with bottom title should be 7 inches or less in depth. In other words, the actual depth and width 12 PREPARATION" OF ILLUSTRATIONS. of a single-page plate in a page of any size must depend on the num- ber of lines in its title, the inclusion of which should not extend the matter much, if any, beyond the dimensions given in the table. A difference of 1 inch or less in the width of a folding plate may determine whether it must be folded once or twice, so that by con- sulting this table an author may save expense in binding and promote the reader's convenience in handling the plate. A text figure (including the title) can not extend beyond the text measure but may be of an}^ size or shape within that measure, as shown on Plate I, figures 4, 8, 9, 10. SUBDIVISIONS OF PLATES AND FIGURES. If a plate consists of two or more parts or photographs each part should be marked with an italic capital letter — A^ B^ etc. — which should be placed directly under each. If it is made up of many parts, in the form of plates that accompany reports on paleontology, each part should be similarly marked with an arable numeral — 1, 2, 3, etc. If a text figure is subdivided into two or more parts, each part should be marked Avith a roman capital — A, B, C, etc.; and if details of a part are to be described each detail should be marked by an italic lower-case letter — a, h, " Strike and dip of Joint planes — y^ Strike of vertical joint planes — y^ Rock exposure v/ithout ^. observed strike and dip "^^ Rock exposure with s\s observed strike and dip *^ Rock exposure with strike ^ and dip of schistosity ^^ General dip of beds having' subordinate folds ^ Anticline with observed pitch 11 Syncline with observed pilch ^^ Axis of anticline i Axis of syncline 1 Axis of overturned anticline /^ Axis of overturned syncline yx Axis of plunging anticline showing direction of pitch j, Axis of plunging syncline showing direction of pitch ^ Glacial striae /n^ Mine shaft H ^ Inclined shaft --'\ Tunnel opening on maps of large scale 7^ Mine tunnels, showing direction ^ z.-:^ (. Raises CD EH a = Winzes _ .._ a iii;ii|iiii Mine workings — j ' Mines or quarries ^ ^ Abandoned mine or quarry 'K' Placer mine, surface mine X Abandoned placer or surface mine X X Prospect ► ^ Mine pits _ crO c=: Mine dump Jj|J/ ^i>x Drillhole... O Inclined drill hole, showing direction. — ^x WATER WELLS Well, character not indicated O Nonfiowing well O Flowing well 9 Unsuccessful or dry well (p Nonfiowing well. ^ with pumping plant ^ Flowing well, with — . pumping plant Spring _ •> Thermal spring "T Mineral spring _ ^ OIL AND GAS WELLS Site for test well + Location of well O We/l being drilled O Dry hole - Dry hole, with show of oil -^ Dry hole, with show of gas ^ Dry hole, with show >j< of oil and gas ' Oil vjsll • Oil well, with show of gas ■♦■ Abandoned oil well Abandoned oil well, with show of gas-- Gas well -J^ Gas well, with show of oil -^ Abandoned gas well ^ Abandoned gas well, X with show of oil t Oil and gas well -^ Abandoned oil and gas well -»■ Oil tanks O^':- COAL OUTCROP SYMBOLS (usually shown in color) Goal outcrop (dotted line hypotheticJ) Exposure or bloom on coal outcrop Drift or slope on coal outcrop .. SYMBOLS USED ON GEOLOGIC MAPS, ECONOMIC MAPS, AND MINE PLANS PREPAEATION OF ILLUSTRATION'S. 21 in the explanation, and the same sj-mbol or number should be repeated at one or more places on the map within the areas to which it refers. Each area that is indicated by a color ^ should be marked with th e proper sy m bol i n order to make its identification sure, for light colors especially are likely to fade and mixed colors can not be discrim- inated with certainty. OIL AKD GAS SYMBOLS. A complete set of symbols for maps showing oil and gas is given on Plate II. Referring to these symbols the chief geologist, in a memorandum to the Director, writes: The symbols used by tbe Survey in its oil and gas maps have not been in accord with those used by the oil companies, nor have they been vpholly logical. It appears that though they were submitted for recommendation they never have been formally approved. Herewith I submit a code prepared by the geologists of the oil and gas section. They conform largely to commercial use and embrace its best features as well as the best and most logical features of our previous usage, the de- partures from which are, after all, of minor consequence. The symbols here submitted [see PI. II] with recommendation for approval are founded on a building-up system, so that the history and the results of drill- ing at any location can be recorded by slight additions to symbol and without erasure. Thus maps may be revised without scratching. In drawing these symbols the draftsman should make the rays of the gas well distinct and in adding the vertical bar or line showing that a hole is dry or abandoned should make it long enough to be distinct. It would be prefer- able to draw this bar obliquely, but an oblique position would coincide with some of the patterns on certain maps, and it should therefore be placed verti- cally. The vertical line indicates the failure or abandonment of the well, the symbol for which is thus scratched off or canceled by the line dravpn through it. The symbols agree so far with commercial usage that oil men will have little need to consult the explanation. SYMBOLS FOR USE ON MAPS SHOWING FEATURES OF GROUND WATER. The symbols used on maps relating to ground water represent the features named below, each of which has been shown in publications already issued. Area of absorption or outcrop. Area that discharges ground water. Depth to water table. Quality of ground water. Contours of water table. Area irrigated with ground water. Fluctuation of water table. Nonflowing well. Depth to water-bearing formation. Flowing vrell. Structure contours of water-bearing Unsuccessful or dry well, formation. Well with pumping plant. Area of artesian flow. Spring. Head of artesian water. The lack of uniformity in the symbols commonly employed to rep- resent these features is due to differences in the number of colors used on the maps and differences in the scale. Standard colors for the 22 PREPARATION OF ILLUSTRATIONS. larger features, such as those for areas of artesian flow, areas of ab- sorption, and curves showing depths to water table or to water-bearing formations, can not be fixed, because of considerations of economy in printing. For example, if light green is the standard color to be used for delineating areas irrigated by ground water and no green is used on other j^arts of the map its use would represent an additional or special printing, whereas a tint of blue, brown, or purple, if any of these colors is used for other features or the map, might be used also for this feature without additional printing. Therefore the general use of any particular color for a water feature seems to be impracticable; but this fact should not preclude the adoption of color standards for use subject to the requirements of economy in pub- lication. The ordinary symbols for wells are the open circle and the solid circle, or dot. Only in the secondary or specific well symbols does there appear to be lack of uniformity, the choice of secondary symbols being governed either by personal preference or by the requirements for specific distinction. All symbols should, if possible, suggest the things they represent. Wells are circular and hence the open circle is most used and most appropriate for nonflowing wells. To indicate a flowing well the circle is made solid, denoting that the well is full of water. For an unsuccessful well the most suggestive symbol would be an open circle with a line drawn through it to denote cancellation. It has been suggested that if water features, including wells, are to be printed in blue, unsuccessful wells, or dry holes, be printed in black. A large circle drawn around the symbol for a flowing or nonflowing well will appropriately denote a pumping plant at the well. The accepted symbol for a spring is a dot with a waved tail repre- senting the direction of flow, if known. Tliis symbol can not be modified without destroying its prime characteristics, but it may be accompanied by a letter indicating the kind of spring. An open circle wnth a tail might be used on large-scale maps, but it would be out of scale on other maps, whereas the black or blue dot and tail will fit maps of any scale. The following colors and symbols can most appropriately be used to represent ground-water features. The well and spring symbols can be varied by adding letters if they are necessary to express other data than those indicated in the list below. General ground-water features. Area of absorption or outcrop: Flat color used on the map to show the geologic system in which the absorbing formation occurs. Areas showing depths to v/ater table: Shades of purple and gray; if possible the shades showing the areas of least depth should be darkest and the shades should grade from those to lighter tints. PREPARATION OF ILLUSTRATIONS. 23 CJontours of water table, or contours on water-bearing formations: Gray or purple curves or lines. Areas of artesian flow : Blue flat tint, or fine ruling in blue. Depth to water- bearing formations: Gradation of a single color or of two related colors from dark for shallow depths to light for greater depths. Nonflowing artesian areas (pumped wells) : Green flat tint, or fine ruling in green. Depth to water-bearing formations shown by gradation of tint if possible from dark for shallow depths to light for greater depths. Head of artesian water : Blue curves or lines. Areas that discharge ground water : Blue flat tint, or fine ruling in blue. Areas irrigated with ground water: Green flat tint, or fine ruling in green. O Well, character not indicated. O Well, nonflowing. ^ Well, flowing. A, Well, unsuccessful or dry. (g) Well, nonflowing, with pumping plant. @ Well, flowing, with pumping plant. 1 9 Springs. •T Spring, thermal. •M Spring, mineral. The standard color scheme should be used if no conditions preclude its use, but if other colors can be used with greater economy with- out sacrificing clearness the use of the standard colors should be waived. BLACK-LINE CONVENTIONS. A complete set of the black-line j)atterns used to distinguish areas on a map is given in Plate VIII (p. 60), and their application to a finished drawing is shown in figure 9 (p. 62). These patterns, however, should preferably not be used by the author in his prelimi- nary work on an illustration. For this purpose water colors or colored crayons are preferable, and the distinctions between areas may be emphasized by letter symbols, MATERIALS USED IN PREPARING MAPS. PAPEH. For large and important maps which may at some time be ex- tended to cover a greater area or which may be made to fit maps already prepared or published the paper used should be mounted on muslin to reduce to a minimum the shrinking or stretching caused by atmospheric changes. Pure white paper produces a better negative than a cream or yellowish paper and will retain its color longer, but all papers become more yellow with age and exposure to light. The following brands of paper are used in the Survey in the preparation of maps : " Normal " K. & E., unmounted. Has an excellent surface and comes in flat sheets, 19 by 24, 22 by 30, and 27 by 40 inches. 24 PREPARATION OF ILLUSTRATIONS. " Paragon " K. & E., mounted on muslin. In 10-yard rolls 72 inches wide. Used in the Survey for large office drawings and maps of large scale. " Anvil " K. & E., mounted on muslin. In 10-yard rolls 42, 62, and 72 inches wide. Used in the Survey for large drawings. '' Whatman's hot pressed," unmounted or mounted on muslin. In sheets ranging in size from 13 by 17 to 31 by 53 inches. An excellent paper for maps. The muslin-backed paper is recommended for use in preparing large detailed maps and base maps that are to be retained as permanent records. The muslin provides a durable and flexible backing that permits the map to be rolled, and paper thus mounted is particularly serviceable for a map which may be sub- jected to considerable revision and to which must be added finally a title, explanation, and other marginal matter. " Ross's relief hand-stipple drawing paper." A stiff enameled or chalk-coated paper whose surface has been compressed into minute points that stand in slight relief so that a shade made on it with pencil or crayon is broken up into dots and can be reproduced by photo-engraving. For use in making shaded drawings, drawings showing relief by light and shade, etc. Similar paper is prepared for parallel-line and other pattern effects. In sheets ranging in size from 11 by 14 to 22 by 28 inches. (See p. 51 for method of using.) Profile and cross-section paper. In sheets of convenient sizes or in rolls. Bears lines printed in blue, green, red, or orange, in many kinds of rulings, which may be selected by reference to catalogues. Profile and cross-section paper printed in orange is recommended for preliminary drawings; blue is recommended for drawings that are made in pencil and submitted for inking in. BBISTOL BOABD. For the smaller maps, such as key maps and maps less than 18 by 24 inches, and for small drawings made for direct reproduction, Rey- nolds's bristol board is recommended on account of its pure- white color and its hardness, which permits erasures to be made without affect- ing redrawing over the corrected area. It is obtained in 2- ply, 3-ply, and 4-ply sheets. The 2-ply and 3-ply are especially useful in mak- ing delicate brush and pencil drawings and pen and ink draw- ings. The sizes used in the Survey are l^ by 20f , 18^ by 22|, and 21^ by 28J inches. TBACINO LINEN. Tracing cloth or linen is especially useful for large work that will require considerable reduction. (See p. 18.) Its advantages are that a tracing that has been carefully made on it over any kind of copy fori direct reproduction by a photo-engraving process can be used fo; PREPARATION" OF ILLUSTRATIONS. 25 making a paper negative for contact printing or blue printing. On. the other hand, it is susceptible to atmospheric changes that affect scale, and the lines traced on it are not reproduced as sharply as those made on paper. It can be obtained in rolls 30 to 54 inches wide. Erasures should be made on tracing linen with a hard rubber eraser, not with a sand rubber or a steel eraser. IJTKS. The best drawing inks are in liquid form, ready for use. They should be waterproof and equal to the grade known as Higgins's waterproof ink. When a suitable waterproof blue ink can not be obtained, a good blue for features of drainage can be made by dis- solving a half pan of Winsor & Newton's prussian blue in water. No good waterproof burnt sienna ink seems to be obtainable, but a good substitute can be made by dissolving Winsor & Newton's water color of that name. Ink lines should be drawn in fidl strength of color — lines that should be black must not appear grayish, for example — and pens should be kept clean. The same pen should not be used for applying two inks, as the mixture thus produced is likely to thicken or coagulate on the pen. A little black should be added to colored inks that are used in making drawings to be reproduced in colors in order to strengthen the lines for photographic reproduction, DKAWING PENS. The pens made by Keuffel & Esser, especially their No. 3202, and Gillott's Nos. 291, 290, 170, and 303 give complete satisfaction. The Gillott numbers are given in the order of fineness of the points. No. 291 being the finest. The best cleaner for a drawing pen is a piece of chamois skin. PENCILS. Pencils used for drawing should have leads of a quality equal to those of the Koh-i-noor brand, in which the grades of hardness are indicated by 3B, 2B, B, HB, F, H, 2H, 311, 4H, 5H, 6H. 7H, 8H, and 9H ; the softest grade is 3B and the hardest 911. The grades most generally used are B, HB, F, 4H, and 6H. BUBBEB EBASERS AND CLEANERS. Two kinds of rubber erasers are usually employed in making erasures on drawings — a hard, dense rubber like the " Kuby," and a soft, pliable rubber like the ''Venus" or "H" (Hardtmuth). The soft rubber is also useful for cleaning large surfaces. Art gum is also recommended for this purpose and has the advantage of not disturbing the surface of the paper. 26 PREPARATION OF ILLUSTRATIONS. COLOBED PENCILS AKD CHATONS. Colored pencils and crayons are useful only for coloring pre- liminary maps. They are not recommended for use on maps that are to be kept for reference or to be submitted for reproduction, be- cause the colors rub off, but they can be used on photographic prints of base maps or on transparent oversheets, for which the unglazed side of tracing cloth is well suited. Wlien they are so used register marks should be added at numerous points on the map and the oversheet, in- cluding the four corners, the color boundaries should be drawn or traced, and finally the colors should be added. Two or more colors should not be used on any one area to modif}' a tone, but each area sliould be colored with a separate crayon. Patterns or designs should not be used except to strengthen contrasts, and for that purpose a pattern may be drawn with a black pencil over a color. WATER COLORS. By dilution to half strength some of the standard water colors will yield a tint or hue that will contrast with other tints or hues pro- duced in the same way quite as well as imdiluted or full colors will contrast with one another. The colors named below, except chrome- j'ellow and emerald-green, are among those that when diluted will afford satisfactory contrasts among themselves and with their full colors and are recommended for use in coloring original maps. Mauve. Hooker's green No. 2. Crimson lake. Emerald-green. Orange-vermilion. Payne's gray. Burnt sienna. > rl"'- Lampblack. Cadmium-yellow. Sepia. Chrome-yellow. Cerulean blue. Olive-green. Other pigments spread better than cerulean blue and emerald-green, but the exceptional purity of color of these two seems to warrant their use. JAPANESE TRANSPARENT WATER COLORS. Japanese transparent water colors, so called, are used by some geologists. They spread evenly and are convenient for field use, but they can not be washed out like other water colors, so that when they are once applied to an area and a change of color becomes necessary they must be bleached out. A good bleach is sodium hypochlorite, which should be applied with a brush until the color disappears, and the area dried with a blotter before recoloring. Light tints of these colors are believed to be somewhat fugitive if exposed to strong light. PREPARATION OF ILLUSTRATIONS. 2T' COLORING GEOLOGIC MAPS. The colors used on most original maps are not pleasing, a fact that is of no particular importance, but — and this is of importance — they often fail to give clear distinctions ; the separate areas can not always be identified or distinguished with certainty. Again, some colors are fugitive, and when laid on in light tints they disappear entirely or become uncertain. Much of the difficulty in identifying and discrimi- nating colors on an author's original maps is due to the promiscuous mixing of colors. Many persons can not match or discriminate mixed .or broken colors. Hence if the supply of a color produced by mixing becomes exhausted and the attempt is made to duplicate it by a second mixture the two will probably fail to match. It is therefore suggested that colors in full strength and colors diluted to half strength be used instead of mixtures of two or more pigments, so that one color in two strengths or tones can be employed to indicate areas that are to be distinguished. The colors listed on page 26 will give 24 satisfactory distinctions and will thus supply all demands for map coloring. To insure satisfactory contrasts between colored areas on a map, unlike colors should be placed next to each other — that is, colors should be placed together that are widely separated in the spectrum, such as yellow and mauve, red and green, blue and orange, burnt sienna and olive-green ; not such as red and orange, blue and purple, orange and 3'ellow, sepia and burnt sienna. A sufficient quantity of water and color pigment to be used for one formation area on a map should be stirred in a saucer until the de- sired tint is produced before it is applied. To maintain the same tone properly the color should be well stirred every time the brush is filled ; if it is not stirred the brush will on the next dipping take up a lighter tint, because most pigments, especially those derived from minerals, tend to precipitate. When the colors are applied the map should preferably be placed in a slightly inclined position, and the coloring should be started at the upper boundaries of an area to be colored, the well-filled brush being pulled toward the painter and worked rapidly back and forth horizontally, the edges of the fresh color being kept wet. If the edges are allowed to dry, a hard line and a smeared or imeven effect will be produced, A strong color should generally be used for small areas unless the map shows also large areas that must have the same color; lighter hues should be used for large areas. Bright colors are best suited for areas of igneous roclvs, dikes, and veins, and these may be reduced in strength for the larger areas. The Survey's color scheme (see p. 63) need not be applied at this stage of preparation, except in the most general way. Appropriate 28 PREPAEATION OF ILLUSTRATIONS. final colors can be best selected when the new map is made ready for engraving. In the author's original maps adequate color distinctions between areas are more important than the use of standard geologic colors. Patterns should not be ruled in one color on an original map to indicate distinctions between different formations of the same age or period, because such patterns are difficult to produce by hand with proper uniformity except by engraving. It is of vital importance that an original base map should be free from colors and from technical symbols in order that it may be kept clean for photographing and preserved for possible future use. Such a map should preferably be photographed in order to obtain prints on which to add the colors and symbols ; the use of an oversheet for this purpose is not nearly so satisfactory. "When photographed a base map should be reduced to publication scale in order to save the addi- tional cost of a larger negative, and this reduced map may be made up for publication by the addition of colors and symbols, title, expla- nation, etc. ; but the lithographer will also need the original base map from which to make his reproduction. DIAGRAMS. ESSENTIAL FEATTTEES. The term " diagrams," as used here, includes such illustrations as mine plans, profiles, sections, stereograms, and maps that are more diagrammatic than cartographic. The first essential in the original drawings for simple diagrams is clearness of copy. Simplicity of subject does not warrant hasty preparation, for an original sketch that has been carelessly drawn and is inaccurate or inconsistent in detail may lead to serious errors. Ruled paper printed especially for platting profiles and cross sections should be used. Curves or graphs made by an author with pencil on blue-lined section paper may be inked by more sldllful draftsmen. An author's pencil sketches are usually satisfactory if they indicate plainly the facts to be represented, but they should be prepared with some care as to detail. Tables and like matter are not generally satisfactory material from which to pre- pare drawings. In drawings for diagrams that are to be printed in the text as figures the use of large, solid black bars or of conspicuous areas of solid black is objectionable, because the black is likely to print gray and to appear uneven in tone. Ruled tints or cross lining give better effects. Stereograms should be prepared by an author with especial care, for they represent facts only as the author sees them, and the author's view must be imparted to the draftsman graphically. The "third dimension" — the relief — in such drawings is not easily expressed and should be brought out clearly in the author's rough sketches. PREPARATION OF ILLUSTRATIONS. 29 For illustrations of apparatus photographs are preferred, but if rough sketches are submitted they should show not only correct relations but all dimensions. PLANS OF MINE WORKINGS. Blue prints obtained from mining companies are acceptable for plans of mines or underground workings, but all unnecessary or irrelevant details on such plans must be canceled and all essential fea- tures retained, and every essential feature, especially any added data, must be clearly interpretable. Many such blue prints are so large and unwieldy that they must be greatly reduced by photography before they can be redrawn. If the lines are too weak to photograph, a trac- ing of the essential parts can be made and reduced to about twice Figure 2. -Conventional lines used in preparing plans and diagrams of mine workings to distinguish different levels. publication size. The shadowless drafting table, described on pages 47-48, is well adapted to the work of making such tracings. Blue prints can also be pantographed to any convenient size if the details are not too minute or complex. The levels in plans of underground workings can be differentiated in finished drawings by a system of conventional outlines in black, as shown in figure 2, by conventional patterns or symbols within plain outlines, or by colors. Such plans should not be printed in colors unless the maze of workings is so complex that lines showing the different levels would become confused or obscure if printed in black. SECTIONS. The standard forms of geologic sections are shown in the geologic folios. Structure sections should be prepared with great care as to 30 PREPARATION OF rLLUSTRATTONS. detail but without attempt at refinement of lines and letterino^. The author's drawing of a section along a line or zone that is not definitely indicated by a line on an accompanying map should be so prepared that it may be copied exactly. On the other hand, the draftsman, in reproducing a section that represents the structure along a given line or zone, may be able to make the outcrops coincide with the topog- raphy and the formation boundaries shown on the map, but the structure, or the interpretation of it to be given, should be carefully worked out by the author. All essential facts relating to bedding, folding, faulting, crosscutting dikes and veins, or other significant details should be indicated with precision. No attempt need be made to draw firm, steady lines so long as the essential facts are clearly expressed. All sections should be drawn to scale, and both the vertical and the horizontal scale should be given on the drawing. These scales should be uniform if possible, or at least the vertical exaggeration should be minimized. Too great vertical exaggeration creates distortion and PiGDBE 3. — Section and perspective view showing relations of surface features to the different kinds of rock and the structure of the beds. is grossly misleading. Sections should be drawn to scale on ruled paper prepared for the use of authors. Such paper may be obtained on requisition. A kind of cross section which is not often used but which gives a more pictorial and clearer conception of underground relations than other kinds is made by adding a sketch of the topography above the section. This sketch should be a perspective view, in which the prominent features shown hypothetically in the section below it will be reflected in the topography. Such a sketch might show, for example, not only monoclinal slopes, " hogbacks " due to steeply up- turned beds, terraces, escarpments, and like features, but volcanic necks or other extruded masses in their true relations to the under- ground geology of the country. (See fig. 3.) In submitting the draft of such an illustration the author should, if possible, submit also a sketch or photographs of the adjacent country and indicate on the section the point of view by notes such as " Sketch A made at this point," " See photograph B." The sketch will be more useful if it is prepared on a scale consistent with the details of the section. PREPARATION OF ILLUSTRATIONS. 31 It may be made with a pencil and should show as well as possible the relations of the features in the landscape to those in the section. Some good examples of illustrations of this type can be found in Powell's " Exploration of the Colorado Kiver," pages 182-193. One simpler figure of the same kind is given on the cover of the geologic folios. In preparing original drawings representing columnar sections, or sections in wells or ravines, the author should indicate all well-defined or important local features of structure, such as cross-bedding, ore bodies, or lenses. If there are no unusual features or details, the sub- divisions need be identified only by names of materials, such as " thin- bedded limestone,'' or "slates with some coal," the coal beds being shown. The sections should, however, be so plotted and subdivided by EXPLANATION CoaL Cannel coal Bony coal Bone Carbonaceous Shaly shale Kmestone Vertical scale SO 10 '■■'•■'' T • Clay LimeatDne to Feet FiGUEB 4. — Sections of coal beds. The figure shows the publication size and the arrange- ment of the sections. Each section should be drawn three-tenths or four-tenths of an inch wide and reduced one-half. Thickness can be indicated by numbers, as shown on sections 1 and 10, or by bar scale. the author that each section or group of sections will be complete in its crude form. The compilation of various parts into one unit and the construction of columnar sections by reference to tables alone is an essential part of the author's original preparation. Sections designed to show the relative thickness of beds of coal, arranged in groups for publication either as plates or figures, should be drawn in columns three or four tenths of an inch wide and reduced one-half, as shown in figure 4. These sections, whether correlated or not, should be drawn to some definite vertical scale and should show the thickness of the coal beds, preferably by numbers indicating feet and inches, the other material being symbolized and the symbols explained graphically, as shown in figure 4. The vertical scale should always be stated for the use of the draftsman. A bar scale may be used instead of figures showing the dimensions of the individual beds. 861754"— 40 3 32 PKEPARATION OF ILLUSTRATIONS. IiITHOLOGIC SYMBOLS. The symbols used to indicate the various kinds of rocks illustrated in sections and diagrams are shown in Plate III. The units or ele- ments of these symbols may be spaced more openly in generalized or diagrammatic sections than in sections that show great detail. Symbols should be used consistently throughout a report, smd in order to make them consistent a set showing the symbol to be used for each kind of rock to be indicated should be prepared before the original drawings are made. Some inconsistencies may be unavoid- able on account of the small size of some areas shown and the con- trast needed between others; but the deviations from the set of symbols adopted should be minimized. USE OF PHOTOGRAPHS AS ILLUSTRATIONS. ESSENTIAL FEATURES. The foundat^i of a good photographic print is a good negative, and the best priMs for reproduction as illustrations are those made from negatives in which tli^i^|(hsaiination is evenly distributed and the details are sharp — such negatives as are obtainable only by the use of small stops and correct focusing. A good print should not present too sharp contrasts between its dark and its light parts ; if it does, the printed reproduction will show a loss of detail in both.. Sufficiency of detail depends largely on focus, stopping down, and timing; brilliancy is the direct result of ample illumination by sun or artificial light, without which a photograph will be dull or "flat"" and generally unsatisfactory for reproduction. Bad weather may prevent good field exposures, yet even in bad weather acceptable negatives may be obtained by judicious focusing, stopping down, and timing. If a negative is overexposed it may be full of detail, but flat and too thin to print well. If underexposed it will show no details in its lighter parts and the shadows will be black; and a black shadow is nothing less than a blemish. Some detail should appear in all shadows and in the middle tones, and some should appear in the high lights ; and a print in which these are evenly de- veloped and in which the illumination is distributed uniformly is technically perfect. Unfortunately not all field photographs are good, so an author must select from his collection those which will make the best half tones. In making this selection he should of course consider, first, the scientific value of the photograxDh, and next, its pictorial or artistic quality, which, though of secondary importance, should nevertheless be kept in mind. A feature worthy of illustration deserves good pic- torial expression; if it is of superior scientific interest it should not be represented by an inferior photograph. Fortunately, a good, PREPARATION OF ILLUSTRATIONS PLATE III ".-ft-: ■ O ■ b ® 1!1'M*I 1 i'Mj I'll ) ' / 1 1 1 1 1 ) i i 1 1 1 ) 1 1 1 1 1 1 1 il'l; @ 15 Sandy limestone Massively bedded limestone Calcareous shale or shaly llmestOTie 16 26 I.I . I . ~r- I I , — r" II I , "^~ Thin-bedded limestone a Shale b Sandy shale Schist Contorted schist II ■vii:^ji ■II ^^ \\„ «■•'■ \< //ll (1 '-■■■^■ // "' * ''^ ■ --: 7/ % ' ' "a"^ Massive igneous rock Massive igneous rock Massive igneous rock 67 -ji n a s_ r68) #*;?;>')» Hf if * » if if. M * i( * if if >!■ it: ^ ^ :^ K if ^ if >( /f * Massive igneous rock Massive igneous rock a Brecciated rock 6 (sedimentary and igneous) Bedrock sind not indicated) TFERENT KINDS OF ROCK 861754 O - 49 (Face p. 32) ■'•/." Tt^^T. SURFIGIAL ® kos°{f. '?M%M -ST SEDIMENTARY ^ BH @)i2^ MET AMORPHIC @ ^'^ @fc^i?l IGNEOUS AND VEIN MATTER @E rtSasffiNiS @ "■" timwutrock @ UTHOLOGIf SYMBOLS t'SKD IN STKUCTURE AND COLUMNAR SECTIONS TO REPRESENT DIFFERENT KINDS OF ROCK PREPARATION OF ILLUSTRATIONS. 33 accurate drawing may be made from a poor photograph, and a photo- graphic view that has only minor defects can be successfully re- touched. Photographs that need much retouching should generally be larger than publication size, for the effects of retouching — brush marks, etc. — will be softened by reduction. Photographs that need only slight retouching need not be larger than publication size. A photogi'aph can rarely be satisfactorily enlarged in reproduction unless it is sharp in detail and requires no retouching. Unmounted prints are always preferable for use in making illustra- tions. A group that is to form a single plate should be placed in an envelope bearing the number of the plate and its title, and each print of the group should bear a corresponding number, written in pencil on its back. The envelope will protect the prints and keep them together, and the nmnbers will identify them. Bed ink should not be used to mark photographs, as it is likely to penetrate the coating or even the fiber of the paper, so that it can not be erased. If a print is of doubtful quality two copies of it should be sub- mitted — one glazed, the other having a dead finish or "mat" sur- face, which is generally preferable if the print must be considerably retouched. The best prints for use as illustrations are those made on " regular " or " special " semimat velox and glossy haloid papers. The author should indicate prints that may be grouped together according to their relation geographically or by subject. Generally two half tones will be combined on a page, and the list of illustrations should be prepared accordingly. With slight trimming and reduction, three photographs measuring 3^ by 5| inches may be made up one above the other to form a full- page octavo plate. Four photogi-aphs in which the longer dimen- sions represent vertical distances may sometimes be used if they are placed sidewise on the page, with side titles. Some photogi-aphs may be reduced to the width of a page by trimming instead of by photogi*aphic reduction, which may involve loss of detail. The author should clearly indicate the extent of such trimming as they may bear without loss of essential details. The trimming is best done during the final preparation. A line should not be drawn across a photograph to mark such trimming, but the position of the line or lines should be indicated either on tem- porary mounts, on the backs of the prints, or by a statement, such as " One inch may be cut off on right, one-fourth inch on left, andi one-half inch at bottom." COPYRIGHTED PHOTOGRAPHS. Section 4965 (ch. 3, title 60) of the Revised Statutes, amended by act of March 2, 1895 (Stat. L., vol. 28, p. 965), provides that no copyrighted photograph may be used without the consent of th© 34 PREPAEATION OF TLLUSTEATIONS. proprietor of the copyright in writing signed in the presence of two witnesses. A penalt}'^ of $1 is imposed for every sheet on which such a photogi'aph is reproduced without consent, " either printing, printed, copied, published, imported, or exposed for sale." An author should therefore obtain the written consent of the owner of a copyrighted photograph to use it, and the letter giving this consent should be submitted with the illustration. SOUKCES OF PHOTOGEAPHS. Every photograph submitted with a manuscript should bear a memorandum giving the name of the photographer or the owner of the negative. If the negative is in the Survey's collection that fact should be stated, as " Neg. Keith 318." The Survey receives many requests for copies of photographs that have been reproduced as illustrations in its publications, and replies to these requests will be facilitated if the Survey's number or the source of each photogi^aph presented for use as an illustration is stated as above on the photo- graph. LENDING ORIGINAL PHOTOGRAPHS AND DRAWINGS. A photograph that has been used in making a half-tone cut for a Survey report can not be lent, but if the negative is on file a print can be furnished at cost ; and a Survey drawing that is well preserved can be photogi-aphed and a print furnished, also at cost. Requests for such prints should be addressed to the Director. UNPUBLISHED PHOTOGRAPHS. The Survey can not issue a copy of an unpublished photograph except upon the written approval or requisition of the person under whose name the negative is filed. This requirement does not apply to a print needed for official use, nor to a print made from an old negative reserved under the name of any present member of the Survey or from a negative that has been released by the person under whose name it is filed. Authors using Survey photographs in unofficial publications are requested to aclniowledge the source of the photogi-aph by adding to the printed title such a statement as " Photograph by U. S. Geological Survey (David T^^lite)." SPECIMENS. GENERAL REQUIREMENTS. Specimens other than fossils that are to be illustrated in a report should be photographed before they are submitted, but the requisi- tion for the photographs should be initialed by the chief illustrator, who will indicate the kinds of prints needed. Duplicate photograplis of the specimens should be made up into temporary plates by the PREPAEATION OF ILLUSTRATIONS. 35 author and submitted with his other illustrations, the specimens be- ing retained subject to call, if needed, when the illustrations are finally prepared. Should a colored illustration of a specimen be needed, however, the specimen must be submitted with the report, and a different kind of print, preferably one made on platinum or other special paper, will be obtained by the section of illustrations. BORROWED AND FRAGILE SPECIMENS. In submitting specimens to be illustrated an author should call attention to those that have been borrowed and to those that are fragile. Borrowed specimens will receive first attention, so that they may be returned promptly. TRANSMITTAL OF PALEONTOLOGIC SPECIMENS. All requests for paleontologic illustrations should be addressed to the Director. The letter of transmittal should state the title of the paper, the form of publication desired (bulletin, professional paper, or monograph) , and the status of the manuscript, whether completed or in preparation. If the paper is unfinished an estimate of the number of illustrations required should be given, and the special rea- sons for prompt preparation should be fully stated. A letter trans- mitting a second or third lot of fossils should refer to the preceding lot or lots if all the fossils are to be used in illustrating the same paper. Fossils that are to be drawn should be sent directly to the section of illustrations, but those that are to be photographed and require unusual posing or that are extremely delicate and valuable may be sent directly to the photographic laboratory to avoid repeated han- dling. Each specimen or, if it is very small, each box or bottle con- taining a specimen should be numbered, and each lot should be accom- panied by a list giving their names and numbers. Full instructions as to size of reproduction, together with sketches showing the point of view preferred and any special features to be displayed should also be submitted. All specimens that show strong colors and all groups of specimens that are not uniform in color will be coated by holding them in the vapor of ammonium chloride unless directions to the contrary are given by the author of the paper. As it may not be desirable to apply this process to soft or fragile specimens or to specimens that have been borrowed an author should indicate any specimens that may not be so treated. Specimens whose color aids in revealing detail are not so coated. If any features of a specimen are unusual that fact should be stated so that the photographer and the retoucher may perform their work according to the requirements. 36 PREPARATION OF ILLUSTRATIONS. MAKING UP PLATES. Two or more illustrations may be combined to fo/m one plate in order to permit easy and close comparison as well as for economy, for if a particular illustration is too small to make a full plate and is not suitable for enlargement other illustrations tha^. are closely related to it may be put on the same plate. The size of che printed page as given in the table on page 11 will determine the size of the plate. In making up plates composed of a number of figures the author should endeavor to group related figures together and at the same time to observe proper regard for artistic effect, but as figures vary in size and shape a grouping according to relations may not be possible in some plates. If related figures can not be kept together the larger and darker figures should be placed in the lower part of the plate and the smaller and lighter above. If a plate consists of one large figure and several smaller ones the large figure should be placed below and the smaller figures above. A number designating a figure should be placed immediately below the figure, and a series of such numbers should preferably begin with 1 in the upper left corner and continue consecutively across and down through the plate. This arrangement is not always possible, however, on account of variations in the size of figures. As drawings of fossils or other specimens are prepared separately and grouped into plates, and as most paleontologists make up their own plates, each in his own wr.y, there is naturally great dissimilarity in methods and in results. Ordinary white or light-gray cardboard should be used, and the figures that are to make up a plate should be arranged as stated above but not securely pasted luitil the grouping is satisfactory. In trimming each drawing or photogi*aph the author should be careful to leave room at its lower edge for the number. Small drawings or photographs, such as paleontologists use, when pasted on bristol board or other board faced with tough paper are difficult or impossible to remove without injury if they have to be remounted; figures pasted on ordinary white or gray cardboard can be removed without difficulty. Each plate should be made up in a size to fit the volume or in its correct proportion to a page in the volume in which it is to be used (see table on p. 11), and each figure should be properly oriented — ^that is, all vertical lines, or the vertical axis of each specimen, should be parallel with the sides of the plate. When the figures are being mounted care should be taken that thf» mucilage or paste does not exude under pressure and cover any part of the drawing or photograph. The same attention should be given to pasting on numbers. Inattention to these details ma}' produce Jesuits that will affect the reproduction of the plates. PREPAEATION OF ILLTJSTRATIONS, 37 Ordinary mucilage may be used for mounting drawings and photo- graphs, but photo paste gives good results and is perhaps cleaner to handle. Dry-mounting tissue is well adapted to mounting single illustrations but not groups of figures. Liquid rubber is sometimes used, but it is not suitable for mounting small figures, such as draw- ings and photographs of fossils. It can be used satisfactorily for mounting temporary plates and for mounting photographs in albums and on large cards for study or exhibition ; but it has not proved to be a permanent adhesive. Its special merit is that it does not cause either the photograph or the mounting sheet to warp. It is applied by spreading it evenly over the back of the photograph with the fingers. The superfluous rubber can easily be removed from the hands and from the cards or sheets when it is dry. Anything mounted with liquid rubber can be easily removed. If a plate is to be made up of a small numl^er of figures that require different reductions, the author, instead of mounting or pasting the -separate figures on one card in the manner already indicated, may draw a rectangle of the size of the printed plate and sketch within it the several figures in their respective sizes and positions. These " dummy " plates or layouts should be numbered as plates, and they may bear captions and titles. The photographs or drawings repre- sented by the sketches should then be numbered to identify them with the sketches on the dummy plate, and those that pertain to each plate should be inclosed in an envelope attached to the dummy plate. A plate made up in this manner will meet every requirement of the photo-engraver or lithographer. If a paleontologist so desires, his plates can be permanently made up after he has transmitted his material, but he should always sub- mit a tentative arrangement, REUSE OF ILLUSTRATIONS. If an author desires to use in modified fonn an illustration already published, whether by the Geological Survey or by an outside pub- lisher, he should furnish a print or tracing of the illustration show- ing the changes desired. If the illustration is not to be modified he need only give the title of the volume in which it was used, with the number of the page, figure, or plate, and he need not make a sketch of the illustration or furnish a dummy ; but its title should be quoted and proper reference should be given in the list of illustrations. Due credit should be given to the author or publisher. The original cuts of illustrations will be kept for one year after the report for which they were made has been published, and authors of later reports may and should reuse, whenever practicable, any such cut that will serve as an illusti^ation. In the author's list of illustrations 38 PREPAKATION OF ILLUSTRATIONS. such a cut should be referred to by its number as plate or figure and the volume in which it was first used. An electrotype of any cut on hand will be furnished for use in pub- lications other than those of the Geological Survey at the cost of maldng, which is 3| to 5| cents a square inch of printing surface. The minimum charge for a single electrotype ranges from 45 to 60 cents. APPROVAL OF FINISHED ILLUSTRATIONS. After the drawings for a report have been prepared they will be submitted to the author or to the chief of his branch or division for examination. The finished drawings will be accompanied by the " originals," with which the author should carefully and thoroughly compare them. After making a thorough comparison he should mark lightly with a pencil, on the finished drawings, all necessary correc- tions, or indicate his approval subject to such corrections and addi- tions as may be required. He should verify all type matter and other lettering and assure himself that no mistakes have been made in grouping the photographs into plates, especialW such as have been regrouped since they left his hands. The author's list of illustra- tions will be submitted with the new drawings for this purpose. REVISION OF ILLUSTRATIONS. All illustrations receive editorial revision before they are sent to the engravers. After they are drawn they are examined with refer- ence to their scientific features and their accuracy, and then in turn with reference to the correctness of geologic names and geographic names and to errors in statement and in spelling. Each illustration thus, before it is completed, receives critical examination by persons qualified in particular kinds of work to detect errors or omissions. SUBMITTAL OF PROOFS. The first proofs of all illustrations are submitted to an author when he is within reach, but if he is in the field and the transmittal of the proofs to him is likely to cause too much delay they are sub- mitted to the chief of the branch or division in which the report was prepared. Second proofs of the more complicated illustrations, particularly geologic maps, may be submitted. An author's exami- nation should be confined principally to the revision of the scientific features of his illustrations, but suggestions as to general elFective- ness are always acceptable. The process to be used in engraving each illustration is stamped in its lower left comer. In examining proofs an author should note the following facts : 1. Changes can not be made in zinc etchings except by eliminating parts, cutting a^way defects, and connecting lines. If additions are PREPARATION OF ILLUSTRATIONS. 39 required reengraving is generally necessary, and reengraving should preferably be avoided. 2. Changes can be made in half-tone plates only by reetching or by tooling parts to make them lighter and by burnishing parts to make them darker. If the proof shows a general loss of detail the fault may lie either in the proving of the cut or in the reproduction. If it is in the reproduction it can not be remedied without reengrav- ing. A slight loss of detail may be expected in all half tones, espe- cially in those that are smaller than the copy submitted. 3. Minor changes can be made in photolithographs and chromo- lithographs, but changes can not be made twice in one place without danger of affecting the printing. It is customary to approve all lithographic proofs subject to the corrections indicated, the printed edition being examined and compared, but if the changes are numer- ous and radical second proofs may be required. Second combined proofs of chromolithographs are very expensive. (See p. 89.) PROOF READING ILLUSTRATIONS. An author should examine the proofs of his illustrations closely and should compare them carefully with the original drawings. A mere cursory examination may fail to detect errors that have not been caught by the regular proof reader. Every correction desired should be clearly indicated with pen and ink in the body of the proof and inclosed in a loop from which a line should be carried to a marginal note or comment, but if the time available is short a pencil may be used. In correcting type matter or lettering (such as that in a geologic legend or explanation) the ordinary proof reader's marks should be used. The author or the person examining the proofs should initial each one at the place indicated by a rubber stamp. Proofs should be held only long enough to examine them properly and to compare them with the original illustrations, for a time limit is fixed in each contract for engraving, and if the author holds proofs beyond a reasonable time he causes a delay in the fulfillment of the contract. As the illustrations for many reports contain important data that will be discussed in the text, proofs of illustrations can not be sup- plied to any applicant without consent from the Director's office. GENERAL CONSIDERATIONS. The following requirements are essential to obtain good original illustrations : 1. The material selected should be pertinent and expressive; it should have the qualities essential to good illustrations. 40 PREPARATION OF ILLUSTRATIONS. 2. The character of the report and the size of the illustrations should be kept clearly in mind. If the report is preliminary or ephemeral the illustrations should be simple and inexpensive. If the report represents the sum of knowledge on the subject treated or the last word on some particular area the illustrations may be more elaborate. The character of a report generally determines the form of publication, which, in turn, determines the size of the pages and the size of the plates and figures. Every sketch made should be larger than publication size — preferably twice publication size — whether it is a simple diagram or a base map. 3. The kind of reproduction that is apparently needed should be fully considered, for it should have some relation to the kind of report. The illustrations for short-lived reports are reproduced by the cheaper processes. Those for hurried reports are reproduced by processes that can be worked quickly, but no process should be considered that will not give a clear reproduction of essential details. 4. Clearness of preparation of original matter is invariably essen- tial. An author should not expect the draftsmen or the editors to supply missing links. Each original should be complete and should be so made that it can be understood and followed without question. Changes made in the finished drawings or on proof sheets are ex- pensive and delay publication. PART II. PREPARATION BY DRAFTSMEN. GENERAL DIRECTIONS. The work of preparing illustrations such as are used in the reports of the Geological Survey is essentially that of making finished draw- ings from more or less crude and imperfect material furnished by authors to illustrate certain features or phenomena discussed in their manuscripts. Each finished drawing must be so prepared that it can be reproduced in multiple by one of several processes of engraving. The author's sketches and other material are commonly called " orig- inals " ; the finished illustrations are known by the engravers as " copy." Though most engraver's copy consists of more or less elaborate drawings that are to be reproduced in facsimile by " di- rect " processes without the interposition of handwork, some of it consists of more roughly prepared copy which is accurate in state- ment but requires complete manual or "indirect" reproduction. The direct processes in use are zinc etching, half-tone engraving, photolithography, three-color half tone, photogravure, and photo- gelatin. The manual or indirect processes are wax engraving, wood engraving, engraving on copper and on stone, plain lithography, and chromolithography. These processes are described on pages 72-90. Part I of this pamphlet contains some matter that is pertinent to final preparation and should be consulted by draftsmen. To prepare a drawing that will be in every way suitable for repro- duction usually requires experience of a kind not acquired in many other kinds of drafting, such as preparing engineers' or architects' drawings, because the drawings themselves or blue prints made di- rectly from them are the things the engineer or the architect desires. Drawings prepared for reproduction are generally made larger than publication size, and it is therefore necessary to gage each line, letter, or feature for a definite reduction. Engineers' and archi- tects' drawings generally do not require preparation for reproduction by any process, but in preparing illustrations for the reports of the Geological Survey reproduction must be fully considered at every step, and each drawing must be made according to the requirements of a certain selected process and gaged for a certain reduction. The draftsman should therefore know how to plan each drawing step by step for an engraved cut, a lithograph, a text figure, or a plate, always with a definite result in view. He should be familiar with processes of engraving and should know the special requirements 41 42 PREPARATION OF ILLUSTRATIONS. of each process, and he should be able to prepare drawings for any sj)ecLfied reduction in a way to insure good, legible reproduction. The geologic draftsman should read and study such textbooks of geology as those of Dana and Geikie and should familiarize himself with structural geology, the geologic time divisions, and geologic nomenclature. He should be able to prepare a simple, effective illus- tration from complicated rough originals and to supply minor miss- ing essential parts or features. To perform his work successfully he must possess mechanical skill and some artistic taste, as well as good eyesight and gi'eat patience. INSTRUMENTS. The following list of draftsmen's instruments is practically com- plete. Those which are considered indispensable are marked by asterisks; the others may be used according to individual preference. The same kind of instrument, may be duplicated in different sizes according to the variation in the demands of the work. Air brush and connections. Beam compass. Bow pen, drop spring. *Bow pen, steel spring. Bow pencil, steel spring. *Brushes, red sable. China saucers. *Color box. *Compass, pen and pencil points. Crayons, assorted colors. Curve rule, adjustable. ♦Dividers, plain. ♦Dividers, proportional. Dividers, steel spring. Drawing boards, several sizes. Eraser, glass. ♦Eraser, rubber, hard. ♦Eraser, rubber, soft. ♦Eraser, steel. lOrasing shield. ♦French curves, xylonite. Miscroscope, low power and lenses Palette knife. Pantograph. Pens, double-pointed. ♦Pens, Gillott's, Nos. 170, 290, 291. Pens, K. & E., drawing. No. 3202. Pens, Payzant's, 1 set. ^Pencils, best quality, graded leads. ♦Protractor. Railroad curves, pearwood, 1 set. Railroad pen. ♦Railroad pencil. Reading glass. ♦Reducing glass. ♦Ruling pen. Scale, boxwood, 12 inches long, with divisions of millimeters and inches. Scales, boxwood, triangular. Section liner (parallel iniling device). Straightedge, steel, 24 inches. Straightedge, steel, 36 inches, with divisions for hundredths of an inch and millimeters. * Straightedge, wood, 24 inches. Swivel or curve pen. Thumb tacks. Tracing point, steel. ♦Triangle, 45°. ♦Triangle, 60°. *T square, pearwood. xylonite edge. *T\veezers, dentist's. CLASSIFICATION OF MATERIAL. The draftsman handling the drawings and other original material submitted by the author of a report for its illustration should first group them, as far as possible, into kinds or classes, in order that PREPAKATION OF ILLUSTRATIONS. 43^ he may decide how each illustration should be prepared (1) to ex- press most effectively the author's purpose, (2) to insure reasonable economy in preparation and in reproduction, and (3) to meet the re- quirements of the processes of reproduction selected. All similar illustrations for one publication should be prepared in the same gen- eral style. In a series of geologic sections, for example, the same lithologic symbols should be used throughout for the same kinds of rocks. The titles, explanations, and captions of the maps should also agree with one another in general style and in details of workmanship. The draftsman should determine in advance the reduction for each drawing or for each group of drawings, in order that he may use the same size of letters or the same kinds of type for the lettering on a series of drawings that require the same reduction. The reduction should preferably be marked in fractions (as "3/2 off," " ^4 off " or " reduce i/^," " reduce ^/4 ") , and the choice of the same reduction for a group of drawings will not only insure greater uniformity in the drafting and in the reproduction but will permit the drawings to be reproduced more economically, for the engraver can photograph, them in groups instead of each one separately. The draftsman should therefore note and consider (1) the special features shown in the author's originals; (2) whether or not these features have been plainly indicated and whether the originals are complete; (3) the size of the printed page of the volume in which the illustrations will appear and the reduction required for each drawing; and (4) the process by which each drawing should be re- produced. If an original is of doubtful or uncertain interpretation or appears to be incomplete the draftsman should confer with the author of the paper if he is within reach or should bring the matter to the attention of the chief of the branch ; otherwise he may waste much time in making the drawing. PREPARATION OF MAPS. PROJECTION. The base maps furnished by authors (see pp. 13-14) are prepared in many different ways and in different degrees of refinement and of crudity, but the work of redrawing them for reproduction involves well-established and generally uniform principles. All maps except those of very extensive areas should be based on a map projection which will show with a minimum of distortion the effect of the curva- ture of the earth. The polyconic projection (see fig. 5) is used for most Government maps. In this projection the central meridian is a straight vertical line, and each parallel of latitude is developed inde- pendently of the others. The mathematical elements of map projec- 44 PREPARATION OF n^LUSTRATIONS. tion are given in tables published by the Geological Survey^ and the Coast and Geodetic Survey.^ Figure 5, however, illustrates the me- chanical or constructional features of the polyconic projection and if used in connection with the published tables will probably be a suffi- cient guide for projecting a map on any desired scale. In projecting a map first select a convenient measuring scale for setting off the dimensions given in the tables, or if no scale is at hand one may be constructed. Measuring scales are made, however, bearing divisions for miles and kilometers and finer subdivisions of 5 to 100 parts. They include the ratios of 1 : 31,250, 1 : 31,G80, 1 : 48,- 000, 1 : 62,500, 1 : 63,360, 1 : 125,000, 1 : 250,000, 1 : 500,000, 1 : 1,000,000, and others. On a map drawn on the scale of 1 to 63,360, for example, Degrees from central meridian- - Distance in meters from central meridian 2° :82,568 4" 365,05* 6° 547,412 8° 7Z9,542 10° 911,379 Figure 5. — Diagram illustrating method of projecting a map. 1 inch would represent 1 mile ; on a map drawn on the scale of 1 to 1,000,000, 1 millimeter would represent 1 kilometer, and so on. It will be seen that the use of a scale that shows in ratios, such as those just given, the actual distance on the ground as compared with the unit representing the same distance on the map will reduce the possibility of error. The method of projecting a map, illustrated in the accompany- ing diagram (fig. 5), is as follows: First draw a straight vertical line (A) through the middle of the sheet to represent the central meridian ^ Gajinett, S. S., Geographic tables and formulas, 4th ed. : U. S. Geol. Survey Bull. 650, 1916. See also Gannett, Henry, Manual of topographic methods : U. S. Geol. Sur- vey Bull. .107, pp. 85-86, 1006. ■* Methods and r<'sults : Tables for the projection of maps and polyconic development ; Appendix No. 6, Report for 1884 ; Tables for a polyconic projection of maps, bafied upon Clarke's reference spheroid of 1886 ; 3d ed., 1910. PREPARATION OF ILLUSTRATIOITS. 45 of the map and a line (B) at the lower end of this line exactly at right angles to it to represent the bottom of the map. Then set off on the line showing the central meridian the distances between parallels given in Table 6 on page 36 of " Geographic tables and formulas" (Bull. 650). It should be noted that the figures in these tables give the distance, in meters and statute miles, of 1° on a meridian measured 30' each way from a point where the meridian is intersected by a parallel. The exaot distances between parallels as measured on the ground are given in the Coast and Geodetic Survey tables, or they may be computed from Table 6 of "Geographic tables and formulas " by adding the sum of the figures given for any two latitudes 1° apart and dividing by 2. The distance between parallels that are 2° apart, as shown in the diagram, may be computed from Table 6 of " Geographic tables and formulas," as follows: Meters. Meters. 1° of latitude on 37th parallel =100,975.1-^2= 55,4S7. 5 1° of latitude on 36th parallel =110,956.2 1° of latitude on 35th parallel=110,937.6-H-2= 55,468.8 True distance from 35° to 37° latitude =221, 912. 5 The distances given in the diagi'am were obtained by adding the figures given in the Coast and Geodetic Survey tables, which yield the same results. Other tables in Bulletin 650 give the true distances in inches on maps of certain standard scales. Through the points thus obtained on the central meridian draw lines at right angles to the vertical line. Along these horizontal lines lay off the dimensions in the column headed X, Table 6 (pp. 39^7) of " Geographic tables and formulas " as required for each individual map — in the diagram every alternate degree. Draw ver- tical lines at these points and set off the distance Y in the same table in a similar manner, and the points so found will be the points of in- tersection of the respective meridians and parallels. Figures are given on the diagram for the thirty-fifth parallel only. DETAILS OF BASE MAPS. Anyone who attempts to draw a base map must, first of all, know how each feature or part of the map should be represented. Most of the conventional symbols for features shown on base maps are well established and should invariably be used; for instance, a line com- posed of alternate long and short dashes (not dashes and dots) repre- sents a county boundary, and a line or two parallel lines across which short lines are drawn at regular intervals represents a railroad. If he finds that two or more symbols have been widely used to represent 46 PREPABATION OF ILLUSTRATIONS. the same feature the draftsman should select the one that is best suited to the map in hand. The correct forms of the conventional symbols or features to be used in preparing miscellaneous maps are shown in Plate IV, but the size and weight of each line or symbol must depend on the size and character of the map. TRANSFERRING OR COPYING. TEACING. The oldest method of transferring a map or parts of a map or other drawing to another sheet is that of copjdng it by means of tracing paper. This method, though still used for simple work, has given way to quicker and more effective methods. By one of these methods a piece of thin, fairly smooth paper (not necessarily trans- parent) is coated with graphite by rubbing over it a soft pencil. When the graphite has been evenly distributed over it, this sheet is laid upon the drawing paper, coated side down, the map or other sub- ject to be copied is laid upon the graphite-coated sheet, and the two outer sheets — the drawing paper and the map — are securely fastened together. By a steel tracing point or very hard pencil the lines and other details of the matter to be copied are then firmly and carefully traced and thus transferred to the clean drawing paper beneath. For maps that show several features in different colors sheets rubbed with blue, orange, brown, or green pencils may be used, one after another, for tracing each set of the features. Red should not be used, as it is not easily erased. This method insures distinctive lines for the separate features and prevents the confusion that might result from the use of one color only. Exact register of the features shown in the several colors used may be insured by fastening one edge of the drawing to be copied to the drawing paper by mucilage or thumb tacks. The colored sheets may then be slipped in and out without altering the position of the lines or s}'mbols for one set of data with relation to those for the others. In the final preparation of a base map to be engraved and printed in colors — for example, black, blue, and brown — tracings of the three colors appearing on the original base should generally be transferred, as described above, to one sheet of paper and thus worked up into a three-colored map. It is usually unnecessary and undesirable to draw each color on a separate sheet. The preparation of separate drawings may facilitate reproduction, but if they are made on tracing cloth the usual uneven shrinking or stretching of the cloth may pro- duce misregister in the printing ; therefore it is safer to make a single drawing, so that the photolithographer can make three negatives and PREPAKATION OF ILLUSTRATIONS. 47 separate the colors by painting out or "opaquing" the colors not wanted on each negative. A map drawn on a single sheet is also less bulky and can therefore be more conveniently handled and com- pared with proof. If for any reason separate tracings for the different colors to be used on a map are considered desirable they should be made on linen cut from one roll and in the same direction according to the warp and woof. CELLITLOID TRANSFERRING. In the celluloid method of transferring a map or parts of a map to paper upon which a complete new map is to be drawn the map or part of the map to be copied is photographed to the exact scale of the new drawing and reproduced in graphite on thin sheets of celluloid. The celluloid sheet is then laid face down in the correct position on the drawing paper and firmly rubbed on the back with a steel burnisher, which makes a perfect offset of the map on the paper. After the parts desired are inked over the rest of the graphite print is easily erased with an ordinary rubber. By using this method it is possible to get absolute scale and more satisfactory^ results than by tracing over a photographic print line for line or by using a pantograph. Requisitions for celluloid prints are made on the form used for requesting photolithographic work. SKETCHING BY RETICULATION. If the sheet bearing the design or matter to be copied may be marred without objection it is ruled lightly into pencil squares of equal size. Corresponding squares of the same size, larger, or smaller, according to the size of the new drawing, are then ruled on the drawing paper, and the work is sketched square by square. If the original sheet uiaj not be marred the same result can be obtained by drawing the lines on a transparent oversheet. This method is serviceable for enlarging or reducing simple work that includes no great amount of detail; if great precision of detail is required the original should be enlarged or reduced by photography or by the pantograph. THE " SHADOWLESS DRAFTING TABLE." One of the most useful contrivances that has been made for tracing a drawing on the same scale is called by its manufacturers the " shadowless drafting table." The essential features of this table are a wooden box inclosing strong incandescent lights and bearing a ground-glass top. A drawing placed on the ground glass can be so 861754° — 49 i 48 PREPAKATION OF ILLUSTRATIONS. illuminated as to make its lines conspicuous and readily traceable even through relatively thick paper. The table is particularly use- ful for tracing sheets upon which the lines are indistinct and would not be discernible under tracing paper with reflected light. It is also useful in preparing drawings in which certain features must register perfectly over each other. In fact any drawing that does not require enlarging or reducing can be traced with great facility by the use of this drafting table, and it is particularly useful for tracing faint lines on old and poorly preserved prints or drawings. Such a table has been installed in the section of illustrations, where it can be used by authors and others. TOPOGRAPHIC FEATURES. RELIEF. The effect of relief is expressed on a map by three methods — by contours, by hachures, and by shading. (See fig. 6.) The first method does not give pronounced pictorial expression of relief, though it gives correct shape and exact jelevation ; the others are more pictorial, but they do not give exact elevation. Contours. — As contoured maps are originally prepared from actual surveys the draftsman should simply follow the copy furnished by the topographer or such original matter as may be given to him for redrawing. If the area mapped is large and the contours are close together the original may be transferred by celluloid tracing (see p. 47), or it may be transferred by tracing with graphite-coated paper (see p. 46). After the contour lines have been transferred they should be traced in ink, in lines of even thickness, except those that represent certain fixed intervals and are to be numbered, which should be made slightly thicker. (See fig. 6, A.) In drawing these lines some draftsmen use an ordinary ruling pen, others the swivel pen ; but considerable practice is required in the use of either before it can be controlled to follow precisely the penciled lines. Still other draftsmen use the Shepard pen or an ordinary drawing pen. The swivel pen, if expertly handled, produces a firm and even line. Italic numbers should be used to indicate the elevation of a con- tour and should be placed in an opening in the line, never between lines. Where the lines run close together great care should be taken that they do not touch unless the interspaces are so narrow that they must touch and combine. The lines should be firm and even, and if the copy or original map shows that they are uniformly very close together it should be enlarged before the tracing is made in order to give more freedom in drawing; but if the enlarged map is to be much reduced care should be taken to make the lines proportionate to the reduction. A photo-engraving of a map on which the contour PREPAKATIOISr OF ILLUSTRATIOlSrS. 49 lines are drawn very close together is likely to be unsatisfactory be- cause, though the spaces between the lines are reduced in width, the lines themselves may show no corresponding reduction in thickness. i^.- c 4». is- Mill l.\ ll-SV^/j > ///> D Figure 6. — Methods of expressing relief: (A) by contour lines, (B) by hachures, (C) by shading on stipple board, and (D) by a brush drawing. Tfee four examples given rep- resent the same area. The drawings were made twice the size of the printed cuts. Certain contour lines are commonly accentuated on a map, gener- ally every fourth or fifth line — that is, for a 10-foot interval every 50-foot line, for a 20-foot interval every 100-foot line, for a 25-foot 50 PREPAEATION OF ILLUSTRATIONS. interval every 100-foot line, for a 50-foot interval every 250-foot line, and for a 100-foot interval every 500-foot line. Uachuring. — The effect of relief can be produced satisfactorily by hachuring but onl}^ by a draftsman who has had considerable well- directed practice in that kind of drawing. In a hachured map the light should seem to come from the west or northwest — that is, the darker parts should be on the east or southeast side of an elevation and the lighter parts on the west or northwest. The highest eleva- tion should be represented by the darkest shade on the right and by a corresponding high light on the left. The hachuring should begin at the crest of a peak, range, or butte and be worked downward toward the gentler slopes, the lines being drawn farther apart and made thinner until the floor of the valley is reached and the effect of shadow is lost by fewer and lighter lines. On a hachured map that is made from a contoured map somewhat definite differences of elevation may be indicated by the intervals between the strokes, and abrupt changes in slope may be indicated by shorter and heavier lines. The strokes should be disjointed, and they should trend at right angles to the upper margin of a cliff and should radiate from a peak. Figure 6, B, represents satisfactory hachuring. Hill shading. — Relief is more easily expressed by shading than by hachuring. (See fig. 6, C, D.) The draftsman can best express it by this means after he has studied contoured maps or photographs of the region mapped, if they are available, in order that he may obtain an idea of the details of its topography. The special means used to produce hill shading will depend on the character of surface of the paper on which the drawing is to be made, the size of the map, the amount of detail and refinement of execution desired, and the amount of reduction to be made in re- producing the drawing. For maps on which it is desired to show some refinement of drawing and detail, a lithographic or wax crayon can be used on paper which has a grained surface. The draftsman must express relief according to the information he has at hand, whether detailed or general, and must employ methods that accord with the purpose of the map and the mode of reproduction selected. If a shaded relief map is to be prepared for direct reproduction by photolithography and the shading is to be printed in a separate color the base map should be completed first and a light photo- graphic or blue print obtained on which to add the relief in black lithographic crayon, to insure perfect fitting of the relief and the base; or the relief can be prepared on an oversheet — a semitrans- parent white paper with sufficient " tooth " or grain to cut the shad- ing up into minute dots. The shadowless drafting table (see p. 47) is especially useful for this purpose. On this oversheet register PREPARATION OF ILLUSTRATIONS. 51 marks should be placed at the four corners and at severa] other points, particularly at the intersection of parallels and meridians. For relief shading on small black and white maps Eoss's hand- stipple drawing paper may be used. (See p. 24.) By rubbing a black wax crayon or pencil over the surface of the paper the de- sired effect is produced in fine dots or in stipple, which may be varied in density of shade at the will of the draftsman. (See fig. 6, C.) High lights can be produced by scraping away the chalky surface of the paper. A lithographic or wax crayon is the best medium to use on this stipple paper, as on the paper referred to in the preceding paragraph, for the shading produced by it is not so easily smeared as that produced in pastel or by a graphite pencil. The object of using either the rough paper or Ross's stipple paper for drawings that are to be reproduced by photo-engraving is to produce a shading that is broken up into dots of varying sizes, which is essential in such reproduction. Relief shading for maps can also be made with a brush in flat washes of either India ink or lampblack. Such shading should be made only over a blue print or an impression of some kind from the map upon which the shading or relief is to be overprinted. If the relief is expressed on the author's original by contours the general shapes of the relief and the drainage lines can be traced and trans- ferred lightly in blue lines to form a base on which to model the shading and at the same time to make the shading fit the streams. Such a drawing can be photographed through a screen and repro- duced by half tone (see fig. 6, D) or mezzotint as a separate plate made to overprint the map in another color. HYDROGEAPHT. General directions. — ^The drainage features of a map should be so ■drawn as to suggest the natural courses of the streams. Streams should not be drawn in straight, hard lines, as such lines are de- cidedly unnatural and produce a crude effect. The course of a river may be straight in general, but it is likely to be somewhat sinuous in detail. If the streams shown on a preliminary map are drawn in a clumsy or characterless fashion they should be redrawn with a freehand effect or made slightly wavy, in order that they may appear more natural. The gradual widening of streams from source to mouth should also be shown in the drawing. On small-scale maps, where the eye can at once see a stream through its full length, this almost imperceptible widening can be expressed by a line of almost uniform weight except for the stretch near the source, where it should grow thinner and taper off. On maps which are to be reproduced directly from drawings in black and white and which are to show 52 PREPAEATION OF ILLUSTRATIONS. both contour lines and drainage the lines representing the streams and other water bodies should generally be drawn freehand and slightly heavier than the contour lines, which should be sharper and more precise. The names of all streams or other bodies of water should be in italic letters, those of the larger streams being lettered in capitals and those of the smaller streams in capitals and lower-case letters. (See "Lettering," p. 53.) Water lining. — The use of water lining on black and white maps should be limited to maps on which the water areas are not readily distinguishable from the land areas. In rough drawings that are to serve only as copy for engravers a flat color may be used for water areas and its conversion into water lines specified. In base maps to be reproduced in three colors a light-blue tint may be used in lieu of water lining, and it can be printed either flat or in a fine ruling transferred to the stone that is to print the drainage. The engraving of water lines is expensive, and the flat blue color should generally be preferred. Water lining usually consists of 30 to 45 lines on engraved or large maps, but on small maps and sketch maps the number may be reduced as desired. Care should be taken that the lines are as nearly parallel as they can be made freehand and of even weight or thickness. The first three to six lines outside the coast line should be somewhat closer together than those farther out and should con- form closely to the coast line, but the spacing between the lines should increase and the lines should become almost imperceptibly less con- formable to the coast line as they reach their outer limit, the last three to six being made with the greatest care and refinement. Water-lined maps that are to be reproduced by photographic processes should be drawn at least twice publication size. The reduction will bring the lines closer together, and the reproduction will show a more refined effect than could possibly be produced by the most skillful drawing. Good examples of water lining, such as are shown on the topo- graphic atlas sheets of the Survey, should be studied by draftsmen before they undertake such work. CULTTJHAL FEATURES. The cultural features represented on a map include " the works of man " — not only cities, towns, buildings, bridges, railroads, and other roads, but State, county, and other boundary lines — in short, all that part of a three-color base map which is shown in black, the engraved plate for the black being called the culture plate. The features named U. S. GEOLOGICAL SURVEY PREPARATION OF ILLUSTRATIONS PLATE IV Boundary lines and surveyors'marks State or international boundary line. _ County boundary line Township, section, and quarter-section lines / Reservation boundary line . . . . . - Land grant boundary line ■ ■ ■ • . . . Civil township boundary line — — — ■ — — City and small park boundary line - Boundary monument _^__. Township and section corners recovered ^ Triangulalion station A Bench mark _ X U. S. mineral orlocating monuments ^ /^60 Public works Railroad, single track Railroad, double track Juxtaposition of railroads Electric railroad and tramway Railroad in wagon road Railroad tunnel. Railroad station Electric power line Wagon roads, good Wagon roads, poor or private... Trail orroule of travel , Telegraph line Telegraph line in roads Telegraph line on trail Fences, of any kind Fence, stone Fence, worm _ Fence, wire Hedge City or town City or town (large scale! Capital I t I I I I I I 'Large'xaiemapi ^; Small scile nap i ?>S^/ i^§g^ ^ - c^aac County seat - (S) Towns _-o •■ # Buildings Ruins * [""■"" Post office ■ /v ' — '' Cemeteries \C£m] [+] + Church .\-Tr.-.^._..\-.— ^ Schoolhouse _ Water features Streams Intermittent stream Unsurveyed streams... Falls and rapids Springs _ Glaciers. _ >»s'WW,W>vi* '"T T~>^^7rV'>'; Lakes or ponds ^^^^^^ ^ — r^ ~cc«**.«x,3 -^.^ <..^«. Intermittent lake or pond ^^?^^^^..\fC -«^^^^^^ Marsh, fresh S^f^^^^ ^m-^ Marsh, salt.... Tidal flat _ _ __^ Canal or ditch -- { = - = ^-■<^^"-- - - s — & Draw bridges Bj! Ferry fpoint upstream).. .._ W^~ Dams _ _ _ _ _ Locks (pomt upstream) Wateriirung and breakwater Relief features Contour lines ._ Hachures - _ Depression contour ,. Woods- _.S Amm above amber line SYMBOLS USED ON BASE MAPS PREPARATION- OF ILLUSTRATIONS. 63 in the list below are the cultural features referred to. (See PI. IV for corresponding symbols.) Aqueduct mains. Aqueduct tunnels. Bench marks. Boundary lines. Boundary monuments. Breakwaters. Bridges. Buildings. Cable lines. Camps. Canal locks. Canals. Cemeteries. Churches. Cities. County lines. Dams. District lin&s. Ditches. Electric power lines Fences. Ferries. Fords. Gas wells. Hedges. Hospitals. Jetties. Land-grant lines. Land-section lines. Levees. Mains. Mineral monuments. Mine tunnels. Mines. National forests. National parks. Oil tanks. Oil wells. Open cuts. Park boundaries. Paths. Pits. Post offices. Precinct lines. Prospects. Province lines. Quarries. Quarter-section lines. Railroads, steam or elec- Windmills, trie. Ranches. Reservation boundaries. Reservoirs. Roads. Ruins. Schoolhouses. Section corners. Section linea Settlements. Shafts. Streets, Telegraph lines. Towns. Township comers. Townships. Trails. Tramways. Triangulation stations. Txmnels. Villages. Water mains. Water wells. Waterworks. LETTERING. GENERAL BIRECTIONS. The cultural features are named on maps by letters of two distinct styles — slanting gothic for public works and roman for habitations and civil divisions. The size of the letters used should indicate in a general way the relative importance of the feature or group to which they are applied, but on some maps the county seats, State capitals, and large cities may be distinguished by different symbols. The names of civil divisions are lettered in sizes depending on their relative grade and the size of the area or space in which the names are to appear. The features shown on a topographic map may be broadly sepa- rated into four groups and are lettered as follows : Civil divisions (countries, States, counties, townships, land grants, reservations, cities, towns, villages, settlements, schools, lodges, ranches, etc.), roman capitals or capitals and lower case. Public works (railroads, tunnels, roads, canals, ferries, bridges, fords, dams, mains, mines, forts, trails, etc.), slanting gothic capitals (light) or capitals and lower case. 54 PREPARATION" OF ILLUSTRATIONS. Hydrographic features (oceans, seas, gulfs, bays, lakes, ponds, rivers, creeks, brooks, springs, wells, falls, rapids, marshes, glaciers, etc.), italic capitals or capitals and lower case. Hypsographic features (mountains, ranges, peaks, plateaus, cliffs, buttes, canyons, valleys, peninsulas, islands, capes, etc.), upright gothic capitals (light) or capitals and lower case. The essential principles of lettering have been described in numer- ous treatises and are well understood by most draftsmen. The cor- rect form of each letter may be learned from such treatises, but spac- ing and arrangement are best learned by observation and experience. Good lettering will not strongly attract attention, but even slight imperfections of form, spacing, slant, and shading will be quickly detected and criticized. Map letterers should note that the name of a place or the number of a symbol should be put to the right of the symbol if possible and a little above or below it — not to the left and directly on a line with it, as Tucsono, iTo, Dallaso, Carsono. Names indicating large areas, if written from west to east, should curve with the parallels, and all names should be so lettered that " if they should fall they would fall on their feet." Every name should be distinctly legible but not so conspicuous as to subordinate the feature it desig- nates. Lines should therefore not be broken in order to make the lettering clear except where there is possible danger that the smaller spaces may be filled up in printing. The lettering on a map should always be so spaced that it will properly fit the area it is intended to designate. In names consisting of two or more words the letters should not be closely spaced if wide spaces are left between the words. In numbers, except those used to indicate elevations on contour lines or elsewhere, thousands should always be set off by commas. Draftsmen often draw bad forms for commas, quotation marks, apostrophes, and question marks. The following forms are correct: Comma , ; quotation marks " " ; apostrophe ' ; question mark ? . LETTERING BY TYPE. Names and short notes printed from type on paper, to be cut out and pasted in proper positions on maps or other drawings, now fur- nish a large proportion of the lettering on the Survey's illustrations. The strips are likely to become detached by the repeated handling of a drawing, however, unless they are securely pasted on. The best results can be obtained by having the type printed on a special brand of " noncurling " gummed paper, from which the lettering is cut in squares or strips, which are dampened and applied to the proper places on the drawing. In handling such strips a pair of dentist's tweezers is useful. When mucilage is applied to printed strips of ordinary paper the moisture causes the paper to warp or curl, often so much as to affect the reproduction of the drawing. This printed U. 8. GEOLOGICAL SURVEY l2-point M} 12'point -.V. ,, x^j. U-pomt i is-p Z.\ --; ]l 18'point ""''' "-^ '^-F'o PREPARATION OF ILLUSTRATIONS PLATE V \Z ^'T! 12-jmnt NORTH CAROLINA 12-point' :1 12-po1nt WE 14-poJnt No»; 12Si56789 : 12-poV ^"'^ ' ■ U-mnt CONNECTICUT 1 2S 1^567 8 9 0& NC .. U-p,[^-J^^J8-pomt ILLINOIS 123^5678900^ 12-POINT No. 29 KENTUCKY 1234567890 12-POINT NO. 30 MISSOURI 12 3 4 5 6 7 8 9 0, 12-POINT No. 31 UTAH 1234567 89 12-POINT No. 6 WISCONSIN 12 3 456789 'O-fDr lO f- 12-POINT NO 7 IDAHO 123456789 ,^ „^,.,-r ^. ''^'^*- '"^"'^ 12-POlN 12-POINT No. 8 OHIO 12 34 5678 l-^-r^f^ll^ I /^C /2-P 12-P 12-POI 14P01NT ALABAMA 1234567890 lO-fDQIhJ-r l\ 12-PC 12-F 12-PC 12 point WEST VIRGINIA WYOMING 123456789 0. 12_ 14.POI''*-PO'"' '^''' "' PENNSYLVANIA 1234567890 12-POIN 7\ ^ ^'^' 1 a'i 12-point '8-point NORTH DAKOTA 1 2 3 4 5 6 7 8 9 Q 19 POINT n!^^"^ 12 P(i4-point24-point UTAH 123456789 '^"' ^^"^' '^ 14-P 18-DOin' ^""'^™' WSTRICT OF COLUMBIA 1234567890 12 POINT' \2qq\^^'^^ HA l^-Point MASSACHUSETTS 1234567890 hT> r-w^iivJ i/ -^S-P^'P'^^-P^^"^ OREGON 1234567890 12-POIN! '"^"P^' oi 12-point 14- POINT (ii:()K(ilA I 2 .'U o (5 7 S 9 1 A OrMMT^ 18-pC 14-poin11(5-P()INT KANSAS 1 2;ur)(i 7n9(> i^-rUIINl ^ ^^■P'^18-poi>^-I'<>I>'I^ INDIANA 1 2 ;U ;> (} Z4-l4-Pj^P(^i)(i.l>()IXT MAINK 1L>845 i2-poii8-]i6.p(i24-P()INT OHIO 12:U 18-point ^18-p IB- 20-1^0/^ pru VT 1 oo 1 24-poi| i^i ^^ 24-1^1:1 ; ^^A/r^ 12-poto d| lt|;;^30-POTNT 12 345 6 14-point 1 2o| ^ 36-POTNT 1284 M:l736-P01NT1284 18-POI136-P01NT 1284 20-POINT MAINE 12345 24-P()INT OHIO 12 3 4 30-POINT 12 3456 36-POINT1234 REDUCTION SHEET USED IN LETTERING ILLUSTRATIONS. The largest size shows the letters unreduced; the other sizes show the letters reduced as indicated in the margin. PREPARATION OF ILLUSTRATIONS. 55 lettering is generally used, however, only for headings, titles, notes, and other matter that stands alone; it should not be used for the geographic names in the body of a map unless only a few names are to appear, for the strips of paper bearing the names may obscure parts of the map. The reproduction of tliis lettering by photo- engraving or photolithography gives results superior to those ob- tained from hand lettering unless each letter is made with the utmost care, work which is considered a waste of time. Type is used also for prmting lettering directly on a drawing exactly in proper position, by a special type holder, somewhat like a self-inking stamp. Most of the styles and sizes of type now used on maps in the Sur- vey's reports are shown in Plate V. If a drawing is to be reduced one-half the smallest type used should be about 2 millimeters in height; if it is to be reduced one- third the smallest type used should be about 1.5 millimeters in height; and so on. No letter whose vertical height after reproduc- tion would be less than about 1 millimeter should be used, and the larger lettering should bear a proper relation to the smaller. Sheets showing the styles of type in use by the Survey, in full size and re- duced one-fourth, one-third, two-fifths, one-half, three-fifths, two- thirds, and three-fourths, will be furnished on request'. If a draw- ing is to be reduced one-half, for example, the sheet that has been reduced one-half will show the size of the lettering on the printed plate, so that the draftsman, by referring to the sheet showing the reduction he desires, can select type of a size that will be legible. Plate V shows a part of this reduction sheet. ABBEEVIATIONS. The following are the correct forms for maps and other illustrations : abbreviations used on A. Arroyo. Is. Islands. Pk. Peak. B. M. Bench mark. Jc. Junction. P. O. Post office. Bdy. Boundary. L. Lake. Pt. Point, Br. Branch, bridge. Lat. Latitude. R. Range, river. C. Cape. Ldg. Landing. Res. Reservation, Can. Canal, canyon. L. S. S. Life-saving sta- ervoir. Cem. Cemetery. tion. R. H. Road house. <^o. County. L. H. Lighthouse. S. South. Cr. Creek. Long. Longitude. Sd. Sound. E. East. M. P. Milepost. S. H. Schoolhouse. EL Elevation. M. M. Mineral monu- Sta. Station. Est. Estuary. ment. Str. Stream. Fk. Fork. Mt. Mount. T. Township. Ft. Fort, foot. Mtn. Moimtain. Tel. Telegraph. Gl. Gulch, glacier. Mts. Mountains. W. West. Hbr. Harbor. N. North. 1. Island. Pen. Peninsula. res- 56 PREPAKATION OF ILLUSTRATIONS. Words like mount, river, point should not be abbreviated where they form a part of the name of a city or town, as Rocky Mount, Fall River, West Point. Neither the word nor the abbreviation for rail- road or railway should be placed on a map ; the chartered name (or initials of the name) and the road symbol are sufficient. Names of States and Territories should be abbreviated, where abbreviation is necessary, as follows: Ala. Ga. Minn. N. J. Tenn. Ariz. lU. Miss. N. Mex. Tex. Ark. Ind. Mo. N. Y. Va. Calif. Kans, Mont. Okla. Vt. Ck)lo. Ky. Nebr. Oreg. Wash. Conn. La. Nev. Pa. W. Va. D. G. Mass. N. C. R. I. Wis. Del. Md. N. Dak. S. C. Wye. Fla. Mich. N. H. S. Dak. Alaska, Guam, Hawaii, Idaho, Iowa, Maine, Ohio, Samoa, and Utah should be written in full. The abbreviations used on the margins of maps for subdivisions of land should be as follows (note punctuation) : T. 2 N., R. 3 W. On large-scale plats the marginal lettering should be as follows: N. i NE. i sec. 1, T. 7 N., R. 2 W. ; fractional sees. 2 and 35, Tps. 7 and 8 N., R. 2 W.; NW. i sec. 20, T. 7 N., R. 2 W. In spelling fractions use half and quarter, not one-half and one-quarter. The abbreviated forms of such names as North Fork and South Fork should be N. Fork and S. Fork, not North Fk. and South Fk. Additional abbreviations used on illustrations are as follows : N. for north, NE. for northeast, NNE. for north-northeast, etc. Capitalize directions affixed to street names, as NW., SE. (1800 F St. NW.). Sec. and sees, for section and sections before a number. Capitalize only at the beginning of a line or sentence. a. m. and p. m. for antemeridian and postmeridian, as 4.30 p. m. Lower- case unless in line of caps. & in names of corporations or companies. On Survey miscellaneous maps *■ and " is spelled out in railroad names. B. t. u. for British thermal units. bbl., bbls. for barrel, barrels. bu. for bushel or bushels. c. c. for cubic centimeter. cm. for centimeter. cwt. for hundredweight. dwt. or pwt. for pennyweight. oz. for ounce or ounces. etc. (not &c.) for et cetera. ft. for foot or feet. H. m. s. for hours, minutes, and seconds. (Use capital H.) in. for inch or inches. kw. for kilowatt or kilowatts £ s. d. for pounds, shillings, and pence. per cent (omitting period) for per centum. Spell out percentage. V. S. GEOLOGICAL SURVEY PREPARATION OF ILLUSTRATIONS PLATE VI 175-LINE SCREEN. 150-LINE SCREEN. 133-LINE SCREEN. 120-LINE SCREEN. 100-LINE SCREEN. 65-LINE SCREEN. HALF-TONE CUTS SHOWING EFFECT OF SEVERAL STANDARD SCREENS IN THE REPRODUCTION OF THE SAME DETAIL. PREPARATION OF ILLUSTRATIONS. 57 ser. for series. St. for Saint or street. U. S. Army for United States Army, as distinguished from United States of America (U. S. A.), yd., yds. for yard, yards. The names of certain months may in some places be abbreviated ; those of others should invariably be spelled out. The following are the correct forms : Jan. Apr. July Oct. Feb. May Aug. Nov. Mar. June Sept. Dec. The abbreviations for number and numbers before figures are No. and Nos. The o should never be raised, as in N°. The abbreviation for Mac is Mc, not M^ All periods should be omitted from abbreviations used in the body of a map unless their omission would cause misunderstanding. They are generally unnecessary, and if used on some maps they are likely to be mistaken for symbols representing certain features, such as houses or flowing wells, if either are shown. Periods used on draw- ings that are to be reproduced " direct' " or photomechanically should always be slightly exaggerated. NAMES OF KAILEOADS. The names of railroads may be written in full or abbreviated, in accordance with the kind of map and the space available. On a sketch map in black and white the initial lettei-s are generally suf- ficient. On a more detailed map, if there is room enough, the names may be spelled out. As already stated, neither the words " railroad " and " railway " nor the abbreviations R. R. and Ry. should be used on a map. MAKE-UP OF MAPS. FOEMS FOE CEETAIN FEATTJEES. The proper forms for certain features of maps, such as the borders, titles, explanations, bar scales, captions, arrows indicating true north and magnetic declination, source, and authorship, are show^n in Plate VII. Note particularly the style and position of the marginal matter. 50EDEE. A finished map border is used or omitted according to the kind of map prepared. Diagrammatic maps and maps on which no par- allels and meridians appear do not need finished borders. On a map that shows complete areal geologic or other coloring, such as a map in a Survey geologic folio, the border lines tend to destroy the sim- ple effect of the whole map. On a map that is not completely colored and on all very large maps borders are really necessary. If borders 68 PREPAKATION OF ILLUSTRATIONS. are used, however, the space between the neat line and the outer line of the border should be only sufficient to provide proper space for the numbers showing latitude and longitude or township and range. A simple rule ^ for determining the width of this space is as follows : Divide the sum of the dimensions of the map by 2 and find the square root of the quotient, which will represent the width of the border in sixteenths of an inch. Example : Map is 20 by 30 inches ; 20 + 30 — 2 — ^ 25 ; square root of 25 = 5 ; width of border = -f-^ inch. The numbers showing latitude and longitude should be in shaded arable numerals and those showing township and range in gothic. The symbols for degree, minute, and second should not be crowded. On a map that has no added border lines the numbers should be in hair-line gothic. TITLE. The title of a map should be in roman letters and if placed at the lower margin should generally be arranged in two lines, unless it is short. If it forms two or more lines the lines should be well bal- anced. The first line should describe the position of the area; the second line should state the purpose of the map, as MAP OF BUTTE AND VICINITY, MONTANA SHOWING LOCATION OF MINES AND PBOSPECTS. A title placed inside the border of a map should be arranged in a series of lines, generally beginning with " Map of " or " Geologic map of." and the line showing the dominant part of the title should be emphasized by larger lettering, thus : MAP OF THE VICINITY OF BUTTE MONTANA SHOWING LOCATION OF MINES AND PROSPECTS. The name of the author or compiler of a map or of the person supplying the geologic or other data shown on it may be placed either beneath the title or in the lower right corner, just below the border line, and the names of the topographers or the source of the base should be stated in the lower left comer, just below the border line. If the title is placed inside the border all notes giving credit for any part or features of the map may be placed beneath the title or scale. (See PL VII.) EXPLANATION. The symbols, patterns, or colors used on a map should be given in a series of rectangles or "boxes," accompanied by explanatory •Worked out by Martin Solem, of the U. S. Geo\ogical Survey. U. S. GEOLOGICAL SURVEY V. S. GEOLOGICAL SURVEY PREPARATION OF ILLUSTRATIONS PLATE VII PROFESSIONAL PAPER Sfl7 PLATE Vn EXPLANATION SEGMENTARY ROCKS 86 00 ^5,_ e 5 A ^ 2 1 7 8 9 10 11 12 J8 17 16 15 l-» 13 19 20 21 22 23 2* 30 29 2B 27 26 25 31 - 33 34 35 36 DIAGRAM OF TOWNSHIP <> 1 Qal q; Alluvium iftream depoeitt) Tt Telluride conglomeratt ipebbUA and bouideri) UNCONFORMITY Kc c Carlile shale {dark HhaJe containing iron concreiiont ) 1 Kg Greenhorn limestone ( jointed dovt-colored titnegtone untk* • * ) Jsd Sundance formation (alUmating >andxtone») "Sd Dolores formation (caJeareowt shale and conglomerate) ■2 1' Ch 1 Hermosa formation (mndstone. shale, and limestone, of grayiAh**) DC Surv«y«d i 87*00' B«s« from U. S. Geoloj^ic tOpOfrAphic map GEOLOGIC MAP OF 25 Mies £0 25 KLometers Contour in(er\a] 50 feet Dabun is metui sea levvl 1920 Ouray limestone (Whxte or Ivght^nU aaccharoidai tirmntone) Ignacio quartzite (/hin-bfdded ffray or pink vavy qnartzii^) Schist (dense bluish-ffray Tocks with subordinate • • ) IGNEOUS ROCKS Tp Picayune andesite (intrusixc masses and sheets) Schist and gneiss (quartz-mica schist, congUmwraU, and * • Fault Strike and dip $ Axis of anticline DETAILS OF THE MAKE-UP OF A GEOLOGIC MAP PREPAKATION OF ILLUSTRATIONS. 59 terms in the form shown in Plate VII, headed " Explanation." If the explanation is small a convenient place for it on some maps may be found within the neat lines. If no space is available there, or if it is so large that there is not room to place it there with- out obscuring other details, it may be placed either vertically along the right margin, as shown in Plate VII, or horizontally under the title. A geologic explanation should preferably be arranged ver- tically, as in Plate VII, so as to show the relative age of the forma- tions by the positions of the boxes. This explanation should be carefully worked out in pencil by the draftsman and approved by the committee on geologic names before it is drawn in inl?:, in order to save time in making corrections. In lettering the explanation roman letters or type should be used for the titles under the boxes and italic of smaller size for the sub- titles or descriptive detail, which should be inclosed in parentheses. The names of geologic periods and systems should be in gothic capi- tals, the names of series or groups should be in italic lower case, and the limit of each period, system, or group should be indicated by braces. The general style and arrangement shown in the Survey's geologic folios should be followed, and this and the arrangement of other matter is shown in Plate VII. Care should be taken not to crowd the explanation, and if corrections are necessary they should be so made that each line of the matter in which they appear will be prop- erly spaced. The explanation for a map that is to be engi-aved or to be repro- duced by lithogi'aphy need only be sketched in to show general style and arrangement. The engraver or the lithographer will supply such matter in proper form according to specifications. For direct reproduction, however, as by photolithography or zinc etching, the lettering must either be carefully drawn with pen or printed from type on slips, which are pasted on the drawing. GRAPHIC SCALES FOE MAPS. A bar scale for miles or feet should be given on every map, and if the map is of international interest the metric scale should be given just beneath the scale of miles or feet. The accepted designs for these scales are shown in figure 7. The scale should be accompanied by any necessary statement pertaining to the base map, such as " Con- tour interval 20 feet," " Datum is mean sea level." The fractional scale ( ^ , for example) should be given an all except the more simple kinds of maps, and the date of publication should also appear just below the scale or scales. The single- line bar scale should be used only on small or simple maps. The length of the bar scale must depend on the size of the map and the space available. Those shown in figure 7 were made over blue prints from scales used by the Survey. ' 861754^ — 49 5 '^ 60 PREPARATION OF ILLUSTRATIONS. To make a bar scale for a map of unknown scale that shows only a single meridian and parallel, or for a map on which no meridians Scale 500,000 25 Miles L .1 .l.u ' 25 Kilometers Contour interval 200 feet. Doutwn. is mjaarv secu level. 1920 5.000 10,000 Feet o Horizontal andvertica! scale _ 500 1000 1500 Feet Vertical scale 200 40O eooFeet Scale 1,500,000 10 EG -loMiles 100& 600 1918 1000 3000 Feet 10 15 Miles 10 15 20 Kilometers Figure 7. — Designs for bar scales. or parallels are shown, first ascertain the distance between two points shown on the map by reference to other authentic maps. If, for example, the distance between two such points is 16.315 miles draw a horizontal line (« in fig. 8) representing this dis- tance on the map, and at its end, at right angles to it, draw another line (&) actually measuring 16.315 units of any convenient de- nomination. Draw a straight line (c) diagonally between the ends of lines aand&. Then set off on line h any convenient number of the units selected, say 5 or 10, and project from the points set off lines exactly parallel with line c to line a. The distance and the nimiber of the units thus 15 Miles Figure 8.- -Method of making a bar scale for a map of unknown scale. marked on line a will indicate the number of miles covered by that distance on the map, as shown in figure 8. U. a GEOLOGICAL SURVEY o o o'oo.o „■ • •• • CooO-ooOi ?o-.0 fa oo o 6-.b.o?»- • -'o • oo £> o.oo-qP .0 ■*■■.■ -■ o o oo.'d.b'o* • ^ I V -) ^ " -1 p <" -7 ^ V- I- y -I t A _ "7 I' ^ . 27 31 28 32 m 37 <^vx_\v.^v\','S'v",v>;<.x, ,x,« ■■■■ ■• ^. ■■".•■:• ■■'■■■■'■'■yAy^<^^ §C«'-'-'- ■ ■ ■■■■•■•■-vy S''>^-^\\'Q^y^>C^' 3:,", ■; 38 PATTERNS USED TO SHOW DISTINCTIONS BET^VEEN AREAS ON BLACK AND WHITE MAPS Contraata may be increased by varying the direction and spacing of lines PREPAKATION OF ILLUSTRATIONS. 61 SYMBOLS. Symbols should be drawn with as much care as letters, though to a critic they may not appear so bad as poor lettering unless he finds them glaringly large or so small that he can discover or identify them only with difficulty. The size of a symbol must depend on its im- portance on the map bearing it. On a map that shows numerous mines, for instance, the crossed hammers or the symbols for shafts should be not only visible but conspicuous. The draftsman who is to make such a map must know beforehand how much his drawing will be reduced in reproduction and must make the symbols in proportion to the reduction. The symbols shown in Plate II (p. 20) should be used in all the Survey's illustrations where they are appropriate. ABEAL PATTERNS FOR BLACK AND WHITE MAPS. The conventional patterns used on a map to distinguish separate areas, chiefly geologic, are shown in Plate VIII. The patterns shown represent the proper combinations of lines, dots, and other forms and should be spaced openly or closely according to the size of the area covered, the contrast needed between areas, and the general clearness and effect desired. If a map is to show both small and large areas dense or closely spaced patterns should generally be used for the smaller areas, even if they may be required for some fairly large areas representing the same formation or condition. On the other hand, open patterns should be used for large areas. Again, it may be neces- sary to make certain areas more conspicuous than others, and this effect can be best produced by drawing the lines closer together rather than by making them heavier, unless the area covered is small or un- less a closely spaced similar pattern has been or will be used else- where on the map. Heavy-line patterns or bars are not desirable. The lines forming a pattern should generally be drawn at an angle of 45 ° to the sides of the map ; they should be drawn vertically or hori- zontally only in small areas or in areas not crossed by meridians or parallels or by other lines running in the same direction. The lines should preferably run across the long axis of an area, not parallel to it, and the predominating trend or general direction of the areas of one geologic formation on a map should decide the direction of the lines for all areas of that formation on the same map, even if the rule must be violated on some of the minor areas. An effort should always be made to produce a pattern that is subordinate in strength to the main lines of the base map on which it is drawn. In black and white maps, as in colored maps, unlike patterns should be placed next to each other. If they are so placed it may not be necessary to rule the lines on two adjacent areas in opposite directions to produce needed distinctions. A section liner or other ruling device should be used in drawing line patterns in 62 PREPAKATION OF ILLUSTRATIONS, order to produce uniformly even spacing. The application of six o! these conventional patterns to a base map is shown in figure 9. FiaoRB 9. — Map bearing six areal line patterns. PEEPAKATION OF ILLTJSTKATIONS. 63 STANDARD COLOKS FOH GEOLOGIC HAPS. The standard series of colors for systems of sedimentary rocks is shown on the maps in the Survey's geologic folios but is subject to modifications for use on maps in other Survey reports. Each system is represented by a different color, and if there are two or more forma- tions in one system they are generally distinguished by using different patterns composed of straight parallel lines in the same color. The patterns for subaerial deposits (chiefly Quaternary) are composed of dots or circles, or combinations of both, and may be printed in any color, but the color most often used is yellow or ochraceous orange. No specific colors are prescribed for igneous rocks, but if onlj a few areas are shown red or pink is preferred. The colors used for igneous rocks are generally more brilliant and purer than those used for sedi- mentary rocks. For small areas they are used " solid " ; for large areas they are reduced in tone by the use of a suitable cross-line pattern or " reticle." Metamorphic rocks are represented by short dashes irregu- larly placed. These dashes may be in black or in color over a ground tint or over an imcolored area, or they may be in white on a ground tint or pattern. The standard colors used for the sedimentary series covering the 12 systems recognized by the Geological Survey are: Quaternarj'- (Q), ochraceoiis orange; Tertiary (T), yellow ocher and isdbeUa color; Cretaceous (K), olive-green or rainette-green; Jurassic (J), Mue-green or niagara-green; Tr'mssic C^), light peacock-bluo or bluish gray-green; Carboniferous (C), blue or columhia-hlue; Devonian (D), gra.y-puri)le or heliotrope-gray ; Silnr'mn (S), purple or argyle-purple; Ordovician (0), red-purple or rocellin-purple ; Cambrian (-G), brick-red or eti^uscan red; Algonkian (A), terra cotta or onion-shin pirOc ; Archean (/R), gray-brown or drah}^ BEDUCTIOK OB ENLABGEMENT OF HAFS. The following is the simplest and most accurate method of mark- ing the reduction or enlargement of a map to a selected scale : Meas- ure the distance between the extreme meridians along one of the parallels. (See fig. 10.) Convert this distance into miles by multi- plying the number of degi-ees it covers (say 3) by the number of miles in a degree. A degree on the forty-third parallel, for example, is 50.669 miles,^^ which multiplied by 3 equals 152.007 miles. Then draw a line on the margin of the map, outside the border, the exact length of the 3 degrees, and just below this line draw another line representing the same number of miles (152.007) on the scale to which the map is to be reduced or enlarged. Then mark to reduce or enlarge the upper line to the lower line, as shown in figure 10, A ^0 Names printed in italic are from " Color standards and nomenclature," by Kobert Ridgway. " See U. S, Geol. Survey Bull. 650, p. 37, 1916. 64 PREPAKATION OF ILLUSTRATIONS. lono^ line will reduce error and give greater accuracy than a short one, and therefore as great a distance should be set off as possible. The number of miles represented by both lines and the fractional scale to which it is to be reduced should be stated on the drawing, for permanent record. Maps that will bear reduction without affecting the clearness of the details they show may be reduced to fit the book in which they are to appear, regardless of definite scale. The reduction for such maps is best marked in fractions, as " 1/2 off," " 1/3 off," " % off." If 4f /Btrfctce/^^ Zt^,3°< J 7° r5 rij:^ / P. /' la ^,0 J / AREA,Nj,UA4^FTX^^0|J''^%fEETPtRSta,NOJ YEARS I81A-I845 SHORT TONS lOO.OOO.OOO ZOO.000,000 3OC,O0O,C0O 400,0 30.000 50C.0O0.000 865,913 1846-1855 1 6.341,783 I856-IS65 B 17.379,502 1866-1875 ^^^^< " 1876-I8S5 1886-1895 ■>.77e.03J ^^^ 153,60 3.664 IB96-I905 1906-191 1 {6ytars) 283.240.2aS ^■M4«l,«< 1.260 IS70 I87S 1880 1885 1890 1895 1900 1905 I9i0 1915 60,000.000 S5,C00,CC0 so.coc.ooo «/■. 2 t- 45.000.000 S 40,000.000 2 2 35.000,000 o 30,000,000 JJ 25,000,000 D 10,000,000 * I5,0C0,CM IO,000,C€0 6,000,000 "111 'III 1 1 1 1 1 • I 1 (III III! Mil "" 1 1 1 1 / /' 11911 1 /\ / '\ / ' 'i ' n J /'"■' ..en parallels. [Parallel given is in center of the degree whose length is stated.] Parallel of latitude. Statute miles. Parallel of latitude. Statute miles. 68. 704 68.725 68. 786 68. 879 68.993 50 69.115 69. 230 69. 324 69. 386 69. 407 10 60 20 70 30 80 40 90 91 92 PREPAEATION OF ILLUSTRATIONS. Metric system and equivalents. [The units of linear measure most commonly used are millimeters (mm.), centimeters (cm.), decimeters (dm.), meters (m.), and kilometers (km.). 1 m.= 10 dm.; 1 dm. = 10 cm.; 1 cm. = 10 mm.; 1 km. = 1,000 meters= 0.62137 mile; 1 m.=39.37 inches= 3.280833 feet.] Meters. Inches. Meters. Feet. Kilometers. Miles. 1 39.37 78.74 118.11 1.57.48 196.85 236.22 275. 59 314.% 354.33 I 3. 280833 6.561667 9.842500 13. 123333 16.404166 19.685000 22. 965833 26. 246666 29.527500 1 0. 62137 2 2 2 1 24274 3 3 3 1.86411 4 4 4 2. 4K548 5 5 5 3. 10685 6 6 6 .. 3.72822 7 7 7 4. 34959 8 8 8 4.97096 9 9::::::::::.::::::::::: 9 5.59233 Inches. Centi- meters. Feet. Meters. MUes. Kilo- meters. 1 ".54 5.08 7.62 10.16 12.70 15.24 17.78 20.32 22.86 1 0. 304801 0.609601 0.914402 1.219202 1.524003 1.828804 2. 133604 2. 438405 2.743205 1 1.60935 2 2 2 3.21869 3 3 3 4. 82804 4 4 4 6. -13739 5 5 5 8.04674 6 6 6 9. 65608 7 7 7 11.26543 8 8 8 12. 87478 9 9 9 14. 48412 The " vara," used in Texas, is equivalent to 33J inches and is computed as representing 2.78 feet. Geologic eras, periods, systems, epochs, and series. Era. Period or system. Ejwch or series. Quaternary /Recent. \Pleistocene (replaces "Glacial"). [Pliocene. J Miocene. C«n0M)ic Mesozolc Cretaceous Jurassic 1 Oligocenc. 1 Eocene. /Upper (Gulf may be used provincially). \Lower (Comanche and Shasta may be used provincially). (Upper. ] Middle. [Lower. Upper. Middle. Carbonifero Devonian.. Silurian. Ordovician Cambrian . . Algonkian. .Archean. .. us Lower. 1 Permian. •{Pennsylvanian (replaces "Upper Carboniferous"). IMississippian (replaces "Lower Carboniferous''). Upper. ■{Middle. Paleozoic [Lower. (Upper (Cincinnatian may be used provincially). ^Miadle (Mohawkian may be used provincially). (Lower. Saratogan (or Upper Cambrian). Protcrozoic Ipre-Cam- / brian. [Waucoban (or Lower Cambrian). PEEPARATION OF ILLUSTRATIONS. Chemical elements and sym'bols. 93 Element. Symbol. Element. Symbol. Element. Symbol. Aluminum Al Sb A As Ba Bi B Br Cd Cs Ca C Ce CI Cr Co Cb Cu gy Er Eu F Gd Ga Ge Gl Au He Holmium Ho H In I Ir Fe Kr La Pb Li Lu Mg Mn Hg Mo Nd Ne Ni Nt N Os Pd P Ft K Pr Ra Rhodium Rh Antimony Rubidium Rb Argon...". Ruthenium Ru Arsenic. Iodine Samarium Sa Barium fVnnrliiim . Sc Selenium Se Boron Krypton Silicon Si Bromine . . T.finthaniiTn. . Silver Aft Lead Sodium N8 Caesium Lithium Strontium Sr Luteciiun Sulphur S Carbon Magnesium Tantalum. Ta To Chlorine Mercury Terbium Tb Chromiimi Molybdenum Thallium Tl Cobalt Th Columbium Neon Thulium Tm Copper Nickel Tin Sn Dysprosium Niton Ti Erbium Nitrogen. Tungsten W Europium Osmium Uraniiun U Fluorine. Oxygen V Xe Galliiun. Ytterbiimi (Neoytter- bium) Germaniuni Platinum Yb Glueinum Yttrium Y Gold Praseodymium Zinc Zn HelJiiT" . Zr Greek alphabet. Caps. Lower- case. Greek name. English soimd. Caps. Lower- case. Greek name. English sound. A a Alpha. A. N V Nu. N. B ^6 Beta. B. 2 ? Xi. X. r 7 Gamma. G. Omicron. short. A 6 Delta. D. n TT tS Pi. P. E e Epsilon. E short. p P Rho. R. Z f Zeta. Z. 2 s cr Sigma. S. H n Eta. E long. T T Tau. T. G 0t? Theta. Th. T V Upsilon. U. I I Iota. I. * 4>

greater than. "D or < less than. 1 perpendicular. ~ difference y integration. O equivalence. : ratio. ■H- geometrical propor- tion. — ; difference, excess. .•. therefore. ■.■ because. CO infinity, y varies as. v' radical. minute. ■ second. NAMES OF ROCKS. The following list was prepared in the geologic branch for the use of geologic draftsmen to enable them to select appropriate symbols for rocks that may be referred to in preliminary drawings by name only. For sedimentary rocks dots and circles, parallel lines, and broken or dotted lines are used ; for metamorphic rocks short dashes arranged without definite patterns; and for igneous Tocks patterns composed of short dashes, triangles, rhombs, crosses, and cross lines. All these patterns are shown in Plate III. Sedimentary material. [Including residual, detrital, eolian, glacial, organic, and chemically precipi- tated material.] Agglomerate. Alabaster. Alluvium. AJum shale. Anhydrite. Apron (alluvial). Argillite. Arkose. Asphalt. Bench gravel. Bentonite. Boulder clay. Brea. Breccia. Brownstone. Burrstone. Calcarenite, Calc sinter. Caliche. Catlinite. Chalk. Chert. Clay. Coal. Conglomerate. Coprolite. Coquina. Detritus. Diatomaceous earth. Diluvium. Dolomite. Drift. Fan (alluvial). Fanglomerate. Flagstone. Flint. Freestone. Fuller's earth. Geyserite. Gravel. Graywacke. Greensand. Grit. Gumbo. Gypsum. Hardpan. Hematite. Infusorial earth. Ironstone (also igneous). Itacolumite. Kame. Kaolin. Laterite. Lignite. Limestone. Limonite. Loess. Marble (also metamor- pliic). Marl. Metaxite. Morainal deposit. Mudstone. Novaculite. Peat. Pelite. Phosphate rock. Phosphorite. Phthanite. Psammites. Psephites. Puddingstone. Pyroclastic material. Quartzite (also metamor- phic). Reddle. Rock salt. Rock stream. Rubble. Salt. Sand. PREPARATION OF ILLUSTRATIONS. 95 Sedimentary waferiat— Continued. Sandstone. Stalagmite. Tufa (=chemically de- Selenite. Talc. posited lime). Shale. Talus. Tuff (= igneous frag- •Silt. Till. ments). Slate (alsometamorphic). Travertine. Wacke. Soil. Tripoli. Wash. Stalactite. Metamorphio material. Adinole. Garnet rock. Ophicalcite. Amphibolite. Garnet schist. Ottrelite schist. Andalusite schist (?). Gneiss. Phyllite. Apo (rhyolite), etc. Granite gneiss. Porcelanite. Argillite. Graywacke (?). Protogene. All gen gneiss (also igne- Green schists. Pyroschists. ous). Greenstone (also Quartz. Biotite schist. igneous) . Quartzite. •Calc schist. Greisen. Quartz schist. ■Cataclastic. Halleflinta. Schist. Chlorite schist. Hornblende schist. Sericite schist, etc. Clay slate. Homfels. Serpentine. Damourite schist. Horustone. Slate. Desmosite. Itabirite. Soapstone. Dynamometamorphic Kinzigite. SodaUte. rock. Knotenschiefer. Spilosite. Eclogite. Knotty schists. Steatite. Epidosite. Lusulianite (igneous?). Talc schist. Erlan. Marble. Topazfels. Erlanfels. Meta (diabase), etc. Topaz rock. Eulysite. Mica schist. Zobtenite. Fibrolite schist. Mylonite. Igneous material. Absarokite. Aplite. Carmeloite. Abyssal. Arkite. Cascadite. Adamellite. Atatschite. Chibinite. Adendiorite. Augen gneiss (also meta- Ciminite. Ailsyte. morphic) . Comendite. Akerite. Angitite. Complementary rocks. Alaskite. Avezacite. Coppaelite. Albitite. Banakite. Cortlaudite. Allivalite. Banatite. Cromaltite. Allochetite. Bandaite. Cumberlandite. Ahioite. Basalt Cuselite. Alsbachite. Basanite. Dacite. Ambonite. Beerbachite. Dellenite. Amherstite. Bekinkinite. Diabase. Analcitite. Bombs. Diallagite. Andesite. Borolanite. Dike rock. Anorthosite. Bostonite. Diorite. Aphanitite. Camptonite. Ditroite. 96 PKEPAEATION OF ILLUSTRATIONS. Igneous mafenoJ-MUontinued. Dolerite. Dnnite. Durbachite. Effusive rock. Ekerite. Elvan. Enstatite. Eruptive rock. Essexite. Estrellite. Eulysite. Extrusive rock. Farrisite. Felsite. Felsophyre. Fergusite. Fortunite. Four Chi te. Foyaite. Gabbro. Gauteite. Garewaite. Giumarrlte. Gladkaite. Granite. Granitite. Granitoid. Granodiorite. Granophyre. Greenstone (also nieta- morpliic). Greisen? Grorudite. Harrisite. Harzburgite. Haiiynophyre. Hawaiite. Hedrumite. Heumite. Holyokeite. Hornblendite. Hypabyssal rock. Hyperite. Hypersthenlte. Ijolite. Intrusive rock. Irruptive (=intrusive) rock. Isenite. Jacupiranglte. Jumillite. Kaiwekite. Kedabekite. Kentallenite. Kenyite. Keratophyre. Kersantite. Kimberlite. Kohalaite. Krablite. Krageroite. Kulaite. Kyschytymite. Lamprophyre. Latite. Laugenite. Laurdalite. Laurvikite. Lava. Lestiwarite. Leucite basalt. Leucite tephrite. Leucitite. Leucocratic. Lherzolite. Linibergite. Lindoite. Liparite. Litchfieldlte. Lithoidite. Luciites. Lujaurite. Madrupite. Maenaite. Magma basalt. Malchite. Malignite. Mangerite. Mariupolite. Melaphyre. Melilite basalt. Mesanite. Mica peridotite. Miuette. Missourite. Monchiquite. Mondholdeite. Monmoutbite. Monzonite. Mugearite. Naujaite. Nelsonite. Nephelinite. Nevadite. Nordmarkita Norite. Obsidian. Odinite. Orbite. Orendite. Ornciite. Orthophyrfe Ortlerite, Ouachitite. Paisanite. Pantellerite. Pegmatita Peridotite. Perknite. Perlite. Phanerite. Phonolite. Pierite. Pitehstone. Plagiaplite. Plagioclastic. Plumasite. Plutonic rock. Pollenite. Porphyry. Pulaskite. Pumice. Pyroxeuite. Rhombenporphyry. Rhyolite. Rizzonite. Rockalite. Santorinite. Sanukite. Saxonite. Scyelite. Shastaite. Shonkinite. Shoshonite. Soda granite. Solvsbergite. Sommaite. Spessartita Sussexite. Syenite. Taimyrite. Tavpite. Tephrite. Teschenite. Therallte. Tilaite. PREPARATION OF ILLUSTEATIONS. 97 Igneous material — Continued. Tinguaita Tjosite. Tonalite. Tonsbergite. Tordrillite. Toscanite (?). Trachy-andesite. Trachyte. Trap. Troctolite. Umptekite. Unakite. Ungaite, Urtite. Valbellite. Venanzite. Verite. Vitrophyre; Yogesite. Volcanic rock. Volhynite. Vulsinite. Websterite. Wehrlite. Windsorite. Wyomingite. Yamasklte. INDEX. A. Page. Abbreviations, forms of 55-57 Adhesive materials, choice of 37 Alaska, maps of, reuse of 17 Albertype. See Photogelatin processes. Apparatus, photographs of, preferred to sketches 29 Approval of finished drawings, features to be covered by 38 of illustrations, regulations governing 8-9 Areas, patterns used to distinguish 23 patterns used to distinguish, plate show- ing 62 Army, Corps of Engineers of the, maps pub- lished by 15 Artotype. See Photogelatin processes. Atlases, published, use of 15 B. Base maps. See Maps, base. Bleaching photographic prints, method and solutions for 69 Border for maps, width and use of. 57-58 Bristol board, kind and sizes used 24, 66 Brush and pencil drawings, materials and methods used in making 66-67, 69 Brushes, kinds and sizes used 66-67,71 C. Celluloid transferring, process of 47 requisitions for 47 Cerotype process, description and advantages of 80-81 Changes in engravings, possible kinds of. . 38-39,90 Changes in original material, draftsman to consult author on 65 Chemical elements, names and symbols of . . . 93 Chromolithography, description of 87-89 Civil divisions, lettering of 53,54 Coal beds, indication of thickness of 31 C'Oast and Geodetic Survey charts, use of 15 Collotype. See Photogelatin processes. Coloring materials, use of 26 Colors, standard, for geologic maps 62-63 use of, for ground-water features 21-23 on original geologic maps 27-28 Commas, form of 54 use of, in numbers 54 Contours, drawing of 48-50 Cooperation, mention of 13 Copper, engraving on 89, 90 etching in relief on, process and advan- tages of 75 Copying, methods of 46^8 C-orrections. See Changes. Cost of photo-engravings 75,78,80,81 County maps, use of 15 Crayons, wax, use of. 26,50,51 Credit for data of maps, indication of 13 Crystals, drawings of, making and lettering of. 70 Page. Cultin-al featmes, lettering of 53, 54 list of. 52-53 Curves, plate showing 64 Cuts. See Engravings. D. Details of a geologic map, plate showing 68 Diagrams, drawing and lettering of 64 features of, plate showing 64 original, general requirements for 28-29 Director of the Survey , order by 9 Divisions of plates and figures, serial letters and numbers for 12 Drafting table, shadowless, description of 47-48 shadowless, use of 29, 48, 60 Draftsmen, detail of, to aid author 9 detail of, to prepare base maps 13-14 experience and reading required by 41-42 general treatment of material by 42-43 Drainage features, depiction of. 51-52 Drawing instruments, list of 42 Drawing materials, kinds used. . . 23-26, 66-67, 69, 71 Drawings, authors', draftsmen may aid in making 9 authors', editorial revision of 38 finished, general requirements for 41-42 requests for photographs of 34 Duplicates of engravings, charges for 38 E. Effectiveness of illustrations, elements that produce 7,39 Electrotypes of engravings, charges for 38 Elements, chemical, names and symbols of. . 93 Engraving on stone, process of. 89-90 See also Lithography. Engravings, changes in 38-39 original, time of keeping 37 Erasers, injiu-y to paper by 67 kinds used 25,67-68 Erasures, smoothing paper after 68 Explanations on maps, arrangement and let- tering of 19, 58-59 F. Figures, differences from plates 10-11 divisions of, serial letters for 12 methods of insert ing, plate showing 12 Formations, geologic, use of letter symbols for 20-21 Fossils. See Specimens. Four-color process, advantage of 80 G. Gas wells, symbols for 21 General ization, true, meaning of 17 Geographic tables and formulas (Buii. 650), use of 44, 45 Geologic periods of time, names of 92 Gouache, use of 67, 69 Great Lakes surveys, maps published by 15 99 100 INDEX. Page. Greek letters, forms, names, and English sounds of 93 Ground-water features, symbols representing. 21-23 H. Hachuring, use of 50 Half-tone engraving, preparation of copy for. 77-78 process and advantages of 75-78 three-color process of 78-80 Half tones, changes in 39 prints of, showing effects produced by different screens 56 requirements for printing 11 Heliotype. See Photogelatin processes. Hill shading, use of 50-51 Hydrographic features, lettering of 54 representation of 51-52 Hypsographic features, lettering of 54 I. Illustrations, kinds of 10-11 Inks, kinds used 25, 67 methods of using 25 Inserting plates and figures, methods of, plate showing 12 Instruments, draftsmen's, list of 42 J. Japanese transparent water colors, use of 26 L. Land Office maps, scales and detail of 14-15 Latitude, length of 1° of, at intervals of 10° 91 Lending of photographs and drawings, rules governing 34 Letter symbols, use of, on geologic maps 20-21 Lettering, directions for 53-55 for lithographing 90 for names of streams 52, 54 on diagrams 64 on drawings of crystals 70 on original maps 19 on plans and cross sections of mines 65-66 reduction sheet used in, plate showing. . . 54 use of type for 54-55 Light, direction and gradation of 06 Lithographs, printing and insertion of 11 Lithography, original process of 83-85 See also Engraving on stone. Longitude, length of 1° of, at latitudesO" to90°. 91 M. Map of the world, millionth-scale, use of, for base maps 14 Maps, arcal patterns for, drawing of 61-62 bar scales for 59-60 base, conventional symbols used on 45-46 including new data, how obtained. . . 13-14 indication of som-ces on 13 of the United States on small scales, use of 15 published maps available for 14-17 reuse of, to be approved 13 black and white, patterns used on, plate showing 62 borders for 57-58 cnltural foatiires on 52-53 Page. Maps, enlargement and reduction of 18 explanations for 19, 5*-59 geologic, details of, plate showing 58 printing of 87-89 standard colors for 62-63 hydrographic features on 51-52 lettering on 53-55 materials used for dra'wing 23-26 orientation of 18 original , margin required on 19 original base, amount of detail on 17 must be free from colors and symbols . 28 preparation of 13-14, 17-18 original geologic, method of coloring 27-28 projection for 18-19,43-45 reduction or enlargment of, marking for.. 63-64 reUef on 48-51 standard scales for 18 symbols used on 20-23 drawing of ^ 61 plates showing 20, 46 titles for 58 topographic, scales of 14-15 Mathematical signs, forms and names of 94 Measures, linear, metric equivalents of 92 Measuring scales for map projection, use of... 44 Meridians used on public-land maps, dia- gram showing 16 Metric measures, English equivalents of 92 MUlionth-scale map, use of 14 Mine plans, conventional lines for 29 fcatiu-cs of 65-^ symbols used on, plate showing 20 Minerals. See Rocks. Mississippi River Commission, maps pub- lished by U N. Names of rocks 94-97 National forest maps and proclamations, use of 15 O. Offset process, description of 87 Oil wells, s>Tnbols for 21 Opaquing, meaning of 18, 47, 86 Orientation of maps, requirements for 18 Original drawings, general treatment of, by draftsmen 42-43 preparation of 12-40 Outdoor sketches, redrawing of 69-70 P. Panoramas, construction of 71 Paper, kinds used for drawings. . 23-24,50,51,66,69 Pastes, use of 37 Patterns, areal, method of drawing 61-62 aroal, plate showing 62 Pen dramngs, materials and methods used in making 67-68,68-69 Pencils, colored, use of 26 drawing, quality and grades of 25,66 Pens, kinds of, used for drawing 25, 48, 67 Photo-engraving, cost of 75, 78, 80, 81 general features of 72-73 Photo-engravings, printing and insertion of. 11 Photo-gelatin processes, desciiption of 82-83 INDEX. 101 Photographs, adaptation of. 33 bleaching of 69 care needed in taking and handling. 32, 33, 39-40 copyrighted, consent for use of 33-34 duplicate prints of, requests for 34 mounting and numbering of 33, 36-37 poor, making of drawings over 68-69 preparation of, for half-tone engraving. . . 77-78 record of source of 34 selection of 32-33 retouching of 68, 70-71 suitabiUty of 9 unpublished, issue and use of 34 Photolithogi'aphs, changes in 39 Photolithography, description of 86-S7 Planographic process, description of 87 Plans of mines, drawing and lettering of. . 29, 65-66 symbols used on, plate showing 20 Plates, differences from figures 10-11 divisions of, serial letters and numbers for. 12 grouping small illustrations on 36-37 methods of inserting, plate showing 12 Political divisions, lettering of 53, 54 Post-route maps, scales and detail of 15 Projection for maps, preparation and check- ing of 18-19,43-45 Proofs, changes in 75 correction of 38-39 duplicate, supplying of 39 submittal of 38 Public-land max)s, meridians, parallels, and township lines used on, diagram showing 16 Public works, lettering of 63 Punctuation marks, forms of 54 Purpose of illustrations in Survey reports 8,40 R. Railroad surveys, data for maps obtainable from 16 Railroads, names of, on maps 57 Reduction of maps, marking drawings for . . . 63-64 means of IS Reduction sheet for lettering, plate showing. 54 use of 55 Relief, methods o f expressing 48-51 Reproduction of illustpations, processes for. . 72-90 relation of, to the drawing supplied 7, 40 Reticulation, sketching by 47 Retouching of photographs, materials and method used in 68, 70-71 Reuse of illustrations, procedure for 37-38 Rocks, igneous, names of 95-OT metamorphic, names of 95 sedimentary, names of 94r-95 symbols used to distinguish 32 See also Specimens. Roman numerals, numbers expressed by 93 Rubber, liquid, use of 37 S. Scales, bar, forms of 59-60 measuring for projection of maps 44 standard, of maps 18 Scope of this manual 7 Screens, half-tone prints showing effects pro- duced by 56 Selection of illustrations, considerations gov- erning 8-9 Page. Sections, columnar, original drawings for 31 columnar, symbols used in, plate showing 32 structure, combination of, with views of topography 30-31 drawing of 64-65 original drawings for 29-31 symbols used in, plate showing 32 vertical exaggeration of 30 Shading, kinds used 67 Signs, mathematical, forms and names of 94 Sizes o f illustrations 11-12, 40 Specimens, borrowed and fragile, care of 35 drawings of, methods ofmaking 66-68 paleontologic, transmittal of 35 photographs of, how printed 68 how used 34-35 Springs, symbols for 22, 23 State maps, use of 15 Stipple, production of 50, 51 Stone, engraving on 89-90 Streams, drawing of 51-52 lettering names of 52 Submittal of illustrations 10 Sym.bols, drawing of 20, 61 for ground-water features, imiformity needed in 21-23 for maps and mine plans, plates showing. 20, 46 uniform use of 20, 45-46 for oil and gas wells, features of 21 for structiue and columnar sections, plate showing 32 lithologic, use of 32 T. Three-colorhalf-tones, process of making 78-80 Titles of illustrations, arrangement and place of 58 printing of 19-20 wording and lettering of 19 Tooling on half-tones, efiects obtained by 77, 78 Topographic atlas sheets, scales of 14 Tracing, method of 46-47 use of colors in 46-47 Tracing linen, use of 24-25 Transferring, celluloid, process of 47 celluloid, requisitions for 47 Type, lettering with 54-55 styles and sizes of 55 V. Value o f illustrations in Survey reports 8 Vara, length of 92 Vignetting, effect obtained by 78 W. Wall map of the United States, use of, for base maps 14 Watercolors, useof 26,67,71 Waterhning, use of 62 Wax engraving, process and advantages of.. . 80-81 Wells, symbols for 22, 23 Wood engraving, processof 81-82 Z. Zinc etchings, changes in 38-39 drawings for 74 insertion of n making and advantages of 73-75 o GETTY CENTER LIBRARY 3 3125 00019 0393