,transcriber's ,note ,italicized text is displayed as ,text and bold text as ,text4 ,whole and fractional parts of numbers are displayed as #d-e_/h4 ,some ,,utf-#h characters were converted to plain ,,ascii4 ,to view them1 see the ,,html or ,,utf-#h version4 ,,department ,,of ,,the ,,interior4 ,john ,barton ,payne1 ,secretary ,united ,states ,geological ,survey ,george ,otis ,smith1 ,director ,,the ,,preparation ,,of ,,illustrations ,,for ,,reports ,,of ,,the ,united ,,states ,,geological ,,survey ,,with ,,brief ,,descriptions ,,of ,,processes ,,of ,,reproduction ,,by ,,john ,l4 ,,ridgway ,,washington ,,government ,,printing ,,office #aibj ,,the ,,preparation ,,of ,,illustrations ,,for ,,reports ,,of ,,the ,,united ,,states ,,geological ,,survey ,,by ,,john ,l4 ,,ridgway ,,contents4 ,part ,i4 ,preparation by ,authors4 ,page4 ,introduction #g ,purpose and value of illustrations #h ,selection and approval of illustrations #h ,submittal of illustrations #aj ,kinds of illustrations #aj ,sizes of illustrations #aa ,subdivisions of plates and figures #ab ,preparation of copy by authors #ab ,character of original material #ab ,preliminary preparation of maps #ac ,material available for base maps #ad ,basic features of maps #ag ,standard scales #ah ,orientation of maps #ah ,projection #ah ,explanation #ai ,titles of maps and other illustrations #ai ,symbols used on maps #bj ,general features #bj ,letter symbols #bj ,oil and gas symbols #ba ,symbols for use on maps showing features of ground water #ba ,black-line conventions #bc ,materials used in preparing maps #bc ,paper #bc ,bristol board #bd ,tracing linen #bd ,inks #be ,drawing pens #be ,pencils #be ,rubber erasers and cleaners #be ,colored pencils and crayons #bf ,water colors #bf ,japanese transparent water colors #bf ,coloring geologic maps #bg ,diagrams #bh ,essential features #bh ,plans of mine workings #bi ,sections #bi ,lithologic symbols #cb ,use of photographs as illustrations #cb ,essential features #cb ,copyrighted photographs #cc ,sources of photographs #cd ,lending original photographs and drawings #cd ,unpublished photographs #cd ,specimens #cd ,general requirements #cd ,borrowed and fragile specimens #ce ,transmittal of paleontologic specimens #ce ,making up plates #cf ,reuse of illustrations #cg ,approval of finished illustrations #ch ,revision of illustrations #ch ,submittal of proofs #ch ,proof-reading illustrations #ci ,general considerations #ci ,part ,,ii4 ,preparation by ,draftsmen4 ,general directions #da ,instruments #db ,classification of material #db ,preparation of maps #dc ,projection #dc ,details of base maps #de ,transferring or copying #df ,tracing #df ,celluloid transferring #dg ,sketching by reticulation #dg ,the shadowless drafting table #dg ,topographic features #dh ,relief #dh ,hydrography #ea ,cultural features #eb ,lettering #ec ,general directions #ec ,lettering by type #ed ,abbreviations #ee ,names of railroads #eg ,make-up of maps #eg ,forms for certain features #eg ,border #eg ,title #eh ,explanation #eh ,graphic scales for maps #ei ,symbols #fa ,areal patterns for black and white maps #fa ,standard colors for geologic maps #fc ,reduction or enlargement of maps #fc ,diagrams #fd ,sections #fd ,plans and cross sections of mines #fe ,drawings of specimens of rocks and fossils #ff ,methods used #ff ,brush and pencil drawings #ff ,pen drawings #fg ,retouching photographs of specimens #fh ,landscape drawings from poor photographs #fh ,pen drawings made over photographs #fh ,brush drawings from poor photographs #fi ,outdoor sketches #fi ,drawings of crystals #gj ,retouching photographs #gj ,part ,,iii4 ,processes of ,reproducing ,illustrations4 ,methods employed #gb ,photoengraving #gb ,general features #gb ,zinc etching #gc ,copper etching in relief #ge ,half-tone engraving #ge ,three-color half-tone process #gh ,wax engraving 7the cerotype process7 #hj ,wood engraving #ha ,photogelatin processes #hb ,lithography #hc ,original process #hc ,photolithography #hf ,offset printing #hg ,chromolithography #hg ,engraving on stone and on copper #hi ,appendix4 ,length of degrees of latitude and longitude #ia ,metric system and equivalents #ib ,geologic eras1 periods1 systems1 epochs1 and series #ib ,chemical elements and symbols #ic ,greek alphabet #ic ,roman numerals #ic ,mathematical signs #id ,names of rocks #id ,,illustrations4 ,page4 ,plate ,i4 ,methods of inserting plates and figures #aj ,,ii4 ,symbols used on geologic maps1 economic maps1 and mine plans #bj ,,iii4 ,lithologic symbols used in structure and columnar sections to represent different kinds of rock #cb ,,iv4 ,symbols used on base maps #eb ,v4 ,reduction sheet used in lettering illustrations #ed ,,vi4 ,half-tone prints showing effects produced by the use of six standard screens #ef ,,vii4 ,details of the make-up of a geologic map #eh ,,viii4 ,patterns used to show distinctions between areas on black and white maps #fj ,,ix4 ,diagrams and curves #fd ,figure #a4 ,diagrams showing principal1 guide1 and auxiliary meridians1 standard and special parallels and correction lines1 and system of numbering townships1 ranges1 and sections #af #b4 ,conventional lines used in preparing plans and diagrams of mine workings to distinguish different levels #bi #c4 ,section and perspective view showing relations of surface features to the different kinds of rocks and the structure of the beds #cj #d4 ,sections of coal beds #ca #e4 ,diagram illustrating method of projecting a map #dd #f4 ,methods of expressing relief by contour lines1 by hachures1 by shading on stipple board1 and by a brush drawing #di #g4 ,designs for bar scales #fj #h4 ,method of making a bar scale for a map of unknown scale #fj #i4 ,map bearing six areal line patterns #fb #aj4 ,diagram showing method of marking maps for reduction or enlargement 7for record7 #fd #aa4 ,structure section showing method of determining the succession of folds #fe ,,the ,,preparation ,,of ,,illustrations ,,for ,,reports ,,of ,,the ,united ,,states ,,geological ,,survey4 ,by ,john ,l4 ,ridgway4 ,,part ,i4 ,,preparation ,,by ,,authors4 ,,introduction4 ,there has been an obvious need in the ,geological ,survey of a paper devoted wholly to illustrations4 ,no complete paper on the character1 use1 and mode of preparation of illustrations has been published by the ,survey1 though brief suggestions concerning certain features of their use have been printed in connection with other suggestions pertaining to publications4 ,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 drawings1 but it is not a technical treatise on drafting4 ,the effectiveness of illustrations does not depend entirely on good drawings nor on good reproduction2 it may be due in large part to the inherent character of the rough material submitted4 ,if this material is effective or striking the finished illustrations1 if well made1 will be equally effective and striking4 ,each step in the making of an illustration--first the preparation of the author's original or rough draft1 next the final drawing1 and last the reproduction--is closely related to the others1 and each is dependent on the others for good results4 ,if the material has been well handled at all three steps the resulting illustration should be above criticism2 if it has been poorly handled at any one of the three the effectiveness of the illustration is either impaired or ruined4 ,a consideration of processes of reproduction is essential in the preparation of all illustrations1 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 processes usually employed by the ,geological ,survey4 ,these descriptions include statements as to the kind of copy that is suitable for each process1 the result produced by each1 and the relative cost of the processes4 ,,purpose ,,and ,,value ,,of ,,illustrations4 ,an illustration in a report of the ,geological ,survey is not merely a picture having a remote bearing on the subject matter of the report2 it must represent or explain something discussed or mentioned in order to become an illustration in the true sense of the term4 ,the illustrations used in the ,survey's reports are not employed for embellishment2 the more pictorial kinds may be in some measure decorative1 but decoration is distinctly not their primary purpose4 ,the illustrations used in popular literature are designed to meet a public demand for ornament or attractiveness4 ,those used in scientific publications should be made plain and direct1 without attempt to ornament or beautify4 ,in the literature of science illustrations made by the reproduction of photographs or of explanatory diagrams or maps are intended simply to furnish greater illumination1 and if the illustrations display photographic reality most statements or conclusions thus illuminated seem less open to dispute4 ,a photograph may thus serve the double purpose of explanation and corroboration4 ,the graphic expression of data and of details in a ,survey report is intended to aid the reader in comprehending the report1 and this is the prime advantage of its use1 but it also enables the writer to omit from his text numerous descriptive details4 ,it would generally be difficult without illustrations to present a clear picture of the geology of a region in its exact relations1 and especially to describe adequately the form and the details of the structure of many fossils4 ,the tasks of both the writer and the reader of reports on geology and kindred subjects are thus greatly facilitated by geologic maps1 sections1 paleontologic drawings1 and illustrations of other kinds4 ,the responsibility for good and effective illustrations rests largely upon the author1 who should select and plan his illustrations with a view to their utility in aiding the reader to understand his report4 ,,selection ,,and ,,approval ,,of ,,illustrations4 ,there is no rule limiting the number of illustrations that may be used in a publication of the ,geological ,survey1 but in selecting illustrations for a report an author may easily fall into the error of over-illustration4 ,the number of diagrammatic drawings or of drawings that express the author's deductions is rarely in excess of the needs of a paper1 but the number of photographs submitted is often excessive4 ,the number of pages in a manuscript may be a factor in determining the proper number of illustrations1 but as the need of illustrations varies greatly from paper to paper this factor alone is not decisive4 ,the tendency to overillustrate led the ,director to issue the following order#a governing the approval of illustrations3 ,footnote #a3 ,from ,survey ,order #fc1 ,oct4 #bj1 #aiae4 ,the primary responsibility for the selection of illustrative material shall rest upon the author and the chief of the branch transmitting the report3 ,no one knows the subject matter of the report better than its author1 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 illustrate4 ,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 adequate1 and the scientific value of the illustrations will not be subject to review in the section of illustrations4 ,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 reproduction4 ,in the consideration of such questions1 especially any relating to maps1 the cooperation of the editor of geologic maps and chief engraver will be expected4 ,the judgment of an author as to the illustrative value of a photograph is likely to be biased by his knowledge of the features that are actually included in the view represented1 not all of which may be shown clearly in the photograph2 his knowledge of all the features enables him to see more in his picture than his readers will be able to recognize without detailed description4 ,photographs in which special or significant features are obscured by foliage or lost in hazy distance do not make acceptable illustrations1 and the use of a picture that requires much description to make it illustrate reverses1 in a measure1 the relations of text and illustrations4 ,a photograph is not necessarily good for reproduction simply because it shows some particular feature to be illustrated2 the quality of the print it will afford when reproduced from an engraved plate should also be considered4 ,some loss of detail by reproduction must be expected1 and therefore only the clearest and most effective prints obtainable should be submitted4 ,if an author has difficulty in making his preliminary or original drawings he may request that a draftsman be detailed to aid him4 ,the request should be made to the ,director through the chief of branch and properly approved4 ,the work will then be done in the section of illustrations as advance preparation1 but finished drawings should not be thus prepared unless the conditions are unusual4 ,the administrative geologist reviews all illustrations submitted and represents the ,director in matters relating to illustrations4 ,,submittal ,,of ,,illustrations4 ,all material intended for illustrations1 except paleontologic specimens1 should be submitted with the manuscript of the paper to be illustrated but in a separate package marked ,illustrations to accompany a paper on ---- by ----4 ,the package should contain a carbon copy of the list of illustrations that accompanies the manuscript or1 if the titles to be printed on or with the illustrations include fuller descriptions than are given in that list1 a carbon copy of the list giving complete titles and descriptions1 the original of which should also accompany the manuscript4 ,in the list each plate and figure should be separately numbered consecutively in the order in which it should appear in the report1 and a figure opposite each title should show the number of the manuscript page on which the illustration is first mentioned or most fully discussed4 ,roman numerals should be used for the plates and arabic numerals for the figures4 ,each drawing or photograph should bear1 in addition to the number and title1 any suggestions concerning preparation1 reduction1 and method of reproduction which the author may consider especially desirable4 ,the list should be headed ,illustrations4 ,specimens other than fossils that are to be illustrated must be submitted directly to the section of illustrations1 but the author may first obtain photographic prints of them in order to make up his plates4 ,the specimens should be carefully packed and any that are fragile should be so marked4 ,,kinds ,,of ,,illustrations4 ,the illustrations in reports of the ,geological ,survey may be classified into five more or less distinct groups--7#a7 maps1 7#b7 diagrams 7including graphs1 sections1 plans1 figures of apparatus1 and stereograms71 7#c7 outdoor photographs1 7#d7 photographs and drawings of specimens1 and 7#e7 sketches4 ,these may be further divided into two large groups1 which may be called permanent and ephemeral4 ,the permanent group includes illustrations that do not lose value through lapse of time or by natural alteration1 such as detailed geologic maps1 well-prepared structure sections1 views of specimens1 and good photographs or drawings of natural phenomena2 the ephemeral group includes maps showing progress1 key maps1 diagrams showing yearly production1 and many others that should be prepared in such a way as to minimize cost of preparation and reproduction4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,i ,,methods ,,of ,,inserting ,,plates ,,and ,,figures4 #a1 #b1 #c1 #e1 #f1 #g1 plates2 #d1 #h1 #i1 #aj1 figures2 #aa1 pocket4 ,the illustrations will be finally divided into plates and figures when they are fully prepared1 but if an author desires to determine the classification in advance of transmittal he should submit his material to the section of illustrations1 where methods1 processes1 and reductions will be decided for each4 ,in determining which shall be plates and which shall be figures1 size and method of reproduction are the only factors to be considered2 there are no other real differences4 ,illustrations that require separate or special printing1 such as those reproduced by ,lithography and by the photogravure1 photogelatin1 and three-color processes1 must be printed separately from the text as plates and inserted in the report at the proper places2 those that are reproduced by relief processes1 such as zinc and copper etching and wax engraving1 if not too large1 can be printed with the text as figures4 ,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 text1 it can be called a figure and be printed with the text4 ,half tones1 though etched in relief1 are rarely made text figures in ,survey reports1 because to give satisfactory impressions they must be printed on the best quality of coated paper1 which is not used for the text4 ,by using the coarser screens shown in ,plate ,,vi 7p4 #ef71 however1 a half-tone cut may be made that can be used in the text if it is smaller than the page4 ,,sizes ,,of ,,illustrations4 ,the regular book publications of the ,geological ,survey are issued in three sizes--7#a7 octavo 7annual reports of the ,director1 statistical reports on mineral resources1 bulletins1 and water-supply papers72 7#b7 quarto 7professional papers and monographs72 7#c7 folio 7geologic folios74 ,the following table gives the measure of the text of each size and the measure of the trimmed page1 in inches3 ,size of text4 ,size of page4 ,octavo #d-c_/h by #g-ae_/af #e-g_/h by #i-a_/h ,quarto #f-a_/af by #i-a_/h #i-a_/d by #aa-e_/h ,folio #ac-ac_/af by #ag-g_/h #ah-a_/b by #ba-c_/d ,most professional papers are printed in two columns of type1 each #c inches wide1 and folios are printed in three columns1 each #d-c_/h inches wide4 ,a text figure in one of these publications can be made to fit one or more columns1 and it may run the full length of the text page4 ,the limits of the dimensions of plates and figures1 in inches1 are given in the following table4 ,if for any reason a plate can not be reduced to the dimensions of a page it can be folded once or more2 and if it is large and unwieldy it may be placed in a pocket on the inside of the back cover4 7,see ,pl4 ,i47 ,single-page ,plate with plate4 one side fold4 ,text figure4 ,octavo #d-c_/h by #g-a_/b #g-a_/b by #h-a_/b #d-c_/h by #g-a_/b ,quarto #f by #i #i-a_/b by #ad-c_/d #c or #f by #h-a_/b ,folio #ae by #ag-a_/b 444444444444 #d-c_/h or #ac-ac_/af by #ag-g_/h ,for an octavo report a single-page plate with side title should be #d inches or less in width1 and a plate with bottom title should be #g inches or less in depth4 ,in other words1 the actual depth and width of a single-page plate in a page of any size must depend on the number of lines in its title1 the inclusion of which should not extend the matter much1 if any1 beyond the dimensions given in the table4 ,a difference of #a inch or less in the width of a folding plate may determine whether it must be folded once or twice1 so that by consulting this table an author may save expense in binding and promote the reader's convenience in handling the plate4 ,a text figure 7including the title7 can not extend beyond the text measure but may be of any size or shape within that measure1 as shown on ,plate ,i1 figures #d1 #h1 #i1 #aj4 ,,subdivisions ,,of ,,plates ,,and ,,figures4 ,if a plate consists of two or more parts or photographs each part should be marked with an italic capital letter--,a1 ,b1 etc4--which should be placed directly under each4 ,if it is made up of many parts1 in the form of plates that accompany reports on paleontology1 each part should be similarly marked with an arable numeral--#a1 #b1 #c1 etc4 ,if a text figure is subdivided into two or more parts1 each part should be marked with a roman capital--,a1 ,b1 ,c1 etc42 and if details of a part are to be described each detail should be marked by an italic lower-case letter--a1 #f1 c1 etc4 ,,preparation ,,of ,,copy ,,by ,,authors4 ,,character ,,of ,,original ,,material4 ,in the ,geological ,survey1 as elsewhere1 the originals--that is1 the original material submitted by authors for the illustration of their reports--differ greatly in character and in degree of clearness4 ,some are carefully prepared2 others are rough1 obscure in part1 and defective in detail4 ,drawings made from poor originals progress slowly1 because the draftsman spends much time in interpreting uncertain features or in conference with the author concerning details4 ,an original should be perfectly clear in detail and meaning1 so that the draftsman can follow it without doubt4 ,it should not consist of parts that must be brought together to make a new drawing1 because the result of the combination of the parts will be uncertain at the outset and may not prove satisfactory4 ,each original illustration should be prepared with the idea that the draftsman who will make the finished drawing will be unfamiliar with the subject and will need definite instructions2 all data should be plotted and each figure or plate should be completely made up before it is submitted4 ,more or less roughly prepared originals are expected1 but they should show no uncertainty in details4 ,obscure features may be cleared up by inclosing the features in penciled loops connected by a line with notes written on the margin1 such as omit this line1 turn at an angle of #cj from true north1 add1 cut out4 ,,preliminary ,,preparation ,,of ,,maps4 ,the base map that generally accompanies a report may be an original field sheet or it may have been compiled from various sources by an author and made to incorporate the results of his field work4 ,it should not be a collection of maps of different scales and standards to be worked into a new map4 ,the source of the data shown on every original base map should be indicated on the map1 whether it is to be used as an illustration or as a record of field work4 ,this information is required as a permanent record for showing the reliability of the map1 for use in comparing data1 and for giving full credit to those who are responsible for the data4 ,an author should see that this requirement is observed in order that proper credit may be given and should especially see that all cooperative agreements and organizations are properly mentioned4 ,an original map should preferably be complete in itself4 ,it should not consist of several parts or sheets unless the data to be represented are unusually complex4 ,all elaborate or technical finish of border lines1 lettering1 or like features should be left to the draftsman or the engraver4 ,base maps that involve the compilation of new data should be prepared by either the topographic branch or the division of ,alaskan mineral resources4 ,if a base map already published is to be reused it should be submitted to the chief topographic engineer or to the chief of the division of ,alaskan mineral resources for approval4 ,this procedure will insure a single standard of geographic accuracy in maps appearing in ,survey publications4 ,a geologist who requires a base map that includes new topographic data should address a request for its preparation to the chief geologist1 who1 through the ,director1 will refer the request to the topographic branch4 ,the request must be accompanied by a full statement regarding the proposed report and the time when it is likely to be submitted4 ,the preparation of such base maps by draftsmen in the division of geology1 the land-classification board1 the water-resources branch1 or the section of illustrations has been discontinued except for the minor adaptations provided for above4 ,if a report requires the preparation of a base map that includes no new topographic data such a map must be compiled from other authentic maps by the division or branch in which the report originates4 ,if1 however1 no draftsmen are available in that division or branch1 an arrangement can be made with any other branch--as the topographic or publication branch--that may have draftsmen available1 with the understanding that the cost of the work shall be reimbursed to the branch doing the work by the branch ordering it4 ,for indicating geologic and other data1 however1 an author may make use of an authentic base map already published1 and after it is reduced or enlarged to appropriate scale by photography such a map may suffice for transmittal with a manuscript4 ,,material ,,available ,,for ,,base ,,maps4 ,the maps already published by the ,geological ,survey#b and other ,government bureaus should always be consulted when a new base is to be compiled4 ,the following list includes most of the maps available3 #a4 ,the ,survey's regular topographic atlas sheets1 published on three scales--#ae-minute sheets1 scale1 #a3fb1ejj2 #cj-minute sheets1 scale1 #a3abe1jjj2 #fj-minute sheets1 scale1 #a3bej1jjj--;approximately #a mile1 #b miles1 and #d miles to #a inch1 respectively--and its special maps1#b some of which are published on other scales4 ,all these maps can be used as bases for detailed geologic maps1 for compiling maps on smaller scales1 and for revising other maps4 #b4 ,the ,united ,states part of the international map of the world1 now being published on the scale of #a3a1jjj1jjj 7approximately #af miles to #a inch74 ,each sheet of this map represents an area measuring #f of longitude and #d of latitude4 ,the published sheets of this map may be used as bases for general maps4 ,the sheets are drawn on the scale of #a3ejj1jjj1 and photolithographs on this scale are available for use as bases for geologic or other maps4 ,the adaptability of the #a3a1jjj1jjj scale map to use as a base for general geologic maps is shown in the geologic maps of the southern peninsula of ,michigan and of ,indiana in ,monograph #ec 7,pls4 ,,iv and ,,vii71 the map of ,florida in ,bulletin #fj 7,pl4 ,i71 and the map of ,vermont in ,water-,supply ,paper #dbd 7,pl4 ,i74 #c4 ,the ,survey's two-sheet wall map of the ,united ,states1 #di by #gf inches1 scale #a3b1ejj1jjj 7approximately #dj miles to #a inch74 ,parts of this map can be used as bases for general geologic or other maps and as copy for index and other small diagrammatic maps4 ,this map is published both with and without contours4 #d4 ,land ,office maps and township plats4 ,these maps are now being published on a scale of #ab miles to #a inch2 they are also photo-lithographed on one-half that scale1 or #bd miles to #a inch4 ,the township plats are printed on a scale of one-half mile to #a inch4 ,the maps are especially useful in compiling maps in which land lines 7townships and sections7 are essential1 and the township plats afford valuable detail and are useful in field work and in revising other maps4 ,township and section lines should appear on all land-classification maps published by the ,survey4 ,on maps on a scale less than #a3bej1jjj only the townships should be shown2 on maps on scales greater than #a3bej1jjj the sections should be shown2 on maps on a scale of #a3bej1jjj the sections should be shown1 unless their representation will materially impair the legibility of the map1 in which case only the townships should be shown4 7,see fig4 #a47 #e4 ,post-route maps1 covering single ,states or groups of adjacent ,states1 published on sheets of different sizes and on scales determined mainly by the size of the ,state4 ,the map of ,texas is published on a scale of #ab miles to #a inch1 that of ,virginia on a scale of #g miles to #a inch1 and that of ,west ,virginia on a scale of #f miles to #a inch4 ,both the ,land ,office and the post-route maps are useful for reference in compiling maps on smaller scales4 ,post-route maps are especially useful for comparing and verifying the location of cities1 towns1 and railroads4 #f4 ,coast and ,geodetic ,survey charts1 published on scales that are governed by the area represented and the amount of detail to be shown4 ,these maps should always be used in compiling and correcting coast lines4 #g4 ,maps and charts published by the ,corps of ,engineers of the ,army1 the ,mississippi ,river ,commission1 the surveys of the ,great ,lakes1 and the boundary surveys4 ,these maps are especially useful if the scale of the map to be compiled requires considerable detail4 #h4 ,the ,survey's three small base maps of the ,united ,states--7a7 a map #ah by #bh inches1 scale #aaj miles to #a inch1 which is published both with and without contours1 or with relief or hypsometric shading2 7b7 a map #aa by #af inches1 scale #aij miles to #a inch2 7c7 a map #g-a_/b by #ab inches1 scale #bfj miles to #a inch1 designed for use as a two-page illustration in a bulletin or a water-supply paper4 #i4 ,the ,century1 ,rand ,mc,nally ,co4's1 ,cram's1 ,stieler's1 ,the ,times1 ,johnston's ,royal1 and county atlases4 #aj4 ,state and county maps4 #aa4 ,railroad surveys1 which are useful in furnishing data for elevations as well as for locations of towns and stations4 #ab4 ,the latest national-forest maps and proclamations4 ,it is1 however1 not necessary that national forests1 bird reservations1 and national monuments be shown on a map in a report unless their addition is specially requested by the author or by the chief of the branch submitting the report1 and they should not be shown if they will obscure other more important data4 ,footnote #b3 ,see ,topographic maps and folios and geologic folios published by the ,united ,states ,geological ,survey 7latest edition74 ,illustration3 ,figure #a4--;,diagrams showing principal1 guide1 and auxiliary meridians1 standard and special parallels and correction lines1 and system of numbering townships1 ranges1 and sections4 ,the ,survey has published numerous maps of parts of ,alaska1 as well as other maps1 which are available for use or reuse in its reports4 ,copies of all base maps for which copper plates have been engraved by the ,survey can be obtained on requisition1 and their use in a new report will save time as well as the cost of engraving4 ,other maps will be found in the ,survey library1 where the latest editions only should be consulted4 ,,basic ,,features ,,of ,,maps4 ,it must be remembered that every map1 whatever its scale1 is a reduction from nature and consequently must be more or less generalized4#c ,the degree of generalization in the geologic and other detail to be shown on a map usually involves a corresponding degree of generalization in its base4 ,absolutely true generalization means the same degree of omission of detail for each kind of feature4 ,if a base map on a scale of #a mile to #a inch1 prepared with the usual detail1 were placed before a camera and reduced to a scale of #af miles to #a inch1 the lines representing the smaller tributaries of streams and the smaller water bodies1 as well as many other features1 would probably be so greatly reduced in length as to be illegible4 ,if from this reduced photograph a new map were prepared1 from which all features not plainly discernible were omitted1 the new map should represent what might be called true generalization4 ,this degree of generalization is1 however1 not practicable1 but unessential detail should be systematically omitted4 ,the amount of detail which a base map should show is limited by its scale1 by the character of the country it represents1 and by the kind of data to be shown4 ,coordinate features of a topographic map should be shown with equal detail4 ,detail in culture may call for detail in drainage1 though relief may be greatly generalized or entirely omitted2 detail in relief may like-wise call for detail in drainage1 though culture may be more generalized4 ,footnote #c3 ,gannett1 ,henry1 ,a manual of topographic methods3 ,u4 ,s4 ,geol4 ,survey ,mon4 #bb1 p4 #ajg1 #ahic4 ,if the three fundamental features of a topographic map--the culture1 the drainage1 and the relief--are to be engraved or photo-lithographed separately and printed in colors1 the best results can be obtained by drawing each feature in a separate color on one sheet unless the work is coarse and great precision in register is not needed4 ,the culture should be drawn in black waterproof ink1 the drainage in ,prussian blue1 and the relief in burnt sienna2 but care should be taken that the colors used will photograph well4 ,to insure a good photograph it is usually necessary to add a little black to the blue and brown4 7,see ,inks1 p4 #be47 ,the photographer will then make three negatives and will opaque or paint out all but one of the three features on each negative4 ,the cost is somewhat greater than that of reproducing three separate drawings1 but the result gives more accurate register than if the drawings were made on separate sheets1 which are likely to change in size before they are reproduced4 ,,standard ,,scales4 ,the standard scales of the maps used in the publications of the ,geological ,survey are fractions or multiples of #a3a1jjj1jjj 7see p4 #ad71 except for a map that is reduced expressly to fit one or two pages of a report or that is reduced horizontally or vertically to fit the text as a small diagrammatic or index map4 ,it should be remembered that a map which may be serviceable for use in compiling a new map1 except as to scale1 can be reduced or enlarged to the scale of the new drawing by photography1 by a pantograph1 or by other means4 7,see p4 #dg47 ,maps compiled by an author should be prepared on a scale of at least #a-a_/b times and preferably twice the size of the scale used on the published map4 ,maps traced on linen should be no less than twice the size of publication4 ,not only is the quality of the reproduction improved by considerable reduction1 but the larger scale of the drawing facilitates the plotting of details4 ,it should be remembered1 however1 that a linear reduction of one-half produces a map only one-fourth the area of the original1 and reduction so great may prevent the addition of data1 such as an extended note in small letters applying to a small area on the face of a map1 which would not be legible when reduced4 ,,orientation ,,of ,,maps4 ,a map that bears no arrow indicating north is supposed to be oriented north and south1 and its title should read from west to east4 ,if1 however1 the area mapped has a general trend in one direction1 as northwest to southeast1 and its squaring up by a north-south line would leave too much blank paper1 this general rule is not followed4 ,the border lines on such a map should conform to the general trend of the area mapped1 an arrow should show north1 and the title and scale should be placed horizontally1 but the projection numbers and town names should follow the direction of the parallels of latitude4 7,see ,pis4 ,x and ,,xii1 ,bull4 #fbh2 and ,pis4 ,,vi1 ,,xv1 and ,,xvi1 ,mon4 #eb47 ,,projection4#d ,footnote #d3 ,see also pp4 #dc-de1 where the method of projecting a map is more fully explained4 ,the polyconic projection has been adopted by the ,geological ,survey for its topographic atlas sheets and must be consistently used for its other maps4 ,if a new map is to be compiled an accurate projection should first be constructed1 and no plotting should be done on it until the projection has been checked and found to be correct4 ,a projection should be checked or proved by some one other than the person who prepared it4 ,next the drainage and the water areas should be outlined2 then the cultural features should be added2 and finally the relief1 whether expressed by contour lines1 hachures1 or shading4#e ,footnote #e3 ,see pp4 #di-dh for methods of tracing and transferring4 ,,explanation4 ,under the heading ,explanation should be placed all matter needed to describe fully the details of an illustration1 whether map1 diagram1 or section1 so that if the illustration became detached it would be a complete self-explanatory unit4 ,the explanation of a map may be placed inside the border lines if there is ample room for it1 or it may be placed outside4 ,the standard arrangement for an outside explanation for geologic maps is shown1 in the geologic folios1 which should be followed in general form4 ,if there is space within the border lines the explanation may be appropriately arranged therein1 either in a vertical column or horizontally1 according to the size and shape of the space available4 ,if the sequence of formation is shown by horizontal arrangement the younger formations are placed at the left and the older at the right4 ,if it is shown by a vertical arrangement the youngest formation is placed at the top4 ,each original map submitted by an author should have at least #d-a_/b inches of blank margin on the right and at the bottom in which to place the explanation1 scale1 title1 and other matter1 but the author should make no attempt to elaborate these features nor should he employ a draftsman to letter them carefully4 ,plainly written ordinary script is quits sufficient for original maps2 the final lettering1 which may consist entirely of impressions from type1 will be added after submittal of a report4 ,,titles ,,of ,,maps ,,and ,,other ,,illustrations4 ,the titles of maps should be supplied by authors but are subject to revision in order to make them agree with established forms4 ,they should be written in ordinary script1 not carefully lettered4 ,they should state concisely the kind of map1 the area shown1 the special features represented1 and the county1 ,state1 or ,territory in which the area is located4 7,see p4 #eh47 ,titles are reproduced directly only on lithographs1 three-color prints1 photogelatin plates1 and other illustrations that are printed by contractors1 not by the ,government ,printing ,office4 ,the titles of illustrations that are reproduced by relief processes1 such as zinc etching1 half tone1 and wax engraving1 are printed at the ,government ,printing ,office from type1 and proofs are submitted to the authors for examination4 ,,symbols ,,used ,,on ,,maps4 ,,general ,,features4 ,more than #bjj symbols have been used on maps to express #be different kinds of data1 a fact indicating at once a notable lack of uniformity and a need of standardization4 ,it is of course impossible to provide a characteristic symbol that can be used uniformly for each kind of feature1 and therefore the same symbol may be used on different maps to express different things4 ,the symbols shown in ,plate ,,ii are those most used on geologic maps4 ,the symbols for dip and strike1 fault lines1 mine shafts1 prospects1 and several others are generally well known1 but on some maps it may be necessary to modify a standard symbol to express additional distinctions4 ,the symbols shown1 however1 will cover all the ordinary requirements of miscellaneous mapping4 ,though the plate shows more than one symbol for some features the symbol most commonly used is given first and should be preferred4 ,the center of each symbol should mark the location of the feature symbolized4 ,symbols are not always platted with sufficient care4 ,on small-scale maps they are difficult to locate and unless great care is taken in platting them they are likely to be several miles out of place4 ,all symbols should be located precisely where they belong4 ,the symbol showing dip and strike should be accurately platted by means of a protractor1 so that the strike will be shown graphically1 without a number and a degree mark1 and not need replatting by a draftsman or engraver4 ,the dip1 however1 should be indicated by a number and a degree mark4 ,,letter ,,symbols4 ,the letter symbols used on most geologic maps to indicate the ages and names of the formations represented consist of two or more letters--an initial capital letter for the name of the system and one or more lower-case letters for the name of the formation or of the material1 as ,qt 7,quaternary--lower terrace deposits72 ,cpv 7,carboniferous--,pottsville formation72 ,c,ok 7,cambrian-,ordovician--,knox dolomite71 etc4 ,the standard usage for this feature is shown in the geologic folios but is subject to modification in other publications4 ,in preparing an original geologic map a letter symbol1 such as has been just described1 or a number should be put in the proper place in the explanation1 and the same symbol or number should be repeated at one or more places on the map within the areas to which it refers4 ,each area that is indicated by a color should be marked with the proper symbol in order to make its identification sure1 for light colors especially are likely to fade and mixed colors can not be discriminated with certainty4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,ii ,,symbols ,,used ,,on ,,geologic ,,maps1 ,,economic ,,maps ,,and ,,mine ,,plans ,,oil ,,and ,,gas ,,symbols4 ,a complete set of symbols for maps showing oil and gas is given on ,plate ,,ii4 ,referring to these symbols the chief geologist1 in a memorandum to the ,director1 writes3 ,the symbols used by the ,survey in its oil and gas maps have not been in accord with those used by the oil companies1 nor have they been wholly logical4 ,it appears that though they were submitted for recommendation they never have been formally approved4 ,herewith ,i submit a code prepared by the geologists of the oil and gas section4 ,they conform largely to commercial use and embrace its best features as well as the best and most logical features of our previous usage1 the departures from which are1 after all1 of minor consequence4 ,the symbols here submitted see ,,pi4 ,,ii with recommendation for approval are founded on a building-up system1 so that the history and the results of drilling at any location can be recorded by slight additions to symbol and without erasure4 ,thus maps may be revised without scratching4 ,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 distinct4 ,it would be preferable to draw this bar obliquely1 but an oblique position would coincide with some of the patterns on certain maps1 and it should therefore be placed vertically4 ,the vertical line indicates the failure or abandonment of the well1 the symbol for which ,is thus scratched off or canceled by the line drawn through it4 ,the symbols agree so far with commercial usage that oil men will have little need to consult the explanation4 ,,symbols ,,for ,,use ,,on ,,maps ,,showing ,,features ,,of ,,ground ,,water4 ,the symbols used on maps relating to ground water represent the features named below1 each of which has been shown in publications already issued4 ,area of absorption or outcrop4 ,area that discharges ground water4 ,depth to water table4 ,quality of ground water4 ,contours of water table4 ,area irrigated with ground water4 ,fluctuation of water table4 ,nonflowing well4 ,depth to water-bearing formation4 ,flowing well4 ,structure contours of water-bearing ,unsuccessful or dry well1 formation4 ,well with pumping plant4 ,area of artesian flow4 ,spring4 ,head of artesian water4 ,the lack of uniformity in the symbols commonly employed to represent these features is due to differences in the number of color on the maps and differences in the scale4 ,standard colors for the larger features1 such as those for areas of artesian flow1 areas of absorption1 and curves showing depths to water table or to water-bearing formations1 can not be fixed1 because of considerations of economy in printing4 ,for example1 if light green is the standard color to be used for delineating areas irrigated by ground water and no green is used on other parts of the map its use would represent an additional or special printing1 whereas a tint of blue1 brown1 or purple1 if any of these colors is used for other features on the map1 might be used also for this feature without additional printing4 ,therefore the general use of any particular color for a water feature seems to be impracticable2 but this fact should not preclude the adoption of color standards for use subject to the requirements of economy in publication4 ,the ordinary symbols for wells are the open circle and the solid circle1 or dot4 ,only in the secondary or specific well symbols does there appear to be lack of uniformity1 the choice of secondary symbols being governed either by personal preference or by the requirements for specific distinction4 ,all symbols should1 if possible1 suggest the things they represent4 ,wells are circular and hence the open circle is most used and most appropriate for nonflowing wells4 ,to indicate a flowing well the circle is made solid1 denoting that the well is full of water4 ,for an unsuccessful well the most suggestive symbol would be an open circle with a line drawn through it to denote cancellation4 ,it has been suggested that if water features1 including wells1 are to be printed in blue1 unsuccessful wells1 or dry holes1 be printed in black4 ,a large circle drawn around the symbol for a flowing or nonflowing well will appropriately denote a pumping plant at the well4 ,the accepted symbol for a spring is a dot with a waved tail representing the direction of flow1 if known4 ,this symbol can not be modified without destroying its prime characteristics1 but it may be accompanied by a letter indicating the kind of spring4 ,an open circle with a tail might be used on large-scale maps1 but it would be out of scale on other maps1 whereas the black or blue dot and tail will fit maps of any scale4 ,the following colors and symbols can most appropriately be used to represent ground-water features4 ,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 below4 ,general ground-water features4 ,area of absorption or outcrop3 ,flat color used on the map to show the geologic system in which the absorbing formation occurs4 ,areas showing depths to water table3 ,shades of purple and gray2 if possible the shades showing the areas of least depth should be darkest and the shades should grade from those to lighter tints4 ,contours of water table1 or contours on water-bearing formations3 ,gray or purple curves or lines4 ,areas of artesian flow3 ,blue flat tint1 or fine ruling in blue4 ,depth to water-bearing formations3 ,gradation of a single color or of two related colors from dark for shallow depths to light for greater depths4 ,nonflowing artesian areas 7pumped wells73 ,green flat tint1 or fine ruling in green4 ,depth to water-bearing formations shown by gradation of tint if possible from dark for shallow depths to light for greater depths4 ,head of artesian water3 ,blue curves or lines4 ,areas that discharge ground water3 ,blue flat tint1 or fine ruling in blue4 ,areas irrigated with ground water3 ,green flat tint1 or fine ruling in green4 ,illustration ,well1 character not indicated4 ,illustration ,well1 nonflowing4 ,illustration ,well1 flowing4 ,illustration ,well1 unsuccessful or dry4 ,illustration ,well1 nonflowing1 with pumping plant ,illustration ,well1 flowing1 with pumping plant4 ,illustration ,springs4 ,illustration ,spring1 thermal4 ,illustration ,spring1 mineral4 ,the standard color scheme should be used if no conditions preclude its use1 but if other colors can be used with greater economy without sacrificing clearness the use of the standard colors should be waived4 ,,black-,,line ,,conventions4 ,a complete set of the black-line patterns used to distinguish areas on a map is given in ,plate ,,viii 7p4 #fj71 and their application to a finished drawing is shown in figure #i 7p4 #fb74 ,these patterns1 however1 should preferably not be used by the author in his preliminary work on an illustration4 ,for this purpose water colors or colored crayons are preferable1 and the distinctions between areas may be emphasized by letter symbols4 ,,materials ,,used ,,in ,,preparing ,,maps4 ,,paper4 ,for large and important maps which may at some time be extended 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 changes4 ,pure white paper produces a better negative than a cream or yellowish paper and will retain its color longer1 but all papers become more yellow with age and exposure to light4 ,the following brands of paper are used in the ,survey in the preparation of maps3 ,normal ,k4 ,e41 unmounted4 ,has an excellent surface and comes in flat sheets1 #ai by #bd1 #bb by #cj1 and #bg by #dj inches4 ,paragon ,k4 ,e41 mounted on muslin4 ,in #aj-yard rolls #gb inches wide4 ,used in the ,survey for large office drawings and maps of large scale4 ,anvil ,k4 ,e41 mounted on muslin4 ,in #aj-yard rolls #db1 #fb1 and #gb inches wide4 ,used in the ,survey for large drawings4 ,whatman's hot pressed1 unmounted or mounted on muslin4 ,in sheets ranging in size from #ac by #ag to #ca by #ec inches4 ,an excellent paper for maps4 ,the muslin-backed paper is recommended for use in preparing large detailed maps and base maps that are to be retained as permanent records4 ,the muslin provides a durable and flexible backing that permits the map to be rolled1 and paper thus mounted is particularly serviceable for a map which may be subjected to considerable revision and to which must be added finally a title1 explanation1 and other marginal matter4 ,ross's relief hand-stipple drawing paper4 ,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-engraving4 ,for use in making shaded drawings1 drawings showing relief by light and shade1 etc4 ,similar paper is prepared for parallel-line and other pattern effects4 ,in sheets ranging in size from #aa by #ad to #bb by #bh inches4 7,see p4 #ea for method of using47 ,profile and cross-section paper4 ,in sheets of convenient sizes or in rolls4 ,bears lines printed in blue1 green1 red1 or orange1 in many kinds of rulings1 which may be selected by reference to catalogues4 ,profile and cross-section paper printed in orange is recommended for preliminary drawings2 blue is recommended for drawings that are made in pencil and submitted for inking in4 ,,bristol ,,board4 ,for the smaller maps1 such as key maps and maps less than #ah by #bd inches1 and for small drawings made for direct reproduction1 ,reynolds's bristol board is recommended on account of its pure-white color and its hardness1 which permits erasures to be made without affecting redrawing over the corrected area4 ,it is obtained in #b-ply1 #c-ply1 and #d-ply sheets4 ,the #b-ply and #c-ply are especially useful in making delicate brush and pencil drawings and pen and ink drawings4 ,the sizes used in the ,survey are #af-a_/b by #bj-c_/d1 #ah-a_/d by #bb-c_/h1 and #ba-a_/b by #bh-c_/d inches4 ,,tracing ,,linen4 ,tracing cloth or linen is especially useful for large work that will require considerable reduction4 7,see p4 #ah47 ,its advantages are that a tracing that has been carefully made on it over any kind of copy for direct reproduction by a photo-engraving process can be used for making a paper negative for contact printing or blue printing4 ,on the other hand1 it is susceptible to atmospheric changes that affect scale1 and the lines traced on it are not reproduced as sharply as those made on paper4 ,it can be obtained in rolls #cj to #ed inches wide4 ,erasures should be made on tracing linen with a hard rubber eraser1 not with a sand rubber or a steel eraser4 ,,inks4 ,the best drawing inks are in liquid form1 ready for use4 ,they should be waterproof and equal to the grade known as ,higgins's waterproof ink4 ,when a suitable waterproof blue ink can not be obtained1 a good blue for features of drainage can be made by dissolving a half pan of ,winsor ,newton's prussian blue in water4 ,no good waterproof burnt sienna ink seems to be obtainable1 but a good substitute can be made by dissolving ,winsor ,newton's water color of that name4 ,ink lines should be drawn in full strength of color--lines that should be black must not appear grayish1 for example--and pens should be kept clean4 ,the same pen should not be used for applying two inks1 as the mixture thus produced is likely to thicken or coagulate on the pen4 ,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 reproduction4 ,,drawing ,,pens4 ,the pens made by ,keuffel ,esser1 especially their ,no4 #cbjb1 and ,gillott's ,nos4 #bia1 #bij1 #agj1 and #cjc give complete satisfaction4 ,the ,gillott numbers are given in the order of fineness of the points4 ,no4 #bia being the finest4 ,the best cleaner for a drawing pen is a piece of chamois skin4 ,,pencils4 ,pencils used for drawing should have leads of a quality equal to those of the ,koh-i-noor brand1 in which the grades of hardness are indicated by #c;,b1 #b;,b1 ,b1 ,,hb1 ,f1 ,h1 #b;,h1 #c;,h1 #d;,h1 #e;,h1 #f;,h1 #g;,h1 #h;,h1 and #i;,h2 the softest grade is #c;,b and the hardest #i;,h4 ,the grades most generally used are ,b1 ,,hb1 ,f1 #d;,h1 and #f;,h4 ,,rubber ,,erasers ,,and ,,cleaners4 ,two kinds of rubber erasers are usually employed in making erasures on drawings--a hard1 dense rubber like the ,ruby1 and a soft1 pliable rubber like the ,venus or ,h 7,hardtmuth74 ,the soft rubber is also useful for cleaning large surfaces4 ,art gum is also recommended for this purpose and has the advantage of not disturbing the surface of the paper4 ,,colored ,,pencils ,,and ,,crayons4 ,colored pencils and crayons are useful only for coloring preliminary maps4 ,they are not recommended for use on maps that are to be kept for reference or to be submitted for reproduction1 because the colors rub off1 but they can be used on photographic prints of base maps or on transparent oversheets1 for which the unglazed side of tracing cloth is well suited4 ,when they are so used register marks should be added at numerous points on the map and the oversheet1 including the four comers1 the color boundaries should be drawn or traced1 and finally the colors should be added4 ,two or more colors should not be used on any one area to modify a tone1 but each area should be colored with a separate crayon4 ,patterns or designs should not be used except to strengthen contrasts1 and for that purpose a pattern may be drawn with a black pencil over a color4 ,,water ,,colors4 ,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 produced in the same way quits as well as undiluted or full colors will contrast with one another4 ,the colors named below1 except chrome-yellow and emerald-green1 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 maps4 ,mauve4 ,hooker's green ,no4 #b4 ,crimson lake4 ,emerald-green4 ,orange-vermilion4 ,payne's gray4 ,burnt sienna4 ,lampblack4 ,cadmium-yellow4 ,sepia4 ,chrome-yellow4 ,cerulean blue4 ,olive-green4 ,other pigments spread better than cerulean blue and emerald-green1 but the exceptional purity of color of these two seems to warrant their use4 ,,japanese ,,transparent ,,water ,,colors4 ,japanese transparent water colors1 so called1 are used by some geologists4 ,they spread evenly and are convenient for field use1 but they can not be washed out like other water colors1 so that when they are once applied to an area and a change of color becomes necessary they must be bleached out4 ,a good bleach is sodium hypochlorite1 which should be applied with a brush until the color disappears1 and the area dried with a blotter before recoloring4 ,light tints of these colors are believed to be somewhat fugitive if exposed to strong light4 ,,coloring ,,geologic ,,maps4 ,the colors used on most original maps are not pleasing1 a fact that is of no particular importance1 but--and this is of importance--they often fail to give clear distinctions2 the separate areas can not always be identified or distinguished with certainty4 ,again1 some colors are fugitive1 and when laid on in light tints they disappear entirely or become uncertain4 ,much of the difficulty in identifying and discriminating colors on an author's original maps is due to the promiscuous mixing of colors4 ,many persons can not match or discriminate mixed or broken colors4 ,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 match4 ,it is therefore suggested that colors in full strength and colors diluted to half strength be used instead of mixtures of two or more pigments1 so that one color in two strengths or tones can be employed to indicate areas that are to be distinguished4 ,the colors listed on page #bf will give #bd satisfactory distinctions and will thus supply all demands for map coloring4 ,to insure satisfactory contrasts between colored areas on a map1 unlike colors should be placed next to each other--that is1 colors should be placed together that are widely separated in the spectrum1 such as yellow and mauve1 red and green1 blue and orange1 burnt sienna and olive-green2 not such as red and orange1 blue and purple1 orange and yellow1 sepia and burnt sienna4 ,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 desired tint is produced before it is applied4 ,to maintain the same tone properly the color should be well stirred every time the brush is filled2 if it is not stirred the brush will on the next dipping take up a lighter tint1 because most pigments1 especially those derived from minerals1 tend to precipitate4 ,when the colors are applied the map should preferably be placed in a slightly inclined position1 and the coloring should be started at the upper boundaries of an area to be colored1 the well-filled brush being pulled toward the painter and ,worked rapidly back and forth horizontally1 the edges of the fresh color being kept wet4 ,if the edges are allowed to dry1 a hard line and a smeared or uneven effect will be produced4 ,a strong color should generally be used for small areas unless the map shows also large areas that must have the same color2 lighter hues should be used for large areas4 ,bright colors are best suited for areas of igneous rocks1 dikes1 and veins1 and these may be reduced in strength for the larger areas4 ,the ,survey's color scheme 7see p4 #fc7 need not be applied at this stage of preparation1 except in the most general way4 ,appropriate final colors can be best selected when the new map is made ready for engraving4 ,in the author's original maps adequate color distinctions between areas are more important than the use of standard geologic colors4 ,patterns should not be ruled in one color on an original map to indicate distinctions between different formations of the same age or period1 because such patterns are difficult to produce by hand with proper uniformity except by engraving4 ,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 use4 ,such a map should preferably be photographed in order to obtain prints on which to add the colors and symbols2 the use of an oversheet for this purpose is not nearly so satisfactory4 ,when photographed a base map should be reduced to publication scale in order to save the additional cost of a larger negative1 and this reduced map may be made up for publication by the addition of colors and symbols1 title1 explanation1 etc42 but the lithographer will also need the original base map from which to make his reproduction4 ,,diagrams4 ,,essential ,,features4 ,the term diagrams1 as used here1 includes such illustrations as mine plans1 profiles1 sections1 stereograms1 and maps that are more diagrammatic than cartographic4 ,the first essential in the original drawings for simple diagrams is clearness of copy4 ,simplicity of subject does not warrant hasty preparation1 for an original sketch that has been carelessly drawn and is inaccurate or inconsistent in detail may lead to serious errors4 ,ruled paper printed especially for platting profiles and cross sections should be used4 ,curves or graphs made by an author with pencil on blue-lined section paper may be inked by more skillful draftsmen4 ,an author's pencil sketches are usually satisfactory if they indicate plainly the facts to be represented1 but they should be prepared with some care as to detail4 ,tables and like matter are not generally satisfactory material from which to prepare drawings4 ,in drawings for diagrams that are to be printed in the text as figures the use of large1 solid black bars or of conspicuous areas of solid black is objectionable1 because the black is likely to print gray and to appear uneven in tone4 ,ruled tints or cross lining give better effects4 ,stereograms should be prepared by an author with especial care1 for they represent facts only as the author sees them1 and the author's view must be imparted to the draftsman graphically4 ,the third dimension--the relief--in such drawings is not easily expressed and should be brought out clearly in the author's rough sketches4 ,for illustrations of apparatus photographs are preferred1 but if rough sketches are submitted they should show not only correct relations but all dimensions4 ,,plans ,,of ,,mine ,,workings4 ,blue prints obtained from mining companies are acceptable for plans of mines or underground workings1 but all unnecessary or irrelevant details on such plans must be canceled and all essential features retained1 and every essential feature1 especially any added data1 must be clearly interpretable4 ,many such blue prints are so large and unwieldy that they must be greatly reduced by photography before they can be redrawn4 ,if the lines are too weak to photograph1 a tracing of the essential parts can be made and reduced to about twice publication size4 ,the shadowless drafting table1 described on pages #dg-dh1 is well adapted to the work of making such tracings4 ,blue prints can also be pantographed to any convenient size if the details are not too minute or complex4 ,illustration3 ,figure #b4--;,conventional lines used in preparing plans and diagrams of mine workings to distinguish different levels4 ,the levels in plans of underground workings can be differentiated in finished drawings by a system of conventional outlines in black1 as shown in figure #b1 by conventional patterns or symbols within plain outlines1 or by colors4 ,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 black4 ,,sections4 ,the standard forms of geologic sections are shown in the geologic folios4 ,structure sections should be prepared with great care as to detail but without attempt at refinement of lines and lettering4 ,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 exactly4 ,on the other hand1 the draftsman1 in reproducing a section that represents the structure along a given line or zone1 may be able to make the outcrops coincide with the topography and the formation boundaries shown on the map1 but the structure1 or the interpretation of it to be given1 should be carefully worked out by the author4 ,all essential facts relating to bedding1 folding1 faulting1 crosscutting dikes and veins1 or other significant details should be indicated with precision4 ,no attempt need be made to draw firm1 steady lines so long as the essential facts are clearly expressed4 ,all sections should be drawn to scale1 and both the vertical and the horizontal scale should be given on the drawing4 ,these scales should be uniform if possible1 or at least the vertical exaggeration should be minimized4 ,too great vertical exaggeration creates distortion and is grossly misleading4 ,sections should be drawn to scale on ruled paper prepared for the use of authors4 ,such paper may be obtained on requisition4 ,illustration3 ,figure #c4--,section and perspective view showing relations of surface features to the different kinds of rock and the structure of the beds4 ,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 section4 ,this sketch should be a perspective view1 in which the prominent features shown hypothetically in the section below it will be reflected in the topography4 ,such a sketch might show1 for example1 not only monoclinal slopes1 hogbacks due to steeply upturned beds1 terraces1 escarpments1 and like features1 but volcanic necks or other extruded masses in their true relations to the underground geology of the country4 7,see fig1 #c47 ,in submitting the draft of such an illustration the author should1 if possible1 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 point1 ,see photograph ,b4 ,the sketch will be more useful if it is prepared on a scale consistent with the details of the section4 ,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 section4 ,some good examples of illustrations of this type can be found in ,powell's ,exploration of the ,colorado ,river1 pages #ahb-aic4 ,one simpler figure of the same kind is given on the cover of the geologic folios4 ,in preparing original drawings representing columnar sections1 or sections in wells or ravines1 the author should indicate all well-defined or important local features of structure1 such as cross-bedding1 ore bodies1 or lenses4 ,if there are no unusual features or details1 the subdivisions need be identified only by names of materials1 such as thin-bedded limestone1 or slates with some coal1 the coal beds being shown4 ,the sections should1 however1 be so plotted and subdivided by the author that each section or group of sections will be complete in its crude form4 ,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 preparation4 ,illustration3 ,figure #d4--,sections of coal beds4 ,the ,figure shows the publications size and the arrangement at the sections4 ,each section should be drawn three-tenths or four-tenths of an inch wide and reduced one-half4 ,thicknesses can be indicated by numbers1 as shown on sections #a and #aj1 or by bar scale4 ,sections designed to show the relative thickness of beds of coal1 arranged in groups for publication either as plates or figures1 should be drawn in columns three or four tenths of an inch wide and reduced one-half1 as shown in figure #d4 ,these sections1 whether correlated or not1 should be drawn to some definite vertical scale and should show the thickness of the coal beds1 preferably by numbers indicating feet and inches1 the other material being symbolized and the symbols explained graphically1 as shown in figure #d4 ,the vertical scale should always be stated for the use of the draftsman4 ,a bar scale may be used instead of figures showing the dimensions of the individual beds4 ,,lithologic ,,symbols4 ,the symbols used to indicate the various kinds of rocks illustrated in sections and diagrams are shown in ,plate ,,iii4 ,the units or elements of these symbols may be spaced more openly in generalized diagrammatic sections than in sections that show great detail4 ,symbols should be used consistently throughout a report1 and 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 made4 ,some inconsistencies may be unavoidable on account of the small size of some areas shown and the contrast needed between others2 but the deviations from the set of symbols adopted should be minimized4 ,,use ,,of ,,photographs ,,as ,,illustrations4 ,,essential ,,features4 ,the foundation of a good photographic print is a good negative1 and the best prints for reproduction as illustrations are those made from negatives in which the illumination is evenly distributed and the details are sharp--such negatives as are obtainable only by the use of small stops and correct focusing4 ,a good print should not present too sharp contrasts between its dark and its light parts2 if it does1 the printed reproduction will show a loss of detail in both4 ,sufficiency of detail depends largely on focus1 stopping down1 and timing2 brilliancy is the direct result of ample illumination by sun or artificial light1 without which a photograph will be dull or flat and generally unsatisfactory for reproduction4 ,bad weather may prevent good field exposures1 yet even in bad weather acceptable negatives may be obtained by judicious focusing1 stopping down1 and timing4 ,if a negative is overexposed it may be full of detail1 but flat and too thin to print well4 ,if underexposed it will show no details in its lighter parts and the shadows will be black2 and a black shadow is nothing less than a blemish4 ,some detail should appear in all shadows and in the middle tones1 and some should appear in the high lights2 and a print in which these are evenly developed and in which the illumination is distributed uniformly is technically perfect4 ,unfortunately not all field photographs are good1 so an author must select from his collection those which will make the best half tones4 ,in making this selection he should of course consider1 first1 the scientific value of the photograph1 and next1 its pictorial or artistic quality1 which1 though of secondary importance1 should nevertheless be kept in mind4 ,a feature worthy of illustration deserves good pictorial expression2 if it is of superior scientific interest it should not be represented by an inferior photograph4 ,fortunately1 a good1 accurate drawing may be made from a poor photograph1 and a photographic view that has only minor defects can be successfully retouched4 ,photographs that need much retouching should generally be larger than publication size1 for the effects of retouching--brush marks1 etc4--will be softened by reduction4 ,photographs that need only slight retouching need not be larger than publication size4 ,a photograph can rarely be satisfactorily enlarged in reproduction unless it is sharp in detail and requires no retouching4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations4 ,,plate ,,iii4 ,,lithologic ,,symbols ,,used ,,in ,,structure ,,and ,,columnar ,,sections ,,to ,,represent ,,different ,,kinds ,,of ,,rock ,unmounted prints are always preferable for use in making illustrations4 ,a group that is to form a single plate should be placed in an envelope bearing the number of the plate and its title1 and each print of the group should bear a corresponding number1 written in pencil on its back4 ,the envelope will protect the prints and keep them together1 and the numbers will identify them4 ,red ink should not be used to mark photographs1 as it is likely to penetrate the coating or even the fiber of the paper1 so that it can not be erased4 ,if a print is of doubtful quality two copies of it should be submitted--one glazed1 the other having a dead finish or mat surface1 which is generally preferable if the print must be considerably retouched4 ,the best prints for use as illustrations are those made on regular or special semimat velox and glossy haloid papers4 ,the author should indicate prints that may be grouped together according to their relation geographically or by subject4 ,generally two half tones will be combined on a page1 and the list of illustrations should be prepared accordingly4 ,with slight trimming and reduction1 three photographs measuring #c-a_/d by #e-a_/b inches may be made up one above the other to form a full-page octavo plate4 ,four photographs in which the longer dimensions represent vertical distances may sometimes be used if they are placed sidewise on the page1 with side titles4 ,some photographs may be reduced to the width of a page by trimming instead of by photographic reduction1 which may involve loss of detail4 ,the author should clearly indicate the extent of such trimming as they may bear without loss of essential details4 ,the trimming is best done during the final preparation4 ,a line should not be drawn across a photograph to mark such trimming1 but the position of the line or lines should be indicated either on temporary mounts1 on the backs of the prints1 or by a statement1 such as ,one inch may be cut off on right1 one-fourth inch on left1 and one-half inch at bottom4 ,,copyrighted ,,photographs4 ,section #dife 7ch4 #c1 title #fj7 of the ,revised ,statutes1 amended by act of ,march #b1 #ahie 7,stat4 ,l41 vol4 #bh1 p4 #ife71 provides that no copyrighted photograph may be used without the consent of the proprietor of the copyright in writing signed in the presence of two witnesses4 ,a penalty of #a is imposed for every sheet on which such a photograph is reproduced without consents1 either printing1 printed1 copied1 published1 imported1 or exposed for sale4 ,an author should therefore obtain the written consent of the owner of a copyrighted photograph to use it1 and the letter giving this consent should be submitted with the illustration4 ,,sources ,,of ,,photographs4 ,every photograph submitted with a manuscript should bear a memorandum giving the name of the photographer or the owner of the negative4 ,if the negative is in the ,survey's collection that fact should be stated1 as ,neg4 ,keith #cah4 ,the ,survey receives many requests for copies of photographs that have been reproduced as illustrations in its publications1 and replies to these requests will be facilitated if the ,survey's number or the source of each photograph presented for use as an illustration is stated as above on the photograph4 ,,lending ,,original ,,photographs ,,and ,,drawings4 ,a photograph that has been used in making a half-tone cut for a ,survey report can not be lent1 but if the negative is on file a print can be furnished at cost2 and a ,survey drawing that is well preserved can be photographed and a print furnished1 also at cost4 ,requests for such prints should be addressed to the ,director4 ,,unpublished ,,photographs4 ,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 filed4 ,this requirement does not apply to a print needed for official use1 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 filed4 ,authors using ,survey photographs in unofficial publications are requested to acknowledge the source of the photograph by adding to the printed title such a statement as ,photograph by ,u4 ,s4 ,geological ,survey 7,david ,whits74 ,,specimens4 ,,general ,,requirements4 ,specimens other than fossils that are to be illustrated in a report should be photographed before they are submitted1 but the requisition for the photographs should be initialed by the chief illustrator1 who will indicate the kinds of prints needed4 ,duplicate photographs of the specimens should be made up into temporary plates by the author and submitted with his other illustrations1 the specimens being retained subject to call1 if needed1 when the illustrations are finally prepared4 ,should a colored illustration of a specimen be needed1 however1 the specimen must be submitted with the report1 and a different kind of print1 preferably one made on platinum or other special paper1 will be obtained by the section of illustrations4 ,,borrowed ,,and ,,fragile ,,specimens4 ,in submitting specimens to be illustrated an author should call attention to those that have been borrowed and to those that are fragile4 ,borrowed specimens will receive first attention1 so that they may be returned promptly4 ,,transmittal ,,of ,,paleontologic ,,specimens4 ,all requests for paleontologic illustrations should be addressed to the ,director4 ,the letter of transmittal should state the title of the paper1 the form of publication desired 7bulletin1 professional paper1 or monograph71 and the status of the manuscript1 whether completed or in preparation4 ,if the paper is unfinished an estimate of the number of illustrations required should be given1 and the special reasons for prompt preparation should be fully stated4 ,a letter transmitting 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 paper4 ,fossils that are to be drawn should be sent directly to the section of illustrations1 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 handling4 ,each specimen or1 if it is very small1 each box or bottle containing a specimen should be numbered1 and each lot should be accompanied by a list giving their names and numbers4 ,full instructions as to size of reproduction1 together with sketches showing the point of view preferred and any special features to be displayed should also be submitted4 ,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 paper4 ,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 treated4 ,specimens whose color aids in revealing detail are not so coated4 ,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 requirements4 ,,making ,,up ,,plates4 ,two or more illustrations may be combined to form one plate in order to permit easy and close comparison as well as for economy1 for if a particular illustration is too small to make a full plate and is not suitable for enlargement other illustrations that are closely related to it may be put on the same plate4 ,the size of the printed page as given in the table on page #aa will determine the size of the plate4 ,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 effect1 but as figures vary in size and shape a grouping according to relations may not be possible in some plates4 ,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 above4 ,if a plate consists of one large figure and several smaller ones the large figure should be placed below and the smaller figures above4 ,a number designating a figure should be placed immediately below the figure1 and a series of such numbers should preferably begin with #a in the upper left corner and continue consecutively across and down through the plate4 ,this arrangement is not always possible1 however1 on account of variations in the size of figures4 ,as drawings of fossils or other specimens are prepared separately and grouped into plates1 and as most paleontologists make up their own plates1 each in his own way1 there is naturally great dissimilarity in methods and in results4 ,ordinary white or light-gray cardboard should be used1 and the figures that are to make up a plate should be arranged as stated above but not securely pasted until the grouping is satisfactory4 ,in trimming each drawing or photograph the author should be careful to leave room at its lower edge for the number4 ,small drawings or photographs1 such as paleontologists use1 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 remounted2 figures pasted on ordinary white or gray cardboard can be removed without difficulty4 ,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 7see table on p4 #aa71 and each figure should be properly oriented--that is1 all vertical lines1 or the vertical axis of each specimen1 should be parallel with the sides of the plate4 ,when the figures are being mounted care should be taken that the mucilage or paste does not exude under pressure and cover any part of the drawing or photograph4 ,the same attention should be given to pasting on numbers4 ,inattention to these details may produce results that will affect the reproduction of the plates4 ,ordinary mucilage may be used for mounting drawings and photographs1 but photo paste gives good results and is perhaps cleaner to handle4 ,dry-mounting tissue is well adapted to mounting single illustrations but not groups of figures4 ,liquid rubber is sometimes used1 but it is not suitable for mounting small figures1 such as drawings and photographs of fossils4 ,it can be used satisfactorily for mounting temporary plates and for mounting photographs in albums and on large cards for study or exhibition2 but it has not proved to be a permanent adhesive4 ,its special merit is that it does not cause either the photograph or the mounting sheet to warp4 ,it is applied by spreading it evenly over the back of the photograph with the fingers4 ,the superfluous rubber can easily be removed from the hands and from the cards or sheets when it is dry4 ,anything mounted with liquid rubber can be easily removed4 ,if a plate is to be made up of a small number of figures that require different reductions1 the author1 instead of mounting or pasting the separate figures on one card in the manner already indicated1 may draw a rectangle of the size of the printed plate and sketch within it the several figures in their respective sizes and positions4 ,these dummy plates or layouts should be numbered as plates1 and they may bear captions and titles4 ,the photographs or drawings represented by the sketches should then be numbered to identify them with the sketches on the dummy plate1 and those that pertain to each plate should be inclosed in an envelope attached to the dummy plate4 ,a plate made up in this manner will meet every requirement of the photo-engraver or lithographer4 ,if a paleontologist so desires1 his plates can be permanently made up after he has transmitted his material1 but he should always submit a tentative arrangement4 ,,reuse ,,of ,,illustrations4 ,if an author desires to use in modified form an illustration already published1 whether by the ,geological ,survey or by an outside publisher1 he should furnish a print or tracing of the illustration showing the changes desired4 ,if the illustration is not to be modified he need only give the title of the volume in which it was used1 with the number of the page1 figure1 or plate1 and he need not make a sketch of the illustration or furnish a dummy2 but its title should be quoted and proper reference should be given in the list of illustrations4 ,due credit should be given to the author or publisher4 ,the original cuts of illustrations will be kept for one year after the report for which they were made has been published1 and authors of later reports may and should reuse1 whenever practicable1 any such cut that will serve as an illustration4 ,in the author's list of illustrations such a cut should be referred to by its number as plate or figure and the volume in which it was first used4 ,an electrotype of any cut on hand will be furnished for use in publications other than those of the ,geological ,survey at the cost of making1 which is #c-a_/b to #e-a_/b cents a square inch of printing surface4 ,the minimum charge for a single electrotype ranges from #df to #fj cents4 ,,approval ,,of ,,finished ,,illustrations4 ,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 examination4 ,the finished drawings will be accompanied by the originals1 with which the author should carefully and thoroughly compare them4 ,after making a thorough comparison he should mark lightly with a pencil1 on the finished drawings1 all necessary corrections1 or indicate his approval subject to such corrections and additions as may be required4 ,he should verify all type matter and other lettering and assure himself that no mistakes have been made in grouping the photographs into plates1 especially such as have been regrouped since they left his hands4 ,the author's list of illustrations will be submitted with the new drawings for this purpose4 ,,revision ,,of ,,illustrations4 ,all illustrations receive editorial revision before they are sent to the engravers4 ,after they are drawn they are examined with reference to their scientific features and their accuracy1 and then in turn with reference to the correctness of geologic names and geographic names and to errors in statement and in spelling4 ,each illustration thus1 before it is completed1 receives critical examination by persons qualified in particular kinds of work to detect errors or omissions4 ,,submittal ,,of ,,proofs4 ,the first proofs of all illustrations are submitted to an author when he is within reach1 but if he is in the field and the transmittal of the proofs to him is likely to cause too much delay they are submitted to the chief of the branch or division in which the report was prepared4 ,second proofs of the more complicated illustrations1 particularly geologic maps1 may be submitted4 ,an author's examination should be confined principally to the revision of the scientific features of his illustrations1 but suggestions as to general effectiveness are always acceptable4 ,the process to be used in engraving each illustration is stamped in its lower left corner4 ,in examining proofs an author should note the following facts3 #a4 ,changes can not be made in zinc etchings except by eliminating parts1 cutting away defects1 and connecting lines4 ,if additions are required reengraving is generally necessary1 and reengraving should preferably be avoided4 #b4 ,changes can be made in half-tone plates only by re-etching certain parts to make them lighter and by burnishing certain parts to make them darker4 ,if the proof shows a general loss of detail the fault may lie either in the proving of the cut or in the reproduction4 ,if it is in the reproduction it can not be remedied without reengraving4 ,a slight loss of detail may be expected in all half tones1 especially in those that are smaller than the copy submitted4 #c4 ,minor changes can be made in photolithographs and chromolithographs1 but changes can not be made twice in one place without danger of affecting the printing4 ,it is customary to approve all lithographic proofs subject to the corrections indicated1 the printed edition being examined and compared1 but if the changes are numerous and radical second proofs may be required4 ,second combined proofs of chromolithographs are very expensive4 7,see p4 #hi47 ,,proof ,,reading ,,illustrations4 ,an author should examine the proofs of his illustrations closely and should compare them carefully with the original drawings4 ,a mere cursory examination may fail to detect errors that have not been caught by the regular proof reader4 ,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 comment1 but if the time available is short a pencil may be used4 ,in correcting type matter or lettering 7such as that in a geologic legend or explanation7 the ordinary proof reader's marks should be used4 ,the author or the person examining the proofs should initial each one at the place indicated by a rubber stamp4 ,proofs should be held only long enough to examine them properly and to compare them with the original illustrations1 for a time limit is fixed in each contract for engraving1 and if the author holds proofs beyond a reasonable time he causes a delay in the fulfillment of the contract4 ,as the illustrations for many reports contain important data that will be discussed in the text1 proofs of illustrations can not be supplied to any applicant without consent from the ,director's office4 ,,general ,,considerations4 ,the following requirements are essential to obtain good original illustrations3 #a4 ,the material selected should be pertinent and expressive2 it should have the qualities essential to good illustrations4 #b4 ,the character of the report and the size of the illustrations should be kept clearly in mind4 ,if the report is preliminary or ephemeral the illustrations should be simple and inexpensive4 ,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 elaborate4 ,the character of a report generally determines the form of publication1 which1 in turn1 determines the size of the pages and the size of the plates and figures4 ,every sketch made should be larger than publication size--preferably twice publication size--whether it is a simple diagram or a base map4 #c4 ,the kind of reproduction that is apparently needed should be fully considered1 for it should have some relation to the kind of report4 ,the illustrations for short-lived reports are reproduced by the cheaper processes4 ,those for hurried reports are reproduced by processes that can be worked quickly1 but no process should be considered that will not give a clear reproduction of essential details4 #d4 ,clearness of preparation of original matter is invariably essential4 ,an author should not expect the draftsmen or the editors to supply missing links4 ,each original should be complete and should be so made that it can be understood and followed without question4 ,changes made in the finished drawings or on proof sheets are expensive and delay publication4 ,,part ,,ii4 ,,preparation ,,by ,,draftsmen4 ,,general ,,directions4 ,the work of preparing illustrations such as are used in the reports of the ,geological ,survey is essentially that of making finished drawings from more or less crude and imperfect material furnished by authors to illustrate certain features or phenomena discussed in their manuscripts4 ,each finished drawing must be so prepared that it can be reproduced in multiple by one of several processes of engraving4 ,the author's sketches and other material are commonly called originals2 the finished illustrations are known by the engravers as copy4 ,though most engraver's copy consists of more or less elaborate drawings that are to be reproduced in facsimile by direct processes without the interposition of handwork1 some of it consists of more roughly prepared copy which is accurate in statement but requires complete manual or indirect reproduction4 ,the direct processes in use are zinc etching1 half-tone engraving1 photolithography1 three-color half tone1 photogravure1 and photogelatin4 ,the manual or indirect processes are wax engraving1 wood engraving1 engraving on copper and on stone1 plain lithography1 and chromolithography4 ,these processes are described on pages #gb-ij4 ,part ,i of this pamphlet contains some matter that is pertinent to final preparation and should be consulted by draftsmen4 ,to prepare a drawing that will be in every way suitable for reproduction usually requires experience of a kind not acquired in many other kinds of drafting1 such as preparing engineers' or architects' drawings1 because the drawings themselves or blue prints made directly from them are the things the engineer or the architect desires4 ,drawings prepared for reproduction are generally made larger than publication size1 and it is therefore necessary to gage each line1 letter1 or feature for a definite reduction4 ,engineers' and architects' drawings generally do not require preparation for reproduction by any process1 but in preparing illustrations for the reports of the ,geological ,survey reproduction must be fully considered at every step1 and each drawing must be made according to the requirements of a certain selected process and gaged for a certain reduction4 ,the draftsman should therefore know how to plan each drawing step by step for an engraved cut1 a lithograph1 a text figure1 or a plate1 always with a definite result in view4 ,he should be familiar with processes of engraving and should know the special requirements of each process1 and he should be able to prepare drawings for any specified reduction in a way to insure good1 legible reproduction4 ,the geologic draftsman should read and study such textbooks of geology as those of ,dana and ,geikie and should familiarize himself with structural geology1 the geologic time divisions1 and geologic nomenclature4 ,he should be able to prepare a simple1 effective illustration from complicated rough originals and to supply minor missing essential parts or features4 ,to perform his work successfully he must possess mechanical skill and some artistic taste1 as well as good eyesight and great patience4 ,,instruments4 ,the following list of draftsmen's instruments is practically complete4 ,those which are considered indispensable are marked by asterisks2 the others may be used according to individual preference4 ,the same kind of instrument may be duplicated in different sizes according to the variation in the demands of the work4 ,air brush and connections4 ,pens1 ,payzant's1 #a set4 ,beam compass4 99,pencils1 best quality1 graded ,bow pen1 drop spring4 leads4 99,bow pen1 steel spring4 99,protractor4 ,bow pencil1 steel spring4 ,railroad curves1 pearwood1 #a set4 99,brushes1 red sable4 ,railroad pen4 ,china saucers4 99,railroad pencil4 99,color box4 ,reading glass4 99,compass1 pen and pencil points4 99,reducing glass4 ,crayons1 assorted colors4 99,ruling pen4 ,curve rule1 adjustable4 ,scale1 boxwood1 #ab inches long1 99,dividers1 plain4 with divisions of millimeters 99,dividers1 proportional4 and inches4 ,dividers1 steel spring4 ,scales1 boxwood1 triangular4 ,drawing boards1 several sizes4 ,section liner 7parallel ruling ,eraser1 glass4 device74 99,eraser1 rubber1 hard4 ,straightedge1 steel1 #bd inches4 99,eraser1 rubber1 soft4 ,straightedge1 steel1 #cf inches1 99,eraser1 steel4 with divisions for hundredths ,erasing shield4 of an inch and millimeters4 99,french curves1 xylonite4 99,straightedge1 wood1 #bd inches4 ,microscope1 low power and ,swivel or curve pen4 lenses4 ,thumb tacks4 ,palette knife4 ,tracing point1 steel4 ,pantograph4 99,triangle1 #de4 ,pens1 double-pointed4 99,triangle1 #fj4 99,pens1 ,gillott's1 ,nos4 #agj1 99,t square1 pearwood1 xylonite edge4 #bij1 #bia4 99,tweezers1 dentist's4 ,pens1 ,k4 ,e41 drawing4 ,no4 #cbjb4 ,,classification ,,of ,,material4 ,the draftsman handling the drawings and other original material submitted by the author of a report for its illustration should first group them1 as far as possible1 into kinds or classes1 in order that he may decide how each illustration should be prepared 7#a7 to express most effectively the author's purpose1 7#b7 to insure reasonable economy in preparation and in reproduction1 and 7#c7 to meet the requirements of the processes of reproduction selected4 ,all similar illustrations for one publication should be prepared in the same general style4 ,in a series of geologic sections1 for example1 the same lithologic symbols should be used throughout for the same kinds of rocks4 ,the titles1 explanations1 and captions of the maps should also agree with one another in general style and in details of workmanship4 ,the draftsman should determine in advance the reduction for each drawing or for each group of drawings1 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 reduction4 ,the reduction should preferably be marked in fractions 7as #a_/b off1 #a_/d off or reduce #a_/b1 reduce #a_/d71 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 economically1 for the engraver can photograph them in groups instead of each one separately4 ,the draftsman should therefore note and consider 7#a7 the special features shown in the author's originals2 7#b7 whether or not these features have been plainly indicated and whether the originals are complete2 7#c7 the size of the printed page of the volume in which the illustrations will appear and the reduction required for each drawing2 and 7#d7 the process by which each drawing should be reproduced4 ,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 branch2 otherwise he may waste much time in making the drawing4 ,,preparation ,,of ,,maps4 ,,projection4 ,the base maps furnished by authors 7see pp4 #ac-ad7 are prepared in many different ways and in different degrees of refinement and of crudity1 but the work of redrawing them for reproduction involves well-established and generally uniform principles4 ,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 curvature of the earth4 ,the polyconic projection 7see fig4 #e7 is used for most ,government maps4 ,in this projection the central meridian is a straight vertical line1 and each parallel of latitude is developed independently of the others4 ,the mathematical elements of map projection are given in tables published by the ,geological ,survey#f and the ,coast and ,geodetic ,survey4#g ,figure #e1 however1 illustrates the mechanical or constructional features of the polyconic projection and if used in connection with the published tables will probably be a sufficient guide for projecting a map on any desired scale4 ,footnote #f3 ,gannett1 ,s4 ,s41 ,geographic tables and formulas1 #dth ed43 ,u4 ,s4 ,geol4 ,survey ,bull4 #fej1 #aiaf4 ,see also ,gannett1 ,henry1 ,manual of topographic methods3 ,u4 ,s4 ,geol4 ,survey ,bull4 #cjg1 pp4 #he-hf1 #aijf4 ,footnote #g3 ,methods and results3 ,tables for the projection of maps and polyconic development2 ,appendix ,no4 #f1 ,report for #ahhd2 ,tables for a polyconic projection of maps1 based upon ,clarke's reference spheroid of #ahhf2 #c;d ed41 #aiaj4 ,illustration3 ,figure #e4--;,diagram illustrating method of projecting a map4 ,in projecting a map first select a convenient measuring scale for setting off the dimensions given in the tables1 or if no scale is at hand one may be constructed4 ,measuring scales are made1 however1 bearing divisions for miles and kilometers and finer subdivisions of #f to #ajj parts4 ,they include the ratios of #a3ca1bej1 #a3ca1fhj1 #a3dh1jjj1 #a3fb1ejj1 #a3fc1cfj1 #a3abe1jjj1 #a3bej1jjj1 #a3ejj1jjj1 #a3a1jjj1jjj1 and others4 ,on a map drawn on the scale of #a to #fc1cfj1 for example1 #a inch would represent #a mile2 on a map drawn on the scale of #a to #a1jjj1jjj1 #a millimeter would represent #a kilometer1 and so on4 ,it will be seen that the use of a scale that shows in ratios1 such as those just given1 the actual distance on the ground as compared with the unit representing the same distance on the map will reduce the possibility of error4 ,the method of projecting a map1 illustrated in the accompanying diagram 7fig4 #e71 is as follows3 ,first draw a straight vertical line 7,a7 through the middle of the sheet to represent the central meridian of the map and a line 7,b7 at the lower end of this line exactly at right angles to it to represent the bottom of the map4 ,then set off on the line showing the central meridian the distances between parallels given in ,table #f on page #cf of ,geographic tables and formulas 7,bull4 #fej74 ,it should be noted that the figures in these tables give the distance1 in meters and statute miles1 of #a on a meridian measured #cj' each way from a point where the meridian is intersected by a parallel4 ,the exact distances between parallels as measured on the ground are given in the ,coast and ,geodetic ,survey tables1 or they may be computed from ,table #f of ,geographic tables and formulas by adding the sum of the figures given for any two latitudes #a apart and dividing by #b4 ,the distance between parallels that are #b apart1 as shown in the diagram1 may be computed from ,table #f of ,geographic tables and formulas1 as follows3 ,meters4 ,meters4 #a of latitude on #cgth parallel #ajj1ige4a _/ #b #ee1dhg4e #a of latitude on #cfth parallel #aaj1ief4b #a of latitude on #ceth parallel #aaj1icg4f _/ #b #ee1dfh4h --------- ,true distance from #ce to #cg latitude #bba1iab4e ,the distances given in the diagram were obtained by adding the figures given in the ,coast and ,geodetic ,survey tables1 which yield the same results4 ,other tables in ,bulletin #fej give the true distances in inches on maps of certain standard scales4 ,through the points thus obtained on the central meridian draw lines at right angles to the vertical line4 ,along these horizontal lines lay off the dimensions in the column headed ,x1 ,table #f 7pp4 #ci-dg7 of ,geographic tables and formulas as required for each individual map--in the diagram every alternate degree4 ,draw vertical lines at these points and set off the distance ,y in the same table in a similar manner1 and the points so found will be the points of intersection of the respective meridians and parallels4 ,figures are given on the diagram for the thirty-fifth parallel only4 ,,details ,,of ,,base ,,maps4 ,anyone who attempts to draw a base map must1 first of all1 know how each feature or part of the map should be represented4 ,most of the conventional symbols for features shown on base maps are well established and should invariably be used2 for instance1 a line composed of alternate long and short dashes 7not dashes and dots7 represents a county boundary1 and a line or two parallel lines across which short lines are drawn at regular intervals represents a railroad4 ,if he finds that two or more symbols have been widely used to represent the same feature the draftsman should select the one that is best suited to the map in hand4 ,the correct forms of the conventional symbols or features to be used in preparing miscellaneous maps are shown in ,plate ,,iv1 but the size and weight of each line or symbol must depend on the size and character of the map4 ,,transferring ,,of ,,copying4 ,,tracing4 ,the oldest method of transferring a map or parts of a map or other drawing to another sheet is that of copying it by means of tracing paper4 ,this method1 though still used for simple work1 has given way to quicker and more effective methods4 ,by one of these methods a piece of thin1 fairly smooth paper 7not necessarily transparent7 is coated with graphite by rubbing over it a soft pencil4 ,when the graphite has been evenly distributed over it1 this sheet is laid upon the drawing paper1 coated side down1 the map or other subject to be copied is laid upon the graphite-coated sheet1 and the two outer sheets--the drawing paper and the map--are securely fastened together4 ,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 beneath4 ,for maps that show several features in different colors sheets rubbed with blue1 orange1 brown1 or green pencils may be used1 one after another1 for tracing each set of the features4 ,red should not be used1 as it is not easily erased4 ,this method insures distinctive lines for the separate features and prevents the confusion that might result from the use of one color only4 ,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 tacks4 ,the colored sheets may then be slipped in and out without altering the position of the lines or symbols for one set of data with relation to those for the others4 ,in the final preparation of a base map to be engraved and printed in colors--for example1 black1 blue1 and brown--tracings of the three colors appearing on the original base should generally be transferred1 as described above1 to one sheet of paper and thus worked up into a three-colored map4 ,it is usually unnecessary and undesirable to draw each color on a separate sheet4 ,the preparation of separate drawings may facilitate reproduction1 but if they are made on tracing cloth the usual uneven shrinking or stretching of the cloth may produce misregister in the printing2 therefore it is safer to make a single drawing1 so that the photolithographer can make three negatives and separate the colors by painting out or opaquing the colors not wanted on each negative4 ,a map drawn on a single sheet is also less bulky and can therefore be more conveniently handled and compared with proof4 ,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 woof4 ,,celluloid ,,transferring4 ,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 celluloid4 ,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 burnisher1 which makes a perfect offset of the map on the paper4 ,after the parts desired are inked over the rest of the graphite print is easily erased with an ordinary rubber4 ,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 pantograph4 ,requisitions for celluloid prints are made on the form used for requesting photolithographic work4 ,,sketching ,,by ,,reticulation4 ,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 size4 ,corresponding squares of the same size1 larger1 or smaller1 according to the size of the new drawing1 are then ruled on the drawing paper1 and the work is sketched square by square4 ,if the original sheet may not be marred the same result can be obtained by drawing the lines on a transparent oversheet4 ,this method is serviceable for enlarging or reducing simple work that includes no great amount of detail2 if great precision of detail is required the original should be enlarged or reduced by photography or by the pantograph4 ,,the ,,shadowless ,,drafting ,,table4 ,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 table4 ,the essential features of this table are a wooden box inclosing strong incandescent lights and bearing a ground-glass top4 ,a drawing placed on the ground glass can be so illuminated as to make its lines conspicuous and readily traceable even through relatively thick paper4 ,the table is particularly useful for tracing sheets upon1 which the lines are indistinct and would not be discernible under tracing paper with reflected light4 ,it is also useful in preparing drawings in which certain features must register perfectly over each other4 ,in fact any drawing that does not require enlarging or reducing can be traced with great facility by the use of this drafting table1 and it is particularly useful for tracing faint lines on old and poorly preserved prints or drawings4 ,such a table has been installed in the section of illustrations1 where it can be used by authors and others4 ,,topographic ,,features4 ,,relief4 ,the effect of relief is expressed on a map by three methods--by contours1 by hachures1 and by shading4 7,see fig4 #f47 ,the first method does not give pronounced pictorial expression of relief1 though it gives correct shape and exact elevation2 the others are mow pictorial1 but they do not give exact elevation4 ,contours4--,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 redrawing4 ,if the area mapped is large and the contours are close together the original may be transferred by celluloid tracing 7see p4 #dg71 or it may be transferred by tracing with graphite-coated paper 7see p4 #df74 ,after the contour lines have been transferred they should be traced in ink1 in lines of even thickness1 except those that represent certain fixed intervals and are to be numbered1 which should be made slightly thicker4 7,see fig4 #f1 ,a47 ,in drawing these lines some draftsmen use an ordinary ruling pen1 others the swivel pen2 but considerable practice is required in the use of either before it can be controlled to follow precisely the penciled lines4 ,still other draftsmen use the ,shepard pen or an ordinary drawing pen4 ,the swivel pen1 if expertly handled1 produces a firm and even line4 ,italic numbers should be used to indicate the elevation of a contour and should be placed in an opening in the line1 never between lines4 ,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 combine4 ,the lines should be firm and even1 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 drawing2 but if the enlarged map is to be much reduced care should be taken to make the lines proportionate to the reduction4 ,a photo-engraving of a map on which the contour lines are drawn very close together is likely to be unsatisfactory because1 though the spaces between the lines are reduced in width1 the lines themselves may show no corresponding reduction in thickness4 ,illustration3 ,figure #f4--,methods of expressing relief3 7,a7 by contour lines1 7,b7 by hachures1 7,c7 by shading on stipple board1 and 7,d7 by a brush drawing4 ,the four examples given represent the same area4 ,the drawings were made twice the size of the printed cuts4 ,certain contour lines are commonly accentuated on a map1 generally every fourth or fifth line--that is1 for a #aj-;foot interval every #ej-;foot line1 for a #bj-;foot interval every #ajj-;foot line1 for a #be-;foot interval every #ajj-;foot line1 for a #ej-;foot interval every #bej-;foot line1 and for a #ajj-;foot interval every #ejj-;foot line4 ,hachuring4--,the effect of relief can be produced satisfactorily by hachuring but only by a draftsman who has had considerable well-directed practice in that kind of drawing4 ,in a hachured map the light should seem to come from the west or northwest--that is1 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 elevation should be represented by the darkest shade on the right and by a corresponding high light on the left4 ,the hachuring should begin at the crest of a peak1 range1 or butte and be worked downward toward the gentler slopes1 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 lines4 ,on a hachured map that is made from a contoured map somewhat definite differences of elevation may be indicated by the intervals between the strokes1 and abrupt changes in slope may be indicated by shorter and heavier lines4 ,the strokes should be disjointed1 and they should trend at right angles to the upper margin of a cliff and should radiate from a peak4 ,figure #f1 ,b1 represents satisfactory hachuring4 ,hill shading4--,relief is more easily expressed by shading than by hachuring4 7,see fig4 #f1 ,c1 ,d47 ,the draftsman can best express it by this means after he has studied contoured maps or photographs of the region mapped1 if they are available1 in order that he may obtain an idea of the details of its topography4 ,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 made1 the size of the map1 the amount of detail and refinement of execution desired1 and the amount of reduction to be made in reproducing the drawing4 ,for maps on which it is desired to show some refinement of drawing and detail1 a lithographic or wax crayon can be used on paper which has a grained surface4 ,the draftsman must express relief according to the information he has at hand1 whether detailed or general1 and must employ methods that accord with the purpose of the map and the mode of reproduction selected4 ,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 photographic or blue print obtained on which to add the relief in black lithographic crayon1 to insure perfect fitting of the relief and the base2 or the relief can be prepared on an oversheet--a semitransparent white paper with sufficient tooth or grain to cut the shading up into minute dots4 ,the shadowless drafting table 7see p4 #dg7 is especially useful for this purpose4 ,on this oversheet register marks should be placed at the four comers and at several other points1 particularly at the intersection of parallels and meridians4 ,for relief shading on small black and white maps ,ross's hand-stipple drawing paper may be used4 7,see p4 #bd47 ,by rubbing a black wax crayon or pencil over the surface of the paper the desired effect is produced in fine dots or in stipple1 which may be varied in density of shade at the will of the draftsman4 7,see fig4 #f1 ,c47 ,high lights can be produced by scraping away the chalky surface of the paper4 ,a lithographic or wax crayon is the best medium to use on this stipple paper1 as on the paper referred to in the preceding paragraph1 for the shading produced by it is not so easily smeared as that produced in pastel or by a graphite pencil4 ,the object of using either the rough paper or ,boss'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 sizes1 which is essential in such reproduction4 ,belief shading for maps can also be made with a brush in flat washes of either india ink or lampblack4 ,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 overprinted4 ,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 transferred 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 streams4 ,such a drawing can be photographed through a screen and reproduced by half tone 7see fig4 #f1 ,d7 or mezzotint as a separate plate made to overprint the map in another color4 ,,hydrography4 ,general directions4--,the drainage features of a map should be so drawn as to suggest the natural courses of the streams4 ,streams should not be drawn in straight1 hard lines1 as such lines are decidedly unnatural and produce a crude effect4 ,the course of a river may be straight in general1 but it is likely to be somewhat sinuous in detail4 ,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 wavy1 in order that they may appear more natural4 ,the gradual widening of streams from source to mouth should also be shown in the drawing4 ,on small-scale maps1 where the eye can at once see a stream through its full length1 this almost imperceptible widening can be expressed by a line of almost uniform weight except for the stretch near the source1 where it should grow thinner and taper off4 ,on maps which are to be reproduced directly from drawings in black and white and which are to show 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 lines1 which should be sharper and more precise4 ,the names of all streams or other bodies of water should be in italic letters1 those of the larger streams being lettered in capitals and those of the smaller streams in capitals and lower-case letters4 7,see ,lettering1 p4 #ec47 ,water lining4--,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 areas4 ,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 specified4 ,in base maps to be reproduced in three colors a light-blue tint may be used in lieu of water lining1 and it can be printed either flat or in a fine ruling transferred to the stone that is to print the drainage4 ,the engraving of water lines is expensive1 and the flat blue color should generally be preferred4 ,water lining usually consists of #cj to #de lines on engraved or large maps1 but on small maps and sketch maps the number may be reduced as desired4 ,care should be taken that the lines are as nearly parallel as they can be made freehand and of even weight or thickness4 ,the first three to six lines outside the coast line should be somewhat closer together than those farther out and should conform closely to the coast line1 but the spacing between the lines should increase and the lines should become almost imperceptibly less conformable to the coast line as they reach their outer limit1 the last three to six being made with the greatest care and refinement4 ,water-lined maps that are to be reproduced by photographic processes should be drawn at least twice publication size4 ,the reduction will bring the lines closer together1 and the reproduction will show a more refined effect than could possibly be produced by the most skillful drawing4 ,good examples of water lining1 such as are shown on the topographic atlas sheets of the ,survey1 should be studied by draftsmen before they undertake such work4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,iv ,,symbols ,,used ,,on ,,base ,,maps ,,cultural ,,features4 ,the cultural features represented on a map include the works of man--not only cities1 towns1 buildings1 bridges1 railroads1 and other roads1 but ,state1 county1 and other boundary lines--in short1 all that part of a three-color base map which is shown in black1 the engraved plate for the black being called the culture plate4 ,the features named in the list below are the cultural features referred to4 7,see ,,pl ,,iv for corresponding symbols47 ,aqueduct mains4 ,aqueduct tunnels4 ,bench marks4 ,boundary ,lines4 ,boundary monuments4 ,breakwaters4 ,bridges4 ,buildings4 ,cable ,lines4 ,camps4 ,canal locks4 ,canals4 ,cemeteries4 ,churches4 ,cities4 ,county lines4 ,dams4 ,district lines4 ,ditches4 ,electric power lines4 ,fences4 ,ferries4 ,fords4 ,gas wells4 ,hedges4 ,hospitals4 ,jetties4 ,land-grant lines4 ,land-section ,lines4 ,levees4 ,mains4 ,mineral monuments4 ,mine tunnels4 ,mines4 ,national forests4 ,national parks4 ,oil tanks4 ,oil wells4 ,open cuts4 ,park boundaries4 ,paths4 ,pits4 ,post offices4 ,precinct lines4 ,prospects4 ,province lines4 ,quarries4 ,quarter-section lines4 ,railroads1 steam or electric4 ,ranches4 ,reservation boundaries4 ,reservoirs4 ,roads4 ,ruins4 ,schoolhouses4 ,section comers4 ,section ,lines4 ,settlements4 ,shafts4 ,streets4 ,telegraph ,lines4 ,towns4 ,township comers4 ,townships4 ,trails4 ,tramways4 ,triangulation stations4 ,tunnels4 ,villages4 ,water mains4 ,water wells4 ,waterworks4 ,windmills4 ,,lettering4 ,,general ,,directions4 ,the cultural features are named on maps by letters of two distinct styles--slanting gothic for public works and roman for habitations and civil divisions4 ,the size of the letters used should indicate in a general way the relative importance of the feature or group to which they are applied1 but on some maps the county seats1 ,state capitals1 and large cities may be distinguished by different symbols4 ,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 appear4 ,the features shown on a topographic map may be broadly separated into four groups and are lettered as follows3 ,civil divisions 7countries1 ,states1 counties1 townships1 land grants1 reservations1 cities1 towns1 villages1 settlements1 schools1 lodges1 ranches1 etc471 roman capitals or capitals and lower case4 ,public works 7railroads1 tunnels1 roads1 canals1 ferries1 bridges1 fords1 dams1 mains1 mines1 forts1 trails1 etc471 slanting gothic capitals 7light7 or capitals and lower case4 ,hydrographic features 7oceans1 seas1 gulfs1 bays1 lakes1 ponds1 rivers1 creeks1 brooks1 springs1 wells1 falls1 rapids1 marshes1 glaciers1 etc471 italic capitals or capitals and lower case4 ,hypsographic features 7mountains1 ranges1 peaks1 plateaus1 cliffs1 buttes1 canyons1 valleys1 peninsulas1 islands1 capes1 etc471 upright gothic capitals 7light7 or capitals and lower case4 ,the essential principles of lettering have been described in numerous treatises and are well understood by most draftsmen4 ,the correct form of each letter may be learned from such treatises1 but spacing and arrangement are best learned by observation and experience4 ,good lettering will not strongly attract attention1 but even slight imperfections of form1 spacing1 slant1 and shading will be quickly detected and criticized4 ,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 it1 as ,tucsono1 #ago1 ,dallaso1 ,carsono4 ,names indicating large areas1 if written from west to east1 should curve with the parallels1 and all names should be so lettered that if they should fall they would fall on their feet4 ,every name should be distinctly legible but not so conspicuous as to subordinate the feature it designates4 ,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 printing4 ,the lettering on a map should always be so spaced that it will properly fit the area it is intended to designate4 ,in names consisting of two or more words the letters should not be closely spaced if wide spaces are left between the words4 ,in numbers1 except those used to indicate elevations on contour ,lines or elsewhere1 thousands should always be set off by commas4 ,draftsmen often draw bad forms for commas1 quotation marks1 apostrophes1 and question marks4 ,the following forms are correct3 ,comma 1 2 quotation marks 2 apostrophe ' 2 question mark 8 4 ,,lettering ,,by ,,type4 ,names and short notes printed from type on paper1 to be cut out and pasted in proper positions on maps or other drawings1 now furnish a large proportion of the lettering on the ,survey's illustrations4 ,the strips are likely to become detached by the repeated handling of a drawing1 however1 unless they are securely pasted on4 ,the best results can be obtained by having the type printed on a special brand of noncurling gummed paper1 from which the lettering is cut in squares or strips1 which are dampened and applied to the proper places on the drawing4 ,in handling such strips a pair of dentist's tweezers is useful4 ,when mucilage is applied to printed strips of ordinary paper the moisture causes the paper to warp or curl1 often so much as to affect the reproduction of the drawing4 ,this printed lettering is generally used1 however1 only for headings1 titles1 notes1 and other matter that stands alone2 it should not be used for the geographic names in the body of a map unless only a few names are to appear1 for the strips of paper bearing the names may obscure parts of the map4 ,the reproduction of this lettering by photo-engraving or photolithography gives results superior to those obtained from hand lettering unless each letter is made with the utmost care1 work which is considered a waste of time4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,v ,,reduction ,,sheet ,,used ,,in ,,lettering ,,illustrations4 ,the largest size shows the letters unreduced2 the other sizes show the letters reduced as indicated in the margin4 ,type is used also for printing lettering directly on a drawing exactly in proper position1 by a special type holder1 somewhat like a self-inking stamp4 ,most of the styles and sizes of type now used on maps in the ,survey's reports are shown in ,plate ,v4 ,if a drawing is to be reduced one-half the smallest type used should be about #b millimeters in height2 if it is to be reduced one-third the smallest type used should be about #a4e millimeters in height2 and so on4 ,no letter whose vertical height after reproduction would be less than about #a millimeter should be used1 and the larger lettering should bear a proper relation to the smaller4 ,sheets showing the styles of type in use by the ,survey1 in full size and reduced one-fourth1 one-third1 two-fifths1 one-half1 three-fifths1 two-thirds1 and three-fourths1 will be furnished on request4 ,if a drawing is to be reduced one-half1 for example1 the sheet that has been reduced one-half will show the size of the lettering on the printed plate1 so that the draftsman1 by referring to the sheet showing the reduction he desires1 can select type of a size that will be legible4 ,plate ,v shows a part of this reduction sheet4 ,,abbreviations4 ,the following are the correct forms for abbreviations used on maps and other illustrations3 ,a4 ,arroyo4 ,b4 ,m4 ,bench mark4 ,bdy4 ,boundary4 ,br4 ,branch1 bridge4 ,c4 ,cape4 ,can4 ,canal1 canyon4 ,cem4 ,cemetery4 ,co4 ,county4 ,cr4 ,creek4 ,e4 ,east4 ,el4 ,elevation4 ,est4 ,estuary4 ,fk4 ,fork4 ,ft4 ,fort1 foot4 ,gl4 ,gulch1 glacier4 ,hrb4 ,harbor4 ,i4 ,island4 ,is4 ,islands4 ,jc4 ,junction4 ,l4 ,lake4 ,lat4 ,latitude4 ,ldg4 ,landing4 ,l4 ,s4 ,s4 ,life-saving station4 ,l4 ,h4 ,lighthouse4 ,long4 ,longitude4 ,m4 ,p4 ,milepost4 ,m4 ,m4 ,mineral monument4 ,mt4 ,mount4 ,mtn4 ,mountain4 ,mts4 ,mountains4 ,n4 ,north4 ,pen4 ,peninsula4 ,pk4 ,peak4 ,p4 ,o4 ,post office4 ,pt4 ,point4 ,r4 ,range1 river4 ,res4 ,reservation1 reservoir4 ,r4 ,h4 ,road house4 ,s4 ,south4 ,sd4 ,sound4 ,s4 ,h4 ,schoolhouse4 ,sta4 ,station4 ,str4 ,stream4 ,t4 ,township4 ,tel4 ,telegraph4 ,w4 ,west4 ,words like mount1 river1 point should not be abbreviated where they form a part of the name of a city or town1 as ,rocky ,mount1 ,fall ,river1 ,west ,point4 ,neither the word nor the abbreviation for railroad or railway should be placed on a map2 the chartered name 7or initials of the name7 and the road symbol are sufficient4 ,names of ,states and ,territories should be abbreviated1 where abbreviation is necessary1 as follows3 ,ala4 ,ga4 ,minn4 ,n4 ,j4 ,tenn4 ,ariz4 ,ill4 ,miss4 ,n4 ,mex4 ,tex4 ,ark4 ,ind4 ,mo4 ,n4 ,y4 ,va4 ,calif4 ,kans4 ,mont4 ,okla4 ,vt4 ,colo4 ,ky4 ,nebr4 ,oreg4 ,wash4 ,conn4 ,la4 ,nev4 ,pa4 ,w4 ,va ,d4 ,c4 ,mass4 ,n4 ,c4 ,r4 ,i4 ,wis4 ,del4 ,md4 ,n4 ,dak4 ,s4 ,c4 ,wyo4 ,fla4 ,mich4 ,n4 ,h4 ,s4 ,dak4 ,alaska1 ,guam1 ,hawaii1 ,idaho1 ,iowa1 ,maine1 ,ohio1 ,samoa1 and ,utah should be written in full4 ,the abbreviations used on the margins of maps for subdivisions of land should be as follows 7note punctuation73 ,t4 #b ,n41 ,e4 #c ,w4 ,on large-scale plats the marginal lettering should be as follows3 ,n4 #a_/b ,,ne4 #a_/d sec4 #a1 ,t4 #g ,n41 ,k #b ,w42 fractional secs4 #b and #ce1 ,tps4 #g and #h ,n41 ,r4 #b ,w42 ,,nw4 #a_/d sec4 #bj1 ,t1 #g ,n41 ,r4 #b ,w4 ,in spelling fractions use half and quarter1 not one-half and one-quarter4 ,the abbreviated forms of such names as ,north ,fork and ,south ,fork should be ,n4 ,fork and ,s4 ,fork1 not ,north ,fk4 and ,south ,fk4 ,additional abbreviations used on illustrations are as follows3 ,n4 for north1 ,,ne4 for northeast1 ,,nne4 for north-northeast1 etc4 ,capitalize directions affixed to street names1 as ,,nw41 ,,se4 7#ahjj ,f ,st4 ,,nw474 ,sec4 and secs4 for section and sections before a number4 ,capitalize only at the beginning of a line or sentence4 a4 m4 and p4 m4 for antemeridian and postmeridian1 as #d4cj p4 m4 ,lower-case unless in line of caps4 in names of corporations or companies4 ,on ,survey miscellaneous maps and is spelled out in railroad names4 ,b4 t4 u4 for ,british thermal units4 bbl41 bbls4 for barrel1 barrels4 bu4 for bushel or bushels4 c4 c4 for cubic centimeter4 cm4 for centimeter4 cwt4 for hundredweight4 dwt4 or pwt4 for pennyweight oz4 for ounce or ounces4 etc4 7not c47 for et cetera4 ft4 for foot or feet4 ,h4 m4 s4 for hours1 minutes1 and seconds4 7,use capital ,h47 in4 for inch or inches4 kw4 for kilowatt or kilowatts4 s4 d4 for pounds1 shillings1 and pence4 per cent 7omitting period7 for per centum4 ,spell out percentage4 ser4 for series4 ,st4 for ,saint or street ,u4 ,s4 ,army for ,united ,states ,army1 as distinguished from ,united ,states of ,america 7,u4 ,s4 ,a474 yd41 yds4 for yard1 yards4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,vi #age-,,line ,,screen #aej-,,line ,,screen #acc-,,line ,,screen #abj-,,line ,,screen #ajj-,,line ,,screen #fe-,,line ,,screen ,,half-,,tone ,,cuts ,,showing ,,effect ,,of ,,several ,,standard ,,screens ,,in ,,the ,,reproduction ,,of ,,the ,,same ,,detail4 ,the names of certain months may in some places be abbreviated2 those of others should invariably be spelled out4 ,the following are the correct forms3 ,jan4 ,apr4 ,july ,oct4 ,feb4 ,may ,aug4 ,nov4 ,mar4 ,june ,sept ,dec4 ,the abbreviations for number and numbers before figures are ,no4 and ,nos4 ,the o should never be raised1 as in ,no4 ,the abbreviation for ,mac is ,mc1 not ,mc4 ,all periods should be omitted from abbreviations used in the body of a map unless their omission would cause misunderstanding4 ,they are generally unnecessary1 and if used on some maps they are likely to be mistaken for symbols representing certain features1 such as houses or flowing wells1 if either is shown4 ,periods used on drawings that are to be reproduced direct or photomechanically should always be slightly exaggerated4 ,,names ,,of ,,railroads4 ,the names of railroads may be written in full or abbreviated1 in accordance with the kind of map and the space available4 ,on a sketch map in black and white the initial letters are generally sufficient4 ,on a more detailed map1 if there is room enough1 the names may be spelled out4 ,as already stated1 neither the words railroad and railway nor the abbreviations ,r4 ,r4 and ,ry4 should be used on a map4 ,,make-,,up ,,of ,,maps4 ,,forms ,,for ,,certain ,,features4 ,the proper forms for certain features of maps1 such as the borders1 titles1 explanations1 bar scales1 captions1 arrows indicating true north and magnetic declination1 source1 and authorship1 are shown in ,plate ,,vii4 ,note particularly the style and position of the marginal matter4 ,,border4 ,a finished map border is used or omitted according to the kind of map prepared4 ,diagrammatic maps and maps on which no parallels and meridians appear do not need finished borders4 ,on a map that shows complete areal geologic or other coloring1 such as a map in a ,survey geologic folio1 the border lines tend to destroy the simple effect of the whole map4 ,on a map that is not completely colored and on all very large maps borders are really necessary4 ,if borders are used1 however1 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 range4 ,a simple rule#h for determining the width of this space is as follows3 ,divide the sum of the dimensions of the map by #b and find the square root of the quotient1 which will represent the width of the border in sixteenths of an inch4 ,example3 ,map is #bj by #cj inches2 7#bj #cj7_/b #be2 square root of #be #e2 width of border #e_/af inch4 ,footnote #h3 ,worked out by ,martin ,solem1 of the ,u4 ,s4 ,geological ,survey4 ,the numbers showing latitude and longitude should be in shaded arabic numerals and those showing township and range in gothic4 ,the symbols for degree1 minute1 and second should not be crowded4 ,on a map that has no added border lines the numbers should be in hair-line gothic4 ,,title4 ,the title of a map should be in roman letters and if placed at the lower margin should generally be arranged in two lines1 unless it is short4 ,if it forms two or more lines the lines should be well balanced4 ,the first line should describe the position of the area2 the second line should state the purpose of the map1 as ,,map ,,of ,,butte ,,and ,,vicinity1 ,,montana ,,showing ,,location ,,of ,,mines ,,and ,,prospects4 ,a title placed inside the border of a map should be arranged in a series of lines1 generally beginning with ,map of or ,geologic map of4 and the line showing the dominant part of the title should be emphasized by larger lettering1 thus3 ,,map ,,of ,,the ,,vicinity ,,of ,,butte ,,montana ,,showing ,,location ,,of ,,mines ,,and ,,prospects4 ,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 corner1 just below the border line1 and the names of the topographers or the source of the base should be stated in the lower left corner1 just below the border line4 ,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 scale4 7,see ,,pi4 ,,vii47 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,vii ,,details ,,of ,,the ,,make-,,up ,,of ,a ,,geologic ,,map ,,explanation4 ,the symbols1 patterns1 or colors used on a map should be given in a series of rectangles or boxes1 accompanied by explanatory terms in the form shown in ,plate ,,vii1 headed ,explanation4 ,if the explanation is small a convenient place for it on some maps may be found within the neat lines4 ,if no space is available there1 or if it is so large that there is not room to place it there without obscuring other details1 it may be placed either vertically along the right margin1 as shown in ,plate ,,vii1 or horizontally under the title4 ,a geologic explanation should preferably be arranged vertically1 as in ,plate ,,vii1 so as to show the relative age of the formations by the positions of the boxes4 ,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 ink1 in order to save time in making corrections4 ,in lettering the explanation roman letters or type should be used for the titles under the boxes and italic of smaller size for the subtitles or descriptive detail1 which should be inclosed in parentheses4 ,the names of geologic periods and systems should be in gothic capitals1 the names of series or groups should be in italic lower case1 and the limit of each period1 system1 or group should be indicated by braces4 ,the general style and arrangement shown in the ,survey's geologic folios should be followed1 and this and the arrangement of other matter is shown in ,plate ,,vii4 ,care should be taken not to crowd the explanation1 and if corrections are necessary they should be so made that each line of the matter in which they appear will be properly spaced4 ,the explanation for a map that is to be engraved or to be reproduced by lithography need only be sketched in to show general style and arrangement4 ,the engraver or the lithographer will supply such matter in proper form according to specifications4 ,for direct reproduction1 however1 as by photolithography or zinc etching1 the lettering must either be carefully drawn with pen or printed from type on slips1 which are pasted on the drawing4 ,,graphic ,,scales ,,for ,,maps4 ,a bar scale for miles or feet should be given on every map1 and if the map is of international interest the metric scale should be given just beneath the scale of miles or feet4 ,the accepted designs for these scales are shown in figure #g4 ,the scale should be accompanied by any necessary statement pertaining to the base map1 such as ,contour interval #bj feet1 ,datum is mean sea level4 ,the fractional scale 7#a_/bej1jjj1 for example7 should be given on all except the more simple kinds of maps1 and the date of publication should also appear just below the scale or scales4 ,the single-line bar scale should be used only on small or simple maps4 ,the length of the bar scale must depend on the size of the map and the space available4 ,those shown in figure #g were made over blue prints from scales used by the ,survey4 ,to make a bar scale for a map of unknown scale that shows only a single meridian and parallel1 or for a map on which no meridians or parallels are shown1 first ascertain the distance between two points shown on the map by reference to other authentic maps4 ,if1 for example1 the distance between two such points is #af4cae miles draw a horizontal line 7a in fig4 #h7 representing this distance on the map1 and at its end1 at right angles to it1 draw another line 7b7 actually measuring #af4cae units of any convenient denomination4 ,draw a straight line 7c7 diagonally between the ends of lines a and b4 ,then set off on line b any convenient number of the units selected1 say #e or #aj1 and project from the points set off lines exactly parallel with line c to line a4 ,the distance and the number of the units thus marked on line a will indicate the number of miles covered by that distance on the map1 as shown in figure #h4 ,illustration3 ,figure #g4--;,designs for bar scales4 ,illustration3 ,figure #h4--,method of making a bar scale for a map of unknown scale4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,viii ,,patterns ,,used ,,to ,,show ,,distinctions ,,between ,,areas ,,on ,,black ,,and ,,white ,,maps ,contrasts may be increased by varying the direction and spacing of ,lines ,,symbols4 ,symbols should be drawn with as much care as letters1 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 difficulty4 ,the size of a symbol must depend on its importance on the map bearing it4 ,on a map that shows numerous mines1 for instance1 the crossed hammers or the symbols for shafts should be not only visible but conspicuous4 ,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 reduction4 ,the symbols shown in ,plate ,,ii 7p4 #bj7 should be used in all the ,survey's illustrations where they are appropriate4 ,,areal ,,patterns ,,for ,,black ,,and ,,white ,,maps4 ,the conventional patterns used on a map to distinguish separate areas1 chiefly geologic1 are shown in ,plate ,,viii4 ,the patterns shown represent the proper combinations of lines1 dots1 and other forms and should be spaced openly or closely according to the size of the area covered1 the contrast needed between areas1 and the general clearness and effect desired4 ,if a map is to show both small and large areas dense or closely spaced patterns should generally be used for the smaller areas1 even if they may be required for some fairly large areas representing the same formation or condition4 ,on the other hand1 open patterns should be used for large areas4 ,again1 it may be necessary to make certain areas more conspicuous than others1 and this effect can be best produced by drawing the lines closer together rather than by making them heavier1 unless the area covered is small or unless a closely spaced similar pattern has been or will be used elsewhere on the map4 ,heavy-line patterns or bars are not desirable4 ,the lines forming a pattern should generally be drawn at an angle of #de to the sides of the map2 they should be drawn vertically or horizontally only in small areas or in areas not crossed by meridians or parallels or by other lines running in the same direction4 ,the lines should preferably run across the long axis of an area1 not parallel to it1 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 map1 even if the rule must be violated on some of the minor areas4 ,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 drawn4 ,in black and white maps1 as in colored maps1 unlike patterns should be placed next to each other4 ,if they are so placed it may not be necessary to rule the lines on two adjacent areas in opposite directions to produce needed distinctions4 ,a section liner or other ruling device should be used in drawing line patterns in order to produce uniformly even spacing4 ,the application of six of these conventional patterns to a base map is shown in figure #i4 ,illustration3 ,figure #i4--,map bearing six areal line patterns4 ,,standard ,,colors ,,for ,,geologic ,,maps4 ,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 reports4 ,each system is represented by a different color1 and if there are two or more formations in one system they are generally distinguished by using different patterns composed of straight parallel lines in the same color4 ,the patterns for subaerial deposits 7chiefly ,quaternary7 are composed of dots or circles1 or combinations of both1 and may be printed in any color1 but the color most often used is yellow or ochraceous orange4 ,no specific colors are prescribed for igneous rocks1 but if only a few areas are shown red or pink is preferred4 ,the colors used for igneous rocks are generally more brilliant and purer than those used for sedimentary rocks4 ,for small areas they are used solid2 for large areas they are reduced in tone by the use of a suitable cross-line pattern or reticle4 ,metamorphic rocks are represented by short dashes irregularly placed4 ,these dashes may be in black or in color over a ground tint or over an uncolored area1 or they may be in white on a ground tint or pattern4 ,the standard colors used for the sedimentary series covering the #ab systems recognized by the ,geological ,survey are3 ,quaternary 7,q71 ochraceous orange2 ,tertiary 7,t71 yellow ocher and isabella color2 ,cretaceous 7,k71 olive-green or rainette-green2 ,jurassic 7,j71 blue-green or niagara-green2 ,triassic 7,,tr71 light peacock-blue or bluish gray-green2 ,carboniferous 7,c71 blue or columibia-blue2 ,devonian 7,d71 gray-purple or heliotrope-gray2 ,silurian 7,s71 purple or argyle-purple2 ,ordovician 7#j71 red-purple or rocellin-purple2 ,cambrian 7-,c71 brick-red or etruscan red2 ,algonkian 7,a71 terra cotta or onion-skin pink2 ,archean 7,,ar71 gray-brown or drab4#i ,footnote #i3 ,names printed in italic are from ,color standards and nomenclature1 by ,robert ,ridgway4 ,,reduction ,,of ,,enlargement ,,of ,,maps4 ,the following is the simplest and most accurate method of marking the reduction or enlargement of a map to a selected scale3 ,measure the distance between the extreme meridians along one of the parallels4 7,see fig4 #aj47 ,convert this distance into miles by multiplying the number of degrees it covers 7say #c7 by the number of miles in a degree4 ,a degree on the forty-third parallel1 for example1 is #ej4ffi miles1#aj which multiplied by #c equals #aeb4jjg miles4 ,then draw a line on the margin of the map1 outside the border1 the exact length of the #c degrees1 and just below this line draw another line representing the same number of miles 7#aeb4jjg7 on the scale to which the map is to be reduced or enlarged4 ,then mark to reduce or enlarge the upper line to the lower line1 as shown in figure #aj4 ,a long line will reduce error and give greater accuracy than a short one1 and therefore as great a distance should be set off as possible4 ,the number of miles represented by both lines and the fractional scale to which it is to be reduced should be stated on the drawing1 for permanent record4 ,footnote #aj3 ,see ,u4 ,s4 ,geol4 ,survey ,bull4 #fej1 p4 #cg4 #aiaf4 ,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 appear1 regardless of definite scale4 ,the reduction for such maps is best marked in fractions1 as #a_/b off1 #a_/c off1 #b_/c off4 ,if the size needed is not exactly represented by these fractions it should be indicated in inches1 as ,reduce this line to #g-a_/b inches1 or ,reduce to #d-c_/h inches in width4 ,illustration3 ,figure #aj4--;,diagram showing method of marking maps for reduction or enlargement 7for record74 ,,diagrams4 ,in preparing a diagram a draftsman should endeavor to make its parts and relations perfectly clear to the reader4 ,he should study the drawing or material furnished by the author until he fully understands it and should endeavor to reproduce it simply and legibly4 ,any lettering that may be needed should generally be in plain upright or slanting gothic type 7see ,pl4 ,,ix71 or it may be in roman4 ,a diagram should generally be drawn on bristol board or on blue-lined section paper and should be marked for reduction to the minimum size4 ,it should bear no title1 as the title will be set up in type by the printer4 ,,sections4 ,the sections used in geologic reports are of two widely different kinds4 ,one shows only the broader relations of parts2 the other shows details of structure as well as relations4 ,one is diagrammatic2 the other is more realistic and graphic4 ,the draftsman should prepare all sections strictly according to the copy supplied by the author but should use proper symbols and make a more finished drawing4 ,the various kinds of sections1 most of them geologic1 are described on pages #bi-cj1 and the conventions used to express lithologic character are shown in ,plate ,,iii4 ,illustration3 ,u4 ,s4 ,,geological ,,survey ,,preparation ,,of ,,illustrations ,,plate ,,viii ,,diagrams ,,and ,,curves4 ,detailed drawings of this kind1 though entirely conventional1 can be so prepared as to give a satisfactory expression of nature4 ,the draftsman should study well-prepared sections in ,geological ,survey reports and should learn the details of folding and faulting from textbooks4 ,he should first ascertain whether or not the vertical scale in the original section has been unduly exaggerated1 and if so he should confer with the author with a view to reducing the exaggeration as much as possible4 ,he should submit to the author all questions as to doubtful points1 as well as all suggestions for improvement in expression1 before he makes any changes1 and he should make corrections only on the author's approval4 ,a seeming inaccuracy in an author's drawing may be a faithful representation of natural conditions4 ,for example1 a formation that seems to be omitted by inadvertence in drawing may really pinch out at a point represented in the section4 7,see a on fig4 #aa47 ,illustration3 ,figure #aa4--,structure section showing method of determining the secession of folds4 ,penciled lines corresponding to those shown by dots in figure #aa should be carefully added in redrawing a roughly sketched section that shows complex folding4 ,an original indefinite sketch that shows complicated structure affords opportunities for error in preparing the new drawing1 and omissions may be detected by following the formations as they would be continued above and below the section1 as shown by the dotted lines in the figure4 ,,plans ,,and ,,cross ,,sections ,,of ,,mines4 ,plans of mines1 like diagrams1 should not be elaborate1 and their lettering should be plain and legible1 yet it should not be so conspicuous as to obscure other details4 ,gothic letters should generally be used1 but some plans require different styles of lettering1 especially for geographic or other names that should be coordinate with those on maps or other illustrations in the book4 ,unless there are good reasons1 however1 for varying the styles of lettering1 plain gothic capitals1 or capitals and lower-case letters1 either upright or slanting1 should be used4 ,abbreviations for the numbers of levels should generally be given thus3 #c;d level1 #fth level1 #bjj-;foot level1 etc41 or the shorter terms may be spelled out1 as third level1 sixth level4 ,the same general scheme of lettering should be used on all plans and cross sections that are to appear in one publication or in one series of similar papers4 ,the reduction of such drawings to the minimum scale consistent with clearness is always advisable4 ,,drawings ,,of ,,specimens ,,of ,,rocks ,,and ,,fossils4 ,,methods ,,used4 ,drawings of specimens or other objects were once made with brush and pencil or with pen and ink1 by means of measurements taken with dividers or by viewing the specimen through a camera lucida4 ,each of these methods is still used1 but by using the camera lucida in sketching3 the outlines and details more accurate proportions and relations can be produced1 whether the object is to be enlarged or reduced1 than by any other means except photography4 ,,brush ,,and ,,pencil ,,drawings4 ,in all drawings or photographs of specimens1 except photomicrographs of thin sections1 the light should appear to come from the upper left quarter4 ,a disregard of the well-established rule that the direction of illumination should be uniform throughout a series of drawings would cause confusion or uncertainty in the interpretation of the relief shown in them4 ,reynolds's three-ply and four-ply bristol board affords a satisfactory surface for brush and pencil drawings4 ,its surface is smooth and hard and1 being free from coating of any kind1 permits satisfactory erasures without great injury2 its color is pure whits2 and it is durable4 ,boss's relief hand-stipple paper is also well adapted to many kinds of brush drawings as well as to its primary use for producing stippled effects4 ,very delicate gradations of color or light and shade can be produced on its surface with brush and lampblack or with india ink1 and high lights can be made by scraping off the chalky surface4 ,the draftsman who is preparing brush and pencil drawings should have first of all a knowledge of the principles of light and shade1 of reflected light1 and 7for drawing specimens7 of shadow perspective4 ,he should also have delicacy of touch and ability to see and interpret form and to reproduce the soft blending of light and shade shown in a good photograph4 ,he should be provided with pencils equal in quality to the ,koh-i-noor ,b1 ,f1 #d;,h1 and #f;,h2 the best quality of red sable brushes of the sizes of ,winsor ,newton's ,nos4 #c1 #d1 and #f2 the best quality of stick india ink2 a cake or pan of lampblack2 and a porcelain saucer or slab4 ,in drawings of fossils and of some other specimens a combination of pencil and brush work produces satisfactory results and tends to increase speed4 ,the gloss produced by penciling1 however1 is objectionable and should be obviated by a preponderance of brush work4 ,stick ,india ink is the best pigment to use in delicate wash drawings1 and lampblack is preferable for large work on which the softer tones of the shading are not so important and for drawings that are to be considerably reduced when engraved4 ,gouache 7an opaque mixture of ,chinese white and lampblack7 may also be used1 but it is best suited for large work4 ,in making corrections on brush drawings the parts to be corrected should be carefully washed out with a small short-cropped brush and water and still further cleaned by using a rubber eraser over an erasing shield or an opening cut in a piece of celluloid4 ,erasures should not be made on delicate work with a knife or a sand rubber1 as either will injure the surface and affect reproduction4 ,in measuring a specimen with dividers the draftsman should be careful not to injure the specimen or to puncture the paper on which he is preparing the drawing4 ,,pen ,,drawings4 ,a draftsman who is preparing drawings of specimens with pen and ink should have a good assortment of pens equal to ,gillott's ,nos4 #bia1 #bij1 and #agj1 liquid waterproof ink equal to that manufactured by ,higgins1 good pencils1 hard and soft rubber erasures1 plain dividers1 and ,reynolds's bristol board4 ,a glass eraser is also useful4 ,good pen drawings of specimens are much more difficult to make than brush drawings4 ,they can be prepared only by a draftsman who has had some artistic training and experience in pen work4 ,few draftsmen can prepare pen drawings that faithfully represent both the detail and the texture of specimens2 the shading on many such drawings confuses and destroys both detail and texture4 ,the pencil sketch over which a pen drawing of a specimen should be made must be prepared in much the same manner as the sketch for a brush drawing1 though the outlines need not be so delicate4 ,this sketch is generally made on bristol board4 ,the pen work should begin with the outlines and should then be carried to the details1 and finally to the shading1 whether in lines or stipple4 ,the texture of a specimen is the best key to the proper shading4 ,if the specimen is decidedly granular1 stippling is appropriate2 if it is smooth or polished1 finely drawn parallel lines1 varied in spacing and character according to depth of shade and texture1 are preferable4 ,erasures can be made with a hard-rubber eraser1 other parts being protected by a shield1 or with a very sharp knife or a glass eraser1 and the parts erased can be resurfaced with an agate burnisher4 ,,retouching ,,photographs ,,of ,,specimens4 ,photographs of specimens1 particularly fossils that have been coated to destroy local color1 should be printed on velox paper1 in a tone somewhat lighter than that of ordinary photographs4 ,the details and relief should1 however1 be strong enough to enable the draftsman to see them clearly1 so that by retouching them and strengthening the shadows and high lights he can make them sufficiently strong for reproduction4 ,this he can do by a combination of pencil and brush work1 the pencil being used sparingly because the gloss produced by the graphite is likely to affect reproduction4 ,a ,no4 #c ,winsor ,newton's red sable brush and lampblack are preferable for the greater part of this work1 and a #d;,h and a #f;,h pencil for the fine details and as a possible aid in producing the finer gradations of shading4 ,the details should be retouched or strengthened under a reading glass to insure accuracy2 the broader effects can be best produced without the aid of a magnifier4 ,erasures on photographs of specimens should be made very carefully with a hard rubber that is free from sand1 and the parts not to be disturbed should be protected with a shield4 ,high lights may be added by carefully scraping or rubbing the surface of the paper4 ,,landscape ,,drawings ,,from ,,poor ,,photographs4 ,a poor photograph or one that has become injured and can not be retouched for direct reproduction can be utilized by making from it1 as described below1 a pen drawing or a brush or crayon drawing1 which will be almost photographically correct4 ,,pen ,,drawings ,,made ,,over ,,photographs4 ,a pen and ink drawing may be made over a blue print or a bromide print 7preferably a blue print7 and the photographic image then bleached out4 ,the blue print should be larger than publication size and should not be so dark that the draftsman can not see his lines4 ,if the negative is available a bromide enlargement can be obtained2 otherwise the picture should be rephotographed in larger size1 preferably twice publication size4 ,the enlargement will give the draftsman greater freedom in drawing details and will make his work appear finer and better in the reduced illustration4 ,if the photographic print is of a subject requiring the use of instruments it should be securely fastened to a drawing board1 square with the board1 so that any horizontal and vertical lines in it may be ruled by the use of a ,t square and triangle4 ,for specimen or landscape work it need not be fastened4 ,for bleaching blue prints a saturated solution of oxalate of potassium 7,k#b;,c#b,o#d ,h#b,o7 has been used with good results4 ,for bleaching bromide prints cyanide of potassium 7,,kcn7 to which a few drops or flakes of iodine have been added should be used4 ,neither kind of print should be bleached until the drawing has been completely finished in every detail1 because bleaching loosens the fibers of the paper1 so that the ink of any added lines is likely to spread4 ,the print should be placed in a hard-rubber pan1 the bleaching solution poured on it1 and the pan rocked until the image disappears4 ,the print should then be carefully removed1 thoroughly washed in running water1 placed between clean white blotters to dry1 and finally mounted on cardboard4 ,for temporary1 hurried work on drawings that are not to be retained for future use the blue print may be mounted first and bleached by pouring the bleaching fluid over the mounted print4 ,,brush ,,drawings ,,from ,,poor ,,photographs4 ,brush drawings may be made directly from photographs by working over an enlarged print with gouache1 or by making a pencil tracing and sketch of the photograph and working it up with lampblack or india ink4 ,the photograph should be larger than publication size to permit greater freedom and breadth in drawing details4 ,the larger size will also afford a more refined and better engraving when reduced4 ,if lampblack or india ink is used and the subject is small1 bristol board is recommended1 but if the photograph is larger than1 say1 #h by #aj inches1 ,whatman's hot-pressed double elephant or similar paper1 laid down with thumb tacks1 will prove satisfactory4 ,if gouache is used over a print a preliminary drawing is of course unnecessary1 but the photograph should be an unglazed print of a size that will require considerable reduction1 and the finished drawing should be protected by an oversheet4 ,if lampblack or india ink and not gouache is used the photograph should be traced and a fairly complete pencil sketch should be made before the brush is used4 ,plates ,i1 ,,iv1 ,a1 ,v1 ,b1 and ,,vii1 ,b1 ,monograph #cd1 were made from gouache drawings4 ,plates ,,iii1 ,a1 ,,vii1 ,a1 ,x1 ,,xi1 ,,xii1 ,,xiii1 ,,xx1 ,,xxviii1 and ,,xxx1 in the same publication1 were made from lampblack or india-ink wash drawings4 ,the originals can be examined at any time4 ,,outdoor ,,sketches4 ,the art of sketching from nature is one in which few but professional artists excel4 ,not many geologists are able to make sketches from nature that are suitable for direct reproduction4 ,an artistic draftsman should be able to redraw the geologist's sketches1 however1 in their true perspective and relations1 with the skill necessary to make them satisfactory illustrations4 ,in most crude outdoor sketches the important features are usually shown with sufficient clearness to follow4 ,if they are not the draftsman should ascertain what those features are and prepare the new drawing in such a way as to display them properly4 ,the new drawing should be made with pen and ink1 generally for reduction to a text figure1 which is the most appropriate form for such an illustration4 ,in all sketches of this kind the lines should be drawn in such a way as to produce natural effects and at the same time to make good printing plates4 ,good examples of pen and ink sketches of this class can be found in ,monograph #cd1 already referred to1 and in the ,seventh ,annual ,report1 especially ,plates ,,xxviii and ,,xxxviii2 ,ninth ,annual ,report1 ,plates ,,xliii and ,,xliv2 ,tenth ,annual ,report1 ,plates ,,xiv and ,,xix and figure #eh2 ,eleventh ,annual ,report1 ,plates ,,xv1 ,,xxvii1 ,,xxxv1 ,,lii1 and ,,liv and figures #ah1 #cj1 #ca1 #fg1 #ih1 and #ii4 ,,drawings ,,of ,,crystals4 ,a crystal should generally be drawn in outline with straight lines4 ,the invisible rear side of a crystal1 if shown1 should be represented by dashed lines4 ,the outer boundary line of a crystal should be slightly heavier than the inside lines1 which should all be of the same weight4 ,striations should be shown by straight lines2 broken or uneven surfaces by irregular lines4 ,a twinning line1 if an intersection edge1 should be solid2 if not an intersection edge it should be broken into dashes4 ,italic1 ,greek1 ,german1 and ,old ,english letters are used to mark crystal faces4 ,all faces of a given form should be marked by the same letter but may be differentiated1 if necessary1 by primes or numerals1 thus3 m1 m'1 m''1 m'''1 m'v4 ,leaders should be short full lines1 or1 if these are likely to be confusing1 they should be dashes4 ,numbers may be used in place of letters for specific purposes4 ,letters indicating twin faces are underscored2 a second twin is doubly underscored or overscored1 thus3 m1 m1 m4 ,twin units may be differentiated by the use of roman numerals4 ,,retouching ,,photographs4 ,an author1 of course1 selects his photographs to illustrate some special features2 he does not always consider their fitness for reproduction4 ,photographs that are blurred or out of focus1 those in which the shadows are too black or lack transparency1 and those which have local defects1 such as bad skies or spots1 must be worked over to make them suitable for reproduction4 ,in order to remedy these defects and produce natural results the draftsman doing work of this sort should be able to see and interpret nature properly and to supply natural effects in a manner corresponding with those produced photographically4 ,he should be sufficiently expert with the brush and pencil and in handling an air brush to duplicate the delicate and soft tones in the photograph1 and he should know how the pigments he uses will take when the subject is reproduced4 ,the retoucher should have access to an air brush and should provide himself with a jar of photo white or blanc d'argent and a color box containing indian red1 crimson lake1 yellow ocher1 lampblack1 and ultramarine--colors with which he can duplicate those shown in any photograph4 ,he should also have the best grade of red sable brushes1 ranging in size from ,no4 #c to ,no4 #h1 a stack of porcelain saucers1 and a jar of oxgall4 ,by mixing the colors to match exactly the shades of a photograph and using a red sable brush he can strengthen details1 spot out flaws1 and remove imperfections1 except those in skies or other large1 flat areas1 for which he must use an air brush4 ,the air brush has become a necessary adjunct to a retoucher's outfit4 ,smooth1 even gradations of flat tones can not be successfully applied to photographs without it1 and it is therefore indispensable1 especially for retouching skies and covering other large areas4 ,before retouching a photograph the draftsman should mix in a saucer a tint that will match the color of the part that is to be retouched and should try this tint and note its effect after it has dried and change it1 if necessary1 until it matches the color exactly4 ,if he is to retouch a number of photographs that have the same local color he may with advantage make up enough of the tint for the entire lot1 thoroughly mixing it and seeing that it is not too thin4 ,in making this tint he should use only pigments of the best grade1 and if he finds that the ,chinese or other white he is using does not photograph well1 or that it does not hold its color1 he should discard it at once and use another brand4 ,photographs that are to be retouched should be large enough to permit sufficient reduction to soften the effects of retouching4 ,in order to eliminate the lines of junction between two or more photographs that are joined together to form a panorama some adjustment or fitting of details by retouching is generally required before the group is rephotographed to obtain a new print of the whole on one piece of paper4 ,as it is often desirable to increase the width of such an illustration the photographer should be instructed to print the photograph on a strip of paper that is wider than the negative1 so that1 if necessary1 the retouching may be carried above or below the new print to add depth to the illustration4 ,panoramas may also be drawn from photographs with either pen or brush in the manner described on pages #fh-fi4 ,,part ,,iii4 ,,processes ,,of ,,reproducing ,,illustrations4 ,,methods ,,employed4 ,the preliminary work in producing illustrations includes the preparation1 from originals submitted by authors1 of drawings and other kinds of copy in such a way that the copy can be reproduced in multiple by printing4 ,several processes are used for preparing plates for printing illustrations1 and each has its peculiar features of excellence4 ,one process may render fine details with facility but may fail in uniformity in large editions2 another may be cheap and effective on the whole but may not reproduce fine details2 and still another may give fine color or tone effects but may be too expensive4 ,therefore a knowledge of the varied uses and results and of the cost of the several processes of reproduction and1 on the other hand1 of the kinds of originals that are best suited for reproduction by any one of the processes is essential to effectiveness and economy in planning1 preparing1 and reproducing an illustration4 ,the following condensed descriptions of processes are intended mainly to aid in determining the kind of copy that is appropriate for each process and the kind and quality of reproduction to be expected1 so that only the principal operations or stages in each process are described4 ,wood engraving1 which was used in making printing plates for many of the illustrations in the early publications of the ,geological ,survey1 is described here only to compare that laborious and indirect method of engraving cuts with the more modern kinds of relief engraving4 ,in #ahib it gave way to photo-engraving4 ,,photo-,,engraving4 ,,general ,,features ,the term photo-engraving is applied to processes by which a black and white line drawing1 photograph1 or like original is reproduced in relief on a metal plate from which prints may be made on an ordinary printing press1 in distinction from processes that print from flat or relatively flat surfaces1 such as the lithographic and photogelatin processes4 ,the photo-engraving processes that are most generally used are those called zinc etching and half-tone engraving4 ,these processes depend on the discovery that gelatin or similar organic material1 if treated with potassium or ammonium bichromate and exposed to the action of light1 is made insoluble in water4 ,if a metal plate coated with bichromatized gelatin or albumen is exposed to light under a negative the parts acted upon by light become insoluble and those not acted upon remain unchanged and may be washed away so as to expose the metal1 which is then etched with acid in order to give relief to the unexposed parts and make of them a printing surface4 ,,zinc ,,etching4 ,zinc etching is adapted to the direct reproduction of a pen and ink drawing composed of lines1 dots1 or solid black areas4 ,on the finished metal plate these lines1 dots1 and solid areas form the printing surface1 and the spaces between them1 which have been etched away1 represent the white or blank parts of the picture4 ,the process is cheap and is almost universally used for reproducing small drawings designed for text illustrations4 ,it is also well adapted to the reproduction of maps and diagrams measuring in print not more than about #aj by #ad inches4 ,one of the chief advantages of this and of all other direct 7photographic7 processes of engraving is that they reproduce a drawing in facsimile1 whereas the personal equation must enter into all engravings made by an indirect method--that is1 by hand--such as wood engraving1 wax engraving1 and engraving on stone or copper1 which make it necessary to compare every detail of the proof with every detail of the drawing before the engraving can be approved4 ,the pen drawing to be reproduced1 which should preferably be considerably larger than the completed engraving1 is first photographed to the proper size or scale on an ordinary negative film4 ,the film is then stripped from the negative and reversed in order that the etched plate may print the design as in the original and that the film may be grouped with other films on one large glass and all printed at the same time4 ,the negative 7whether a single film or several7 is then placed in a specially constructed printing frame in contact under pressure with a sensitized zinc plate and exposed to light4 ,after the zinc plate has been removed from the printing frame 7in the dark room7 the plate is rolled with printer's transfer ink1 which resists acid1 and placed in a shallow tray containing water1 in which it is rocked for several minutes1 and then taken out and rubbed gently with cotton4 ,the parts of the coating of the plate that were acted on by light have become insoluble and will therefore be unaffected by the water1 but the parts of the coating not acted on by light and therefore not hardened will be removed by the washing1 which will expose the metal and leave the parts acted on by light--the picture--in black lines1 dots1 etc4 ,the plate is then dusted with topping powder1 a resinous substance which adheres only to the parts carrying the ink4 ,the plate is then heated so that the resin and the ink that remain fuse together and form1 when cooled1 a resistant surface which will not be affected by the acid to be used later in etching the unprotected parts of the plate4 ,the plate is now ready for a preliminary etching in a fluid consisting of water and a few drops of nitric acid4 ,it is placed in a tray1 rocked gently for a short time1 and then removed1 washed well in running water1 drained1 and dried with gentle heat4 ,dragon's blood1 a resinous powder that resists the action of acid1 is next applied to the plate1 in order to protect the sides of the lines and the dots from the acid1 and the plate is then heated just sufficiently to melt the powder and units it with the ink4 ,a small quantity of nitric acid is now added to the etching bath1 and the plate is subjected to its first thorough biting or etching4 ,it is then removed from the bath1 washed under a tap1 carefully wiped with a damp rag1 and dried with gentle heat4 ,the plate is thus treated three or more times until it is etched deep enough to insure satisfactory printing1 and it is then ready for finishing1 which consists of deepening the larger open spaces between the lines with a routing machine and of cutting away with hand gravers lines that are improperly connected or that are so close together that they will not print separately4 ,the routing machine is provided with a cutting tool mounted on a revolving spindle that projects downward into the engraved plate1 which is securely fastened4 ,the movement of the arm that holds the cutter is universal and can be controlled with great precision4 ,the plate is then proved that is1 a proof is taken from it on paper and if the proof is satisfactory the plate is nailed to a block of wood on which it will be type high 7#j4iah inch71 for printing4 ,most drawings for zinc etching are made with a pen in black ink and consist of lines1 dots1 or masses of black1 but drawings may also be prepared by using some medium that will produce a fine stipple1 such as a black crayon on rough paper or ,ross's stipple paper4 7,see p4 #bd47 ,the drawing should be one and one-half to two or three times as large as the printed illustration1 for it is impossible to obtain a satisfactory reproduction of a pen and ink drawing without some reduction4 ,if the drawing has not been reduced the lines appear heavier in the reproduction than in the drawing1 and imperfections thus become more noticeable2 if it has been properly reduced1 imperfections are diminished and the lines and dots become thinner and finer than those in the drawing4 ,in making a drawing that is to be reduced the draftsman can also space his lines farther apart and work out his details more easily4 ,an author should carefully examine and approve the finished drawings1 which can1 of course1 be greatly altered1 if necessary1 before they are engraved2 but similar corrections can not be made on proof sheets of zinc cuts1 which should not be marked for alterations except by eliminating parts4 ,minor changes can be made in such a cut by an expert finisher1 but if the cut is small it is generally cheaper to correct the drawing and have a new cut made4 ,zinc etchings cost about #aj to #be cents a square inch1 the cost being varied according to a standard scale which is based upon the ascertained cost of reproduction4 ,the minimum charge for a single cut is #b4 ,,copper ,,etching ,,in ,,relief4 ,copper etching1 which produces a line cut in relief1 requires the same kind of copy that is most often marked for zinc etching and is used to obtain deeper etching and a more permanent cut4 ,it is said to produce better printing plates than those etched on zinc and is used largely for reproducing script lettering and other fine work4 ,as copper plates will hold up longer in printing than zinc1 a cut etched on copper may not need to be electrotyped4 ,the chemical part of the process is practically the same as that employed for etching half-tone plates1 described under the next heading4 ,the cost of etching on copper is considerably greater than the cost of etching on zinc4 ,this process is not often used in reproducing illustrations for publications of the ,geological ,survey4 ,,half-,,tone ,,engraving4 ,the half-tone process is1 in name at least1 familiar to almost everyone who has had any connection with the making of books1 whether as author1 editor1 illustrator1 or printer4 ,the invention of a photomechanical process of reproducing a line drawing to make a metal plate that could be printed along with type on an ordinary printing press naturally led to attempts to reproduce similarly a photograph4 ,it was known that the intermediate shades between white and black in a photograph--the half tones--can be reproduced on an ordinary printing press only by breaking them up into dots or lines that will form a good printing surface and that by their variation in size or density will give for each shade the effect of a uniform tone4 ,in the half-tone process this effect is produced by photographing the picture or object through a screen4 ,the half-tone screen consists of two plates of glass1 on each of which lines running generally at an angle of #de to the sides of the plate have been engraved1 cemented together so that the lines cross at right angles4 ,the lines1 which are minute grooves filled with an opaque black pigment1 thus appear as a series of black crossed lines on a white ground4 ,the screen is placed in the camera in front of the negative4 ,screens are made that show from #fj lines to an inch for the coarser newspaper illustrations to #bej lines or more to the inch for fine book work4 ,the screens used for magazine illustrations generally show #abj to #aej lines4 ,those used for ,survey publications show #aej to #age lines1 and for reproducing delicate drawings and photographs of fossils screens bearing #bjj lines to the inch are sometimes specified2 but these finer screens require the use of highly super-coated papers1 some of them made of cheap fiber and not known to be permanent4 ,for a half tone that is to be printed in the text a #ajj-line or a #abj-line screen is specified4 7,see ,pl4 ,,vi1 p4 #ef47 ,the method of etching a half-tone plate does not differ greatly from that used in zinc etching1 and there are several kinds of half-tone plates1 though most of them are etched on copper1 not on zinc1 those etched on zinc being used principally for newspaper illustrations4 ,the half-tone screen is used also in other processes to obtain a negative4 ,when a half-tone negative hag been made the film is stripped from the glass plate and reversed1 as in the zinc-etching process1 though some half-tone engravers use a mirror box or prism by which the picture is so disposed on the negative that it does not need stripping and reversing4 ,a perfectly flat1 clean1 and highly polished copper plate1 generally large enough to accommodate several such films1 is then coated with a sensitive film according to one of several formulas1 all based on the fact that gelatin or some similar body1 if sensitized with certain chromic salts1 becomes hardened and insoluble in water on exposure to light4 ,this plate is then placed in the printing frame in contact1 under pressure1 with the glass negative plate and is exposed to light in the usual manner4 ,the copper plate is then removed from the frame in the dark room and made ready for etching4 ,for etching half-tone plates on copper a saturated solution of perchloride of iron is used instead of the solution of nitric acid used for zinc etching4 ,the time of etching ranges from about #e to #ae minutes1 according to the strength of the solution4 ,one etching is generally sufficient1 but it may be necessary to give the plate another biting if it has not been etched deep enough1 or to re-etch it in order to strengthen contrasts4 ,if1 for instance1 the sky in a half-tone plate shows too dark or is uneven in tint it can be made lighter or more even by re-etching4 ,on the other hand1 if certain features on a plate are too light they can be darkened by burnishing--rubbing the surface with a highly polished steel burnisher under just sufficient pressure to flatten slightly the fine points that form the printing surface of the plate4 ,when the plate leaves the hands of the etcher it is turned over to the finisher1 who with a graver removes spots or any other imperfections that may appear on it4 ,sometimes a roulette is used to lighten parts1 and other tools are used for special purposes4 ,after a plate that shows two or more pictures has been etched and finished it is divided by sawing them apart4 ,each one is then put into a beveling machine1 where its edges are trimmed and the usual border is made1 if it is desired4 ,the separate plates are then ready to be proved and mounted on blocks of wood which make them type high1 ready for printing4 ,the half-tone process is used almost exclusively for reproducing photographs and wash drawings1 though it will produce a facsimile of any kind of copy1 such as impressions from type1 old manuscripts1 or typewriting1 but a shade composed of minute black dots will appear over the entire print and there will be no absolutely whits areas unless they are produced by routing the plate or cutting out the high lights4 7,see p4 #gd47 ,the reproduction of an ordinary outdoor photograph requires very little handwork1 except for re-etching1 burnishing1 and cutting the borders4 ,in the reproduction of copy that is made up of separate parts1 such as groups of photographs of specimens that are to appear on a white ground1 the half-tone tint--or more properly shade--between and around the several figures must be removed and numbers must be added4 ,this operation requires two negatives--one half tone and one line--and produces what is called a combination plate4 ,therefore the difference in the cost of making a half-tone cut from a single photograph of a landscape and from a cut made from copy of the same size consisting of a number of small photographs or drawings1 to which numbers or letters are added1 is considerable 7about #ej per cent greater7 and depends upon the amount of additional work involved4 ,routing1 when needed1 must be done with extreme care lest the edges of a figure be marred1 and this work requires skill that can be gained only by experience4 ,copy for the half-tone process should be as nearly perfect as possible4 ,only the best photographs should be selected4 ,prints on semimat velox and glossy haloid papers are regarded as the best photographic copy for reproduction4 ,every part of the photograph or drawing should be absolutely clean4 ,if any part that should be pure white becomes soiled or stained the defects will be reproduced4 ,if a photograph needs retouching it should be retouched with great care and just sufficiently to correct defects and to bring out or strengthen the important details4 ,in many photographs the skies may be muddy or uneven in tone1 and this defect can be corrected by the use of an air brush1 the only medium that will produce an almost even tone4 ,as already stated1 half-tone plates can be improved by re-etching and tooling1 but tooling tends to destroy the effects of nature and produces an artificial appearance in the print4 ,one who is preparing wash drawings for reproduction by the half-tone process should remember that brush marks and other inequalities of tone will be reproduced with as much fidelity as other details4 ,such drawings should therefore be made two or three times larger than the engraved cut in order to subdue all unnatural effects and to soften the general tones4 ,line drawings are not generally suitable copy for the half-tone process1 but it is occasionally desirable to use that process instead of zinc etching for reproducing a line drawing that has been inexpertly prepared if the cost of redrawing would more than offset the difference in cost between zinc etching and the more expensive half-tone process4 ,in reproducing a pen drawing by half tone the lines become softened and represent the details and shading only2 but the pen drawing may be further developed by brush work4 ,examples of this type of reproduction are ,plates ,v1 ,a1 ,,vi1 ,a1 and ,,xv1 figure #aj1 and other illustrations in ,survey ,monograph #cd4 ,vignetting1 which consists of a skillful grading off of the edges of a picture1 as well as extensive tooling or hand engraving1 is often employed for artistic effect but should be specified only for exceptional illustrations4 ,the plates made for the ,survey are either square trimmed or the ground tint is entirely omitted or routed away2 they are not usually tooled or vignetted4 ,half-tone cuts etched on copper cost #bj to #fj cents a square inch1 the cost being varied according to a standard scale based on the ascertained cost of reproduction4 ,those that require a screen finer than #aej lines cost #be per cent additional4 ,the minimum charge for a single cut is #c4 ,half tones etched on zinc 7#ajj-line screen or coarser7 cost #be per cent less than those etched on copper4 ,,three-,,color ,,half-,,tone ,,process4 ,the three-color process is practically an adaptation of the half-tone process to color printing based on the theory that all colors or hues in nature can be reproduced by combinations of three colors of the spectrum--red1 blue1 and yellow4 ,the process differs from the ordinary half-tone process particularly in the use of color filters in making the negatives and in the character of screens and diaphragms used4 ,this process1 like all others1 is worked somewhat differently in different establishments4 ,in what is called the indirect method1 the one most commonly used1 twelve photographic operations are necessary to produce one illustration1 or the three plates or cuts from which one illustration is to be reproduced by printing4 ,these twelve operations produce three chromatic negatives1 each representing one color2 three transparencies or positives1 made from the chromatic negatives2 three half-tone negatives1 made from the positives2 and finally three contact prints1 made on sensitized metal plates4 ,in what is called the direct method the half-tone screen is placed in front of the photographic plate so that it becomes also a half-tone negative from which a print is made on a sensitized metal plate4 ,thus the photographic operations in the direct method are reduced to six1 but the interference to the passage of light offered by the half-tone screen and by the prism used to reverse the image on the negative lengthens the time of exposure4 ,unfortunately1 no pigments have been found that can reproduce in purity the colors of the spectrum1 and to this fact is due the failure of the process to reproduce exactly all the colors1 tints1 and shades of an original4 ,when a drawing in black on white paper is photographed only the white paper affects the negative film4 ,the transparent parts of the developed negative thus represent the black1 and the opaque parts1 which have been acted upon by light1 represent the whits4 ,theoretically1 when a chromatic negative is made for the yellow plate a purple-violet filter cuts out all the yellow and allows the red and blue rays to affect the plate2 when a negative is made for the blue plate an orange filter similarly cuts out the blue and allows the yellow and red rays to affect the plate2 and when a negative is made for the red plate a green filter cuts out the red and permits the blue and yellow rays to affect the plate4 ,these color filters1 which are usually made of transparent stained gelatin1 are generally placed in front of the lens4 ,when printing plates like those used in the half-tone process have been made from the three negatives and the plates have been inked with yellow1 blue1 and red ink1 respectively1 a combined impression from them will produce a close approximation of the subject photographed4 ,the colored inks often used are light yellow1 peacock or prussian blue1 and bright1 transparent crimson4 ,the ordinary half-tone screen1 which bears lines cut at an angle of #de to the sides of the plate1 is rectangular1 but the screens used for three-color work are made circular in order that they may be turned in the camera to make the lines intersect at other angles1 the angles being varied to avoid producing an undesirable pattern or a moire effect4 ,turning the screen also prevents the exact coincidence or superposition of the red1 blue1 and yellow dots1 which would produce black4 ,in other respects the screens do not differ essentially from those used in ordinary half-tone work4 ,as special experience is necessary in printing three-color plates the engraver generally delivers the printed illustrations to the purchaser instead of the plates1 which he furnishes for other kinds of relief printing4 ,the copy for this process may consist of anything in color1 such as specimens1 objects1 paintings1 or properly colored photographs4 ,the process does not usually reproduce all the colors and tints of an original with equal exactness and is not used by the ,survey for work that demands precise reproduction of color1 but it is satisfactory for reproducing most colored drawings1 colored photographs of specimens1 or the specimens themselves if they show individual variations in color4 ,as the process is entirely photomechanical it gives more scientific accuracy in detail than chromolithography1 in which there is much hand work1 and it is much less expensive4 ,if the colors shown in proofs are not satisfactory they can be modified4 ,the four-color process1 in which four color plates are used1 gives a closer approximation of true color values than the three-color process1 and at a comparatively small increase of cost4 ,the additional color used is generally a neutral gray or black4 ,,wax ,,engraving 7,,the ,,cerotype ,,process74 ,the wax or cerotype process does not require finished drawings and is especially suitable for making text illustrations and small maps1 although it may be used also for large work4 ,for this process blue prints1 pencil sketches1 old prints1 or rough copy of any kind may be submitted--that is1 it is not necessary to furnish carefully prepared drawings in black ink1 as it would be for photo-engraving1 for the wax engraver will reproduce in proper form any illustration in which the copy and the instructions show what is wanted1 just as an experienced draftsman will make a good drawing from the rough original furnished by an author4 ,full and clear instructions should always be given1 however1 as to the size of the cut wanted and what it is to show4 ,in this process a polished copper plate is coated with a film consisting of beeswax1 a whitening medium1 and other ingredients1 and the coating1 which varies in thickness according to the nature of the copy1 is sensitized as in the ordinary photographic processes4 ,the map or other design to be engraved is first photographed to publication size and a contact print is made on the wax coating from the negative4 ,the lines and other parts of the photographed image are then traced or cut through the wax to the copper plate with steel tools and straightened or perfected by the engraver1 but the lettering is set in printer's type1 which is pressed into the wax until it also touches the metal plate4 ,after the work of cutting through the wax has been completed the larger open spaces between the lines are built up by the addition of wax to give greater depth to the plate1 so that the wax plate thus built up corresponds to an electrotype mold4 ,the plate is then dusted with powdered graphite and suspended in a solution containing copper1 where by electrolytic action a copper shell is formed over its surface4 ,when this shell is sufficiently thick it is removed from the solution and reinforced on the back with metal1 and proofs are taken from it4 ,if the proofs are satisfactory the plate is blocked type-high4 ,wax-engraved plates may be used for printing colored maps or diagrams1 in which variations of tint are produced by various kinds of machine rulings4 ,the effect of some of the colors thus produced is almost a flat tint1 in which a pattern can be detected only by close scrutiny4 ,some color work is printed from a wax base plate in combination with half-tone color plates4 ,the price of a wax engraving depends entirely on the size of the cut1 the amount of work involved1 and the character of the original copy1 but it should not exceed very much the cost of a carefully prepared pen drawing plus the cost of a zinc etching made from it4 ,cuts engraved by the wax process1 like zinc and half-tone plates1 are delivered to the purchaser4 ,if colored work is ordered1 however1 the printed sheets1 not the cuts1 are delivered4 ,,wood ,,engraving4 ,wood engraving was once the universal method of producing cuts for illustrations that were designed to be printed on an ordinary press4 ,it is said to be the oldest of all methods of engraving illustrations4 ,the engraving is made on a block of boxwood1 a very dense1 hard wood of a light-yellow color4 ,the block is cut type-high across the grain1 and the engraving surface is made perfectly smooth by nibbing it with pumice or other stone4 ,when a cut is to be larger than #c or #d inches square the wood block is made up of pieces securely dovetailed or joined together to prevent splitting and warping4 ,a woodcut is not used for printing but is electrotyped and the electrotype is used in the press4 ,originally the smoothed surface of the wood block was coated with prepared chalk or ,chinese whits1 and on this coating a finished drawing was made with a brush and pencil by an illustrator4 ,according to more recent practice the surface of the wood is covered with a sensitized coating1 on which the drawing or design to be engraved is photographed4 ,the engraver then1 with various kinds of gravers and other tools1 cuts out the parts of the picture that are to be represented by white paper and leaves the lines1 dots1 and black areas as a printing surface1 thus translating the shades and tints of the picture into a system of lines and dots which exactly duplicate1 in effect1 the details and tones of the original design4 ,in order to produce a line effect of an area in which the tone is intermediate between whits and black the engraver must space his lines so that one-half the area will remain as printing surface and the other half as white spaces1 and he must give character and direction to his lines1 so that1 if he is skillful1 he can reproduce not only the delicate tones but the texture and details of the original picture4 ,many wood engravers became noted for their artistic rendering of magazine illustrations1 of famous paintings1 and of other works of art4 ,the ,survey began to abandon this method of engraving in #ahhd1 when the ,sixth ,annual ,report was in press1 substituting for it the cheaper photomechanical processes1 zinc etching and half-tone engraving1 and entirely abandoned its use in #ahib4 ,many good examples of wood engraving may be found in the early monographs and annual reports of the ,geological ,survey4 ,monograph #b contains numerous examples4 ,,photogelatin ,,processes4 ,bichromatized gelatin is used in several photomechanical processes of reproducing illustrations1 but in the photogelatin processes the gelatin not only receives the image by exposure to light through a negative but becomes a printing surface on a plate from which prints are made somewhat as in lithography4 ,the several photogelatin processes are much the same as the original collotype process and are best known by the names collotype1 heliotype1 albertype1 artotype1 and the ,german name lichtdruck4 ,in working these processes a thick plate of glass1 after certain preliminary treatment1 is coated with sensitized gelatin4 ,the plate is then placed in a drying room or oven having a temperature of #abj ,f41 baked until it is thoroughly dry1 and allowed to cool gradually4 ,the subject to be reproduced is then photographed in the usual manner1 and unless a prism or mirror box has been used the negative is stripped and reversed in order to make the print reproduce the original in proper position4 ,from the negative a contact print is made on the gelatin-coated plate1 the parts or molecules of gelatin being hardened in proportion to the amount of light that affects them4 ,after the contact print has been made the gelatin plate is thoroughly washed in cold water1 in order to dissolve and wash out the bichromate and stop any further action of light on the plate1 and is then thoroughly dried4 ,before prints are made from the gelatin-coated plate water is flowed on it and penetrates different parts of the gelatin according to their hardness4 ,the darkest parts of the picture will correspond to the hardest and densest parts of the gelatin1 which will not absorb water2 the lighter parts will take up more water4 ,the surface water is then removed with a rubber straight edge and an absorbent roller and the plate is ready for inking4 ,the ink1 being greasy1 has no affinity for water1 and when it is rolled over the plate it adheres only to the dry parts of the gelatin1 and in the press is carried to the paper in all the lights and shades of the illustration4 ,the plate is kept moist in printing4 ,the paper used for printing from photogelatin plates must be free from chemicals that will affect the gelatin4 ,a nearly pure rag paper is generally used4 ,the photogelatin process is well adapted to the reproduction of paleontologic drawings1 wash drawings1 photographs1 photomicrographs1 works of art1 old manuscripts--in fact1 any kind of subject in which the reproduction of delicate lights and shades is essential4 ,if properly manipulated it has distinct advantages over the half-tone process in that it can reproduce details and light and shade without showing the effect of a screen and without the use of coated paper4 ,excellent reproductions by the heliotype process are also made in color by first printing the design in a neutral tone and superposing appropriate transparent colors on this print1 somewhat as in chromolithography1 so that the colors softly blend with the shaded groundwork4 ,reproductions made by the photogelatin process are more expensive than those made by the half-tone process1 for the prints are generally made on better paper and are printed with greater care4 ,they give no screen effect and are perhaps unrivaled by prints obtained by any other process except photogravure1 in which the image is printed from a metal plate that has been sensitized1 exposed under a reversed negative1 and etched4 ,changes can not be made on photogelatin plates except by making over the corrected parts4 ,all retouching must be done on the originals or on the negatives made from then4 ,,lithography4 ,,original ,,process4 ,the general term lithography is sometimes used to indicate not only the original process so named1 said to have been invented by ,senefelder1 but chromolithography1 photolithography1 and engraving on stone1 as well as engraving on copper as a means of supplying matter to be transferred to and printed from a lithographic stone4 ,senefelder discovered that limestone will absorb either grease or ,water1 and that neither one will penetrate a part of the surface previously affected by the other4 ,he found that if a design is drawn on limestone with a greasy crayon and the stone afterward properly prepared with a solution of nitric acid and gum1 greasy ink will adhere only to the parts that are covered with the crayon1 and that the stone will give off an impression of the design4 ,lithographic stone is described as a fine1 compact1 homogeneous limestone1 which may be either a pure carbonate of lime or dolomitic--that is1 it may contain magnesium4 ,although limestone is one of the most common rocks1 limestone of a quality suitable for use in lithography is found at only a few localities4#aa ,there are two general classes of lithographic stone1 known to the trade as blue or hard stone and yellow or soft stone4 ,the blue stone is adapted for engraving and to the better grade of fine-line printing2 the yellow stone is rated as somewhat inferior4 ,footnote #aa3 ,kubel1 ,s4 ,j41 ,lithographic stone3 ,u4 ,s4 ,geol4 ,survey ,mineral ,resources1 #aijj1 pp4 #hfi-hgc1 #aija4 ,in the original process1 which may here be termed plain lithography1 two methods are employed in putting on stone the design to be reproduced4 ,in one the subject or picture to be reproduced is drawn on the printing stone either with a lithographic crayon or with a pen dipped in lithographic ink or tusche1 which is oily or fatty1 like the crayon4 ,in the other method the drawing is made on transfer paper and transferred to the stone4 ,in drawing on stone it is necessary to reverse the design1 so that all lettering must be drawn backward4 ,in doing this the artist often uses a mirror to aid him4 ,if the drawing is made on transfer paper the design and the lettering are copied as in the original--not reversed4 ,before a drawing is made on stone a stone of the quality suited to the particular design in hand is selected4 ,the stone is then ground and polished1 and if the drawing is to be made with crayon it is grained according to the special requirements of the subject4 ,if the drawing is to be made with a pen and is to consist of line work the stone is polished4 ,the first step is to obtain on the stone an outline or faint of the design4 ,there are several ways to do this4 ,by one method a tracing of the design is made1 a sheet of thin paper covered with red chalk is laid face downward on the stone1 the tracing is laid face downward over it1 and the design is again traced in red-chalk lines on the stone4 ,the method described is simple1 but there are others that are more complicated and that are particularly applicable to the reproduction of photographs and other illustrations4 ,crayon work is often used in combination with pen and ink1 stipple1 and brush work4 ,this method of drawing on stone is used also for preparing color stones in the process of chromolithography1 in which there are many added details of manipulation4 ,after the drawing has been made on the stone or transferred to it the stone is gummed--that is1 it is covered with a solution of gum arabic and nitric acid--and dried4 ,the stone is then dampened with water and carefully rolled with lithographic ink1 which adheres to the pen or crayon work and is repelled elsewhere4 ,it is then rubbed over with powdered rosin and talcum1 which adheres to the ink and further protects the drawing from the effects of the etching fluid1 which is next to be applied to the stone4 ,this fluid consists of a #aj per cent solution of gum arabic to which #b to #g per cent of nitric acid has been added1 the degree of acidity being varied according to the subject and the hardness of the stone4 ,the fluid is applied with a brush or sponge and is left on the stone just long enough to decompose slightly the carbonate of lime on its surface and1 after washing1 to leave the design or drawing in very slight relief4 ,the stone is again gummed and dried1 and the design is washed out or brought out by removing the surface gum with a wet sponge and applying to the stone a rag sprinkled with turpentine and charged with printing ink4 ,these operations wash away the tusche and the crayon that have been decomposed by the acid and expose the design faintly in white at first1 but it gradually grows darker as it becomes charged with printing ink from the rag4 ,the stone is next rolled up or inked4 ,the slightly moistened surface repels the ink and the design takes it up1 so that when the stone is run through the press the design is carried to the paper4 ,lithographic prints from stones prepared in this way are made on a flat-bed press4 ,the stone is carried forward to print and on its return is dampened and inked1 an operation slower than that of rotary printing4 ,corrections and changes are made on the stone by carefully scraping or polishing away the parts to be corrected and making the changes with a crayon or pen1 but the design can not ordinarily be corrected twice in the same place1 as the scraping or polishing removes a part of the surface of the stone and thus lessens the pressure at that place1 and the impression there may be imperfect or may completely fail4 ,this form of lithography is seldom used for ,survey illustrations but was formerly much used and is well adapted to the reproduction of drawings of fossils1 particularly of remains of dinosaurs and other types of large extinct animals4 ,examples may be seen in ,monographs #h and #aj and in other early reports of the ,geological ,survey4 ,the drawings for these illustrations were made directly on stone4 ,a drawing made on one stone may be transferred in duplicate or in any desired number to another stone1 or to a properly grained sheet of zinc and aluminum1 from which impressions may be printed on a lithographic press4 ,both these metals are also used for lithographic printing on rotary presses1 the zinc or aluminum plate being bent and secured around a cylinder which rotates continuously in one direction4 ,as one impression is made at each revolution of the cylinder the printing is rapid2 but the best printing from a metal plate is inferior to the best printing from a lithographic stone4 ,,photolithography4 ,photolithography1 like other lithographic processes1 has been improved greatly during the last few years--not particularly in results but in methods--by the introduction of metal plates1 the rubber blanket offset1 the ,ben ,day films1 and many mechanical and chemical devices1 so that a brief description of it will not explain the process except in a most general way4 ,as photolithography is a direct process and is relatively cheap it is the one most used for reproducing large maps and other line drawings that have been carefully prepared4 ,zinc and aluminum plates are now much used in photolithography1 for a direct contact photographic print can be made on them1 they can be printed flat or bent for use on a rotary press1 and they can be stored for future use more economically than stones4 ,there are two somewhat distinct methods of producing photolithographs4 ,in both the ordinary photographic methods are used1 but it is often necessary to cut or trace parts of the negative in order to open up lines and other features that are not sharp or well defined1 so that the negative will print them sharp and clear4 ,if the copy to be reproduced shows three colors1 three negatives are made1 one for each color1 and the parts to be shown by each are preserved by opaquing or painting out all other parts4 ,by the older method the negative thus perfected is placed in a printing frame in contact1 under pressure1 with sensitized transfer paper and is exposed to light4 ,the printing frame is then carried to the dark room and the paper is removed from the frame and its surface covered with transfer ink4 ,the paper is then laid face upward on water and soaked for several minutes1 after which it is placed in the same position upon a slab of stone or metal and thoroughly washed with water4 ,this washing removes the ink and the sensitive film from the parts that were unaffected by the action of light 7the parts corresponding to the white paper in the design71 but the ink still adheres to the lines of the design in the precise sharpness and clearness of the negative4 ,the design is now ready to be transferred to the printing stone or zinc plate4 ,the sheet is again slightly dampened between moist blotters and laid face downward in its correct position on a prepared stone or zinc plate1 which is then pulled through a press under heavy pressure4 ,the paper is then removed from the stone or plate1 to which it has carried the design4 ,from this point the gumming1 etching1 and other operations are practically the same as those used in ordinary lithography4 ,the bichromate-gelatin transfer process described above has been replaced in the ,survey by a more satisfactory one1 which insures absolute scale and reproduces the finest line drawings perfectly without thickening the lines or without distortion4 ,in this process1 which is known as the planographic process1 a photographic negative of the copy is placed in a vacuum printing frame in contact with a zinc or aluminum plate that has been sensitized with a bichromate-albumen solution and exposed in front of an arc lamp4 ,after proper exposure the plate is removed from the frame1 inked over1 and placed under water4 ,the parts not hardened by the action of light 7the unexposed parts7 are then rubbed away with cotton1 and the plate is chemically etched1 gummed over1 and dried4 ,the plate is then ready to be printed from in a lithographic press4 ,if a large map is to be reproduced it is photographed in parts1 and contact prints are made on zinc plates4 ,from these plates transfers are pulled and the parts are assembled and laid down in proper position on a stone or an aluminum plate1 which is then prepared for printing4 ,a drawing that is to be reproduced by photolithography should be made on pure-white paper in lines1 dots1 or black masses with black waterproof ink4 ,it should be one and one-half to two or three times the size of the finished print4 ,photolithography is particularly adapted to the reproduction of maps1 plans1 and other large drawings4 ,within certain limitations1 lines may be changed and details may be added after proofs have been submitted4 ,the process is ordinarily used for reproducing illustrations in one color 7black71 but it is used also for printing in more than one color1 generally over a black outline base1 each color being printed from a separate stone1 as in chromolithography4 ,,offset ,,printing4 ,in the offset process the design is offset from a lithographic plate or stone to a rubber blanket on a cylinder1 from which it is printed4 ,by thus obtaining an impression from an elastic surface the finest details can be printed on rough1 uncoated paper1 which can not be used in other processes1 which can be folded without danger of breaking1 and which is more durable than coated paper4 ,plates ,,ii1 ,,iii1 ,,iv1 ,,vii1 and ,,viii in this pamphlet were printed by this process4 ,,chromolithography4 ,the chromolithographic process1 by which illustrations are printed in color from stone1 is used in ,survey publications principally for reproducing geologic maps1 but it is sometimes used for reproducing colored drawings of specimens4 ,there are several kinds of color printing from stones4 ,one produces a picture by superimposing colors that combine and overlap without definite outlines and thus reproduce the softly blended colors of the original4 ,another reproduces the original by printing colors within definite outlines on a base which has been previously printed in black4 ,the first kind is used by the ,survey for reproducing colored drawings of specimens4 ,the second is followed in reproducing geologic maps4 ,as each color must be printed from a separate stone and properly fitted with respect to the others a tracing from the original is made of the precise outlines of each color2 or1 if the design is to be reduced1 a tracing is made over a properly reduced photographic print4 ,this tracing can be made on specially prepared tracing paper or on a sheet of transparent gelatin or celluloid1 which is laid over the copy and on which all the outlines and overlaps of the various colors are scratched with a steel point4 ,the scratches thus made on the celluloid are filled with red chalk or like substance1 and rubbed in with cotton1 and by reversing the sheet and rubbing it the chalk lines are deposited on as many stones as are needed to produce the colors of the original design1 each stone bearing all the outlines of the design4 ,sometimes all the outlines are engraved on what is called a key stone and an impression from it is laid down on each of the color stones4 ,the parts on each stone that are to have one color are then inked in or engraved1 and at the same time guide marks are indicated1 so that in the composite print from the stones each color will fit its proper place4 ,this fitting is called register and is an important part of printing1 for each stone must be adjusted to a nicety while on the press in order to make each impression fit the others exactly4 ,the process was originally manipulated entirely by hand1 but photography has now replaced much of the handwork and has given rise to several methods by which the same kinds of subjects are reproduced in radically different ways4 ,tints are sometimes produced by the half-tone and other screens and by machine ruling1 and printer's type is used almost exclusively for titles and other matter that was formerly engraved or drawn on the stone4 ,in reproducing a geologic map the base may be engraved on stone or on copper or it may be photo-lithographed4 ,by either process the map may be transferred to the printing stone4 ,the color stones for geologic maps are prepared by hand1 but the geologic patterns1 which are printed in colors1 are engraved separately on plates1 from which impressions are pulled when needed and transferred to their proper places on the printing stones in the shapes required according to the key design4 ,the lighter1 more transparent colors are generally printed first1 and often twelve or more colors and many distinctive patterns are used to produce a geologic map4 ,when proofs of such a map are pulled each stone must be taken up and carefully adjusted on the press1 so that the work of proving maps that are printed from a considerable number of color stones is laborious and expensive4 ,it is therefore customary to approve first combined proofs conditionally--that is1 subject to the corrections and changes indicated on the proofs--and to hold the lithographer responsible for any failure to make the corrections4 ,this process is the most expensive one used for reproducing illustrations4 ,changes may be indicated on proofs1 but changes can not be made on a stone twice in the same place without danger of affecting the printing or making it necessary to retransfer the parts affected4 ,all changes are expensive because a slight modification at one point may involve corresponding changes on a number of stones1 each of which must be taken up1 corrected1 and proved to insure the exact coincidence of the parts affected4 ,it is often less expensive to retransfer the entire job than to make extensive changes on the original stones4 ,,engraving ,,on ,,stone ,,and ,,on ,,copper4 ,engraving on stone is distinctly lithographic1 but engraving on copper is sometimes included among lithographic processes because the work produced by it is usually printed from stone and thus becomes lithographic4 ,in other respects engraving on copper is not a lithographic process4 ,roughly prepared maps and any rough line copy that is accurate in statement and clear as to intent are appropriate for both methods of engraving1 but drawings that are expertly prepared are more suitable for reproduction by photolithography4 ,in engraving on stone the lines of a design are scratched on the blackened surface of a stone with a steel-pointed tool2 in engraving on copper the lines are cut with a graver on a sheet or plate of copper1 the matter to be engraved being first shown on the plate by what is called the photo-tracing process1 which was devised in the ,geological ,survey4 ,there is1 however1 no great or essential difference in the printed results of the two processes1 but most lithographers employ only stone engravers4 ,a stone on which a design is to be engraved is ground and polished according to the kind of work to be engraved1 is coated with a thin solution of gum arable and allowed to dry1 and is then washed until the superficial gum is removed while the surface pores remain filled4 ,as the lines made by the engraver must be visible the stone is blackened with a pigment composed of lampblack and gum or is covered evenly with red chalk or ,venetian red4 ,it is then ready to receive the design to be engraved4 ,if the design is a map which is to show culture1 streams1 and surface contours1 and each of these sets of features is to be printed in a separate color1 impressions of the work to be engraved must be placed on three stones4 ,one method of doing this is to make a scratch tracing of the original drawing on a sheet of transparent gelatin or celluloid in the manner employed in chromolithography1 except that a dry pigment1 generally chrome-yellow1 is used to fill the scratch lines instead of red chalk or ,venetian red4 ,from this tracing a faint or imprint of all the details of the three separate features of the map is made on each of the three stones1 and the engraver then cuts on each stone only the lines and other features1 including ample register marks1 that are to be printed in one color1 the imprint made from the tracing making it possible to engrave each set of features in its exact position relative to the other two4 ,by another method the matter to be engraved is photographed directly on the stone4 ,the engraving is done with a steel needle inserted in a small wooden cylinder1 an instrument resembling an ordinary lead pencil4 ,the size and shape of the needles used are varied according to the requirements of the matter to be engraved4 ,with this instrument the lines and lettering are lightly scratched into the stone through the dark coating and show as light lines4 ,the points of some of the needles are fine2 those of others are ,v-shaped2 and some have spoon-shaped points1 for use in thickening lines and shading letters4 ,all features are engraved in reverse4 ,after the engraving is completed the stones are prepared for printing by wiping off all the superficial color and filling the engraved lines with a greasy ink--generally a thin printing ink--which is rubbed into the lines with a soft rag4 ,impressions are then pulled on transfer paper and transferred to three printing stones for use in printing the three colors1 the register marks enabling the pressman to fit each color exactly in its proper place4 ,in all lithographic processes the titles and other marginal lettering can be and usually are transferred from type impressions to the printing stones4 ,it is therefore unnecessary to letter such matter carefully on an original drawing that is made for lithographic reproduction1 for appropriate faces of type will give better printed results than hand lettering4 ,corrections can not be made on a stone or copper engraving as readily as on a drawing4 ,if a stone engraver makes an error or if a change is required after his engraving is finished1 the parts to be corrected must be scraped off and a new ground laid before the correction can be made4 ,sometimes he will engrave the parts corrected on another part of the original stone and transfer it to the printing stone4 ,corrections are made on copper plates by hammering up the plate from beneath1 polishing off a new surface1 and reengraving the part to be corrected4 ,,appendix4 ,the matter given in this appendix is much used in making geologic maps and other illustrations4 ,the ,greek alphabet and the groups of signs presented are given chiefly to show the correct formation of each letter and sign4 ,,miscellaneous ,,tables4 ,length of #a of longitude measured along given parallels from the ,equator to the poles4 ,from ,u4 ,s4 ,coast and ,geodetic ,survey ,report for #ahhd1 ,appendix #f4 ,parallel of ,statute ,parallel of ,statute ,parallel of ,statute latitude4 miles4 latitude4 miles4 latitude4 miles4 ---------------------------------------- --------------------------- #j #fi4agb #ca #ei4cfe #fa #cc4fbc #a #fi4afb #cb #eh4gaf #fb #cb4efj #b #fi4acj #cc #eh4jga #fc #ca4dhh #c #fi4jgh #cd #fg4djg #fd #cj4djf #d #fi4jje #ce #ff4gbe #fe #bi4cae #e #fh4iaa #cf #ff4jbg #ff #bh4bae #f #fh4gie #cg #fe4caa #fg #bg4ajf #g #fh4ffj #ch #fd4fgi #fh #bf4ihh #h #fh4ejd #ci #fc4hbi #fi #bd4hfb #i #fh4cbf #dj #ec4jfc #gj #bc4gbi #aj #fh4abi #da #fb4bha #ga #bb4ehi #aa #fg4iaj #db #ea4dhc #gb #ba4dda #ab #fg4fgj #dc #fj4ffi #gc #bj4bhg #ac #fg4daj #dd #di4hdj #gd #ai4abg #ad #fg4aca #de #dh4iie #ge #ag4ifj #ae #ff4hcj #df #dh4acf #gf #af4ghh #af #ff4eaj #dg #dg4bfa #gg #ae4faa #ag #ff4afi #dh #df4cgb #gh #ad4dbh #ah #fe4hjh #di #de4dfi #gi #ac4bdb #ai #fe4dbg #ej #dd4feb #hj #ab4jea #bj #fe4jbf #ea #dc4fba #ha #aj4heg #ba #fd4fjf #eb #db4fgf #hb #i4fei #bb #fd4aff #ec #da4gai #hc #h4deh #bc #fc4gjf #ed #dj4gdi #hd #g4bef #bd #fc4bbh #ee #ci4gff #he #f4jdi #be #fb4gbi #ef #ch4gga #hf #d4hdb #bf #fb4bab #eg #cg4gfd #hg #c4fcb #bg #fa4fgf #eh #cf4gde #hh #b4dbb #bh #fa4abb #ei #ce4gaf #hi #a4baa #bi #fj4edh #fj #cd4fgd #ij 4#jjj #cj #ei4ief ,length of #a of latitude measured along a meridian at given parallels4 ,parallel given is in center of the degree whose length is stated4 ,parallel of ,statute latitude4 miles4 ---------------------- #j #fh4gjd #aj #fh4gbe #bj #fh4ghf #cj #fh4hgi #dj #fh4iic #ej #fi4aae #fj #fi4bcj #gj #fi4cbd #hj #fi4chf #ij #fi4djg ,metric system and equivalents4 ,the units of linear measure most commonly used are millimeters 7mm471 centimeters 7cm471 decimeters 7dm471 meters 7m471 and kilometers 7km471 #a m4 #aj dm42 #a dm4 #aj cm42 #a cm4 #aj mm42 #a km4 #a1jjj meters #j4fbacg mile2 #a m4 #ci4cg inches #c4bhjhcc feet4 ,meters4 ,inches4 ,meters4 ,feet4 ,kilometers4 ,miles4 ---------------------------------------- ------------------------- #a #ci4cg #a #c4bhjfcc #a #j4fbacg #b #gh4gd #b #f4efaffg #b #a4bdbgd #c #aah4aa #c #i4hdbejj #c #a4hfdaa #d #aeg4dh #d #ac4abcccc #d #b4dhedh #e #aif4he #e #af4djdaff #e #c4ajfhe #f #bcf4bb #f #ai4fhejjj #f #c4gbhbb #g #bge4ei #g #bb4ifehcc #g #d4cdiei #h #cad4if #h #bf4bdffff #h #d4igjif #i #ced4cc #i #bi4ebgejj #i #e4eibcc ,inches4 ,centimeters4 ,feet4 ,meters4 ,miles4 ,kilometers4 ---------------------------------------- -------------------------- #a #b4ed #a #j4cjdhja #a #a4fjice #b #e4jh #b #j4fjifja #b #c4bahfi #c #g4fb #c #j4iaddjb #c #d4hbhjd #d #aj4af #d #a4baibjb #d #f4dcgci #e #ab4gj #e #a4ebdjjc #e #h4jdfgd #f #ae4bd #f #a4hbhhjd #f #i4fefjf #g #ag4gh #g #b4accfjd #g #aa4bfedc #h #bj4cb #h #b4dchdje #h #ab4hgdgh #i #bb4hf #i #b4gdcbje #i #ad4dhdab ,the vara1 used in ,texas1 is equivalent to #cc-a_/c inches and is computed as representing #b4gh feet4 ,geologic eras1 periods1 systems1 epochs1 and series4 ,era4 ,period or system4 ,epoch or series4 ,recent4 ,quaternary4 ,pleistocene 7replaces ,glacial74 ,cenozoic4 ,pliocene4 ,tertiary4 ,miocene4 ,oligocene4 ,eocene4 ,upper 7,gulf may be used provincially74 ,cretaceous4 ,lower 7,comanche and ,shasta may be used provincially74 ,upper4 ,mesozoic4 ,jurassic4 ,middle4 ,lower4 ,upper4 ,triassic4 ,middle4 ,lower4 ,permian4 ,pennsylvanian 7replaces ,upper ,carboniferous4 ,carboniferous74 ,mississippian 7replaces ,lower ,carboniferous74 ,upper4 ,devonian4 ,middle4 ,lower4 ,paleozoic4 ,silurian4 ,upper 7,cincinnatian may be used provincially74 ,ordovician4 ,middle 7,mohawkian may be used provincially74 ,lower4 ,saratogan 7or ,upper ,cambrian74 ,cambrian4 ,acadian 7or ,middle ,cambrian74 ,waucoban 7or ,lower ,cambrian74 ,algonkian4 pre-,cambrian4 ,proterozoic4 ,archean4 ,chemical elements and symbols4 ,element4 ,symbol4 ,element4 ,symbol4 ,element4 ,symbol4 ,aluminum ,al ,holmium ,ho ,rhodium ,rh ,antimony ,sb ,hydrogen ,h ,rubidium ,rb ,argon ,al ,indium ,in ,ruthenium ,ru ,arsenic ,as ,iodine ,i ,samarium ,sa ,barium ,ba ,iridium ,ir ,scandium ,sc ,bismuth ,bi ,iron ,fe ,selenium ,se ,boron ,b ,krypton ,kr ,silicon ,si ,bromine ,br ,lanthanum ,la ,silver ,ag ,cadmium ,cd ,lead ,pb ,sodium ,na ,cesium ,cs ,lithium ,li ,strontium ,sr ,calcium ,ca ,lutecium ,lu ,sulphur ,s ,carbon ,c ,magnesium ,mg ,tantalum ,ta ,cerium ,ce ,manganese ,mn ,tellurium ,te ,chlorine ,cl ,mercury ,hg ,terbium ,tb ,chromium ,cr ,molybdenum ,mo ,thallium ,tl ,cobalt ,co ,neodymium ,nd ,thorium ,th ,columbium ,c ,neon ,ne ,thulium ,tm ,copper ,cu ,nickel ,ni ,tin ,sn ,dysprosium ,dy ,niton ,nt ,titanium ,ti ,erbium ,er ,nitrogen ,n ,tungsten ,w ,europium ,eu ,osmium ,os ,uranium ,u ,fluorine ,f ,oxygen ,o ,vanadium ,v ,gadolinium ,gd ,palladium ,pd ,xenon ,xe ,gallium ,ga ,phosphorus ,p ,ytterbium ,germanium ,ge ,platinum ,pt 7,neoytterbium7 ,yb ,glucinum ,gl ,potassium ,k ,yttrium ,y ,gold ,au ,praseodymium ,pr ,zinc ,zn ,helium ,he ,radium ,ra ,zirconium ,zr ,greek alphabet4 ,caps4 ,lower-case4 ,greek name4 ,english sound4 ,greek3 ,a ,greek3 a ,alpha4 ,a4 ,greek3 ,b ,greek3 b ,beta4 ,b4 ,greek3 ,g ,greek3 g ,gamma4 ,g4 ,greek3 ,d ,greek3 d ,delta4 ,d4 ,greek3 ,e ,greek3 e ,epsilon4 ,e short4 ,greek3 ,z ,greek3 z ,zeta4 ,z4 ,greek3 ,h ,greek3 h ,eta4 ,e long4 ,greek3 ,th ,greek3 th ,theta4 ,th4 ,greek3 ,i ,greek3 i ,iota4 ,i4 ,greek3 ,k ,greek3 k ,kappa4 ,k4 ,greek3 ,l ,greek3 l ,lambda4 ,l4 ,greek3 ,m ,greek3 m ,mu4 ,m4 ,greek3 ,n ,greek3 n ,nu4 ,n4 ,greek3 ,x ,greek3 x ,xi4 ,x4 ,greek3 ,o ,greek3 o ,omicron4 ,o short4 ,greek3 ,p ,greek3 p ,pi4 ,p4 ,greek3 ,r ,greek3 r ,rho4 ,r4 ,greek3 ,s ,greek3 s ,sigma4 ,s4 ,greek3 ,t ,greek3 t ,tau4 ,t4 ,greek3 ,u ,greek3 u ,upsilon4 ,u4 ,greek3 ,f ,greek3 f ,phi4 ,f4 ,greek3 ,ch ,greek3 ch ,chi4 ,ch4 ,greek3 ,ps ,greek3 ps ,psi4 ,ps4 ,greek3 ,om ,greek3 om ,omega4 ,o long4 ,roman numerals4 ,i #a ,,ix #i ,,lxx #gj ,d #ejj ,,ii #b ,x #aj ,,lxxx #hj ,,dc #fjj ,,iii #c ,,xix #ai ,,xc #ij ,,dcc #gjj ,,iv #d ,,xx #bj ,c #ajj ,,dccc #hjj ,v #e ,,xxx #cj ,,cl #aej ,,cm #ijj ,,vi #f ,,xl #dj ,,cc #bjj ,m #ajjj ,,vii #g ,l #ej ,,ccc #cjj ,,md #aejj ,,viii #h ,,lx #fj ,,cd #djj ,,mcm #aijj ,mathematical signs4 plus4 difference - minus4 integration4 multiplied by4 equivalence4 divided by4 3 ratio4 equality4 geometrical proportion4 plus or minus4 -3 difference1 excess4 square4 therefore4 rectangle4 because4 triangle4 infinity4 circle4 varies as4 angle4 radical4 right angle4 degree4 or greater than4 ' minute4 or less than4 second4 perpendicular4 ,,names ,,of ,,rocks4 ,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 only4 ,for sedimentary rocks dots and circles1 parallel lines1 and broken or dotted lines are used2 for metamorphic rocks short dashes arranged without definite patterns2 and for igneous rocks patterns composed of short dashes1 triangles1 rhombs1 crosses1 and cross lines4 ,all these patterns are shown in ,plate ,,iii4 ,sedimentary material4 ,including residual1 detrital1 eolian1 glacial1 organic1 and chemically precipitated material4 ,agglomerate4 ,ironstone 7also igneous74 ,alabaster4 ,itacolumite4 ,alluvium4 ,kame4 ,alum shale4 ,kaolin4 ,anhydrite4 ,laterite4 ,apron 7alluvial74 ,lignite4 ,argillite4 ,limestone4 ,arkose4 ,limonite4 ,asphalt4 ,loess4 ,bench gravel4 ,marble 7also metamorphic74 ,bentonite4 ,marl4 ,boulder clay4 ,metaxite4 ,brea4 ,morainal deposit4 ,breccia4 ,mudstone4 ,brownstone4 ,novaculite4 ,burrstone4 ,peat4 ,calcarenite4 ,pelite4 ,calc sinter4 ,phosphate rock4 ,caliche4 ,phosphorite4 ,catlinite4 ,phthanite4 ,chalk4 ,psammites4 ,chert4 ,psephites4 ,clay4 ,puddingstone4 ,coal4 ,pyroclastic material4 ,conglomerate4 ,quartzite 7also metamorphic74 ,coprolite4 ,reddle4 ,coquina4 ,rock salt4 ,detritus4 ,rock stream4 ,diatomaceous earth4 ,rubble4 ,diluvium4 ,salt4 ,dolomite4 ,sand4 ,drift4 ,sandstone4 ,fan 7alluvial74 ,selenite4 ,fanglomerate4 ,shale4 ,flagstone4 ,silt4 ,flint4 ,slate 7also metamorphic74 ,freestone4 ,soil4 ,fuller's earth4 ,stalactite4 ,geyserite4 ,stalagmite4 ,gravel4 ,talc4 ,graywacke4 ,talus4 ,greensand4 ,till4 ,grit4 ,travertine4 ,gumbo4 ,tripoli4 ,gypsum4 ,tufa 7chemically deposited lime74 ,hardpan4 ,tuff 7igneous fragments74 ,hematite4 ,wacke4 ,infusorial earth4 ,wash4 ,metamorphic material4 ,adinole4 ,hornstone4 ,amphibolite4 ,itabirite4 ,andalusite schist 7874 ,kinzigite4 ,apo 7rhyolite71 etc4 ,knotenschiefer4 ,argillite4 ,knotty schists4 ,augen gneiss 7also igneous74 ,luxulianite 7igneous874 ,biotite schist4 ,marble4 ,calc schist4 ,meta 7diabase71 etc4 ,cataclastic4 ,mica schist4 ,chlorite schist ,mylonite4 ,clay slate4 ,ophicalcite4 ,damourite schist4 ,ottrelite schist4 ,desmosite4 ,phyllite4 ,dynamometamorphic rock4 ,porcelanite4 ,eclogite4 ,protogene4 ,epidosite4 ,pyroschists4 ,erlan4 ,quartz4 ,erlanfels4 ,quartzite4 ,eulysite4 ,quartz schist4 ,fibrolite schist ,schist4 ,garnet rock4 ,sericite schist1 etc4 ,garnet schist4 ,serpentine4 ,gneiss4 ,slate4 ,granite gneiss4 ,soapstone4 ,graywacke 7874 ,sodalite4 ,green schists4 ,spilosite4 ,greenstone 7also igneous74 ,steatite4 ,greisen4 ,talc schist4 ,halleflinta4 ,topazfels4 ,hornblende schist ,topaz rock4 ,hornfels4 ,zobtenite4 ,igneous material4 ,absarokite4 ,dolerite4 ,abyssal4 ,dunite4 ,adamellite4 ,durbachite4 ,adendiorite4 ,effusive rock4 ,ailsyte4 ,ekerite4 kerite4 ,elvan4 ,alaskite4 ,enstatite4 ,albitlte4 ,eruptive rock4 ,allivalite4 ,essexite4 ,allochetite4 ,estrellite4 ,alnlte4 ,eulysite4 ,alsbachite4 ,extrusive rock4 ,ambonite4 ,farrisite4 ,amherstite4 ,felsite4 ,analcitite4 ,felsophyre4 ,andesite4 ,fergusite4 ,anorthosite4 ,fortunite4 ,aphanitite4 ,fourchite4 ,aplite4 ,foyaite4 ,arkite4 ,gabbro4 ,atatschite4 ,gauteite4 ,augen gneiss 7also metamorphic74 ,garewaite4 ,augitite4 ,glumarrite4 ,avezacite4 ,gladkaite4 ,banakite4 ,granite4 ,banatite4 ,granitite4 ,bandaite4 ,granitoid4 ,basalt4 ,granodiorite4 ,basanite4 ,granophyre4 ,beerbachite4 ,greenstone 7also metamorphic74 ,bekinkinite4 ,greisen 7874 ,bombs4 ,grorudite4 ,borolanite4 ,harrisite4 ,bostonite4 ,harzburgite4 ,camptonite4 ,haynophyre4 ,carmeloite4 ,hawaiite4 ,cascadite4 ,hedrumite4 ,chibinite4 ,heumite4 ,ciminite4 ,holyokeite4 ,comendite4 ,hornblendite4 ,complementary rocks4 ,hypabyssal rock4 ,coppaelite4 ,hyperite4 ,cortlandite4 ,hypersthenite4 ,cromaltite4 ,ijolite4 ,cumberlandite4 ,intrusive rock4 ,cuselite4 ,irruptive 7,intrusive7 rock4 ,dacite4 ,isenite4 ,dellenite4 ,jacupirangite4 ,diabase4 ,jumillite4 ,diallagite4 ,kaiwekite4 ,dike rock4 ,kedabekite4 ,diorite4 ,kentallenite4 ,ditroite4 ,kenyite4 ,igneous material4--,continued4 ,keratophyre4 ,perlite4 ,kersantite4 ,phanerite4 ,kimberlite4 ,phonolite4 ,kobalaite4 ,pierite4 ,krablite4 ,pitchstone4 ,kragerite4 ,plagiaplite4 ,kulaite4 ,plagioclastic4 ,kyschytymite4 ,plumasite4 ,lamprophyre4 ,plutonic rock4 ,latite4 ,pollenite4 ,laugenite4 ,porphyry4 ,laurdalite4 ,pulaskite4 ,laurvikite4 ,pumice4 ,lava4 ,pyroxenite4 ,lestiwarite4 ,rhombenporphyry4 ,leucite basalt4 ,rhyolite4 ,leucite tephrite4 ,rizzonite4 ,leucitite4 ,rockalite4 ,leucocratic4 ,santorinite4 ,lherzolite4 ,sanukite4 ,limbergite4 ,saxonite4 ,lindoite4 ,scyelite4 ,liparite4 ,shastaite4 ,litchfieldite4 ,shonkinite4 ,lithoidite4 ,shoshonite4 ,luciitss4 ,soda granite4 ,lujaurite4 ,slvsbergite4 ,madrupite4 ,sommaite4 ,maenaite4 ,spessartite4 ,magma basalt4 ,sussexite4 ,malchite4 ,syenite4 ,malignite4 ,taimyrite4 ,mangerite4 ,tawite4 ,mariupolite4 ,tephrite4 ,melaphyre4 ,teschenite4 ,melilite basalt4 ,theralite4 ,mesanite4 ,tilaite4 ,mica peridotite4 ,tinguaite4 ,minette4 ,tjosite4 ,missourite4 ,tonalite4 ,monchiquite4 ,tonsbergite4 ,mondholdeite4 ,tordrillite4 ,monmouthite4 ,toscanite 7874 ,monzonite4 ,trachy-andesite4 ,mugearite4 ,trachyte4 ,naujaite4 ,trap4 ,nelsonite4 ,troctolite4 ,nephelinite4 ,umptekite4 ,nevadite4 ,unakite4 ,nordmarkite4 ,ungaite4 ,norite4 ,urtite4 ,obsidian4 ,valbellite4 ,odinite4 ,venanzite4 ,orbite4 ,verite4 ,orendite4 ,vitrophyre4 ,ornite4 ,vogesite4 ,orthophyre4 ,volcanic rock4 ,ortlerite4 ,volhynite4 ,ouachitite4 ,vulsinite4 ,paisanite4 ,websterite4 ,pantellerite4 ,wehrlite4 ,pegmatite4 ,windsorite4 ,peridotite4 ,wyomingite4 ,perknite4 ,yamaskite4 ,,index4 ,a4 ,abbreviations1 forms of4 #ee-fg ,adhesive materials1 choice4 #cg ,alaska1 maps of1 reuse of4 #ag ,albertype4 ,see ,photogelatin processes4 ,apparatus1 photographs of1 preferred to sketches4 #bi ,approval of finished drawings1 features to be covered by4 #ch of illustrations1 regulations governing4 #hj ,areas1 patterns used to distinguish4 #bc patterns used to distinguish1 plate showing4 #fb ,army1 ,corps of ,engineers of the1 maps published by4 #ae ,artotype4 ,see ,photogelatin processes4 ,atlases1 published1 use of4 #ae ,b4 ,base maps4 ,see ,maps1 base4 ,bleaching photographic prints1 method and solutions for4 #fi ,border for maps1 width and use of4 #eg-eh ,bristol board1 kind ,mid sizes used4 #bd1ff ,brash and pencil drawings1 materials and methods used in making4 #ff-fg1 #fi ,brushes1 kinds and sizes used4 #ff-fg1ga ,c4 ,celluloid transferring1 process of4 #dg requisitions for4 #dg ,cerotype process1 description and advantages of4 #hj-ha ,changes in engravings1 possible kinds of4 #ch-ci1 #ij ,changes in original material1 draftsman to consult author on4 #fe ,chemical elements1 names and symbols of4 #ih ,chromolithography1 description of4 #hg-hj ,civil divisions1 lettering of4 #ec1 #ed ,coal beds1 indication of thickness of4 #ca ,coast and ,geodetic ,survey charts1 use of4 #ae ,collotype4 ,see ,photogelatin processes4 ,coloring materials1 use of4 #bf ,colors1 standard1 for geologic maps4 #fb-fc use of1 for ground-water features4 #ba-bc on original geologic maps4 #bg-bh ,commas1 form of4 #ed use of1 in numbers4 #ed ,contours1 drawing of4 #dh-ej ,cooperation1 mention of4 #ac ,copper1 engraving on4 #hi1 #ij etching in relief on1 process and advantages of4 #ge ,copying methods of4 #df-dh ,corrections4 ,see ,changes4 ,cost of photo-engravings4 #ge1 #gh1 #hj1 #ha ,county maps1 use of4 #ae ,crayons1 wax1 use of4 #bf1 #ej1 #ea ,credit for data of maps1 indication of4 #ac ,crystals1 drawings of1 making and lettering of4 #gj ,cultural features1 lettering of4 #ec-ed list of4 #eb-ec ,curves1 date showing4 #fd ,cuts4 ,see ,engravings4 ,d4 ,details of a geologic map1 plate showing4 #eh ,diagrams1 drawing and lettering of4 #fd features of1 plate showing4 #fd original1 general requirements for4 #bh-bj ,director of the ,survey1 order by4 #i ,divisions of plates and figures1 serial letters and numbers for4 #ab ,drafting table1 shadowless1 description of4 #dg-dh shadowless1 use of4 #bi1 #dh1 #ej ,draftsmen1 detail of1 to aid author4 #i detail of1 to prepare base maps4 #ac-ad experience and reading required by4 #da-db general treatment of material by4 #db-dc ,drainage features1 depiction of4 #ea-eb ,drawing instruments1 list of4 #db ,drawing materials1 kinds used4 #bc-bf1 #ff-fg1 #fi1 #ga ,drawings1 authors'1 draftsmen may aid in making4 #i authors'1 editorial revision of4 #ch finished1 general requirements for4 #da-db requests for photographs of4 #cd ,duplicates of engravings1 charges for4 #ch ,e4 ,effectiveness of illustrations1 elements that produce4 #g1 #cj ,electrotypes of engravings1 charges for4 #ch ,elements1 chemical1 names and symbols of4 #ic ,engraving on stone1 process of4 #hi-ij ,see also ,lithography4 ,engravings1 changes in4 #ch-ci original1 time of keeping4 #cg ,erasers1 injury to paper by4 #fg kinds used4 #be1 #fg-fh ,erasures1 smoothing paper after4 #fh ,explanations on maps1 arrangement and lettering of4 #ai1 #eh-ej ,f4 ,figures1 differences from plates4 #aj-aa divisions of1 serial letters for4 #ab methods of inserting1 plate showing4 #ab ,formations1 geologic1 use of letter symbols for4 #bj-ba ,fossils4 ,see ,specimens4 ,four-color process1 advantage of4 #hj ,g4 ,gas wells1 symbols for4 #ba ,generalization1 true1 meaning of4 #ag ,geographic tables and formulas 7,bull4 #fej71 use of4 #dd1 #de ,geologic periods of time1 names of4 #ib ,gouache1 use of4 #fg1 #fi ,great ,lakes surveys1 maps published by4 #ae ,greek letters1 forms1 names1 and ,english sounds of4 #ic ,ground-water features1 symbols representing4 #ba-bc ,h4 ,hachuring1 use of4 #ej ,half-tone engraving1 preparation of copy for4 #gg-gh process and advantages of4 #ge-gh three-color process of4 #gh-hj ,half tones1 changes in4 #ci prints of1 showing effects produced by different screens4 #ef requirements for printing4 #aa ,heliotype4 ,see ,photogelatin processes4 ,hill shading1 use of4 #fj-ea ,hydrographic features1 lettering of4 #ed representation of4 #ea-eb ,hypsographic features1 lettering of4 #ed ,i4 ,illustrations1 kinds of4 #aj-aa ,inks1 kinds used4 #be1 #fg methods of using4 #be ,inserting plates and figures1 methods of1 plate showing4 #ab ,instruments1 draftsmen's1 list of4 #db ,j4 ,japanese transparent water colors1 use of4 #bf ,l4 ,land ,office maps1 scales and detail of4 #ad-ae ,latitude1 length of #a of1 at intervals of #aj4 #ia ,lending of photographs and drawings1 rules governing4 #cd ,letter symbols1 use of1 on geologic maps4 #bj-ba ,lettering1 directions for4 #ec-ee for lithographing4 #ij for names of streams4 #eb1 #ed on diagrams4 #fd on drawings of crystals4 #gj on original maps4 #ai on plans and cross sections of mines4 #fe-ff reduction sheet used in1 plate showing4 #ed use of type for4 #ed-ee ,light1 direction and gradation of4 #ff ,lithographs1 printing and insertion of4 #aa ,lithography1 original process of4 #hc-he ,see also ,engraving on stone4 ,longitude1 length of #a of1 at latitudes #j to #ij4 #ia ,m4 ,map of the world1 millionth-scale1 use of1 for base maps4 #ad ,maps1 areal patterns for1 drawing of4 #fa-fb bar scales for4 #ei-fj base1 conventional symbols used on4 #de-df including new data1 how obtained4 #ac-ad indication of sources on4 #ac of the ,united ,states on small scales1 use of4 #ae published maps available for4 #ad-ag reuse of1 to be approved4 #ac black and whits1 patterns used on1 plate showing4 #fb borders for4 #eg-fh cultural features on4 #eb-ec enlargement and reduction of4 #ah explanations for4 #ai1 #eh-ei geologic1 details of1 plate showing4 #eh printing of4 #hg-hi standard colors for4 #fb-fc hydrographic features on4 #fa-eb lettering on4 #ec-fe materials used for drawing4 #bc-bh orientation of4 #ah original1 margin required on4 #ai original base1 amount of detail on4 #ag must be free from colors and symbols4 #bh preparation of4 #ac-ad1 #ag-ah original geologic1 method of coloring4 #bg-bh projection for4 #ah-ai1 #dc-de reduction or enlargement of1 marking for4 #fc-fd relief on4 #dh-ea standard scales for4 #ah symbols used on4 #bj-bc drawing of4 #fa plates showing4 #bj1 #df titles for4 #eh topographic1 scales of4 #ad-ae ,mathematical signs1 forms and names of4 #id ,measures1 linear1 metric equivalents of4 #ib ,measuring scales for map projection1 use of4 #dd ,meridians used on public-land maps1 diagram showing4 #af ,metric measures1 ,english equivalents of4 #ib ,millionth-scale map1 use of4 #ad ,mine plans1 conventional lines for4 #bi features of4 #fe-ff symbols used on1 plate showing4 #bj ,minerals4 ,see ,rocks4 ,mississippi ,river ,commission1 maps published by #ae ,n4 ,names of rocks4 #id-ig ,national forest maps and proclamations1 use of4 #ae ,o4 ,offset process1 description of4 #hg ,oilwells1 symbols for4 #ba ,opaquing1 meaning of4 #ah1 #dg1 #hf ,orientation of maps1 requirements for4 #ah ,original drawings1 general treatment of1 by draftsmen4 #db-dc preparation of4 #ab-dj ,outdoor sketches1 redrawing of4 #fi-gj ,p4 ,panoramas1 construction of4 #ga ,paper1 kinds used for drawings4 #bc-bd1 #fj1 #fa1 #ff1 #fi ,pastes1 use of4 #cg ,patterns1 areal1 method of drawing4 #fa-fb areal1 plate showing4 #fb ,pen drawings1 materials and methods used in making4 #fg-fh1 #fh-fi ,pencils1 colored1 use of4 #bf drawing1 quality and grades of4 #be1 #ff ,pens1 kinds of1 used for drawing4 #be1 #dh1 #fg ,photoengraving1 cost of4 #ge1 #gh1 #hj1 #ha general features of4 #gb-gc ,photoengravings1 printing and insertion of4 #aa ,photogelatin processes1 description of4 #hb-hc ,photographs1 adaptation of4 #hc bleaching of4 #fi care needed in taking and handling4 #cb1 #cc1 #ci-dj copyrighted1 consent for use of4 #cc-cd duplicate prints of1 requests for4 #cd mounting and numbering of4 #cc1 #cf-cg poor1 mating of drawings over4 #fh-fi preparation of1 for half-tone engraving4 #gg-gh record of source of4 #cd selection of4 #cb-cc retouching of4 #fh1 #gj-ga suitability of4 #i unpublished1 issue and use of4 #cd ,photolithographs1 changes in4 #ci ,photolithography1 description of4 #hf-hg ,planographic process1 description of4 #hg ,plans of mines1 drawing and lettering of4 #bi1 #fe-ff symbols used on1 plate showing4 #bj ,plates1 differences from figures4 #aj-aa divisions of1 serial letters and numbers for4 #ab grouping small illustrations on4 #cf-cg methods of inserting1 plate showing4 #ab ,political divisions1 lettering of4 #ec1 #ed ,post-route maps1 scales and detail of4 #ae ,projection for maps1 preparation and checking of4 #ah-ai1 #dc-de ,proofs1 changes in4 #gf correction of4 #ch-ci duplicate1 supplying of4 #cj submittal of4 #ch ,public-land maps1 meridians1 parallels1 and township lines used on1 diagram showing4 #af ,public works1 lettering of4 #ec ,punctuation marks1 forms of4 #ed ,purpose of illustrations in ,survey reports4 #h1 #dj ,r4 ,railroad surveys1 data for maps obtainable from4 #ae ,railroads1 names of1 on maps4 #eg ,reduction of maps1 marking drawings for4 #fc-fd means of4 #ah ,reduction sheet for lettering1 plate showing4 #ed use of4 #ee ,relief1 methods of expressing4 #dh-ea ,reproduction of illustrations1 processes for4 #gb-ij relation of1 to the drawing supplied4 #g1 #dj ,reticulation1 sketching by4 #dg ,retouching of photographs1 materials and method used in4 #fh1 #gj-ga ,reuse of illustrations1 procedure for4 #cg-ch ,rocks1 igneous1 names of4 #ie-ig metamorphic1 names of4 #ie sedimentary1 names of4 #id-ie symbols used to distinguish4 #cb ,see also ,specimens4 ,roman numerals1 numbers expressed by4 #ic ,rubber1 liquid1 use of4 #cg ,s4 ,scales1 bar1 forms of4 #ej-fj measuring for projection of maps4 #dd standard1 of maps4 #ah ,scope of this manual4 #g ,screens1 half-tone prints showing effects produced by4 #ef ,selection of illustrations1 considerations governing4 #h-i ,sections1 columnar1 original drawings for4 #ca columnar1 symbols used in1 plate showing4 #cb structure1 combination of1 with views of topography4 #cj-ca drawing of4 #fd-fe original drawings for4 #bi-ca symbols used in1 plate showing4 #cb vertical exaggeration of4 #cj ,shading1 kinds used4 #fg ,signs1 mathematical1 forms and names of4 #jd ,sises of illustrations4 #aa-ab1 #dj ,specimens1 borrowed and fragile1 care of4 #ce drawings of1 methods of making4 #fj-fh paleontologic1 transmittal of4 #ce photographs of1 how printed4 #fh how used4 #cd-he ,springs1 symbols for4 #bb1 #bc ,state maps1 use of4 #ae ,stipple1 production of4 #ej1 #ea ,stone1 engraving on4 #hi-ij ,streams1 drawing of4 #ea-eb lettering names of4 #eb ,submittal of illustrations4 #aj ,symbols1 drawing of4 #bj1 #fa for ground-water features1 uniformity needed in4 #ba-bc for maps and mine plans1 plates showing4 #bj1 #df uniform use of4 #bj1 #de-df for oil and gas wells1 features of4 #ba for structure and columnar sections1 plate showing4 #cb lithologic1 use of4 #cb ,t4 ,three-color half-tones1 process of making4 #gh-hj ,titles of illustrations1 arrangement and place of4 #eh printing of4 #ai-bj wording and lettering of4 #ai ,tooling on half-tones1 effects obtained by4 #gg1 #gh ,topographic atlas sheets1 scales of4 #ad ,tracing1 method of4 #df-dg use of colors in4 #df-dg ,tracing linen1 use of4 #bd-be ,transferring1 celluloid1 process of4 #dg celluloid1 requisitions for4 #dg ,type1 lettering with4 #ed-ee styles and sizes of4 #ee ,v4 ,value of illustrations in ,survey reports4 #h ,vara1 length of4 #ib ,vignetting1 effect obtained by4 #gh ,w4 ,wall map of the ,united ,states1 use of1 for basemaps4 #ad ,water colors1 use of4 #bf1 #fg1 #ga ,waterlining1 use of4 #eb ,wax engraving1 process and advantages of4 #hj-ha ,wells1 symbols for4 #bb1 #bc ,wood engraving1 process of4 #ha-hb ,z4 ,zinc etchings1 changes in4 #ch-ci drawings for4 #gd insertion of4 #aa making and advantages of4 #gc-ge ,illustration3 circle 99 99 99 99 99 ,transcriber's ,note ,paragraphs split by illustrations were rejoined4 ,where ,greek characters occurred in the original1 ,greek3 was substituted for them4 ,to see these characters1 view the ,,utf-#h or ,,html version4