- . 
 
 . 
 I mi ' 
 
 ftp 
 
 an ' . . If 
 
 '. 1 ' 
 
 : 
 
 m 
 
 m 
 
Elements of Drawing 
 
 BY 
 
 GEORGE F. BLESSING, M.E., PH.D. 
 
 Professor of Mechanical Engineering and in charge of Engineering, Swarthmore College 
 Formerly Assistant Professor of Machine Design, Cornell University 
 
 AND 
 
 LEWIS A. DARLING, E. IN M.E. 
 
 Engineering Department Remy Electric Co., Formerly Assistant Professor of 
 Machine Design, Cornell University 
 
 FIRST EDITION 
 
 SECOND THOUSAND 
 
 NEW YORK 
 
 JOHN WILEY & SONS 
 
 LONDON: CHAPMAN & HALL, LIMITED 
 1913 
 
BY THE SAME AUTHORS 
 
 ELEMENTS OF DESCRIPTIVE 
 GEOMETRY 
 
 8vo, xvii +219 pages, 168 figures. Cloth, 
 $1.50 net. 
 
 CONTENTS. Preface. Introduction. Definitions, 
 Notation and First Principles, Problems on the 
 Point. Point and Line Problems. Line and Plane 
 Problems. Solids. Tangent Planes and Double- 
 Curved Surfaces of Revolution. Sections. Inter- 
 sections and Developments. 
 
 COPYRIGHT, 1912, 
 
 BY 
 GEORGE F. BLESSING AND LEWIS A. DARLING 
 
 Stanbopc jprcss 
 
 F. H. GILSON COMPANY 
 BOSTON, U.S.A. 
 
PREFACE 
 
 IT is the purpose of this book to present a course of instruc- 
 tion in Elementary Drawing for beginners who intend to pursue 
 a course in engineering or who desire to prepare themselves to 
 do commercial drafting. The work herein outlined, as well as 
 that contained in the companion volume, "Elements of De- 
 scriptive Geometry" by the same authors, is based on the 
 drawing-room courses required of all first-year students in 
 Mechanical and Electrical Engineering in Sibley College, Cornell 
 University, as a preparation for the more advanced work of 
 design in the second and third years of the course, which is also 
 required of all students in the college. 
 
 The task of writing the book and its companion volume was 
 undertaken by the authors,, at the writer's request, while they 
 were members of the staff of instruction of the Department of 
 Machine Design and Construction of Sibley College. The object 
 in view was twofold, namely, to obtain a book exactly suited to 
 the needs of the Department, which we had heretofore been 
 unable to do; and also to put into permanent shape the methods 
 and principles used in this* work, thus forming one of a correlated 
 series of texts which eventually, it is expected, will fully cover 
 the entire work of the department. The authors brought to 
 the task a full knowledge of the more advanced work of the 
 Department, having had experience in teaching these advanced 
 subjects in design which, with their experience elsewhere both in 
 practical and teaching positions, was of great aid in improving 
 and refining this more elementary work. 
 
 There is nothing experimental in the principles or methods 
 outlined in the book, as most of them have been in constant use 
 in Sibley College for years and have been productive of most 
 excellent results, not only in teaching the art of elementary 
 drawing but as a preparation for the more advanced work in 
 design. 
 
 295883 
 
vi PREFACE 
 
 Particular attention is given in the drawing-room work in 
 Sibley College to the art of lettering and the methods presented 
 in the chapter on lettering have been remarkably successful. 
 Only two alphabets have been presented, it being considered 
 best to confine the student's efforts to a thorough study and 
 practice of those two which are of almost universal use rather 
 than to make a superficial study of more elaborate alphabets 
 which find very limited, or no use. The system of spacing was 
 very largely developed by Prof. John T. Williams, who has 
 taught it for a number of years with marked success. The authors 
 have refined the system and also developed and presented a 
 spacing chart, as it is believed that some instructors may prefer 
 its use to that of rules. 
 
 In regard to the material on "drawing-room system," no 
 claim is made by the authors that it is the best in the sense that 
 there is a best system, but it is their belief, which is based on 
 considerable experience, that if this system is well understood 
 by the student he will have no trouble in understanding any 
 other he may be called upon to work with. 
 
 Chapter V has been presented because of the growing popu- 
 larity of isometric drawing in practically all branches of tech- 
 nical work. 
 
 It will be noted that though the book is based on the practice 
 of Sibley College it is written in a flexible manner so as to be 
 adaptable to almost any logical sequence of presentation, the 
 general text matter applying equally to the drawing-board 
 course presented or to a beginners' course arranged by in- 
 structors in the subject. The following suggestions by the 
 authors as to the use of this book will make this clearer. 
 
 The text matter is intended to give in a practical and concise 
 form such information as the beginner should have in order to 
 intelligently pursue the drawing-board work. 
 
 It is not supposed that lessons be assigned for recitation after 
 the manner usually followed in teaching textbooks, that is, by 
 beginning with Chapter I and assigning consecutive para- 
 graphs to the end. The paragraphs should be assigned at the 
 time the information can be applied directly to the drawing 
 being executed. To facilitate this method each drawing plate 
 
PREFACE Vii 
 
 has certain paragraphs assigned and at the completion of the 
 plate there should be an examination, oral or written, covering 
 these paragraphs. The proper method of covering the text 
 previous to examinations will depend upon the methods of the 
 institution using the book. It is most desirable to have regular 
 recitation periods, and the authors believe one hour per week 
 upon recitation should cover the work satisfactorily. Where 
 this is impracticable the instructor should question the student 
 as he proceeds with his work in the drawing-room. Especial 
 attention should be directed to points where the student's work 
 shows a lack of knowledge and he should be required to refer 
 at this time to the parts of the text covering the points in ques- 
 tion. 
 
 Where the book is used in this manner, that is, simply as a 
 book of reference, a preliminary examination should be held 
 after the completion of each plate. The instructor should con- 
 stantly keep in mind the object of this book, which is to teach 
 the student: 
 
 ist, how to select, care for, and use drawing instruments. 
 2nd, how to make and read technical drawings. 
 3rd, how to think over the drawing board. 
 4th, to lead him to consider the relation drawing bears to 
 design, shop processes, and shop organization. 
 
 The third and fourth items are not usually given the attention 
 their importance demands, and it is not unusual to see a college 
 graduate make a beautiful drawing whjch is full of errors, due 
 to the fact that all thought has been given to the drawing paper 
 and none to the object it represents or to the shop methods 
 necessary to produce this object. To aid in overcoming this 
 difficulty the authors have avoided the use of models of the 
 geometric or kindergarten type or of machine parts selected 
 at random. 
 
 The models selected are parts of a wood-turning speed lathe, 
 and are selected because the students will most likely be more 
 familiar with this machine than any other. Also in most 
 places where this course is taught the student will be working on 
 his wood-turning exercises in the shop, on this machine, at about 
 
viii PREFACE 
 
 the same time he is doing his drawing. For this reason he is 
 most apt to study the principles of design involved, the relation of 
 parts, etc., and thus do his work in a much more intelligent 
 manner than if he held no further interest in the model than 
 that of making a dimensional picture of it. 
 
 DEXTER S. KJMBALL, 
 Professor of Machine Design and Construction, 
 
 Cornell University. 
 June 8, 1912. 
 
 AUTHORS' NOTE 
 
 The authors are deeply indebted to Prof. J. T. Williams of 
 Sibley College, Cornell University, without whose assistance 
 and cooperation this book in its present form would not have 
 been possible. 
 
 Grateful acknowledgment is also made of assistance by Prof. 
 D. S. Kimball in developing the book and outlining its scope, 
 and to Prof. G. W. Lewis, Messrs. A. Kessler and L. J. Brad- 
 ford for assistance in preparing material and reading proof. 
 
CONTENTS. 
 
 PAGE 
 
 FRONTISPIECE i 
 
 Perspective View of Wood-turning Speed Lathe. Partial Longi- 
 tudinal Section through Headstock. Partial Longitudinal Section 
 through Tailstock. 
 
 PREFACE v 
 
 General Purpose of the Book. Basis on which the Book is Planned. 
 Special Attention Given to Lettering. Growing Popularity of Iso- 
 metric Drawing. Flexibility of the Book. The General Text to be 
 Referred to as Needed and Consecutive Text Lessons not to be Given. 
 Points to be Kept in Mind by the Instructor. Models Selected for 
 the Courses in Drawing are Parts of a Wood-turning Speed Lathe. 
 Author's Acknowledgment. 
 
 CHAPTER I. 
 
 SELECTION, CARE AND USE OF DRAWING INSTRUMENTS AND MATERIALS. 
 SEC. 
 
 1. Introductory i 
 
 Quality of Instruments. Care of Instruments. Description of 
 Instruments and Supplies. 
 
 2. List of Instruments and Supplies Necessary for Complete Courses. . 2 
 
 3. Drawing Paper 4 
 
 Selection. Quality. Paper for Inked Drawings. Paper for Pencil 
 Drawings. Working Side. Detail Manila Paper. Whatman Paper. 
 
 4. Ruled Paper 5 
 
 Purpose. Cross-section Ruling. Isometric Ruling. Cleaning Ruled 
 Paper. 
 
 5. Tracing Paper 6 
 
 Description. Blue Prints from. 
 
 6. Tracing Cloth 6 
 
 Description. The Glazed Side. The Dull Side. Cutting Tracing 
 Cloth to Size. Quality to Use. 
 
 7. Blue-print Paper 6 
 
 Description. Formula for Making Blue-print Paper. Storage. 
 
 8. Drawing Boards 7 
 
 Material and Design. Testing. 
 
 9. Thumb Tacks 
 
 Best Design. Use of. 
 
 ix 
 
X CONTENTS 
 
 SEC. PAGE 
 
 10. T-Squares 8 
 
 Purpose. Design and Materials. To Test. Care of. Use of. 
 
 11. Triangles 10 
 
 Design and Materials. Desirable Size. Testing the Angles and 
 Edges. Use of. 
 
 12. Irregular Curves 13 
 
 Design and Materials. Use of. 
 
 13. Pencil Pointer 14 
 
 Design and Use of. 
 
 14. Lead Pencils 14 
 
 Essential Qualities. Commercial Rating. Design of. Care of. 
 
 To Sharpen. The Cone Point. The Chisel Edge. To sharpen Lead 
 for Bow Pencil or Compass. 
 
 15. Erasers and Erasures f 16 
 
 Purpose and Quality. Method of Making Erasures. 
 
 16. Erasing Shield 17 
 
 Use and ^Design of. 
 
 17. Soapstone 18 
 
 Description and Use of. 
 
 18. Drawing Ink 18 
 
 Requirements of a Good Drawing Ink. Colored Drawing Inks. 
 
 Care of. 
 
 19. Ordinary Pens 18 
 
 Description of Common Styles. Ball-pointed Pen. Crow-quill Pen. 
 
 Selecting a Pen. "Breaking in" and Use of Pen. 
 
 20. Pen Holders 20 
 
 Design of. 
 
 21. Ruling Pens 20 
 
 Design and Materials. To Adjust. To Fill. Proper Use of. 
 Care of. To Clean Pen Blades. To Sharpen. To Test. 
 
 22. Compasses 23 
 
 Purpose. Names of Parts. Materials of. Design of. The Socket- 
 joint and Head-joint Design. The Needle Point. The Extension 
 Bar. To Prepare and Use the Compass. 
 
 23. Dividers 26 
 
 Purpose. Design and Materials. Use of. 
 
 24. Bow Dividers 27 
 
 Purpose and Advantage. 
 
 25. Bow Pencils , 27 
 
 Purpose and Advantage- Ordinary Design of. Materials of. Special 
 Design of. To Prepare the Bow Pencil. To Test. 
 
 26. Bow Pens 28 
 
 Purpose. Requirements. Care and Use of. 
 
 27. Scales 29 
 
 Purpose. Engineer's Scale. Architect's Scale. Materials and 
 Design. Scale of Triangular Cross Section. Proper Use. To Test. 
 
 28. Protractors 31 
 
 Purpose. Materials and Design, Use of. 
 
CONTENTS XI 
 
 SEC. PAGE 
 
 29. Machinist's Calipers, Dividers, and Steel Rule 32 
 
 Use of. Materials and Design. Outside Calipers. Inside Calipers. 
 Proper Use of Calipers. Design and Use of Dividers. Microme- 
 ters and Extremely Accurate Measurements. 
 
 30. Blotter, Penwiper, and Instrument Rag 33 
 
 Use of Blotter. Use of Linen Pen Rag. Use of Instrument Rag. 
 
 CHAPTER II. 
 LETTERS, NUMERALS, AND LETTERING. 
 
 31. Introductory 34 
 
 Importance of Good Lettering. Simple Style of Lettering. Gothic 
 Alphabet. Ability to Letter. 
 
 32. The Study of Lettering 34 
 
 Not a Purely Mechanical Process. Outline and Characteristics of 
 Letters. Grouping of Letters. Sense of Proportion. Practice and 
 Patience. Critical Study of Lettering. 
 
 33. Slope of Letters 36 
 
 Advantages of the Inclined Alphabet. Slope Used in this Work, and 
 how Obtained. 
 
 34. General Description of Model Letters 37 
 
 The Stem, Definition of. Top, Bottom, and Side Guide Lines. Center 
 Lines in lettering. Dimensions on Model Letters. Slope of Model 
 Letters. Direction Arrows with Numbers. System of Strokes. 
 
 35. Spacing . 39 
 
 Importance of Correct Spacing. How to Judge Spacing. Distance 
 between Letters. Element of Adjacency, Defined. Spacing for 
 Various Line Combinations in Capital Letters. Spacing of Numerals. 
 Spacing of Capital Letters in Combination with Small Letters and of 
 Small Letters. Spacing between Words. Spacing between Sentences. 
 
 Spacing Allowed for Punctuation Marks. 
 
 36. Systematic Method of Lettering 44 
 
 37. The Size and the Lettering of Letter Sheets 44 
 
 SET OF FREE-HAND LETTERING EXERCISES 
 
 38. Outline and Characteristics of Capital (or Upper-case) Letters . 
 
 Composed of Straight Lines Only 44 
 
 Detailed Description of each of the Following Straight-line Capital 
 Letters: /, L, F, E, II, T, N, M, Y, V, X, A, K, Z and W. 
 
 39. Sheet A 4 
 
 Exercise in Making Large-size, Straight-line Capital Letters Free-hand. 
 (See Fig. 39, page 49.) 
 
 40. The Sloping Ellipse 5 
 
 Construction of. Medium Slope. Extreme Slope. 
 
 41. Outline and Characteristics of Capital (or Upper-case) Letters. 
 
 Composed Wholly or Partly of Curved Lines 51 
 
 Detailed Description of Each of the following Curved-line Capital 
 Letters: 0, Q, C, G, D, U, J, P,R,B, S, and the Abbreviation &. 
 
xii CONTENTS 
 
 SEC. PAGE 
 
 42. Sheet B 54 
 
 Exercise in Making Large-size, Curved-line Capital Letters Free-hand. 
 (See Fig. 41, page 55.) 
 
 43. Sheet C 56 
 
 Exercise in Making Capital Alphabet Free-hand to a Reduced Size. (See 
 
 Fig. 42, page 57.) 
 
 44. Outline and Characteristics of Numerals 58 
 
 Detailed Description of each of the Numerals: 4, 7, o, g, 6, 5, 8, j, and 2. 
 
 45. Sheet D 60 
 
 Exercise in Making Numerals of Both Large and Reduced Size Free- 
 hand. (See Fig. 43, page 6 1.) 
 
 46. Sheet E 60 
 
 Free-hand Exercise in Making Slant, Capital, Gothic Letters of a Size 
 Suitable for Notes on Drawings. (See Fig. 44, page 62.) 
 
 47. The Small (or Lower-case) Letters of the Inclined Gothic 
 
 Alphabet. . 60 
 
 Detailed Description of Each of the Lower-case Letters Grouped as 
 Follows: o. a, d, g, q. b, p. c, e. n, r, h, m. u, y. /, i, k, 
 t,f,j- s.v, w. x. z. 
 
 48. Sheet F 67 
 
 Free-hand Exercise in Making the Small (or Lower-case) Letters to a 
 Large and Reduced Scale. (See Fig. 45, page 68.) 
 
 49. Designing Headings and Titles 69 
 
 50. Sheet G 69 
 
 Free-hand Lettering Exercise in Laying Out a Practical Title Form 
 
 and Bill of Material. (See Fig. 47, page 70.) 
 
 51. Examination on Chapter II 69 
 
 CHAPTER III. 
 MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE. 
 
 52. Introductory 71 
 
 The Purpose and Field of Drawing. A Perspective Drawing. A 
 Mechanical Drawing. Symbols and Notes on Drawings. 
 
 53. Projection and Projected Views 73. 
 
 Orthographic Projection. Vertical Plane of Projection. Horizontal 
 Plane of Projection. Third Angle Projection. Various Methods of 
 
 " Folding " Planes of Projection. Plan View. Side Elevation. 
 Front Elevation. 
 
 54. Conventional Lines 76 
 
 Contrast between Lines. "Weight" of a Line, Denned. Construction 
 
 and Weight of the Visible Line, the Invisible Line, the Section Line, the 
 Dimension Line, Arrow Heads, the Reference Line, and the Center 
 Line. Symbol for Center line. A " Finished " Line. A Clear-cut 
 Line. A Line Free from Waves. A Line of Unvarying Width. 
 A Line Colored to the Same Degree throughout. 
 
 55. Sectioning and Sectional Views 79 
 
 Purpose of a " Section." Longitudinal Section. Transverse Section. 
 Simple Section. Compound Section. Conventional Sectioning. 
 Sectioning Adjoining Pieces. A Number to Represent a Material. 
 
CONTENTS xiii 
 
 SEC. PAGE 
 
 How to Draw and Space Section Lines. Section Liner. To Section 
 a Large Area. Location of the Section. Certain Details not Sec- 
 tioned. A Quarter Section View. A "Turned-up" Section. 
 
 56. Number and Arrangement of Views 83 
 
 Determining on the Views, their Number and Arrangement. Views 
 Arranged According to Third Angle Projection. Position in which to 
 Represent a Part. Blocking Out the Sheet. 
 
 57. Detail Drawings 85 
 
 Purpose of a Detail Drawing. The Number of Parts Detailed on a 
 Single Sheet. Operation Sheets. Grouping Parts on a Sheet. Work- 
 ing Up the Views. 
 
 58. Assembly Drawings 86 
 
 Purpose of Assembly Drawings. Dimensions on Assembly Drawings. 
 
 59. Conventional Methods 87 
 
 Various Uses of. Lack of Uniformity in Common Conventions (see 
 Fig. 65, page 88). Conventional Method of Showing Each of the Fol- y 
 lowing: Solid Shaft, Bearing, Timber Section, Hollow Shaft, Holes 
 Equally Spaced Around a Circle, Broken Lines to Represent a Moving 
 Arm in Extreme Positions, Broken Lines to Represent a Part in Several 
 Positions, Broken Lines to Represent a Part not Completely Drawn, 
 Visible V Threads, Invisible V Threads, Square Thread, National Acme 
 Thread, Drilled Holes, Tapped Holes, Reference Numbers, and Cross- 
 section of Steel Shapes. 
 
 60. Drawing to Scale 9 
 
 Explanation of. Method of Making a Scale. "Scales " in Common 
 Use. To "Read" a Scale. Shrink Rule for Pattern Makers. 
 
 61. Choice of a Scale in Drawing 93 
 
 Best "Scale" to Use. To Determine the Largest Scale Permissible. 
 
 To Find the Scale for Each of Several Parts Represented on the Same 
 Sheet. 
 
 62. Dimensioning Working Drawings 94 
 
 Importance of Dimensions. How to Select the Dimensions. When 
 Dimensioning is Satisfactory. Results of Inaccurate Dimensioning. 
 
 To Check Dimensions. Dimensions not to Scale. Arrowheads, Loca- 
 tion of. Dimension Numbers, the Selection and Location of. Abbre- 
 viation for "Feet." Symbol for Inches. Refinement in Dimensions. 
 Dimensioning Rough Castings. Limits in Dimensioning. Overall 
 and Sub-divided Dimensions. Repetition of a Dimension. Distribu- 
 tion of Dimensions. Dimensioning Similar Parts. "Leader," Defini- 
 tion of. Dimensions which Fall on a Sectioned Area. Dimensioning a 
 Circle, a Cored Hole, Fillets, a Radius, a Threaded Piece, a Tapped Hole, 
 Angles and Tapers. 
 
 63. Notes on a Drawing 7 
 
 When Necessary. How to Compose and Lay Out. Style of Lettering 
 
 to Use in this Work. 
 
 64. Indicating the Finish of Surfaces 9& 
 
 When a Surface is "Rough." When a Surface is "Finished." - Some 
 
 of the Kinds of Shop Finishes. To Indicate the Finish Desired. 
 
xiv CONTENTS 
 
 SEC. PAGE 
 
 65. Use of Record Forms and Titles 98 
 
 A Complete Record of Each Drawing is Essential. Information which 
 
 is Necessary and which Should be Recorded. Changes on Drawings, 
 Record of. 
 
 66. The Title-form on a Drawing 100 
 
 Location. No One Standard Form. Title Form Used in this Work. 
 
 Style, Size and Arrangement of Lettering in Title Form. 
 
 67. Bill of Material 101 
 
 Where Used and Purpose of. Form Used in this Work. Location of. 
 
 Style and Size of Lettering to Use in. Complete Explanation of the 
 Bill of Material Form to be Used. How to Call for Standard Parts. 
 Materials, Abbreviations of, in Bill of Material. 
 
 68. Numbering and Indicating the Size of Drawings 103 
 
 Purpose of. Sizes Most Generally Used. Size of Paper for Mechan- 
 ical Drawings in this Work. Numbering of Drawings in this Work. 
 
 69. Part Numbers on a Drawing 104 
 
 Purpose and Location of. Layout of Part Numbers Used in this 
 Work. 
 
 70. Recording Patterns on a Drawing 104 
 
 Purpose and Method of Numbering Patterns. Method of Selecting 
 
 and Recording Pattern Numbers to be Followed in this Work. 
 
 71. Time Keeping in Drawing 105 
 
 Method and Purpose of, in Practice. System of, in this Work. 
 
 72. Border Lines 106 
 
 Location and Purpose of. To Lay Out Border Lines in this Work. 
 
 73. To Fasten the Paper or Tracing Cloth to the Board 107 
 
 Method of Procedure. Location of Paper and Tracing Cloth on the 
 Board in this Work. 
 
 74. To Make a Pencil Drawing 108 
 
 General Instructions. Systematic Procedure and Specific Instruc- 
 tions in this Work. 
 
 75. Inking Drawings no 
 
 To Prepare the Pencil Drawing for Inking. Inspecting the Ruling 
 
 Pen and "Charging" it with Ink. To Keep the Ruling Pen Working 
 Satisfactorily. General Instructions for. Faulty and Ragged Lines. 
 
 Drawing Ink not to be Blotted. Ink-bottle Holders. Specific 
 Instructions for Inking Drawings in this Work. 
 
 76. Checking Drawings 113 
 
 Importance of Efficient Checking. General Discussion on. Specific 
 Instructions for. 
 
 77. Tracing 114 
 
 A Tracing, Defined. Use of a Tracing. How to Make a Tracing. 
 Moisture Spoils Tracing Cloth. To Clean Tracing Cloth. Erasures 
 
 on a Tracing. 
 
 78. Blueprints 1 16 
 
 How Made. Changes on. 
 
CONTENTS xv 
 
 SET OF MECHANICAL DRAWING EXERCISES 
 
 SEC. PAGE 
 
 79. Drawing C-ioi n6 
 
 Detail Drawings of Lathe Spindle, Key, Fiber and Steel Washer, and 
 
 of Special Nut (see Fig. 82, page 1 1 8). General and Specific In- 
 structions for Making. 
 
 80. Tracing Drawing C-ioi 121 
 
 General and Specific Instructions Given. 
 
 81. Blueprint of Tracing C-ioi 121 
 
 Purpose of Making. Specific Instructions Given. 
 
 82. Drawing C-I02 122 
 
 Detail Drawing of Lathe Leg. (See Fig. 85, page 123.) 
 
 83. Drawing C-i<>3. 124 
 
 Detail Drawing of Lathe Bed and Bracket. (See Fig. 88, page 125.) 
 
 84. Drawing C-IO4 126 
 
 Drawings of Bolts, Nuts and Screws, the Proportions of which are De- 
 termined by the Student from Empirical Formulas Given in the Text. 
 (See Fig. 89, page 128.) 
 
 85. Tracing Drawing C-I02 129 
 
 86. Tracing Drawing C-ioa 129 
 
 87. Drawing C-ios 129 
 
 Detail Mechanical Drawings made from Sketches of the following Lathe 
 Parts: Tail Stock Center, Shell, Tail Stock Spindle and Tail Stock 
 Spindle Clamp. 
 
 88. Drawing C-io6 130 
 
 Assembly Drawing of Lathe Tail Stock Complete, Built Up from Draw- 
 ings or Sketches of Each of the Parts Composing it. 
 
 89. Tracing Drawing C-io6 130 
 
 90. Examination on Chapter III r 130 
 
 CHAPTER IV. 
 FREE-HAND WORKING SKETCHES. 
 
 91. Introductory 131 
 
 Value of Free-hand Sketches. Some Uses of Free-hand Sketches. 
 
 92. Free-hand Copies of Working Drawings 131 
 
 Purpose of Making. 
 
 93. Free-hand Sketches from Objects 132 
 
 Working Sketch, Defined. Importance of Making Sketches Correct. 
 Discrimination in Selecting and Placing Dimensions on Sketches. 
 Proportioning Sketches by the Eye and without Direct Measurements. 
 
 To Make an "Eye Estimate" of a Distance. 
 
 94. Making Sketches from Memory 134 
 
 Good Method of. 
 
 95. The Free-hand Pencil Line i34 
 
 The First Essential. Specific Instructions for Making. Drawing a 
 Horizontal Free-hand Line. Drawing a Vertical Free-hand Line. 
 Manipulating the Pencil. To Draw a Curved Free-hand Line. 
 
XVl CONTENTS 
 
 SEC. PAGE 
 
 96. Free-hand Inked Line 136 
 
 Penciled Work to First be Correct. Specific Instructions for Drawing 
 
 a Free-hand Inked Line. Effects of too Much and too Little Ink on 
 the Pen. Care of Pen. 
 
 97. Building up a Sketch 137 
 
 Determining on the Views. To Begin a View. Building up and 
 Completing a Sketch, General Method of. 
 
 98. Title Form on Small Sheets 138 
 
 Title Form on Sketch Sheets in this Work. Style of Lettering in. 
 
 99. Size and Numbering of Sketch Sheets 139 
 
 Standard for this Work. 
 
 SET OF FREE-HAND DRAWING EXERCISES 
 
 100. Sheet No. i 139 
 
 Free-hand Sketches of Lathe Shim, Small Stud, and Clamp Stud (see 
 
 Fig. 97, page 140). General and Specific Instructions. 
 
 101. Sheet No. 2 141 
 
 Sketch of Main Casting of Lathe Headstock (see Fig. 99, page 143). 
 
 Specific Instructions. 
 
 102. Sheet No. 3 142 
 
 Sketches of Lathe Face Plate, Tail Stock Center, and Special Nut. 
 (See Fig. 104, page 145.) 
 
 103. Sheet No. 4 144 
 
 Sketches of Lathe Tail Stock Spindle and Shell. (See Fig. 105, page 146.) 
 
 104. Sheet No. 5 147 
 
 Sketches of Lathe Clamp Bolt, Hand Wheel and End Cap. (See Fig. 
 
 109, page 148.) 
 
 105. Sheet No. 6 147 
 
 Sketch of Lathe Clamp Copied from Model Sketch, the Dimensions for 
 which are Obtained by Direct Measurement of the Clamp and which are 
 Recorded on the Exercise Sketch. (See Fig. in, page 149.) 
 
 106. Sheet No. 7 150 
 
 Sketch of Lathe Tool Rest Support Slide and of Lathe Clamp for Tail 
 Stock Spindle. These sketches are made directly from the objects 
 themselves. 
 
 107. Sheet No. 8 ^o 
 
 Sketch of Lathe Tail Stock Screw and of Tail Stock Nut. (See Fig. 1 16, 
 page 151.) 
 
 108. Sheet No. 9 *S2 
 
 Sketch of Main Casting of Lathe Tail Stock. (See Fig. 119, page 153.) 
 
 109. Sheet No. 10 *5 2 
 
 Sketches Made Directly from Lathe Bearing Cap and Stationary Flange. 
 
 no. Sheet No. u X S 2 
 
 Sketch of Lathe Cone Pulley Made on Plain Paper (not Cross-section 
 
 Paper) and Directly from the Part Itself. 
 in. Sheet No. 12 J 5* 
 
 Copying a Sketch of the Pattern and Core Box of Lathe Cone Pulley. 
 
 (See Fig. 122, page 155.) 
 
CONTENTS XVli 
 
 SEC - PAGE 
 
 112. Inking Sheet No. i I54 
 
 This exercise gives practice in making free-hand inked straight lines. 
 
 113. Inking Sheet No. 2 z ^ 
 
 This exercise gives practice in making free-hand inked curved lines. 
 
 114. Inking Sheet No. n z ^ 4 
 
 This exercise gives practice in inking on ordinary unruled paper. 
 
 1 15. Examination on Chapter IV z 54 
 
 CHAPTER V. 
 
 ISOMETRIC DRAWING AND SKETCHING. 
 
 116. Introductory z ^6 
 
 General Discussion of the Subject of Isometric Drawing. Some Uses 
 
 of Isometrics. Advantages and Disadvantages of Isometric Drawings. 
 
 117. Principles I57 
 
 Statement of Important Principles on which Isometric Drawing is Based. 
 
 118. Isometric Drawing of a Cube 157 
 
 Method of Constructing. 
 
 1 19. Definitions 158 
 
 Definition of Isometric Axes, Isometric Origin, an Isometric Line, and 
 
 a Non-isometric Line. How Measurements must be Made in Iso- 
 metric Drawing. 
 
 120. Isometric Drawing of a Circle 159 
 
 Method of Constructing. Definition of "Construction Lines" and 
 
 ' ' Isometric Posi tion . " 
 
 121. Approximate Method of Making an Isometric Drawing of a Circle. 160 
 
 122. Isometric Drawing of a Plane Figure Composed of Straight and 
 
 Curved Lines 160 
 
 General Method of Constructing. 
 
 123. Isometric Drawing of a Cube Cut by a Plane 161 
 
 General Method of Constructing. 
 
 124. Isometric Drawing of Wall 162 
 
 With Axes in Ordinary Position. With Axes Reversed. 
 
 125. Isometric of a Cylinder 163 
 
 Method of Constructing. 
 
 126. Isometric of Screw Thread 163 
 
 Method of Showing "Conventional" Isometric Thread. 
 
 127. Hollow Cylinder with a Quarter Section Removed 164 
 
 Isometric Drawing of Lathe Spindle Taken as an Example. 
 
 128. Offset Construction in Isometric Drawing 164 
 
 129. Isometric Drawing of a Sphere 165 
 
 General Method of Constructing. Isometric Drawing of a Half 
 Sphere; of One-eighth of a Sphere. 
 
 130. Isometric Drawing of Lathe Cap 166 
 
 General Method of Constructing. 
 
 131. Size and Numbering of Sketch Sheets 166 
 
 Isometric-ruled Paper. 
 
Xviii CONTENTS 
 
 SET OF FREE-HAND ISOMETRIC EXERCISES 
 
 SEC. PAGE 
 
 132. Sheet 1 167 
 
 Isometric Sketch of Tool Rest Support Slide for Lathe (see Fig. 138, 
 page 1 68). General and Specific Instructions. 
 
 133. Sheet II 169 
 
 Isometric Sketches of Lathe Key, Shim, Stud, Washer and Special Nut. 
 
 (See Fig. 144, page 170.) 
 
 134. Sheet III 171 
 
 Isometric Drawing of Lathe Collar and Bearing, the drawing and all 
 dimensions made by reference to the objects themselves. 
 
 135. Sheet IV 171 
 
 Isometric Drawing of Lathe Spindle, the drawing to be inked and made 
 from observation of the object itself. 
 
 136. Sheet V 172 
 
 Isometric Drawing of Lathe Cap. 
 
 137. Sheet VI 172 
 
 Isometric Drawings of Lathe Shelf-Bracket. (See Fig. 150, page 173.) 
 
 138. Examination on Chapter V 174 
 
 APPENDIX A. Drawing Room System 
 
 140. Commercial Drawing Rooms 175 
 
 Some System Usually Required. Value of Systematically Carrying on 
 this Work. General Method of Procedure. Sizes of Drawings. 
 Position of Sheet or Drawing on the Board. Border Lines. Number- 
 ing and Lettering of Sheets and Drawings. Title-Form and Its Loca- 
 tion. Bill of Material and Its Location. Style of Lettering. Con- 
 ventions and Abbreviations. 
 
 INDEX 179 
 
ELEMENTS OF DRAWING 
 
 CHAPTER I 
 
 SELECTION, CARE AND USE OF DRAWING INSTRU- 
 MENTS AND MATERIALS 
 
 i. Introductory. The accuracy and finish of mechanical and 
 geometrical drawings, as well as the speed with which the drafts- 
 man works, depend to a very large extent upon the quality of 
 instruments used. To secure the best results the most experienced 
 draftsman requires instruments of a first-class quality, and as 
 the beginner needs all the assistance possible, he should not 
 handicap himself by using instruments of an inferior grade. 
 Since, in this work, a knowledge is required of what goes to 
 make up instruments of a first-class quality, such knowledge 
 should be gained before purchases are made, in order that the 
 fullest benefits may be obtained. Thus unsatisfactory work, 
 in so far as it results from the use of inferior instruments and 
 supplies, can be avoided. 
 
 The quality of an instrument must not be judged entirely by 
 its cost, but by its design, accuracy of workmanship, and the 
 materials from which it is made. Some of the more costly in- 
 struments are designed for extreme accuracy of adjustment, and 
 are so delicate in mechanical construction that ordinary usage 
 soon renders them less accurate than the cheaper but more sub- 
 stantial makes. Hence, in selecting instruments it is best to 
 avoid those of extremely delicate construction, for as a rule 
 instruments of simple design prove most satisfactory, especially 
 for beginners. 
 
 The best of instruments, however, will soon deteriorate and 
 become unsatisfactory unless properly cared for, and the beginner 
 is especially urged to cultivate the habit of seeing that his instru- 
 ments are always kept in the best shape possible. 
 
OF DRAWING 
 
 In the following paragraphs instruments are briefly described 
 and the essential points which determine their superiority are 
 noted. Before purchasing instruments read the first portion of 
 each item referred to in the following paragraph and, if possible, 
 consult with some experienced person as to the names of reliable 
 makers of instruments and supplies. 
 
 2. List of Instruments and Supplies Necessary for the Com- 
 plete Course: 
 
 Drawing Paper (M)*. 10 sheets of drawing paper accurately 
 cut to 12" X 18" and punched. (See page 4, 3.) 
 
 Ruled Paper (L), (S). (a) 36 sheets 8" X loj" standard 
 punched (for #10 Manila cover), extra heavy weight cross-section 
 paper, ruled on one side only with lines " apart and every eighth 
 line heavy. (See page 5, 4.) (b) (S) 6 sheets 8" X ioj" 
 standard punched extra heavy weight isometric paper ruled 
 on one side only. (See page 5, 4.) 
 
 Tracing Cloth (M). 4 yards i8|"-wide tracing cloth of best 
 quality. (See page 6, 6.) 
 
 Blue-print Paper (M). J yard 36" wide slow acting blue- 
 print paper of best quality. Not to be purchased until required. 
 (See page 6, 7.) 
 
 Drawing Boards (M). (a) i pine drawing board 19" X 26". 
 (See page 7, 8.) (b) (L), (S). i well seasoned pine board 
 10" X 12" X T V thick. 
 
 Thumb Tacks (A), i dozen thumb jfe^cks with small round 
 heads about fV" diameter. (See page 8,' 9.) 
 
 T-Square (M). i T-square with solid head and polished 
 surfaces. Blade 26" long and preferably having edges lined with 
 transparent strips. (See page 8, 10.) 
 
 Triangles (M). (a) i 7" transparent triangle, 45. (See page 
 10, n.) (b) i 10" transparent triangle, 3o-6o. (See page 
 10, ii.) 
 
 Irregular Curve (M) i transparent irregular curve. Similar 
 to K. & E. #21 or Dietzgen #20. (See page 13, 12.) 
 
 " The instruments or materials marked (L) are required in lettering; 
 (M) in mechanical drawing; (S) in sketching; (A) in all courses. 
 
DRAWING INSTRUMENTS AND MATERIALS 3 
 
 Pencil Pointer (A), i medium-cut file (see page 14, 13) or 
 a small pad of fine sandpaper. 
 
 Pencils (A), (a) i 4.H pencil of hexagon cross section. (See 
 page 14, 14.) (b) (M) i 6H pencil of hexagon cross section. 
 (See page 14, 14.) 
 
 Erasers (A), (a) i block of " Artgum " or a sponge rubber. 
 (See page 16, 15.) (b) Faber's (or equivalent) soft green 
 "Emerald" eraser. (See page 16, 15.) 
 
 Erasing Shield (A), i metal or celluloid erasing shield. (See 
 page 17, 16.) 
 
 Soapstone (A). Small piece of soapstone. (See page 18, 17.) 
 
 Drawing Ink (A), i bottle of black waterproof drawing ink- 
 (See page 18, 18.) 
 
 Pens (A), (a) i each of D. Leonardt & Co.'s #506 F. and 516 
 E.F., ball-pointed pens, (b) i each of Gillott #170 and #303; 
 i Esterbrook #182 and i Spencerian #i. (See page 18, 19.) 
 
 Penholders (A), (a) i penholder for ball-pointed pens. (See 
 page 20, 20.) (b) i penholder for ordinary pens. Cork- tipped 
 holders preferred. 
 
 Drawing Instruments (M). i set of drawing instruments 
 of good design and quality, consisting of at least the following: 
 
 (a) Ruling pen, 5" instrument of best quality. (See page 20, 
 
 21.) 
 
 (b) Compass, 5", pivot-jointed instrument (see page 23, 22) 
 with handle, lengthening bar, detachable pencil and pen legs. 
 
 (c) Dividers, 5" instrument with hair-spring adjustment. (See 
 page 26, 23.) 
 
 (d) Bow dividers having a maximum capacity of ij" radius. 
 (See page 27, 24.) 
 
 (e) Bow pencil having a maximum capacity of ij" radius. 
 (See page 27, 25.) 
 
 (f) Bow pen of best quality and having a maximum capacity 
 of i|" radius. (See page 28, 26.) 
 
 (g) Case for set of drawing instruments. 
 
 Scale (M), (S). i architect's 1 2-inch triangular boxwood 
 drawing scale, graduated as follows: |", i", f", |", f", i", ij", 
 2", 3", 4", and one " edge " graduated in inches and sixteenths of 
 an inch. (See page 29, 27.) 
 
4 ELEMENTS OF DRAWING 
 
 Protractor (M). Not absolutely necessary in this course. 
 (See page 31, 28.) 
 
 Machinist's Calipers (S). (a) i pair 6" outside spring-cali- 
 pers. (See page 32, 29.) (b) i pair 6" inside spring- 
 calipers. 
 
 Machinist's Scale (S). i 2-foot length machinist's scale. 
 Not absolutely necessary in this course. (See page 32, Fig. 36.) 
 
 Machinist's Dividers (S). i pair 6" machinist's dividers. 
 Not absolutely necessary in this course. (See page 33, 29.) 
 
 Blotter, i ordinary 4" X 9" blotter. (See page 33, 30.) 
 
 Pen Wiper (A), i piece of linen cloth about 9" X 9". 
 (See page 33, 30.) 
 
 Instrument Cleaner (A), i piece of cotton cloth about 
 1 8" X 1 8" for brushing off drawings and cleaning instruments. 
 (See page 33, 30.) 
 
 Manila Covers (L), (S). 3 standard (#10) Manila covers. 
 
 Paper Fasteners (A), i dozen #3 brass paper fasteners with 
 washers. 
 
 Carbonate of Soda (M). Small quantity of soda for making 
 changes on blue-print paper. 
 
 3 . Drawing Paper. In selecting paper to use for any particular 
 drawing, the character of the work and the purpose for which the 
 drawing is to be made are the determining factors. 
 
 In general a good drawing paper should be tough, strong, and 
 of uniform thickness. It should not become brittle or discolored 
 with age, and should not wrinkle nor warp during changing 
 weather. The surface should stretch evenly and admit of con- 
 siderable erasing without injury. 
 
 For inked drawings, the surface of the paper selected should 
 neither repel nor absorb liquids. If the paper repels ink the 
 lines will be irregular and uneven. An illustration of this is 
 seen if an inked line is drawn on oily paper. If the paper 
 absorbs ink, the line will spread and resemble a line drawn upon 
 blotting paper. For pencil drawings, paper with an unpolished 
 surface should be selected, since it will take a pencil mark more 
 readily than paper with a polished surface and does not require 
 the same care in making erasures. There is little difference in 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 the two sides of good drawing paper, but the side from which the 
 "water-mark" reads correctly is meant to be the working side. 
 
 A cheap grade of Manila paper will do for such pencil work as 
 .shop drawings, preliminary sketches, drawings to be traced, and 
 in general all drawings not requiring extreme accuracy nor 
 intended to be of permanent value. A better grade of paper 
 should be used for work of a more exacting character. 
 
 Whatman paper is used extensively for making permanent ink 
 drawings. There are two grades suitable for this purpose; 
 namely, hot pressed and cold pressed. The hot pressed 
 (marked H.P.) has a smooth surface, and is used principally for 
 fine-line drawings. The cold pressed (marked N. to signify not 
 hot pressed, and sometimes marked C.P.) is used extensively for 
 tinted and water-color work. 
 
 4. Ruled Paper. In the study of free-hand lettering and in 
 sketching, the beginner can save much time and secure greater 
 accuracy by using specially ruled paper, the advantage being 
 that proportion can be obtained without the aid of measuring 
 instruments. 
 
 Fig. i (a) shows cross-section ruling, the small squares being 
 one-eighth inch, 
 and every eighth 
 line is extra 
 heavy so that the 
 one-inch squares 
 stand out promi- 
 nently. This 
 paper is used in 
 ordinary sketch- 
 ing, etc. 
 
 (a) Cross-Section Ruling. (b) Isometric Ruling. 
 
 Fig. i. Ruled Paper. 
 
 Fig. i (b) shows isometric ruling, which is used in making 
 isometric perspective sketches. 
 
 Care must be exercised in cleaning drawings made on cross- 
 section paper, as cleaning with either the eraser or the "artgum" 
 tends to dim the section lines and thus spoil the work. 
 
 Make all lines light weight and with a medium soft pencil 
 then retrace the lines that are to be permanent and clean the 
 drawing. This method insures the least amount of erasing. 
 
6 ELEMENTS OF DRAWING 
 
 5. Tracing Paper. Tracing paper is a thin, transparent paper 
 which is used for making tracings that are usually (but not 
 always) to be of a temporary character. It is cheaper than 
 tracing cloth, but inferior to it in permanency. Blue prints 
 made from drawings on tracing paper require longer exposure 
 and are not so distinct as those made from drawings on tracing 
 cloth. 
 
 6. Tracing Cloth. Tracing cloth is a specially prepared linen, 
 having one side finished with a smooth glazed surface and the 
 other dull finished. Either side will take ink and there is a differ- 
 ence of opinion among draftsmen as to which is the better side to 
 work on. The glazed side is better for lettering and free-hand 
 work in general, as there is less tendency to catch the pen point 
 and cause blotting; also, since the glazed coating holds the ink 
 and keeps it from soaking into the fibers of the cloth, it is easier 
 to erase ink from this side. The chief disadvantages are that 
 the glazed side does not take the ink quite so readily; also 
 the tracing tends to curl up when the inking has been done on 
 the glazed side. The dull side takes ink more easily, and if any 
 lines are to be penciled directly on the cloth (as in making alter- 
 ations, additions, etc.) the rough surface of the dull side takes 
 these lines more readily. For the same reason the dirt collects 
 from the triangles and T-square. The glazed side is recom- 
 mended for beginners and with experience the draftsman will 
 determine his preference. 
 
 In cutting the tracing cloth (called for in the list of neces- 
 sary supplies) into sheets for use, see that each sheet is large 
 enough to permit of cutting off the margin containing the thumb 
 tack holes when the tracing is finally trimmed to the standard 
 size (12" X 18"). Also, in cutting the cloth, care must be exer- 
 cised to avoid breaking its surface, as creases and broken places 
 render the cloth unfit for use. 
 
 Only a good quality tracing cloth should be used. 
 
 * 
 
 7. Blue-print Paper is a specially prepared paper, having one 
 side coated with chemicals which are sensitive to light and which 
 will turn a rich permanent blue after the paper has been exposed 
 
DRAWING INSTRUMENTS AND MATERIALS 7 
 
 to the light and washed in clean water. Blue-print paper is 
 seldom prepared in the drafting room since it can be bought 
 cheaper in the open market. A formula for preparing blue-print 
 paper is as follows : 
 
 2\ ounces Red Prussiate of Potassium in i pint of water. 
 
 4 ounces Citrate of Iron and Ammonia in i pint of water. 
 
 Dissolve thoroughly and filter; then mix and apply evenly on 
 one side of the paper with a sponge or a broad, thin brush. The 
 paper must be prepared in a dark place and must be stored in 
 a dark dry place. 
 
 8. Drawing Boards. A drawing board should be made of a 
 light weight material which is not greatly affected by changes of 
 weather, and which will take the thumb tacks easily and hold 
 them securely. Also, the board should be designed to allow for, 
 or resist as far as possible, any change in shape due to warping or 
 handling. The best material for a drawing board is thoroughly 
 seasoned, soft, white pine, free from knots or pitch. The best 
 design depends largely on the size of the board. 
 
 The board recommended for use in this work, both as to 
 design and size, is shown in Fig. 2. This board consists of a 
 
 Fig. 2. Ordinary Drawing Board. 
 
 central portion or " body," in which part the grain should run 
 lengthwise, and " end strips " so placed that the grain runs at 
 right angles to that of the body. 
 
 The body and end strips are united by a glued tongue and 
 grooved joint. In some instances the end strips are made of 
 hard wood in order to better resist warping or being nicked in 
 handling. This construction will resist excessive warping in 
 
& ELEMENTS OF DRAWING 
 
 small boards, but the larger sizes are usually made with a pair 
 of hard-wood ledges screwed or dovetailed to the back, and in 
 addition there is a series of saw grooves cut lengthwise on the 
 back of the body of the board. 
 
 The drawing board should be covered with a light coat of 
 shellac to protect it from moisture and to keep it clean. 
 
 The top surface is termed the working face (see Fig. 2, 
 page 7), and should be a perfectly smooth plane. The left-hand 
 edge is termed the working edge, because it acts as a guide for 
 the T-square head. The working edge should be perfectly 
 straight and smooth and free from nicks. The straightness of 
 the working edge should be tested occasionally by placing a 
 standard straightedge, or the edge of a T-square blade which is 
 known to be perfectly straight, along it to see if the two coin- 
 cide throughout. 
 
 9. Thumb Tacks. For all ordinary work the drawing paper 
 or tracing cloth is secured to the drawing board with thumb 
 
 tacks. These tacks are inexpensive and only the 
 best should be used. A good form is shown in 
 
 Fig. 3- 
 
 The tack should be small and the outer edge 
 of the " head " should be thin so as not to inter- 
 ^ \r"'^**' f ere with the free use of the T-square and triangles; 
 i as a rule, small thumb tacks are preferable, say T 6 g " 
 
 Fig. 3. ordinary diameter. 
 
 One tack^ should be used at each corner of the 
 sheet, and if the drawing of tracing is large, enough thumb tacks 
 should be placed along the edges to hold the paper or cloth 
 securely on the drawing board. Tracing especially can be done 
 much more rapidly if the cloth fits closely to the paper drawing. 
 
 10. T-Squares. The T-square derives its name from its resem- 
 blance to the letter T and from its use in " squaring " the paper 
 on the drawing board. It is intended primarily to serve as a 
 ruling edge in drawing horizontal lines (that is, lines perpendicular 
 to the working edge of the drawing board), and to provide an 
 edge for guiding the triangles in drawing vertical or inclined lines. 
 
DRAWING INSTRUMENTS AND MATERIALS 9 
 
 In its simplest form (see Fig. 4) the T-square consists of a thin 
 "blade" securely fastened at right angles to a thicker and shorter 
 piece termed the " head." 
 
 Fig. 4. Ordinary T-Square. 
 
 In a more elaborate design the head is pivoted so that it can 
 be adjusted and fastened at any angle with the blade. This 
 arrangement enables the draftsman to use the working edge of 
 the drawing board to guide the T-square in drawing a series of 
 parallel lines that are not perpendicular to that edge. While 
 this "swivel head" is sometimes an advantage, it is not neces- 
 sary for ordinary use and the design shown in Fig. 4 is 
 recommended. 
 
 T-squares are made of wood, rubber and metal, the most satis- 
 factory being made of wood and having the edges of the blade 
 lined with a narrow strip of transparent amber or celluloid. The 
 blade should be as long as the drawing board, and it is desirable 
 to have the blade and the head exactly at right angles in order 
 that the lines drawn with the T-square will be at right angles 
 to the working edge of the drawing board. This, however, 
 is not absolutely necessary, for if the working edge is straight 
 and the T-square is properly used, the lines are always drawn 
 with reference to the working edge of the board, and are there- 
 fore parallel, and the drawing will be accurate. 
 
 The T-square should be polished or given a coat of shellac in 
 order that dirt may not adhere to its surface; for unless the 
 blade is perfectly clean it will soon soil the drawing in rubbing 
 over it. 
 
 To test the straightness of the working edge, use a pencil 
 having hard lead sharpened to a fine chisel edge (see page 15, 14) ; 
 hold it against the working edge of the T-square and draw a line 
 the full length of the blade. Turn the blade over (i.e., revolve 
 about the lines just drawn) so as to bring the opposite side 
 against the paper, and if the working edge does not coincide with 
 
10 ELEMENTS OF DRAWING 
 
 the line throughout its entire length, this edge is not "true." 
 The inside edge of the T-square head may be tested by apply- 
 ing any standard straightedge to it. 
 
 Care must be taken that the blade is not loosened, and that 
 the working edges are perfectly straight and free from nicks. 
 The T-square must not be used to hammer thumb tacks into 
 place, and the top or working edge of the blade must never be 
 used to guide the knife in cutting paper or tracing cloth, as the 
 smallest nick will disfigure all lines drawn by the aid of that 
 portion of the blade. The lower edge of the T-square, however, 
 may be used as a straightedge for trimming drawings or cutting 
 paper. 
 
 To use the T-square, hold it near the center of the head with 
 the left hand, and, with a steady but unstrained grip, slide the 
 inner face of the head along the working edge of the drawing 
 board until the top edge of the blade is in the proper position for 
 drawing the line or guiding the triangle. The lower edge of 
 the blade should never be used in this way, as it may not be 
 parallel to the working edge, and as a result all lines drawn 
 would not be parallel. 
 
 The habit should be cultivated of "feeling" that the T-square 
 is in perfect contact before drawing a line. That is, the head 
 should set firmly against the working edge of the drawing board 
 and the blade should lie perfectly flat on the drawing. 
 
 ii. Triangles. Triangles are used as a guide for the ruling pen 
 or the pencil in drawing lines at an angle to the T-square blade. 
 All the angles of a triangle must be true and its edges straight 
 and free from nicks. The material of which it is made should 
 not warp easily, or show tendency to gather and hold dust; it 
 should be light enough to be easily handled and hard enough to 
 hold its edge under use. Triangles are made of wood, rubber, 
 amber, celluloid, or metal. Metal triangles are accurate and 
 durable, but are difficult to handle, and if dropped on a drawing 
 the corners puncture the surface. Those made of wood are 
 cheap and light in weight, but warp easily and are hard to 
 keep clean. The triangles made of transparent amber or cellu- 
 loid meet most of the requirements of a first-class instrument 
 
DRAWING INSTRUMENTS AND MATERIALS n 
 
 and are to be preferred. An additional advantage is that, due 
 to their transparency, the draftsman is enabled to see work 
 already completed although it may be covered with the triangle. 
 The triangles most generally used are the 45 [see Fig. 5 (a)] and 
 the 3o-6o, or what is generally 
 called the 60, triangle [see Fig. 
 
 The most desirable size of tri- 
 angle to use depends largely on 
 the work to be done, but the 
 working edges should be long (a) 4 ' 5 o Tdangle ; (b > 6o o' Triangle> 
 
 enough not tO require Working Fig. 5.- Ordinary Triangles. 
 
 too close to the corners, since they become rounded with use 
 and are therefore inaccurate. Accuracy in triangles is of the 
 greatest importance and they should be tested when purchased 
 as well as occasionally thereafter, as they may lose their 
 accuracy by use. In testing the accuracy of the triangles, 
 use a 6H pencil with lead sharpened to a fine chisel edge. (See 
 page 15, 14). All edges of the triangle should be first tested 
 for straightness by holding them against an accurate straight- 
 edge, or by the method given for testing the T-square blade (see 
 page 9, 10) and then the angles should be tested. 
 
 To test the 90 angle for accuracy, place one of the short sides 
 of the triangle against the working edge of the T-square blade 
 and, with the chisel edge of the pencil held close to the triangle, 
 draw a vertical line. Next turn the triangle over (i.e., revolve 
 it about the line just drawn) so as to bring the opposite side 
 against the paper, and, using the same edge as a guide for the 
 pencil, draw a second vertical line through a point at either ex- 
 tremity of the first line. If these two lines do not coincide 
 throughout, the 90 angle is not accurate. 
 
 To test the 45 angle for accuracy, place one of the short edges 
 of the triangle against the working edge of the T-square blade, 
 and, using the longest edge of the triangle as a guide for the pencil, 
 draw a line. Next turn the triangle over so as to bring the 
 opposite side against the paper, and revolve it until the second 
 short edge is against the working edge of the T-square blade, and, 
 again using the long edge of the triangle as a guide for the pencil, 
 
12 
 
 ELEMENTS OF DRAWING 
 
 draw a second line through a point at either extremity of the 
 first. If the two lines do not coincide throughout, the 45 angle 
 is not accurate. 
 
 To test the 30 and 60 angles for accuracy, draw a horizontal 
 line with the T-square, then place the shortest side of the tri- 
 angle against the working edge of the T-square blade, and, using 
 the longest edge as a guide for the pencil, draw a line to intersect 
 the first line. Next turn the triangle over (i.e., revolve it 
 about the line drawn) so as to bring the opposite side against the 
 paper; with the same short side against the T-square, again use 
 the longest edge as a guide for the pencil, and construct a triangle 
 by drawing a third line to intersect the other two. If all three 
 sides of the triangle drawn are not of equal length, the 30 and 60 
 
 angles are not accurate. 
 Fig. 6 shows the 
 method of using the 
 triangle in connection 
 with the T-square, the 
 left hand manipulating 
 and holding the triangle 
 and the T-square. 
 
 The draftsman should 
 arrange his work so as to avoid being in a strained position, 
 and the light should come from a direction that will not cause 
 the T-square and triangle to cast a shadow along the edges 
 being used as a guide to the pen or pencil. 
 
 Fig. 6. Using the Triangle in Connection with 
 the T-square. 
 
 Fig. 7. Exact Angles that can be drawn, using Triangles and T-Square. 
 
 Fig. 7 shows the angles that can be accurately drawn by using 
 the 60 and 45 triangles and T-square. 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 A triangle should not be used alone in drawing lines parallel or 
 at a given angle with one another, but should be guided by the 
 working edge of the T-square or 
 another triangle. Fig. 8 shows 
 the method of drawing parallel 
 lines, using one triangle as a 
 guide for the other. In a sim- 
 ilar manner the T-square blade 
 
 , , . Fig. 8. Drawing Parallel Lines using one 
 
 Can also be USed as a gUlde Triangle as a guide to another. 
 
 for the triangle to draw a series of parallel lines at any 
 angle. 
 
 12. Irregular Curves. The irregular or French curves are 
 used as a guide to the pen or pencil in drawing curved lines that 
 cannot be conveniently or accurately made with the compasses. 
 French curves are made of the same materials as triangles, 
 and the remarks on materials for triangles, therefore, apply to 
 French curves (see page 10, 11). They 
 may be had of many different shapes, but 
 those shown in Fig. 9 probably have the 
 widest use. 
 
 To use the French curve, locate a series 
 of points on the line to be drawn, and 
 carefully sketch a very light free-hand 
 pencil line through them; next place the 
 French curve so that its edge coincides with the longest segment 
 of the free-hand line possible, and draw this segment of the line 
 by using the edge of the curve as a guide. The French curve 
 is then shifted to coincide with another part of the line and the 
 process repeated until the entire curve is drawn. Great care 
 must be taken that the segments are well joined and that the 
 entire line appears uniform and continuous. In inking such 
 a curved line, the blades of* the pen must at all times be 
 tangent to the curve; otherwise the line will not be of uniform 
 width. In drawing an irregular curve, especially when inking, 
 it is best to first leave a slight break between segments and then, 
 by a separate operation, join all segments so that the curve is 
 continuous and the joined points do not show. 
 
 Fig. 9. Ordinary Irregular 
 (French) Curves. 
 
14 ELEMENTS OF DRAWING 
 
 13. Pencil Pointer. A small medium cut file, with the 
 end flattened to an edge and curved (see Fig. 10), serves the 
 
 double purpose of a tack lifter 
 and pencil pointer. 
 
 Fig. 10. -Combination Pencil Sharpener J n US i n or the file it should be 
 
 and Tack Lifter. 
 
 frequently tapped to remove the 
 
 lead filings. While filing the lead or tapping the file, care 
 must be taken that the filings do not fall on and smear the 
 drawing. 
 
 14. Lead Pencils. The essential qualities of a good pencil 
 depend somewhat on the work to be done, but the lead should 
 always be smooth and free from grit, making a clear-cut, distinct 
 mark as sharp as an inked line, yet one which can be easily and 
 completely erased. To meet all requirements lead is made in 
 different degrees of hardness, and the grade selected will depend 
 upon the kind of work to be done and the nature of the surface 
 on which the drawing is made. Should the lead be too soft, the 
 lines will smear, especially if the drawing is subjected to con- 
 siderable handling; whereas if the lead is too hard, considerable 
 pressure on the pencil point is necessary to make a visible line. 
 This indents the paper, anot erasing and changing of such lines 
 are difficult and unsatisfactory. 
 
 Manufacturers usually indicate the degree of hardness of the 
 lead in a drawing pencil by the capital letter H, which is repeated 
 as often as necessary; thus, an H pencil is the softest, then comes 
 HH, then HHH, etc. 
 
 The HHHH (called 4H) pencil is a satisfactory grade for such 
 work as putting in dimensions, arrowheads, lettering, making 
 sketches, and in general for free-hand work. 
 
 The 6H pencil is a satisfactory grade for making mechanical 
 drawings. 
 
 The degree of hardness of the lead in some cases is indicated 
 by a number, beginning with No. i for the softest, the numbers 
 progressing as the degree of hardness increases. 
 
 Drawing pencils of either a hexagonal or round cross section 
 are made but the hexagonal pencil is to be preferred since it is 
 not so liable to roll off the drawing board. 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 To do satisfactory work the pencil must be kept well sharpened, 
 and it is important that the beginner learn the best method of 
 keeping the pencil in condition. The lead may be given either 
 the round "cone point" or the flat "chisel edge." Each of these 
 forms has its particular use and it is often an advantage to have 
 both ends of a pencil sharpened, one end having the cone point, 
 the other the chisel edge. 
 
 The cone point is used by many draftsmen for all ordinary 
 drawing, and is absolutely necessary for lettering, dimensioning, 
 locating points on a drawing, and all free-hand work. 
 
 The following method of sharpening a pencil gives a point 
 that will " stand up " well under use. 
 
 With a sharp knife, make a long, sloping cut (about seven- 
 eighths inch in length), removing sufficient wood to expose a 
 cylinder of lead, say, about three- 
 eighths inch long. (See Fig. 
 n). 
 
 Hold the pencil at an angle 
 with the surface of a file (or a 
 piece of fine sandpaper), and 
 draw the lead across the rough 
 surface, at the same time ro- 
 tating the pencil in such a way 
 that the lead is worn to a cone shape of the longest slope pos- 
 sible, but do not file to a sharp 
 point. 
 
 Next raise the pencil to an 
 angle of about 15 and file 
 the end of the lead away 
 until pointed. The pencil 
 point should then appear as shown in Fig. 12. 
 
 A few strokes across the file at frequent intervals will keep 
 the pencil lead in good working condition, and the long slope 
 of the lead saves cutting away the wood every time the pencil 
 point is sharpened. 
 
 The disadvantage of a cone point is that it wears away very 
 rapidly, and to be kept in good shape must be frequently re- 
 pointed. When a number of long, continuous lines are to be 
 
 Fig. ii. Pencil sharpened to Lead 
 Cylinder only. 
 
 Fig. 12. Pencil Lead sharpened to Long 
 Cone and to Point. 
 
i6 
 
 ELEMENTS OF DRAWING 
 
 drawn, many draftsmen prefer to use a chisel edge (see Fig. 14). 
 To form a chisel edge cut away the wood as explained above. 
 Next hold the pencil so it will not rotate, and at such an angle 
 that by drawing it across the file the lead is worn to a bev- 
 eled surface of the longest slope possible. Do not file to the 
 center of the lead before turning the pencil over to file a similar 
 beveled surface on the reverse side (see Fig. 13). At this stage 
 the pencil should not have a sharp edge. 
 Next raise the pencil to an angle of about 
 15, and by moving back and forth, at the 
 same time slightly rolling, file the tip on 
 one side, and then on the other side, until 
 a rounded chisel edge is 
 produced. (See Fig. 14.) 
 The lead point must 
 never be moistened, as 
 lead softens from mois- 
 ture, and then produces 
 Fig.i3. Pencil Lead sharp- a smeared line which 
 
 ened to Rough Chisel Form t fe satisfactorily 
 
 but not to Edge. (Front J 
 
 and Side View.) erased. 
 
 To put a chisel edge on the lead of the 
 bow pencil or compass, fasten the lead in 
 the instrument so that it projects about one Fi e- 14. Pencil Lead sharp- 
 
 . . , . -. , . . ened to Working Chisel 
 
 quarter of an inch, and file to a chisel edge Edge. (Side and Front 
 as explained above, always keeping the edge View>) 
 of the lead perpendicular to the radius of the instrument, that 
 is, tangent to the arcs to be drawn. 
 
 15. Erasers and Erasures. Erasers are used for removing 
 pencil or ink lines and for cleaning the drawing. 
 
 The pencil eraser should be made of soft, fine-grained rubber, 
 free from sand or grit, and of a texture that will not glaze, smear, 
 or injure the surface of the drawing. 
 
 The ordinary ink eraser is hard and gritty but should be flexible. 
 Ink erasers often contain so much grit that they injure the surface 
 of the drawing, and for this reason many draftsmen prefer a fine- 
 grained, soft eraser that can be used for both pencil and ink erasing. 
 
DRAWING INSTRUMENTS AND MATERIALS 17 
 
 For cleaning drawings sponge rubber, kneaded rubber, and 
 " artgum " are used. The eraser should be entirely free from 
 grit and soft enough to wear away rapidly, so that it will not 
 mar or scratch the surface of the paper or injure the lines of the 
 drawing and will constantly present a clean rubbing surface. 
 
 In making an erasure, rub over the line with a light pressure 
 until it disappears; then brush off the particles of rubber and 
 paper with a clean rag so that the drawing will not become 
 smeared. Beginners are liable to press too heavily when erasing, 
 thinking thereby to save time. This should not be done as it 
 injures the surface of the drawing. Neither should erasing be 
 done so rapidly that the colored rubber heats and streaks the 
 work. The surface of the drawing is liable to injury if a knife 
 edge is used to scratch out lines. If the surface of the paper 
 or cloth is injured in erasing, it can be improved by rubbing 
 briskly over the injured area (which must be perfectly clean) 
 with a smooth, hard surface (such as the bone handle of a pocket- 
 knife) until the surface has become smooth. Soapstone may 
 also be effectively used for this purpose. (See page 18, 17.) 
 
 An eraser should be perfectly clean when used, and if the 
 rubbing surface does not wear off fast enough to keep clean, the 
 eraser end should be rubbed upon some clean spot of the draw- 
 ing board until it is free from dirt. 
 
 Never attempt to make an erasure on a drawing which is 
 not securely fastened with thumb tacks, for if held down only 
 with the fingers, the drawing frequently slips and it is liable to 
 be spoiled by being creased or wrinkled. 
 
 As little erasing as possible should be done when making a 
 drawing to avoid injuring the drawing surface. 
 
 1 6. Erasing Shield. When erasing a line, letter, or dimension, 
 care must be taken that the surrounding / ^ 
 
 work is not injured. To prevent injury, 
 thin sheets of flexible metal or transparent 
 celluloid, provided with slots and holes of I c 
 various shapes and sizes, are used to protect Fig . I5 ._ ordinary Erasing 
 the drawing while making erasures over a Shield, 
 
 limited area through these openings. Fig. 15 shows the ordinary 
 
1 8 ELEMENTS OF DRAWING 
 
 form of erasing shield. It is important that the shield always 
 be kept clean on both sides, otherwise when using it the drawing 
 is liable to become smeared. 
 
 17. Soapstone. Soapstone is a soft mineral (a compact, 
 granular variety of talc) which gets its name because of its 
 soapy feel. If the surface of paper or tracing cloth has been 
 injured in erasing, it may be improved by rubbing soapstone 
 over the injured portion and polishing with a clean, dry rag. 
 
 18. Drawing Ink. Drawing ink differs from the ordinary 
 ink used for writing, in that it is heavier and has no penetrating 
 qualities, but merely lies upon the surface of the paper or cloth. 
 
 The requirements of a good drawing ink are that it will flow 
 freely, dry readily, and will not gum; it must contain no chemicals 
 that will have an injurious effect upon the instruments or paper, 
 and it must be absolutely waterproof. To be waterproof means 
 that the ink will not redissolve after drying, and the lines drawn 
 with it will not become blurred or defaced when exposed to 
 moisture. 
 
 Drawing ink of practically any color can be obtained, but 
 only black ink should be used in making working drawings 
 unless there is some special reason for using inks of other colors. 
 Red ink is used occasionally for making dimension lines, center 
 lines, etc., but this is considered bad practice, as the ink becomes 
 faded with age, and in the case of a tracing the lines will not 
 be sufficiently opaque to print well. 
 
 The use of bottled India ink is almost universal in modern 
 drafting-room practice. Drawing ink gradually thickens due 
 to evaporation and the bottle should therefore be kept tightly 
 closed when not in use. When the drawing ink becomes too 
 thick it may be thinned by adding a few drops of diluted 
 ammonia or distilled water. 
 
 If the stopper and filler are left out of the bottle, the ink will 
 dry upon them, and the solid particles of dry ink will form 
 small clots, which may be transferred to the pen and obstruct 
 the free flow of the ink. 
 
 19. Ordinary pens. Four styles of pens are found in drafting 
 rooms: (i) the ordinary writing pen with fine point; (2) the or- 
 
DRAWING INSTRUMENTS AND MATERIALS 19 
 
 dinary writing pen with stub point; (3) the ball-pointed pen; 
 and (4) the crow-quill pen. The style of pen selected is largely 
 determined by the width of the lines to be made. An expert 
 draftsman can use the ordinary fine-pointed writing pen for 
 almost all classes of work, but the beginner will find it easier 
 to make relatively heavy lines with the stub-pointed or the ball- 
 pointed pen. 
 
 The ball-pointed pen is designed to glide smoothly in any 
 direction and at the same time make a line of uniform width. 
 It has little tendency to catch in the surface and splash the ink, 
 and therefore permits of greater freedom in any direction and 
 order of strokes when lettering or making free-hand lines. 
 
 The crow-quill pen is not satisfactory for ordinary work, 
 especially for tracing, as the tendency is to make the lines so fine 
 that they will not reproduce in printing. 
 
 A good general rule to follow in selecting a pen is that, when 
 perfectly clean and carrying a reasonable quantity of ink, it will 
 make a line of the desired width without requiring a pressure 
 great enough to open the point. 
 
 The pen selected is largely a matter of individual preference, 
 and experience will soon dictate the best pen for the different 
 kinds of work. Until the beginner has had sufficient experience 
 to make an intelligent selection, only those pens called for in the 
 list of supplies should be used. (See page 3, 2.) 
 
 A new pen often gives trouble from two causes: (i) the flow 
 of the ink may not be free and uniform; (2) the point may be 
 stiff and catch in or scratch the surface. The coating of oil 
 which has been put on the pen by the makers, to prevent rust- 
 ing, is usually the cause of the ink's not flowing freely on a new 
 pen. This oil can be removed by moistening and thoroughly 
 wiping the pen several times, or by rubbing the pen with finely 
 pulverized crayon or tracing-cloth powder. Dried ink on the 
 pen point will also give trouble and for this reason the pen 
 should be thoroughly cleaned each time before dipping for a new 
 supply of ink. 
 
 If the pen is stiff it may be improved by slightly drawing the 
 temper. This is done by holding a lighted match to the point, 
 care being taken not to overheat it. 1 
 
20 ELEMENTS OF DRAWING 
 
 If the pen point catches in or scratches the drawing it should 
 be rounded by a few light strokes on an oilstone or on a piece 
 of very fine emery cloth. 
 
 A new pen always requires " breaking in " and for this reason 
 an experienced draftsman will take as much care in preserving 
 his pen as if it were one of his more costly instruments. Before 
 putting the pen away always clean it thoroughly with a rag free 
 from lint. Common writing ink should not be used on a pen 
 intended for drawing, as it corrodes the pen and renders it unfit 
 for further use with drawing ink. 
 
 20. Penholders. The penholder should hold the pen securely 
 and firmly and should be of such a size and shape that the hand 
 will not be cramped. Holders of small diameter are 
 therefore unsatisfactory. The cork-tipped holder 
 has the double advantage of being easy on the fingers 
 and of absorbing moisture. 
 
 21. Ruling Pens. The simplest, and probably the 
 best, form of ruling pen consists of two "blades" 
 made of a single piece of metal and fastened to a 
 handle, as shown in Fig. 16. In order to hold a fine 
 edge the blades must be made of the best tempered 
 steel. The inner blade (into which the screw is 
 tapped) should be almost straight. The outer blade 
 should be slightly curved, so that, when the points 
 are together, there exists a cavity of sufficient capacity 
 to hold enough ink to do a reasonable amount of 
 work and not evaporate too rapidly as it would if the 
 film of ink were very thin. The "nibs" must be 
 even in length and terminate in a slightly rounded 
 
 dinary Ruling point; they must have a moderately sharp edge, and 
 must be broad enough not to wear away too rapidly. 
 
 The handle should not be made of a material which breaks easily. 
 The adjusting screws of all instruments should have an 
 
 occasional application of light oil to prevent rusting. 
 
 To adjust the pen, hold it toward the light, or over a piece of 
 
 white paper, so that the space between the nibs can be seen; then 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 21 
 
 Fig. 17. Charging Ruling Pen with 
 Ink. 
 
 turn the thumb-screw until this distance is the width of the line 
 
 to be drawn. To fill the pen (see Fig. 17), use the filler that is 
 
 attached to the stopper of the 
 
 ink bottle, and let the ink flow 
 
 between the nibs until it is nearly 
 
 one-quarter of an inch from the 
 
 points. 
 While filling the pen never 
 
 hold it over the drawing as ink is often dropped during the 
 
 process. After the pen has been filled, see if any ink has gotten 
 
 on the outside of the nibs, and if so, wipe them off with a clean 
 
 rag (seepage 33, 30). 
 
 To use the pen (see Fig. 18), hold it with the thumb and the 
 
 first two fingers, so that the thumb-screw is away from the body, 
 
 and the pen perpendicular to the surface 
 of the drawing. The third and fourth 
 fingers should rest lightly on the triangle 
 or T-square blade, to steady the hand 
 and control the pressure of the pen 
 against the drawing. This pressure and 
 the speed at which the pen is moved 
 along the ruling edge must not vary, 
 
 Qr the ^ ^ ^ ^ uniform thrOUgh- 
 
 out its length. The pen may be inclined slightly in the direc- 
 tion in which the line is being drawn, so that, in moving, the 
 point is pulled after the body of the pen; but 
 under no condition should it be inclined in the 
 opposite direction, making it necessary to push 
 the point in advance of the body of the pen. 
 Move the pen from left to right in drawing 
 lines, which are horizontal or nearly so, from 
 bottom to top in drawing lines which are vertical 
 or nearly so, and in either direction (depend- 
 ing upon the angle) in drawing inclined lines 
 (see Fig. 10). Always hold the pen so that a Fi *- '9.- Direction m 
 
 v/ J * which to draw Ruled 
 
 line of the least width is drawn for a given set- Lines. 
 
 ting of the nibs. In no case is the ruling pen to be used in 
 
 making free-hand lines as this is liable to injure the nibs. 
 
 Fig. 18. Using the Ruling Pen. 
 
22 ELEMENTS OF DRAWING 
 
 The blades of all pens must be kept absolutely clean, both 
 inside and out, if good results are to be obtained. More unsatis- 
 factory work results from the neglect of this precaution than 
 from any other. No pen can be expected to make a good line 
 when the blades are incrusted with dried ink. Ink corrodes the 
 metal points, as shown by the magnified view in Fig. 20, and the 
 
 pen is finally rendered unfit for use. 
 
 As soon as the ink in the pen begins to thicken, pass 
 
 a str *P ^ P a P er or c ^ ot ^ between the blades, and refill 
 
 the pen; but never refill without first cleaning the inner 
 
 surface of the blades. 
 Fig. 20. To clean the inner surface of the blades, fold a piece 
 
 Ruling Pen - , , A , , ' ., , . , 
 
 Blade cor- of unglazed paper, or the rag penwiper, until thick 
 
 spring the nibs slightly when passed between 
 them. Draw the paper or cloth between the blades, 
 from the screw to the tip, several times, or until it shows no 
 ink, even after being moistened. (See Fig. 75, page no.) 
 Besides frequently cleaning the pen while in use, the blades 
 should be opened wide and given a thorough cleaning with the 
 instrument wiper before it is put away. 
 
 The points of the pen will wear dull after it has been used for 
 some time, and in order to again make a clear-cut line they 
 must be resharpened. 
 
 To sharpen the ruling pen, first clean thoroughly and then 
 close the blades until they nearly touch. This can be judged by 
 properly holding the pen to the light or over a piece of white 
 paper. Next, keeping the pen per- 
 pendicular to the surface of a flat, 
 close-grained oilstone, move back 
 and forth until the nibs are " square " 
 and of equal length. The nibs are 
 then rounded to a radius of one 
 thirty-second of an inch by ruling a 
 line on the oilstone and continually 
 
 Fig. 21. Rounding the Nibs of 
 
 changing the inclination of the pen, the Pen. 
 
 as shown in Fig. 21. This process dulls the edge of the points 
 and they must then be sharpened by slightly opening the blades 
 and rubbing the outer surface of the nibs on the oilstone. Care 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 must be taken that the rounded shape of the end is not altered; 
 also a " wire edge " must not be produced, as this will cut the 
 surface of the paper or tracing cloth. 
 
 To test the condition of the pen, clean it thoroughly and draw 
 a light and heavy inked line ; if 
 both are not clear-cut and even, 
 the pen requires attention. 
 
 JOINT- 
 
 SOCKET JOI 
 
 22. Compasses. The compass 
 is used in drawing circles and 
 arcs of circles. A complete com- 
 pass outfit (see Fig. 2 2) consists of 
 five parts: (i) the "headpiece"; 
 (2) the "needle point"; (3) the 
 "pencil leg"; (4) the "pen leg"; 
 (5) the "extension bar." 
 
 The instrument may be made 
 of iron, brass, steel, aluminum, 
 or German silver, the best being 
 made of rolled (not cast) German 
 silver. It is difficult to deter- 
 mine the quality of German sil- 
 ver by inspection, but the cast 
 material can usually be detected 
 by its high glossy finish. 
 
 The de- 
 sign of the 
 compass 
 should be 
 
 such that the "head" and "knee joints" 
 a allow free movement of the parts and at 
 the same time give proper rigidity. They 
 should be so designed as to exclude dirt 
 and moisture and should fit accurately. 
 
 Fig. 2 3 .-Head- Joint Design. The SQcket j oints should fit the shank 
 
 accurately, hold the leg in proper alignment, and have a clamping 
 device that will hold the interchangeable parts rigid. Fig. 23 
 shows the details of a good design for the head joint. 
 
 Fig. 22. Compass Outfit Complete. 
 
ELEMENTS OF DRAWING 
 
 TONGUE SLfT 
 
 (a) Superior design. 
 
 The legs are alike at this joint, and two pivoted screws are 
 inserted in the yoke of the handle to hold the legs in position; 
 small set screws prevent the pivoted screws from turning in the 
 yoke. All contact surfaces are made circular, which insures a 
 close fit for all positions of the legs, and thus excludes dirt and 
 moisture. 
 
 Several forms of socket joints are shown in Fig. 24, the 
 design as shown in Fig. 24 (a) being the best. The hole is made 
 
 circular and slightly tapered. The socket 
 is split, and the clamping screw is lo- 
 cated on the side. 
 
 The handle of the compass is some- 
 times designed so that no matter in 
 what position the upper portion of the 
 legs are set, it always keeps a central 
 position relative to them, and conse- 
 quently is approximately perpendicular 
 to the surface of the drawing when the 
 instrument is being used. This is an 
 advantage unless the device is so deli- 
 cately constructed that the wear and tear arising from ordinary 
 use soon render the entire instrument valueless. 
 
 The needle point consists of a finely tempered steel wire which 
 fits into a cylindrical socket in the lower end of the attached leg. 
 It should fit the socket with a snug, sliding fit, and be clamped 
 with a thumbscrew. The lower end of the needle point (which 
 enters the drawing) has a shoulder to support the weight and 
 pressure on the instrument when in use and thus prevents a 
 hole being bored in the drawing. 
 
 Besides the knee joint and the shank of the pencil leg, the small, 
 cylindrical, split socket that receives the lead, and the clamping 
 device that holds the lead should be examined. The socket 
 should be drilled accurately and of the proper size to receive 
 the lead of an ordinary drawing pencil. The clamping device 
 should exert a uniform pressure along the entire length of the 
 socket and hold the lead secure and firm. 
 
 The remarks on the design and care of the ruling pen (see 
 page 20, 21) apply generally to the pen leg of the compass. 
 
 (b) Inferior designs. 
 Fig. 24. Socket-joint Designs. 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 The extension bar is used to increase the range of the com- 
 pass, by making it possible to draw circles of a larger diameter 
 than can be drawn with the compass proper. Its design is 
 determined by the design of the socket joint of the compass. 
 
 The joints of instruments should have an occasional applica- 
 tion of light oil to prevent rusting and insure easy working. 
 
 To prepare the compass for use, insert the pen leg in the socket 
 as far as it will go, and then clamp it securely in position. Ad- 
 just the needle point so that the point of the pen and the shoulder 
 of the needle are even when the compass is completely closed. 
 The needle point is now adjusted for either pen or pencil and 
 should not be changed. As the lead in the pencil wears away, 
 making readjustment necessary, the position of the lead should 
 be changed and not the needle point. The lead is usually 
 sharpened to a chisel edge (see page 15, 14) which must be 
 tangent to the arc it draws. It is adjusted by clamping the pencil 
 leg in the instrument and adjust- 
 ing the lead until the end is even 
 with the needle point when the 
 compass is completely closed. 
 
 To draw a circle, bend both 
 legs at the knee joints an equal 
 amount, and enough to bring the 
 marking point and the needle 
 point each perpendicular to the 
 
 Fig. 25. Using the Compass. 
 
 surface of the drawing when 
 
 the instrument is being used. This adjustment (see Fig. 25) 
 
 places the needle point in 
 such a position that it will 
 make the smallest hole pos- 
 sible in the drawing and 
 | insures both nibs of the pen 
 bearing evenly on the paper. 
 The proper opening be- 
 tween the points (the ra- 
 dius) may be taken from the 
 
 Fig. 26. -Setting or Reading the Instrument. measuring SCale, as shown 
 
 in Fig. 26, or the extremities of the radius may be marked from 
 
26 
 
 ELEMENTS OF DRAWING 
 
 the scale directly on the drawing in their proper position and the 
 compass set to them, the latter method being preferable as there 
 is less chance of injury to the scale division marks. 
 
 To use the compass hold the handle of the instrument lightly 
 between the thumb and the first and second fingers; guide the 
 needle point to the center of the circle by sliding it on a finger 
 of the left hand; hold the compass so that both the marking 
 and the needle points are perpendicular to the surface of the 
 drawing and remain so while making the circle. Place the needle 
 point at the center, and the marking point at the bottom of the 
 g in circle, and with a slight pressure against the drawing 
 rotate the compass right handed, that is, in the same 
 direction as the hands of a clock move (never the 
 reverse) by rolling the handle between the thumb 
 and first finger. 
 
 All inked arcs and circles should be made by one 
 continuous revolution, and where any portion of a 
 line is so thin or ragged as to require retracing, the 
 entire line should be retraced. 
 
 The compass should be manipulated with one 
 hand, unless the lengthening bar is used, then the 
 needle point should be steadied with one hand, and 
 the marking point rotated with the other. 
 
 23. Dividers. The dividers (see Fig. 27) are used 
 to transfer distances from one point to another, or 
 to divide lines or circles into equal parts, but they 
 should not be used to transfer measurements from 
 the scale to the drawing when this process injures the 
 division marks on the scale. See page 25, Fig. 26. 
 Neither should the dividers be used where it is 
 possible to lay off or measure distances accurately 
 Fig. 27. or- with the drawing scale. See page 30, Fig. 32. 
 iary Dividers. j n Design ne dividers are similar to the compass, 
 and the main points considered with reference to the compass 
 apply to the dividers (see page 23 , 2 2) . The legs of the dividers 
 must be of the same length, and the steel points should be conical 
 and sharp. One of the legs should be provided with a hair- 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 POINTS 
 
 Fig. 28. Ordinary Bow 
 Dividers. 
 
 spring, controlled by a thumbscrew, to facilitate delicate 
 adjustment. 
 
 To divide, or step off, a line or circle, manipulate the dividers 
 with one hand, and, with first one divider point and then the 
 other as a center, rotate the dividers alter- 
 nately to the right, then to the left as if 
 describing a series of semicircles. 
 
 To insure accuracy and neatness, the 
 dividers should never be lifted entirely off 
 the paper while being used, and the points 
 should merely rest on the drawing and not 
 puncture it. 
 
 24. Bow Dividers. The bow dividers 
 (see Fig. 28) are used in the same manner 
 and for the same purpose as the large 
 dividers (see page 26, 23). 
 
 The bow dividers when once set main- 
 tain a fixed distance or radius and there- 
 fore in "stepping off" distances they should be used in preference 
 
 to the large dividers. 
 
 The points to be observed in select- 
 ing, using, and caring for the other bow 
 instruments apply largely to the bow 
 dividers (see 25, this page). 
 
 25. Bow Pencils. This instrument 
 is practically a pencil compass of small 
 radius. In making small arcs or circles 
 it has the advantage of being easier to 
 handle than the large compass, also in 
 drawing several arcs or circles of the 
 same diameter (as for example in repre- 
 senting bolt holes, boiler tubes, fillets, 
 corners, etc.) there is less liability that 
 the distance between the points (that is the radius) will be 
 changed in the handling of the instrument. The ordinary form 
 of Bow Pencil is shown in Fig. 2Q(a). 
 
 LEAD 
 
 (a) Ordinary Design. 
 Fig. 29. Bow Pencils. 
 
28 ELEMENTS OF DRAWING 
 
 The legs of the bow pencil should be made of one continuous 
 piece of steel, finished and tempered ; the handle should be made 
 of metal, as ivory and bone handles break too easily; the needle 
 point should be made of tempered steel and should have a well- 
 formed shoulder (see page 24, 22). The spring should be 
 strong and stiff; the threaded parts cut smooth and true, and 
 the adjusting screw capable of bringing the needle and lead 
 points together. 
 
 Another design of spring instruments [see Fig. 29 (b)] has a 
 central thumbscrew and a right and left thread working in swivel 
 sockets. The advantage claimed for this design 
 is that the instrument can be set in one half the 
 time required to set the instrument shown in 
 Fig. 2 9 (a) . The disadvantages are that the radius 
 is much more liable to change in handling, and 
 the swivel sockets are necessarily delicate, easily 
 injured and wear rapidly. 
 
 The lead used is the same as for the compass, 
 and it is sharpened and adjusted in the same 
 manner (see page 25, 22), except for extremely 
 small circles, when the lead should be sharpened 
 to a conical point (see page 15, 14). 
 
 To set the bow pencil shown in Fig. 2g(a), first 
 (b) instrument with make an approximate adjustment by compress- 
 
 Ce mg'f^-^T' in g the s P rin S with the fin S ers and settin S the 
 Pencils. thumbscrew (this will minimize the wear on the 
 
 adjusting screw thread); then make the final adjustment with 
 the thumbscrew. The bow pencil is manipulated in the same 
 manner as the compass (see page 25, 22). 
 
 An important test of the bow pencil is to remove the lead and 
 clamp a needle point in its place (the instrument now has two 
 needle points); then close the instrument, and if the two points 
 meet exactly, the sockets for the lead and for the needle point 
 are accurately drilled and the instrument should do satisfactory 
 work; otherwise work is liable to be inaccurate. 
 
 26. Bow Pens. The bow pen (see Fig. 30) is used to ink the 
 circles and arcs that have been penciled with the bow pencil. 
 
DRAWING INSTRUMENTS AND MATERIALS 29 
 
 Its advantages over the compass are the same as those of the bow 
 pencil (see page 27, 25). The general requirements of the bow 
 pen are about the same as those for the bow pencil, and the 
 remarks on the care, use, and sharpening of the ruling pen apply 
 to the bow pen (see page 20, 21). 
 
 The edge of the pen should be tangent to the circle, being 
 drawn so that a clear cut line of uniform width is made, 
 and when the instrument is closed the 
 needle point should touch the pen at 
 the middle of the blade end. 
 
 27. Scales. The purpose of the scale 
 is to make measurements on the draw- 
 ing, and it should never be used as a 
 straightedge for drawing lines. 
 
 There are two drawing scales in gen- 
 eral use: the civil engineer's, or, as it is 
 usually called, the "engineer's scale/' 
 and the mechanical engineer's, or the 
 "architect's scale." These scales differ 
 in the way their inch spaces are sub- 
 divided. 
 
 The engineer's scale divides the inch into such decimal parts 
 as tenths, twentieths, thirtieths, etc., and is used in such work as 
 map drawing, plotting stress diagrams, measuring indicator cards, 
 and in certain government work. 
 
 The architect's scale is graduated into duodecimals (twelfths), 
 to correspond to the ordinary foot rule used by the workman in 
 the shop; the duodecimal is divided into halves, quarters, 
 eighths, sixteenths, thirty-seconds, etc., and the scale is used for 
 making all drawings of objects which are to be dimensioned in 
 the ordinary foot-rule denominations. This includes practically 
 all mechanical drawings. 
 
 The best scales are made of boxwood and have beveled edges 
 lined with a white material resembling ivory. The division 
 marks and figures are printed in black on this white background, 
 and are very distinct and easy to read. There are two forms of 
 scale in general use: the flat scale with beveled edges, and the 
 
 NEEDLE POnVT 
 
 Fig. 30. Ordinary Bow Pen. 
 
ELEMENTS OF DRAWING 
 
 scale of triangular cross section. The latter form is shown in 
 Fig. 31 and has the advantage of combining eleven distinct 
 scale divisions on a single instrument. 
 
 Scales are made of different lengths, but, in order to be provided 
 with a full-size one-foot rule, the twelve-inch length (not counting 
 the small spaces at each end, which are to protect the end grad- 
 uations) is recommended. The numerals printed on these end 
 
 Fig. 31. Ordinary Triangular Scale. 
 
 spaces indicate the size of the scale along that bevel; thus the 
 number ij on the end of the scale (shown in Fig. 31) denotes 
 that this bevel is divided into spaces one and one-half inches 
 long and is used to make drawings in which a length of i| 
 inches represents i foot (12") of the object represented. The 
 first inch and one-half length is subdivided into twelve equal 
 parts, and each of these divisions represents one-twelfth of a 
 foot, or one inch. The row of figures o, i, 2, 3, etc., indicates 
 the divisions that represent i ft., 2 ft., 3 ft., etc. (measuring from 
 the o mark), on a scale on which ij inches equal one foot. On 
 some scales the length taken to represent one foot is so small 
 that inches cannot be indicated. Thus, on the -/y scale the 
 unit (sV) is divided into four parts, so that each of these sub- 
 divisions represents one-fourth of one foot, or 3 inches, and the 
 eye is relied upon to divide this space, representing 3 inches, 
 
 into still smaller divisions. 
 
 To use the scale in mark- 
 ing off a distance, apply it to 
 the drawing so that it lies flat 
 on the surface (see Fig. 32) 
 and in a position to receive 
 
 Fig. 32. - Using the Scale. ^ best light poss ible on the 
 
 division marks and numerals; then mark the points, defining 
 the distance, with a 6H pencil sharpened to a fine cone point 
 (seepage 15, 14). The scale is applied in a similar manner 
 in measuring distances on a drawing. 
 
DRAWING INSTRUMENTS AND MATERIALS 31 
 
 Care must be taken not to injure the sharpness of the edge of 
 the scale or the division marks and numerals. 
 
 Measurements should ordinarily be taken directly from the 
 scale and not transferred from the scale to the drawing by means 
 of a pair of dividers, especially if by so doing the scale divisions 
 become defaced. 
 
 Where it is necessary to set an instrument to a measurement, 
 as for example the radius of an arc, the best method is to lay 
 the scale on the paper and adjust the instrument along its edge, 
 so as to avoid scratching or defacing the graduations on the 
 scale with the points of the instrument. Where this method is 
 not accurate, set the instrument as shown in Fig. 26, page 25. 
 
 To mark off a number of consecutive measurements, such as 
 2", 5", i", and |", along any straight line, keep the scale station- 
 ary, and, beginning at zero, mark off in succession the distances 2", 
 2 * + 5" = 7", 2" + 5" + i" = 8", and 2" + 5" + i" + y = 8J". 
 By this method the length of the line is equal to the sum of the 
 lengths of all its parts, and the accumulation of error which is 
 likely to result from moving the scale along the line and mak- 
 ing each measurement an independent operation is avoided. 
 
 To test the accuracy of a scale, mark off the divisions to' be 
 tested along a straight line. Reverse the scale, and if the sub- 
 divisions do not coincide, the scale is inaccurate. 
 
 28. Protractors. The protractor is an instrument for measur- 
 ing or laying off angles. It may be made of paper, celluloid, 
 brass, German silver, or steel. 
 The two latter materials are the 
 most satisfactory. 
 
 Fig. 33 illustrates the style of 
 protractor in most general use, 
 but more elaborate designs may 
 be had. 
 
 TO USe this protractor, place Fig. 33- -Ordinary Protractor. 
 
 it so that the two zero marks coincide with the given line 
 (produced if necessary), and the center (C) coincides with the 
 vertex of the desired angle. The protractor is now in correct 
 position for reading. If a line is to be drawn, making a desired 
 
ELEMENTS OF DRAWING 
 
 angle with the given line, use a cone-pointed pencil (see page 15, 
 14) and mark a very fine point on the drawing just at the 
 outer edge of the protractor and opposite the desired angle- 
 division on the scale, and a line drawn through this point and 
 the point C will make the desired angle with the original line. 
 
 29. Machinist's Calipers, Dividers, and Steel Rule. To make 
 a drawing of any existing object, for example a machine, all of 
 the principal dimensions must be obtained. These measure- 
 ments should always be made with a two-foot rule or a ma- 
 chinist's steel rule and not with the draftsman's scale. Apply 
 the measuring rule as close to the part to be measured as possible. 
 
 By use of the dividers and the 
 calipers, measurements otherwise 
 inaccessible can often be made. 
 The best calipers and dividers 
 are made of finely tempered steel 
 and are provided with a spring 
 nut (see Figs. 34, 35, and 38) 
 which admits of rapid adjust- 
 ment. 
 
 The outside calipers (see Fig. 
 34) are used to determine the 
 diameters of cylinders, the thick- 
 ness of flat parts, etc., and the inside calipers (see Fig. 35) are 
 used to determine the diameters of holes or other inside dimen- 
 sions inaccessible to the scale. 
 
 To insure accurate results, the calipers 
 must always be held against the piece 
 being measured in such a manner that the 
 dimension desired will be a line which is 
 the shortest distance between the points of 
 the calipers. For example, to find the 
 diameter of a cylinder, the calipers should 
 be held in a plane perpendicular to the axis 
 of the cylinder, and then adjusted until 
 its points will just pass freely over the cylinder. To read the 
 distance between the points of outside calipers, place one of the 
 
 Fig. 34- Ordinary 
 Outside Calipers. 
 
 ig' 35- Ordinary 
 Inside Calipers. 
 
 Fig. 36. Reading the 
 Outside Calipers. 
 
DRAWING INSTRUMENTS AND MATERIALS 
 
 33 
 
 points against the end of the rule and the other against the face, 
 as shown in Fig. 36. To read the distance between the points of 
 the inside calipers, place the end of the rule and one point of 
 the calipers against a flat surface, as 
 shown in Fig. 37. 
 
 The dividers (see Fig. 38) can often 
 be used to determine dimensions with 
 a greater degree of ac- 
 curacy than is possible 
 with the rule. To make 
 a measurement with the 
 dividers, their points 
 
 are adjusted to fit the Fig< 37 ._ Reading the Inside 
 limits of the distance calipers, 
 
 to be measured, and the points of the dividers 
 are then applied to the steel rule, as shown in 
 Fig. 26, page 25. 
 
 Measurements that must be made extremely 
 Fig. 3 8.- ordinary accurate cannot always be obtained satisfactorily 
 Machinist's Dividers. w ith either the measuring instruments or by 
 the methods of making measurements as described above. 
 
 To measure accurately in hundred ths, thousandths, etc., of 
 an inch, special instruments are used, the most common of 
 which is the Micrometer; a discussion of this instrument, how- 
 ever, is beyond the scope of this work. 
 
 30. Blotter, Penwiper and Instrument Rag. An ordinary 
 blotter is often useful to the beginner to remove the top of a 
 blot globule, but should never be used to blot the lines of the 
 drawing. This dims the lines and tends to smear the work. 
 
 A small linen rag should be kept handy for cleaning the ink 
 off the pens. 
 
 The instrument rag should be soft and free from lint. It is 
 used in keeping instruments clean, but especially in removing 
 dust and dirt from the triangles and from the T-square blade. 
 If these instruments are not perfectly clean, they quickly soil 
 the drawing in sliding over the surface. This rag should not be 
 used to clean the ink off the pens. 
 
CHAPTER II 
 LETTERS, NUMERALS, AND LETTERING 
 
 31. Introductory. Good lettering and dimensioning on work- 
 ing drawings is of prime importance and cannot be too strongly 
 urged. A drawing may be well made and correct in all its de- 
 tails, but if the lettering be poorly done, the general appearance 
 will be unsatisfactory and the value questionable. In most draw- 
 ings the appearance is quite important, and in all it is desirable 
 to secure the most pleasing effect possible. This does not mean 
 that the lettering should be elaborate, or an effort made to secure 
 artistic effects. There is no demand for such lettering on working 
 drawings, but a style which is neat, well-appearing, easily read 
 and easily made is required. The inclined Gothic alphabet, 
 being free from unnecessary ornamental and superfluous features, 
 fulfills all the requirements of lettering on engineering drawings 
 and has been very generally adopted in practice. 
 
 The ability to do good lettering with this style of alphabet 
 depends only upon a degree of manual skill that any beginner 
 can acquire by intelligent practice combined with careful obser- 
 vation of the characteristics of the alphabet. 
 
 32. The Study of Lettering. Most beginners look upon free- 
 hand lettering as a difficult but purely mechanical process. This 
 is a serious mistake, and as a result progress is retarded and the 
 work is uninteresting. 
 
 The letters and numerals in the alphabets have been evolved 
 through years of use, and unless the beginner studies their form 
 and proportions and endeavors to reproduce them, he cannot 
 hope to acquire the art of lettering. The outline and character- 
 istics of each letter and numeral must be carefully studied and 
 fixed in the mind. The beginner is greatly aided in learning 
 the characteristics of the letters of the alphabet by so grouping 
 
 34 
 
LETTERS, NUMERALS, AND LETTERING 35 
 
 them that comparisons can be made as to their points of sim- 
 ilarity and difference; for example, groups could be made up as 
 follows: 
 
 (a) Letters composed entirely of straight lines. 
 
 (b) Letters composed wholly or partly of curved lines. 
 
 (c) Letters of the same width. 
 
 (d) Letters of the same height. 
 
 (e) Letters of similar outline. 
 
 Thus, /, Z,, E, and F form a group of letters all of which 
 begin with a line of " standard slope" (i.e., a line which has the 
 same slope as the alphabet) and have parallel branches. The 
 " bar " in both the E and F is exactly midway between the top 
 and bottom of the letter, and its length is the same as its dis- 
 tance from the top or bottom; it is more than one-half but less 
 than three-fourths as long as the upper width of the letter. The 
 top width of the E equals that of the F, but the lower width of 
 the E is five units while the lower width of the L is only four and 
 one-half units. The fact that E is wider at the bottom than at 
 the top suggests another group, composed of E, B, K, Z, and X, 
 all of which are wider at the bottom than at the top. The 
 reason for making these letters wider at the bottom is to give 
 an appearance of stability. If these letters are made the same 
 width throughout, they appear top-heavy. The /, H, N, and M 
 have parallel sides which have the slope of the alphabet and 
 would not appear well if made wider at the bottom. There is a 
 difference in the slope of similar sides of V and W, and neither 
 contains a line of standard slope. Other groups that should 
 be studied are O, Q, C, and G; P, R, and B; U and /; a, d, q, 
 and so on. This method of studying the alphabet and compar- 
 ing letters will develop a fine sense of proportion and will also 
 train the eye to see form properly, both of which are essential 
 not only in lettering but also in sketching and drawing. 
 
 Ultimately the draftsman does not rely upon his memory for 
 spaces, widths, heights, and proportions of the letters, but this 
 sense of proportion enables the eye to judge the accuracy of 
 the construction, the alignment of the letters, and the proper 
 spacing while the letters are being formed, and lettering free-hand 
 
36 ELEMENTS OF DRAWING 
 
 is then no more difficult or tiresome than writing. Progress at 
 the start will depend in a large measure upon the beginner's 
 ability to criticize his own work and his willingness to correct 
 all errors as soon as they are detected. 
 
 If patience and thought are exercised from the start the be- 
 ginner will soon acquire the ability to do good lettering and it 
 will then take no longer to make well-formed letters than poorly- 
 made ones. 
 
 To make a critical study of lettering, note as follows : 
 
 (a) Whether the tops and bottoms of the letters appear to be 
 in line. 
 
 (b) If the proper spacing has been maintained between letters, 
 words, sentences, and lines of lettering. 
 
 (c) If each letter has the proper slope. 
 
 (d) If each letter has the proper proportion of height to width. 
 
 (e) If the different lines composing each letter are the proper 
 relative length and shape. 
 
 It will be observed that the first thing to notice is whether the 
 letters appear to be in line. In lettering, mathematical measure- 
 ments will not always produce satisfactory results. On account 
 of the sharp angles of such letters as A , V, W, and the curves of 
 O, C, Q, G, they appear shorter than such letters as H, N, E, 
 M, when made exactly the same height, and for this reason it 
 is best to make them extend very slightly beyond the guide line 
 in order to have them appear the same height. Also it often 
 happens that a deviation from the standard width of letters is 
 an advantage. Thus, an L followed by an A can be made nar- 
 rower than if it were followed by an N or an H, or than if it were 
 at the end of a word. 
 
 33. Slope of Letters. The vertical and the inclined alphabets 
 are used in practice, but the inclined letters are usually preferred, 
 since it is more difficult to make vertical letters appear uniformly 
 regular. This is because the eye naturally compares the free- 
 hand vertical lines of the letters with the mechanically made 
 vertical lines of the drawing and consequently any slight im- 
 perfection is noticeable. Also, to be correct and appear well, 
 
LETTERS, NUMERALS, AND LETTERING 37 
 
 the vertical letters must always be exactly vertical or at right 
 angles with the bottom guide line, while with the inclined letters 
 the exact angle of inclination is not of great importance as long 
 as uniformity of inclination is maintained, and the draftsman 
 may give his letters the slope that is easiest for him to maintain. 
 While, as has been said, inclined lettering is usually preferred, 
 there are many instances, however, where vertical lettering, if 
 well done, is preferable. 
 
 The slope to be used in this work is 2 to i, which corresponds 
 to an angle of about 63^. To obtain a slope of two to one, lay 
 off any convenient distance along a straight line and twice this 
 distance on a second straight line erected at the right-hand 
 end of and at a right angle with the first line. A third line 
 joining the extreme outer ends of these two lines has the 
 slope desired. The beginner should notice that the lines of the 
 inclined alphabet which are drawn with a slope of two to one 
 (that is, standard slope lines) correspond to the vertical lines of 
 the vertical alphabet. 
 
 34. General Description of Model Letters. The illustrations 
 in 38, page 44, and 41, page 51, show the correct propor- 
 tions of the letter, and the written matter calls attention to 
 certain important points to be kept in mind when forming the 
 letter. To help in this work, " guide lines," " center lines," 
 " dimension lines," and " direction arrows " are made use of. 
 
 The stem of a letter is any portion of the outline which is 
 straight and has the slope of the alphabet, this term being most 
 commonly used in connection with the description of the small 
 letters of the alphabet. 
 
 The top and bottom guide lines limit the height of the letters 
 and are an aid in keeping them in line. The side guide lines 
 have the same slant as the alphabet. They limit the width of 
 the letters, and aid in maintaining the proper slope. 
 
 Center lines are used on letters having a form which can 
 be divided more or less symmetrically by such lines; they also 
 determine the points where certain letters are tangent to the 
 guide lines. Center lines that are parallel to the top and bot- 
 tom guide lines are called horizontal center lines; those having 
 
38 ELEMENTS OF DRAWING 
 
 the same slope as the alphabet are called standard slope center 
 lines, and those having a slope other than that of the alphabet 
 are called sloping center lines. A letter is built around a center 
 line in somewhat the same manner as a sketch would be built 
 about its center lines. (See page 137, 97.) 
 
 Guide lines and center lines for lettering should be drawn con- 
 tinuous or unbroken throughout their length, but very light, as they 
 are erased as soon as the lettering is completed. 
 
 The dimensions shown on the model letters will enable the 
 beginner to study the relative ratio of width to height of let- 
 ters and the relative proportions of the different lines forming 
 the individual letters. (See page 45, 38.) 
 
 The numbers appearing with the letter-dimension lines on 
 the model indicate the units of space between the arrowheads. 
 This unit is the length of the side of a small square of the sec- 
 tion paper, and on the paper used for this work the length of 
 a side is \ inch, so that 3 would indicate the length of three 
 of the small squares, or f inch; 5 would indicate five squares, 
 or f inch, etc. (See page 58, 44.) 
 
 When the term standard slope is used in describing the model 
 letters and numerals, it refers to a line of the letter having the 
 same slope as the alphabet, which throughout this work is the 
 slope corresponding to 2 to i or approximately to 63 J. 
 
 Direction arrows on the model letters point in the direction the 
 pencil should move in making each stroke. (See page 64.) 
 
 The number written across the direction arrow indicates the 
 order in which the strokes should be made. (See page 64.) 
 
 This system of strokes should be closely followed by the 
 beginner, as it points the way to easy and rapid lettering. 
 Later on, when more familiar with the characteristics of the 
 letters and when greater skill has been gained in handling the 
 pencil or pen, the number of strokes may be reduced in order to 
 acquire speed, but the first stroke should be the one which determines 
 the spacing between the letter being formed and the preceding letter, 
 the order of the strokes should follow the easiest method of secur- 
 ing the desired outline, and the general direction of strokes should 
 be either down (toward the body) or toward the right when 
 lettering free-hand. 
 
LETTERS, NUMERALS, AND LETTERING 
 
 39 
 
 35 Spacing. It is fully as important to place letters the 
 proper distance from one another as it is to form them correctly. 
 Each letter in a word may be perfectly formed, but if all the 
 letters have not been properly spaced the lettering will not 
 appear uniform. The eye judges the space between letters as 
 an area rather than a linear distance, and if separated by 
 exactly equal distances, the areas outlined between adjacent 
 letters will not be uniform in different combinations of straight 
 and curved letters. Thus, a combination of letters with stand- 
 ard slope sides falling adjacent, as MINE, would call for wide 
 spacing as compared with such a combination as COG; while 
 the adjacent sides of the letters of the word A T would have to 
 " overhang" so that the spacing may appear uniform. Another 
 extreme combination can be formed of half-open-side letters, as 
 FTY. If it were possible to make these combinations fall in 
 groups as illustrated, it would not be difficult to state rules 
 for spacing; but with twenty-six different letters a great many 
 different combinations are possible, and the problem of spacing 
 cannot be covered by a single rule. Rules that will prove valuable 
 to the beginner are given below but the appearance of the fin- 
 ished work, in so far as spacing is concerned, will in the end 
 depend upon the judgment exercised in maintaining the ap- 
 pearance of equal areas between the letters. 
 
 The distance between letters is measured in a line parallel to 
 the top or bottom guide-line and between the side-guide-lines 
 which fall adjacent. Based on this idea the " Key to Spacing " 
 (see page 43) has been compiled and the distances given below 
 
 4- 
 
 \ 
 
 8 
 
 21-21 
 
 / 
 
 ', 
 
 f 
 
 
 4^- 
 
 -/// 
 
 A3- 
 
 -// 
 
 have been carefully found by laying out on a large scale various 
 side-line combinations (see above figure) and determining a spac- 
 
40 ELEMENTS OF DRAWING 
 
 ing that, in view of the area enclosed, gives the best spacing for 
 such a combination. In the illustration the shaded portion rep- 
 resents the " area " to be considered in determining the spacing 
 which is shown between the side-guide-lines. 
 
 By element of adjacency is meant that side-line of a letter 
 which is nearest to the adjacent letter under consideration. 
 
 (A) Spacing for various line combinations in Capital Letters 
 presented in three different forms as follows: 
 
 (I) Combinations classified by space units. 
 
 (II) Combinations classified by side-line grouping. 
 
 (III) Side-line combinations and corresponding spacing shown 
 by chart. 
 
 In learning to space method (I) should be the guide but as a 
 further aid in certain combinations method (II) or (III) can be 
 used but " spacing " has not been properly grasped until the 
 judgment alone is relied on for satisfactory results. 
 
 (I) COMBINATIONS CLASSIFIED BY SPACE UNITS 
 
 A standard slope side followed by a standard slope side re- 
 quires three and one half spaces, thus, N S ^N 3 ^E. 
 
 A standard slope side adjacent to a curve side requires 
 three spaces, thus, C Z H 3 S I S C 3 E. 
 
 A combination side followed by a standard slope or a curve 
 side, also two curve sides adjacent, require two and one half 
 spaces, thus, P^R^I^S^M^^S. 
 
 A standard slope side followed by any one of the letters, Z, 
 V, W, A, X, also any one of the letters Z, V, K, W, A, X, 
 followed by V or W or by a standard slope side, require two 
 spaces, thus, M-^A^K^E. 
 
 A standard slope side followed by Y or T; a curve or combi- 
 nation side followed by any one of the letters Z, F, W, A , X; 
 the letters K, X, or Z followed by a curve side; any one of the 
 letters L, F, F, or T followed by a standard slope side require 
 one and one half spaces, thus, F^L^E^W. 
 
 All other combinations require one space, thus T 1 O 1 Y 1 S, except 
 r, Y and F when followed by A, X or Z; also the L or A when 
 followed by T or F, which require zero spacing, thus L Q A Y or 
 A Q T, etc. 
 
LETTERS, NUMERALS, AND LETTERING 41 
 
 (II) COMBINATIONS CLASSIFIED BY SIDE-LINE 
 GROUPING 
 
 Letters with a standard slope side [H, I, M, N] when followed 
 
 (1) by a standard slope side [B, D, E, F, H, I, K, L, M, N, 
 P, R, U] require 3^ spaces. 
 
 (2) by a curved side [C, O, G, Q, S] require 3 spaces. 
 
 (3) by a _L or a 45 side [V, W-A, X, Z] require 2 spaces. 
 
 (4) by a half -open side [T, Y, /] require i^ spaces. 
 
 Letters with a curved side [C, 0, G, Q-J, U-B, D] when followed 
 
 (1) by a standard slope side [B, D, E, F, H, I, K, L, M, N, P, 
 R, U] require 3 spaces, 
 
 (2) by a curved side [C, O, G, Q, S] require 2\ spaces. 
 
 (3) by a J_ or a 45 side [V, W-A, X, Z] require i| spaces. 
 
 (4) by a half -open side [T, Y, /] require i space. 
 
 Letters with a combination side [R, E, P, S] when followed 
 
 (1) by a standard slope side [B, D, E, F, H, I, K, L, M, N, 
 P, R, U] or by a curved side [C, 0, G, Q, S] require 2\ 
 spaces. 
 
 (2) by a J_ or a 45 side [V, W-A, X, Z] require i^ spaces. 
 
 (3) by a half-open side [T, Y, J] require i space. 
 
 Letters with a -L or a 45 or a full open side [F, W-A-K, X, Z] 
 when followed 
 
 (1) by a standard slope side [B, D, E, F, H, /, K, L, M, N, P, 
 R, U] require 2 spaces. 
 
 (2) by a _L side [V, W] require 2 spaces. 
 
 (3) by a curved side [C, O, G, Q, S] require ij spaces. 
 
 (4) by a 45 side [A , X, Z] require i space. 
 
 (5) by a half -open side [T, Y-J] require i space or o space. 
 
 .Letters with a half-open side [L-F, T, Y] when followed 
 
 (1) by a standard slope side [B, D, E, F, H, I, K, L, M, N, 
 P, R, U] require i| spaces. 
 
 (2) by a _L or a curved side [V, W-C, O, G, Q, S] require i space. 
 
 (3) by a 45 or a half -open side [A, X y Z-T, Y-J] require i space 
 or o space. 
 
42 ELEMENTS OF DRAWING 
 
 (III) SIDE-LINE COMBINATIONS AND CORRESPOND- 
 ING SPACING SHOWN BY CHART 
 
 The chart given on page 43 is used in the following manner. 
 Assume as an example that the letters of the word COLLEGE are 
 to be spaced. First, in the left-hand column locate the letter C, 
 then move horizontally and to the right until the column contain- 
 ing the capital at the top is located, and it is seen that the side- 
 line classification is curved side followed by curved side, and, reading 
 directly under the and in line with the C, the spacing is i\ 
 units. Similarly the combination of the letters O and L is a 
 curved side followed by standard slope line, and in a horizontal 
 line with the O and directly under the L the chart shows the 
 spacing as 3 units. Studying out all the combinations, the spac- 
 ing is as follows: C^O^Li^Li^^GsE. 
 
 (B) Spacing for Numerals. The " standard " spacing for 
 numerals is two and one half space units but in such combina- 
 tions as involve the left hand side of the j, the 4 and the 7 this 
 distance should be slightly reduced and in such combinations as 
 involve the i or the right hand side of the 4 (measured from the 
 stem) this standard spacing is slightly increased. 
 
 (C) Spacing for Capital Letters in combination with Small 
 Letters and for Small Letters. Small letters are about two thirds 
 the height of capital letters and numerals of the same alphabet 
 and hence small letters require a spacing of about two thirds that 
 given for a similar side-line combination of the capital letters. 
 
 (D.) Spacing between words and between sentences. Care 
 must be taken to have the proper space between words and a 
 greater space between sentences, otherwise the lettering is not so 
 easily read, even though the individual letters are correctly 
 formed and spaced. 
 
 The spacing between words should be slightly more than 
 twice the average space separating letters. 
 
 The spacing between sentences should be about twice that 
 separating words. 
 
 Where punctuation marks are necessary extra space is allowed. 
 The punctuation mark is placed nearer the word which precedes 
 
LETTERS, NUMERALS, AND LETTERING 
 
 43 
 
 
 \ 
 
 ^^ 
 
 i 
 
 ^ 
 
 
 
 . 
 
 1 
 1 
 1 
 
 . 
 
 X 
 
 d 
 
 i 
 
 - 
 
 i 
 "J I 
 
 v ' 
 
 ^ 
 
 
 1 
 
 
 \ 
 
 k X 
 
 |k 
 
 ^> 
 
 
 ^ 
 
 
 
 rv 
 
 1 
 I 
 
 \ 
 
 i 
 
 i 
 i 
 
 & 
 
 c 
 
 i | 
 
 V ' 
 i l 
 
 ^ 
 
 
 
 
 Uj 
 
 
 
 
 
 
 
 | 
 
 
 
 
 
 l l 
 
 
 
 
 
 I 
 
 
 
 
 
 
 
 1 
 
 
 i 
 
 
 
 1 l 
 
 
 
 I 
 | 
 
 i 
 
 
 \ 
 
 
 N,^ 
 
 
 
 \ 
 
 I 
 
 1 
 
 N^ 
 
 i 
 1 
 
 V 
 
 
 l i 
 
 \! , i 
 
 \ 
 
 
 
 1 
 
 \ $ 
 
 
 
 ^ 
 
 
 
 (V 
 
 I 
 | 
 
 X 
 
 ^ 
 
 
 
 ** 
 
 v*^ 
 
 -J 
 
 ^ 
 
 k"^ 
 
 
 8* 
 
 
 
 
 
 ' 
 
 
 
 
 1 
 
 
 
 i i 
 
 
 
 1 
 
 Q 
 
 | 
 
 
 a 
 
 
 M\ 
 
 I 
 
 
 ^(\, 
 
 
 i 
 
 
 
 i i 
 
 
 
 1 
 
 Q 
 
 
 
 \ 
 
 
 X 
 
 
 
 ^^ 
 
 
 
 
 
 i i 
 
 
 
 
 i. 
 
 G 
 
 UJ \ 
 
 
 
 
 
 
 
 1 
 
 
 l 
 l 
 
 
 
 i i 
 
 
 
 1 
 
 
 f\ ^" 
 
 
 
 
 
 
 
 
 
 
 
 
 i i 
 
 
 
 | 
 
 Uj Uj 
 
 ^T j^_ 
 
 
 
 
 
 
 
 1 
 
 
 i 
 
 
 
 
 
 
 
 > 
 
 ? ^ i - 
 
 
 
 ^ 
 
 i 
 
 
 (V 
 
 1 
 
 \ 
 
 <\j 
 
 
 
 ^ 
 
 v^ 
 
 ^J 
 
 ^ 
 
 t^^ 
 
 M 
 
 s 
 
 
 
 
 
 
 
 1 
 
 
 i 
 
 
 
 1 1 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 1 1 
 
 
 
 
 ^ 
 
 0) (0 
 
 ^ ^ 
 
 
 
 
 
 
 
 1 
 | 
 
 
 i 
 i 
 
 
 
 1 1 
 1 1 
 
 
 
 | 
 
 1 
 
 s ^ 
 
 k Uj 
 
 S 
 
 V. 
 
 /v_ 
 
 V. 
 
 ^a 
 
 J 
 
 v^ 
 
 1 
 
 ^ 
 
 i 
 
 Vj 
 
 ^-f\ 
 
 j O-MVI 
 
 ^ 
 
 ' 
 
 vj 
 
 
 ^ o 
 
 ^ 
 
 Oij 
 
 ^ 
 
 l v 
 
 
 rv 
 
 ^J 
 
 \ 
 
 i 
 
 - ' 
 
 "* 
 
 V > ^ 
 
 -J 
 
 ^ 
 
 k"^ 
 
 -J xj 
 
 Uj Uj 
 
 s o 
 
 
 
 
 
 
 
 1 
 
 
 i 
 i 
 
 
 
 i i 
 1 | 
 
 
 
 i 
 
 k i 
 
 "X 
 
 
 
 
 
 
 
 1 
 I 
 
 
 i 
 
 
 
 i i 
 
 
 - 
 
 
 h k 
 
 IV 
 
 
 "- n. 
 
 x 
 
 
 
 4, 
 
 
 
 i 
 
 N 
 
 
 i i 
 
 
 
 
 i 
 
 to 
 
 
 ^ u 
 
 ^ 
 
 (Y) 
 
 ^N 
 
 r^ 
 
 
 rv 
 
 (\J 
 
 
 Oj 
 
 
 
 ^V 
 
 v^i 
 
 "v^ 
 
 '^ 
 
 j ^\^ 
 
 
 
 ^ S 
 
 
 
 
 
 
 
 1 
 
 . 
 
 
 
 
 1 1 
 
 
 
 i 
 
 THE LEFT HAND >S 
 
 STANDARD SLOPE SI 
 
 DEFH/KLMF 
 
 g 
 
 C 
 
 1 
 
 l 
 
 SPACING -. 
 
 1 
 
 C 
 
 1 
 
 ' 
 
 
 
 
 8 
 
 SPACING 
 
 1 
 
 I 
 
 SPACING 
 
 1 
 
 SPAC/NG-. 
 
 OMBINA T/ON- 
 SPACING 
 
 S 
 
 1 
 
 SPACING . 
 
 OMBI NATION- 
 SPACING 
 
 
 CD 
 
 
 ) 
 
 L 
 
 i 
 
 
 * 
 
 
 
 ^ 
 
 
 ^ 
 
 
 * 
 
 
 
 10 
 
 ^ 
 
 iy 
 
 N 
 
 
 
 p, 
 
 
 IV 
 
 
 \ 
 
 
 (H 
 
 
 v 
 
 xj 
 
 
 
 ITHE RIGHT HANL 
 SIDES OF THE LCTTE 
 
 BELOW ARE fH EL 
 A<TA/r.S OFADJACEI\ 
 C CNSfDERED. 
 
 STANDARD SLOPE S/i 
 
 HIMN 
 
 CURVE SIDE J> 
 
 i 
 
 c 
 
 
 COWBi 'NATION 31 DE 
 
 | REPS 
 
 APPF1GX 4- 5 SIDE 
 
 i 
 
 \PERPENDICULAR SID 
 
 - 
 
 FULL OPEN SIDE 
 
 KXZ 
 
 i 
 
 ^ 
 
 
 k 
 
 k 
 
44 ELEMENTS OF DRAWING 
 
 it than the one which follows. The comma and the semicolon 
 each require a space between the mark and the following word 
 equal to the space between words. 
 
 36. Systematic Method of Lettering. Before starting the out- 
 line of a letter, draw very lightly all guide lines and center lines 
 that will be an aid in its construction. 
 
 When forming a letter, make all lines very light at first, and, 
 with the outline correct, retrace, making the lines of medium 
 weight. 
 
 All construction lines are then erased, and the correct outline, 
 which will be made dim by the erasing, is again retraced and 
 made clear cut and of the desired weight. In retracing, the 
 strokes should always be made in the direction and order indi- 
 cated by the arrows on the model letters. See 38, this page. 
 
 For full instructions as to how to make free-hand lines see 
 page 134, 95, also page 136, 96. ^ 
 
 37. The Size and the Lettering of Letter Sheets. Exercises in 
 free-hand lettering will be done on small sheets of standard letter 
 size (8" X ioj"), heavy weight, cross-section paper ruled on one 
 side (see page 5, 4), and punched for standard #10 Manila 
 cover. 
 
 The order in which free-hand lettering sheets are executed will 
 be indicated by capital letters, beginning with A and continuing 
 as far as necessary. For full information as to the general sys- 
 tem to be followed, see Appendix, page 175. 
 
 SET OF FREE-HAND LETTERING EXERCISES. 
 
 38. Outline and Characteristics of Capital (or Upper-case) 
 Letters Composed of Straight Lines Only. Over half of the 
 capital letters of the inclined Gothic alphabet are composed 
 entirely of straight lines, and several of these straight-line letters 
 are very similar. In the following paragraphs the characteristics 
 of straight-line capital letters are pointed out. 
 
 In order to fully understand the subject matter of this para- 
 graph, carefully read 34, page 37. 
 
LETTERS, NUMERALS, AND LETTERING 
 
 45 
 
 
 1 ^ 
 
 -3- 
 
 *H 
 
 
 
 
 )l 
 
 
 
 l 
 
 / 
 
 
 
 ^ 
 
 Y 
 
 
 
 i X 
 
 1 
 
 
 
 y 
 
 
 
 
 / 
 
 
 
 Capital I. i stroke of standard slope. The 
 width of the letter is the width of the line and 
 should not differ from that of all other standard 
 slope lines. Do not V 
 
 dot the capital /. G.L- 
 
 Capital L. 2 strokes. 
 If i is standard si 
 #2 is drawn horizontal. Note that $2 is 
 shorter than the corresponding line of E. 
 
 -41 
 
 CO 
 
 
 
 
 t/ 
 
 
 
 
 M 
 
 
 
 / 
 
 
 
 
 
 / 
 
 
 
 y 
 
 
 
 
 
 I 
 
 
 i 
 
 
 
 
 
 
 j~ 
 
 
 
 
 
 
 
 / 
 
 
 
 /vm 
 
 HOL 
 
 -2- 
 
 5- 
 
 
 / 
 
 
 ^ 
 
 -s: 
 
 -< 
 
 [7__ 
 
 3. 
 
 7 
 
 
 G.L 
 
 (See this page.) 
 Capital F. 3 
 
 strokes. #i is standard slope; $2 is the 
 same as #2 of E (see this page) ; #3 starts 
 from the middle of #i and is drawn 
 horizontal and should never be drawn 
 below the middle of the letter or be as 
 long as #2. 
 
 Capital E. 4 strokes. %i is standard 
 slope; #2 the same as $2 of F; (see this 
 page) ; #3 the same as #3 of F. #4 is par- 
 allel to #2 but is slightly longer. $2 is 
 also longer than the corresponding line 
 of the L. (See this page.) Note that 
 #2 and #4 are each shorter than the 
 corresponding lines of Z (see page 47). 
 
 Capital H. 
 
 co 
 
 $ 
 
 A 
 
 r fr 
 
 3 strokes. 
 
 and #2 
 
 are each standard slope. Note that 
 these two parallel lines would do for 
 the N. (See page 46.) #3 starts at 
 the middle of #i, is drawn horizontal 
 and should never be drawn below the 
 
 middle of the letter. L c! J 
 
 2 
 
 Capital T. 2 strokes. #i is drawn horizontal. 
 #2 is standard slope and is drawn from a 
 point slightly to the left of the center of #i. 
 Note that #i is longer than the correspond- 
 ing lines of E (see this page), F (see this 
 page), and Z (see page 47). 
 
 Stf 
 
ELEMENTS OF DRAWING 
 
 Capital N. 3 strokes, fti and ft2 are 
 each standard slope, as in the H. (See 
 page 45.) Stroke ft3 must meet fti and 
 #2 exactly at the extremes of the proper 
 
 ends. 
 
 II 
 
 Capital M. 
 
 4 strokes. 
 
 fti and ft2 are each standard slope, 
 and are drawn a distance apart 
 equal to the height of the letter. 
 ft3 and ft4 are first drawn very lightly, 
 the lower segments of which are erased in the finished letter. 
 The angle between ft3 and ft4 must not be too acute or the letter 
 -will appear to be compressed, or if too large the letter will appear 
 " widened." The M is not the same as the W inverted. (See 
 
 Page 47-) , 
 
 Capital Y. 3 strokes, fti is a standard 
 
 slope line drawn through the center of the 
 
 letter but slightly less than the lower half is 
 
 used in the completed letter. Strokes ft2 and 
 
 ft3 each start from points on the top guide 
 
 line which are equidistant from the inter- 
 section of fti (extended) and the top guide 
 
 line and meet fti slightly below the center. 
 
 Capital V. 2 strokes. Note especially 
 that fti is vertical and ft2 makes 45 with 
 it; also the letter is wider at the top than 
 any straight line letter excepting the M 
 (see this page) and the W. (See page 
 47.) Also fti is not 
 parallel to ft2 of the 
 
 A (see page 47), and no line has 
 
 the standard slope. The capital and 
 
 the small v are similar (see page 67). 
 Capital X. 2 strokes. ft2 has a 
 
 slope of 2 to i and should cross fti _J j* 
 
 at a point on the sloping center line slightly^ 
 
 above the center of the letter, thus making 
 
 
 
 - 
 
 
 -5- 
 
 -p 
 
 - 
 
 'r 
 
 *~ 
 
 
 
 \\ 
 
 
 / 
 
 
 /, 
 
 f 
 
 
 
 s 
 
 / 
 
 / 
 
 4 
 
 
 
 
 
 A 
 
 '/ 
 
 ^ 
 
 
 
 
 
 
 n 
 
 
 ._. 
 
 ~ 
 
 
 
 
 / 
 
 / 
 
 
 
 
 * 
 
 s| 
 
 
 
 
 7 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 ] 
 
 
 
 
 
 A\ 
 
 ^ 
 
LETTERS, NUMERALS, AND LETTERING 
 
 47 
 
 the letter wider at the bottom than at the top, otherwise it 
 appears top-heavy. The capital and the small x are similar. 
 See page 67. 
 
 Capital A. 3 strokes, fti makes 45 
 with top and bottom guide lines. ft2 is 
 drawn from the extreme top of fti to the 
 base of the right guide line and is not a 
 - vertical line, thus ft 2 is not parallel to fti of 
 the V. (See page 46.) ft3 is horizontal 
 and one-third the distance from the bot- 
 tom to the top of the letter, and thus is 
 always below the center of the letter. 
 Note that no lines of this letter have the standard slope. 
 Capital K. 3 strokes, fti is standard 'p 5 
 
 slope, ft 2 is drawn to meet fti at a 
 point one- third the height of letter; 
 i.e., below center of letter. ft3 is drawn 
 very lightly, the upper segment of 
 which is erased in the finished letter. 
 Note that the letter has a greater width 
 at the bottom than at the top. 
 
 Capital Z. 3 strokes. Draw very 
 lightly two sloping side guide lines. 
 fti is horizontal and starts from the 
 left guide line. ft3 is parallel to fti, 
 but slightly longer. Note that fti and 
 ft3 are longer than the corresponding 
 lines of the E. (See .page 45.) The 
 "i capital and the small z are similar. See page 67. 
 Capital W. 4 strokes. No stroke ^j 
 has the standard slope, fti and ft3 
 each incline slightly to the right 
 and are parallel; also ft 2 and ft4 are 
 parallel. Note that the letter W 
 inverted would not be the same 
 as the M. (See page 46.) The 
 capital and the small w are similar. 
 See page 67. 
 
48 ELEMENTS OF DRAWING 
 
 39. Sheet A. The purpose of this sheet is to teach the form 
 and characteristics of the capital letters of the inclined Gothic 
 alphabet, which are constructed entirely of straight lines, also 
 to give practice in making these letters. 
 
 Before starting this sheet read and be prepared for examina- 
 tion on the following paragraphs: 
 
 The Pencil Pointer, see page 14, 13, Lead Pencil, see page 
 14, 14, Erasers and Erasures, see page 16, 15, The 
 Free-hand Pencil Line, see page 134, 95, Introductory, see 
 page 34, 31, the Study of Lettering, see page 34, 32,- 
 The Spacing of Letters, Words and Sentences, see page 39, 35, 
 and for information on the general system to be followed see 
 page 175, Appendix A. 
 
 Exercises on Sheet A. These exercises consist of capital 
 letters of the simplest form. Before beginning the construction 
 of any letter, study carefully the illustration of that letter in 
 the model alphabet (see page 44, 38) and read all .descriptive 
 matter relating to it. Also see 37, page 44. 
 
 Do not use a straightedge in doing any part of a free-hand 
 exercise as this will seriously impair the value of this work. 
 Lines so made are easily detected and as a result the sheet will 
 not be accepted. 
 
 Specific Instructions for Executing Sheet A . Tack down the 
 sheet (see page 8, 9), stamp in title form (see page 138, 98) 
 and the wording in the title form is next to be neatly written 
 in ink. 
 
 The title of sheet A is CAPITAL LETTERS. 
 
 Proceed with the letters systematically, and complete the sheet 
 as shown in Fig. 39, but omit arrows. Practice making a free- 
 hand pencil line on scrap paper before starting sheet A . This 
 practice can best be accomplished by making a free-hand copy 
 of some simple drawing, such as Fig. 97 on page 140, continuing 
 to practice until a " clear cut" line can be made (see page 78, 
 54). Also the beginner should at this time learn to sharpen 
 a pencil with care (see page 15, 14) and to use an eraser to 
 the best advantage (see page 16, 15). 
 
LETTERS, NUMERALS, AND LETTERING 
 
 49 
 
 
 
 
 
 
 
 
 
 
 
 
 
 'M 
 
 to t 
 
 
 1 
 
 d 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 s 
 
 x^ 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 *x 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^0 
 
 
 
 
 
 
 -> 
 
 
 
 Vi^ 
 
 
 
 s, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 \j 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ' 
 
 ! 
 
 
 
 
 
 
 
 
 
 
 ^s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 <*. 
 
 
 
 
 
 
 
 
 
 "Si 
 
 
 
 . 
 
 C. 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X 
 
 ^ 
 
 
 x^ 
 
 
 
 
 
 
 s (\j 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rv 
 
 1 
 
 
 
 
 \ 
 
 J 
 
 
 
 ^ 
 
 
 
 ^ 
 
 ^ 
 
 
 vr 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -1 
 
 * 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 1 
 
 I 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 "S 
 
 X 
 
 
 
 
 
 n 
 
 1 
 
 
 
 
 
 
 
 
 
 
 I 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
 Q 
 
 
 
 
 
 s 
 
 x^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
 p 
 
 
 
 
 g 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 *-^ 
 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 <c 
 
 
 
 
 
 .2 
 
 
 
 
 
 
 
 
 
 +^ 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 ! 
 
 l 
 
 
 
 
 CO 
 
 
 
 
 
 
 
 
 nT" 
 
 X^, 
 
 
 
 
 
 
 
 j 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 | 
 
 | 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 N 
 
 x^ 
 
 
 
 
 
 
 
 
 
 y 
 
 
 
 
 
 
 
 C 
 
 | 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 
 
 x^ 
 
 
 
 
 
 
 
 S,, 
 
 
 ^H 
 
 j 
 
 
 
 
 
 | 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s. 
 
 ^J 
 
 
 
 
 
 I 
 
 g 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X N 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 > 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 
 
 
 
 N f 
 
 1^ 
 
 x^ 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 I 
 
 
 
 
 
 & 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 1 V 
 
 
 
 ' 
 
 x^ 
 
 
 
 
 n 
 
 
 s 
 
 
 
 
 H ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 <j 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 <^- 
 
 
 
 
 
 
 *x. 
 
 
 
 
 
 
 
 
 
 '. 
 
 - 
 
 \ 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 x^ 
 
 
 y 
 
 
 8 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 i 
 
 
 
 
 
 -, 
 
 
 
 
 
 x^ 
 
 
 
 
 
 
 
 * 
 
 v^ 
 
 
 ^ 
 
 
 
 
 
 , 
 
 3 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 ta 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 Vu 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 J 
 
 
 
 
 
 
 | 
 
 
 
 
 
 
 Ct 
 
 
 
 
 
 
 
 
 X, 
 
 
 
 
 
 7 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 O 
 
 
 
 
 
 
 
 
 
 
 X,, 
 
 
 
 J 
 
 V1 
 
 v 
 
 y 
 
 
 
 
 
 
 
 
 
 
 I 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 ! 
 
 
 
 
 
 
 
 
 
 
 
 
 1*1 
 
 
 
 
 
 
 n 
 
 1 U 
 
 
 
 
 
 s 
 
 ^ 
 
 s 
 
 ^6 
 
 
 
 
 
 rJ 
 
 ? 
 
 
 
 
 
 
 6) 
 
 
 
 
 
 M 
 
 
 
 
 
 
 
 J 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 4 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s s 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 bb 
 
 
 
 
 
 
 
 
 0-) 
 
 
 n 
 
 
 
 
 
 ^ 
 
 
 
 
 
 N 
 
 
 
 
 
 ' 
 
 f 
 
 
 
 
 
 
 fe 
 
 
 
 
 
 X 
 
 V 
 
 X^ 
 
 
 
 - 
 
 
 *! 
 
 
 
 
 s 
 
 
 
 
 <*L 
 
 
 
 
 
 '1 
 
 i 
 
 
 
 
 
 
 
 
 
 li- 
 
 
 
 
 
 1 
 
 \ 
 
 
 
 
 
 k) 
 
 
 
 J 
 
 S 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ft 
 
 
 
 
 
 
 
 
 x. 
 
 
 
 
 
 ~ t 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 J 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 s 
 
 s 
 
 
 
 \ 
 
 
 (ft 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 4 
 
 
 
 
 
 
 
 
 
 
 s s 
 
 
 
 
 s. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 u 
 
 
 
 ^ 
 
 x^ 
 
 
 
 
 
 
 
 
 
 
 Sy 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 c 
 
 
 
 
 
 N 
 
 ^ 
 
 
 
 
 
 <b 
 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 x. 
 
 
 
 
 
 
 
 
 s, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f. 
 
 
 
 
 
 
 
 
 X. 
 
 f\j 
 
 
 
 
 
 
 
 k > 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 9, 
 
 
 
 
 
 
 
 
 
 1: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \J 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 A 
 
 
 
 X 
 
 ^ 
 
 
 
 
 
 - 
 
 \\ 
 
 
 
 
 
 
 
 
 
 
 X 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 "* 
 
 x^ 
 
 
 
 S 
 
 
 n 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 X 
 
 x^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ** 
 
 ^ 
 
 
 
 
 - 
 
 
 s^ 
 
 
 
 
 
 
 
 
 
 
 -s 
 
 Xj 
 
 
 
 
 
 
 
 T 
 
 
 
 s^ 
 
 
 
 
 
 
 
 
 
 r(y 
 
 
 ^ 
 
 X, 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 X 
 
 ^ 
 
 
 
 
 \\ 
 
 T 
 
 _ 
 
 ^^ 
 
 
 
 
 N> 
 
 ^ 
 
 
 
 
 X 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 II J 
 
 
 
 
 
 
 ^ 
 
 i^ 
 
 
 o 
 
 ft 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X 
 
 s 
 
 
 
 
 
 
 
 
 r 
 
 
 
 
 
 
 
 
 
 
 Jt 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 x 
 
 n 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X 
 
 s. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -^ 
 
 
 
 
 
 
 
 
 
 
 
 -4- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^u p- 
 
50 ELEMENTS OF DRAWING 
 
 The first letter to be drawn is the capital /, and the bottom 
 of this letter is to be located 23 spaces from the top edge and 
 14! spaces from the first heavy vertical cross-section line on the 
 left side of the sheet. 
 
 Having satisfactorily completed the outline of all letters, 
 clean the sheet (see page 17, 15), and go over all lines, making 
 them clear cut and finished. See page 78, 54. 
 
 Thoroughly examine the work to see that nothing has been 
 omitted; correct any errors, and, after the sheet has been in- 
 spected, write the Date Finished and the Total Actual Hours in 
 the title form, and submit the sheet for final approval. 
 
 40. The Sloping Ellipse. A large number of capitals, small 
 letters, and numerals of the inclined Gothic alphabet have an 
 outline which is partly or entirely oval. This oval approaches 
 :more nearly the "sloping ellipse" than any other curve, and the 
 .beginner should understand the construction of such a curve be- 
 fore attempting to form the curved letters. The exact shape of 
 any ellipse is determined by the ratio between its long and 
 short axes. Fig. 40 (a) shows an ellipse with its long axis 
 vertical and having a ratio of width to height of 5 to 6, this ratio 
 ibeing common to many letters. This ellipse is tangent to the 
 guide lines at the points i, 2, 3, 4, and is symmetrical about 
 i>oth the long axis and the short one. Therefore the diagonals 
 5 to 7 and 6 to 8 are of equal length, also the four shaded areas 
 outside the ellipse are equal and have the same shape. 
 
 A "sloping ellipse" is shown in Fig. 40 (b). In this con- 
 struction the long axis has the slope of the alphabet (2 to i), but 
 the short axis remains horizontal. When this curve is drawn in 
 a parallelogram and is tangent at the extremities of the axes, 
 the lines i to 3 and 2 to 4 do not divide the ellipse symmetri- 
 cally. The shaded areas are therefore not of the same shape, 
 but those diametrically opposite are the reverse of each other. 
 That is, in the sloping ellipse the upper left-hand quadrant of 
 the curve is the same as the lower right-hand quadrant but 
 reversed in relative position, and similarly the upper right-hand 
 quadrant is the same as the lower left-hand quadrant but re- 
 versed in relative position. The " sloping ellipse " is therefore 
 
LETTERS, NUMERALS, AND LETTERING 
 
 not of the true ellipse construction but is an ellipse so modified 
 that its major axis has the slope of the alphabet, and the curve 
 is tangent to the limiting parallelogram at the extremities of the 
 In certain portions of the outlines of some of the capital 
 
 axes. 
 
 n / 
 
 
 
 
 \r 
 
 
 / 
 
 
 
 
 [7.1*1 
 
 
 
 
 y 
 
 ^T7 
 
 ^ 
 
 
 / 
 
 
 
 
 
 A 
 
 / / 
 
 
 6 
 
 
 
 
 
 
 
 % 
 
 
 
 
 
 
 
 
 
 A? 
 
 y 
 
 
 
 
 
 
 / 
 
 8' 
 
 /' 
 
 7> 
 
 f 
 
 
 
 
 P i 
 
 ,: 
 
 i 
 
 \^ 
 
 
 ^^(j^w 
 
 
 
 
 
 Cf.L.n 
 
 r 
 
 
 3 
 
 
 / V 
 
 
 
 
 
 
 
 ?.L 
 
 (a) Vertical. 
 
 (b) Medium Slope. 
 Fig. 40. Ellipses. 
 
 (c) Extreme Slope. 
 
 letters and in the case of certain small letters a much better 
 shaped letter is obtained if the slope of the ellipse is made 
 greater than the standard slope as shown in Fig. 4o(c). Ap- 
 proximately the same effect can be obtained in some of the 
 capital letters by the use of circular arcs as shown in Z>, U, J, 
 P, B, and R, pages 52 and 53. The use of the small ellipse [see 
 Fig. 4o(c)] in small letters is shown on pages 63, 64 and 65. 
 
 41. Outline and Characteristics of Capital (or Upper-case) 
 Letters Composed Wholly or Partly of Curved Lines. For gen- 
 eral discussion of guide lines, center lines, dimension lines, 
 and arrows as used in connection with lettering and numbering, 
 see page 37, 34. 
 
 Capital O. 3 strokes. Draw 
 two side-guide-lines such that 
 their distance apart is equal to 
 the width of the letter. Bisect 
 the parallelogram by two center 
 lines, as shown, and locate the: 
 points of tangency of the guide 
 ^>* lines and ellipse. Draw in the 
 
 sloping ellipse in the order of the strokes. For full description 
 and construction of the " sloping ellipse " see page 50, 40. 
 The capital Q and the small o are similar. See page 63. 
 
 1 
 
 
 
 
 / 
 
 1 _. 
 
 / 
 
 
 
 / 
 
 Cs 
 
 
 
 
 / 
 
 / 
 
 SI 
 
 ^ 
 
 ^ 
 
 / 
 
 
 
 
 
 /^ 
 
 / 
 
 / 
 
 
 V 
 
 / 
 
 
 
 
 / 
 
 / 
 
 
 / 
 $6 
 
 
 
 7 
 
 
 
 
 
 / 
 
 
 
 
 7 
 
 / 
 
 
 
 
 / 
 
 i 
 
 
 / 
 
 
 s, 
 
 / 
 
 
 
 
 
 / 
 
 x 
 
 ^--_ 
 
 2] 
 
 
 S 
 
 
 P 
 
 L. 
 
 
 / 
 
 
 
 / 
 
 
 1 
 
 
 u 
 
ELEMENTS OF DRAWING 
 
 Capital Q. 4 strokes. Three 
 strokes, as for O. (See page 51.) 
 #4 is drawn very lightly from the 
 left-hand point of tangency to the 
 intersection of the right-hand and 
 bottom guide lines. Erase about 
 two-thirds of the left-hand portion 
 of this line and retrace the remain- 
 ing portion medium weight. 
 
 
 
 
 
 / , 
 
 
 / 
 
 
 
 / 
 
 
 
 
 / 
 
 L*-* 1 
 
 / 
 
 s 
 
 
 / 
 
 
 
 
 
 // 
 
 \ 
 
 
 / 
 
 
 V 
 
 / 
 
 
 
 
 / 
 
 / 
 
 
 / 
 
 
 
 7 
 
 
 
 
 
 / 
 
 X 
 
 
 
 ' 
 
 / 
 
 
 
 
 / 
 
 \v 
 
 
 5 
 
 s 
 
 c 
 
 / 
 
 i 
 
 
 
 
 / 
 
 V 
 
 ^ 
 
 
 ^> 
 
 
 / 
 
 T 
 
 
 
 1 
 
 
 
 7 
 
 . . 
 
 
 X 
 
 W * 
 
 
 
 Capital C. 3 strokes. Proceed 
 as with O (see page 51), excepting 
 that #2 and #3 are shortened. The 
 opening in the ellipse is slightly 
 greater than one-third the height of 
 letter and nearer the bottom than the 
 top guide line but the letter width is the 
 same as the O. The capital C and the small c 
 See page 64. 
 4 strokes. #i and #3 
 
 t 
 
 
 
 AJt 
 
 ^ 
 
 
 
 N L 
 
 / 
 
 C\j 
 
 1 
 
 
 
 Z 
 
 
 
 
 \ 
 
 / 
 
 t 
 
 1 
 
 
 / 
 
 / 
 
 
 / 
 
 
 
 / 
 
 "b, 
 
 
 
 1 
 
 
 / 
 
 
 
 
 / 
 
 / 
 
 
 
 
 , 
 
 u 
 
 
 / 
 
 
 s 
 
 / 
 
 
 ~^ 
 
 & 
 
 i 
 
 ' 
 
 V 
 
 ^ 
 
 -'2 
 
 ^^^ 
 
 / 
 
 / 
 
 
 
 / 
 
 
 
 / 
 
 
 
 
 are similar. 
 Capital G. 
 
 are the same as for C. (See this 
 page.) #2 is longer than #2 in C and 
 extends up one-third the height of 
 letter. $4 is horizontal and extends 
 one-third across the letter. 
 
 Capital D. 3 strokes. #i is standard 
 slope. The right-hand half of the letter 
 practically the same as the right 
 Er i: half of O. (See page 51.) The D 
 is slightly narrower than the O. 
 
 Capital U. 2 strokes. ,^ 7 ^ 
 
 Upper half of letter con- j 
 
 , i sists of standard slope 
 ' lines, and lower half 
 is practically the same as lower half 
 of O. (See page 51.) The U is 
 slightly narrower than the O. 
 
LETTERS, NUMERALS AND LETTERING 
 
 53 
 
 ^o 
 
 T7 
 
 F- 
 
 Capital J. 3 strokes. S3 is two- 
 thirds the upper portion of a standard 
 slope line. Note that / is relatively 
 
 - narrow. The lower portion of the 
 ' letter is part of a small modified 
 
 - sloping ellipse. See page 50, 40, 
 i Fig. 40 (c). 
 
 P. 3 strokes. #i is 
 fti 
 
 
 
 
 - 
 
 7 
 
 ----- 
 
 
 * 
 
 /I 
 
 -<- 
 / 
 
 ^ 
 
 
 
 
 >/ 
 
 -m* 
 
 _ 
 
 i 
 
 
 
 >i 
 
 ,.. 
 
 eo|^ 
 
 
 
 / 
 
 l 
 
 
 \ 
 
 
 v 
 
 ? 
 
 
 T 
 
 ^ 
 
 
 a 
 
 
 
 
 -^ 
 
 ^/ 
 
 
 
 
 
 i 
 
 I 
 
 
 \ 
 
 
 \\ 
 
 y 
 
 
 
 
 1 
 
 / 
 
 
 
 T 
 
 
 1 
 
 
 
 
 
 ! 
 
 / 
 
 
 
 I 
 
 
 V 
 
 
 
 
 
 
 -< . 
 
 
 _ f 
 
 -1 
 
 / 
 
 
 
 i 
 
 i 
 i 
 
 i 
 
 
 Ci 
 
 3P 
 
 ital 
 
 _J 2 U- Capital 
 
 standard slope. S2 is 
 partly horizontal and partly small 
 modified sloping ellipse. See page 
 51, 40. Note that portions of 
 
 52 and S3 are parallel. 
 
 Capital R. 4 strokes. #i, #2, and S3 same as 
 
 Si, #2, and S3 for P. (See this page.) 
 S4 is drawn so as to make the R 
 r wider at the bottom than at the 
 top and should be drawn in such a 
 direction that it would intersect Si 
 (extended) slightly above the top 
 guide line. , 
 
 B. 4 strokes, fti, [ ~ 5 ^^ 
 82, and part of S3 same as Si, #2, and 
 
 53 for P. (See this page.) The lower 
 half (or lobe) of B is of the same form 
 but slightly wider than the upper lobe. 
 
 Capital S. 3 strokes. Draw all 
 
 guide and center lines. The outline of the 
 
 letter consists of portions of two tangent 
 
 modified ellipses, exactly the same 
 size and slope but in reversed rela- 
 tive position. Si is the left half of 
 upper ellipse and the right half of 
 lower ellipse. #2 is drawn from the 
 top point of tangency, S3 to the 
 lower point of tangency. Locate 
 accurately the seven points of 
 
 tangency before "roughing in" ellipses and see that the outline 
 
 
 
 
 1 
 
 - 
 
 *_ 
 
 
 - 
 
 y 
 
 ... 
 
 !* 
 
 
 
 / 
 
 / 
 
 
 
 
 2, 
 
 Q 
 
 
 *. 
 
 
 
 '/ 
 
 *?. 
 
 
 
 * 
 
 
 
 
 
 D 
 
 / 
 
 / 
 
 
 
 i 
 
 , > 
 
 7 
 
 
 
 1 
 
 
 f/ 
 
 
 
 
 V 
 
 f) 
 
 
 
 
 T 
 
 
 / 
 
 ^=- 
 
 
 v~ 
 
 ^ 
 
 '/ 
 
 
 
 
 
 Jie 
 >nt 
 
 
 
 5, 
 
 r~ 
 
 2> 
 
 k 
 
 -< 
 
 
 
 
54 
 
 ELEMENTS OF DRAWING 
 
 is tangent at the center of the letter but is not drawn below 
 the horizontal center line at the 
 middle of the letter. The capital 
 and the small s are similar. See 
 page 66. 
 
 Abbreviation &. 5 strokes. #i, 
 #2, and $3 are almost the same as 
 for the numeral 8. (See page 
 59.) Note especially where #4 
 and #5 begin and end. 
 
 42. Sheet B. The purpose of this sheet is to teach the form 
 and characteristics of the capital letters of the inclined Gothic 
 alphabet, which are constructed wholly or partially of curved 
 lines, and to give practice in making these letters. 
 
 Having had the experience of making sheet A, again 
 read paragraph 34, page 37, with reference to the Model 
 letters. 
 
 For information on the general system to be followed see 
 Appendix A, page 175. 
 
 Exercises on Sheet B. These exercises include all capital 
 letters of the inclined Gothic alphabet not given on Sheet A . 
 
 Before attempting to form a letter, study carefully the illus- 
 tration and description of that letter in the model alphabet. See 
 page 51, 41- 
 
 Specific Instructions for Executing Sheet B. Tack down the 
 sheet, stamp in and fill out the title form. The wording in the 
 title form is to be neatly written in ink. 
 
 The title of Sheet B is CAPITAL LETTERS. 
 
 Locate the letters on the sheet according to the space dimen- 
 sions shown in Fig. 41 . Proceed with the lettering systematically 
 (seepage 44, 36) and complete, as shown in Fig. 41. Having 
 satisfactorily completed the outline of all letters, clean the sheet 
 and retrace all lines, making them clear cut and of the desired 
 weight. 
 
 Carefully examine the work to see that nothing has been 
 omitted; correct any errors, and, after the sheet has been 
 thoroughly inspected, write in with ink the Date Finished 
 
LETTERS, NUMERALS, AND LETTERING 
 
 55 
 
 *>r 
 
 5 
 
 i 
 
 ^ 
 
 j 
 
 .0). 
 
 ^ 
 
56 ELEMENTS OF DRAWING 
 
 s and Total Actual Hours, and submit the sheet for final 
 approval. 
 
 43. Sheet C. The purpose of this sheet is to teach the beginner 
 to correctly maintain all relative proportions of letters and spacing 
 in lettering of the size usually found on practical drawings. 
 
 The first alphabet at the top of the sheet is reduced to one-half 
 size; this means that dimensions given on Sheet A (page 49, 
 Fig. 39) and Sheet B (page 55, Fig. 41), including the spacing, 
 are reduced one-half. 
 
 The second alphabet on Sheet C is reduced to one-third size, 
 and the unit of space is one- third that given on Sheets A and B. 
 
 The lettering in the note at the bottom of Sheet C is only one 
 space high, that is, it is one-sixth size, and the spacing between 
 letters, words, and sentences must be reduced accordingly. 
 
 Specific Instructions .for Executing Sheet C. Tack down the 
 sheet, stamp in and fill out the title form. 
 
 The title of Sheet C is REDUCED-SIZE LETTERING. 
 
 Locate numbers and letters on sheet, as shown in Fig. 42. 
 
 When all lettering has been satisfactorily completed in pen- 
 cil, clean the sheet and retrace all lines, making them the proper 
 weight. 
 
 Every possible precaution should be taken to prevent soiling 
 the sheet and to avoid the necessity of making changes. As this 
 sheet is to be inked, any erasing which tends to injure the sur- 
 face of the drawing makes satisfactory inking very difficult. 
 This sheet must be finally approved in pencil before it is 
 inked in. 
 
 Thoroughly examine the work to see that nothing has been 
 omitted; correct any errors, and, after inspection and approval, 
 the sheet is ready for inking. Before attempting to ink any 
 work the beginner should practice inking on scrap paper. See 
 page 136, 96. Such preliminary practice accustoms the hand 
 to the touch of the pen and avoids experiments on approved 
 penciled sheets, which would most likely spoil them. 
 
 Specific instructions for Inking Sheet C. Tack down the ap- 
 proved penciled sheet on the drawing board and, before be- 
 ginning to practice inking on scrap paper, read and prepare 
 
LETTERS, NUMERALS, AND LETTERING 
 
 57 
 
 -q- 
 
ELEMENTS OF DRAWING 
 
 for examination on the following paragraphs. Free-hand Inked 
 Lines, page 136, 96, Drawing Ink, page 18, 18, The Ordinary 
 Pen, page 18, 19. 
 
 44. Outline and Characteristics of Numerals. For general 
 discussion of guide lines, center lines, dimension lines, and arrows 
 as used in connection with letters and numbers, see page 37, 
 34- 
 
 / Four. 3 strokes. #i is standard 
 
 slope and its location in the limiting 
 parallelogram of guide lines is very 
 important, being a distance of 
 three-fourths the total width of 
 agure from the left guide line. #2 
 Grlr. extends downward two-thirds the 
 height of the numeral. #3 is hori- 
 zontal and extends entirely across 
 the limiting parallelogram and gives the figure its real width, 
 which is greater than any other numeral. 
 
 
 
 
 
 
 V 
 
 s 
 
 1 
 
 I 
 
 ! 
 
 Q 
 
 
 
 \ 
 
 
 
 
 / N 
 
 
 
 
 
 / 
 
 s 
 
 
 
 / 
 
 ' 
 
 
 
 
 
 
 - 
 
 mmm' 
 
 3 
 
 -> 
 
 / 
 
 
 
 
 Seven. 2 strokes. Note especially 
 the width of the numeral, the curvature 
 of #2, and that the end of #2 does not 
 meet the bottom guide line of the 
 limiting parallelogram equally distant 
 from the side guide lines. 
 
 Naught. 3 
 
 -4- 
 
 
 
 
 f\ 1 
 
 
 
 
 
 ^ 
 
 
 
 I 
 
 ^m 
 
 mar 
 
 -7- 
 
 j 
 
 / 
 
 
 
 
 
 
 
 
 / 
 
 / 
 
 / 
 
 
 
 / 
 
 
 
 
 % 
 
 / 
 
 
 
 
 / 
 
 
 
 Z 
 
 '' 
 
 1 
 
 \ 
 
 
 / 
 
 
 
 / 
 
 / 
 
 ft 
 
 
 Crj 
 
 
 , / 
 
 
 
 / 
 
 
 
 
 1 
 
 
 / 
 
 o 
 
 
 
 
 / 
 
 
 
 
 
 1 
 
 
 
 ' 
 
 /< 
 
 ^^ 
 
 - 
 
 ^^ 
 
 
 ' 
 
 
 
 
 / 
 
 
 , 
 
 
 
 ) 
 
 
 i 
 
 
 / 
 
 r 
 
 
 / 
 
 Ci 
 
 
 1 
 
 / 
 
 
 
 
 L 
 
 
 : 
 
 
 
 V 
 
 
 
 
 / 
 
 u 
 
 
 / 
 
 
 -y 
 
 / 
 
 
 
 ! 
 
 
 V 
 
 ^ 
 
 ^ 
 
 f 
 
 ', 
 
 
 
 
 \c ' r ' 
 
 strokes. Formed the ' 
 same as the (see page 51) but 
 slightly narrower. 
 Nine. 3 
 
 -5f 
 
 strokes. A 
 mall sloping ellipse 
 
 [see Fig. 40 (c)] forms 
 part of the outline. Note especially 
 the angle of the center line of the small 
 ellipse and that the slope of the portion of the r* 5 
 large ellipse is the slope of the numeral [see Fig. 40 (b)]. The 
 form of the Q is exactly the same as the 6 inverted (see page 59) 
 
LETTERS, NUMERALS, AND LETTERING 
 
 59 
 
 Six. 3 strokes. The form of the 
 6 is exactly the same as the p in- 
 verted (see page 58). This neces- 
 sitates a change in the order of 
 strokes. 
 
 Five. 4 strokes. Lower part of 5 
 
 is similar to lower 
 
 i i 
 
 ellipse of 6 (see 
 
 this page) . fti is standard slope, extend- 
 ing to ellipse only. Note that #i is 
 slightly to the right but parallel to the 
 left-hand guide line and therefore is 
 not tangent to #2. #4 extends to right 
 guide line. Note that extreme width of the 
 numeral is from starting point of #2 to right- 
 hand point of tangency. , 7 , ( _. 1 _^\ i 
 Eight. 4 strokes. The outline of the numeral " ? *]j * pT 
 is made up of two tangent ellipses. The 
 lower half of the numeral is similar in 
 outline to the upper half but slightly i 
 wider. Note the similarity to 5 (see 
 
 page 53). 
 
 Three. 4 strokes, j 
 Consists of portions " 
 of two ellipses of the same dimensions. 
 Note that less of the upper ellipse is 
 used than the lower ; this is in order that 
 the numeral will not appear top heavy. 
 The 3 is similar to the 8 (see this page). 
 Two. 4 strokes. 
 The upper half of 
 
 the numeral consists of part of an 
 
 ellipse, which is one-half the figure 
 
 height and the full figure width. #i 
 
 and #3 are both tangent to left guide 
 
 line. Note the curvature of #3 and that 
 
 begins lower down than on the numeral 
 
 (see this page). 
 
60 ELEMENTS OF DRAWING 
 
 45. Sheet D. The purpose of this sheet is to teach the 
 beginner the characteristics of the numerals and to give 
 practice in making them. Locate the numerals on the sheet 
 as shown in Fig. 43. 
 
 The slope of fractions must be the same as that of the alphabet; 
 for example, take any ordinary fraction, say, five-eighths, the 
 eight is not vertically below the five, but a standard slope line 
 drawn through the center of the 5 passes through the center of 
 the 8. The line separating the numerator from the denominator 
 must always be a straight line parallel with the line of printing. A 
 sloping dividing line may lead to error in reading a fraction. The 
 figures in the numerator and in the denominator must never 
 touch the dividing line. The total height of a fraction should 
 be about one and one-half times the height of whole numbers. 
 
 Follow specific instructions given for preceding sheets in so far 
 as they apply to this sheet. 
 
 The title of sheet D is NUMERALS. 
 
 46. Sheet E. The purpose of this sheet (see Fig. 44) is to 
 give practice in lettering of a size suitable for notes on working 
 drawings. 
 
 Follow specific instructions given for the preceding sheets in so 
 far as applicable. 
 
 The title of sheet E is LETTERING. 
 
 Specific Instructions for Inking Sheet E. Tack down the 
 approved penciled sheet on the drawing board, and carefully ink 
 each letter in the order in which they come. Clean the pen 
 frequently and maintain a steady and even pressure on the pen 
 point. Extra care must be taken in inking this sheet other- 
 wise it is liable to be spoiled. 
 
 47. The Small (or Lower-case) Letters of the Inclined Gothic 
 Alphabet. In studying characteristics of the lower-case alphabet, 
 carefully read 34, page 37, and remember that the direction 
 and order of strokes is of prime importance. As in the case of 
 free-hand capital letters, all strokes which are horizontal or nearly 
 so are made toward the right, while all others are made down- 
 ward or toward the draftsman. This avoids the possibility of 
 catching the pen point in the drawing and splashing the ink. 
 
LETTERS, NUMERALS, AND LETTERING 6l 
 
 Ss* 
 
 ii 
 
62 
 
 ELEMENTS OF DRAWING 
 
 if 
 
 * 
 
LETTERS, NUMERALS, AND LETTERING 
 
 This alphabet requires a total height of eight blocks for the 
 model letters, but in practice only four horizontal guide lines are 
 necessary. These lines are numbered from the bottom to the top. 
 Thus, #i limits the letter when its stem (seepage 37, 34) extends 
 below the body of the letter, as in g, j, p, q, y; $2 limits the bot- 
 tom of the body; #3, the top of the body; and #4, the stems when 
 they extend above the body, as in b, d,f, k, h, and /. The distance 
 between the first and second lines and between the third and 
 fourth lines is two spaces, or one-half of that between the second 
 and third lines. The height and width of a, c, e, n, o, u, andfl is 
 the same and is equal to four unit spaces. 
 
 The letter o is similar to the sloping 
 ellipse described in 40, page 50, and 
 makes up wholly or partially the outline 
 of all letters having a body more or less 
 elliptical. The horizontal and the slope 
 guide lines form a parallelogram and 
 the horizontal center line intersects these guide lines at their mid- 
 points, which determine the touching points of the ellipse, but 
 the sloping center line runs from the lower left hand corner to 
 the upper right hand corner [see Fig. 40 (c), page 51]. Thus the 
 small oval letters "tilt" more than the capital oval letters, though 
 the slope of the letters appears the same. Consequently the 
 small letters are more in harmony with the capital letters 
 previously described. The small o is similar to the capital O 
 (seepage 51). 
 
 Letters a, d, g, and q differ as to the length and position of their 
 stems. All these stems have standard 
 .,,,,_ slope and are tangent to the elliptical body 
 
 T7.LT As^^^i'^JX/ f 
 ~~r?\/\W}~~ a ^ e same corre ~ 
 h**?felErffflB sponding point. 
 
 - -G.I. The vertical height 
 
 of the elliptical J 
 
 body (or lobe) is 
 
 equal to its width and is the same as for 
 the o (see this page). The body of the a, i ^ \ 
 d, g, and q should be made with two strokes, as shown; stroke 
 #3 lies along the slope guide line. 
 
6 4 
 
 ELEMENTS OF DRAWING 
 
 d repeats a, except that stroke #3 begins 
 at guide line #4. 
 
 g repeats a but U 4 *-j 
 
 stroke ft3 continues ]/ , '/, 
 
 with a sweeping 
 curve to guide line fti , 
 
 q exactly 
 the a construction 
 
 but'stroke #3 continues to guide line fti. 
 
 The stem of the b 
 is the first stroke 
 and coincides with 
 the left-slope 
 guide line; stroke 
 ft2 ends at the 
 touching point of 
 the ellipse and 
 left-slope guide line; stroke ft3 continues to the stem. 
 p differs from the b only in the position of the stem. 
 Letters c and e. 
 Thee has the same 
 height and width G.I 
 as the o (see page 
 63), but the open- 
 ing in the ellipse is 
 such that strokes 
 ft2 and ft3 begin at different touching points on the right-slope 
 guide line. The small c is similar to the capital C (see 
 page 52). 
 
 The e differs slightly from the c in that stroke ft 2 ends on the 
 horizontal center line; stroke ft4 starts from the point of tangency 
 of stroke fti, and, following the center line, joins stroke ft2. 
 
 V Letters n, r } hj and m. The curved 
 portion of the n consists of the upper 
 portion of the ellipse exactly as that of 
 the u consists of the lower portion of 
 'G.L. the o. Stroke fti is standard slope; 
 stroke ft2 ends where the ellipse comes 
 
 # 
 
 / 
 
 -* 
 
 y- 
 
LETTERS, NUMERALS, AND LETTERING 
 
 tangent to the left-slope guide line, and 
 stroke #3 follows the guide line from the 
 point of tangency. Strokes #i and #3 must 
 be parallel, beginning at their points of 
 tangency with the ellipse. 
 
 The r is the same as the left half of the 
 n except that stroke #2 continues along 
 the top guide line a short distance. 
 
 The h differs from the n only in the length 
 of the stem, or stroke #i. Note that though 
 the first three strokes of the I ? 
 m are similar to those 
 of the n, the width is 1 
 different; strokes #4 4 
 #5 are a repetition ofj 
 #2 and #3. All stems are parallel and 
 
 have standard slope. H 6 H 
 
 u and y. The curved portion of "the u consists of the 
 v r* 4 *\ lower part of the 
 
 n . ij uc. |_j js ellipse, exactly as 
 
 G.I.T- T! -"PT -T- VX* tar that of then con- 
 
 portion of the o. 
 Note that stroke 
 #3 continues to 
 line # 2 - 
 
 t 
 
 
 > 
 
 
 
 
 
 1 
 
 
 
 /^ 
 
 >^ 
 
 
 y 
 
 1 
 v*. 
 
 N 
 
 / 
 
 ^ 
 
 x 
 
 ^ 
 
 / 
 
 
 // 
 
 '*" 
 
 <k 
 
 
 2 
 
 
 4- 
 
 
 A' 
 
 -S 
 
 ./ 
 
 
 U- 
 
 * 4- - 
 
 
 
 ff 
 
 JT 
 
 ^ 
 
 >, 
 
 ^ 
 
 
 / 
 
 
 
 ^ 
 
 % 
 
 
 
 
 ^ 
 
 1 ~ t 
 
 A 
 
 
 2 
 
 / 
 
 i 
 
 2 
 
 
 ^ 
 
 ^ 
 
 r 
 
 
 1 
 
 
 t) 
 
 ^ 
 
 ^ 
 
 S/ 
 
 
 
 ^ 
 
 
 
 
 i / 
 
 
 
 CM 
 
 7 
 
 
 
 
 / 
 
 
 
 y repeats the w, but stroke #3 continues to guide line #i 
 exactly as in the g. (See page 64.) 
 
 ZcJfers /, *, ^, /,/, andj. The / is a simple standard slope line 
 drawn toward the draftsman and is six spaces high. 
 
 The i is a single stroke of standard slope, and the dot is 
 placed exactly where the stem if extended would cut the hori- 
 zontal #4. 
 
 The k has a standard slope line as stroke #i; stroke #2 starts 
 on the horizontal guide line #3 but to the left of the slope guide 
 line, so that the latter is not so wide at the top as at the bottom; 
 stroke #3 begins below the middle of stroke #2, and extends to the 
 
66 
 
 ELEMENTS OF DRAWING 
 
 horizontal guide line #2, giving the lower part of the letter the 
 standard 4-space width. 
 
 G.L- 
 
 The / is five spaces high and has the standard slope. Stroke 
 $2 is the horizontal cross-bar which coincides with horizontal 
 
 i 
 
 ^ 
 
 
 
 
 ?->. 
 
 
 
 
 b 
 
 
 
 
 
 
 ?- 
 
 
 
 
 
 
 / 
 
 IT 
 
 SN 
 
 / 
 
 ^ .g 
 
 S 
 
 
 
 
 
 
 / 
 
 t 
 
 .m^ 
 
 -2- 
 
 /' 
 
 
 I 
 
 
 * 
 
 
 
 
 
 
 
 / 
 
 
 
 / 
 
 
 
 1 
 
 
 i i 
 
 
 
 
 
 
 / 
 
 
 1 
 
 
 // 
 
 
 / 
 
 
 
 \ 
 
 h- 
 
 
 
 
 
 ^y 
 
 _ 
 
 1 
 
 /' 
 
 7 
 
 
 
 
 
 
 
 
 
 
 / 
 
 ' 
 
 
 1 ~ 
 
 I 
 
 
 ,/ 
 
 
 
 
 
 
 
 
 
 //^ 
 
 
 
 / 
 
 
 
 /i 
 
 
 
 
 Q 
 
 
 
 
 / 
 
 / 
 
 
 
 
 
 7 
 
 j 
 
 
 
 
 
 
 
 ^X 
 
 ?' A 
 
 
 
 
 
 *j 
 
 2 
 
 1 
 
 
 
 
 
 
 ^ 
 
 7 
 
 ?* 
 
 
 
 
 
 guide line #3 and which is two spaces long but is not bisected 
 by the stem of the letter. 
 
 The / repeats the t except that by adding stroke #3 the letter 
 is brought to the height of the /. 
 
 The.; repeats the i, but is carried to the horizontal guide line 
 #i by adding a curve with a sweep one-half space less than the 
 tail curve of the g and that of the y. (See pages 64 and 65.) 
 
 Letter s. The s is formed in three 
 strokes. Stroke #i is a double and 
 reverse (ogee) curve which is horizon- 
 tal at the top, bottom, and the middle 
 _Q ^ for a very short distance. Strokes #2 
 and #3 are short curves from left to 
 right. If the bottom oval of the 
 letter should be completed it would be four spaces wide, while 
 the upper oval would be only three and a half, thus making the 
 
LETTERS, NUMERALS, AND LETTERING 
 
 6 7 
 
 letter wider at the base than at the top. The small s is similar 
 to the capital S. (See page 53.) 
 
 Letters v and w. The v contains the only vertical line hi this 
 alphabet which 
 is stroke #i. It 
 has full-letter G ' Lr 
 width of four 
 spaces at the 
 top. The small ^ 
 
 . i Cy H A *"J H*~w* 
 
 v is similar to 
 
 the capital F. (See page 46.) 
 
 Stroke fti of the w is not the same as stroke #i of the v, nor 
 is it twice as wide as the v; that is, the w is not made up of 
 two v's. The small w is similar to the capital W. (See page 47.) 
 
 Letter x. The x is made with two 
 strokes, intersecting slightly above the 
 middle of the sloping center line. The top 
 is three and a half spaces wide, while the 
 bottom width is the standard four 
 
 / 
 
 Q . 
 
 ' ' 
 
 
 
 
 
 
 
 i 
 
 1 
 
 
 / 
 
 
 ^7 
 
 X 
 
 "", 
 
 X-i, 
 
 
 1 
 
 1^ 
 
 ^ 
 
 
 / 
 
 
 ', 
 
 
 
 y 
 
 
 / 
 
 
 I 
 
 / 
 
 ^mm 
 
 c 
 
 -~ 
 
 / 
 
 
 ; , r , 'spaces. Note that this slight difference 
 
 ^. ^ 4~^\ i n top and bottom width is the same with the 
 s and z. The smalls is similar to the capital X. (See page 46.) 
 
 Letter z. The z is made up of three 
 strokes. The top and bottom of the letter 
 have the same widths as that of the x 
 and s. The small z is similar to the 
 capital Z. (See page 47.) 
 
 48. Sheet F. The exercises on this sheet 
 (see Fig. 45) give practice in making the 
 
 small letters of the Gothic alphabet and afford an opportunity to 
 study in detail the characteristics of each of the lower-case letters. 
 For detailed description see 47, page 60. Note especially the. 
 relative size of capitals and numerals used with this alphabet. 
 
 This sheet is to be inked but is to be perfected and approved 
 in pencil before inking is done. 
 
 Follow the specific instructions given for preceding sheets as far 
 as applicable. 
 
 The title of sheet F is LOWER-CASE LETTERS. 
 
68 
 
 ELEMENTS OF DRAWING 
 
LETTERS, NUMERALS, AND LETTERING 69 
 
 49. Designing Headings and Titles. A very quick method 
 of laying out the title is to sketch the lines of lettering on 
 transparent paper of good quality and then transfer them in 
 their proper relative position. The transferring is best done by 
 blackening the back of the paper upon which the lettering is 
 sketched, using a soft lead pencil sharpened to a chisel point and 
 held flatwise. The paper is next placed in its proper position 
 on the drawing and the outline of each letter carefully traced 
 over with a moderately sharp pencil; this transfers the letters 
 in dim lines. These outlines will not be so true as the original 
 lines and must be gone over with a pencil before being inked. 
 
 After a little experience, a simple title can be made directly 
 on the drawing by using horizontal guide lines and arranging the 
 lettering symmetrically about a vertical center line. This letter- 
 ing should be sketched in very lightly at first, and when correct 
 the entire title should be retraced in pencil before being inked. 
 
 When lettering a drawing if a name or a 
 / sentence cannot be printed in a horizontal 
 &r line, the proper way to have the inclined 
 
 lettering read is shown in Fig. 46. 
 
 50. Sheet G. The purpose of this sheet 
 (see Fig. 47) is to give practice in laying out 
 Fig. 46- Direction in the bill of material and the title for a drawing. 
 Before beginning work on _this sheet read 
 carefully 49, this page. This sheet is graded 
 upon the quality of the lettering, and the accuracy shown in 
 locating the different lines of lettering. 
 
 Follow specific instructions previously given in so far as appli- 
 cable. 
 
 NOTE. The straight border and limiting lines of the title 
 form can be drawn by use of a straight edge, but they should be 
 made neatly and in the exact location as shown in Fig. 47. 
 The title of sheet G is TITLE FORM. 
 
 51. Examination on Chapter II. Lay out a sheet of vertical 
 Gothic letters or any other sheet of lettering assigned. Prepare 
 for examination on the principal subject matter of this chapter. 
 
70 
 
 ELEMENTS OF DRAWING 
 
 
 
 
 
 
 
 ;a. 
 
 IS 
 
 JO S 
 
 8p: 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 p 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 v,^^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
 
 
 
 
 
 
 1 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 r^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 y 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 t- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X 
 
 ^ 
 
 
 
 
 
 
 i 
 
 r N 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 U) 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 sl 
 
 
 
 
 
 
 \ 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 L 
 
 \ 
 
 
 
 \ 
 
 r 
 
 N 
 
 \ 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 S 
 
 
 
 
 
 
 
 
 
 ry> 
 
 r 
 
 J 
 
 r\. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 i 
 
 
 
 QC 
 
 Y 
 
 LJ 
 
 K 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 <^ 
 
 
 
 
 
 
 k 
 
 
 
 ^ 
 
 [ 
 
 
 
 v^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i . 
 
 
 
 I 
 
 \ 
 
 
 
 <v. 
 
 ( 
 
 ^ 
 
 rr 
 
 -X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 lr 
 
 K 
 
 \l 
 
 
 k! 
 
 
 
 
 X 
 
 
 
 ^ 
 
 1 
 
 i 
 
 \ 
 
 ri 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 kl 
 
 k 
 
 s| 
 
 
 ^j 
 
 
 
 
 
 
 
 -^ 
 
 r 
 
 - 1 
 
 n 
 
 r \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ? 
 
 5 
 
 ( v 
 
 
 g 
 
 
 
 I 
 
 . 
 
 
 
 
 
 ^ 
 
 ? 
 
 v^ 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 rn 
 
 rn 
 
 x 
 
 \ 
 
 > 
 
 
 
 
 k 
 
 
 
 \\- 
 
 C 
 
 ) 
 
 
 y. 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 r-r 
 
 rT 
 
 kl 
 
 I, 
 
 r < 
 
 
 
 
 
 
 
 S 
 
 
 > 
 
 r^ 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 3 
 
 \^ 
 
 k 
 
 tj 
 
 k 
 
 
 
 N 
 
 
 
 
 2 
 
 * 
 
 
 2 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 pj 
 
 A! 
 
 ty 
 
 
 
 I 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 IP 
 
 
 
 Oi 
 
 
 
 
 
 
 
 
 
 
 U 
 
 
 y 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^J 
 
 i"} 
 
 l \l 
 
 * 
 
 
 
 ^ 
 
 T 
 
 
 
 
 > 
 
 
 
 Or 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 < 
 
 
 
 J) 
 
 S 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ( 
 
 f) 
 
 I 
 
 i 
 
 P 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 "N, 
 
 V 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f/ 
 
 \ 
 
 ^ 
 
 j 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ( 
 
 \ 
 
 
 
 1 
 
 j 
 
 >. 
 
 j 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 u 
 
 J 
 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 w 
 
 
 
 
 1 
 
 . 
 
 
 
 1 
 
 \ 
 
 \ 
 
 
 kl 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 k 
 
 
 
 
 4 
 
 1 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 | 
 
 i 
 
 
 
 
 
 \ 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 p 
 
 ^J 
 
 
 
 1, 
 
 
 \ 
 
 1 
 
 I. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 \ 
 
 
 
 V 
 
 
 
 ^' 
 
 1 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 > 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rv 
 
 
 
 fX 
 
 kj 
 
 
 
 I 
 
 n 
 
 
 
 
 
 u 
 
 
 v 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 rl* 
 
 to 
 
 rn 
 
 U J 
 
 ki 
 
 
 
 
 j 
 
 
 
 
 
 
 
 
 r^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 14 j 
 
 
 
 fy 
 
 3 
 
 
 
 
 
 
 
 
 X 
 
 v 
 
 ^j 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Ij 
 
 y 
 
 ^ 
 
 ^> 
 
 k 
 
 
 
 
 
 
 
 ( 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 V 
 
 D 
 
 
 
 
 
 
 
 
 
 r 
 
 
 
 >P 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2 
 
 
 
 
 
 
 
 
 I 
 
 
 ~s 
 
 k 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 
 
 
 1 
 
 
 
 
 
 
 
 } 
 
 
 
 1 
 
 ** 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 - 
 
 
 i 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 <i 
 
 3 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
CHAPTER III 
 
 MECHANICAL DRAWING AND DRAFTING ROOM 
 PRACTICE 
 
 52. Introductory. The difficulty of describing an object so that 
 its form and proportions can be completely understood and the 
 object made by following the written description will be appre- 
 ciated if such a description is attempted with reference to some 
 comparatively simple object. The art of drawing is made use 
 of to overcome these difficulties and drawing might be considered 
 a " short hand " method of expressing form and proportion. The 
 field of usefulness of drawing is very broad and the value of being 
 able to draw and to read drawings becomes more apparent when 
 it is realized that practically all buildings and construction, as 
 well as most manufactured articles, were planned and drawn 
 before their construction or manufacture was started. In study- 
 ing this subject, the beginner should make every effort to become 
 proficient in the reading as well as in the making of mechani- 
 cal drawings. It is probable that most persons will never be 
 called upon to make any but the simplest of drawings, but all 
 those connected in any way with engineering work must be able 
 to read them, and the ability to read drawings quickly and cor- 
 rectly is of the greatest value. There are several branches of 
 drawing, and the branch to which the reader has likely become 
 most accustomed is perspective drawing or, in other words, draw- 
 ings which represent an object in a single view, as it would ap- 
 pear to the eye or in a photograph. A perspective drawing, 
 however, is usually difficult to make and does not offer the 
 possibilities for recording dimensions and other information which 
 is often necessary to the engineer and which can be easily re- 
 corded on a mechanical drawing. 
 
 A mechanical drawing does not represent an object by a single 
 view, as it would appear to the eye or in a photograph but repre- 
 sents it by a series of pictures termed " projected views " which 
 
 71 
 
ELEMENTS OF DRAWING 
 
 will be explained later. Each of these views represents some 
 " face " of the object as it would appear if it actually existed in 
 space, its appearance assumed to be unaffected by the laws of 
 perspective. See 53, page 73. 
 
 Briefly stated, a mechanical drawing must contain complete 
 and absolutely accurate information of what is desired; every 
 line on the drawing should be a fixed and measurable distance 
 from every other line and should stand for something definite; 
 the views, lettering, and dimensioning must be well arranged, 
 and neatly and accurately done, so that the drawing as a whole 
 will be exactly understood and present a pleasing and business- 
 like appearance. 
 
 When lines cannot express ideas in a plain, direct, and un- 
 mistakable manner, abbreviations, symbols and printed notes 
 must be used so that those who are to read or interpret the 
 drawing will be in possession of all the information necessary to 
 carry out every detail of the designer's or draftsman's wishes 
 without further instructions, either written or spoken. 
 In just so far as a drawing fails to contain all necessary infor- 
 mation in the best form possible it is unsatisfactory, regardless 
 of how well it may conform to the principles of mechanical draw- 
 ing or the degree of precision and elegance with which it has 
 been made. 
 
 Symbols on a mechanical drawing usually consist of printed 
 abbreviations or conventional signs, which signs are more easily 
 
 drawn than the true form of the object 
 to be represented. Thus, instead of 
 representing screw threads in their exact 
 form, as shown in Fig. 48, and which 
 would be difficult and tedious to draw, 
 especially on a small scale, the conventional method of rep- 
 resenting ordinary screw threads, as 
 shown in Fig. 49, is widely made use 
 of in practical drawing rooms. 
 
 The relation of parts to one another, 13 Thds. per inch. L. H. 
 
 - f ., r t Fig. 49. Threads Conventionally 
 
 processes of manufacture, the final represented. 
 
 finish of surfaces, and similar data are indicated by notes, 
 
 abbreviations and conventional signs. 
 
 Trued Form. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 73 
 
 The printed matter consists of dimensions, notes of instruction 
 or specifications, names of parts, titles, and similar information. 
 
 Each of these three divisions the drawing of the views, the 
 application of conventional signs, and the composing and 
 printing of notes, titles, dimensions, etc., is in a way of equal 
 importance, and it should be remembered that mechanical 
 drawing, as it is generally understood and applied, especially in 
 the manufacture of machinery, etc., is not intended to produce 
 artistic effects, but to give instruction and to convey information 
 of a definite character in the simplest way possible. 
 
 53. Projection and Projected Views. Mechanical drawing 
 is based upon the principles of orthographic projection, and a 
 knowledge of the fundamental principles of orthographic pro- 
 jection is necessary in order to understand even the simplest 
 drawing. A short discussion is given here and a more extended 
 discussion of this subject will be found in the authors' book on 
 "Elements of Descriptive Geometry" and in other books on the 
 same subject. 
 
 Orthographic projection consists in representing the form of an 
 object as it would appear if projected upon two or more planes 
 (termed planes of projection) at right angles to one another. 
 The projecting is assumed to be done by rays of light respec- 
 tively perpendicular to these planes and extending from the 
 planes to the points on the object being projected. 
 
 One plane of projection is assumed in the position of an ordi- 
 nary wall (i.e., vertical) and is termed the vertical plane of pro- 
 jection, the other occupies a position corresponding to the floor 
 (i.e., horizontal) and is termed the horizontal plane of projec- 
 tion. Both vertical and horizontal planes of projection are as- 
 sumed to be transparent, and every ray of light which extends 
 from the vertical plane to a point of the object will be horizon- 
 tal because all of these rays are perpendicular to the vertical 
 plane; similarly the rays which extend from the horizontal 
 plane to the object will be vertical. This is clearly illustrated 
 in Fig. 50, where a part of the lathe is shown projected. The 
 object which is shown projected is called the Tool Rest Sup- 
 port Slide and is shown in perspective in Fig. 112, page 150. 
 
74 
 
 ELEMENTS OF DRAWING 
 
 A careful study of this illustration will make clear the process of 
 projecting in space. To produce a drawing by the principles 
 of Orthographic Projection it is necessary to make further as- 
 sumptions in order to establish a relation between the trans- 
 
 Fig. 50. Illustrating the Method of Orthographic Projection 
 by the Use of Transparent Planes. 
 
 (a) Showing the Plan, Front and Side 
 Views Brought into a Single Plane. 
 
 
 
 (b) Arrangement of Views 
 Ordinarily Used in Making a Drawing. 
 
 Fig. 31. Usual Relation of Views on a Flat Surface. 
 
 parent planes at right angles in space and the drawing paper 
 which is in a single plane. It is seen that the object is behind 
 the vertical plane and below the horizontal plane, and this is 
 termed third angle projection. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 75 
 
 Assume that after the views of the object are projected 
 upon the planes these planes are unfolded so as to be brought to 
 a single plane or flat surface, as shown in Fig. 51. This opera- 
 tion brings the top-view above the front-view, and the right- 
 side-view to the right of the front-view. By connecting projec- 
 tions of corresponding points of the different views with straight 
 dashed lines (as shown), it will be found that these lines are 
 perpendicular to the lines (G-L and Gi-Li) which mark the edges 
 of the planes of projection. These dashed lines serve to connect, 
 
 (a) Showing Plan and Front Views " Folded 
 the Plane of the Side View. 
 
 into 
 
 (b) Showing Front and Side Views " Folded " into the Plane of the Plan View. 
 Fig. 52. Various Arrangements of Views. 
 
 from one view to another, points which are projections of a single 
 point on the object represented. They are the same length as the 
 projecting rays of light and represent them on the drawing paper. 
 The relative position of the different views as shown in Fig. 51 
 is a very common arrangement in practice, but the arrange- 
 ments of views as shown in Fig. 5 2 (a) and 52(b) are equally 
 correct and may be used if for any reason they are found more 
 convenient. The top view is known as the plan, and the side 
 or front views as the side elevation or front elevation. 
 
76 ELEMENTS OF DRAWING 
 
 54. Conventional Lines. If all the lines of a drawing were 
 identical in character, that is, unbroken throughout their 
 length and of the same weight, 1 the drawing would be lacking in 
 contrasts and would be difficult to read. This difficulty is 
 overcome by using lines of different construction and weight 
 for different purposes. For example, solid unbroken lines 
 (called "visible lines") of fair width are used to represent 
 visible parts of an object; fine lines (called "invisible lines") 
 composed of short dashes are used to represent invisible parts. 
 Dimension lines are unbroken (except for the dimension figures) 
 but are not so prominent as the lines representing visible out- 
 lines of the object. 
 
 The meaning of the construction of the various lines is 
 given below, but no single rule can be stated as to the proper 
 weight of the different classes of lines since this depends on 
 circumstances. 
 
 The visible line is an unbroken, heavy line used to represent the 
 outline of the object and the surfaces that are in full view 
 
 Fig. 53- " Standard " Visible Line. 
 
 of the draftsman. The weight of the line must be varied at 
 times, depending on the size and the accuracy required of the 
 drawing, but the standard weight is shown in Fig. 53. 
 
 The invisible line is used to represent the parts of an object 
 which are hidden or invisible to the draftsman. Such lines are 
 broken into short dashes about one-eighth inch long, separated 
 by spaces of one-half this length, and are only about two- thirds 
 
 Fig. 54. " Standard " Invisible Line. 
 
 the weight of the visible lines. When an invisible line is very 
 short, the dashes and spaces must be shortened accordingly. 
 Dashes must be made of one length and spaces of another, the 
 spaces always being smaller than the dashes (see Fig. 54). 
 
 1 The weight of the line determines its prominence. Variation in weight 
 is secured by making the line of different widths if drawn with ink, and 
 by making it lighter or darker in color by varying the pressure and hard- 
 ness of the lead if drawn with a pencil. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 77 
 
 Section lines (see Fig. 55) are drawn parallel and usually close 
 together (say, T y to |") and covering those areas which are 
 assumed cut and exposed to view. They are light weight con- 
 tinuous lines in construction. (See Fig. 63, page 81.) 
 
 Fig- 55. "Standard" Section Line. 
 
 Dimension lines (see Fig. 56) are for the purpose of indicat- 
 ing the limits between which dimension figures apply. Dimen- 
 sion lines are drawn light weight and are unbroken except for 
 
 - - /Q- - _ 
 
 2 
 
 Fig. 56. "Standard" Dimension Line. 
 
 a distance, usually in the center, to allow for the dimension 
 figures. Under no circumstances should this line pass through the 
 dimension figures. 
 
 An arrowhead is drawn at the end of a dimension line to 
 indicate its extremity and the place to which the dimension 
 applies. 
 
 Arrowheads appear much better when drawn long, sloping, 
 
 (a) Correct. (b) Incorrect. 
 
 Fig. 57. Arrowhead. 
 
 and narrow, as shown by Fig. 5 7 (a), and they should not be 
 drawn spreading, as shown by Fig. 57(b). 
 
 Reference lines extend out from a part to be dimensioned to 
 receive the arrowheads at the ends of the dimension lines. They 
 consist of groups of three dashes two short and one long 
 repeated as often as necessary to make the line as long as re- 
 
 Fig. 58. "Standard" Reference Line. 
 
 quired. The line should begin with the two short dashes and 
 end with the long one, and the relation between short dashes, 
 long dashes, and spaces is the same as in center lines. (See page 
 78.) A short space should always separate the reference line from 
 the object. Fig. 58 shows the standard reference line. 
 
78 ELEMENTS OF DRAWING 
 
 The center line is a line around which a sketch or drawing 
 is "built," and is usually an axis of symmetry. It is composed 
 of short and long dashes. The short dashes are about one- 
 eighth inch long, and the length of the long dashes will depend 
 on the size of the drawing. The space separating long and 
 short dashes is about one-sixteenth inch. (See Fig. 59.) 
 
 Fig. 59- "Standard " Center Line. 
 
 The center line of a part not detailed is often shown on a 
 drawing in its true relative position to the parts that are drawn. 
 In such a case the symbol <_ is written across the center line of 
 the part not detailed, but this symbol is not used on center 
 lines of parts that are drawn. Thus, on part No. i of drawing 
 C-ioi (see page 118, Fig. 82) the center line of the shaft is not 
 marked, but the positions of the bearings are located by drawing 
 their center lines and marking them ^ OF BEARING. 
 
 Some drawings do not require center lines, while others may 
 require several, depending usually on the number of axes of 
 symmetry. The center-line construction is also used to indicate 
 the location of a cutting plane in making a cross-sectional view, 
 and the two should not be confused. 
 
 All finished lines, whether drawn free-hand or mechanically, 
 with pencil or with ink, must be : 
 
 (a) Clear cut. 
 
 (b) Free from waves. 
 
 (c) Of the same width throughout. 
 
 (d) Colored to the same degree throughout. 
 
 A line is clear cut when the edges are free from irregularities, 
 that is, when the outer edges are not " ragged " or " sketchy." 
 
 A line is free from waves when it does not deviate locally 
 from the general direction it should follow. Both the wavy and 
 the ragged free-hand lines usually result from holding the pencil, 
 or particularly the pen, with such a tense grip as to cause the 
 hand to tremble. Hold the pencil or pen easily, as you would 
 in ordinary writing. 
 
 A line is of unvarying width when the outer edges run paral- 
 lel throughout its length. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 79 
 
 A line is colored to the same degree (i.e., of even color) when 
 the coloring matter (such as lead or ink) is evenly distributed 
 throughout the line. To avoid making a pencil or ink line 
 appear dark at one point and light at another, that is, variable in 
 degree of color, apply even pressure in making the finished line, 
 and in inking maintain a uniform flow of ink by frequently 
 cleaning and refilling the pen. 
 
 55. Sectioning and Sectional Views. If an object has hollow 
 portions it is often necessary to know the exact form and the 
 dimensions of the interior. 
 
 Since invisible portions of an object are represented on draw- 
 ings by means of broken lines, views which represent the exte- 
 rior or visible portion and at the same time attempt to show the 
 interior form of an object are frequently complicated and hard to 
 read. To overcome this difficulty it is often convenient to im- 
 agine the object cut open with a saw [see page 80, Fig. 60 (a) 
 and 60 (b)] and then represent it as if the plane of the cut MN 
 were an outside surface of the object. [See Fig. 6o(c).] 
 
 Such a view of an object is termed a sectional view, a cross 
 section, or simply a section of the part. If a section is taken 
 in the direction of the length of an object, it is termed a longi- 
 tudinal section; if taken perpendicular to the length, it is termed 
 a transverse section. 
 
 A complete section is not always assumed in a single plane, but 
 may be made up of partial sections in several planes. A built- 
 up cross section is intended to give information in such a way 
 as to make it unnecessary to draw several cross-sectional views 
 or perhaps a complete view of the object. In Fig. 61 the cut- 
 ting planes move along the line HPST and the section should 
 be referred to as the section HPST. 
 
 The method of accurately determining complicated sections 
 in true projection is beyond the scope of this work and is ex- 
 plained more fully in the authors' book on " Descriptive Geom- 
 etry " and in other books on the same subject. 
 
 In order to make sectional views easily understood, the dif- 
 ferent kinds of material assumed to be cut are sometimes in- 
 dicated on the drawing by conventional methods. The usual 
 
8o 
 
 ELEMENTS OF DRAWING 
 
 u 
 
 a o 
 
 II 
 
 I! 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 8 1 
 
 method is termed sectioning and consists of various combina- 
 tions of spacing, and light and heavy weight lines drawn parallel 
 and covering the area which represents the surface assumed to 
 be cut and exposed to view. No uniformity exists in practice 
 as to the combination of lines and spaces that shall represent a 
 particular material. Those combinations given in Fig. 62 are 
 fairly general in their application, but it is readily seen that, 
 because of the great variety of materials in use and the fact that 
 
 CAST IRON 
 
 WROUGHT IRON 
 
 (a) Ordinary Sectioning, (b) Sectioning Adjoining 
 
 Pieces. 
 
 Fig. 62. " Conventional " Sectioning. 
 
 new materials are constantly being introduced, it is better 
 practice to use only the simple parallel lines [see Fig. 63 (a)] 
 and then designate the ma- 
 terial by writing its abbre- 
 viation (see page 103, 67) 
 on the ruled surface or in 
 some other simple manner. 
 Where a number is used Fig. 63. sectioning. 
 
 to indicate a material, it has the advantage that the number can 
 also represent the quality, heat treatment, etc., or, in the case 
 of alloys, the composition. The number therefore does not 
 only represent the name of the material but also its properties 
 both physical and chemical and in reality is a specification 
 number. A further advantage of this method is that, should 
 the material originally called for prove unsatisfactory, as is 
 frequently the case, a change in the number can be made on 
 the drawing without erasing the section lines. 
 
82 ELEMENTS OF DRAWING 
 
 Section lines of adjoining pieces [see Fig. 63 (b)] are drawn 
 in different directions, if possible, so as to more clearly define 
 the limits of the parts. 
 
 Section lines should be drawn at 45 to the horizontal when- 
 ever possible, and should be made about one-half the weight of 
 the lines used to represent the outline of the section. To section 
 an area evenly requires practice and a steady hand. Beginners 
 usually make the mistake of drawing the section lines too close. 
 Also the tendency is to vary the distance between section lines, 
 usually increasing the spacing as the work proceeds. Such sec- 
 tioning is unsatisfactory, and can be avoided by glancing back 
 over the completed area for each eight or ten lines drawn, thus 
 bringing to mind the original unit of spacing. If a section line 
 has been drawn too far from the preceding one, the next line 
 should be drawn at a distance less than the unit spacing; this 
 has the effect of giving an even appearance and the normal 
 spacing should then be continued. 
 
 The spacing between section lines should be T V' to ", depend- 
 ing upon the size of the cross section, but must be the same 
 throughout the area of any single part being represented in sec- 
 tion. To insure uniform spacing, draftsmen sometimes use 
 section liners. The simplest form, and one easily made, is 
 shown in Fig. 64. It consists of a small 
 straight-edge cut out to receive one side 
 of the triangle. The length of the slot 
 portion is equal to the length of the side 
 of the triangle plus the approximate 
 . SCT/0 " Lmr * I . distance desired between the section 
 
 ^ STRAIGHT EDGE OF 
 
 ^ T-SQUARE BLADE \ lines. To use this device, place it on 
 Fig. 6 4 . section Liner. fa e d raw i n g w ith the triangle against 
 the left-hand stop, as shown in Fig. 64; draw a line along 
 the slope side; hold the triangle stationary with the fingers of 
 the left hand, and with the thumb move the strip to the left 
 until it is stopped by the triangle. Next hold the strip sta- 
 tionary and slide the triangle until it comes in contact with 
 the left-hand stop of the strip, and draw the second line. This 
 process is repeated until the sectioning is completed. When 
 the section is very large, the section lining is sometimes placed 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 83 
 
 at the edges only, as this saves time and usually gives a better 
 appearance ; in such cases the distance between the section lines 
 would be increased somewhat. 
 
 Sectional views may be drawn in any suitable position on 
 the drawing, but it is always best to locate them as close to the 
 place at which they are taken as is convenient. To indicate 
 the location of the section, a line must always be drawn across 
 the original view of the object, and the extremities of the line 
 (which represents the cutting plane) should be lettered as shown 
 in Fig. 85, page 123. 
 
 It is not always necessary to draw the cross sectioning over 
 the entire surface that lies within the cutting plane, and in 
 general such details as a shaft, key, bolt, gear tooth, rib or arm 
 of a wheel, are not sectioned. 
 
 Where a part shown in section is symmetrical about a center 
 line, such as a part turned on a lathe, a half or a quarter longi- 
 tudinal section, together with an end view, is often the best choice 
 of views. Thus, a drawing of the Tail Stock Spindle (see Fig. 
 103, page 144) or the Shell (see Fig. 104, page 144) would usually 
 consist of an end view and a top or side view shown in section; 
 that is, the Spindle is assumed to be sawed in two lengthwise, 
 the front or top half removed, and a drawing made of the remain- 
 ing half as it appears when looking directly at the cut surface. 
 
 When a drawing is made of an object assumed to be so cut 
 that one-fourth of the piece is removed, the view is termed a 
 quarter-section view. 
 
 Sometimes by turning up a section directly on the first view 
 space is saved and a second view of a part is unnecessary. In 
 such cases all the lines of the original view must be drawn in, 
 even though they may conflict somewhat with the lines of the 
 turned up section. (See Key shown in Fig. 82, page 118.) 
 
 56. Number and Arrangement of Views. There is always a 
 choice of views, and those views should be made which convey 
 the greatest amount of information consistent with clearness. 
 In determining the number of views required, the purpose of 
 the drawing, the form of the object drawn, and the character of 
 the views must all be considered. The rule to be followed as 
 
84 ELEMENTS OF DRAWING 
 
 to the number of views is that there shall be the least number 
 made to accomplish the purposes of the drawing. In general, 
 three views of an object are sufficient to illustrate its form and 
 the processes necessary in its manufacture. If, however, its 
 construction is complex, it may require sectional views in ad- 
 dition to the three general views 'ordinarily taken. If the part 
 is quite simple and symmetrical, as, for example, a washer, 
 bolt, screw, shaft, plain key (see Fig. 82, page 118), a single 
 view is sufficient. The draftsman should imagine himself read- 
 ing the drawing, and make as many views (and no more) as 
 are necessary to give complete information in a clear and 
 unmistakable manner. While making or checking a drawing if 
 the question arises as to whether certain views or cross sections 
 -are needed in order that the drawing may convey all information 
 necessary, these views or sections should always be drawn, for 
 it is reasonable to assume that any point of uncertainty not fully 
 cleared up by the draftsman or checker leaves the way open for 
 those using the drawing, especially for the first time, to make 
 mistakes. An effort on the part of the draftsman or checker to 
 rush work or "save" time often leads to costly errors on the part 
 of those who must work with the drawing, besides causing a loss of 
 time by each person who must read the drawing. A note should 
 be used when it will save drawing a view. In general, several sec- 
 tions are preferable to a single view containing many dashed lines. 
 
 The arrangement of the views must be such that their relation 
 to one another will be what is technically termed third-angle pro- 
 jection (see page 74, 53). Sectional views and other auxiliary 
 views should be placed close to the main view of the part which 
 they partially represent. 
 
 Where practical the main views of an object should represent 
 it in a similar position to that which it will occupy on the ma- 
 chine, that is, a part should not be represented upside down, etc. 
 
 The different views should be arranged symmetrically on the 
 sheet, in order that space may be used to the best advantage and 
 that the drawing as a whole may present a pleasing appearance. 
 
 This can be accomplished best by blocking out the sheet 
 with free-hand rectangles, drawn to scale, to include each view 
 (see page 93, 61). These should be sketched in very lightly, 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 85 
 
 and, after provision has been made for all the views, if the rec- 
 tangles are not well distributed they can be easily rearranged. 
 
 57. Detail Drawings. A detail drawing is one which repre- 
 sents a single part and contains all information necessary for its 
 manufacture. Before a detail drawing is made, therefore, an ex- 
 perienced draftsman will determine exactly and to the minutest 
 detail the purpose of the finished part and the shop operations 
 necessary to produce it. It often occurs that the draftsman 
 knows exactly what is wanted in the finished part but has not 
 had sufficient shop experience to know the best method of produc- 
 ing it. In such cases this information should be obtained from 
 a reliable source before the drawing is carried too far. Generally 
 a single detail drawing serves for all departments of a manufac- 
 turing plant, but it may happen in complex work that different 
 details are required for the different classes of workmen, such 
 as the pattern maker, the blacksmith, the machinist, etc. Such 
 drawings give the dimensions and notes required only by the 
 particular class of workmen for whom they are intended. 
 
 The number of parts detailed on a single sheet will depend 
 on circumstances, but it is becoming more common to detail each 
 part on a separate sheet. This method has the advantage that 
 fewer workmen are affected in case a drawing has to be recalled 
 for any reason. Also, as the drawing can be easily and quickly 
 obtained, the chances of costly mistakes are lessened in case a 
 change must be made on a part. In cases where an article is 
 standard and is produced in great quantity it is sometimes 
 advisable to represent a part on several sheets called operation 
 sheets, that is, a drawing which shows only the operation to 
 be performed on the part by a single workman. In establish- 
 ments where a system of representing several parts on a single 
 sheet is practiced it is customary to group parts in a logical 
 manner; for instance, parts which fit together may be detailed 
 on the same sheet, say, in the case of the lathe the details of the 
 Headstock might make up one sheet; parts made of the same 
 material, such as cast-iron parts, might be grouped; or parts 
 which are manufactured by similar processes, and hence in the 
 same shop department, are detailed on the same sheet. If parts 
 
86 ELEMENTS OF DRAWING 
 
 which fit together are detailed on the same sheet they are more 
 easily checked, but in practice it is often difficult to maintain a 
 fixed system of grouping. Certain advantages are to be gained 
 by the beginner in grouping detail drawings and hence several 
 parts will be shown on a single sheet in this course rather than 
 each part drawn on a separate sheet. 
 
 In making a detail drawing, roughly "block out" in very 
 light lines the different views in their approximate relative loca- 
 tion on the sheet before beginning the actual pencil drawing. 
 
 It is usually better to work up all the views of a part at the 
 same time rather than to endeavor to complete one view and 
 then 'pass to the next. As a rule, one part should be detailed 
 completely, including all its views, dimensions, notes, etc., 
 before the detailing of another part is started. 
 
 58. Assembly Drawings. The detail drawings show the form 
 and size of each part but give no idea how the various parts 
 fit together or how the machine or structure as a whole will 
 appear. The assembly drawing illustrates the general design 
 of a machine or structure and contains information which en- 
 ables a workman to sort out the finished parts and assemble 
 them into the machine. The assembly drawing is, therefore, a 
 representation of the completed machine or structure with all 
 its parts collected and arranged in their proper relation to 
 one another. // should be drawn part by part from the detail 
 drawings and serves as a last check that all parts fit together. 
 Such drawings may show some detail, but too much of the inside 
 construction should not be shown (in dashed lines) or the drawing 
 may be difficult to read. If the machine is complex two or more 
 views and cross sections through several parts may be required, 
 in order to give all necessary information and still avoid too 
 much dashed-line construction. Such minor parts, as bolts, nuts, 
 screws, keys, etc., are seldom drawn in detail upon the assembly 
 drawing, but their position is usually indicated by center lines. 
 
 Only over-all and important main dimensions should be 
 given on assembly drawings. It sometimes adds to the value 
 of an assembly drawing to give parts a reference number or 
 letter so that they can be easily referred to. See page 104, 69, 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 87 
 
 59. Conventional Methods. As has been stated elsewhere, 
 the purpose of a mechanical drawing is to give instruction and 
 information, and not to produce elaborate picture effects. For 
 this reason it is often best to represent an object by as few lines 
 as possible if in doing so clearness is not sacrificed. Such abridged 
 methods of representing forms and constructions on a drawing 
 are termed " conventions " or " conventional methods " and are 
 universally used to represent details that are of frequent occur- 
 rence, such as screws, bolts, threads, etc. 
 
 Conventional methods may be used in several ways, for ex- 
 ample, as a drawing which approximates the form of the object 
 being represented; cross-sectioning, shown in color or by lines 
 which symbolically represent the materials ; methods of represent- 
 ing the planes in which an object is assumed to be cut; the path 
 and the direction of motion of a moving point; shop operations, 
 such as the finish of surfaces, etc. Unfortunately no list of 
 conventions can be universally adopted, and upon entering the 
 employ of a company the draftsman must study and adhere 
 to their particular system. Fig. 65, page 88, illustrates common 
 conventions, some of which are used in this course. 
 
 Group A, Fig. 65, shows the following conventions: 
 
 1. Method of representing a shaft of circular section so that 
 space can be saved on the drawing. This method of repre- 
 senting an object, as if a portion were omitted, cannot be used 
 unless the form of the portion omitted is exactly the same as 
 the part shown. Thus, that portion of a shaft with a keyway 
 could not be omitted in any way that would leave any infor- 
 mation as to the dimensions and location of the keyway lacking. 
 
 2. Method of representing a bearing. Note that the distance 
 between bearings is given from the center line of one to the 
 center line of the other. 
 
 3. Method of representing the broken end of a timber viewed 
 from the side, also method of showing cross section of timber. 
 
 Group B shows the following conventions: 
 
 i. Method of representing a long hollow part and contracting 
 the drawing lengthwise. The break differs from that of the 
 shaft in that the proportional thickness of the shell is shown. 
 
88 
 
 ELEMENTS OF DRAWING 
 
 u 
 
 
 >i I 
 
 vj 
 
 s 
 
 BH-o 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 89 
 
 2. Method of dimensioning a series of holes equally spaced 
 around a circle. Note that the holes are spaced each side of 
 the vertical and horizontal center lines, and not on these center 
 lines. 
 
 Group C shows conventional uses of broken or dashed lines 
 
 which are distinct and must not be confused with the conven- 
 tional method of representing the invisible lines of an object. 
 See page 76, 54. 
 
 (a) Shows a method of representing a moving arm when in 
 its extreme positions, one position of the arm being represented 
 by full lines, the other by dashed lines. 
 
 (b) Shows a lever in its central position and the outline 
 of the lever is shown by broken lines in each of its extreme 
 positions. In designing and in bringing out certain information 
 clearly it is often best to represent a part in several positions. 
 In checking the drawing of an assembly of parts this method is 
 effective in making sure that parts which change position do not 
 interfere at any time during a complete cycle. 
 
 (c) This shows the conventional method of representing a part 
 not completely drawn, and which is adjacent to the part drawn. 
 
 Group D shows the conventional methods of representing 
 screw threads. 
 
 (a) Shows the conventional method representing the visible 
 and invisible V threads. In each case the threads begin and 
 end with the short line, and in the invisible or dashed threads the 
 dashes of one line are opposite the spaces of the adjacent lines. 
 The short lines represent the bottom line of the V and should 
 be of equal length; all long lines representing the top line of 
 the V should be drawn to meet the side lines. Note that the 
 short lines in the visible thread are about twice the weight of 
 the long lines. 
 
 (b) Shows the conventional Square Thread. 
 
 (c) Shows the conventional National Acme Thread. 
 
 Where a part is threaded for some length it is customary to 
 show only a few threads at the beginning and at the end of the 
 threaded portion, thus saving time without sacrificing clearness. 
 The threaded portion can be represented to scale or may be 
 
go ELEMENTS OF DRAWING 
 
 shown broken, as in the case of a shaft, etc. See Group A-i, 
 59, page 87. 
 
 Group E shows the conventional method of representing a 
 drilled hole, a " tapped " or threaded hole. 
 
 1. If the hole is comparatively small a note usually states the 
 size and the fact that the hole is drilled and a leader is drawn 
 from the note to the place where it applies. 
 
 2. If the hole is to be tapped a note stating the size of drill 
 to be used, depth of hole, number of threads per inch and the 
 form of thread is printed and -a leader run to the place where the 
 note applies. 
 
 Thus, a note written H"Drl X f " X 16 U. S. tap would 
 indicate that the hole is to be f " deep and the standard tap to 
 give 1 6 U. S. threads per inch is to be used. 
 
 Group F shows conventional lines as ordinarily used in draw- 
 ing. This subject is taken up on page 76, 54. 
 
 Group G shows the method of giving reference numbers. 
 
 This subject is taken up on page 104, 69. 
 
 Group H shows the usual method of indicating a cross sec- 
 tion of structural sheet steel, also steel shapes, such as boiler 
 plate. Instead of section lines being used, the cut surface is 
 made solid black. Note that in the case of several pieces being 
 bolted or riveted together, they are shown slightly separated, 
 since this adds to the clearness of the drawing. 
 
 60. Drawing to Scale. Usually in making a drawing the 
 object can not or need not be represented actual size, and in 
 order to get the drawing on a piece of paper of convenient 
 dimensions, it must be made "to scale," that is, the actual meas- 
 urements on the drawing must bear some fixed ratio to the cor- 
 responding measurements on the object. The method of making 
 a scale to such a ratio is to choose an arbitrary distance and let 
 that distance represent one foot. This distance which represents 
 one foot is then divided into twelve equal divisions, each of 
 which therefore represents one inch. One of the twelve divisions 
 is then divided into halves, quarters, eighths, etc. (see Fig. 31, 
 page 30), to represent one-half inch, one-quarter inch, and so 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 91 
 
 on, until such subdivisions become too small to be conveniently 
 read. To illustrate, suppose a drawing is to be made one-fourth 
 size. To compute the length of every line on the drawing would 
 be a slow and tedious process, and would require that every 
 dimension on the object be divided by 4 to get the corresponding 
 dimension on the drawing. To overcome the necessity of making 
 such computations, imagine an ordinary foot rule uniformly 
 compressed until exactly one-fourth its original length. It would 
 then be only three inches long but marked " twelve," and the 
 divisions marked "one inch" would actually be one-quarter of 
 an inch long, those marked " one-half inch" would actually be 
 one-eighth, etc. That is, all the dimensions would be reduced 
 to one-quarter size and any desired dimension, such as 5! or gf , 
 etc., could be marked off or read directly upon the drawing 
 (which is one-quarter size) with this compressed rule and no 
 computations whatever would be necessary. 
 
 SCALES IN COMMON USE 
 
 Actual Measurement on 
 Drawing. 
 
 Actual Measurement on Object 
 Represented. 
 
 Size of Drawing Compared with 
 Actual Size of Object Represented. 
 
 | inch 
 
 One foot 
 
 g^th size (o.oio) 
 
 \ inch 
 
 One foot 
 
 t'ffth size (0.021) 
 
 | inch f 
 
 One foot 
 
 3*2 nd size (0.031) 
 
 inch 
 
 One foot 
 
 2*5 th size (0.042) 
 
 f inch f 
 
 One foot 
 
 i^th size (0.063) 
 
 i inch 
 
 One foot 
 
 t^th size (0.083) 
 
 i inches * 
 
 One foot 
 
 |th size (0.125) 
 
 3 inches * 
 
 One foot 
 
 th size (0.250) 
 
 4 inches f 
 
 One foot 
 
 rd size (0.3330) 
 
 6 inches * 
 
 One foot 
 
 % size (0.500) 
 
 * Desirable scale for ordinary use. 
 
 f Rarely used. 
 
 The above table should be thoroughly understood as beginners 
 are often misled by the way the instrument is marked. 
 
 For example, the " J" marked on the instrument does not indi- 
 cate that this scale is for making a drawing \ size, but that J inch 
 
92 ELEMENTS OF DRAWING 
 
 has been divided to represent some convenient division of inches 
 in one foot. This scale of J inch to the foot is 12" -i- J" = ^ 
 full size, while the J size would be 12" X J = 3'', or a scale of 3" 
 to the foot. Another fact to remember is that dimension 
 numbers which the draftsman prints on the drawing are the 
 actual dimensions as measured on the object represented, and 
 not the distance obtained by measurement on the drawing with 
 the ordinary foot rule unless the drawing happens to be full size. 
 
 The scales most used in practice are full size, or 12 inches 
 equals i foot; one-half size, or 6 inches equals i foot; one-fourth 
 size, or 3 inches equals i foot, and one-eighth size, or ij inches 
 equals i foot. If an object is very small the scale of the draw- 
 ing may be increased in order to make a satisfactory drawing. 
 For example, twice size would mean 12 inches on the drawing 
 represents 6 inches on the object. It is often useful to be able 
 to read these scales directly from the foot rule and not be depend- 
 ent upon the special graduation. This is easily done by remem- 
 bering that for a scale of 6 inches to the foot, i inch will 
 be represented on the scale by \ inch, and reading each \ inch as 
 i inch, the subdivisions of the foot rule would read as follows: 
 J" on the drawing .= |" on the object, f " = J", T V" = i", etc. 
 
 For 3 inches to the foot, or J size, i inch is represented by 
 J inch, and the subdivisions would be read thus: J" = \ ", 
 
 1 * i" r*f"r* 
 
 TS "~ 4 i eu " 
 
 For ij inches to the foot, or f size, i inch is represented by 
 inch, and the subdivisions are read thus: tV' = %", sV" = J", etc. 
 
 u ^i Sometimes an unusual 
 scale is required, such as a 
 shrink rule for pattern 
 makers. To construct such 
 a scale or rule, secure a 
 Fig. 66. -shrink Rule. standard twelve-inch rule 
 
 and the blank rule that is to represent twelve inches on the new 
 scale, as shown in Fig. 66. Make a ruling gauge, G, of thin sheet 
 metal, with a guide flange turned down to bear against the 
 outer edge of the blank. Slide the gauge along the blank and 
 mark the graduations as the upper edge of the gauge coincides 
 with the standard graduations. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 93 
 
 61. Choice of Scale in Drawing. The best scales to use in 
 making shop drawings are full size, half size, three inches to the 
 foot, and one and one-half inches to the foot. The one used 
 depends on the relative proportion of the size of the object 
 and the size of the drawing desired. The scale of a drawing 
 should not be so small that all dimensions and information 
 cannot be clearly given. After the scale of a drawing has been 
 decided upon, it must be rigidly adhered to throughout the 
 construction of the views of a single part, but different parts 
 may be drawn to different scales if there is any advantage to 
 be gained in so doing. 
 
 To illustrate how to determine the largest scale that can be 
 used for any particular drawing, suppose a drawing of the Lathe 
 Leg (see page 122, Fig. 84) 
 is to be made on a stand- 
 
 E 
 
 CO 
 
 ard i2"Xi8" sheet and 
 is to consist of three views. 
 A rough sketch as shown in 
 Fig. 67 is made to some 
 scale, and the size of the 
 rectangle required to in- 
 close the necessary views, 
 when grouped in their 
 proper relation to one an- 
 other, is determined. This 
 rectangle measures 42" by 
 36", and therefore if 
 drawn one-half size it 
 
 WOUld be ( Of 42 = 21 by Fi *- 67- Determining the Scale. 
 
 \ of 36 = 1 8) 21 " by 1 8", and could not be drawn on the sheet 
 which has a working space of only 16" by n" (see page 106, 
 Fig. 73). The largest scale possible, if the part is represented 
 vertically on the sheet, will next be determined. Dividing n 
 by 42" gives approximately 0.26, and, referring to 60, page 91, 
 it is seen that the nearest desirable scale corresponding to 0.26 
 is J size, or 3" = i foot. This scale is therefore adopted, 
 the drawing is arranged vertically on the sheet, and the balance 
 of the space is available for other purposes. 
 
94 ELEMENTS OF DRAWING 
 
 When it is desired to represent a number of parts on a single 
 sheet of fixed size, each part should be handled as described 
 above. After the scale has been decided on, the rectangles 
 should be laid out very lightly on the sheet and arranged sym- 
 metrically before beginning the actual work of drawing, care 
 being taken that views are separated by sufficient space to prop- 
 erly allow for all dimensions. 
 
 62. Dimensioning Working Drawings. The dimensions are 
 the most important feature of the drawing, and so far as the 
 workman is concerned the drawing serves only to show where 
 the dimensions apply. 
 
 To be of use the dimensioning must be done systematically, 
 and with the needs of those who will use the drawing constantly 
 in mind. The proper dimensions are determined by considering 
 the processes the material must undergo in the making of the 
 part. In considering such processes the methods "and available 
 tools of the different departments of the shop through which 
 the part will pass to reach the finished state must be kept in 
 mind, and those dimensions given which the workmen will 
 require. 
 
 A drawing has been completely dimensioned when it has all 
 information necessary for getting out stock, making patterns 
 and cores, machining, erecting, etc., the information being in 
 such shape that no workman will be required to make a compu- 
 tation to get a necessary dimension, or to seek information of 
 any kind beyond that recorded on the drawing or specifications. 
 
 The ability to dimension a drawing satisfactorily comes from 
 experience and a thorough knowledge of the shop processes used 
 in making each part. A few general requirements, however, 
 can be given, and these should be carefully studied by the 
 beginner before attempting to dimension a drawing. 
 
 The dimensions on a drawing must be accurate, useful, clear, 
 and complete. If the dimensioning is inaccurate, no degree of 
 perfection otherwise can redeem the drawing; it is worse than 
 useless, for when the part the drawing represents is made it will 
 be wrong, and the labor and, depending on the magnitude of 
 the error, material will be totally or partially lost. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 95 
 
 To lessen chances of making an error, check computed dimen- 
 sions by scaling and scaled dimensions by computation, and if 
 the two do not agree determine which is wrong. Always bear 
 in mind that the dimension figures on a drawing represent the 
 actual measurements on the object, and not the measurements 
 on the drawing, so that in case the " scaled" dimensions and the 
 calculated dimensions fail to agree, the workman will assume that 
 the figures are correct and make the part accordingly. 
 
 If a dimension is not to scale, however, indicate the fact in 
 some manner. This is sometimes done by underlining these 
 figures which are not to scale. 
 
 Place arrowheads so no mistake can be made as to where the 
 dimension applies. There must never be the least doubt in 
 this regard, and the dimension line must always be drawn far 
 enough from other lines to avoid confusion. The dimension 
 numbers must be perfectly plain and placed as near the center 
 of the dimension line as practicable, and they should read from 
 the bottom or right-hand side of the drawing. Never place di- 
 mension numbers on center lines and never draw a line of any 
 kind through such numbers. 
 
 The numbers expressing a dimension should be so selected 
 that they can be conveniently used by the workmen feet, inches, 
 fractions, or decimals, as the case may be. Because of the 
 general use made of the two-foot rule, dimension figures up to 
 24 inches should be expressed in inches; from and including 24 
 inches they should be expressed in feet and inches. 
 
 To avoid chance of mistakes the abbreviation Ft. should be 
 written after the number of feet, and the double accent mark 
 used to indicate inches. The numbers representing feet and 
 representing inches are separated by a dash one-eighth of an 
 inch long, thus 18 Ft. -7". 
 
 In some classes of work, such as locomotive work, dimensions 
 are often given in inches only. 
 
 Judgment must be used in the degree of refinement called for by the 
 dimension. Rough castings, even if small, cannot be measured 
 to one-sixteenth of an inch accurately, and therefore it is useless 
 to give a precise measurement between a finished surface and 
 the end of a casting, while in the case of such work as a force fit 
 
96 ELEMENTS OF DRAWING 
 
 the dimension may be given to several decimal places, the vari- 
 ation allowable from the given figure being indicated in the 
 following manner: 3- 128^'*, meaning that a variation of 
 0.005 above or below 3.128 is permissible. 
 
 Where dimensions on the drawing indicate the final dimen- 
 sions of the part when complete, no allowances are made by 
 the draftsman for shrinkage of castings, finishing, etc., as this is 
 usually taken care of in the shop. 
 
 The over^alLdimensions are so frequently useful in estimating, 
 getting out stock, etc., that they should always be given. Place 
 over-all dimensions outside of subdimensions, and in cases where 
 dimensions are grouped in parallel lines the shortest dimension 
 should be inside, the longest outside, and all others so arranged 
 that dimension lines do not cross. 
 
 Always check over-all dimensions carefully to see that they 
 agree with the sum of the dimensions which go to make them up. 
 Do not rely upon scaling alone in adding up a line of subdi- 
 mensions to determine an over-all dimension, because if the 
 drawing is slightly out of scale the result will be wrong. 
 
 If a subdivided dimension is between a finished surface and 
 the end of a casting, the last subdivided dimension should be 
 omitted and an over-all dimension given. 
 
 The inexperienced draftsman will often give dimensions on 
 a drawing which it is impossible for the workman to use in 
 making the part. For this reason the dimensions placed on a 
 drawing in a haphazard way, even if accurate, are very often 
 worse than useless. All- measurements possible should be from 
 center lines that are convenient for the workman to locate on the 
 object or from finished surfaces. Give the distance between 
 centers of important parts, and if the object is symmet- 
 rical, give the distance of these centers from the main center 
 line. 
 
 Do not repeat dimensions unnecessarily as this increases the 
 possibility of error. Where it is necessary to repeat dimensions 
 an error is more likely to be discovered if the dimensions are 
 placed in corresponding positions on the different views. 
 
 Similar parts should be similarly dimensioned and dimensions 
 which are related should be kept near one another. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 97 
 
 Do not crowd all dimensions on a single view, but distribute 
 them to avoid confusion. 
 
 Dimensions should not be crowded into limits inadequate to 
 receive them, and if the space is too small for the figures, they 
 may be placed outside, with or without a leader that is, a 
 line drawn to indicate where a note or dimension applies (see 
 Fig. 88, page 125). 
 
 If the space between reference lines is too small to receive well- 
 formed arrowheads, the arrowheads may be reversed and placed 
 outside of the space to be dimensioned, see Fig. 82, page 118. 
 When a dimension falls on a sectioned area, the section lining 
 is omitted at the place where the dimension numbers are given. 
 
 Where a complete circle is shown on the drawing, such as 
 a bored hole or turned piece, give the diameter. Cored holes 
 are dimensioned by giving the diameter and stating that they 
 are to be cored; thus, |"core. Fillets and rounded corners are 
 given by their radii. In giving the radius of a circle, R or Rad. 
 is written after the dimension figures, and an arrowhead is 
 placed at the arc but not at the center. Threaded pieces and 
 tapped holes are dimensioned by giving the diameter and num- 
 ber of threads per inch; thus, i"-i3 thd., or |"-I3 tap. 
 
 Dimensions of angles should be given in degrees and minutes 
 or by coordinates from a reference line, depending on how they 
 are to be used. Tapers should be stated per foot of length 
 and in the case of conical surfaces should be given as taper on 
 the diameter. 
 
 63. Notes on a Drawing. Lengthy notes should not be re- 
 quired on a drawing to make it clear, but there are times when 
 the art of drawing fails in its purpose and a brief note carefully 
 worded saves the workman much uncertainty. In such cases 
 an explicit note of instruction is not only permissible but abso- 
 lutely essential. When possible, notes should be placed in hori- 
 zontal lines and very close to the part to which they refer, in order 
 that they may be quickly read and easily understood. All notes 
 should consist of short, explicit and concise sentences, should 
 leave no doubt as to their exact meaning, and should read from 
 the bottom or the right-hand side of the drawing. 
 
98 ELEMENTS OF DRAWING 
 
 State all special directions and instructions pertaining to 
 making, painting, shipping, erecting, etc., in properly worded 
 notes. No lettering of notes should be attempted on the draw- 
 ing without first ruling very light guide lines to insure an even 
 height and slope of letters. Guide lines should be drawn very 
 lightly and erased after the note is completed. Retrace any 
 letters made dim by erasing. All notes on drawings in this 
 course must be lettered in the standard Gothic capitals, unless 
 otherwise stated. The letters must be ?V high. Figures in a 
 note should be made slightly higher than the letters, say, J" high. 
 
 64. Indicating the Finish of Surfaces. The surfaces of a 
 casting or forging are spoken of as " rough " when in the condi- 
 tion in which they leave the foundry or mill, and "finished" 
 when the piece has been subjected to some tool operation. 
 Some of the shop operations for finishing surfaces with cutting 
 tools are turning, planing, milling, grinding, reaming, filing, 
 scraping, and chipping; besides these processes, surfaces are 
 often polished, grained, matted, etc., to produce artistic effects. 
 It is necessary to indicate on the drawing the kind of finish a 
 surface is to be given, so that the proper department will attend 
 to it, and also in order that the pattern maker or blacksmith 
 will allow for the material that must be removed in producing 
 this finish. The usual method of indicating a finish made by 
 machining is to place the letter / across the edge mew of the 
 
 surface to be so finished. (See Fig. 68.) If it is 
 to be other than the ordinary machine finish, a 
 note to that effect should be added and a leader 
 run from the note to the finish mark. If all the 
 of indicating ordi- surface of a part is to be finished the several "/" 
 aZZr*" D marks are omitted and the note "f ALL OVER" 
 is printed near the part number. As shop methods 
 and processes are continually being changed in an effort to 
 increase production and reduce the cost of manufacture the 
 drawing should not specify the process by which the finish is 
 to be obtained. 
 
 65. Use of Record Forms and Titles. A complete record 
 must be kept of every drawing, and most of this record should 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 99 
 
 be on the drawing itself in a particular and invariable space re- 
 served for that purpose. That portion of the record which is 
 placed on the drawing should be systematically tabulated accord- 
 ing to a fixed form and should embrace at least the following items: 
 
 (i) An appropriate title which will adequately describe the con- 
 tents of the drawing. 
 
 (2) The name and address of the firm for which the drawing 
 is made. 
 
 (3) The title and names or initials of those who are responsible 
 for the finished drawing; this includes at least the checker and, 
 the approving engineer. 
 
 (4) The drawing number and a " part number " where necessary- 
 
 (5) A record of all changes made in the drawing to adjust it to* 
 meet conditions other than those for which it was originally intended^ 
 
 (6) The date the drawing is officially adopted. 
 
 (7) The size of the drawing should be indicated in some manner 
 so that it can be properly and systematically filed. 
 
 Besides the above information some companies insist that the 
 drawing bear the name and initial of all those responsible for it 
 in any way. If this burdens the drawing with information use- 
 ful in the drawing department only, the complete history of the 
 drawing can be recorded on cards or in a special book reserved 
 for that purpose. Also the machine or apparatus for which a 
 part is usually first designed is recorded and some scheme is 
 adopted such that if a part is used on several different machines 
 the fact is recorded in such a manner that unnecessary dupli- 
 cation of patterns or uncertainty as to the number of pieces to 
 be kept in stock is avoided. 
 
 It is very common practice to indicate the " scale " to which 
 the parts represented on a drawing have been made, but the 
 value of this practice is questionable, as there is a rule almost 
 universally applied that " the workman must not scale a draw- 
 ing to obtain a dimension." Also during the life of a drawing 
 it frequently happens that dimensions are changed, but the 
 drawing is not "kept to scale"; and for these reasons the 
 11 scale " on a drawing might be a temptation to break 
 the above rule and in addition be misleading. 
 
100 ELEMENTS OF DRAWING 
 
 In practice many different systems are used to keep a record 
 of changes on a drawing, the purpose being to have a history 
 of progress made, and to be able to furnish repair parts for 
 machines in service. There are several features to be taken 
 care of in this connection but it is not within the scope of this 
 book to go beyond pointing out the necessity of keeping a 
 thoroughly reliable history of changes made during the life of a 
 drawing. 
 
 66. The Title-form on a Drawing. The best location for a 
 title-form is the lower right-hand corner of the sheet. This 
 information so placed makes it easy to handle and file the 
 drawing and particularly tracings. 
 
 There is no accepted standard for the outline and dimensions 
 of a title-form, or the information recorded, but each individual 
 establishment evolves .one that is suited to its own use. Care 
 should be taken in the final selection of a title-form as it is a 
 very important item in a drawing room system. 
 
 The title-form shown in Fig. 69 represents a general average, 
 and will be used in this work on all mechanical drawings of the 
 
 
 P3 
 
 2 
 
 \f 
 
 $ 
 
 Print Title Here. 
 
 5<o 
 
 \ 
 
 ^"MACHINE DESIGN 
 
 'SIBLEY COLLEGE 
 
 ^-'ITHACA, NEW YORK '^ 
 
 DRAWN BY"^^ 
 INSPECTED F 
 
 \?<b 
 
 DATE APR V'D 
 
 -JJRAWING-C IOI 
 
 | 
 
 <u 
 
 <- r" 
 
 T,?"" 
 
 
 **- 8 
 
 *- 8 
 
 Fig. 69. Title-form to be used in this Work. 
 
 12" X 18" size. This title-form, while especially applied to 
 this work, follows closely the one now used successfully by 
 several large manufacturing concerns. 
 
 All the lettering in the title-form is the Capital Slant Gothic 
 style. By using the method described on page 69, 49, the 
 lettering in the title can be more satisfactorily arranged by the 
 beginner. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE IOI 
 
 The lettering of the title (or name of the drawing) is T Y' 
 high, and is located " centrally " in the space provided for that 
 purpose which is If" X 5!". 
 
 All other lettering in the title-form is " high except the 
 words DRAWING and SIBLEY COLLEGE (or whatever the 
 name of the institution), which are jY r high. 
 
 The space between all lines of lettering in the title-form is 
 iV on the right-hand side and J" on the left-hand side. 
 
 67. Bill of Material. A bill of material should be placed on 
 every detail drawing to give the information required to make 
 up the orders for the pattern shop, foundry, machine and forge 
 
 ^ 
 
 -Id 
 
 BORDER LINE 
 
 OF SHEET 
 
 Fig. 70. Bill of Material Form used in this Work. 
 
 shops; to get out machine lists, figure stock, cost, etc. The 
 form for tabulating this data varies with different companies, as 
 does also the place it occupies on the drawing. Fig. 70 shows 
 a form for the bill of material that has proven entirely satisfac- 
 tory under severe conditions and will be adopted for this work. 
 In Fig. 70 the space if " X 5f " directly in the corner is reserved 
 for the title-form (see page 100, 66). Unless otherwise stated, 
 locate the bill of material form just above the title-form, and 
 provide at least as many -fa" spaces as there are parts detailed 
 and standard parts called for on the drawing. In practice 
 extra tV spaces are drawn to provide for future addition of 
 parts. 
 
102 ELEMENTS OF DRAWING 
 
 All lettering in the bill of material is ^Y' high? is of the slant 
 Gothic style, and is preferably all capitals. 
 
 The first column on the left contains the number of pieces 
 required to make one complete machine (or structure) in this 
 case one lathe. The second column contains information as to 
 the material of which the part is to be made. The third column 
 is for cross reference and refers to patterns, other drawings, 
 punches, dies, etc., and conveys some special information or 
 instruction which is required to make the data in column four 
 complete. Thus, if the bill of material on one drawing called for 
 a piece, say, a washer, exactly the same as had been previously 
 detailed on another drawing for a different machine, then column 
 three would contain the word " punching," which explains how 
 the part is made, and in column four would be written," C-iyi," 
 which would be the size and number of the drawing on which the 
 washer is detailed. Should a part require the use of a pattern 
 which has already been made for another machine, that fact 
 could be recorded by writing in column three the abbreviation 
 " Patt." for pattern, and the number of the pattern would be 
 printed in column four. The fourth column contains pattern 
 numbers (see page 104, 70) when the part is a casting, punch 
 and die numbers when the part is a punching, etc., and for 
 other classes of work may be used as indicated above. The 
 fifth column contains the part numbers. See page 104, 69. 
 The sixth column contains the name of the part and any other 
 information thought necessary to identify the part. 
 
 This particular form of a bill of material has distinctive and 
 valuable features which should be understood. It is so laid out 
 that the part numbers, pattern letters, etc., read from the bottom 
 upward; this is done in order that a new part number may be 
 added at any time. Also it is often found necessary to make a 
 machine differing very little from one already detailed, and ad- 
 ditional columns, each of which is exactly the same width as 
 column one (see page 119, Fig. 83), can be added to the left of 
 column one and new groups made. To illustrate, suppose a 
 firm manufacturing the speed lathe should receive an order 
 for a lathe of the same general design as the standard machine 
 but to have a bed six inches longer. All that is necessary under 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 103 
 
 this system is to make out a new list to the left of column one 
 and call it group two; schedule all parts in this group as in 
 group one except the bed; add another part number to the top 
 of the bill of material, and schedule the longer bed. Then add 
 a note near the drawing of the original bed stating that for 
 group 2 the bed is to be a certain length, and the drawings 
 would be ready to go through the shop on the new order. 
 
 Wherever possible, parts which fit together on the complete 
 machine should be recorded in the bill of material as consecutive 
 items, as this simplifies checking and erecting. For example, if 
 two castings fit together and are given the part numbers i and 
 2, the bolts or screws for fastening them together should be 
 number 3. 
 
 When standard parts are required, such as standard bolts, 
 nuts, washers, screws, etc., they are not detailed on the drawing, 
 but are given a part number, and this number is printed in the 
 regular way close to the place where the part is to fit, and an 
 arrow from the circle points to the exact place it is used. This 
 part number is also printed in the bill of material. 
 
 The name of the material is usually abbreviated in the bill 
 of material, some of the more common abbreviations being: 
 Cast Iron, C.I.; Wrought Iron, W.I.; Malleable Iron, Mal.L; 
 Machine Steel, M.S.; Cold Rolled Steel, C.R.S.; Cast Steel, C.S.; 
 Steel Forging, S. Forg.; Steel Tubing, S. Tube.; Brass, B.; 
 Bronze, Bz.; Phosphor Bronze, Ph. Bz.; Copper, Cop.; Babbitt, 
 Bbt. ; Fiber, Fbr. Where it is necessary to use a material of an 
 exact analysis or specification it is best to call for it by a number 
 (see page 81, 55). 
 
 68. Numbering and Indicating the Size of Drawings. In 
 
 order to be easily classified, recorded, filed, and referred to, draw- 
 ings should be given a number. There is no universally accepted 
 system for numbering drawings, and the method followed by 
 each particular firm depends largely on the magnitude and 
 variety of its business. 
 
 It is also necessary to have some simple and effective means 
 of indicating the size of a drawing, as those of different sizes are 
 usually filed in different cases or drawers. 
 
104 ELEMENTS OF DRAWING 
 
 In order to secure uniformity, and also to save waste in cutting 
 paper and tracing cloth, four standard sizes of drawings have 
 been adopted in most commercial drawing rooms, and these 
 sizes are indicated on the drawing by a capital letter used in 
 connection with the number of the drawing. For instance, the 
 sizes indicated by the letter might be as follows : The letter A 
 to indicate a drawing 24" X 36"; B, a drawing 18" X 24"; C, a 
 drawing 12" X 18"; D, a drawing 9" X 12". 
 
 In this course all exercises in mechanical drawing are worked 
 on paper 12" X 18", and consequently their size is indicated by 
 the capital letter C, and the block of numbers reserved for 
 this work begins with 101 and extends to 200. Thus drawing 
 C-I03 would be 12" X 18" in size, and the third consecutive 
 mechanical drawing made in the course. 
 
 69. Part Numbers on a Drawing. In order to refer to any 
 individual part (or element of a machine) in making up orders, 
 tabulating bills of material, etc., each part detailed on a drawing 
 is given a number to identify it. This identifying number is 
 termed the "part number" (or reference number), and is printed 
 near the views of the part and is inclosed in a circle. On a 
 pencil drawing both number and circle A 
 are double lined, but these are drawn $, ^ 
 
 solid when inked. (See Fig. 71.) The . 
 circle should always be drawn after Fig. 71. Layout of " Part 
 the number is formed and in such a Numbers " as used * this Work ' 
 position that the number appears " central " in the circle. 
 
 It sometimes happens that a single part will require more 
 than one part number. As an example, take the washer detailed 
 on drawing C-ioi. Two washers are required, of exactly the 
 same form and dimensions, but are made of different materials. 
 Therefore, in place of repeating the drawing of the washer, the 
 one drawing is given two numbers, and the material of which 
 each is made is called for at the proper place in the bill of 
 material. 
 
 70. Recording Patterns on a Drawing. When a pattern is 
 required in order to produce a part, the pattern should be given 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 105 
 
 a number so that it can be listed, identified and referred to. 
 This riumber is usually assigned in the drawing room and is re- 
 corded in the bill of materials. This will be explained more 
 fully later. When practical these numbers are fastened to the 
 pattern in raised figures and letters, and therefore appear on 
 the casting. By this means a broken or obsolete part of a 
 machine may be replaced by simply ordering the part by its 
 number from the manufacturers. 
 
 The method to be followed in this course for marking pat- 
 terns will be to give to them the same number as the drawing on 
 which the part is first detailed, and then add a capital letter to 
 identify the patterns required by the different parts detailed on 
 a single sheet. The pattern letters on each drawing begin with A 
 and continue through the alphabet in the order they are recorded 
 in the bill of material. Thus, the first pattern required on 
 drawing 158 would be marked " Patt. I58-A"; the second 
 would be marked " Patt. 158-6," and so on through the alpha- 
 bet as far as necessary. It often occurs that in a new machine 
 some part requiring a pattern will be the same as the corre- 
 sponding part of an old machine. In such cases the old pattern 
 number must be given on the new drawing, and the old pattern 
 used for the new machine. For example, suppose the fourth 
 pattern required on drawing 136 could be used for the first 
 pattern required by drawing 158. Instead of numbering 
 the pattern I58-A, it would keep its old number (136-0) and 
 would be recorded as 136-0 on drawing 158. The lettering 
 of the new patterns required on drawing 158 would not be 
 affected by the fact that one or more old patterns are called 
 for. In marking patterns, such letters as /, 0, and Q should 
 be avoided, as they are easily confused with numerals of 
 similar outline. 
 
 71. Time Keeping in Drawing. In practice the draftsman is 
 usually required to keep a record of the time devoted to each 
 drawing. This record is usually kept in a time book or on cards, 
 and is of value in computing drawing-room expenses, as well 
 as useful in determining to some extent the value of the drafts- 
 man's services to the company. 
 
io6 
 
 ELEMENTS OF DRAWING 
 
 FINISHED. 
 
 TOTAL HOURS. 
 
 Fig. 72. Time-keeping Form 
 used in this Work. 
 
 In order to apply the principle of 
 time-keeping in this course and yet 
 avoid using the card system the form 
 as shown in Fig. 72 will be used. 
 This form is to be printed with the 
 rubber stamp (provided for the pur- 
 pose) just above the lower border 
 line, and to the left of the title-form, 
 unless another location is indicated. 
 
 72. Border Lines. Border lines are drawn parallel to and 
 near the edges of the paper to form a frame for the drawing. 
 
 EDGE OF PAPER- 
 
 
 J 
 
 ^ ^ 
 
 
 
 
 
 
 -70" 
 
 BOR 
 
 DE:/? L/WE > 
 
 
 
 c 
 
 I 
 
 | 
 
 1 f\" 
 
 
 / 
 
 
 -4BORl 
 
 ER LLN.E 
 
 *H 
 S 
 
 < t 
 
 
 
 \ 
 
 . 
 
 n 
 
 i~>i 
 
 
 
 \ 
 
 
 
 t 
 
 
 
 
 EDGE OF PAPER'S 
 
 
 
 
 Fig. 73- Layout of Standard Drawing as used in this Work. 
 
 Their principal object is to set off a margin, which gives the 
 drawing a finished appearance, and to lessen the chances of poor 
 results in trimming and blue printing. The border lines should 
 be drawn very close, say, | inch from the edge of the paper, as this 
 margin represents so much waste space. The border lines should 
 be the first lines drawn on a pencil drawing, in order to act as match 
 lines to reset the drawing in case it has to be temporarily re- 
 moved or shifted. The border lines are drawn in last on an inked 
 drawing and should not be too heavy, say, not over ^V' wide, the 
 exact width depending somewhat on the size of the drawing. 
 
 Fig. 73 shows the layout of border line to be used in this 
 work. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 107 
 
 Having placed the paper " square " on the board (see this 
 page, 73), draw a very light horizontal line entirely across 
 the paper, |" from the top edge; make a mark on this line 
 y from the right-hand edge of the paper, and then with the 
 aid of the triangle, guided by the working edge of the T- 
 square blade, draw in very lightly the right-hand vertical line 
 through this point. Next, lay off the distance between the 
 right and left hand border lines along the top border line, and 
 by aid of the T-square and the triangle draw in the left-hand 
 border line. On this line lay off the distance between the top 
 and bottom border lines, and with the T-square draw in the 
 bottom border line. Any part of the lines extending beyond 
 the corners must be erased, and the whole border retraced and 
 the lines made clear cut and of the desired weight. The wide 
 margin on the left is to allow for binding the sheets of this 
 course together. In practice, however, it is customary to have 
 the same margin on all sides. 
 
 73. To Fasten the Paper or Tracing Cloth to the Board. The 
 
 paper or cloth should be " square" with the board; it should lie 
 perfectly flat and smooth, and only one drawing should be tacked 
 
 Fig. 74. Placing a Drawing on the Board. 
 
 on the board at a time. Place the paper about midway between 
 top and bottom, and rather close to the left-hand edge (i.e., 
 working edge) of the drawing board and insert a thumb tack 
 in the upper left-hand corner. Then, holding the T-square in 
 its proper position with the left hand, manipulate the paper or 
 cloth with the right hand until the upper edge of the paper and 
 the working edge of the T-square are in line. (See Fig. 74.) 
 Smooth the paper diagonally with the right hand from the 
 upper left-hand to the lower right-hand corner and tack this 
 
I08 ELEMENTS OF DRAWING 
 
 corner down. Next, smooth the paper from the center to each 
 of the other two corners and tack them down. To securely 
 fasten large sheets, it is usually necessary to use thumb tacks 
 along the edges as well as at each corner of the sheet. All 
 thumb tacks should be so placed that the outer edge of the 
 head comes about even with the edge of the drawing paper or 
 tracing cloth. Also the thumb-tack head must be pushed tight 
 against the paper so that the head will offer the least obstruc- 
 tion to the triangles and T-square. It is often advisable in 
 doing accurate work to temporarily remove a thumb tack if the 
 head interferes with the free use of triangles or T-square, but 
 in such cases the alignment of the drawing must not be dis- 
 turbed. 
 
 Stretching or smoothing the paper or tracing-cloth with soiled 
 or moist hands injures the drawing surface. 
 
 Unless stated to the contrary, the drawing paper for this 
 course should be tacked down with short dimensions parallel to the 
 working edge of the drawing board. 
 
 74. To make a Pencil Drawing. Good penciling is a requi- 
 site to good inking, and a drawing is seldom improved in inking 
 if poorly done in pencil. The pencil must be kept well sharp- 
 ened (see page 15, 14), so that the lines drawn will be clear, 
 sharp, and of the proper weight. 
 
 The direction in which mechanically made lines in either 
 pencil or ink should be drawn is shown on page 21, Fig. 19. 
 Vertical lines and all those lying in the angle AOC are ruled 
 against the left-hand edge of the triangle and the lines in the 
 angle COE are ruled against the right-hand edge. 
 
 Center lines should first be drawn as light continuous lines, 
 and later be retraced in their proper construction, being left 
 broken where necessary to avoid crossing a dimension figure. 
 Such a break in a center line should be made about the middle 
 of a long dash and should not immediately precede or follow a 
 short dash of the line. If the center lines are drawn heavy at 
 first they must be erased at the places where they would cross 
 dimensions, and if not gone over again the ends next to where 
 the erasing was done are ragged. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE IOO/ 
 
 Do not complete each view separately, but, having one well 
 along, commence the drawing of others. In this manner errors 
 are more readily detected, and the drawing of each view be- 
 comes a check on the others. All the views, however, repre- 
 senting one part should be completed before starting to draw 
 another part on the same sheet. 
 
 In making drawings of spindles, shafts, and parts where most 
 of the lines are at right angles to one another, measure off the 
 horizontal lengths along the center line, and through these 
 points draw the vertical lines of the drawing very lightly and of 
 indefinite length. On these vertical lines measure the diameters, 
 and through these points draw in the horizontal lines. These 
 may be put in full weight at once, since their limits are denned 
 by the light vertical lines. Next, that portion of the light ver- 
 tical line which is needed is drawn in heavy. All the lightly 
 drawn horizontal lines which are to become dimension lines are 
 next gone over (between the proper reference lines) and formed 
 into the two short and one long dash construction. These lines 
 should be made of the proper weight, and left properly broken 
 for their dimension figures. When all of the dimension lines 
 are on the drawing, put in the arrowheads and dimensions, then 
 letter in the necessary notes. Do not print in the dimension 
 numbers until the drawing is completed, as this insures greater 
 accuracy. There should be a space of at least T V' between a 
 note and any line of the drawing, including dimension lines and 
 figures. In laying off dimensions, point them off directly from 
 the scale (see page 30, Fig. 32), and do not transfer them from 
 the scale to the drawing by use of the dividers. 
 
 Time is often gained and the work is usually more accurate 
 if the drawing is systematically done. A good method of pro- 
 cedure in making a pencil drawing is as follows : 
 
 1. Draw border lines. 
 
 2. Block out bill of material and title form. 
 
 3. Arrange the views (see page 74, Figs. 50 and 51, also 
 page 75, Fig. 52) and draw main center lines. 
 
 4. Draw the main lines of the part, using very light continuous 
 lines. 
 
 5. Complete all views of the part. 
 
110 ELEMENTS OF DRAWING 
 
 6. Put in dimensions and notes. 
 
 7. Retrace center lines, making them the proper weight and of 
 the characteristic dot and dash construction. 
 
 8. Complete title and bill of material. 
 
 75. Inking Drawings. Before beginning to ink, thoroughly 
 clean the drawing, removing all dust, lint, particles of worn- 
 off rubber, etc., and be exceedingly careful that the hands and 
 instruments, especially the triangles and the T-square, are clean 
 and free from dust, so that they will not soil the drawing. 
 
 Examine the points of the bow pen, compass, or ordinary 
 pen before using them, to make sure that the nibs are clean, 
 are of the same length, and come together evenly. Always 
 shake the ink bottle well before using the ink, since, when the 
 bottle stands undisturbed for some time, the coloring matter 
 in the ink gradually settles to the bottom. Under such con- 
 ditions the charge of ink carried by the pen will not be of the 
 same density, but will be more highly colored at first, and as the 
 thinner ink from above reaches the drawing surface the line will 
 vary in color; that is, taking the case of black ink, it will vary 
 from a jet black to a grayish black in appearance. When such 
 lines are on tracings it is impossible to obtain satisfactory blue- 
 prints. After filling the instrument with ink, test it on a sepa- 
 rate piece of paper to see that the ink is flowing properly and 
 that the width of the line is correct. If the ink does not flow 
 freely, touch the point of the pen to the drawing board, the 
 penwiper, or the end of the finger. If ink still does not flow, 
 
 slightly dampen the finger and touch 
 it to the point of the pen, or remove 
 the dried ink with a slip of thin paper 
 drawn between the nibs. (See Fig. 
 75.) As a last resort, thoroughly 
 
 Fig. 75- Cleaning the Ruling Pen. ' 6 J 
 
 clean and refill the pen. More un- 
 satisfactory work results from the use of a dirty pen than from any 
 other cause, hence the nibs of the pen should be cleaned each time 
 a charge of ink has been exhausted, and under no circumstances 
 should the pen be put away without having been first thoroughly 
 cleaned. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE III 
 
 Before inking a line, understand what kind of a line it is, 
 that is, whether full or broken, the purpose of the line, and 
 where it begins and ends. Start inking at the top and left-hand 
 side, and work down and toward the right, for in this way the 
 wet ink is not smeared with the hand, T-square, or triangles. 
 
 In drawing a line, hold the pen at the starting point for an 
 instant until the ink begins to flow, and then move it along the 
 pencil line at a uniform and moderate speed. On reaching the 
 end of the line, immediately raise the pen from the drawing, 
 otherwise the ink continues to flow and the line spreads at the 
 end. If a good line is not produced at the first attempt, do not 
 push the pen backward over the line, but go over it a second time 
 in the proper direction, taking care not to widen the line in 
 retracing. If several lines meet at a point, allow sufficient time 
 for each line in turn to dry, and, if possible, ink from, and not 
 toward, the point of intersection. Since it is difficult for a be- 
 ginner to join two lines so that they appear smooth and contin- 
 uous, the pen should hold sufficient ink at the beginning to complete 
 the line. Too much ink in the pen gives a heavier line than 
 is desired, and too little ink results in too light a line. 
 
 Blotting and faulty lines are two of the main sources of trouble 
 in inking a drawing. Blotting may result from overloading the 
 pen with ink; from allowing the ruling edge to come in contact 
 with a line before it is dry; from lint, particles of worn-off 
 rubber, or dust being caught on the point of the pen; from 
 inclining the pen toward the ruling edge so that ink is drawn 
 under the edge of the T-square or triangle; from getting ink on 
 the outside of the nibs in filling the pen, or because of the nibs 
 being nicked, corroded, or otherwise out of condition. If a blot 
 is made, absorb the surplus ink by applying the corner of a 
 blotter to the top of the ink globule. To lay the blotting paper 
 directly on the blot tends to spread the ink and to injure the ' 
 wet surface. 
 
 Faulty lines are usually of variable width or ragged along the 
 edges. A line of variable width may result from changing the 
 speed at which the pen is moved, thus causing a variable flow 
 of ink; and from varying the pressure against the drawing 
 or ruling edge, thus springing the blades and changing the dis- 
 
112 ELEMENTS OF DRAWING 
 
 tance between the nibs. The pen point may encounter lint, dust, 
 or particles of worn-off rubber in its path, thus causing the 
 ink to flow irregularly, or the pen may be too full or not suffi- 
 ciently full of ink, thus varying the rate of ink flow. 
 
 A ragged line may result from the pen not being clean; the 
 nibs being so dull that the edges of the line are broken; both nibs 
 not touching the drawing at the same time, due either to the 
 blades being of different length or because the pen is not held 
 in a vertical plane parallel to the working edge. 
 
 Always allow ink to become thoroughly dry before attempting to 
 erase it. 
 
 Drawing ink should never be blotted as this causes the lines 
 to appear dim and blotting on a tracing destroys the opaque 
 qualities of the line for printing. A very wide line should be 
 " built up" of a series of narrower merging lines made by par- 
 allel strokes. 
 
 Do not place the ink bottle on the drawing board as ink 
 
 may be accidentally 
 spilled. The danger of 
 overturning may be 
 lessened by using an ink 
 bottle holder, sev- 
 eral styles of 
 which are on the 
 market. A circu- 
 lar piece of wood 
 
 Fig. 76. Two Simple Designs of Ink Bottle Holders. r f 
 
 or a piece of draw- 
 ing paper cut to receive the bottle and hold it securely, as shown 
 in Fig. 76, is commonly used. 
 
 The drawing, when not in use, should be kept covered with 
 an extra piece of paper to protect it from the dust and dirt. 
 
 Never begin inking a drawing until it has been completely 
 finished in pencil; and, in order to get the best results and to 
 save time, do the inking systematically. Opinions differ as to 
 the best order of inking the lines on a drawing, but on one 
 point all are practically agreed, namely, that curves tangent to or 
 joining straight lines should be inked first, and the straight lines 
 drawn to the curves. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 113 
 In inking, a very good method of procedure is as follows: 
 
 (1) circles and arcs, beginning with the smallest; 
 
 (2) outlines, beginning with the lightest and inking all of one 
 weight before taking up the next heavier; 
 
 (3) hidden surface lines; 
 
 (4) extension lines and dimension lines; 
 
 (5) arrowheads, dimensions and notes; 
 
 (6) cross-section lines; 
 
 (7) bill of material and title; 
 
 (8) border lines. 
 
 76. Checking Drawings. The process of checking consists lit 
 making a thorough examination of every detail and feature of 
 the drawing to detect any errors it may contain. The impor- 
 tance of efficient checking is realized when the ease with which, 
 an error can be corrected on a drawing is compared with the 
 difficulties and expense that would result if the same changes 
 had to be made on a pattern, casting, or forging. Final check- 
 ing should not be done by the same draftsman who made the 
 drawing, as one does not readily detect his own errors. In 
 most drawing rooms there is an official " checker " whose duty 
 it is to see that drawings are correct in every detail and who is 
 responsible for the accuracy of drawings which bear the official 
 mark to indicate they have been checked. The checker usually 
 signs his initials and the date of checking in the title form of 
 the drawing. 
 
 The beginner should always check his own work thoroughly in 
 order to gain some knowledge of checking, as well as to detect 
 any oversights or errors it may contain. The checker must first 
 inform himself of what is wanted, and then by methodical steps 
 examine the drawing to see if it completely fulfills all require- 
 ments. A good method of procedure in checking is as follows: 
 
 1. See that a drawing of every part and of necessary assem- 
 blies has been made, and that enough views are correctly drawn to 
 completely represent each part. 
 
 2. See that all scale dimensions agree with the dimension 
 figures given on the drawing, and that where a series of sub- 
 
114 ELEMENTS OF DRAWING 
 
 dimensions make up an " over all " (total dimension) no error has 
 been made. 
 
 3. See that related parts do not interfere; i.e., check each part 
 with those parts to which it will be adjacent in the assembled 
 machine, to see that corresponding dimensions agree, and that 
 proper clearances have been allowed. 
 
 4. See that dimensions are given correctly, so that no com- 
 puting or scaling will be necessary when working with the draw- 
 ing, and that notes and figures are plain and in the position in 
 which the reader is most likely to look for them. 
 
 5. See that no arrowheads are missing, and that all marks 
 for feet and accents for inches are correct and none omitted. 
 
 6. Lay out to scale and on a separate sheet the path of 
 motion for moving parts, and see that the proper clearances are 
 maintained in all positions. 
 
 7. See that no center lines are missing, and that they are all 
 correctly shown. 
 
 8. See that finished surfaces are properly indicated. 
 
 9. See that all stock material, such as screws, bolts, rivets, keys, 
 etc., are as far as possible of standard size. 
 
 10. Check supplementary notes and all instructions and every 
 feature of the bill of material and title. 
 
 In addition to the above see that all the instructions given 
 in Appendix A, page 175, are carried out with reference to 
 exercises in this course. 
 
 77. Tracing. A tracing is an exact copy of a drawing, made 
 by placing transparent cloth (see page 6, 6) or paper (see 
 page 6, 5) over the drawing and tracing on this cloth or paper 
 lines to correspond to those of the original drawing. 
 
 In commercial drafting rooms the tracing is the permanent 
 record of the drawing and is used as a negative to produce addi- 
 tional copies of the drawing, usually by the blueprint process.- 
 
 To make a tracing, stretch the cloth over the drawing to be 
 traced until it is fairly taut and perfectly smooth and even. 
 Place a thumb tack in each corner, and a sufficient number around 
 the edges to hold it flat and well stretched. Before beginning 
 to ink, sprinkle the surface of the cloth with powdered chalk, 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 115 
 
 and rub lightly with a soft, clean rag to overcome the effects of 
 any oil that may be present; then brush off the chalk with a clean 
 rag so that it will not pile up in front of the pen when inking. 
 
 Greater care is required to make a drawing on tracing cloth 
 than on drawing paper, especially if the glazed side of the cloth 
 is used. One very important precaution to be taken is 10 see 
 that the pen is clean, sharp, and otherwise in good condition. 
 The pen should carry less ink than when working on paper, 
 as the ink has a greater tendency to spread. Take special 
 care to draw the ink lines exactly over the pencil lines of 
 the drawing being traced. Be very careful in inking lines 
 that meet or intersect, since if the first line is not dry (ink 
 dries slower on cloth than on paper) before the second is 
 drawn, a blot will result at the point of meeting. Work only on 
 one part of the tracing at a time, and whenever possible com- 
 plete a view before leaving the drawing for any length of time, 
 the reason for this being that moisture in the air affects the 
 cloth, and may cause it to warp to such an extent that it 
 will be difficult to complete the view later on. When the cloth, 
 warps, remove thumb tacks and readjust it to fit over the 
 lines of the drawing as accurately as possible. Moisture will 
 destroy the surface and transparency of tracing cloth, rendering 
 it unfit for printing or drawing. For this reason avoid working 
 on the cloth with damp hands. A tracing may be cleaned with 
 a rag or sponge moistened with benzine or gasoline. Never fold 
 or crease tracing cloth. 
 
 The same systematic order given for inking a drawing should 
 be followed in tracing. See page no, 75. 
 
 Erasures on a tracing must be avoided as far as possible, but 
 it is often necessary in practice to make complete changes of por- 
 tions of a view, and for this reason the beginner must learn to 
 make erasures without spoiling a tracing. After the erasure has 
 been made, the smooth surface must be restored before again 
 applying ink. To smooth the surface, rub the injured area with 
 a soapstone pencil and polish with a cloth. See page 18, 17. 
 
 Never use a knife to scratch out lines on tracing cloth, as this 
 may cause permanent injury to the surface of the cloth. In 
 drawing over an erased area, set the pen for a finer line than is 
 
Il6 ELEMENTS OF DRAWING 
 
 required and build the line up to the required width by making 
 several strokes. 
 
 78. Blueprints. A tracing is used as a negative in reproduc- 
 ing copies of a drawing by the blueprint process. Such prints 
 are termed " blueprints " because the reproduced drawing is 
 in white lines on a blue background. The prints are usually 
 made in a printing frame, which is a device for holding the tracing 
 and the prepared paper flat and smooth against a glass front. 
 The right side of the tracing (i.e., the side on which the drawing 
 has been made) is placed next to the glass; the chemically pre- 
 pared side of the paper is placed next to the tracing and the 
 back of the frame fastened down. The frame is then placed so 
 that the glass front is exposed for a short time (the exact time 
 depending on sensitiveness of the blueprint paper and the in- 
 tensity of the sunlight) to the light and preferably to the direct 
 rays of the sun, after which the exposed blueprint paper is 
 taken out and washed in clean water. This method of printing 
 depends more or less upon weather conditions, and to overcome 
 all uncertainty and avoid delays, printing machines which print 
 by electric light are used by many manufacturers. 
 
 Changes and alterations on blue prints may be made by several 
 methods. A solution of common soda and water, or quicklime 
 and water, used as ink, will give a white line; but the best 
 method is to use a white pencil for making new lines, and a blue 
 pencil for striking out white lines. 
 
 SET OF MECHANICAL DRAWING EXERCISES. 
 
 79. Drawing C-ioi. A mechanical detail drawing to full-size 
 scale is to be made of the Lathe Spindle (see Fig. 77), the Key 
 
 Fig. 77- Perspective of Lathe Spindle. 
 
 (see Fig. 78), the Fiber and Steel Washers (see Fig. 79), and the 
 Special Nut (see Fig. 80). 
 
 The purpose of the exercises on this drawing is to give practice 
 in the use of the instruments required in making a simple me- 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 117 
 
 chanical drawing; to illustrate one method of arranging views, 
 one method of dimensioning and lettering, the use of the title- 
 form, the making up of a bill of material, and the use of the 
 drawing-room system to be followed throughout this course. 
 
 Fig. 78. Perspective 
 of Key. 
 
 Fig. 70. Perspective of Fibef 
 or Steel Washer. 
 
 Fig. 80. Perspective 
 of Special Nut. 
 
 Study carefully the "Introductory," page 71, 52, and " Detail 
 Drawings," page 85, 57, before attempting to draw. Also study 
 the location and learn the purpose of each part on the assembled 
 machine before drawing it. (See Frontispiece.) Fig. 82 shows 
 
 
 
 
 
 
 -^CUTTING EDGE OF PAPER -id BORDER LINE O F DRAWING 
 / ( 1 -/-I 
 
 
 O 
 
 
 k. 
 
 
 / 
 
 - 
 
 C 
 
 P 
 
 : 
 
 i 
 
 
 \ 
 
 { O" -s <- C"" 5 
 
 
 
 
 I 
 
 I 
 
 LI 
 
 
 M' 4 
 
 -< 
 
 O | V 
 
 T 
 
 T 
 
 jn 
 
 
 
 
 
 
 
 
 
 
 Fig. 81. Layout of Drawing C-ioi. 
 
 the complete detail drawings of these parts, drawn to a reduced 
 scale, and their location on the sheet is shown in Fig. 81. As 
 it is essential to be able to arrange the views of a drawing 
 symmetrically on the sheet, this is the only drawing in which 
 the arrangement of views is given. It is also the only one for 
 
u8 
 
 ELEMENTS OF DRAWING 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 119 
 
 which the bill of material and title has been made out. (See 
 Fig. 83.) These features should therefore be noted carefully. 
 
 Before starting on Drawing C-ioi read, and prepare for exam- 
 ination, subjects taken up in paragraphs as follows: 
 
 Introductory, page i, i, Drawing Paper, page 4, 3. 
 
 Drawing Boards, page 7, 8. Thumb Tacks, page 8, 9. 
 
 T-squares, page 8, 10. Triangles, page 10, 11. Pen- 
 cil Sharpener, page 14, 13. Lead Pencils, page 14, 14. 
 Erasers and Erasures, page 16, 15. Erasing Shield, page 17, 
 16. Bow Pencils, page 27, 25. Scales, page 29, 27. 
 Instrument Rag, page 33, 30. Introductory, page 34, 31. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 FBR: 
 
 
 
 s 
 
 WASHER 
 
 / 
 
 M.S. 
 
 
 
 4 
 
 WASHER 
 
 (? 
 
 M.S~ 
 
 
 
 3 
 
 SPECIAL. NUT 
 
 / 
 
 C.R.S. 
 
 
 
 
 
 KEY* 
 
 1 
 
 3. TUBE 
 
 
 
 1 
 
 SPINDLE 
 
 SPEED LATHE DETAILS 
 
 MACHINE: DESIGN 
 S/BLEr COLLEGE 
 
 JTHACA, NEW yORK 
 
 DRAWN BY* 
 
 INSRECrEO 
 
 DATE ARR'\/'C> 
 
 DRAWING-CIO/ 
 
 
 Fig. 83. Complete Title and Bill of Material for Drawing C-ioi. 
 
 Systematic Method in Lettering, page 44, 36. Designing 
 Headings and Titles, page 69, 49. Conventional Lines, page 
 76, 54. Border Lines, page 106, 72. To Fasten the Paper 
 or Tracing Cloth on the Drawing Board, page 107, 73. To 
 Make a Pencil Drawing, page 108, 74. Checking Drawings, 
 page 113, 76. 
 
 Before making this drawing also be prepared to answer ques- 
 tions relating to mechanical construction as follows: 1 For what 
 
 1 Questions of this nature should be asked with reference to each draw- 
 ing to be made in order that the beginner will realize from the start that 
 there is a relation existing between drawing, machine design and shop work. 
 
120 ELEMENTS OF DRAWING 
 
 reason is the spindle finished to so many different diameters? 
 What is the purpose of the hole through the spindle, also of the 
 Morse taper at the end ? Why is the spindle made of steel ? 
 Of what use is the Key, the Special Nut, and the Washers? 
 
 Specific Instructions, (a) Tack down the sheet (see page 107, 
 73). (b) Draw border line and title-form (see page 106, 72, 
 and page 100, 66), and the bill of material form, shown in Fig. 
 70, page 101. (c) With the rubber stamp print in the blank 
 form shown on page 106, Fig. 72, just above the lower border line 
 and to the left of the title-form, (d) Write in with ink your 
 NAME (and initials), and fill in the DATE BEGUN, etc. 
 (e) The center line of the spindle detail should then be drawn, 
 not in its finished form and weight, but as a very light contin- 
 uous line (see page 78, 54). Study 74, page 108, before actu- 
 ally starting the drawing. After the outline of the view is 
 completed, the center line can be made according to the conven- 
 tional method, broken where necessary to allow for dimensions, 
 and of the proper weight. Next, the outline of the spindle is 
 drawn, in very light lines, after which the details of the view, also 
 the section is drawn. The portion of any line extending beyond 
 its proper limit must now be erased. When completed, all lines 
 must be retraced and made the proper weight. (See page 76, 
 54.) Next draw in the reference lines, being careful to always 
 leave a space next to the surface from which the line is extended. 
 If this is not done, it appears that the lines have been drawn 
 carelessly and that they extend beyond their proper limit. Put 
 in all dimension lines and arrowheads and write in all dimen- 
 sion figures and notes, always making them read from the bot- 
 tom or right-hand side of the drawing. (/) The details of the 
 key and the washer are to be next drawn. Since all details 
 on this drawing are to be machine finished all over, the note 
 " / " ALL OVER is printed near the part number of each de- 
 tail, (g) Fill in the DATE FINISHED, TOTAL ACTUAL 
 HOURS (required to complete the work), and the TITLE of 
 the drawing. The Title of Drawing C-ioi is SPEED LATHE 
 DETAILS, (h) Check the drawing (see page 113, 76), to see 
 that all lines, dimensions, and notes are correct, that the bill of 
 material is correct, and that the part numbers (see page 104, 69) 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 121 
 
 have been put in. (i) Finally, have the drawing inspected, 
 checked, and approved. (See page 175, Appendix A.) 
 
 80. Tracing Drawing C-ioi. After the pencil drawing C-ioi 
 has been approved it is to be traced. 
 
 Before starting to trace this drawing read, and prepare for 
 examination, the subjects taken up in paragraphs as follows : 
 
 Tracing Cloth, page 6, 6. Erasers and Erasures, page 
 16, 15. Erasing Shield, page 17, 16. Soapstone, page 18, 
 17. Drawing Ink, page 18, 18. Ordinary Pens, page 18, 
 19. Penholders, page 20, 20. Ruling Pens, page 20, 
 21. Bow Pens, page 28, 26. To Fasten the Paper or 
 Tracing Cloth on the Drawing Board, page 107, 73. Inking 
 Drawings, page no, 75. Tracing, page 114, 77. Free- 
 hand Inked Lines, page 136, 96. 
 
 Specific Instructions. Tack down the drawing "square" on 
 the board and fasten the tracing cloth so that it lies smooth and 
 close to the drawing with the glazed side up. (See page 1 14, 77.) 
 
 Chalk the tracing cloth and clean thoroughly with a soft rag. 
 
 Ink the tracing according to the instruction given in 75, 
 page no. 
 
 Remember that inked lines are of three weights: those repre- 
 senting visible surfaces or outlines are drawn heavy; all construc- 
 tion lines, reference lines, center lines, dimension lines, section 
 lines, etc., are drawn light; and lines representing hidden sur- 
 faces or parts are drawn medium, that is, one half the weight 
 of visible lines and twice the weight of center lines and dimen- 
 sion lines. 
 
 After the tracing is inked, thoroughly examine the work to see 
 that nothing has been omitted, correct any errors, and when the 
 tracing has been checked, submit it for approval, then follow 
 instructions in 81 this page. 
 
 81. Blueprint of Tracing C-ioi. A blueprint is to be made 
 of Tracing C-ioi before it is submitted for final approval. 
 The purpose of making the blueprint at this time is to give 
 the beginner the benefit of this experience before making a 
 second tracing. Examine the print very carefully to see if all 
 
122 
 
 ELEMENTS OF DRAWING 
 
 lines are white and clear, and in case some are not, examine the 
 tracing to find the reason, and profit by this knowledge in mak- 
 ing succeeding tracings. All Blueprints must be trimmed and 
 filed with the drawings and tracings. 
 
 In connection with this exercise read, and prepare for exami- 
 nation on, paragraphs, as follows: 
 
 Tracing paper, page 6, 5. Blueprint Paper, page 6, 
 7. Drawing Ink, page 18, 18. Blueprints, page 116, 78. 
 
 Having made a satisfactory blueprint, submit same for final 
 approval. 
 
 Any tracing spoiled by moisture in the process of blueprinting 
 must be made over. 
 
 82. Drawing -102. A mechanical drawing 
 of the Lathe Leg (see Fig. 84) is to be made 
 one-quarter size. The purpose of this exer- 
 cise is to introduce the problem of joining 
 straight lines to curves, arranging views sym- 
 metrically on the sheet, making a drawing to 
 scale, listing patterns in the Bill of Material, 
 and indicating finished surfaces ; to illustrate 
 the use of cross sections and to provide 
 practice in drawing, lettering, and dimen- 
 sioning. Fig. 85 shows the views, etc. 
 
 Before starting on Drawing C-IO2 read, 
 and prepare for examination, the subjects 
 taken up in paragraphs as follows : 
 
 Soapstone, page 18, 17. Compasses, 
 page 23, 22. Dividers, page 26, 
 23. Bow Dividers, page 27, 24. 
 The Study of Lettering, page 34, 32. Projection and Pro- 
 jected Views, page 73, 53. Choice of Scale in Drawing, 
 page 93, 61. Title-form on a Drawing, page 100, 66. 
 Bill of Material, page 101, 67. Numbering and Indicating 
 the Size of Drawings, page 103, 68. Recording Patterns on a 
 Drawing, page 104, 70. 
 
 Before making this drawing also be prepared to answer ques- 
 tions as follows : 
 
 Fig. 84. Perspective of 
 Lathe Leg. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 123 
 
 Fig- 85. Details for Drawing C-IO2. 
 
124 ELEMENTS OF DRAWING 
 
 State the reason for finishing the surfaces as indicated. Ex- 
 plain exactly how the legs and bed are held together. What 
 is the purpose of the three " drilled holes on the lathe bed? 
 Explain the reason for selecting the cross section shown on the 
 drawing. 
 
 Specific Instructions, (a) Tack down sheet, (b) Draw bor- 
 der line and title-form, (c) Stamp printed form just above 
 lower border line and to left of title-form, (d) Write, with ink, 
 NAME (and initials), fill in DATE BEGUN, etc. (e) Arrange 
 views. See page 83, 56, on Number and Arrangement of 
 Views. (/) Proceed to make the drawing. See page 85, 57, 
 on Detail Drawing, (g) Fill in TITLE, BILL OF MATE- 
 RIAL, DATE FINISHED, and TOTAL ACTUAL HOURS. 
 The title of Drawing C-io2 is SPEED LATHE DETAILS. 
 (ti) Check drawing, and submit for final approval. (See page 
 175, Appendix A.) 
 
 Fig. 86. Perspective of Lathe Bed. 
 
 83. Drawing -103. A mechanical detail drawing (see 
 Fig. 88) is to be made of the Lathe Bed (see Fig. 86) and the 
 Bracket for the shelf (see Fig. 87), also the 
 Standard Parts belonging to the above 
 parts are to be listed in the Bill of Material. 
 Following is a complete list of parts which 
 are to be called for in the Bill of Material: 
 Part #i Bed. 
 Part #2 y X 4" Square-head Cap 
 
 Screw. 
 
 Part #3 y X i" Square-head Cap Screw. 
 Part #4 Bracket for shelf. 
 Fig. 87. -Perspective of p ar t #5 _" x i|" Square-head Cap Screw. 
 
 Shelf Bracket. ''> . 
 
 Before starting this exercise read and pre- 
 pare for examination on paragraphs as follows: 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 125 
 
 FIT 
 
 - 
 
 
 
 T~~7~) 
 
 
 
 tf >3 
 
 i 
 
 ~~ 
 
 
 if 
 
 
 - 
 
 T; 
 
 
 
 
 
 - 
 
 tfr ) 
 
 I 
 
 fc 
 
 ^ 
 
 I- 
 i 
 
 
 
 
 
 
 
 > 
 N 
 
 * 
 > 
 
 2 
 
 i 
 J 
 
 j 
 
 -T 
 
 
 
 
 
126 ELEMENTS OF DRAWING 
 
 Introductory, page 71, 52. Conventional Lines, page 76, 
 54. Sectioning and Sectional Views, page 79, 55. Num- 
 ber and Arrangement of Views, page 83, 56. Detail Draw- 
 ings, page 85, 57. Indicating the Finish of Surfaces, page 
 98, 64. Part Numbers on a Drawing, page 104, 69. 
 
 Determine the number of each of these parts required, assign 
 pattern numbers as necessary, etc. 
 
 The drawing is to be made to a scale of 4" = i ft., and the 
 title of the drawing will be SPEED LATHE DETAILS. No 
 drawing is made of the standard parts (see page 103, 67), but 
 their reference numbers must be properly shown on the drawing 
 from which a " leader " must be run to the exact place that the 
 standard part is used on the part detailed. 
 
 Follow specific instructions given for preceding drawings, in so 
 far as they apply to this drawing. 
 
 84. Drawing 0-104. This drawing represents Bolts, Nuts 
 and Screws, and is intended to introduce the method of propor- 
 tioning parts by empirical formulas, i.e., formulas which have not 
 been " derived" by purely theoretical consideration; also it is 
 intended to teach the relative proportions (or dimensions) of 
 U. S. (United States) Standard Bolts and Nuts. 
 
 This drawing is further intended to teach the relative pro- 
 portions of the ordinary forms of screw heads in common use, 
 the conventional method of representing screw threads and the 
 method of calling for all such parts in a Bill of Material. 
 
 Before taking up this exercise read and be prepared for exam- 
 ination on paragraphs as follows: 
 
 Slope of Letters, page 36, 33. Conventional Methods, 
 page 87, 59. 
 
 It is coming to be more and more the common practice in the 
 United States to use the U. S. form of thread, whether the piece 
 threaded be a bolt, nut, screw or rod. 
 
 In the case of screws the manufacturers of the United States 
 are gradually adopting the A. S. M. E. (American Society of 
 Mechanical Engineers) standard. 
 
 Ordinarily none of these " standard " parts need be drawn 
 out, but the exercises on this drawing will be very valuable to 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 127 
 
 the beginner because they will associate in the mind the form and 
 proportion, the number of threads per inch and the method of 
 calling for such parts in the Bill of Material. 
 
 Specific Instructions. Ideas as to this drawing can be gained 
 by reference to Fig. 89, page 1 28. Having drawn the border line 
 and the title-form, lay out and fill in the Bill of Material, the 
 items being given below. The items in the Bill of Material 
 can be abbreviated, but, owing to the limited space, it is even 
 then necessary to compress the lettering which should be 
 blocked out in very light lines before being printed in final 
 form. Care must be taken, however, to correctly space letters 
 and words. 
 
 The following items are to appear in the Bill of Material : 
 
 Part .#i 
 Part #2 
 Part #3 
 Part #4 
 Part #5 
 Part #6 
 Part #7 
 Part #8 
 
 y X 6" Square-head Bolt, Nut, Check Nut. 
 y X 6" Hexagon-head Bolt, Nut, Check Nut. 
 f" X 2y Hexagon-head Cap Screw, 
 f" X 2" Fillister-head Cap Screw, 
 f " X 2" Round-head Cap Screw. 
 y X 1 1" Flat-head Cap Screw. 
 y X ij" Set Screw. 
 
 f" X i" Headless Set Screw. 
 
 The following Table of Threads is to be placed exactly above, 
 and |" from the Bill of Material. 
 
 Diam. of Bolt. . 
 
 i" 
 
 4 
 
 &' 
 
 r 
 
 16 
 
 &" 
 
 r 
 13 
 
 A' 
 
 12 
 
 5." 
 
 I" 
 IO 
 
 f* 
 
 9 
 
 I* 
 
 it* 
 
 7 
 
 i** 
 
 if 
 
 2" 
 
 2|" 
 
 3* 
 
 Threads per inch 
 
 20 
 
 18 
 
 14 
 
 II 
 
 8 
 
 6 
 
 5 
 
 ti 
 
 4 
 
 3^ 
 
 The title of this drawing is BOLTS, NUTS, AND SCREWS. 
 
 The next step is to make substitutions in the formulas and 
 work out the dimensions of the bolts, nuts, and screws. These 
 computations must be neatly inked on standard computation 
 paper, and the sheets attached with paper fasteners to the 
 drawing when it is handed in. 
 
 As an illustration of how the computations are to be arranged, 
 Item No. 7 is worked out as follows: 
 
128 
 
 ELEMENTS OF DRAWING 
 
 CAP SCREW HEAD 
 
 FILLISTER HEAD 
 
 E=A; C=2A 
 
 DISTANCE ACROSS FLAT=B 
 WHEN A <" 
 
 '' WHEN A > 4r 
 
 J 
 
 f.-.i 
 
 E-A; C=2. 
 
 SET SCRHW 
 
 ; D-2A 
 
 H-f 
 
 T=D 
 
 ROUND HEAD 
 
 C-jA;D=lJA 
 
 FINISH FOR ENDS OF 
 
 BOLTS, CAP SCREWS 
 
 AND STUDS 
 
 FINISH FOR ENDS OF 
 MACHINE SCREWS 
 
 Fig. 89. "Standard" Proportions of Ordinary Nuts, Screw Heads, etc. 
 
MECHANICAL DRAWING AND DRAFTING ROOM PRACTICE 129 
 
 Item No. 7: 
 
 y X iy Set Screw. 
 
 E = A = y. 
 
 c = 2 A = 2 x y = i*. 
 
 7~) 3. A 3. v i" -3 " 
 LJ s -n- 8 /\ 2 ~ 1'B" 
 
 The computations for each item must be kept as shown, and 
 as many items should be placed on a sheet as possible without 
 crowding. 
 
 Having computed the dimensions of all the parts to appear 
 on Drawing 0-104, block out the space to the best advantage, 
 and complete the drawing, keeping in mind the following facts: 
 
 Conventionally drawn threads begin and end with a short line. 
 (See page 72, Fig. 49.) 
 
 Bolts are threaded any desired length, and the check nut is 
 usually screwed on the bolt first, then the ordinary nut. 
 
 Cap screws up to and including i" diameter by 4" long are 
 threaded for three-quarters of their length and those above i" in 
 diameter are threaded one-half their length. 
 
 85. Tracing Drawing -102. After submitting drawing 0-104 
 and making a blueprint of tracing C-ioi, trace the finally 
 approved pencil drawing C-io2. Follow specific instructions 
 previously given in so far as they apply to this exercise. 
 
 86. Tracing Drawing -103. After submitting tracing C-IO2, 
 trace the approved pencil drawing 0-103. Follow specific instruc- 
 tions previously given in so far as they apply to this exercise. 
 
 87. Drawing -105. Make a mechanical drawing from 
 sketches of the following parts: 
 
 Tail Stock Center, see Fig. 101, page 144, also sketch #3, page 
 145. Shell,* see Fig. 103, page 144, also sketch #4, page 146. 
 Tail Stock Spindle,* see Fig. 102, page 144, also sketch #4, 
 page 146. Tail Stock Spindle Clamp,* see Fig. 113, page 150,. 
 
 Before starting this drawing read, and prepare for examina- 
 tion on, paragraphs, as follows: 
 
 * Dimensions for these parts are to be obtained by making direct measure- 
 ments of the objects themselves. See page 32, 29, and page 94, 62. 
 
130 ELEMENTS OF DRAWING 
 
 Conventional Methods, page 87, 59. Drawing to Scale, 
 page 90, 60. Dimensioning Working Drawings, page 94, 
 62. Notes on a Drawing, page 97, 63. Indicating the 
 Finish of Surfaces, page 98, 64. Use of Record Forms and 
 Titles, page 98, 65. 
 
 Follow specific instructions previously given in so far as they 
 apply to this exercise. . Give special attention to arranging the 
 views and filling in the Bill of Material. 
 
 88. Drawing C-io6. Make a full-size longitudinal section of 
 the Tail Stock with all its parts assembled. See Frontispiece. 
 
 Before starting this drawing read, and prepare for examination 
 on, paragraphs, as follows: 
 
 Sectioning and Sectional Views, page 79, 55. Assembly 
 Drawings, page 86, 58. Dimensioning Working Drawings, 
 page 94, 62. Time Keeping in Drawing, page 105, 71. 
 
 Specific Instructions. To get all the necessary information 
 for making this drawing refer to the approved Drawing C-ic>5, 
 also figures and sketches, as follows: 
 
 Tail Stock Main Casting, Fig. 117, page 152, also sketch #9, 
 page 153. Tail Stock Screw, Fig. 114, page 150, also sketch #8, 
 page 151. Tail Stock Hand Wheel, Fig. 107, page 147, also 
 sketch #5, page 148. Tail Stock Special Nut, Fig. 115, page 
 150, also sketch #8, page 151. Ordinary Nut, Fig. 89, page 128. 
 
 The title of this drawing is ASSEMBLED TAIL STOCK. 
 
 Go over the drawing carefully before submitting same, to 
 see that all lines, dimensions, etc., are up to the required 
 standard. 
 
 89. Tracing Drawing C-io6. Follow specific instructions 
 previously given in so far as they apply to this exercise. 
 
 90. Examination on Chapter III. As a final examination any 
 drawings assigned are to be made of Lathe Parts or of any other 
 machine, and examination questions concerning previous work 
 (including Drawing C-I05) will be asked. As a general review, 
 in preparation for examination, carefully read paragraphs on 
 pages 71 to 116 inclusive; also 12, page 13, and 28, page 31. 
 
CHAPTER IV 
 
 FREE-HAND WORKING SKETCHES 
 
 91. Introductory. The ability to make a good free-hand work- 
 ing sketch is an accomplishment of great value to the engineer. 
 Much less time is required to make a free-hand sketch than a 
 mechanical drawing, and in developing a design it frequently 
 occurs that there are several solutions to the problem, and 
 that the best may be as easily determined from a sketch as from 
 a more elaborate mechanical drawing. If definite movements 
 must be provided for, the vital positions of the related parts 
 may be shown in skeleton outlines drawn to scale with instru- 
 ments and each important element or part needed to be drawn 
 can be sketched in free-hand. 
 
 In commercial drafting rooms preliminary sketches of new 
 ideas are often filed away to be worked up later into detail 
 mechanical drawings. Such sketches serve as a visible record of 
 the idea and may prove valuable in establishing a priority claim 
 for a patent. 
 
 Another common use of technical sketches is found in detail- 
 ing parts that must be renewed and for which no drawings exist. 
 Also in making additions or alterations, drawings of a machine 
 may not be available and yet, in order that the new parts fit 
 into position and act without interference, a drawing may be 
 necessary. Whenever data must be obtained from machines in 
 existence, a record of all measurements is usually made on a 
 free-hand sketch, and the ability to make a clear sketch, accu- 
 rately dimensioned, complete in all respects, and free from mis- 
 takes and oversights so that additional trips to the machine for 
 further information are not necessary, is of great value to the 
 draftsman or engineer. 
 
 92. Free-hand Copies of Working Drawings. To beginners 
 the value of making free-hand sketches from mechanical draw- 
 ings is to train the hand to make good free-hand lines, and the 
 
132 ELEMENTS OF DRAWING 
 
 eye to judge proportion, so that the ability to scheme work and 
 to plan details without using the drawing instruments will be 
 acquired. 
 
 93. Free-hand Sketches from Objects. It must be understood 
 that working sketches as discussed here are not perspective 
 representations of the object, but economical substitutes (both 
 as to time and cost saved) for mechanical drawings. If the 
 sketch is proportioned accurately (say on cross-section paper) 
 in accordance with measurements of the object, it is in reality 
 a working drawing, differing from a mechanical drawing only in 
 that it is made free-hand. 
 
 In making sketches from the object the beginner often con- 
 siders the dimension figures the only important feature of the 
 work, and makes the drawing so crude that other persons can- 
 not work from it. Such a sketch is of very little value. If a 
 sketch is to be a permanent record it must be so clear and 
 complete that any one will be able to work from it, and this can- 
 not be done unless the actual drawing is well executed. On 
 the other hand if the sketches accurately represent the object 
 it may not be necessary to have all the dimensions recorded 
 exactly as they measure on the object. For example, rough 
 castings and forgings will vary in thickness, and a part in- 
 tended to be symmetrical about a center line will often deviate 
 without apparent reason. The beginner must learn to make a 
 distinction between dimensions as some measurements must be 
 recorded more exactly than others. For example, if a pipe 
 flange measured 15!" in diameter, a 15" flange could be re- 
 corded, but if the standard bolt circle of a pipe flange should 
 be i3i," it must be so recorded, or the flange will not match 
 others drilled according to the standard. The degree of refine- 
 ment exercised in recording measurements between unfinished 
 ends of a casting or between one finished and one rough end 
 will depend on the size of the casting. In very small castings, 
 such as the small parts of the lathe, dimensions can be fre- 
 quently " rounded off " to, say, the nearest J", but measure- 
 ments made between surfaces of parts which fit to other parts 
 of a machine must be made with extreme accuracy. Center lines 
 
FREE-HAND WORKING SKETCHES 
 
 133 
 
 and lines of symmetry must also be carefully located, and 
 wherever possible measurements should be made from such 
 lines or from finished surfaces. 
 
 A sketch made without direct measurements of the object 
 has no definite scale but is proportioned by the eye. In such 
 cases the proper relation of distances, i.e., lengths of lines, is 
 secured by making comparisons. The relative width of a part 
 is compared to its length, and if a detail on the machine is one- 
 fourth as long as the over-all dimension, it should be drawn one- 
 fourth as long as the over-all on the drawing. To assist in 
 making an eye estimate of a distance, hold the pencil between 
 the eye and the object and so that the thumb nail can be moved 
 along its length (see Fig. 90) ; sight along one end of the pencil 
 
 Fig. 90. Estimating Proportion by Means of the Eye and a Pencil. 
 
 and bring it in line with the end of the part being measured; 
 move the thumb along the pencil until it sights the opposite end. 
 This length along the pencil is then compared with the length of 
 the over-all dimension similarly measured. In the figure the 
 two diverging lines represent the limits of the angle of sight. 
 The left eye usually is closed when estimating. The special 
 precautions necessary in this method are that the pencil shall 
 always be held the same way and the same distance from the eye, 
 and the lengths, being compared on the object, shall be approxi- 
 mately the same distance from the eye. The pencil should be 
 held at arm's length in making measurements, as this insures the 
 
134 ELEMENTS OF DRAWING 
 
 distance being kept constant. In this method of estimating pro- 
 portionate lengths no one estimated length should be greater than 
 a convenient length on the pencil, but the distance from the eye 
 to the object being sketched should be such that the estimating 
 can be on the largest scale possible. The sketch can be made 
 to any desired scale, provided the proportions of the sketch are kept 
 the same as estimated with the pencil. This method of mak- 
 ing a sketch of an object is equivalent to tracing each line of the 
 object on a pane of glass which is held at arm's length and in 
 a plane at right angles to an imaginary line drawn from the eye 
 to the " center " of the object. 
 
 94. Making Sketches from Memory. The beginner should 
 occasionally make sketches from memory. For this purpose 
 select some simple object, or mechanical drawing, and after 
 making a careful study of the object or drawing, make free- 
 hand sketches comprising all necessary views and accurately 
 dimension them from memory. 
 
 95. The Free-hand Pencil Line. The first essential in^ making 
 free-hand sketches is to learn to draw a finished free-hand line. 
 This requires, first, that the direction of the line and, second, that 
 the quality of the line be correct. That is, the lines must 
 have the proper direction and relation to one another to cor- 
 rectly represent the outline of the object, and they must also 
 be perfectly smooth and clear-cut, see page 78, 54, so as to 
 present a satisfactory appearance. 
 
 A good method of drawing a free-hand straight line is as 
 follows : 
 
 (1) Sketch in very lightly a series of short dashes to follow as 
 closely as possible the exact direction required of the line. See 
 Fig. 91 (a). 
 
 (2) Correct the main portions which are out of true, locating these 
 by sighting along the line and marking inaccuracies. See Fig. 91 (b) . 
 
 (3) Retrace the line, which is now true in direction but "sketchy" 
 in quality, making it uniform and of medium weight. See 
 Fig. 91 (c). 
 
 (4) Erase all preliminary work, and, as the true line is made 
 
FREE-HAND WORKING SKETCHES 
 
 135 
 
 dim in the process, retrace it with the longest strokes possible, leav- 
 ing it true in direction and finished in quality. See Fig. Qi(d). 
 
 (a) First Attempt to Get Correct Direction. 
 
 Use a HHHH pencil 
 
 with conical point (see 
 
 page 15, 14), and as the A =*= *- ' B 
 
 first attempt will Seldom ( b ) Corrections Made at Points of Inaccurate Direction. 
 
 result in a line true in A -^^ -^- - -~=\~ B 
 
 (c) Line Perfected in Direction but not Quality. 
 
 A ' B 
 
 either direction or qual- 
 ity, all preliminary work 
 must be done with very 
 light lines. The pencil 
 should be moved toward the right [see Fig. 9 2 (a)] when drawing 
 lines which are horizontal or nearly so, and toward the body or 
 
 (d) Line Perfected in Both Direction and Quality. 
 Fig. 91. Drawing a Free-hand Line. 
 
 (a) Drawing a Horizontal Free-hand Line. 
 
 (b) Drawing a Vertical Free-hand Line. 
 Fig. 92. Method of Holding the Pencil to Draw a Free-hand Line. 
 
 downward [see Fig. 92 (b)] when drawing lines which are vertical 
 or nearly so. In drawing free-hand lines it is very important 
 
136 ELEMENTS OF DRAWING 
 
 that the pencil be held " freely " and not with a strained grip 
 and the relation of the pencil, the fingers and the paper is 
 shown in Fig. 92. Motion to the pencil or pen should not be 
 given by movement of the fingers but by an easy movement of 
 the hand and forearm. When a finished line, straight or curved, 
 is drawn with more than one stroke of the pencil, considerable 
 care must be exercised in joining the segments, so that the line 
 will be continuous and appear to have been drawn at a single 
 stroke. A curved line is drawn by locating a series of points to 
 mark its direction, and then proceeding as with the straight line. 
 Do not erase the first lines drawn but only that portion which does 
 not follow the direction desired. This leaves portions of the line 
 to act as a guide and the final line is brought to its proper direc- 
 tion and traced in somewhat heavier than the preliminary lines. 
 When a line has been drawn exact in direction, all preliminary 
 work, and as much of the true line as is necessary to destroy the 
 appearance of the short sketchy strokes, is erased (using a clean 
 eraser and when necessary an eraser shield), and "the line is finally 
 retraced and made of satisfactory quality. 
 
 96. Free-hand Inked Lines. The beginner should not ink 
 any work unless the original pencil work has been checked and 
 approved. 
 
 To draw an inked free-hand line, fill the pen with an average 
 amount of ink, and, holding the point at the beginning of the line, 
 slightly press the pen until the ink begins to flow (which is indi- 
 cated by a dot of ink on the drawing), then with an even pressure 
 continue from that point, making the line uniform in width from 
 start to finish. 
 
 The width of the free-hand inked line will depend on the 
 following conditions: 
 
 (1) Fineness of the pen point. 
 
 (2) Pressure exerted on the pen. 
 
 (3) Condition of the pen point as regards cleaniness, i. e., 
 whether there is dried or partially dried ink on the point. 
 
 (4) Amount of ink carried on the pen. 
 
 (5) Speed at which the pen is moved when drawing the line. 
 
FREE-HAND WORKING SKETCHES 137 
 
 In general, free-hand inked lines should be formed with strokes 
 toward the draftsman, or in a right-hand direction. (See Fig. 92, 
 page 135.) Upward strokes of the pen should be avoided as much 
 as possible, as the pen point is liable to catch in the drawing 
 and splash the ink; also this is not the most natural way to 
 make free-hand lines. 
 
 Care must be exercised in joining two segments of a line when 
 inking, otherwise the point at which they are joined is easily 
 detected and the completed line will not present a finished 
 appearance. 
 
 To get the best results there should be a steady and uniform 
 flow of ink from the pen, and this is best secured by frequently 
 cleaning and refilling the pen. 
 
 Too much ink on the pen will make a blot or a line of greater 
 width than desired, while too little ink dries upon the points 
 and obstructs the free flow of the ink from above. Frequent 
 filling of the pen tends to maintain an average quantity of ink 
 and overcomes both of these difficulties. If too much ink has 
 been gathered on the pen point touch the pen to the neck of 
 the bottle to permit the surplus ink to flow back into the bottle. 
 
 Always clean the pen point thoroughly before putting it away. 
 
 97. Building up a Sketch. To start a sketch, study the 
 part to be represented and determine the view which shows the 
 most essential features and from which related views can be best 
 obtained. The relation of views and the principles underlying 
 machine sketching are exactly the same as for mechanical drawings. 
 (See page 73, 53.) 
 
 Having determined the views (and sections, if any are neces- 
 sary) and the size of the views, draw in the main center lines in 
 such a position that when the views are completed they will 
 be arranged symmetrically on the sheet and present a neat 
 appearance. 
 
 In beginning each view, draw several of the most important 
 limiting lines first, and then fill in the detail parts. 
 
 In general it is best to work from the center of a view, i.e., 
 from the center lines, or from the central parts outward. 
 
 Always complete the views satisfactorily before putting in 
 reference lines, dimension lines, and arrowheads. 
 
138 ELEMENTS OF DRAWING 
 
 The outline of one view should be completed as far as possible 
 before starting another. In working up views it is often con- 
 venient to use a strip of paper to transfer the principal dimen- 
 sions from one view to another. When a circle or circular arc 
 is to be drawn, several points should be marked off equally distant 
 from the center and the curve drawn through them. 
 
 In some cases it may be found best to draw in the principal 
 dimensions of the object to scale and finish up the detail parts 
 of a view free-hand; but sketching as a rule is not done to scale, 
 although the proportions are made approximately correct. 
 
 Draw in all the dimension lines and arrowheads, but do not 
 put in dimension figures until the last. 
 
 Draw all lines very lightly at first, and, after inaccuracies have 
 been corrected, retrace the sketch and make the lines of medium 
 weight. 
 
 When the correct outlines of all views have been drawn of 
 medium weight, the entire sheet is to be cleaned with the sponge 
 rubber or art gum (see page 16, 15), and such other erasing done 
 with the pencil eraser as is necessary. Then all the dimmed lines 
 of the views should be retraced and made of the desired weight. 
 
 98. Title-form on Small Sheets. Where the drawing sheet is 
 small a small title-form is preferable, and this title-form is usu- 
 ally located in the lower right-hand corner. 
 
 TITLE 
 
 MACHINE DES/GN-S/BLEY COLLEGE- ITHACA, NX 
 
 NAME- _ SECT/ON^. -DESK N& 
 
 BEGUN, FINISHED TOTAL MRS.-. 
 
 INSPECTED ARRVO. \SHEE71. 
 
 Fig. 93. Title-form to be used in this work on small sheets. 
 
 There is no accepted standard title-form, but the one shown 
 in Fig. 93 represents a general average and will be used in this 
 work on all drawing sheets of the 8" X io|" size. 
 
FREE-HAND WORKING SKETCHES 139 
 
 All lettering in title-form, unless otherwise specified, is to be 
 of the slant Gothic style and is to be carefully arranged and 
 properly proportioned. 
 
 99. Size and Numbering of Sketch Sheets. Exercises in 
 sketching will be done on small sheets of standard letter size 
 (8" X iof")> heavy weight, cross-section paper ruled on one side 
 (see page 5, 4) and punched for standard #10 Manila cover. 
 
 The order in which free-hand sketch sheets are executed will 
 be indicated by Arabic numbers beginning with No. i and con- 
 tinuing as far as necessary, and the title-form is to be as shown 
 in Fig. 93, page 138. 
 
 SET OF FREE-HAND DRAWING EXERCISES 
 
 100. Sheet tfi. The sketches on this sheet consist of 
 a Shim (see Fig. 94) for the bearings, a Small Stud (see 
 Fig. 95) and a Clamp Stud (see 
 Fig. 96) for the tail stock of the 
 Lathe. Fig. 97, page 140, shows 
 the general layout of this sheet. 
 
 The exercises on this sheet give Fig ' 94. -Perspective of shim, 
 practice in making sketches of objects requiring only 
 one view, and in drawing free-hand lines and arrow- 
 heads. Note especially how the diameters of 
 bolts are shown. This method applies to such 
 parts as bolts, screws, etc., but the diameters of 
 circular parts in general should be given on the 
 view showing the circle. 
 
 Before beginning this sheet determine, either 
 from referring to the actual machine or else to 
 the frontispiece, exactly where each piece is 
 located, and its purpose on the finished ma- 
 7^6. chine, also what other parts it must fit into or against. 
 Perspec- p or f u j]_ information as to the general system to be 
 
 tive of J 
 
 clamp followed see page 175, Appendix A. 
 
 Study, and prepare for examination on, paragraphs, as 
 follows : 
 
 Thumb Tacks, page 8, 9. Pencil Pointer, page 14, 13. 
 
140 
 
 ELEMENTS OF DRAWING 
 
 I i 
 
 -1 
 
 I I 
 
 i 
 
 
 
 i i 
 i i 
 
 ! ! 
 
 -IIHI 
 
FREE-HAND WORKING SKETCHES 141 
 
 Lead Pencils, page 14, 14. Erasers and Erasures, page 16, 
 15. Conventional Lines, page 76, 54. Checking Drawings, 
 page 113, 76. Introductory, page 131, 91. The Free-hand 
 Pencil Line, page 134, 95. Title-form for Sheets, page 138, 
 98. Size and Numbering of Sketch Sheet, page 139, 99. 
 
 Specific Instructions, (a) Fasten the sheet on the small draw- 
 ing board. (See page 2, 2.) (b) Stamp in and fill out Title- 
 form. (See page 138, 98.) The title of this sketch is LATHE 
 DETAILS, (c) Copy the sketches, being careful to see that 
 the work is correct in every particular. 
 
 Use a HHHH pencil and draw the sketches free-hand on cross- 
 section paper. Group the figures centrally on the sheet in about 
 the relative position and proportion shown in Fig. 97, page 140. 
 
 In making the sketch of the Stud, the center line is drawn first 
 and the sketch built symmetrically about it. All center lines, ref- 
 erence lines, dimension lines, and arrowheads are to be drawn in. 
 
 Do not make any measurements with scale or dividers, but 
 proportion the sketches by eye. (See page 133, 93.) (d) Thor- 
 oughly examine the work to see that nothing has been omitted; 
 correct any errors, and after inspection write, with ink, the Date 
 Finished and Total Actual Hours, and submit the sheet for 
 checking and approval. 
 
 101. Sheet #2. The sketch on this sheet (see Fig. 99, page 143) 
 consists of three views of the main casting of the Headstock (see 
 Fig. 98, page 142) of the Lathe. All dimension figures on Fig. 99 
 represent the number of spaces between arrowheads and not the 
 number of inches. 
 
 The purpose of this exercise is to illustrate the use of cross- 
 section paper; to provide practice in making free-hand curved 
 lines, and in making a sketch of an object which requires several 
 views. 
 
 The relation of the different views of this sketch to one another 
 must be carefully studied, and the sketch not merely copied. 
 
 Before starting this work read, and be prepared for examina- 
 tion on, paragraphs, as follows: 
 
 Cross-section Paper, page 5, 4. Erasing Shield, page 17, 
 16. Projection and Projected Views, page 73, 53. Num- 
 
142 ELEMENTS OF DRAWING 
 
 ber and Arrangement of Views, page 83, 56. Dimension- 
 ing Working Drawings, page 94, 62. Indicating the Finish 
 of Surfaces, page 98, 64. Free-hand Copies of Working 
 Drawings, page 131, 92. 
 
 Fig. 98. Perspective of Main Casting of Headstock. 
 
 Determine the location and purpose of the Headstock. See 
 Frontispiece. 
 
 Specific Instructions, (a) Fasten the sheet on the small draw- 
 ing board. (See page 2, 2.) (b) Stamp in and fill out title- 
 form. (See page 138, 98.) The title of this sketch is LATHE 
 DETAILS, (c) Having located main center lines, refer to the 
 " space dimensions " given in Fig. 99 and accurately locate a 
 sufficient number of points to determine the outline of the side 
 view (a), which is then sketched in very lightly. The end views 
 are next drawn. 
 
 After all views have been completed in a satisfactory manner, 
 clean the sheet and retrace all lines, making them clear-cut and 
 of the desired weight. 
 
 Having gone over the work and brought it to the highest 
 standard possible, submit the sheet for approval. 
 
 102. Sheet #3. The sketches on this sheet represent a Face 
 Plate (see Fig. 100, page 144), a Tail Stock Center (see Fig. 101, 
 
144 
 
 ELEMENTS OF DRAWING 
 
 page 144), and a Special Nut (see Fig. 80, page 117) for head- 
 stock spindle. Fig. 104 shows the general layout of this sheet. 
 The purpose of the exercises on this 
 sheet is to provide practice in free-hand 
 sketching and in making a working draw- 
 ing which will have all dimensions, notes, 
 and other data necessary for the construc- 
 tion of the parts in the shop. Before 
 starting this sheet study the system of 
 dimensioning, noting especially how circles, 
 arcs, angles, and tapers are dimensioned, 
 and how related dimen- 
 sions are kept together. 
 
 Study and prepare Fig. 101. Perspective of 
 for examination on paragraphs as follows: 
 
 Detail Drawings, page 85, >;7. Conventional Methods, 
 page 87, 59. Indicating the Finish of Surfaces, page 98, 
 64. Use of Record Forms and Titles, page 98, 65. Making 
 Sketches from Memory, page 134, 94. 
 
 What is meant by " counterbore " and " countersink." How 
 do you determine the number of threads per inch on a given 
 diameter ? 
 
 Follow the specific instructions previously given in so far as they 
 
 apply to this sheet. 
 
 Fig. 100. Perspective of 
 Face Plate. 
 
 103. Sheet #4. 
 
 Fig. ^.-Perspective of Tailstock Spindle. ^ ^^ Qn ^ 
 
 sheet are sketches of the Tail Stock Spindle (see Fig. 102) and 
 Shell (see Fig. 103). 
 
 These exercises illustrate the method 
 of representing simple symmetrical parts 
 in the clearest way possible with the 
 minimum amount of drawing. Fig. 
 105 gives the general layout of this 
 
 J Fig. 103. Perspective of Shell. 
 
 sheet. 
 
 Before starting this work read, and be prepared for examina- 
 tion on, paragraphs, as follows: 
 
FREE-HAND WORKING SKETCHES 
 
 145 
 
146 
 
 ELEMENTS OF DRAWING 
 
FREE-HAND WORKING SKETCHES 
 
 147 
 
 Sectioning and Sectional Views, page 79, 55. Notes 
 on a Drawing, page 97, 63. The Title form on a 
 Drawing, page 100, 66. 
 
 104. Sheet #5. The exercises on this sheet consist of 
 
 sketches of the Clamp Bolt (see Fig. 106) the Hand 
 
 Wheel (see Fig. 107) and the End Cap (see Fig. 108). 
 
 Fig. 109, page 148, gives the general layout of sheet. 
 
 The system of dimensioning is the main point to be 
 
 noted in sketching these 
 parts. Dimensions which 
 are related are kept to- 
 gether, as, for example, the 
 partial dimensions making 
 up the length of the Clamp 
 Bolt. These are given on 
 
 Fig. 1 06. 
 
 the same side of the view Perspective 
 and not scattered. With of ^ t mp 
 partial dimensions, an over- 
 all dimension is given, which of 
 course must be the sum of the 
 partial dimensions. 
 Note also the method of dimensioning curves; the different 
 views in which the different diameters are shown on the draw- 
 ing; the method of " turning up " the section 
 in the arm of the hand wheel, and that in the 
 section of the hand wheel the arms are not 
 sectioned, although the cutting plane passes 
 through them. 
 
 Fig. 107. Perspective of Hand Wheel. 
 
 Fig. 1 08. Perspective 
 of End Cap. 
 
 105. Sheet #6. The exercises on this sheet 
 consist of three undimensioned views of the 
 Clamp (see Fig. in, page 150). Fig. no, 
 page 149, gives the general layout of this sheet which is to be 
 copied and then the dimensions filled in from measurements 
 taken on the Clamp that the drawing illustrates. 
 
 Before drawing this sheet read, and be prepared for examina- 
 tion on, paragraphs, as follows: 
 
148 
 
 ELEMENTS OF DRAWING 
 
FREE-HAND WORKING SKETCHES 
 
 149 
 
ELEMENTS OF DRAWING 
 
 Machinist's Calipers, Dividers and Steel Rule, page 32, 29. 
 Choice of Scale in Drawing, page 93, 61. Dimensioning 
 
 Working Drawings, page 94, 62. 
 Notes on a Drawing, page 97, 
 63. To make a Pencil Draw- 
 ing, page 1 08, 74. Free-hand 
 Sketches from Objects, page 132, 
 
 93- 
 
 1 06. Sheet #7. Make sketches 
 of the Tool Rest Support Slide 
 (see Fig. 112) and of Clamp for 
 113). This sheet is to be made 
 
 Fig. in. Perspective of Tailstock 
 Clamp Strip. 
 
 Tailstock Spindle (see Fig. 
 directly from these parts. 
 
 Before starting the 
 work read, and be 
 prepared for exam- 
 ination on, para- 
 graphs, as follows: 
 
 Projection and pig. 112. Perspective of Tool Rest Support Slide. 
 
 Projected Views, 
 
 page 73, 53. Drawing to Scale, page 90, 60. Notes 
 
 on a Drawing, page 97, 63. Building up a Sketch, page 137, 
 
 97- 
 
 Determine the purpose and 
 location of the above parts on 
 the lathe. 
 
 107. Sheet $8. Make 
 sketches of the Tailstock 
 Screw (see Fig. 114) and 
 the Nut (see Fig. 115) following the general layout shown 
 in Fig. 116, page 151. Determine the location and purpose 
 of each of these parts on the lathe and be prepared for 
 
 Fig. 114. Perspective of Tailstock Screw. 
 
 Fig. 113. Perspective of Tailstock 
 Spindle Clamp. 
 
 Fig. 115. Perspective 
 of Tailstock Nut. 
 
FREE-HAND WORKING SKETCHES 
 
 * 
 
152 
 
 ELEMENTS OF DRAWING 
 
 examination on paragraph 59, page 87, with reference to 
 Conventional Methods. 
 
 Copy sketch and fill in dimension figures from measurements 
 made on the objects which are illustrated. 
 
 This sheet illustrates the method of showing and dimensioning 
 key ways and the Acme National Thread (see page 88, section D, 
 drawing c). Notice that the direction of the thread shown on 
 the section of the nut is reversed from that on the screw and 
 be able to explain the 
 reason for this. 
 
 1 08. Sheet $9. Make a 
 working sketch, showing 
 three views of the main 
 casting of the Tailstock 
 (see Fig. 117). 
 
 Keep that portion of 
 the surface of the draw- 
 ing not in use covered 
 with a clean piece of paper 
 and avoid smearing the 
 drawing. Fig. 119, page 
 153, shows the general lay- 
 out for this sheet. 
 
 Fig. 117. Perspective of Main Casting of Tailstock. 
 
 109. Sheet #10. Make working sketches 
 directly from the Bearing Cap (see Fig. 118) and 
 The Stationary Flange (see Fig. 120, page 154). 
 
 no. Sheet #11. Make working sketches of 
 the Cone Pulley (see Fig. 121, page 154), on 
 Fig. i is. Perspective ordinary standard size paper (not cross-section 
 
 of Bearing Cap. \ j ^ ,1 n 
 
 paper) and see that the views are well pro- 
 portioned. In practice sketches are frequently made on unruled 
 paper. 
 
 in. Sheet #12. Make a copy of the sketch of the pattern 
 and core box for the Cone Pulley (see Fig. 122, page 155). 
 
FREE-HAND WORKING SKETCHES. 
 
 153 
 
154 
 
 ELEMENTS OF DRAWING 
 
 112. Inking Sheet #i. The purpose of inking this sheet is to 
 give practice in making straight free-hand inked lines. 
 
 Where only a limited number of pieces are to be made from a 
 drawing, it frequently happens that the work does not warrant 
 the expense of making a tracing and a penciled sketch is not 
 sufficiently permanent, therefore an inked sketch is made. 
 
 Before starting this exercise study, and be 
 prepared for examination on, paragraphs, as 
 follows : 
 
 Drawing Ink, page 18, 18. Ordinary Pens, 
 page 18, 19. Penholders, page 20, 20. 
 Conventional Lines, page 76, 54. The Free- 
 hand Inked Line, page 136, 96. 
 
 To avoid spoiling a pencil drawing practice 
 making an inked line on a piece of scrap paper 
 before starting to ink the penciled work. Do not 
 start inking until the penciled sketch has been 
 checked and approved. 
 
 Fig. 120. Perspec- 
 tive of Small Flange. 
 
 113. Inking Sheet #3. The purpose of inking this sheet is 
 to give practice in making inked curved lines free-hand. 
 
 114. Inking Sheet 
 
 #i i . This exercise gives 
 practice in inking on 
 ordinary paper. 
 
 115. Examination on 
 Chapter IV. As a final ex- 
 amination, any sketches 
 assigned are to be made 
 in pencil or in ink of 
 Lathe Parts or parts of 
 any other machine, this 
 
 WOrk tO be done On Fig. 12I . -Perspective of ConePulley. 
 
 plotting or on plain paper as directed. Also examination ques- 
 tions concerning the main subject matter of this chapter will 
 be asked. 
 
FREE-HAND WORKING SKETCHES 
 
 155 
 
CHAPTER V 
 
 ISOMETRIC DRAWING AND SKETCHING 
 
 116. Introductory. Isometric drawings are often preferable 
 to mechanical drawings because they are very easily understood, 
 even by those who have little or no knowledge of technical 
 drawing. 
 
 While mechanical drawings can be made so that they com- 
 pletely represent an object both as to its form and dimensions, 
 several views are usually required to represent the object fully; 
 and in order to read and understand such drawings it is necessary 
 to visualize the object from these views. This usually requires 
 considerable study on the part of the reader, and the disadvan- 
 tages of mechanical drawings can be largely overcome by the 
 use of isometric drawings to represent the object. Isometrics 
 are coming to be used much more frequently in illustrating pip- 
 ing plans and layouts, structural details, " bird's eye " views of 
 buildings, etc., although they have already been extensively 
 used in making patent office drawings and in illustrating tech- 
 nical books and catalogues. Isometrics are also especially useful 
 in illustrating shop processes and methods, and certain manu- 
 facturing firms operating under the so-called "scientific manage- 
 ment " use this method of giving very definite and minute 
 instructions to the workmen, as, for examples, the best method 
 of fastening a certain piece of work in a machine, the proper way 
 to take cuts from the piece, etc. Some of the large steel manu- 
 facturers are using isometric drawings practically to the exclusion 
 of mechanical drawings. 
 
 Some of the advantages of isometric drawings are: (a) they 
 can be easily made and understood; (b) they give, in a single 
 view, the information that requires two or more views if a me- 
 chanical drawing is made use of; (c) practically no ability to 
 " visualize " is necessary in reading isometric drawings, and in 
 this respect they resemble perspective drawings but possess an 
 
 156 
 
ISOMETRIC DRAWING AND SKETCHING 157 
 
 advantage over perspective drawings in that they can, in a 
 limited way, be measured and dimensioned similarly to 
 mechanical drawings. 
 
 Some of the disadvantages of isometric drawings are : (a) they 
 show an object " distorted " and often make it appear unreal; 
 (b) they can be measured (i.e., " scaled ") only in certain direc- 
 tions; (c) angles shown in isometric cannot be measured in 
 degrees; (d) all circles show in isometric as ellipses, and an ellipse 
 is more difficult to draw with instruments than a circle, but this 
 is rather an advantage in free-hand isometric drawing. 
 
 117. Principles. Isometric drawing is based on the principles 
 of isometric projection, but it is beyond the scope of this text to 
 take up the discussion of the principles underlying this art. For 
 the purpose of this work it will be necessary to state only two new 
 principles not included in orthographic projection, viz: 
 
 (1) The object to be represented is so placed with reference 
 to the projection plane that instead of presenting a single face for 
 projection, three faces at right angles to each other and repre- 
 senting the length, width, and thickness of the object will be 
 equally inclined to this projection plane and thus all three faces 
 are presented in a single view. 
 
 (2) With an object placed as stated in principle (i) above, all 
 vertical lines of the object will be drawn vertical, and all hori- 
 zontal lines of the object will be drawn at 60 degrees to the 
 vertical or at 30 degrees to a,' true horizontal line. 
 
 These principles can be best illustrated by making an isometric 
 drawing of a cube. See 118, this page. 
 
 118. Isometric Drawing of a Cube. A mechanical drawing 
 of a cube is shown in Fig. 123 (a) and an isometric drawing of the 
 same size cube is shown in Fig. 123 (b), see page 158. 
 
 To construct the isometric drawing, draw the vertical line O-Y 
 and lay off B-F equal in length to the edge B-F of the cube; 
 that is, equal to b'-f. 
 
 From O draw 0-X to the left and O-Z to the right, each line 
 making 120 degrees with O-Y; that is, each of these lines will 
 make 30 degrees with a horizontal line. 
 
158 
 
 ELEMENTS OF DRAWING 
 
 On O-X lay off a distance equal to the length of the edge 
 B-A of the cube; that is, equal to b'-a'. 
 
 On O-Z lay off a distance equal to the edge B-C of the cube; 
 that is, equal to b'-c'. 
 
 From A draw A-D equal and parallel to B-C. From C draw 
 C-D equal and parallel to B-A. The rhombus* A-B-C-D is 
 the isometric drawing of the square top a-b-c-d of the cube. 
 
 Y 
 
 (a) Mechanical. (b) Isometric. 
 
 Fig. 123. Drawing of Cube. 
 
 From C draw C-G equal and parallel to B-F and from F draw 
 F-G equal and parallel to B-C. The rhombus F-B-C-G is the 
 isometric drawing of the square face/'-ft'-c'-g' of the cube. 
 
 The face A-B-F-E is similarly determined. 
 
 1 19. Definitions. The following definitions will be more easily 
 remembered by referring to Fig. 123 (b), this page. 
 
 (a) The isometric axes are three intersecting lines drawn at 
 1 20 degrees to one another, one of which lines is vertical, and the 
 other two will be 30 degrees to the true horizontal and in opposite 
 directions. The isometric axes are sometimes referred to as the 
 X, Y, and Z axes. 
 
 (b) The isometric origin is the intersection of the isometric 
 axes and it is usually marked O. 
 
 (c) An isometric line is one which is parallel to any one of the 
 three isometric axes. 
 
 (d) A non-isometric line is one which is not parallel to any one 
 of the three isometric axes. 
 
 * The rhombus (or rhomb) is an oblique parallelogram whose sides are all equal. 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 159 
 
 (e) Measurements can only be made on isometric lines and 
 
 can never be made on non-isometric lines. That is, an isometric 
 drawing of a solid can be measured or scaled in only three direc- 
 tions and of a plane figure in only two directions, these directions 
 always being parallel to the isometric axes. This principle is 
 illustrated in Fig. 123 (b), page 158. Lines which lie in the face 
 B-C-G-F can be scaled, or measured, if parallel to O-Z or 0-Y 
 but not if parallel to O-X. This will be understood if diagonals 
 are drawn from B to G and from F to C, for though these diagonals 
 are actually equal in length they do not project equally. 
 
 120. Isometric Drawing of a Circle. The isometric drawing 
 of a circle is always an ellipse. To determine points on the ellipse 
 enclose the circle within a square as shown in Fig. 124 (a) and 
 next draw the construction lines 1-2, 3-4, 5-6, etc., so as to in- 
 tersect on the circle at points i, j, k, I. Let it be assumed that 
 the circle lies in a 
 vertical plane. Then 
 the isometric drawing 
 of the circumscribed 
 square a-b-c-d can be 
 drawn exactly as if it 
 were the face F-G-C-B 
 shown in Fig. 123 (b), 
 page 158. The sides 
 of the square a-d and 
 d-c are made to coin- 
 cide with the isometric 
 axes O-Y and O-Z, respectively, in Fig. 124 (b), hence D-6 
 of Fig. 124 (b) can be measured off equal to d-6 of Fig. 124 (a) 
 and D-i of Fig. 124 (b) can be made equal to d-i of Fig. 124 (a). 
 The points j and 8 of Fig. 1 24 (b) are found in a similar manner, 
 and through the points i, 6, etc., the construction lines are drawn 
 parallel to D-C and D-A ; these lines, such as 1-2, and 6-5, are 
 isometric lines and their intersection / is the isometric position 
 of j, a point on the circle. All other points on the circle, such as 
 , 7, H, etc., are similarly located and the ellipse which is drawn 
 through these points is the isometric drawing of the circle. The 
 
 (a) Mechanical. 
 
 A 
 
 y 
 
 (b) Isometric. 
 Fig. 124. Drawing of Circle. 
 
i6o 
 
 ELEMENTS OF DRAWING 
 
 ellipse through Ii-Ji-Ki-Li represents the isometric drawing of 
 the same circle when it lies in a vertical plane parallel to the 
 plane of the isometric axes O-Y and O-X. The ellipse through 
 Iz-Jz-Kz-Lz represents the isometric drawing of the circle when 
 it lies in a horizontal plane. The points on these ellipses are found 
 exactly as the points I-J-K-L of the first ellipse were found. 
 
 121. Approximate Method of Making an Isometric Drawing 
 of a Circle. The ellipse when constructed as described in 120, 
 page 159, represents the true isometric drawing of the circle, but 
 
 an approximate method which is much 
 simpler and at the same time sufficiently 
 accurate for most purposes is shown in 
 Fig. 125. The sides C-D and D-A are 
 bisected respectively by the lines B-A 
 and E-C, which are drawn directly from 
 A and C with the 30-60 degree triangle. 
 With C as a center and C-E as a radius 
 describe the arc E-F. With A as a 
 center and with C-E as a radius describe 
 the arc G-B. With the intersection 
 point P of the lines A-B and C-E as a center and with P-E as 
 a radius describe the arc E-B. Similarly describe the arc F-G. 
 If this work has been accurately done the resulting figure will 
 appear as a " smooth " ellipse. The ellipses in the vertical 
 planes can be similarly constructed. 
 
 Fig. 125. Approximate Method 
 of Drawing an Isometric of a 
 Circle. 
 
 122. Isometric Drawing 
 Straight and Curved 
 Lines. Assume that any 
 
 Bh 
 
 plane outline as shown 
 in Fig. 126 (a) is to be 
 represented in isometric. 
 Circumscribe a square or 
 rectangle about the figured 3 *s 
 to be drawn in isometric 
 as shown in Fig. 126 
 (a). Through important Fig. 126.- 
 
 of a Plane Figure Composed of 
 
 
 
 
 
 \ 
 
 _ 
 
 
 
 
 ~J 
 
 
 
 / 
 
 
 
 \E 
 
 
 
 
 
 \ 
 
 F 
 
 J 
 
 / 
 
 
 
 ^ 
 
 
 
 
 (a) Mechanical. 
 
 J?" 
 
 (b) Isometric. 
 Drawing of Any Plane Figure. 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 161 
 
 points on the figure draw lines parallel to the sides of the circum- 
 scribed square. These lines will be isometric lines of the isometric 
 drawing, hence I-K, K-6, K-F, F-j, etc., of Fig. i26(b) are 
 drawn respectively equal to I-K, K-6, K-F, F-j, etc., of Fig. 
 126 (a); the isometric position of the points such as E, F, K 
 being found by laying off A-i, 1-2, 2-3, 3-4, etc., D-I, I- 77, 
 77-777, etc., of Fig. 126 (b), equal to the corresponding distances 
 of Fig. 126 (a). Through these points, lines are drawn parallel 
 to the proper sides of the rhombus and the intersections of these 
 lines determine the isometric position of the required points. 
 
 Fig. 126 (b) shows the figure in the horizontal and in the two 
 different vertical isometric planes. 
 
 123. Isometric Drawing of a Cube Cut by a Plane. Assume 
 the cube cut by a plane through its edge and at any angle. First 
 draw one face of the 
 cube in orthographic 
 projection, and draw 
 the lines O-/J, 0-jo, 
 0-45, etc., from the 
 corner and making 
 15 degrees, 30 degrees, 
 etc. , respectively, with 
 the line O-O, see Fig. 
 
 (d) 
 Fig. 127. Cube cut by Planes. 
 
 (e) 
 
 127 (a). In Fig. 127 (b) is shown the isometric drawing of 
 this face of the cube with the lines 0-15, O-jo, etc., represented 
 as making 15 degrees, 30 degrees, etc., with O-O. In this figure 
 the included corresponding angles #re not equal to those of 
 
162 
 
 ELEMENTS OF DRAWING 
 
 Fig. 127 (a), but the distances 0-15, O-jo, etc., measured on 
 the bottom line of Fig. 127 (b) are equal to the corresponding 
 distances of Fig. 127 (a). 
 
 In Fig. 127 (c) a cube is shown in isometric as it would appear if 
 cut by a plane through the edge O-A , and at 60 degrees to O-O. 
 
 In Fig. 127 (d) a cube is shown in isometric as if cut by two 
 planes, one at 15, the other at 60 with the back top edge 0-D. 
 
 In Fig. 127 (e) a cube is shown in isometric as it would appear 
 if cut, first, as in Fig. 127 (c), and then as in 127 (d). 
 
 124. 
 
 Fig. 128. 
 
 Isometric Drawing of Wall. Fig. 1 28 (a) shows a mechan- 
 ical (or orthographic) drawing of a rectangular 
 object, and Fig. 128 (b) shows isometric draw- 
 ings of the block in three different positions. 
 
 (c) shows 
 
 Fig. 128 (c) snows an 
 ordinary isometric draw- 
 ing which represents a 
 wall built of blocks as 
 shown in Fig. 128 (b). 
 Fig. 128 (d) shows a 
 different view of a wall 
 similar to that of Fig. 
 128 (c) but having the 
 horizontal lines in a 
 downward direction 
 instead of upward as 
 in previous work. 
 Drawing the horizon- 
 tal downward is called 
 reversing the axes, and 
 this method can be 
 used to show the lower 
 face of an object, rep- 
 resenting it as if tilted 
 backward instead of 
 forward, the method 
 of construction, how- 
 ever, being the same 
 
 (d) Isometric with Axes Reversed. 
 -Isometric Drawings of Wall Built of Blocks. in either 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 I6 3 
 
 Make a drawing of a cube 
 
 
 125. Isometric of a Cylinder. 
 
 that will just enclose the 
 cylinder then draw the 
 ellipse within the rhom- 
 bus that represents the 
 top of the cube See Fig. 
 129. Likewise construct 
 the base of the cube, and 
 connect the top and the 
 base with tangent lines 
 as shown in the figure. 
 
 126. Isometric of Screw Threads. In order to save time the 
 true forms of screw threads are never shown in isometric draw- 
 ings. The conventional method of representing the threads is 
 
 Fig. 129. Isometric Drawings of Cylinder in Different 
 Positions. 
 
 \ 
 
 Fig. 130. Nut and Bolt with Conventional 
 Isometric Thread. 
 
 shown in Fig. 130. To make such a drawing consider the body 
 of the bolt as a cylinder and proceed as in 125, this page. The 
 ellipse which represents the base of the cylinder is to be repeated 
 in the proper positions to indicate the threads, the distances be- 
 tween the ellipses usually being taken equal to the pitch of the 
 thread; that is, the distance between the ellipse centers is equal 
 to the thread pitch. See " centers " at i, 2, j, etc., in Fig. 130. 
 
ELEMENTS OF DRAWING 
 The internal thread shown in the Nut is similarly constructed. 
 
 127. Hollow Cylinder with a Quarter Section Removed. It is 
 
 very often advisable to show an object with a section removed 
 as in Fig. 131. 
 
 This drawing is of a Lathe Spindle (see Frontispiece, also 
 Fig- 147 > P a g e i? 2 )- To construct such a drawing proceed as in 
 
 Fig. 131. Isometric of Lathe Spindle 
 with Section removed. 
 
 125, page 163, to obtain the outline of the cylinder. Next, con- 
 sider the hole in the cylinder as a second cylinder and draw -in its 
 outline. To " take out " the section a plane such as A-B-D-C 
 is assumed passed vertically through the axis A-B of the spindle 
 and a plane, such as A-E-F-B, is assumed passed horizontally 
 through the axis. In this construction note that the centers of 
 all ellipses are on the axis A-B and their respective distances 
 from the ends of the spindle are measured on this axis. 
 
 128. Offset Construction in Isometric Drawing. It is not 
 
 always necessary to enclose the object completely in a cube or 
 rectangle, as described in 122, page 160, in order to make an 
 isometric drawing. See also 125, page 163. It frequently 
 occurs that the isometric lines can be drawn more readily by the 
 offset construction as illustrated in Fig. 132, page 165. 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 129. Isometric Drawing of a Sphere. The isometric drawing 
 of a sphere is represented by a circle. To determine the radius of 
 this circle, make an isometric drawing of a circle having the same 
 
 i^. 132. Offset Construction. 
 
 diameter as the sphere. The radius of the circle which represents 
 the sphere will be equal to one-half the major axis of the ellipse 
 which represents the circle. In Fig. 133 is shown a sphere of 
 diameter D. The dashed ellipse shown in Fig. 133 (b) is the 
 
 (b) 
 Fig- 133. Drawing of a Sphere. 
 
 isometric drawing of a circle having a diameter D. The radius, 
 R, of the circle which represents the isometric drawing, of the 
 sphere is one-half the length oj the major axis of the ellipse. 
 
 To draw a half-sphere construct the outline of the sphere as 
 described above. Next draw the ellipse which represents a great 
 
i66 
 
 ELEMENTS OF DRAWING 
 
 circle of the sphere. In Fig. 134 (a) is shown the lower half of a 
 sphere and in Fig. 134 (b) is shown the upper half. 
 
 (a) Lower half. (b) Upper half. 
 
 Fig. 134. Isometric of a Half Sphere. 
 
 Fig. 135. Isometric of 
 One-eighth Sphere. 
 
 To draw one-eighth of a Sphere construct the sphere as de- 
 scribed above and next draw the great circles at right angles to 
 one another as shown in Fig. 135. 
 
 130. Isometric Drawing of 
 Lathe Cap. To get an idea 
 of the exact shape of the Lathe 
 Cap see Frontispiece and Fig. 
 148, page 172. The Cap is a 
 combination of a cylinder (see 
 125, page 163), a half sphere 
 (see 129, page 165) and of 
 V threads (see 126, page 
 
 163). 
 
 Fig. 136 shows an isometric 
 drawing of the Lathe Cap with 
 one-quarter section removed. 
 
 131. Size and Numbering 
 
 Fig. i 3 6.-lsometric of Lathe Cap. Qf Sketch Sheetg> Exercises 
 
 in isometric sketching are to be done on small sheets of standard 
 letter size (8" X io|") heavy weight isometric-ruled paper (see 
 4, page 5), the ruling on one side only. The paper is to be 
 punched for standard No. 10 Manila cover. As previously stated, 
 one of the disadvantages of making isometric drawings me- 
 chanically is due to the frequent necessity of drawing ellipses. 
 This, however, is an advantage in free-hand sketching, since the 
 ellipse is more easily drawn free-hand than the circle. The chief 
 
ISOMETRIC DRAWING AND SKETCHING 167 
 
 objection to making isometric sketches is due to the difficulty of 
 maintaining the thirty-degree angle. This difficulty can be 
 entirely overcome by the use of isometric ruled paper, see Fig. i (b) , 
 page 5. This paper has, besides the regular vertical and hori- 
 zontal ruling of the ordinary cross-section paper, also lines ruled 
 at thirty degrees to the horizontal. This ruling insures the proper 
 slope to all isometrically horizontal lines and the draftsman needs 
 no other instruments than a pencil and measuring rule to make 
 isometric drawings of the most complex nature. 
 
 The order in which free hand isometric sketch sheets are exe- 
 cuted will be indicated by Roman numbers beginning with I and 
 continuing as far as necessary. For the general system to be 
 followed see Appendix A, page 175. 
 
 SET OF FREE-HAND ISOMETRIC EXERCISES. 
 
 132. Sheet I. The purpose of this sheet is to give practice in 
 making an Isometric Drawing of a simple object and also to bring 
 out some of the elementary principles of Isometric Sketching. 
 
 Before starting to draw, read, and be prepared for examination 
 on, paragraphs, as follows: 
 
 Ruled Paper, page 5, 4. Lead Pencil, page 14, 14.- 
 Erasers and Erasures, page 16, 15. The Free-hand Pencil 
 Line, page 134, 95. Introductory, page 156, 116. Prin- 
 ciples, page 157, 117. Isometric Drawing of a Cube, page 157, 
 118. Definitions, page 158, 119. Isometric Drawing of a 
 Circle, page 159, 120. Size and Numbering of Sketch Sheets, 
 page 1 66, 131, and for information on the general system to be 
 followed see page 175, Appendix A. 
 
 Exercise on Sheet I. 
 This exercise con- 
 sists of an Isometric 
 sketch of Tool Rest 
 Support Slide for the 
 Lathe, see Fig. 137; 
 
 , ' . . Fig. 137- Perspective of Tool Rest Support Slide. 
 
 also Frontispiece. 
 
 Specific Instructions for Executing Sheet I. Tack down the 
 isometric ruled sheet, stamp in the title-form (see Fig. 93, page 
 138) in the lower right-hand corner of sheet, and neatly write with 
 ink the wording of the title. 
 
1 68 
 
 ELEMENTS OF DRAWING 
 
 2 
 
 \ / 
 
 \ 
 
 \ 
 
 
 / 
 
 / 
 
 \/ 
 
 V 
 
 \ 
 
 \ 
 
 \ 
 
 * 
 
 / 
 
 / 
 
 V 
 
 \, 
 
 V 
 
 \ 
 
 ?v 
 
 / \ 
 
 X 
 
 [/ 
 
 \ / 
 
 \/ 
 
 '\ 
 
 A 
 
 x\ 
 
 A 
 
 /i 
 
 \ / 
 
 \ / 
 
 \A 
 
 
 
 
 
 / 
 
 v 
 
 \ 
 
 \ 
 
 \ 
 
 
 / 
 
 / 
 
 \2 
 
 V 
 
 \ 
 
 
 
 
 / 
 
 s/ 
 
 \/ 
 
 Y 
 
 \ 
 
 '\ 
 
 /\ 
 
 /" 
 
 X 
 
 s / 
 
 s / 
 
 \ 
 
 A 
 
 /\ 
 
 /\ 
 
 yv 
 
 / 
 
 j\ 
 
 5 
 
 \ 
 
 
 
 ' 
 
 / 
 
 V 
 
 V 
 
 \ 
 
 \ 
 
 
 / 
 
 
 V 
 
 \/ 
 
 \ 
 
 \ 
 
 
 / \ 
 
 X 
 
 Y 
 
 \/ 
 
 \ 
 
 Y 
 
 A 
 
 /\ 
 
 A 
 
 / 
 
 \ x 
 
 \ / 
 
 \x\ 
 
 
 
 / 
 
 / 
 
 x 
 
 \ 
 
 \ ; 
 
 \ 
 
 
 / 
 
 / 
 
 1 , 7 
 
 \/ 
 
 \/ 
 
 
 
 
 / 
 
 y 
 
 \/ 
 
 \/ 
 
 \ 
 
 Y 
 
 / \ 
 
 /\ 
 
 / 
 
 \ / 
 
 \ / 
 
 \ 
 
 \ 
 
 /\ 
 
 /\ 
 
 x\/ 
 
 / 
 
 V 
 
 \ 
 
 \ 
 
 ' 
 
 ' 
 
 / 
 
 2 
 
 J2 
 
 \ 
 
 \ 
 
 \ 
 
 
 / 
 
 / 
 
 2 
 
 v 
 
 V 
 
 \ 
 
 ' \ 
 
 / \ 
 
 / 
 
 2 
 
 \/ 
 
 \ 
 
 \ 
 
 A 
 
 /\ 
 
 A 
 
 f 
 
 \ / 
 
 \/ 
 
 \/\ 
 
 
 
 / 
 
 /' 
 
 
 
 X 
 
 \ 
 
 
 / 
 
 / 
 
 / 
 
 \/ 
 
 V 
 
 
 / \ 
 
 / 
 
 / 
 
 ,/ 
 
 \/ 
 
 \/ 
 
 \ 
 
 
 /\ 
 
 7 
 
 7 
 
 / 
 
 \ / 
 
 \ 
 
 \ 
 
 /\ 
 
 /\ 
 
 ZZ 
 
 / 
 
 V 
 
 \ 
 
 \ 
 
 
 
 / 
 
 j 
 
 ' / 
 
 S 
 
 \ 
 
 . 
 
 
 / 
 
 / 
 
 \/ 
 
 fe 
 
 h 
 
 \ 
 
 
 \ 
 
 / 
 
 *2 
 
 v> 
 
 5 
 
 \ 
 
 /\ 
 
 / \ 
 
 2 
 
 / 
 
 \/ 
 
 \ / 
 
 v_\ 
 
 
 
 / 
 
 / 
 
 K / 
 
 
 
 
 \ 
 
 
 / 
 
 / 
 
 v / 
 
 \ / 
 
 \ 
 
 
 ' \ 
 
 // 
 
 V 
 
 V 
 
 // 
 
 \ 
 
 A 
 
 x v 
 
 /\ 
 
 \ 
 
 / 
 
 / 
 
 ^ / 
 
 \ 
 
 5 
 
 A 
 
 /\ 
 
 "27 
 
 / 
 
 V 
 
 v 
 
 \ 
 
 A 
 
 " 
 
 / 
 
 / 
 
 v 
 
 \/ 
 
 V 
 
 ' \^ 
 
 / \ 
 
 7 
 
 Y 
 
 k 
 
 v 
 
 V 
 
 \ 
 
 \ 
 
 /^ 
 
 \ 
 
 /x 
 
 \x 
 
 \; 
 
 ^ 
 
 /\ 
 
 /\ 
 
 A 
 
 X' 
 
 \x 
 
 \/ 
 
 \/\ 
 
 \ 
 
 
 / 
 
 / 
 
 V 
 
 V 
 
 V 
 
 \ 
 
 
 / 
 
 2 
 
 V/ 
 
 V 
 
 V 
 
 
 2 
 
 r 
 
 / 
 
 J 
 
 ^ 
 
 V 
 
 V 
 
 \\ 
 
 x\ 
 
 X x 
 
 X 
 
 \x 
 
 V 
 
 v 
 
 A 
 
 /\ 
 
 x\ 
 
 zz 
 
 / 
 
 \/ 
 
 V 
 
 '\ 
 
 '\ 
 
 
 / 
 
 ,/ 
 
 ^ 
 
 \/ 
 
 \ 
 
 ' \ 
 
 
 / v 
 
 
 
 
 A 
 
 5 
 
 / \ 
 
 ^ 
 
 2 
 
 
 
 \x 
 
 \/ 
 
 K 
 
 ^ 
 
 A 
 
 x x 
 
 X 
 
 \x 
 
 \/ 
 
 Y\ 
 
 \ 
 
 
 / 
 
 / 
 
 "2 
 
 \/ 
 
 \ 
 
 \ 
 
 / \ 
 
 / \ 
 
 / 
 
 2 
 
 \/ 
 
 V 
 
 /\ 
 
 / \ 
 
 / 
 
 7 
 
 s/ 
 
 
 Y> 
 
 ^ 
 
 /\ 
 
 V 
 
 X N 
 
 x 
 
 \> 
 
 \ / 
 
 V 
 
 A 
 
 /\ 
 
 x\ 
 
 77 
 
 ,/ 
 
 \/ 
 
 \ 
 
 \ 
 
 \ 
 
 
 / 
 
 (/ 
 
 \/ 
 
 \/ 
 
 \ 
 
 A 
 
 / \ 
 
 // 
 
 y 
 
 \/ 
 
 y 
 
 \ 
 
 \ 
 
 /V 
 
 X 1 -- 
 
 S 
 
 \x 
 
 \> 
 
 \/ 
 
 5 
 
 A 
 
 S 
 
 7^ 
 
 y 1 
 
 xX 
 
 \/ 
 
 \/'\ 
 
 \ 
 
 
 / 
 
 / 
 
 K/ 
 
 \/ 
 
 \ 
 
 ' \ 
 
 
 / \ 
 
 
 (/ 
 
 \/ 
 
 A/ 
 
 
 'V 
 
 / 
 
 / 
 
 Y 
 
 x/ 
 
 y/ 
 
 \ 
 
 'w 
 
 x\ 
 
 K 
 
 / 
 
 \ / 
 
 \> 
 
 k \ , 
 
 \ 
 
 /\ 
 
 / \ 
 
 x\x 
 
 2 
 
 v 
 
 \/ 
 
 \ 
 
 / \ 
 
 
 / 
 
 / 
 
 \/ 
 
 v 
 
 \ 
 
 \ 
 
 /A 
 
 / 
 
 
 // 
 
 \ 
 
 \ 
 
 '/ 
 
 3 
 
 / N 
 
 / 
 
 a 
 
 \/ 
 
 v 
 
 <N 
 
 /\ 
 
 /v 
 
 A 
 
 x 
 
 NX 
 
 \/ 
 
 Y'\ 
 
 \ 
 
 
 
 / 
 
 ,/ 
 
 \/ 
 
 Y 
 
 \ 
 
 / \ 
 
 
 A 
 
 
 \/ 
 
 \/ 
 
 
 7\ 
 
 / 
 
 / 
 
 2 
 
 // 
 
 \ 
 
 \ 
 
 /\ 
 
 \S 
 
 X N 
 
 \ 
 
 \X 
 
 \/ 
 
 v 
 
 SNj 
 
 A 
 
 x\ 
 
 27 
 
 / 
 
 Y 
 
 \y 
 
 \j 
 
 ?\ 
 
 /\ 
 
 / 
 
 2 
 
 y 
 
 V 
 
 ^ 
 
 * 
 
 /\ 
 
 2 
 
 / 
 
 N/ 
 
 \ 
 
 y 
 
 X X 
 
 / \ 
 
 7 
 
 s/ 
 
 \/ 
 
 \7 
 
 \^ 
 
 s 
 
 \\ 
 
 /\ 
 
 X' 
 
 v\ 
 
 \X 
 
 \/ 
 
 Y'\ 
 
 \i 
 
 /\ 
 
 / \ 
 
 7 
 
 2 
 
 v 
 
 S 
 
 \ 
 
 /\ 
 
 /\ 
 
 ft 
 
 V 
 
 \/ 
 
 y 
 
 
 /^ 
 
 / 
 
 U 
 
 \V 
 
 \/ 
 
 v 
 
 \ 
 
 /\ 
 
 y\ 
 
 S 
 
 x 
 
 2 
 
 \x 
 
 V 
 
 \ 
 
 \ 
 
 x^ 
 
 22 
 
 / 
 
 
 \/ 
 
 X 
 
 /\ 
 
 
 7> 
 
 / 
 
 V 
 
 \/ 
 
 s 
 
 
 / \ 
 
 '/i 
 
 
 \/ 
 
 2 
 
 <r 
 
 \ 
 
 /\ 
 
 / s 
 
 X 
 
 V 
 
 \ 7 
 
 \! 
 
 
 x \' 
 
 V 
 
 / ^ 
 
 / 
 
 \> 
 
 ^ 
 
 V'\ 
 
 \ 
 
 
 7 
 
 y 
 
 2 
 
 \/ 
 
 v 
 
 \ 
 
 / \ 
 
 /A 
 
 / 
 
 / 
 
 Z 
 
 \, 
 
 
 /y 
 
 y 
 
 7 
 
 \/ 
 
 \/ 
 
 \/ 
 
 \ 
 
 5 
 
 /\ 
 
 /\ 
 
 
 \x 
 
 / 
 
 
 \ 
 
 
 r 
 
 TjrX 
 
 / 
 
 y 
 
 Y 
 
 \ 
 
 /\ 
 
 
 / 
 
 7 
 
 v 
 
 \/ 
 
 Y 
 
 V 
 
 7\ 
 
 
 
 // 
 
 y 
 
 \ 
 
 s 
 
 /\ 
 
 7 
 
 / 
 
 \x 
 
 V 
 
 \i 
 
 
 i 
 
 f\ 
 
 7 
 
 / 
 
 y 
 
 v 
 
 55 
 
 A 
 
 
 / 
 
 7 
 
 y 
 
 \/ 
 
 v 
 
 J\ 
 
 /A 
 
 /\ 
 
 7 
 
 // 
 
 \/ 
 
 V 
 
 
 /v 
 
 /\ 
 
 A 
 
 ^/ 
 
 \/ 
 
 \/ 
 
 \ 
 
 /\ 
 
 /\ 
 
 VN 
 
 x 
 
 ? 
 
 V 
 
 v 
 
 '\ 
 
 5 
 
 x^ 
 
 /Y 
 
 / 
 
 / 
 
 \/ 
 
 \ 
 
 /\ 
 
 /\ 
 
 / 
 
 // 
 
 Y 
 
 \/ 
 
 y 
 
 \ 
 
 /\ 
 
 X s 
 
 
 /,/ 
 
 ji 
 
 
 
 \ 
 
 /\ 
 
 /^ 
 
 / 
 
 N x 
 
 \X 
 
 V 
 
 v 
 
 
 >K 
 
 /I 
 
 / 
 
 \x 
 
 X/ 
 
 YA 
 
 \ 
 
 / \ 
 
 / \ 
 
 / 
 
 xX 
 
 \/ 
 
 V 
 
 A 
 
 A 
 
 / \ 
 
 /\ 
 
 / 
 
 \ / 
 
 y> 
 
 
 /\ 
 
 S 
 
 7 
 
 / 
 
 \/ 
 
 \/ 
 
 \ 
 
 /\ 
 
 / \ 
 
 x^ 
 
 y^ 
 
 </ 
 
 v 
 
 ^ 
 
 \ 
 
 X X 
 
 X x 
 
 72 
 
 ,/ 
 
 J 
 
 Y 
 
 \, 
 
 \ 
 
 T^J 
 
 /A 
 
 / 
 
 V 
 
 / 
 
 \ 
 
 <\ 
 
 3 
 
 
 
 V 
 
 f 
 
 Sj 
 
 s 
 
 /\ 
 
 y 
 
 / 
 
 \/ 
 
 Y 
 
 v 
 
 S 
 
 /\ 
 
 / \ 
 
 / 
 
 v/, 
 
 <x 
 
 \/ 
 
 \/\ 
 
 
 /\ 
 
 /I 
 
 / 
 
 \/ 
 
 Y 
 
 r 
 
 \ /i 
 
 
 Yi 
 
 /\ 
 
 /" 
 
 \ 
 
 ,/ 
 / / 
 
 \. 
 
 A 
 
 K 
 
 
 
 / 
 
 x / 
 
 V 
 
 
 /\ 
 
 /\ 
 
 / 
 
 x/ 
 
 \/ 
 
 v 
 
 \/ 
 
 X 
 
 /\ 
 
 7 
 
 // 
 
 J/ 
 
 / 
 
 \/ 
 
 \ 
 
 \ 
 
 // 
 
 /H 
 
 / 
 
 3 
 
 \ 7 
 
 \ 
 
 5 
 
 x\ 
 
 r 
 
 j 
 
 \Y 
 
 c 
 
 v 
 
 l\ 
 
 /\ 
 
 /\ 
 
 / 
 
 \x 
 
 y 
 
 \, 
 
 \ 
 
 /\ 
 
 y 
 
 2 
 
 / 
 
 \x 
 
 \/ 
 
 \x\ 
 
 \ 
 
 r 
 
 X" 
 
 /i 
 
 / 
 
 x/ 
 
 / 
 
 \ 
 
 /\ 
 
 S 
 
 7 
 
 x / 
 
 ^s 
 
 \, 
 
 \ 
 
 X A 
 
 ,/v 
 
 7 
 
 '/ 
 
 v 
 
 y 
 
 \ 
 
 x \ 
 
 ^\ 
 
 X v 
 
 / 
 
 / 
 
 v 
 
 X/ 
 
 \ 
 
 /\ 
 
 X x 
 
 Z2 
 
 2 
 
 V 
 
 \/ 
 
 5 
 
 S 
 
 '' 
 
 / 
 
 / 
 
 xX 
 
 \ 
 
 ^ 
 
 \ 
 
 /\ 
 
 X 
 
 / 
 
 \( 
 
 / 
 
 s 
 
 \ 
 
 /\ 
 
 /\ 
 
 / 
 
 / 
 
 V 
 
 V 
 
 \ 
 
 f\ 
 
 2 
 
 /] 
 
 V/ 
 
 v 
 
 v 
 
 NX\ 
 
 s 
 
 
 / s 
 
 // 
 
 ; 
 
 / 
 
 \, 
 
 \ 
 
 7\ 
 
 ~/\ 
 
 \ 
 
 / 
 
 \ / 
 
 v 
 
 ^A 
 
 5 
 
 r\ 
 
 
 / 
 
 \/ 
 
 v 
 
 \ 
 
 \ 
 
 
 / l 
 
 / 
 
 v 
 
 v 
 
 \/ 
 
 \ 
 
 / \ 
 
 / s 
 
 X sX 
 
 / 
 
 X 
 
 , / 
 
 A 
 
 y 
 
 
 /\ 
 
 / 
 
 .,/ 
 
 / 
 
 V 
 
 s\ 
 
 /\ 
 
 7 
 
 ^y 
 
 \/ 
 
 \/ 
 
 v 
 
 \ 
 
 /\ 
 
 / X 
 
 / 
 
 \/ 
 
 V 
 
 v 
 
 \ 
 
 7 X 
 
 / \ 
 
 y" 
 
 N/ 
 
 \/ 
 
 5 
 
 Y\ 
 
 \ 
 
 
 // 
 
 7 
 
 // 
 
 j 
 
 \, 
 
 \ 
 
 'V 
 
 /\ 
 
 /) 
 
 3 
 
 \/ 
 
 t 
 
 \ 
 
 S 
 
 /\ 
 
 /' 
 
 / 
 
 / 
 
 V 
 
 V 
 
 5 
 
 /\ 
 
 / 
 
 
 V 
 
 V 
 
 V 
 
 \ 
 
 /\ 
 
 7 
 
 /V/ 
 
 2 
 
 / 
 
 
 -V 
 
 . 
 
 
 /4 
 
 - 
 
 (/ 
 
 r~ 
 
 \ 
 
 \ 
 
 V 
 
 / x 
 
 J 
 
 ^ 
 
 ^/ 
 
 v 
 
 \ 
 
 /\ 
 
 A 
 
 / 
 
 2 
 
 T 
 
 V 
 
 tf> 
 
 / \ 
 
 x ^ 
 
 / ~ 
 
 v 
 
 \/ 
 
 v 
 
 \A 
 
 5 
 
 \ 
 
 A 
 
 / 
 
 v 
 
 / 
 
 \ , 
 
 \ 
 
 /\ 
 
 / \ 
 
 /) 
 
 / 
 
 \> 
 
 \; 
 
 \ 
 
 /\ 
 
 ^ X 
 
 7 
 
 / 
 
 / 
 
 \/ 
 
 \J 
 
 7 \ 
 
 r\ 
 
 /; 
 
 y 
 
 V 
 
 V 
 
 V 
 
 \ 
 
 /\ 
 
 X x 
 
 XV 
 
 2 
 
 x 
 
 Y 
 
 \ 
 
 \ 
 
 /\ 
 
 y 
 
 / 
 
 \/ 
 
 
 \ 
 
 \ 
 
 /\ 
 
 \ 
 
 / 
 
 v 
 
 V 
 
 \, 
 
 \ 
 
 f\ 
 
 
 X' 
 
 / 
 
 N/ 
 
 
 
 \ 
 
 7\ 
 
 
 x 
 
 
 V 
 
 5 
 
 \/\ 
 
 \ 
 
 \ 
 
 7> 
 
 / 
 
 / 
 
 V 
 
 v ( 
 
 \ 
 
 A 
 
 /\ 
 
 / 
 
 / 
 
 \ / 
 
 \" 
 
 A 
 
 5 
 
 
 S 
 
 / 
 
 ,/ 
 
 \/ 
 
 \, 
 
 5 
 
 a 
 
 /^ 
 
 
 v 
 
 \/ 
 
 \/ 
 
 \ 
 
 / \ 
 
 7> 
 
 XV 
 
 2 
 
 / 
 
 
 \ 
 
 \ 
 
 /\ 
 
 /- 
 
 / 
 
 \ / 
 
 \ J 
 
 \ 
 
 \ 
 
 /\ 
 
 2 
 
 V 
 
 /> 
 
 \/ 
 
 \ / 
 
 \ 
 
 5 
 
 /\ 
 
 /\ 
 
 / 
 
 xX 
 
 *,/ 
 
 v 
 
 \ 
 
 /\ 
 
 A 
 
 / 
 
 y 
 
 \/ 
 
 S 
 
 VN 
 
 5 
 
 \ 
 
 /> 
 
 7 
 
 / 
 
 
 \ 
 
 \ 
 
 /-, 
 
 /\ 
 
 / 
 
 / 
 
 \ / 
 
 V 
 
 /\ 
 
 S x 
 
 /\ 
 
 / 
 
 / 
 
 \/ 
 
 \/ 
 
 \, 
 
 X 
 
 /\ 
 
 /\ 
 
 X 
 
 N/ 
 
 S 
 
 \, 
 
 \ 
 
 /\ 
 
 A 
 
 /\/ 
 
 v 
 
 / 
 
 \ ^ 
 
 \ 
 
 \ 
 
 
 
 /s 
 
 s/ 
 
 / 
 
 \ * 
 
 \ 
 
 \ 
 
 / \ 
 
 2 
 
 / 
 
 71 
 
 
 s 
 
 \ 
 
 /\ 
 
 / 
 
 /, 
 
 
 \/ 
 
 \/ 
 
 \ 
 
 A 
 
 7\ 
 
 / ' 
 
 2 
 
 y 
 
 Y 
 
 \'\ 
 
 '\ 
 
 \ 
 
 2 
 
 / 
 
 / 
 
 , 
 
 ' 
 
 \ 
 
 (\ 
 
 /\ 
 
 r 
 
 / 
 
 y 
 
 \J 
 
 \ 
 
 A 
 
 
 7 
 
 / 
 
 v 
 
 Y 
 
 Xj 
 
 Y 
 
 /\ 
 
 7 
 
 / 
 
 \x 
 
 \/ 
 
 Y 
 
 \ 
 
 /\ 
 
 A 
 
 Z2 
 
 "7 
 
 / 
 
 
 \ 
 
 5 
 
 '" 
 
 / 
 
 / 
 
 y 
 
 
 \ 
 
 \ 
 
 T\ 
 
 / x 
 
 / 
 
 v 
 
 
 \, 
 
 \ 
 
 A 
 
 /\ 
 / / 
 
 /' 
 
 xX 
 
 \/ 
 
 \/ 
 
 \ 
 
 /\ 
 
 A 
 
 / ] 
 
 / 
 
 \X 
 
 Y 
 
 Y\ 
 
 A 
 
 \ 
 
 y 
 
 / 
 
 / 
 
 
 \ 
 
 \ 
 
 A 
 
 / 
 
 / 
 
 / 
 
 \/ 
 
 S 
 
 ^ 
 
 5 
 
 /\ 
 
 / v 
 
 / 
 
 / 
 
 x, 
 
 M 
 
 \ 
 
 / \ 
 
 7 
 
 x 
 
 \x 
 
 \/ 
 
 Y 
 
 
 / \ 
 
 / j 
 
 X A 
 
 ,/ 
 
 / 
 
 
 \ 
 
 /\ 
 
 /\ 
 
 y 
 
 / 
 
 \/ 
 
 \ 
 
 \ 
 
 \ 
 
 /\ 
 
 7 
 
 / 
 
 \/ 
 
 Y 
 
 \, 
 
 \ 
 
 X 
 
 x\ 
 
 X 
 
 2 
 
 \/ 
 
 \/ 
 
 \ 
 
 K 
 
 /\ 
 
 y 
 
 / 
 
 \x 
 
 5 
 
 Y\ 
 
 A 
 
 \ 
 
 y 
 
 / 
 
 / 
 
 
 \ 
 
 \ 
 
 A 
 
 A 
 
 / 
 
 / 
 
 \/ 
 
 v 
 
 \ 
 
 ' \ 
 
 
 7 
 
 / 
 
 / 
 
 y 
 
 V 
 
 \ 
 
 / \ 
 
 /^ 
 
 / 
 
 \/ 
 
 \x 
 
 \J 
 
 \ 
 
 \ 
 
 / ' 
 
 X V 
 
 , / 
 
 
 
 \ 
 
 /\ 
 
 /> 
 
 /' 
 
 / 
 
 \/ 
 
 \ 7 
 
 \ 
 
 \ 
 
 /\ 
 
 / ! 
 
 / 
 
 s/ 
 
 
 Y 
 
 X 
 
 \ 
 
 7> 
 
 X 
 
 x 
 
 \ / 
 
 \, 
 
 \ 
 
 Y 
 
 / \ 
 
 X 1 
 
 / 
 
 \x 
 
 V 
 
 Y\ 
 
 \ 
 
 /\ 
 
 v> 
 
 / 
 
 / 
 
 
 \ 
 
 \ 
 
 /\ 
 
 / \ 
 
 7 
 
 s/ 
 
 
 \ / 
 
 r 
 
 3 
 
 v 
 
 // 
 
 / 
 
 / 
 
 \^ 
 
 \ 
 
 Y 
 
 / \ 
 
 2 
 
 / 
 
 N X 
 
 V 
 
 Y 
 
 \ 
 
 /\ 
 
 / ^ 
 
 /'/ 
 
 , / 
 
 / 
 
 \ 
 
 \ 
 
 /\ 
 
 
 7 
 
 / 
 
 \/ 
 
 \/ 
 
 \ 
 
 \ 
 
 / " 
 
 / * 
 
 ^ 
 
 / 
 
 \/ 
 
 \, 
 
 \ 
 
 \ 
 
 /^ 
 
 / 
 
 sX 
 
 \/ 
 
 Y 
 
 \, 
 
 \ 
 
 
 X 
 
 / 
 
 y 
 
 Y 
 
 Y N 
 
 A 
 
 /\ 
 
 /\ 
 
 / 
 
 X 
 
 
 Y 
 
 \ 
 
 /\ 
 
 /\ 
 
 /" 
 
 / 
 
 
 
 J 
 
 
 ^ ^ 
 
 7 
 
 / 
 
 / 
 
 i; 
 
 \ 
 
 x \ 
 
 /v 
 
 X" 
 
 / 
 
 \/ 
 
 V 
 
 S 
 
 \ 
 
 /\ 
 
 7> 
 
 XV 
 
 , / 
 
 
 \ 
 
 \ 
 
 /\ 
 
 /\ 
 
 2 
 
 / 
 
 \/ 
 
 \ / 
 
 \) 
 
 \ 
 
 /\ 
 
 /* 
 
 / 
 
 ^/ 
 
 \ / 
 
 \, 
 
 \ 
 
 /\ 
 
 /^ 
 
 x 
 
 X 
 
 \ / 
 
 Y 
 
 \ 
 
 3 
 
 /\ 
 
 ,/ v 
 
 / 
 
 \x 
 
 5 
 
 v\ 
 
 A 
 
 /\ 
 
 7* 
 
 / 
 
 \/ 
 
 
 \, 
 
 \ 
 
 /\ 
 
 /x l 
 
 7 
 
 / 
 
 \/ 
 
 Y 
 
 \ 
 
 5 
 
 7> 
 
 / x 
 
 / 
 
 \/ 
 
 \ / 
 
 \ 
 
 x \ 
 
 /\ 
 
 y 
 
 / 
 
 v/ 
 
 \x 
 
 Y 
 
 \ 
 
 ^\ 
 
 7 
 
 x\x 
 
 ^/ 
 
 
 \ , 
 
 \ 
 
 A 
 
 
 /' 
 
 / 
 
 \/ 
 
 \/ 
 
 S 
 
 \ 
 
 /\ 
 
 /~~ 
 
 / 
 
 2 
 
 \/ 
 
 S 
 
 \ 
 
 ^N 
 
 7^ 
 
 / 
 
 xX 
 
 \/ 
 
 Y 
 
 \ 
 
 A 
 
 A 
 
 7 
 
 Z 
 
 \x 
 
 \/ 
 
 \/\ 
 
 \ 
 
 /\ 
 
 /> 
 
 / 
 
 ,X 
 
 
 Y 
 
 \ 
 
 /\l 
 
 /\l 
 
 2 
 
 / 
 
 \/ 
 
 \/( 
 
 \ 
 
 5 
 
 /\ 
 
 2 
 
 / 
 
 \/ 
 
 Su 
 
 
 x \ 
 
 /\ 
 
 2 
 
 X 
 
 X X 
 
 Y 
 
 \/ 
 
 \ 
 
 /\ 
 
 /> 
 
 XNX 
 
 J 
 
 v 
 
 Y 
 
 \ 
 
 /\ 
 
 /\ 
 
 / 
 
 / 
 
 \/ 
 
 \ 
 
 t 
 
 \ 
 
 /\ 
 
 / 
 
 / 
 
 2 
 
 
 V 
 
 \ 
 
 /\ 
 
 y 
 
 / 
 
 2 
 
 Y 
 
 v 
 
 -\ 
 
 A 
 
 /\ 
 
 / v 
 
 x 
 
 \x 
 
 V 
 
 YN 
 
ISOMETRIC DRAWING AND SKETCHING 169 
 
 The title of sheet I is Support Slide. 
 
 Do not use a straight-edge in any of this free-hand course as 
 this will seriously impair the value of the work. 
 
 Make a pencil perspective sketch of the Support Slide on central 
 portion of the sheet, and to about the scale shown in Fig. 138. 
 Dimension the sketch, and when the sheet has been cleaned and 
 all the lines made clear cut and of the desired weight and con- 
 struction, and the work is thoroughly checked, submit it for in- 
 spection and approval. Compare this sketch with Fig. 51 (b), 
 page 74, and determine in your own mind which conveys the 
 necessary information with the fewer lines, also which would be 
 the more readily understood by the average person who would 
 use drawings. 
 
 133. Sheet II. The purpose of these exercises is to give 
 further practice in making Isometric Sketches of simple objects. 
 
 Before starting this exercise, read and be prepared for exami- 
 nation on, paragraphs, as follows: 
 
 Approximate Method of making an Isometric Drawing of a 
 Circle, page 160, 121. Isometric Drawing of a Plane Figure 
 composed of Straight and Curved Lines, page 160, 122. 
 Isometric of a Cylinder, page 163, 125. Isometric of a Screw 
 Thread, page 163, 126. 
 
 Exercises on Sheet II. The exercises on this sheet consist of 
 pencil Isometric Sketches of a Key (see Fig. 139), of a Shim (see 
 
 Fig. 139. Perspective Fig. 140. Perspective 
 
 of Key. of Shim. 
 
 Fig. 141. Perspective 
 
 of Stud. 
 
 Fig. 142. Perspective of Fiber Fig. 143. Perspective 
 
 or Steel Washer. of Special Nut. 
 
 Fig. 140), of a Stud (see Fig. 141), of a Washer (see Fig. 142), and 
 of a Nut (see Fig. 143), all of these being parts of the Speed Lathe 
 as shown on Frontispiece. 
 
170 
 
 ELEMENTS OF DRAWING 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 171 
 
 Specific Instructions. Stamp the title-form (see Fig. 93, page 
 138) in lower right-hand corner of sheet and write in ink the 
 wording of the title. 
 
 The title of this sheet is Speed Lathe Details. 
 
 Sketch in these parts similar to the way they are shown in Fig. 
 144, dimensioning the figures. 
 
 Having perfected the sketches, submit for approval. 
 
 Compare the sketches on this sheet with similar parts shown 
 in Fig. 82, page 118, and Fig. 97, page 140, and in your own 
 mind determine which is the best and quickest method of 
 representing these objects. 
 
 134. Sheet III. The purpose of the exercises on this sheet is 
 to give practice in making Isometric Sketches directly from the 
 object and in dimensioning these sketches, the 
 dimensions being obtained by direct measure- 
 ment of the object. 
 
 Exercises and Specific Instructions. The 
 exercises on this sheet consist of Isometric 
 Sketches of a Collar (see Fig. 145) and of a 
 Bearing (see Fig. 146) made from direct 
 observation of these parts, and all dimensions 
 and notes necessary are to be put in, the 
 dimensions being obtained by measurements 
 made directly on the Collar and the Bearing. 
 
 Stamp in and fill out the title form. 
 
 The title of this sheet is Speed Lathe Details. 
 
 Check the drawing thoroughly and submit 
 for approval. 
 
 Fig. I4S- Perspective 
 of Collar. 
 
 Fig. 146. Perspective 
 of Bearing. 
 
 135. Sheet IV. The purpose of this exercise is to give practice 
 in making an isometric sketch in ink and in showing an object 
 with a quarter section removed, the sketch being on plain paper. 
 
 Before starting to draw, read and be prepared for examination 
 on paragraphs as follows: 
 
 Freehand Inked Line, page 136, 96. Isometric Drawing of 
 a Cube cut by a Plane, page 161, 123. Hollow Cylinder with 
 a Quarter Section Removed, page 164, 127. 
 
172 
 
 ELEMENTS OF DRAWING 
 
 Exercise and Specific Instructions. Tack down a standard 
 size sheet of plain paper of good quality to take ink and make an 
 Isometric Sketch, in pencil first, of Lathe Spindle (see Fig. 147) 
 
 Fig. 147. Perspective of Tailstock Spindle. 
 
 similar to Fig. 131, page 164, except the key way is to be shown 
 and the sketch dimensioned from the object. The sketch having 
 
 been perfected in pencil, it is to be neatly 
 
 inked in. 
 
 The title of this sheet is Lathe Spindle. 
 
 Fig. 148. Perspective 
 of Lathe Cap. 
 
 136. Sheet V. Make an isometric drawing 
 of a Lathe Cap (see Fig. 148), with a quarter 
 section removed (see Fig. 136, page 166). 
 
 Before starting to draw, read and be prepared 
 for examination on paragraphs as follows : 
 Isometric Drawing of a Sphere, page 165, 129. Isometric 
 Drawing of a Lathe Cap, page 166, 130. 
 
 Specific Instructions. Stamp in and fill out the title form. 
 The title of this sheet is Lathe Cap. 
 
 Make all lines very light until the correct outline is obtained; 
 
 clean the sheet and sketch in the object clear cut and complete. 
 
 Submit the sheet for approval. 
 
 137. Sheet VI. An isometric sketch is to 
 be made of a Lathe Shelf Bracket (see Fig. 
 149), showing the object in two different posi- 
 tions, as illustrated in Fig. 1 50, page 1 73. This 
 sketch is to be finished up in pencil and then 
 inked in freehand. 
 
 Before starting this drawing, read, and be 
 prepared for examination on, paragraphs, as F ~ 149 ._ perspective of 
 
 follows: Shelf Bracket. 
 
 Isometric Drawing of a Wall, page 162, 124. Offset con- 
 struction in Isometric Drawing, page 164, 128. 
 The title of this sheet is Shelf Bracket. 
 
ISOMETRIC DRAWING AND SKETCHING 
 
 173 
 
 *7 
 
 7^ 
 
 W 
 
 Y 
 
 y 
 
 \ 
 
 7 
 
 A/ 
 
 \/\ 
 
 A, 
 
 Y 
 
 * 
 
 
 ^zv 
 
 Yx 
 
 X) 
 
 \ 
 
 2 
 
 7v 
 
 /\ 
 
 2 
 
 \/ 
 
 Y 
 
 \/ 
 
 X 
 
 v/ 
 
 A 
 
 2 
 
 A 
 
 /v/5 
 5Ag 
 
 /SS 
 
 V 
 
 V 
 
 I 
 
 7 
 
 Y 
 
 V 
 
 \7 
 
 7\ 
 
 i 
 
 ^J^ 
 
174 ELEMENTS OF DRAWING 
 
 138. Examination on Chapter V. As a final examination on 
 this chapter make an Isometric Drawing of Tool Rest Support 
 (see Fig. 151) or of any other parts of the Lathe or of parts of 
 any other machine assigned, on plain or ruled paper, and in 
 pencil or ink as directed. Also study the subject matter con- 
 tained in 1 1 6, page 156, to 132, page 167, in preparation for 
 examination. 
 
 Fig. 151. Perspective of Tool Rest Support. 
 
APPENDIX A. 
 
 DRAWING ROOM SYSTEM. 
 
 139. Commercial Drawing Rooms. In practically all com- 
 mercial drawing rooms work is carried on under some fixed 
 system, the nature of which depends upon the character and 
 scope of the work to be accomplished. Such systems usually 
 require that drawings be made to certain standard sizes; that 
 a certain title form providing for specific information be used; 
 that certain styles of lettering be used; that certain conventions 
 and abbreviations be used, and so forth. The value of doing 
 the work of this course under an efficient system can therefore 
 be readily understood, and it is expected that either the system 
 as outlined below or a system provided by the instructor will 
 be followed. 
 
 (a) General Method of Procedure. Having secured instru- 
 ments and supplies (see 2, page 2) proceed with the drawing 
 course beginning with the set of Freehand Lettering Exercises 
 as outlined in 38, page 44 to 52. Next take up the set 
 of Mechanical Drawing Exercises as outlined in 79, page 116, 
 to 91. Then take up the set of Freehand Drawing Exercises 
 as outlined in 100, page 139, to 116, and finally take up the set 
 of Isometric Freehand Sketching Exercises as outlined in 132, 
 page 167, to 139. 
 
 In working up the exercises on each sheet or drawing proceed 
 in the following manner: 
 
 1. Read all text matter assigned and be prepared for ex- 
 amination on same. 
 
 2. Tack down the sheet or drawing (see 73, page 107) and 
 where necessary draw in the border line (see 72, page 106). 
 
 3. Put the title form in the lower right-hand corner. Write, 
 in with ink the wording of the title form as far as possible. 
 
 4. Proceed with the actual drawing as instructed in the text. 
 NOTE. Satisfactory progress can be made only when the 
 
 beginner learns to criticise his own work intelligently as it 
 
 175 
 
176 APPENDIX 
 
 proceeds and when he forms the habit of making at once any 
 changes found necessary from his own criticism or suggested 
 by the instructor. 
 
 Before requesting the instructor to finally inspect a piece of work, 
 the student must check every exercise and bring the work as a whole 
 up to the highest standard of perfection of which he is capable. 
 
 When the exercises appear satisfactory to the instructor, he 
 signs his name (or initials) in the title form after the word " IN- 
 SPECTED." The student is then to write with ink the DA TR 
 FINISHED and the TOTAL ACT UAL HO URS expended on 
 the work; it is then deposited in some prescribed place in order 
 that the instructor may further check it if thought best. 
 
 If deficiencies are found in checking the work, it will be returned 
 once for the student to make the corrections and changes indi- 
 cated. Exceptional care must be taken, when making changes 
 to avoid spoiling the work. 
 
 Work not neatly and accurately corrected will not be approved. 
 
 All changes and corrections indicated must be made at the 
 earliest possible date and the corrected work immediately 
 returned to the proper place by the student. 
 
 If the quality of work done on any part of the sheet, drawing, 
 tracing, or plate is unsatisfactory and cannot be brought to the 
 required standard of perfection by the student, it must be repeated 
 until all requirements are met. 
 
 When inspected work is not returned to the student within a 
 reasonable length of time, this indicates that the instructor in 
 further checking has found no serious deficiencies and has given 
 the work final approval. 
 
 In no case is a student to trace a drawing, make a drawing from 
 a sketch, or do any advanced work which depends upon work previ- 
 ously done, unless the original has been finally approved by the 
 proper instructor. 
 
 (b) Sizes of Drawings. All lettering, sketching and computing 
 work is to be done on " sheets " measuring 8" by loj". (See 
 page 44, 37; page 139, 99; page 166, 131.) All mechanical 
 drawing is to be done on paper or tracing cloth, measuring 12" 
 by 18", this size to be designated by a Capital C. (See page 
 106, 72.) 
 
APPENDIX 177 
 
 (c) Position of Sheet or Drawing on the Board. All sheets 
 and drawings are to be tacked down with the short dimensions 
 to the sides unless other instructions are given. The punched 
 holes of the " sheets " should be at the top and the punched 
 holes of the " drawings " on the left-hand side. (See page 107, 
 
 73.) 
 
 (d) Border Lines. No border line is to be used on small 
 " sheets," but on " drawings " the border line shown in Fig. 73, 
 page 1 06, is to be used. 
 
 (e) Numbering and Lettering of Sheets and Drawings. 
 Sheets of Lettering will be designated by capital letters, begin- 
 ning with A. Sheets of Freehand Drawing will be designated 
 by Arabic numbers beginning with /. Sheets of Isometric 
 Freehand Drawing will be designated by Roman numbers 
 beginning with I. Mechanical Drawings will be designated by 
 the word " DRAWING" followed by the capital Letter C, which 
 is then followed by the number of the drawing the first draw- 
 ing being 101, thus DRAWING C 101. 
 
 (/) Title Form and its Location. On small " sheets " of 
 Lettering, Sketching, and Computing the small Title Form as 
 shown in Fig. 93, page 138, is to be used. For Mechanical 
 Drawings of the 12" by 18" size the large Title Form as shown in 
 Fig. 69, page 100, is to be used. The wording, however, is to be 
 appropriately modified. 
 
 On sheets the title form is to be located in the lower right-hand 
 corner. On drawings with border lines the title form is to be 
 located in the lower right-hand corner just within the border 
 lines, unless other instructions are given. 
 
 (g) Bill of Material and its Location. On drawings requiring 
 a bill of material the Bill of Material form shown in Fig. 70, 
 page 101, is to be used and is to be located just above the title 
 form, unless other instructions are given. 
 
 (h) Style of Lettering. The Freehand Slant Gothic alphabet 
 is to be used. (See Fig. 42, page 57; Fig. 43, page 61; 44, 
 page 62; 45, page 68). 
 
 (i) Conventions and Abbreviations as given in the text 
 matter are to be used whenever necessary, and uniformity in 
 this regard is to be strictly maintained. 
 
INDEX. 
 
 A. 
 
 A, description of the letter, p. 47, 38; p. 63, 47. 
 Abbreviation "&," description of, p. 54, 41. 
 
 for "feet," p. 95, 62. 
 
 for "radius," p. 97, 62. 
 
 for materials, p. 103, 67. 
 Ability to letter, p. 34, 3 1. 
 Acme thread, p. 89, 59. 
 
 Adjacent part conventionally shown, p. 89, 59. 
 Alphabet, Gothic (see also Letters, description of), p. 34, 31. 
 Angles, dimensioning of, p. 97, 62. 
 Appendix A, p. 175, 139. 
 Architect's scale, p. 29, 27. 
 Area, cross-sectioning an, p. 82, 55. 
 Arrangement of views, p. 75, 53. 
 
 and number of views, p. 83, 56. 
 Arrowheads, p. 77, 54. 
 
 position of, p. 95, 62. 
 Arrows, direction, in lettering, p. 38, 34. 
 A. S. M. E. standard screws, p. 126, 84. 
 Assembly drawings, p. 86, 58. 
 Axes, isometric, p. 158, 119. 
 
 isometric reversed, p. 162, 124. 
 
 B. 
 
 B, description of the letter, p. 53, 41; p. 64, 47. 
 
 Ball-pointed pen, p. 3, 2; p. 19, 19. 
 
 Bearing conventionally shown, p. 87, 59. 
 
 Bill of material, general description of, p. 101, 67. 
 
 used in this work, p. 101, 67. 
 
 Blocking or laying out a drawing, p. 84, 56; p. 93, 61. 
 Blotter, p. 4, 2; p. 33, 30. 
 use of a, p. in, 75. 
 
 Blot on a drawing, to remove, p. in, 75. 
 Blue print paper, p. 2, 2; p. 6, 7. 
 
 changes on, p. 116, 78. 
 method of making, p. 7, 7. 
 method of using, p. 116, 78. 
 Blue printing machines, p. 116, 78. 
 Blue print, exercise in making a, p. 121, 81. 
 
 frame, p. 116, 78. 
 Board, drawing, p. 2, 2; p. 7, 8. 
 
 use of, p. 107, 73. 
 
 Bolts, table of U. S. Standard, p. 127, 84. 
 Border lines, layout of, in this work, p. 106, 72. 
 
 use of, on a drawing, p. 106, 72. 
 Bottle holder, p. 112, 75. 
 Bow dividers, p. 3, 2; p. 27, 24. 
 pencils, p. 3, 2; p. 27, 25. 
 design of, p. 27, 25. 
 selection of, p. 27, 25. 
 
 179 
 
l8o INDEX 
 
 Bow pencil^, to test, p. 28, 25. 
 use of, p. 28, 25. 
 pens, p. 3, 2; p. 28, 26. 
 to test, p. 29, 26. 
 use of, p. 28, 26. 
 
 Broken lines, conventional, p. 76, 54; p. 89, 59. 
 Broken sections, conventional, p. 87, 59. 
 Building up a drawing or sketch, p. 137, 97. 
 
 C. 
 
 C, description of the letter, p. 52, 41; p. 64, 47. 
 Calipers, machinists', p. 4, 2; p. 32, 29. 
 inside, p. 32, 29. 
 outside, p. 32, 29. 
 use of, p. 32, 29. 
 Cap screws, p. 128, 84. 
 Capital letters, characteristics of curved, p. 51, 41. 
 
 characteristics of straight line, p. 44, 38. 
 description of, p. 44, 38; p. 51, 41. 
 
 detailed description of each letter (see Letters, description of), 
 spacing of, p. 40, 35. 
 
 Capital and small letters, spacing between, p. 42, 35. 
 Carbonate of soda, p. 4, 2; p. 116, 78. 
 Care of instruments, p. i, i. 
 Center lines, p. 78, 54. 
 
 in lettering, p. 37, 34. 
 on a drawing, p. 108, 74. 
 Center line, symbol for, p. 78, 54. 
 Changes on a drawing, p. 99, 65. 
 
 blue prints, p. 116, 78. 
 tracings, p. 17, 15. 
 Checking drawings, p. 113, 76. 
 Checking, how to proceed in, p. 113, 76. 
 Choice of dimensions, p. 95, 62. 
 
 a scale, p. 93, 61. 
 Circle, dimensioning a, p. 97, 62. 
 Circle, isometric drawing of, p. 159, 120. 
 
 approximate method of making isometric drawing of, p. 160, 121. 
 Cleaning drawings, p. 16, 15. 
 Cloth, tracing, p. 2, 2; p. 6, 6. 
 Colored inks, p. 18, 18. 
 Compasses, p. 3, 2; p. 23, 22. 
 design of, p. 23, 22. 
 use of, p. 25, 22. 
 Compass, head-joint design, p. 23, 22. 
 
 socket-joint design, p. 24, 22. 
 Conventions, p. 87, 59. 
 
 common, p. 88, Fig. 65. 
 Conventional drawing of bearing, p. 87, 59. 
 drilled hole, p. 90, 59. 
 hollow part, p. 87, 59. 
 lines, p. 76, 54; p. 89, 59. 
 methods, p. 87, 59. 
 method of showing an adjacent part, p. 89, 59. 
 
 screw threads in isometric, p. 163, 126. 
 method of showing timber, p. 87, 59. 
 National Acme thread, p. 89, 59 
 screw thread, p. 72, 52; p. 89, 59. 
 sectioning, p. 81, 55. 
 shaft, p. 87, 59. 
 square thread, p. 89, 59. 
 
INDEX l8l 
 
 Conventional steel shape, p. 90, 59. 
 tapped hole, p. 90, 59. 
 V thread, p. 89, 59. 
 Construction of lines, p. 76, 54. 
 Cored holes, p. 97, 62. 
 Covers, Manila, p. 4, 2. 
 Cross sectioning, p. 82, 55. 
 
 conventional, p. 8r, 55; p. 90, 59. 
 instrument for, p. 82, Fig. 64. 
 Cross section, p. 79, 55; p. 83, 55. 
 
 paper, p. 2, 2; p. 5, 4. 
 Crow-quill pen, p. 3, 2; p. 19, 19. 
 Cube, isometric drawing of, p. 157, 118. 
 
 cut by a plane, p. 16*, 123. 
 Curves, French or irregular, p. 2, 2; p. 13, 12. 
 
 use of, p. 13, 12. 
 
 Cylinder, hollow, shown in isometric, p. 164, 127. 
 isometric of, p. 163, 125. 
 
 D. 
 
 D, description of the letter, p. 52, 41; p. 63, 47. 
 Definitions, isometric drawings, p. 158, 119. 
 
 Description of capital letters (see also Letters, description of), p. 44, 38; p. 51, 41. 
 numerals, (see detailed description of), 
 small letters, (see also Letters, description of), p. 60, 47. 
 Detail drawings, p. 85, 57. 
 
 paper, p. 5, 3. 
 
 Dimensioning, p. 34, 31; p. 94, 62. 
 angles, p. 97, 62. 
 castings, p. 95, 62. 
 circles, p. 97, 62. 
 cored holes, p. 97, 62. 
 
 drawings and sketches, p. 94, 62; p. 132, 93. 
 fillets, p. 97, 62. 
 of holes, p. 89, 59. 
 radiuses, p. 97, 62. 
 refinement in, p. 95, 62. 
 rough castings, p. 95, 62. 
 rules for, p. 94, 62. 
 tapers, p. 97, 62. 
 tapped holes, p. 97, 62. 
 threaded pieces, p. 97, 62. 
 working drawings, p. 94, 62. 
 Dimension lines, p. 77, 54. 
 
 numbers, p. 95, 62. 
 Dimensions, purpose of, p. 94, 62. 
 checking, p. 95, 62. 
 choice of, p. 95, 62. 
 limits in, p. 95, 62. 
 location of, p. 96, 62. 
 not to scale, p. 95, 62. 
 numbers, expressing, p. 95, 62. 
 on model letters, p. 38, 34. 
 overall, p. 96, 62. 
 related, p. 96, 62. 
 
 Direction arrows in lettering, p. 38, 34. 
 Distance between letters, p. 39, 35. 
 Dividers, p. 3, 3; p. 26, 23. 
 
 bow, p. 3, 2; p. 27, 24. 
 machinists', p. 4, 2; p. 33, 29. 
 
 use of, p. 33, 29; p. 26, 23. 
 
182 INDEX 
 
 Drawing, an assembly, p. 86, 58. 
 
 arrangement and number of views on, p. 83, 56. 
 blocking out a, p. 84, 56; p. 93, 61. 
 boards, p. 2, 2; p. 7, 8. 
 care of, p. 8, 8. 
 design of, p. 7, 8. 
 use of, p. 107, 73. 
 border line for a, p. 106, 72. 
 building up an assembly, p. 86, 58. 
 
 a detail, p. 137, 97- 
 care of, p. 15, 14. 
 changes on a, p. 99, 65. 
 checking a, p. 113, 76. 
 cleaning a, p. 16, 15. 
 conventional, p. 87, 59. 
 definitions in isometric, p. 158, 119. 
 detail, p. 85, 57. 
 
 dimensioning a working, p. 94, 62. 
 exercises in mechanical, p. 116, 79. 
 free-hand, p. 139, 100. 
 isometric free-hand, p. 167, 132. 
 ink, p. 3, 2; p. 18, 18; p. no, 75. 
 
 care of, p. 18, 18. 
 
 selection of, p. 18, 18. 
 
 use of, p. no, 75. 
 instruments, p. 3,. 2. 
 isometric, p. 156, 116. 
 isometric, of a cube, p. 157, 118. 
 paper, p. 2, 2; p. 4, 3. 
 
 selection of, p. 4, 3. 
 
 part or reference number on a, p. 90, 57; p. 104, 69. 
 pencils, p. 3, 2; p. 14, 14. 
 
 to sharpen, p. 15, 14. 
 
 pens, unsatisfactory results with, p. no, 75. 
 perspective, p. 71, 52. 
 position in which to tack down, p. 108, 73. 
 mechanical, Chapter III, p. 71, 52. 
 notes on a, p. 73, 52; p. 97, 63. 
 numbering and size of, in this work, p. 103, 68. 
 record on a, p. 98, 65. 
 recording patterns on a, p. 104, 70. 
 requirements of a, p. 72, 52. 
 room system, Appendix A, p. 175, 139. 
 scale of a, p. 93, 61. 
 
 selection of, p. 14, 14 
 
 size and numbering of, in this work, p. 103, 68. 
 symbols on a, p. 72, 52. 
 time keeping in, p. 105, 71. 
 title-form on a, p. 100, 66. 
 to fasten on board, p. 107, 73. 
 to ink a, p. no, 75. 
 to make a pencil, p. 108, 74. 
 to protect a, p. 112, 75. 
 to scale, p. 90, 60. 
 Drilled hole, conventional, p. 90, 59. 
 
 E. 
 
 E, description of the letter, p, 45 38; p. 64, 47. 
 Eight, description of the numeral, p. 59, 44. 
 Element of adjacency, definition of, p. 40, 35. 
 
INDEX 183 
 
 Elevation, front and side, p. 75, 53- 
 Ellipse, the sloping, p. 50, 40. 
 Engineer's scale, p. 29, 27. 
 Erasers, p. 3, 2; p. 16, 15. 
 care of, p. 17, 15. 
 selection of, p. 16, 15. 
 use of, p. 16, 15. 
 Erasing shield, p. 3, 2; p. 17, 16. 
 Erasures, how to make, p. 17, 15. 
 
 on tracing cloth, p. 115, 77. 
 Examination in free-hand drawing, p. 154, 115. 
 
 isometric free-hand drawing, p. 174, 138. 
 lettering, free-hand, p. 69, 51. 
 mechanical drawing, p. 130, 90. 
 Exercises in free-hand drawing, p. 139, 100, etc. 
 
 isometric drawing, p. 167, 132, etc. 
 lettering, p. 44, 38, etc. 
 mechanical drawing, p. 116, 79, etc. 
 numerals, p. 60, 45, etc. 
 
 F. 
 
 F, description of the letter, p. 45, 38; p. 66, 47. 
 Fastening the paper or tracing cloth on the board, p. 107, 73. 
 Fasteners, paper, p. 4, 2. 
 
 Faulty lines, p. in, 75. 
 
 Feet, abbreviation for, p. 95, 62. 
 
 Fillets, dimensioning, p. 97, 62. 
 
 Finish mark, p. 98, 64. 
 
 Finished line, p. 78, 54. 
 
 Finish of a surface, p. 98, 64. 
 
 Fit, force, p. 95, 62. 
 
 Five, description of the numeral, p. 59, 44. 
 
 Flat scale, p. 29, 27. 
 
 Force fit, p. 95, 62. 
 
 Formula for making blue-print paper, p. 7, 7. 
 
 Four, description of the numeral, p. 58, 44. 
 
 Fractions, slope of, p. 60, 45. 
 
 how to print, p. 60, 45. 
 Free-hand copies of working sketches, p. 131, 92. 
 
 drawing exercises, set of, p. 139, 100, etc., see also Chapter IV, Table 
 
 of Contents, 
 examination in, p. 154, 115. 
 
 inked lines, p. 136, 96. 
 
 isometric exercises, set of, p. 167, 132, see also Chapter V, Table of 
 
 Contents, 
 examination in, p. 174, 138. 
 
 lines, to draw, p. 134, 95. 
 
 penciled lines, p. 134, 95. 
 
 sketching, p. 132, 93. 
 
 sketches made directly from objects, p. 133, 93. 
 
 working sketches, p. 131, Chapter IV. 
 French curves, p. 2, 2; p. 13, 12. 
 Front elevation, p. 75, 53-. 
 
 G. 
 
 G, description of the letter, p. 52, 41; p. 64, 47. 
 
 Gothic alphabet (see also Letters, description of), p. 34, 31. 
 Guide lines in lettering, p. 37, 34. 
 
184 INDEX 
 
 H. 
 
 H, description of the letter, p. 45, 38; p. 65, 47. 
 Headings and titles, design of, p. 69, 49. 
 Headstock, assembly of lathe, Frontispiece. 
 Holder, bottle, p. 112, 75. 
 
 pen, p. 3, 2; p. 20, 20. 
 Hole, drilled or tapped, p. 90, 59. 
 
 cored, p. 97, 62. 
 Holes, dimensioning, p. 89, 59. 
 
 tapped, dimensioning, p. 97, 62. 
 Hollow part, conventional, p. 87, 59. 
 Horizontal plane of projection, p. 73, 53. 
 
 I. 
 
 /, description of the letter, p. 45, 38; p. 65, 47. 
 Inches, symbol for, p. 95, 62. 
 Inclined lines of lettering, p. 69, 49. 
 Ink, bottle holder, p. 112, 75. 
 colored, p. 18, 18. 
 drawing, p. 3, 2; p. 18, 18; p. no, 75. 
 
 requirements of, p. 18, 18. 
 
 quantity to carry on pen, p. in, 75; p. 137, 96. 
 too little on pen, p. in, 75. 
 too much on pen, p. ni, 75. 
 Inked lines, blotting, p. in, 75. 
 free-hand, p. 136, 96. 
 which meet or intersect, p. in, 75. 
 Inking a drawing, p. 21, 21; p. no, 75. 
 
 order of, p. 113, 75. 
 Instrument cleaner, p. 4, 2; p. 33, 30. 
 Inside calipers, p. 32, 39. 
 Inking exercises, in free-hand drawing, p. 154, 112-114. 
 
 free-hand lettering, p. 56, 43; p. 60, 46; p. 67, 48. 
 isometric free-hand drawing, p. 171, 135 and 137. 
 mechanical drawing, p. 110, 75. 
 Instruments, care of, p. i, i. 
 drawing, p. 3, 2. 
 list of, p. 2, 2. 
 quality of, p. i, i. 
 rag for cleaning, p. 4, 2; p. 33, 30. 
 selection of, p. i. 
 
 Intersecting inked lines, p. in, 75. 
 Invisible line, p. 76, 54. 
 
 threads, p. 89, 59. 
 Irregular curves, p. 2, 2; p. 13, 12. 
 
 selection of, p. 13, 12. 
 use of, p. 13, 12. 
 Isometrics, p. 156, 116. 
 Isometric axes, p. 158, 119. 
 
 reversed, p. 102, 124. 
 conventional thread, p. 163, 126. 
 drawing of a lathe cap, p. 166, 130. 
 
 plane figure, p. 160, 122. 
 sphere, p. 165, 129. 
 wall, p. 162, 124. 
 
 Isometric drawing, offset construction in, p. 164, 128. 
 advantages of, p. 156, 116. 
 and sketching, p. 156, Chapter V. 
 definitions, p. 158, 119. 
 
INDEX 185 
 
 Isometric drawing, disadvantages of, p. 157, 116. 
 of a circle, p. 159, 120. 
 
 approximate method, p. 160, 121. 
 cube, p. 157, 118. 
 cube cut by a plane, p. 161, 123. 
 exercises, set of, p. 167, 132 (see also Chapter Viable of 
 
 Contents). 
 
 principles of, p. 157, 117. 
 line, p. 158, 119. 
 measurements, p. 159, 119. 
 of a cylinder, p. 163, 125. 
 of a half sphere, p. 165, 129. 
 
 of a hollow cylinder with section removed, p. 164, 127. 
 of one-eighth sphere, p. 166, 129. 
 of screw threads, p. 163, 126. 
 origin, p. 158, 119. 
 position, p. 159, 1 20. 
 projection plane, p. 157, 117. 
 sketching, examination in, p. 174, 138. 
 sketching sheets, p. 166, 131. 
 Isometrics, exercises in, p. 167, 132, etc. 
 principles of, p. 157, 117. 
 
 J. 
 
 J, description of the letter, p. 53, 41; p. 66, 47. 
 
 K. 
 
 .K, description of the letter, p. 47, 38; p. 65, 47. 
 Key or chart for spacing, p. 43, 35. 
 
 L. 
 
 L, description of the letter, p. 45, 38; p. 65, 47. 
 Lathe, speed, perspective drawing of, Frontispiece. 
 Laying out or blocking out a drawing, p. 84, 56. 
 Lead pencil, p. 3, 2; p. 14, 14. 
 care of, p. 15, 14. 
 selection of, p. 14, 14. 
 to sharpen, p. 15, 14. 
 Leader, definition of, p. 97, 62. 
 Lengthening or extension bar, p. 23, 22. 
 Letter, ability to, p. 34, 31. 
 Lettering, p. 34, 31. Chapter II. 
 
 and size of letter sheets, p. 44, 37. 
 
 critical study of, p. 36, 32. 
 
 exercises in, p. 44, 38 (see also Chapter II, Table of Contents). 
 
 in bill of material, p. 102, 67. 
 
 inclined lines of p. 69, 49. 
 
 in title form, p. 100, 66. 
 
 on working drawings, p. 34, 31. 
 
 pens, requirements of, p. 19, 19. 
 to break in, p. 20, 19. 
 
 systematic method of, p. 44, 36. 
 Letter A, capital, descr ption of, p. 47, 38. 
 
 Mn ii y '.' _ s . ^_ 
 
 a, small, 
 
 B, capital, 
 
 b, small, 
 
 C, capital, 
 
 c, small, 
 
 D, capital, 
 
 d, small, 
 
 P- 63, 47- 
 P- 53, 
 p. 64, 
 
 P- 52, 
 p. 64, 
 
 P- 52, 
 
 P- 63, 47. 
 
i86 
 
 INDEX 
 
 Letter E, capital, description of, p. 45, 
 
 38. 
 
 e, small, 
 
 ' P- 64, 
 
 
 F, capital, 
 
 P-45, 
 
 38^ 
 
 f, small, 
 
 ' " P- 66, 
 
 47- 
 
 G, capital, 
 
 " P- 52, 
 
 41. 
 
 g, small, 
 H, capital, 
 
 " P-64, 
 p. 45, 
 
 47- 
 38. 
 
 h, small, 
 
 ' p. 65, 
 
 47- 
 
 I, capital, 
 
 P- 45, 
 
 38. 
 
 i, small, 
 
 p. 65, 
 
 47- 
 
 J, capital, 
 
 " P- 53, 
 
 41. 
 
 j, small, 
 
 " P.66, 
 
 47- 
 
 K, capital, 
 
 p. 47, 
 
 38. 
 
 k, small, 
 
 p. 65, 
 
 47- 
 
 L, capital, 
 
 p. 45, 
 
 38. 
 
 1, small, 
 
 p. 65, 
 
 47- 
 
 M, capital, 
 
 " P-46, 
 
 38. 
 
 m, small, 
 
 " P-65, 
 
 47- 
 
 N, capital, 
 
 ' "p. 46, 
 
 38. 
 
 n, small, p. 64, 
 
 47- 
 
 O, capital, p. 51, 
 
 41. 
 
 o, small, " p. 63, 
 
 47. 
 
 P, capital, p. 53, 
 
 41. 
 
 p, small, 
 
 p. 64, 
 
 47- 
 
 Q, capital, 
 
 p. 52, 
 
 41. 
 
 q, small, 
 R, capital, 
 
 P- 64, 
 P- 53, 
 
 47- 
 
 r, small, 
 
 P- 65, 
 
 47- 
 
 S, capital, 
 
 p. 53, 
 
 41. 
 
 s,, small, 
 
 ' " p. 66, 
 
 47- 
 
 T, capital, 
 
 P- 45, 
 
 38. 
 
 t, small, 
 
 1 P- 66, 
 
 47- 
 
 U, capital, 
 
 P- 52, 
 
 41. 
 
 u, small, 
 
 P- 65, 
 
 47- 
 
 V, capital, 
 
 " P-4M 
 
 38. 
 
 v, small, 
 
 " P-6 7 , 
 
 47- 
 
 W, capital, 
 
 P- 47, 
 
 38. 
 
 w, small, 
 
 ' P- 67, 
 
 47- 
 
 X, capital, 
 
 P- 46, 
 
 38. 
 
 x, small, 
 
 p. 67, 
 
 47- 
 
 Y, capital, 
 
 " P-46, 
 
 38. 
 
 y, small, 
 
 P- 65, 
 
 47- 
 
 Z, capital, 
 
 P- 47, 
 
 38. 
 
 z, small, 
 
 " P- 67, 
 
 47- 
 
 &, the symbol, ' p. 54, 
 Letters, capital or upper-case (see Letters, 
 
 General Description of). 
 
 center lines for, p. 37, 34. 
 description of model, p. 37, 34. 
 distance between, p. 39, 35. 
 general appearance of, p. 35, 
 lodel, 
 
 32 
 
 general description of m 
 
 44; p. 60, 47. 
 grouping of, p. 35, 32. 
 guide lines for, p. 37, 34- 
 pattern, p. 105, 70. 
 slope of, p. 36, 33. 
 
 in this work, p. 37, 33. 
 small, p. 42, 35. 
 
 small or lower-case (see Letter, Description of), 
 spacing key or chart for, p. 43, 35. 
 spacing of, p. 39, 35. 
 
 capital, p. 40, 35- 
 stem of, denned, p. 37, 34. 
 
 P. 37, 345 P- 44, 38; P- 5i, 4i; P- 58,, 
 
INDEX 187 
 
 Lettering, examination in, p. 69, 51. 
 
 inclined, lines of, p. 69, 49. 
 in title form, p. 100, 66. 
 study of, p. 34, 32. 
 system of strokes in, p. 38, 34. 
 Limits, dimension, p. 95, 62. 
 Line, an isometric, p. 158, 119. 
 
 a non-isometric, p. 158, 119. 
 
 a "clear-cut," or finished, p. 78, 54. 
 
 to draw an inked, p. in, 75; p. 136, 96. 
 
 to draw a pencil, p. 134, 95. 
 Liner, section, p. 82, 55. 
 Lines, border, p. 106, 72. 
 
 center, p. 78, 54. 
 
 construction of, p. 76, 54. 
 
 conventional, p. 76, 54; p. 89, 59. 
 
 dimension, p. 77, 54. 
 
 faulty, p. in, 75. 
 
 finished, p. 78, 54. 
 
 free-hand inked, p. 136, 96. 
 
 free-hand penciled, p. 135, 95. 
 
 intersecting inked, p. in, 75. 
 
 invisible, p. 76, 54. 
 
 on tracing cloth, p. 115, 77. 
 
 reference, p. 77, 54- 
 
 section, p. 77, 54. 
 
 to draw free-hand, p. 134, 95. 
 
 to draw finished, p. 78, 54. 
 
 to draw parallel, p. 13, n. 
 
 to draw perpendicular, p. 12, n. 
 
 visible, p. 76, 54. 
 
 "weight" of, p. 76, 54. 
 List of instruments and supplies, p. 2, 2. 
 Longitudinal section, p. 79, 55. 
 Lower-case or small letters (see also Letters, Description of), p. 60, 47. 
 
 M. 
 
 M, description of the letter, p. 46, 38; p. 65, 47. 
 Machine screws, p. 126, 84. 
 Machinist's calipers, p. 4, 2; p. 32, 29. 
 dividers, p. 4, 2; p. 33, 29. 
 selection of, p. 32, 29. 
 use of, pp. 32 and 33, 29. 
 scale, p. 4, 2; p. 32, 29. 
 Manila covers, p. 4, 2. 
 Materials, conventions for, p. 81, 55. 
 
 abbreviations for, p. 103, 67. 
 bill of, p. 101, 67. 
 indicated by numbers, p. 81, 55. 
 Measurements, p. 30, 27. 
 
 in isometric drawing, p. 159, 119. 
 Mechanical drawing, Chapter III, p. 71, 52. 
 
 examination in, p. 130, 90. 
 
 principles underlying, p. 71, 52. 
 
 set of exercises in, p. 116, 79 (see also Chapter III, Table 
 
 of Contents). 
 
 Memory, sketching from, p. 134, 94. 
 
 Method of drawing angles with triangles and T-square, p. 12, n. 
 parallel lines, p. 13, n. 
 
1 88 INDEX 
 
 Micrometer, p. 33, 29. 
 
 Model Letters, general description of, p. 37, 34. 
 
 N. 
 
 TV, description of the letter, p. 46, 38; p. 64, 47. 
 
 National acme thread, p. 89, 59. 
 
 Naught, the numeral, description of, p. 58, 44. 
 
 Needle point for instruments, p. 24, 22. 
 
 Nine, description of the numeral, p. 58, 44. 
 
 Non-isometric lines, p. 158, 119. 
 
 Notes on a drawing, p. 73, 52; p. 97, 63. 
 
 style of lettering for, p. 98, 63. 
 Number and arrangement of views, p. 83, 56. 
 
 reference or part, p. 90, 59; p. 104, 69. 
 
 used to indicate materials, p. 81, 55. 
 Numbering and size of sheets, p. 139, 99; p. 166, 131. 
 
 of drawings, p. 103, 68. 
 
 Numbers (see Numerals, description of), p. 37, 34. 
 Numeral i, description of, same as capital I, p. 45, 38. 
 
 P- 59, 8 44- 
 p. 59, 44. 
 p. 58, 44. 
 P- 59, 44- 
 
 P- 59, 44- 
 I! P-S8,44. 
 P- 59, 44- 
 " P- 58, 44- 
 naught, description of, p. 58, 44. 
 Numerals, exercise in making, p. 60, 45. 
 spacing of, p. 42, 35. 
 
 O. 
 
 O, description of the letter, p. 51, 41; p. 63, 47. 
 Objects, sketches of, p. 132, 93. 
 Offset construction in isometric drawing, p. 164, 128. 
 Operation sheets, p. 85, 57. 
 Order of inking a drawing, p. 113, 75. 
 checking a drawing, p. 113, 76. 
 penciling a drawing, p. 109, 74. 
 Ordinary pens, p. 3, 2; p. 18, 19. 
 
 care of, p. 19, 19. 
 
 selection of, p. 19, 19. 
 
 use of, p. 137, 95. 
 Origin, isometric, p. 158, 119. 
 Orthographic projection, p. 73, 53- 
 Outside calipers, p. 32, 29. 
 Overall dimensions, p. 96, 62. 
 
 P. 
 
 P, description of the letter, p. 53, 41; p. 64, 47. 
 Paper, blue print, p. 2, 2; p. 6, 7; p. 116, 78. 
 
 cross section ruled, p. 2, 2; p. 5, 4. 
 
 drawing, p. 2, 2; p. 4, 3. 
 
 fasteners, p. 4, 2. 
 
 isometric ruled, p. 2, 2; p. 5, 4. 
 
 ruled, p. 2, 2; p. 5, 4. 
 
 to fasten on drawing board, p. 107, 73. 
 
 tracing, p. 6, 5. 
 
 Whatman's, p. 5, 3. 
 
INDEX 189 
 
 Parallel lines, method of drawing, p. 13, n. 
 Part or reference number, p. 90, 59; p. 104, 69. 
 Part numbers in bill of materials, p. 102, 67. 
 Parts, detailed on a single sheet, p. 85, 57. 
 
 grouping of, on a single sheet, p. 85, 57. 
 standard, p. 103 67; p. 26, 84. 
 Pattern letters on a drawing, p. 105, 70. 
 Pattern maker's rule, p. 92, 60. 
 Pattern numbers, p. 105, 70. 
 
 in a bill of material, p. 102, 67. 
 Patterns, recording on a drawing, p. 104, 70. 
 Pen, quantity of ink to carry on a, p. 137, 96. 
 Pencil, bow, p. 3, 2; p. 27, 25. 
 
 drawing, method of making a, p. 108, 74. 
 
 eraser, p. 3, 2; p. 16, 15. 
 
 lead, p. 3, 2; p. 14, 14. 
 
 lines, free-hand, p. 134, 95. 
 
 pointer or sharpener, p. 3, 2; p. 14, 13. 
 
 sharpener or pointer, p. 14, 13. 
 
 sketching, p. 134, 95. 
 
 to form a chiseled edge on a, p. 16, 14. 
 
 cone point on a, p. 15, 14. 
 to sharpen a, p. 15, 14. 
 Penciling, order in which to do, p. 109, 74. 
 Penholders, p. 3, 2; p. 20, 20. 
 Pens, ball -pointed, p. 3, 2; p. 19, 19. 
 bow, p. 3, 2; p. 28, 26. 
 crow-quill, p. 3, 2; p. 19, 19. 
 for lettering, p. 19, 19. 
 ordinary, p. 3, 2; p. 18, 19. 
 ruling or drawing, p. 3, 2; p. 20, 21. 
 styles of, p. 18, 19. 
 to adjust the ruling, p. 20, 21. 
 to clean the ruling, p. 22, 21. 
 to fill the ruling, p. 21, 21. 
 to sharpen the ruling, p. 22, 21. 
 to test, -the ruling, p. 23, 21. 
 use of the ruling, p. 21, 21. 
 wiper for, p. 33, 3- 
 Pen-wiper, p. 4, 2; p. 33, 30. 
 Perspective drawing, p. 71, 52. 
 Plan view, p. 75, 53. 
 
 Plane figure, isometric drawing of a, p. 160, 122. 
 Planes of projection, p. 73, 53. 
 Position, isometric, p. 159, 120. 
 Principles of mechanical drawing, p. 71, 52. 
 isometric drawing, p. 157, 117. 
 Problems (see Exercises) . 
 Projecting rays, p. 73, 53. 
 Projection, p. 73, 53. 
 
 isometric, p. 157, 117. 
 orthographic, p. 73, 53. 
 planes of, p. 73, 53. 
 third angle, p. 74, 53; p. 84, 56. 
 Proportioning by eye, p. 133, 93. 
 Protractors, p. 4, 2; p. 31, 28. 
 use of, p. 31, 28. 
 
 Q. 
 
 Q, description of the letter, p. 52, 41; p. 64, 47. 
 Quarter -section view, p. 83, 55. 
 
I QO INDEX 
 
 R. 
 
 R, description of the letter, p. 53, 41; p. 65, 47. 
 Radius, dimensioning a, p. 97, 62. 
 
 symbol or abbreviations for, p. 97, 62. 
 Rag, instrument, p. 4, 2; p. 33, 30. 
 Rays, projection, p. 73, 53. 
 Record forms and titles, p. 98, 65. 
 
 kept on a drawing, p. 98, 65. 
 Recording patterns on a drawing, p. 104, 70. 
 Reference lines, p. 77, 54. 
 
 or part numbers, p. 90, 59; p. 104, 69. 
 Reversed axes, isometric, p. 162, 124. 
 Rhombus (or rhomb), footnote, p. 158. 
 ^Ruled paper, p. 2, 2; p. 5, 4- 
 
 care and use of, p. 5, 4. 
 
 Rule or scale, p. 3, 2; p. 29, 27; p. 32, 29. 
 shrink, p. 92, 60. 
 special, p. 92, 60. 
 Rules for dimensioning, p. 94, 62. 
 Ruling or drawing pens; p. 3, 2; p. 20, 21. 
 care of, p. 22, 21. 
 design of, p. 20, 21. 
 to adjust, p. 20, 21. 
 to clean, p. 22, 21. 
 to fill, p. 21, 21. 
 to sharpen, p. 22, 21. 
 to test, p. 23, 21. 
 use of, p. 21, 21. 
 
 S. 
 
 S, description of the letter, p. 53, 41; p. 66, 47. 
 Scale or rule, p. 3, 2; p. 29, 27; p. 32, 29. 
 architects', p. 29, 27. 
 care of, p. 31, 27. 
 choice of, in drawing, p. 93, 61. 
 design of, p. 29, 27. 
 determining the, p. 93, 61. 
 divisions on a, p. 90, 60. 
 drawing, p. 90, 60. 
 engineers', p. 29, 27. 
 flat, p. 29, 27. 
 
 for several parts on a single sheet, p. 94, 61. 
 machinists', p. 4, 2; p. 32, 29. 
 most commonly used, p. 91, 60. 
 of a drawing, p. 93, 61. 
 to draw to, p. 90, 60. 
 to read a, p. 91, 60. 
 to test the accuracy of, p. 31, 27. 
 triangular, p. 30, 27. 
 use of, p. 30, 27. 
 Screw thread, p. 72, 52; p. 89, 59. 
 
 conventionally shown, p. 89, 59. 
 isometric drawing of, p. 163, 126. 
 Screws, cap, p. 128, 84. 
 
 A.S.M.E. standard, p. 126, 84. 
 machine, p. 126, 84. 
 various forms of, p. 126, 84. 
 Section, a turned-up, p. 83, 55. 
 compound, p. 79, 55. 
 liner, p. 82, 55. 
 
INDEX IQI 
 
 Section, lines, p. 77, 54- 
 
 longitudinal, p. 79, 55. 
 transverse, p. 79, 55. 
 Sectional views, p. 79, 55. 
 
 location of, p. 83, 55. 
 Sectioning adjoining pieces, p. 82, 55. 
 an area, p. 82, 55. 
 and sectional views, p. 79, 55. 
 conventional, p. 79, 55. 
 isometric, p. 164, 127. 
 ordinary, p. 81, 55. 
 spacing of lines in, p. 82, 55. 
 Selection of instruments, p. i, i. 
 Sentences, spacing between, p. 42, 35. 
 Set of free-hand drawing exercises, p. 139, 100, etc. 
 
 isometric drawing exercises, p. 167, 132, etc. 
 lettering exercises, p. 44, 38, etc. 
 mechanical drawing exercises, p. 116, 79, etc. 
 Seven, description of the numeral, p. 58, 44. 
 Shaft, conventionally shown, p. 87, 59. 
 Sharpener, pencil, p. 3, 2; p. 14, 13. 
 Sheets, operation, p. 85, 57. 
 
 size and numbering of, p. 139, 99; p. 166, 131. 
 title form for, p. 138, 98. 
 Shield, erasing, p. 3, 2; p. 17, 16. 
 Shrink rule, p. 92, 60. 
 Side elevations, p. 75, 53. 
 
 Size and numbering of sheets, p. 139, 99; p. 166, 131. 
 Six, description of the numeral, p. 59, 44. 
 
 and lettering of letter sheets, p. 44, 37. 
 and numbering of drawings, p. 103, 68. 
 Sketches, free-hand, from objects, p. 132, 93. 
 on cross-section paper, p. 133, 
 value and use of, p. 131, 91. 
 Sketching, examination in free-hand exercises (see Exercises in Free-hand Drawing 
 
 and Exercises in Isometric Free-hand Sketches), p. 154, 115. 
 Sketching from memory, p. 134, 94. 
 Sketch sheets, size and numbering of, p. 139, 99; p. 166, 131. 
 
 to build up a, p. 137, 97. 
 Slope of fractions, p. 60, 45. 
 
 letters, p. 36, 33. 
 Sloping ellipse, p. 50, 40. 
 Small or lower-case letters, detail description of (see also Letters), p. 60, 47. 
 
 spacing of, p. 42, 35. 
 Soapstone, p. 3, 2; p. 18, 17. 
 
 use of, p. 18, 17. 
 
 Soda, carbonate of, p. 4, 2; p. 116" 78. 
 Spacing for various line-combinations in lettering, p. 39, 35. 
 Speed lathe, perspective of, Frontispiece. 
 Sphere, isometric drawing of a, p. 165, 129. 
 Spacing, key or chart for, p. 43, 35. 
 
 between section lines, p. 82, 55. 
 of capital letters, p. 40, 35. 
 of numerals, p. 42, 35. 
 of words and sentences, p. 42, 35. 
 Standard parts, p. 103, 67; p. 126, 84. 
 Steel scale, p. 4, 2; p. 32, 29. 
 Structural steel cross-sections, p 90, 59. 
 Studs, p. 127, 84. 
 Square, T-, p. 2, 2; p. 8, 10. 
 Square thread conventionally shown, p. 89, 59. 
 
IQ2 INDEX 
 
 Steel shapes, conventional, p. 90, 59. 
 
 Stem of letters, p. 37, 34. 
 
 Strokes, system of, in lettering, p. 38, 34. 
 
 Study of lettering, p. 34, 32. 
 
 Sub-dimensions, p. 96, 62. 
 
 Supplies, list of, p. 2, 2. 
 
 quality of, p. i, i. 
 Surfaces, finished, p. 98, 64. 
 Symbols on a drawing, p. 72, 52. 
 Symbol for "center line," p. 78, 54. 
 
 "inches," p. 95, 62. 
 
 Systematic method of lettering, p. 44, 36. 
 System, drawing-room, p. 175, Appendix A. 
 
 T. 
 
 r, description of the letter, p. 45, 38; p. 66, 47. 
 T-square, p. 2, 2; p. 8, 10. 
 care of, p. 10, 10. 
 design of, p. 9, 10. 
 test of, p. 9, 10. 
 use of, p. 10, 10. 
 
 Table of U. S. standard bolts, p. 127, 84. 
 Tacks, thumb, p. 2, 2; p. 8, 9. 
 Tail stock, assembly of, Frontispiece. 
 Tapers, dimensioning, p. 97, 62. 
 Tapped holes, conventionally shown, p. 90, 59. 
 
 dimensioning, p. 97, 62. 
 Test for T-square, p. 9, 10. 
 
 ruling pen, p. 23, 21. 
 triangles, p. u, 12. 
 
 Third angle projection, p. 74, 53; p. 84, 56. 
 Threads, conventionally shown, p. 72, 52. 
 Thread, invisible, p. 89, 59. 
 
 National Acme, p. 89, 59. 
 square, conventional p. 89, 59. 
 V, conventional, p. 89, 59. 
 Threaded piece, dimensioning a, p. 97, 62. 
 
 portion, length of, p. 89, 59. 
 Three, description of the numeral, p. 59, 44. 
 Threads, forms of, p. 89, 59. 
 Thumb tacks, p. 2 2; p. 8, 9. 
 
 selection of, p. 8, 9. 
 . use of, p. 8, 9. 
 Time-keeping in drawing, p. 105, 71. 
 Timber, conventionally shown, p. 87, 59. 
 Title form on a drawing, p. 100, 66. 
 
 small sheets, p. 138, 98. 
 Titles and headings, design of, p. 69, 49. 
 
 on a drawing, p. 69, 49; p. 98, 65. 
 Tracing, p. 114, 77. 
 
 care of, p. 6, 6; p. 115, 77. 
 cloth, p. 2, 2; p. 6, 6. 
 
 choice of working side, p. 6, 6; p. 115, 77. 
 to clean, p. 115, 77. 
 to fasten on drawing board, p. 107, 73. 
 use of, p. 6, 6. 
 erasures on a, p. 115, 77. 
 exercises in (see also set of Mechanical Drawing Exercises in, Table of 
 
 Contents, Chapter III), 
 paper, p. 6, 5. 
 to make a, p. 114, 77. 
 
INDEX 193 
 
 Transverse section, p. 79, 55. 
 Triangle, p. 2, 2; p. 10, n. 
 
 selection of, p. 10, n. 
 
 use of, p. 12, ii. 
 
 test for 90 angle of a, p. II, $ XI. 
 45 angle of a, p. 11, 11. 
 30 also 60 angle of a, p. 12, 11. 
 Triangular scales, p. 30, 27. 
 Turned-up section, p. 83, 55. 
 Two, description of the numeral, p. 59, 44. 
 
 U. 
 
 U, description of the letter, p. 52, 41; p. 65, 47. 
 Upper-case or capital letters (see Letters, Description of). 
 U. S. standard bolts, p. 127, 84. 
 
 V. 
 
 V, description of the letter, p. 46, 38; p. 67, 47. 
 
 Vertical plane of projection, p. 73, 53. 
 
 View, plan, front and side, p. 75, 53. 
 
 Views, arrangement of, p. 75, 53; p. 83, 56. 
 
 how to work up, p. 74, 53; p. 86, 57; p. 109, 74. 
 
 number of, p. 83, 56; p. 103. 
 
 projected, p. 73, 53. 
 Visible lines, p. 76, 54. 
 V thread, conventional, p. 89, 59. 
 
 W. 
 
 W, description of the letter, p. 47, 38; p. 67, 47. 
 Wall, isometric drawing of a, p. 162, 124. 
 Wedge, pencil sharpened to a, p. 16, 14. 
 Weight of lines, p. 76, 54. 
 Whatman paper, p. 5, 3. 
 Wiper, pen, p. 4, 2; p. 33, 30. 
 Words, spacing between, p. 42, 35. 
 Working drawings, dimensioning, p. 94, 62. 
 
 X. 
 
 X, description of the letter, p. 47, 38; p. 67, 47. 
 
 Y. 
 
 F, description of the letter, p. 46, 38; p. 65, 47. 
 
 Z. 
 
 Z, description of the letter, p. 47, 38; p. 67, 47. 
 
-:,: ' 
 
 
 ; . 
 
 , 
 
UNIVERSITY OF CALIFORNIA LIBRARY 
 
 i 
 
 : 
 
 . . : . g | 
 
 - :v-. HI 
 
 ;/: : H :':,- 
 
 I