Part II. Preparation by Draftsmen.

General directions 41 Instruments 42 Classification of material 42 Preparation of maps 43 Projection 43 Details of base maps 45 Transferring or copying 46 Tracing 46 Celluloid transferring 47 Sketching by reticulation 47 The "shadowless drafting table" 47 Topographic features 48 Relief 48 Hydrography 51 Cultural features 52 Lettering 53 General directions 53 Lettering by type 54 Abbreviations 55 Names of railroads 57 Make-up of maps 57 Forms for certain features 57 Border 57 Title 58 Explanation 58 Graphic scales for maps 59 Symbols 61 Areal patterns for black and white maps 61 Standard colors for geologic maps 63 Reduction or enlargement of maps 63 Diagrams 64 Sections 64 Plans and cross sections of mines 65

Drawings of specimens of rocks and fossils 66 Methods used 66 Brush and pencil drawings 66 Pen drawings 67 Retouching photographs of specimens 68 Landscape drawings from poor photographs 68 Pen drawings made over photographs 68 Brush drawings from poor photographs 69 Outdoor sketches 69 Drawings of crystals 70 Retouching photographs 70