Peridotite. Wyomingite. Perknite. Yamaskite. INDEX. A. Abbreviations, forms of. 55-67 Adhesive materials, choice. 37 Alaska, maps of, reuse of. 17 Albertype. _See_ Photogelatin processes. Apparatus, photographs of, preferred to sketches. 29 Approval of finished drawings, features to be covered by. 38 of illustrations, regulations governing. 80 Areas, patterns used to distinguish. 23 patterns used to distinguish, plate showing. 62 Army, Corps of Engineers of the, maps published by. 15 Artotype. _See_ Photogelatin processes. Atlases, published, use of. 15 B. Base maps. _See_ Maps, base. Bleaching photographic prints, method and solutions for. 69 Border for maps, width and use of. 57-58 Bristol board, kind Mid sizes used. 24,66 Brash and pencil drawings, materials and methods used in making. 66-67, 69 Brushes, kinds and sizes used. 66-67,71 C. Celluloid transferring, process of. 47 requisitions for. 47 Cerotype process, description and advantages of. 80-81 Changes in engravings, possible kinds of. 38-39, 90 Changes in original material, draftsman to consult author on. 65 Chemical elements, names and symbols of. 98 Chromolithography, description of. 87-80 Civil divisions, lettering of. 53, 54 Coal beds, indication of thickness of. 31 Coast and Geodetic Survey charts, use of. 15 Collotype. _See_ Photogelatin processes. Coloring materials, use of. 26 Colors, standard, for geologic maps. 62-63 use of, for ground-water features. 21-23 on original geologic maps. 27-28 Commas, form of. 54 use of, in numbers. 54 Contours, drawing of. 48-50 Cooperation, mention of. 13 Copper, engraving on. 89, 90 etching in relief on, process and advantages of. 75 Copying methods of. 46-48 Corrections. _See_ Changes. Cost of photo-engravings. 75, 78, 80, 81 County maps, use of. 15 Crayons, wax, use of. 26, 50, 51 Credit for data of maps, indication of. 13 Crystals, drawings of, making and lettering of. 70 Cultural features, lettering of. 53-54 list of. 52-53 Curves, date showing. 64 Cuts. _See_ Engravings. D.