Chicago pin map for population, 246 Chicago telephone rates, 126 Choice of scales, 352

Cincinnati, homes of factory workers, 214 Circle and sectors, 5 Circles compared, 36, 37 Clamps for hanging maps, 232 Cleveland Plain Dealer, 92 Cloak and suit industry in New York, 166 Coals, comparative value of, 88 Coloring maps, 209 Color-printing, 5, 331 Colors for chart work, 57 Columns of figures, order for, 45 Combined curves, 125 Commerce of the United States, 70, 71

of the world, 76 Commercial geography, 21 Commercial Museum of Philadelphia, 70,

74, 76, 112 Commission on Economy and Efficiency,

33, 34 Comparisons, 20

involving time, 36 Comparison of curves, 107 Compo-board, 232

Component parts, 1

parts grouped, 33

parts shown by curves, 138 Compound-interest curve, 131 Conjugal condition of population, 9

of population of United States, 168, 169 Construction of graphical charts, 335 Co-ordinate lines, spacing of, 362

paper, 55

paper for weekly records, 150

paper, universal, 60

ruling, 284 Copper production, 26 Copying drawings, 329 Copyrights on maps, 237 Cork composition for map mounting, 232 Corn crop in United States, 44

planting dates in United States, 213

yield and rainfall, 124

yield per acre in United States, 217 Corporation directors, 289, 298

executives, 28D

financial reports, 307

record department, 292 Correlation, 129, 199

definition of, 199 Corrugated straw-board for map pins, 191 Cost analysis by pin boards, 191, 192

of handling freight, 184, 188, 192 Cotton goods, production and export, 74,

Cotton production, 22

production and export of United States, Country Gentlevian, 213, 215, 232 Cows, individual record curves for, 278, 279 Crayons for coloring maps, 57, 221 Crayons, paraffin, 57 Crests and valleys of curves, 79