Gasoline Engines, v, 156-61; in aeroplanes, 231; efficiency, 155; compared with motors, vii, 223; operation, 123-33 Gas Plant, xiii, 136-7 Gas Shells, i, 308, 314, viii, 263 Gastric Digestion, ix, 234-6, x, 319-25 Gastric Glands, control of, ix, 162, 240-2 Gastric Juice, viii, 358, ix, 234-8, x, 319-20; control of secretion of, ix, 240-2; conveyance of, 189-90; disorders of, x, 321-3; historical studies of, ix, 239-40; indigestion from failure of, 239-41 Gas Warfare, viii, 262-4, x, 186-8 Gatling Guns, v, 362-3, 364, 380 Gatun Lake, Panama, xiv, 195 Gaurs, xii, 330 Gay-Lussac, balloon ascensions, i, 18; chemical work, xvi, 133, 160, 162 Gazelles, xii, 327 Gearing, in turbine-driven ships, v, 105, 153-4, vii, 329 Gears, v, 25-31; hydraulic, 104-6; spiral, 38-9; toothed, disadvantages, 104; worm, 37 (fig.), 38 Geckos, xii, 205-6 Geese, xii, 257, 258 Gelatine, colloidal state, viii, 314, 315, 356; food value, ix, 288 General Electric Company, autotransformers, vi, 337; bulletin on motor costs, vii, 224-6; machinery for Niagara Plant, vi, 374, 375, 376, 377; Mazda lamps, 267; radio engineering work, vii, 274; small power sets, 232 Generators, vi, 49-56, vii, 369; alternating current, vi, 158-9, 196-216 (see also Alternators); armature reaction, vii, 145-6; direct current, vii, 175-94 (see also Direct Current Generators); efficiency, vi, 192-4, 214-15, 357, 379; electrostatic, 298-301; induction motors as, 249-50; neutral points, vii, 373; operation in power plants, vi, 357-8, 362; of Niagara Plant, 374-5; principal parts, 176; purpose and parts, vii, 367; radio, 274-8, 282-3, 290-1; ratings, vi, 192-4, 214-15; regulation of output, vii, 144-50; short-circuit protection, 49; size of units, vi, 378-9; slow and high speed, 182; turbine-driven, v, 151, 154; use in therapeutics, vii, 236-7, 241-5 (see also Dynamos) Genetics, xvi, 157-8 Geneva Lake, filling of, by Rhone River, xiv, 53; former connections, 185; slow movement of water, 210 Genital Organs, foci of infection in, x, 220, 221 Genius, Bessel on, ii, 93; obstacles and, xvi, 30; reflex action of, xi, 36; Titchener on, 225-6 Genoa, growth of, xiv, 308; sea captains of, 310 Gentians, xiii, 190, 205 Genus, Genera, defined, xii, 28, xiii, 170, 171 Geocentric Theory, ii, 9-10, 34-5 (see Ptolemaic System) Geo-Chemistry, viii, 190-203 Geocoronium, i, 192, 373 Geographical Change, agents of, xiv, 31-2, 33-79 Geographical Cycles, xiv, 29, 34-5, 48 (see Cycles of Erosion) Geographical Distribution, science of, xvi, 140