SUBJECT INDEX 



997 



Sylvite: 



density of -, 79 



susceptibility of -, 310 

 Synclines, 15, 61, 151, 153, 161, 252, 259, 

 262, 263, 396, 400, 772, 773 



T 



Tagg interpretation method, 726-731 

 Talc: 

 density of -, 80 



- deposits, 55 

 Tangent galvanometer, 365 

 Tangent method, 349, 365 

 Tank experiments, 701, 734, 7'S3 

 Tank farms, magnetic effects of, 374 

 Tanks, water, 912 



Taylor seismograph, 609 

 Taylor shale, 285 

 Telemeter, 930, 931 

 Telescope, zenith, 113 

 Tellurides, resistivity of, 657 

 Temperature : 



- coefficient of resistivity, 639 



- coefficient of torsion wire, 197 



- correction for pendulum, 118 

 effect of -, on gravimeters, 133, 134 

 effect of -, on magnetometers, 326-328, 



331, 337, 338, 366, 367 

 effect of -, on rock magnetism, 16, 317 

 effect of -, on torsion balance, 197, 198 



- gradient (see Gradient, geothermal) 

 low -, 899 



- measurements in wells, 9, 33, 41, 42, 



47, 837-862 



- of rocks, 839, 844-853 

 transient -, causes of, 853-860 



- variation, diurnal and annual, 860- 



862 

 Tension tests, 457 



Terraces, 45, 70, 514, 516, 517, 520, 521, 529 

 Terrain: 



- corrections and effects, 11, 14, 71, 



137-140, 169, 213-240, 375, 376, 

 509, 551, 622, 623, 702, 703, 763, 

 771, 808, 809, 816, 860, 861 



- in relation to geophysical operations, 



6, 48 

 Terrain-clearance indicator, 64, 813, 



817, 942 

 Terrestrial magnetism, 3 

 Terrometer, 628, 823 

 Tertiary formations, density of -, 82 

 Test block (see Shaking table) 

 Testing methods: 



- for density, 71, 72 

 dynamic -, 914-928 



- for elasticity, 452-466, 927 



- for electrical properties, 642-656 



- for magnetism, 297-309 



- for radioactivity, 876-883 



- for thermal properties, 849-951 

 well -, 825-869 



Tetrahedrite, density of, 78 



Thal§n-Tiberg magnetometer, 349 

 Thenardite, density of, 78 

 Theodolite, magnetic, 355-358, 366 

 Thermal conductivity, 847-853, 860 

 Thermal detection, 9, 64 

 Thermal diffusivity, 846, 847, 860, 861 

 Thermal gradient (see Gradient, geo- 

 thermal) 

 Thermocouple, 840, 841, 843, 850 

 Thermoelement, 844 

 Thermometer : 



bimetallic -, 843 



Bourdon tube -, 366 



- carriers, containers, 841, 842 

 maximum -, 841, 842, 843 

 mercury -, 321, 334, 840, 841 

 overflow -, 841 



resistance -, 840, 843, 850 

 thermocouple - (see Thermocouple) 

 Thermonatrite, density of, 78 

 Thermostat, 133 

 Third curve, 829 

 Thomson-Thal6n magnetometer, 347, 



348, 351 

 Thorium, 870, 872-874, 877 

 Three-dimensional geologic bodies, 

 144-150, 153, 250, 253-258, 265, 266, 

 269, 270, 375, 381-385, 390-395 

 Tides, 163, 164 

 effect of -, on gravity, 165, 166 

 effect of -, on torsion balance, 166 

 Time constant, 757, 758, 760-762 

 Time gradient, 557, 558, 564-566 

 Time signals (see also Transmission of 

 time signals and Shot-instant 

 transmission), 106, 113-115 

 Time variations of gravitational field, 



162-167 

 Time variations of magnetic field, 367- 



372 

 Timing, time marking, 20, 464, 465, 



552, 555, 614, 615 

 Tin, 51, 73 



Titanite, density of, 78 

 Titano-magnetite, 314 

 Tonpilz, 946, 948 

 Topaz, density of, 80 

 Topographic correction (see Terrain cor- 

 rection) 

 Topography (see Terrain) 

 Top soil (see Soil) 



Torsion balance (Eotvos) 8, 9, 11, 13, 40, 

 45-48, 52, 53, 55, 61, 170-292 

 Askania -, 193-195 

 Bamberg -, 193 

 Berroth -, 191 



calculation of results, 199-210 

 Cavendish -, 85 



- coast effect, 241-242 



- corrections, 210-244 



- equations for three positions, 180 



- equations for four positions, 181 



- equations for five positions, 183-184 



