998 



SUBJECT INDEX 



Torsion balance (cont'd) : 

 Fechner -, 193 

 Gepege -, 194 

 graphical representation of data, 244- 



250 

 Haalck -, 186 

 Haff -, 194 

 Hecker -, 186 

 interpretation: 



- diagrams (Barton), 266, 267 



- diagrams (Numerov), 265 



- integraph (Askania), 269-270 



- method (Below), 268 



- of results, 14, 15, 215-270, 393 

 Kilchling -, 189 



magnetic -, 303, 355, 380 



- in mining, 286-292 

 Nikiforov -, 194 

 Numerov -, 187 

 Oertling -, 193 



- in oil exploration, 272-286 

 operation of -, 206-210, 239-240 

 principal equation of -, 178 

 principle of -, 13-15, 170-178 



- regional gradient, correction for, 



240-241, 246, 251, 262, 281 



- results, 270-292, 409-4U 

 rotating -, 189 



Rybar -, 194 

 Schweydar -, 194 

 sensitivity of -, 198, 199 

 Suess ^, 193, 194 

 Tangl -, 194 



- terrain corrections, 71, 75, 213-240 

 theory of -, 175-192 



tilt beam -, 13, 194, 195 



Tsuboi -, 193 



-underground corrections, 242-244 



Z beam -, 194 

 Torsion coefficient {see Coefficient) 

 Torsionless position, 14, 177, 178, 179, 



184, 199, 200, 204, 206 

 Torsion tests, 460 

 Torsion wire, 11, 13, 177, 178, 194-198, 342 



calibration of -, 195-197 

 Total intensity (magnetic)^ 16, 293, 

 295, 319, 342-344, 364, 379-390, 

 400, 418 

 Tourmaline, density of, 80 

 Trachyte: 



density of -, 81 



heat conductivity of -, 849 



radioactivity of -, 874 

 Transceiver, 497, 955 

 Transducer, 552, 591, 593, 595, 933 

 Transformer: 



differential -, 696, 820 



reference -, 695, 696, 781, 783 

 Transients : 



electrical - (see also Eltran methods), 

 30, 625, 757-763 



seismic -, 587, 588, 590 



Transmission: 



- constant, 594, 595, 602, 603, 606, 617 



- factor, 811 



- of time signals and shot instant, 10, 



20, 106, 113-117, 465, 496, 497, 503, 

 504, 950, 951 



Transmission and reception points, spac- 

 ing of, 7, 19, 437, 621-623 



Transmitters : 

 coil -, 821-824 



- in electromagnetic prospecting, 774- 



778 

 radio-, 114-116, 496, 497, 812, 815-817, 



819, 823, 824, 950, 951 

 sound -, 936-937, 945-956 

 Transportation, 6, 44 

 Transverse: 

 -waves, 447, 448, 450-452, 472, 473, 

 913, 926 



- wave velocities, 472-474, 913, 927 

 Trap rock: 



density of -, 75 



heat conductivity of -, 849 



resistivity of -, 661 



Travel time, 4, 20, 22, 44, 484, 494, 497, 

 498, 500, 502, 504-507, 509-517, 

 519, 521-525, 527, 528, 533-536, 

 541-544, 546-549, 556-572, 576, 578, 

 579, 863, 940, 941, 944, 952 



Travel-time curve, 441, 451, 499-502, 

 504-512, 514, 516-522, 525-529, 531, 

 534, 537-542, 544-546, 557, 560, 

 561, 863 



Treasure finders, 33, 63, 818-824 

 high-frequency -, 629, 821-824 

 low-frequency -, 627, 819-821 



Trifilar suspension, 11, 128, 131, 132 



Trolley lines, 372, 680 



Tuning factor, 481, 587-589, 590, 601, 

 602, 604-607 



Tuning fork, 555, 615, 618 



Tungsten, 50, 52 



Tunnel investigations, 6, 14, 57, 58, 

 63, 376, 404-407, 741, 863, 928-930, 

 933, 959-962 



Turbidity, 897 



Twin-pendulum method, 101, 102, 121- 

 123 



Two-dimensional geologic bodies, 144- 



146, 150, 157, 169,243, 247, 251, 252, 



254, 257-270, 385-388, 395-400, 768 



relation of -, to three-dimensional 



bodies, 257, 258 



U 



Uley graphite, 756 

 Ultramicrometer, 125, 931, 932 

 Ultrasonic transmission, 945-949, 952, 



953 

 Unconformities, 5, 551, 864 

 Unconsolidated formations, 23, 61, 74, 



452, 468, 474-476, 663, 664 



