972 



SUBJECT INDEX 



Depth (cont'd): 



- penetration of curved ray, 542-545 



- penetration of electrical energy, 619, 



621, 625, 627, 683-686, 708, 736, 

 761, 763, 765, 773, 806, 809, 811, 

 , 812, 815, 816, 819, 824 

 variation of seismic and sound velocity 

 (see Vertical variation of seismic, 

 and sound velocity) 

 Derricks, magnetic effects of, 375, 425 

 Detection coil (see Coil, reception) 

 Detector (see also Seismograph and 

 Microphone) : 

 capacitive -, 20, 593, 610-612, 932, 948 

 electromagnetic -, 593-597, 609, 612, 

 862, 912, 917, 937, 940, 942, 948, 951 

 gas -, 35, 36, 868, 887, 892-898 

 inductive -, 20, 593-595, 597, 609-612, 



912, 917, 937, 940, 942, 948, 951 

 magnetostriction, 948, 955, 956 

 piezoelectric (crystal) -, 20, 463, 593, 



613, 937, 948, 949, 953, 960 

 reluctance -, 20, 595-597, 610, 611, 



862, 937, 953-955 

 seismic -, 20-22, 35, 503, 505, 551, 552, 

 554, 555, 556, 593-597, 609-613, 

 862, 912, 917 

 thermal -, 58, 59 

 Detrusion meter, 454, 460 

 Devonian, 735, 736, 772, 885 

 apparent resistivity on Devonian an- 

 ticline, 736 

 vertical velocities in -, 473 

 Dewar flask, 900 

 Diabase : 

 coercive force and remanent magneti- 

 zation of -, 308, 309, 316 

 density of -, 73, 81 

 elastic moduli of -, 467 

 magnetic effects of -, 414, 417 

 radioactivity of ^, 874 

 resistivity of -, 660, 661 

 susceptibility of -, 308, 309, 313, 314 

 Diagrams, interpretation - (see Graphi- 

 cal interpretation) 

 Diagrams, wave front (see Wave front) 

 Diamagnetism, 7, 299, 423 

 Diamond, 50, 52, 56 



density of -, 80 

 Diatomaceous earth, 55, 74, 637 

 Dielectric constant: 

 apparent -, 640, 641, 666, 667 

 determination of -, 649-656 

 phase shift method, 651 

 polarization measurements, 651-656 

 resonance method, 649-650 

 substitution method, 650, 651 



- of minerals, 665-666 



- of rocks and formations, 666, 667 

 true -, 622, 631, 633, 665, 666, 667, 811, 



812, 813 

 Dielectric current conduction, 632, 640 

 Differences, method of, 23, 548, 549, 



572, 576 



Diffusion (of gases), 884, 887, 905, 906 

 Diffusion potential, 33, 624, 630, 631, 



831-833 

 Diffusivity, thermal (see Thermal diffu- 



sivity) 

 Dikes, 29, 45, 46, 70, 151-153, 259, 261- 

 264, 385, 396, 398, 399, 401, 402, 

 411, 414, 417-419, 422, 433, 750- 

 752, 865, 870 

 Dilation, 442, 443 



Diluvial sands, longitudinal wave velo- 

 city of -, 469 

 Diolefins, 889 

 Diorite: 

 coercive force and remanent magneti- 

 zation of -, 316 

 density of -, 80 

 dielectric constant of -, 666 

 elastic moduli of -, 467 

 radioactivity of -, 874 

 resistivity of -, 660 

 susceptibility of -, 313 

 Dip, apparent, 525, 526, 567 

 Dip determination,. and effect of dip: 



- on apparent resistivity, 722, 734, 



735, 739, 740 



- on electromagnetic field, 763, 767, 



771, 772, 790, 791, 794, 800-803, 805 



- on equipotential-line anomalies, 701, 



706 



- on geothermal data, 852, 853 



- on gravity, 153, 162 



- on magnetic anomalies, 384-386, 388, 



398, 399, 403, 410, 411, 412, 419, 420 



- on potential ratio, 748-751, 754 



- on reflection travel times, 563-571, 



579 



- on refraction travel times, 502, 504, 



521-536, 538-539, 546, 547 



- on spontaneous potential, 671, 674, 



675 



- on torsion balance, 251, 252, 261-263, 



288, 290 



- in wells, 834, 865 



Dip, magnetic (see Inclination) 



Dip needle, 17, 345, 346, 347, 35&-358, 



403, 413, 415, 422, 436 

 Dip shooting, 25, 567, 568, 570, 571, 579 

 Dipping needle, 345, 346 

 Direct current, 25, 403, 600, 601, 617, 619, 



624, 631, 633, 642-645, 681, 685, 



692, 723, 725, 758, 827 

 Directional transmission, 937, 945 

 Direction finding, 36, 37, 64, 938, 63, 



941, 942, 951, 960-962 

 Dirigibles, 813 

 Disintegration, 16, 318, 478 

 Dispersion, seismic (see Seismic waves, 



dispersion of) 

 Dispersion of electroscope, 876-881 

 Displacement current, 640, 641, 649. 



685, 686, 811 

 Displacement recorders (see Strain 



gauges) 



