SUBJECT INDEX 



975 



Ellipsoid: 



- of reference, 97, 167, 168 



- of rotation, 91, 97, 167, 376, 381, 389, 



392 393 700 834 

 Elliptical' bodies, 376, 381, 389, 392, 393, 



698, 699 

 Elliptical polarization: 



- of electrical field, 653-655, 681, 685, 



687-692, 693, 701 



- of electromagnetic field, 690, 779, 



787-789, 807 



- of radio waves, 651-655, 689, 692, 818 

 Ellstone structure, Texas, 433 



Eltran method, 30, 47, 623, 625, 631, 



757-763, 817, 901, 908 

 Emanation : 

 actinium -, 873 



- chamber, 865, 876, 879, 880, 881 

 radium -, 865, 870-881, 884, 885 

 thorium -, 873, 877 



Emergence angle, 533, 539, 541, 545, 



952, 962 

 Emersio, 451 



Emery testing machine, 457 

 Enargite, density of, 78 

 Energy, absorption of (see Absorption) 

 Engineering: 



- applications of geophysics, 57-64, 



297, 408, 433-436, 441, 503, 505, 

 624, 679-681, 706, 741, 742, 755, 

 765, 818-824, 866, 911-934, 956, 

 959, 961, 962 



civil -, 6, 9, 58, 297, 433-436, 441, 503, 

 505, 624, 679-681, 706, 735, 741, 

 755, 765, 866, 911-934, 956, 959, 

 962 



foundation -, 58, 60, 435, 441, 503, 505, 

 624, 741-743, 755, 911-914, 919- 

 931, 933 



gas -, 6, 868, 869 



- geology (see also - applications), 



6, 408 

 highway -, 6, 8, 58, 69, 435, 441, 503, 



505, 624, 735, .741-742, 743, 911, 



915, 928 

 hydraulic - (see also Water, Pipe 



lines, and Engineering, founda- 

 tion), 58, 60, 911 

 military -, 6, 9, 37, 42, 59, 60, 63, 64, 



297, 433-436, 624, 706, 940, 942, 



943, 951, 956, 958, 961 

 mining - (see also Mining and Mine 



safety), 167, 928-934 

 pipe line - (see Pipe lines) 

 sanitary -, 58, 60, 911 



- seismology, 441, 910-928 

 structural -, 6, 9, 58, 910-912, 915, 



917-919, 928-930, 934 

 transportation (see also Engineering, 



highway and structural), 58, 60 

 Enstatite porphyry, coercive force and 



remanent magnetization of, 316 

 Eocene, vertical velocities in, 473 



Eotvos torsion balance (see Torsion 



balance) 

 Eotvos unit, 89, 166, 170, 191, 192, 213, 



216, 245, 380 

 Epeirogenic movements, 163, 165, 317 

 Epidote, density of, 80 

 Equilibrium, radioactive (see Radio- 

 active equilibrium) 

 Equipotential-line method, 26, 27, 78, 

 681-706 

 conditions for A.C. fields, 685-692 

 conditions for stationary fields, 681- 



684 

 equipment, 692-696 

 generators, 692, 694 

 interpretation in, 28, 697-703 

 power electrodes, 692-694 

 procedure, 671, 693-696 

 results, 703-706 



search electrodes, 670, 671, 692, 694, 695 

 Equipotential lines, 26, 27, 39, 40, 624, 

 669, 670, 671, 675, 676, 681, 682, 

 688, 692-694, 696, 697, 699, 700- 

 706, 756, 817 

 quadrature -, 696, 701 

 Equipotential surfaces : 

 convergence of -, 13, 15, 170, 172, 175 

 curvatures of - (see Curvature) 

 cylindrical -, 169, 174 

 electrical -, 476, 682, 683, 693, 834 

 - of gravity, 12-15, 70, 89, 167-172, 

 174-176 

 Erosion, effect of on gravity, 165 

 Erosional channels, 61, 70, 292, 416, 417, 



421, 439, 501, 502, 624, 678 

 Eruptive rocks (see Igneous rocks) 

 Escarpments, 15, 514, 516, 517, 519, 520 

 Essexite, density of, 80 

 Ethane, 36, 888-892, 894-896, 899, 900, 



902, 903, 906, 908-910 

 Evinrude pump, 491, 492 

 Ewing seismograph, 127, 580 

 Expanding electrode system, 747, 748, 



749, 754 

 Explosion, instant of (see Shot instant) 

 Explosives (see Dynamite and Blasting 



caps) 

 Extension, 443, 444, 454-457 

 Extensometer (see also Strain gauges), 



454-456 

 Extractors, 901 



Fan shooting, 20, 499-504, 546 



- accelerations, 500-501 



- equipment, 503-540 



- in mining, 501-502 



- in oil exploration, 499-504, 546 

 Faraday constant, 620, 629, 6311 

 Faraday's law, 642 

 Fathometer, 954-955 



Fatty acids, 901 



