SUBJECT INDEX 



986 



Melaphyre, density of, 81 

 Melting point, 891, 892 

 Mentor beds, 84 

 Mercury, 73, 123, 124 

 Meridian, magnetic, 295, 321, 325, 334, 

 338, 341-342, 345-347, 350, 353, 

 357, 361, 363, 378, 379, 405 

 Metallascope, 628, 823, 824 

 Metal mining, geophysical methods in 

 (see also Mining exploration), 49, 

 50, 51, 52 

 Metamorphic rocks, 48, 61, 287, 315, 

 410, 412, 419, 424, 439, 678, 734, 

 756, 848, 849, 874 

 coercive force and remanent magneti- 

 zation of -, 316 

 densities of -, 74, 81 

 heat conductivity of -, 849 

 longitudinal wave velocities of -, 472 

 radioactivity of -, 874 

 resistivities of -, 637, 660, 661 

 susceptibilities of -, 312 

 Meteorological factors and magnetic 



variations, 369, 370 

 Meteorology, 3 

 Meteors, 70, 422 

 Methane, 36, 888-897, 899, 900, 902- 



907 

 Mho-centimeter, 633 

 Mica: 

 density of -, 80 



- deposits, 55 



dielectric constant of -, 666 

 elastic moduli of -, 467 

 heat conductivity of -, 848 

 resistivity of -, 658 

 Microgal, 88, 139, 150, 154 

 Microgauss, 622, 793-795 

 Microphone, 20, 866, 867 

 carbon -, 937, 948, 953, 960 

 coil -, 20, 937, 940, 942, 948, 951 

 condenser -, 20, 932, 948 

 crystal -, 21, 937, 948, 949, 953, 960 

 hot wire -, 938, 940, 948, 960 

 magnetostriction -, 946-948, 952, 953, 



955, 956 

 reluctance -, 20, 937, 954, 955 

 Microtimer, 952 



Military engineering, 6, 9, 37, 42, 59, 60, 

 63, 64, 297, 433-436, 624, 706, 940, 

 942, 943, 951, 956, 958, 961 

 Millerite, density of, 78 

 Milligal, 10, 88, 101, 104, 106, 110, 113, 

 117, 118, 123-127, 129, 130, 132-137, 

 141, 143, 158-162, 164, 165, 170, 

 248, 249, 272, 274, 283 

 Mine: 



- caving, 36, 63, 914, 928-930, 933 



- safety, 9, 956, 960, 961 

 -workings (see Underground workings) 



Mineral composition, effect on, of: 



elastic rock properties, 474 



rock density, 73 



rock magnetism, 314 

 Mineral density, 74 



Mineral deposit, classifications, 49, 50, 51 

 Minerals, resistivities of, 657, 658 

 Minette, 51 

 Mining: 



acoustic»methods in -, 37, 956-963 



- compass, 17, 320, 345, 346, 403 

 electromagnetic methods in -, 31, 52, 



55, 626, 771-773, 800-809 

 equipotential-line method in -, 27, 52, 



624, 703-706 



-exploration, 6, 17, 19, 23, 49-56, 70, 



161, 162, 286-292, 297, 404^22, 



439, 501-503, 505, 623 

 gravitational methods in -, 52, 53, 54, 



55, 161, 162, 286-292, 520 

 magnetic methods in -, 17, 19, 49, 51, 



52, 54, 56, 297, 404-422 



- operations, effect on gravity, 167 

 potential-drop -ratio method in -, 29, 



52, 625, 755-757 

 radioactivity methods in -, 35, 884, 885 

 radio methods in -, 32, 627, 813, 816, 817 

 resistivity methods in -, 28, 52-55, 



625, 739-741 



seismic methods in -, 21, 23, 49, 50, 53, 

 54, 55, 439, 501-503, 505, 520 



self-potential methods in -, 26, 52, 53, 

 624, 675-679 



strain gauging in -, 36, 63, 928-934 

 Mint, 63 



Mirror device, 115, 116, 496, 616 

 Mississippian formation, 735, 736 



vertical velocities in -, 473 

 Model experiments, 41, 42 



electrical -, 28, 623, 700, 701, 734, 735, 

 771, 800, 801, 802, 812 



gravimetric -, 88 



magnetic -, 19, 402-404 



seismic -, 62, 911, 912, 914, 917 



- for strain measurements, 63, 933 

 Moduli, elastic, 442-446, 467-468, 911, 



926, 927 



dissipative -, 483 



measurement of -, 452-466 

 Moisture, effect on, of: 



density, 74, 76 



dielectric constant, 641 



elastic rock properties, 475 



high-frequency and radio fields (see 

 also Near-surface interference), 

 655, 806, 809, 815 



rock resistivity, 634-639 



thermal properties, 847, 848, 849 

 Moll galvanometer, 841 

 Molybdenite : 



density of -, 78 



- deposits, 50 

 resistivity of -, 657 



