 | Balfour Stewart - Heat - 1866 - 424 pages
...would appear, from an investigation by the author of this work, that auroras and earth-currents are to be regarded as secondary currents due to small but rapid changes in the earth's magnetism, and that the body of the earth may be likened to the magnetic core of a Ruhmkorff's machine, the lower... | |
 | Alexander Buchan - Atmosphere - 1867 - 204 pages
...currents in the surface of the earth. Dr Balfour Stewart considers that aurorse and earth-currents are to be regarded as secondary currents due to small but rapid changes in the earth's magnetism, and that the body of the earth may be likened to the magnetic core of a Kuhmkorff s machine, the lower... | |
 | Alexander Buchan - Meteorology - 1868 - 408 pages
...179 Oct., 497 236 Mar., 440 240 July, 87 244 Nov., 285 215 April, 312 267 Aug., 217 238 Deo., 225 159 regarded as secondary currents due to small but rapid changes in the earth's magnetism ; and that the body of the earth may be likened to the magnetic core of a Euhmkorff's machine, the... | |
 | Alexander Buchan - Meteorology - 1868 - 432 pages
...July, 87 244 Nov., 285 215 April, 312 267 Aug., 217 238 Dec., 225 159 312 MISCELLANEOUS. regar led as secondary currents due to small but rapid changes in the earth's magnetism ; and that the body of the earth may bo likened to the magnetic core of a RuhmkorfFs machine, the lower... | |
 | Alexander Buchan - Meteorology - 1871 - 260 pages
...currents in the surface of the earth. Dr Balfour Stewart considers that auroras and earth-currents are to be regarded as secondary currents due to small but rapid changes in the earth's magnetism; and that the body of the earth may be likened to the magnetic core of a Ruhmkorff's machine, the lower... | |
 | Arthur Parnell - Lightning - 1882 - 406 pages
...probably independent of its radiant heat and bight." (-D0.) (57.) Balfour Stewart considers earth currents as secondary currents due to small but rapid changes in the earth's magnetism. (Do.) (58.) Earth currents are constantly passing through the telegraph wires, " due to the varying... | |
 | Jacques Wardlaw Redway - Physical geography - 1900 - 404 pages
...sun. " Professor Balfour Stewart has advanced the opinion that both auroras and earth currents are secondary currents due to small but rapid changes in the earth's magnetism. The body of the earth may be compared to the magnetic core of an induction coil, the lower strata being... | |
 | Thomas O'Conor Sloane - Electricity - 1924 - 840 pages
...constant direction of arc with reference to the magnetic meridian (qv) and act upon the magnetic needle ; in high latitudes they affect telegraph circuits violently....aurora a phenomenon of induced currents. Then the sun may be regarded as the instigator of the primary changes in the earth's lines of force representing... | |
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Ruhmkorff's machine, the lower strata of the air forming an insulator, -while the upper and rarer, and therefore electricallyconducting strata, may be likened to the secondary coil; and the sun perhaps likened to the primary current... 