UNSOLVED PROBLEMS IN TERRESTRIAL 



MAGNETISM AND ELECTRICITY IN 



THE POLAR REGIONS 



L. A. Bauer 



The accumulation of additional magnetic and electric data in the 

 polar regions is of paramount importance to the definite solution of 

 some of the unsolved problems pertaining to the earth's magnetism 

 and electricity. Increased importance will result also from the fact 

 that the Arctic and the Antarctic differ so greatly as regards physical 

 features. Thus an analysis of the earth's magnetic field for 1922 by 

 the writer clearly indicated effects on the distribution of the earth's 

 magnetism and its secular change related apparently to the distribu- 

 tion of land and water.^ Since in the Arctic there is a preponderance 

 of water and in the Antarctic a preponderance of land, opportunity 

 will be afforded, if sufficient magnetic data of the required accuracy 

 be obtained, to test this interesting question anew. 



Improvement of Magnetic Charts 



The following statements will give some idea as to errors m the 

 lines of equal magnetic declination, commonly called by the mariner 

 "lines of equal magnetic variation," in the Arctic regions, for example. 



During the Canadian Arctic Expedition of 1913-1918, under the 

 leadership of Mr. Vilhjalmur Stefansson, magnetic declinations 

 were observed in the years 1915-1917 at 26 points with prismatic 

 compasses between the parallels 74° to 80° N. and meridians 98° to 

 124° W. The differences^ between the values thus obtained and 

 those scaled from the isogenic chart (No. 2598) published by the 

 British Admiralty for 1922 ranged in the region concerned from 

 - 34° to +21°. In consequence, Mr. H. Spencer Jones, then connected 

 with the Greenwich Observatory, undertook the construction of 

 revised lines of equal magnetic declination for the polar regions, epoch 

 1922, utilizing all the data available to him at the time.^ The differ- 

 ences between the Canadian Arctic Expedition observations and the 

 values of Jones's revised chart ranged from +12° to — 15°. 



iL. A. Bauer: Chief Results of a Preliminary Analysis of the Earth's Magnetic Field for 1922, 

 Terrestr. Magnet and Atmospher. Electr., Vol. 28, 1922, pp. 1-28; reference on pp. 6-9. 



2F. A. McDiarmid: Geographical Determinations of the Canadian Arctic Expedition, Geogr. 

 Journ., Vol. 62, 1923, pp. 293-302; reference on pp. 301-302. 



3 H. Spencer Jones: The Magnetic Variation in the Neighbourhood of the North Pole, Geogr. Journ.. 

 Vol. 62, 1923, pp. 419-423, with chart, 1:37,000,000. 



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