THE iMAGNETIC WORK OF THE GALILEE, 1905-1908. 



By L. a. Bauer, W. J. Peters, and J. A. Fleming. 



GENERAL REMARKS. 



The Department of Terrestrial Magnetism of the Carnegie Institution of Wash- 

 ington was authorized, in 1905, to undertake a magnetic survey of the Pacific Ocean, 

 according to a plan submitted to the Institution on October 3, 1904, by L. A. Bauer 

 and G. W. Littlehales.^ 



While the state of our knowledge of the distribution of the Earth's magnetic 

 forces over ocean areas, owing to the paucity of precise data, was then in general 

 exceedingly unsatisfactory, this was especially true for the Pacific Ocean, rapidly 

 developing in commercial importance. Except for data from occasional expeditions 

 and such as had been acquired in wooden vessels long previously, the magnetic charts 

 used by the navigator over the Pacific Ocean depended largely upon observations 

 on islands and along the coasts. But because of prevalent local disturbances, mag- 

 netic observations on land are frequently not representative of the true values. 

 It was therefore impossible to make any statement as to the correctness of the 

 charts then in use. 



Professor Arthur Schuster, in a letter dated January 26, 1902, had stated : 



"I believe that no material progress of terrestrial magnetism is possible until the mag- 

 netic constants of the great ocean basins, especially the Pacific, have been determined more 

 accurately than they are at present. There is reason to believe that these constants may 

 be affected by considerable systematic errors. It is possible that these errors have crept 

 in by paying too much attention to measurements made on islands and along the sea coast. 

 What is wanted are more numerous and more accurate observations on the sea itself." 



Captain Ettrick W. Creak, at one time superintendent of the compass depart- 

 ment of the British Admiralty, in a letter dated August 31, 1904, said: 



"The North Pacific Ocean is, with the exception of a voyage of the Challenger (1872-76) 

 nearly a blank as regards magnetic observations." 



Professor Schuster's surmise as to the possible existence of "considerable sys- 

 tematic errors" in the magnetic charts for the great ocean basins has been abundantly 

 verified by our ocean magnetic work from 1905 to the present date. When it is 

 recalled that the ocean areas embrace nearly three-fourths of the entire surface of the 

 Earth, it is easily understood that lack of accurate data for this portion of the globe 

 has greatly retarded the settlement of important problems pertaining to the Earth's 

 magnetism. Thus the demands of science, as well as those of commerce and navi- 

 gation, called for a systematic magnetic survey of the oceans under the most favor- 

 able conditions and required that the work be done under the auspices of some 



'Bauer, L. A., and G. W. Littlehales. Proposed magnetic survey of the North PaoiBc Ocean, Carnegie Inst, of Washing- 

 ton. Year Book No. 3, 1904. 269-273 (Jan. 1905), Washington. Also, somewhat abridged, in Terr. Mag., vol. 9, 163-166, 

 1904, Washington. 



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