DEPARTMENT OF TERRESTRIAL MAGNETISM. 249 



cent) from 60° N. to 60° S. Some of the chief results obtained will be found 

 stated in the introductory remarks on the "Composition of the Earth's 

 magnetic field" (see pp. 229-230). 



Regarding measures of magnetic characterization of days. Louis A. Bauer. Terr. Mag., 

 vol. 28, 41-44 (March-June 1923), and Bull. 3, Sect. Terr. Mag. and Electr., 

 Internat. Geod. Geophys. Union, 115-117 (October 1923). 



This paper continues the discussion and comparison of various measures of 

 daily magnetic activity (see p. 292 of last year's report) looking toward the 

 adoption of a measure which may fulfil more satisfactorily than the present 

 "magnetic character numbers" the desiderata for such a measure. It 

 appears best to continue the present scheme at all stations, meanwhile having 

 a limited number of representative well-equipped stations compile, in addition, 

 results at minimum time and labor which will serve to test out suggested 

 measures. 



On the organization and aims of the American Geophysical Union. Louis A. Bauer. 

 International and national work of the American Geophysical Union, July 1, 1922, to April 

 30, 1923. Louis A. Bauer. 



These are reports on the administration of the Union, the first presented at 

 the annual meeting of the American Geophysical Union, Washington, April 17, 

 1923, and the second at the annual meeting of the Division of Foreign Rela- 

 tions of the National Research Council, Washington, April 25, 1923. 



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

 ington. Louis A. Bauer. 



This report, prepared for the Second Pan-Pacific Science Congress, held 

 August 13 to September 3, 1923, at Sydney and Melbourne, Australia, gives 

 an account of the organization and history of the Department of Terrestrial 

 Magnetism. It also summarizes in detail, and with particular reference 

 to the Pacific Ocean and adjoining continents, the work accomplished, includ- 

 ing (1) ocean magnetic surveys by the Galilee and by the Carnegie, (2) land 

 magnetic surveys in countries adjoining and on the islands of the Pacific 

 Ocean, and (3) observatory work at the Watheroo and Huancayo magnetic 

 observatories and, in cooperation with the New Zealand government, at the 

 Apia Observatory. 



Note regarding the annual variation of the atmospheric potential gradient. Louis A. Bauer. 

 Science, vol. 58, 67-68 (July 27, 1923). 



A brief discussion of an article in Science of May 25, 1923 (pp. 616-618), 

 by Dr. Sanford, in which he attempts to account theoretically for the annual 

 variation of the atmospheric potential gradient; his theory is shown not to 

 be in accord with the chief observational results. 



Earth-current observations. Louis A. Bauer. Science, vol. 56, 592-594 (November 24, 

 1922). 



An abstract of the matter contained in this paper is given on pages 290 to 

 291 of the Director's annual report for 1922. 



Solar activity and atmospheric electricity. Louis A. Bauer. Nature, vol. 112, 203-205 

 (August 11, 1923). 



Dr. Chree, in a recent paper* giving the results of his investigation based 

 on the Kew atmospheric-electric data, reaches the following interesting con- 

 clusion, as given in his statement: "The results obtained are on the whole 

 not incompatible with Dr. Bauer's conclusion, but they indicate that if a 

 relationship of the kind supposed exists, the sun-spot influence must be very 



^ A supposed relationship between sun-spot frequency and the potential gradient of atmos- 

 pheric electricity. Proc. Phys. Soc, London, vol. 35, part 3, 129-136 (April 15, 1923). 



