ABSTRACTS 



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 this issue. 



GEOPHYSICS. — General results of the work in atmospheric electricity 

 • aboard the "Carnegie," 1909-1914- L. A. Bauer. Proc. Am. Phil, 

 Soc, 54: 14r-17. 1915. 

 A paper presented at the annual meeting of the American Philo- 

 sophical Society at Philadelphia on April 24, 1915. It contains a gen- 

 eral account of the progress made by the Department of Terrestrial 

 Magnetism of the Carnegie Institution, in its work in atmospheric 

 electricity aboard the Carnegie and at the laboratory in Washington. 

 The Department can now enter actively, with increased facilities, upon 

 participation in another world-wide project, namely, the mapping of 

 the Earth's electric field and the study of its variations at fixed points. 



J. A. F. 



TERRESTRIAL MAGlSiETmM.— Distribution of the magnetic declina- 

 tion in the United States for January 1, 1915, with isogonic chart 

 and secular change tables. D. L. Hazard. U. S. Coast and Geo- 

 detic Survey Special Publication No. 33, Serial No. 18. 1915. 

 The general distribution of the magnetic declination in the Uaited 

 States on January 1, 1915, is shown graphically by means of an isogonic 

 chart, on which the lines of equal declination are drawn for each degree. 

 It is based on about 6000 values of the magnetic declination, including 

 about 800 in Canada and 300 in Mexico and the West Indies. In order 

 that the results represented may be used for other dates than the epoch 

 of the chart, tables are given showing the secular change of the mag- 

 netic declination at one or more places in each State from 1750 or the 

 date of the earliest observations to 1915. In addition the values of 

 annual change of declination for 1915 are shown graphically on the 

 chart by means of lines of equal annual change. On account of the 

 large number of results available, it was impossible to represent all of 



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