DEPARTMENT OF TERRESTRIAL MAGNETISM. 



271 



Pi-elimmary ocean values of the annual changes of the magnetic elements as determined 

 from the Galilee and Carnegie results, 1905-1917. li. A. Bauer, W. J. Peters. 

 J. P. Ault, and C. C. Ennis. 



The frequent intersections of the Carnegie's tracks, November 1916 to March 

 1917 (San Francisco to Buenos Aires), with the previous ones of the Galilee 

 and the Carnegie, gave opportunity for amplifying tables 97 and 98, published 

 on page 433 of Volume III (Researches of the Department of Terrestrial Mag- 

 nestism). The same methods were used as described on pages 431 and 432 

 of that volume. For the sake of completeness table 96 is also given here as 

 table 3, though no new values Avere added. As will be seen from tables 3, 4, 

 and o, the preliminary values of the annual changes are of the same general 

 order of magnitude as disclosed by observations on land. The discussion of 

 the values is deferred until additional data have been obtained. 



Table 3. — Average annual changes for the Indian Ocean} 



^The first three entries of the table are derived from the intersections of the tracks of the Car- 

 negie in 1911 with those of the Gauss (the vessel of the German Antarctic Expedition, 1902 and 

 1903); see Terr. Mag., v. 16, p. 136, 1911. 



H'wo groups only. 



Table 4. — Average annual changes for the Atlantic Ocean. 



'Three groups only. 



'One adjustment of 34 results; probable error ±1'5. 



-Two groups only. 



