TABLES 577-578. 



TERRESTRIAL MAGNETISM (continued). 

 TABLE 577. Agonic Line. 



433 



The line of no declination appears to be still moving westward in the United States, but, as the line of no annual 

 change is only a short distance to the west of it, it is probable that the extreme westerly position will soon be reached. 



TABLE 578. Mean Magnetic Character of Each Month in the Years 1906 to 1917.* 



Means derived from daily magnetic characters based upon the following scale: o, no disturbance; i, moderate 

 disturbance, and 2, large disturbance. 



* Compiled from annual reviews of the "Caractere magnetique de chaque jour" prepared by the Royal Meteoro- 

 logical Institute of the Netherlands for the International Commission for Terrestrial Magnetism. The number of 

 stations supplying complete data for the above years were respectively, 30, 32, 36, 38, 34, 39, 43, 42, 37, 35, 35, 35- 

 Data from Sitka, Ekaterinburg, Stonyhurst, Wilhelmshaven, Potsdam-Seddin, De Bilt, Greenwich, Kew, Val Joyeux, 

 Pola, Cheltenham, Honolulu, Bombay, Porto Rico, and Buitenzorg were employed for all of the years. 



SMITHSONIAN TABLES. 



