Comparisons of Magnetic Standards, 1915-21 



417 



Table 4E. Results of Social-Test Declination Comparisons at Hie Standardizing Magnetic Observatory of the 

 Department of Terrestrial Magnetism at Washington, 1915. 



1 C. I. W. No. 3 was at station N m and D. O. No. 1977 at station <S m throughout; all values are referred to station 

 IV.; N m = Sm+0'.5, see Table 4B. Observers: D. O. No. 1977, C. A. French of the Dominion Observatory; C. I. W. No. 3, 

 H. W. Fisk of the Department of Terrestrial Magnetism. 



These are values obtained with C. I. W. No. 3 referred to I. M. S.; I. M. S. C. I. W. No. 3= -O'.l. 



' The vertical displacement between highest-possible and lowest-possible positions of magnet 14 in the magnet-house 

 of D. O. No. 1977 is about 1 mm. only. 



Table 4F.- 



-Results of Horizontal-Intensity Comparisons at the Standardizing Magnetic Observatory of the Department 

 of Terrestrial Magnetism at Washington, 1915. 



1 All values are referred to station N m ; N m = S*+5.8y, as derived from this series. Observers: D. O. No. 1977, C. A. 

 French of the Dominion Observatory; C. I. W. No. 3, H. W. p'isk of the Department of Terrestrial Magnetism. 



* These are values obtained with C. I. W. No. 3, using constants of December 12, 1910, referred to I. M. S. ; I. M. S. 

 C. I. W. No. 3 = 0.O0O0OH. 



Using magnets 46 and 10, constants being those adopted for the year 1914 by the Dominion Observatory. 



Table 4G. Results of Horizontal-Intensity Comparisons at the Standardizing Magnetic Observatory of the 

 Department of Terrestrial Magnetism at Washington, 1915. 



1 All values are referred to station N m ; N n = E + 1.6y, as derived from this series. Observers: D. O. No. 15, W. F. 

 Wallis of the Department of Terrestrial Magnetism; C. I. W. No. 3, H. W. Fisk of the Department of Terrestrial Magnetism. 



2 These are the values obtained with C. I. W. No. 3, using constants of December 12, 1910, referred to I. M. S.; I. M. 

 S. C. I. W. No. 3=O.00000H. 



Constants of December 29, 1915, were used in obtaining these values. 



