426 



Special Reports 



i Station-difference between Tent 1919 and the Greenwich declinometer station, upon observations at which the mag- 

 uetogram base-line value depends, is assumed to be negligible. 



Table 6E. Results of Horizontal-Intensity Comparisons at the Greenwich Observatory, 1919. 



Date 



1919 

 Apr. 5 

 5 

 6 



Local mean time 



From 



h in 



14 07 



15 44 

 9 52 



11 35 

 14 14 



To 



h m 

 14 50 

 16 23 



11 20 



12 20 

 14 55 



Hor. int. obtained 1 



I. M. S. Greenwich 



18444 

 417 

 433 



18466 

 442 

 452 



Mean value of (I. M. S. Greenwich) . 



I. M. S.- 

 Green- 

 wich 



-22 



-19 



Remarks 



C. I. W. magnetometer No. 13 

 at the intensity pier through- 

 out. 



-22.0-y or -0.0011!)// 



1 The Greenwich values are from the magnetograms, the base-line for which is determined from observations with the 

 Greenwich magnetometer Gibson No. 3 at the intensity pier. 



Table 6F. Results of Inclination Comparisons at the Greenwich Observatory, 1919. 



1 It is assumed that any station-difference between the station Tent 1919 and the inductor pier is negligible. 



SUMMARY. 



Assembling the chief results and using only inductor-comparisons for inclination, 

 we obtain mean values as follows: 



(6) I. M.S. -Greenwich (Declinometer) =- I '.3 (1915-1919). 



(6a) I. M. S.- Greenwich (Gibson magnetometer No. 3) = -0.00058/Y (1915). 



(6b) I. M.S. -Greenwich (Gibson magnetometer No. 3)= -0.001 19/Y (1919). 



(6c) I. M.S. -Greenwich (Earth inductor) = -0'. 7 (1915). 



