( 775 ) 



So the aniouiil of the movement is TcUily well independent ol tlie 

 (iiirulion, from whieli resiills inversely (li;it the sliorter the inereKóC 

 of H ii, the (flicker it is. 



Let us llnally observe that the appearing of the slight easterly 

 movement did not show any preference for certain times of day or year. 



BUITENZORG. 



Since May 1906 a T()PFER-Schulzk magnetograph has registered at 

 Bnitenzorg, which gives the curves of the three elements on the 

 same registering-strip; this circumstance besides that of giving finer 

 lines, greater sensilnlity and wider measure of time, is very suitable 

 for the study of the initial-movement. 



For the period May 1906 — Nov. 1907 1 measured 29 cases and 

 from that material it was clearly evident that in most cases the 

 movements of the elemejits display a certain independence of each 

 other and <lo not alivays begin at the same moment. 



I calculated the azimuth of the liorizontal component of the vector 

 for the first part of the movement, so be/ore the movement of J) 

 is inverted, and 1 found in 20 cases directions between the extremes 

 iX and N 58° IV, an average of 



.V2i°]r. 



Vertical Intensity. 



The results for A Z were surprising; for the vertical component 

 showed, different from that of Batavia, an introductory positive 

 movement followed l)y the slow negative movement known of 

 Batavia. 



Here no instrumental cause had anything to do with the matter : 

 both magnetographs (of Adie and Schulze) registered this premove- 

 ment at one lime at Batavia very rarely, but at Buitenzorg regu- 

 larly. Luckily registrations have been made for more than a year 

 at Bafavia and at Buitenzorg at the same time and from (hose 

 registrations it was evident that the introductory movement at 

 Buitenzorg precedes that of Batavia. The introductory movement at 

 Buitenzorg commences (according to the average of 29 cases) 0.3 

 minute after the //-movement begins and lasts about 1 to 3 minutes, 

 after which the Z-lines of both places show simultaneously a decrease. 



Answkrs to the questions. 



The data on the initial movement were asked for in my letter 



