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REPORT — 1893. 

 Barometrical Effects. 



On the soft, marshy ground near Wilhelmsliaven, Dr. von Rebenr- 

 Paschwitz observes that a change in the vertical of ^" corresponds to a 

 change of 1 mm. in barometrical pressure ; in fact, the district behaves as 

 if it were the vacuum chamber of an aneroid. In Tokio the effects are 

 not so pronounced, yet in many instances a N.N.B. tilting has corre- 

 sponded with a rise in the barometer. On two or three days when the 

 barometrical changes have been small the daily movements have been 

 small, but there are other instances where the daily movement has 

 continued and the barometer has been steady. In the smaller movements, 

 and in the few cases where the direction of one component of the daily 

 movement has been reversed, there does not appear to be any connection 

 with the barometer. 



Mr. T. Wada, of the Meteorological Observatory, tells me that the daily 

 maximum and minimum barometrical changes vary with the season, the 

 yearly average being as follows : — 



Those which are italicised are the most pronounced. In winter there 

 are two other periods, viz. : — 



I have not observed any change accompanying these periods. 



Possible BelationsMp with Magnetic Movements. 



The relationship between the movements of the pendulums and the 

 daily changes in magnetic declination suggests the idea that the pheno- 

 mena which are being observed are not altogether unconnected with 

 magnetic influences. 



In Tokio the declination is farthest west about 2 p.m., and farthest 

 east at 8 a.m. ; that is to say, when the magnetic needle is farthest 

 east the north end of a north south boom of my instrument is farthest 

 west. That the movements of the horizontal pendulums and those of a 

 magnetic needle take place at the same time but in opposite directions 

 has also been observed by Dr. von Rebeur-Paschwitz in Potsdam and 

 Wilhelmshaven. In my instrument the pivot, which is a steel needle point 

 8 mm. in length, is pivoted at its southern end. 



Geological Structure and Direction of Movements. 



A very significant fact, possibly connecting the observed movements 

 with geological structure, is that the N.E, or N.N.E. direction of tilting 



