ON THE EAETHQUAKE AND VOLCANIC PHENOMENA OF JAPAN. 217 



FiGf. 1. — Average daily N.E.-S.W. tilting of a stone column in Tokio, February 



and March 1893. 



Noon, I Z 3 4 5 6 7 S 9 W it m I. Z 3 4- 3 6 7 8 9 W UKocn. 



The following table is a comparison of the movements observed by 

 Dr. von Rebeur-Pascbwitz and those observed in Tokio : — 



Effects of Chmujes in Temperature. 



The tests whicli have been applied to determine the effects produced 

 by a change in temperature have been severe. After closing all doors a 

 stove -which stands about 3 feet distant from the S.W. corner of the 

 column has been lighted, and the temperature raised, for example, from 

 49° F. to 85° F. This took three hours, and during this time the corner 

 of the column became sensibly warm to the hand. All was then allowed 

 to cool. The effect as shown upon the photographic trace and partly 

 by other instruments upon the column was that about half-an-hour after 

 lighting the fire the N.B. side of the column very quickly sank, indicating 

 a tilting from S.W, to N.B. of 2". After this it sank until an amplitude 

 of 6" was reached. Here it remained for several hours, and then gradually 

 rose. This, it will be observed, is a result that can be obtained by a 

 change of temperature of 36° F. 



Undoubtedly temperature effects exist in the records I have taken ; but 

 as it has often happened that the change in temperature during twenty- 

 four hours inside my observatory has not been more than 4° F., while 

 the daily movements have exceeded that which I obtain by a change of 

 36° F., I cannot attribute the movements I observe to fluctuations in 

 atmospheric temperature in the vicinity of the column. 



To determine how far slow and regular changes in temperature may 

 modify the diagrams will be a subject for future investigation. 



