ON THE EARTHQUAKE AND VOLCANIC PHENOMENA OF JAPAN. 105 



2. Daily Frequency of EartJiquaJces. 



The following table is a classification of earthquakes according to the 

 time of occurrence •• — 



Thus we see that the maximum frequency occurred from 6 to 8 A.M. 

 and from 2 to 3 p.m.. whereas the minimum frequency occurred from 3 to 

 -5 a.m. 



3. Intensity of Earthquakes. 



The remarkable earthquakes recorded in Tokio were those of February 

 18 and December 31, already referred to, which had durations of 8 minutes 

 and 5 minutes 20 seconds respectively ; and one on August 5, which had a 

 duration of 4 minutes 20 seconds. 



There was only one earthquake which had a maximum range greater 

 than 20 mm. No other earthquake occurred with a maximum range 

 .greater than 10 mm. There were 12 earthquakes with a maximum range 

 greater than 1 mm., and 25 earthquakes less than 1 mm. There were 

 75 earthquakes whose movement was so slight as to render it impossible to 

 ■observe the range of oscillation. We therefore had very few severe dis- 

 .tui'bances during the year, although a large number of earthquakes 

 were recorded. 



