402 



F. OMorj : 



TABLE II. 



Number of Destructive Earthquakes in Japan. 



5. From Table II it will be seen that the numbei-s of destruc- 

 tive earthquakes in the öth, ()th, and 7tli centuries are very 

 few. This circumstance may of course be due to tlie imperfection of 

 historical records in those early times, it being only from the 

 endoftheTth century that the records begin to augment. Taking 

 as starting point December, 678 A.D., when the first of the two 

 destructive earthquakes in the 7th century took place, we have 220 

 such earthquakes in Japan^ in the interval of 1220 years 

 down to the end of 1898, there being on the average one des- 

 tructive earthquake in every -5 years and 7 months. As, however, 

 the earthquake records in old times, which relate to remote 

 provinces, would naturally be imperfect, the above average 

 interval between two successive destructive shocks is without 

 doubt somewhat longer than what was actually the case. On 



1) Forniosa excepted. 



