ON THE VOLCANIC PHENOMENA OF JAPAN. 



425 



(e) Special Earthquakes. — On April 13, at 5.50 a.m., a strong earth- 

 quake, extending over 4,980 ri, was felt in the north part of the main 

 island. It commenced with a rumbling, and the shaking lasted for three 

 minutes. It does not appear to have been felt in Yezo, from which the 

 shaken districts are only separated by straits, which at one point are only 

 10 miles in width. At Nemuro, at the north-eastern corner of Yezo, a 



