14 



EAETHQUAKES. 



history called * Gokanjo,' and the translation of this de- 

 scription rims as follows : — 



*Iii the first year of Yoka, a.d. 136, a Chinese called 

 Choko invented the seismometer shown in the accompany- 

 ing drawing. This instrument consists of a spherically 

 formed copper vessel, the diameter of which is eight feet. 

 It is covered at its top, and in form resembles a wine- 



FlG. 1. 



bottle. Its outer part is ornamented by the figures of 

 different kinds of birds and animals, and old peculiar- 

 looking letters. In the inner part of this instrument a 

 column is so suspended that it can move in eight direc- 

 tions. Also, in the inside of the bottle, there is an 

 arrangement by which some record of an earthquake is 

 made according to the movement of the pillar. On the 

 outside of the bottle there are eight dragon heads, each 



