92 



//. Slmotom,ai — Tarumai Dome in Japan. 



gave positive instead of negative images v^lien developed by 

 the normal process. This curious phenomenon was afterwards 

 experimentally proved by him to have been caused by a 

 momentary attack of the sulphur dioxide on the films. 



The exact date of the formation of these fissures is unknown. 



Fig. 4. 



Map and section of Tarumai, 1916. 



Fig. 4. In the map the meridian is marked by a lateral edge. The sche- 

 matic section passes from east to west, including the highest point in the 

 somma wall (1016 m.). Scale, 1 : 150,000 approx. 



but in photographs which were taken on the 23d of April 

 such depressions are not visible, while in those taken on the 

 1st of May, 1909, we can recognize, on the eastern side of the 

 dome, some traces of the termination of the trench just as we 

 now see it. 



