THE ERUPTION OP BANDAI-SAX. 145 



fissure lines whence steam issued with great violence, the gorges 

 filled with water (new lakes), and the regions at the base of vertical 

 cliffs down which earth and rocks, and even slabs measuring one 

 or two hundred metres, were constantly thundering. Otherwise 

 the conditions were as favourable as could reasonably be expected in 

 the circumstances. Not that the inside of the crater was anything 

 like a level plain. Far from it ; it was cut up by precipitous 

 hills, deep chasms, wild depressions of all imaginable shapes and 

 sizes. PI. XIX shows a prominent rock-hill inside the crater, on 

 which was located one of our stations. The crater-bed was full 

 of these boulder-mounds, and was so irregular that we spent nearly 

 two days in fixing upon a suitable base-line. We were, however, 

 fortunate in finding a nearly straight narrow band in the bottom of a 

 valley in which to locate the base-line. 



For five successive days Mr. I. Toya laboured indefatigably, 

 until all the important points were measured from prominent 

 heights in and round the crater. When this was done, we removed 

 to Ottate, a spa on the south flank of bandai, and mapped the results 

 of the triangulation. 



The form of the crater, as deduced from the plan, is semi-ellip- 

 tical, or like a horse-shoe. It opens toward the north, its bed gently 

 inclining outwards. The plan in PI. XXIII shows the general 

 outline. It is surrounded by precipitous walls and steep cliffs of 

 great height especially on the southern side, where a part of Kobandai 

 still 'remains with rugged edges, and where Kushigamine exposes a 

 clean section. The heights of the wall as may be seen from the 

 numbers indicated on the plan gradually become smaller as we 

 approach toward the mouth, at last reaching to the same level as the 

 crater-bed. The heights in and round the crater were measured by 

 taking altitude angles and were afterward referred to sea-level. The 



