( 230 ) 



sliailüw (Icplli, lo 1)0 ;il)l(^ t(» reatM so locallv oii tlic local difrerciicos 

 of the surface. 



Near the solfatare of 11)01 the Riiuleii^aii-atrio is iiiternipted l)v 

 a steep liill-raiii;e,. on account of some groii|)s of blocks Ibiiiid on 

 its back, a rather conspicuous feature iu the whollv graveloiis oi 

 sandy siu-ioundiniis, most likely an old covered stream of l)lock-la\a, 

 having issued from or at the foot of the Sopoetan-cone and being 

 mox'ed radially onward towai'ds the cii-cnlar wall. Abox'e (page 226) 

 we have already alluded to the fact thai in the immediate neigh- 

 bourhood such a slow eruption was i-ealized iu li)0(j and 11)07. 

 The considerable eruptive mass that was produced on that occasion 

 is sket(died on the map according to iiidicalioii> for which I am 

 indebted to Dr. Sciioch. 1 intend to revert to this eruption in the 

 second |)art of these j)()tes. 



The solfatare lies exactly there where the hill-range in (pieslion 

 ends against the I'entoe. The left-baidv of the l)rook-chamiel which 

 does not exceed two meteors iu width and ni depth, can at present 

 only be recognized with diflicidty : that chamicl-wall now gradiudly 

 passes over into the adjacent foot of the hill by the regular c()\eriug 

 of mud ejected by the solfatare. This sloping mud-tield had a pecidiar 

 [tarallel-stripcd appeai'auce by the downwai'd running furrows made 

 iu it by till' rains right through to the under-lying So[)oetan-gra\'eI. 



The solfatare itself, a ])ool estimated at three to four meters wide 

 and at that time in a \ iolently boiling condition, lies in a hole with 

 steep walls, which must ha\e been formed at the initial outburst, had 

 enlarged itself afterwai'ds by the tumbling down of the wall at the 

 hiirher side, and at the time of our visit mav ha\e been about 

 twelve meters wide, measui-ed along the edge. Thei-e was no pos- 

 sibility of getting down into this hole and lo the sides of the hot 

 pool. .So the dimensions given here are but rough estimatioJis. 



Standing on the outer edge I could not fully account for \vhat 

 really occurred under the dense cloiul of vapours, i^ut from the 

 hardly three meter long connection of that hole, sliding olfobli(piely 

 to the Pentoe-bed, we could observe that the boiling was attended 

 by the throwing up of perpendicular jets, the height of which until 

 their vanishing into the dense steam-cloutl, might be estimated at 

 al)0ut one meter; their formation is doubtless coimected with the 

 viscosity of the boiling mass, but lilvewise indicates the great 

 pressure with which this mass was driven out, nmst likely through 

 sevej-al narrou^ canals. In the nearest vicinity a smell of sid- 

 phuretted hydrogen w^as easily, sometimes even strongly, to be 

 observed. 



