VESUVIUS 379 



some higlily desirable observations could not lie made. On attainino; a 

 certain distance, however, it was found that a return hy tlie same route 

 was impossible, so that we were fortunately oblioed to ,siO to tlie bottom 

 and ascend by the usual track. 



The descent was begun at a low point on the northwest rim, about 200 

 meters north of the' abandoned funicular station. The upper part was 

 steep, tlie wall consisting of faces of lava-sheets interbedded with some- 

 what consolidated agglomerate and beds of scoria. There were no well- 

 dclined fumaroles along this portion, Init eonsideralde steam, higlily 

 charged with HCl and SOo, was emitted fi'oin the crevices. 



.Vt a depth of rather over 100 meters t!ie heail of a talus slo[ie at least 

 '<!()0 meters long and with a slope of 31° was reached, ajid the descent 

 (■out iiiued down this. 



Tlie floor of the crater is somewhat domed toward the center, covered 

 with ash, in wliicli small, loose augite crystals may be gathered, and is 

 strewn with many angular blocks fallen fr(nn the walls above. Many of 

 these are several cubic meters in size. No saline incrustations were seen, 

 probably because of their removal by the prolonged rainy weather. There 

 were no rumai'oK's projier, a central group formerly |)resent having ceased 

 activity after thi' sulisidence of 1012, but hot vapors issued i-ont iiiiiously 

 from the ei-eviees ami the loose material. HCl and SO, could be readily 

 detected. There wtM'e also pi'eseiit uiupiestionably SO., and pi'ohalily CO.,. 

 I, lit no [|.,S was ol)ser\ed. The blue mist produced by these gases and the 

 ahuiidant steam made good ])hotographs impossible. 



At the foot of the north and east walls was a long, narrow, and deep 

 cresci'iitie \allev. which was i'ornie<l toward the end of November, 1911. 

 The highest |ioin1 of the lloor. near the center, is 327' meters below the 

 higliest point of the rim, and the depth of the \alley is ahout (id meters. 

 as determined by Malladra in l!tl3. 



In the southwest part of the Hoor is the funnel, the diameter of which 

 was judged to he ahout l"in meters, with a depth of ahout ;'>(! meters. 

 The sides of this slope at 30° and are composed of loose ash and scoria, 

 with comparatively few laig'e blocks. 



Sli<ditlv aho\e ami to the northwest of the lowest iioint of this is the 

 '•hocca" or mouth — a roughly circiilai- oi' elliptical orillce some lO-lTi 

 meters across — with rougli, approximately vertical walls, which could he 

 approached within a few meters. Beyond this on the north was a vertical 

 wall of lava, sprinkled with drililets and small stalactites of lava. 



l''i'(iiii this inoiilh issued two ji^ts of smoke, in large rounded piifFs, 

 every four to six seconds, accompanied hv rather huid roars, while a con- 

 tinuous low rumhling could he heard helow. The eastern jet was some- 

 what the lariier. and the pulls nf the two were not usually synelironous. 



