AFRO-INDIAN REGIONS. 



469 



crevice of eruption extending directly towards Mauna Kea; there was 

 no issuing lava-stream, but lava had been spattered out, and there were 

 some hillocks of the light streamy masses of scoria, first seen on the 

 opposite brink, and afterwards on the bottom of the crater. Just be- 

 yond, I came upon the real Crevice of formation and eruption ; extend- 

 ing Northeast entirely clear of Mauna Kea, and marked by a long series 

 of scoria-hillocks on the top of a distinguishable prominence of the 

 mountain-flank ; much resembling the broad parallel ridge from the 

 Great Crater in the distance. A mile and a half farther on, I left the 

 including rim, which continued traceable around a wide shallow de- 

 pression ; and proceeding direct, reached the Encampment 62 hours 

 after starting; so that allowance being made for walking very leisurely, 

 the circumference of the three craters cannot exceed nine miles. 



The Eleventh day, I descended into the crater down the Southern 

 slope; a steep and difficult declivity. The bottom proved of the same 

 character as on the opposite side ; so that travelling over it, was almost 

 continual climbing. Proceeding towards tlie Western wall, I reached 

 the hillock of cindery pumice-like scoria, forty feet or more high, which 

 forms a conspicuous object from the brink above. Beyond this hillock, 

 the lava-surface became smoother, as though more recently melted; 

 and - there were various indications of the close vicinity of the fire. 

 " Fumaroles" were frequent, and contrary to our experience in the 

 bottom of the Great Crater, most of them emitted more or less steam ; 

 the sulphur fumes being in some places so abundant, as to render 

 crossing difficult. Besides the incrustations of impure sulplmr in the 

 clefts of issue, a tasteless whitish powder was intermingled ; which, 

 where the steam was hottest, was sometimes formed into little stalactites, 

 by reversing the usual process. The Western wall, chiefly perpendi- 

 cular, was found to be composed in great part of the compact greenish- 

 grey rock above-mentioned; probably altogether argiUaceous, but re- 

 sembling some varieties of lime-stone ; and found afterwards forming a 

 portion of the component rock of Mauna Kea. Being the rock in 

 situ, and not lava, here was the original wall of the crater in the ori- 

 ginal summit ; showing, that Mauna Roa is not a colossal pile of accu- 

 mulated lava-streams, as migbt otherwise be supposed. The principal 

 portion of the Western wall is however composed of unequivocal lava, 

 of ancient date, yet much resembling that of the walls of the Great 

 Crater; in some places reddish, in other places blackish, containing 

 irregularly-shaped cells, and also studded with little tufts of indistinct 



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