STRANGE GEOLOGICAL FORMATION 
and yellow tints, or else great stretches of grey volcanic 
ashes and earth mixed, as well as sharply angular frag¬ 
ments of igneous rock, which showed that they had not 
travelled there by rolling on the ground or been propelled 
by w T ater. 
After this we passed close to another curious spur of 
mountains on the east, quite isolated and of a red vertical 
columnar formation. Its summit was broken up, much 
more so than that of the plateau-like range to the south 
of us, which we were following in a parallel line. The 
highest point of that range, to the south, was wooded, and 
so were the two conical-topped hills which towered over 
it. The strata where exposed showed a slight dip to the 
north. We crossed the range by two low cols at elevations 
of 1,550 feet and 1,560 feet respectively. On the summit 
and even lower upon the sides of those cols we found 
huge boulders of eruptive rock, highly ferruginous. 
Globular lumps, big and small, of spattered, smooth¬ 
surfaced, yellow lava were to be found in myriads; also 
many spherical pellets of ferruginous, highly baked rock, 
with innumerable holes produced while in a state of 
ebullition. Some of the ferruginous rocks had pellets of 
yellow lava firmly embedded in them, which had evidently 
penetrated, while liquid, into the hollows of the ferru¬ 
ginous rock, which was already in a semi-solid, or perhaps 
solidified, condition. At any rate, when it happened, the 
ferruginous rock was already harder than the lava. 
While I was studying attentively the geological con¬ 
ditions of that region, the sky suddenly became as black 
as ink to the south, and a heavy shower, which lasted 
half an hour, drenched us all to the marrow of our bones. 
Then it cleared up, and the sun, supplemented by our 
natural heat, dried our clothes upon us as we went on. 
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