A STRANGE PHENOMENON 
Fahrenheit. But during the day, at nine a.m., the ther¬ 
mometer already registered 85° Fahrenheit. 
The sky, half covered by flimsy, transparent mist to 
the east, and by globular, thin clouds, large overhead and 
of smaller dimensions to the west, developed later in the 
day into a charming mackerel sky, with two great arches 
of mist to the south, and delicate, horizontal layers of 
mist near the earth. 
It was only when we were some distance off that we 
obtained a full and glorious view of the western side of 
the Paredao. The upper stratum showed a slight dip 
north, then there was a ledge on which grass seemed to 
flourish, and below it two parallel strata in a wavy line 
from north to south. Those two strata could be traced 
again, after a dip, in the range with two cones, separated, 
as we have seen, by a deep gap from the great wall-cliffs 
of the Paredao. The indication of what must have been 
once an enormous dome over a huge cavity or cauldron 
could be noticed in the western cliff, and also numerous 
chambers, large and small — at least, judging by the 
arches in great numbers noticeable in the wall. In other 
words, you had there the same effect as the one often seen 
in cities when houses are pulled down and the remains of 
the various rooms are visible on the remaining side walls. 
Looking north as we left the disturbed region of the 
Paredao Grande, we came upon a great valley, with a 
depression in its centre. We were still travelling on 
volcanic, ochre-coloured sand in deep layers, especially 
as we rose to an altitude of 2,810 feet, overlooking a huge 
basin. We had then a good general view of the southern 
aspect of the Paredao Grande. In its side a huge gap 
with vertical walls — a vent perhaps — could be noticed, 
reaching as far as the summit of the mountain. It was 
interesting to note that all the great cracks in the earth’s 
crust found in that region almost invariably had a 
direction from north to south, so that the ranges which 
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