ACROSS UNKNOWN SOUTH AMERICA 
encountering some obstacle, had its run interrupted and 
had cooled down, while its upper portion, from the impetus 
received, curled over the summit of the arrested, solidified 
rock below. 
In fact, there was plenty of evidence to show that while 
the lower stratum cooled down, other sheets of lava flowed 
above it, forming many successive layers. In the eastern 
part, where they were at an angle of 40°, these had cracked 
considerably in cooling. The central part of the great 
wave was entirely made up of vertically fissured strata. 
The lower half of the mass of rock showed markedly that 
it was an anterior wave to the upper. 
There was a wide gap formed by the volcanic crack 
between this and the continuation of the undulations to 
the southwest, which got lower and lower. Perhaps before 
the crack occurred that hill was like the others on the 
east and west of it, padded with red earth. It must have 
become barren by the great shock which caused the surface 
of the earth to divide, and which no doubt shook the 
surface deposits down. In examining its northeastern 
neighbour it could be seen that it actually tumbled over 
when the subsidence occurred, leaving a gap a few 
hundred metres wide. 
A short distance beyond, on the south-southeast, was 
an interesting tableland sloping to the northeast, on the 
north side of which could be observed yet one more 
beautiful, semicircular, extinct crater. The rim, or lip 
of lava of this crater, had fissured in such a peculiar way 
as to give the appearance of a row of rectangular windows. 
The sections of the crater which remained standing showed 
two conical buttresses above massive cylindrical bases. 
From the crater started a huge, deep crack, 30 to 50 feet 
deep and 20 to 100 feet wide, which farther down became 
the actual bed of the stream. On both sides of this crack 
was a deep deposit of red earth and sand, the stratum 
below this being a solid mass of lava. The crater on the 
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