A FREAK OF NATURE 
surface one found that they contained inside beautiful 
white marble or else greyish granite. The latter was 
striated with thin layers, not more than a quarter or half 
an inch thick, of crystallized matter, forming veins in the 
blocks or dividing two strata. 
Everywhere could be noticed remarkable perforations 
of all sizes in the rocks, great spherical or ovoid hollows, 
or cylindrical, tubular channels. In the ground were 
many volcanic vents with lips baked by fire. 
On our right, a kilometre or so farther on, after having 
gone through an extensive stretch of red sand and lapilli, 
we came across three hills, the central one of which had 
the appearance of a cylindrical tower of masonry with 
windows and doors. It was a wonderful freak of nature. 
Under this huge tower were several caves and grottoes. 
Descending upon the opposite side of the range, at 
an elevation of 1,200 feet we found the dry bed of a 
streamlet, which flowed in a northerly direction, when it 
did flow at all. On emerging from the wide hill mass — 
about eighteen kilometres across — we found ourselves 
among a lot of burity palms on the western spur of the 
Serra Azul. When we were actually upon them, the Blue 
Mountains lost their blue appearance and were more of a 
greyish green, owing to the vegetation which covered most 
of their slopes. The range was formed of three distinct ter¬ 
races, the lower one being of greater height than the two 
upper ones. A number of low hill ranges, starting from 
the main range, branched off like spurs toward the south. 
The uppermost terrace of the main range was supported on 
a high, vertical wall of red rock. 
On meeting the Rio Coralzinho we skirted it for some 
distance through the forest, then marched among a great 
many domes, small and large; after which we crossed a 
wonderful field of huge monoliths, superposed boulders, 
and rocks of all kinds of fantastic shapes. 
We had marched thirty kilometres that day. We en- 
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