the night, but it was
so damp that my men felt the cold intensely, especially as there were
gusts of a sharp breeze from the north-east. Moreover, in the deep hollow
with thick grass in which we camped (elev. 2,200 ft. above the sea level)
we suffered absolute torture from the swarms of _carrapatos_ of all
sizes, mosquitoes, and flies. The air and earth were thick with them. The
water was dirty and almost undrinkable, as it passed through a lot of
decomposing vegetation.

I was glad when Filippe reappeared and we were able to leave that
terrible spot. Great undulations were now met with, 300 ft. and more in
height.

Only 11/2 kil. farther on we came to the Presidente stream, flowing south
(elev. 2,100 ft.) over a bed of ashes, while its banks were formed of
thick deposits of finely powdered yellow volcanic sand and dust.

We went over a huge dome covered with a stratum of brown sand, exposing
on its western side a large wall of igneous rock with much-fissured
strata dipping to the north-west. Immense isolated rocks showed vertical
strata, demonstrating plainly that they had been considerably disturbed
at some epoch or other.

We were on the bank of another stream (elev. 1,950 ft.) flowing
south--the Capim Branco. We were then in another great and deep basin
extending from north-west to south-east, in the north-western part of
which could be seen on the summit of the rounded hill-tops and spurs an
overlapping of rock, evidently produced when in a molten condition. In
the south-western part of the slope encircling this great valley there
stood another great barrier, formed also by a flow of molten rock curling
over itself, as it were, and above this stood angular and pointed shoots
of molten stuff of a subsequent origin. Large slabs of the latter could
be separated easily from the underlying flow.

From the summit of that rocky prominence was obtained a lovely panorama
of a great plateau, a portion of which had been eroded into a wall
(E.N.E.) with three buttresses: another portion was gradually assuming a
similar shape. The plateau had a great spur projecting westward. A crater
had formed with a broken-up side to the west, leaving the conical-shaped
remains of its fragmentary mouth. The plateau ended after describing a
sweeping curve--almost a semicircle.

In the centre of the immense basin before us were successions of high
undulations--like great waves--extending southward in parallel lines
(east to west). From