On leaving camp--nearly at noon, after a serious quarrel and fight among
my men, which left me worried to death by the petty nonsense and
incessant grumbling of my followers--we journeyed at an elevation of
2,300 ft., finding shortly after an almost circular _cuvette_ of deep
grey cinders, 100 ft. deep (elevation at the bottom 2,200 ft.).

Twelve kilometres farther on we came upon another great depression
extending from east to west, with an enormous belt of grassy land. There
was the usual cluster of trees and palms in the centre, but larger than
usual. To the south were campos--lovely prairies--with sparse and stunted
trees--chiefly _Goma arabica_ or acacias.

The elevation of the upper edge of the _cuvette_ was 2,500 ft., that of
the bottom 2,450 ft. We continued our journey on the top of the plateau,
with slight undulations varying in height from 50 to 70 ft.
Snuff-coloured soil and red sand were invariably noticeable on the higher
points, and grey ashes in the lower points, where erosion had caused
depressions.

Then, farther on, the plateau, with an elevation of 2,450 ft., was
absolutely flat for several kilometres, and showed sparse vegetation and
miserable-looking anaemic trees--the thin soil over solid rock affording
them inadequate nourishment.

Eighteen kilometres from our last camp we came upon another oval basin
(elev. 2,400 ft. above the sea level), extending longitudinally from
N.N.E. to S.S.W. On its huge deposits of cinders grew deliciously green,
fresh-looking, healthy grass, and a thick clump of _burity_ palms, and
_birero_ trees of immense height and thick foliage. Those beautiful trees
were called by the people of Goyaz "_cutiba_" and "_pintahyba_." They
were marvellous in their wonderful alignment among the surrounding circle
of gorgeous palms. The latter were in their turn screened in their lower
part by a belt of low scrub--so that upon looking at that oasis one could
hardly realize that it had not been geometrically laid out by the hands
of a skilful gardener.

On the outer rim of the _cuvette_--away from the moisture--hundreds, in
fact, thousands of cones, cylinders and domes, from 4 to 6 ft. high, the
work of ants, could be seen, all constructed of bluish grey ashes.

We had here a wonderful example, quite sufficient to persuade the most
sceptical, of the influence of agglomerations of trees in the formation
of clouds. The sky was perfectly clear everywhere except directly above
the e