v. 1,400 ft.) was a circular depression some 300 metres
in diameter, perfectly flat-bottomed and grassy. It was surrounded by
cones from 80 to 100 ft. high. On the south-east side of the range--very
steep--was abundant rock, whereas to the north-west side was a padding of
brown earth on a gentle incline divided into terraces. Here and there
pointed noses of volcanic blocks, similar to those we had found on the
opposite side of the range, showed through. We went across a depression
where water dripping down the mountain-side had remained stagnant,
rendering that spot almost impassable. The animals sank chest-deep into
slush, crashing through the thick and much-entangled growth of live and
fallen bamboos.

More campos, fairly wide, were found beyond this, and great stretches of
foliated slate and sandstone in strata turned over into a vertical
position, and quantities of debris. Then again we cut our way through a
cool growth of bamboos, handsome _palmeiras_ and _akuri_ palms; after
which we emerged into campos once more, rising gradually to an elevation
of 1,550 ft. upon an undulating terrace of the second section of the
Estivado range.

Pulling and pushing the mules and horses over a lot of boulders and up a
steep incline, we reached the highest point of the range on our
route--1,800 ft. above the sea level. Again the stratification of red and
grey rock in layers from 6 ins. to 1 ft. thick, standing vertically,
showed what a geological commotion there must have been in those regions.
The summit of the range, extending from north to south, appeared like the
teeth of a saw, so broken up was it into repeated undulations. On the
west side of the range we found a gentle slope of clear campos with
merely a few stunted trees upon them.

Before us to the west stood high the level sky-line of a table-land,
showing perfectly straight parallel strata of rock extending all along
its face, but slightly undulated near the summit of the range. Otherwise
its grassy slopes were quite undisturbed in their virgin smoothness.

In the distance to the north of our course was a great lagoon--the Lagoa
dos Veados, "Lagoon of the Deer"--a most important point in South
America, for it was there that the great Arinos (Tapajoz) River rose. The
lagoon--3 kil. long and less than 1 kil. wide--had no visible outlet, but
some hundreds of metres away a spring came out of the earth, forming the
Rio Preto (Black River). The Rio Preto, soon joined by th