red lava.

The green country before us, in great sweeping undulations, reminded one
much, in its regularity, of the great waves of the ocean--what sailors
call "long seas." Where the stream had cut through and left the
underlying dome of lava exposed one could easily judge of the thick
deposits of sand, ashes and pulverized rock which formed the strata above
it.

We travelled over more red volcanic sand for some four kilometres, rising
to 1,400 ft., on which elevation was thick _matto_, or stunted, much
entangled forest. Then we emerged once more into glorious open country,
marching over a stratum 8 ft. thick of whitish tufa and ashes, this
stratum lying immediately above one of red volcanic earth. The strata
were easily measurable where rivulets had cut deep grooves in the softer
superficial strata and had reached the foundation layer of lava.

The campos seemed to get more and more beautiful as we went west. What
magnificent grazing land! One could imagine on it millions and millions
of happy, fat cattle; but no, not one was to be seen anywhere. What a
pity to see such wonderful country go to waste! There was everything
there, barring, perhaps, easy transport, to make the happiness and
fortune of thousands upon thousands of farmers--excellent grazing,
fertile soil, good healthy climate and delicious and plentiful water--but
the country was absolutely deserted.

For miles the beautiful prairies extended, especially to the south-west,
where in the distant background loomed a high, flat-topped tableland,
interrupted by two deep cuts in its extensive monotonous sky-line. Those
cuts were near its southern end. To the south stood a long range of
wooded hills--also with an absolutely flat sky-line. We ourselves were
not higher than 1,400 ft. above the sea level. My animals stumbled along
over a region of much-broken-up debris; then again travelling was easier,
although heavy, over tufa, sand and ashes. On descending to a stream,
1,200 ft. above sea level, we slipped terribly on the steep argillaceous
slope, and the animals had great difficulty in climbing up on the
opposite side, where we made our camp.

[Illustration: Curious Domes of Lava with Upper Stratum of Earth,
Sand and Ashes.]

[Illustration: Great Undulating Campos of Matto Grosso.]

The streamlet flowed east into a larger stream, which we also crossed,
and which flowed south-west.

It seemed to be getting colder at night as we went westward (May 18th,
m