Directly south-west the evenness of the sky-line was again interrupted by two mountains—flat-topped, one not unlike the gabled roof of a house, the other like a cylindrical tower on the top of a high conical hill. We again rose to an elevation of 1,950 ft., still travelling on the summit of the plateau bordering the deep depression. We were compelled to describe a curve in our route, and had reached a height of 2,000 ft. We perceived to the north-east and east a long, uninterrupted—almost flat—sky-line. We had described a sweeping curve right round the irregular edge of the undulating plateau. We could now look back upon the southern aspect of the vertical black and brown rocky cliff, on the summit of which we had been travelling. The rocky cliffs were particularly precipitous and picturesque in the western portion. Interminable campos were still before us.
I occasionally picked up interesting plants and flowers for my botanical collection. Innumerable in this region were the plants with medicinal properties. The sentori (centaurea) for instance—plentiful there, with its sweetly pretty mauve flower—when boiled in water gave a bitter decoction good for fever.
We came upon a patch of landir or landirana trees, with luxuriant dark green foliage. They grew near the water, and were by far the tallest and handsomest, cleanest-looking trees I had so far seen in Matto Grosso. They attained a great height, with extraordinarily dense foliage, especially at the summit, but also lower down at the sides. Then burity palms were fairly abundant wherever one met landir trees in groups or tufts. We were now travelling at an elevation of 2,050 ft., then soon after at 2,100 ft. above the sea level. There was merely stunted vegetation growing upon the red earth and sand.
On descending from that high point we came upon extraordinary scenery. To our right (north) was another concave depression with a further subsidence in its central part. Due west and north-west, from the spot where we first observed the scene, appeared four curious hemispherical domes forming a quadrangle with three less important ones beyond. In the south-easterly portion of the depression was a great rocky mass, while due north another, and higher, conical mount, much higher than all the others, could be observed.
In the eastern part of the depression a wide circle of big volcanic boulders—undoubtedly an extinct crater—was to be seen, with huge masses of spattered yellow lava in large blocks as well as ferruginous rock. That great depression—taken in its entirety—was subdivided into three distinct terraces, counting as third the summit of the plateau. A mighty, deep, impressive chasm, smothered in vegetation, could be observed within the central crater—in the north-east side of the circle.
The summit of the plateau, varying in elevation from 2,000 ft. to 2,100 ft., on which we were travelling was entirely covered by sand and grey ashes.
The valley in the depression extended in lovely campos from south-west to north-east—in fact, as far as the giant table-land which stood majestic in the distance.
The scene, as we stood on the edge of the plateau, was impressive in its grandeur, in its silence. In the morning the sky was almost entirely covered with transparent clouds in scales like a fish. In the afternoon the sky above changed into horizontal layers of globular clouds, which stood as still as death. Leaden black globular accumulations covered one-third of the sky vault, great unshapen masses overhead rendering the air heavy.
We marched all that day on a deep layer of ashes. On descending from the plateau we had on our left great clean campos and plentiful burity palms in a slight depression where moisture filtered through. As the caravan was moving along gaily, a veado (deer) gracefully leapt in front and, turning its head back two or three times to look at us, ran before us. Filippe, the negro, in his excitement, gave wild yells which set the mules stampeding, while green parrots in couples, scared at the sudden disturbance, flew overhead, adding piercing shrieks to the rapid tinkling of the mules' bells, the rattling of the baggage on the pack-saddles, and the shouts of the men trying to stop the excited mules. All those sudden noises mingled together were quite a change for us, accustomed to a constant deathly silence.
Before us on the W.N.W.—as we still sank in grey ashes—were two conical hillocks. In the distance, to the west, two small flat-topped plateaux rose above the sky-line, and also two hills shaped not unlike the backs of two whales. On our left we had an immense crack or fissure extending from north-east to south-west between the hill-range on which we travelled and another on the south—both showing huge domes of eruptive rock, apparently extensive flows of red lava subsequently blackened on the surface by weathering. On the opposite side to ours the rock was exposed all along the fissure for a great height, except the surface padding on the summit, where beautiful fresh green grass was in contrast to the deep tones of the rock. On our side we were still struggling in ashes and sand, with striated and much indented boulders of lava showing through.
