To come to great geographical mistakes which came under my direct observation, I found a very palpable one in the head-waters of the Cuyabá River, which had their source to the north of the Serra Azul and not to the south, as marked on many maps, including the Brazilian official maps.
We had to our left the Serra das Pedra—"Range of Rocks"—an extraordinarily rocky range, which was crossed almost at right angles by the Chapadão das Porcas. We marched through a wonderful growth of palmeiras, some of the palms being as much as 30 ft. high. Buritys were innumerable along a small stream—the Rio Estivado—flowing south-west into the Cubayá River. There were great quantities of mangabeira trees. We proceeded northward along a chapada—a capital Brazilian name which denotes a locality that is neither a forest nor a prairie. The chapada had scanty trees and scrub, but not enough to make it into a forest.
We were marching over low hills with surface deposits of sand and cinders. We gradually reached an elevation of 1,050 ft. some 18 kil. from camp, and shortly after—and only 50 ft. lower—entered a refreshing grove of giant palmeiras and buritys along the Rio das Porcas, flowing westward. There, north of the stream, we went across more clean campos, 1,700 metres wide, bounded to the north by the thickly-wooded hill-range Keboh, extending before us from east to west.
We crossed this range in the centre, during a strong gale from the south-west. The wind cleared the sky, that had been overcast and had made the atmosphere heavy. Again that afternoon, when the wind ceased, I noticed the peculiar striations in the sky—not in straight lines that time, but in great and most regular curves converging to the west.
The valley got narrower as we went along. Two twin conical hills ended the northern extremity of the range (south-east to north-west) which we had on our left—a great mass of granite blocks in the centre of the plain rising higher and higher into regular domes. The plain itself, on an incline, showed two swellings of great magnitude, the one to our right about 120 ft. higher than the plain, the elevation of which was 1,000 ft. On the west side of those two swellings was a confused mass of huge blocks of granite—of all sizes and shapes—which to all appearances had been shot up from underneath by some internal force. They were outwardly much blackened by the action of fire, but internally were of a grey tint. A little farther we were encircled by basaltic columns of great height, many of them fractured, forming a fantastic sky-line. Some resembled the spires of a cathedral; groups of others had the appearance of the ruins of an ancient fortress; others stood up like giant obelisks; while accumulations of others formed more or less regular pyramids.
After leaving that strange basin, we were once more travelling across patches of clean chapada and dirty chapada—according to the soil and quantity of moisture; then over arid campos spreading for 15 kil. without one single drop of water.
At sundown, after having gone over several undulations varying from 850 to 900 ft. above the sea level, we went over a hill slightly higher—950 ft.—with a summit of ashes, red earth, and yellow lava pellets, as well as great sheets of foliated lava.
Under a most wonderful effect of light to the west—three superposed horizontal bands of luminous yellow, violet and brilliant vermilion, over the deep cobalt mountain range in the distance—we arrived, my men being thirsty and tired, at a little rivulet. We had marched 42 kil. that day.
My men felt the cold intensely during the night—the minimum temperature was 48° Fahr., with a high, cutting wind. Yet we were at a low elevation, merely 750 ft. above the sea level. There were, as usual, moans and groans all night, more toothache and rheumatic pains and bones aching in the morning. The discontent among my men had reached a trying point. They worried me continuously to such an extent—indeed, as never in my life I had been worried before—that I was within an ace of breaking my vow of never losing my patience and calm. In my long experience of exploring I have always had to deal with the most troublesome types of men imaginable, but never with any quite so unpleasant as those I had in Brazil.
When, the next morning, I ordered them to pack the animals in order to proceed on our journey, there was an unpleasant scene approaching mutiny. They knocked things about and refused to go on. Then they sat, rifles in hand, a little way off, grumbling and grunting, with vicious expressions upon their faces. They were going to do wonderful things—they were indeed! I overheard them. One man came forward—the spokesman. The men claimed their money up to date since the last payment made to them—only a fortnight before. They all wished to go.