A pretty little islet of gravel, 100 m. long, 20 m. wide, and rising 6 ft. above the water, had a tuft of trees growing on it, and a spur, also of gravel, extending westward for more than another 100 m. The river in that section flowed in a W.N.W. direction for 1,400 m.
We soon after came to a shallow basin (1 ft. deep) 100 m. wide, in which eddies were strong and troublesome. There were many pointed rocks scattered about in its bed of gravel, as well as three parallel rocky barriers right across the basin.
A rivulet 2 m. wide at the mouth entered the Arinos on the right side, while on the left side we had an island 800 m. long, leaving two channels, one 10 m. wide, the other 40 m. A tiny streamlet flowed into the main stream on the left. Banks, regular dunes of gravel, were formed where the river broadened into basins. We came to a basin 400 m. wide and extremely shallow. Three channels—W.N.W., N.W., and N.N.E.—were formed in the river by two islands, each 400 m. long—the Two Sisters Islands—which were in the centre. We found the N.N.E. channel the best. Where the river narrowed again to a width of 50 m. huge rocks stood in the centre. From that point for some 300 m. we went over a succession of gravel banks and nasty rocks forming barriers across the stream.
Small streamlets entered the Arinos, one on the left, the other on the right. A cluster of high rocks was on the right bank. On both sides were extensive white sand beaches. The river soon widened to 100 m. in a basin with an islet 12 ft. high, and a cluster of trees on its north-east side. Another island 6 ft. high, 80 m. long—Mosquito Island—with a spit of gravel to the south, was near it.
Rubber trees were most plentiful on the right bank where the forest was thick, whereas on the left bank was chapada. Huge gorgeous butterflies with black-striped brown wings and velvety bodies flew in great numbers around the canoe. Some settled on my hat, hands, and on the sleeves of my white shirt. They were so unaccustomed to see human beings that when touched they did not attempt to fly away.
The river was getting more and more wonderful every hour as we went along—in great straight lines of 3,500 m., 3,000 m., 2,200 m., 2,000 m., 4,000 m., in length.
Some ducks rose from the water only a few yards in front of the canoe. The man who was behind me fired with his carbine close to my head. The bullet grazed my right ear. It was a trifle trying to be travelling with such careless sportsmen, but the best thing was to say nothing and go on.
A big island—Passos Island—300 m. long, preceded by a smaller islet 80 m. long—Passos Junior I.—was subsequently passed, where the river formed a channel (N.W.) 50 m. wide and a minor one (W.) 30 m.
The river there changed from a westerly course to W.S.W. Once more we had before us a great wall of red rock which at first seemed to bar our way. In the lower section of the wall was a cave eroded by water and extending some way back. It was too low to be entered by the canoe. The lower stratum of the wall was at an angle—in other words, had a dip of 21°—while the stratum above it, 30 ft. in thickness, intersected by a yellow band, was perfectly horizontal. On the left side of this high natural wall was a charming waterfall of limpid water. Farther on a great land-slip displayed for a length of 40 m. brilliant red earth over a stratum 60 ft. thick of white chalk. The river, which described a number of turns, was bordered on the left side by a hill range covered with handsome trees.
The ardour of my men for rowing had already passed away. They smoked and sang the whole time, and let the current—fortunately strong—carry us along. Whenever I remonstrated they scooped the water carelessly with their paddles for a few minutes. As is the case with individuals mentally deficient, everything seemed to distract them. One moment it was the flight of a jacutinga—a handsome black gallinaceous bird with a white crest. Another moment it was the jump of an inquisitive fish. Many mergulhão commun (Podiceps Americanus), wonderfully graceful, velvety black birds with long beaks, flew about unconcerned from tree to tree. Whenever anything moved about anywhere, the paddles were abandoned, the rifles were seized, and there was a regular fusillade. The men seldom hit anything, although on many occasions, with the unsteady canoe, we all of us had narrow escapes. One day the man in front of me fired a shot at a bird—but so close to my head, not more than one foot away, that the concussion blinded me for several seconds. On other occasions the rifles went off when they were not expected to. I had ceased to give orders of any kind about the careful use of the weapons. It was time and lung-power absolutely wasted, and only made things worse.
