Immense quantities of fish could be seen in the river. No sooner had we made camp than we got out lines and hooks of all sizes, which we baited with pieces of toucinho. One end of the bigger lines we made fast to trees, as the fish we often caught were so powerful that on several occasions they had dragged us into the water and we lost not only the fish but the line as well. We had great sport that night and caught quantities of trahira (Macradon trahira)—not unlike a giant salmon and quite as good to eat; and also some surubim (Platystoma Lima), a large fish belonging to the herring family. The surubim was flat-headed, and not unlike the pintado fish which I have described in a previous chapter. It had thin scales over the body, and an abnormally powerful lower jaw, with vicious-looking, sharply-pointed teeth on the edge of the upper and lower lip. These curiously situated teeth were far apart, and so firmly inserted in the hard lips that it took a violent blow to remove them.
Although after a few minutes we had killed fish enough to last us—had we been able to preserve it—for some weeks, my men sat up the greater part of the night hauling quantities to the bank. The excitement each time a fish 80 or 100 lb. in weight was hauled out of the water was considerable. The wild yells and exquisite language whenever one of my men was dragged into the water kept me awake the entire night.
We left that camp at 7.30 on July 17th, the minimum temperature having been 66° F. during the night. Heavy globular clouds covered the entire sky. We were then in a region extraordinarily rich in rubber; quantities of Siphonia elastica trees were to be seen. It made one's heart bleed to think that nobody was there to collect the riches of that wonderful land.
The river flowed in short sections from north-west to north-north-east, barring a long stretch of 4,000 m., when we came to a great basin 600 m. wide, with two large islands in it; the eastern island—Orlando Island—being 100 m. wide, the western—Elizabeth Chimay Island—220 m. broad and not less than 500 m. long. South of both these islands were islets of gravel 50 m. each in diameter.
Nine thousand five hundred metres below these islands an important tributary, 8 m. wide, flowed into the Arinos from the right bank. It came from the south-east. Close to the left bank, from which it had been separated by the current, leaving a channel only 5 m. wide, another island—Isabel Island—300 m. long was found.
Shortly afterwards we came to a big equilateral-triangular island—Armida Island—fully 1 kil. a side. Albert Island, next to it, was of a narrow elongated shape.
From the beginning of Armida Island the river flowed for 4,000 m. in a direct line to 310° b.m. Four large rocks in a cluster stood in the centre of the stream at the north-north-westerly end of the island. Then we had another stretch of 4,300 m., during which the river was squeezed through a narrow neck, 100 m. wide, between low rocks. Immediately afterwards we emerged into a bay 800 m. broad, with three islets on one side of it. They were rather dry and somewhat mean-looking. I called them Faith, Hope, and Charity Islands.
After that the river was 800 m. wide. A deposit of gravel some 300 m. long was exposed on the right side beyond the last island of the group.
Three kilometres farther we halted for an hour or so, just time enough for me to take the latitude and longitude and for our lunch to be cooked. The usual torture had to be endured from the innumerable insects. The heat was also terrible—107° F. in the sun, 93° in the shade. Lat. 11° 23′·9 S.; long. 57° 39′ W.
When we left, we saw 3,500 m. beyond our halting place, beside a great heap of rocks on the left side of the river, a rivulet, 3 m. wide, entering the Arinos on the left.