This great gaiety seemed most weird in that region where silence reigned supreme always. The voices seemed to travel immense distances, echoed from one side to the other of the river. Words were reproduced with great clearness by the echo two or three times over. Especially when we had forest on both sides of the stream was the echo particularly perfect.
Quantities of rubber trees—absolutely going to waste—were to be seen now on one side, then on the other, of the river where the banks were wooded.
A Rapid on the Arinos River.
Taking the Canoe through a Narrow Channel.
Another most beautiful island, 800 m. long and 80 m. wide—Pedro de Toledo Island—was passed. It had a channel 10 m. wide in a north-westerly direction, another, which we followed, 50 m. broad, north-east. On emerging from this channel at the end of the island we were in a basin 140 m. in diameter. Some 3 kils. farther, another great basin was crossed—very shallow, only 2 ft. deep—with a gravel bottom. The current was swift. Then, 2 kils. beyond, yet another basin, 100 metres wide, 1½ ft. deep, with strong eddies, was crossed. The river, which had so far kept more or less in a northerly direction, at that point actually swung round in two consecutive angles from 350° north to due south, in which direction it flowed for 1,000 m. An immaculately white beach was on the right of us, on which we duly stranded. It was quite enough for Alcides to see an obstacle of any kind in the river for him to send the canoe right over it. I seized that opportunity to land and commence a most interesting collection of the innumerable minute sand plants which were to be found on those beaches.
Where the river turned north once more there stood a hill 100 ft. high, the lower half of which was of red volcanic rock, the upper half of yellow earth. Along the water's edge a thick and florid growth of bamboo could be seen in many places, while on the edge of the forest hung myriads of purple convolvuli. For hundreds of kilometres the Arinos was indeed one of the most ideally beautiful rivers I have ever seen. Its banks of alluvial formation, 25 to 30 ft. high, had chapada on their tops. Farther on the chapada gave way once more to dense forest with plentiful rubber trees. Another basin, 150 m. in diameter, was met with, after which we entered a channel from 40 to 50 m. wide, through which the stream was compressed.