Remember the Rainforest 1
caa-apuam (ie, "round, convex bush"; likewise and the word cama-apoam) (camapuan, common place name, properly formed of "round chest, changed into a hill").
The islands along the continent (Tupi: ibi-rete, that is, "own land, true"), and the islands divided by holes, called igapo by the Indians (really, serpentine water), an expression also used for lowland, flooded on the banks. If these flooded regions are muddy, in the language of the Indians they are called Tijuca-pan, meaning "all rotten."
The aspect of the islands of a particular body of river is constant throughout its course and equal to the ends of Brazil. They are low, flat, without cliffs or reefs, presenting sandbanks, which are flooded at the time of the floods, having in the center characteristic thick vegetation, with whitish trunks of the embaubas,
and are rarely swampy. Many of them measure one German mile in length, with relative width. The islands formed by much larger stretches of terra firma are covered with dense virgin forest and correspond in their physical characteristics to those of the neighboring regions. One has a glimpse of the sheer extent of the Amazon River when you consider the low altitude of these islands. The largest of these are: Paricatuba Island, with 72 square leagues of surface;
Tupinambaranas Island, with 442;
and Marajo's, in fact situated on the sea, but surrounded by fresh water, with 960 square leagues.
So Marajo, therefore, where 10,500 men live, far surpasses the area of Switzerland, which has 1,900,000 inhabitants.
The depth of the river can only be calculated approximately. La Condamine observed that he would sometimes gather several deep dewatering valleys, parallel to each other. This circumstance, in addition to the width of the channels between the islands and the current, not only makes the drilling work very painful, but even dangerous for the experimenter, who can only govern with both arms the heavy probe in a long cable. To favor probing (in tupi, saang-typu), we sought the oars gall to keep the canoe stationary against the current; but the attempt was often frustrated by the shock of the lead in the boat or the violence of the river, which tore the weight off. I believe that, in general, 15 bracas of the main channel can be evaluated below the junction of Japura with Solimoes,
and 24 bracas equally under the confluence with Madeira to Obidos.
Confluence at Obidos
To the east of Obidos, or rather from the mouth of the Tapajos, the main channel takes extraordinary width and depth, as the islands are more along the bank than in the middle of the riverbed.
The depth should measure here about 50 to 60 bracas. In the Obidos Strait, no rig had yet touched the bottom. It was only by special instruments that the amount of water the river could carry at any given time could be accurately measured. Assuming that the Obidos river bed is 869 wide, which in the middle is 60 deep and on the edge 20, thus a cross section of the one-piece long bed results in a capacity of 208.160 feet. Cubic. The average rapidity of the river current per second is estimated at 2.4 feet; it must therefore carry, by the Pauxis strait, per second, 499,584 cubic feet.
Straits of Obidos
The current of the river and its depth are conditions upon which detailed observations do not warrant any conclusion, that is, the movement of the waters is not only very different in different places, but also during the highest floods, it is much more fiery than in the ebb;
Port of Obidos
Finally, the speed is at least once more impetuous in the middle of the river course than along the banks, where, furthermore, a movement of the waters upstream must necessarily concur. It is only in the middle of the main channel that waves of considerable height (from one to two feet) are struck, and equally violent is the movement where local obstacles are countered: bank advance, fallen trees, etc .; Aside from this, the river is very calm and regular along the banks, and there are even many channels of the river, such as the one in Aquiqui, which, by their multiple and narrow turns, hinder the movements; these channels look like dead waters compared to the most raging rivers. The violent rapids are called by the Tupi Indians tipaquena; On the other hand, the channels, which run slowly, are called igarape-iakumatiman, that is, "a channel where no rudder is needed."