The distance hence to the mouth of the Madeira is about thirty miles. After passing the end of the long island, called Tamitari, that lies opposite McCulloch's, we had to cross the river, which there is about two miles wide. The shores are low on either hand, and well wooded with apparently small trees. I always felt some anxiety in crossing so large an expanse of water in such a boat as ours, where violent storms of wind are of frequent occurrence. Our men, with their light paddles, could not keep such a haystack as our clumsy, heavy boat either head to wind or before it, and she would, therefore, lie broadside to in the trough of the sea, rolling fearfully, and threatening to swamp. I should have had sails fitted to her in Barra.
After crossing the river, we passed the mouth of two considerable streams. The lower one, called Uauta, is two hundred yards wide at its mouth, and has a considerable current. It is said to have a large lake near its headwaters, with outlets from this lake, communicating with the Amazon above, and also with the Madeira; that is, it is a paranamiri of the Amazon, widening into a lake at some part of its course. At half-past 8 p. m. we made fast for the night to some bushes on the low, western bank of the Madeira.
A large island occupies the middle of the Amazon, opposite the mouth of the Madeira. This mouth is also divided by a small island. The western mouth, up which I pulled nearly to the head of the island, (a distance of about a mile,) is three-quarters of a mile wide, with sixty-six feet of depth, and a bottom of fine white and black sand. The current runs at the rate of three and a quarter miles the hour. This current, like that of all the rivers, varies very much, according to the season. I was told afterwards, in Obidos, that, when the river was low—in the months of August, September, and October—there was very little current, and that a vessel might reach Borba from the mouth in three days; but that, when it is full and falling—in the months of March, April, and May—there is no tributary of the Amazon with so strong a current; and then it requires twenty days to reach Borba.
The eastern mouth is a mile and a quarter wide. The island which divides the mouth, is low and grassy at its outer extremity, but high and wooded at its upper. I looked long and earnestly for the broad L that Gibbon was to cut on a tree at the mouth of whatever tributary he should come down, in hopes that he had already come down the Madeira, and, not being able to go up stream to Barra, had gone on down; but it was nowhere to be seen.
The Madeira is by far the largest tributary of the Amazon. Once past its cascades, which are about four hundred and fifty miles from its mouth, and occupy a space of three hundred and fifty miles in length, it is navigable for large vessels by its great tributaries—the Beni and Mamoré—into the heart of Bolivia; and by the Guaporé or Itenes, quite through the rich Brazilian province of Matto Grosso. The Portuguese astronomers, charged with the investigation of the frontiers, estimate that it drains a surface equal to forty-four thousand square leagues. We shall, however, know more of this river on the arrival of Mr. Gibbon, whom last accounts left at Trinidad de Moxos, on the Mamoré, one of the tributaries of this great stream.
The rapids of the Madeira are not impassable; Palâcios, the Brazilian officer before quoted, descended and ascended them in a canoe, though he had occasionally to drag the canoe over portages. And Mr. Clay, our chargé at Lima, was told that a Brazilian schooner-of-war had ascended the Madeira above the rapids, and fired a salute at Exaltacion, which is in Bolivia, above the junction of the Beni. Palâcios probably descended at low water, and the schooner went up when the river was full.
The village of Serpa, where we arrived in the afternoon, is situated on the left bank of the Amazon, thirty miles below the mouth of the Madeira. It is a collection of mud-hovels of about two hundred souls, built upon a considerable eminence, broken and green with grass, that juts out into the river. There is a point of land just above Serpa, on the opposite side, which, throwing the current off, directs it upon the Serpa point, and makes a strong eddy current for half a mile above the town close in shore.
Serpa has a considerable lake back of it called Saracá, on the lower end of which is the village of Silves, a little larger than Serpa. That entrance to the lake which communicates with the Amazon near Serpa is not large enough for my boat to enter; that near Silves will admit large schooners. A mark on a tree shows that the river rises about twelve feet above its present level.
We left Serpa at 6 p. m., and drifted all night. We are compelled to travel at night, for there is so much wind and sea during the day that we make no headway. We are frequently compelled to lay by, and are sometimes in danger of being swamped, even in the little nooks and bays where we stop. The most comfortable way of travelling is to make the boat fast to a floating tree, for this keeps the boat head on to the wind and sea, and drags her along against these with the velocity of the current.
About fifteen miles above Villa Nova, which is one hundred and fifty miles below Serpa, a boat manned by soldiers pulled out from a hut on the shore, and told us we must stop there until examined and despatched by the officer in charge, called inspector. I could not well pull back against the stream, for we had already passed the hut; so I sent word to the inspector that I had letters from the President, and pulled in shore abreast of where I was. The inspector had the civility to come down to me and inspect my papers. This is a "resisto," or coast-guard, stationed above the port of entry of Villa Nova, to stop vessels from passing, and to notify them that they must go into that port. There is another below Villa Nova, to stop vessels coming up, and to examine the clearances from the custom-house of those coming down.