The night of July 10th was cool—minimum temperature 58° F. When we departed at 7.10 in the morning the river was extremely tortuous at first—in one place actually veering from north to due south. On the right side of us was a lake divided by a low bank, 3 to 5 ft. high, from the river by which it was fed. The entrance into the lake was narrow. We had hardly gone 1 kil. when we found ourselves in a great basin 300 m. long, 200 m. wide, with one large island—Nellie Island—150 m. in length, and several other small islets in its centre.

Another lagoon was shortly after reached on the right bank, its inlet being 10 m. wide.

The waters of the Arinos were, at this point, of a leaden placidity. We seemed to travel slowly now that the current did not help us. The river was again compressed into a deep channel 50 m. wide. Before us loomed a cliff 100 ft. high, reflected with irreproachable faithfulness in the almost still waters of the stream. There was not a breath of wind to disturb the mirror-like surface, nor to cool our sweating brows in the stifling heat of the broiling sun. The lower 40 to 60 ft. of the cliff was red, the upper light yellow—almost white. Where we reached this rocky wall there was a circle 150 m. in diameter, with a low, thickly-wooded triangular island, 80 m. long, 100 m. wide—Eleonora Island.

The north-eastern passage was shallow, with a stony bottom. We followed the northern channel along the vertical wall. On leaving the island we came to a stretch 2,500 m. long of beautiful water flowing due north, with ideally fascinating banks embellished by dense vegetation—neat, clean, and healthy—of the richest green.

After crossing a bay, 100 m. wide, with volcanic rocks showing through on both banks and in the river bed, the stream was squeezed through a rocky neck 25 m. wide, and spread again immediately afterwards to its normal width of 50 m. We were beginning to find big rocks more frequently, many in the river channel—a bad sign for us, for I feared we might soon encounter rapids.

Wonderful oleo pardo trees (Myrocarpus frondosus Fr. All.), with their octopus-like branches hanging down to the water, were fairly common in that region. There were two kinds of oleo trees in Brazil—the brown or oleo pardo and the red or oleo vermelho, the latter technically known as Myrospermum erytroxylon Fr. All.

We subsequently entered a basin 150 m. wide which contained a circular island 100 m. in diameter—Horus Island.

Eight hundred metres farther we came to another large circular bay with a large globular mass of lava on its left side. The current was very swift over a nasty rocky bottom. The canoe was suddenly flung by the current between an accumulation of rocks and an island, and, as we found it impossible to turn, floated down at an uncomfortable speed through a narrow channel, dodging as best we could the many ugly rocks just below the surface of the water. At the end of this channel we encountered violent eddies forming wide circles of most treacherous water—although on the surface it looked placid enough.

The tributary Sumidoro, 30 m. wide at its mouth, entered the Arinos from the west-south-west at this point. Its water was deliciously clear. A little way off to the left we could hear the noise of a waterfall on the Sumidoro, before it joined the Arinos.

The river, after the meeting of this important tributary, became even more exquisitely beautiful than before. Rocks strewn about added to the picturesqueness of the landscape as well as to the dangers of navigation, while springs of crystalline water, cool and quite delicious to drink, descended here and there from the banks.

The river had an average width of 60 m. in this part, and was much strewn with broken-up volcanic boulders, especially on the left bank. On the right bank was a beach of immaculate white sand. For 300 m. we went over a great stony place with shallow water. We had to be careful, but all the same many times did we bump with great force and get stuck upon submerged rocks—which we could not see owing to the blinding, glittering refraction of the sun upon the troubled waters. A tributary 4 m. wide, coming from the north-east, entered the Arinos on the right bank. A great number of rubber trees were to be seen on the right bank, where the forest was luxuriant; but not on the left bank, where the growth of trees was scanty. CarandÁ or burity or tucuman palms were plentiful along the water's edge near the spot where a small rivulet entered the Arinos on the left bank. Two thousand metres farther down we came upon denuded country, low, and liable to inundation when the river rose. Farther on were campos and open country, with the exception of a thin row of trees immediately along the river. On the left we had luxuriant forest, wonderfully healthy, neat and clean. The stream was there beautiful—60 to 70 m. wide.

When we had gone 10 kils. 800 m. more the entire channel became strewn with rocks and mounds only 1 ft. below the surface of the water, and not unlike parallel small dunes of sand with a deposit of gravel upon them. For 700 m. the river was obstructed and navigation rendered somewhat troublesome.

Where the river turned from bearings magnetic 310° to 360° (due N.) we went over a nasty stony place with a strong corrideira above it, and we were confronted with a rocky barrier almost the entire width across the stream. We kept on the west side, the only way where it was possible to get the canoe through. A little farther another corrideira, stronger than the first, obliged us to find a passage on the east side of the river—which bore upon its bank campos and chapada. Curious mounds of white sand and gravel were visible in the centre of the river, and also near the left bank below the second corrideira; then we came to parallel ridges of white sand and gravel right across the river bottom at an angle of 45° in relation to the general direction of the stream.

Two tributaries, one 3 m. wide on the left bank, the other 4 m. wide on the right side (the latter coming from the north-east), swelled the Arinos from that point. The width of the stream was now increased to 80 m., the water being shallow. The bed of the river was ever changing, and supplied me with constant interest. It was adorned with strangely precise triangles of beautiful white sand exposed through a layer of gravel which covered most of the river bottom.

A thickly-wooded hill range, 150 ft. high and extending from W.S.W. to E.N.E., stood to the north of us. Its slopes, eroded by the water, had caused a landslip, leaving bare vertical red rock for half the height of the hill-range and two much eroded spurs of bright yellow and white earth extending into the stream.

The river at that point turned from north to east. Open country was again on our right after leaving the hill range, and lowlands liable to inundation. Soon afterwards, however, higher land appeared with banks 35 ft. high.

Swarms of small white butterflies played upon the banks on the edge of the water.

Sand and gravel mounds were numerous in the centre of the channel, with occasional basins of shallow water with corrideiras upon them. For instance, in one of those places for 150 m. the river was only from 1 to 3 ft. deep, and we had to drag the long heavy canoe, which drew 2 ft. of water, along the undulating gravel bed. In fact, we spent a good deal of our time every day in the water, pushing or pulling along the canoe over innumerable obstacles, her great length making it difficult to navigate her properly through the many shallow and tortuous passages.

In a circular basin, 120 m. in diameter, beyond that point we encountered strong eddies near the left bank. On the north side big rocks emerged from the water and a corrideira was formed.

An island 50 m. long and two other islets were separated from the mainland by two channels, one 20 m. wide and only 3 in. deep—the other 60 m. wide and 3 ft. deep. The right bank was there 45 ft. high.

Fifteen hundred metres farther down we entered another basin 200 m. in diameter, with an island 80 m. long and eight dry beaches of gravel.

My men were greatly excited in trying to capture a capivara they had wounded. We actually got the animal on board, but my men were so timid in going near it that it jumped overboard again and made its escape.

The right bank, which had been high, was now reduced to only 4 ft. above the water; whereas the left bank rose to a height of 46 ft. A rivulet 3 m. wide coming from the west had cut its way through the latter bank.

The main river was getting more and more magnificent at every turn. I should have enjoyed the journey very much had it not been for the constant attention I had to pay to my men, who left their paddles and steering gear at every moment in order to fire recklessly at birds or ariranhas or capivaras, much to the danger of everybody on board. They would blaze away with their repeating rifles—and bullet cartridges, of course—at parrots and even colibri birds 100 or 200 metres off. They said the rifles were bad because they could never hit anything! I had ceased scolding them. They made me positively ill with pity, I was only praying for our supply of cartridges to come to an end soon, so that if we were to die at all it might not be through being pierced by one of our own bullets.

The river had been flowing, with slight deviations, northwards.

We came to an enchanting island 70 m. wide, with thick vegetation upon it and fine rocks.

The river in that portion flowed practically north in great stretches of 6,000 and 4,000 m. Another large and beautiful island, 250 m. long and 70 wide—Ghislaine Island—was passed, and we admired the gorgeous vegetation upon it.

Below the island the river was 100 m. wide and very shallow—not more than from 1 to 4 ft. in depth. We halted at sunset, having gone that day 92 kil. 300 m.

During the night of July 11th my men suffered a great deal from cold, the thermometer being as low as 45° Fahrenheit. In the morning there was a thick fog over the river—so thick that we had to delay our departure until eight o'clock, as we could not see more than two or three metres ahead.

Two kilometres beyond we came to a rivulet, 2 m. wide, on the left bank, and soon after to a small corrideira with a navigable channel in the centre. Three hundred metres farther down we passed another tributary on the right bank. There was open country with sparse stunted trees on the left of us, thick forest with plenty of rubber trees on the right. I noticed several good specimens of the pao dolce—a tree with a curious cluster of yellow flowers not unlike the flower of wistaria upside down. Not only was the pao dolce pretty to look at, but a most refreshing beverage could be made from a decoction of its leaves.

The course of the river was winding, with basins and rapids of no great importance. Another tributary 2 m. wide was reached on the left bank, and soon after another tiny streamlet entered the Arinos from the same side.

I had a narrow escape. One of the men, who was sitting behind me in the canoe, saw an ariranha (Lutra Brasiliensis) put its head out of the water only ten metres in front of the canoe. In his great hurry to kill the beautiful animal he seized his rifle and emptied the eight shots out of his magazine, firing the first three shots close to my head on the left side, the other five just as close on the other side. The muzzle of his rifle was so near my ear that the noise deafened me for several minutes and my hair was almost singed off. The ariranha, needless to say, escaped unhurt, and luckily so did I.

We went over a long strip of shallow water from 1 to 3 ft. deep. We now had open country on the right bank, with a small streamlet finding its way into the Arinos on that side. The river was flowing again in long straight stretches—3,000 m., 2,000 m., 2,500 m. in length. In the portions where the banks were thickly wooded innumerable rubber trees were to be seen.

In the centre of a basin 150 m. wide we found another island, 100 m. long and 50 m. wide, absolutely smothered in vegetation and with a handsome gravel spit at its southern end. Two kilometres farther another basin, 300 m. broad, appeared. An amazing quantity of rubber trees was to be seen round that basin. Near the water we also found fine specimens of the mate (Ilex Paraguayensis St. Hil.), with its wax-like leaves, much used in certain parts of South America for making a kind of tea.

For close upon 13 kils. the river flowed—with slight deviations—almost always due north, and with its limpid waters was of extraordinary beauty. The country was open on the right side of us. We saw that day two white urubÚ (Cathartes). The Brazilians have a curious superstition about them. They say that if you write with a quill taken from the wing of one of these birds any business which you may be transacting will go well; in fact, anything you may wish to do and which you set down on paper with one of these quills and ink is sure to turn out successfully.

That day I again suffered much, while taking astronomical observations, from the millions of bees and other insects which settled in swarms upon my hands and face and stung me all over. We were then in lat. 12° 26'·5 S., long. 56° 37' W. The temperature in the sun was not unbearable—merely 85° Fahr.

In the afternoon, after we had enjoyed an excellent lunch of fish, tinned provisions, and rice—my men also enjoying their feijao (boiled beans)—we continued our journey. The river for 9,000 m. displayed first clean campos and chapada on the left bank and dense forest on the right, then campos on the right bank and a belt of forest along the river on the left.

The campos were particularly neat in that region—merely a few burity and tucum palms flourishing on the edge of the water. In other localities a thick growth of beautiful bamboos interspersed with gigantic palms lined the banks.

Where the river turned due east we came to fairly strong rapids. The water was shallow with mounds of gravel, and we bumped about a great deal. Eventually we all had to get into the water and push the canoe along for greater comfort.

The river next formed a huge basin, 900 m. long and 200 m. wide. A small tributary flowed into the Arinos in the crescent-shaped bank on the right. That bank had a height of 80 ft. On its summit quantities of Siphonia elastica were to be admired. Farther down it was on the left side that the river had high banks, some 60 ft. high.

We went over a charming little corrideira. Strong eddies were encountered on emerging from the rapids. Where the right bank became lower—only 40 ft.—chapada replaced the forest. The left bank was but 1 ft. above the level of the river, and the low country beyond (south) was naturally liable to inundation. For 4,000 m. the left bank was never higher than 4 ft. The right bank also suddenly became very low in that region.

Where the river turned from 290° b.m. to 320° b.m., there was a basin 700 m. broad with low banks. An island—Lydia Island—200 m. in circumference, rose within this basin on the north side and was luxuriantly wooded.

We found that day beautiful beaches of gravel, mostly on the right side. Then strong rapids and corrideiras; below these more clean-looking gravel beaches—this time on the left—were visible, and an extensive island of gravel close to the right bank.

For 8,000 m. the gorgeous stream flowed almost in a direct line northward, with dense forest and a wealthy growth of rubber trees on both sides. Wonderful figueira trees with their spotless white branches embellished the landscape.

On the left a tributary of some size entered the Arinos from the south-east in two arms with an island between; the largest arm was 40 m. wide, the smaller 10 m. Then another stream entered the Arinos on the right side.

We were again confronted by a large basin enclosed on the north by a crescent-shaped wall 100 ft. high, at the foot of which at the level of the river was a quantity of dÉbris of yellow rock. The river at that spot turned sharply from 20° b.m. (N.N.E.) to 290° b.m.—that is to say, almost north-west. The width of the Arinos at this point was from 80 to 100 m.

Towards sunset we came to a beautiful island 200 m. long. We cleared a sufficiently large space in the dense and gorgeous vegetation to make our camp for the night.