Travels on the Amazon

We therefore cast loose again, and kept at a distance of a quarter or half a mile from the ship by rowing when requisite. We were incessantly baling the whole night. Ourselves and everything in the boats were thoroughly drenched, so we got little repose: if for an instant we dozed off into forgetfulness, we soon woke up again to the realities of our position, and to see the red glare which our burning vessel cast over us. It was now a magnificent spectacle, for the decks had completely burnt away, and as it heaved and rolled with the swell of the sea, presented its interior towards us filled with liquid flame,—a fiery furnace tossing restlessly upon the ocean.

At length morning came; the dangers of the night were past, and with hopeful hearts we set up our little masts, and rigged our sails, and, bidding adieu to the still burning wreck of our ship, went gaily bounding along before a light east wind. And then pencils and books were hunted out, and our course and distance to Bermuda calculated; and we found that this, the nearest point of land in the vast waste of waters round us, was at least seven hundred miles away. But still we went on full of hope, for the wind was fair, and we reckoned that, if it did not change, we might make a hundred miles a day, and so in seven days reach the longed-for haven.

As we had supped but scantily the night before, we had now good appetites, and got out our ham and pork, biscuit and wine and water, and made a very hearty meal, finding that even uncooked meat was not to be despised where no fire could be got to cook it with.

The day was fine and warm, and the floating seaweed, called gulf-weed, was pretty abundant. The boats still required almost incessant baling, and though we did not ship many seas, yet there was quite enough spray to keep us constantly wet. At night we got a rope fastened to the long-boat, for her to tow us, in order that we might not get separated; but as we sailed pretty equally, we kept both sails up. We passed a tolerable night under the circumstances. The next day, the 8th, was fine, gulf-weed still floated plentifully by us, and there were numerous flying-fish, some of which fell into our boats, and others flew an immense distance over the waves. I now found my hands and face very much blistered by the sun, and exceedingly sore and painful. At night two boobies, large dusky sea-birds with very long wings, flew about us. During the night I saw several meteors, and in fact could not be in a better position for observing them, than lying on my back in a small boat in the middle of the Atlantic. We also saw a flock of small birds fly by, making a chirping noise; the sailors did not know what they were.

The 9th was again fine and hot, and my blistered hands were very painful. No ship appeared in sight, though we were crossing the track of the West India vessels. It was rather squally, and I passed a nervous, uncomfortable night; our boats did not, however, now leak so much, which was a great satisfaction.

The 10th was squally, and the wind veered to the south-west, so that we could not make our course for Bermuda, but were obliged to go to the north of it. The sea ran very high, and sudden gusts of wind would frequently heel us over in a manner very alarming to me. We had some heavy showers of rain, and should have liked to have caught some fresh water, but could not, as all our clothes and the sails were saturated with salt. Our position at noon was in latitude 31° 59´ north, longitude 57° 22´ west.

The 11th was still rough and squally. There was less gulf-weed now. The wind got still more to the westward, so that we were obliged to go nearly north. Our boats had now got swollen with the water, and leaked very little. This night I saw some more falling stars.

On the 12th the wind still kept foul, and we were getting quite out of the track of ships, and appeared to have but little chance of reaching Bermuda. The long-boat passed over some green water to-day, a sign of there being soundings, probably some rock at a moderate depth. Many dolphins swam about the boats; their colours when seen in the water are superb, the most gorgeous metallic hues of green, blue, and gold: I was never tired of admiring them.

On the 13th the wind was due west, blowing exactly from the point we wanted to go to. The day was very fine, and there were several stormy petrels, or Mother Cary's chickens, flying about us. We had now been a week in the boats, and were only halfway to the Islands, so we put all hands on short allowance of water before it was too late. The sun was very hot and oppressive, and we suffered much from thirst.

The 14th was calm, and we could not get on at all. The sun was scorching and we had no shelter, and were parched with thirst the whole day. Numerous dolphins and pilot-fish were about the boats. At night there was a very slight favourable breeze, and as we had by this time got our clothes pretty dry we slept well.

On the 15th the wind again died away, and we had another calm. The sea was full of minute Medusæ, called "blubber" by the sailors: some were mere whitish oval or spherical lumps, others were brown, and beautifully constructed like a little cap, swimming rapidly along by alternate contractions and expansions, and so expelling the water behind them. The day was very hot, and we suffered exceedingly from thirst. We were almost in despair about seeing a ship, or getting on to the Islands. At about 5 P.M., while taking our dinner, we saw the long-boat, which was at some distance from us, tack. "She must see a sail," said the captain, and looking round we saw a vessel coming nearly towards us, and only about five miles distant. We were saved!

The men joyfully drank the rest of their allowance of water, seized their oars, and pulled with hearty goodwill, and by seven o'clock we were alongside. The captain received us kindly on board. The men went first to the water-casks, and took long and hearty draughts, in which we joined them, and then enjoyed the almost forgotten luxury of tea. From having been so long cramped in the boats, I could hardly stand when I got on board.

That night I could not sleep. Home and all its pleasures seemed now within my grasp; and crowding thoughts, and hopes and fears, made me pass a more restless night than I should have done, had we still been in the boats, with diminished hopes of rescue. The ship was the Jordeson, Captain Venables, from Cuba, bound for London, with a cargo of mahogany, fustic, and other woods. We were picked up in latitude 32° 48´ north, longitude 60° 27´ west, being still about two hundred miles from Bermuda.

For several days afterwards we had fine weather and very light winds, and went creeping along about fifty miles a day. It was now, when the danger appeared past, that I began to feel fully the greatness of my loss. With what pleasure had I looked upon every rare and curious insect I had added to my collection! How many times, when almost overcome by the ague, had I crawled into the forest and been rewarded by some unknown and beautiful species! How many places, which no European foot but my own had trodden, would have been recalled to my memory by the rare birds and insects they had furnished to my collection! How many weary days and weeks had I passed, upheld only by the fond hope of bringing home many new and beautiful forms from those wild regions; everyone of which would be endeared to me by the recollections they would call up,—which should prove that I had not wasted the advantages I had enjoyed, and would give me occupation and amusement for many years to come! And now every thing was gone, and I had not one specimen to illustrate the unknown lands I had trod, or to call back the recollection of the wild scenes I had beheld! But such regrets I knew were vain, and I tried to think as little as possible about what might have been, and to occupy myself with the state of things which actually existed.

On the 22nd of August we saw three water-spouts, the first time I had beheld that curious phenomenon. I had much wished once to witness a storm at sea, and I was soon gratified.

Early in September we had a very heavy gale. The barometer had fallen nearly half an inch during the night; and in the morning it was blowing strong, and we had a good deal of canvas up when the captain began to shorten sail; but before it could be taken in, four or five sails were blown to pieces, and it took several hours to get the others properly stowed. By the afternoon we were driving along under double-reefed topsails. The sea was all in a foam, and dashed continually over us. By night a very heavy sea was up, and we rolled about fearfully, the water pouring completely over the bulwarks, deluging the decks, and making the old ship stagger like a drunken man. We passed an uncomfortable night, for a great sea broke into the cabin skylight and wetted us all, and the ship creaked and shook, and plunged so madly, that I feared something would give way, and we should go to the bottom after all; all night, too, the pumps were kept going, for she leaked tremendously, and it was noon the next day before she was got free of water. The wind had now abated, and we soon had fine weather again, and all hands were busy bending new sails and repairing the old ones.

We caught at different times several dolphins, which were not bad eating. I did not see so much to admire in the colours of the dying dolphin; they are not to be compared with the colours of the living fish seen in the blue transparent water.

We were now getting rather short of provisions, owing to the increased number of mouths: our cheese and ham were finished,—then our peas gave out, and we had no more pea-soup,—next the butter came to an end, and we had to eat our biscuit dry,—our bread and pork, too, got very short, and we had to be put upon allowance. We then got some supplies from another ship; but our voyage was so much prolonged, and we had adverse winds and another heavy gale, so that we were again in want, finished our last piece of meat, and had to make some scanty dinners off biscuit and water. Again we were relieved with a little supply of pork and some molasses, and so managed pretty well.

We were in the Channel on the night of the 29th of September, when a violent gale occurred, that did great damage to the shipping, and caused the destruction of many vessels much more seaworthy than our own. The next morning we had four feet of water in the hold.

On the 1st of October the pilot came on board, and Captain Turner and myself landed at Deal, after an eighty days' voyage from Pará; thankful for having escaped so many dangers, and glad to tread once more on English ground.

CHAPTER XIV

THE PHYSICAL GEOGRAPHY AND GEOLOGY OF THE AMAZON VALLEY

The basin of the Amazon surpasses in dimensions that of any other river in the world. It is entirely situated in the Tropics, on both sides of the Equator, and receives over its whole extent the most abundant rains. The body of fresh water emptied by it into the ocean, is therefore far greater than that of any other river; not only absolutely, but probably also relatively to its area, for as it is almost entirely covered by dense virgin forests, the heavy rains which penetrate them do not suffer so much evaporation as when they fall on the scorched Llanos of the Orinooko or the treeless Pampas of La Plata. For richness of vegetable productions and universal fertility of soil it is unequalled on the globe, and offers to our notice a natural region capable of supporting a greater population, and supplying it more completely with the necessaries and luxuries of life, than any other of equal extent. Of this wonderful district we will now describe the principal physical peculiarities.

From about 4° north latitude to 20° south, every stream that flows down the eastern slope of the Andes is a tributary of the Amazon. This is as if every river, from St. Petersburg to Madrid, united their waters into one mighty flood.

The Marañon, which is generally considered the main stream of the Amazon, deserves that title on several accounts. It rises to the westward of all the other great tributaries, and it receives all the waters which flow nearest to the Pacific, and most remote in a direct line from the mouth of the river. It flows for a considerable distance in the most westerly valley of the Andes, separated by one range only from the Pacific, and at the point where it breaks through the eastern chain of the Andes, in 78° west longitude, is already a large river, on a meridian where all the other streams which can lay a claim to be considered the head-waters of the Amazon have as yet no existence. On going up the Amazon from its mouth, it is that branch on which you can keep longest in the general east and west direction of the river; and if the actual length of its course is considered, it still keeps its place, for I find that there is not more than ten or twenty miles' difference between it and the Uaycali, reckoning to the most distant source of the latter; and its course is at present so uncertain, that future surveys may increase or diminish it considerably.

These considerations, I think, decide the question as to the propriety of considering the Marañon as the true source of the Amazon. We find that from its origin in the Lake Lauricocha, to its mouth in longitude 50° west, in length, following the main curves, but disregarding the minuter windings, is 2,740 English miles.

Its extent, in a straight line from east to west, is about 2,050 miles; and from north to south, its tributary streams cover a space of 1,720 miles.

The whole area of its basin, not including that of the Tocantins, which I consider a distinct river, is 2,330,000 English square miles, or 1,760,000 nautical square miles. This is more than a third of all South America, and equal to two-thirds of all Europe. All western Europe could be placed in it without touching its boundaries, and it would even contain our whole Indian empire.

The numerous tributary streams of the Amazon, many of them equal to the largest rivers of Europe, differ remarkably in the colour of their waters, the character of the vegetation on their banks, and the animals that inhabit them. They may be divided into three groups,—the white-water rivers, the blue-water rivers, and the black-water rivers.

The main stream of the Amazon itself is a white-water river, this name being applied to those waters which are of a pale yellowish olive-colour. This colour does not seem to depend entirely on free earthy matter, but rather on some colouring material held in solution; for in lakes and inlets, where the waters are undisturbed and can deposit all their sediment, they still retain the colour.

The waters of the Amazon continue of the same colour up to the mouth of the Uaycali, when they become blue or transparent, and the white waters are extended up that branch.

This has been taken as an evidence of the Uaycáli being the main stream of the Amazon; but I cannot consider that it has anything to do with the question. It is evident that if equal quantities of clear and muddy water are mixed together, the result will differ very little from the latter in colour, and if the clear water is considerably more in quantity the resulting mixture will still be muddy. But the difference of colour between the white-and blue-water rivers, is evidently owing to the nature of the country they flow through: a rocky and sandy district will always have clear-water rivers; an alluvial or clayey one, will have yellow or olive-coloured streams. A river may therefore rise in a rocky district, and after some time flow through an alluvial basin, where the water will of course change its colour, quite independently of any tributaries which may enter it near the junctions of the two formations.

The Iça and Japurá have waters very similar in colour to the Amazon. The Rio Branco, a branch of the Rio Negro from the north, is remarkable for its peculiar colour: till I saw it, I had not believed it so well deserved its name. The Indians and traders had always told me that it was really white, much more so than the Amazon; and on descending the Rio Negro in 1852 I passed its mouth, and found that its waters were of a milky colour mixed with olive. It seemed as if it had a quantity of chalk in solution, and I have little doubt of there being on its banks considerable beds of the pure white clay which occurs in many parts of the Amazon, and which helps to give the waters their peculiar whiteness. The Madeira and Purús have also white waters in the wet season, when their powerful currents bring down the alluvial soil from their banks; but in the dry season they are a dark transparent brownish-olive.

All the rivers that rise in the mountains of Brazil have blue or clear water. The Tocantins, the Xingú, and the Tapajóz, are the chief of this class. The Tocantins runs over volcanic and crystalline rocks in the lower parts of its course, and its waters are beautifully transparent; the tide, however, enters for some miles, and renders it turbid, as also the Xingú. The Tapajóz, which enters the Amazon about five hundred miles above Pará, is clear to its mouth, and forms a striking contrast to the yellow flood of that river.

It is above the Madeira that we first meet with the curious phenomenon of great rivers of black water. The Rio Negro is the largest and most celebrated of these. It rises in about 2° 30´ N. lat., and its waters are there much blacker than in the lower part of its course. All its upper tributaries, the smaller ones especially, are very dark, and, where they run over white sand, give it the appearance of gold, from the rich colour of the water, which, when deep, appears inky black. The small streams which rise in the same district, and flow into the Orinooko, are of the same dark colour. The Cassiquiare first pours in some white or olive-coloured water. Lower down, the Cababurís, Maravihá, and some smaller white-water streams help to dilute it, and then the Rio Branco adds its flood of milky water. Notwithstanding all this, the Rio Negro at its mouth still appears as black as ink; only in shallow water it is seen to be paler than it is up above, and the sands are not dyed of that pure golden tint so remarkable there.

On the south of the Amazon there are also some black-water streams—the Coary, the Teffe, the Juruá, and some others. The inhabitants have taken advantage of these, to escape from the plague of the mosquitoes, and the towns of Coary and Ega are places of refuge for the traveller on the Upper Amazon, those annoying insects being scarcely ever found on the black waters. The causes of the peculiar colour of these rivers are not, I think, very obscure; it appears to me to be produced by the solution of decaying leaves, roots, and other vegetable matter. In the virgin forests, in which most of these streams have their source, the little brooks and rivulets are half choked up with dead leaves and rotten branches, giving various brown tinges to the water. When these rivulets meet together and accumulate into a river, they of course have a deep brown hue, very similar to that of our bog or peat water, if there are no other circumstances to modify it. But if the streams flow through a district of soft alluvial clay, the colour will of course be modified, and the brown completely overpowered; and I think this will account for the anomalies observed, of streams in the same districts being of different colours. Those whose sources are pretty well known are seen to agree with this view. The Rio Negro, the Atabapo, the Isanna, and several other smaller rivers, have their sources and their whole course in the deep forest; they flow generally over clean granite rocks and beds of sand, and their streams are gentle, so as not to wear away the soft parts of their banks.

The Iça, Japurá, and Upper Amazon, on the contrary, flow through a long extent of alluvial country, and, having their sources on the slopes of the Andes, are much more liable to sudden floods, and by their greater velocity bring down a quantity of sediment. In fact, it seems clear, that a thorough knowledge of the course of each river would enable us to trace the colour of its waters to the various peculiarities of the country through which it flows.

With the exception of the streams rising in the Andes, the boundaries of the Amazon basin, or the most distant sources of its tributaries on the north and south, are comparatively little elevated above the level of the sea. The whole basin, with the exception of a very small portion, is one great plain of the most perfect and regular character.

The true altitude of the source in the Lake Lauricocha has not been ascertained. At Tomependa Humboldt states it to be 1,320 feet above the sea: this is as near as possible 2,000 miles in a straight line from the mouth; so that the average rise is only eight inches in a mile. But if we take the height at Tabatinga, on the boundary of Brazil, which, according to Spix and Martius is 670 feet, we shall find, the distance being about 1,400 miles, that the rise is only five and a half inches per mile. If we had the height of Barra do Rio Negro accurately, we should no doubt find the rise to that point not more than two or three inches in a mile. The distance is, in a straight line, about 700 miles, and we may therefore probably estimate the height at less than 200, and perhaps not more than 150 feet.

This height I am inclined to believe quite great enough, from some observations I made with an accurate thermometer, reading to tenths of a degree, on the temperature of boiling water. This instrument I received from England, after leaving Pará. The mean of five observations at Barra, some with river and some with rain-water, gave 212.5° as the temperature of boiling water; a remarkable result, showing that the barometer must stand there at more than thirty inches, and that unless it is, in the months of May and August, considerably more than that at the sea-level, Barra can be but very little elevated above the sea.

For the height of the country about the sources of the Rio Negro, Humboldt is our only authority. He gives 812 feet as the height of São Carlos; he, however, states that the determination is uncertain, owing to an accident happening to the barometer; I may, therefore, though with great diffidence, venture to doubt the result. The distance, in a straight line, from the mouth of the Rio Negro to São Carlos, is rather less than from the same point to Tabatinga, whose height is 670 feet. The current, however, from Tabatinga is much more rapid than down the Rio Negro, the lower part of which has so little fall, that in the month of January, when the Amazon begins to rise, the water enters the mouth of the Rio Negro, and renders that river stagnant for several hundred miles up. The falls of the Rio Negro I cannot consider to add more than fifty feet to the elevation, as above and below them the river is not very rapid. Thus, from this circumstance alone, we should be disposed to place São Carlos at a rather less elevation than Tabatinga, or at about 600 feet. My observations up the Rio Negro gave consistent results. At Castanheiro, about five hundred miles up, the temperature of boiling water was 212·4°, at the mouth of the Uaupés 212·2°, and at a point just below São Carlos, 212·0°. This would not give more than 250 feet for the height of São Carlos above Barra; and, as we have estimated this at 200 feet above the sea, the height of São Carlos will become 450 feet, which I think will not be found far from the truth.

The velocity of the current varies with the width of the stream and the time of the year; we have little accurate information on this subject. In a Brazilian work on the Province of Pará, the Madeira is stated to flow 2,970 braças, or about three and a half miles, an hour in the wet season. At Obidos I made an observation in the month of November, when the Amazon is at the lowest level, and found it four miles an hour; but this by no means represents the current in the rainy season. On descending to Pará, in the month of June, 1852, I found that we often floated down about five miles an hour, and as the wind was strong directly up the river, it probably retarded us, rather than helped us on, our vessel not being rigged in the best manner.

Martius calculates that 500,000 cubic feet of water per second pass Obidos. This agrees pretty well with my own calculations of the quantity in the dry season; when the river is full, it is probably much greater. If we suppose, on a moderate calculation, that seventy-two inches, or six feet, of rain fall annually over the whole Amazon valley, it will amount to 1,500,000 cubic feet per second, the whole of which must either evaporate, or flow out of the mouth of the Amazon; so that if we increase the amount given by Martius by one half, to take in the lower part of the Amazon and to allow for the whole year, we shall have the evaporation as one half of the rain falling annually.