Notes of a naturalist in South America

During the night of the 12th we passed Cape Parinas, the westernmost headland of South America, and before sunrise were in the roads of Payta. Being aware that the so-called rainless zone of Peru extends northward to this place, I was especially anxious to see as much of it as possible. During the night the temperature had fallen, especially after rounding Cape Parinas, and at sunrise stood at 74°. In the cooler air, and under the excitement of pleasant anticipation, the lassitude of the two preceding days utterly disappeared; and as day dawned I stood on deck, with my tin box slung to my back, ready to go ashore long before there was any possibility of doing so. The officers told me, indeed, that there was no use in taking a botanical box, as the country about Payta was absolutely without vegetation. I have many times had the same assurance given me, but the time had not yet come when I was to find it correct, and I felt that Payta was not one of such rare spots on the earth.

The appearance of the place and of its surroundings is unquestionably very strange, and the contrast between it and the shores of the neighbouring Gulf of Guayaquil is simply marvellous. Saving the presence of a mean little modern church, with two shabby wooden towers coated with plaster, the aspect of the little town reminded me of Suez, with the difference that the surrounding desert is here raised about a hundred feet above the sea-level. The place, I presume, is improved since it was visited and described by Squiers, and I found that on the slope between the base of the plateau and the beach there is ample space for some mean streets.

FLORA OF PAYTA.

With several companions who were kind enough to interest themselves in plant-hunting, I at once turned towards the sea-beach at the south-western side of the town, keeping along the base of the low cliffs that here descend to the water’s edge. The seaward face of the cliffs is furrowed by numerous gullies, and in one of the broadest of these I was delighted to observe numerous stunted bushes well laden with crimson flowers. This turned out to be Galvesia limensis, a plant found only at a few spots in Peru, whose nearest but yet distant European ally is the common snapdragon. In the upper part of the same gully were the withered remains of several other species, most of which have been since identified. Emerging on the plateau, we found ourselves on a wide plain, apparently unbroken, leading up to a range of hills some fifteen or twenty miles distant. Though we were here only five degrees from the equator, and before we returned to the ship the sun had risen as high as on a summer’s noon in England, the southerly breeze felt delightfully cool and fresh, and at midday, under the vertical sun, the temperature on board ship was not quite 75°.

Vegetation, as I anticipated, was not entirely absent from the plateau, but it was more scarce than I had anywhere seen it, except in the tracts west of the Nile above Cairo, where the drifting sands covers up and bury everything on the surface. In the northern Sahara, about Biskra, where rain is much less infrequent than here, vegetation, though scanty, is nearly continuous, and it is not easy to find spaces of several square yards absolutely without a single plant. About Suez, and on parts of the isthmus where a slight infiltration from the sweet water canal has not developed a more varied vegetation, the number of species in a given tract is often very limited; but tufts of vigorous growth, especially of the salt-loving species, are seen at frequent intervals. On the plateau of Payta, where, as we rambled about, several pairs of eyes were on the alert, but a single tuft of verdure visible at a distance could be made out. This was formed by several bushes of Prosopis limensis growing together. Elsewhere the few plants seen were confined to the occasional shallow depressions where rain rests longest. All, of course, had perennial roots, and scarcely one of them rose as much as three inches from the ground.3

I found it difficult to account for the origin of the sands which are sparingly scattered over the plateau, but accumulated to a considerable depth on the slopes behind the town. The underlying rock seen in ascending to the plateau is a tolerably compact shale; but the hard crust forming the superficial stratum appears to consist of different materials, and not to be made up from the disintegrated materials of the shale. At several places, both below the cliffs and on the plateau, I found large scattered fragments of what appeared to be a very recent calcareous formation, largely composed of shells of living species; but this was nowhere seen in situ, and I was unable to conjecture the origin of these fragments.

CLIMATE OF NORTHERN PERU.

Before returning to the Islay, I had the advantage of a short conversation with the very intelligent gentleman who acts as British consular agent at Payta, and whose ability would perhaps be seen to advantage in a more conspicuous post. The information received from him fully confirmed the impressions formed during my short excursion. The appearance of the gullies that furrow the seaward face of the plateau sufficiently showed that, however infrequent they may be, heavy rains must sometimes visit this part of the coast. I now learned that, in point of fact, abundant rain lasting for several days recurs at intervals of three or four years, the last having been seen in the year 1879. As happens everywhere else in the arid coast zone, extending nearly two thousand miles from Payta to Coquimbo in North Chili, abundant rainfall is speedily followed by an outburst of herbaceous vegetation covering the surfaces that have so long been bare. During the long dry intervals slight showers occur occasionally a few times in each year. These are quite insufficient to cause any general appearance of fresh vegetation, but suffice, it would seem, to maintain the vitality of the few species that hold their ground persistently. The ordinary supply of water in Payta, obtained from a stream descending from the Andes seventeen miles distant, is carried by donkeys that are despatched every morning for the purpose. There was something quite strange in the appearance of a few bundles of fresh grass which we saw in the plaza. They had come that morning by the same conveyance for the support of the very few domestic animals that it is possible to keep in such a place.

The problems suggested by the singular climatal conditions of this region of South America have not, I think, been as fully discussed as they deserve to be, and I here venture on some remarks as a contribution to the subject.

The existence of the so-called rainless zone on the west coast of South America is usually accounted for by two agencies whose union is necessary to produce the result. The great range of the Andes, it is said, acts as a condenser on the moisture that is constantly carried from the Atlantic coasts by the general westward drift of the atmosphere in low latitudes. The copious rainfall thus produced on the eastern slopes of the great range leaves the air of the highlands of Peru and Bolivia relatively dry and cool, so that any portion that may descend to the coast on the western declivity tends to prevent rather than to cause fresh aqueous precipitations. Meanwhile the branch of the Antarctic Ocean current known as the Humboldt current, which sets northward along the sea-board from Western Patagonia, is accompanied by an aërial current, or prevailing breeze, which keeps the same direction. The cold air flowing towards the equator, being gradually warmed, has its capacity for holding vapour in suspension constantly increased, and is thus enabled to absorb a large portion of the vapour contained in the currents that occasionally flow inland from the Pacific, so that the production of rain is a rare event, recurring only at long intervals. Admitting the plausibility of this explanation, a first difficulty presents itself. If the Andes act as a barrier against the vapour-laden atmosphere of eastern tropical America throughout Peru, Bolivia, and Northern Chili why, it may be asked, do they fail to perform the same function in Ecuador and Colombia? Whence the absolute contrast in point of climate that exists between these regions? Why is the littoral zone between the Gulf of Guayaquil and that of Panama, a distance of some eight hundred miles, not merely less dry than that of Peru, but actually more moist than most parts of the coast of Brazil or Guiana?

CAUSES OF THE ARID COAST CLIMATE.

Some answer may, I think, be given to these questions. In the first place, comparing the orography of Peru and Bolivia with that of Ecuador, some important differences must be noted. In Eastern Peru, as is at once shown by the direction of the principal rivers, we find no less than four parallel mountain ranges, increasing in mean elevation as we travel from east to west. The westernmost range, to which in Peru the name Cordillera is exclusively applied, does not everywhere include the highest peaks, but has the highest mean elevation. The second range, exclusively called Andes in Peru, rivals the first in height and importance. I know of no collective names by which to distinguish the third range, dividing the valley of the Huallaga from that of the Ucayali, nor the fourth range, forming the eastern boundary of the latter stream. In South Peru and Bolivia the mountain ranges are less regularly disposed, but cover a still wider area; and throughout the whole region it is obvious that the warm and moist currents drifting slowly westward have to traverse a zone of lofty mountains varying from four to six hundred miles in width, and can carry no moisture available to produce rain on the western seaboard. In Ecuador the two principal ranges – the Cordillera and the Andes – are much nearer together than they usually are in Peru, and no parallel ranges flank them on the east. The numerous tributaries of the Maranon flow in a tolerably direct course east or south-east, many of them rising within a hundred and fifty miles of the Pacific coast. It follows that the atmospheric currents meeting less preliminary obstruction reach the eastern slopes of the main range still very heavily charged with vapour. In crossing the barrier a large portion of the burthen must be deposited; but it is probable that a large amount is nevertheless carried to the western side of the range.

It may be said that this explanation, whatever it may be worth, cannot apply to the territory of Colombia, where the Andes are broken up into at least three lofty ranges, and the mountains cover as wide a space as they do in Peru. My impression is that the abundant supply of moisture on the west coast of Colombia arises from a different source. The effects of the Isthmus of Panama as a barrier against atmospheric currents must be absolutely insignificant, and I have no doubt that those which flow eastward along the coast of the Caribbean Sea are in part diverted south-east and south along the west coast of Colombia.

There can, however, be little doubt that in determining the climate of the west coast the influence of the Humboldt current, and of the cool southerly breezes that accompany it, is far greater than that of the disposition of the mountain ranges. A glance at the map shows that about the fifth and sixth degrees of south latitude the direction of the coast undergoes a considerable change. On the voyage from Panama, we had hitherto steered somewhat west of south; henceforward our course lay between south-south-east and south-east. All the currents of the ocean and atmosphere, whose existence arises from the unequal distribution of heat on the earth’s surface, vary somewhat in their course throughout the year with the changes of season, and this doubtless holds good on the American coast. I believe, however, that both the sea and air currents from the south are normally deflected away from the coast at the promontory of Ajulla (sometimes written “Ahuja”), a short distance south of Payta. A further portion is again deflected westward at Cape Parinas, north of which headland they seem not to be ordinarily met. I infer, however, from the testimony of seamen, that at some seasons they are felt near the coast as far north as the equator, and even beyond it. This inference was confirmed by observing the parched appearance of the seaward slope of Cabo Sta. Elena, north of the Gulf of Guayaquil, which apparently does not fully share in the frequent rains that elsewhere visit the coast of Ecuador.

INFLUENCE OF THE HUMBOLDT CURRENT.

Whatever force there may be in the above suggestions, I confess that they do not seem to me adequate to account for the extraordinary difference of climate between places so near as Payta and Tumbez – not quite a hundred miles apart – and I trust that further light may be thrown upon the matter by a scientific traveller able to spare the necessary time. So far as I know, no such abrupt and complete a change is known elsewhere in the world. I was unable to obtain any information as to a range of hills or mountains, marked in Arrowsmith’s map “Sa. Amatapi,” which appears to extend east or east-north-east from Cape Parinas. Its height can scarcely be considerable, as it does not appear to have attracted the attention of the seamen who are familiar with this coast; but, on the other hand, there is some reason to think that the southerly breezes prevailing on the coast do not extend to any great height above the sea-level. It would be interesting if we should find on the opposite sides of a range of unimportant hills the same contrasts of climate and vegetation that are known to prevail between the eastern and western slopes of the Peruvian Andes.4

Along the coast of Northern Peru are numerous small islets, evidently at some period detached from the continent either by subsidence or by marine erosion. Here, in the almost complete absence of rain, were formed those secular accumulations deposited by sea-birds, which, when known in Europe under the name of guano, suddenly rivalled the mines of the precious metals as sources of easily acquired wealth. The two most considerable groups are respectively named Lobos de tierra and Lobos de afuera; a smaller group near to Payta is also called Lobos. At the western end of the largest of the latter group the waves have excavated a natural arch, which, after a sufficient period of further excavation, will fall and give rise to a new detached islet. A brisk southerly breeze made the air feel cooler than it had done since we entered the tropics, as we ran about due south until sunset, when, after passing abreast of the promontory of Ajulla, our course was altered to nearly due south-east. I was assured by a native passenger that the promontory of Ajulla, for a distance of thirty or forty miles, is an absolute desert, without a drop of water or the slightest trace of vegetation. Experience has made me somewhat sceptical as to statements of this nature made by non-scientific observers. During the day we frequently observed a fish which appears distinct from the flying-fish of the Atlantic. The pectoral fins appear to be less developed, and in consequence the flight is shorter, and the animal seems to have less command over its movements.

GUANO ISLANDS.

Our course on April 14 lay rather far from land. It was known that yellow fever had broken out at Truxillo, and it was decided that we should run direct to Callao, without touching at that or any of the smaller places on the coast sometimes visited by the steamers. Although the air appeared to be somewhat hazy, the range of the Cordillera, more than a hundred miles distant, was distinctly seen in the afternoon. Very soon after we ran into a dense bank of fog, in which we were immersed for several hours, our cautious captain remaining meanwhile on the bridge, and the frequent cry of the steam-whistle ceased only when we steamed out of the fog into a brilliant star-lit night.

LOW TEMPERATURE OF THE COAST.

These fogs, which are frequent along the Peruvian coast, are the chief, if not the only, difficulty with which the navigator has to contend. When they rest over the land it becomes extremely difficult to make the ports, and at sea they involve the possible risk of collision. If this risk is at present but slight, it must become more serious when intercourse increases, as it must inevitably do if the Ship Canal should ever be completed; and for the general safety it may be expedient to prescribe special rules as to the course to be taken by vessels proceeding north or south along the coast. The origin of the fogs must be obvious to any one who considers the physical conditions of this region, to which I have already referred. The air must be very frequently near the point of saturation, and a slight fall of temperature, or the local intermixture of a body of moister air, must suffice to produce fog. The remarkable thing is that this should so very rarely undergo the further change requisite to cause rain. To some young Englishmen on board, the remarkable coolness of the air along this coast was a continual subject of jesting comment; and on more than one occasion the “Tropics” were emphatically declared to be “humbugs.” It is certain that for thirty-six hours before reaching Callao the shaded thermometer never reached 70°, and stood at noon, with a clear sky and a brisk southerly breeze, no higher than 68°.

CHAPTER II

Arrival at Callao – Quarantine – The war between Chili and Peru – Aspect of Lima – General Lynch – Andean railway to Chicla – Valley of the Rimac – Puente Infernillo – Chicla – Mountain-sickness – Flora of the Temperate zone of the Andes – Excursion to the higher region – Climate of the Cordillera – Remarks on the Andean flora – Return to Lima – Visit to a sugar-plantation – Condition of Peru – Prospect of anarchy.

The steam-whistle, sounding about daybreak on April 15, announced that we were again wrapped in fog. As the Islay advanced at half speed the fog lightened without clearing, until about nine a.m. we made the island of San Lorenzo, and, as the haze finally melted away into bright sunshine, found ourselves half an hour later in the harbour of Callao. The moment was exciting for those who, like myself, approached as strangers the shore which had in our childhood seemed so strange, so adventure-fraught, so distant. Already some one had pointed out the towers of the Cathedral of Lima, with the Cordillera apparently so near that the mountains must begin outside the gates. All stood on deck prepared to land – some already looking forward to luncheon in the city of Pizarro – and waiting only for the usual formalities of the visit of the sanidad. At length the officials came, and, after the usual parley over the ship’s side, it became apparent that the visit was no mere formality. At last the ominous word quarantine was heard, received at first with mere incredulity, as something too absurd, but at last taking the consistence of a stern fact. Since the outbreak of yellow fever among the troops at Truxillo, the Chilian authorities have naturally become nervously anxious to protect the occupying army from this danger, and every precaution is put in force. Under these circumstances, a ship coming from Guayaquil was naturally an object of suspicion. There certainly was not at the time any epidemic fever at that place; but, if reports be true, sporadic cases are not unfrequent, and that city is rarely, if ever, quite free from malignant zymotic disease. At last the discussion was closed, by a definite order that we should repair to the quarantine ground under the lee of the island of San Lorenzo.

IN QUARANTINE AT CALLAO.

Up to this time we had scarcely given attention to the scene immediately surrounding us; yet the harbour of Callao is at any time an interesting sight, and at this moment its aspect was peculiarly expressive. Although the Chilian forces had before this time become absolute masters of the entire seaboard of Peru, and there was no reason to apprehend any renewal of the struggle by sea, the memorials of the desperate encounters which marked the earlier phase of the war were here still fresh. Near the shore in several different directions were the wrecks of ships which had sunk while the captors were endeavouring to bring them into harbour, the masts sticking up idly above water and doing the duty of buoys. Still afloat, though looking terribly battered and scarcely seaworthy, was that remarkable little ship, the Huascar, looking a mere pigmy beside the warships in the harbour from which the Chilian, American, French, and Italian flags were flying, England being for the moment unrepresented.

The naval war between Chili and Peru was conducted at such a distance from Europe, and its causes were so little understood, that it excited but feeble interest. Even the circumstance that, in an encounter brought about by the incompetence and rashness of a British commander, the pigmy Peruvian force was able with impunity to inflict an affront on the national flag, scarcely excited in England more than momentary surprise. Nevertheless the story of the war, which yet awaits an impartial chronicler,5 abounds with dramatic incident. The record is ennobled by acts of heroic bravery on both sides, while at the same time it suggests matter for serious consideration to the professional seaman. The important part which small fast ships, carrying one or two heavy guns only, may play in the altered conditions of naval warfare has been often pointed out, but has been practically illustrated only in the war between Chili and Peru. It does not seem as if the importance of the lesson had been yet fully appreciated by those responsible for the naval administration of the great European powers.

For the remainder of the day, and during the whole of the 16th, we lay at anchor about half a mile from the shore of the island of San Lorenzo, a bare rough hill, mainly formed, it would seem, of volcanic rock overlaid in places by beds of very modern formation. All naturalists are familiar with the evidence adduced by Darwin, proving the considerable elevation of the island and the adjacent mainland since the period of the Incas, as well as Tschudi’s arguments going to show that in more recent times there has been a period of subsidence.

BLACK PELICANS.

Of the objects near at hand the most interesting were the large black pelicans which in great numbers frequent the bay or harbour of Callao, attracted, no doubt, by the offal abundantly supplied from the town and the shipping. Seemingly indefatigable and insatiable, these birds continued for hours to circle in long sweeping curves over the water, swooping down on any object that attracted their appetite. The body appears to be somewhat slighter than that of the white pelican of the East, but the breadth of wing and length of the neck are about the same. When on the wing the plumage appears to be black, but in truth it is of a dark bluish slate colour.

Our detention in quarantine might have been prolonged but for the fortunate circumstance that the contents of the mail-bags carried by the Islay were at this moment the object of anxious curiosity to the Chilian authorities, and to the representatives of foreign powers. The position of affairs was already sufficiently critical, and the attitude recently assumed by the Government of the United States had added a new element of uncertainty to the existing difficulties. Mr. Hurlbut, the last American representative, had died, and Mr. Trescott, who supplied his place, was ostensibly charged with the attempt to bring about a peace between Chili and Peru, but was supposed to be chiefly intent on extricating his Government from a position into which it had been led by a series of proceedings which had neither raised the national reputation nor secured the good-will of either Chili or Peru.

While we lay off the harbour, watched day and night by the crew of a launch stationed beside us to prevent communication with the land, we received three successive visits from the officers of the American man-of-war lying in the harbour, who approached near enough to hold conversation with our captain. The message was a request, finally conveyed in somewhat imperious terms, that the dispatches addressed to the American envoy should at once be delivered. The American foreign office is not, I believe, accustomed to forward diplomatic dispatches in a separate bag, but merely uses the ordinary post. Our captain properly declined to take the responsibility of opening the mail-bags, which he was bound to deliver intact to the postal authorities as soon as we were admitted to pratique. The result was that on Monday, just as we were beginning to be seriously uneasy at the prospect of a long detention, a steam launch was seen to approach, having a number of officials on board. A seemingly interminable conversation between these and the captain and medical officer of our ship finally resulted in a Chilian medical man coming on board to make a careful examination of the ship, the crew, and the passengers. After we had been duly marshalled and inspected – the first-class passengers on the spar-deck, the others on the main-deck – the welcome announcement, “Admitted to pratique,” ran through the ship. Not much time was lost in moving up to the proper moorings in the harbour, some two miles distant, and about noon we were set on land close to the custom-house.