Early on the 5th of May we were before Antofagasta, now the most thriving place on this coast, if a place can be said to thrive which exists under such unnatural conditions. It is, however, slightly better off than its neighbours to the north. A gentleman who resided here for some time assured me that at intervals of five or six years a heavy fall of rain occurs here. At such times not only the coast region, but the Atacama desert lying between the Cordillera and the sea is speedily covered with fresh vegetation, which after a few months is dried up and disappears. At such times the guanacos descend from the mountains, and actually reach the coast.
We must, without my attention being called to the fact while in my cabin, have turned back to the northward after leaving Antofagasta, as in the dusk we were before Mejillones, which lies fully thirty miles north of the former place. It stands on a little bay, well sheltered from the south by a considerable rocky promontory, and, as I had been led to expect, the ground is here broken and irregular, offering more promise of safe retreat for the indigenous vegetation than anywhere else on this coast. I had looked forward with interest to an hour or two on this more promising ground, and it was a disappointment to be unable to profit by a comparatively long stay, for we remained at anchor after nightfall, embarking cargo and some passengers until midnight. For the third time within twenty-four hours we crossed the Tropic of Capricorn, and thenceforward remained in the south temperate zone. But in this region the term is in no way specially appropriate to the coast climate of Chili, for nothing can be more truly temperate than that of the so-called tropical zone which we were now leaving. During the voyage from Callao the thermometer properly shaded had but once (while anchored at Arica) reached 70° Fahr. It usually stood by night at 64° to 65°, and at about 68° by day, except occasionally when exposed to the cool southern breeze, when it fell rapidly on two occasions, marking only 62·2°.
My aneroid barometer by Casella, graduated only to 19 inches, and therefore useless during my visit to the Cordillera, did not appear to have suffered, as these instruments often do, by the reduced pressure. It did not vary during seven days by so much as one-twentieth of an inch from the constant pressure 29·9, and agreed closely with the ship’s mercurial barometer. Perhaps, owing to the fact that my observations were not sufficiently frequent and recorded with sufficient accuracy, I failed to detect on this coast of America the daily oscillations of pressure, which in this latitude probably amount to about one-twentieth of an inch.
UNIFORMITY OF THE CLIMATE.
On the 6th of May we reached Taltal, a small place, the general aspect of which reminded me of Tocopilla, and my first impression on landing was that this was equally devoid of vegetable and animal life. But on reaching the rocky slope, which rises very near the landing-place, I at once perceived some indications of water having flowed over the surface, and in the course of the short half-hour which was allowed ashore I found three flowering plants, two of them in a condition to be determined, the third dried up and undistinguishable. In the evening we touched at Chañeral, a place rising into importance as being the port of a rich mining district. The southerly breeze had been rather stronger than usual during the afternoon, and some passengers complained of the motion of the ship. An addition of seventy tons of copper in the hold, which was shipped here by torchlight, appeared to have a remarkable effect in steadying the vessel.
We reached Caldera early on the 7th, and remained for five or six hours. This is the port of Copiapò, the chief town of Northern Chili—the only one, indeed, which could have grown up under natural conditions. A considerable stream, the Rio de Copiapò, which drains the western slope of the Cordillera, passes by the town. Caldera, the port, is not at the mouth of the river, but several miles further north, and water is doubtless conveyed there in some abundance, as, for the first time since leaving Arica, a few bushes in little enclosed gardens could be descried from the harbour, and I was afterwards shown two stately trees, the ornament of the place, which were nearly fifteen feet in height. I went inland about a mile and a half, visiting a slight eminence where the rock, evidently very recent, crops out at the surface, and one or two other promising spots. Most of the country was covered with sand, in places soft and deep, and anywhere else in the world I should have thought it wretchedly barren, but after my recent experience the meagre vegetation appeared almost luxuriant.
There is much interest attaching to the flora of this desert region of South-western America. The species which grow here are the more or less modified representatives of plants which at some former period existed under very different conditions of life. In some of them the amount of modification has been very slight, the species, it may be presumed, possessing a considerable power of adaptation. Thus one composite of the sun-flower family, which I found here, and also at Payta, is but a slight variety of Encelia canescens,[17] which I had seen growing luxuriantly in the gravelly bed of the Rimac near Lima, and along that river to a height of six thousand feet above the sea. In this parched region the plant is stunted, and the leaves are hoary with minute white hairs, which may serve as a protection against evaporation. The same species, with other slight modifications, extends to all the drier portions of the western coast as far south as Central Chili. A dwarf shrub with yellow flowers like those of a jessamine, but with very different two-horned fruit, called Skytanthus, was an example of a much greater amount of change. Its only allies are two species in tropical Brazil, very different in appearance, though nearly similar in essential structure. We may safely conclude that a long period has elapsed since these forms diverged from a common stock, and that many intermediate links have perished during the interval.
BRITISH PACIFIC SQUADRON.
Several of the ships composing the British Pacific squadron were lying at Caldera at this time, and after returning from my short excursion ashore, I went on board the Triumph, Captain Albert Markham, bearing the flag of Admiral Lyons, commander-in-chief. With regret I declined the admiral’s hospitable invitation to accompany the squadron to Valparaiso, but I was unable to refuse Captain Markham’s kind suggestion that, as his ship was under orders to return to England on the arrival of the Swiftsure, then expected, I should become his guest on the passage from Valparaiso to Montevideo. The Triumph having been detained in Chilian waters many weeks longer than was then expected, I was afterwards forced to forego the agreeable prospect of a voyage in company with an officer whose varied accomplishments and extensive observation of nature under the most varied conditions make his society equally agreeable and instructive.
Leaving Caldera soon after midday, the Ayacucho reached Coquimbo early on the following morning. With only the exception of Talcahuano, this is the best port in Chili, being sheltered from all troublesome winds, and affording good anchorage for large ships. The town of La Serena, the chief place in this part of Chili, stands on moderately high ground about two miles from the sea, and may be reached in about twenty minutes from the port by frequent trains which travel to and fro. We were warned that our stay was to be very short, and that those who went to the city could not remain there for more than half an hour. I had no difficulty in deciding to forego the attractions of the city, whatever they might be, for a far more tempting alternative offered itself. The range of low but rather steep slopes that rises immediately behind the chief line of street was actually dotted over with bushes, veritable bushes, and the unusual greenish-grey tint of the soil announced that it was at least partially covered with vegetation. In the spring, as I was assured, the hue is quite a bright green. To a man who for the preceding week had seen nothing on land but naked rocks or barren sand, the somewhat parched and meagre vegetation of Coquimbo appeared irresistibly attractive. I could not expect to add anything of value to what is already known, through the writings of Darwin and other travellers, respecting the evidences of elevation of the coast afforded by the raised terraces containing recent shells, whose seaward face forms the seeming hills behind the town, and I felt free to give every available moment to collecting the singular plants of this region.