Notes of a naturalist in South America

by John Ball

With regard to mountain-sickness, the only matter for surprise, as it seems to me, is that it is not more frequently felt at lower elevations, and that the human economy is able so readily to adapt itself to the altered conditions when transferred to an atmosphere of say two-thirds of the ordinary density, where the diminished supply to the lungs is aggravated by the increased mechanical effort requisite to move the limbs, and raise the weight of the body in an attenuated medium. Observation shows that the effects actually produced at great heights vary much with different individuals, and that in healthy subjects the functions after a short time adapt themselves to the new conditions. It is obvious that this process must have a limit, which has probably been very nearly attained in some cases.

In spite of some statements lately published, I am inclined to believe that the utmost limit of height compatible with active exertion will be found to lie, according to individual constitution, between twenty and twenty-five thousand feet. As regards our experiences at Chicla, the difficulty is to account for the fact that the effects produced while the body is at rest should disappear during active exercise; and whatever the nature of the disturbance of the functions, this was not accompanied by any discernible derangement of the respiration or the circulation. It appeared to me that the seat of disturbance, such as it was, was limited to the nervous system.

On the evening of our arrival we met at the hotel the commandant of the Chilian detachment, and on presenting my letter from the commander-in-chief, he was profuse in offers of assistance. It was speedily arranged that we should start on the following morning, to ride as far as the tunnel at the summit of the pass to Oroya, where I promised myself an ample harvest among the plants of the higher region of the Andes. When morning broke, after a sleepless night with a splitting headache, I found or fancied myself unfit for a hard day’s work; and, my companion being in much the same plight, we sent at an early hour to request that the excursion should be postponed till the following day. By the time, however, that we had dressed and breakfasted, the troubles of the night were all forgotten. A new vegetable world was outside awaiting us, and we were soon on the slopes above the station, where, in the person of my friend W——, I had the advantage of a kind and zealous assistant in the work of plant-collecting.

FIRST DAY IN THE ANDES.

Deferring to a later page some remarks on the vegetation of the Cordillera, I need merely say that of this first delightful day the morning hours were devoted to the steep declivity of the mountain overhanging the left bank of the stream, while the afternoon was given to the less precipitous but more broken and irregular slopes on the opposite, or right, bank.

Having soon made the discovery that the supplies at Chicla were very limited, we had taken measures to procure a few creature comforts through the obliging conductor of the train, which left Chicla, in the morning, and was to return from Lima on the following evening. A far more serious deficiency was at the same time apparent. I had quite underrated the quantity of paper required to dry the harvest of specimens that I was sure to collect here, and no one but a botanist can measure the intensity of distress with which I viewed the prospect of losing precious specimens, and seeing shapes of beauty converted into repulsive masses of corruption, for want of the material necessary for their preservation. I addressed an urgent note to Mr. Nation, on whose sympathy as a brother naturalist I could safely count, telling him that unless I could find two reams of suitable drying-paper on my return, I should infallibly require accommodation in a lunatic asylum at Lima.

The scenery at Chicla is wild, but neither very beautiful nor very imposing. As in the lower valley of the Rimac, the slopes of the mountains are steep, but the summits are deficient in boldness and variety of form. Those lying on the watershed of the Cordillera, at a distance of fifteen or twenty miles, apparently range from seventeen to eighteen thousand feet in height, and on the first day of our visit showed but occasional streaks and patches of snow, while the sombre tints of the rocks exhibited little variety of hue even in the brightest sunshine.

Although the stream at Chicla is the main branch of the Rimac, its volume is here much reduced, not having yet received the numerous tributaries that fall into it between this place and Matucana. It is here no more than a brawling torrent, swelling rapidly after even a very moderate fall of rain, but prevented from ever dwindling very low by the snows, of which some patches at least remain at all seasons on the upper summits of the Cordillera. In a country without wood, and where the art of building in stone had made little progress, one of the most serious obstacles to any advance in civilization must have arisen from the difficulty of crossing the streams by which the upper ranges of the Andes are everywhere intersected.

ANDEAN SUSPENSION BRIDGES.

The art of constructing suspension bridges must have originated in the subtropical zone of Eastern Peru, where the abundance of climbing plants with long, flexible, tough stems supplied the requisite materials. These, being light and easily transported, were everywhere used in the valleys of the Andes to sustain hanging bridges, of which the roadway was formed of rough basket-work. The only change that has resulted from the introduction of European arts is that of late years iron wire is used instead of flexible lianes to sustain the bridges; but the roadway is still made of basket-work, which is rapidly worn by the feet of passing men and animals, and the natives have a disagreeable habit of stopping up the holes, not by mending the basket-work where this has begun to give way, but by laying a flat stone over the weak place. Being very slight and not nicely adjusted, these bridges swing to and fro under the feet of a passenger to an extent that is at first rather startling, but, as in everything else, habit soon makes one indifferent. Our first experience this afternoon was very easy, as the bridge connecting the station with the pueblo, or village of Chicla, was new and more solid than usual.