CHAPTER XX
PERU: PHYSICAL CHARACTERISTICS
The country of Peru has three distinct sections longitudinally: the Coast region, the Sierra, and the Montaña—the first well known and fairly settled, the second with the greater population, the third having much the largest area, but thinly peopled chiefly by wild Indians, and not thoroughly explored. The term montaña, one of the Spanish words for mountain, in Peru is generally applied to the forest region on the eastern slope of the Andes and the plains beyond; the plateau and mountain section with the narrow valleys included form the sierra.
The Coastal Region
The coast of Peru is a strange one, presenting to the uninformed traveler a series of surprises. One expects to find it hot in the tropics, at least at sea level; but on ship-board sailing south when 3° below the equator, at least in the winter season, which it must be remembered is during our summer, warm clothing if not heavy underwear is necessary with blankets at night. One is amazed too to find at Paita (for some steamers the first port of call), a real desert, in striking contrast to the rich vegetation near the Guayas River.
The chief reason for the comparatively cool temperatures experienced on the entire coast of Peru is found in the Humboldt or Antarctic current which flows from the icy realms far south, with chilling effect, close along the shore to the region of the equator, where near the most western points of the continent it turns west across the Pacific.
The high mountains too, here quite near the shore, have some cooling influence and are a prime cause of the existing desert. The hot moist winds, which in the equatorial regions blow west from the Atlantic dropping more or less of their vapor on the way, on reaching the highest Andes lose all the rest, as every bit of the moisture is condensed by the freezing mountain sides; the average height of the range in Peru is above 17,000 feet. After passing the mountains the winds descend cool and dry to the plains. The damp chilly winds which come north with the Antarctic current, as they blow over the shore, find this warmer than the ocean, so the moisture is not condensed.
Thus it is that the coast of Peru with that of northern Chile, being practically rainless, is called a desert, though in Peru it is not wholly barren. From her mountains 58 streams come down toward the Pacific, though not all reach the ocean or last throughout the year. In these valleys there is green, a beautiful and welcome contrast to the desert; in most of them are irrigation and agriculture. Because the nitrates have not been washed out of the soil by rain, where a suitable water supply can be provided, the land constitutes one of the finest agricultural regions on the globe.
In proportion to its length the area of the coast line is small, as the Andes here run closer to the shore than in Ecuador, especially in the central portion, where spurs from the main range sometimes end in bold bluffs rising 500 feet from the sea. In general the width of the coast land varies from 20 to 50 miles, in places reaching to 100. Unfortunately the coast is slightly indented by gulfs and bays and therefore has few good harbors.
The Sierra
In the sierra country we find the greatest development of the mountain system of the Andes attained in its entire course. For the most part it here consists of three ranges, the Maritime, the Central, and the East Cordillera. The first two, near together, are regarded as of similar origin, separated during ages by the action of water. They include volcanoes and mineral springs; and in some parts of the lofty region between the two, cold alpine lakes, sources of coast rivers and also of Amazon tributaries.
The Maritime Cordillera is not connected with the coast ranges of Chile, but is a continuation of that cordillera which forms the eastern limit of the coastal Chilian desert and the western boundary of the great Bolivian plateau. In Bolivia and Southern Peru it is a volcanic chain with some peaks of great height, over 20,000 feet. Though generally quiescent, one volcano in Peru south of Arequipa in the year 1700 erupted continuously for two weeks. El Misti, altitude 19,200 feet, above Arequipa is well known. From the summit a little smoke may be seen in the depths of the crater. The volcanoes seem to have some connection with earthquakes, with which this region is often affected. Though the quakes are mostly slight tremors, severe shocks occur; 70 of a destructive nature have been reported since 1570. The worst, which in 1746 completely destroyed Callao, was followed by 220 shocks within 24 hours. The city was overwhelmed by a tidal wave 80 feet high from which not half a dozen inhabitants escaped. The earthquake of 1868, which was felt over most of South America, half destroyed Arequipa, and tidal waves swept over Arica and Iquique. In 1877 nearly half of the southern ports were submerged; in 1906 a good portion of Valparaiso, Chile, was laid in ruins, a fate within a period of 12 months shared by San Francisco and by Kingston, Jamaica. At about 10° S. Lat. the Maritime Cordillera separates into two ranges for a distance of 100 miles, the Cordillera Negra, and the Cordillera Blanca, the two enclosing the Huailas Valley; north of where the Santa River breaks through toward the coast, the Black Range begins to subside, the Maritime continuing to Ecuador in a single chain.
The Central Cordillera is the true divide, forming the continental watershed. A single river, the Marañon, breaks through in its lower northern part, while 20 coast streams rising in the Central cut the Maritime range; the East Cordillera is fractured by six Peruvian rivers, the Marañon, Huallaga, Perené, Mantaro, Apurimac, Vilcamayu, and Paucartambo, all but the first being affluents of the Ucayali, which some authorities call a tributary of the Marañon. Oftener these two are said to unite to form the Amazon.
The East Cordillera. While the Central Cordillera is volcanic in part, the East is of Silurian formation, older and non-volcanic except at the edge of Lake Titicaca. The last, in Bolivia a splendid range, is lower in Peru. It has the high plateau region on the west; east is the Amazon Basin into which its spurs extend for varying distances. The Central and Eastern Andes are connected by a transverse mountain knot at Vilcanota, or Cuzco, while a similar knot occurs at Cerro de Pasco. Farther north the Central Cordillera separates the valleys of the Marañon and the Huallaga, while the eastern Andes is between the latter and the Ucayali. The three ranges are clearly defined much of the way in Peru, and back of Chimbote in the section including the Huailas Valley there are four.
The Montaña
The third longitudinal division in Peru, the Trans-Andine, usually referred to as the montaña, is the region of subtropical and tropical forest. It is traversed by great rivers, largely navigable. Partly in the sierra country are the Marañon, 600, and the Huallaga, 400 miles long, before their union; 150 miles beyond they are joined by the Ucayali, a great river with a course of 600 miles, more navigable than the other two. These three rivers with their affluents drain the northern and the central part of Peru. The streams of the southern portion are tributary to the Madre de Dios which flows into the Beni, the latter uniting with the Mamoré to form the Madeira. The montaña section, 800 miles from north to south, has a sub-tropical region on the lower slopes of the Andes, the branches of which run out 60 or 80 miles towards the lowlands, and the tropical forests of the latter. In the northern section a considerable district between the Huallaga and the Ucayali rivers, traversed by the Andes, is composed of grassy plains called the Pampa del Sacramento. Some of this northern region is called the montaña, having its characteristics, although not east of the East Cordillera.
Climate
The climate of Peru, a country like those preceding entirely within the tropics, has similar though greater variations from altitude, as its mountains are higher, its table-lands more lofty and extensive. With a larger area of temperate climate on its highlands, it has also, in wide contrast to the others, a fairly temperate region along its entire coast. This last, however, differs from the ordinary climate of the temperate zone, as does that at an altitude of 6000 or 8000 feet, in having weather which is never so hot as often in almost all parts of the United States, and at the same time is never so cold. At Lima, eight miles from the sea, the mean temperature is 66°; in the warm season, December to March, the mercury occasionally climbs a little above 80°, and in winter, June to September, it rarely falls below 50°. It is a little warmer farther north, and on the broad desert in the sun it is hot, hotter, hottest; as I once found to my sorrow. But comparatively few persons have occasion to travel there, and when they do they are likely to journey in the late afternoon and night; a more agreeable season for such cross country riding. On the deserts, too, it is colder at night as happens the world over.
The winter season at Lima is damp and cloudy, the atmosphere raw and chilly; with the mercury below 60° a fire would be most acceptable, but they never have one. On account of the dampness and the evaporation from the heat of the body, the cold is felt more than the temperature warrants, so that overcoats and warm wraps may be donned for sitting in the house. Conditions vary on other parts of the coast; in general there is less fog and greater heat farther north and more fog and mist towards the south. Mollendo is particularly damp and disagreeable. Some shore places near Lima have much more sunshine than that city, and 20 miles from the sea one gets beyond the fog belt into a region of perpetual spring. Although the climate of Lima is said to be rather enervating to permanent residents, many dwellers in the temperate zone would prefer it to that of any other coast city within the tropics.
On the highlands the climate is widely diverse. The seasons are opposite, as there it is the dry season from May to October, when it is damp on the coast, while the chief precipitation above occurs during their summer, the dry months below. At an altitude of 7000 or 8000 feet the climate is considered agreeable, at Arequipa averaging 57°, at Cajamarca 52°. At 12,000 to 15,000 feet it is generally cool, perhaps bracing to those accustomed thereto, but often trying to the visitor, who is likely to suffer from soroche, the name applied to mountain sickness.
In the montaña there is variation due to altitude, as in the sierra, as this region includes the forested district from an altitude of nearly 10,000 feet down to 1000 or less in the basin of the large Amazon tributaries. From 3000 to 7000 feet the climate is delightful to those who do not enjoy greater contrasts. Huánuco, altitude 6270 feet, has an annual temperature of 74°, other places a lower temperature, and far down, as at Iquitos, a higher. Most of the region is healthful, as is also the sierra, for persons of sound constitution under suitable living conditions and employing intelligent care. In some parts of the lowlands malaria is occasional or permanent, in other parts it is unknown.