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.