of 1908, by direct negotiation if possible, or, failing this,
by arbitration. The decision of the president of Argentina of
the 9th of July 1909, in regard to the remainder of this extensive
territory, was a compromise, and divided it into two nearly
equal parts. The line adopted starts from Lake Suches, the
source of a small river of that name flowing into the north of
Lake Titicaca, crosses the Cordillera by the Palomani to the
Tambopata river, follows that stream to the mouth of the Lanza,
thence crosses to the source of the Heath river, which forms the
dividing line down to its junction with the Madre de Dios,
descends that river to the mouth of the Torosmonas, thence in
a straight line north-westerly to the intersection of the Tahuamanu
river by the 69th meridian, and thence north on that
meridian to the Brazilian frontier. This decision at first gave
offence to the Bolivians, but friendly overtures from Peru led
to its acceptance by both parties with the understanding that
modifications would be made in locating the line wherever actual
settlements had been made by either party on territory awarded
to the other. With Chile the de jure line is that of the Camarones
ravine which separated the old department of Moquegua (including
the provinces of Tacna and Arica) from that of Tarapaca.
The de facto line is that of the Sama river (usually dry), which
opens on the coast a little south of Sama point, near 18° S., Chile
retaining possession of the two above-mentioned provinces in
violation of the treaty of Ancon, which she forced upon her
defeated antagonist.
Physical Geography.—Peru is divided longitudinally into three well-defined regions, the coast, the sierra and the montana. The coast, extending from the base of the Western or Maritime Cordillera to the Pacific Ocean, consists of a sandy desert crossed at intervals by rivers flowing through narrow, fertile valleys. The sierra is the region of the Andes, and is about 250 m. in width. It contains stupendous chains of mountains, elevated plains and table-lands, warm and fertile valleys and ravines. The montana is the region of tropical forests within the valley of the Amazon, and skirts the eastern slopes of the Andes.
The coast has been upraised from the ocean at no very distant geological epoch, and is nearly as destitute of vegetation as the African Sahara. It is watered, however, by fifty streams which cross the desert at intervals. Half of these have their origin in the summits of the Andes, and run with a permanent supply of water into the ocean. The others,The Coast. rising in the outer range, which does not reach the snow-line and receives less moisture, carry a volume of water to the sea during the rainy season, but for the rest of the year are nearly dry. The absence of rain here is ascribed to the action of the lofty uplands of the Andes on the trade-wind and to the influence of the cold Humboldt current sweeping northward along the west coast of the continent. The south-east trade-wind blows obliquely across the Atlantic Ocean until it reaches Brazil. By this time it is heavily laden with vapour, which it continues to bear along across the continent. depositing it and supplying the sources of the Amazon and La Plata. When the wind rises above the snow-capped Andes, the last particle of moisture is wrung from it that a very low temperature can extract. Passing the summit of that range, it rushes down as a cool and dry wind on the Pacific slopes beyond. Meeting with no evaporating surface, and with no temperature colder than that to which it is subjected on the mountain-tops, this wind reaches the ocean before it becomes charged with fresh moisture. The constantly prevailing wind on the Peruvian coast is from the south, which is a cold wind from the Humboldt current. As it moves north it becomes gradually warmed and takes up moisture instead of depositing it as rain. From November to April there are usually constant dryness, a clear sky, and considerable, though by no means oppressive, heat. From June to September the sky is obscured for weeks together by fog, which is often accompanied by drizzling rain called garua. At the time when it is hottest and driest on the coast it is raining heavily in the Andes, and the rivers are full. When the rivers are at their lowest, the garua prevails on the coast. The climate of various parts of the coast, however, is modified by local circumstances.
The Western Cordillera, overhanging the Peruvian coast, contains a long line of volcanic mountains, most of them inactive, but their presence is probably connected with the frequent and severe earthquakes, especially in the southern section of the coast. Since 1570 seventy violently destructive earthquakes have been recorded on the west coast of South America, but the register is incomplete in its earlier part. The most terrible was that of 1746, which destroyed Callao, on the 28th of October, and there were 220 shocks in the following twenty-four hours. The town was overwhelmed by a vast wave, which rose 80 ft.; and the shocks continued until the following February. On the 13th of August 1868 an earthquake nearly destroyed Arequipa, and great waves rolled in upon the ports of Arica and Iquique. On the 9th of May 1877 nearly all the southern ports were overwhelmed.
The deserts between the river-valleys vary in extent, the largest being more than 70 m. across. On their western margin steep cliffs generally rise from the sea, above which is the tablazo or plateau, in some places slightly undulating, in otheis with ridges of considerable height rising out of it. The surface is generally hard, but in many places there are large accumulations of drifting sea-sand. The sand usually forms isolated hillocks, called medanos, of a half-moon shape, having their convex sides towards the trade wind. They are from 10 to 20 ft. high, with an acute crest, the inner side perpendicular, the outer with a steep slope. Sometimes, especially at early dawn, there is a musical noise in the desert, like the sound of distant drums, which is caused by the eddying of grains of sand in the heated atmosphere, on the crests of the medamos.
Apparently the deserts are destitute of all vegetation yet three kinds of herbs exist, which bury themselves deep in the earth, and survive long periods of drought. One is an amaranthaceous plant, whose stems ramify through the sand hills; the other two are a Martyma and an Aniseia, which maintain a subterranean existence during many years, andCoast Flora. only produce leafy stems in those rare seasons when sufficient moisture penetrates to the roots. In a few hollows which are reached by moisture the trees of the desert find support, the algarrobo (Prosopis horrida), a low tree of very scraggy growth, the vichaya (Capparis crotonoides) and the zapote del perro (Colicodendrum scabridum), mere shrubs. Near the Cordillera and on its lower slopes a tall branched cactus is met with, and there are Salzcormas and Salsolas near the coast. But, when the mists set in, the low hills near the coast bordering the deserts, which are called lomas, undergo a change as if by magic. A blooming vegetation of wild flowers for a short time covers the barren hills. Near Lima one of the low ranges is brightened by the beautiful yellow lily called amancaes (Ismene Amancaes). The other flowers of the lomas are the papita de San Juan (Begonia geranifolia), with red petals contrasting with the white inner sides, valerians, the beautiful Bomarea ovata, several species of Oxalis, Solanum and crucifers. But this carpet of flowers is very partially distributed and lasts but a short time.
The valleys form a marvellous contrast to the surrounding desert. A great mass of pale-green foliage is usually composed of the algarrobo trees, while the course of the river is marked by lines or groups of palms, by fine old willows (Salix humboldtiana), fruit-gardens, and fields of cotton, Indian corn, sugar-cane and alfalfa (lucerne). In some valleys there are expanses of sugar-cane, in others cotton, whilst in others vineyards and olive-yards predominate. The woods of algarrobo are used for pasture, cattle and horses enjoying the pendulous yellow pods.
For purposes of description the coast-region of Peru may be divided into five sections, beginning from the north: (1) the Piura region; (2) the Lambayeque and Trujillo section; (3) the Santa valleys; (4) the section from Lima to Nasca; (5) the Arequipa and Tacna section.Sections of the Coast.
(1) The great desert-region of Piura extends for nearly 200 m. from the Gulf of Guayaquil to the borders of the Morrope Valley, and is traversed by three rivers—the Tumbes, Chira and Piura, the two former receiving their waters from the inner Cordillera and breaking through the outer range. It is here that the coast of South America extends farthest to the westward until it reaches Capes Blanco and Pariña, and then turns southward to the Bay of Paita. The climate of Piura is modified by the lower latitude, and also by the vicinity of the forests of Guayaquil. Fog and garua are much less frequent than in the coast-region farther south, while rain sometimes falls. At intervals of three or four years there are occasional heavy showers of rain from February to April. (2) The second section of the coast-region includes the valleys of the Morrope, the Chiclayo, and Lambayeque, the Sana, the jequetepeque, the Chicama, Moche, Viru and Chao. With the intervening deserts this section extends over 200 m. All these valleys, except Morrope and Chao, are watered by rivers which have their sources far in the recesses of the mountains, and which furnish an abundant supply in the season when irrigation is needed. (3) The third section, also extending for 200 m., contains the valleys of Santa, Nepena, Casma, Huarmey, Fortaleza, Pativilca, Supé and Huaura. The river Santa, which rises in the lake of Conococha, 12,907 ft. above the sea, and has a length of 180 m., is remarkable for its long course between the outer and central ranges of the Andes, in a. trough known as the “Callejon de Huaylas,” 100 m. in length. It then breaks through in a deep gorge, and reaches the sea after a course of 35 m. over the coast-belt, and after fertilizing a rich valley. The Santa and Nepeña valleys are separated by a desert 8 leagues in width, on the shores of which there is a good anchorage in the bay of Ferrol, where the port of Chimbote is the terminus of a railway. The Nepeia, Casma, Huarmey, Fortaleza and Supé rivers rise on the slope of an outer range called the Cordillera Negra, and are consequently dry during the great part of the year. Wells are dug in their beds, and the fertility of the valleys is thus maintained. The Pativilca (or Barranca) river and the Huaura break
