Boundaries.— The republic is bounded on the W. by the Pacific Ocean, on the E. by Brazil and Bolivia, on the N. by Ecuador, and on the S. by Chili. The northern boundary commences at the village of Santa Rosa, near the southern shore of the Gulf of Guayaquil, whence it passes southwards to the river Macara, a tributary of the Chira, which falls into the Pacific. It takes the course of the Macara, up the ravine of Espindula, to its source in the cordillera of Ayavaca; in the Amazonian basin it follows the river Cauches to its junction with the Chinchipe, and the Chinchipe to the Marañon. The Maraπon then forms the boundary until the first Brazilian town is reached at Tabatinga. The frontier with Brazil was determined by article ii. of the treaty of San Ildefonso in 1777. A treaty dated 23d October 1851 further settled the boundary, which was fixed by the commissioners who explored the Yavari in 1866 and 1871. It first follows the course of the Yavari from the point where it falls into the Amazon, in 4° 13' 21" S., up to a point near its source in 7° Γ 17" S.; from this it forms a straight line to a point in 6° 52' 15" S. on the left bank of the Madeira, being half the distance between the mouth of the Mamoré and that of the Madeira. This is the point where the frontiers of Peru, Brazil, and Bolivia meet. The Peru-Bolivian frontier, within the basin of the Amazon, has not been accurately defined. It follows the Madeira to the mouth of the Mamoré, then the Beni and its tributary the Madidi to the junction of the latter with a stream called the Pablo-bamba, ascending the ravine of the Pablo-bamba to the source of that stream in the eastern Andes. The line then crosses the Andes in a straight line southwards to the village of Conima on the shore of Lake Titicaca. Thence it passes across the lake in another straight line to the isthmus of Yunguyo, and thence to the mouth of the Desaguadero. From the Desaguadero the frontier-takes a south-south-west direction to the source of the river Mauri, and then, until the recent war with Chili, it ran south along the watershed of the Maritime Cordillera to the source of the river Loa, which falls into the Pacific. The southern boundary separating the Peruvian province of Tarapaca from the Bolivian province of Atacama was formed by the ravine of Duende, south of the Loa, to the coast of the Pacific in 22° 23' S. near Tocapilla. This part of the frontier was carefully delineated in 1628, and the boundary marks are recorded in a document which is still extant. But the Chilians conquered and in 1884 annexed the Peruvian province of Tarapaca.

Physical Geography.— Peru is divided longitudinally into three well-defined regions, the coast, the sierra, and the montaña. The coast, extending from the base of the Maritime Cordillera to the Pacific Ocean, consists of a sandy desert crossed at intervals by rivers, along the banks of which there are fertile valleys. The sierra is the region of the Andes, and is about 250 miles in width. It contains stupendous chains of mountains, elevated plains and table-lands, warm and fertile valleys, and ravines. The montaña 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 still nearly as destitute of vegetation as the African Sahara. It is, however, watered 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, 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 caused by the action of the lofty uplands of the Andes on the trade-wind. 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 Amazons and La Plata. Finally, the trade-wind arrives at the snow-capped Andes, and here the last particle of moisture is wrung from it that the very low temperature can extract. Coming to 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. 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.” In 1877 the maximum temperature at Lima was 78∣° Fahr, in February and the minimum 61J 0 Fahr, in July. 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 is, however, modified by local circumstances.

The deserts between the river-valleys vary in extent, the largest being upwards of 70 miles 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 others with ridges of considerable height rising out of it, the whole apparently quite bare of vegetation. The surface is generally hard, but in many places there are great 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 feet 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 “medanos.” 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 amar-anthaceous plant, whose stems ramify through the sandhills; the other two are a Martynia and an Aniseia, which maintain a subterranean existence during many years, and 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 “zapote del perro” {C olicodendrum scabridum), mere shrubs. Far away towards the first ascents to the Andes a tall branched cactus is met with, and there are Salicornias 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 O·xalis, Solanum, and crucifers. But this carpet of flowers is very partially distributed and lasts but a short time. Generally the deserts present a desolate aspect, with no sign of a living creature or of vegetation. Only in the very loftiest regions of the air the majestic condor or the turkey buzzard may be seen floating lazily; perhaps a lizard will dart across the path; and occasionally a distant line of mules or a solitary horseman seems to shimmer weirdly in the refraction on the distant horizon.

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, maize, sugar, and 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 greedily enjoying the pendulous yellow pods.

For purposes of description the coast-region of Peru may be divided into six sections, commencing from the north :—(1) the Piura region; (2) the Lambayeque and Truxillo section; (3) the Santa valleys; (4) the section from Lima to Nasca; (5) the Arequipa and Tacna section; (6) Tarapaca.

(1) The great desert-region of Piura extends for nearly 200 miles from the Gulf of Guayaquil to the borders of the Morrope valley, and is traversed by three rivers—the Tumbez, 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 λvestward until it reaches Capes Blanco and Pariña, and then turns southward to the Bay of Payta. 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 positive rain sometimes falls. At intervals of about ten 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 Chieama, Moche, Viru, and Chao. With the intervening deserts this section extends over 200 miles. 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 miles, contains the valleys of Santa, Nepeña, Casma, Huarmey, Fortaleza, Pativilca, Supé, and Huaura. The river Santa, which rises in the lake of Conococha, 12,907 feet above the sea, and has an entire length of 180 miles, 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 miles in length. It then breaks through in a deep gorge, and reaches the sea after a course of 35 miles 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 to be the terminus of a projected railway. The Nepeña, 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 through the outer range from their distant sources in the snowy cordillera, and have a perennial supply of water. There are 9 leagues of desert between the Nepeña and Casma, 16 between the Casma and Huarmey, and 18 between the Huarmey and Fortaleza. The latter desert, much of which is loose sand, is called the “Pampa de Mata Cavallos,” from the number of exhausted animals which die there. Between the Supé and Pativilca is the desert called the “Pampa del Medio Mundo.” (4) The next coast-section extends for over 300 miles from Chancay to Nasca, and includes the rivers of Chancay or Lacha, of Carabayllo, Rimae, Lurin, Mala, Cañete, Chincha, Pisco or Chunchanga, Yea, and Rio Grande. Here the maritime range approaches the ocean, leaving a narrower strip of coast, but the fertile valleys are closer and more numerous. Those of Carabayllo and Rimae are connected, and the view from the Bay of Callao extends over a vast expanse of fertile plain bounded by the Andes, with the white towers of Lima in a setting of verdure. Lurin and Mala are smaller valleys, but the great vale of Cañete is one green sheet of sugar-cane; and narrow strips of desert separate it from the fertile plain of Chincha, and Chincha from the famous vineyards of Pisco. The valleys of Yea, Palpa, San Xavier, and Nasca are rich and fertile, though they do not extend to the sea; but between Nasca and Acari there is a desert 60 miles in width. (5) The Arequipa and Tacna section extends over 350 miles, and comprises the valleys of Acari, Atequipa, Atico, Ocoña, Maj es or Camana, Quilca, with the interior valley of Arequipa, Tambo, Ylo or Moquegua, Ité or Locumba, Sama, Tacna, and Azapa or Arica. Here the Maritime Cordillera recedes, and the important valley of Arequipa, though on its western slope, is 7000 feet above the sea, and 90 miles from the coast. Most of the rivers here have their sources in the central range, and are well supplied with water. The coast-valleys through which they flow, especially those of Majes and Locumba, are famous for their vineyards, and in the valley of Tambo there are extensive olive plantations. (6) The most southern coast-section is that of Tarapaca, extending, between the cordillera and the Pacific, in a narrow strip from the ravine of Camarones, south of Arica, to the former southern frontier of Peru. Only two rivers reach the sea in Tarapaca, the Tiliviche in the north of the province, and the Loa in the extreme south. The other streams are lost in the desert soon after they issue from their ravines in the Andes. The reason of this is that in Tarapaca there is an arid range of hills parallel with the sea-shore, which is about 30 miles in width, and covered with sand and saline substances. Between this coast-range and the Andes is the great plateau called the “Pampa de Tamarugal,” from 3000 to 3500 feet above the sea, which is about 30 miles wide, and extends the whole length of Tarapaca. This plateau is covered with sand, and contains vast deposits of nitrate of soda. Here and there a few “tamarugas” or acacia trees are met with, which give their name to the region.

The coast of Peru has few protected anchorages, and the headlands are generally abrupt and lofty. These and the few islands are frequented by myriads of sea-birds, whence come the guano-deposits, the retention of ammonia and other fertilizing properties being due to the absence of rain. The islets off the coast are all barren and rocky.

The most northern is Foca, in 5° 13' 30" S., near the coast to the south of Payta. The islands of Lobos de Tierra and Lobos de Afuera (2), in 6° 27' 45" S. and 6° 56' 45" S. respectively, are off the desert of Sechura, and contain deposits of guano. The two Afuera islands are 60 and 36 miles from the coast at the port of San José. The islets of Macabi, in 7° 49' 20" S., also have guano-deposits, now nearly exhausted. The two islets of Guañape, surrounded by many rocks, in 8° 34' S., contain rich deposits. Chao rises 450 feet above the sea, off the coast, in 8° 46' 30" S. Corcobado is in 8° 57' S. La Viuda is off the port of Casma, in 9° 23' 30" S.; and Tortuga is 2 miles distant to the north. Santa Islet lies off the bay of Cosca, in 9° 1' 40", and the three high rocks of Ferrol in 9° 8' 30" S. Farther south there is the group of islets and rocks called Huaura, in 11° 27' S., the chief of which are El Pelado, Tambillo, Chiquitana, Bravo, Quitacaizones, and Mazorque. The Hormigas are in 11° 4' S. and 11° 58', and the Pescadores in 11° 47' S. The island of San Lorenzo, in 12° 4' S., is a lofty mass, 4⅛ miles long by 1 broad, forming the Bay of Callao; its highest point is 1050 feet. Off its south-east end lies a small but lofty islet called Fronton, and to the south-west are the Palomitas Rocks. Horadada Islet, with a hole through it, is to the south of Callao Point. Off the valley of Lurin are the Pachacaraac Islands, the most northern and largest being half a mile long. The next, called San Francisco, is like a sugar-loaf, perfectly rounded at the top. The others are mere rocks. Asia Island is farther south, 17 miles north-west of Cerro Azul, and about a mile in circuit. Pisco Bay contains San Gallan Island, high, with a bold cliff outline, 2⅜ miles long by 1 broad, the Ballista Islets, and farther north the three famous Chincha Islands, whose vast guanodeposits are now exhausted. South of the entrance to Pisco Bay is Zarate Island, and farther south the white level islet of Santa Rosa. The Infiernillo rock is quite black, about 50 feet high, in the form of a sugar-loaf, a mile west of the Point of Santa Maria, which is near the mouth of the Yea river. Alacran is a small islet off the lofty “morro” of Arica. A low island protects the anchorage of Iquique on the coast of Tarapaca, and farther south are the three islets of Patillos in 20° 46' 20" S., and the Pajaros, with guanodeposits, in 22° 6' 4" S. All these rocks and islets are barren and uninhabitable, mere outworks of the desert headlands.

The more common sea-birds, which haunt the islets and headlands in countless myriads, are the Sula variegata or guano-bird, a large gull called the Larus modestus, the Pelecanus thayus, and the Sterna Ynca, a beautiful tern with curved white feathers on each side of the head. The rarest of all the gulls is also found on the Peruvian coast, namely, the Xema furcatum. The immense flocks of birds, as they fly along the coast, appear like clouds, and one after another is incessantly seen to plunge from a height into the sea to devour the fishes, which they find in extraordinary numbers. The guano-deposits are in layers from 40 to 50 feet thick, of a greyish-brown colour outside, and more and more solid from the surface downwards, owing to the gradual deposit of strata and evaporation of fluid par-tides. Sea-lions (Otaria forst eri) are common on the rocky islands and promontories. These large creatures frequent particular islets for the purpose of breathing their last, the wounded or aged being helped there by their companions.

The Maritime 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 the year 1570 there have been seventy violently destructive earthquakes recorded on the west coast of South America, but the register is of course incomplete in its earlier part. The most terrible was that of 1745, which destroyed Callao. There had been subterranean noises for some days previously; the first shock was at 10.30 p.m. on 28th October, and there were 220 shocks in the following twenty-four hours. The town was overwhelmed by a vast wave, which rose 80 feet; and the shocks continued until the following February. On 13th August 1868 an earthquake nearly destroyed Arequipa,...