imposing ruin of Gutenfels, and facing it, on a rock in the middle of the Rhine, the small castle Pfalz, or Pfalzgrafenstein, where, according to legend, the Palatine countesses awaited their confinement, but which in reality served as a toll-gate for merchandise on the Rhine.
Caub, first mentioned in the year 983, originally belonged to the lords of Falkenstein, passed in 1277 to the Rhenish Palatinate, and attained civic rights in 1324. Here Blücher crossed the Rhine with the Prussian and Russian armies, on New Year’s night 1813–1814, in pursuit of the French.
CAUCA, a large coast department of Colombia, South America, lying between the departments of Bolivar, Antioquia, Caldas and Tolima on the E., and the Pacific Ocean and Panama on the W., and extending from the Caribbean Sea S. to the department of Nariño. Pop. (1905, estimate) 400,000; area 26,930 sq. m. Although Cauca was deprived of extensive territories on the upper Caquetá and Putumayo, and of a large area bordering on Ecuador in the territorial redistribution of 1905, it remained the largest department of the republic. The Western Cordillera, traversing nearly its whole length from south to north, and the Central Cordillera, forming a part of its eastern frontier, give a very mountainous character to the region. It includes, besides, the fertile and healthful valley of the upper Cauca, the hot, low valley of the Atrato, and a long coastal plain on the Pacific. The region is rich in mines and valuable forests, but its inhabitants have made very little progress in agriculture because there are not adequate transportation facilities. The capital of the department is Popayán at its southern extremity, with an estimated population in 1905 of 10,000, other important towns are Cali (16,000), Buga, Cartago and Buenaventura.
CAUCASIA, or Caucasus, a governor-generalship of Russia, occupying the isthmus between the Black Sea and the Sea of Azov on the west and the Caspian Sea on the east, as well as portions of the Armenian highlands. Its northern boundary is the Kuma-Manych depression, a succession of narrow, half-desiccated lakes and river-beds, only temporarily filled with water and connecting the Manych, a tributary of the Don, with the Kuma, which flows into the Caspian. This depression is supposed to be a relic of the former post-Pliocene connexion between the Black Sea and the Caspian, and is accepted by most geographers as the natural frontier between Europe and Asia, while others make the dividing-line coincide with the principal water-parting of the Caucasus mountain system. The southern boundary of Caucasia is in part coincident with the river Aras (Araxes), in part purely conventional and political. It was shifted several times during the 19th century, but now runs from a point on the Black Sea, some 20 m. south of Batum, in a south-easterly and easterly direction to Mt. Ararat, and thence along the Aras to within 30 m. of its confluence with the Kura, where it once more turns south-east, and eventually strikes the Caspian at Astara (30° 35′ N.). This large territory, covering an area of 180,843 sq. m., and having in 1897 9,248,695 inhabitants (51 per sq. m.), may be divided into four natural zones or sections:—(i.) the plains north of the Caucasus mountains, comprising the administrative division of Northern Caucasia; (ii.) the Caucasus range and the highlands of Daghestan; (iii.) the valleys of the Rion and the Kura, between the Caucasus range and the highlands of Armenia; and (iv.) the highlands of Armenia.
(i.) The plains of Northern Caucasia, which include most of the provinces of Kubañ and Terek and of the government of Stavropol, slope gently downwards from the foot of the Caucasus range towards the Kuma-Manych depression. It is only in their centre that they reach altitudes of as much as 2000–2500 ft. e.g. in the Stavropol “plateau,” which stretches northwards, separating the tributaries of the Kubañ from those of the Terek and the Kuma. Towards the foothills of the Caucasus they are clothed with thick forests, while in the west they merge into the steppes of south Russia or end in marshy ground, choked with reeds and rushes, in the delta of the Kubañ. In the north and east they give place, as the Manych and the coasts of the Caspian are approached, to arid, sandy, stony steppes. The soil of these plains is generally very fertile and they support a population of nearly 2,800,000 Russians, composed of Cossacks and peasant immigrants, settled chiefly along the rivers and grouped in large, wealthy villages. They carry on agriculture—wheat-growing on a large scale—with the aid of modern agricultural machines, and breed cattle and horses. Vines are extensively cultivated on the low levels, and a variety of domestic trades are prosecuted in the villages. The higher parts of the plains, which are deeply trenched by the upper tributaries of the rivers, are inhabited by various Caucasian races—Kabardians and Cherkesses (Circassians) in the west, Ossetes in the middle, and several tribal elements from Daghestan, described under the general name of Chechens, in the east; while nomadic Nogai Tatars and Turkomans occupy the steppes.
(ii.) The Caucasus range runs from north-west to south-east from the Strait of Kerch to the Caspian Sea for a length of 900 m., with a varying breadth of 30 to 140 m., and covers a surface of 12,000 sq. m. The orographical characteristics of the Caucasus are described in detail under that heading.
(iii.) The combined valleys of the Rion and the Kura, which intervene between the Caucasus and the Armenian highlands, and stretch their axes north-west and south-east respectively, embrace the most populous and most fertile parts of Caucasia. They correspond roughly with the governments of Kutais, Tiflis, Elisavetpol and Baku, and have a population of nearly 3,650,000. The two valleys are separated by the low ridge of the Suram or Meskes mountains.
Spurs from the Caucasus and from the Armenian highlands fill up the broad latitudinal depression between them. Above (i.e. west of) Tiflis these spurs so far intrude into the valley that it is reduced to a narrow strip in breadth. But below that city it suddenly widens out, and the width gradually increases through the stretch of 350 m. to the Caspian, until in the Mugan steppe along that sea it measures 100 m. in width. The snow-clad peaks of the main Caucasus, descending by short, steep slopes, fringe the valley on the north, while an abrupt escarpment, having the characteristics of a border ridge of the Armenian highlands, fronts it on the south. The floor of the valley slopes gently eastwards, from 1200 ft. at Tiflis to 500 ft. in the middle, and to 85 ft. below normal sea-level beside the Caspian. But the uniformity of the slope is interrupted by a plateau (2000–3000 ft. in altitude) along the southern foothills of the east central Caucasus, in the region known as Kakhetia, drained by the Alazan, a left-hand tributary of the Kura. The deep, short gorges and glens which seam the southern slopes of the Caucasus are inhabited by Ossetes, Tushes, Pshavs and Khevsurs in the west, and by various tribes of Lesghians in the east. In these high and stony valleys every available patch of ground is utilized for the cultivation of barley, even up to altitudes of 7000 and 8000 ft. above the level of the sea; but cattle-breeding is the principal resource of the mountaineers, whose little communities are often separated from one another by passes, few of which are lower than 10,000 ft. The steppes along the bottom of the principal valley are for the most part too dry to be cultivated without irrigation. It is only in Kakhetia, where numerous mountain streams supply the fields and gardens of the plateau of Alazan, that wheat, millet and maize are grown, and orchards, vineyards and mulberry plantations are possible. Lower down the valley cattle-breeding is the chief source of wealth, while in the small towns and villages of the former Georgian kingdom various petty trades, exhibiting a high development of artistic taste and technical skill, are widely diffused. The slopes of the Armenian highlands are clothed with fine forests, and the vine is grown at their base, while on the wide-stretching steppes the Turko-Tatars pasture cattle, horses and sheep. The lower part of the Kura valley assumes the character of a dry steppe, the rainfall not reaching 14 in. annually at Baku, and it is still less in the Mugan steppe, though quite abundant in the adjacent region of Lenkoran. The vegetation of the steppe is on the whole scanty. Trees are generally absent, except for thickets of poplars, dwarf oaks and tamarisks along the course of the Kura, the delta of which is smothered under a jungle of reeds and rushes. The Mugan steppe is, however, in spite of its dryness, a more fertile region in virtue of the irrigation practised; but the Kura has excavated its bed too deeply to admit of that being done along its course. The Lenkoran district, sometimes called Talysh, on the western side of the Kizil-Agach bay, is blessed with a rich vegetation, a fertile soil, and a moist climate.
The inhabitants of the Kura valley consist principally of Iranian Tates and Talyshes, of Armenians and Lesghians, with Russians, Jews and Arabs. This conjoint valley of the Rion-Kura was in remote antiquity the site of several Greek colonial settlements, later the seat of successive kingdoms of the Georgians, and for centuries it has formed a bulwark against hostile invasions from the south and east. It is still inhabited chiefly by Georgian tribes—Gurians, Imeretians, Mingrelians, Svanetians—in the basin of the Rion, and by Georgians intermingled with Armenians in the valley of the Kura, while the steppes that stretch away from the lower course of the latter river are ranged over by Turko-Tatars. Mingrelia and Imeretia (valley of Rion) are the gardens of Caucasia, but the high valleys of Svanetia, farther north on the south slopes of the Caucasus mountains, are wild and difficult of access. In the cultivated parts the land is so exceedingly fertile and productive that it sells for almost fabulous prices, and its value is still further enhanced by the discovery of manganese and copper mines in the basin of the Rion, and of the almost inexhaustible supplies of naphtha and petroleum at Baku in the Apsheron peninsula. The principal products of the soil are mentioned lower down, while the general