The high grounds which divide the table-land from the basin of the Ebro cannot be considered as a mountain ridge in all their extent. Towards the western extremity of the river basin no mountain range divides it from the table-land. East of the town of Burgos rises the Sierra de Oca, which extends from west-north-west to east-south-east, and is followed by the Sierra de Cameros. Contiguous to it, and in the same direction, is tho Sierra de Mencaye, which has its eastern termination near 2° W. long. From this point the edge of the table land is leas marked. It runs to the river Jalon, which it crosses near Calatayud, and afterwards in a south-eastern direction along the high grounds which form the right bank of the river Jiloca, which gradually rise into mountains near the town of Montalban, whence tho moun tain chain continues to the boundary between Aragon and Valencia. Thence the edge of the table-land runs southward along the elevated ridge which extends east of the river Turia, or Ouadalaviar. It crosses this river north of Requena, and afterwards the river Juear below its confluence with the Cabriel, and then continues southward, leaving the town of Alisiansa to the west, to the vicinity of Villcca. South of the Jucar the edge of the table-land is not marked by a continuous ridge, though some isolated mountains occur along it. Near Villena is the Sierra del earache, which runs first south-west, and afterwards north-west, to the neighbourhood of Albacete (39° N. lat., 1° 55' W. long.). The Sierra del earache seems to rise only a little above the table-land, but it presents a considerable ascent from the deep valley of the Segura, and that of the Mundo, a tributary of the Segura. Along the southern border of the table-land extends that range, or rather mountain region, which is called Sierra Morena. [A2vner.ucte.] Other mountain ranges occur on the table-land itself. Ono of them constitutes a continuous range, traversing the plain in all its extent from east to west. It begins on the east near the high summit of the Sierra de Moncayo, and extends in a west-south-west direction through Castilla la Vieja, separates the province of Leon from Extremadura, and then passes into Portugal. [CeszthLe Le Viz.re.] The table-land of Castilla in Nueva and Estremadura comprehends these two provinces, with the south-western districts of Aragon and the northern part of Murcia. The surface is much more diversified by hills and mountains than that of the northern plain. The mountain chains are of considerable extent, but they do not form continuous ranges, being interrupted by several depressions, which sink nearly to the level of the country. In the eastern districts of the table-land is the Sierra Molina, which begins north-west of the town of Molina, and south of the coufluence of the Jiloca with the Jalon, in 41° N. lat. and 1' 30' W. long. It does not appear to be connected with the Sierra do Deza by • mountain ridge, but only by high ground. The Sierra de Molina rune eouthward, and does not rise much more than 1000 feet above the general level of the country in the northern parts. Where the rivers Tagna and Turin originate it sends off a branch, the Sierra de Albarracin, which runs south-east between the Turin on the east and the Juear on the west, and extends to the edge of the table land, near the town of Requena. From the sources of the Tagus the Sierra de Molina rune south-west, but near 40° S. lat., west of the town of Cuenca, it turns again to the south, and soon subsides into bills, which are slightly elevated above the level of the country. The Sierra de Molina is of very iucousiderable width, but it constitutes the watershed between the rivers which fall into the Mediterranean and those that run to the Atlantic. West of Cuenca a ridge of low moun tains branches off from the Sierra de Molina, and runs westward, dividing the upper branches of the Tagus from those of the Guadiana. It terminates probably near Tarrancon, east of Aranjuez. Thence to about 4' W. long., where the Sierra de Toledo seems to take its rise, the watershed between the Tagus and Guadiana Is formed by high ground broken into steep hills. The Sierra de Toledo extends to 5° W. long., running east and went; but we are very imperfectly acquainted with this ridge. It does not appear to occupy a great width, nor to rise more than 1000 feet above the plain. It is not traversed by auy road. Near 5° W. long. it sinks down to the level of the plain, but another range rises out of it., called the Sierra de Guadalupe, which extends westward to the boundary of Portugal, and enters that kingdom, where it is called Sierra de Portalegre. The Sierra del Guadalupe resembles the Sierra Morena more than the Mountains of Toledo. It consists of a number of narrow steep ridges, whose general direction is north-east or north-west, and they are sometimes connected by other ridges running east and west, but fre quently unconnected, and separated by fiesta The width of this region is considerable, as it fills nearly the whole tract between the riven Tagus and Guadiana west of 5' W. long. None of the summits attain
a at elevation above the level of the country.
The eastern portion of the tableland of Castilla in Nueva and Estremadura, comprehending the province of Cncncs., the northern districts of Murcia, and the adjacent countries, is the highest part of the table-land, and about 3000 feet above tho level of the sea. The surface is very uneven, with the exception of the higher ground between the river-basins, which in some places extends in plains, and in others is diversified by numerous hills or low ridges. A very 'mall portion of this region, which lies In the valleys along the rivers, and in some depressions of the plain, is under cultivation; the remainder has rather a sterile and very dry soil, and is either quite useless or only used as sheep-walk..
The ceutral region of the table-land is between 3° and 5' W. long It consists of two plains, the Plain of Madrid and Toledo, which lice north of the Mountains of Toledo, and the high broken ground which forms the watershed between the rivers Tagus and Guadiana; and the Plain of La Mancha, which lies to the south. These two plain, are about 2000 feet above the sea-level. The productive powers and the surface of these two plains are nearly the same. The country consist of extensive levels, intersected by short ridges of low hill/ and rocks. It is destitute of trees, except some groves of evergreen oak, which are found near the hills, and plantations of olive-trees and vines near the villages. The level tmcta produce wheat, bnt as part of these tracts are at a great distance from the villages, in whicl alone the farms are situated, a large portion of them is badly culti ...tad, and some tracts are partly overgrown with broom and the flax leaved dapbne (Daphne On (damns).
Tiro western portion of the table-land of Castilla la Nueva and Estremadura comprehends the country from 5' W. long. to the boundary of Portugal, or the province of Estremadura. This country has a very mountainous surface. The ridges of the Sierra de Guada upe cover nearly ell the country between the Tagus and the Guadiana. North of the Tagus several offsets of the Sierra de Oates traverse tho :ountry in a south-western direction. South of the Guadiana several aranches of the Sierra Morena advance within a short distance of the iver. Plains of some extent occur only along the banks of the prin :ipal rivers. They are small on the banks of the Tagus, but rather extensive on those of the Guadiana. The general level of the country te lower than in the plains farther east, as we may infer from the ;:ireumatance that snow and frost are not common in the Sierra de Guadalupe, in which the merino sheep pass the winter without the [east injury in the open air. The productive powers of this region differ greatly in different parts. In the districts north of the Tagus there are wide valleys, containing much level ground, between the ridges of the Sierra do Gate; they have a rich soil, are well cultivated, and yield good crops. The hilly tract between the Tagus and Gua diana is nearly a desert. The summits of the ridges are bare ; their elopes are clothed with forests of the evergreen oak, but the lower parts are destitute oven of bushea. They are never cultivated, but preserved as the pasture-grounds of the merino sheep in winter. The cultivated spots are only found in the narrower valleys, and they are few and of small extent, even in the level country on the banks of the Guadiana, between Merida and Badajoz. To the south of the Gua diana the country improves. At no great distance from the river are plantations of olive-trees, which increase in number as we proceed up the valleys of the Sierra Morena. [CASTILLA LA NUEVA ; ESTEE. MADURA. ] Rain is comparatively scarce on the table-land of Spain. It is stated that the annual quantity on an average does not amount to more than 10 inches, which is partly to be ascribed to the elevation of the more level part of the table-land, and partly to the circumstance that it is in most parts bounded by mountains which rise considerably above the general level of the plain, and prevent the moisture from reaching the flat country. The rain generally falls iu the winter, and only a few showers occur in other seasons. The least quantity of rain falls in the mountain region of the Sierra de Guadalupe, and on the high plains of Cuenca and Murcia, where sometimes eight or nine mouths pass without a drop of rain falling. To this scarcity of rain the want of cultivation is chiefly to be attributed which is observed in the two last-mentioned regions. Iu summer excessive beat, and in winter a great degree of cold, are experienced.