22 A Journey in Spain [Jan. 



The tertiary layers are observed thick at Briviesca in Old 

 Castile, and in the undulating plain to the south of Madrid, 

 and at Cuesta de la Reyna, on the sides of the great cut 

 which exists in this plain near Aranjuez, where the Tagus 

 and Jarama unite. The sea in which these tertiary forma- 

 tions are deposited appears to have extended in the direction 

 from Bayonne to Cadiz over Aragon, and to have commu- 

 nicated with the Mediterranean by an opening across the 

 mountains of Valencia and Catalonia, which was probably 

 the ancient strait of Gibraltar. The southern part of Spain 

 seems to have been only recently disjoined from Africa. 

 The epoch of the elevation of Central Spain is referred by 

 Le Play to that of the principal chain of the Alps ; the na- 

 ture of the soil, the directions of the chains of mountains, 

 the course of the rivers, the stratification of the rocks, 

 being sufficient traces of a revolution contemporaneous 

 with the appearance of the ophites. 



The Sommo Sierra chain, whose summits are clad with 

 snow during the whole year, is almost entirely composed of 

 granite, which has broken a thick layer of gneiss and mica 

 slate, at some remote period. 



No trees adorn the desolate plain which extends from 

 Sommo Sierra to Madrid; and no symptom of an approach- 

 ing capital is observed until the traveller fairly reaches 

 Madrid, which forms a perfect oasis. Over the small stream 

 Manzanares, an elegant bridge conducts to the capital of 

 Spain. Here the only object of interest is a cabinet of 

 natural history, derived from Spain and its colonies, but 

 arranged according to the systems extant in the reign of 

 Charles III. 



Within a few years Government have instituted a school 

 of mines, which although well supported in some of its 

 departments, with the exception of a considerable library, 

 collections of minerals and apparatus, is defective in the 

 necessary means for instructing students. 



The great plains which extend from the Tagus to the 

 mountains of Guadarrama, consist of clay and sand. The 

 greatest part is uncultivated; but the abundant natural 

 harvest of lavender and leguminous plants, is a sufficient 

 proof of the fertility of the soil. At Talavera, however, the 

 soil is richly cultivated, and the numerous aqueducts which 



