406 COSMOS. 



The conformation here described of a considerable portion 

 of the surface of the earth, which only began to be established 

 by careful measurements since the year 1803, must not be 

 confounded with those swellings of the soil which are met 

 with enclosed between two mountain- chains which bound 

 them as it were like walls, as in Bolivia at the Lake of 

 Titicaca, and in Central Asia, between the Himalaya and 

 Kuen-lim. The former of these, the South American eleva- 

 tion, which at the same time forms the bottom of a valley, 

 is on an average according to Pentland, 12.847 feet above the 

 level of the sea, the latter, or Thibetian, according to 

 Captain Henry Strachey, Joseph Hooker, and Thomas 

 Thomson, is upwards of 14,996. The wish expressed by 

 me half a century since in my circumstantial " Analyse de 

 T Atlas Geographique et Physique du Hoyaume de la Nouvelle- 

 Espagne ( xiv), that my profile of the elevated plain be- 

 tween Mexico and Guanaxuato might be continued by 

 measurements over Durango and Chihuahua as far as 

 Santa Fe del Nuevo Mexico, is now completely realized. 

 The length of way, reckoning only one-fourth for the inflec- 

 tions, amounts to far more than 1200 geographical miles, and 

 the characteristic feature of this so long unobserved con- 

 figuration of the earth (the soft undulation of the swelling, 

 audits breadth in a transverse section, amounting sometimes 

 to 240 or 280 geographical miles) is manifested by the fact 

 that the distance (from Mexico to Santa Fe), comprising a 

 difference of parallels of fully 16 20 ; about the same as that 

 from Stockholm to Florence, is travelled over in four- 

 wheeled carriages, on the ridge of the table-land, without the 

 advantage of artificially prepared roads. The possibility 

 of such a medium of intercourse was known to the Spaniards 

 so early as the end of the 16th century, when the Viceroy, 

 the Coude de Monterey, 11 planned the first settlements from 

 Zacatecas. 



In confirm ...it-ion of what has been stated in a general way 



11 By Juan de Onate, 1594. Memoir of a Tour to Northern Mexico 

 in 1846 and 1847 by Dr. Wislizenus. On the influence of the con- 

 figuration of the soil (the wonderful extent of the table-land) on the 

 internal commerce and the intercourse of the tropical zone with the 

 north, when once civic order, legal freedom and industry increase ia 

 these parts, see Essai Pol., t. iv., p. 38, and Dana, p. 612. 



