GEOGRAPHICAL RELATIONS OF MEXICO. 295 



south-east of the port of Vera Cruz, is the narrowest part ; Chap.xxiv 



the distance from the Atlantic Ocean to the South Sea t ^^ ^ 



istntniis of 



being there only 155 miles. The question of opening a Panama 

 communication by a canal between the two oceans at ^^"^^ 

 this point, the isthmus of Panama, or several others 

 which he mentions, is fully discussed by the author. 

 He discredits the idea that the level of the South Sea is 

 higher than that of the Gulf of Mexico, and imagines 

 tliat were a rupture of the intervening barrier effected^ 

 the current would establish itself in the direction 

 opposite to that usually apprehended. 



When a general view is taken of the whole surface of Sub(ii\'isions 

 Mexico, it is seen that one-half is situated within the ° ^^"^°" 

 tropic, while the rest belongs to the temperate zone. 

 This latter portion contains 716,100 square miles. The 

 physical climate of a country does not altogether depend 

 upon its distance from the pole, but also upon its eleva- 

 tion, its proximity to the ocean, and other circumstances ; 

 so that of the 596,750 square miles in the torrid zone, 

 more than three-fifths have a cold, or at least temperate 

 atmosphere. The whole interior of Mexico, in fact, 

 constitutes an immense table-land, having an elevation 

 which varies from 6562 to 8202 feet above the level of 

 the sea. 



The chain of mountains which forms this vast plain is Mexican 

 continuous with the Andes of South America. In the ^ ® 

 southern hemisphere tlie cordillera is every where broken 

 up by fissures or valleys of small breadth ; but in Mexico 

 it is the ridge itself that constitutes the platform. In 

 Peru the most elevated summits form tlie crest of the 

 Andes, while in the other the prominences are irregu- 

 larly scattered over the plain, and have no relation or 

 parallelism to the direction of the cordillera. In Peru Transversa 

 and New Grenada there are transverse valleys, having^ ^^^ 

 sometimes 4590 feet of perpendicular depth, which en- 

 tirely prevent the use of carriages ; while in New Spain 

 vehicles are used along an extent of more than 1726 

 miles. The general height of the table-land of Mexico is 

 equal to that of Mount Cenis, St Gothard, or the Great 



