228 COSMOS. 



cheerful, or a stern and magnificent character, according as 

 they are adorned with vegetation or surrounded by a dreary 

 barrenness. I have quite recently endeavored to bring to- 

 gether in a separate atlas a number of outlines of the Cordil- 

 leras of Quito and Mexico, sketched from my own drawings. 

 As basalt occurs sometimes in conical domes somewhat 

 rounded at the summit, sometimes in the form of closely- 

 arranged twin-mountains of unequal elevation, and some- 

 times in that of a long horizontal ridge bounded at each ex- 

 tremity by a more elevated dome, so we principally distin- 

 guish in trachyte the majestic dome form* (Chimborazo, 

 21,422 feet), not to be confounded with the form of the un- 

 opened but less massive bell-shaped mountains. The con- 

 ical form is most perfectlyt exhibited in Cotopaxi (18,877 

 feet), and next to this in Popocatepetl^: (1-7,727 feet), as seen 

 on the beautiful shores of the lake of Tezcuco, or from the 

 summit of the ancient Mexican step-pyramid of Cholula ; 

 and in the volcano of Orizaba§ (17,374 feet; according to 

 Ferrer, 17,879 feet). A strongly truncated conical form|| is 

 exhibited by the Nevado de Cayambe-Urcu (19,365 feet), 

 which is intersected by the equator, and by the volcano of 

 Tolima (18,129 feet), visible above the primeval forest at 

 the foot of the Paramo de Quindiu, near the little town of 

 Ibague.^ To the astonishment of geognosists an elongated 

 ridge is formed by the volcano of Pichincha (15,891 Teet), at 

 the less elevated extremity of which the broad, still ignited 

 crater** is situated. 



Fallings of the walls of craters, induced by great natural 

 phenomena, or their rupture by mine-like explosion from the 



* Humboldt, Umrisse von Vulkanen der Cordillerm von Quito una 

 Mexico, ein Beitrag zur Physiognomik der Natur, Tafel iv. (^Kleinere 

 Schrifien, bd. i., s. 133-205). 



f Umrisse von Vulkanen, Tafel vi. 



X Op. cit. sup., Tafel viii. (Kleinere Schri/ten, bd. i., s. 463-467). On 

 the topographical position of Popocatepetl (smoking mountain in the 

 Aztec language), near the (recumbent) White woman, Iztaccihuatl, 

 and its geographical relation to the western lake of Tezcuco and the 

 pyramid of Cholula situated to the eastward, see my Atlas Geogra- 

 phique et Physique de la JVouvelle Espagne, pi. 3.- 



§ Umi-isse von Vulkanen., Tafel ix. ; the Star-mountain, in the Aztec 

 language Citlaltepetl; Kleinere Schriften, bd. i., s. 467-470, and my 

 Aths Geogr. et Phys. de la Nouvelle Espagne, pi. 17. 



II Umrisse von Vtdkanen, Tafel ii. 



^ Humboldt, Vnes des Cordillercs et Monumens des peuples indigenes 

 de VAmerique (fol.), pi. Ixii. 



** Umrisse von Vulkanen, Tafel i. and x. {Kleinere Schriften, bd. i., 

 s. 1-99). 



