TRUE VOLCANOES. 229 



depths of the interior, produce remarkable and contrasting 

 forms in conical mountains : such as the cleavage into dou- 

 ble pyramids of a more or less regular kind in the Carguai- 

 razo (15,667 feet), which suddenly fell in* on the night of 

 the 19th July, 1698, and in the still more beautiful pyra- 

 midsf of Ilinissa (17,438 feet); and a crenulation of the up- 

 per walls of the crater, in which two very similar peaks, op- 

 posite to each other, betray the previous primitive form (Ca- 

 pac-Urcu, Cerro del Altar, now only 17,456 feet in height). 

 Among the aborigines of the highlands of Quito, between 

 Chambo and Lican, between the mountains of Condorasto 

 and Cuvillan, the tradition has been universally preserved 

 that fourteen years before the invasion of Huayna Capac the 

 son of the Inca Tupac Yupanqui, and after eruptions which 

 lasted uninterruptedly for seven or eight years, the summit 

 of the last-mentioned volcano fell in, and covered the entire 

 plateau, in which New Riobamba is situated, with pumice- 

 stone and volcanic ashes. The volcano, originally higher 

 than Chimborazo, was called, in the Inca or Quichua lan- 

 guage, capac, the king or prince of mountains (urcu\ becausfe 

 the natives saw its summit rise to a greater height above the 

 lower snow-line than that of any other mountain of the 

 neighborhood.! The great Ararat, the summit of which 



* Umrisse von Vulkanen, Tafel iv. 



t Ibid., Tafel iii. and vii. 



j Long before the visit of Bouguer and La Condamine (1736) to the 

 plateau of Quito, long before any measurements of the mountains by 

 astronomers, the natives knew that Chimborazo was higher than any 

 other Nevado in that region. They had detected two lines of level 

 which remained almost exactly the same all the year round that of 

 the lower limit of perpetual snow, and that of the elevation to which 

 a single, occasional snow-fall reached down. As in the equatorial re- 

 gion of Quito, the snow-line, as I have proved by measurements else- 

 where (Asie Centrale, t. iii., p. 255), only varies about 190 feet in eleva- 

 tion on six of the most colossal peaks ; and as this variation, as well as 

 smaller ones caused by local conditions, is imperceptible to the naked 

 eye when seen from a great distance (the height of the summit of 

 Mont Blanc is the same as that of the lower equatorial snow-limit), 

 this circumstance gives rise within the tropics to an apparently unin- 

 terrupted regularity of the snowy covering, that is to say, .the form of 

 the snow-line. The pictorial representation of this horizontally is as- 

 tounding to the physicists who are only accustomed to the irregularity 

 of the snowy covering in the variable, so-called temperate zones. The 

 uniformity of elevation of the snow about Quito, and the knowledge of 

 the maximum of its oscillation, presents perpendicular bases of 15,777 

 feet above the surface of the sea, and of 6396 feet above the plateau 

 in which the cities of Quito, Hambato, and Nuevo Riobamba are situ- 

 ated; bases which, combined with very accurate measurements of 



