ON ITS EXTERIOR. VOLCANOES. 257 



The one of the Cape de Verde Islands which rises be- 

 tween S. lago and Brava had early received from the 

 Portuguese the name of Ilha do Fogo, because, like 

 Stromboli, it incessantly emitted fire ; and it continued 

 to do so from 1680 to 1713. After a long interval of 

 repose, this volcano was rekindled in the summer of 

 1798, a short time after the last lateral outbreak of the 

 Peak of Teneriffe in the crater of Chahorra, which crater 

 was erroneously named, as if it had been a distinct 

 mountain, the " Volcano of Chahorra." 



The most active of all the volcanoes of South America, 

 and indeed of all those which I have here enumerated, 

 is Sangay; also called Volcan de Macas, because the 

 remains of the ancient and, at the time of the Conquista, 

 populous city of that name are situated only twenty- 

 eight miles to the south of it, on the Eio Upano. This 

 colossal mountain, 17,124 feet high, has been elevated 

 on the eastern declivity of the Eastern Cordillera, be- 

 tween two systems of tributaries to the Great Kiver of 

 the Amazons, i.e. the river-systems of the Pastaza and 

 of the Upano. The great an4 incomparable igneous 

 phenomenon now presented by this volcano would appear 

 to have only begun in 1728. In the measurement of 

 an arc of the meridian by Bouguer and La Condamine 

 (1738 to 1740), Sangay served them as a perpetual fire 

 signal. ( 382 ) I myself heard its thunder for months in 

 1802 (particularly in the early morning) from Chillo 

 near Quito, the pleasant country seat of the Marques 

 de Selvalegre, as, half a century before, Don Jorge Juan 

 had heard " the ronquidos del Sangay " from a point 

 rather more to the north-east, near Pintac at the foot of 

 Antisana. ( 383 ) In the years 1842 and 1843, when the 



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