TRUE VOLCANOES. 249 



crater of elevation (Monte Nnovo) in the Phlcgrocan Fields, 

 to which Scacchi* ascribes a height of 432 feet from accu- 

 rate measurement. The permanent activity of the volcano 

 of Izalco, which was long considered as a safety-valve for 

 the neighborhood of San Salvador, did not, however, pre- 

 serve the town from complete destruction on Easter eve in 

 this year (185-1). 



One of the Cape Verd Islands, which rises between S. Jago 

 and Brava, early received from the Portuguese the name of 

 Jlha do Fogo, because, like Stromboli, it produced fire unin- 

 terruptedly from 1G80 to 1713. After a long repose, the 

 volcano of this island resumed its activity in the summer of 

 the year 1798, soon after the last lateral eruption of the 

 Peak ofTeneriffc in the crater of Chahorra, which is errone- 

 ously denominated the volcano of Chahorra, as if it were a 

 distinct mountain. 



The most active of the South American volcanoes, and 

 indeed of all those which I have here specially indicated, is 

 the Sangay, which is also called the Volcan de Mams, be- 

 cause the remains of this ancient city, so populous in the 

 early period of the Conquista, are situated upon the Rio 

 Upano, only 28 geographical miles to the south of it. The 

 colossal mountain, 17,128 feet in height, has risen on the 

 eastern declivity of the eastern Cordillera, between two sys- 

 tems of tributaries of the Amazons, those of the Pastaza and 

 the Upano. The grand and unequaled fiery phenomenon 

 which it now exhibits appears only to have commenced in 

 the year 1728. During the astronomical measurements of 

 degrees by Bouguer and La Condamine (1738 to 1740), the 

 Sangay served as a perpetual fire signal. f In the year 

 1802, I myself heard its thunder for months together, espe- 

 cially in the early morning, in Chillo, the pleasant country 

 seat of the Marquis de Selvalegre near Quito, as half a cen- 

 tury previously Don Jorge Juan had perceived the ronquidos 

 del Sangay, somewhat further toward the northeast, near 

 Pintac, at the foot of the Antisana.J In the years 1842 



* Memorie geologiche sulla Campania, 1849, p. Gl. I found the 

 height of the volcano of Jorullo to be 1GS2 feet above the plain in 

 which it rose, and 42G6 feet above the sea-level. 



f La Condamine, Journal du Voyage a t Equateur, p. 163 ; and in 

 the Mesure de Trois Degres de la Mcridienne de V Hemisphere Austral., 

 p. 56. 



X In the country house of the Marquis of Selvalegre, the father of 

 my unfortunate companion and friend, Don Carlos Montufar, one was 

 often inclined to ascribe the Iramidos, which resembled the discharge 



L2 



