84 



inhabitants call the volcano of Temanfaya^ 

 spread desolation over a most fertile and highly 

 cultivated region ; nine villages were entirely 

 destroyed by the lavas. This catastrophe had 

 been preceded by a tremendous earthquake, and 

 for several years shocks equally violent were 

 felt. This last phenomenon is so much the more 

 singular, as it seldom happens at the end of an 

 eruption, when the elastic vapours have found 

 vent by the crater, after the ejection of the 

 melted matter. The summit of the great vol- 

 cano is a rounded hill, but not entirely conic. 

 From the angles of altitude which I took at dif- 

 ferent distances, it's absolute elevation did not 

 appear to exceed three hundred toises. The 

 neighbouring hills, and those of Alegranza and 

 Isla Clara, were scarcely above one hundred or 

 one hundred and twenty toises. We may be 

 surprised at not finding these summits at a 

 greater elevation, which seen at sea wear so 

 majestic a form ; but nothing is more uncertain 

 than our judgment on the greatness of angles, 

 which are subtended by objects close to the ho- 

 rizon. From illusions of this sort it arose, that 

 before the measures * of Messrs. de Churruca 

 and Galleano, at Cape Pilar, navigators con- 

 sidered the mountains of the Straits of Magel- 

 lan, and those of Terra del Fuego, as being ex- 

 tremely elevated. 



* Churruca, Apendice a la Relation del Viaje al Magel- 

 lanes, 1793, p. 76. 



