22 



fifty or sixty toises; but this assertion is founded 

 on no measurement whatever. I am informed, 

 that in the province of Quito also 5 the people, at 

 every period of great commotions, imagine, that 

 the volcano of Tunguragua is diminished in 

 height. — It has been affirmed, in many descrip- 

 tions published of the destruction of Caraccas, 

 " that the mountain of the Silla is an extin- 

 guished volcano ; that a great quantity of vol- 

 canic substances are found on the road from La 

 Guayra to Caraccas * ; that the rocks do not 

 present any regular stratification ; and that every 

 thing bears the stamp of the action of fire/' It 

 is even added, " that, twelve years before the 

 great catastrophe, Mr. Bonpland and myself, 

 from our physical and mineralogical researches, 

 had considered the Silla as a very dangerous 

 neighbour to the city, because that mountain 

 contained a great quantity of sulphur, and that 

 the commotions must come from the North-East." 

 It is seldom that natural philosophers have to 

 justify themselves for an accomplished predic- 

 tion ; but I think it my duty to combat ideas, 



* See the account given by Mr. Drouct of Guadaloupe, 

 translated in the Trans, of New Yorki vol. i, p. 308. The 

 author, in giving to the Silla nine hundred toises of absolute 

 height, has confounded the height of the mountain, in my 

 measurement, above the level of the sea, with its height 

 above the valley of Caraccas, which makes a difference of 

 four hundred and sixty toises. 



