290 VOLCANO OF JORULLO. 



CHAP.xxiii. tinually burning. The eruptions of this central volcano 

 rnipTions of continued till February 1760, when they became less 

 joruUo. frequent. The Indians, who liad abandoned all the 

 villages within thirty miles of it, returned once more to 

 their cottages, and advanced towards the mountains of 

 Aguasarco and Santa Incs, to contemplate the streams 

 of fire that issued from the numberless apertures. The 

 roofs of the houses of Queretaro, more than 166 miles 

 distant, were covered with volcanic dust. Mr Lyell 

 (Princij)les of Geology, vol. i. p. 379) states, on the 

 authority of Captain Vetch, that another eruption hap- 

 j)ened in 1819, accompanied by an earthquake, during 

 which ashes fell at the city of Guanaxuato, 140 miles 

 distant from Jorullo, in such quantities as to lie six 

 inches deep in the streets.* 

 Rise of tiie When Humboldt visited this place, the natives assured 

 thermome- him that the heat of the hornitos had formerly been 

 much greater. The thermometer rose to 203° when 

 placed in the fissures exhaling aqueous vapour. Each 

 of the cones emitted a thick smoke, and in many of them 

 a subterranean noise was heard, wliich seemed to indicate 

 the proximity of a fluid in ebullition. Two streams 

 were at that period seen bursting through the argillaceous 

 vaults, and were found by the traveller to have a tem- 

 perature of 1 26'9°. Tlie Indians gave tliem the names 

 Rivers ^^ tlie two rivers Avhich had been engulfed, because in 



eiiguiphei several parts of the Malpais great masses of water are 

 heard flowing in a direction from east to west. Our 

 author considers all the district to he hollow ; but 

 Scrope and Lyell find it more suitable to their views of 

 volcanic agency to represent the conical form of the 



• In the fourth edition (Lond. 1835) of his Principles, Mr Lyell 

 saj's, that there appears to liave been some mistake in this state- 

 ment ; fur iMr IJiirkait, w!io examined Jorullo in l!i27, ascertained 

 that there had been no eruption there since Humboldt's visit in 

 IHOIJ. Tliere was still a slij^lit evolution of sul[)hurous acid vapours 

 from the bottom of the crater; but the "hornitos" had ceased to 

 send forth steam, and vegetation liad made great progress on the 

 Hanks of the new hills, the rich soil of the surrounding country being 

 once more covered with luxuriant crops of sujjar-cane and indigo. 



