340. -- VOLCANO OF JORULLO. 
quent. The Indians, who had abandoned all the 
villages within thirty miles of it, returned once 
more to their cottages, and advanced towards the 
mountains of Aguasarco and Santa Ines, to con- 
template 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 (Principles 
of Geology, vol. i. p. 379) states, on the authority of 
Captain Vetch, that another eruption happened in 
1819, accompanied by an earthquake, during which 
ashes fell at the city of Guanaxuato, 140 miles dis- 
tant from Jorullo, in such quantities as to lie six 
inches deep in the streets. 
When Humboldt visited this place, the natives 
assured him that the heat of the hornitos had for- 
merly 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, which 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 temperature 
of 126:9°. The Indians give them the names of the 
two rivers which had been engulfed, because in se- 
veral 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 be hollow; but 
Scrope and Lyell find it more suitable to their views 
of volcanic agency to represent the conical form of 
the ground as resulting from the flow of lava over 
the original surface of the plain. 
The Indians of this province are represented as 
being the most industrious of New Spain. They 
