Eruption of the Volcano of Jorullo. 53 



rection is from the N.N.E. to the S.S.E. This is the phe- 

 nomenon of the Montenovo of Naples, several times repeated 

 in a range of volcanic hills. The most elevated of these enor- 

 mous masses, which bears some resemblance to the pays de 

 fAuvergne, is the great Volcan de Jorullo. It is continually 

 burning, and has thrown up from the north side an immense 

 quantity of scorified and basaltic lavas, containing fragments 

 of primitive rocks. These great eruptions of the central vol- 

 cano continued till the month of 1760. In the following 

 years they became gradually less frequent. The Indians, 

 frightened at the horrible noises of the new volcano, abandon- 

 ed, at first, all the villages situated within seven or eight 

 leagues distance of the playas de Jorullo. They became 

 gradually, however, accustomed to this terrific spectacle ; and, 

 having returned to their cottages, they advanced towards the 

 mountains Aguasarco and Santa Ines, to admire the streams 

 of fire discharged from an infinity of great and small volcanic 

 apertures. The roofs of the houses of Queretaro were then 

 covered with ashes at a distance of more than 48 leagues in a 

 straight line from the scene of the explosion. Although the 

 subterraneous fire now appears far from violent,* and the 

 Malpays, and the great volcano, begin to be covered with 

 vegetables, we, nevertheless, found the ambient air heated to 

 such a degree by the action of the small ovens (Jiornifos,) that 

 the thermometer, at a great distance from the surface, and in 

 the shade, rose as high as 48° (109° of Fahrenheit.) This 

 fact appears to prove, that there is no exaggeration in the ac- 

 counts of several old Indians, who affirm that, for many 

 years after the first eruption, the plains of Jorullo, even 

 at a great distance from the scene of the explosion, were 

 uninhabitable, from the excessive heat which prevailed in 

 them. 



The traveller is still shown, near the Cerro de Santa Ihes, 

 the rivers of Cuitamba and San Pedro, of which the limpid 



* We found, in the bottom of the crater, the air at 116°, 1.30°, and 

 139° of Fahrenheit. We passed over crevices which exhaled a sulphu- 

 reous vapour, in which the thermometer rose to 185 Fahrenheit. The pas- 

 sage over these crevices and heaps of scoria, which cover considerable hol- 

 lows, render the descent into the crater very dangerous. 



