52 M. Humboldt's Account of the 



ous noise recommenced. The affrighted Indians fled to the 

 mountains of Aguasarco. A tract of ground from three to four 

 square miles in extent, which goes by the name of Malpays, rose 

 up in the shape of a bladder. The bounds of this convulsion 

 are still distinguishable in the fractured strata. The Malpays 

 near its edges is only 39 feet above the old level of the plain 

 called the playas de Jorullo ; but the convexity of the ground 

 thus thrown up increases progressively towards the centre to 

 an elevation of 524 feet. See Plate I. Fig. 6. 



Those who witnessed this great catastrophe from the top 

 of Aguasarco assert that flames were seen to issue forth for 

 an extent of more than half a square league, that fragments 

 of burning rocks were thrown up to prodigious heights, and 

 that, through a thick cloud of ashes, illumined by the volcanic 

 fire, the softened surface of the earth was seen to swell up like 

 an agitated sea. The rivers of Cuitamba and San Pedro pre- 

 cipitated themselves into the burning chasms. The decom- 

 position of the water contributed to invigorate the flames, 

 which were distinguishable at the city of Pascuaro, though 

 situated on a very extensive table land 1400 metres (4592 feet) 

 elevated above the plains of las playas de Jorullo. Erup- 

 tions of mud, and especially of strata of clay, enveloping balls 

 of decomposed basaltes in concentrical layers, appear to indi- 

 cate, that subterraneous water had no small share in produc- 

 ing this extraordinary revolution. Thousands of small cones, 

 from two to three metres (from 6.5 feet to 9-8 feet) in height, 

 called by the indigenes ovens (hornitos,) issued forth from the 

 Malpays. Although within the last fifteen years, according 

 to the testimony of the Indians, the heat of these volcanic 

 ovens has suffered a great diminution, I have seen the ther- 

 mometer rise to 95° (202° of Fahrenheit) on being plunged in- 

 to fissures which exhale an aqueous vapour. Each small cone 

 is a fumarola, from which a thick vapour ascends to the 

 height of ten or fifteen metres. In many of them a subter- 

 raneous noise is heard, which appears to announce the proxi- 

 mity of a fluid in ebullition. 



In the midst of the ovens six large masses, elevated from 

 4 to 500 metres (from 312 to 1640 feet) each above the old 

 level of the plains, sprung up from a chasm, of which the di- 



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