VOLCANOES OF JORUI.f.O. ' 83 



They who witnessed this grand catastrophe from the top The event de- 

 of Aguasarco assert, that they saw flames issue out of the Stnbed * 

 ground for the space of more than half a league square; 

 that fragments of red hot rocks were thrown to a prodigious 

 height : and that through a thick cloud of ashes, illumined 

 by the volcanic tire, and resembling a stormy sea, the soft- 

 ened crust of the earth was seen to swell up. The rivers 

 of Cuitiroba and San Pedro then precipitated themselves 

 into the burning- crevices. The decomposition of the water 

 contributed to reanimate the flames, which were percepti- 

 ble at the city of Pascuoro, though standing- on a very wide 

 plain 1400 met. [1530 yards] above the level of the playas 

 de Jorullo. Eruptions of mud, particularly of the strata 

 of clay including decomposed nodules of basaltes with con- 

 centric layers, seem to prove, that subterranean waters had 

 no small part in this extraordinary revolution. Thousands 

 of small cones, only two or three yards high, which the 

 Indians call ovens, issued from the raised dome of the Mal- 

 pays. Though the heat of these volcanic ovens has dimi- 

 nished greatly within these fifteen years, according to the 

 testimony of the Indians, I found the thermometer rise to 

 95° [if centig. 203° F.] in the crevices that emitted an 

 aqueous vapour. Each little cone is a chimney, from which 

 a thick smoke rises to the height of ten or fifteen met. [l I 

 or 16 yards]. In several a subterranean noise is heard like 

 that of some fluid boiling at no great depth. 



Amid these ovens, in a fissure, the direction of which is six large hills 

 from N. N. E. to S. S. E., six large hummocks rise 400 in one line * 

 or 500 met. [440 or 550 yards] above the old level of the 

 plain. This is the phenomenon of Monte Novo at Naples 

 repeated several times in a row of volcanic hills. Tie lof- 

 tiest of these huge hummocks, which reminded me of the 

 country of Auvergne, is the large volcano of Jorullo. It 

 is constantly burning, and has thrown out on the north side 

 an immense quantity of scorified and basaltic lava, includ- 

 ing fragments of primitive rocks. These grand eruptions 

 of the central volcano continued till February, 176*0. In 

 the succeeding years they became gradually less frequent. 

 The Indians, alarmed by the horrible noise of the new vol- 

 cano, at first deserted the villages for seven or eight leagues 



G 2 round 



