VOLCANO OF JORULLO, 



289 



Autumnal 

 raius. 



Volcano. 



Mechoacan ; and, notwithstanding a continuance of criAP.xxill 



heavy autumnal rains, descended by Patzquaro, which 



is situated on the edge of an extensive lake towards the 



shores of the Pacific Ocean, to the plains of Jorullo. 



Here they entered the great crater, making their way 



over crevices exhaling ignited sulphuretted hydrogen, 



and experiencing much danger from the brittleness of 



the lava. 



The formation of this volcano is one of the most ex- 

 traordinary phenomena which have been observed on 

 our globe. The plain of Malpais, covered with small 

 cones from six to ten feet in height, is part of an elevated 

 table-land bounded by hills of basalt, trachyte, and 

 volcanic tufa. From the period of the discovery of 

 America to the middle of the last century, this district 

 had undergone no change of surface, and the seat of the 

 crater was then covered with a plantation of indigo and 

 sugar-cane ; when, in June 1759, hollow sounds were 

 heard, and a succession of earthquakes continued for 

 two months, to the great consternation of the inhabitants. 

 From the beginning of September every thing seemed to 

 announce the re-establishment of tranquillity ; but in 

 the night of the 28th the frightful subterranean noises 

 again commenced. The Indians fled to the neighbouring 

 mountains. A tract not less than from three to four volcanic 

 square miles in extent rose up in the shape of a dome ; action, 

 and those who witnessed the phenomenon asserted, that 

 flames were seen issuing from a space of more than six 

 square miles, while fragments of burning rocks were 

 projected to an immense height, and tlae surface of the 

 ground undulated like an agitated sea. Two brooks 

 which watered the plantations precipitated themselves 

 into the burning chasms. Thousands of the small cones 

 described above suddenly appeared, and in the midst of 

 these eminences, called hornitos or ovens, six great masses, 

 having an elevation of from 1312 to 1640 feet above the 

 original level of the plain, sprung up from a gulf running 

 from N.N.E. to S.S.W. The most elevated of these 

 mounds is the great volcano of Jorullo, which is con- 



