VOLCANO OF JORULLO. 



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THE VOLCANO OF JORULLO 



" Six volcanic cones, composed of scoriae and fragmentary lava, 

 were formed on the line of a chasm which ran in a direction from 

 N. N. E. to S. S. W. The least of these cones was 300 feet in 

 height, and Jorullo, the central volcano, was elevated 1,600 feet 

 above the level of the plain. It sent forth great streams of basal- 

 tic lava, containing included fragments of rocks, and its ejections 

 did not cease till the month of February, 1760. 



" Humboldt visited the country more than forty years after this 

 occurrence, and was informed by the Indians, that when they re- 

 turned, long after the catastrophe, to the plain, they found the 

 ground uninhabitable from the excessive heat. When he himself 

 visited the place, there appeared around the base of the cones, and 

 spreading from them, as from a centre, over an extent of four square 

 miles, a mass of matter of a convex form, about 550 feet high at its 

 junction with the cones, and gradually sloping from them in all 

 directions towards the plain. This mass was still in a heated state, 

 the temperature in the fissures being on the decrease from year to 

 year, but in 1780 it was still sufficient to light a cigar at the depth 

 of a few inches. On this slightly convex protuberance, the slope 

 of which must form an angle of about 6° with the horizon, were 

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