GEOLOGY. 623 



missionaries of America saw in the b limine; mountains of 

 the New World, not the hand of God, but the hand of Satan, 

 and went in procession to the edges of their craters in order 

 to exorcise them. The legend says that the monks of Nic- 

 aragua climbed the terrible volcano of Momotombo in order 

 to quiet it by their spells, but never returned, the fire 

 having consumed them." 



Many countries of our globe, now buried in the most per- 

 fect repose and covered with a vigorous vegetation, were, at 

 an epoch that cannot at present be definitely fixed, every- 

 where convulsed by volcanic fires ; rich harvests now 

 abound where formerly rolled burning streams of lava. 

 Ancient craters now display only grass and moss in the 

 depths of their mouths, which formerly vomited torrents 

 of fire. This spectacle is even met with in the centre of 

 France, in all the mountains of Auvergne. 



Active volcanoes are common at the present time on the 

 surface of the globe. But by this it is not meant that they 

 are agitated by perpetual convulsions. Nearly all awake 

 to their terrible activity only at long intervals, and during 

 the space of time between the eruptions their internal tur- 

 moil is only revealed outwardly by slight and deceptive 

 phenomena. 



Humboldt states the number of active volcanoes at 223 ; 

 Keith Johnston raises it to 270, of which more than the 

 half (190) are comprised in the great volcanic belt which 

 forms almost a circle of fire around the Pacific Ocean. 



When a formidable eruption breaks out it is often accom- 

 panied by dull roars which seem to shake the mountain. In 

 a short time the fiery mouth launches into the air sheets of 



