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never ha\"e eruptions, but which were active at one 

 time are called extinct volcanoes. The interior of 

 these great mountains o£ fire, or the mouth is called a 

 crater, which in some places is immensely large. The 

 crater of Mt. Vesuvius is one of the largest in existence. 

 There is gi'eat danger in approaching these, especially 

 after an eruption. The material which has been 

 thrown out, though appearing to be cold, is so intense- 

 ly hot as to burn the shoes of a person walking upon 

 it. The substances usually thrown from these volca- 

 noes are lava, (melted rock), fire, smoke and sometimes 

 large stones, which are thrown violently to a great 

 height. Showers of ashes are also frequent, being 

 thrown u]3 to settle down on surrounding objects. Lava 

 is the chief substance discharged, and the quantity is 

 sometimes so great as to entirely bury villages and 

 towns, the inhabitants perishing unless succeeding in 

 escaping to some elevated position where .the fire and 

 smoking lava cannot reach them. Cities which have 

 been thus buried in former times are afterwards dug 

 into, or in other ways discovered, and the houses and 

 contents are sometimes found in the exact state in 

 which the terrified owners left them. Many and curi- 

 ous relics have been found in these underground cities. 

 The great destruction which came upon Pompeii from 

 volcanic eruption is familiar to many, it being one of 

 the many flourishing towns which have met the same 

 fate, and in which so many people lost their lives. A 

 vivid picturing of the city and the terrible inundation 

 of lava may be viewed at Fairmount Park, Philadelphia. 



