650 THE UNIVERSE. 



crown their craters, their enaptions produce impetuous 

 torrents, which, precipitating theniselves,'*lDear with them 

 smoking scoria?, fragments of rock, and blocks of ice. 



At a great distance most volcanoes look just like 

 pointed cones vomiting flames or vapours by a very narrow 

 fissure. But wdien jmtience and courage have carried us 

 to the rugged crests of their burning mouths, or when we 

 have penetrated their sides, we are astonished at the scenes 

 of grandeur Avhich present themselves to our eyes in the 

 midst of these frightful and dangerous abysses, where the 

 heat and deleterious gases threaten to suffocate the tra- 

 veller. I had felt astonished at the dimensions of the 

 ancient craters of France and Ital}-, the one filled up Avith 

 lakes, the other transformed into forests. I experienced 

 the same feehng in exploring Vesuvius and Etna; but 

 nothing in their fiery mouths can be compared with what 

 is found in America. The immense crater of Orizaba, 

 according to Baron MilUer, is not less than 6000 metres 

 (19,725 feet) in circumference. Persons standing on the 

 opposite sides of it are almost invisible to each other. 



On another mountain in Mexico we find again a crater of 

 very remarkable dimensions, that of Popocatepetl. Placed 

 on the summit of a crest in the Cordilleras, from whence 

 can be seen at the same time the two seas which bathe 

 America, and in the distance INIexico encircled by its fairy 

 lake, this crater, which is nearly circular, is, according to 

 M. Boscovitz, 5000 feet in its longest diameter. The 

 gullet of this giant has never l:)een disturbed since the 

 discovery of the New World; but in former times it must 

 have thrown out flames abundantly, as thick beds of its 

 ashes are found for more than twenty leagues round about. 

 Where it has heen possible for them to accumulate, their 

 mass sometimes displays a depth of more than fifty metres 



