Despumant flammis urgentibus
ignei rivi pigro fluxu totas delambentes plagas, et in lapidem indurescunt."
Cones of eruption are sometimes uplifted on these fissures; the larger ones,
which are erroneously termed 'new volcanoes', are ranged together in line
marking the direction of a fissure, which is soon reclosed, while the
smaller ones are grouped together covering a whole district with their
dome-like or hive-shaped forms. To the latter belong the 'hornitos de
Jorullo',I the cone of Vesuvius erupted in October, 1822, that of Awatscha,
according to Postels, and those of the lava-field mentioned by Erman, near
the Baidar Mountains, in the peninsula of Kamtschatka.
[footnote] See my drawing of the volcano of Jorullo, of its 'hornitos', and
of the uplifted 'malpays', in my 'Vues de Cordilleres', pl. xliii., p. 239.
[Burckhardt states that during the twenty-four years that have intervened
since Baron Humboldt's visit to Jorullo, the 'hornitos' have either wholly
disappeared or completely changed their forms. See 'Aufenthalt und Reisen
in Mexico in 1825 und 1834'.] -- Tr.
When volcanoes are not isolated in a plain, but surrounded, as in the double
chain of the Andes of Quito, by a table-land having an elevation from nine
to thirteen thousand feet, this circumstance may probably explain the cause
why no lava streams are formed* during the most dreadful eruption of ignited
scoriae accompanied by detonations heard at a distance of more than a
hundred miles.
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