Volcanoes in the different regions of the Earth. 9SS 



Flashes issued from the column of ashes in all directions, and 

 the thunder, which was easily distinguished from the noises of 

 the volcano, was distinctly heard. In no other eruption was 

 the manifestation of the electric powers so astonishing. 



On the morning of the 26th October, a surprising noise was 

 heard, which seemed to arise from a torrent of boiling water that 

 was ejected from the crater, and descended along the declivity of 

 the cone of the ashes. Monticelli, the learned and zealous ob- 

 server of the volcano, immediately discovered that an optical il- 

 lusion had occasioned this erroneous rumour. The supposed 

 torrent was a great heap of dry ashes, which issued from a 

 crevice in the upper edge of the crater. A drought which 

 spread desolation in the fields, had preceded the eruption of Ve- 

 suvius. Toward the end of this phenomenon, the volcanic 

 thunder storm which we have just been describing, occasioned an 

 extremely heavy and long continued rain. In all countries, the 

 cessation of an eruption is characterized by a similar meteor. 

 So long as the present one lasted, the cone of ashes being gene- 

 rally enveloped with clouds, and the rain being heaviest in its 

 vicinity, torrents of mud were seen flowing on all sides. The 

 affrighted husbandman thought it was water, that, after ascend- 

 ing from the bottom of the volcano, issued by the crater. The 

 geologist thought he discovered in it sea water, or muddy 

 productions of the volcano, or, to use the expression of the 

 French old systematic writers, products of an igno-aqueous li- 

 quefaction. 



When the summit of the volcano, as is almost always the case 

 in the Andes, rises above the region of snow, or attains a height 

 double that of Etna, the snow, by melting and flowing toward 

 the lower regions, produces frequent and disastrous inunda- 

 tions. These are phenomena which the meteors connect with 

 the eruptions of volcanoes, and which are variously modified by 

 the height of the mountain, the extent of its summit covered with 

 perpetual snows, and the heating of the walls of the cone of 

 cinders. They cannot at all be regarded as true volcanic phe- 

 nomena, being merely the effects of such phenomena. In vast 

 cavities, sometimes on the dechvity, sometimes at the foot of 

 volcanoes, are found subterranean lakes which communicate in 

 various ways with the alpine torrents. When the commotions 



