154 ACTION 



general principle in this has been already noticed 

 and illustrated at some length in the case of water, 

 but there are still more magnificent displays of the 

 triumph of heat over matter, which take place on 

 the great scale. Volcanoes, whether under the dry 

 land or the sea, are instances of that kind of action, 

 and so also are earthquakes ; and the chief difference 

 between these is, that in the volcano the heat drives 

 the expanding matters through one aperture, while 

 in the case of the earthquake, the escape is by one 

 rent or many rents. The difference between the 

 eruption of the volcano and the shock of the earth- 

 quake very much resembles that between shots 

 which " blow out" with a loud report and shots that 

 smoulder, in the blasting of rocks. 



The shot with the loud report may raise a few 

 fragments, and send them to a considerable distance, 

 but it is the smouldering shot that tears the rock to 

 pieces. Just so the volcano may raise to the sum- 

 mit of the loftiest mountain, from a great depth in 

 the earth, a vast mass of materials, and according as 

 those materials may happen to be, it may pour over 

 the mountain, and even over the surrounding coun- 

 try, a deluge of boiling water, or boiling mud ; or it 

 may cast red-hot stones and cinders, and volley 

 masses the size of little hills, red-hot, to great ele- 

 vations in the air, from which they may descend 

 with crashes like thunder ; it may turn day into night 

 by clouds of ashes in the air, and those clouds may 

 fall (as they have fallen) upon cities, and bury them 

 and all their inhabitants, or they may be wafted 

 across the seas and produce disease and famine in 

 other countries ; or the mountain may give a speci- 

 men of the mode in which nature can play the 

 founder, and after the most stubborn strata of the 

 earth have been molten, the fiery flood may be 

 poured from the mighty crucible, roll down the slope, 

 and proceed over the country, tumbling and curdling, 

 and creeping more and more slowly ; but still so 



