OF HEAT. 151 



earthquake, the escape is by one rent, or many 

 rents. The difference between the eruption of the 

 volcano, and the shock of the earthquake, 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 load report may raise a few 

 fragments, and send them to a considerable dis- 

 tance, but it is the smouldering shot that tears 

 the rock to pieces. Just so, the volcano may 

 raise to the summit of the loftiest mountain, from 

 a great depth in the earth, a vast mass of mate- 

 rials, and according as those materials may hap- 

 pen to be, it may pour over the mountain, and 

 even over the surrounding country, 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 elevations 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 specimen 

 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 curd- 

 ling, and creeping more and more slowly; but 

 still so terrible in its heat, that all the vegetation 

 is on fire, and the abodes of mankind crumbling 

 into powder at a considerable distance before its 

 march of terrific desolation. So also, if it is 



