104 volcanoes; earth qu axes. 



years, that by them mountains have been made to 

 rise, and valleys have been filled up; if, at the 

 same time, we reflect upon the wide distribution of 

 the volcanoes, and their behaviour altogether ; we 

 must conclude that, in volcanic districts there must 

 be enormous tunnels, and those at very great 

 depths, because they do not impair the general 

 firmness of the outer crust of the earth. 



More convincing proofs of the existence of deep 

 underground channels, filled with liquid, are de- 

 rived from the earthquakes that are often felt at 

 the same time over vast tracts of country. The 

 frightful earthquake, by which Caraccas was de- 

 stroyed in 1812, was felt at the same time over a 

 space a thousand miles across ; and the still more 

 awful shocks by which, in 1755, Lisbon was laid 

 in ruins, and a great part of the city sunk in 

 unfathomable depths, were perceived at the same 

 time on the coast of Africa, in the Canary Isles, in 

 Ireland, and even at many places in Germany. 

 Neither can we doubt that the earthquake in 

 Chili, the discharge of the neighbouring volcano- 

 chain, the rising of the land around Conception, 

 and the volcanic outburst at the same time near 

 Juan Fernandez, were but parts of one great 

 convulsion. 



These, and a great number of similar actions, can 

 only be explained by supposing that there are vast 

 branching tunnels under whole continents, stretch- 



