348 DOMAIN XII.* VOLCANIC. 



comparison will show the great changes which 

 have taken place in this volcano within the 

 space of twenty years ; that is, from the time 

 Riedesei. when it was visited by Baron Riedesel in 1?67, 

 to that of my journey in 1788. At the time 

 when that traveller made his observations, the 

 crater was enlarged towards the east, with an 

 aperture which now no longer exists. He has 

 not given the measure of its circuit, nor has he 

 mentioned the interior aspect of the crater; pro- 

 bably because he had not seen it, having been, 

 as I imagine, prevented by the quantity of 

 smoke which he tells us continually ascended 

 from it. 



" It is worthy of notice, however, that at that 

 time there was not at the bottom of the crater 

 the hard flat surface I have described ; since the 

 stones thrown into it did not return the smallest 

 sound. Within the gulf itself was heard a noise 

 similar to that of the waves of the sea when agi- 

 tated by a tempest, which noise probably pro- 

 ceeded from the lava within the bowels of the 

 mountain, liquefied and in motion. We may 

 hence conceive how easily a volcano may begin 

 to rage on a sudden, though before apparently 

 in a state of complete tranquillity; for if we 

 suppose a superabundant quantity of elastic 

 substances to have been suddenly developed in 



