VOLCANOES. 
399 
base of the mountain a sort of rampart from forty 
to seventy feet in height, consisting of masses of 
melted stone. In this spot, which appears to be 
the place alluded to by Von Troil, where he speaks 
of the hill as being surrounded with lofty glazed 
walls, and filled with high glazed cliffs not to be 
compared to any thing he ever saw before, our 
travellers found it necessary to leave their horses; 
and their guide, under the pretence that he was 
suddenly attacked with a head-ache, excused 
lain seif from attending them farther on their 
journey. The ridge of lava was climbed with 
extreme difficulty, for the stones of which it was 
composed lay detached, and there were so many 
deep holes between them, that it was necessary 
to use the greatest caution in walking to prevent 
accidents. The ground shortly after becoming 
more solid, their road was consequently materially 
improved, and they began their ascent on the 
western side, where the continual cracking of the 
rock under their feet at first caused them some 
uneasiness, till, upon more attentive observation, 
they found that the whole mountain itself was re¬ 
duced to a mere pumice stone, lying in horizontal 
strata of moderate thickness, everv where full of 
fissures ; and hence, they observe, may be formed 
some idea of the intensity of the fire, whereby 
an immense mountain has been so far consumed 
