1>E1‘XU OJ? THE CAIMSBA. 
77 
glued to the extremity of the brink. On the west the rock, 
is perforated ; and a large opening gives a view of the hori- 
zon ot the sea. The force of the elastic vapours perhaps 
formed this natural aperture, at the time of some inundation 
ot lava thrown out from the crater. 
'I he inside of this funnel indicates a volcano, which for 
thousands oi years has vomited no lire but from its sides. 
I hi® conclusion is not founded on the absence of great open- 
ings, which might he expected in the bottom of the Caldera. 
Those whose experience is founded on personal observation, 
know that several volcanoes, in the intervals of an eruption, 
appear tilled up, and almost extinguished; but that in these 
same mountains, the crater of the volcano exhibits layers of 
scoria, rough, sonorous, and shining. We observe hillocks 
.md intumescences caused by the action of the elastic vapours, 
cones of broken scoria, and ashes which cover the funnels! 
these phenomena characterise the crater of the peak 
of leneriife ; its bottom is not in the state which ensues at 
the close ot an eruption. Prom the lapse of time, and the 
action ot the vapours, the inside walls are detached, and have 
covered the basin with great blocks of lithoid lavas. 
I he bottom ot the Caldera is reached without danger. 
In a volcano, the activity of which is principally directed 
towards the summit, such as Vesuvius, the depth of the 
crater varies before and after each eruption ; but at the peak 
of Tencriffe the depth appears to have remained unchanged 
for a long time. Eden, in 1715, estimated it at 115 feet; 
Cordier, , in 1803, at 110 feet. Judging by mere inspection, 
1 should have thought the funnel of still less depth. Its 
present state is that o! a sollatara; and it is rather an object 
ot curious investigation, than of imposing aspect. The 
majesty ot the site consists in its elevation above the level 
0 I ! e Sl pb \n the profound solitude of these lofty regions, 
and in the immense space over which the eye ranges from 
the summit of the mountain. 
~ |] ie "“U compact lava, forming the enclosure of the 
Caldera, is snow-white at its surface. The same colour 
prevails in the inside of the Solfatara of Puzzuoli. When 
we break these lavas, which might be taken at some distance 
tor calcareous stone, we find in them a blackish brown 
nucleus. Porphyry, with basis of pitch-stone, is whitened 
