22 Teneriffe. | Jan., 
large ravine which I have already mentioned as having been formed 
by a waterspout in November, 1826. In some parts of it, I» 
counted no less than 75 various layers of lava and vegetable earth ; 
some of the layers consisted of compact basalt, trachytic porphyry, 
and phonolite, between some of them were layers of vegetable earth 
three and four inches thick, with fine roots of plants turned into 
charcoal. Sir Wiliam Hamilton found that it took several centuries 
before the compact lavas of Vesuvius became covered with a thick 
layer of vegetable earth, here were various strata with layers of 
earth between them, showing that ages must have elapsed between 
some of the eruptions. 
The question naturally occurs, Is there any probability of such 
eruptions occurring again? The crater of the Peak emits smoke 
and steam at intervals all the year round ; after heavy rains I have 
often seen the crater throwing up dense columns of steam; as a 
proof that the fires are not far below, when I thrust my staff a 
few feet into crust of the crater, and withdrew it, I could not 
touch it, as it was quite hot. 
In 1797, the town of Garrachica was entirely destroyed by an 
eruption from the volcano of Chajorra, which is about 2,000 feet 
lower than the top of the Peak, but whose crater is nearly a 
quarter of a mile in diameter. The Port of the unfortunate town 
was entirely filled up, and you now see churches, convents, and 
houses without roofs, and the walls protuding a few feet above the 
solid mass of basaltic lava. But the eruption of that yeax must 
have been a mere nothing in comparison with those of the distant 
times when the whole island was covered with liquid lava, forming 
the high cliffs which now guard its shores, and when masses of 
obsidian, many tons in weight, were launched into the air like huge 
voleanic bombs, some miles from the volcanic vent. 
It may be interesting to know what is the best time of the 
year to ascend the Peak; from the experience I had from my . 
frequent ascents to the Cumbre, at an elevation of upwards of 
7,000 feet, I observed that the seasons above were much earlier 
than they were below, consequently the latter part of the spring 
is the best season to visit the Peak. While August and September 
have a mean temperature of nearly 73° at the Villa de Orotava, 
1,141 feet above the sea, I found it was cold in the shade at an 
elevation of between 7,000 and 8,000 feet, with an extreme 
radiation and distressing dryness. During the latter part of the 
autumn the cold is most intense at night above, even much greater 
than during January and February, when the cold even on the 
summit of the Peak is far from excessive. When I ascended the 
Peak in October to an elevation of 10,700 feet, I found the cold 
greater than it was in February. J am aware that this is against 
the generally received opinion, but I give merely the result of 
