1866. | Teneriffe. 15 
It will be seen that all this pumice contains a smaller amount 
of silica than that from the Lipari Isles, which according to 
Klaproth contains 77°50 of silica and 17°50 of alumina. 
Some of the blocks of lava I examined higher up the Peak had 
more of a porphyritic than a trachytic character, as they contained 
blotches of crystals of a greenish and greyish-white colour, which I 
mistook for ordinary felspar ; but I was informed on good authority 
that they were pyroxene, labradorite, and chrysolite, therefore the 
blocks may be more properly considered a species of basalt, though 
they had all the spongy and rough appearance of a trachyte. 
Occasionally there were detached blocks of phonolite, of a greyish- 
blue colour, containing much felspar and mesotype; it made a 
smooth fracture, and had the peculiar metallic sound of that rock 
when struck with a hammer. 
After a very fatiguing but not difficult ascent, which took us 
an hour, includmg the time occupied in examining the lavas, we 
arrived at a part of the Peak called La Estancia de los Ingleses 
de Abaxo (the lower halting place of the English), which is 
9,930 feet above the level of the sea. The pumice here forms a 
tolerably level surface of a few hundred feet square; towards the 
N.N.E. side of it are some large scattered blocks of obsidian, under 
the lee of one of them we piled up some pieces of lava to form a 
sight shelter from the wind, which was extremely cold, and blew 
such a gale that we were frequently obliged to hold on to the rocks 
to avoid being blown away, and which for some time made all our 
efforts useless to light a fire of mountain broom. 
At sunset it suddenly abated, and two hours after there was 
a calm, occasionally interrupted by violent gusts of wind, which 
rushed along with a noise like distant thunder in a mountainous 
country. 
After partaking of a supper of hot coffee, bread, and roasted 
potatoes, we made a trench in the pumice, in which I placed my 
guide and muleteer, and then covered them up to the neck with 
light pumice-dust, over which I put my cloak. This simple plan 
so effectually protected them from the bitter cold, that I soon 
found they had forgotten all the fatigues in a sound slumber. 
As I wished to note the barometer and thermometer every 
hour, and had agreed with some friends at Port Orotava and the 
Villa, to observe them at the same time during part of the twenty- 
four hours, I was unable to take the rest which I so much required. 
The strange and interesting scene around me caused a feeling 
which partook in some degree of pleasure and pain; not having 
anyone to whom I could express my feelings, produced a painful 
void. The peculiar wildness of the scene was in some degree 
enlivened by the splendour of the starry vault above, which was so 
extremely blue, that if it had been seen in a picture, it might have 
