by the name of the Peak of Teneriffe, and which is the highest land not only in the island, but in all the Canaries; the mean of various observations making it 12,500 feet above the level of the sea. It is visible at a great distance; we saw it perfectly distinct 34 leagues off by chronometrical observation, when it appeared rising like a cone from the bed of the ocean; and I have heard that it has been clearly distinguished at a distance of fortyfive leagues.

The rocks and strata of the Island of Teneriffe are wholly volcanic; a long chain of mountains, which may be termed the central chain, traverses the island from the foot of the second region of the Peak sloping down on the eastern, western, and northern sides, to the sea, Towards the south, or more properly the S.S.W. the mountains are nearly perpendicular, and, though broken into ridges and occasionally separated by deep ravines that are cut transversely as well as Jongitudinally, there are none of those plains nor that gradual declination of strata that the south-eastern and north-western sides of the island exhibit.

From the Barranco Seco, in the neighbourhood of Santa Cruz, to the northerly point called Punta del Hidalgo, a series of steep and abrupt mountains form headlands to the sea, separated from the central chain by the valley of Laguna; these mountains are rugged and peaked, drawn up, if the term may be used, in a column, and are di vided by deep ravines. The sides of these mountains are steep, being in many places cut nearly perpendicular to the horizon, and are all composed of lava generally of the

basaltic formation, mixed with beds of tufa and pumice. From Hidalgo point to that of Teno, the most westerly point of the island, the strata vary from beds of pumice and decomposed lava and ash, which form the plains of Laguna Ticaronte and Songal, to streams and currents and headlands of lava similar to those of the Barranco Hundo, San Ursula, Las Horcas, and Las Guanchas. The slope from the central chain is here gradual, intersected by ravines and streams of lava. The soil famed for its fertility and which produces the Teneriffe wine, is composed of lava and ash in a state of decomposi tion. Headlands, some of them from two to three hundred feet in height, project into the sea between San Ursula and Orotava, forming perpendicular cliffs. At the western extremity of the island from Punta di Teno to Puerto de los Christianos, the strata rise in a broken ridge to the Peak, the land ascending gradually from Punta de Teno by a chain of small peaked hills; the point itself being very low and projecting as a promontory into the sea. The declination of the strata is similar from the Peak to Puerto de los Christianos. This south-westerly chain is broken into many abrupt ridges, and is cut nearly perpendicular down to the I could not perceive any base or shelf as on the other sides of the Peak, from which the cone arose, but the fall is regular though steep. From Puerto de los Christianos to Santa Cruz, comprising the southern and south-eastern sides of the island, the form is similar to that in the vicinity of Orotava, but it is barren and desolate, laid waste by streams of lava. In the short space

sea.

of

of a few leagues I counted no less than seven cones of extinct volcanoes, and the country is covered with scoria, exhibiting no appearance of culture, and hardly any of vegetation; it is more broken into ravines and more intersected by lava torrents than on any of the other sides of the island. Numerous peaked and conical mountains rise upon the slope of the chain, and the whole country is covered by scoria, and is one continued stream of lava. The Montana Roxa itself is a singular example of the dislocation of strata so commonly found in countries of volcanic formation; it is evidently a slip or fall of semi-columnar lava, and slopes into the sea at an highly inclined angle.

The ordinary strata of the island are as follows, reckoning from below upwards: 1st. the porphyritic lava covered by scoria and sometimes by pumice. This lava is composed of hornblende and feldspar, and contains no other substance. The next stratum graduates into what the Spaniards call Roccaverde or greenstone, and is composed of feldspar and hornblende; upon this is generally a thick stratum of pumice, and last of all towards the surface is the basaltic lava covered also by tufa and ash. This lava decomposes the soonest. It also contains the greatest variety of extraneous substances, and is sometimes divided by a layer of large crystals of olivine some inches long, and towards the northeast is often intersected by strata of porphyritic slate. These lavas are more earthy and cellular than those which I have had an opportunity of observing elsewhere, yet they contain fewer extraneous sub

stances than those of Ætna and Vesuvius; they are in some places exposed to view in the vallies şimilar to those of the Corral in the island of Madeira. The valley of Las Guanchas on the north-west side of the Peak, contains, according to M. Escolar, above 100 strata of lava, the one reposing upon the other, at times alternating with pumice and tufa. The depth of these strata varies. M. Escolar has seen one of basaltic lava between 100 and 150 feet in depth in one solid mass, cellular at the surface, but gradually becoming more compact towards the bottom. This basaltic lava contains olivine and hornblende, and in the caves on the coast, zeolite. This substance is also found in stalactites and in masses, sometimes in layers spread between the strata and diffused over the rock.

Nodules of chalcedony are sometimes also found, but these substances occur only in the chain of mountains towards the north-east, from the northern extremity of Santa Cruz to the point of Hidalgo,

The lavas of the island are of an endless variety, and the number of streams that have flowed are much beyond all enumeration. The whole surface is either ash, or solid or decomposed lava, which seems again and again to have been perforated by volcanic eruptions; the number of small extinct volcanoes is prodigious, they are to be found in all parts of the island, but the stream that has flowed from even the largest of them, such as the lava of the Peak called el Mal Pais, is trifling in comparison with that immense mass of lava mountains which constitute the central chain of the island, and which stretch out

I never found in situ those masses of columnar basaltic rock that are so common in the island of Madeira: but in the valley of las Esperanzas, in the chain of hills to the north-castward of the town of Santa Cruz, they lie scattered about in considerable numbers, and M. Escolar told me that he had seen strata of them to a considerable extent, exhibiting with precision the columnar basaltic form; the modern lavas of the Peak are all basaltic; that of 1704 is decidedly so, as well as that of 1798, though not exhibiting any prismatic form. Prisms of basaltic lava are yet found on the peak: I picked up one, though there are no strata of them to be met with. The metals are rare, and afford but little variety; specular and micaceous iron, black and grey manganese, are all that have hitherto been discovered. The saits that are so common on Vesuvius, are here seldom met with. Augite is also rare, and mica and leucite, though carefully sought after, have hitherto not been found.

In that part of the island between Laguna and Tacaronte, where there are few streams of lava, the soil is evidently volcanic. I examined many of the clods that were turned up b the plow, and found them all alike: they contained much strong clay, with crystals of feldspar, olivine, and specular iron.Dr. Gillan, who accompanied Mr. Barrow and Sir G. Staunton, has advanced an opinion, that between Laguna and Matanzos there are no signs of volcanic formation. That the currents of lava occur but seldom is most true; but the mountains in the vicinity of Laguna are

crater, besides, the assertion would prove too much; for it would go to maintain that the Campagna Felice, as well as the plains of Catania, were not created by the ash and pumice eruption of Vesuvios and ina. The bed of soil is here very deep. I examined some ravines that the rain had laid open to the depth of 30 or 40 feet: the strata were indurated at the bottom, and resembled the tufa in the vicinity of Naples, and all contained the substances mentioned above.This tufaceous character changes as you ascend the hill that separates Laguna from Santa Cruz; the hill itself, and the whole neighbourhood of the latter city, is one continued stream of lava, hardly at all decomposed, with little or no vegetation; but here and there in the hollows some few stunted plants of the aloe algarvensis, and the cytisus.

Having given a general account of the island, I shall now attempt to describe the country of the Peak, which mountain I ascended on the 16th of September, 1810. The road from Puerto Orotava to the city of Orotava, is a gradual and easy slope for three or four miles, through a highly cultivated country. The soil is composed of volcanic ash and earth, and to the eastward of the town of Puerto di Orotava are the remains of a recent volcano, the crater and cone being distinctly visible. Leaving the town of Oralava, after a steep ascent of about an hour through a deep ravine, we quitted the cultivated part of the slope or valley, and entered into a forest of chesnuts; the trees are here of a large size. This forest of chesnuts is mixed with the erica arborea, or

tree neath, which shrub rises to the height of 18 or 20 feet. Some of the stems are as thick as the arm of a man, joined together in bunches or tufts like the common heath. The form of this forest is oblong; it covers the flank of those hills which I have already denominated the central chain from their summit to half their elevation from the plain. The soil here is deep, and formed of decomposed lava, small ash, and pumice. I examined several chan nels in the strata or ravines worn by the rains, and there was no appearance of any other rock. Leaving this forest, the track passes over a series of green hills which we traversed in about two hours, and at last halted to water our mules at a spot called el barranco del pino de la meruendu, where there is a small spring of bad and brackish water issuing from a lava rock. The ravine is of considerable depth. After the vegetable earth, which is two or three feet deep, a layer of tufa succeeds, which is followed by a lava of a greyish-blue colour, 30 or 40 feet in depth. It is compact, contains olivine, and the strata lap over each other, but shew no appearance of columnar formation. The range of green hills extends a mile or two further, the soil shallowing by degrees, more lava and scoria shewing themselves on the surface, the ravines or channels, worn by the rains, becoming more common, the trees and shrubs gradually dwindling in size, and of them all the Spanish broom alone at length covers the ground. Leaving behind us this range of green hills, the track, still ascending, leads, for several hours, across a steep and difficult mass of lava rock, broken here and there. into strange and

fantastic forms, worn into deep ravines, and scantily covered in places by a thin layer of yellow pumice. The surface of the country, for miles and miles around, is of this one continuous stream of lava; the rents or ravines of which seem to be formed partly by the torrents from the hills flowing for so many ages, and partly from that tendency, characteristic of a lava current, to keep itself up in embankments, and in its cooling process to open out into those hollows which I have uniformly found in every eruption of lava that I have had an opportunity of examining. This lava is cellular beyond any I have ever seen, is of a clayey earthy porphyritic composition, and contains few. if any, pieces of olivine, though here and there feldspar in a semicrystallised form. As we proceeded on our road, the hills on our left, though broken at times in deep ravines, gradually rose in height till the summits were lost in those of the central chain, while on our right we were rapidly gaining an elevation above the lower range of the peak. This range forms one flank of the plain or valley of Orotava, stretching from south-east to north-west, and is broken into steep precipices, cut down in sʊme places perpendicular to the horizon, and called las Horcas: it joins the central chain at the high elevation of the pumice plains, sweeps down the side of the valley, and forms a headland near 200 feet high projecting into the sea, some miles from Orotava; we traversed this country an hour or two, till we reached the point of intersection of las Horcas with the plains of pumice. On the road are several small conical hills or mouths of

extinct