We lost sight of the small islands of Alegranza, Montana Clara, and Graciosa, which appear never to have been inhabited by the Guanches. They are now visited only for the purpose of gathering archil, which production is, however, less sought after, since so many other lichens of the north of Europe have been found to yield materials proper for dyeing. Montana Clara is noted for its beautiful canary-birds. The note of these birds varies with their flocks, like that of our chaffinches, which often differs in two neighbouring districts. Montana Clara yields pasture for goats, a fact which proves that the interior of this islet is less arid than its coasts. The name of Alegranza is synonymous with the Joyous, (La Joyeuse,) which denomination it received from the first conquerors of the Canary Islands, the two Norman barons, Jean de Bethencourt and Gadifer de Salle. This was the first point on which they landed. After remaining several days at Graciosa, a small part of which we examined, they conceived the project of taking possession of the neighbouring island of Lancerota, where they were welcomed by Guadarfia, sovereign of the Guanches, with the same hospitality that Cortez found in the palace of Montezuma. The shepherd king, who had no other riches than his goats, became the victim of base treachery, like the sultan of Mexico.
We sailed along the coasts of Lancerota, of the island of Lobos, and of Forteventura. The second of these islands seems to have anciently formed part of the two others. This geological hypothesis was started in the seventeenth century by the Franciscan, Juan Galindo. That writer supposed that king Juba had named six Canary Islands only, because, in his time, three among them were contiguous. Without admitting the probability of this hypothesis, some learned geographers have imagined they recognized, in the two islands Nivaria and Ombrios, the Canaria and Capraria of the ancients.
The haziness of the horizon prevented us, during the whole of our pa.s.sage from Lancerota to Teneriffe, from discovering the summit of the peak of Teyde. If the height of this volcano is 1905 toises, as the last trigonometrical measure of Borda indicates, its summit ought to be visible at a distance of 43 leagues, supposing the eye on a level with the ocean, and a refraction equal to 0.079 of distance. It has been doubted whether the peak has ever been seen from the channel which separates Lancerota from Forteventura, and which is distant from the volcano, according to the chart of Varela, 2 degrees 29 minutes, or nearly 50 leagues. This phenomenon appears nevertheless to have been verified by several officers of the Spanish navy. I had in my hand, on board the Pizarro, a journal, in which it was noted, that the peak of Teneriffe had been seen at 135 miles distance, near the southern cape of Lancerota, called Pichiguera. Its summit was discovered under an angle considerable enough to lead the observer, Don Manual Baruti, to conclude that the volcano might have been visible at nine miles farther. It was in September, towards evening, and in very damp weather. Reckoning fifteen feet for the elevation of the eye, I find, that to render an account of this phenomenon, we must suppose a refraction equal to 0.158 of the arch, which is not very extraordinary for the temperate zone. According to the observations of General Roy, the refractions vary in England from one-twentieth to one-third; and if it be true that they reach these extreme limits on the coast of Africa, (which I much doubt,) the peak, in certain circ.u.mstances, may be seen on the deck of a vessel as far off as 61 leagues.
Navigators who have much frequented these lat.i.tudes, and who can reflect on the physical causes of the phenomena, are surprised that the peaks of Teyde and of the Azores* (* The height of this peak of the Azores, according to Fleurieu, is 1100 toises; to Ferrer, 1238 toises; and to Tofino, 1260 toises: but these measures are only approximative estimates. The captain of the Pizarro, Don Manuel Cagigal, proved to me, by his journal, that he observed the peak of the Azores at the distance of 37 leagues, when he was sure of his lat.i.tude within two minutes. The volcano was seen at 4 degrees south-east, so that the error in longitude must have an almost imperceptible influence in the estimation of the distance.
Nevertheless, the angle which the peak of the Azores subtended was so great, that the captain of the Pizarro was of opinion this volcano must be visible at more than 40 or 42 leagues. The distance of 37 leagues supposes an elevation of 1431 toises.) are sometimes visible at a very great distance, though at other times they are not seen when the distance is much less, and the sky appears serene and the horizon free from fogs. These circ.u.mstances are the more worthy of attention because vessels returning to Europe, sometimes wait impatiently for a sight of these mountains, to rectify their longitude; and think themselves much farther off than they really are, when in fine weather these peaks are not perceptible at distances where the angles subtended must be very considerable. The const.i.tution of the atmosphere has a great influence on the visibility of distant objects. It may be admitted, that in general the peak of Teneriffe is seldom seen at a great distance, in the warm and dry months of July and August; and that, on the contrary, it is seen at very extraordinary distances in the months of January and February, when the sky is slightly clouded, and immediately after a heavy rain, or a few hours before it falls. It appears that the transparency of the air is prodigiously increased, as we have already observed, when a certain quant.i.ty of water is uniformly diffused through the atmosphere. Independent of these observations, it is not astonishing, that the peak of Teyde should be seldomer visible at a very remote distance, than the summits of the Andes, to which, during so long a time, my observations were directed.
This peak, inferior in height to those parts of the chain of Mount Atlas at the foot of which is the city of Morocco, is not, like those points, covered with perpetual snows. The Piton, or Sugar-loaf, which terminates the peak, no doubt reflects a great quant.i.ty of light, owing to the whitish colour of the pumice-stone thrown up by the crater; but the height of that little truncated cone does not form a twenty-second part of the total elevation. The flanks of the volcano are covered either with blocks of black and scorified lava, or with a luxuriant vegetation, the ma.s.ses of which reflect the less light, as the leaves of the trees are separated from each other by shadows of more considerable extent than that of the part enlightened.
Hence it results that, setting aside the Piton, the peak of Teyde belongs to that cla.s.s of mountains, which, according to the expression of Bouger, are seen at considerable distances only in a NEGATIVE MANNER, because they intercept the light which is transmitted to us from the extreme limits of the atmosphere; and we perceive their existence only on account of the difference of intensity subsisting between the aerial light which surrounds them, and that which is reflected by the particles of air placed between the mountains and the eye of the observer. As we withdraw from the isle of Teneriffe, the Piton or Sugar-loaf is seen for a considerable s.p.a.ce of time in a POSITIVE MANNER, because it reflects a whitish light, and clearly detaches itself from the sky.
But as this cone is only 80 toises high, by 40 in breadth at its summit, it has recently been a question whether, from the diminutiveness of its ma.s.s, it can be visible at distances which exceed 40 leagues; and whether it be not probable, that navigators distinguish the peaks as a small cloud above the horizon, only when the base of the Piton begins to be visible on it. If we admit, that the mean breadth of the Sugar-loaf is 100 toises, we find that the little cone, at 40 leagues distance, still subtends, in the horizontal direction, an angle of more than three minutes. This angle is considerable enough to render an object visible; and if the height of the Piton greatly exceeded its base, the angle in the horizontal direction might be still smaller, and the object still continue to make an impression on our visual organs; for micrometrical observations have proved that the limit of vision is but a minute only, when the dimensions of the objects are the same in every direction. We distinguish at a distance, by the eye only, trunks of trees insulated in a vast plain, though the subtended angle be under twenty-five seconds.
As the visibility of an object detaching itself in a brown colour, depends on the quant.i.ties of light which the eye meets on two lines, one of which ends at the mountain, and the other extends to the surface of the aerial ocean, it follows that the farther we remove from the object, the smaller the difference becomes between the light of the surrounding atmosphere, and that of the strata of air before the mountain. For this reason, when less elevated summits begin to appear above the horizon, they present themselves at first under a darker hue than those we discern at very great distances. In the same manner, the visibility of mountains seen only in a negative manner, does not depend solely on the state of the lower regions of the air, to which our meteorological observations are limited, but also on the transparency and physical const.i.tution of the air in the most elevated parts; for the image detaches itself better in proportion as the aerial light, which comes from the limits of the atmosphere, has been originally more intense, or has undergone less loss in its pa.s.sage. This consideration explains to a certain point, why, under a perfectly serene sky, the state of the thermometer and the hygrometer being precisely the same in the air nearest the earth, the peak is sometimes visible, and at other times invisible, to navigators at equal distances. It is even probable, that the chance of perceiving this volcano would not be greater, if the ashy cone, at the summit of which is the mouth of the crater, were equal, as in Vesuvius, to a quarter of the total height. These ashes, being pumice-stone crumbled into dust, do not reflect as much light as the snow of the Andes; and they cause the mountain, seen from afar, to detach itself not in a bright, but in a dark hue. The ashes also contribute, if we may use the expression, to equalize the portions of aerial light, the variable difference of which renders the object more or less distinctly visible. Calcareous mountains, devoid of vegetable earth, summits covered with granitic sand, the high savannahs of the Cordilleras,* (* Los Pajonales, from paja, straw. This is the name given to the region of the gramina, which encircles the zone of the perpetual snows.) which are of a golden yellow, are undoubtedly distinguished at small distances better than objects which are seen in a negative manner; but the theory indicates a certain limit, beyond which these last detach themselves more distinctly from the azure vault of the sky.
The colossal summits of Quito and Peru, towering above the limit of the perpetual snows, concentre all the peculiarities which must render them visible at very small angles. The circular summit of the peak of Teneriffe is only a hundred toises in diameter.
According to the measures I made at Riobamba, in 1803, the dome of the Chimborazo, 153 toises below its summit, consequently in a point which is 1300 toises higher than the peak, is still 673 toises (1312 metres) in breadth. The zone of perpetual snows also forms a fourth of the height of the mountain; and the base of this zone, seen on the coast of the Pacific, fills an extent of 3437 toises (6700 metres). But though Chimborazo is two-thirds higher than the peak, we do not see it, on account of the curve of the globe, at more than 38 miles and a third farther distant. The radiant brilliancy of its snows, when, at the port of Guayaquil, at the close of the rainy season, Chimborazo is discerned on the horizon, may lead us to suppose, that it must be seen at a very great distance in the South Sea. Pilots highly worthy of credit have a.s.sured me, that they have seen it from the rock of Muerto, to the south west of the isle of Puna, at a distance of 47 leagues.
Whenever it has been seen at a greater distance, the observers, uncertain of their longitude, have not been in a situation to furnish precise data.
Aerial light, projected on mountains, increases the visibility of those which are seen positively; its power diminishes, on the contrary, the visibility of objects which, like the peak of Teneriffe and that of the Azores, detach themselves in a brown tint. Bouguer, relying on theoretical considerations, was of opinion that, according to the const.i.tution of our atmosphere, mountains seen negatively cannot be perceived at distances exceeding 35 leagues. It is important here to observe, that these calculations are contrary to experience. The peak of Teneriffe has been often seen at the distance of 36, 38, and even at 40 leagues.
Moreover, in the vicinity of the Sandwich Islands, the summit of Mowna-Roa, at a season when it was without snows, has been seen on the skirt of the horizon, at the distance of 53 leagues. This is the most striking example we have hitherto known of the visibility of a mountain; and it is the more remarkable, that an object seen negatively furnishes this example.
The volcanoes of Teneriffe, and of the Azores, the Sierra Nevada of Santa Martha, the peak of Orizaba, the Silla of Caracas, Mowna-Roa, and Mount St. Elias, insulated in the vast extent of the seas, or placed on the coasts of continents, serve as sea-marks to direct the pilot, when he has no means of determining the position of the vessel by the observation of the stars; everything which has a relation to the visibility of these natural seamarks, is interesting to the safety of navigation.
CHAPTER 1.2.
STAY AT TENERIFE.
JOURNEY FROM SANTA CRUZ TO OROTAVA.
EXCURSION TO THE SUMMIT OF THE PEAK OF TEYDE.
From the time of our departure from Graciosa, the horizon continued so hazy, that, notwithstanding the considerable height of the mountains of Canary,* (* Isla de la Gran Canaria.) we did not discover that island till the evening of the 18th of June. It is the granary of the archipelago of the Fortunate Islands; and, what is very remarkable in a region situated beyond the limits of the tropics, we were a.s.sured, that in some districts, there are two wheat harvests in the year; one in February, and the other in June.
Canary has never been visited by a learned mineralogist; yet this island is so much the more worthy of observation, as the physiognomy of its mountains, disposed in parallel chains, appeared to me to differ entirely from that of the summits of Lancerota and Teneriffe. Nothing is more interesting to the geologist, than to observe the relations, on the same point of the globe, between volcanic countries, and those which are primitive or secondary.
When the Canary Islands shall have been examined, in all the parts which compose the system of these mountains, we shall find that we have been too precipitate in considering the whole group as raised by the action of submarine fires.
On the morning of the 19th, we discovered the point of Naga, but the peak of Teneriffe was still invisible: the land, obscured by a thick mist, presented forms that were vague and confused. As we approached the road of Santa Cruz we observed that the mist, driven by the winds, drew nearer to us. The sea was strongly agitated, as it most commonly is in those lat.i.tudes. We anch.o.r.ed after several soundings, for the mist was so thick, that we could scarcely distinguish objects at a few cables" distance; but at the moment we began to salute the place, the fog was instantly dispelled. The peak of Teyde appeared in a break above the clouds, and the first rays of the sun, which had not yet risen on us, illumined the summit of the volcano.
We hastened to the prow of the vessel to behold the magnificent spectacle, and at the same instant we saw four English vessels lying to, and very near our stern. We had pa.s.sed without being perceived, and the same mist which had concealed the peak from our view, had saved us from the risk of being carried back to Europe.
The Pizarro stood in as close as possible to the fort, to be under its protection. It was on this sh.o.r.e, that, in the landing attempted by the English two years before our arrival, in July 1797, admiral Nelson had his arm carried off by a cannon-ball.
The situation of the town of Santa Cruz is very similar to that of La Guayra, the most frequented port of the province of Caraccas.
The heat is excessive in both places, and from the same causes; but the aspect of Santa Cruz is more gloomy. On a narrow and sandy beach, houses of dazzling whiteness, with flat roofs, and windows without gla.s.s, are built close against a wall of black perpendicular rock, devoid of vegetation. A fine mole, built of freestone, and the public walk planted with poplars, are the only objects which break the sameness of the landscape. The view of the peak, as it presents itself above Santa Cruz, is much less picturesque than that we enjoy from the port of Orotava. There, a highly cultured and smiling plain presents a pleasing contrast to the wild aspect of the volcano. From the groups of palm trees and bananas which line the coast, to the region of the arbutus, the laurel, and the pine, the volcanic rock is crowned with luxuriant vegetation. We easily conceive how the inhabitants, even of the beautiful climates of Greece and Italy, might fancy they recognised one of the Fortunate Isles in the western part of Teneriffe. The eastern side, that of Santa Cruz, on the contrary, is every where stamped with sterility. The summit of the peak is not more arid than the promontory of basaltic lava, which stretches towards the point of Naga, and on which succulent plants, springing up in the clefts of the rocks, scarcely indicate a preparation of soil. At the port of Orotava, the top of the Piton subtends an angle in height of more than eleven degrees and a half; while at the mole of Santa Cruz* (* The oblique distances from the top of the volcano to Orotava and to Santa Cruz are nearly 8600 toises and 22,500 toises.) the angle scarcely exceeds 4 degrees 36 minutes.
Notwithstanding this difference, and though in the latter place the volcano rises above the horizon scarcely as much as Vesuvius seen from the mole of Naples, the aspect of the peak is still very majestic, when those who anchor in the road discern it for the first time. The Piton alone was visible to us; its cone projected itself on a sky of the purest blue, whilst dark thick clouds enveloped the rest of the mountain to the height of 1800 toises.
The pumice-stone, illumined by the first rays of the sun, reflected a reddish light, like that which tinges the summits of the higher Alps. This light by degrees becomes dazzlingly white; and, deceived like most travellers, we thought that the peak was still covered with snow, and that we should with difficulty reach the edge of the crater.
We have remarked, in the Cordillera of the Andes, that the conical mountains, such as Cotopaxi and Tungurahua, are oftener seen free from clouds, than those of which the tops are broken into bristly points, like Antisana and Pichincha; but the peak of Teneriffe, notwithstanding its pyramidical form, is a great part of the year enveloped in vapours, and is sometimes, during several weeks, invisible from the road of Santa Cruz. Its position to the west of an immense continent, and its insulated situation in the midst of the sea, are no doubt the causes of this phenomenon. Navigators are well aware that even the smallest islets, and those which are without mountains, collect and harbour the clouds. The decrement of heat is also different above the plains of Africa, and above the surface of the Atlantic; and the strata of air, brought by the trade winds, cool in proportion as they advance towards the west.
If the air has been extremely dry above the burning sands of the desert, it is very quickly saturated when it enters into contact with the surface of the sea, or with the air that lies on that surface. It is easy to conceive, therefore, why vapours become visible in the atmospherical strata, which, at a distance from the continent, have no longer the same temperature as when they began to be saturated with water. The considerable ma.s.s of a mountain, rising in the midst of the Atlantic, is also an obstacle to the clouds, which are driven out to sea by the winds.
On entering the streets of Santa Cruz, we felt a suffocating heat, though the thermometer was not above twenty-five degrees. Those who have for a long time inhaled the air of the sea suffer every time they land; not because this air contains more oxygen than the air on sh.o.r.e, as has been erroneously supposed, but because it is less charged with those gaseous combinations, which the animal and vegetable substances, and the mud resulting from their decomposition, pour into the atmosphere. Miasms that escape chemical a.n.a.lysis have a powerful effect on our organs, especially when they have not for a long while been exposed to the same kind of irritation.
Santa Cruz, the Anaza of the Guanches, is a neat town, with a population of 8000 souls. I was not struck with the vast number of monks and secular ecclesiastics, which travellers have thought themselves bound to find in every country under the Spanish government; nor shall I stop to enter into the description of the churches; the library of the Dominicans, which contains scarcely a few hundred volumes; the mole, where the inhabitants a.s.semble to inhale the freshness of the evening breeze; or the famed monument of Carrara marble, thirty feet high, dedicated to Our Lady of Candelaria, in memory of the miraculous appearance of the Virgin, in 1392, at Chimisay, near Guimar. The port of Santa Cruz may be considered as a great caravanserai, on the road to America and the Indies. Every traveller who writes the narrative of his adventures, begins by a description of Madeira and Teneriffe; and if in the natural history of these islands there yet remains an immense field untrodden, we must admit that the topography of the little towns of Funchal, Santa Cruz, Laguna, and Orotava, leaves scarcely anything untold.
The recommendation of the court of Madrid procured for us, in the Canaries, as in all the other Spanish possessions, the most satisfactory reception. The captain-general gave us immediate permission to examine the island. Colonel Armiaga, who commanded a regiment of infantry, received us into his house with kind hospitality. We could not cease admiring the banana, the papaw tree, the Poinciana pulcherrima, and other plants, which we had hitherto seen only in hot-houses, cultivated in his garden in the open air. The climate of the Canaries however is not warm enough to ripen the real Platano Arton, with triangular fruit from seven to eight inches long, and which, requiring a temperature of 24 centesimal degrees, does not flourish even in the valley of Caracas. The bananas of Teneriffe are those named by the Spanish planters Camburis or Guineos, and Dominicos. The Camburi, which suffers least from cold, is cultivated with success even at Malaga, where the temperature is only 18 degrees; but the fruit we see occasionally at Cadiz comes from the Canary Islands by vessels which make the pa.s.sage in three or four days. In general, the musa, known by every people under the torrid zone, though hitherto never found in a wild state, has as great a variety of fruit as our apple and pear trees. These varieties, which are confounded by the greater part of botanists, though they require very different climates, have become permanent by long cultivation.
We went to herborize in the evening in the direction of the fort of Pa.s.so Alto, along the basaltic rocks that close the promontory of Naga. We were very little satisfied with our harvest, for the drought and dust had almost destroyed vegetation. The Cacalia Kleinia, the Euphorbia canariensis, and several other succulent plants, which draw their nourishment from the air rather than the soil on which they grow, reminded us by their appearance, that this group of islands belongs to Africa, and even to the most arid part of that continent.
Though the captain of the Pizarro had orders to stop long enough at Teneriffe to give us time to scale the summit of the peak, if the snows did not prevent our ascent, we received notice, on account of the blockade of the English ships, not to expect a longer delay than four or five days. We consequently hastened our departure for the port of Orotava, which is situated on the western declivity of the volcano, where we were sure of finding guides. I could find no one at Santa Cruz who had mounted the peak, and I was not surprised at this. The most curious objects become less interesting, in proportion as they are near to us; and I have known inhabitants of Schaffhausen, in Switzerland, who had never seen the fall of the Rhine but at a distance.
On the 20th of June, before sunrise, we began our excursion by ascending to the Villa de Laguna, estimated to be at the elevation of 350 toises above the port of Santa Cruz. We could not verify this estimate of the height, the surf not having permitted us to return on board during the night, to take our barometers and dipping-needle. As we foresaw that our expedition to the peak would be very precipitate, we consoled ourselves with the reflection that it was well not to expose instruments which were to serve us in countries less known by Europeans. The road by which we ascended to Laguna is on the right of a torrent, or baranco, which in the rainy season forms fine cascades; it is narrow and tortuous. Near the town we met some white camels, which seemed to be very slightly laden. The chief employment of these animals is to transport merchandise from the custom-house to the warehouses of the merchants. They are generally laden with two chests of Havannah sugar, which together weigh 900 pounds; but this load may be augmented to thirteen hundred-weight, or 52 arrobas of Castile.
Camels are not numerous at Teneriffe, whilst they exist by thousands in the two islands of Lancerota and Forteventura; the climate and vegetation of these islands, which are situated nearer Africa, are more a.n.a.logous to those of that continent. It is very extraordinary, that this useful animal, which breeds in South America, should be seldom propagated at Teneriffe. In the fertile district of Adexe only, where the plantations of the sugar-cane are most considerable, camels have sometimes been known to breed. These beasts of burden, as well as horses, were brought into the Canary Islands in the fifteenth century by the Norman conquerors. The Guanches were previously unacquainted with them; and this fact seems to be very well accounted for by the difficulty of transporting an animal of such bulk in frail canoes, without the necessity of considering the Guanches as a remnant of the people of Atlantis, or a different race from that of the western Africans.
The hill, on which the town of San Christobal de la Laguna is built, belongs to the system of basaltic mountains, which, independent of the system of less ancient volcanic rocks, form a broad girdle around the peak of Teneriffe. The basalt on which we walked was darkish brown, compact, half-decomposed, and when breathed on, emitted a clayey smell. We discovered amphibole, olivine,* (* Peridot granuliforme. Hauy.) and translucid pyroxenes, * (* Augite.--Werner.) with a perfectly lamellar fracture, of a pale olive green, and often crystallized in prisms of six planes.
The first of these substances is extremely rare at Teneriffe; and I never found it in the lavas of Vesuvius; but those of Etna contain it in abundance. Notwithstanding the great number of blocks, which we stopped to break, to the great regret of our guides, we could discover neither nepheline, leucite,* (* Amphigene.--Hauy.) nor feldspar. This last, which is so common in the basaltic lavas of the island of Ischia, does not begin to appear at Teneriffe, till we approach the volcano. The rock of Laguna is not columnar, but is divided into ledges, of small thickness, and inclined to the east at an angle of 30 or 40 degrees. It has nowhere the appearance of a current of lava flowing from the sides of the peak. If the present volcano has given birth to these basalts, we must suppose, that, like the substances which compose the Somma, at the back of Vesuvius, they are the effect of a submarine effusion, in which the liquid ma.s.s has formed strata. A few arborescent Euphorbias, the Cacalia Kleinia, and Indian figs (Cactus), which have become wild in the Canary Islands, as well as in the south of Europe and the whole continent of Africa, are the only plants we see on these arid rocks. The feet of our mules were slipping every moment on beds of stone, which were very steep. We nevertheless recognized the remains of an ancient pavement. In these colonies we discover at every step some traces of that activity which characterized the Spanish nation in the 16th century.
As we approached Laguna, we felt the temperature of the atmosphere gradually become lower. This sensation was so much the more agreeable, as we found the air of Santa Cruz very oppressive. As our organs are more affected by disagreeable impressions, the change of temperature becomes still more sensible when we return from Laguna to the port: we seem then to be drawing near the mouth of a furnace. The same impression is felt, when, on the coast of Caracas, we descend from the mountain of Avila to the port of La Guayra. According to the law of the decrement of heat, three hundred and fifty toises in height produce in this lat.i.tude only three or four degrees difference in temperature. The heat which overpowers the traveller on his entrance into Santa Cruz, or La Guayra, must consequently be attributed to the reverberation from the rocks, against which these towns are built.
The perpetual coolness which prevails at Laguna causes it to be considered in the Canaries a delightful abode. Situated in a small plain, surrounded by gardens, protected by a hill which is crowned by a wood of laurels, myrtle, and arbutus, the capital of Teneriffe is very beautifully placed. We should be mistaken if, relying on the account of some travellers, we believed it seated on the border of a lake. The rain sometimes forms a sheet of water of considerable extent; and the geologist, who beholds in everything the past rather than the present state of nature, can have no doubt but that the whole plain is a great basin dried up. Laguna has fallen from its opulence, since the lateral eruptions of the volcano have destroyed the port of Garachico, and since Santa Cruz has become the central point of the commerce of the island. It contains only 9000 inhabitants, of whom nearly 400 are monks, distributed in six convents. The town is surrounded with a great number of windmills, which indicate the cultivation of wheat in these high countries. I shall observe on this occasion, that different kinds of grain were known to the Guanches. They called wheat at Teneriffe tano, at Lancerota triffa; barley, in the grand Canary, bore the name of aramotanoque, and at Lancerota it was called tamosen. The flour of roasted barley (gofio) and goat"s-milk const.i.tuted the princ.i.p.al food of the people, on the origin of which so many systematic fables have been current. These aliments sufficiently prove that the race of the Guanches belonged to the nations of the old continent, perhaps to those of Caucasus, and not like the rest of the Atlantides,* to the inhabitants of the New World (* Without entering here into any discussion respecting the existence of the Atlantis, I may cite the opinion of Diodorus Siculus, according to whom the Atlantides were ignorant of the use of corn, because they were separated from the rest of mankind before these gramina were cultivated.); these, before the arrival of the Europeans, were unacquainted with corn, milk, and cheese.
A great number of chapels, which the Spaniards call ermitas, encircle the town of Laguna. Shaded by trees of perpetual verdure, and erected on small eminences, these chapels add to the picturesque effect of the landscape. The interior of the town is not equal to its external appearance. The houses are solidly built, but very antique, and the streets seem deserted. A botanist ought not to complain of the antiquity of the edifices. The roofs and walls are covered with Canary house-leek and those elegant trichomanes, mentioned by every traveller. These plants are nourished by the abundant mists.
Mr. Anderson, the naturalist in the third voyage of captain Cook, advises physicians to send their patients to Teneriffe, on account of the mildness of the temperature and the equal climate of the Canaries. The ground on these islands rises in an amphitheatre, and presents simultaneously, as in Peru and Mexico, the temperature of every climate, from the heat of Africa to the cold of the higher Alps. Santa Cruz, the port of Orotava, the town of the same name, and that of Laguna, are four places, the mean temperatures of which form a descending series. In the south of Europe the change of the seasons is too sensibly felt to present the same advantages.
Teneriffe, on the contrary, situated as it were on the threshold of the tropics, though but a few days" sail from Spain, shares in the charms which nature has lavished on the equinoctial regions.
Vegetation here displays some of her fairest and most majestic forms in the banana and the palm-tree. He who is alive to the charms of nature finds in this delicious island remedies still more potent than the climate. No abode appeared to me more fitted to dissipate melancholy, and restore peace to the perturbed mind, than that of Teneriffe or Madeira. These advantages are the effect not of the beauty of the site and the purity of the air alone: the moral feeling is no longer harrowed up by the sight of slavery, the presence of which is so revolting in the West Indies, and in every other place to which European colonists have conveyed what they call their civilization and their industry.
In winter the climate of Laguna is extremely foggy, and the inhabitants often complain of the cold. A fall of snow, however, has never been seen; a fact which may seem to indicate that the mean temperature of this town must be above 18.7 degrees (15 degrees R.), that is to say, higher than that of Naples. I do not lay this down as an unexceptional conclusion, for in winter the refrigeration of the clouds does not depend so much on the mean temperature of the whole year, as on the instantaneous diminution of heat to which a district is exposed by its local situation. The mean temperature of the capital of Mexico, for instance, is only 16.8 degrees (13.5 degrees R.), nevertheless, in the s.p.a.ce of a hundred years snow has fallen only once, while in the south of Europe and in Africa it snows in places where the mean temperature is above 19 degrees.
The vicinity of the sea renders the climate of Laguna more mild in winter than might be expected, arising from its elevation above the level of the ocean. I was astonished to learn that M. Broussonnet had planted in the midst of this town, in the garden of the Marquis de Nava, the bread-fruit tree (Artocarpus incisa), and cinnamon-tree (Laurus Cinnamomum). These valuable productions of the South Sea and the East Indies are naturalized there as well as at Orotava. Does not this fact prove that the bread-fruit might flourish in Calabria, Sicily, and Granada? The culture of the coffee-tree has not equally succeeded at Laguna, though its fruit ripens at Teguesta, as well as between the port of Orotava and the village of St. Juan de la Rambla. It is probable that some local circ.u.mstances, perhaps the nature of the soil and the winds that prevail in the flowering season, are the cause of this phenomenon.
In other regions, in the neighbourhood of Naples, for instance, the coffee-tree thrives abundantly, though the mean temperature scarcely rises above 18 centigrade degrees.
No person has ascertained in the island of Teneriffe, the lowest height at which snow falls every year. This fact, though easy of verification by barometrical measurements, has. .h.i.therto been generally neglected under every zone. It is nevertheless highly interesting both to agriculture in the colonies and meteorology, and fully as important as the measure of the limit of the perpetual snows. My observations furnished me with the data, set down in the following table:--
Column 1: North lat.i.tude.
Column 2: Lowest height in toises at which snow falls.
Column 3: Lowest height in metres at which snow falls.
Column 4: Inferior limit in toises of the perpetual snows.
Column 5: Inferior limit in metres of the perpetual snows.
Column 6: Difference in toises of columns 4 and 5.
Column 7: Difference in metres of columns 4 and 5.
Column 8: Mean temperature degrees centigrade.
Column 9: Mean temperature degrees Reaum.