This breccia, or calcareous sandstone, is a local and partial formation, peculiar to the peninsula of Araya, the coasts of Cumana, and Caracas. We again found it at Cabo Blanco, to the west of the port of Guayra, where it contains, besides broken shells and madrepores, fragments, often angular, of quartz and gneiss. This circumstance assimilates the breccia to that recent sandstone called by the German mineralogists nagelfluhe, which covers so great a part of Switzerland to the height of a thousand toises, without presenting any trace of marine productions. Near Cumana the formation of the calcareous breccia contains:—first, a compact whitish grey limestone, the strata of which, sometimes horizontal, sometimes irregularly inclined, are from five to six inches thick; some beds are almost unmixed with petrifactions, but in the greatest part the cardites, the turbinites, the ostracites, and shells of small dimension, are found so closely connected, that the calcareous matter forms only a cement, by which the grains of quartz and the organized bodies are united: second, a calcareous sandstone, in which the grains of sand are much more frequent than the petrified shells; other strata form a sandstone entirely free from organic fragments, yielding but a small effervescence with acids, and enclosing not lamellae of mica, but nodules of compact brown iron-ore: third, beds of indurated clay containing selenite and lamellar gypsum.
The breccia, or agglomerate of the sea-coast, just described, has a white tint, and it lies immediately on the calcareous formation of Cumanacoa, which is of a bluish grey. These two rocks form a contrast no less striking than the molasse (bur-stone) of the Pays de Vaud, with the calcareous limestone of the Jura. It must be observed, that, by contact of the two formations lying upon each other, the beds of the limestone of Cumanacoa, which I consider as an Alpine limestone, are always largely mixed with clay and marl. Lying, like the mica-slate of Araya, north-east and south-west, they are inclined, near Punta Delgada, under an angle of 60 degrees to south-east.
We traversed the forest by a narrow path, along a rivulet, which rolls foaming over a bed of rocks. We observed, that the vegetation was more brilliant, wherever the Alpine limestone was covered by a quartzose sandstone without petrifactions, and very different from the breccia of the sea-coast. The cause of this phenomenon depends probably not so much on the nature of the ground, as on the greater humidity of the soil. The quartzose sandstone contains thin strata of a blackish clay-slate,* (* Schieferthon.) which might easily be confounded with the secondary thonschiefer; and these strata hinder the water from filtering into the crevices, of which the Alpine limestone is full. This last offers to view here, as in Saltzburg, and on the chain of the Apennines, broken and steep beds. The sandstone, on the contrary, wherever it is seated on the calcareous rock, renders the aspect of the scene less wild. The hills which it forms appear more rounded, and the gentler slopes are covered with a thicker mould.
In humid places, where the sandstone envelopes the Alpine limestone, some trace of cultivation is constantly found. We met with huts inhabited by mestizoes in the ravine of Los Frailes, as well as between the Cuesta de Caneyes, and the Rio Guriental. Each of these huts stands in the centre of an enclosure, containing plantains, papaw-trees, sugar-canes, and maize. We might be surprised at the small extent of these cultivated spots, if we did not recollect that an acre planted with plantains* (* Musa paradisiaca.) produces nearly twenty times as much food as the same space sown with corn. In Europe, our wheat, barley, and rye cover vast spaces of ground; and in general the arable lands touch each other, wherever the inhabitants live upon corn. It is different under the torrid zone, where man obtains food from plants which yield more abundant and earlier harvests. In those favoured climes, the fertility of the soil is proportioned to the heat and humidity of the atmosphere. An immense population finds abundant nourishment within a narrow space, covered with plantains, cassava, yams, and maize. The isolated situation of the huts dispersed through the forest indicates to the traveller the fecundity of nature, where a small spot of cultivated land suffices for the wants of several families.
These considerations on the agriculture of the torrid zone involuntarily remind us of the intimate connexion existing between the extent of land cleared, and the progress of society. The richness of the soil, and the vigour of organic life, by multiplying the means of subsistence, retard the progress of nations in the paths of civilization. Under so mild and uniform a climate, the only urgent want of man is that of food. This want only, excites him to labour; and we may easily conceive why, in the midst of abundance, beneath the shade of the plantain and bread-fruit tree, the intellectual faculties unfold themselves less rapidly than under a rigorous sky, in the region of corn, where our race is engaged in a perpetual struggle with the elements. In Europe we estimate the number of the inhabitants of a country by the extent of cultivation: within the tropics, on the contrary, in the warmest and most humid parts of South America, very populous provinces appear almost deserted; because man, to find nourishment, cultivates but a small number of acres. These circumstances modify the physical appearance of the country and the character of its inhabitants, giving to both a peculiar physiognomy; the wild and uncultivated stamp which belongs to nature, ere its primitive type has been altered by art. Without neighbours, almost unconnected with the rest of mankind, each family of settlers forms a separate tribe. This insulated state arrests or retards the progress of civilization, which advances only in proportion as society becomes numerous, and its connexions more intimate and multiplied. But, on the other hand, it is solitude that develops and strengthens in man the sentiment of liberty and independence; and gives birth to that noble pride of character which has at all times distinguished the Castilian race.
From these causes, the land in the most populous regions of equinoctial America still retains a wild aspect, which is destroyed in temperate climates by the cultivation of corn. Within the tropics the agricultural nations occupy less ground: man has there less extended his empire; he may be said to appear, not as an absolute master, who changes at will the surface of the soil, but as a transient guest, who quietly enjoys the gifts of nature. There, in the neighbourhood of the most populous cities, the land remains studded with forests, or covered with a thick mould, unfurrowed by the plough. Spontaneous vegetation still predominates over cultivated plants, and determines the aspect of the landscape. It is probable that this state of things will change very slowly. If in our temperate regions the cultivation of corn contributes to throw a dull uniformity upon the land we have cleared, we cannot doubt, that, even with increasing population, the torrid zone will preserve that majesty of vegetable forms, those marks of an unsubdued, virgin nature, which render it so attractive and so picturesque. Thus it is that, by a remarkable concatenation of physical and moral causes, the choice and production of alimentary plants have an influence on three important objects at once; the association or the isolated state of families, the more or less rapid progress of civilization, and the individual character of the landscape.
In proportion as we penetrated into the forest, the barometer indicated the progressive elevation of the land. The trunks of the trees presented here an extraordinary phenomenon; a gramineous plant, with verticillate branches,* climbs, like a liana, eight or ten feet high, and forms festoons, which cross the path, and swing about with the wind. (* Carice, analogous to the chusque of Santa Fe, of the group of the Nastusas. This gramineous plant is excellent pasture for mules.) We halted, about three o'clock in the afternoon, on a small flat, known by the name of Quetepe, and situated about one hundred and ninety toises above the level of the sea. A few small houses have been erected near a spring, well known by the natives for its coolness and great salubrity. We found the water delicious. Its temperature was only 22.5 degrees of the centigrade thermometer, while that of the air was 28.7 degrees. The springs which descend from the neighbouring mountains of a greater height often indicate a too rapid decrement of heat. If indeed we suppose the mean temperature of the water on the coast of Cumana equal to 26 degrees, we must conclude, unless other local causes modify the temperature of the springs, that the spring of Quetepe acquires its great coolness at more than 350 toises of absolute elevation. With respect to the springs which gush out in the plains of the torrid zone, or at a small elevation, it may be observed, in general, that it is only in regions where the mean temperature of summer essentially differs from that of the whole year, that the inhabitants have extremely cold spring water during the season of great heat. The Laplanders, near Umea and Soersele, in the 65th degree of latitude, drink spring-water, the temperature of which, in the month of August, is scarcely two or three degrees above freezing point; while during the day the heat of the air rises in the shade, in the same northern regions, to 26 or 27 degrees. In the temperate climates of France and Germany, the difference between the air and the springs never exceeds 16 or 17 degrees; between the tropics it seldom rises to 5 or 6 degrees. It is easy to account for these phenomena, when we recollect that the interior of the globe, and the subterraneous waters, have a temperature almost identical with the annual mean temperature of the air; and that the latter differs from the mean heat of summer, in proportion to the distance from the equator.
From the top of a hill of sandstone, which overlooks the spring of Quetepe, we had a magnificent view of the sea, of cape Macanao, and the peninsula of Maniquarez. At our feet an immense forest extended to the edge of the ocean. The tops of the trees, intertwined with lianas, and crowned with long wreaths of flowers, formed a vast carpet of verdure, the dark tint of which augmented the splendour of the aerial light. This picture struck us the more forcibly, as we then first beheld those great masses of tropical vegetation. On the hill of Quetepe, at the foot of the Malpighia cocollobaefolia, the leaves of which are extremely coriaceous, we gathered, among tufts of the Polygala montana, the first melastomas, especially that beautiful species described under the name of the Melastoma rufescens.
As we advanced toward the south-west, the soil became dry and sandy. We climbed a group of mountains, which separate the coast from the vast plains, or savannahs, bordered by the Orinoco. That part of the group, over which passes the road to Cumanacoa, is destitute of vegetation, and has steep declivities both on the north and the south. It has received the name of the Imposible, because it is believed that, in the case of hostile invasion, this ridge of mountains would be inaccessible to the enemy, and would offer an asylum to the inhabitants of Cumana. We reached the top a little before sunset, and I had scarcely time to take a few horary angles, to determine the longitude of the place by means of the chronometer.
The view from the Imposible is finer and more extensive than that from the table-land of Quetepe. We distinguished clearly by the naked eye the flattened top of the Brigantine (the position of which it would be important to fix accurately), the embarcadero or landing-place, and the roadstead of Cumana. The rocky coast of the peninsula of Araya was discernible in its whole length. We were particularly struck with the extraordinary configuration of a port, known by the name of Laguna Grande, or Laguna del Obispo. A vast basin, surrounded by high mountains, communicates with the gulf of Cariaco by a narrow channel which admits only of the passage of one ship at a time. This port is capable of containing several squadrons at once. It is an uninhabited place, but annually frequented by vessels, which carry mules to the West India Islands. There are some pasture grounds at the farther end of the bay. We traced the sinuosities of this arm of the sea, which, like a river, has dug a bed between perpendicular rocks destitute of vegetation. This singular prospect reminded us of the fanciful landscape which Leonardo da Vinci has made the back-ground of his famous portrait of Mona Lisa, the wife of Francisco del Giacondo.