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IMMENSE PRECIPICE.

reaching the eastern summit before sunset, and of returning to the hollow separating the two peaks, where they might pass the night. With this view they sent half of their attendants to procure a supply, not of olives, but of salt beef. These arrangements were scarcely made when the east wind began to blow violently, and in less than two minutes the clouds dispersed. The obstacles presented by the vegetation gradually diminished as they approached the eastern summit, in order to attain which it was necessary to go close to the great precipice. Hitherto the guests had preserved its lamellar structure; but as they climbed the cone of the Silla they found it passing into granite, containing, instead of garnets, a few scattered crystals of hornblende. In three-quarters of an hour they reached the top of the pyramid, which was covered with grass, and for a few minutes enjoyed all the serenity of the sky. The elevation being 8633 feet, the eye commanded a vast range of country. The slope, which extends nearly to the sea, had an angle of 53° 28', though when viewed from the coast it seems perpendicular. Humboldt remarks that a precipice of 6000 or 7000 feet is a phenomenon much rarer than is usually believed, and that a rock of 1600 feet of perpendicular height has in vain been sought for among the Swiss Alps. That of the Silla is partly covered with vegetation, tufts of befariæ and andromedæ appearing as if suspended from the rock.

Seven months had elapsed since they were on the summit of the Peak of Teneriffe, where the apparent horizon of the sea is six leagues farther distant than on the Silla; yet while the boundary line was seen distinct in the former place it was completely blended with the air in the latter. The western dome concealed the town of Caraccas; but they distinguished the villages of Chacao and Petare, the coffee-plantations, and the course of the Rio Guayra. While they were examining the part of the sea

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where the horizon was well defined, and the great chain of mountains in the distant south, a dense fog arose from the plains, and they were obliged to use all expedition in completing their observations.

When seated on the rock, employed in determining the dip of the needle, Humboldt found his hands covered by a species of hairy bee, a little smaller than the honey-bee of Europe. These insects make their nest in the ground, seldom fly, move very slowly, and are apt to use their sting, the guides asserting that they do so only when seized by the legs.

The temperature varied from 52° to 57°, according as the weather was calm or otherwise. The dip of the needle was one centesimal degree less than at Caraccas. The breeze was from the east, which might indicate that the trade-winds extend in this latitude much higher than 9600 feet. The blue of the atmosphere was deeper than on the coasts, Saussure's cyanometer indicating 26 5°, while at Caraccas it generally gave only 18° in fine dry weather. The phenomenon that most struck the travellers was the apparent aridity of the air, which seemed to increase as the mist thickened, the hygrometer retrograding, and their clothes remaining dry.

As it would have been imprudent to remain long in a dense fog on the brink of a precipice, the travellers descended the eastern dome, and on regaining the hollow between the two summits, were surprised to find round pebbles of quartz, a phenomenon which perhaps indicates that the mountain has been raised by a power applied from below. Relinquishing their design of passing the night in that valley, and having again found the path which they had cut through the wood, they soon arrived at the district of resinous shrubs, where they lingered so long collecting plants that darkness surprised them as they entered the savanna. The moon was up, but every M

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DESCENT-RAVINE OF TIPE.

now and then obscured by clouds. The guides who carried the instruments slunk off successively to sleep among the cliffs; and it was not until ten that the travellers arrived at the bottom of the ravine, overcome by thirst and fatigue.

During the excursion to the Silla, and in all their walks in the valley of Caraccas, they were very attentive to the indication of ores which they found in the gneiss mountains. In America that rock has not hitherto been found to be very rich in metals; the most celebrated mines of Mexico and Peru being in primitive and transition slate, trap, porphyry, graywacke, and alpine limestone. In several parts, of the region now visited, a small quantity of gold was found disseminated in veins of quartz, sulphuretted silver, blue copper-ore, and leadglance; but these deposites did not seem of any importance. In the group of the western mountains of Venezuela the Spaniards, in 1551, attempted the gold mine of Buria, but the works were soon given up. In the vicinity of Caraccas some had also been wrought, but to no great extent. In short, the mines here afforded little gratification to the cupidity of the conquerors, and were almost totally abandoned; those of Arva, near San Felipe el Fuerte, being the only ones in operation when Humboldt visited the country.

In the course of their investigations the travellers examined the ravine of Tipe, situated in that part of the valley which opens towards Cape Blanco. The first portion of the road was over a barren and rocky soil, on which grew a few plants of Argemone Mexicana. On either side of the defile was a range of bare mountains, and at this spot the plain on which the town is built communicates with the coast near Catia by the valleys of Tacagua and Tipe. In the former they found some plantations of maize and plantains, and a very extensive one of cactuses fifteen feet high. They met with several

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veins of quartz, containing pyrites, carbonated ironore, sulphuretted silver, and gray copper. The works that had been undertaken were superficial, and now filled up.

CHAPTER XIII.

Earthquakes of Caraccas.

Extensive Connexion of Earthquakes-Eruption of the Volcano of St. Vincent's-Earthquake of the 26th March, 1812--Destruction of the City--Ten Thousand of the Inhabitants killed-Consternation of the Survivors-Extent of the Commotions.

THE Valley of Caraccas, a few years after Humboldt's visit, became the theatre of one of those physical revolutions which from time to time produce violent alterations upon the surface of our planet; involving the overthrow of cities, the destruction of human life, and a temporary agitation of those elements of nature on which the system of the universe is founded. In the narrative of his Journey to the Equinoctial Regions of the New Continent, he has recorded all that he could collect with certainty respecting the earthquake of the 26th March, 1812, which destroyed the city of Caraccas, together with 20,000 inhabitants of the province of Venezuela.

When our travellers visited those countries, they found it to be a general opinion that the eastern parts of the coasts were most exposed to the destructive effects of such concussions, and that the elevated districts, remote from the shores, were in a great measure secure; but in 1811 all these ideas were proved groundless.

At Humboldt's arrival in Terra Firma, he was struck with the connexion which appeared between

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EARTHQUAKE OF CARACCAS.

the destruction of Cumana in 1797 and the eruption of volcanoes in the smaller West India islands. A similar principle was manifested in 1812, in the case of Caraccas. From the beginning of 1811 till 1813, a vast extent of the earth's surface, limited by the meridian of the Azores, the valley of the Ohio, the cordilleras of New-Grenada, the coasts of Venezuela, and the volcanoes of the West Indies, was shaken by subterranean commotions, indicative of a common agency exerted at a great depth in the interior of the globe. At the period when these earthquakes commenced in the valley of the Mississippi, the city of Caraccas felt the first shock in December, 1811; and on the 26th of March 1812 it was totally destroyed.

"The inhabitants of Terra Firma were ignorant of the agitation, which on the one hand the volcano of the island of St. Vincent had experienced, and on the other the basin of the Mississippi, where, on the 7th and 8th of February, 1812, the ground was day and night in a state of continual oscillation. At this period the province of Venezuela laboured under great drought; not a drop of rain had fallen at Caraccas, or to the distance of 311 miles around, during the five months which preceded the destruction of the capital. The 26th March was excessively hot; the air was calm and the sky cloudless. It was Holy Thursday, and a great part of the population was in the churches. The calamities of the day were preceded by no indications of danger. At seven minutes after four in the evening the first commotion was felt. It was so strong as to make the bells of the churches ring. It lasted from five to six seconds, and was immediately followed by another shock of from ten to twelve seconds, during which the ground was in a continual state of undulation, and heaved like a fluid under ebullition. The danger was thought to be over, when a prodigious subterranean noise was heard, resembling the rolling