EARTHQUAKES AT CARACAS. CONNECTION OF THOSE PHENOMENA WITH THE VOLCANIC ERUPTIONS

OF THE WEST INDIA ISLANDS.

On the evening of the 7th of February we took our departure from Caracas. Since the period of our visit to that place, tremendous earthquakes have changed the surface of the soil. The city, which I have described, has disappeared; and on the same spot, on the ground fissured in various directions, another city is now slowly rising. The heaps of ruins, which were the grave of a numerous population, are becoming anew the habitation of men. In retracing changes of so general an interest, I shall be led to notice events which took place long after my return to Europe. I shall pass over in silence the popular commotions which have taken place, and the modifications which society has undergone. Modern nations, careful of their own remembrances, snatch from oblivion the history of human revolutions, which is, in fact, the history of ardent passions and inveterate hatred. It is not the same with respect to the revolutions of the physical world. These are described with least accuracy when they happen to be contemporary with civil dissensions. Earthquakes and eruptions of volcanoes strike the imagination by the evils which are their necessary consequence. Tradition seizes on whatever is vague and marvellous; and amid great public calamities, as in private misfortunes, man seems to shun that light which leads us to discover the real causes of events, and to understand the circumstances by which they are attended.

I have recorded in this work all I have been able to collect, and on the accuracy of which I can rely, respecting the earthquake of the 26th of March, 1812. By that catastrophe the town of Caracas was destroyed, and more than twenty thousand persons perished throughout the extent of the province of Venezuela. The intercourse which I have kept up with persons of all classes has enabled me to compare the description given by many eye-witnesses, and to interrogate them on objects that may throw light on physical science in general. The traveller, as the historian of nature, should verify the dates of great catastrophes, examine their connection and their mutual relations, and should mark in the rapid course of ages, in the continual progress of successive changes, those fixed points with which other catastrophes may one day be compared. All epochs are proximate to each other in the immensity of time comprehended in the history of nature. Years which have passed away seem but a few instants; and the physical descriptions of a country, even when they offer subjects of no very powerful and general interest, have at least the advantage of never becoming old. Similar considerations, no doubt, led M. de la Condamine to describe in his Voyage a l’Equateur, the memorable eruptions of the volcano of Cotopaxi,* which took place long after his departure from Quito. I feel the less hesitation in following the example of that celebrated traveller, as the events I am about to relate will help to elucidate the theory of volcanic reaction, or the influence of a system of volcanoes on a vast space of circumjacent territory.

[* Those of the 30th of November, 1744, and of the 3rd of September, 1750.]

At the time when M. Bonpland and myself visited the provinces of New Andalusia, New Barcelona, and Caracas, it was generally believed that the most eastern parts of those coasts were especially exposed to the destructive effects of earthquakes. The inhabitants of Cumana dreaded the valley of Caracas, on account of its damp and variable climate, and its gloomy and misty sky; whilst the inhabitants of the temperate valley regarded Cumana as a town whose inhabitants incessantly inhaled a burning atmosphere, and whose soil was periodically agitated by violent commotions. Unmindful of the overthrow of Riobamba and other very elevated towns, and not aware that the peninsula of Araya, composed of mica-slate, shares the commotions of the calcareous coast of Cumana, well-informed persons imagined they discerned security in the structure of the primitive rocks of Caracas, as well as in the elevated situation of this valley. Religious ceremonies celebrated at La Guayra, and even in the capital, in the middle of the night,* doubtless called to mind the fact that the province of Venezuela had been subject at intervals to earthquakes; but dangers of rare occurrence are slightly feared. However, in the year 1811, fatal experience destroyed the illusion of theory and of popular opinion. Caracas, situated in the mountains, three degrees west of Cumana, and five degrees west of the volcanoes of the Caribbee islands, has suffered greater shocks than were ever experienced on the coast of Paria or New Andalusia.

[* For instance, the nocturnal procession of the 21st of October, instituted in commemoration of the great earthquake which took place on that day of the month, at one o’clock in the morning, in 1778. Other very violent shocks were those of 1641, 1703, and 1802.]

At my arrival in Terra Firma, I was struck with the connection between the destruction of Cumana on the 14th of December, 1797, and the eruption of the volcanoes in the smaller West India Islands. This connection was again manifest in the destruction of Caracas on the 26th of March, 1812. The volcano of Guadaloupe seemed in 1797 to have exercised a reaction on the coasts of Cumana. Fifteen years later, it was a volcano situated nearer the continent (that of St. Vincent), which appeared to have extended its influence as far as Caracas and the banks of Apure. Possibly, at both those periods, the centre of the explosion was, at an immense depth, equally distant from the regions towards which the motion was propagated at the surface of the globe.

From the beginning of 1811 to 1813, a vast superficies of the earth,* bound 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 smaller West India Islands, was shaken throughout its whole extent, by commotions which may be attributed to subterranean fires. The following series of phenomena seems to indicate communications at enormous distances. On the 30th of January, 1811, a submarine volcano broke out near the island of St. Michael, one of the Azores. At a place where the sea was sixty fathoms deep, a rock made its appearance above the surface of the waters. The heaving-up of the softened crust of the globe appears to have preceded the eruption of flame at the crater, as had already been observed at the volcanoes of Jorullo in Mexico, and on the appearance of the little island of Kameni, near Santorino. The new islet of the Azores was at first a mere shoal; but on the 15th of June, an eruption, which lasted six days, enlarged its extent, and carried it progressively to the height of fifty toises above the surface of the sea. This new land, of which captain Tillard took possession in the name of the British government, giving it the name of Sabrina Island, was nine hundred toises in diameter. It has again, it seems, been swallowed up by the ocean. This is the third time that submarine volcanoes have presented this extraordinary spectacle near the island of St. Michael; and, as if the eruptions of these volcanoes were subject to periodical recurrence, owing to a certain accumulation of elastic fluids, the island raised up has appeared at intervals of ninety-one or ninety-two years.*

[* Between latitudes 5 and 36° north, and 31 and 91° west longitude from Paris.]

[* Malte–Brun, Geographie Universelle. There is, however, some doubt respecting the eruption of 1628, to which some accounts assign the date of 1638. The rising always happened near the island of St. Michael, though not identically on the same spot. It is remarkable that the small island of 1720 reached the same elevation as the island of Sabrina in 1811.]

At the time of the appearance of the new island of Sabrina, the smaller West India Islands, situated eight hundred leagues south-west of the Azores, experienced frequent earthquakes. More than two hundred shocks were felt from the month of May 1811, to April 1812, at St. Vincent; one of the three islands in which there are still active volcanoes. The commotion was not circumscribed to the insular portion of eastern America; and from the 16th of December, 1811, till the year 1813, the earth was almost incessantly agitated in the valleys of the Mississippi, the Arkansas river, and the Ohio. The oscillations were more feeble on the east of the Alleghanies, than to the west of these mountains, in Tennessee and Kentucky. They were accompanied by a great subterranean noise, proceeding from the south-west. In some places between New Madrid and Little Prairie, as at the Saline, north of Cincinnati, in latitude 37° 45′, shocks were felt every day, nay almost every hour, during several months. The whole of these phenomena continued from the 16th of December 1811, till the year 1813. The commotion, confined at first to the south, in the valley of the lower Mississippi, appeared to advance slowly northward.

Precisely at the period when this long series of earthquakes commenced in the Transalleghanian States (in the month of December 1811), the town of Caracas felt the first shock in calm and serene weather. This coincidence of phenomena was probably not accidental; for it must be borne in mind that, notwithstanding the distance which separates these countries, the low grounds of Louisiana and the coasts of Venezuela and Cumana belong to the same basin, that of the Gulf of Mexico. When we consider geologically the basin of the Caribbean Sea, and of the Gulf of Mexico, we find it bounded on the south by the coast-chain of Venezuela and the Cordilleras of Merida and Pamplona; on the east by the mountains of the West India Islands, and the Alleghanies; on the west by the Andes of Mexico, and the Rocky Mountains; and on the north by the very inconsiderable elevations which separate the Canadian lakes from the rivers which flow into the Mississippi. More than two-thirds of this basin are covered with water. It is bordered by two ranges of active volcanoes; on the east, in the Carribee Islands, between latitudes 13 and 16°; and on the west in the Cordilleras of Nicaragua, Guatimala, and Mexico, between latitudes 11 and 20°. When we reflect that the great earthquake at Lisbon, of the 1st of November, 1755, was felt almost simultaneously on the coasts of Sweden, at lake Ontario, and at the island of Martinique, it may not seem unreasonable to suppose, that all this basin of the West Indies, from Cumana and Caracas as far as the plains of Louisiana, should be simultaneously agitated by commotions proceeding from the same centre of action.

It is an opinion very generally prevalent on the coasts of Terra Firma, that earthquakes become more frequent when electric explosions have been during some years rare. It is supposed to have been observed, at Cumana and at Caracas, that the rains were less frequently attended with thunder from the year 1792; and the total destruction of Cumana in 1797, as well as the commotions felt in 1800, 1801, and 1802, at Maracaibo, Porto Cabello, and Caracas, have not failed to be attributed to an accumulation of electricity in the interior of the earth. Persons who have lived long in New Andalusia, or in the low regions of Peru, will admit that the period most to be dreaded for the frequency of earthquakes is the beginning of the rainy season, which, however, is also the season of thunder-storms. The atmosphere and the state of the surface of the globe seem to exercise an influence unknown to us on the changes which take place at great depths; and I am inclined to think that the connection which it is supposed has been traced between the absence of thunder-storms and the frequency of earthquakes, is rather a physical hypothesis framed by the half-learned of the country than the result of long experience. The coincidence of certain phenomena may be favoured by chance. The extraordinary commotions felt almost continually during the space of two years on the banks of the Mississippi and the Ohio, and which corresponded in 1812 with those of the valley of Caracas, were preceded at Louisiana by a year almost exempt from thunder-storms. The public mind was again struck with this phenomenon. We cannot be surprised that there should be in the native land of Franklin a great readiness to receive explanations founded on the theory of electricity.

The shock felt at Caracas in the month of December 1811, was the only one which preceded the terrible catastrophe of the 26th of March, 1812. The inhabitants of Terra Firma were alike ignorant of the agitations of the volcano in the island of St. Vincent, and of those felt in the basin of the Mississippi, where, on the 7th and 8th of February, 1812, the earth was day and night in perpetual oscillation. A great drought prevailed at this period in the province of Venezuela. Not a single drop of rain had fallen at Caracas or in the country to the distance of ninety leagues round, during five months preceding the destruction of the capital. The 26th of March was a remarkably hot day. The air was calm, and the sky unclouded. It was Ascension-day, and a great portion of the population was assembled in the churches. Nothing seemed to presage the calamities of the day. At seven minutes after four in the afternoon the first shock was felt. It was sufficiently forcible to make the bells of the churches toll; and it lasted five or six seconds. During that interval the ground was in a continual undulating movement, and seemed to heave up like a boiling liquid. The danger was thought to be past, when a tremendous subterranean noise was heard, resembling the rolling of thunder, but louder and of longer continuance than that heard within the tropics in the time of storms. This noise preceded a perpendicular motion of three or four seconds, followed by an undulatory movement somewhat longer. The shocks were in opposite directions, proceeding from north to south, and from east to west. Nothing could resist the perpendicular movement and the transverse undulations. The town of Caracas was entirely overthrown, and between nine and ten thousand of the inhabitants were buried under the ruins of the houses and churches. The procession of Ascension-day had not yet begun to pass through the streets, but the crowd was so great within the churches that nearly three or four thousand persons were crushed by the fall of the roofs. The explosion was most violent towards the north, in that part of the town situated nearest the mountain of Avila and the Silla. The churches of la Trinidad and Alta Gracia, which were more than one hundred and fifty feet high, and the naves of which were supported by pillars of twelve or fifteen feet diameter, were reduced to a mass of ruins scarcely exceeding five or six feet in elevation. The sinking of the ruins has been so considerable that there now scarcely remain any vestiges of pillars or columns. The barracks, called el Quartel de San Carlos, situated north of the church of la Trinidad, on the road from the custom-house of La Pastora, almost entirely disappeared. A regiment of troops of the line, under arms, and in readiness to join the procession, was, with the exception of a few men, buried beneath the ruins of the barracks. Nine-tenths of the fine city of Caracas were entirely destroyed. The walls of some houses not thrown down, as those in the street San Juan, near the Capuchin Hospital, were cracked in such a manner as to render them uninhabitable. The effects of the earthquake were somewhat less violent in the western and southern parts of the city, between the principal square and the ravine of Caraguata. There, the cathedral, supported by enormous buttresses, remains standing.

It is computed that nine or ten thousand persons were killed in the city of Caracas, exclusive of those who, being dangerously wounded, perished several months after, for want of food and proper care. The night of the Festival of the Ascension witnessed an awful scene of desolation and distress. The thick cloud of dust which, rising above the ruins, darkened the sky like a fog, had settled on the ground. No commotion was felt, and never was a night more calm or more serene. The moon, then nearly at the full, illumined the rounded domes of the Silla, and the aspect of the sky formed a perfect contrast to that of the earth, which was covered with the bodies of the dead, and heaped with ruins. Mothers were seen bearing in their arms their children, whom they hoped to recall to life. Desolate families were wandering through the city, seeking a brother, a husband, or a friend, of whose fate they were ignorant, and whom they believed to be lost in the crowd. The people pressed along the streets, which could be traced only by long lines of ruins.

All the calamities experienced in the great catastrophes of Lisbon, Messina, Lima, and Riobamba were renewed at Caracas on the fatal 26th of March, 1812. Wounded persons, buried beneath the ruins, were heard imploring by their cries the help of the passers-by, and nearly two thousand were dug out. Never was pity more tenderly evinced; never was it more ingeniously active than in the efforts employed to save the miserable victims whose groans reached the ear. Implements for digging and clearing away the ruins were entirely wanting; and the people were obliged to use their bare hands, to disinter the living. The wounded, as well as the invalids who had escaped from the hospitals, were laid on the banks of the small river Guayra, where there was no shelter but the foliage of trees. Beds, linen to dress the wounds, instruments of surgery, medicines, every object of the most urgent necessity, was buried in the ruins. Everything, even food, was wanting; and for the space of several days water became scarce in the interior of the city. The commotion had rent the pipes of the fountains; and the falling in of the earth had choked up the springs that supplied them. To procure water it was necessary to go down to the river Guayra, which was considerably swelled; and even when the water was obtained vessels for conveying it were wanting.

There was a duty to be fulfilled to the dead, enjoined at once by piety and the dread of infection. It being impossible to inter so many thousand bodies, half-buried under the ruins, commissioners were appointed to burn them: and for this purpose funeral piles were erected between the heaps of ruins. This ceremony lasted several days. Amidst so many public calamities, the people devoted themselves to those religious duties which they thought best fitted to appease the wrath of heaven. Some, assembling in processions, sang funeral hymns; others, in a state of distraction, made their confessions aloud in the streets. In Caracas was then repeated what had been remarked in the province of Quito, after the tremendous earthquake of 1797; a number of marriages were contracted between persons who had neglected for many years to sanction their union by the sacerdotal benediction. Children found parents, by whom they had never till then been acknowledged; restitutions were promised by persons who had never been accused of fraud; and families who had long been at enmity were drawn together by the tie of common calamity. But if this feeling seemed to calm the passions of some, and open the heart to pity, it had a contrary effect on others, rendering them more rigorous and inhuman. In great calamities vulgar minds evince less of goodness than of energy. Misfortune acts in the same manner as the pursuits of literature and the study of nature; the happy influence of which is felt only by a few, giving more ardour to sentiment, more elevation to the thoughts, and increased benevolence to the disposition.

Shocks as violent as those which in about the space of a minute* overthrew the city of Caracas, could not be confined to a small portion of the continent. Their fatal effects extended as far as the provinces of Venezuela, Varinas, and Maracaibo, along the coast; and especially to the inland mountains. La Guayra, Mayquetia, Antimano, Baruta, La Vega, San Felipe, and Merida, were almost entirely destroyed. The number of the dead exceeded four or five thousand at La Guayra, and at the town of San Felipe, near the copper-mines of Aroa. It would appear that on a line running east-north-east and west-south-west from La Guayra and Caracas to the lofty mountains of Niquitao and Merida, the violence of the earthquake was principally directed. It was felt in the kingdom of New Grenada from the branches of the high Sierra de Santa Martha* as far as Santa Fe de Bogota and Honda, on the banks of the Magdalena, one hundred and eighty leagues from Caracas. It was everywhere more violent in the Cordilleras of gneiss and mica-slate, or immediately at their base, than in the plains; and this difference was particularly striking in the savannahs of Varinas and Casanara.* In the valleys of Aragua, between Caracas and the town of San Felipe, the commotions were very slight; and La Victoria, Maracay, and Valencia, scarcely suffered at all, notwithstanding their proximity to the capital. At Valecillo, a few leagues from Valencia, the yawning earth threw out such an immense quantity of water, that it formed a new torrent. The same phenomenon took place near Porto–Cabello.* On the other hand, the lake of Maracaybo diminished sensibly. At Coro no commotion was felt, though the town is situated on the coast, between other towns which suffered from the earthquake. Fishermen, who had passed the day of the 26th of March in the island of Orchila, thirty leagues north-east of La Guayra, felt no shock. These differences in the direction and propagation of the shock, are probably owing to the peculiar position of the stony strata.

[* The duration of the earthquake, that is to say the whole of the movements of undulation and rising (undulacion y trepidacion), which occasioned the horrible catastrophe of the 26th of March, 1812, was estimated by some at 50 seconds, by others at 1 minute 12 seconds.]

[* As far as Villa de Los Remedios, and even to Carthagena.]

[* This is easily explained according to the system of those geologists who are of opinion that all chains of mountains, volcanic and not volcanic, have been formed by being raised up, as if through crevices.]

[* It is asserted that, in the mountains of Aroa, the ground, immediately after the great shocks, was found covered with a very fine and white earth, which appeared to have been projected through crevices.]

Having thus traced the effects of the earthquake to the west of Caracas, as far as the snowy mountains of Santa Martha, and the table-land of Santa Fe de Bogota, we will proceed to consider their action on the country eastward of the capital. The commotions were very violent beyond Caurimare, in the valley of Capaya, where they extended as far as the meridian of Cape Codera: but it is extremely remarkable that they were very feeble on the coasts of Nueva Barcelona, Cumana, and Paria; though these coasts are the continuation of the shore of La Guayra, and were formerly known to have been often agitated by subterranean commotions. Admitting that the destruction of the four towns of Caracas, La Guayra, San Felipe, and Merida, may be attributed to a volcanic focus situated under or near the island of St. Vincent, we may conceive that the motion might have been propagated from north-east to south-west in a line passing through the islands of Los Hermanos, near Blanquilla, without touching the coasts of Araya, Cumana, and Nueva Barcelona. This propagation of the shock might even have taken place without any commotion having been felt at the intermediate points on the surface of the globe (the Hermanos Islands for instance). This phenomenon is frequently remarked at Peru and Mexico, in earthquakes which have followed during ages a fixed direction. The inhabitants of the Andes say, speaking of an intermediary tract of ground, not affected by the general commotion, “that it forms a bridge” (que hace puente): as if they mean to indicate by this expression that the undulations are propagated at an immense depth under an inert rock.

At Caracas, fifteen or eighteen hours after the great catastrophe, the earth was tranquil. The night, as has already been observed, was fine and calm; and the commotions did not recommence till after the 27th. They were then attended by a very loud and long continued subterranean noise (bramido). The inhabitants of the destroyed city wandered into the country; but the villages and farms having suffered as much as the town, they could find no shelter till they were beyond the mountains of los Teques, in the valleys of Aragua, and in the llanos or savannahs. No less than fifteen oscillations were felt in one day. On the 5th of April there was almost as violent an earthquake as that which overthrew the capital. During several hours the ground was in a state of perpetual undulation. Large heaps of earth fell in the mountains; and enormous masses of rock were detached from the Silla of Caracas. It was even asserted, and this opinion prevails still in the country, that the two domes of the Silla sunk fifty or sixty toises; but this statement is not founded on any measurement. I am informed that, in like manner, in the province of Quito, the people, at every period of great commotions, imagine that the volcano of Tunguragua diminishes in height. It has been affirmed, in many published accounts of the destruction of Caracas, that the mountain of the Silla is an extinguished volcano; that a great quantity of volcanic substances are found on the road from La Guayra to Caracas; that the rocks do not present any regular stratification; and that everything bears the stamp of the action of fire. It has even been stated that twelve years prior to the great catastrophe, M. Bonpland and myself had, from our own observations, considered the Silla as a very dangerous neighbour to the city of Caracas, because the mountain contained a great quantity of sulphur, and the commotions must come from the north-east. It is seldom that observers of nature have to justify themselves for an accomplished prediction; but I think it my duty to oppose ideas which are too easily adopted on the LOCAL CAUSES of earthquakes.

In all places where the soil has been incessantly agitated for whole months, as at Jamaica in 1693, Lisbon in 1755, Cumana in 1766, and Piedmont in 1808, a volcano is expected to open. People forget that we must seek the focus or centre of action, far from the surface of the earth; that, according to undeniable evidence, the undulations are propagated almost at the same instant across seas of immense depth, at the distance of a thousand leagues; and that the greatest commotions take place not at the foot of active volcanoes, but in chains of mountains composed of the most heterogeneous rocks. In our geognostical observation of the country round Caracas we found gneiss, and mica-slate containing beds of primitive limestone. The strata are scarcely more fractured or irregularly inclined than near Freyburg in Saxony, or wherever mountains of primitive formation rise abruptly to great heights. I found at Caracas neither basalt nor dorolite, nor even trachytes or trap-porphyries; nor in general any trace of an extinguished volcano, unless we choose to regard the diabases of primitive grunstein, contained in gneiss, as masses of lava, which have filled up fissures. These diabases are the same as those of Bohemia, Saxony, and Franconia;* and whatever opinion may be entertained respecting the ancient causes of the oxidation of the globe at its surface, all those primitive mountains, which contain a mixture of hornblende and feldspar, either in veins or in balls with concentric layers, will not, I presume, be called volcanic formations. Mont Blanc and Mont d’Or will not be ranged in one and the same class. Even the partisans of the Huttonian or volcanic theory make a distinction between the lavas melted under the mere pressure of the atmosphere at the surface of the globe, and those layers formed by fire beneath the immense weight of the ocean and superincumbent rocks. They would not confound Auvergne and the granitic valley of Caracas in the same denomination; that of a country of extinct volcanoes.

[* These grunsteins are found in Bohemia, near Pilsen, in granite; in Saxony, in the mica-slates of Scheenberg; in Franconia, between Steeben and Lauenstein, in transition-slates.]

I never could have pronounced the opinion, that the Silla and the Cerro de Avila, mountains of gneiss and mica-slate, were in dangerous proximity to the city of Caracas because they contained a great quantity of pyrites in subordinate beds of primitive limestone. But I remember having said, during my stay at Caracas, that the eastern extremity of Terra Firma appeared, since the great earthquake of Quito, in a state of agitation, which warranted apprehension that the province of Venezuela would gradually be exposed to violent commotions. I added, that when a country had been long subject to frequent shocks, new subterranean communications seemed to open with neighbouring countries; and that the volcanoes of the West India Islands, lying in the direction of the Silla, north-east of the city, were perhaps the vents, at the time of an eruption, for those elastic fluids which cause earthquakes on the coasts of the continent. These considerations, founded on local knowledge of the place, and on simple analogies, are very far from a prediction justified by the course of physical events.

On the 30th of April, 1812, whilst violent commotions were felt simultaneously in the valley of the Mississippi, in the island of St. Vincent, and in the province of Venezuela, a subterranean noise resembling frequent discharges of large cannon was heard at Caracas, at Calabozo (situated in the midst of the steppes), and on the borders of the Rio Apure, over a superficies of four thousand square leagues. This noise began at two in the morning. It was accompanied by no shock; and it is very remarkable, that it was as loud on the coast as at the distance of eighty leagues inland. It was everywhere believed to be transmitted through the air; and was so far from being thought a subterranean noise, that in several places, preparations were made for defence against an enemy, who seemed to be advancing with heavy artillery. Senor Palacio, crossing the Rio Apure below the Orivante, near the junction of the Rio Nula, was told by the inhabitants, that the firing of cannon had been heard distinctly at the western extremity of the province of Varinas, as well as at the port of La Guayra to the north of the chain of the coast.

The day on which the inhabitants of Terra Firma were alarmed by a subterranean noise was that of the great eruption of the volcano in the island of St. Vincent. That mountain, near five hundred toises high, had not thrown out lava since the year 1718. Scarcely was any smoke perceived to issue from it, when, in the month of May 1811, frequent shocks announced that the volcanic fire was either rekindled, or directed anew to that part of the West Indies. The first eruption did not take place till the 27th of April, 1812, at noon. It was merely an ejection of ashes, but attended with a tremendous noise. On the 30th, the lava overflowed the brink of the crater, and, after a course of four hours, reached the sea. The sound of the explosion is described as resembling that of alternate discharges of very large cannon and musketry; and it is worthy of remark, that it seemed much louder to persons out at sea, and at a great distance from land, than to those within sight of land, and near the burning volcano.

The distance in a straight line from the volcano of St. Vincent to the Rio Apure, near the mouth of the Nula, is two hundred and ten leagues.* The explosions were consequently heard at a distance equal to that between Vesuvius and Paris. This phenomenon, in conjunction with a great number of facts observed in the Cordilleras of the Andes, shows that the sphere of the subterranean activity of a volcano is much more extensive than we should be disposed to admit, if we judged merely from the small changes effected at the surface of the globe. The detonations heard during whole days together in the New World, eighty, one hundred, or even two hundred leagues distant from a crater, do not reach us by the propagation of the sound through the air; they are transmitted by the earth, perhaps in the very place where we happen to be. If the eruptions of the volcano of St. Vincent, Cotopaxi, or Tunguragua, resounded from afar, like a cannon of immense magnitude, the noise ought to increase in the inverse ratio of the distance: but observations prove, that this augmentation does not take place. I must further observe, that M. Bonpland and I, going from Guayaquil to the coast of Mexico, crossed latitudes in the Pacific, where the crew of our ship were dismayed by a hollow sound coming from the depth of the ocean, and transmitted by the waters. At that time a new eruption of Cotopaxi took place, but we were as far distant from the volcano, as Etna from the city of Naple............