Part 58

The approach to the springs lies up the valley of the creek. On the right of the valley rises the hot mountain, with the springs issuing at its foot; on the left, the cold mountain, which is little more than a confused and mighty pile of stones. The hot mountain is about 300 feet high, rising quite steep, and presenting occasionally ledges of rocks; it terminates above in a confused mass of broken rocks. The steep and otherwise sterile sides are covered with a luxuriant growth of vines. The valley between this and the cold mountain is about fifty yards wide.

The springs issue at the foot of the hot mountain, at an elevation of about ten feet above the level of the creek; they are very numerous all along the hill-side, and the water, which runs in copious streams, is quite hot; it will scald the hand, and boil an egg hard in ten minutes. Its temperature is considered that of boiling water, but Dr. Andrews, of Red River, thinks it is not above 200° Fahr. There is a solitary spring, situated seventy feet higher than the others on the side of the mountain, but it is of an equal temperature, and differs in no respect from those below. A dense fog continually hangs over the springs and upon the side of the hill, which at a distance looks like a number of furnaces in blast. To this fog, condensed into water, is attributed the rank growth of the vines on the side of the mountain.

Very little is known of the chemical nature of the water; an analysis is said to have been made, which indicated a little carbonate of lime. An abundance of beautiful green moss grows at the edges of the springs, and the paths of their waters are marked by a brighter vegetation than occurs elsewhere. The substance of the rocks here, are, limestone, slate, and quartz.--_Schoolcroft, Lead Mines of Missouri_, p. 258.

We shall conclude this chapter with an account of VARIOUS OTHER BURNING SPRINGS.--There are many burning springs in different parts of the world, particularly one in France, in the department of Isere, near Grenoble; another near Hermanstadt, in Transylvania; a third at Chermay, a village near Switzerland; a fourth in the canton of Friburg; and a fifth not far from the city of Cracow, in Poland. There also is, or was, a famous spring of this kind at Wigan, in Lancashire, which, upon the approach of a lighted candle, would take fire and burn like spirit of wine for a whole day. But the most remarkable one in England, or at least that of which we have the minutest description, was discovered in 1711, at Brosely, in Shropshire. The following account of this remarkable spring was given by the Rev. Mr. Mason Woodwardin, Professor at Cambridge, dated Feb. 18th. 1746:--"The well, for four or five feet deep, is six or seven feet wide; within that, is another less hole of like depth, dug in the clay, in the bottom whereof is placed a cylindric earthen vessel, of about four or five inches diameter at the mouth, having the bottom taken off, and the sides well fixed in the clay, which is rammed close about it. Within the pot is a brown water, thick and puddly, continually forced up with a violent motion beyond that of boiling water, and a rumbling hollow noise, rising or falling by fits, five or six inches; but there was no appearance of any vapour rising, which perhaps might have been visible, had not the sun shone so bright. Upon putting a candle down at the end of a stick, at about a quarter of a yard distance, it took fire, darting and flashing after a very violent manner for about half a yard high, much in the manner of spirits in a lamp, but with great agitation. It was said, that a teakettle had been made to boil in nine minutes, and that it had been left burning for forty-eight hours without any sensible diminution. It was extinguished by putting a wet mop upon it; which must be kept there for a little time, otherwise it would not go out. Upon the removal of the mop, there arises a sulphureous smoke, lasting about a minute, and yet the water is very cold to the touch." In 1755, this well totally disappeared, by the sinking of a coal-pit in its neighbourhood. The cause of the inflammable property of such waters is with great probability supposed to be their mixture with petroleum, which is one of the most inflammable substances in nature, and has the property of burning on the surface of water.

CHAP. XLVIII.

CURIOSITIES RESPECTING EARTHQUAKES.

Earthquakes, Nature's agonizing pangs, Oft shake the astonish'd isles; the Solfaterre Or sends forth thick, blue, suffocating steams, Or shoots to temporary flames. A din, Wild, thro' the mountain's quivering rocky caves, Like the dread crash of tumbling planets, roars. When tremble thus the pillars of the globe, Like the tall cocoa by the fierce north blown, Can the poor brittle tenements of man Withstand the dread convulsion? Their dear homes, Which shaking, tottering, crashing, bursting, fall, The boldest fly; and, on the open plain Appall'd in agony, the moment wait, When, with disrupture vast, the waving earth Shall whelm them in her sea-disgorging womb. Nor less affrighted are the bestial kind: The bold steed quivers in each panting vein, And staggers, bath'd in deluges of sweat: The lowing herds forsake their grassy food, And send forth frighted, woful, hollow sounds: The dog, thy trusty centinel of night, Deserts the post assign'd, and piteous howls. Wide ocean feels-------- The mountain waves, passing their custom'd bounds, Make direful loud incursions on the land, All overwhelming: sudden they retreat, With their whole troubled waters; but anon Sudden return, with louder, mightier force; The black rocks whiten, the vext shores resound; And yet, more rapid, distant they retire. Vast corruscations lighten all the sky With volum'd flames, while thunder's awful voice, From forth his shrine by night and horror girt, Astounds the guilty, and appals the good. _Grainger._

EARTHQUAKES AND THEIR CAUSES.--From A. de Humboldt's Personal Narrative of Travels, translated by Helen Maria Williams.

"It is a very old and commonly received opinion at Cumana, Acapulca, and Lima, that a perceptible connection exists between earthquakes, and the state of the atmosphere that precedes these phenomena. On the coast of New Andalusia, the inhabitants are alarmed, when, in excessively hot weather, and after long droughts, the breeze suddenly ceases to blow, and the sky, clear and without clouds at the zenith, exhibits near the horizon, at six or eight degrees elevation, the appearance of a reddish vapour. These prognostics are however very uncertain; and when the whole of the meteorological variations, at the times when the globe has been the most agitated, are called to mind, it is found, that violent shocks take place equally in dry and in wet weather, when the coolest winds blow, or during a dead and suffocating calm. From the great number of earthquakes, which I have witnessed to the north and south of the equator; on the continent, and in the bason of the seas; on the coasts, and at 2500 toises height; it appears to me, that the oscillations are generally very independent of the previous state of the atmosphere. This opinion is embraced by a number of enlightened persons, who inhabit the Spanish colonies; and whose experience extends, if not over a greater space of the globe, at least to a greater number of years than mine. On the contrary, in parts of Europe where earthquakes are rare compared to America, natural philosophers are inclined to admit an intimate connection between the undulations of the ground, and certain meteors, which usually take place at the same epocha. In Italy, for instance, the sirocco and earthquakes are suspected to have some connection; and at London, the frequency of falling stars, and those southern lights which have since been often observed by Mr. Dalton, were considered as the forerunners of those shocks which were felt from 1748 to 1756.

"On the days when the earth is agitated by violent shocks, the regularity of the horary variations of the barometer is not disturbed under the tropics. I have verified this observation at Cumana, at Lima, and at Riobamba; and it is so much the more worthy of fixing the attention of natural philosophers, as in St. Domingo, at the town of Cape François, it is asserted that a water barometer was observed to sink two inches and a half immediately before the earthquake of 1770. It is also related, that at the time of the destruction of Oran, a druggist fled with his family, because, observing accidentally, a few minutes before the earthquake, the height of the mercury in his barometer, he perceived that the column sunk in an extraordinary manner. I know not whether we can give credit to this assertion: but as it is nearly impossible to examine the variations of the weight of the atmosphere during the shocks, we must be satisfied in observing the barometer before or after these phenomena have taken place. In the temperate zone, the aurora borealis does not always modify the variation of the needle, and the intensity of the magnetic forces: perhaps also earthquakes do not act constantly in the same manner on the air that surrounds us.

"We can scarcely doubt, that the earth, when opened and agitated by shocks, occasionally sends forth gaseous exhalations through the atmosphere, in places remote from the mouths of volcanoes not extinct. At Cumana, as we have already observed, flames and vapours, mixed with sulphureous acid, spring up from the most arid soil. In other parts of the same province, the earth ejects water and petroleum. At Riobamba, a muddy and inflammable mass, which is called moya, issues from crevices that close again, and accumulates into elevated hills. At seven leagues from Lisbon, near Colares, during the terrible earthquake of the 1st of November, 1755, flames, and a column of thick smoke, were seen to issue from the flanks of the rocks of Alvidras, and, according to some witnesses, from the bosom of the sea. This smoke lasted several days, and it was the more abundant in proportion as the subterraneous noise, which accompanied the shocks, was louder.

"Elastic fluids thrown into the atmosphere may act locally on the barometer, not by their mass, which is very small compared to the mass of the atmosphere; but because, at the moment of the great explosions, an ascending current is probably formed, which diminishes the pressure of the air. I am inclined to think, that in the greater number of earthquakes, nothing escapes from the agitated earth, and that, when gaseous exhalations and vapours take place, they oftener accompany or follow, than precede, the shocks. This last circumstance explains a fact, which seems indubitable; I mean that mysterious influence, in equinoctial America, of earthquakes accompanying a change of climate, and the order of the dry and rainy seasons. If the earth generally acts on the air only at the moment of the shocks, we can conceive why it is so rare that a sensible meteorological change becomes the presage of these great revolutions of nature.

"The hypothesis, according to which, in the earthquakes of Cumana, elastic fluids escape from the surface of the soil, seems confirmed by the observation of the dreadful noise which is heard during the shocks at the borders of the wells in the plain of Charas. Water and sand are sometimes thrown out twenty feet high. Similar phenomena have not escaped the observation of the ancient inhabitants of Greece and Asia Minor, abounding with caverns, crevices, and subterraneous rivers. Nature, in its uniform progress, every where suggests the same ideas of the causes of earthquakes, and the means by which man, forgetting the measure of his strength, pretends to diminish the effect of the subterraneous explosions. What a great Roman naturalist has said of the utility of wells and caverns, is repeated in the New World by the most ignorant Indians of Quito, when they shew travellers the guaicos, or crevices of Pichincha.

"The subterraneous noise, so frequent during earthquakes, is generally not in the ratio of the strength of the shocks. At Cumana it constantly precedes them; while at Quito, and lately at Caraccas, and in the West India Islands, a noise like the discharge of a battery was heard a long time after the shocks had ceased. A third kind of phenomenon, the most remarkable of the whole, is the rolling of those subterraneous thunders, which last several months, without being accompanied by the least oscillating motion of the ground.

"In every country subject to earthquakes, the point where (probably by a disposition of the stony strata) the effects are the most sensible, is considered as the cause and the focus of the shocks. Thus, at Cumana, the hill of the castle of St. Antonio, and particularly the eminence on which the convent of St. Francis is placed, are believed to contain an enormous quantity of sulphur, and other inflammable matter. We forget, that the rapidity with which the undulations are propagated to great distances, even across the basin of the ocean, proves that the centre of action is very remote from the surface of the globe. From this same cause, no doubt, earthquakes are not restrained to certain species of rocks, as some naturalists pretend, but all are fitted to propagate the movement. In order to keep within the limits of my own experience, I shall here cite the granites of Lima and Acapulco; the gneiss of Caraccas; the mica-slate of the peninsula of Araya; the primitive thonschiefer of Tepecuacuilco, in Mexico; the secondary limestones of the Apennines; Spain, and new Andalusia; and finally, the trappean porphyries of Quito and Popayan. In these different places the ground is frequently agitated by the most violent shocks; but sometimes, in the same rock, the superior strata form invincible obstacles to the propagation of the motion. Thus, in the mines of Saxony, we have seen workmen hasten up, affrighted by oscillations which were not felt at the surface of the ground.

"If, in regions the most remote from each other, primitive, secondary, and volcanic rock, share equally in the convulsive movements of the globe; we cannot but admire also, that in ground of little extent, certain classes of rocks oppose themselves to the propagation of the shocks. At Cumana, for instance, before the catastrophe of 1797, the earthquakes were felt only along the southern and calcareous coast of the gulf of Cariaco, as far as the town of this name; while in the peninsula of Araya, and at the village of Marinaquez, the ground did not partake of the same agitation. The inhabitants of this northern coast, which is composed of mica-slate, built their huts on a motionless earth; a gulf three or four thousand fathoms in breadth separated them from a plain covered with ruins, and overturned by earthquakes. This security, founded on the experience of several ages, has vanished; and since the fourteenth of December, 1797, new communications appear to have been opened in the interior of the globe. At present the peninsula of Araya is not merely subject to the agitation of the soil of Cumana; the promontory of mica-slate is become in its turn a particular centre of the movements. The earth is sometimes strongly shaken at the village of Marinaquez, when on the coast of Cumana the inhabitants enjoy the most perfect tranquillity. The gulf of Cariaco nevertheless is only sixty or eighty fathoms deep.

"It is thought, from observations made both on the continent and in the islands, that the western and southern coasts are most exposed to shocks. This observation is connected with the ideas which geologists have long formed of the position of the high chains of mountains, and the direction of their steepest declivities: the volcanic phenomena of the Cordilleras and Caraccas, and the frequency of the oscillations on the eastern and northern coast of Terra Firma, in the gulf of Paria, at Carupano, at Cariaco, and at Cumana, are proofs of the certainty of this opinion. In New Andalusia, as well as in Chili and Peru, the shocks follow the course of the shore, and extend but little inland. This circumstance, as we shall soon find, indicates an intimate connection between the causes that produce earthquakes and volcanic eruptions. If the earth was most agitated on the coasts, because they are the lowest part of the land, why should not the oscillations be equally strong and frequent on those vast savannas or meadows, which are scarcely eight or ten toises above the level of the ocean?

"The earthquakes of Cumana are connected with those of the West India Islands; and it has even been suspected, that they have some connection with the volcanic phenomena of the Cordilleras of the Andes. On the fourth of November, 1797, the soil of the province of Quito underwent such a destructive commotion, that, notwithstanding the extreme thinness of the population of that country, near forty thousand natives perished, buried under the ruins of their houses, swallowed up in the crevices, or drowned in lakes that were suddenly formed. At the same period, the inhabitants of the eastern Antilles were alarmed by shocks, which continued during eight months, when the volcano of Guadaloupe threw out pumice stones, ashes, and gusts of sulphureous vapours. This eruption of the twenty-seventh of September, during which very long-continued subterraneous noises were heard, was followed on the fourteenth of December by the great earthquake of Cumana. Another volcano of the West India Islands, that of St. Vincent's, has lately given a fresh instance of these extraordinary connections. This volcano had not emitted flames since 1718, when they burst forth anew, in 1812. The total ruin of the city of Caraccas preceded this explosion thirty-five days, and violent oscillations of the ground were felt, both in the islands, and on the coasts of Terra Firma.

"It has long been remarked, that the effects of great earthquakes extend much farther than the phenomena arising from burning volcanoes. In studying the physical revolutions of Italy, and carefully examining the series of the eruptions of Vesuvius and Etna, we can scarcely recognize, notwithstanding the proximity of these mountains, any traces of simultaneous action. It is, on the contrary, undeniable, that at the period of the last and preceding destruction of Lisbon, the sea was violently agitated even as far as the New World, for instance, at the island of Barbadoes, more than twelve hundred leagues distant from the coasts of Portugal.

"Several facts tend to prove, that the causes which produce earthquakes have a near connection with those that act in volcanic eruptions. We learnt at Pasto, that the column of black and thick smoke, which in 1797 issued for several months from the volcano near this shore, disappeared at the very hour when, sixty leagues to the south, the towns of Riobamba, Hambato, and Tacunga, were overturned by an enormous shock. When, in the interior of a burning crater, we are seated near those hillocks formed by ejections of scoria and ashes, we feel the motion of the ground several seconds before each partial eruption takes place. We observed this phenomenon at Vesuvius in 1805, while the mountain threw out scoria; we were witnesses of it in 1812, on the brink of the immense crater of Pichincha, from which nevertheless at that time clouds of sulphureous acid vapours only issued.

"Every thing in earthquakes seems to indicate the action of elastic fluids seeking an outlet to spread themselves in the atmosphere. Often, on the coasts of the South Sea, the action is almost instantaneously communicated from Chili to the gulf of Guayaquil, a distance of six hundred leagues; and, what is very remarkable, the shocks appear to be so much the stronger, as the country is more distant from burning volcanoes. The granitic mountains of Calabria, covered with very recent breccia, the calcareous chain of the Apennines, the country of Pignerol, the coasts of Portugal and Greece, and those of Peru and Terra Firma, afford striking proofs of this assertion. The globe, it may be said, is agitated with greater force, in proportion as the surface has a smaller number of funnels communicating with the caverns of the interior. At Naples and Messina, at the foot of Cotopaxi and of Tunguragua, earthquakes are dreaded only when vapours and flames do not issue from the crater. In the kingdom of Quito, the great catastrophe of Riobamba, which we have before mentioned, has led several well-informed persons to think, that this unfortunate country would be less often desolate, if the subterraneous fire would break the porphyritic dome of Chimborazo; and this colossal mountain should become a burning volcano. At all times analogous facts have led to the same hypothesis. The Greeks, who, like ourselves, attributed the oscillations of the ground to the action of elastic fluids, cited, in favour of their opinion, the total cessation of the shocks at the island of Euboea, by the opening of a crevice in the Lelantine plain."

The following is an account of an Earthquake of Caraccas; by M. Palacio Faxar:--

"The ridge of mountains, which branches out from the Andes near the isthmus of Panama, and which, taking the direction of the eastern coast, crosses part of New Granada and Venezuela, seems to have been the seat of that earthquake, which, on the 26th March, 1812, destroyed many populous towns of the province of Caraccas. It is this branch of the Cordilleras, that forms the Sierra-nevada of Chita, that of Merida de Maracaybo, and the height called La Silla de Caracca; and it is between these three remarkable points that the gold mines of Pamplona, the mineral water of Merida de Maracaybo, and the copper mines of Aroa, are found. Between the picturesque Sierra-nevada of Merida de Maracaybo, and La Silla de Caracca, where spring is perpetual, the earthquake was most strongly felt.