The explosions of mud, called by the natives bledeg, are, as we have already seen, a great curiosity. This volcanic phenomenon is in the center of a limestone district, and is first discovered, on approaching it from a distance, by a large volume of smoke, which rises and disappears at intervals of a few seconds, and resembles the vapors arising from a violent surf. A dull noise, like that of thunder, is at the same time heard; and on a nearer approach, when the vision is no longer impeded by the smoke, a large hemispherical mass is observed, consisting of black earth, mixed with water, about sixteen feet in diameter, rising up to the hight of twenty or thirty feet in a perfectly regular manner, and, as it were, pushed up by a force beneath. This mass suddenly explodes with a dull noise, and scatters, in every direction, a volume of black mud. After an interval of a few seconds, the hemispherical body of earth or mud again rises and explodes. In the same manner this volcanic ebullition goes on without interruption, throwing up a globular body of mud, and dispersing it with violence through the neighboring plain. The spot where the ebullition occurs is nearly circular, and perfectly level, and is entirely covered with the earthy particles, impregnated with salt water, which are thrown up from below. The circumference may be estimated at about half a mile. In order to conduct the salt water to the circumference, small passages, or gutters, are made in the loose muddy earth, which lead it to the borders, where it is collected in holes, or salt wells, dug in the ground, for the purpose of evaporation. The mud recently thrown up, possesses a degree of heat greater than that of the surrounding atmosphere, and emits a strong, pungent and sulphurous smell. This volcanic phenomenon is situated near the center of the large plain which interrupts the series of the more considerable volcanoes, and owes its origin to the general cause of the numerous volcanic eruptions which occur in the island of Java.
The tremendous violence with which nature marks the operations of volcanoes in these regions, will be best exemplified by the following details of the extraordinary and wide-spreading phenomena which accompanied the eruption of the Tomboro mountain, in the island of Sumbawa, one of the Javanese cluster. This eruption, which happened in April, 1815, was sensibly felt over the whole of the Molucca islands, over Java, and over a considerable portion of Celebes, Sumatra and Borneo, to a circumference of a thousand statute miles from its center, by tremulous motions and loud explosions; while, within the range of its more immediate activity, embracing a space of three hundred miles around it, it produced the most astonishing effects and excited the most alarming apprehensions. On Java, at the distance of three hundred miles, it seemed to be awfully present. The sky was overcast at noonday with a cloud of ashes; the sun was enveloped in an atmosphere, the palpable density of which it was unable to penetrate; showers of ashes covered the houses, the streets and the fields, to the depth of several inches; and, amid this darkness, explosions were heard at intervals, like the report of artillery, or the noise of distant thunder. Every one conceived, that the effects experienced might be caused by eruptions of some of the numerous volcanoes on the island; but no one could have conjectured, that the shower of ashes which darkened the air, and covered the ground of the eastern district of Java, could have proceeded from a mountain in Sumbawa, at the distance of several hundred miles.
The first explosions were heard at Java, on the evening of the fifth of April, and continued until the following day, when the sun became obscured, and appeared to be enveloped in a fog. The weather was sultry; the atmosphere close; and the pressure of the latter, added to the general stillness, seemed to forebode an earthquake. This lasted for several days, the explosions continuing, but not with so much violence as at first. On the evening of the tenth, the eruptions, however, were more loud and more frequent; ashes fell in abundance; the sun was nearly obscured; and in several parts of the island a tremulous motion of the earth was felt. On the following day, the explosions were so tremendous as to shake the houses perceptibly in the more eastern districts.
In the island of Sumbawa itself, there was a great loss of lives, and the surviving inhabitants were reduced to extreme misery. It appears from the account of the rajah, who was a spectator of the eruption, that on the evening of the tenth of April, three distinct columns of flame, all apparently within the verge of the crater of the Tomboro mountain, burst forth, and, after ascending separately to a very great hight, united their tops in the air. The whole of the mountain now appeared like a body of liquid fire, extending itself in every direction. Stones and ashes were precipitated; and a whirlwind ensued, which blew down the greater part of the houses in an adjoining village. It tore up by the roots the largest trees, and carried them into the air, together with men, horses, cattle, and whatever came within its influence. The sea rose nearly twelve feet higher than usual, a phenomenon commonly attendant on earthquakes, overwhelming the plantations of rice, and sweeping away houses, with whatever came within its reach. It is calculated that full twelve thousand individuals perished. The trees and herbage of every description, along the whole of the north and west sides of the peninsula, were completely destroyed, with the exception of a high point of land near the spot where the village of Tomboro stood.
The extreme misery to which the inhabitants of the western part of the island were reduced, was dreadful to behold. The roads were strewed with dead bodies; the villages were almost entirely deserted, and the houses fallen down. The peasants wandered in all directions in search of food; and the famine became so severe, that one of the daughters of the rajah died of hunger. To judge of the violence of the eruption, it will suffice to state, that the cloud of ashes which had been carried with so much celerity as to produce utter darkness, extended, in the direction of the island of Celebes, two hundred and seventeen nautical miles from the seat of the volcano; and, in a direct line toward Java, upward of three hundred geographical miles.
BASALTIC AND ROCKY WONDERS.
THE GIANT’S CAUSEWAY.
This vast collection of basaltic pillars is in the vicinity of Ballimony, in the county of Antrim, Ireland. The principal, or grand causeway, (there being several less considerable and scattered fragments of a similar nature,) consists of an irregular arrangement of many hundred thousands of columns, formed of a black rock, nearly as hard as marble. The greater part of them are of a pentagonal figure, but so closely and compactly situated on their sides, though perfectly distinct from top to bottom, that scarcely anything can be introduced between them. These columns are of an unequal hight and breadth: several of the most elevated, visible above the surface of the strand, and at the foot of the impending angular precipice, are of the hight of about twenty feet, which they do not exceed, at least not any of the principal arrangement. How deeply they are fixed in the strand, has never yet been ascertained.