« PreviousContinue »
The mountain of Cotopaxi is in the neighbourhood of Quito, and became a volcano at the time of the Spaniards’ first arrival in that country. Its eruptions since have been frequent and furious. One happened in 1743, overflowing the adjacent country like a vast lake, and carrying away all the buildings within its reach. The llames rose higher than 2000 feet, and the explosion was heard at the distance of 300 miles ; while the quantity of cinders vomited up was so great, that the sky continued as dark as night until the third hour after mid-day. Jorullo was formed in 1759. Subterraneous noises had been heard for some months previous, when che plain began to be agitated like a sea, and a tract of ground from three to four miles in extent rose in the shape of a bladder, the convexity gradually increasing to the centre, which is 524 feet high. Thousands of small cones appeared emitting smoke and fames; and from these cones a thick and hot vapour is still ascending. Chimborazo is an extinguished volcano.
VII.--EARTHQUAKES. EARTHQCAKES are intimately connected with volcanic eruptions, but their effects are at once more rapid and more destructive.
no signs which unequivocally indicate their approach ; for the subterraneous noise, which is their infallible forerunner, is scarcely heard before the earth gives way. The terrible effects of earthquakes have attracted attention in every age, and records of some of such convulsions have descended to us from very remote ages. No period of our earth's history has been more noted for the violenco and extent of earthquakes than that between the first and third centuries, and the middle of the fourteenth. China was terribly convulsed for ten years from 1333, when Kiang-si, its capital, was swallowed up; mountains were engulfed; and floods occasioned by the obstruction of the course of rivers, destroyed vast multitudes of human beings. The successions extended westwards, and Asia Minor and Egypt were violently shaken in
1346; while, in the following year, several earthquakes were experienced in Cyprus, Greece, and Italy. In 1692, the island of Jamaica was visited by a most terrible earthquake, in which enormous masses of earth and rock were detached from the Blue Mountains; and vast quantities of timber hurled from their flanks, covered the adjacent sea like floating islands. It was during this earthquake, that the city of Port Royal, with a tract of adjacent land estimated at 1000 acres, sunk in one minute into the deep. In the succeeding year, great earthquakes in Sicily destroyed the city of Catania, and 140 other towns and villages in that island, where upwards of 100,000 persons perished. In 1746 Lower Peru suffered severely from this calamity. The ocean burst in upon the land with irresistible force, when the barrier of land sunk into the sea. Lima was overwhelmed, and the present port of Callao formed. These convulsions were accompanied by eruptions of water and mud from several volcanoes among the Andes. In 1750, the city of Conception, in Chili, disappeared during an earthquake, and the sea rolled over it. In 1755, Lisbon was in a great measure destroyed by one of the most terrible earthquakes that ever visited Europe. The mountain chains between the Douro and the Tagus were most dreadfully convulsed. The new mole at Lisbon, to which the multitude had fled as to a place of safety, sunk suddenly into a hideous abyss, and not one body floated to the surface, nor were any fragments of the vessels, sucked into the chasm, rendered up; and on the spot there is now one hundred fathoms of water. In this awful convulsion at Lisbon, sixty thousand persons perished in about six minutes. A violent shock threw down the greatest part of the city, and the sea retired, leaving the bar momentarily dry; but suddenly a mighty wave, fifty feet high, rolled in on the devoted city. The extent of the earthquake, on this occasion, is very remarkable. The violence of the shocks, which were accompanied by a fearful subterranean noise, like the loudest thunder, was chiefly felt in Portugal, Spain, and Northern Africa; but its effects were perceived over a considerable part of Europe, and were even experienced in the West Indies.
Our Scottish lakes, particularly Loch Ness and Loch Lomond, rose and fell repeatedly on that dreadful day. Ships at sea were affected by the shocks, as if they had struck on rocks, and their crews were, in some instances, thrown down by the violence of the concussions. In 1766, the island of Trinidad, and great part of Columbia, were violently agitated by earthquakes; an islet in the Orinoco disappeared, and land in other parts of the coast was raised above the waters. In 1772 the lofty volcano of Papandayang (the loftiest mountain in Java) disappeared, and an area around, fifteen miles by six, was swallowed up.
Most terrible earthquakes desolated Calabria in 1783, wherein, by the sinkings of the land, numerous fissures were formed, some of them a mile in length, and two hundred feet in depth ; while many of the inhabitants were crushed by the falling of cliffs, or swept away by the sea breaking over the shore.
In the year 1797, Upper Peru was terribly convulsed. The shocks of earthquakes continued with great violence for three months, and the face of the country in the centre of the convulsion was totally changed. In 1811, violent earthquakes shook the valley of the Mississippi, by which lakes of considerable extent disappeared, and new ones were formed. But these were less terrific than . the catastrophe whích destroyed the city of Caraccas in 1812.. On the 26th March there were heard subterranean thunderings; the ground undulated, as if agitated by a boiling liquid, and at one shock this fine city entombed in its ruins 10,000 of its inhabitants. During the earthquake the great lake of Maracaibo had its level lowered, and the riven earth at Puerto Cabello and Valentia poured forth enormous torrents of water. It is remarkable, that the volcano of St Vincent, which had been quiescent for a century, burst out with prodigious violence on the 27th of April in the same year, and threw out clouds of ashes, which rose to an immense height into the air. Much of the island was ruined by showers of scoriæ and ashes; and such was the violence of the eruption, that the decks of vessels 200 miles to the windward of St Vincent, were covered with an impalpable dust. On the day of this eruption, subterranean
thunderings were distinctly heard at Caraccas, and even on the Rio Apure, 210 leagues in a right line from St Vincent. In 1822, Chili was visited by a most destructive earthquake. The shock was strongly felt at the same time throughout a line of coast 1200 miles in extent It is stated on good authority, that the coast for 100 iniles sustained an elevation of from two to four feet; and about a mile inland from Valparaiso, it was raised from six to seven feet. The sudden elevation of the coast was indicated by shell-fish being found adhering to the rocks considerably above high-water mark. The shocks continued for about a year; and the area over which the permanent alteration of level extended, is believed to embrace the country from the base of the Andes to the sea, a surface of not less than 100,000 square miles. In 1827, Popayan and Bogota suffered most severely from earthquakes, during which vast fissures opened in the elevated plains around the latter city.
The last earthquake of consequence in Europe occurred. in Murcia in 1829, near Alicante. Several villages, in an area of above four square miles, were thrown down by vertical movements in the valley through which the Rio Segura flows, and many small fissures were formed in the alluvial soil ; while black mud, sand, and marine shells, were thrown up from small cavities formed near
Such are some of the severer earthquakes on record; but less considerable shocks are of frequent occurrence in various countries, especially in South America and Italy. Smart shocks are occasionally felt in Scotland; they have often occurred at Comrie in Perthshire. A smart shock rent the spire on the Town Hall of Inverness in the year 1816; and another earthquake was felt at Lancaster in 1834, which shattered chimneys, and alarmed the inhabitants. A slight shock was felt at Comrie in 1839, and at the same moment at Edinburgh, and on the banks of Loch Lomond. But all the shocks experienced in our island, have, fortunately, been insignificant, compared to those which have been felt in many countries.
VIIL-THE FROZEN SEA. ICEBERGS.
WAEN we reflect on the nature of the icy sea, it is difficult to believe that navigators can ever explore its extent. Every where they have encountered fixed ice, which has arrested their progress; or moveable ice, which, threatening to enclose them, has put all their courage to flight.. Captain Wood, who firmly believed in the possibility of a northern passage, found his further progress stopped at 76° by a continent of ice which united together Nova Zembla, Spitzbergen, and Greenland. Captain Souter, on the contrary, in 1780, continued his course as far as. 82° 6', in a smooth and open channel. The fixed ice, however, which bounded on each side bis watery way, beginning to be detached, he dreaded lest his return should be cut off, and, accordingly, abandoned the enterprise. Although the courageous Baffin, and a few others, have been able to make the circuit of the bay that bears his name, this sea has been generally found closed by a mass of ice, many hundred miles in length, and containing mountains · four hundred feet high.. Captain Wafer confesses that he mistook fixed ice, five hundred feet in height, for genuine islands. It often happens that this floating ice is found covered with large stones and trees torn up by the roots, which produces the illusion of a land covered with vegetation. It is quite uncertain whether the Dutch discovered to the east. of Spitzbergen an actual coast, or only an expanse of ice. Two islands of ice have continued stationary for half a century in one of these northern bays. Dutch whalers have visited them, and have given them names.
An equal degree of danger attends moveable ice. The shock of these enormous masses produces a tremendous crash, which warns the seaman how easily his vessel would be crushed to pieces if it were caught between these floating islands. Frequently the wood that drifts upon this sea, which is often found in great quantities, and is supposed to be brought by the Bahama stream from the American shores, takes fire in consequence of the violent friction to which it is exposed by the movement of the ice, and smoke and flames burst forth in