EARTHQUAKES. 



shock was not less severe in the volcanic district of Auvergne ; its 

 direction was from ihe soiiih-easl : and on that day and the following 

 there were several eruptions from Vesuvius. 



The frequency of earthquakes, at particular periods, is well deser- 

 ving of notice. In the fourth and 61th centuries, some of the most 

 civilized parts of the world were almost desolated by these awful 

 visitations. Thrace, Asia Minor, and Syria, according to cotempo- 

 rary historians, suffered most severely : the earth was agitated contin- 

 ually lor long periods, and flames were seen to burst from the earth, 

 over a vast extent of surface. On the 26th of January, A. D. 447, 

 subterranean thunders were heard from the Black to the Red Sea, 

 and the earth was convulsed, without intermission, for the space of 

 six months ; in many places, the air seemed to be on fire ; towns and 

 large tracts of ground were swallowed up in Phrygia. On the 20th 

 of May, A. D. 520, the city of Antioch was overturned by a dread- 

 ful earthquake, and two hundred and fifty thousand of its inhabitants 

 are said to have been crushed in ruins. A raging fire covered the 

 ground on which the city was built, and the district around ; spreading 

 over an extent of forty-two miles in diameter, and a surface of four- 

 teen hundred square miles. 



About the middle of the last century, after the earthquake at Lis- 

 bon, Europe, Africa, and America, were, for some time, repeatedly 

 agitated, by subterranean explosions ; as may be seen by referring 

 to the journals of that time, .^tna, which had been in a state of 

 profound repose for eighty years, broke out with great activity ; and, 

 according to Humboldt, some of the most tremendous earthquakes 

 and volcanic eruptions ever recorded in history were witnessed in 

 Mexico. In the night of the 19th of September, 1759, a vast Vol- 

 cano broke out in a lofty cultivated plain ; a tract of ground more 

 than twelve miles in extent, rose up like a bladder to the height of 

 five hundred and twenty-four feet, and six new mountains were form- 

 ed, higher than the Malvern Hills, in Worcestershire. More recently 

 (in 1812) the tremendous earthquakes in the Caraccas were follow- 

 ed by an eruption in the Island of St. Vincent's, from a volcano that 

 had not been burning since the year 1718; and violent oscillations 

 of the ground were felt both in the islands and on the coasts of Ameri- 

 ca. It may be inferred from these circumstances, that the cause of 

 earthquakes and volcanic eruptions is seated deep below the surface 

 of the earth ; in confirmation of which, it will only be necessary to 

 state, that on the same day on which Lisbon was nearly destroyed, 

 all Europe, and a great part of northern Africa, felt the shock more 

 or less severely: its effects were also sensible across the Atlantic, 

 both in the United States and the West Indies. Incredible as it 

 may seem, one fourth of the northern hemisphere was agitated by the 

 same earthquake. The bed of the Atlantic was raised above the 

 surface of the ocean, and flame and vapour were discharged : this 

 was observed by vessels at sea. If we take a terrestrial globe, and 



