126 JW. Humboldt on Volcanoes » [Aug. 



which this part of the world is so terribly visited, furnish remark- 

 able evidences of the existence of subterraneous communication, 

 not only between countries without volcanoes, as was known 

 long ago, but even between craters which are far distant from 

 each other. Thus the volcano of Pasto, situated to the east of 

 the river Guaytara, miinterruptedly vomited a high column of 

 smoke, during three months of the year 1797 ; and this column 

 disappeared at the very moment, when, at the distance of 

 nearly 300 miles, the great earthquake of Riobamba and 

 the mud eruption of the Moya, killed from 30,000 to 40,000 

 Indians. The sudden appearance of the Azoric island Sabrina, 

 on the 30th of January, 1811, was the forerunner of those dread- 

 ful shocks, which, further to the west, shook, almost uninterrupt- 

 edly, from the month of May, 1811, to that of June, 1813, first 

 the Antilles, afterwards the plains of the Ohio and the Missis- 

 sippi, and at last the opposite coast of Venezuela. Thirty days 

 after the complete destruction of the town of Caraccas, the erup- 

 tion of the volcano of St. Vincent in the neighbouring Antilles 

 took place.; at the same moment when this explosion happened, 

 on the 30th of April, 1811, a subterranean noise was heard 

 throughout a country of 2200 geographical square miles, or 

 47,900 English square miles, in extent. 



The inhabitants near the Apure, where it is joined by the 

 Rio Nula, as well as those of the most distant part of the coast, 

 compared this noise to that of artillery. From where the Rio 

 Nula falls into the Apure, through which river I came into the 

 Orinoco, to the volcano of St. Vincent, the distance, in a direct 

 line, is 731 English miles. The noise just alluded to, which 

 certainly was not communicated through the air, must, there- 

 fore, have had a deep internal cause. Its intensity on the coast 

 of the AntilUc sea was scarcely greater than in the interior of the 

 country. 



It would be useless to augment the number of examples, but 

 for the purpose of recaUing to memory a phenomenon which has 

 become historically interesting to Europe, I will mention the 

 earthquake at Lisbon. At the same time with this, on the 1st 

 of November, 17o5, not only were the Swiss lakes, and the sea 

 on the Swedish shores violently agitated, but even in the easterly 

 Antilles, around Martinique, Antigua, and Barbadoes, where the 

 tide never exceeds 28 inches, it suddenly rose to 20 feet. All 

 these phtenomena prove, that the subterranean powers act either 

 dynamically, by pr.oducing tension and vibration, as in earth- 

 quakes ; or chemically, by producing or altering substances, as 

 in volcanoes. They prove, likewise, that these powers do not 

 act from superficial causes, from the exterior crust of the earth ; 

 but from deeply-seated causes, from the interior of our planet ; 

 extending their simultaneous effects to the most distant parts of 

 the earth, through fissures and empty veins. 



The more ditierent the structure of volcanoes ; that is to say, 

 of those raised masses which surround the canal through which 



