1824.] Vokanos at present in Activity. 203 



100 feet. According to Doloinieu the eruption of 1755 produced 

 a current of lava four leagues in length, half a league wide, and of 

 at least 200 feet mean depth. In reflecting on the immense void, 

 that eruptions so considerable must have produced in the moun- 

 tain and at its base, is there not yet cause for wonder that erup- 

 tions, like that of 1787 for instance, should still occur at the 

 summit, the height of which is 10,600 feet above the level of 

 the sea. 



Stromholi. — M. de Humboldt has remarked that the activity 

 of volcanos appears to be in the inverse ratio of their mag- 

 nitude. Stromboli is a striking confirmation of this principle ; 

 it is perpetually sending forth flames ; but with this peculiarity, 

 that for 2000 years it has not, strictly speaking, made any erup- 

 tions, although the nature of the surrounding country shows, that 

 it was formerly subject to them. Mount Epomea, in the island 

 of Ischia, ought not to be considered as a volcano, but it would 

 probably become one if Stromboli were extinct. 



Santorini was the site of a great eruption in 1707. As this 

 phsenomenon has not been repeated, and as the island exhibits 

 no crater, of the true chimney of a volcano, 1 have not inserted 

 it in the catalogue. 



Volcanos in Iceland. — The last eruption of Hecla occurred in 

 1766. The eruptions of this volcano, according to Sir George 

 Mackenzie, are not in general so extensive as they have been 

 represented. The most recent eruption of Krabla occurred in 

 1724. In 1750, between January and September, there were 

 five eruptions of Kattlagiaa ; since which period this volcano 

 remained perfectly tranquil, until the 26th of July, 1823, when 

 strong eruptions occurred accompanied with earthquakes. 



Eyajialta-Jokid, which appeared to be extinct for more than 

 a century, emitted torrents of flames from its summit on the 20th 

 of Dec. 1821. Eye-witnesses report, that the column of fire was 

 still visible on the 1st of Feb. 1822, and that it projected stones 

 weighing from 50 to 80 pounds, with so much force as to cause 

 them to fall at a distance of two leagues from the mountain. The 

 mountain burst at its base on the 26th June, 1822, and a great 

 quantity of lava issued from it. 



Eyrefa-Jokul. — The last eruption occurred in 1720 



Skaptua-J oknl and Skaptaa-Syssel. — The eruptions of these 

 two volcanos, which occurred in 178 , occupy the first rank in 

 phenomena of this nature ; they ravaged an immense extent of 

 country. During a whole year after the eruptions, the atmo- 

 sphere of Iceland was mixed with clouds of dust, which the sun's 

 rays scarcely penetrated. 



Wester-Jokul. — An eruption of ashes and stones happened in 

 January, 1823. 



Esk. — This volcano was discovered and visited in 1817 by 

 Mr. Scoresby. It made an eruption at the end of April, 1818 ; 



