Ch. XXHL] 



OF VOLCANIC EEGIONS. 



583 



i 



j 



s. 



a 



'* 



> 



con 



vulsed. 



M. 



from the earthquakes by -which it has been 

 Boussingault declares his belief, that if a 

 fill register had been kept of all the convulsions experienced 

 i ere and in other populous districts of the Andes, it would 

 be found that the trembling of the earth had been inces- 

 ant. The frequency of the movement, he thinks, is not due 

 to volcanic explosions, but to the continual falling in of masses 

 of rock which have been fractured and upheaved in a solid 

 form at a comparatively recent . epoch ; but a longer series 

 of observations would be requisite to confirm this opinion. 

 According to the same author, the height of several moun- 

 tains of the Andes has diminished in modern times* 



The great crest or cordillera of the Andes is depressed at 

 the Isthmus of Panama to- a height of about 1,000 feet, and 

 at the lowest point of separation between the two seas near 



Mi 



» 



What 



pliers regard as a continuation of that chain in Central 

 America lies to the east of a series of volcanos, many of 

 which are active in the provinces of Pasto, Popayan, and 

 Guatemala. Coseguina, on the south side of the Gulf of 

 Fonseca, was in eruption in January 1835, and some of its 



Mexico 



me 



in Jamaica, the same shower of ashes fell, having been car- 

 ried by an upper counter-current against the regular east 

 wind which was then blowing. 

 distant from Coseguina, 



Kin 



must 



more than four days in the air, having travelled 1 70 miles a 

 day. Eight leagues to the southward of the crater, the ashes 

 covered the ground to the depth of three yards and a half, 

 destroying the woods and dwellings. Thousands of cattle 



many instances one mass 



scorched flesh. 



Deer and other wild animals sought the 

 towns for protection ; many birds and quadrupeds were found 

 suffocated in the ashes, and the neighbouring streams were 

 strewed with dead fish.f Such facts throw light on geolo- 

 gical monuments, for in the ashes thrown out at remote 



f Caldcleugh, Phil. Trans. 1836, 



* Bull, de la Soc. Geol. de France, 

 to m. vi. p. 56. 



p. 27. 



