1824.] Volcanos at present in Activity. 213 



Archipelago of the Ladrones. 

 There are nine volcanos in this Archipelago ; but I do not 

 know if they are all to be placed in the class of those which are 



still burning. 



Sandwich Islands. 



The Mouna-Roa, in Owhyhee, appears to be, or at least to 

 have been a volcano ; but is it the same as the mountain of 

 Mowee, which Vancouver has called the Volcanic Mountain. 



The Island of Amsterdam. 

 The island of Amsterdam was burning when D'Entrecasteaux 

 saw it in the month of March, 1792. Some attribute this phe- 

 nomenon to the effect simply of a great fire ; others have con- 

 cluded that the island contains a volcano. 



The Islands of the Marquis de Traverse. 

 The islands lately discovered by the Russian navigators, 

 between New t Georgia and Sandwich Land, contain an active 

 volcano. There exists one equally so in Sandwich Land. 



General Summary. 

 Number of active volcanos. 

 On the Continent. In the Isles. Total. 



Europe 1 11 12 



Africa 6 6 



America ... 58 3 61 



Asia. 8 24 32 



Oceania .... 52 £>2 



"67 ~96 163 



Before I finish this account, I shall remark, that if the two 

 volcanos in the central part of Asia are excepted, the existence 

 of which may appear doubtful, not one will be found in the pre- 

 ceding list which is more than 50 leagues from the sea. It 

 seeimTdifficult not to draw the conclusion from this curious fact, 

 that water acts an important part in volcanic eruptions. 



A phenomenon equally worthy the attention of observers, is 

 the propagation of sound which precedes or accompanies erup- 

 tions. It has been previously shown, that in 1815 the explosions 

 at Tomboro, in Sombrero, were heard at Sumatra, distant in a 

 right line 300 leagues from the mountain. M. de Humboldt 

 states in his excellent work a circumstance nearly as surprising. 

 The explosions which announced the first eruption of ashes from 

 St. Vincent, did not appear louder to the inhabitants of the 

 island than the report of a large cannon. These explosions not- 

 withstanding were heard perfectly upon the Rio-Apure, at the 

 confluence of Rio Nula, 200 leagues from the volcano, which is 



