40 Mr C. Martins on the Nature and Origin of 



Ashes are conveyed by the winds to considerable distances. 

 After the violent detonations, like the discharge of artillery, 

 which alarmed the inhabitants of Barbadoes on the 30th 

 April 1812, there was seen the following day, 1st May, 

 above the horizon of the sea, a black cloud which already 

 covered the rest of the sky, and which soon after spread it- 

 self in the part where the light of the twilight began to appear. 

 The darkness then became so great that in rooms it was 

 impossible to discern the place of the windows, and in the 

 open air many could not discern either the trees or outlines 

 of the neighbouring houses, nor even white handkerchiefs 

 placed five inches from the eyes. This phenomenon was 

 caused by the fall of a great quantity of volcanic dust arising 

 from the eruption of a volcano in the island of St Vincent. 

 This new kind of rain, and the darkness resulting from it, 

 did not terminate till between twelve and one o'clock. The 

 island of St Vincent is 170 kilometres west from Barbadoes. 

 During the eruption of Hecla, in 1766, the clouds of smoke 

 produced such a darkness, that at Glaumba, 50 leagues dis- 

 tant, people could not walk but by groping their way. In 

 1794 the whole of Calabria was enveloped in thick clouds 

 vomited from Etna. 



If examples are desired of transportation to greatdistances, 

 the following may be given as proofs. Procopius assures us 

 that in 472, the ashes of Vesuvius were carried as far as 

 Constantinople, that is 250 leagues. In the formidable 

 eruption of Tomboro, a volcano in the island of Sumbava, 

 which took place in 1815, the ashes extended to Java, Ma- 

 cassar, and Batavia ; they even reached Bencoolen, and Suma- 

 tra, which is as remote from the point of departure as Etna 

 is distant from Hamburg, namely, 16 degrees of latitude, or 

 more than 1500 kilometres. 



If we compare these results, arising from an insulated 

 eruption, with those which must be produced by multiplied 

 and continuous eruptions at the two extremities of Europe, 

 in Calabria on the one hand, and in Iceland on the other, we 

 will not hesitate to ascribe to them, along with Toaldo and 

 Van Swinden, the origin of the dry fog of 1783. 



