DYNAMICAL GEOLOGY. 265 



No phenomena of eruption proceed from them ; no volcanic 

 event connects them with the earth's interior; and only 

 seldom is there any evidence of continued volcanic activity 

 within such craters, or in their neighbourhood." 



The chief argument insisted upon by Buch was the high 

 inclination of the lava flows, which he thought proved that they 

 had been uplifted after their emission. He never accepted 

 Scrope's explanation that the streams of red-hot magma could 

 solidify in this position. Elie de Beaumont examined Etna, 

 and, after accurate measurements of the angle of inclination, 

 likewise refuted the possibility of solidification in situ. He 

 allowed rather more significance than Von Buch to the 

 accumulation of ejected scoriae and debris, but held upheaval 

 for the most important factor in the formation of a volcanic 

 cone. Wilhelm Abich and Sainte-Claire Deville were amongst 

 the more able supporters of the Elevation -Crater theory ; 

 Abich in his illustrative work on Vesuvius and Etna (1836), and 

 Deville in his description of the Eruption of Vesuvius in 1855. 



Von Buch's theory was now thought to have been 

 successfully defended, and was accepted in the standard text- 

 books, in the monographs of Daubeny and Landgrebe, and 

 above all in the Cosmos of Humboldt. But the three chief 

 antagonists of the theory, Constant Prevost, Lyell, and Poulett- 

 Scrope, continued to publish their own views, and in two 

 masterly polemical papers in the Quarterly Journal of the 

 Geological Society of London (1856 and 1859), Scrope was able 

 to endorse the opinions he had formed thirty years earlier, 

 and to demonstrate the origin of volcanic cones from ejected 

 material in a manner absolutely convincing. 



During the following decade, corroborative evidence in 

 the same direction rapidly gathered in geological literature. 

 Dr. George Hartung, who had been with Sir Charles Lyell in 

 the Canary Islands, and had also made a number of 

 observations in Madeira and the Azores Islands, openly 

 disputed Von Buch's views in Germany, and said that the 

 present shape of the large "cauldrons" in Palma and Gran 

 Canaria had been produced by erosion. Dana's investigations 

 in the Sandwich Isles and Junghuhn's excellent descriptions 

 of the volcanoes in Java added further records of volcanic 

 cones built up by ejected material; and Fouque in 1866 

 arrived at the conclusion that in the case of the Santorin 

 Islands Buch's theory could not be applied. Thus the 



